Los autores agradecen el apoyo generoso de la James Madison University Departamento de biología y la James Madison University microscopía de luz y centro de la proyección de imagen. Dr. Mark L. Gabriele para consejos útiles con respecto a la preparación de jóvenes tejido postnatal, y DRS. Justin W. Brown y Corey L. Cleland generoso coordinación de espacio y materiales quirúrgicos. Esta investigación fue financiada en parte por una beca de investigación colaborativa 4-VA, una colaboración para el avance de la Commonwealth de Virginia (G.S.V.) y por Virginia Academia de ciencia pequeño proyecto de investigación becado (G.S.V.). Se ha generosamente apoyado por una dotación de Betty Jo Butler amoroso 58 para la beca de investigación de pregrado (a K.M.B.), una beca de investigación de verano de Farrell (para K.M.B.), James Madison University segundo siglo becado (a K.M.B.), un James Beca centenario de la Universidad de Madison (a C.J.H.), una Universidad James Madison búsqueda 30 Lucy Robinson Memorial Scholarship (para Z.L.H.) y una Universidad de James Madison de la ciencia y las matemáticas Facultad ayuda subsidio (G.S.V.).

<ol>
	<li>Southwell, D. G., Froemke, R. C., Alvarez-Buylla, A., Stryker, M. P., Gandhi, S. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cortical+plasticity+induced+by+inhibitory+neuron+transplantation.">Cortical plasticity induced by inhibitory neuron transplantation.</a> Science. 327 (5969), 1145-1148 (2010).</li><li>Hanson, J. E., Madison, D. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Presynaptic+FMR1+genotype+influences+the+degree+of+synaptic+connectivity+in+a+mosaic+mouse+model+of+fragile+X+syndrome.">Presynaptic FMR1 genotype influences the degree of synaptic connectivity in a mosaic mouse model of fragile X syndrome.</a> J. Neurosci. 27 (15), 4014-4018 (2007).</li><li>Patel, A. B., Hays, S. A., Bureau, I., Huber, K. M., Gibson, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Target+Cell-Specific+Role+for+Presynaptic+Fmr1+in+Regulating+Glutamate+Release+onto+Neocortical+Fast-Spiking+Inhibitory+Neurons.">A Target Cell-Specific Role for Presynaptic Fmr1 in Regulating Glutamate Release onto Neocortical Fast-Spiking Inhibitory Neurons.</a> J. Neurosci. 33 (6), 2593-2604 (2013).</li><li>Patel, A. B., Loerwald, K. W., Huber, K. M., Gibson, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Postsynaptic+FMRP+promotes+the+pruning+of+cell-to-cell+connections+among+pyramidal+neurons+in+the+L5A+neocortical+network.">Postsynaptic FMRP promotes the pruning of cell-to-cell connections among pyramidal neurons in the L5A neocortical network.</a> J. Neurosci. 34 (9), 3413-3418 (2014).</li><li>McConnell, M. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mosaic+Copy+Number+Variation+in+Human+Neurons.">Mosaic Copy Number Variation in Human Neurons.</a> Science. 342 (6158), 632-637 (2013).</li><li>McConnell, M. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intersection+of+diverse+neuronal+genomes+and+neuropsychiatric+disease:+The+Brain+Somatic+Mosaicism+Network.">Intersection of diverse neuronal genomes and neuropsychiatric disease: The Brain Somatic Mosaicism Network.</a> Science. 356 (6336), eaal1641 (2017).</li><li>Gu, H., Marth, J. D., Orban, P. C., Mossmann, H., Rajewsky, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deletion+of+a+DNA+polymerase+beta+gene+segment+in+T+cells+using+cell+type-specific+gene+targeting.">Deletion of a DNA polymerase beta gene segment in T cells using cell type-specific gene targeting.</a> Science. 265 (5168), 103-106 (1994).</li><li>Hodges, J. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Astrocytic+Contributions+to+Synaptic+and+Learning+Abnormalities+in+a+Mouse+Model+of+Fragile+X+Syndrome.">Astrocytic Contributions to Synaptic and Learning Abnormalities in a Mouse Model of Fragile X Syndrome.</a> Biol. Psychiatry. (17), 1-11 (2016).</li><li>Young, P., Qiu, L., Wang, D., Zhao, S., Gross, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-neuron+labeling+with+inducible+cre-mediated+knockout+in+transgenic+mice.">Single-neuron labeling with inducible cre-mediated knockout in transgenic mice.</a> Nat. Neurosci. 11 (6), 721-728 (2011).</li><li>Zong, H., Espinosa, J. S., Su, H. H., Muzumdar, M. D., Luo, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mosaic+Analysis+with+Double+Markers+in+Mice.">Mosaic Analysis with Double Markers in Mice.</a> Cell. 121 (3), 479-492 (2005).</li><li>Hippenmeyer, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+mosaic+dissection+of+Lis1+and+Ndel1+in+neuronal+migration.">Genetic mosaic dissection of Lis1 and Ndel1 in neuronal migration.</a> Neuron. 68 (4), 695-709 (2010).</li><li>De la Rossa, A., Jabaudon, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+rapid+gene+delivery+into+postmitotic+neocortical+neurons+using+iontoporation.">In vivo rapid gene delivery into postmitotic neocortical neurons using iontoporation.</a> Nat. Protoc. 10 (1), 25-32 (2015).</li><li>Lu, W., Bushong, E. A., Shih, T. P., Ellisman, M. H., Nicoll, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cell-autonomous+role+of+excitatory+synaptic+transmission+in+the+regulation+of+neuronal+structure+and+function.">The cell-autonomous role of excitatory synaptic transmission in the regulation of neuronal structure and function.</a> Neuron. 78 (3), 433-439 (2013).</li><li>Duan, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Semaphorin+5A+inhibits+synaptogenesis+in+early+postnatal-+and+adult-born+hippocampal+dentate+granule+cells.">Semaphorin 5A inhibits synaptogenesis in early postnatal- and adult-born hippocampal dentate granule cells.</a> eLife. 3, 1-24 (2014).</li><li>Dixit, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+Gene+Delivery+into+Multiple+CNS+Territories+Using+In+utero+Electroporation.">Efficient Gene Delivery into Multiple CNS Territories Using In utero Electroporation.</a> J. Vis. Exp. (52), e2957 (2011).</li><li>Matsui, A., Yoshida, A. C., Kubota, M., Ogawa, M., Shimogori, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+in+utero+Electroporation:+Controlled+Spatiotemporal+Gene+Transfection.">Mouse in utero Electroporation: Controlled Spatiotemporal Gene Transfection.</a> J. Vis. Exp. (54), e3024 (2011).</li><li>Briz, C. G., Navarrete, M., Esteban, J. A., Nieto, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+utero+Electroporation+Approaches+to+Study+the+Excitability+of+Neuronal+Subpopulations+and+Single-cell+Connectivity.">In utero Electroporation Approaches to Study the Excitability of Neuronal Subpopulations and Single-cell Connectivity.</a> J. Vis. Exp. (120), (2017).</li><li>Saito, T., Nakatsuji, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+gene+transfer+into+the+embryonic+mouse+brain+using+in+vivo+electroporation.">Efficient gene transfer into the embryonic mouse brain using in vivo electroporation.</a> Dev. Biol. 240 (1), 237-246 (2001).</li><li>Saito, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+electroporation+in+the+embryonic+mouse+central+nervous+system.">In vivo electroporation in the embryonic mouse central nervous system.</a> Nature protocols. 1 (3), 1552-1558 (2006).</li><li>Tabata, H., Nakajima, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+in+utero+gene+transfer+system+to+the+developing+mouse+brain+using+electroporation:+Visualization+of+neuronal+migration+in+the+developing+cortex.">Efficient in utero gene transfer system to the developing mouse brain using electroporation: Visualization of neuronal migration in the developing cortex.</a> Neuroscience. 103 (4), 865-872 (2001).</li><li>Matsuda, T., Cepko, C. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Controlled+expression+of+transgenes+introduced+by+in+vivo+electroporation.">Controlled expression of transgenes introduced by in vivo electroporation.</a> Proc. Natl. Acad. Sci. U.S.A. 10 (3), 1027-1032 (2007).</li><li>Pacary, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visualization+and+Genetic+Manipulation+of+Dendrites+and+Spines+in+the+Mouse+Cerebral+Cortex+and+Hippocampus+using+In+utero+Electroporation.">Visualization and Genetic Manipulation of Dendrites and Spines in the Mouse Cerebral Cortex and Hippocampus using In utero Electroporation.</a> J. Vis. Exp. (65), e4163 (2012).</li><li>Mizuno, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NMDAR-Regulated+Dynamics+of+Layer+4+Neuronal+Dendrites+during+Thalamocortical+Reorganization+in+Neonates.">NMDAR-Regulated Dynamics of Layer 4 Neuronal Dendrites during Thalamocortical Reorganization in Neonates.</a> Neuron. 82 (2), 365-379 (2014).</li><li>Luo, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Supernova:+A+Versatile+Vector+System+for+Single-Cell+Labeling+and+Gene+Function+Studies+in+vivo.">Supernova: A Versatile Vector System for Single-Cell Labeling and Gene Function Studies in vivo.</a> Sci. Rep. 6, 35747 (2016).</li><li>Mader, S. L., Libal, N. L., Pritchett-Corning, K., Yang, R., Murphy, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Refining+timed+pregnancies+in+two+strains+of+genetically+engineered+mice.">Refining timed pregnancies in two strains of genetically engineered mice.</a> Lab animal. 38 (9), 305-310 (2009).</li><li>Vidal, G. S., Djurisic, M., Brown, K., Sapp, R. W., Shatz, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell-Autonomous+Regulation+of+Dendritic+Spine+Density+by+PirB.">Cell-Autonomous Regulation of Dendritic Spine Density by PirB.</a> eNeuro. 3 (5), 1-15 (2016).</li><li>Byers, S. L., Wiles, M. V., Dunn, S. L., Taft, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+estrous+cycle+identification+tool+and+images.">Mouse estrous cycle identification tool and images.</a> PLoS ONE. 7 (4), 1-5 (2012).</li><li>Andreu-Agullo, C., Maurin, T., Thompson, C. B., Lai, E. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ars2+maintains+neural+stem-cell+identity+through+direct+transcriptional+activation+of+Sox2.">Ars2 maintains neural stem-cell identity through direct transcriptional activation of Sox2.</a> Nature. 481, 195-198 (2011).</li><li>Scotto-Lomassese, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fragile+X+mental+retardation+protein+regulates+new+neuron+differentiation+in+the+adult+olfactory+bulb.">Fragile X mental retardation protein regulates new neuron differentiation in the adult olfactory bulb.</a> J. Neurosci. 31, 2205-2215 (2011).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Plasmids 101: A Desktop Resource. , (2017).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Pipette Cookbook. , (2015).</li><li>Cuddington, B., Verschoor, M., Mossman, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Handling+of+the+Cotton+Rat+in+Studies+for+the+Pre-clinical+Evaluation+of+Oncolytic+Viruses.">Handling of the Cotton Rat in Studies for the Pre-clinical Evaluation of Oncolytic Viruses.</a> J. Vis. Exp. (93), e52232 (2014).</li><li>Leary, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> AVMA Guidelines for the Euthanasia of Animals: 2013 Edition. , (2013).</li><li>Anderson, S. A., Eisenstat, D. D., Shi, L., Rubenstein, J. L. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interneuron+Migration+from+Basal+Forebrain+to+Neocortex:+Dependence+on+Dlx+Genes.">Interneuron Migration from Basal Forebrain to Neocortex: Dependence on Dlx Genes.</a> Science. 28 (5337), 474-476 (1997).</li><li>Parker, J. M., Austin, J., Wilkerson, J., Carbone, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+Multimodal+Analgesia+on+the+Success+of+Mouse+Embryo+Transfer+Surgery.">Effects of Multimodal Analgesia on the Success of Mouse Embryo Transfer Surgery.</a> J. Am. Assoc. Lab. Anim. Sci. 50 (4), 466-470 (2011).</li><li>Kim, J. -. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Viral+transduction+of+the+neonatal+brain+delivers+controllable+genetic+mosaicism+for+visualising+and+manipulating+neuronal+circuits+in+vivo.">Viral transduction of the neonatal brain delivers controllable genetic mosaicism for visualising and manipulating neuronal circuits in vivo.</a> Eur. J. Neurosci. 37 (8), 1203-1220 (2013).</li><li>Pierfelice, T. J., Gaiano, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasound-Guided+Microinjection+into+the+Mouse+Forebrain+In+Utero+at+E9.5.">Ultrasound-Guided Microinjection into the Mouse Forebrain In Utero at E9.5.</a> J. Vis. Exp. (45), e2047 (2010).</li></ol>

