Chromosomal variation, macroevolution and possible parapatric speciation in Mepraia spinolai Porter Hemiptera: Reduviidae. Fax: , E-Mail: danfrias discovery. Mepraia spinolai is an endemic species in Chile that lives in wild and domestic habitats. It is the only species of the Reduviidae family that shows alate polymorphism; females are always wingless, but males can be found with and without wings.
The M. Experimental crosses suggest that the genes for wings are linked in the Y chromosome and also that there are two cytologically indistinguishable types of neo-Y chromosomes. One form Y 1 bears a gene or genes for wings while the other Y 2 lacks such genes.
These chromosomes and morphological changes are correlated with a shift of the southern population into more arid habitats of the interior in the metropolitan region and region III. The main domestic vector of Chagas' disease in Chile is Triatoma infestans, but the endemic species, Mepraia spinolai, found in wild and domestic habitats, can be a vector of this malady Schofield et al. The presence of an alate polymorphism resulted in taxonomic confusion, and Mazza et al.
However, his name was not recognized Frias et al. Recently, Lent et al. They recognized the monotypic genus Mepraia as distinct from Triatoma because of a combination of many morphological and male genital differences. The evolution process is often accompanied by structural rearrangement of the genome White, , The nature of these rearrangements is determined by chromosome architecture and behavior. Certain patterns which commonly occur in some taxa are rare or never occur in others.
Thus, in organisms with localized centromeres, acentric fragments are lost during cell divisions. The process of fragmentation contributes to evolutionary changes in the karyotype only if such fragments fuse with a competent chromosome or fragments with a centromere.
