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Evolución adaptativa de los genes de visión del color en los primates superiores
S K Shyue1, D Hewett-Emmett, H G Sperling
1Human Genetics Center, School of Public Health, University of Texas, Houston 77225, USA.
Science (New York, N.Y.)
|September 1, 1995
Resumen
Los monos ardilla y las marmosetas muestran genes de pigmento fotográfico de color muy divergentes, lo que sugiere una evolución independiente o una conversión genética extensa. Es probable que estos alelos distintos persistieran durante millones de años debido a la selección sobredominante.
Área de la Ciencia:
- Genética evolutiva de la genética evolutiva.
- Evolución molecular de los primates en su evolución molecular.
- La evolución del gen del pigmento visual en la evolución de los genes.
Sus antecedentes:
- El locus de pigmento fotográfico de color vinculado a X es crucial para la visión.
- Los polimorfismos en este locus pueden dar lugar a variaciones en la percepción del color.
- La comprensión de la dinámica evolutiva de estos genes proporciona información sobre la adaptación de los primates.
Objetivo del estudio:
- Para analizar las secuencias de intrón 4 de alelos polimórficos en el locus de pigmento fotográfico de color en monos ardilla y marmosetas.
- Investigar la historia evolutiva y los patrones de divergencia de estos alelos dentro de cada especie.
- Inferir los mecanismos que impulsan la diversidad y persistencia de los alelos.
Principales métodos:
- Secuenciación de las regiones intrónicas 4 del gen del pigmento fotográfico de color ligado a X.
- Análisis comparativo de secuencias a través de múltiples alelos dentro de cada especie de primate.
- Análisis filogenético y enfoques de genética de poblaciones moleculares.
Principales resultados:
- Se identificaron alelos polimórficos excepcionalmente divergentes tanto en monos ardilla como en marmosetas.
- Los sistemas trialélicos parecen haber evolucionado independientemente en cada linaje o han implicado una extensa conversión génica.
- La evidencia sugiere que al menos siete deleciones/inserciones (14 en total) fueron homogeneizadas entre alelos dentro de cada especie.
Conclusiones:
- La divergencia alelo observada sugiere una larga persistencia evolutiva, probablemente más de 5 millones de años.
- Se propone la selección sobredominante como el mecanismo primario que mantiene estos alelos altamente divergentes.
- Los hallazgos destacan vías evolutivas únicas para los genes de pigmento visual en los monos del Nuevo Mundo.
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