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La evidencia genómica para la evolución ameiotic en el bdelloid rotifer Adineta vaga
Jean-François Flot1, Boris Hespeels, Xiang Li
1University of Namur, Department of Biology, URBE, Laboratory of Evolutionary Genetics and Ecology, 5000 Namur, Belgium. jean-francois.flot@ds.mpg.de
Nature
|July 23, 2013
Resumen
Los rotiferos bdelloides, animales microscópicos, desafían la teoría de la evolución al persistir asexuadamente durante millones de años. Su estructura genómica única, incompatible con la meiosis convencional, revela nuevas estrategias evolutivas.
Área de la Ciencia:
- Biología evolutiva Biología evolutiva.
- La genómica es la genómica.
- Animalialia Animalia es un género de animales.
Sus antecedentes:
- La pérdida de la reproducción sexual es típicamente un callejón sin salida evolutivo para los animales.
- Los rotiferos bdelloides son invertebrados microscópicos que aparentemente se han reproducido asexuadamente durante millones de años.
- La ausencia de meiosis y de órganos reproductores masculinos en los bdelloides desafía los principios evolutivos establecidos.
Objetivo del estudio:
- Para investigar la estructura del genoma de la bdelloid rotifer Adineta vaga.
- Comprender los mecanismos genéticos que permiten la reproducción asexual a largo plazo en bdelloides.
- Para explorar las implicaciones evolutivas de la reproducción asexual bdelloide.
Principales métodos:
- Secuenciación del genoma de Adineta vaga.
- Análisis genómico comparativo.
- Identificación de familias de genes y reordenamientos genómicos.
Principales resultados:
- El genoma de Adineta vaga es tetraploide con regiones alélicas reorganizadas, incompatible con el emparejamiento meiotico.
- La evidencia de la conversión genética abundante sugiere un mecanismo para limitar las mutaciones dañinas sin meiosis.
- Se identificaron familias de genes expandidos relacionados con la resistencia a la oxidación, el metabolismo de los carbohidratos y la defensa de los transposones.
- Aproximadamente el 8% de los genes son de origen no metazoario, probablemente adquiridos a través de la transferencia horizontal de genes.
Conclusiones:
- La estructura única del genoma de Adineta vaga proporciona un mecanismo para la reproducción asexual a largo plazo, desafiando la necesidad del sexo para la supervivencia de los metazoos.
- La conversión génica y la transferencia génica horizontal parecen ser estrategias evolutivas clave para los rotiferos bdelloides.
- Este estudio ofrece nuevos conocimientos sobre el significado evolutivo del sexo y la adaptabilidad de las formas de vida.
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