Los autores no tienen conflictos de interés divulgar.

Aquí, presentamos la combinación de la electroporación en el útero con recombinase de Cre en los ratones de floxed para generar el tejido del cerebro de mosaico. Una ventaja de este enfoque es que una nueva línea de mouse no es necesario que se generan cada vez un diferente subtipo celular debe orientarse: electroporación en el útero puede utilizarse para apuntar neuronas excitatorias, las neuronas inhibitorias o glia dependiendo de la época y la ubicación de electroporación1...

La generación de un mosaico genético, es un paradigma experimental clásico para entender la función de un gen de interés. Para determinar si un gen es necesario para un fenotipo celular, el enfoque más sencillo está causando una pérdida de función del gen en el organismo (por ejemplo, knockout). Sin embargo, para determinar si un gen se requiere específicamente en un determinado tipo de célula, golpe de gracia del gene en el organismo no es un enfoque válido. En cambio, se requiere un método que causará la pérdida de función de un gen en una célula determinada, mientras que está rodeado por tejido de tipo salvaje (es decir, genéticamente imperturbable), en otras palabras, crear tejido mosaico. Si la célula mutante muestra un fenotipo mutante, pero no las células circundantes de tipo salvaje, las funciones del gene de una manera autónoma de células. Análisis de tejido de mosaico, en el que las células mutantes están rodeadas por tejido de tipo salvaje, es ideal para la comprensión de la célula autónoma funciones de genes, especialmente en el cerebro donde las neuronas y glia forman una vasta red interconectada de tejido.
Varias formas de tejido cerebral de mosaico han proporcionado poderosos modelos para investigar la célula autónoma funciones de genes. Estudios se centraron en el trasplante neuronal1, mosaicism ligadas al cromosoma X femenino2,3,4, y mosaicism somático endógena5,6 han extraído sus conclusiones basados en mosaico tejido cerebral. Supresión condicional de un gen a través del sistema de recombinación del Cre-lox es un método que aprovecha la gran disponibilidad de líneas de ratón transgénico. En este método, se introducen dos loxP sitios a ambos lados de una secuencia necesaria de un gen (como un exón), dejándola flanqueado por sitios loxP que enfrentan a ambos en la misma dirección ("floxed"). Recombinase de CRE accisas la secuencia entre la loxP sitios7. Recombinación mediada por la CRE se logra por los ratones de floxed paso a otra línea de ratón expresan recombinase de Cre junto con un marcador fluorescente en un subconjunto de células ("línea de la reportera de Cre"). Esto se ha demostrado en una variedad de maneras para descubrir las funciones de un gen en subconjuntos de células como neuronas excitatorias o astrocitos8. Líneas de reportero de CRE pueden expresar CreERT2 para permitir la recombinación mediada por la Cre a ser droga-inducible (solo-neurona etiquetado con knockout inducible Cre-mediada, o SLICK)9. En otra estrategia llamada análisis de mosaico con doble marcadores (MADM)10,11, Cre-mediada intercromosomal recombinación permite un mutante homocigótico para crearse junto con tejido heterozigótico. En estos enfoques, una nueva línea de ratones debe ser producido cada vez para cada gen candidato o subtipo celular que se ha probado. Por otra parte, recombinase de Cre puede introducirse postnatal a través de iontoforesis12 o vectores virales (e.g. virus adeno-asociados13 o lentivirus14 llevar celulares específicos de subtipo promotores). Esta estrategia crea fuerte y postnatal de etiquetado. Para desarrollar las neuronas corticales cerebrales escasamente y prenatally, una estrategia ideal es en el útero la electroporación del recombinase de Cre con un marcador fluorescente.
Además de combinar la recombinación del Cre-lox a través de electroporación en el útero para producir mosaico tejido en vivo, introducimos varias adaptaciones a los procedimientos de otros protocolos publicados15,16, 17,18,19,20,21. Proporcionamos información para mejorar el éxito en las mujeres embarazadas en tiempo de cría. También describiremos nuestros dos estrategias para introducir rala y brillante etiqueta de neuronas en el tejido cortical: una estrategia es valorar los niveles de una construcción única codificación recombinase de Cre y un marcador fluorescente22. Otra estrategia es utilizar el sistema de "Supernova", diseñado específicamente con estos parámetros en mente23,24. Además, nos ofrecen mejoras en la producción de microinyección consistente pipetas y simplificaciones a la cirugía en el útero la electroporación. Finalmente, describiremos los pasos críticos en un preparado histológico simplificado que permite el análisis de espinas dendríticas y cenadores dendríticas y axonales, sin más manchas o inmunohistoquímica.

