Los autores desean dar las gracias a Michael Alifrangis y Abildtrup Ulla para el genotipado de los parásitos y Holm Christina para su excelente asistencia técnica. Este trabajo fue financiado por el Howard Hughes Medical Institute (subvención de 55.005.511), la Fundación Lundbeck (subvención R9-A840) y por la Fundación Niels Bohr.

1. La generación de recién seleccionada eritrocitos infectados Para este ensayo, los mejores resultados se obtienen cuando se utilizan cultivos recién seleccionadas para la expresión en superficie de la proteína PfEMP1. En este experimento particular la P. 3D7 linaje falciparum fue seleccionado utilizando anticuerpos específicos como se ha descrito anteriormente 1. Día 1 <ol><li> Cosecha de 200 l de células de sangre envasados ​​de una P. falciparum cultivo que contiene 2-5% IE etapa tardía por centrifugación a 800 xg durante 8 minutos a temperatura ambiente. </li><li> Se resuspende el sedimento en sangre 2 ml de 37 ° C cálido solución 0,75% de gelatina en un tubo de 14 ml estéril, y se deja durante 15-20 min a 37 ° C para permitir que el IE no infectado y anillo etapa-a sedimentos. </li><li> Se recoge el IE en etapa tardía, es decir, la fase superior, en un tubo de 14 ml nuevo y se lava dos veces con 10 ml de 37 ° C cálidos RBC-medios de lavado. </li><li> Diluir 50 l de anticuerpos específicos anti-PfEMP1 anticuerpos en 2 ml de 37 ° C cálidos RBC-medios de lavado y filtro estéril. </li><li> Mezclar el lavado la fase final del IE con los antisueros esterilizado diluida en un tubo de 14 ml estéril y se incuba durante 30 min a 37 ° C con agitación suave. </li><li> Centrifugue a 800 xg durante 8 minutos a temperatura ambiente, y se lava dos veces con 10 ml de 37 ° C cálidos RBC-medios de lavado. </li><li> Lávese 50 l de Proteína Dynabead Una suspensión dos veces con RBC-lavado de los medios de comunicación utilizando un imán DynaMaq-15. </li><li> Resuspender las Dynabeads en 300 L RBC-lavado de los medios de comunicación y añadirlos a la última etapa de lavado IE. Incubar durante 30 min a 37 ° C con agitación suave. </li><li> Transferir el tubo en el imán DynaMaq-15. Dejar reposar 1-2 minutos y retirar todo el líquido. </li><li> Resuspender las Dynabeads en 4-5 ml de RBC-lavado de medios de comunicación. Transfiera la parte posterior del tubo en el imán y se deja durante 1-2 minutos antes de retirar todo el líquido. Repetir la etapa de lavado una vez. </li><li> Transfiera las perlas lavadas a un 25 cm 2 f cultivo estérillask contiene 200 mu l recién concentrados de glóbulos rojos. Añadir 5-6 ml de Albumax medios de comunicación en la cultura. Guarde la noche a 5% de CO 2 a 37 ° C. </li></ol> Día 2 <ol start="12"><li> Eliminar las Dynabeads de la cultura cuando la IE ha seleccionado reinvadido las células rojas de la sangre fresca mediante la transferencia de todo el cultivo a un tubo de 14 ml estéril. Poner el tubo en el imán DynaMaq-15 y se deja durante 1-2 min. Luego, vierta todo el líquido nuevamente a un frasco de cultivo. </li><li> Cultura para el mayor número posible de ciclos hasta un 5-10% de parasitemia y los parásitos se encuentran en el ringstage. </li><li> Es decir, se analizaron por FACS para asegurarse de que el fenotipo de la superficie correcta, es decir, la expresión de la proteína de cualquiera de and/orPF11_0008 PFD1235w se ha obtenido 1. </li></ol> 2. Preparación de sondas Las sondas de ARN antisentido se generaron a partir de las regiones más variables de la PFD1235w y la var PF11_0008 &lt;/ Em&gt; genes de P. falciparum 3D7 ADN genómico. El ADN fue amplificado por PCR y clonado en el vector pSPT18 o 19 para la transcripción, respectivamente de acuerdo con la descripción del fabricante (Roche). Las sondas (580 pares de bases (pb) y 590 pb de longitud) fueron marcadas con digoxigenina (DIG) o biotina usando un kit de marcaje de ARN DIG o una mezcla de biotina ARN etiquetado, respectivamente. Se confirmó la especificidad de las sondas tanto por análisis de transferencia Northern y por una sola etiqueta análisis FISH 1. 3. Frotis delgado y fijación de los parásitos antes de la hibridación in situ Día 1 Todos los pasos se realizan en un ambiente libre de RNasa y todos los reactivos son RNasa libre o pre-tratado con pirocarbonato de dietilo (DEPC) o RNasa Zap (Invitrogen). Los portaobjetos y cubreobjetos debe limpiarse con alcohol para eliminar la grasa residual de fabricación. Es importante realizar el protocolo sin ninguna pausa entre pasoscon el fin de minimizar el riesgo de contaminación con nucleasas. <ol><li> Hacer una película delgada de sangre por el método estándar de difusión 3. Usando el lente objetivo 100x aceite del microscopio, cuente el IE y calcular el porcentaje de IE en la cultura. Compruebe que las etapas de parásitos están en sincronía aproximada, en el ring y las primeras etapas del ciclo de trofozoíto IE. Estos son el pre-replicación, etapas uni-nucleado, que expresan mRNA del gen var y adecuado para ensayos de células individuales de transcripción de peces de este tipo. </li><li> Transferir 50 l de la cultura parásito, a una parasitemia de 5-10%, a un 1,5 ml de RNasa libre de tubo Eppendorf. Centrifugar durante 1 min a 2.000 rpm a temperatura ambiente. </li><li> Retire el papel y añadir 50 l de PBS pH 7,2 en agua tratada con DEPC. Agite suavemente el tubo. Repetir la etapa de sedimentación centrífuga dos veces para lavar las células libres de los medios de comunicación y los residuos celulares. </li><li> Haga cuatro buenos frotis finos de calidad. Para cada mancha, hacer un frotis enuno de 11 mm de diámetro y de una diapositiva 4 bien, es decir, cuatro placas de vidrio en total, en una campana de RNasa libre (un paso crítico). Wave desliza brevemente en el aire para secar. Hacer tres diapositivas adicionales para controles de frotis negativo y uno para la tinción única sonda para cualquier gen no pertinente mediante el uso de una sonda