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Una sola mutación de aminoácidos contribuye al patrón de color adaptativo del ratón de playa
Hopi E Hoekstra1, Rachel J Hirschmann, Richard A Bundey
1Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA. hoekstra@ucsd.edu
Science (New York, N.Y.)
|July 11, 2006
Resumen
Una sola mutación genética en el receptor de la melanocortina-1 (Mc1r) explica la significativa variación de color en las poblaciones de ratones salvajes de playa. Este hallazgo vincula los cambios moleculares con la evolución adaptativa en entornos naturales.
Área de la Ciencia:
- Biología evolutiva Biología evolutiva.
- Genética La genética.
- Coloración de los animales.
Sus antecedentes:
- Los ratones de playa muestran patrones de color distintos en comparación con sus parientes del continente, impulsados por la selección natural para el camuflaje (cripsis).
- El receptor de melanocortina-1 (Mc1r) es un gen clave involucrado en la pigmentación.
- La evolución convergente de una coloración de luz similar en poblaciones de ratones de playa en diferentes costas plantea preguntas sobre los mecanismos genéticos subyacentes.
Objetivo del estudio:
- Identificar la base genética para la variación adaptativa del color en ratones de playa.
- Para investigar el papel del gen del receptor de melanocortina-1 (Mc1r) en la pigmentación del ratón de playa.
- Explorar los mecanismos moleculares detrás de la evolución convergente de la coloración en poblaciones aisladas.
Principales métodos:
- Se realizaron cruces genéticas para analizar la herencia de los rasgos de pigmentación.
- Se cuantificó la variación alélica en el gen Mc1r y se correlacionó con la variación fenotípica.
- Se evaluó la distribución geográfica de los alelos Mc1r en diferentes poblaciones de ratones de playa.
Principales resultados:
- Se identificó una mutación derivada de aminoácidos con cambio de carga en Mc1r en ratones de playa, reduciendo la función del receptor.
- La variación alélica Mc1r representó del 9,8% al 36,4% de la variación en siete rasgos de pigmentación.
- El alelo Mc1r derivado se encontró en ratones de playa de la Costa del Golfo, pero ausente en ratones de la costa atlántica con una coloración de luz similar.
Conclusiones:
- Una sola mutación codificante en Mc1r está vinculada a la variación cuantitativa adaptativa en las poblaciones de ratones salvajes de playa.
- Diferentes mecanismos moleculares pueden ser la base de la evolución convergente de la coloración de la luz en poblaciones geográficamente separadas de ratones de playa.
- Este estudio proporciona un vínculo directo entre una mutación genética específica y la evolución fenotípica adaptativa en un entorno natural.
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