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Hay evidencia de una alta frecuencia de sustituciones simultáneas de doble nucleótido
1Institute of Molecular Biology and Biotechnology (IMBB)-FORTH, Vassilika Vouton, 711 10 Iraklio, Crete, Greece.
Science (New York, N.Y.)
|February 26, 2000
Resumen
Las sustituciones simultáneas de doble nucleótido, donde múltiples bases de ADN adyacentes cambian a la vez, ocurren con más frecuencia de lo que se suponía anteriormente. Este estudio estima su tasa en aproximadamente 0,1 por sitio por mil millones de años.
Área de la Ciencia:
- Genética La genética.
- Biología Molecular Biología Molecular
- Biología evolutiva Biología evolutiva.
Sus antecedentes:
- Las mutaciones puntuales típicamente implican cambios de un solo nucleótido.
- Los mecanismos de mutación no excluyen intrínsecamente cambios simultáneos en nucleótidos adyacentes.
Objetivo del estudio:
- Para estimar la frecuencia de las sustituciones simultáneas de doble nucleótido.
- Para investigar la ocurrencia de múltiples cambios de nucleótidos adyacentes en un solo evento mutacional.
Principales métodos:
- Análisis de los conmutadores de codón (TCN a AGY) para los residuos de serina conservados en las proteínas.
- Identificación de las sustituciones de doble nucleótido en secuencias de ADN no codificantes de primates.
Principales resultados:
- Dos métodos independientes arrojaron altas estimaciones similares para las tasas de sustitución de dobles.
- La tasa estimada de sustituciones de nucleótidos dobles es de aproximadamente 0,1 por sitio por mil millones de años.
Conclusiones:
- Las sustituciones simultáneas de doble nucleótido son un factor significativo en la mutación genética.
- Los hallazgos desafían el enfoque exclusivo en los cambios de un solo nucleótido en los estudios de mutación.
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