B CHROMOSOME NUMBER POLYMORPHISM AND MOSAICISM OF THE KOREAN FIELD MOUSE APODEMUS PENINSULAE (RODENTIA) IN THE
RUSSIAN FAR EAST
G. V. Roslik,1 I. V. Kartavtseva
Institute of Biology and Soil Science FEB RAS, Vladivostok;
1 e-mail: roslik_g@mail.ru
Karyotype analysis of the Apodemus peninsulae (n = 355) from 41 trapping points from the Russian Far East made it possible to reveal B chromosomes
in 87.9 % animals, where 61.7 % among them were mosaics. Different levels of B chromosome numbers variability such as inter - and intrapopulational, and intraindividual
(mosaicism) as well have been studied. It has been revealed that frequencies of occurrence of individuals with B chromosomes and mosaicism were not constant between
different population's samples. The range of the modal B chromosome number variations and the xB index variability (from 0 to 4, xB averaged 1.67) both have been fist
investigated in different samples and populations of this species. Individuals with the predominant B chromosome numbers (as a rule, 0-2) have been revealed in both
groups of animals (with stable and mosaic karyotypes) but the frequency was different in the geographical regions. The spectra of B chromosome variability were wider in
mosaics (0-7) in comparison with animals with stable karyotypes (0-4). High frequency of individuals with B chromosomes and with mosaicism, and their significance for the
species is discussed. The adaptive role of the low number of B chromosomes (1-2) is assumed and the B chromosome system seems not to be balanced in the species in
whole.
Key words: Apodemus peninsulae, the Russian Far East, B chromosomes, mosaicis, xB index
| Pdf |
Back |
Contents |
Main |
