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Una señal de calcio en anafase controla la disyunción cromosómica en los primeros embriones de erizo de mar
1Department of Physiological Sciences, University of Newcastle Upon Tyne Medical School, United Kingdom.
Cell
|February 11, 1998
Resumen
Un aumento transitorio en la concentración de calcio intracelular desencadena la separación cromosómica durante la anafase del embrión de erizo de mar. Esta señal de calcio es esencial para la disyunción cromatídica, revelando un papel clave en la progresión del ciclo celular.
Área de la Ciencia:
- Biología celular Biología celular.
- Biología del desarrollo Biología del desarrollo.
- Biología Molecular Biología Molecular
Sus antecedentes:
- La progresión del ciclo celular implica eventos críticos como la segregación cromosómica.
- Los iones de calcio (Ca2+) son moléculas de señalización conocidas en varios procesos celulares.
- El papel preciso del calcio en el inicio de los eventos de anafase sigue siendo incompletamente entendido.
Objetivo del estudio:
- Para investigar el papel de los transitorios de calcio intracelulares en el desencadenamiento de la aparición de la anafase en embriones de erizo de mar.
- Para determinar si la señalización de calcio es un requisito previo para la disyunción cromatídica y el alargamiento del huso.
Principales métodos:
- Microinyección de quelantes de calcio y heparina (antagonista del receptor InsP3).
- Fotorrelases del calcio y el trisfosfato de inositol (InsP3).
- Observación de la separación cromosómica, el alargamiento del eje y la reformación nuclear.
Principales resultados:
- Un aumento transitorio en la concentración de calcio intracelular ([Ca2+]i) precede a la disyunción cromatídica y el alargamiento del husillo.
- La inhibición de la señalización del calcio bloqueó la separación cromosómica.
- La restauración de los niveles de calcio o InsP3 revirtió el bloqueo.
- Los antagonistas del calcio retrasaron pero no bloquearon la reformación nuclear.
Conclusiones:
- La señal de calcio es un disparador crítico para la disyunción cromosómica durante la anafase.
- Las vías independientes del calcio contribuyen a la dinámica de los microtúbulos y a los eventos nucleares en la anafase.
- Este hallazgo explica los resultados contradictorios anteriores y sugiere un papel conservado para el calcio en la anafase a través de diferentes tipos de células.
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