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Evolución de un locus expandido de determinación del sexo en Volvox
Patrick Ferris1, Bradley J S C Olson, Peter L De Hoff
1The Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
Science (New York, N.Y.)
|April 17, 2010
Resumen
Los orígenes de los sexos dimórficos siguen sin estar claros. En Volvox carteri, el locus de apareamiento (MT) muestra una divergencia significativa y una regulación génica específica del sexo, lo que sugiere su papel en la evolución de la reproducción sexual.
Área de la Ciencia:
- Biología evolutiva Biología evolutiva.
- Genética La genética.
- Biología del desarrollo Biología del desarrollo.
Sus antecedentes:
- Los sexos dimórficos son comunes en los eucariotas multicelulares, pero sus orígenes evolutivos no se comprenden bien.
- El locus de apareamiento (MT) controla la reproducción sexual y la producción de gametos.
- Volvox carteri, una alga multicelular, exhibe sexos dimórficos, a diferencia de su pariente unicelular Chlamydomonas reinhardtii.
Objetivo del estudio:
- Para investigar los orígenes evolutivos de los sexos dimórficos.
- Analizar las diferencias genéticas y regulatorias en el locus de apareamiento (MT) entre Volvox carteri y Chlamydomonas reinhardtii.
- Comprender cómo los loci determinantes del sexo influyen en la evolución de genes relacionados con el sexo y no relacionados con el sexo.
Principales métodos:
- Análisis comparativo del transcriptoma de Volvox carteri y Chlamydomonas reinhardtii.
- Identificación de transcripciones específicas de género y transcripciones reguladas por sexo.
- Análisis de la regulación génica, incluido el empalme alternativo y las presiones de selección.
Principales resultados:
- El Volvox carteri MT se ha expandido y divergido significativamente en comparación con el Chlamydomonas reinhardtii.
- Se observó un programa de expresión génica gamética recableado en los genes Volvox MT.
- Se identificaron múltiples transcripciones específicas de género y reguladas por el sexo.
- El gen MAT3, un homólogo supresor de tumores de retinoblastoma, muestra un empalme alternativo regulado sexualmente y una selección específica de género.
Conclusiones:
- Los loci determinantes del sexo juegan un papel crucial en la evolución de los genes relacionados con el sexo y no relacionados con el sexo.
- Los cambios genéticos y regulatorios observados en la MT de Volvox carteri proporcionan información sobre la evolución del dimorfismo sexual.
- La cooptación de genes como el MAT3 en el ciclo sexual es un mecanismo que impulsa la evolución de la determinación del sexo.
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