Telomeric heterochromatin and meiotic recombination in three species of Coleoptera (Dorcadion olympicum Ganglebauer, Stephanorrhina princeps Oberthür and Macraspis tristis Laporte)

Abstract

Centromeres are generally embedded in heterochromatin, which is assumed to have a negative impact on meiotic recombination in adjacent regions, a condition required for the correct segregation of chromosomes at anaphase I. At difference, telomeric and interstitial regions rarely harbour large heterochromatic fragments. We observed the presence at the heterozygote status of heterochromatin in telomere region of some chromosomes in 3 species of Coleoptera: Dorcadion olympicum; Stephanorrhina princeps and Macraspis tristis. This provided us with the opportunity to study the relationship between heterochromatin, chiasma location and meiotic recombination independently from the proximity of centromeres in this order of insects. In acrocentric chromosomes, the presence of heterochromatin in telomere region of the long arm displaces recombination near the centromere. In sub-metacentrics, recombination is almost always restricted to the other arm. This at distance effect of heterochromatin may deeply influence genetic drift.