Este trabajo fue apoyado por una Harold y Leila Y. Mathers G. Premio a HL y una subvención del NIH (R24 GM080527) a RESCEJ era un Postdoctoral Fellow NRSA (NIH F32GM9037222) y actualmente es apoyado por un Premio al Desarrollo Científico Mentored Investigación de la Nacional Instituto del Envejecimiento (K01AG04435). Nos gustaría agradecer a los revisores por sus valiosos comentarios.

1 Preparación de ADN plásmido, agujas, y platos de inyección <ol><li> Preparar el ADN de plásmido usando un kit Maxi de alta velocidad o Midi y se concentra el ADN a 2,5 mg / ml utilizando la precipitación con etanol. El sedimento de ADN se debe disolver en agua desionizada libre de nucleasa. Almacene el ADN en 10-20 alícuotas a -20 ° C. (Véase el cuadro 1 complementario para obtener una lista de vectores disponibles) </li><li> Hacer un plato de inyección utilizando agarosa para construir un canal para la celebración de los embriones en una placa de 100 x 15 mm de Petri. <ol><li> Colocar un portaobjetos de microscopio de vidrio 75 x 50 en una placa de 100 x 15 mm Petri en un ángulo. Vierta aproximadamente 50 ml de 2% de agarosa fundido en un medio de Hydra 24 en la placa de Petri. Alternativamente, se vierte la agarosa en el plato primero y flotar un &quot;Mold Microinyección Fish&quot; en la parte superior. </li><li> Después de la agarosa se ha solidificado, retirar el portaobjetos de vidrio o el molde. Si se ha utilizado un portaobjetos de vidrio, cortar el exceso de agarosa con un bla de afeitarde para formar una pared. Verter medio Hydra en el plato y utilizar inmediatamente o almacenarlo a 4 ° C hasta que se necesite. Nota: los platos de inyección pueden ser reutilizados si se almacenan a 4 ° C entre usos. </li></ol></li><li> Tire las agujas de capilares de vidrio borosilicato con un filamento en el extractor de micropipeta usando las siguientes condiciones: calor 525, tire 75, velocidad 100, tiempo 50. Tienda las agujas de comprimirlos en una estrecha franja de tierra batida en un plato de Petri de manera que sean mantenida en paralelo a la parte inferior del plato. </li><li> Para preparar la solución de inyección, combinar 3 l de solución de ADN de plásmido de 2,5 mg / ml con 2 l de 10% de fenol rojo. Vortex la solución brevemente y luego girar por 10 min a velocidad máxima en una microcentrífuga para eliminar las partículas que pueden obstruir la aguja. </li><li> Bajo un microscopio de disección, corte la aguja unos pocos milímetros de la punta con fórceps para crear una pequeña abertura. Nota: Hay una cierta flexibilidad en el tamaño adecuado de la aperturaing porque la presión se puede ajustar en el paso 3.3 para acomodar esta variación. </li><li> Coloque la placa de Petri de modo que se mantiene la aguja en una posición vertical con la punta hacia abajo. Cargar la aguja con aproximadamente 0,5 l de solución de inyección con la pipeta el líquido en el extremo posterior de la aguja. Permitir que la acción capilar para tirar de la solución en la punta de la aguja. </li></ol> 2 Preparación de embriones para inyección <ol><li> Sobre una base diaria escanear el cultivo de la cepa Hydra AEP para los pólipos producen huevos. Reunir estos pólipos y déjelos a un lado en una placa de cultivo separado. Observar estos pólipos cada pocas horas durante el día para controlar el progreso de la formación del huevo. Cuando los huevos se rompen a través del ectodermo y se sientan en un anillo de células ectodérmicas retraídos que están listos para inyección 25. Coloque estos pólipos en un plato con varios Hydra que tienen testículos durante al menos 1 hora antes de la inyección para permitir la fertilización. Hydra &lt;/ Em&gt; machos lanzará esperma sin ninguna manipulación especial. </li><li> Si las hembras se encuentran en la colonia AEP con los huevos completamente formados, que son aproximadamente 400 micras de diámetro 25, o de 1 a embriones en estadio de 8 células, también recoger estos para inyección. Inmediatamente inyectar embriones que han comenzado escisión. Nota: No es posible establecer la diferencia entre los huevos completamente formadas y cigotos unicelulares, por lo tanto estas deben ser incubadas con los