Esta publicación fue financiada por la investigación de horizonte 2020 de la Unión Europea y la innovación del programa bajo el Convenio de subvención de Marie Sklodowska-Curie No 642893 (IMPRESS), la oficina de costo (COST Action FA 1205, AQUAGAMETE) y el centro de investigación de excelencia- 1476-4/2016/FEKUT.

Todos los procedimientos para trabajar con anguila europea se describe en este protocolo fueron aprobados por el Comité de ética de la experimentación Animal en la Universitat Politècnica de València, siguiendo las leyes españolas y las regulaciones que controlan los experimentos y procedimientos en animales vivos.
1. pescado mantenimiento
<ol><li>Las anguilas europeas a un centro de investigación y poner en un acuario de 200 L con un sistema de recirculación. Utilice termostatos y refrigeradores para mantener una temperatura constante de 20 ° C.</li>
	<li>Mantener los peces en condiciones de oscuridad para evitar estrés22 y con ninguna comida durante el experimento.</li>
	<li>Mantener los peces en agua dulce durante los 3 primeros días. Luego 1/3 del agua y rellenar con agua de mar cada tercer día hasta llegar a una salinidad de 37.0 ± 0,3 g/L.</li>
</ol>2. hormonal tratamiento
Nota: El tratamiento hormonal consiste en inyecciones semanales de gonadotropina coriónica humana (hCG) a lo largo de toda la duración (nueve semanas) del experimento.
<ol><li>Preparar la hormona hCG con antelación a una concentración de 1 IU/μl diluyendo la hormona en solución salina (0,9% NaCl). Nota: La hormona se puede preservar diluido a la concentración de más de una semana a-18 ° C.</li>
	<li>Para anestesiar el pescado, preparar un cubo flexible de 40 L con 5 L de agua del sistema.<ol>
<li>En un matraz de 250 mL, diluir a 300 mg de benzocaína en 100 mL de etanol al 70%.</li>
		<li>Vierta la benzocaína diluida en el cubo (concentración final 0,36 mM) y mezclar bien. Se trata de una concentración de benzocaína final de 60 mg/L.</li>
		<li>Transferencia de los peces, individualmente, en el agua con benzocaína y espere unos segundos hasta que la benzocaína en vigor y los peces es correctamente anestesiado. Nota: Para confirmar que el pescado está anestesiado, coloque el pescado en una posición supina y comprobar que se mantiene en esa posición.</li>
	</ol>
</li>
	<li>Administrar la hormona, pesar el pescado y preparar la hormona hCG en dosis de 1,5 UI/g de pescado, en un tubo de plástico de 1,5 mL.<ol>
<li>Llene una jeringa de 1 mL con la hormona hCG desde el tubo de plástico.</li>
		<li>Coloque el pescado anestesiado en posición supina y con la ayuda o la jeringa, inyecte la hormona cuidadosamente en la zona intraperitoneal.</li>
	</ol>
</li>
	<li>Volver los peces a los acuarios y vigilar hasta que se recuperó completamente. Nota: La administración hormonal debe realizarse semanalmente durante todo el experimento. Anguila europea iniciar normalmente, spermating después de 6-7 semanas de tratamiento hormonal.</li>
</ol>3. espermatozoides muestreo
<ol><li>Para obtener las mejores muestras de calidad, extracto espermatozoide 24 h después de la administración hormonal6,23.</li>
	<li>Anestesiar el pez con benzocaína como se describe en el paso 2.2.</li>
	<li>Coloque el pescado anestesiado en posición supina, limpie el área genital con un chorro de agua destilada y secar cuidadosamente con papel, para evitar la contaminación de las heces presente en el área genital o activación de espermatozoides accidental por contacto con agua salada de los acuarios.</li>
	<li>Colocar los dedos en ambos lados laterales de los peces, masaje con cuidado presionando lateralmente de las aletas pectorales a la zona genital para forzar el esperma hacia fuera.<ol>
<li>Repita el masaje hasta que no hay más esperma salga por la abertura genital.</li>
	</ol>
</li>
	<li>Recoger los espermatozoides en tubos de plástico de 15 mL con una bomba de vacío.</li>
	<li>Diluir el esperma extraído 1:10 en modificado Tanaka´s extensor de solución24 (137 mM NaCl, 76,2 mM NaHCO3, agua destilada) a 4 º c. Nota: Los espermatozoides en la solución de extender deben mantenerse a 4 º c.</li>
</ol>4. evaluación de la calidad de espermatozoides
<ol><li>Preparar agua de mar artificial13 (en mM: NaCl 354.7, MgCl2 52.4, CaCl2 9.9, Na2SO4 28.2, KCl 9.4, en agua destilada) con 2% albúmina de suero bovino (BSA) (p), ajustar el pH a 8.2, osmolalidad a 1100 mOsm/kg y mantener él a 4 º c para evitar el crecimiento bacteriano.</li>
	<li>Abra el software para el análisis de los espermatozoides asistido por ordenador (CASA) y seleccione el módulo de esperma de peces.<ol>
<li>Haga clic en propiedades para abrir la configuración del software del sistema. Allí, definir las opciones de captura 60 imágenes por segundo. Seleccionar fase negativa óptica, cámara de Makler y escala X 10.</li>
		<li>En los valores de análisis, seleccione peces como especie y área de partículas mayores de 2 μm2 y menor que 20 μm2.</li>
		<li>Sobre los parámetros de velocidad, ajuste a lento cuando las células moverse entre 10 y 45 μm/s, al medio cuando se mueve entre 45 y 100 μm/s y a rápido cuando se mueve más rápido que 100 μm/s. Nota: Espermatozoides con velocidad menor que 10 μm/s se consideran fijos.</li>
		<li>Seleccionar los valores progresistas como el 80% de rectitud (STR) y guardar las propiedades.</li>
		<li>Haga clic en Capturar el campo (se abrirá una ventana con las imágenes en vivo de la cámara). Nota: El sistema de análisis de semen asistida por ordenador está formado por un microscopio, una cámara y un software de análisis de imagen.</li>
