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Quantitation and Analysis of the Formation of HO-Endonuclease Stimulated Chromosomal Translocations by Single-Strand Annealing in Saccharomyces cerevisiae
Published on: September 23, 2011
Los sitios de ruptura de doble hebra inducidos por la meiosis se determinan por la estructura de la cromatina de la
1Laboratory of Biochemistry, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
Science (New York, N.Y.)
|January 28, 1994
Resumen
Las rupturas de ADN de doble hebra inician la recombinación meiotica en sitios específicos del ADN en la levadura. La estructura de la cromatina, particularmente las regiones promotoras de la transcripción, influye en dónde ocurren estas rupturas cruciales del ADN antes de la meiosis.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Genética La genética.
- Investigación de la levadura Investigación de la levadura
Sus antecedentes:
- Las rupturas de ADN de doble hebra (DSB) son eventos clave en la meiosis, iniciando la recombinación genética.
- Se sabe que los DSB ocurren en "puntos calientes de recombinación" específicos en el genoma.
- La regulación precisa de los sitios de iniciación de DSB no se entiende completamente.
Objetivo del estudio:
- Para investigar la relación entre los sitios de ruptura del ADN y las características genómicas en la meiosis de la levadura.
- Determinar si la estructura de la cromatina influye en el inicio de la recombinación meiotica.
- Comprender el papel de los promotores de la transcripción en la formación de DSB.
Principales métodos:
- Análisis de sitios DSB en tres regiones distintas del genoma de Saccharomyces cerevisiae.
- Evaluación de la hipersensibilidad a la desoxirribonucleasa I en los sitios de DSB tanto en la cromatina mitótica como en la meiotica.
- Cambios correlativos en la estructura de la cromatina con la aparición de DSBs.
Principales resultados:
- Se encontró que los DSB se producen en o cerca de muchos promotores potenciales de transcripción.
- La evidencia sugiere que los DSB inician la mayoría de los eventos de recombinación meiotica.
- Los sitios de DSB exhibieron hipersensibilidad a la desoxirribonucleasa I, lo que indica estructuras abiertas de cromatina.
- Las alteraciones en la estructura de la cromatina impactaron directamente en la ocurrencia de DSB.
Conclusiones:
- Las características de la cromatina pre-meiótica juegan un papel importante en la determinación de los sitios de iniciación de la DSB.
- Los promotores de la transcripción están asociados con la formación de DSB, lo que sugiere un vínculo regulatorio.
- Los DSB son iniciadores críticos de la recombinación meiótica, guiados por la organización de la cromatina.
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