Apoyado por el Premio de Desarrollo Profesional de Investigación para Prevención de la Ceguera, NIH EY 019312, y subvención sin restricciones de Investigación para Prevención de la Ceguera y EY 02687 (Departamento de Oftalmología y Ciencias Visuales en la Universidad de Washington).

Hacer electrodos <ol><li> Hacer los electrodos de registro utilizando un extractor de micropipeta y pulir los electrodos con filamento de calefacción bajo el microscopio. Para la grabación del ratón cono de succión de una sola célula, el diámetro interior en la punta del electrodo es de unos 6.7 micras. </li><li> Preparar electrodos de referencia. Pesar 1% de agar en agua destilada. Derretir la solución de agar en un baño de agua caliente. Llenar las pipetas de vidrio (L = 100 mm, OD / ID = 1/0.75 mm) con 1% de agar con una jeringa. Solidificar el agar a temperatura ambiente durante 10 minutos. </li><li> Cortar las pipetas en dos mitades con un cuchillo de diamante. </li><li> Sumerja los electrodos de referencia en la solución de referencia por lo menos 24 horas a 4 ° C. </li></ol> Configuración del experimento <ol start="5"><li> Dark adaptar un ratón en una jaula de negro durante la noche. </li><li> Prepare una solución de 100 ml de referencia y una solución de perfusión L (ver abajo) y el filtro de la solución. </li><li> Disolver 0,1% de BSA y 10 mM de glucosa en 20 ml de solución de referencia. </li><li> Calibrar la intensidad de la luz del estimulador óptico con fotómetro. </li><li> Monte la cámara de grabación en la platina del microscopio invertido. </li><li> La burbuja de la solución de perfusión con 95% O 2 / 5% CO 2, que se incuba a 40 ° C baño de agua para aumentar la solubilidad de CO 2. La solución de los flujos de la botella a la cámara de grabación que pasa a través de una resistencia de cerámica de calentamiento a 36-38 ° C. El calentador debe colocarse lo más cerca a la cámara de grabación como sea posible, idealmente en la platina del microscopio. </li><li> Ajuste el regulador de flujo para un caudal de alrededor de 1-1,5 ml / min. </li><li> Llenar el electrodo de registro con la solución de referencia. Insertar el electrodo en un porta-electrodos. Asegúrese de que no haya burbujas en el electrodo. Monte el soporte en el headstage del amplificador. Conecte el soporte a un dispositivo de succión, que se construye mediante la conexión de la tubería parcialmente llena con aceite mineral para el puerto lateral del porta-electrodos. El otro extremo del tubo está conectado a un pequeño depósito de aceite mineral, a la que la presión se puede aplicar por vía oral. </li><li> Conecte el electrodo de referencia al otro polo de la headstage. Obligar a la par térmico (TC) para el electrodo de referencia. Asegúrese de que las puntas de los electrodos y TC están muy juntos para que la lectura de la temperatura se toma como cerca de la célula como sea posible. </li><li> Encienda la iluminación infrarroja para visualizar el electrodo. El electrodo es visto por la cámara de infrarrojos conectada a un monitor. Centro del electrodo de la imagen en el campo visual y del monitor mediante un micromanipulador. </li><li> Ajustar la posición de la punta del electrodo de referencia cerca (2-4 mm) a la punta del electrodo de registro. </li><li> Ajustar el voltaje de CC para el calentador de modo que la temperatura de la solución es de 36-38 º C. </li><li> Realizar una prueba de sello para comprobar la resistencia de electrodo de registro, por lo general alrededor de 900 kW. </li></ol> Aislamiento de la retina del ratón <ol start="18"><li> Bajo tenue luz roja, la eutanasia el ratón adaptado a la oscuridad con el CO 2 y la dislocación cervical. Marcar los globos oculares con la punta de una antorcha de metal caliente de la cauterización de los punto más dorsal de la esclerótica un poco. Enucleación del globo ocular con unas tijeras. Todos los procedimientos posteriores se realizan bajo la luz infrarroja. </li><li> Hemisect los ojos bajo el microscopio con iluminación infrarroja y los convertidores de la imagen. </li><li> Retire la córnea y el cristalino. Eliminar la mayor cantidad de vítreo como sea posible. </li><li> Para grabar cono M-respuestas, eliminar la parte ventral de la ojera 4 con una cuchilla de afeitar a juzgar por la marca de la cauterización. </li><li> Pelar la retina de la capa de epitelio pigmentario. </li><li> Aplanar la retina y lo coloca en la parte inferior de la placa de Petri llenas de 1.2 ml solución de referencia. </li><li> Cortar la retina en pequeños trozos delgados con una cuchilla de afeitar y se incuba la preparación en una caja a prueba de luz saturada con oxígeno puro. </li></ol> Grabaciones <ol start="25"><li> Apague el calentador de forma temporal. Cambiar el flujo de perfusión a una tubería de derivación para evitar que la cámara de secado. </li><li> Drenan la mayor parte de la solución en la cámara usando un pedazo de tejido Kimwipe. Transferir la suspensión de la retina a la cámara de grabación con una pipeta de vidrio. </li><li> Espere unos 2 minutos hasta que las rodajas de retina se establecen. Interruptor de la perfusión de nuevo. Encender el calefactor. </li><li> Activar la iluminación infrarroja para visualizar la preparación. Búsqueda de un pedazo de retina tendido en la cámara con segmentos fotorreceptor exterior sobresaliendo (ver figura ejemplo). Dibuja los segmentos internos suavemente en el electrodo por la succión. En esta configuración, varios núcleos y segmentos internos debe ser elaborado en el electrodo. Registrar la photoresponse un destello brillante para probar si un segmento de cono interno está en el electrodo de la célula y si es curartu, a juzgar por la cinética de la respuesta y la amplitud. </li><li> Inferior del depósito mineral para aplicar una ligera presión negativa a la punta del electrodo para ayudar a sostener el segmento de interior en el electrodo. </li><li> Registro de flash de prueba, las respuestas de atenuar la intensidad luminosa vez que una célula se encuentra bien. Destellos de prueba son siempre de un estimulador de calibrado óptico de 5. La intensidad del flash y la longitud de onda son controlados por un conjunto de filtros de densidad neutra y filtros de interferencia de banda estrecha, respectivamente. Prueba de Flash duración (20 ms) es controlado por ordenador basada persianas. </li></ol> Soluciones <ol><li> Ratón solución de perfusión: 112,5 mM NaCl, 3,6 mM KCl, 2,4 mM MgCl 2, 1,2 mM CaCl 2, 10 mM HEPES (pH 7,4), 20 mM NaHCO 3, 3 mM Na succinato, 0,5 mM Na glutamato, 0,02 mM EDTA, y 10 mM de glucosa. </li><li> Grabación del ratón electrodo solución: 140 mM NaCl, 3,6 mM KCl, 2,4 mM MgCl 2, 1,2 mM CaCl 2, 3 mM HEPES (pH 7,4), 0,02 mM EDTA. </li></ol>

