Embryological tests of genetic male sterility in the house mouse

Abstract

A-ew Pork, X . r I n previous papers the existence of male sterility in the house mouse caused hy the combination of diff erent recessive mutations of the t type was reported (Eryson, '44; Dunn and Gluecksohn-Schoenheimer, '43). These mutations all occur in one linkage group (no. TX) and do not show any crossing o r e r with each other. Three of them have been shown to suppress crossing over in a region of 1-5 crossover units in chromosome IX and they all are probably coniiected with chromosonial rearrangernents of one kind or another.The first mutation of this kind to be discovered was t o (Chesley and Dunn, '36). I n combiiiatioii with T (dominant short tail mutation) it produces taillessness, while in homozygous condition ( t " / V ) it is lethal and t O / P embryos die soon after implantation in the uterus. another recessive mutation related closely to t" is tl ; it also produces taillessness in combination with T and is lethal when homozygous, the tl/fl zygotes d j k g even before implantation ; the combination t"/t', however, resnlts in normal tailed progeny (Dunn, '37). While such normal tailed females t o / t l breed normally, the males are sterile (Dunn arid Gluecksoliii-Schoenheimer, '43). 9 third mutation in this series (t') turned out to be identical with t' (Dunn, '39). Recently, still another mutation in this series ( P I was analyzed. It also produces taillessness in conibinanation with T a i d does not show any crossing over with the other mutatioiis in the l' series, lout the homozygotes ( i 3 / t 3 )

A structural gene (Tcp-1) within the mouse t complex is separable from effects on tail length and lethality but may be associated with effects on spermatogenesis

“…The t 6 haplotype has a typical tcs-2 factor, but either a wild-type or mildly abnormal allele at tsc-1 (M. Lyon, personal communication). