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Hay evidencia de una endosimbiosis procariótica temprana
1Department of Molecular, Cellular and Developmental Biology, University of California, Los Angeles, California 90095, USA. lake@mbi.ucla.edu
Nature
|August 21, 2009
Resumen
El estudio sugiere que las bacterias gramnegativas se originaron a partir de una simbiosis entre las antiguas actinobacterias y los clostridia. Este evento procariótico tuvo un profundo impacto en la vida, permitiendo la emergencia de los eucariotas y la atmósfera de oxígeno de la Tierra.
Área de la Ciencia:
- Biología evolutiva Biología evolutiva.
- La genómica microbiana es la genómica microbiana.
- Evolución de los procariotas en la evolución procariota.
Sus antecedentes:
- Se sabe que los eventos endosimbióticos han moldeado significativamente la vida eucariota.
- El impacto de la endosimbiosis en la evolución de los procariotas generalmente se considera mínimo.
- Las bacterias gramnegativas poseen una estructura distintiva de doble membrana.
Objetivo del estudio:
- Para investigar los orígenes evolutivos de los procariotas gram-negativos.
- Explorar el papel potencial de la endosimbiosis en la evolución de las procariotas.
- Para analizar los flujos de la familia de proteínas como evidencia de eventos simbióticos.
Principales métodos:
- Análisis de flujos genéticos de la familia de proteínas entre antiguos linajes bacterianos.
- Genómica comparativa para inferir relaciones ancestrales y transferencia de genes.
- Análisis filogenético para reconstruir la historia evolutiva.
Principales resultados:
- La evidencia sugiere que las bacterias gramnegativas surgieron de un evento simbiótico entre un antiguo actinobacterium y un antiguo clostridium.
- Este evento endosimbiótico dio como resultado el exitoso taxón procariótico de doble membrana.
- Los flujos de la familia de proteínas indican un intercambio genético significativo que contribuye a este nuevo linaje.
Conclusiones:
- El origen de las bacterias gramnegativas a través de la endosimbiosis es un evento fundamental en la historia de la vida.
- Esta simbiosis procariótica fue crucial para la posterior evolución de los eucariotas.
- La aparición de la fotosíntesis oxigenada, facilitada por estas bacterias, transformó la atmósfera de la Tierra.
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