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Tres genomas de cocodrilos revelan patrones ancestrales de evolución entre los archosaurios
Richard E Green1, Edward L Braun2, Joel Armstrong3
1Department of Biomolecular Engineering, University of California, Santa Cruz, CA 95064, USA. ed@soe.ucsc.edu david.a.ray@ttu.edu.
Science (New York, N.Y.)
|December 16, 2014
Resumen
Los genomas de cocodrilos revelan una evolución excepcionalmente lenta, lo que sugiere que este rasgo es anterior a las aves y los dinosaurios. Esta investigación reconstruye el antepasado del archosaurio.
Área de la Ciencia:
- Biología evolutiva Biología evolutiva.
- La genómica es la genómica.
- La genómica comparada es una genómica comparada.
Sus antecedentes:
- Los arcosaurios, incluidos los cocodrilos, los dinosaurios y las aves, experimentaron una diversificación significativa.
- Comprender los cambios genómicos que impulsan esta diversificación requiere datos genómicos comparativos de linajes clave.
Objetivo del estudio:
- Proporcionar un contexto genómico para la diversificación de los archosaurios.
- Para investigar las tasas evolutivas y las historias de población de los cocodrilos.
- Para reconstruir el genoma del ancestro común del archosaurio.
Principales métodos:
- Se generaron borradores de genomas para tres especies de cocodrilos: el cocodrilo americano, el cocodrilo de agua salada y el gharial indio.
- Se analizó la evolución del genoma a través de múltiples niveles: sustituciones de nucleótidos, indels, elementos transponibles, familias de genes y síntesis.
- Datos genómicos integrados de cocodrilos con genomas de aves y tortugas publicados.
Principales resultados:
- Se observó una evolución excepcionalmente lenta del genoma en cocodrilos en todos los niveles analizados.
- Se dedujo que la evolución lenta del genoma probablemente estaba presente en el antepasado común del archosaurio, siendo la evolución rápida un rasgo derivado en las aves.
- Se analizó la heterocigosidad de los cocodrilos, lo que sugiere una reducción del tamaño de la población durante el Pleistoceno.
- Se reconstruyó un genoma parcial del ancestro común del archosaurio.
Conclusiones:
- Los cocodrilos exhiben un genoma notablemente conservado, lo que indica una tasa lenta de evolución molecular.
- El archosaurio ancestral probablemente poseía un genoma de evolución lenta, en contraste con la rápida evolución observada en las aves.
- El genoma reconstruido del antepasado del archosaurio sirve como un valioso recurso para futuros estudios evolutivos.
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