Robertsonian house mouse populations in Tunisia: A karyological and biochemical study

Abstract

A new population of Mus musculus domesticus showing Robertsonian translocations (2n = 22) has been identified in Tunisia. Mice carried 9 pairs of 10.17) and Rb(13.15). Five ot the nine translocations are not known to occur elsewhere. In two populations only 2n = 22 mice were present, whereas in a third one a mixture of karyotypes (2n = 22, 38, 39, 40) was found. The slight electrophoretic differentiation observed for other Robertsonian populations as well as the hybrid nature of the karyotypically heterogeneous populations are confirmed. Allele frequency differences between the 2n = 22 and 2n = 40 mice in the latter population show that local electrophoretic differentiation exists and allow to compare chromosome flow and gene flow. The presence of a chromosome-I polymorphism for additional fragments of heterochromatin present in the Robertsonian population provides a convenient marker of recombinational events in the hybrid zone.

The HSR on chromosome 1 of the house mouse, Mus domesticus: distribution and frequency in Switzerland

“…In addition to the Rhone valley, there appear to be at least two other places within the range of M. domesticus where the HSR is found well outside the distribution of metacentrics: Sidi-Bouzid in Tunisia (Said et al 1986) and Posadas in Argentina (Gimenez & Bidau, 1993). Also, although the HSR is found throughout the range of M. musculus (Winking et al 1991, metacentrics are only known from one locality in that semispecies (Zima et al 1990).…”

“…Winking et al (1991a) studied 157 mice over a small geographic area (the Key to references: (a) Gropp et al 1972;(b) Adolph & Klein, 1981;(c) Adolph, 1982; Gropp et al 1982; (e) Traut et al 1984; (f) Said et al 1986; (g) Bauchau et al 1989;(h) Winking et al 1991 b;(i) Searle, 1991;(j) Searle et al 1993; Agulnik et al 1993c; (1) Gimenez & Bidau, 1993. Baltic island of Gland) and Sabantsev et al (1993) studied 284 mice over a huge continental expanse (Siberia and middle Asia). From these studies and others on M. domesticus (see references in Table 1) it is clear that there is considerable variation in HSR frequency between particular well-studied sites.…”

Fertility estimates in the Tunisian all-acrocentric and Robertsonian populations of the house mouse and their chromosomal hybrids

“…In Monastir (Tunisia) the Rb populations of house mice are fixed for nine pairs of Rb fusions (2n = 22), the combination of which is not known to occur elsewhere (Said et al, 1986(Said et al, , 1991.…”

The HSR and heterochromatin distribution in natural populations ofMus musculus domesticus(Rodentia: Murinae) from Greece

“…Several natural populations of both subspecies have been found with HSRs in homozygous or heterozygous condition (Yakimenko and Korobitsyna 1988;Winking et al 1991a;Winking et al 1991b;Sabantsev et al 1993;Hübner et al 1994). Particularly in M. m. domesticus, the chromosome 1 carrying an HSR, can either be a typical acrocentric or part of an Rb chromosome (Saïd et al 1986;Winking et al 1988;Searle 1991;Searle et al 1993;Hübner et al 1994).…”