machos antes de la inyección. </li><li> Antes de la inyección, eliminar la mayor parte del tejido parental encima y por debajo del embrión usando un escalpelo con una cuchilla # 15. Dejar sólo el embrión con un pequeño trozo de la columna cuerpo adjunto, que se utiliza para manipular el embrión con pinzas si es necesario. Nota: El tejido que se diseca lejos del embrión regenerará y debe ser guardado para asegurar que las mujeres permanecen en la colonia Hydra. </li><li> Utilizando una pipeta Pasteur, mover el plato de embriones para inyección, disponiéndolos en paralelo a la pared de laa través de agarosa. </li></ol> 3. microinyección de ADN plásmido <ol><li> Monte el microinyector en un soporte magnético que se sienta en una placa de hierro. Montar el soporte de inyección, que es la parte de la microinyector que mantiene la aguja, en un micromanipulador joystick. Monte el manipulador joystick a la plancha de hierro, con un soporte magnético. Coloque esta todo el conjunto-en el lado derecho de un microscopio de disección y colocar el soporte de inyección de modo que sea visible en el campo de observación. </li><li> Coloque el plato de la inyección con embriones bajo el microscopio de disección, orientada de tal manera que la pared vertical de la cubeta de agarosa está a la izquierda. Insertar la aguja en el soporte de inyección y bajar la punta de la aguja en el medio Hydra en el plato. </li><li> Girar lentamente el pomo de la jeringa en la dirección de las agujas del reloj hasta que el aceite mineral se llena la parte superior de la aguja y un flujo constante de solución de inyección se observa que sale de la aguja en el hidrun medio. Si la corriente es demasiado fuerte, reduzca la presión girando la perilla a la izquierda. Practicar este paso para obtener de forma rutinaria una presión adecuada, que depende del tamaño de la abertura de la aguja (es decir, cómo se recorta la aguja en el paso 1.5). Nota: Si la corriente es demasiado fuerte, el embrión no sobrevivió a la inyección. </li><li> Mientras observa a través del microscopio de disección, mover el plato de inyección de manera que el primer embrión está en el centro del campo. Mover la aguja de modo que está en contacto con ese embrión. Utilice el micromanipulador para perforar el embrión con la aguja. Nota: La pared vertical de la cubeta de agarosa mantendrá el embrión sea empujado a un lado por la aguja. </li><li> Deje que la solución inyectable fluya hacia el embrión 1 o 2 segundos y luego retire la aguja rápidamente. Si el embrión tiene más de una celda, inyectar cada célula individual. El uso de fórceps para reorientar el embrión para alinear la siguiente celda con la punta de la aguja. </li><li> Después de la primera embryse inyecta o, mover el plato para que la próxima embrión se encuentra en la posición de inyección y repita el procedimiento; continuará hasta que se hayan inyectado todos los embriones. </li></ol> 4. El cultivo y la eclosión de embriones <ol><li> Mover todos los embriones inyectados en un plato con algunos Hydra que tienen testículos (esto es para asegurar que todos los embriones son fertilizados). Incubar los embriones en una incubadora a 18 °, mientras continúan la embriogénesis. </li><li> Una vez que se alcanza la etapa de cutícula, mover cada embrión inyectado a un pozo individual de una placa de 24 pocillos con medio lleno Hydra. </li><li> Incubar los embriones inyectados durante 2 semanas en la oscuridad a 18 ° C. </li><li> Después del periodo de incubación de 2 semana, comprobar cada embrión inyectado bajo la lupa. Tenga en cuenta los casos en los que el embrión cutícula etapa ha desprendido de la pequeña muestra de tejido de los padres y el tejido de los padres ha regeneradas. Eliminar este pólipo regenerado inmediatamente de modo que no es mistaken de una nueva cría. </li><li> Mueva el plato de embriones inyectados bajo una luz del acuario a RT. Compruebe los platos cada día y recoger las crías. Nuevas crías serán blancas porque el típico color rosa de pólipos Hydra viene de la Artemia que comen. </li><li> Observar las crías bajo un microscopio de fluorescencia para detectar la expresión del transgén. </li></ol>

