No genomic mosaicism in a putative hybrid butterfly species

Publisher Website
Google Scholar
Abstract
Recent descriptions of hybrid animal species have spurred interest in this phenomenon, but little genomic data exist to support it. Here, we use frequency variation for 657 amplified fragment length polymorphism (AFLP) markers and DNA sequence variation from 16 genes to determine whether the genome ofHeliconius pachinus, a suspected hybrid butterfly species, is a mixture of the putative parental species,Heliconius cydnoandHeliconius melpomene. Despite substantial shared genetic variation among all three species, we show that the genome ofH. pachinusis not a mosaic; both AFLP and DNA sequence data overwhelmingly associateH. pachinuswith just one of the potential parents,H. cydno. This pattern also applies to the genewingless, which is tightly linked to the locus that determines forewing colour—one specificH. pachinustrait that has been hypothesized to have originated fromH. melpomene. As a whole, the data support a traditional, bifurcating model of speciation in whichH. pachinussplit from a common ancestor withH. cydnowithout a genetic contribution fromH. melpomene. However, comparison of our data to DNA sequence data for another putative hybridHeliconiusspecies,Heliconius heurippa, suggests that theH. heurippagenome may be a mosaic.