<ol>
	<li>Yau, K. W., Lamb, T. D., Baylor, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light-induced+fluctuations+in+membrane+current+of+single+toad+rod+outer+segments.">Light-induced fluctuations in membrane current of single toad rod outer segments.</a> Nature. 269, 78-80 (1977).</li><li>Nikonov, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photoreceptors+of+Nrl+-/-+mice+coexpress+functional+S-+and+M-cone+opsins+having+distinct+inactivation+mechanisms.">Photoreceptors of Nrl -/- mice coexpress functional S- and M-cone opsins having distinct inactivation mechanisms.</a> J Gen Physiol. 125, 287-304 (2005).</li><li>Nikonov, S. S., Kholodenko, R., Lem, J., Pugh, E. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physiological+features+of+the+S-+and+M-cone+photoreceptors+of+wild-type+mice+from+single-cell+recordings.">Physiological features of the S- and M-cone photoreceptors of wild-type mice from single-cell recordings.</a> J Gen Physiol. 127, 359-374 (2006).</li><li>Applebury, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+murine+cone+photoreceptor:+a+single+cone+type+expresses+both+S+and+M+opsins+with+retinal+spatial+patterning.">The murine cone photoreceptor: a single cone type expresses both S and M opsins with retinal spatial patterning.</a> Neuron. 27, 513-523 (2000).</li><li>Cornwall, M. C., Fein, A., MacNichol, E. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+mechanisms+that+underlie+bleaching+and+background+adaptation.">Cellular mechanisms that underlie bleaching and background adaptation.</a> J Gen Physiol. 96, 345-372 (1990).</li><li>Calvert, P. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phototransduction+in+transgenic+mice+after+targeted+deletion+of+the+rod+transducin+alpha+-subunit.">Phototransduction in transgenic mice after targeted deletion of the rod transducin alpha -subunit.</a> Proc Natl Acad Sci U S A. 97, 13913-13918 (2000).</li></ol>