<ol>
	<li>Wittlieb, J., Khalturin, K., Lohmann, J. U., Anton-Erxleben, F., Bosch, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transgenic+Hydra+allow+in+vivo+tracking+of+individual+stem+cells+during+morphogenesis.">Transgenic Hydra allow in vivo tracking of individual stem cells during morphogenesis.</a> Proc Natl Acad Sci U S A. 103, 6208-6211 (2006).</li><li>Glauber, K. M., Dana, C. E., Steele, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydra.">Hydra.</a> Curr Biol. 20, 964-965 (2010).</li><li>Holstein, T. W., Hobmayer, E., David, C. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pattern+of+epithelial+cell+cycling+in+hydra.">Pattern of epithelial cell cycling in hydra.</a> Dev Biol. 148, 602-611 (1991).</li><li>Dubel, S., Hoffmeister, S. A., Schaller, H. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differentiation+pathways+of+ectodermal+epithelial+cells+in+hydra.">Differentiation pathways of ectodermal epithelial cells in hydra.</a> Differentiation. 35, 181-189 (1987).</li><li>Khalturin, K., 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=Transgenic+stem+cells+in+Hydra+reveal+an+early+evolutionary+origin+for+key+elements+controlling+self-renewal+and+differentiation.">Transgenic stem cells in Hydra reveal an early evolutionary origin for key elements controlling self-renewal and differentiation.</a> Dev Biol. 309, 32-44 (2007).</li><li>Bosch, T., David, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stem+Cells+of+Hydra+magnipapillata+can+differentiate+into+somatic+cells+and+germ+line+cells.">Stem Cells of Hydra magnipapillata can differentiate into somatic cells and germ line cells.</a> Dev Biol. 121, 182-191 (1987).</li><li>David, C. N., Murphy, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+interstitial+stem+cells+in+hydra+by+cloning.">Characterization of interstitial stem cells in hydra by cloning.</a> Dev Biol. 58, 372-383 (1977).</li><li>Chapman, J. A., 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=The+dynamic+genome+of+Hydra.">The dynamic genome of Hydra.</a> Nature. 464, 592-596 (2010).</li><li>Boehm, A. M., Bosch, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Migration+of+multipotent+interstitial+stem+cells+in+Hydra.">Migration of multipotent interstitial stem cells in Hydra.</a> Zoology (Jena). 115, 275-282 (2012).</li><li>Glauber, K. M., 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+small+molecule+screen+identifies+a+novel+compound+that+induces+a+homeotic+transformation+in+Hydra.">A small molecule screen identifies a novel compound that induces a homeotic transformation in Hydra.</a> Development. 140, 4788-4796 (2013).</li><li>Siebert, S., Anton-Erxleben, F., Bosch, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+type+complexity+in+the+basal+metazoan+Hydra+is+maintained+by+both+stem+cell+based+mechanisms+and+transdifferentiation.">Cell type complexity in the basal metazoan Hydra is maintained by both stem cell based mechanisms and transdifferentiation.</a> Dev Biol. 313, 13-24 (2008).</li><li>Anton-Erxleben, F., Thomas, A., Wittlieb, J., Fraune, S., Bosch, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasticity+of+epithelial+cell+shape+in+response+to+upstream+signals:+a+whole-organism+study+using+transgenic+Hydra.">Plasticity of epithelial cell shape in response to upstream signals: a whole-organism study using transgenic Hydra.</a> Zoology (Jena). 112, 185-194 (2009).</li><li>Hemmrich, G., 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=Molecular+signatures+of+the+three+stem+cell+lineages+in+Hydra+and+the+emergence+of+stem+cell+function+at+the+base+of+multicellularity.">Molecular signatures of the three stem cell lineages in Hydra and the emergence of stem cell function at the base of multicellularity.</a> Mol Biol Evol. , (2012).</li><li>Juliano, C. 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=PIWI+proteins+and+PIWI-interacting+RNAs+function+in+Hydra+somatic+stem+cells.">PIWI proteins and PIWI-interacting RNAs function in Hydra somatic stem cells.</a> Proc Natl Acad Sci U S A. 111, 337-342 (2014).</li><li>Nishimiya-Fujisawa, C., Kobayashi, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Germline+stem+cells+and+sex+determination+in+Hydra.">Germline stem cells and sex determination in Hydra.</a> Int J Dev Biol. 56, 499-508 (2012).</li><li>Milde, 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=Characterization+of+taxonomically+restricted+genes+in+a+phylum-restricted+cell+type.">Characterization of taxonomically restricted genes in a phylum-restricted cell type.</a> Genome Biol. 10, 8 (2009).</li><li>Nakamura, Y., Tsiairis, C. D., Ozbek, S., Holstein, T. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autoregulatory+and+repressive+inputs+localize+Hydra+Wnt3+to+the+head+organizer.">Autoregulatory and repressive inputs localize Hydra Wnt3 to the head organizer.</a> Proc Natl Acad Sci U S A. 108, 9137-9142 (2011).</li><li>Gee, 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=beta-catenin+plays+a+central+role+in+setting+up+the+head+organizer+in+hydra.">beta-catenin plays a central role in setting up the head organizer in hydra.</a> Dev Biol. 340, 116-124 (2010).</li><li>Fraune, 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=In+an+early+branching+metazoan,+bacterial+colonization+of+the+embryo+is+controlled+by+maternal+antimicrobial+peptides.">In an early branching metazoan, bacterial colonization of the embryo is controlled by maternal antimicrobial peptides.</a> Proc Natl Acad Sci U S A. 107, 18067-18072 (2010).</li><li>Bridge, D., 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=FoxO+and+stress+responses+in+the+cnidarian+Hydra+vulgaris.">FoxO and stress responses in the cnidarian Hydra vulgaris.</a> PLoS One. 5, e11686 (2010).</li><li>Boehm, A. M., 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=FoxO+is+a+critical+regulator+of+stem+cell+maintenance+in+immortal+Hydra.">FoxO is a critical regulator of stem cell maintenance in immortal Hydra.</a> Proc Natl Acad Sci U S A. 109, 19697-19702 (2012).</li><li>Franzenburg, 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=MyD88-deficient+Hydra+reveal+an+ancient+function+of+TLR+signaling+in+sensing+bacterial+colonizers.">MyD88-deficient Hydra reveal an ancient function of TLR signaling in sensing bacterial colonizers.</a> Proc Natl Acad Sci U S A. 109, 19374-19379 (2012).</li><li>Dana, C. E., Glauber, K. M., Chan, T. A., Bridge, D. M., Steele, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Incorporation+of+a+horizontally+transferred+gene+into+an+operon+during+cnidarian+evolution.">Incorporation of a horizontally transferred gene into an operon during cnidarian evolution.</a> PLoS One. 7, e31643 (2012).</li><li>Lenhoff, H. M., Lenhoff, H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Hydra: Research Methods. , 29-34 (1983).</li><li>Miller, M. A., Technau, U., Smith, K. M., Steele, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oocyte+development+in+Hydra+involves+selection+from+competent+precursor+cells.">Oocyte development in Hydra involves selection from competent precursor cells.</a> Dev Biol. 224, 326-338 (2000).</li><li>Lenhoff, H. M., Lenhoff, H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Hydra: Research Methods. , 53-62 (1983).</li></ol>