específica, otra diapositiva para el tratamiento de RNasa y una tercera diapositiva que contiene IE no expresan el gen de interés. Deje que los portaobjetos se sequen en el banquillo durante 10-20 min. </li><li> Fijar las películas delgadas mediante la adición de 60 l de solución de fijación que contiene 4% de paraformaldehído y 5% de ácido acético glacial en los pocillos. Dejar durante 10 minutos en el banquillo a temperatura ambiente. </li><li> Lavar los portaobjetos en tampón SSPE 2x por 5 min por agitación suave a temperatura ambiente. Brevemente eliminar el exceso de líquido al tocar los pocillos que contienen las células suavemente con un pañuelo de papel. </li><li> Cubrir los portaobjetos con 0,01% de pepsina en HCl 0,01 M durante 2 min a 37 ° C (un paso extremadamente crítico). Lavar los portaobjetos en 2 x SSPE durante 5 min a temperatura ambiente. </li><li> Diluir la solución de RNasa hasta una concentración final de 10 mg / ml. Cubrir los frotis de control negativo con 60 l de la solución de RNasa. Incubar durante 30 min a 37 ° C y lavar los portaobjetos en 2 x SSPE durante 5 min a temperatura ambiente. </li><li> Se procede inmediatamente a la etapa de hibridación. </li></ol> 4. La hibridación de sondas de ARN a las diapositivas fijas Día 1 <ol><li> Prepare la cámara de hibridación, como un Thermostar 100 HC4 o una caja de puntas de pipeta vacía puso en un horno limpio, rociando con RNasa Zap y límpiela con un pañuelo de papel. Llenar los canales de la cámara de hibridación o la parte inferior de la caja con agua tratada con DEPC para asegurarse de que los portaobjetos no se sequen durante la hibridación. Cerrar la cubeta y precalentar a 48 ° C. </li><li> Diluir las sondas en la solución de hibridación a una concentración final de 12 ng / l. Desnaturalizar la solución de sonda a 65 ° C durante 5 min en un bloque calefactor. Inmediatamente enfriar en hielo. </li><li> En pocas palabras Secar las preparaciones después del lavado 2x SSPE. Retire cuidadosamente el exceso de líquido alrededor de los pocillos con un pañuelo de papel. </li><li> Abra la cámara de hibridación y coloque las diapositivas en la cámara. Aplicar una o ambas sondas en un volumen total de 60 l por pocillo. Cubra cuidadosamente la caída de líquido con un cubreobjetos RNasa libre con unas pinzas estériles. </li><li> Cerrar la cámara y se hibridan los portaobjetos a 48 ° C durante al menos 16 horas durante la noche. </li></ol> 5. Conjugación de anticuerpo y amplificación de fluorescencia Día 2 Los siguientes pasos se basan en el sistema de fluorescencia TSA Plus paleta de Perkin Elmer. Todos los pasos se realizan a temperatura ambiente. <ol><li> Lavar los portaobjetos 3 veces en tampón TNT por 5 min con agitación suave. </li><li> Bloquear los pocillos en 150 l de tampón TNB para 30 min. </li><li> Diluir el conjugado HRP-α-DIG anticuerpo en tampón TNB en una proporción de 1:100 y el anticuerpo HRP-conjugado de α-biotina en tampón TNB, en una proporción de 1:500. Retire el exceso de buffer de TNB las diapositivas con un pañuelo de papel. Al detectar simultáneamente dos transcripciones, ambos anticuerpos pueden ir a la vez. Aplique una cantidad total de 100 ml de la solución de anticuerpo por TNB bien y con cuidado cubrir con un cubreobjetos. Incubar los portaobjetos durante 2 horas. </li><li> Quitar los cubreobjetos con cuidado. Lavar los portaobjetos en tampón TNT 3 veces durante 5 min. </li><li> Diluir la FITC-fluoróforo en el reactivo de amplificación tiramida en una proporción de 1:500 y se aplican 100 ml de la solución a cada pocillo. Cubrir los pocillos con cubreobjetos y se incuba durante 12 min. </li><li> Quite el cubreobjetos con cuidado y lavar los portaobjetos 3 veces durante 5 minutos en tampón de TNT por agitación suave. </li><li> Diluir la Cyan3-fluoróforo en el reactivo de amplificación tiramida en una proporción de 1:500. Añadir 100 l porasí de esta solución. Cubrir los pocillos con cubreobjetos y se incuba durante 12 min. </li><li> Quite el cubreobjetos con cuidado y luego enjuague los portaobjetos rápidamente por inmersión en una solución tampón TNT. </li><li> Lavar los portaobjetos 3 veces con tampón TNT por 5 min. </li><li> Sumergir los portaobjetos rápidamente en agua tratada con DEPC. </li><li> Deje que los portaobjetos se seque al aire. Montar las diapositivas con anti-fade reactivo que contiene DAPI. Selle las esquinas de las hojas de la cubierta con esmalte de uñas. </li><li> Los portaobjetos ahora está listo para la microscopía. Mantenga las diapositivas cubiertas con papel de aluminio y se almacenan a 4 ° C si el experimento se completará al día siguiente. Un sellado completo de los lados de las láminas puede llevarse a cabo 24 horas después de aplicar el reactivo anti-fade. Esto permitirá que las láminas se fotografió por hasta una semana después de que el protocolo se ha completado. </li></ol> 6. La visualización de las sondas hibridadas <ol><li> Encender el microscopio. Un microscopio de inmunofluorescencia estándar es sufficient para este tipo de experimento, pero si usted tiene acceso a un microscopio confocal también puede usar esto para imágenes en 3D o para obtener los vídeos de las células teñidas. Permitir microscopio se caliente durante 15-30 min. Encienda el ordenador y el software. </li><li> Compruebe la calidad de la tinción al microscopio de inmunofluorescencia. Elija un lugar que contiene unos cuantos parásitos. </li><li> Ajuste la ganancia de cada láser manual. Ajuste el pixel de espera en 4-6 m -1 s -1 y los pasos a 512 x 512 píxeles. </li><li> Tome una fotografía de prueba utilizando Frame Lambda. Vuelva a ajustar la ganancia del láser. </li><li> Tome un mínimo de 20 buenas fotos de fluorescentes células individuales. Al menos 2-5 imágenes de un campo que contiene 5-20 parásitos son necesarios a fin de obtener una visión general ajustada del porcentaje de parásitos positivos. </li></ol>

