COMPARATIVE-ANALYSIS OF G-BANDED AND C-BANDED CHROMOSOMES OF 5 SPECIES OF THE DIDELPHIDAE (MARSUPIALIA) FAMILY

Comparative analysis of G- and C-banded chromosomes of five species of opossums of the Didelphidae family: Marmosa sp (2n = 14, NFa = 24); Metachirus nudicaudatus (2n = 14, NFa = 20); Monodelphis osgoodi (2n = 18, NFa = 32), Didelphis marsupialis (2n = 22, NFa = 20); Philander meilhennyi (2n = 22, NFa = 20) was carried out. High degree of the banding similarity of different chromosomes or their whole arms was found. Slight differences in alternation of G-bands are explained by the pericentric inversions mainly. According to the sizes, morphology and peculiarities of G-banding of heterochromosomes, four variants of Y-chromosome and four variants of X-chromosome were distinguished among the species under study. Y-chromosome variability in mainly connected with that of quantity of heterochromatin. In addition, variability of X-chromosome is connected with constitutive rearrangements. Our results corroborate the idea of the archaic karyotype of marsupials with diploid chromosome number 14. On this basis the karyotypes with more chromosome number are suggested to be originated as a result of centric dissociations.