The authors have nothing to disclose

Hydra reproduce asexualmente rutinariamente, pero requiere de estímulos ambientales para comenzar gametos productores. Estos estímulos no están bien definidas-para la mayoría de las especies Hydra y pueden diferir de cepa a cepa. Un obstáculo significativo a la producción de transgénicos Hydra es la obtención de embriones sobre una base regular, ya que puede resultar difícil en un entorno de laboratorio para inducir Hydra para convertirse sexual. La cepa AEP 25, si...

Hydra se ha utilizado para estudiar la regeneración, la formación de patrones, y las células madre para unos 250 años 2 Hydra tiene un plan de cuerpo simple que consiste en tres linajes celulares:. Epitelio ectodérmico, endodérmico epitelial y intersticial. El cuerpo tubular está formado por la ectodérmico y endodérmico linajes epiteliales, cada uno de los cuales es una sola capa de células. Todas las células epiteliales en la columna de la carrocería son mitótico. Cuando las células epiteliales se desplazan en las extremidades 3, la cabeza (boca y tentáculos) en el extremo oral o el pie (disco basal) en el extremo aboral, que detención en la fase G2 del ciclo celular y cambiar el destino celular 4. Las células del linaje intersticial residen dentro de los intersticios entre las células epiteliales. Este linaje es apoyado por las células madre multipotentes que se encuentran en la capa epitelial ectodérmica de la columna de cuerpo 5. Las células madre intersticiales dan lugar a tres cel somáticatipos l (nervios, células de la glándula, y nematocytes) y las células germinales 6,7. Como miembro del filo Cnidaria, el grupo hermano de todos los bilaterales, Hydra puede arrojar luz sobre los procesos biológicos fundamentales compartidos entre los animales multicelulares. Hasta hace poco, estos esfuerzos fueron obstaculizados por la falta de métodos fiables para la perturbación de la función génica. Sin embargo, con el desarrollo de la metodología transgénico 1, ahora somos capaces de sacar el máximo provecho de Hydra para obtener una mejor comprensión de los mecanismos básicos comunes a los animales multicelulares, como la función de células madre, la regeneración y el patrón. Líneas transgénicas Hydra son establecidos por inyección de plásmido de ADN en embriones, lo que resulta en la integración aleatoria y de expresión quimérico en una frecuencia sustancial de las crías. Una línea con expresión uniforme en un linaje particular puede ser establecida por la propagación asexual. La capacidad de propagar clonalmente transgENIC Hydra líneas es una ventaja sobre la mayoría de los modelos animales, que puede ser propagada sólo por reproducción sexual. Además, las células transgénicas se pueden rastrear fácilmente in vivo debido a la transparencia del animal y la ausencia de proteínas fluorescentes endógenos 8. En los siete años transcurridos desde las primeras líneas transgénicas Hydra fueron hechas 1, dichas líneas se han utilizado para una variedad de aplicaciones. La expresión de proteínas fluorescentes en diferentes tipos de células ha permitido rastrear el movimiento celular, observar los cambios en la forma de la célula, y la pista destino celular, tanto en condiciones de tipo salvaje y después de la perturbación química 1,5,9-12. Además, la expresión de diferentes proteínas fluorescentes en los diversos linajes permite el aislamiento de FACS de poblaciones celulares específicas. Esta técnica ha sido utilizada para la secuenciación de ARNm específicos de células madre y linaje específico de pequeños RNAs 13,14. Mientras que el promotor deuno de los dos genes de actina Hydra se ha utilizado más ampliamente, unos pocos de tipo celular promotores específicos han sido identificados y se utiliza para controlar la expresión de GFP en transgénicos Hydra 9,11,15,16. En el futuro, promotores específicos de tipo celular permitirá para la observación y la recogida de cualquier tipo de célula específico. Además, un enfoque transgénico se utilizó con éxito para definir los elementos reguladores que actúan en cis del promotor Wnt3 17. El desarrollo de métodos transgénicos en Hydra proporciona un enfoque robusto para probar la función de los genes por la expresión ectópica, la sobreexpresión, y caída. Los animales transgénicos se han hecho que expresan proteínas fluorescentemente marcadas con el fin de examinar la función y localización celular 18-20. Además, la expresión de ARN horquillas en el 3&#39;UTR de un transgén GFP lleva a desmontables de genes diana 21,22. En estos enfoques se requiere para identificar las buenas prácticas agrariasy rastrear el tejido transgénico durante la creación de la línea transgénica. Sin embargo, es probable que en algunos casos la molécula de GFP podría interferir con la función de la proteína etiquetada. Un estudio reciente demuestra que los genes Hydra pueden ser dispuestos en una configuración operón, es decir, se hacen polycistronic transcripciones, que luego son separados por trans-empalmados Además líder y traducido por separado 23. Mediante la colocación de un gen que codifica una proteína o un ARN de horquilla en la posición aguas arriba de un operón y un gen de proteína fluorescente en la posición aguas abajo, se puede realizar un seguimiento de tejido transgénico sin tener que etiquetar el gen que codifica la proteína o ARN de horquilla. Este método se ha utilizado para expresar una horquilla de ARN en una configuración operón con DsRed2 a fin de lograr gen desmontables 14.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">AEP Hydra Strain</td>
			<td style="width:112px;">NA</td>
			<td style="width:119px;">NA</td>
			<td style="width:576px;">Email: Celina Juliano at celina.juliano@yale.edu or Hiroshi Shimizu bubuchin2006@yahoo.co.jp</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">High Speed Maxi Kit</td>
			<td style="width:112px;">Qiagen</td>
			<td align="right" style="width:119px;">12662</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">100 x 15 mm Petri Dishes</td>
			<td style="width:112px;">BD Falcon</td>
			<td align="right" style="width:119px;">351029</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">75 x 50 mm Glass Microscope Slide</td>
			<td style="width:112px;">Sigma</td>
			<td>CLS294775X50</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Microinjection Fish Mold</td>
			<td style="width:112px;">IBI Scientific</td>
			<td style="width:119px;">FM-600</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Borosilicate Glass with Filament</td>
			<td style="width:112px;">Sutter Instrument</td>
			<td style="width:119px;">BF100-50-10</td>
			<td>O.D.: 1.0 mm, I.D.: 0.50 mm, 10 cm length</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Flaming/Brown Micropipette Puller</td>
			<td style="width:112px;">Sutter Instrument</td>
			<td style="width:119px;">P-97</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Phenol Red</td>
			<td style="width:112px;">Sigma</td>
			<td style="width:119px;">P3532</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Jewelers Forceps, Durmont #5</td>
			<td style="width:112px;">Sigma</td>
			<td>F6521</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Scalpel Blade #15</td>
			<td style="width:112px;">Fisher</td>
			<td style="width:119px;">50-822-421</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Mineral oil</td>
			<td style="width:112px;">Sigma</td>
			<td style="width:119px;">M8410-500ML</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Microinjector</td>
			<td style="width:112px;">Narishige</td>
			<td style="width:119px;">IM-9B</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Magnetic Stand</td>
			<td style="width:112px;">Narishige</td>
			<td style="width:119px;">GJ-1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Iron Plate</td>
			<td style="width:112px;">Narishige</td>
			<td style="width:119px;">IP</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Joystick Micromanipulator</td>
			<td style="width:112px;">Narishige</td>
			<td style="width:119px;">MN-151</td>
			<td></td>
		</tr>
	</tbody>
</table>

