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La mutación del melanismo industrial en las polillas pimientas británicas es un elemento transponible
Arjen E Van't Hof1, Pascal Campagne1, Daniel J Rigden1
1Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK.
Nature
|June 3, 2016
Resumen
La mutación que causó el melanismo industrial en las polillas era un elemento transponible que se insertaba en el gen de la corteza. Esta inserción, alrededor de 1819, aumentó la expresión génica de la corteza, impulsando la adaptación a la contaminación.
Área de la Ciencia:
- Biología evolutiva
- La genética
- Biología molecular
Sus antecedentes:
- El melanismo industrial en polillas (Biston betularia) es un ejemplo clásico de adaptación.
- La base genética para la forma melánica (carbonaria) ha sido localizada pero no identificada.
- Comprender la mutación que impulsa esta respuesta evolutiva visible es crucial.
Objetivo del estudio:
- Para identificar la mutación específica responsable del melanismo industrial en las polillas.
- Para aclarar el mecanismo molecular por el cual esta mutación causa el cambio fenotípico.
- Para determinar el momento de la mutación.
Principales métodos:
- Mapeo fino del lugar de las carbonarias.
- Análisis de secuencias para identificar diferencias genéticas.
- Inferencia estadística del tiempo de transposición.
- Análisis de cambios en la expresión génica.
Principales resultados:
- La mutación es un elemento transponible grande y repetido en tándem insertado en el primer intrón del gen de la corteza.
- El análisis estadístico sugiere que la transposición se produjo alrededor de 1819.
- El elemento transponible aumenta la abundancia de transcripciones de la corteza.
- La proteína de la corteza está involucrada en la regulación del ciclo celular durante el desarrollo de las alas.
Conclusiones:
- El descubrimiento identifica la mutación específica que impulsa el melanismo industrial en las polillas.
- Los elementos transponibles pueden ser una fuente de gran novedad fenotípica y rápida adaptación.
- Este hallazgo proporciona una explicación molecular para un evento evolutivo icónico.
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