<ol>
	<li>Joergensen, L., Bengtsson, D. C., Bengtsson, A., Ronander, E., Berger, S. S., Turner, L., Dalgaard, M. B., Cham, G. K., Victor, M. E., Lavstsen, T., Theander, T. G., Arnot, D. E., Jensen, A. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+co-expression+of+two+different+PfEMP1+antigens+on+single+Plasmodium+falciparum-infected+erythrocytes+facilitates+binding+to+ICAM1+and+PECAM1.">Surface co-expression of two different PfEMP1 antigens on single Plasmodium falciparum-infected erythrocytes facilitates binding to ICAM1 and PECAM1.</a> PLoS Pathog. 2, 1001083 (2010).</li><li>Pinaud, R., Mello, C. V., Velho, T. A., Wynne, R. D., Tremere, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+two+mRNA+species+at+single-cell+resolution+by+double-fluorescence+in+situ+hybridization.">Detection of two mRNA species at single-cell resolution by double-fluorescence in situ hybridization.</a> Nat. Protoc. 3, 1370-1379 (2008).</li><li>Cheeseborough, 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> District Laboratory Practice in Tropical Countries. , (2006).</li><li>Brolin, K. J., Ribacke, U., Nilsson, S., Ankarklev, J., Moll, K., Wahlgren, M., Chen, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+transcription+of+duplicated+var2csa+gene+copies+in+individual+Plasmodium+falciparum+parasites.">Simultaneous transcription of duplicated var2csa gene copies in individual Plasmodium falciparum parasites.</a> Genome Biol. 10, R117 (2009).</li><li>Epp, C., Li, F., Howitt, C. A., Chookajorn, T., Deitsch, K. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chromatin+associated+sense+and+antisense+noncoding+RNAs+are+transcribed+from+the+var+gene+family+of+virulence+genes+of+the+malaria+parasite+Plasmodium+falciparum.">Chromatin associated sense and antisense noncoding RNAs are transcribed from the var gene family of virulence genes of the malaria parasite Plasmodium falciparum.</a> RNA. 15, 116-127 (2009).</li><li>Freitas-Junior, L. H., Hernandez-Rivas, R., Ralph, S. A., Montiel-Condado, D., Ruvalcaba-Salazar, O. K., Rojas-Meza, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Telomeric+heterochromatin+propagation+and+histone+acetylation+control+mutually+exclusive+expression+of+antigenic+variation+genes+in+malaria+parasites.">Telomeric heterochromatin propagation and histone acetylation control mutually exclusive expression of antigenic variation genes in malaria parasites.</a> Cell. 121, 25-36 (2005).</li><li>Obernosterer, G., Martinez, J., Alenius, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Locked+nucleic+acid-based+in+situ+detection+of+microRNAs+in+mouse+tissue+sections.">Locked nucleic acid-based in situ detection of microRNAs in mouse tissue sections.</a> Nature Protoc. 2, 1508-1514 (2007).</li><li>Li, F., Sonbuchner, L., Kyes, S. A., Epp, C., Deitsch, K. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nuclear+non-coding+RNA+are+transcribed+from+the+centromeres+of+Plasmodium+falciparum+and+are+associated+with+centromeric+chromatin.">Nuclear non-coding RNA are transcribed from the centromeres of Plasmodium falciparum and are associated with centromeric chromatin.</a> J. Biol. Chem. 283, 5692-5698 (2008).</li><li>Thompson, J., Sinden, 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=In+situ+detection+of+Pbs21+mRNA+during+sexual+development+of+Plasmodium+berghei.">In situ detection of Pbs21 mRNA during sexual development of Plasmodium berghei.</a> Mol. Biochem. Parasitol. 68, 189-196 (1994).</li><li>Thompson, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+situ+detection+of+RNA+in+blood-+and+mosquito-stage+malaria+parasites.">In situ detection of RNA in blood- and mosquito-stage malaria parasites.</a> Methods Mole Med. 72, 225-235 (2002).</li><li>Arnot, D. E., Ronander, E., Bengtsson, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+progression+of+the+intra-erythrocytic+cell+cycle+of+Plasmodium+falciparum+and+the+role+of+the+centriolar+plaques+in+asynchronous+mitotic+division+during+schizogony.">The progression of the intra-erythrocytic cell cycle of Plasmodium falciparum and the role of the centriolar plaques in asynchronous mitotic division during schizogony.</a> Int. J. Parasitol. 41, 71-80 (2011).</li><li>Osborne, C. S., Chakalova, L., Brown, K. E., Carter, D., Horton, A., Debrand, E., Goyenechea, B., Mitchell, J. A., Lopes, S., Reik, W., Fraser, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Active+genes+dynamically+colocalize+to+shared+sites+of+ongoing+transcription.">Active genes dynamically colocalize to shared sites of ongoing transcription.</a> Nat. Genet. 36, 1065-1071 (2004).</li></ol>