<table>
	<tbody>
		<tr>
			<td>C57BL/6J mice</td>
			<td>The Jackson Laboratory</td>
			<td>#000664</td>
			<td>See &#34;1. Mouse set-up&#34; (step 1.1, &#34;wildtype mice&#34;)</td>
		</tr>
		<tr>
			<td>GFP.Cre empty vector</td>
			<td>AddGene</td>
			<td>#20781</td>
			<td>See &#34;2. DNA set-up&#34; (step 2.1 &#34;single DNA construct that codes for Cre recombinase as well as a fluorescent marker&#34;). GFP.Cre empty vector was a gift from Tyler Jacks.</td>
		</tr>
		<tr>
			<td>pK029.CAG-loxP-stop-loxP-RFP-ires-tTA-WPRE (Supernova)</td>
			<td>AddGene</td>
			<td>#69138</td>
			<td>See &#34;2. DNA set-up&#34; (step 2.1 &#34;Supernova&#34; system) and http://snsupport.webcrow.jp/. pK029.CAG-loxP-stop-loxP-RFP-ires-tTA-WPRE (Supernova) was a gift from Takuji Iwasato.</td>
		</tr>
		<tr>
			<td>pK031.TRE-Cre (Supernova)</td>
			<td>AddGene</td>
			<td>#69136</td>
			<td>See &#34;2. DNA set-up&#34; (step 2.1 &#34;Supernova&#34; system) and http://snsupport.webcrow.jp/. pK031.TRE-Cre (Supernova) was a gift from Takuji Iwasato.</td>
		</tr>
		<tr>
			<td>pK038.CAG-loxP-stop-loxP-EGFP-ires-tTA-WPRE (Supernova)</td>
			<td>AddGene</td>
			<td>#85006</td>
			<td>See &#34;2. DNA set-up&#34; (step 2.1 &#34;Supernova&#34; system) and http://snsupport.webcrow.jp/. pK038.CAG-loxP-stop-loxP-EGFP-ires-tTA-WPRE (Supernova) was a gift from Takuji Iwasato.</td>
		</tr>
		<tr>
			<td>EndoFree Plasmid Maxi Kit (10)</td>
			<td>Qiagen</td>
			<td>#12362</td>
			<td>See &#34;2. DNA set-up&#34; (step 2.3 &#34;endotoxin-free plasmid purification kit&#34;)</td>
		</tr>
		<tr>
			<td>Trypan Blue powder, BioReagent grade</td>
			<td>Sigma</td>
			<td>T6146-5G</td>
			<td>See &#34;2. DNA set-up&#34; (step 2.5 &#34;trypan blue&#34;)</td>
		</tr>
		<tr>
			<td>Sodium Chloride, ACS, 2.5 kg</td>
			<td>VWR</td>
			<td>BDH9286-2.5KG</td>
			<td>See &#34;2. DNA set-up&#34; (step 2.5 &#34;NaCl&#34;)</td>
		</tr>
		<tr>
			<td>Potassium Chloride, ACS, 500 g</td>
			<td>VWR</td>
			<td>#97061-566</td>
			<td>See &#34;2. DNA set-up&#34; (step 2.5 &#34;KCl&#34;)</td>
		</tr>
		<tr>
			<td>Sodium phosphate dibasic, ReagentPlus, 100 g</td>
			<td>Sigma-Aldrich</td>
			<td>S0876-100G</td>
			<td>See &#34;2. DNA set-up&#34; (step 2.5 &#34;Na2HPO4&#34;)</td>
		</tr>
		<tr>
			<td>Potassium phosphate monobasic, ReagentPlus, 100 g</td>
			<td>Sigma-Aldrich</td>
			<td>P5379-100G</td>
			<td>See &#34;2. DNA set-up&#34; (step 2.5 &#34;KH2PO4&#34;)</td>
		</tr>
		<tr>
			<td>Hydrochloric acid, ACS reagent, 500 mL</td>
			<td>Fisher Scientific</td>
			<td>A144-500</td>
			<td>See &#34;2. DNA set-up&#34; (step 2.5 &#34;HCl&#34;)</td>
		</tr>
		<tr>
			<td>P-97 Micropipette Puller</td>
			<td>Sutter Instrument</td>
			<td>P-97</td>
			<td>See &#34;3. Pipette set-up&#34; (step 3.1 &#34;glass capillary puller&#34;)</td>
		</tr>
		<tr>
			<td>3.0 mm wide trough filament</td>
			<td>Sutter Instrument</td>
			<td>FT330B</td>
			<td>See &#34;3. Pipette set-up&#34; (step 3.1 &#34;glass capillary puller&#34;)</td>
		</tr>
		<tr>
			<td>Thin Wall Glass Capillaries, 4&#34;, 1 / 0.75 OD/ID</td>
			<td>World Precision Instruments</td>
			<td>TW100-4</td>
			<td>See &#34;3. Pipette set-up&#34; (step 3.1.1 &#34;glass capillary&#34;)</td>
		</tr>
		<tr>
			<td>Single Ply Soft-Tech Wipes, 4.5&#34;</td>
			<td>Phenix</td>
			<td>LW-8148</td>
			<td>See &#34;3. Pipette set-up&#34; (step 3.2.1 &#34;single-ply task wipe&#34;); other single-ply wipes (e.g. Kimwipes) can be used.</td>
		</tr>
		<tr>
			<td>Graefe Forceps, 7 cm, Straight, 0.7 mm 1x2 Teeth</td>
			<td>World Precision Instruments</td>
			<td>#14140</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.1 &#34;Graefe forceps&#34;)</td>
		</tr>
		<tr>
			<td>Iris Scissors, 11.5 cm, Straight, 12-pack</td>
			<td>World Precision Instruments</td>
			<td>#503708-12</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.1 &#34;iris scissors&#34;)</td>
		</tr>
		<tr>
			<td>Hartman Mosquito Forceps, 9 cm, Straight, 12-pack</td>
			<td>World Precision Instruments</td>
			<td>#503728-12</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.1 &#34;Hartman mosquito forceps&#34;)</td>
		</tr>
		<tr>
			<td>General Purpose Non-Woven Sponges, 2&#34; x 2&#34;, 4-ply</td>
			<td>Medrepexpress</td>
			<td>#2204-c</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.1 &#34;non-woven gauze sponges&#34;)</td>
		</tr>
		<tr>
			<td>Ring Tipped Forceps, 10 cm, Straight, 2.2mm ID</td>
			<td>World Precision Instruments</td>
			<td>#503203</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.1 &#34;ring-tipped forceps&#34;)</td>
		</tr>
		<tr>
			<td>Pyrex petri dishes complete, O.D. &#215; H 100 mm &#215; 20 mm</td>
			<td>Sigma-Aldrich</td>
			<td>CLS3160102-12EA</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.1 &#34;Petri dishes&#34;)</td>
		</tr>
		<tr>
			<td>Flat Type Instrument Tray, Stainless Steel, 13-5/8&#34; x 9-3/4&#34; x 5/8&#34;</td>
			<td>Amazon</td>
			<td>B007SHGAHA</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.1 &#34;stainless steel tray&#34;)</td>
		</tr>
		<tr>
			<td>Platinum Tweezertrode, 5 mm</td>
			<td>BTX</td>
			<td>#45-0489</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.3 and 4.16 &#34;tweezer-type electrodes&#34;)</td>
		</tr>
		<tr>
			<td>ECM 830 Foot Pedal</td>
			<td>BTX</td>
			<td>#45-0211</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.3 and 4.17 &#34;foot pedal&#34;)</td>
		</tr>
		<tr>
			<td>ECM 830 Generator</td>
			<td>BTX</td>
			<td>#45-0052</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.3 &#34;generator&#34;)</td>
		</tr>
		<tr>
			<td>Single Animal Isoflurane Anesthesia System with Small Induction Box</td>
			<td>Harvard Apparatus</td>
			<td>#72-6468</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.4 and 4.6 &#34;nose cone&#34;, step 4.4 &#34;induction chamber&#34;)</td>