Una sola célula de grabación de aspiración de las células fotorreceptoras se desarrolló hace 3 décadas. Que nos permite grabar través de la membrana cambio de corriente inducida por la estimulación de la luz, sin penetrar la membrana celular. Debido a la alta adhesión célula-célula, es difícil aislar la barra saludable único y el cono de la retina del ratón, como la retina de anfibios y es difícil de encontrar conos individuales debido al bajo porcentaje (3%) y pequeño tamaño. El segmento de interior-en...

single-cell suction recordings from mouse cone photoreceptors

Fotorreceptores de los bastones y conos en la retina es responsable de la detección de la luz. En la oscuridad, los nucleótidos cíclicos-cerrada (CNG) de canales en el segmento externo están abiertos y permiten el flujo de cationes a ritmo constante hacia el interior a través de la membrana, despolarización de la célula. Exposición a la luz desencadena el cierre de los canales de GNC, bloquea el flujo de cationes corriente de entrada, por lo que resulta en la hiperpolarización de la célula. Con base en la polaridad de los fotorreceptores, un método de grabación de succión se desarrolló en 1970 que, a diferencia de la clásica técnica de patch-clamp, no requiere penetrar en la membrana plasmática<sup&gt; 1</sup&gt;. Dibujar el segmento externo en una pipeta de vidrio bien instalados llena con solución extracelular permite registrar los cambios actuales en las células individuales a la exposición de pruebas flash. Sin embargo, esta bien establecido &quot;exterior del segmento en el (OS-in)&quot; de grabación de succión no es adecuado para las grabaciones de cono del ratón, por el bajo porcentaje de conos en la retina del ratón (3%) y las dificultades para identificar el cono segmentos exteriores. Recientemente, un segmento interno-en (IS-in) de registro de configuración ha sido desarrollado para dibujar el segmento de interior / región nuclear de los fotorreceptores en la pipeta de grabación<sup&gt; 2,3</sup&gt;. En este video, vamos a mostrar cómo grabar desde cada photoresponses ratón cono con una sola célula de electrodos de succión.

Watch this Scientific Journal Video about Single-cell Suction Recordings from Mouse Cone Photoreceptors at JoVE.com

Single-cell Suction Recordings from Mouse Cone Photoreceptors

Le mostraremos cómo registrar las respuestas de flash de conos ratón utilizando un electrodo de succión.

Una sola célula grabaciones de succión de los conos del ratón

Rod and cone photoreceptors in the retina are responsible for light detection. In darkness, cyclic nucleotide-gated (CNG) channels in the outer segment ...

single-cell-suction-recordings-from-mouse-cone-photoreceptors

Research

JoVE Journal

Biology

11.7K vistas.  Washington University in St. Louis, School of Medicine. Le mostraremos cómo registrar las respuestas de flash de conos ratón utilizando un electrodo de succión.