No hay conflictos de interés declarado.

Análisis de ARN FISH, en contraste con los métodos tales como transferencia Northern y RT-PCR, permite la discriminación de los transcritos de ARNm específicos en el nivel de célula única. Esto hace que sea posible discriminar entre células transcripcionalmente activos e inactivos, en este ejemplo, P. falciparum protozoos parásitos dentro de los glóbulos rojos. Tales células enteras observaciones son a menudo necesarias y puede desentrañar los patrones transcripcionales importantes y novedosas 1...

<table border="1"><tbody><tr><td> Nombre del reactivo </td><td> Empresa </td><td> Número de catálogo </td><td> Comentarios </td></tr><tr><td> Ácido Acético </td><td> Sigma / Aldrich </td><td> 338826-100ml </td><td></td></tr><tr><td> Albumax medios de comunicación: RPMI 1640 Glutamina solución </td><td> Lonza </td><td> BE12-115F </td><td> 500 ml de medio RPMI 1640 5 ml de solución de glutamina </td></tr><tr><td> Albumax medios de comunicación: Gentamicina sulfato Albumax-solución </td><td> Lonza </td><td> BE02-012E </td><td> 2,5 ml de gentamicina sulfato 50 ml de solución de Albumax </td></tr><tr><td> Albumax-solución: hipoxantina </td><td> Sigma-Aldrich </td><td> H9377 </td><td> 0,8 g de hipoxantina </td></tr><tr><td> Albumax-solución: Albumax II </td><td> Yonvitrogen </td><td> 11021-037 </td><td> 200 g Albumax </td></tr><tr><td> Albumax-solución: RPMI 1640 </td><td> Lonza </td><td> BE12-115F </td><td> 4 litros RPMI 1640 Disolver con el imán en el máximo. 50 ° C. Filtrar esterilizar y almacenar a -20 ° C en alícuotas. </td></tr><tr><td> Amberlite </td><td> Sigma </td><td> A5710-110G </td><td> Resina para desionizar formamida. </td></tr><tr><td> Anti-biotina peroxidasa de cabra pAb </td><td> Calbiochem </td><td> 203206 </td><td></td></tr><tr><td> Anticuerpo anti-DIG </td><td> Novus Productos Biológicos </td><td> NB100-41330 </td><td></td></tr><tr><td> Anti-fade reactivo con DAPI </td><td> Invitrogen </td><td> P36931 </td><td> Los medios de montaje tiene que curar durante 24 h antes de sellar la corredera completamente. </td></tr><tr><td> La biotina RNA Labeling Mix </td><td&gt; Roche </td><td> 11685597910 </td><td></td></tr><tr><td> Cámara digital de </td><td> Digital Nikon vista DC-F11 </td><td></td><td></td></tr><tr><td> Cubreobjetos </td><td> Menzel-Glaser </td><td> 631-1570 </td><td></td></tr><tr><td> frasco de cultivo de 25 cm 2 de superficie Nunclon </td><td> Nunc </td><td> 156340 </td><td></td></tr><tr><td> DEPC </td><td> Fluka / Sigma </td><td> 32490-100ml </td><td> 1 ml DEPC en 1000 ml de agua deinonized. Añadir una barra de agitación y se agita durante 12 h. Esterilizar en autoclave durante 30 min. </td></tr><tr><td> Cámara digital </td><td> Digital Nikon vista DC-F11 </td><td></td><td></td></tr><tr><td> Dynabeads Proteína A </td><td> Invitrogen </td><td> 10002D </td><td></td></tr><tr><td> DynaMaq-15 Imán </td><td> Invitrogen </td><td> 123-01D </td><td></td></tr><tr><td> Bioultra formamida 99% </td><td> Fluka/ Sigma </td><td> 47671-1l-F </td><td> Formamida desionizada: 5 g de resina de intercambio iónico por 100 ml de formamida. Se agita 30 min. Filtrar a través de papel Whatman. </td></tr><tr><td> . 0 Gelatina solución al 75%: Gelatina </td><td> Sigma-Aldrich </td><td> G2500 </td><td> 3,75 g de gelatina en 500 ml de RPMI 1640. Calentar a 56 ° C para disolver. Filtrar esterilizar cuando 56 ° C. Almacenar a -20 ° C en alícuotas. </td></tr><tr><td> . Gelatina 0 solución de 75%: RPMI 1640 </td><td> Lonza </td><td> BE12-115F </td><td> 3,75 g de gelatina en 500 ml de RPMI 1640. Calentar a 56 ° C para disolver. Filtrar esterilizar cuando 56 ° C. Almacenar a -20 ° C en alícuotas. </td></tr><tr><td> La glutamina solución: L-glutamina </td><td> Sigma-Aldrich </td><td> G3126 </td><td> 14,6 g L-glutamina en 500 ml de NaCl al 0,9%. Disolver, filtro sterilize y almacenar a -20 ° C en alícuotas. </td></tr><tr><td> Glutamina solución: HCl </td><td> Sigma </td><td> H1758 </td><td> 14,6 g L-glutamina en 500 ml de NaCl al 0,9%. Disolver, filtrar esterilizar y almacenar a -20 ° C en alícuotas. </td></tr><tr><td> Solución de hibridación: formamida al 99% de ultra Bio SSC 20x </td><td> Fluka / Sigma </td><td> 47671-1l-F </td><td> Total 20 ml, mantener congelado a -20 ° C en alícuotas 10 ml de formamida desionizada </td></tr><tr><td> Solución de hibridación: el concentrado 50x de Denhardt </td><td> Sigma </td><td> D2532 </td><td> 5ml 20xSSC </td></tr><tr><td> Solución de hibridación: Levadura tRNARoche reactivo de bloqueo </td><td> Sigma </td><td> R-6750 </td><td> 2 ml 50x Denhardt 250 l 20 mg por ml de ARNt de levadura </td></tr><tr><td><strong&gt; Solución de Hibridación: DNA de esperma de salmón </td><td> Fluka / Sigma </td><td> 31149-106GF </td><td> 0,4 g Roche reactivo de bloqueo 1 ml de 10 mg por ml de ADN de esperma de salmón (Critical: desnaturalizan salmón spermDNA a 96 ° C durante 5 min antes de añadir a la solución de hibridación) </td></tr><tr><td> Hybridizer Thermostar 100 HC4 </td><td> Quantifoil Instruments GmbH </td><td> 1004-0011 </td><td> Puede ser reemplazado por el horno de hibridación y las cámaras de RNasa libre de hibridación rellenados con agua DEPC. </td></tr><tr><td> Inmersión en aceite UV transparente, libre de fluorescencia </td><td> Sigma </td><td> 10976-1EA </td><td></td></tr><tr><td> Microscopio confocal de inmunofluorescencia o </td><td> Nikon D-Eclipse TE2000C </td><td></td><td></td></tr><tr><td> Nailpolish </td><td> Disponible en cualquier farmacia </td><td></td><td></td></tr><tr><td> 20x PBS: NaCl KCl Na 2 HPO 4 x 2 H 2 O KH 2 PO 4 DEPC desionizada H 2 O </td><td></td><td></td><td> Adecuar el pH a 7,4 160 g 4 g 23 g 4 g 1 l </td></tr><tr><td> Paraformaldehído al 4% </td><td> Fluka / Chemika </td><td> 76240 </td><td> 4 g PFA en 80 ml de PBS / DEPC. Calentar a 65 ° C hasta que se disuelve el PFA. Añadir 20 ml de PBS, permitir que la solución se enfríe. Ajustar el pH a 7,4. Filtrar. Almacenar en alícuotas a -20 ° C. </td></tr><tr><td> Paraformaldehído al 4% / ácido acético 5% </td><td></td><td></td><td> 950 paraformaldhyde l de ácido acético + 50 l </td></tr><tr><td> Pepsina </td><td> Sigma / Aldrich </td><td> P7000 </td><td></td></tr><tr><td> Conjugado con peroxidasa anti-biotina </td><td> Calbiochem </td><td> 203206 </td><td></td></tr><tr><td> RBC-wash medios de comunicación: RPMI 1640 Glutamina solución </td><td> Lonza </td><td> BE12-115F </td><td> 500 ml de RPMI 1640 5 ml de solución de glutamina </td></tr><tr><td> RBC-wash medios de comunicación: Sulfato de Gentamicina </td><td> Lonza </td><td> BE02-012E </td><td> 2,5 ml de gentamicina sulfato </td></tr><tr><td> RNasa </td><td> Sigma / Aldrich </td><td></td><td> Hacer una dosis de 10 mg / ml de solución madre. </td></tr><tr><td> RNasa libre de 1,5 ml tubo </td><td> Ambion </td><td> AM12450 </td><td></td></tr><tr><td> RNasa Zap </td><td> Ambion </td><td> AM9780 </td><td></td></tr><tr><td> Diapositivas 4 pozos de 11 mm </td><td> Thermo Scientific </td><td> MENZXER306W </td><td></td></tr><tr><td> 20x SSC: NaCl </td><td> Sigma / Aldrich </td><td> S9625 </td><td> 3 M NaCl (175 g / l) 0,3 M Na citrato x 3 H 2 O (88 g / l) Ajustar a pH 7,0 con HCl 1M </td></tr><tr><td> SSC 20x: Citrato de sodio dihidrato </td><td> Sigma / Aldrich </td><td> W302600 </td><td> 3 M NaCl (175 g / l) 0,3 M Na citrato x 3 H 2 O (88 g / l) Ajustar a pH 7,0 con HCl 1M </td></tr><tr><td> SSPE 20x: NaCl </td><td> Sigma / Aldrich </td><td> S9625 </td><td> 175,3 g de NaCl </td></tr><tr><td> SSPE 20x: NaH 2 PO 4 </td><td> Sigma / Aldrich </td><td> S0751 </td><td> 27,6 g NaH 2 PO 4. </td></tr><tr><td> SSPE 20x: 4 EDTA en polvo </td><td></td><td></td><td> 9,4 g de EDTA en polvo Añadir agua DEPC, ajustar el pH 7,4. AutoHendió durante 20 min </td></tr><tr><td> TNB buffer: tampón TNT </td><td></td><td></td><td> 10 ml tampón TNT </td></tr><tr><td> TNB búfer: reactivo de bloqueo </td><td></td><td></td><td> 0,05 g de reactivo de bloqueo Para disolver el reactivo de bloqueo, se calienta la solución a 60 ° C durante una hora con agitación. Conservar a -20 ° C. (Derivado de la Perkin Elmer TSA-protocolo). </td></tr><tr><td> TNT tampón: Tris / HCl </td><td> Sigma </td><td> T1503 </td><td> 1 M Tris / HCl, pH 8,0 </td></tr><tr><td> TNT buffer: NaCl </td><td> Sigma Aldrich </td><td> S9625 </td><td> 100 ml </td></tr><tr><td> TNT buffer: Tween20 </td><td> Sigma </td><td> 93773 </td><td> 5 M NaCl 30 ml 1 ml DEPC dH 2 O869 Ml Ajustar el pH a 7,5 a temperatura ambiente. (Derivado de la Perkin Elmer TSA-protocolo). </td></tr><tr><td> TSA más Cyanine3 / fluoresceína sistema </td><td> Perkin Elmer </td><td> NEL753000IKT </td><td> Leer el protocolo de la TSA Plus sistema de fluorescencia paleta cuidadosamente antes de iniciar el experimento. </td></tr><tr><td> Tubos de 14 ml estéril </td><td> Almeco - CM Aps LAB </td><td> 91016 </td><td></td></tr></tbody></table>

