Genetics, Vol 127, 161-168, Copyright © 1991


INVESTIGATIONS

Low Diversity of t Haplotypes in the Eastern Form of the House Mouse, Mus musculus L

A. Ruvinsky, A. Polyakov, A. Agulnik, H. Tichy, F. Figueroa and J. Klein
Academy of Sciences of the USSR, Siberian Branch, Institute of Cytology and Genetics, Novosibirsk 630090, Soviet Union

In previous studies, 13 different recessive embryonic lethal genes have been associated with t haplotypes in the wild mice of the species Mus domesticus. In this communication we have analyzed five populations of Mus musculus for the presence and identity of t haplotypes. The populations occupy geographically distant regions in the Soviet Union: Altai Mountains, western and eastern Siberia, Azerbaijan and Turkmenistan. No t haplotypes were found in mice from eastern Siberia. In the remaining four populations, t haplotypes occurred with frequencies ranging from 0.07 to 0.21. All the t haplotypes extracted from these populations and analyzed by the genetic complementation test were shown to carry the same lethal gene tcl-w73. In one population (that of western Siberia), another lethal gene (tcl-w5) was found to be present on the same chromosome as tcl-w73. This situation is in striking contrast to that found in the populations of the western form of the house mouse, M. domesticus. In the latter species, tcl-w73 has not been found at all and the different populations are characterized by the presence of several different lethal genes. The low diversity of t haplotypes in M. musculus is consistent with lower genetic variability of other traits and indicates a different origin and speciation mode compared to M. domesticus. Serological typing for H-2 antigenic determinants suggests that most, if not all, of the newly described t haplotypes might have arisen by recombination of t(w73) from M. musculus with t haplotypes from M. domesticus either in the hybrid zone between the two species or in regions where the two species mixed accidentally.