Mechanisms of differentiation in the sex chromosomes of some Lacertidae

Abstract

AbstractCytological and molecular evidence is provided to characterize the sex chromosomes of several species of Lacertidae. Observations on pachytene and lampbrush stages show that sex chromosomes have different condensation cycles and are only partially paired during meiosis. Bkm probe hybridization to Pst I-treated genomic DNA of Podarcis sicula and Lacerta vivipara shows the same pattern both in males and females. In situ hybridization of the same probe to Lacerta vivipara chromosomes shows no preferential localization of this DNA sequence. The results obtained clearly exclude the possible involvement of Bkm in sex-chromosome differentiation in the species investigated.