	</ol>
</li>
	<li>En la cámara de cuenta, ponga 4 μL de agua de mar artificial y añadir 0,5 μl de solución de semen (esperma diluida en solución diluyente).<ol>
<li>Enfocar la imagen con el microscopio con aumentos de 10 en la fase negativa. 15 s después de la activación, haga clic en captura - video en el software de análisis de espermatozoides asistido por ordenador.</li>
		<li>Analizar todas las muestras en triplicado y seleccionadas muestras con una motilidad superior al 70% para la criopreservación. Nota: Es muy importante seleccionar únicamente esperma de alta calidad para el éxito de este protocolo de criopreservación.</li>
	</ol>
</li>
</ol>5. método de congelación de espermatozoides
<ol><li>Preparar de antemano líquido nitrógeno (aproximadamente 2,5 L) en un 34 x 34 cm x 30 cm y 5 cm Grosor espuma de poliestireno caja. Nota: Mantener un nivel de nitrógeno líquido de 4-5 cm de altura en todo momento.<ol>
<li>Construir una estructura flotante para congelar previamente el semen. 2 piezas de poliestireno (20 x 5 cm), enlazar con 2 tubos de plástico y coloque la estructura sobre el nitrógeno líquido. Esta estructura debe flotar sobre el nitrógeno líquido a una altura aproximada de 3 cm sobre la superficie (figura 1).</li>
	</ol>
</li>
</ol><img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/56835/56835fig1.jpg"> Figura 1 . Esquema de la estructura flotante utilizada para la congelación por nitrógeno líquido. La estructura consta de dos piezas de baja densidad de espuma de poliestireno de 20 cm x 4 cm x 5 cm conectado con tubos de plástico de 14 cm. La paja se coloca sobre los tubos de plástico en 3 cm sobre el nitrógeno líquido. <a href="//cloudflare.jove.com/files/ftp_upload/56835/56835fig1large.jpg" target="_blank">Haga clic aquí para ver una versión más grande de esta figura.</a>
<ol start="2"><li>Preparar la solución de criopreservación mediante la mezcla de esperma, solución de extender y metanol en proporción de 1:8:1 en plástico de 1,5 mL los tubos y agitar suavemente.</li>
	<li>Con la ayuda de una pipeta, añadir 480 μl de la solución de criopreservación en la paja de los 500 μl y si es necesario, marcarlas por el cierre de uno de los extremos con plastilina.</li>
	<li>Poner la paja en el dispositivo flotante a una altura de 3 cm por encima del nitrógeno líquido durante 3 minutos. Luego, colocar la paja en el nitrógeno líquido.</li>
	<li>Después de 10-15 min, transferir las pajillas en un tanque de almacenamiento de nitrógeno líquido con unas pinzas largas y mantenerlos sumergidos en nitrógeno líquido en todo momento. Aquí, los espermatozoides pueden ser almacenados indefinidamente.</li>
</ol>6. método de descongelación
<ol><li>Prepare una caja de espuma de poliestireno con nitrógeno líquido como se describe en el paso 5.1 y preparar un baño de agua con un vaso de precipitados de 3 L de agua a 40 º c.</li>
	<li>Transferir las pajillas con semen congelado desde el tanque de almacenamiento en la caja de la espuma de poliestireno con nitrógeno líquido con unas pinzas largas.<ol>
<li>Poner cada paja en un baño de agua a 40 º c 13 s.</li>
		<li>Vierta el semen en un tubo de plástico de 1,5 mL cortando los extremos cerrados de la paja con una tijera.</li>
	</ol>
</li>
	<li>Analizar la motilidad espermática mediante sistema de análisis de semen asistido por computadora como se explica en el paso 4.1.</li>
	<li>Mantener 100 μl de semen para analizar la viabilidad de los espermatozoides con un citómetro de flujo.</li>
</ol>7. flujo Cytometry
<ol><li>Utilice un kit fluorescente con yoduro de propidio (PI), que es un compuesto fluorescente rojo que tiñe los núcleos de las células muertas y un compuesto fluorescente nuclear membrana-permeant, que verde tiñe los núcleos de las células vivas.<ol>
<li>Preparar la solución de tinción fluorescente verde mediante la dilución de la solución madre (1 mM) 1:10 en medio de Tanaka´s a una solución de trabajo de 100 μm.</li>
		<li>No diluir la solución de PI. La solución está en 2,4 mM.</li>
	</ol>
</li>
	<li>Para cada muestra, tomar 50 μl de semen fresco o descongelado y agregar 0,5 μl de verde fluorescente, coloración de la solución de trabajo (concentración final 1 μm) y 2 μl de solución de PI (concentración final 100 μm).</li>
	<li>Incubar las muestras que contienen los tintes (PI y tinción fluorescente verde) en la oscuridad durante 5 minutos.<ol>
<li>Diluir las muestras en 500 μl de solución de extensor de Tanaka´s y analizar con el citómetro de flujo.</li>
	</ol>
</li>
	<li>Encienda el citómetro de flujo y crear un nuevo protocolo que contenga por lo menos 2 parcelas: SS registro registro vs FS y FL1 vs FL3. Nota: Ambos, verde fluorescente yoduro de propidio la coloración y a puede ser excitado con luz de longitud de onda visible. Cuando se une a ADN, la emisión de fluorescencia máxima de estos tintes son 516 nm y 617 nm, respectivamente.<ol>
<li>Ajustar las tensiones de los diferentes láseres: SS = 199; FS = 199; FL1 = 377; FL3 = 372</li>
		<li>Configurar el acuerdo de ajustes de adquisición máxima eventos = s 5000 o 15 (la concentración final de la muestra debe ser aproximadamente 1 millón de células/mL). Lea la muestra usando un flujo de baja .</li>
		<li>Seleccione el modo de lectura solo tubo fijada modo de posición.</li>
		<li>Coloca la muestra en el número correcto del carrusel</li>
		<li>Leer la muestra (presionando F9) y guardar los datos recogidos en un archivo de excel (pulsando F7) para su posterior análisis.</li>
	</ol>
</li>
</ol>