Video: Single-cell Suction Recordings from Mouse Cone Photoreceptors

Methods for Patch Clamp Capacitance Recordings from the Calyx

We demonstrate the basic techniques for presynaptic patch clamp recording at the calyx of Held, a mammalian central nervous system nerve terminal. Electrical recordings from the presynaptic terminal allow the measurement of action potentials, calcium channel currents, vesicle fusion (exocytosis) and subsequent membrane uptake (endocytosis). The fusion of vesicles containing neurotransmitter causes the vesicle membrane to be added to the cell membrane of the calyx. This increase in the amount of cell membrane is measured as an increase in capacitance. The subsequent reduction in capacitance indicates endocytosis, the process of membrane uptake or removal from the calyx membrane. Endocytosis, is necessary to maintain the structure of the calyx and it is also necessary to form vesicles that will be filled with neurotransmitter for future exocytosis events. Capacitance recordings at the calyx of Held have made it possible to directly and rapidly measure vesicular release and subsequent endocytosis in a mammalian CNS nerve terminal. In addition, the corresponding postsynaptic activity can be simultaneously measured by using paired recordings. Thus a complete picture of the presynaptic and postsynaptic electrical activity at a central nervous system synapse is achievable using this preparation. Here, the methods for slice preparation, morphological features for identification of calyces of Held, basic patch clamping techniques, and examples of capacitance recordings to measure exocytosis and endocytosis are presented.

We demonstrate the basic techniques for presynaptic patch clamp recording at the calyx of Held, a mammalian central nervous system nerve terminal.

Métodos para grabaciones de parche Capacidad de la pinza del cáliz

We demonstrate the basic techniques for presynaptic patch clamp recording at the calyx of Held, a mammalian central nervous system nerve terminal. ...

Investigación

Biología

Whole Cell Recordings from Brain of Adult Drosophila

In this video, we demonstrate the procedure for isolating whole brains from adult Drosophila in preparation for recording from single neurons. We begin by describing the dissecting solution and capture of the adult females used in our studies. The procedure for removing the whole brain intact, including both optic lobes, is illustrated. Dissection of the overlying trachea is also shown.  The isolated brain is not only small but needs special care in handling at this stage to prevent damage to the neurons, many of which are close to the outer surface of the tissue. We show how a special holder we developed is used to stabilize the brain in the recording chamber. A standard electrophysiology set up is used for recording from single neurons or pairs of neurons. A fluorescent image, viewed through the recording microscope, from a GAL4 line driving GFP expression (GH146) illustrates how projection neurons (PNs) are identified in the live brain. A high power Nomarski image shows a view of a single neuron that is being targeted for whole cell recording. When the brain is successfully removed without damage, the majority of the neurons are spontaneously active, firing action potentials and/or exhibiting spontaneous synaptic input. This in situ preparation, in which whole cell recording of identified neurons in the whole brain can be combined with genetic and pharmacological manipulations, is a useful model for exploring cellular physiology and plasticity in the adult CNS.

This video demonstrates the procedure for isolating whole brains from adult Drosophila in preparation for recording from single neurons using standard whole cell technology. It includes images of GFP labeled cells and neurons viewed during recording.

Las grabaciones de células enteras del cerebro del adulto de Drosophila

In this video, we demonstrate the procedure for isolating whole brains from adult Drosophila in preparation for recording from single neurons. We begin by ...

Preparation of Single-Cell Suspensions from Mouse Spleen with the gentleMACS Dissociator

Single-cell suspensions are a prerequisite for experiments in cell separation, cell analysis and cell culture.  To avoid tedious and often painful manual dissociations the gentleMACS Dissociator allows one to dissociate tissue very efficiently under controlled and reproducible conditions.  The gentleMACS Dissociator can optimally dissociate mouse spleen, combining timesaving and standardization with user-safety.

This video describes how to dissociate mouse spleens using the gentleMACS Dissociator, an automated bench-top device that can mechanically disrupt tissues using special tubes to produce viable cell suspensions. Following dissociation, spleens are filtered, centrifuged, and resuspended for further applications.

This video describes a simple, time-saving technique for automated tissue dissociation using the gentleMACS Dissociator to prepare single-cell suspensions of mouse splenocytes.

Preparación de una sola célula suspensiones de bazo de ratón con el disociador gentleMACS

Single-cell suspensions are a prerequisite for experiments in cell separation, cell analysis and cell culture.  To avoid tedious and often painful manual ...

