Karyological study of some Corvine birds (Corvidae, aves)

Abstract

Karyotypes were studied in the hooded and carrion crows, their naturally occurred hybrids, the jungle crow, the azure-winged magpie (2n = 80 in all aforementioned birds), and the magpie (2n = 82). Corvine birds of Primorskii Krai were karyotyped for the first time. In addition to the similarity in the diploid chromosome sets, corvine birds were shown to have a similar structure of karyotype: in all studied birds, 14 macrochromosomes (Mchs) classified into three groups according to their size were detected. By karyotype structure, birds belonging to the same genus are similar. Some intergeneric differences are due to a change in the position of centromeres of the largest and sex chromosomes. Karyotypes of interspecific hybrids of crows are remarkable for the presence of heteromorphic (t/st) chromosome pair 2 in some individuals, which apparently does not affect their fecundity. Using differential C-banding, the sex chromosome W in female magpies was identified. In addition, heteromorphism was detected in C-bands of homologs of Mch pair 4 in the hooded crow. In the jungle crow, the azure-winged magpie, and the magpie, bright QH-bands and numerous G-bands were detected on Mchs and on some microchromosomes only. Active Ag-NOR-bands were detected on one macrochromosome pair in the magpie. In all, the karyotype structure of corvine birds is comparable to the basic structural scheme of the karyotype in the order Passeriformes, which confirms the concept of conservatism of the avian karyotype.