<ol>
	<li>ICES_Working_Group_on_Eels. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Report of the 2011 Session of the Joint EIFAAC/ICES Working Group on Eels. , 246 (2011).</li><li>Moriarty, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=European+Catches+of+Elver+of+1928-1988.">European Catches of Elver of 1928-1988.</a> Int. Rev. Hydrobiol. 75 (6), 701-706 (1990).</li><li>Dekker, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+fractal+geometry+of+the+European+eel+stock.">The fractal geometry of the European eel stock.</a> ICES J. Mar. Sci. 57 (1), 109-121 (2000).</li><li>Jacoby, D., Gollock, 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> Anguilla anguilla. The IUCN red list of threatened species. Version 2014.2. , (2014).</li><li>Asturiano, J. F., 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=Effects+of+hCG+as+spermiation+inducer+on+European+eel+semen+quality.">Effects of hCG as spermiation inducer on European eel semen quality.</a> Theriogenology. 66 (4), 1012-1020 (2006).</li><li>P&#233;rez, 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=Induction+of+maturation+and+spermiation+in+the+male+European+eel:+assessment+of+sperm+quality+throughout+treatment.">Induction of maturation and spermiation in the male European eel: assessment of sperm quality throughout treatment.</a> J. Fish Biol. 57 (6), 1488-1504 (2000).</li><li>Gallego, V., 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=Study+of+the+effects+of+thermal+regime+and+alternative+hormonal+treatments+on+the+reproductive+performance+of+European+eel+males+(Anguilla+anguilla)+during+induced+sexual+maturation.">Study of the effects of thermal regime and alternative hormonal treatments on the reproductive performance of European eel males (Anguilla anguilla) during induced sexual maturation.</a> Aquaculture. 354, 7-16 (2012).</li><li>Asturiano, J. F., S&#248;rensen, S. R., P&#233;rez, L., Lauesen, P., Tomkiewicz, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=First+Production+of+Larvae+Using+Cryopreserved+Sperm:+Effects+of+Preservation+Temperature+and+Cryopreservation+on+European+Eel+Sperm+Fertilization+Capacity.">First Production of Larvae Using Cryopreserved Sperm: Effects of Preservation Temperature and Cryopreservation on European Eel Sperm Fertilization Capacity.</a> Reprod. Domestic Anim. 51 (4), 485-491 (2016).</li><li>Di Biase, 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=Co-treatment+with+androgens+during+artificial+induction+of+maturation+in+female+eel,+Anguilla+anguilla:+Effects+on+egg+production+and+early+development.">Co-treatment with androgens during artificial induction of maturation in female eel, Anguilla anguilla: Effects on egg production and early development.</a> Aquaculture. 479, 508-515 (2017).</li><li>Lokman, P., Wylie, M. J., Downes, M., Di Biase, A., Damsteegt, E. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Artificial+induction+of+maturation+in+female+silver+eels,+Anguilla+australis:+The+benefits+of+androgen+pre-treatment.">Artificial induction of maturation in female silver eels, Anguilla australis: The benefits of androgen pre-treatment.</a> Aquaculture. 437, 111-119 (2015).</li><li>Mylonas, C. C., Duncan, N. J., Asturiano, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hormonal+manipulations+for+the+enhancement+of+sperm+production+in+cultured+fish+and+evaluation+of+sperm+quality.">Hormonal manipulations for the enhancement of sperm production in cultured fish and evaluation of sperm quality.</a> Aquaculture. , (2016).</li><li>Ohta, H., Izawa, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diluent+for+cool+storage+of+the+Japanese+eel+(Anguilla+japonica)+spermatozoa.">Diluent for cool storage of the Japanese eel (Anguilla japonica) spermatozoa.</a> Aquaculture. 142 (1-2), 107-118 (1996).</li><li>Pe&#241;aranda, D. 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=European+Eel+Sperm+Diluent+for+Short-term+Storage.">European Eel Sperm Diluent for Short-term Storage.</a> Reprod. Domestic Anim. 45 (3), 407-415 (2010).</li><li>Ohta, H., Kagawa, H., Tanaka, H., Unuma, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Control+by+the+environmental+concentration+of+ions+of+the+potential+for+motility+in+Japanese+eel+spermatozoa.">Control by the environmental concentration of ions of the potential for motility in Japanese eel spermatozoa.</a> Aquaculture. 198 (3), 339-351 (2001).</li><li>Asturiano, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Media+and+methods+for+the+cryopreservation+of+European+eel+(Anguilla+anguilla)+sperm.">Media and methods for the cryopreservation of European eel (Anguilla anguilla) sperm.</a> Fish Physiol. Biochem. 28 (1), 501-502 (2003).</li><li>Asturiano, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physio-chemical+characteristics+of+seminal+plasma+and+development+of+media+and+methods+for+the+cryopreservation+of+European+eel+sperm.">Physio-chemical characteristics of seminal plasma and development of media and methods for the cryopreservation of European eel sperm.</a> Fish Physiol. Biochem. 30 (3), 283-293 (2004).</li><li>Szab&#243;, 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=Cryopreservation+of+European+eel+(Anguilla+anguilla)+sperm+using+different+extenders+and+cryoprotectants.">Cryopreservation of European eel (Anguilla anguilla) sperm using different extenders and cryoprotectants.</a> Acta. Biol. Hung. 56 (1-2), 173-175 (2005).</li><li>M&#252;ller, T., 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=Cryopreservation+of+sperm+of+farmed+European+eel+Anguilla+anguilla.">Cryopreservation of sperm of farmed European eel Anguilla anguilla.</a> J World Aquac Soc. 35 (2), 225-231 (2004).</li><li>Pe&#241;aranda, D. S., P&#233;rez, L., Gallego, V., Jover, M., Asturiano, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improvement+of+European+eel+sperm+cryopreservation+method+by+preventing+spermatozoa+movement+activation+caused+by+cryoprotectants.">Improvement of European eel sperm cryopreservation method by preventing spermatozoa movement activation caused by cryoprotectants.</a> Cryobiology. 59 (2), 119-126 (2009).</li><li>Marco-Jim&#233;nez, F., 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=Cryopreservation+of+European+eel+(Anguilla+anguilla)+spermatozoa:+effect+of+dilution+ratio,+foetal+bovine+serum+supplementation,+and+cryoprotectants.">Cryopreservation of European eel (Anguilla anguilla) spermatozoa: effect of dilution ratio, foetal bovine serum supplementation, and cryoprotectants.</a> Cryobiology. 53 (1), 51-57 (2006).</li><li>Asturiano, J. F., 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=Effect+of+sperm+cryopreservation+on+the+European+eel+sperm+viability+and+spermatozoa+morphology.">Effect of sperm cryopreservation on the European eel sperm viability and spermatozoa morphology.</a> Reprod. Domestic Anim. 42 (2), 162-166 (2007).</li><li>Mordenti, M., Di Biase, A., Sirri, R., Modugno, S., Tasselli, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induction+of+Sexual+Maturation+in+Wild+Female+European+Eels+(Anguilla+anguilla)+in+Darkness+and+Light.">Induction of Sexual Maturation in Wild Female European Eels (Anguilla anguilla) in Darkness and Light.</a> Isr. J. Aquac. 64, (2012).</li><li>Ohta, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Artificial+induction+of+maturation+and+fertilization+in+the+Japanese+eel,+Anguilla+japonica.">Artificial induction of maturation and fertilization in the Japanese eel, Anguilla japonica.</a> Fish Physiol. Biochem. 17 (1), 163-169 (1997).</li><li>Tanaka, 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=Long-term+cryopreservation+of+sperm+of+Japanese+eel.">Long-term cryopreservation of sperm of Japanese eel.</a> J. Fish Biol. 60 (1), 139-146 (2002).</li><li>Gallego, V., 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=Subpopulation+pattern+of+eel+spermatozoa+is+affected+by+post-activation+time,+hormonal+treatment+and+the+thermal+regimen.">Subpopulation pattern of eel spermatozoa is affected by post-activation time, hormonal treatment and the thermal regimen.</a> Reprod. Fertil. Dev. 27 (3), 529-543 (2015).</li><li>Asturiano, J. F., Cabrita, E., Horv&#225;th, &. #. 1. 9. 3. ;. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Progress,+challenges+and+perspectives+on+fish+gamete+cryopreservation:+A+mini-review.">Progress, challenges and perspectives on fish gamete cryopreservation: A mini-review.</a> Gen. Comp. Endocrinol. , (2016).</li><li>Kime, D. 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=Computer-assisted+sperm+analysis+(CASA)+as+a+tool+for+monitoring+sperm+quality+in+fish.">Computer-assisted sperm analysis (CASA) as a tool for monitoring sperm quality in fish.</a> Comp. Biochem. Physiol. C Toxicol. Pharmacol. 130 (4), 425-433 (2001).</li><li>Rurangwa, E., Kime, D. E., Ollevier, F., Nash, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+measurement+of+sperm+motility+and+factors+affecting+sperm+quality+in+cultured+fish.">The measurement of sperm motility and factors affecting sperm quality in cultured fish.</a> Aquaculture. 234 (1-4), 1-28 (2004).</li><li>Verstegen, J., Iguer-Ouada, M., Onclin, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Computer+assisted+semen+analyzers+in+andrology+research+and+veterinary+practice.">Computer assisted semen analyzers in andrology research and veterinary practice.</a> Theriogenology. 57 (1), 149-179 (2002).</li><li>Magnotti, C., 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=Cryopreservation+and+vitrification+of+fish+semen:+a+review+with+special+emphasis+on+marine+species.">Cryopreservation and vitrification of fish semen: a review with special emphasis on marine species.</a> Rev. Aquacult. , (2016).</li><li>Dziewulska, K., Rzemieniecki, A., Czerniawski, R., Domaga&#322;a, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Post-thawed+motility+and+fertility+from+Atlantic+salmon+(Salmo+salar+L.)+sperm+frozen+with+four+cryodiluents+in+straws+or+pellets.">Post-thawed motility and fertility from Atlantic salmon (Salmo salar L.) sperm frozen with four cryodiluents in straws or pellets.</a> Theriogenology. 76 (2), 300-311 (2011).</li><li>Babiak, I., Bolla, S., Ottesen, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Suitable+methods+for+cryopreservation+of+semen+from+Atlantic+halibut,+Hippoglossus+hippoglossus+L.">Suitable methods for cryopreservation of semen from Atlantic halibut, Hippoglossus hippoglossus L.</a> Aquac. Int. 16 (6), 561-572 (2008).</li><li>M&#252;ller, T., 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=Japanese+eel+(Anguilla+japonica+Temminck+&amp;+Schlegel,+1846)+propagation+using+cryopreserved+sperm+samples.">Japanese eel (Anguilla japonica Temminck &amp; Schlegel, 1846) propagation using cryopreserved sperm samples.</a> J. Appl. Ichthyol. 33 (3), 550-552 (2017).</li></ol>

