Geographical Variability in the Frequency of B-Chromosome Occurrence in Wood Mouse Sylvaemus flavicollis of Eastern Europe

The karyotypes of 95 specimens (57 males and 38 females) of yellow-necked field mouse (Sylvaemus flavicollis Melchior, 1834) caught at seven points in Eastern Europe were studied. Only one specimen had an extra chromosome. It was shown that, in Sylvaemus flavicollis in the surveyed sites from the central part of the range (Eastern Europe), the frequency of occurrence of specimens with B chromosomes is very low and probably does not depend on the ecological conditions of habitats.

Automated summary

The karyotypes of 95 specimens of yellow-necked field mouse caught in Eastern Europe were studied. Only one specimen had an extra chromosome. It was shown that the frequency of individuals with B chromosomes in Sylvaemus flavicollis from the surveyed sites in Eastern Europe is very low and probably not influenced by ecological conditions.