analysis of single-cell gene transcription by rna fluorescent in situ hybridization (fish)

La adhesión de Plasmodium falciparum eritrocitos infectados (IE) a receptores humanos endoteliales durante las infecciones de malaria está mediada por la expresión de PfEMP1 variantes de proteínas codificadas por los genes var. El P. haploide falciparum genoma alberga aproximadamente 60 genes diferentes var de que ha sido único que se cree que ser transcrito por célula en un momento durante la fase sanguínea de la infección. Como tal regulación mutuamente excluyente de la transcripción de genes var que se logra es clara, ya que es la identificación de los genes var individuales o subgrupos de genes var asociados con diferentes receptores y la consecuencia de unión diferencial sobre el resultado clínico de P. infecciones por P. falciparum. Recientemente, el paradigma de la transcripción mutuamente excluyentes ha sido puesta en duda por los ensayos de transcripción basado en individuo P. falciparum identificación única transcripción en infeja células eritrocitarias utilizando ARN hibridación in situ fluorescente (FISH) El análisis de la transcripción de genes var por el parásito en los núcleos individuales de P. falciparum IE 1. Aquí, se presenta un protocolo detallado para llevar a cabo la metodología de ARN-FISH para el análisis de la transcripción de genes var en un solo núcleo de P. falciparum infecta los eritrocitos humanos. El método se basa en el uso de digoxigenina y biotina marcado con sondas de ARN antisentido utilizando el TSA Plus fluorescencia sistema de paletas 2 (Perkin Elmer), los análisis microscópicos y recién seleccionado P. falciparum IE. El método de hibridación in situ se puede utilizar para controlar la transcripción y la regulación de una variedad de genes expresados ​​durante las diferentes etapas de la P. ciclo de vida falciparum y es adaptable a otras especies de parásito de la malaria y otros organismos y tipos de células.

La Figura 1 ilustra un diagrama de flujo de los pasos principales y el tiempo de duración de la metodología de ARN FISH. Una serie de imágenes representativas de bien y mal conservados experimentos manchadas de ARNm de peces utilizando solo P. falciparum IE se muestra en la Figura 2. Este protozoo intracelular tiene un pequeño (1-1.5 m de diámetro) núcleo que se tiñe de azul con DAPI. Veinticuatro horas después de la invasión de los eritroc...

Watch this Scientific Journal Video about Analysis of Single-cell Gene Transcription by RNA Fluorescent In Situ Hybridization FISH at JoVE.com

Analysis of Single-cell Gene Transcription by RNA Fluorescent In Situ Hybridization FISH

Fluorescente<em&gt; In situ</emHibridación&gt; (FISH) para identificar las transcripciones de mRNA en células individuales permite el análisis de la actividad poligénica tales como la transcripción simultánea de más de un miembro de la<em&gt; Var</em&gt; Multigene familia en<em&gt; Plasmodium falciparum</em&gt; Eritrocitos infectados<sup&gt; 1</sup&gt;. La técnica es adaptable y puede ser utilizado en diferentes tipos de genes, células y organismos.

Análisis de la transcripción de genes de una sola célula de ARN fluorescente<em&gt; In Situ</em&gt; La hibridación (FISH)

Adhesion of Plasmodium falciparum infected erythrocytes (IE) to human endothelial receptors during malaria infections is mediated by expression of PfEMP1 ...

analysis-single-cell-gene-transcription-rna-fluorescent-situ

Research

JoVE Journal

Biology

Analysis of Single-cell Gene Transcription by RNA Fluorescent In Situ Hybridization (FISH)

15.3K vistas.  University of Copenhagen. Fluorescente In situ (FISH) para identificar las transcripciones de mRNA en células individuales permite el análisis de la actividad poligénica tales como la transcripción simultánea de más de un miembro de la Var Multigene familia en Plasmodium falciparum Eritrocitos infectados 1. La técnica es adaptable y puede ser utilizado en diferentes tipos de genes, células y organismos.

Video: Analysis of Single-cell Gene Transcription by RNA Fluorescent In Situ Hybridization FISH

Zebrafish Whole Mount High-Resolution Double Fluorescent In Situ Hybridization

Whole mount in situ hybridization is one of the most widely used techniques in developmental biology. Here, we present a high-resolution double fluorescent in situ hybridization protocol for analyzing the precise expression pattern of a single gene and for determining the overlap of the expression domains of two genes. The protocol is a modified version of the standard in situ hybridization using alkaline phosphatase and substrates such as NBT/BCIP and Fast Red 1,2. This protocol utilizes standard digoxygenin and fluorescein labeled probes along with tyramide signal amplification (TSA) 3. The commercially available TSA kits allow flexible experimental design as fluorescence emission from green to far-red can be used in combination with various nuclear stains, such as propidium iodide, or fluorescence immunohistochemistry for proteins. TSA produces a reactive fluorescent substrate that quickly covalently binds to moieties, typically tyrosine residues, in the immediate vicinity of the labeled antisense riboprobe. The resulting staining patterns are high resolution in that subcellular localization of the mRNA can be observed using laser scanning confocal microscopy 3,4. One can observe nascent transcripts at the chromosomal loci, distinguish nuclear and cytoplasmic staining and visualize other patterns such as cortical localization of mRNA. Studies in Drosophila indicate that roughly 70% of mRNAs exhibit specific patterns of subcellular localization that frequently correlate with the function of the encoded protein 5. When combined with computer-aided reconstruction of 3D confocal datasets, our protocol allows the detailed analysis of mRNA distribution with sub-cellular resolution in whole vertebrate embryos.