generation of transgenic hydra by embryo microinjection

As a member of the phylum Cnidaria, the sister group to all bilaterians, Hydra can shed light on fundamental biological processes shared among multicellular animals. Hydra is used as a model for the study of regeneration, pattern formation, and stem cells. However, research efforts have been hampered by lack of a reliable method for gene perturbations to study molecular function. The development of transgenic methods has revitalized the study of Hydra biology1. Transgenic Hydra allow for the tracking of live cells, sorting to yield pure cell populations for biochemical analysis, manipulation of gene function by knockdown and over-expression, and analysis of promoter function. Plasmid DNA injected into early stage embryos randomly integrates into the genome early in development. This results in hatchlings that express transgenes in patches of tissue in one or more of the three lineages (ectodermal epithelial, endodermal epithelial, or interstitial). The success rate of obtaining a hatchling with transgenic tissue is between 10% and 20%. Asexual propagation of the transgenic hatchling is used to establish a uniformly transgenic line in a particular lineage. Generating transgenic Hydra is surprisingly simple and robust, and here we describe a protocol that can be easily implemented at low cost.

El establecimiento de líneas transgénicas de Hydra Alimente las crías transgénicas cada 2-3 días con nauplios de Artemia. Las crías a veces no comen por un día o dos después de la eclosión. Algunas de las nuevas crías nunca van a comer, y por lo tanto no va a sobrevivir. Si la cría es transgénica ya sea en el ectodérmica (Figura 1A) o tejido epitelial endodérmico, permitir que el animal brote y recoger los brotes que tienen el tejido más transg?...

Watch this Scientific Journal Video about Generation of Transgenic Hydra by Embryo Microinjection at JoVE.com

Generation of Transgenic Hydra by Embryo Microinjection

Stably transgenic Hydra are made by microinjection of plasmid DNA into embryos followed by random genomic integration and asexual propagation to establish a uniform line. Transgenic Hydra are used to track cell movements, overexpress genes, study promoter function, or knock down gene expression using RNAi.

Generación de transgénicos<em&gt; Hydra</em&gt; Por microinyección de embriones

As a member of the phylum Cnidaria, the sister group to all bilaterians, Hydra can shed light on fundamental biological processes shared among ...

generation-of-transgenic-hydra-by-embryo-microinjection

Research

JoVE Journal

Biology

Generation of Transgenic Hydra by Embryo Microinjection

13.9K vistas.  Yale University School of Medicine. Stably transgenic Hydra are made by microinjection of plasmid DNA into embryos followed by random genomic integration and asexual propagation to establish a uniform line. Transgenic Hydra are used to track cell movements, overexpress genes, study promoter function, or knock down gene expression using RNAi. 

Video: Generation of Transgenic Hydra by Embryo Microinjection

Microinjection of A. aegypti Embryos to Obtain Transgenic Mosquitoes

In this video, Nijole Jasinskiene demonstrates the methodology employed to generate transgenic Aedes aegypti mosquitoes, which are vectors for dengue fever.  The techniques for correctly preparing microinjection needles, dessicating embryos, and performing microinjection are demonstrated.

In this video, Nijole Jasinskiene demonstrates the methodology employed to generate transgenic Aedes aegypti mosquitoes, which are vectors for dengue fever. The techniques for correctly preparing microinjection needles, dessicating embryos, and performing microinjection are demonstrated.

Microinyección de A. aegypti embriones para obtener los mosquitos transgénicos

In this video, Nijole Jasinskiene demonstrates the methodology employed to generate transgenic Aedes aegypti mosquitoes, which are vectors for dengue ...

Investigación

Biología

Generation of Stable Transgenic C. elegans Using Microinjection

Transgenic Caenorhabditis elegans can be readily created via microinjection of a DNA plasmid solution into the gonad 1. The plasmid DNA rearranges to form extrachromosomal concatamers that are stably inherited, though not with the same efficiency as actual chromosomes 2. A gene of interest is co-injected with an obvious phenotypic marker, such as rol-6 or GFP, to allow selection of transgenic animals under a dissecting microscope. The exogenous gene may be expressed from its native promoter for cellular localization studies. Alternatively, the transgene can be driven by a different tissue-specific promoter to assess the role of the gene product in that particular cell or tissue. This technique efficiently drives gene expression in all tissues of C. elegans except for the germline or early embryo 3. Creation of transgenic animals is widely utilized for a range of experimental paradigms. This video demonstrates the microinjection procedure to generate transgenic worms. Furthermore, selection and maintenance of stable transgenic C. elegans lines is described.

