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Tanto los reguladores positivos como los negativos de la transcripción HO son necesarios para el cambio de tipo de
Cell
|February 27, 1987
Resumen
Los nuevos genes SDI1 y SDI2 permiten a las células hijas expresar el gen HO, que inicia el cambio de tipo de apareamiento en la levadura. Esto sugiere una transcripción HO.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Genética de la levadura Genética de la levadura
- El Reglamento del Ciclo Celular.
Sus antecedentes:
- El gen HO es crucial para iniciar el cambio de tipo de apareamiento en la levadura.
- La transcripción del gen HO ocurre solo en las células madre durante START, no en las células hijas.
- Se sabe que seis genes (SWI1-6) son esenciales para la transcripción de HO.
Objetivo del estudio:
- Para identificar y caracterizar nuevos genes involucrados en la regulación de la transcripción HO.
- Para investigar el papel de SWI5 en la expresión específica de la célula madre de HO.
- Comprender el mecanismo subyacente a la transcripción dependiente del ciclo celular de HO.
Principales métodos:
- Aislamiento y caracterización de mutaciones en nuevos genes SDI1 y SDI2.
- Análisis del cambio de tipo de apareamiento en varias cepas de levadura mutantes (swi5- sdi1- y SWI5+ sdi1-).
- Investigando el efecto de SDI1 y SDI2 en la expresión génica HO en células hijas.
Principales resultados:
- Las mutaciones en SDI1 y SDI2 suprimen parcialmente el requisito de SWI5.5.
- Las mutaciones SDI1 y SDI2 permiten la expresión del gen HO en las células hijas.
- El análisis indica que SWI5 actúa selectivamente en las células madre para conferir especificidad de transcripción HO.
Conclusiones:
- La especificidad de la transcripción HO en las células madre está determinada únicamente por la acción selectiva de SWI5 en las células madre.
- SDI1 codifica un represor que se une al promotor HO, impidiendo la transcripción en las células hijas.
- SDI1 asegura que la transcripción HO sea totalmente dependiente de SWI5, restringiéndola así a las células madre.
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