		</tr>
		<tr>
			<td>Ophthalmic ointment</td>
			<td>Hanna Pharmaceutical Supply Co</td>
			<td>#0536108691</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.7 &#34;veterinary ophthalmic ointment&#34;)</td>
		</tr>
		<tr>
			<td>Space Gel (AIMS)</td>
			<td>VWR</td>
			<td>#95059-640</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.8 &#34;sealed pouch filled with supersaturated salt solution&#34;)</td>
		</tr>
		<tr>
			<td>Hair Remover Gel Cream, Sensitive Formula</td>
			<td>Veet</td>
			<td>#062200809951</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.9 &#34;depilatory cream&#34;)</td>
		</tr>
		<tr>
			<td>10ul Low Retention Tip Starter (960 tips/pk)</td>
			<td>Phenix Research Products</td>
			<td>TSP-10LKIT</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.12 &#34;sterile 10 &#181;L micropipette tip&#34;)</td>
		</tr>
		<tr>
			<td>Aspirator tube assemblies for calibrated microcapillary pipettes</td>
			<td>Sigma-Aldrich</td>
			<td>A5177</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.15 &#34;aspirator tube assembly&#34;)</td>
		</tr>
		<tr>
			<td>Braided Absorbable Suture, 4-0, Needle NFS-2(FS-2), 27&#34;</td>
			<td>Medrepexpress</td>
			<td>MV-J397</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.19 &#34;absorbable sutures&#34;)</td>
		</tr>
		<tr>
			<td>&#8220;LiquiVet Rapid&#8221; Tissue Adhesive</td>
			<td>Medrepexpress</td>
			<td>VG3</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.20 &#34;tissue adhesive&#34;)</td>
		</tr>
		<tr>
			<td>Hypodermic syringes, polypropylene, Luer lock tip, capacity 1.0 mL</td>
			<td>Sigma-Aldrich</td>
			<td>Z551546-100EA</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.21 &#34;1 mL syringe&#34;)</td>
		</tr>
		<tr>
			<td>BD Precisionglide syringe needles gauge 26, L 1/2 in.</td>
			<td>Sigma-Aldrich</td>
			<td>Z192392-100EA</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.21 &#34;26G, &#189;&#8221; needle&#34;)</td>
		</tr>
		<tr>
			<td>Nestlets Nesting Material</td>
			<td>Ancare</td>
			<td>NES3600</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.24 &#34;nesting materials&#34;)</td>
		</tr>
		<tr>
			<td>Sunflower Seeds, Black Oil, Sterile</td>
			<td>Bio-Serv</td>
			<td>S5137</td>
			<td>See &#34;4. In utero electroporation&#34; (step 4.24 &#34;sunflower seeds&#34;)</td>
		</tr>
		<tr>
			<td>Paraformaldehyde, 97%</td>
			<td>Alfa Aesar</td>
			<td>A11313</td>
			<td>See &#34;5. Histology&#34; (step 5.1.1 &#34;PFA&#34;)</td>
		</tr>
		<tr>
			<td>Economy Tweezers #3, 11 cm, 0.2 x 0.4 mm tips</td>
			<td>World Precision Instruments</td>
			<td>#501976</td>
			<td>See &#34;5. Histology&#34; (step 5.5 &#34;tweezers&#34;)</td>
		</tr>
		<tr>
			<td>Agar powder</td>
			<td>Alfa Aesar</td>
			<td>#10752</td>
			<td>See &#34;5. Histology&#34; (step 5.8.1 &#34;agar&#34;)</td>
		</tr>
		<tr>
			<td>Single-edge razor blades, #9 blade</td>
			<td>Stanley Tools</td>
			<td>#11-515</td>
			<td>See &#34;5. Histology&#34; (step 5.9 &#34;single-edge razor blade&#34;)</td>
		</tr>
		<tr>
			<td>Specimen disc S D 50 mm</td>
			<td>Leica</td>
			<td>#14046327404</td>
			<td>See &#34;5. Histology&#34; (step 5.9 &#34;vibrating microtome specimen disc&#34;)</td>
		</tr>
		<tr>
			<td>Buffer tray S assembly</td>
			<td>Leica</td>
			<td>#1404630132</td>
			<td>See &#34;5. Histology&#34; (step 5.10 &#34;buffer tray&#34;)</td>
		</tr>
		<tr>
			<td>VT1000 S Vibratome</td>
			<td>Leica</td>
			<td>#14047235612</td>
			<td>See &#34;5. Histology&#34; (step 5.10 &#34;vibrating microtome&#34;)</td>
		</tr>
		<tr>
			<td>Double Edge Razor Blades</td>
			<td>Personna</td>
			<td>BP9020</td>
			<td>See &#34;5. Histology&#34; (step 5.10 &#34;blade&#34;)</td>
		</tr>
		<tr>
			<td>Knife Holder S</td>
			<td>Leica</td>
			<td>#14046230131</td>
			<td>See &#34;5. Histology&#34; (step 5.10 &#34;knife holder&#34;)</td>
		</tr>
		<tr>
			<td>Studio Elements Golden Taklon Short Handle Round Brush Set</td>
			<td>Amazon</td>
			<td>B0089KU6XE</td>
			<td>See &#34;5. Histology&#34; (step 5.12.1 &#34;fine tipped paintbrush&#34;)</td>
		</tr>
		<tr>
			<td>Superfrost Plus Slides</td>
			<td>Electron Microscopy Services</td>
			<td>#71869-11</td>
			<td>See &#34;5. Histology&#34; (step 5.12.1 &#34;microscope slide&#34;)</td>
		</tr>
		<tr>
			<td>ProLong Diamond Antifade Mountant, 10 ml</td>
			<td>Thermofisher</td>
			<td>P36970</td>
			<td>See &#34;5. Histology&#34; (step 5.12.3-5.12.4 &#34;mountant&#34;)</td>
		</tr>
		<tr>
			<td>Cover Glass, 24 x 50 mm, No. 1</td>
			<td>Phenix Research Products</td>
			<td>MS1415-10</td>
			<td>See &#34;5. Histology&#34; (step 5.12.4 &#34;coverslip&#34;)</td>
		</tr>
		<tr>
			<td>4&#8242;,6-Diamidino-2-phenylindole dihydrochloride (DAPI)</td>
			<td>Sigma-Aldrich</td>
			<td>D9542</td>
			<td>See &#34;5. Histology&#34; (step 5.13.1 &#34;DAPI&#34;)</td>
		</tr>
		<tr>
			<td>Fixed Stage Upright Microscope</td>
			<td>Olympus</td>
			<td>BX51WI</td>
			<td>See &#34;5. Histology&#34; (step 5.15 &#34;light microscope&#34;)</td>
		</tr>
		<tr>
			<td>Laser Scanning Confocal Microscope</td>
			<td>Nikon</td>
			<td>TE2000/C2si</td>
			<td>See &#34;5. Histology&#34; (step 5.15 &#34;confocal microscope&#34;)</td>
		</tr>
		<tr>
			<td>4x objective, NA = 0.20</td>
			<td>Nikon</td>
			<td>CFI Plan Apo Lambda 4X</td>
			<td>See &#34;5. Histology&#34; (step 5.15 &#34;low-power objective&#34;)</td>
		</tr>
		<tr>
			<td>20x objective, NA = 0.75</td>
			<td>Nikon</td>
			<td>CFI Plan Apo Lambda 20X</td>
			<td>See &#34;5. Histology&#34; (step 5.15 &#34;medium-power objective&#34;)</td>
		</tr>
		<tr>
			<td>60x objective, NA = 1.40</td>
			<td>Nikon</td>
			<td>CFI Plan Apo VC 60X Oil</td>
			<td>See &#34;5. Histology&#34; (step 5.15 &#34;high-power objective&#34;)</td>
		</tr>
	</tbody>
</table>