Zebrafish Whole Mount High-Resolution Double Fluorescent In Situ Hybridization

Whole mount in situ hybridization is one of the most widely used techniques in developmental biology. Here, we present a high-resolution double fluorescent in situ hybridization protocol for analyzing the precise expression pattern of a single gene and for determining the overlap of the expression domains of two genes. We include a propidium iodide nuclear counter-stain to highlight tissue organization.

Pez cebra todo el montaje de alta resolución doble fluorescente In Situ La hibridación

Whole mount in situ hybridization is one of the most widely used techniques in developmental biology.  Here, we present a high-resolution double ...

Investigación

Biología

Fluorescence in situ hybridization (FISH) Protocol in Human Sperm

Aneuploidies are the most frequent chromosomal abnormalities in humans. Most of these abnormalities result from meiotic errors during the gametogenic process in the parents. In human males, these errors can lead to the production of spermatozoa with numerical chromosome abnormalities which represent an increased risk of transmitting these anomalies to the offspring.
For this reason, the technique of fluorescence in situ hybridization (FISH) on sperm nuclei has become a protocol widely incorporated in the context of clinical diagnosis. This practice provides an estimate of the frequencies of numerical chromosome abnormalities in the gametes of the patients that seek for genetic reproductive advice.
To date, the chromosomes most frequently included in sperm FISH analysis are chromosomes X, Y, 13, 18 and 21.
This video-article describes, step by step, how to process and fix a human semen sample, how to decondense and denature the sperm chromatin, how to proceed to obtain sperm FISH preparations, and how to visualize the results at the microscope. Special remarks of the most relevant steps are given to achieve the best results.

Fluorescence in situ hybridization FISH Protocol in Human Sperm

This video-article describes, step by step, how to process a semen sample to achieve good-quality fluorescence in situ hybridization on human spermatozoa. Preparations obtained can be used for aneuploidy screening in the context of clinical diagnosis.

Fluorescencia In situ</emHibridación> (FISH) Protocolo en el esperma humano

Aneuploidies are the most frequent chromosomal abnormalities in humans. Most of these abnormalities result from meiotic errors during the gametogenic ...

In vitro Transcription and Capping of Gaussia Luciferase mRNA Followed by HeLa Cell Transfection

In vitro transcription is the synthesis of RNA transcripts by RNA polymerase from a linear DNA template containing the corresponding promoter sequence (T7, T3, SP6) and the gene to be transcribed (Figure 1A). A typical transcription reaction consists of the template DNA, RNA polymerase, ribonucleotide triphosphates, RNase inhibitor and buffer containing Mg2+ ions.
Large amounts of high quality RNA are often required for a variety of applications. Use of in vitro transcription has been reported for RNA structure and function studies such as splicing1, RNAi experiments in mammalian cells2, antisense RNA amplification by the "Eberwine method"3, microarray analysis4 and for RNA vaccine studies5. The technique can also be used for producing radiolabeled and dye labeled probes6. Warren, et al. recently reported reprogramming of human cells by transfection with in vitro transcribed capped RNA7. The T7 High Yield RNA Synthesis Kit from New England Biolabs has been designed to synthesize up to 180 &mu;g RNA per 20 &mu;l reaction. RNA of length up to 10kb has been successfully transcribed using this kit. Linearized plasmid DNA, PCR products and synthetic DNA oligonucleotides can be used as templates for transcription as long as they have the T7 promoter sequence upstream of the gene to be transcribed.
Addition of a 5' end cap structure to the RNA is an important process in eukaryotes. It is essential for RNA stability8, efficient translation9, nuclear transport10 and splicing11. The process involves addition of a 7-methylguanosine cap at the 5' triphosphate end of the RNA. RNA capping can be carried out post-transcriptionally using capping enzymes or co-transcriptionally using cap analogs. In the enzymatic method, the mRNA is capped using the Vaccinia virus capping enzyme12,13. The enzyme adds on a 7-methylguanosine cap at the 5' end of the RNA using GTP and S-adenosyl methionine as donors (cap 0 structure). Both methods yield functionally active capped RNA suitable for transfection or other applications14 such as generating viral genomic RNA for reverse-genetic systems15 and crystallographic studies of cap binding proteins such as eIF4E16.
In the method described below, the T7 High Yield RNA Synthesis Kit from NEB is used to synthesize capped and uncapped RNA transcripts of Gaussia luciferase (GLuc) and Cypridina luciferase (CLuc). A portion of the uncapped GLuc RNA is capped using the Vaccinia Capping System (NEB). A linearized plasmid containing the GLuc or CLuc gene and T7 promoter is used as the template DNA. The transcribed RNA is transfected into HeLa cells and cell culture supernatants are assayed for luciferase activity. Capped CLuc RNA is used as the internal control to normalize GLuc expression.

In vitro Transcription and Capping of Gaussia Luciferase mRNA Followed by HeLa Cell Transfection

This method describes high yield in vitro synthesis of both capped and uncapped mRNA from a linearized plasmid containing the Gaussia luciferase (GLuc) gene. The RNA is purified and a fraction of the uncapped RNA is enzymatically capped using the Vaccinia virus capping enzyme. In the final step, the mRNA is transfected into HeLa cells and cell culture supernatants are assayed for luciferase activity.

En la transcripción in vitro y la nivelación de mRNA de luciferasa Gaussia Seguido por transfección de células HeLa

In vitro transcription is the synthesis of RNA transcripts by RNA polymerase from a linear DNA template containing the corresponding promoter sequence ...

Radioactive in situ Hybridization for Detecting Diverse Gene Expression Patterns in Tissue

Knowing the timing, level, cellular localization, and cell type that a gene is expressed in contributes to our understanding of the function of the gene. Each of these features can be accomplished with in situ hybridization to mRNAs within cells. Here we present a radioactive in situ hybridization method modified from Clayton et al. (1988)1 that has been working successfully in our lab for many years, especially for adult vertebrate brains2-5. The long complementary RNA (cRNA) probes to the target sequence allows for detection of low abundance transcripts6,7. Incorporation of radioactive nucleotides into the cRNA probes allows for further detection sensitivity of low abundance transcripts and quantitative analyses, either by light sensitive x-ray film or emulsion coated over the tissue. These detection methods provide a long-term record of target gene expression. Compared with non-radioactive probe methods, such as DIG-labeling, the radioactive probe hybridization method does not require multiple amplification steps using HRP-antibodies and/or TSA kit to detect low abundance transcripts. Therefore, this method provides a linear relation between signal intensity and targeted mRNA amounts for quantitative analysis. It allows processing 100-200 slides simultaneously. It works well for different developmental stages of embryos. Most developmental studies of gene expression use whole embryos and non-radioactive approaches8,9, in part because embryonic tissue is more fragile than adult tissue, with less cohesion between cells, making it difficult to see boundaries between cell populations with tissue sections. In contrast, our radioactive approach, due to the larger range of sensitivity, is able to obtain higher contrast in resolution of gene expression between tissue regions, making it easier to see boundaries between populations. Using this method, researchers could reveal the possible significance of a newly identified gene, and further predict the function of the gene of interest.