Standardized Preparation of Single-Cell Suspensions from Mouse Lung Tissue using the gentleMACS Dissociator

The preparation of single-cell suspensions from tissues is an important prerequisite for many experiments in cellular research. The process of dissociating whole organs requires specific parameters in order to obtain a high number of viable cells in a reproducible manner. The gentleMACS Dissociator optimizes this task with a simple, practical protocol. The instrument contains pre-programmed settings that are optimized for the efficient but gentle dissociation of a variety of tissue types, including mouse lungs. In this publication the use of the gentleMACS Dissociator on lung tissue derived from mice is demonstrated.

Dissociating cells from specific tissue types requires specific parameters for tissue agitation to obtain a high volume of viable, culturable cells. The Miltenyi gentleMACS dissociator optimizes this task with a simple, practical protocol. In this publication the use of this apparatus on lung tissue is explained.

La preparación estandarizada de un solo suspensiones de células de tejido pulmonar de ratón con el disociador gentleMACS

The preparation of single-cell suspensions from tissues is an important prerequisite for many experiments in cellular research. The process of ...

Generation of Single-Cell Suspensions from Mouse Neural Tissue

Within the nervous system, hundreds of neuronal and glial cell types have been described. Each specific cell type in the brain or spinal cord has a repertoire of cell surface molecules, or molecular determinants, through which it can be identified and characterized. Currently, robust cell identification and separation technologies require single-cell preparations to be generated while simultaneously limiting cell death and destruction of characteristic surface protein. The gentleMACS Dissociator, when used in combination with trypsin or papain-based dissociation kits, can effectively and gently dissociate brain tissue while preserving antigen epitopes and limiting cell loss. Standardized preparation of single-cell suspensions is achieved using C Tubes and optimized, preset gentleMACS Programs. Once generated, single-cell suspensions can be treated with monoclonal conjugates like Anti-Prominin-1 MicroBeads, which identify neural progenitors, or purified further using Myelin Removal Beads.

Dissociating cells from specific tissue types requires specific parameters for tissue aggitation to obtain a high volume of viable, culturable cells. The Miltenyi gentleMACS Dissociator optimizes this task with a simple, practical protocol. In this publication the use of this apparatus on nerual tissue is explained.

Generación de un solo suspensiones de células de tejido de ratón Neural

Within the nervous system, hundreds of neuronal and glial cell types have been described. Each specific cell type in the brain or spinal cord has a ...

Obtaining High Quality RNA from Single Cell Populations in Human Postmortem Brain Tissue

We proposed to investigate the gray matter reduction in the superior temporal gyrus seen in schizophrenia patients, by interrogating gene expression profiles of pyramidal neurons in layer III. It is well known that the cerebral cortex is an exceptionally heterogeneous structure comprising diverse regions, layers and cell types, each of which is characterized by distinct cellular and molecular compositions and therefore differential gene expression profiles. To circumvent the confounding effects of tissue heterogeneity, we used laser-capture microdissection (LCM) in order to isolate our specific cell-type i.e pyramidal neurons.
Approximately 500 pyramidal neurons stained with the Histogene staining solution were captured using the Arcturus XT LCM system. RNA was then isolated from captured cells and underwent two rounds of T7-based linear amplification using Arcturus/Molecular Devices kits. The Experion LabChip (Bio-Rad) gel and electropherogram indicated good quality a(m)RNA, with a transcript length extending past 600nt required for microarrays. The amount of mRNA obtained averaged 51&mu;g, with acceptable mean sample purity as indicated by the A260/280 ratio, of 2.5. Gene expression was profiled using the Human X3P GeneChip probe array from Affymetrix.

We describe a process using laser-capture microdissection to isolate and extract RNA from a homogeneous cell population, pyramidal neurons, in layer III of the superior temporal gyrus in postmortem human brains. We subsequently linearly amplify (T7-based) mRNA, and hybridize the sample to the Affymetrix human X3P microarray.

La obtención de ARN de alta calidad a partir de poblaciones de células individuales en tejido cerebral humano post-mortem

We proposed to investigate the gray matter reduction in the superior temporal gyrus seen in schizophrenia patients, by interrogating gene expression ...

