[Unusually high number of B-chromosomes and mosaicism among them in the Asiatic forest mouse Apodemus peninsulae (Rodentia, Muridae)]. / Neobychno vysokoe chislo B-khromosom i mozaitsizm po nim u Aziatskoi lesnoi myshi Apodemus peninsulae (Rodentia, Muridae).

Karyological analysis of Apodemus peninsulae from Western Siberia was made. It was established that animals under study are characterized both by interindividual variation of B-chromosome number or polymorphism which was described previously and by intraindividual variation or mosaicism. Diploid numbers are 55-57, 58-61, 61-65 and 68-72, i. e. studied animals possess 3, 4, 5 and 5 cell clones, respectively. The highest number of B-chromosomes in mammals was found to be 24.

[Nature and role of accessory chromosomes in silver-gray foxes. IV. The behavior of accessory chromosomes in meiosis]. / Issledovanie prirody i roli dobavochnykh khromosom serebristochernykh lisits. Soobschchenie IV. Povedenie dobavochnykh khromosom v meioze.

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.