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07:45
Imaging Calcium in Drosophila at Egg Activation
Published on: August 6, 2016
Las oscilaciones del calcio en los huevos de mamíferos son provocadas por una proteína del esperma soluble
J Parrington1, K Swann, V I Shevchenko
1MRC National Institute for Medical Research, The Ridgeway, London, UK.
Nature
|January 25, 1996
Resumen
Los investigadores identificaron una proteína del esperma, la oscilina, que desencadena las oscilaciones del calcio esenciales para la activación de los óvulos de los mamíferos y el desarrollo embrionario. Este descubrimiento revela un factor clave en el inicio de la fertilización y el desarrollo.
Área de la Ciencia:
- Biología Reproductiva Biología Reproductiva.
- Biología del desarrollo Biología del desarrollo.
- La señalización celular.
Sus antecedentes:
- Las oscilaciones de calcio (Ca2+) inducidas por el esperma en los óvulos son cruciales para la fertilización de mamíferos y el desarrollo embrionario.
- El mecanismo preciso por el cual el esperma inicia estas oscilaciones de Ca2+ sigue siendo desconocido.
- No se ha establecido un vínculo directo entre la interacción espermatozoide-óvulo y la liberación intracelular de Ca2+.
Objetivo del estudio:
- Para identificar el factor derivado del esperma responsable de iniciar las oscilaciones de Ca2+ en los huevos de mamíferos.
- Para dilucidar el mecanismo molecular subyacente a la activación del óvulo desencadenado por el esperma.
Principales métodos:
- Microinyección de extractos de esperma en huevos de mamíferos para observar las oscilaciones de Ca2+.
- Caracterización bioquímica de las proteínas de los espermatozoides con actividad Ca2+ que induce la oscilación.
- Clonado y análisis de secuencia de la proteína del esperma identificada.
Principales resultados:
- Se identificó una proteína del esperma soluble, denominada oscilina, con una potente actividad de Ca2+ que induce la oscilación ('oscillógeno') en los huevos.
- La oscilina existe como un oligómero con una subunidad 33K y está localizada en el segmento ecuatorial del esperma.
- El ADN complementario para la subunidad 33K de oscilina muestra similitud con la isomerasa de fosfato de hexose procariótica.
Conclusiones:
- La oscilina se identifica como un factor clave derivado del esperma que desencadena las oscilaciones de Ca2+ necesarias para la activación del óvulo de los mamíferos.
- Esta proteína probablemente representa el disparador fisiológico para el desarrollo embrionario en los mamíferos.
- Los hallazgos proporcionan una base molecular para comprender el inicio de la fertilización y el desarrollo temprano.
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