Single Cell Transcriptional Profiling of Adult Mouse Cardiomyocytes

While numerous studies have examined gene expression changes from homogenates of heart tissue, this prevents studying the inherent stochastic variation between cells within a tissue. Isolation of pure cardiomyocyte populations through a collagenase perfusion of mouse hearts facilitates the generation of single cell microarrays for whole transcriptome gene expression, or qPCR of specific targets using nanofluidic arrays. We describe here a procedure to examine single cell gene expression profiles of cardiomyocytes isolated from the heart. This paradigm allows for the evaluation of metrics of interest which are not reliant on the mean (for example variance between cells within a tissue) which is not possible when using conventional whole tissue workflows for the evaluation of gene expression (Figure 1). We have achieved robust amplification of the single cell transcriptome yielding micrograms of double stranded cDNA that facilitates the use of microarrays on individual cells. In the procedure we describe the use of NimbleGen arrays which were selected for their ease of use and ability to customize their design. Alternatively, a reverse transcriptase - specific target amplification (RT-STA) reaction, allows for qPCR of hundreds of targets by nanofluidic PCR. Using either of these approaches, it is possible to examine the variability of expression between cells, as well as examining expression profiles of rare cell types from within a tissue. Overall, the single cell gene expression approach allows for the generation of data that can potentially identify idiosyncratic expression profiles that are typically averaged out when examining expression of millions of cells from typical homogenates generated from whole tissues.

Single cell expression profiling allows the detailed gene expression analysis of individual cells. We describe methods for the isolation of cardiomyocytes, and preparing the resulting lysates for either whole transcriptome microarray or qPCR of specific targets.

Perfiles de transcripción de los organismos unicelulares de los cardiomiocitos de ratón adulto

While numerous studies have examined gene expression changes from homogenates of heart tissue, this prevents studying the inherent stochastic variation ...

Generation of Mice Derived from Induced Pluripotent Stem Cells

The production of induced pluripotent stem cells (iPSCs) from somatic cells provides a means to create valuable tools for basic research and may also produce a source of patient-matched cells for regenerative therapies. iPSCs may be generated using multiple protocols and derived from multiple cell sources. Once generated, iPSCs are tested using a variety of assays including immunostaining for pluripotency markers, generation of three germ layers in embryoid bodies and teratomas, comparisons of gene expression with embryonic stem cells (ESCs) and production of chimeric mice with or without germline contribution2. Importantly, iPSC lines that pass these tests still vary in their capacity to produce different differentiated cell types2. This has made it difficult to establish which iPSC derivation protocols, donor cell sources or selection methods are most useful for different applications.
The most stringent test of whether a stem cell line has sufficient developmental potential to generate all tissues required for survival of an organism (termed full pluripotency) is tetraploid embryo complementation (TEC)3-5. Technically, TEC involves electrofusion of two-cell embryos to generate tetraploid (4n) one-cell embryos that can be cultured in vitro to the blastocyst stage6. Diploid (2n) pluripotent stem cells (e.g. ESCs or iPSCs) are then injected into the blastocoel cavity of the tetraploid blastocyst and transferred to a recipient female for gestation (see Figure 1). The tetraploid component of the complemented embryo contributes almost exclusively to the extraembryonic tissues (placenta, yolk sac), whereas the diploid cells constitute the embryo proper, resulting in a fetus derived entirely from the injected stem cell line.
Recently, we reported the derivation of iPSC lines that reproducibly generate adult mice via TEC1. These iPSC lines give rise to viable pups with efficiencies of 5-13%, which is comparable to ESCs3,4,7 and higher than that reported for most other iPSC lines8-12. These reports show that direct reprogramming can produce fully pluripotent iPSCs that match ESCs in their developmental potential and efficiency of generating pups in TEC tests. At present, it is not clear what distinguishes between fully pluripotent iPSCs and less potent lines13-15. Nor is it clear which reprogramming methods will produce these lines with the highest efficiency. Here we describe one method that produces fully pluripotent iPSCs and "all- iPSC" mice, which may be helpful for investigators wishing to compare the pluripotency of iPSC lines or establish the equivalence of different reprogramming methods.