Los autores declaran que no tienen intereses financieros que compiten.

Este protocolo describe el proceso completo para la criopreservación de maduración, la manipulación y el esperma de anguila europea. Las condiciones de cría descritas aquí son óptimas para la producción de altos volúmenes de esperma de alta calidad en esta especie 6,7,25y maduración rápida. El éxito de este protocolo de criopreservación y su potencial uso para la fertilización después de descongelar dependen mucho ...

En los últimos 25 años, el número de anguila europea (Anguilla anguilla) al llegar a la Costa Europea ha disminuido constantemente en 90% 1,2,3. Hay varios factores que explican esta caída drástica como contaminación, infecciones, sobrepesca y fragmentación del hábitat. Todo esto ha tenido un profundo efecto sobre esta especie, conduce a la inclusión de la anguila europea en la Unión Internacional para la lista de conservación de la naturaleza (UICN) en peligro de extinción crítico 4. En consecuencia, el desarrollo de técnicas y protocolos para la reproducción en cautiverio es necesario.
La maduración de la anguila europea en cautividad se consigue por tratamiento hormonal 5,6,7 pero la producción de gametos en ambos sexos es difícil sincronizar 8. Aunque el desarrollo de nuevos implantes de andrógenos ha demostrado acelerar la Oogénesis en anguilas 9,10, el tiempo de maduración final en las mujeres es altamente variable y difícil de controlar 11. Por lo tanto, almacenamiento a corto plazo de esperma 12,13,14 y criopreservación de las técnicas son necesarias para la gestión de la reproducción, haciendo innecesario de sincronización de gametos 8.
Criopreservación de espermatozoides de la anguila europea ha sido desarrollada desde 2003 15,16. Varios investigadores diseñaron protocolos exitosos utilizando dimetilsulfóxido (DMSO) o metanol como crioprotectores 16,17,18,19,20. Aunque ambos protocolos se han utilizado con éxito, la viabilidad de las células obtenidas de semen descongelado congelados con DMSO es menor que con metanol 20,21. Por otra parte, eel esperma se activa al contacto con el DMSO y requiere de manipulación de espermatozoides más tedioso 19, por lo tanto, el metanol es más adecuado crioprotector para que la esperma de anguila europea de DMSO.
Aquí, el protocolo para el manejo óptimo y tratamiento hormonal de la anguila europea se describirán a continuación. Además, el protocolo de criopreservación de esperma de anguila europea mejor usando metanol como crioprotector y un protocolo para la evaluación de la calidad del esperma en esta especie también se describe.

