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Los ARN que interactúan con Piwi protegen el ADN contra la pérdida durante el reordenamiento del genoma de Oxytricha
Wenwen Fang1, Xing Wang, John R Bracht
1Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
Cell
|December 11, 2012
Resumen
Los ARN que interactúan con Piwi (piRNA) del núcleo materno guían la programación del genoma en Oxytricha. Estos pequeños ARN aseguran la retención del ADN esencial, actuando como portadores epigenéticos transgeneracionales.
Área de la Ciencia:
- Epigenética y biología molecular.
- La genómica y los estudios de herencia estudian la herencia.
- Investigación de los protozoos ciliados.
Sus antecedentes:
- Los protozoos ciliados como Oxytricha exhiben dualidad genómica, con distintos genomas somáticos y de línea germinal.
- El desarrollo del genoma somático implica la eliminación programada de ~95% del ADN de la línea germinal, incluidos los transposones.
- Comprender los mecanismos de esta eliminación selectiva del ADN es crucial para comprender la herencia y la regulación del genoma.
Objetivo del estudio:
- Investigar el papel de los ARN pequeños en la especificación de regiones genómicas para la retención durante el desarrollo del genoma somático en Oxytricha.
- Determinar si los ARN maternos que interactúan con Piwi (piARN) pueden dirigir la programación epigenética del genoma para la próxima generación.
- Explorar el potencial de los ARN pequeños como portadores transgeneracionales de información epigenética.
Principales métodos:
- Análisis de las poblaciones de Oxytricha piRNA y su mapeo a la línea germinal y los genomas somáticos.
- Inyección de piARN sintéticos correspondientes a regiones genómicas normalmente eliminadas en núcleos en desarrollo.
- Evaluación de la retención de regiones genómicas inyectadas en generaciones posteriores.
Principales resultados:
- Los piARN de Oxytricha se relacionan predominantemente con el ~5% retenido del ADN de la línea germinal que constituye el genoma somático.
- Los piARN maternos especifican regiones genómicas para su retención durante el proceso de eliminación del ADN.
- Los piARN sintéticos dirigidos a regiones normalmente eliminadas indujeron con éxito su retención en generaciones posteriores.
Conclusiones:
- Los ARN que interactúan con Piwi (piRNA) son mediadores clave de la transferencia de información epigenética a través de generaciones en Oxytricha.
- Los ARN pequeños actúan como determinantes críticos para la programación del genoma, guiando la retención selectiva del ADN.
- Este estudio revela un nuevo mecanismo para la herencia epigenética transgeneracional mediada por ARN pequeños.
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