This video demonstrates the technique of microinjection into the gonad of C. elegans to create transgenic animals.

Generación de transgénicos estable C. elegans con microinyección

Transgenic Caenorhabditis elegans can be readily created via microinjection of a DNA plasmid solution into the gonad 1.  The plasmid DNA rearranges to ...

Microinjection Techniques for Studying Mitosis in the Drosophila melanogaster Syncytial Embryo

This protocol describes the use of the Drosophila melanogaster syncytial embryo for studying mitosis1. Drosophila has useful genetics with a sequenced genome, and it can be easily maintained and manipulated. Many mitotic mutants exist, and transgenic flies expressing functional fluorescently (e.g. GFP) - tagged mitotic proteins have been and are being generated. Targeted gene expression is possible using the GAL4/UAS system2. 

The Drosophila early embryo carries out multiple mitoses very rapidly (cell cycle duration, &asymp;10 min). It is well suited for imaging mitosis, because during cycles 10-13, nuclei divide rapidly and synchronously without intervening cytokinesis at the surface of the embryo in a single monolayer just underneath the cortex. These rapidly dividing nuclei probably use the same mitotic machinery as other cells, but they are optimized for speed; the checkpoint is generally believed to not be stringent, allowing the study of mitotic proteins whose absence would cause cell cycle arrest in cells with a strong checkpoint. Embryos expressing GFP labeled proteins or microinjected with fluorescently labeled proteins can be easily imaged to follow live dynamics (Fig. 1). In addition, embryos can be microinjected with function-blocking antibodies or inhibitors of specific proteins to study the effect of the loss or perturbation of their function3. These reagents can diffuse throughout the embryo, reaching many spindles to produce a gradient of concentration of inhibitor, which in turn results in a gradient of defects comparable to an allelic series of mutants. Ideally, if the target protein is fluorescently labeled, the gradient of inhibition can be directly visualized4. It is assumed that the strongest phenotype is comparable to the null phenotype, although it is hard to formally exclude the possibility that the antibodies may have dominant effects in rare instances, so rigorous controls and cautious interpretation must be applied. Further away from the injection site, protein function is only partially lost allowing other functions of the target protein to become evident.

Microinjection Techniques for Studying Mitosis in the Drosophila melanogaster Syncytial Embryo

This protocol describes the use of microinjection and high resolution imaging in the Drosophila melanogaster syncytial embryo to study mitosis.

Técnicas de microinyección para el estudio de la mitosis en el Drosophila melanogaster Embrión sincitial

This protocol describes the use of the Drosophila melanogaster syncytial embryo  for studying mitosis1.  Drosophila has useful genetics with a sequenced ...

Production of Transgenic Xenopus laevis by Restriction Enzyme Mediated Integration and Nuclear Transplantation

Stable integration of cloned gene products into the Xenopus genome is necessary to control the time and place of expression, to express genes at later stages of embryonic development, and to define how enhancers and promoters regulate gene expression within the embryo. The protocol demonstrated here can be used to efficiently produce transgenic Xenopus laevis embryos. This transgenesis approach involves three parts: 1. Sperm nuclei are isolated from adult X. laevis testis by treatment with lysolecithin, which permeabilizes the sperm plasma membrane. 2. Egg extract is prepared by low speed centrifugation, addition of calcium to cause the extract to progress to interphase of the cell cycle, and a high-speed centrifugation to isolate interphase cytosol. 3. Nuclear transplantation: the nuclei and extract are combined with the linearized plasmid DNA to be introduced as the transgene and a small amount of restriction enzyme. During a short reaction, egg extract partially decondenses the sperm chromatin and the restriction enzyme generates chromosomal breaks that promote recombination of the transgene into the genome. The treated sperm nuclei are then transplanted into unfertilized eggs. Integration of the transgene usually occurs prior to the first embryonic cleavage such that the resulting embryos are not chimeric. These embryos can be analyzed without any need to breed to the next generation, allowing for efficient and rapid generation of transgenic embryos for analyses of promoter and gene function. Adult X. laevis resulting from this procedure also propagate the transgene through the germline and can be used to generate lines of transgenic animals for multiple purposes.

Production of Transgenic Xenopus laevis by Restriction Enzyme Mediated Integration and Nuclear Transplantation

This video protocol demonstrates a method for generating transgenic Xenopus laevis by introduction of transgenes into sperm nuclei followed by nuclear transplantation into unfertilized eggs.

La producción de transgénicos Xenopus laevis Integración mediada por la enzima de restricción y transferencia nuclear

Stable integration of cloned gene products into the Xenopus genome is necessary to control the time and place of expression, to express genes at later ...