<table border="0" cellpadding="0" cellspacing="0" width="538">
	<tbody>
		<tr height="19">
			<td height="19" style="height:19px;width:151px;">AQUACEN BENZOCA&#205;NA +D2A2:D24</td>
			<td style="width:128px;">AQUACEN</td>
			<td style="width:119px;">3394ESP</td>
			<td style="width:141px;">Benzocaine</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">NaCl</td>
			<td>Avantor&#160;</td>
			<td>3624-19</td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Syringe</td>
			<td>BD Plastipak</td>
			<td>305501</td>
			<td>Syringe 1 mL</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">FC500</td>
			<td>Beckman Coulter</td>
			<td></td>
			<td>Flow cytometer</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Air pump 100</td>
			<td>EHEIM</td>
			<td>4011708370032</td>
			<td>Modified for suction</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Eppendorf 1.5</td>
			<td>Eppendorf</td>
			<td>175508</td>
			<td>Plastic tubes 1.5 mL</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Falcon tubes</td>
			<td>Falcon</td>
			<td>175747</td>
			<td>Plastic tubes 15 mL</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Flexible bucket</td>
			<td>Fiel</td>
			<td>1040101</td>
			<td>40 L, Black color.</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Ethanol</td>
			<td>Guinama SL</td>
			<td>Mg96270</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Cyopreservation straws&#160;</td>
			<td>IMV Technologies</td>
			<td>14550</td>
			<td>500 &#181;L straws</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Live/Dead Sperm Viability Kit</td>
			<td>Invitrogen</td>
			<td>L7011</td>
			<td>Cytometer Kit</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Modelling clay</td>
			<td>JOVI</td>
			<td>Art 30</td>
			<td>4 different colors</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Precision scale PCB</td>
			<td>KERN &#38; Sohn GmbH</td>
			<td>PCB35002</td>
			<td>Digital scale</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Saline solution Vitulia 0.9%</td>
			<td>Laboratorios Ern, S.A.</td>
			<td>C.N. 999790.8</td>
			<td>Saline solution</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Forceps</td>
			<td>Levantina de Lab. SL</td>
			<td>3710025</td>
			<td>30 cm metal forceps</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Scissors</td>
			<td>Levantina de Lab. SL</td>
			<td>3700014</td>
			<td>Scissors 14cm</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Ovitrelle (r-hCG)</td>
			<td>Merck SL</td>
			<td>EMEA/H/C/000320</td>
			<td>Human chorionic gonadotropin</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Nikon Eclipse 80i</td>
			<td>Nikon</td>
			<td></td>
			<td>Microscope</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">CaCl2</td>
			<td>Panreac Quimica SAU</td>
			<td>2112211210</td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Na2SO4</td>
			<td>Panreac Quimica SAU</td>
			<td>3257091611</td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">NaHCO3</td>
			<td>Panreac Quimica SAU</td>
			<td>1416381210</td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">782M Camera</td>
			<td>Proiser</td>
			<td>782M</td>
			<td>Camera for CASA</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">ISAS v1</td>
			<td>Proiser</td>
			<td>ISAS v1</td>
			<td>CASA software</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">SpermTrack-10</td>
			<td>Proiser</td>
			<td>SpermTrack-10</td>
			<td>Countig chamber for CASA</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Beaker Pyrex 3L</td>
			<td>PYREX</td>
			<td>2110668</td>
			<td>Glass beaker 3L</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Flask Pyrex 250 GL-45</td>
			<td>PYREX</td>
			<td>21801365</td>
			<td>Glass flask 250 mL</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">KCl</td>
			<td>Scharlab SL</td>
			<td>PO02000500</td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Methanol</td>
			<td>Scharlab SL</td>
			<td>ME03061000</td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">MgCl2</td>
			<td>Scharlab SL</td>
			<td>MA00370500</td>
			<td></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">BSA</td>
			<td>Sigma Aldrich</td>
			<td>05482</td>
			<td>Bovine serum albumina</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;">Styrofoam box</td>
			<td></td>
			<td></td>
			<td>34x34x30 cm and 5cm thick</td>
		</tr>
	</tbody>
</table>

handling and treatment of male european eels (anguilla anguilla) for hormonal maturation and sperm cryopreservation

Durante los últimos años, varios grupos de investigación han estado trabajando en el desarrollo y mejora de nuevos protocolos para el manejo de la anguila europea y la maduración. Como de sin embargo, inyecciones semanales de gonadotropina coriónica humana (hCG) han demostrado lo machos después de sólo 5-6 semanas de tratamiento, produciendo altos volúmenes de esperma de alta calidad durante varias semanas. Además, protocolos de criopreservación de espermatozoides utilizando diferentes diluyentes, crioprotectores y enfriamiento y descongelamiento veces se han descrito previamente para la anguila europea. Aquí, mostramos que Tanaka´s solución de extender puede ser utilizado directamente para la fertilización o para la criopreservación, haciendo innecesario el uso de diferentes tipos de soluciones y diluciones. Además, el uso de metanol como crioprotector hace este Protocolo fácil de usar como metanol tiene baja toxicidad y no activa el esperma. El esperma no necesita ser congelados inmediatamente después de la adición del crioprotector, y puede ser utilizado durante mucho tiempo después de ser descongelado. Por otra parte, la motilidad del esperma sigue siendo alta después de descongelar, aunque es menor que la del semen fresco. El objetivo de este trabajo es mostrar el mejor protocolo disponible para la anguila europea, manipulación, maduración y criopreservación de esperma.

Semen de 18 morenas con una motilidad del esperma de 70% o más, fue seleccionado para este estudio. Los resultados mostraron una reducción en todos los parámetros de calidad después de deshelar en comparación con los de esperma fresca (tabla 1 y figura 2). Los resultados de motilidad (promedio ± SEM, n = 18) demostró una mayor motilidad total y una motilidad progresiva en esperma fresca que la motilidad total y motilidad progresiva enc...

Watch this Scientific Journal Video about Handling and Treatment of Male European Eels Anguilla anguilla for Hormonal Maturation and Sperm Cryopreservation at JoVE.com

Handling and Treatment of Male European Eels Anguilla anguilla for Hormonal Maturation and Sperm Cryopreservation

Protocolos de criopreservación de maduración y esperma de anguila europea han sido mejorados en los últimos años. Este artículo describe el protocolo mejor disponible con gonadotropina coriónica humana (hCG) para inducir la maduración y metanol como crioprotector.

Manejo y tratamiento del hombre europeo anguilas (Anguilla anguilla) de maduración Hormonal y criopreservación de esperma

During the last years, several research groups have been working on the development and improvement of new protocols for the European eel handling and ...

