Pericentric inversion polymorphism in aiolopus strepens (Orthoptera: Acrididae): Effects on chiasma formation

Abstract

Seven out of 61 males and five out of 48 females from a Spanish population of Atolopus strepens were heterozygous for a pericentric inversion in the smallest member of the complement (Sn). The inverted segment occupied about 5096 of total length of the chromosome which was present either as a telocentric (standard) or a metacentric (inverted) element. Mean chiasma frequency was similar in both standard homozygous and in heterozygous males. However, the pattern of chiasma localization in the three S-bivalent was different in these two types of males. In SM bivalents heterozygous for the inversion the single chiasma was always terminally located, while in the standard homozygous bivalents the chiasma was sited interstitially in about 3096 of diplotene cells. Furthermore, in males heterozygous for the Sn-inversion the S9 and Sj0 bivalents also show a single terminal chiasma at a higher frequency than that present in males homozygous for the standard Sn. © 1982 Taylor & Francis Group, LLC.