Radioactive in situ Hybridization for Detecting Diverse Gene Expression Patterns in Tissue

This protocol is successfully used to quantitatively detect levels and spatial patterns of mRNA expression in multiple tissue types across vertebrate species. The method can detect low abundance transcripts and allows processing of hundreds of slides simultaneously. We present this protocol using expression profiling of avian embryonic brain formation as an example.

Radioactivo In situ La hibridación para la detección de diversos patrones de expresión génica en el tejido

Knowing the timing, level, cellular localization, and cell type that a gene is expressed in contributes to our understanding of the function of the gene. ...

Detection of Viral RNA by Fluorescence in situ Hybridization (FISH)

Viruses that infect cells elicit specific changes to normal cell functions which serve to divert energy and resources for viral replication. Many aspects of host cell function are commandeered by viruses, usually by the expression of viral gene products that recruit host cell proteins and machineries. Moreover, viruses engineer specific membrane organelles or tag on to mobile vesicles and motor proteins to target regions of the cell (during de novo infection, viruses co-opt molecular motor proteins to target the nucleus; later, during virus assembly, they will hijack cellular machineries that will help in the assembly of viruses). Less is understood on how viruses, in particular those with RNA genomes, coordinate the intracellular trafficking of both protein and RNA components and how they achieve assembly of infectious particles at specific loci in the cell. The study of RNA localization began in earlier work. Developing lower eukaryotic embryos and neuronal cells provided important biological information, and also underscored the importance of RNA localization in the programming of gene expression cascades. The study in other organisms and cell systems has yielded similar important information. Viruses are obligate parasites and must utilise their host cells to replicate. Thus, it is critical to understand how RNA viruses direct their RNA genomes from the nucleus, through the nuclear pore, through the cytoplasm and on to one of its final destinations, into progeny virus particles 1.
FISH serves as a useful tool to identify changes in steady-state localization of viral RNA. When combined with immunofluorescence (IF) analysis 22, FISH/IF co-analyses will provide information on the co-localization of proteins with the viral RNA3. This analysis therefore provides a good starting point to test for RNA-protein interactions by other biochemical or biophysical tests 4,5, since co-localization by itself is not enough evidence to be certain of an interaction. In studying viral RNA localization using a method like this, abundant information has been gained on both viral and cellular RNA trafficking events 6. For instance, HIV-1 produces RNA in the nucleus of infected cells but the RNA is only translated in the cytoplasm. When one key viral protein is missing (Rev) 7, FISH of the viral RNA has revealed that the block to viral replication is due to the retention of the HIV-1 genomic RNA in the nucleus 8. 
Here, we present the method for visual analysis of viral genomic RNA in situ. The method makes use of a labelled RNA probe. This probe is designed to be complementary to the viral genomic RNA. During the in vitro synthesis of the antisense RNA probe, the ribonucleotide that is modified with digoxigenin (DIG) is included in an in vitro transcription reaction. Once the probe has hybridized to the target mRNA in cells, subsequent antibody labelling steps (Figure 1) will reveal the localization of the mRNA as well as proteins of interest when performing FISH/IF.

Detection of Viral RNA by Fluorescence in situ Hybridization FISH

A fluorescence in situ hybridization (FISH) method was developed to visually detect viral genomic RNA using fluorescence microscopy. A probe is made with specificity to the viral RNA that can then be identified using a combination of hybridization and immunofluorescence techniques. This technique offers the advantage of identifying the localization of the viral RNA or DNA at steady-state, providing information on the control of intracellular virus trafficking events.

La detección de ARN viral por fluorescencia<em&gt; In situ</em&gt; La hibridación (FISH)

Viruses  that infect cells elicit specific changes to normal cell functions which serve  to divert energy and resources for viral replication. Many ...

Chromosome Replicating Timing Combined with Fluorescent In situ Hybridization

Mammalian DNA replication initiates at multiple sites along chromosomes at different times during S phase, following a temporal replication program. The specification of replication timing is thought to be a dynamic process regulated by tissue-specific and developmental cues that are responsive to epigenetic modifications. However, the mechanisms regulating where and when DNA replication initiates along chromosomes remains poorly understood. Homologous chromosomes usually replicate synchronously, however there are notable exceptions to this rule. For example, in female mammalian cells one of the two X chromosomes becomes late replicating through a process known as X inactivation1. Along with this delay in replication timing, estimated to be 2-3 hr, the majority of genes become transcriptionally silenced on one X chromosome. In addition, a discrete cis-acting locus, known as the X inactivation center, regulates this X inactivation process, including the induction of delayed replication timing on the entire inactive X chromosome. In addition, certain chromosome rearrangements found in cancer cells and in cells exposed to ionizing radiation display a significant delay in replication timing of &gt;3 hours that affects the entire chromosome2,3. Recent work from our lab indicates that disruption of discrete cis-acting autosomal loci result in an extremely late replicating phenotype that affects the entire chromosome4. Additional 'chromosome engineering' studies indicate that certain chromosome rearrangements affecting many different chromosomes result in this abnormal replication-timing phenotype, suggesting that all mammalian chromosomes contain discrete cis-acting loci that control proper replication timing of individual chromosomes5.
Here, we present a method for the quantitative analysis of chromosome replication timing combined with fluorescent in situ hybridization. This method allows for a direct comparison of replication timing between homologous chromosomes within the same cell, and was adapted from6. In addition, this method allows for the unambiguous identification of chromosomal rearrangements that correlate with changes in replication timing that affect the entire chromosome. This method has advantages over recently developed high throughput micro-array or sequencing protocols that cannot distinguish between homologous alleles present on rearranged and un-rearranged chromosomes. In addition, because the method described here evaluates single cells, it can detect changes in chromosome replication timing on chromosomal rearrangements that are present in only a fraction of the cells in a population.

Chromosome Replicating Timing Combined with Fluorescent In situ Hybridization

A quantitative method for the analysis of chromosome replication timing is described. The method utilizes BrdU incorporation in combination with fluorescent in situ hybridization (FISH) to assess replication timing of mammalian chromosomes. This technique allows for the direct comparison of rearranged and un-rearranged chromosomes within the same cell.

Replicación del cromosoma Timing Combinado con fluorescente<em&gt; In situ</em&gt; La hibridación

Mammalian DNA replication initiates at multiple sites along chromosomes at different times during S phase, following a temporal replication program. The ...

Whole Mount RNA Fluorescent in situ Hybridization of Drosophila Embryos

Assessing the expression pattern of a gene, as well as the subcellular localization properties of its transcribed RNA, are key features for understanding its biological function during development. RNA in situ hybridization (RNA-ISH) is a powerful method used for visualizing RNA distribution properties, be it at the organismal, cellular or subcellular levels 1. RNA-ISH is based on the hybridization of a labeled nucleic acid probe (e.g. antisense RNA, oligonucleotides) complementary to the sequence of an mRNA or a non-coding RNA target of interest 2. As the procedure requires primary sequence information alone to generate sequence-specific probes, it can be universally applied to a broad range of organisms and tissue specimens 3. Indeed, a number of large-scale ISH studies have been implemented to document gene expression and RNA localization dynamics in various model organisms, which has led to the establishment of important community resources 4-11. While a variety of probe labeling and detection strategies have been developed over the years, the combined usage of fluorescently-labeled detection reagents and enzymatic signal amplification steps offer significant enhancements in the sensitivity and resolution of the procedure 12. Here, we describe an optimized fluorescent in situ hybridization method (FISH) employing tyramide signal amplification (TSA) to visualize RNA expression and localization dynamics in staged Drosophila embryos. The procedure is carried out in 96-well PCR plate format, which greatly facilitates the simultaneous processing of large numbers of samples.