inducing cre-lox recombination in mouse cerebral cortex through in utero electroporation

Funciones neuronales células autónomas de genes pueden ser reveladas por una pérdida o ganan de función de un gen en una población pequeña y escasa de neuronas. Para ello requiere generar un mosaico en que las neuronas con la pérdida o ganancia de función de un gen están rodeadas por tejido genéticamente imperturbable. Aquí combinamos el sistema de recombinación del Cre-lox con electroporación en el útero con el fin de generar el tejido de cerebro de mosaico que se puede utilizar para estudiar la función celular Autónoma de genes en las neuronas. Construcciones de ADN (disponibles en repositorios), codificación para una etiqueta fluorescente y recombinase de Cre, se introducen en el desarrollo de las neuronas corticales que contienen genes flanqueados con sitios loxP en los cerebros de embriones de ratón con el útero en electroporación. Asimismo, describen varias adaptaciones para el método de electroporación en el útero que aumentan la supervivencia y reproducción. Este método también implica establecer un título para la recombinación mediada por la Cre en una población densa o escasa de neuronas. Preparaciones histológicas de tejido cerebral marcada no requieren (pero puede ser adaptadas a) immunohistochemistry. Los constructos utilizados garantizan que etiqueta fluorescente las neuronas llevan el gen del recombinase de Cre. Preparaciones histológicas permiten análisis morfológico de neuronas a través de la proyección de imagen confocal de cenadores dendríticas y axonales y espinas dendríticas. Debido a la pérdida o ganancia de función se realiza en tejido mosaico escaso, este método permite el estudio de la célula autónoma necesidad y suficiencia de productos gen en vivo.

La sola construcción GFP. CRE (véase lista de materiales) fue electroporated en E15.5 y visualizados en P14. Dependiendo de la concentración de la construcción y el volumen de la inyección, puede obtenerse un resultado escaso o densa22,26. Por ejemplo, la inyección de 1 μl de 2 mg/mL GFP. Resultados CRE en una escasa distribución de las células marcadas, algunas de las cuales pueden ser brillante (fig...

Watch this Scientific Journal Video about Inducing Cre-lox Recombination in Mouse Cerebral Cortex Through In Utero Electroporation at JoVE.com

Inducing Cre-lox Recombination in Mouse Cerebral Cortex Through In Utero Electroporation

Funciones célula Autónoma de genes en el cerebro pueden ser estudiadas mediante la inducción de la pérdida o ganan de función en poblaciones dispersas de las células. Aquí, describimos en el útero la electroporación para entregar recombinase de Cre en poblaciones escasas de desarrollo de las neuronas corticales con genes floxed a causar la pérdida de función en vivo.

Inducción de la recombinación del Cre-lox en la corteza Cerebral de ratón a través de electroporación en el útero

Cell-autonomous neuronal functions of genes can be revealed by causing loss or gain of function of a gene in a small and sparse population of neurons. To ...

inducing-cre-lox-recombination-mouse-cerebral-cortex-through-utero

Research

JoVE Journal

Neuroscience

Inducing Cre-lox Recombination in Mouse Cerebral Cortex Through In Utero Electroporation

11.6K vistas.  James Madison University. Funciones célula Autónoma de genes en el cerebro pueden ser estudiadas mediante la inducción de la pérdida o ganan de función en poblaciones dispersas de las células. Aquí, describimos en el útero la electroporación para entregar recombinase de Cre en poblaciones escasas de desarrollo de las neuronas corticales con genes floxed a causar la pérdida de función en vivo.

