Multiple introgressions shape mitochondrial evolutionary history in Drosophila paulistorum and the Drosophila willistoni group

• Hybridization and the consequent introgression of genomic elements is an important source of genetic diversity for biological lineages. This is particularly evident in young clades in which hybrid incompatibilities are still incomplete and mixing between species is more likely to occur. Drosophila paulistorum, a representative of the Neotropical Drosophila willistoni subgroup, is a classic model of incipient speciation. The species is divided into six semispecies that show varying degrees of pre-and post-mating incompatibility with each other. In the present study, we investigate the mitochondrial evolutionary history of D. paulistorum and the willistoni subgroup. For that, we perform phylogenetic and comparative analyses of the complete mitochondrial genomes and draft nuclear assemblies of 25 Drosophila lines of the willistoni and saltans species groups. Our results show that the mitochondria of D. paulistorum are polyphyletic and form two non-sister clades that we name alpha and beta. Identi-fication and analyses of nuclear mitochondrial insertions further reveal that the willistoni subgroup has an alpha-like mitochondrial ancestor and strongly suggest that both the alpha and beta mitochondria of D. paulistorum were acquired through introgression from unknown fly lineages of the willistoni subgroup. We also uncover multiple mito-chondrial introgressions across D. paulistorum semispecies and generate novel insight into the evolution of the species.

Ämnesord

NATURVETENSKAP  -- Biologi -- Evolutionsbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Evolutionary Biology (hsv//eng)

Nyckelord

Mitochondria

Drosophila

Evolution

Genomics

Introgression

Publikations- och innehållstyp

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