Generating induced pluripotent stem cell (iPSC) lines produces lines of differing developmental potential even when they pass standard tests for pluripotency. Here we describe a protocol to produce mice derived entirely from iPSCs, which defines the iPSC lines as possessing full pluripotency1.

Generación de ratones derivados de células madre pluripotentes inducidas

The production of induced pluripotent stem cells (iPSCs) from somatic cells provides a means to create valuable tools for basic research and may also ...

Trans-inner Cell Mass Injection of Embryonic Stem Cells Leads to Higher Chimerism Rates

In an effort to increase efficiency in the creation of genetically modified mice via ES Cell methodologies, we present an adaptation to the current blastocyst injection protocol. Here we report that a simple rotation of the embryo, and injection through Trans-Inner cell mass (TICM) increased the percentage of chimeric mice from 31% to 50%, with no additional equipment or further specialized training. 26 different inbred clones, and 35 total clones were injected over a period of 9 months. There was no significant difference in either pregnancy rate or recovery rate of embryos between traditional injection techniques and TICM. Therefore, without any major alteration in the injection process and a simple positioning of the blastocyst and injecting through the ICM, releasing the ES cells into the blastocoel cavity can potentially improve the quantity of chimeric production and subsequent germline transmission.

Here we present a protocol to increase chimera production without the use of new equipment. A simple orientation change of the embryo for injection can increase the number of embryos produced, and potentially reduce the timeline to germline transmission.

Trans-interno celular masiva inyección de células madre embrionarias conduce a mayores tasas de quimerismo

In an effort to increase efficiency in the creation of genetically modified mice via ES Cell methodologies, we present an adaptation to the current ...

Isolation of Endothelial Cells from the Lumen of Mouse Carotid Arteries for Single-Cell Multi-Omics Experiments

Atherosclerosis is an inflammatory disease of the arterial regions exposed to disturbed blood flow (d-flow). D-flow regulates the expression of genes in the endothelium at the transcriptomic and epigenomic levels, resulting in proatherogenic responses. Recently, single-cell RNA sequencing (scRNAseq) and single-cell Assay for Transposase Accessible Chromatin sequencing (scATACseq) studies were performed to determine the transcriptomic and chromatin accessibility changes at a single-cell resolution using the mouse partial carotid ligation (PCL) model. As endothelial cells (ECs) represent a minor fraction of the total cell populations in the artery wall, a luminal digestion method was used to obtain EC-enriched single-cell preparations. For this study, mice were subjected to PCL surgery to induce d-flow in the left carotid artery (LCA) while using the right carotid artery (RCA) as a control. The carotid arteries were dissected out two days or two weeks post PCL surgery. The lumen of each carotid was subjected to collagenase digestion, and endothelial-enriched single cells or single nuclei were obtained. These single-cell and single-nuclei preparations were subsequently barcoded using a 10x Genomics microfluidic setup. The barcoded single-cells and single-nuclei were then utilized for RNA preparation, library generation, and sequencing on a high-throughput DNA sequencer. Post bioinformatics processing, the scRNAseq and scATACseq datasets identified various cell types from the luminal digestion, primarily consisting of ECs. Smooth muscle cells, fibroblasts, and immune cells were also present. This EC-enrichment method aided in understanding the effect of blood flow on the endothelium, which could have been difficult with the total artery digestion method. The EC-enriched single-cell preparation method can be used to perform single-cell omics studies in EC-knockouts and transgenic mice where the effect of blood flow on these genes has not been studied. Importantly, this technique can be adapted to isolate EC-enriched single cells from human artery explants to perform similar mechanistic studies.

We present a method for isolating endothelial cells and nuclei from the lumen of mouse carotid arteries exposed to stable or disturbed flow conditions to perform single-cell omics experiments.

Aislamiento de células endoteliales de la luz de arterias carótidas de ratón para experimentos multiómicos unicelulares

Atherosclerosis is an inflammatory disease of the arterial regions exposed to disturbed blood flow (d-flow). D-flow regulates the expression of genes in ...