Video: Inducing Cre-lox Recombination in Mouse Cerebral Cortex Through In Utero Electroporation

Transfection of Mouse Retinal Ganglion Cells by in vivo Electroporation

The targeting and refinement of RGC projections to the midbrain is a popular and powerful model system for studying how precise patterns of neural connectivity form during development. In mice, retinofugal projections are arranged in a topographic manner and form eye-specific layers in the Lateral Geniculate Nucleus (dLGN) of the thalamus and the Superior Colliculus (SC). The development of these precise patterns of retinofugal projections has typically been studied by labeling populations of RGCs with fluorescent dyes and tracers, such as horseradish peroxidase1-4. However, these methods are too coarse to provide insight into developmental changes in individual RGC axonal arbor morphology that are the basis of retinotopic map formation. They also do not allow for the genetic manipulation of RGCs.
Recently, electroporation has become an effective method for providing precise spatial and temporal control for delivery of charged molecules into the retina5-11. Current retinal electroporation protocols do not allow for genetic manipulation and tracing of retinofugal projections of a single or small cluster of RGCs in postnatal mice. It has been argued that postnatal in vivo electroporation is not a viable method for transfecting RGCs since the labeling efficiency is extremely low and hence requires targeting at embryonic ages when RGC progenitors are undergoing differentiation and proliferation6. 
In this video we describe an in vivo electroporation protocol for targeted delivery of genes, shRNA, and fluorescent dextrans to murine RGCs postnatally. This technique provides a cost effective, fast and relatively easy platform for efficient screening of candidate genes involved in several aspects of neural development including axon retraction, branching, lamination, regeneration and synapse formation at various stages of circuit development. In summary we describe here a valuable tool which will provide further insights into the molecular mechanisms underlying sensory map development.

Transfection of Mouse Retinal Ganglion Cells by in vivo Electroporation

We demonstrate an in vivo electroporation protocol for transfecting single or small clusters of retinal ganglion cells (RGCs) and other retinal cell types in postnatal mice over a wide range of ages. The ability to label and genetically manipulate postnatal RGCs in vivo is a powerful tool for developmental studies.

La transfección de células de ratón del ganglio de la retina por In vivo La electroporación

The targeting and refinement of RGC projections to the midbrain is a popular and powerful model system for studying how precise patterns of neural ...

Investigación

Neurociencias

Efficient Gene Delivery into Multiple CNS Territories Using In Utero Electroporation

The ability to manipulate gene expression is the cornerstone of modern day experimental embryology, leading to the elucidation of multiple developmental pathways. Several powerful and well established transgenic technologies are available to manipulate gene expression levels in mouse, allowing for the generation of both loss- and gain-of-function models. However, the generation of mouse transgenics is both costly and time consuming. Alternative methods of gene manipulation have therefore been widely sought. In utero electroporation is a method of gene delivery into live mouse embryos1,2 that we have successfully adapted3,4. It is largely based on the success of in ovo electroporation technologies that are commonly used in chick5. Briefly, DNA is injected into the open ventricles of the developing brain and the application of an electrical current causes the formation of transient pores in cell membranes, allowing for the uptake of DNA into the cell. In our hands, embryos can be efficiently electroporated as early as embryonic day (E) 11.5, while the targeting of younger embryos would require an ultrasound-guided microinjection protocol, as previously described6. Conversely, E15.5 is the latest stage we can easily electroporate, due to the onset of parietal and frontal bone differentiation, which hampers microinjection into the brain. In contrast, the retina is accessible through the end of embryogenesis. Embryos can be collected at any time point throughout the embryonic or early postnatal period. Injection of a reporter construct facilitates the identification of transfected cells.
To date, in utero electroporation has been most widely used for the analysis of neocortical development1,2,3,4. More recent studies have targeted the embryonic retina7,8,9 and thalamus10,11,12. Here, we present a modified in utero electroporation protocol that can be easily adapted to target different domains of the embryonic CNS. We provide evidence that by using this technique, we can target the embryonic telencephalon, diencephalon and retina. Representative results are presented, first showing the use of this technique to introduce DNA expression constructs into the lateral ventricles, allowing us to monitor progenitor maturation, differentiation and migration in the embryonic telencephalon. We also show that this technique can be used to target DNA to the diencephalic territories surrounding the 3rd ventricle, allowing the migratory routes of differentiating neurons into diencephalic nuclei to be monitored. Finally, we show that the use of micromanipulators allows us to accurately introduce DNA constructs into small target areas, including the subretinal space, allowing us to analyse the effects of manipulating gene expression on retinal development.

Efficient Gene Delivery into Multiple CNS Territories Using In Utero Electroporation

In utero electroporation allows for rapid gene delivery in a spatially- and temporally-controlled manner in the developing central nervous system (CNS). Here we describe a highly adaptable in utero electroporation protocol that can be used to deliver expression constructs into multiple embryonic CNS domains, including the telencephalon, diencephalon and retina.

Entrega génica eficaz en los territorios del SNC múltiples utilizando In Utero La electroporación

The ability to manipulate gene expression is the cornerstone of modern day experimental embryology, leading to the elucidation of multiple developmental ...

Mouse in Utero Electroporation: Controlled Spatiotemporal Gene Transfection

In order to understand the function of genes expressed in specific region of the developing brain, including signaling molecules and axon guidance molecules, local gene transfer or knock- out is required. Gene targeting knock-in or knock-out into local regions is possible to perform with combination with a specific CRE line, which is laborious, costly, and time consuming. Therefore, a simple transfection method, an in utero electroporation technique, which can be performed with short time, will be handy to test the possible function of candidate genes prior to the generation of transgenic animals 1,2. In addition to this, in utero electroporation targets areas of the brain where no specific CRE line exists, and will limit embryonic lethality 3,4. Here, we present a method of in utero electroporation combining two different types of electrodes for simple and convenient gene transfer into target areas of the developing brain. First, a unique holding method of embryos using an optic fiber optic light cable will make small embryos (from E9.5) visible for targeted DNA solution injection into ventricles and needle type electrodes insertion to the targeted brain area 5,6. The patterning of the brain such as cortical area occur at early embryonic stage, therefore, these early electroporation from E9.5 make a big contribution to understand entire area patterning event. Second, the precise shape of a capillary prevents uterine damage by making holes by insertion of the capillary. Furthermore, the precise shape of the needle electrodes are created with tungsten and platinum wire and sharpened using sand paper and insulated with nail polish 7, a method which is described in great detail in this protocol. This unique technique allows transfection of plasmid DNA into restricted areas of the brain and will enable small embryos to be electroporated. This will help to, open a new window for many scientists who are working on cell differentiation, cell migration, axon guidance in very early embryonic stage. Moreover, this technique will allow scientists to transfect plasmid DNA into deep parts of the developing brain such as thalamus and hypothalamus, where not many region-specific CRE lines exist for gain of function (GOF) or loss of function (LOF) analyses.

Mouse in Utero Electroporation: Controlled Spatiotemporal Gene Transfection

A gene transfer method into the developing mouse brain is described by using a unique surgical method and special shape of electrodes. This unique technique allows transfection of plasmid DNA temporally and spatially, which will aid many neuroscientists in studying brain development.

Del ratón en el útero de electroporación: Transefection controlada Gene espacio-temporal

In order to understand the function of genes expressed in specific region of the developing brain, including signaling molecules and axon guidance ...

