Genomic changes in speciation of the family Chironomidae, Diptera

Article info: Received: 20 May 2014 Accepted: 18 September 2014 ABSTRACT The mode of speciation adopted by a species or group of related species of animals (insects) is clearly determined to a certain extent by the architecture of their genetic system. Chromosome rearrangements, the localization and appearance of the heterochromatin as well as the reproductive relations in sympatric, allopathric speciation and intrograssion process of different species of Chironomidae family are considered. A high chromosome polymorphism and changes in the constitutive heterochromatin are shown as predominant mechanism in the phyletic evolution of some species. Based on an analysis of inversions in different chromosome arms, a chromosome evolution in the "plumosus" group (genus Chironomus) is traced. It was found that the floating inversions in an initial standard karyotype became fixed in a derived karyotype and underlined that the heterochromatin is a dynamic element in the speciation of family Chironomidae. In addition, hybridization tests revealed that pre and postmating isolating mechanisms were operating in process of formation in different sibling species. It is concluded that the species with overlapping ranges are characterized by more complex chromosome changes, while in species with allopatric speciation there are less chromosome rearrangements. In this case, the distance between the populations is a very important factor as well.