Hi, my name is Juan Asturiano from the Polytechnic University of Valencia, and we are with some of our colleagues from the Szent Istv

handling-treatment-male-european-eels-anguilla-anguilla-for-hormonal

Research

JoVE Journal

Developmental Biology

Handling and Treatment of Male European Eels (Anguilla anguilla) for Hormonal Maturation and Sperm Cryopreservation

7.8K vistas.  Universitat Politècnica de València. Hi, my name is Juan Asturiano from the Polytechnic University of Valencia, and we are with some of our colleagues from the Szent Istv

Video: Handling and Treatment of Male European Eels Anguilla anguilla for Hormonal Maturation and Sperm Cryopreservation

Manipulation and In Vitro Maturation of Xenopus laevis Oocytes, Followed by Intracytoplasmic Sperm Injection, to Study Embryonic Development

Amphibian eggs have been widely used to study embryonic development. Early embryonic development is driven by maternally stored factors accumulated during oogenesis. In order to study roles of such maternal factors in early embryonic development, it is desirable to manipulate their functions from the very beginning of embryonic development. Conventional ways of gene interference are achieved by injection of antisense oligonucleotides (oligos) or mRNA into fertilized eggs, enabling under- or over-expression of specific proteins, respectively. However, these methods normally require more than several hours until protein expression is affected, and, hence, the interference of gene functions is not effective during early embryonic stages. Here, we introduce an experimental system in which expression levels of maternal proteins can be altered before fertilization. Xenopus laevis oocytes obtained from ovaries are defolliculated by incubating with enzymes. Antisense oligos or mRNAs are injected into defolliculated oocytes at the germinal vesicle (GV) stage. These oocytes are in vitro matured to eggs at the metaphase II (MII) stage, followed by intracytoplasmic sperm injection (ICSI). By this way, up to 10% of ICSI embryos can reach the swimming tadpole stage, thus allowing functional tests of specific gene knockdown or overexpression. This approach can be a useful way to study roles of maternally stored factors in early embryonic development.

Manipulation and In Vitro Maturation of Xenopus laevis Oocytes, Followed by Intracytoplasmic Sperm Injection, to Study Embryonic Development

We describe methods of manipulating Xenopus laevis immature oocytes, in vitro maturation of oocytes to eggs, and intracytoplasmic sperm injection. This protocol allows degradation of some maternal proteins and overexpression of genes of interest at fertilization, and hence is valuable to study roles of specific factors in early embryonic development.

La manipulación y<em&gt; In Vitro</em&gt; La maduración de<em&gt; Xenopus laevis</em&gt; Los ovocitos, seguido de inyección intracitoplasmática de espermatozoides, para estudiar el desarrollo embrionario

Amphibian eggs have been widely used to study embryonic development. Early embryonic development is driven by maternally stored factors accumulated during ...

Investigación

Biología del Desarrollo

Isolation and Cryopreservation of Neonatal Rat Cardiomyocytes

Cell culture has become increasingly important in cardiac research, but due to the limited proliferation of cardiomyocytes, culturing cardiomyocytes is difficult and time consuming. The most commonly used cells are neonatal rat cardiomyocytes (NRCMs), which require isolation every time cells are needed. The birth of the rats can be unpredictable. Cryopreservation is proposed to allow for cells to be stored until needed, yet freezing/thawing methods for primary cardiomyocytes are challenging due to the sensitivity of the cells. Using the proper cryoprotectant, dimethyl sulfoxide (DMSO), cryopreservation was achieved. By slowly extracting the DMSO while thawing the cells, cultures were obtained with viable NRCMs. NRCM phenotype was verified using immunocytochemistry staining for &#945;-sarcomeric actinin. In addition, cells also showed spontaneous contraction after several days in culture. Cell viability after thawing was acceptable at 40-60%. In spite of this, the methods outlined allow one to easily cryopreserve and thaw NRCMs. This gives researchers a greater amount of flexibility in planning experiments as well as reducing the use of animals.

The isolation of neonatal rat cardiomyocytes is a time consuming and unpredictable procedure. This study describes methods for cryopreservation and thawing of neonatal rat cardiomyocytes that allows for more efficient use of cells. The thawed NRCMs can be used for various experiments without the need for performing isolations each time.

El aislamiento y criopreservación de rata neonatal cardiomiocitos

Cell culture has become increasingly important in cardiac research, but due to the limited proliferation of cardiomyocytes, culturing cardiomyocytes is ...

Modified MicroSecure Vitrification: A Safe, Simple and Highly Effective Cryopreservation Procedure for Human Blastocysts

Clinical embryo vitrification evolved with the development of unique vitrification devices in the 21st century and with the misconception that ultra-rapid cooling in an &#34;open&#34; system (i.e., direct LN2 contact) was a necessity to optimize vitrification success. The dogma surrounding the importance of cooling rates led to unsafe practices subject to technical variation and to the creation of vitrification devices that disregarded important quality-control factors (e.g., ease of use, repeatability, reliability, labeling security, and storage safety). Understanding the quality-control flaws of other devices allowed for the development of a safe, secure, repeatable, and reliable &#181;S-VTF method aimed to minimize intra- and inter-technician variation. Equally important, it combined the availability of two existing FDA-compliant devices: 1) a 0.3-mL ionomeric resin embryo straw with internalized, dual-colored, tamper-proof labeling with repeatable weld seal potential; and 2) shortened, commonly-used, 300-&#181;m ID sterile flexipettes to directly load the embryo(s) in order to create a highly-effective global vitrification device. Like other aseptic, closed vitrification systems (e.g., High Security Vitrification (HSV), Rapid-i, and VitriSafe) effectively used in reproductive medicine, microSecure Vitrification (&#181;S-VTF) has proven that it can achieve high post-warming survival and pregnancy outcomes with its attention to simplicity, and reduced technical variation. Although the 0.3-mL embryo straw containing an internal hydrophobic plug was commercially replaced with a standard semen straw possessing cotton-polyvinyl pyrrolidone (PVP) plugs, it maintained its ionomeric resin composition to ensure weld sealing. However, the cotton plugs can wick out the fluid-embryo contents of the flexipettes upon contact. A modified &#181;S-VTF method was adapted to include an additional internal weld seal before the plug on the device loading side. The added technical step to the &#181;S-VTF procedure has not affected its successful application, as high survival rates (&#62; 95%) and pregnancy rates continue today.

MicroSecure Vitrification was developed as a non-commercial, aseptic closed vitrification device system that is compliant with FDA good manufacturing and tissue-handling practices. Due to the withdrawal of hydrophobic plugged embryo straws from the industry, the vitrification procedure was modified to include an inner seal before the standard internal cotton plug.

La vitrificación modificada MicroSecure: Un procedimiento altamente seguro, simple y eficaces de crioconservación de blastocistos humanos

Clinical embryo vitrification evolved with the development of unique vitrification devices in the 21st century and with the misconception that ultra-rapid ...