Whole Mount RNA Fluorescent in situ Hybridization of Drosophila Embryos

Here we describe a whole-mount fluorescent in situ hybridization (FISH) protocol for determining the expression and localization properties of RNAs expressed during embryogenesis in the fruit fly, Drosophila melanogaster.

Todo el monte ARN fluorescente<em&gt; In situ</em&gt; La hibridación de<em&gt; Drosophila</em&gt; Los embriones

Assessing  the expression pattern of a gene, as well as the subcellular localization  properties of its transcribed RNA, are key features for ...

RNA In situ Hybridization in Whole Mount Embryos and Cell Histology Adapted for Marine Elasmobranchs

Marine elasmobranchs are valued animal models for biomedical and genomic studies as they are the most primitive vertebrates to have adaptive immunity and have unique mechanisms for osmoregulation 1-3. As the most primitive living jawed-vertebrates with paired appendages, elasmobranchs are an evolutionarily important model, especially for studies in evolution and development. Marine elasmobranchs have also been used to study aquatic toxicology and stress physiology in relationship to climate change 4. Thus, development and adaptation of methodologies is needed to facilitate and expand the use of these primitive vertebrates to multiple biological disciplines. Here I present the successful adaptation of RNA whole mount in situ hybridization and histological techniques to study gene expression and cell histology in elasmobranchs.
Monitoring gene expression is a hallmark tool of developmental biologists, and is widely used to investigate developmental processes 5. RNA whole mount in situ hybridization allows for the visualization and localization of specific gene transcripts in tissues of the developing embryo. The expression pattern of a gene's message can provide insight into what developmental processes and cell fate decisions a gene may control. By comparing the expression pattern of a gene at different developmental stages, insight can be gained into how the role of a gene changes during development.
While whole mount in situ's provides a means to localize gene expression to tissue, histological techniques allow for the identification of differentiated cell types and tissues. Histological stains have varied functions. General stains are used to highlight cell morphology, for example hematoxylin and eosin for general staining of nuclei and cytoplasm, respectively. Other stains can highlight specific cell types. For example, the alcian blue stain reported in this paper is a widely used cationic stain to identify mucosaccharides. Staining of the digestive tract with alcian blue can identify the distribution of goblet cells that produce mucosaccharides. Variations in mucosaccharide constituents on short peptides distinguish goblet cells by function within the digestive tract 6. By using RNA whole mount in situ's and histochemical methods concurrently, cell fate decisions can be linked to gene-specific expression.
Although RNA in situ's and histochemistry are widely used by researchers, their adaptation and use in marine elasmobranchs have met limited and varied success. Here I present protocols developed for elasmobranchs and used on a regular basis in my laboratory. Although further modification of the RNA in situ's hybridization method may be needed to adapt to different species, the protocols described here provide a strong starting point for researchers wanting to adapt the use of marine elasmobranchs to their scientific inquiries.

RNA In situ Hybridization in Whole Mount Embryos and Cell Histology Adapted for Marine Elasmobranchs

By combining methods for RNA whole mount in situ hybridization and histology, gene expression can be linked with cell fate decisions in the developing embryo. These methods have been adapted to marine elasmobranchs and facilitate the use of these animals as model organisms for biomedical, toxicology and comparative studies.

ARN<em&gt; In situ</emHibridación&gt; Los embriones en todo el montaje y la histología de células Adaptado para elasmobranquios marinos

Marine  elasmobranchs are valued animal models for biomedical and genomic studies as  they are the most primitive vertebrates to have adaptive immunity ...

Visualization and Analysis of mRNA Molecules Using Fluorescence In Situ Hybridization in Saccharomyces cerevisiae

The Fluorescence in situ Hybridization (FISH) method allows one to detect nucleic acids in the native cellular environment. Here we provide a protocol for using FISH to quantify the number of mRNAs in single yeast cells. Cells can be grown in any condition of interest and then fixed and made permeable. Subsequently, multiple single-stranded deoxyoligonucleotides conjugated to fluorescent dyes are used to label and visualize mRNAs. Diffraction-limited fluorescence from single mRNA molecules is quantified using a spot-detection algorithm to identify and count the number of mRNAs per cell. While the more standard quantification methods of northern blots, RT-PCR and gene expression microarrays provide information on average mRNAs in the bulk population, FISH facilitates both the counting and localization of these mRNAs in single cells at single-molecule resolution.

Visualization and Analysis of mRNA Molecules Using Fluorescence In Situ Hybridization in Saccharomyces cerevisiae

This protocol describes an experimental procedure for performing Fluorescence in situ Hybridization (FISH) for counting mRNAs in single cells at single-molecule resolution.

Visualización y Análisis de las moléculas de ARNm mediante fluorescencia<em&gt; In Situ</em&gt; La hibridación en<em&gt; Saccharomyces cerevisiae</em

The Fluorescence in situ Hybridization (FISH) method allows one to detect nucleic acids in the native cellular environment. Here we provide a protocol for ...

Analysis of Global RNA Synthesis at the Single Cell Level following Hypoxia

Hypoxia or lowering of the oxygen availability is involved in many physiological and pathological processes. At the molecular level, cells initiate a particular transcriptional program in order to mount an appropriate and coordinated cellular response. The cell possesses several oxygen sensor enzymes that require molecular oxygen as cofactor for their activity. These range from prolyl-hydroxylases to histone demethylases. The majority of studies analyzing cellular responses to hypoxia are based on cellular populations and average studies, and as such single cell analysis of hypoxic cells are seldom performed. Here we describe a method of analysis of global RNA synthesis at the single cell level in hypoxia by using Click-iT RNA imaging kits in an oxygen controlled workstation, followed by microscopy analysis and quantification.&nbsp; Using cancer cells exposed to hypoxia for different lengths of time, RNA is labeled and measured in each cell. This analysis allows the visualization of temporal and cell-to-cell changes in global RNA synthesis following hypoxic stress.

We describe a technique for analysis of global RNA synthesis in hypoxia using imaging. Click-chemistry labeling of RNA has not previously been performed under hypoxia and allows visualization of global RNA changes at the single cell level. This approach complements the existing averaged RNA techniques, allowing direct visualization of cell-to-cell changes in global RNA synthesis.

Análisis de RNA Global Síntesis en el nivel de células individuales siguiente Hipoxia

Hypoxia or lowering of the oxygen availability is involved in many physiological and pathological processes. At the molecular level, cells initiate a ...