Copy number variation and transposable elements feature in recent, ongoing adaptation at the Cyp6g1 locus.
PLoS Genet
; 6(6): e1000998, 2010 Jun 24.
Article
en En
| MEDLINE
| ID: mdl-20585622
ABSTRACT
The increased transcription of the Cyp6g1 gene of Drosophila melanogaster, and consequent resistance to insecticides such as DDT, is a widely cited example of adaptation mediated by cis-regulatory change. A fragment of an Accord transposable element inserted upstream of the Cyp6g1 gene is causally associated with resistance and has spread to high frequencies in populations around the world since the 1940s. Here we report the existence of a natural allelic series at this locus of D. melanogaster, involving copy number variation of Cyp6g1, and two additional transposable element insertions (a P and an HMS-Beagle). We provide evidence that this genetic variation underpins phenotypic variation, as the more derived the allele, the greater the level of DDT resistance. Tracking the spatial and temporal patterns of allele frequency changes indicates that the multiple steps of the allelic series are adaptive. Further, a DDT association study shows that the most resistant allele, Cyp6g1-[BP], is greatly enriched in the top 5% of the phenotypic distribution and accounts for approximately 16% of the underlying phenotypic variation in resistance to DDT. In contrast, copy number variation for another candidate resistance gene, Cyp12d1, is not associated with resistance. Thus the Cyp6g1 locus is a major contributor to DDT resistance in field populations, and evolution at this locus features multiple adaptive steps occurring in rapid succession.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Elementos Transponibles de ADN
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Sistema Enzimático del Citocromo P-450
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Proteínas de Drosophila
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Drosophila melanogaster
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Variaciones en el Número de Copia de ADN
Límite:
Animals
Idioma:
En
Revista:
PLoS Genet
Asunto de la revista:
GENETICA
Año:
2010
Tipo del documento:
Article
País de afiliación:
Australia