Multilocus analysis of nucleotide variation in Drosophila madeirensis, an endemic species of the Laurisilva forest in Madeira

• Autor(a) principal: Khadem, M.
• Data de Publicação: 2012
• Outros Autores: Munté, A., Camacho, R., Aguadé, M., Segarra, C.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.13/3689
• topic: DNA divergence; DNA polymorphism; Introgression; Molecular evolution; Speciation; .; Faculdade de Ciências da Vida

Drosophila madeirensis is an endemic species of Madeira that inhabits the island Laurisilva forest. Nucleotide variation in D. madeirensis is analysed in six genomic regions and compared to that previously reported for the same regions in Drosophila subobscura, an abundant species in the Palearctic region that is closely related to D. madeirensis. The gene regions analysed are distributed along the O3 inversion. The O3 arrangement is monomorphic in D. madeirensis, and it was present in ancestral populations of D. subobscura but went extinct in this species after the origin of the derived OST and O3+4 arrangements. Levels of nucleotide polymorphism in D. madeirensis are similar to those present in the OST and O3+4 arrangements of D. subobscura, and the frequency spectrum is skewed towards rare variants. Purifying selection against deleterious nonsynonymous mutations is less effective in D. madeir ensis. Although D. madeirensis and D. subobscura coexist at present in Madeira, no clear evidence of introgression was detected in the studied regions.