Abstract: | Comparison of chromosome number at somatic and spermatogonial mitoses has demonstrated the increase in the number of additional chromosomes in cells of germinal tissue. This may evidence a mechanism of B-chromosomes accumulation in foxes. B-chromosomes may lag as univalents, may form bivalent associations, or occasionally form trivalents at the stage of diakinesis-metaphase I, and they may associate with macrobivalents (A-chromosome bivalents). The analysis of metaphase II has shown that the distribution of B-chromosomes in the second metaphase is random resulting in gametes with various numbers of B-chromosomes. |