Generation of Transgenic C. elegans by Biolistic Transformation

The number of laboratories using the free living nematode C. elegans is rapidly growing. The popularity of this biological model is attributed to a rapid generation time and short life span, easy and inexpensive maintenance, fully sequenced genome, and array of RNAi resources and mutant animals. Additionally, analysis of the C. elegans genome revealed a great similarity between worms and higher vertebrates, which suggests that research in worms could be an important adjunct to studies performed in whole mice or cultured cells. A powerful and important part of worm research is the ability to use transgenic animals to study gene localization and function. Transgenic animals can be created either via microinjection of the worm germline or through the use of biolistic bombardment. Bombardment is a newer technique and is less familiar to a number of labs. Here we describe a simple protocol to generate transgenic worms by biolistic bombardment with gold particles using the Bio-Rad PDS-1000 system. Compared with DNA microinjection into hermaphrodite germline, this protocol has the advantage of not requiring special skills from the operator with regards to identifying worm anatomy or performing microinjection. Further multiple transgenic lines are usually obtained from a single bombardment. Also in contrast to microinjection, biolistic bombardment produces transgenic animals with both extrachromosomal arrays and integrated transgenes. The ability to obtain integrated transgenic lines can avoid the use of mutagenic protocols to integrate foreign DNA. In conclusion, biolistic bombardment can be an attractive method for the generation of transgenic animals, especially for investigators not interested in investing the time and effort needed to become skilled at microinjection.

Generation of Transgenic C. elegans by Biolistic Transformation

Transgenic worms are commonly used in C. elegans research. Described is a simple, yet effective, protocol to introduce transgenes into worms using biolistic bombardment with DNA-coated gold particles. The effort involved and results of bombardment compare favorably with microinjection for the generation of transgenic animals.

Generación de transgénicos C. elegans Por la transformación biolística

The number of laboratories using the free living nematode C. elegans is rapidly growing. The popularity of this biological model is attributed to a rapid ...

Analysis of mRNA Nuclear Export Kinetics in Mammalian Cells by Microinjection

In eukaryotes, messenger RNA (mRNA) is transcribed in the nucleus and must be exported into the cytoplasm to access the translation machinery. Although the nuclear export of mRNA has been studied extensively in Xenopus oocytes1 and genetically tractable organisms such as yeast2 and the Drosophila derived S2 cell line3, few studies had been conducted in mammalian cells. Furthermore the kinetics of mRNA export in mammalian somatic cells could only be inferred indirectly4,5. In order to measure the nuclear export kinetics of mRNA in mammalian tissue culture cells, we have developed an assay that employs the power of microinjection coupled with fluorescent in situ hybridization (FISH). These assays have been used to demonstrate that in mammalian cells, the majority of mRNAs are exported in a splicing dependent manner6,7, or in manner that requires specific RNA sequences such as the signal sequence coding region (SSCR) 6. In this assay, cells are microinjected with either in vitro synthesized mRNA or plasmid DNA containing the gene of interest. The microinjected cells are incubated for various time points then fixed and the sub-cellular localization of RNA is assessed using FISH. In contrast to transfection, where transcription occurs several hours after the addition of nucleic acids, microinjection of DNA or mRNA allows for rapid expression and allows for the generation of precise kinetic data.

Here we describe an assay that employs the power of microinjection coupled with fluorescent in situ hybridization in order to accurately measure the nuclear export kinetics of mRNA in mammalian somatic cells.

Análisis de la cinética de exportación nuclear de ARNm en células de mamífero por microinyección

In eukaryotes, messenger RNA (mRNA) is transcribed in the nucleus and must be exported into the cytoplasm to access the translation machinery. Although ...

Analyzing the Function of Small GTPases by Microinjection of Plasmids into Polarized Epithelial Cells

Epithelial cells polarize their plasma membrane into biochemically and functionally distinct apical and basolateral domains where the apical domain faces the 'free' surfaces and the basolateral membrane is in contact with the substrate and neighboring cells. Both membrane domains are separated by tight junctions, which form a diffusion barrier. Apical-basolateral polarization can be recapitulated successfully in culture when epithelial cells such as Madin-Darby Canine Kidney (MDCK) cells are seeded at high density on polycarbonate filters and cultured for several days 1 2. Establishment and maintenance of cell polarity is regulated by an array of small GTPases of the Ras superfamily such as RalA, Cdc42, Rab8, Rab10 and Rab13 3 4 5 6 7. Like all GTPases these proteins cycle between an inactive GDP-bound state and an active GTP-bound state. Specific mutations in the nucleotide binding regions interfere with this cycling 8. For example, Rab13T22N is permanently locked in the GDP-form and thus dubbed 'dominant negative', whereas Rab13Q67L can no longer hydrolyze GTP and is thus locked in a 'dominant active' state 7. To analyze their function in cells both dominant negative and dominant active alleles of GTPases are typically expressed at high levels to interfere with the function of the endogenous proteins 9. An elegant way to achieve high levels of overexpression in a short amount of time is to introduce the plasmids encoding the relevant proteins directly into the nuclei of polarized cells grown on filter supports using microinjection technique. This is often combined with the co-injection of reporter plasmids that encode plasma membrane receptors that are specifically sorted to the apical or basolateral domain. A cargo frequently used to analyze cargo sorting to the basolateral domain is a temperature sensitive allele of the vesicular stomatitis virus glycoprotein (VSVGts045) 10. This protein cannot fold properly at 39&deg;C and will thus be retained in the endoplasmic reticulum (ER) while the regulatory protein of interest is assembled in the cytosol. A shift to 31&deg;C will then allow VSVGts045 to fold properly, leave the ER and travel to the plasma membrane 11. This chase is typically performed in the presence of cycloheximide to prevent further protein synthesis leading to cleaner results. Here we describe in detail the procedure of microinjecting plasmids into polarized cells and subsequent incubations including temperature shifts that allow a comprehensive analysis of regulatory proteins involved in basolateral sorting.

