COMPARATIVE KARYOTYPE ANALYSIS OF 24-CHROMOSOME RANA SPECIES (R-CHENSINENSIS AND R-ARVALIS, AMPHIBIA, ANURA)

Results of a comparative study of the karyotypes of Rana chensinensis and R. arvalis are reported. On the basis of detail morphometrical ana lysis of each chromosome pair significant karyotype differences were e stablished between two species concerning localization of secondary co nstriction, the centromere position of 6th chromosome pair and the abs olute length of 3 chromosome pairs. The possible mechanisms giving ras e to the differences between both karyotypes were discussed. It was su ggested that karyotypic divergence of R. arvalis was caused by a peric entric inversion, independent local deletions and transpositions with a consequent amplification of NOR-sites.