Maturation of Human Stem Cell-derived Cardiomyocytes in Biowires Using Electrical Stimulation

Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) have been a promising cell source and have thus encouraged the investigation of their potential applications in cardiac research, including drug discovery, disease modeling, tissue engineering, and regenerative medicine. However, cells produced by existing protocols display a range of immaturity compared with native adult ventricular cardiomyocytes. Many efforts have been made to mature hPSC-CMs, with only moderate maturation attained thus far. Therefore, an engineered system, called biowire, has been devised by providing both physical and electrical cues to lead hPSC-CMs to a more mature state in vitro. The system uses a microfabricated platform to seed hPSC-CMs in collagen type I gel along a rigid template suture to assemble into aligned cardiac tissue (biowire), which is subjected to electrical field stimulation with a progressively increasing frequency. Compared to nonstimulated controls, stimulated biowired cardiomyocytes exhibit an enhanced degree of structural and electrophysiological maturation. Such changes are dependent upon the stimulation rate. This manuscript describes in detail the design and creation of biowires.

The cardiac biowire platform is an in vitro method used to mature human embryonic and induced pluripotent stem cell-derived cardiomyocytes (hPSC-CM) by combining three-dimensional cell cultivation with electrical stimulation. This manuscript presents the detailed setup of the cardiac biowire platform.

La maduración de madre humanas cardiomiocitos derivado de células en Biowires uso de la estimulación eléctrica

Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) have been a promising cell source and have thus encouraged the investigation of their ...

A Standardized Approach for Multispecies Purification of Mammalian Male Germ Cells by Mechanical Tissue Dissociation and Flow Cytometry

Fluorescence-activated cell sorting (FACS) has been one of the methods of choice to isolate enriched populations of mammalian testicular germ cells. Currently, it allows the discrimination of up to 9 murine germ cell populations with high yield and purity. This high-resolution in discrimination and purification is possible due to unique changes in chromatin structure and quantity throughout spermatogenesis. These patterns can be captured by flow cytometry of male germ cells stained with fluorescent DNA-binding dyes such as Hoechst-33342 (Hoechst). Herein is a detailed description of a recently developed protocol to isolate mammalian testicular germ cells. Briefly, single cell suspensions are generated from testicular tissue by mechanical dissociation, double stained with Hoechst and propidium iodide (PI) and processed by flow cytometry. A serial gating strategy, including the selection of live cells (PI negative) with different DNA content (Hoechst intensity), is used during FACS sorting to discriminate up to 5 germ cell types. These include, with corresponding average purities (determined by microscopy evaluation): spermatogonia (66%), primary (71%) and secondary (85%) spermatocytes, and spermatids (90%), further separated into round (93%) and elongating (87%) subpopulations. Execution of the entire workflow is straightforward, allows the isolation of 4 cell types simultaneously with the appropriate FACS machine, and can be performed in less than 2 h. As reduced processing time is crucial to preserve the physiology of ex vivo cells, this method is ideal for downstream high-throughput studies of male germ cell biology. Moreover, a standardized protocol for multispecies purification of mammalian germ cells eliminates methodological sources of variables and allows a single set of reagents to be used for different animal models.

This work describes the standardization of a method to obtain purified germ cell populations from testicular tissue of different mammalian species. It is a straightforward protocol that combines mechanical testis dissociation, staining with Hoechst-33342 and propidium iodide, and FACS sorting, with wide applications in comparative studies of male reproductive biology.

Un enfoque estandarizado para la purificación multiespecífica de células germinales masculinas de mamíferos por disociación mecánica de tejidos y citometría de flujo

Fluorescence-activated cell sorting (FACS) has been one of the methods of choice to isolate enriched populations of mammalian testicular germ cells. ...

Induction and Validation of Cellular Senescence in Primary Human Cells

Cellular senescence is a state of permanent cell cycle arrest activated in response to different damaging stimuli. Activation of cellular senescence is a hallmark of various pathophysiological conditions including tumor suppression, tissue remodeling and aging. The inducers of cellular senescence in vivo are still poorly characterized. However, a number of stimuli can be used to promote cellular senescence ex vivo. Among them, most common senescence-inducers are replicative exhaustion, ionizing and non-ionizing radiation, genotoxic drugs, oxidative stress, and demethylating and acetylating agents. Here, we will provide detailed instructions on how to use these stimuli to induce fibroblasts into senescence. This protocol can easily be adapted for different types of primary cells and cell lines, including cancer cells. We also describe different methods for the validation of senescence induction. In particular, we focus on measuring the activity of the lysosomal enzyme Senescence-Associated &#946;-galactosidase (SA-&#946;-gal), the rate of DNA synthesis using 5-ethynyl-2&#39;-deoxyuridine (EdU) incorporation assay, the levels of expression of the cell cycle inhibitors p16 and p21, and the expression and secretion of members of the Senescence-Associated Secretory Phenotype (SASP). Finally, we provide example results and discuss further applications of these protocols.

Here, we discuss a series of protocols for induction and validation of cellular senescence in cultured cells. We focus on different senescence-inducing stimuli and describe the quantification of common senescence-associated markers. We provide technical details using fibroblasts as a model, but the protocols can be adapted to various cellular models.

Inducción y validación de senescencia celular en las células humanas primarias

Cellular senescence is a state of permanent cell cycle arrest activated in response to different damaging stimuli. Activation of cellular senescence is a ...

Fluorimetric Techniques for the Assessment of Sperm Membranes

Standard spermiograms describing sperm quality are mostly based on the physiological and visual parameters, such as ejaculate volume and concentration, motility and progressive motility, and sperm morphology and viability. However, none of these assessments is good enough to predict the semen quality. Given that maintenance of sperm viability and fertilization potential depends on membrane integrity and intracellular functionality, evaluation of these parameters might enable a better prediction of sperm fertilization competence. Here, we describe three feasible methods to evaluate sperm quality using specific fluorescent probes combined with fluorescence microscopy or flow cytometry analyses. Analyses assessed plasma membrane integrity using 4&#39;,6-diamidino-2-phenylindole (DAPI) and propidium iodide (PI), acrosomal membrane integrity using fluorescein isothiocyanate-conjugated Pisum sativum agglutinin (FITC-PSA) and mitochondrial membrane integrity using 5,5&#39;,6,6&#39;-tetra-chloro-1,1&#39;,3,3&#39;-tetraethylbenzimidazolyl carbocyanine iodide (JC-1). Combinations of these methods are also presented. For instance, use of annexin V combined with PI fluorochromes enables assessing apoptosis and calculating the proportion of apoptotic sperm (apoptotic index). We believe that these methodologies, which are based on examining spermatozoon membranes, are very useful for the evaluation of sperm quality.