Methods for Study of Neuronal Morphogenesis: Ex vivo RNAi Electroporation in Embryonic Murine Cerebral Cortex

The cerebral cortex directs higher cognitive functions. This six layered structure is generated in an inside-first, outside-last manner, in which the first born neurons remain closer to the ventricle while the last born neurons migrate past the first born neurons towards the surface of the brain1. In addition to neuronal migration2, a key process for normal cortical function is the regulation of neuronal morphogenesis3. While neuronal morphogenesis can be studied in vitro in primary cultures, there is much to be learned from how these processes are regulated in tissue environments.
We describe techniques to analyze neuronal migration and/or morphogenesis in organotypic slices of the cerebral cortex4,6. A pSilencer modified vector is used which contains both a U6 promoter that drives the double stranded hairpin RNA and a separate expression cassette that encodes GFP protein driven by a CMV promoter7-9. Our approach allows for the rapid assessment of defects in neurite outgrowth upon specific knockdown of candidate genes and has been successfully used in a screen for regulators of neurite outgrowth8. Because only a subset of cells will express the RNAi constructs, the organotypic slices allow for a mosaic analysis of the potential phenotypes. Moreover, because this analysis is done in a near approximation of the in vivo environment, it provides a low cost and rapid alternative to the generation of transgenic or knockout animals for genes of unknown cortical function. Finally, in comparison with in vivo electroporation technology, the success of ex vivo electroporation experiments is not dependant upon proficient surgery skill development and can be performed with a shorter training time and skill.

Methods for Study of Neuronal Morphogenesis: Ex vivo RNAi Electroporation in Embryonic Murine Cerebral Cortex

To conduct a rapid assessment of the function of genes in the development of cerebral cortex, we describe methods involving the ex vivo electroporation of plasmids co-expressing inhibitory RNA (RNAi) and GFP in murine embryonic cortex. This protocol is amenable to the study of various aspects of neurodevelopment such as neurogenesis, neuronal migration and neuronal morphogenesis including dendrite and axon outgrowth.

Métodos de estudio de la morfogénesis neuronal:<em&gt; Ex vivo</em&gt; RNAi electroporación en la corteza cerebral embrionario murino

The cerebral cortex directs higher cognitive functions. This six layered structure is generated in an inside-first, outside-last manner, in which the ...

Visualization and Genetic Manipulation of Dendrites and Spines in the Mouse Cerebral Cortex and Hippocampus using In utero Electroporation

In utero electroporation (IUE) has become a powerful technique to study the development of different regions of the embryonic nervous system 1-5. To date this tool has been widely used to study the regulation of cellular proliferation, differentiation and neuronal migration especially in the developing cerebral cortex 6-8. Here we detail our protocol to electroporate in utero the cerebral cortex and the hippocampus and provide evidence that this approach can be used to study dendrites and spines in these two cerebral regions.
Visualization and manipulation of neurons in primary cultures have contributed to a better understanding of the processes involved in dendrite, spine and synapse development. However neurons growing in vitro are not exposed to all the physiological cues that can affect dendrite and/or spine formation and maintenance during normal development. Our knowledge of dendrite and spine structures in vivo in wild-type or mutant mice comes mostly from observations using the Golgi-Cox method 9. However, Golgi staining is considered to be unpredictable. Indeed, groups of nerve cells and fiber tracts are labeled randomly, with particular areas often appearing completely stained while adjacent areas are devoid of staining. Recent studies have shown that IUE of fluorescent constructs represents an attractive alternative method to study dendrites, spines as well as synapses in mutant / wild-type mice 10-11 (Figure 1A). Moreover in comparison to the generation of mouse knockouts, IUE represents a rapid approach to perform gain and loss of function studies in specific population of cells during a specific time window. In addition, IUE has been successfully used with inducible gene expression or inducible RNAi approaches to refine the temporal control over the expression of a gene or shRNA 12. These advantages of IUE have thus opened new dimensions to study the effect of gene expression/suppression on dendrites and spines not only in specific cerebral structures (Figure 1B) but also at a specific time point of development (Figure 1C).
Finally, IUE provides a useful tool to identify functional interactions between genes involved in dendrite, spine and/or synapse development. Indeed, in contrast to other gene transfer methods such as virus, it is straightforward to combine multiple RNAi or transgenes in the same population of cells. 
In summary, IUE is a powerful method that has already contributed to the characterization of molecular mechanisms underlying brain function and disease and it should also be useful in the study of dendrites and spines.

Visualization and Genetic Manipulation of Dendrites and Spines in the Mouse Cerebral Cortex and Hippocampus using In utero Electroporation

This article describes in detail a protocol to electroporate in utero the cerebral cortex and the hippocampus at E14.5 in mice. We also show that this is a valuable method to study dendrites and spines in these two cerebral regions.

La visualización y la manipulación genética de las dendritas y espinas en la corteza cerebral y el hipocampo del ratón usando<em&gt; En el útero</em&gt; La electroporación

In utero electroporation (IUE) has become a powerful technique to study the development of different regions of the embryonic nervous system 1-5. To date ...

Dual Electrophysiological Recordings of Synaptically-evoked Astroglial and Neuronal Responses in Acute Hippocampal Slices

Astrocytes form together with neurons tripartite synapses, where they integrate and modulate neuronal activity. Indeed, astrocytes sense neuronal inputs through activation of their ion channels and neurotransmitter receptors, and process information in part through activity-dependent release of gliotransmitters. Furthermore, astrocytes constitute the main uptake system for glutamate, contribute to potassium spatial buffering, as well as to GABA clearance. These cells therefore constantly monitor synaptic activity, and are thereby sensitive indicators for alterations in synaptically-released glutamate, GABA and extracellular potassium levels. Additionally, alterations in astroglial uptake activity or buffering capacity can have severe effects on neuronal functions, and might be overlooked when characterizing physiopathological situations or knockout mice. Dual recording of neuronal and astroglial activities is therefore an important method to study alterations in synaptic strength associated to concomitant changes in astroglial uptake and buffering capacities. Here we describe how to prepare hippocampal slices, how to identify stratum radiatum astrocytes, and how to record simultaneously neuronal and astroglial electrophysiological responses. Furthermore, we describe how to isolate pharmacologically the synaptically-evoked astroglial currents.

The preparation of acute brain slices from isolated hippocampi, as well as the simultaneous electrophysiological recordings of astrocytes and neurons in stratum radiatum during stimulation of schaffer collaterals is described. The pharmacological isolation of astroglial potassium and glutamate transporter currents is demonstrated.

Dos registros electrofisiológicos de sinápticamente respuestas evocadas neuronal y astroglial en agudas rodajas de hipocampo

Astrocytes form together with neurons tripartite synapses, where they integrate and modulate neuronal activity. Indeed, astrocytes sense neuronal inputs ...

Generation of Topically Transgenic Rats by In utero Electroporation and In vivo Bioluminescence Screening

In utero electroporation (IUE) is a technique which allows genetic modification of cells in the brain for investigating neuronal development. So far, the use of IUE for investigating behavior or neuropathology in the adult brain has been limited by insufficient methods for monitoring of IUE transfection success by non-invasive techniques in postnatal animals. 
 For the present study, E16 rats were used for IUE. After intraventricular injection of the nucleic acids into the embryos, positioning of the tweezer electrodes was critical for targeting either the developing cortex or the hippocampus. 
 Ventricular co-injection and electroporation of a luciferase gene allowed monitoring of the transfected cells postnatally after intraperitoneal luciferin injection in the anesthetized live P7 pup by in vivo bioluminescence, using an IVIS Spectrum device with 3D quantification software. 
 Area definition by bioluminescence could clearly differentiate between cortical and hippocampal electroporations and detect a signal longitudinally over time up to 5 weeks after birth. This imaging technique allowed us to select pups with a sufficient number of transfected cells assumed necessary for triggering biological effects and, subsequently, to perform behavioral investigations at 3 month of age. As an example, this study demonstrates that IUE with the human full length DISC1 gene into the rat cortex led to amphetamine hypersensitivity. Co-transfected GFP could be detected in neurons by post mortem fluorescence microscopy in cryosections indicating gene expression present at &ge;6 months after birth.
 We conclude that postnatal bioluminescence imaging allows evaluating the success of transient transfections with IUE in rats. Investigations on the influence of topical gene manipulations during neurodevelopment on the adult brain and its connectivity are greatly facilitated. For many scientific questions, this technique can supplement or even replace the use of transgenic rats and provide a novel technology for behavioral neuroscience.