This article details the procedures involved in overexpression and analysis of small GTPases in polarized epithelial cells using microinjection technique.

El análisis de la función de las pequeñas GTPasas de la microinyección de plásmidos en células epiteliales polarizadas

Epithelial cells polarize their plasma membrane into biochemically and functionally distinct apical and basolateral domains where the apical domain faces ...

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c

Apoptosis, or programmed cell death, is a conserved and highly regulated pathway by which cells die1. Apoptosis can be triggered when cells encounter a wide range of cytotoxic stresses. These insults initiate signaling cascades that ultimately cause the release of cytochrome c from the mitochondrial intermembrane space to the cytoplasm2. The release of cytochrome c from mitochondria is a key event that triggers the rapid activation of caspases, the key cellular proteases which ultimately execute cell death3-4.
The pathway of apoptosis is regulated at points upstream and downstream of cytochrome c release from mitochondria5. In order to study the post-mitochondrial regulation of caspase activation, many investigators have turned to direct cytoplasmic microinjection of holocytochrome c (heme-attached) protein into cells6-9. Cytochrome c is normally localized to the mitochondria where attachment of a heme group is necessary to enable it to activate apoptosis10-11. Therefore, to directly activate caspases, it is necessary to inject the holocytochrome c protein instead of its cDNA, because while the expression of cytochrome c from cDNA constructs will result in mitochondrial targeting and heme attachment, it will be sequestered from cytosolic caspases. Thus, the direct cytosolic microinjection of purified heme-attached cytochrome c protein is a useful tool to mimic mitochondrial cytochrome c release and apoptosis without the use of toxic insults which cause cellular and mitochondrial damage.
In this article, we describe a method for the microinjection of cytochrome c protein into cells, using mouse embryonic fibroblasts (MEFs) and primary sympathetic neurons as examples. While this protocol focuses on the injection of cytochrome c for investigations of apoptosis, the techniques shown here can also be easily adapted for microinjection of other proteins of interest.

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c

In this protocol, we describe the direct cytoplasmic microinjection of cytochrome c protein into fibroblasts and primary sympathetic neurons. This technique allows for the introduction of cytochrome c protein into the cytoplasm of cells and mimics the release of cytochrome c from mitochondria, which occurs during apoptosis.

La activación de la apoptosis mediante microinyección citoplasmática del citocromo C</em

Apoptosis, or programmed cell death, is a conserved and highly regulated pathway by which cells die1.  Apoptosis can be triggered when cells encounter a ...

Generation of Myospheres From hESCs by Epigenetic Reprogramming

Generation of a homogeneous and abundant population of skeletal muscle cells from human embryonic stem cells (hESCs) is a requirement for cell-based therapies and for a "disease in a dish" model of human neuromuscular diseases. Major hurdles, such as low abundance and heterogeneity of the population of interest, as well as a lack of protocols for the formation of three-dimensional contractile structures, have limited the applications of stem cells for neuromuscular disorders. We have designed a protocol that overcomes these limits by ectopic introduction of defined factors in hESCs - the muscle determination factor MyoD and SWI/SNF chromatin remodeling complex component BAF60C - that are able to reprogram hESCs into skeletal muscle cells. Here we describe the protocol established to generate hESC-derived myoblasts and promote their clustering into tridimensional miniaturized structures (myospheres) that functionally mimic miniaturized skeletal muscles7.

Here, we describe a protocol based on epigenetic reprogramming of human embryonic stem cells (hESCs) toward generating a homogeneous population of skeletal muscle progenitors that under permissive culture conditions form three-dimensional clusters of contractile myofibers (myospheres), which recapitulate biological features of human skeletal muscles.

Generación de Myospheres De hESCs por epigenética Reprogramación

Generation of a homogeneous and abundant population of skeletal muscle cells from human embryonic stem cells (hESCs) is a requirement for cell-based ...

Culturing Caenorhabditis elegans in Axenic Liquid Media and Creation of Transgenic Worms by Microparticle Bombardment

In this protocol, we present the required materials, and the procedure for making modified&#160;C. elegans&#160;Habituation and Reproduction media (mCeHR). Additionally, the steps for exposing and acclimatizing C. elegans grown on E. coli to axenic liquid media are described. Finally, downstream experiments that utilize axenic C. elegans illustrate the benefits of this procedure. The ability to analyze and determine C. elegans&#160;nutrient requirement was illustrated by growing N2 wild type worms in axenic liquid media with varying heme concentrations. This procedure can be replicated with other nutrients to determine the optimal concentration for worm growth and development or, to determine the toxicological effects of drug treatments. The effects of varied heme concentrations on the growth of wild type worms were determined through qualitative microscopic observation and by quantitating the number of worms that grew in each heme concentration. In addition, the effect of varied nutrient concentrations can be assayed by utilizing worms that express fluorescent sensors that respond to changes in the nutrient of interest. Furthermore, a large number of worms were easily produced for the generation of transgenic C. elegans using microparticle bombardment.

Culturing Caenorhabditis elegans in Axenic Liquid Media and Creation of Transgenic Worms by Microparticle Bombardment

C. elegans is usually grown on solid agar plates or in liquid cultures seeded with E. coli. To prevent bacterial byproducts from confounding toxicological and nutritional studies, we utilized an axenic liquid medium, CeHR, to grow and synchronize a large number of worms for a range of downstream applications.