A hybridization area between two chromosomal races of Mus domesticus - one, the Apennines «CB» with a 22 chromosome karyotype, and the other with the karyotype of 40 chromosomes all telocentric - was analysed from the karyological point of view. Ten animals were found to be simple structural hétérozygotes for different number of Rb metacentrics, from 1 to 6. One animal was found to be complex hétérozygote with four monobrachial homologous Rb metacentrics, namely the chromosomes Rb(2.17) and Rb(9.16), present in the parental CB-22 chromosome karyotype, and the chromosomes Rb(2.16) and Rb(9.17) which are not included in the CB-22 karyotype as in other karyotypes of neighbouring populations of Mus domesticus. The above chromosome configuration, during the meiotic pairing, forms a tetravalent ring. Hypotheses on the origin of such a situation have been proposed.
ASJC Scopus subject areas
- Environmental Science(all)
- Earth and Planetary Sciences(all)
- Agricultural and Biological Sciences(all)