Generation of Topically Transgenic Rats by In utero Electroporation and In vivo Bioluminescence Screening

Genes can be manipulated during development of the cortex or the hippocampus of the rat via in utero electroporation (IUE) at E16, to enable fast and targeted modifications in neuronal connectivity for later studies of behavior or neuropathology in adult animals. Postnatal in vivo imaging for control of IUE success is performed by bioluminescence of activating co-transfected luciferase.

Generación de ratas transgénicas por vía tópica<em&gt; En el útero</em&gt; La electroporación y<em&gt; En vivo</em&gt; Detección bioluminiscencia

 In utero electroporation (IUE) is a technique which allows genetic modification of cells in the brain for investigating neuronal development. So far, the ...

Genetic Manipulation of the Mouse Developing Hypothalamus through In utero Electroporation

Genetic modification of specific regions of the developing mammalian brain is a very powerful experimental approach. However, generating novel mouse mutants is often frustratingly slow. It has been shown that access to the mouse brain developing in utero with reasonable post-operatory survival is possible. Still, results with this procedure have been reported almost exclusively for the most superficial and easily accessible part of the developing brain, i.e. the cortex. The thalamus, a narrower and more medial region, has proven more difficult to target. Transfection into deeper nuclei, especially those of the hypothalamus, is perhaps the most challenging and therefore very few results have been reported. Here we demonstrate a procedure to target the entire hypothalamic neuroepithelium or part of it (hypothalamic regions) for transfection through electroporation. The keys to our approach are longer narcosis times, injection in the third ventricle, and appropriate kind and positioning of the electrodes. Additionally, we show results of targeting and subsequent histological analysis of the most recessed hypothalamic nucleus, the mammillary body.

Genetic Manipulation of the Mouse Developing Hypothalamus through In utero Electroporation

Despite the functional and medical importance of the hypothalamus, in utero genetic manipulation of its development has rarely been attempted. We show a detailed procedure for in utero electroporation into the mouse hypothalamus and show representative results of total and partial (regional) hypothalamic transfection.

La manipulación genética del ratón en desarrollo a través de Hipotálamo<em&gt; En el útero</em&gt; La electroporación

Genetic  modification of specific regions of the developing mammalian brain is a very  powerful experimental approach. However, generating novel mouse ...

Cortex-, Hippocampus-, Thalamus-, Hypothalamus-, Lateral Septal Nucleus- and Striatum-specific In Utero Electroporation in the C57BL/6 Mouse

In utero electroporation is a widely used technique for fast and efficient spatiotemporal manipulation of various genes in the rodent central nervous system. Overexpression of desired genes is just as possible as shRNA mediated loss-of-function studies. Therefore it offers a wide range of applications. The feasibility to target particular cells in a distinct area further increases the range of potential applications of this very useful method. For efficiently targeting specific regions knowledge about the subtleties, such as the embryonic stage, the voltage to apply and most importantly the position of the electrodes, is indispensable.
Here, we provide a detailed protocol that allows for specific and efficient in utero electroporation of several regions of the C57BL/6 mouse central nervous system. In particular it is shown how to transfect regions the develop into the retrosplenial cortex, the motor cortex, the somatosensory cortex, the piriform cortex, the cornu ammonis 1-3, the dentate gyrus, the striatum, the lateral septal nucleus, the thalamus and the hypothalamus. For this information about the appropriate embryonic stage, the appropriate voltage for the corresponding embryonic stage is provided. Most importantly an angle-map, which indicates the appropriate position of the positive pole, is depicted. This standardized protocol helps to facilitate efficient in utero electroporation, which might also lead to a reduced number of animals.

Cortex-, Hippocampus-, Thalamus-, Hypothalamus-, Lateral Septal Nucleus- and Striatum-specific In Utero Electroporation in the C57BL/6 Mouse

This protocol describes in detail how to specifically transfect different regions in the C57BL/6 central nervous system via in utero electroporation. Included in this protocol are detailed instructions for transfections of regions that develop into the cortex, hippocampus, thalamus, hypothalamus, lateral septal nucleus and striatum.

Específica Striatum Cortex, hipocampo, Thalamus-, hipotálamo, núcleo-septal lateral y<em&gt; In Utero</em&gt; Electroporación en el ratón C57BL / 6

In utero electroporation is a widely used technique for fast and efficient spatiotemporal manipulation of various genes in the rodent central nervous ...

Time-lapse Confocal Imaging of Migrating Neurons in Organotypic Slice Culture of Embryonic Mouse Brain Using In Utero Electroporation

In utero electroporation is a rapid and powerful approach to study the process of radial migration in the cerebral cortex of developing mouse embryos. It has helped to describe the different steps of radial migration and characterize the molecular mechanisms controlling this process. To directly and dynamically analyze migrating neurons they have to be traced over time. This protocol describes a workflow that combines in utero electroporation with organotypic slice culture and time-lapse confocal imaging, which allows for a direct examination and dynamic analysis of radially migrating cortical neurons. Furthermore, detailed characterization of migrating neurons, such as migration speed, speed profiles, as well as radial orientation changes, is possible. The method can easily be adapted to perform functional analyses of genes of interest in radially migrating cortical neurons by loss and gain of function as well as rescue experiments. Time-lapse imaging of migrating neurons is a state-of-the-art technique that once established is a potent tool to study the development of the cerebral cortex in mouse models of neuronal migration disorders.

Time-lapse Confocal Imaging of Migrating Neurons in Organotypic Slice Culture of Embryonic Mouse Brain Using In Utero Electroporation

This protocol provides instructions for direct observation of radially migrating cortical neurons. In utero electroporation, organotypic slice culture, and time-lapse confocal imaging are combined to directly and dynamically study the effects of overexpression or downregulation of genes of interest in migrating neurons and to analyze their differentiation during development.

Time-lapse Imágenes confocales de las neuronas migratorias en la cultura organotípica en rebanadas de cerebro de ratón embrionario<em&gt; En Utero</em&gt; Electroporación

In utero electroporation is a rapid and powerful approach to study the process of radial migration in the cerebral cortex of developing mouse embryos. It ...

Inducción de la recombinación del Cre-lox en la corteza Cerebral de ratón a través de electroporación en el útero

Resumen

Explorar más videos

Capítulos en este video

La transfección de células de ratón del ganglio de la retina por In vivo La electroporación

Entrega génica eficaz en los territorios del SNC múltiples utilizando In Utero La electroporación

Del ratón en el útero de electroporación: Transefection controlada Gene espacio-temporal

Métodos de estudio de la morfogénesis neuronal:

La visualización y la manipulación genética de las dendritas y espinas en la corteza cerebral y el hipocampo del ratón usando

Dos registros electrofisiológicos de sinápticamente respuestas evocadas neuronal y astroglial en agudas rodajas de hipocampo

Generación de ratas transgénicas por vía tópica

La manipulación genética del ratón en desarrollo a través de Hipotálamo

Específica Striatum Cortex, hipocampo, Thalamus-, hipotálamo, núcleo-septal lateral y

Time-lapse Imágenes confocales de las neuronas migratorias en la cultura organotípica en rebanadas de cerebro de ratón embrionario