Here, we present methodologies to evaluate spermatozoan membrane integrity, a cellular feature associated with sperm fertilization competence. We describe three techniques for the fluorimetric assessment of sperm membranes: simultaneous staining with specific fluorescent probes, fluorescence microscopy, and advanced sperm-dedicated flow cytometry. Examples of combining the methodologies are also presented.

Fluorimétrica de técnicas para la evaluación de las membranas del esperma

Standard spermiograms describing sperm quality are mostly based on the physiological and visual parameters, such as ejaculate volume and concentration, ...

Measuring Sperm Guidance and Motility within the Caenorhabditis elegans Hermaphrodite Reproductive Tract

Successful fertilization is fundamental to sexual reproduction, yet little is known about the mechanisms that guide sperm to oocytes within the female reproductive tract. While in vitro studies suggest that sperm of internally fertilizing animals can respond to various cues from their surroundings, the inability to visualize their behavior inside the female reproductive tract creates a challenge for understanding sperm migration and mobility in its native environment. Here, we describe a method using C. elegans that overcomes this limitation and takes advantage of their transparent epidermis. C. elegans males stained with a mitochondrial&#160; dye are mated with adult hermaphrodites, which act as modified females, and deposit fluorescently labeled sperm into the hermaphrodite uterus. The migration and motility of the labeled sperm can then be directly tracked using an epi-fluorescence microscope in a live hermaphrodite. In wild-type animals, approximately 90% of the labeled sperm crawl through the uterus and reach the fertilization site, or spermatheca. Images of the uterus can be taken 1 h after mating to assess the distribution of the sperm within the uterus and the percentage of sperm that have reached the spermatheca. Alternatively, time-lapse images can be taken immediately after mating to assess sperm speed, directional velocity and reversal frequency. This method can be combined with other genetic and molecular tools available for the C.elegans to identify novel genetic and molecular mechanisms that are important in regulating sperm guidance and motility within the female reproductive tract.

Measuring Sperm Guidance and Motility within the Caenorhabditis elegans Hermaphrodite Reproductive Tract

Sperm must successfully navigate through the oviduct to fertilize an oocyte. Here, we describe an assay for measuring sperm migration within the C. elegans hermaphrodite uterus. This assay can provide quantitative data on sperm distribution within the uterus after mating, as well as on speed, directional velocity, and reversal frequency.

Medición de la orientación y la motilidad del esperma dentro del tracto reproductivo de la Caenorhabditis elegans hermafrodita

Successful fertilization is fundamental to sexual reproduction, yet little is known about the mechanisms that guide sperm to oocytes within the female ...

Defining the Program of Maternal mRNA Translation during In vitro Maturation using a Single Oocyte Reporter Assay

Events associated with oocyte nuclear maturation have been well described. However, much less is known about the molecular pathways and processes that take place in the cytoplasm in preparation for fertilization and acquisition of totipotency. During oocyte maturation, changes in gene expression depend exclusively on the translation and degradation of maternal messenger RNAs (mRNAs) rather than on transcription. Execution of the translational program, therefore, plays a key role in establishing oocyte developmental competence to sustain embryo development. This paper is part of a focus on defining the program of maternal mRNA translation that takes place during meiotic maturation and at the oocyte-to-zygote transition. In this method paper, a strategy is presented to study the regulation of translation of target mRNAs during in vitro oocyte maturation. Here, a Ypet reporter is fused to the 3&#39; untranslated region (UTR) of the gene of interest and then micro-injected into oocytes together with polyadenylated mRNA encoding for mCherry to control for injected volume. By using time-lapse microscopy to measure reporter accumulation, translation rates are calculated at different transitions during oocyte meiotic maturation. Here, the protocols for oocyte isolation and injection, time-lapse recording, and data analysis have been described, using the Ypet/interleukin-7 (IL-7)-3&#39; UTR reporter as an example.

This protocol describes a reporter assay to study the regulation of mRNA translation in single oocytes during in vitro maturation.

Definición del programa de traducción del ARNm materno durante la maduración in vitro utilizando un solo ensayo de reportero de ovocitos

Events associated with oocyte nuclear maturation have been well described. However, much less is known about the molecular pathways and processes that ...

Combinación de imágenes con un sistema de administración de estimulantes para estudiar esperma de ratón vivo

Real-Time Imaging of Acrosomal Calcium Dynamics and Exocytosis in Live Mouse Sperm

Acrosome exocytosis (AE), in which the sperm&#39;s single exocytotic vesicle fuses with the plasma membrane, is a complex, calcium-dependent process essential for fertilization. However, our understanding of how calcium signaling regulates AE is still incomplete. In particular, the interplay between intra-acrosomal calcium dynamics and the intermediate steps leading to AE is not well-defined. Here, we describe a method that provides spatial and temporal insights into acrosomal calcium dynamics and their relationship to membrane fusion and subsequent exocytosis of the acrosome vesicle. The method utilizes a novel transgenic mouse expressing an Acrosome-targeted Sensor for Exocytosis (AcroSensE). The sensor combines a genetically encoded calcium indicator (GCaMP) fused with mCherry. This fusion protein was specifically designed to enable the concurrent observation of acrosomal calcium dynamics and membrane fusion events. Real-time monitoring of acrosomal calcium dynamics and AE in live AcroSensE sperm is achieved using a combination of high frame-rate imaging and a stimulant delivery system that can target single sperm. This protocol also provides several examples of basic methods to quantify and analyze the raw data. Because the AcroSensE model is genetically encoded, its scientific significance can be augmented by using readily available genetic tools, such as crossbreeding with other mouse genetic models or gene-editing (CRISPR) based methods. With this strategy, the roles of additional signaling pathways in sperm capacitation and fertilization can be resolved. In summary, the method described here provides a convenient and effective tool to study calcium dynamics in a specific subcellular compartment-the sperm acrosome-and how those dynamics regulate the intermediate steps leading to membrane fusion and acrosome exocytosis.

Autor destacado: Una técnica de imagen de células vivas para estudiar la señalización del calcio y la exocitosis acrosómica en esperma de ratón 

The AcroSensE mouse model and live cell imaging methods described here provide a new approach to studying calcium dynamics in the subcellular compartment of the sperm acrosome and how they regulate intermediate steps leading to membrane fusion and acrosome exocytosis.

Imágenes en tiempo real de la dinámica del calcio acrosómico y la exocitosis en espermatozoides de ratón vivos

Acrosome exocytosis (AE), in which the sperm&#39;s single exocytotic vesicle fuses with the plasma membrane, is a complex, calcium-dependent process ...