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Quantitative Comparison of cis-Regulatory Element (CRE) Activities in Transgenic Drosophila melanogaster
Published on: December 19, 2011
Evolución adaptativa del ADN no codificante en Drosophila
1Section of Ecology, Behavior and Evolution, Division of Biological Sciences, University of California San Diego, La Jolla, California 92093, USA. pandolfatto@ucsd.edu
Nature
|October 21, 2005
Resumen
Una porción significativa del ADN no codificante en Drosophila es funcionalmente importante, evolucionando tanto bajo restricción como bajo selección positiva. Esto sugiere que los cambios adaptativos en el ADN no codificante son comunes en la evolución.
Área de la Ciencia:
- Biología evolutiva Biología evolutiva.
- La genómica es la genómica.
- Evolución molecular de la evolución molecular.
Sus antecedentes:
- Los genomas eucariotas contienen una gran proporción de ADN no codificante con funciones en gran medida desconocidas.
- Comprender la dinámica evolutiva del ADN no codificante es crucial para obtener una imagen completa de la evolución del genoma.
Objetivo del estudio:
- Investigar las tasas evolutivas y las presiones selectivas que actúan sobre varias clases de ADN no codificante en Drosophila.
- Determinar el alcance de la importancia funcional y la evolución adaptativa en regiones genómicas no codificantes.
Principales métodos:
- Análisis comparativo de secuencias de ADN de diferentes especies de Drosophila.
- Aplicación de una prueba extendida de McDonald-Kreitman para diferenciar entre la purificación y la selección positiva.
- Estimación de la restricción evolutiva mediante la comparación de la evolución del ADN no codificante con sitios sinónimos.
Principales resultados:
- Las regiones de ADN no codificantes (intergénicas, UTR, intrones) evolucionan más lentamente que los sitios sinónimos, lo que indica una restricción selectiva.
- Un exceso significativo de divergencia sobre el polimorfismo sugiere una evolución adaptativa en estas regiones.
- Las estimaciones indican que el 40-70% de los nucleótidos no codificantes están bajo restricción, con el 20-60% de la divergencia impulsada por la selección positiva.
Conclusiones:
- Una gran fracción de ADN no codificante es funcionalmente significativa y está formada tanto por la purificación como por la evolución adaptativa.
- La evolución adaptativa en el ADN no codificante puede ser más frecuente de lo que se pensaba anteriormente en la evolución de Drosophila melanogaster.
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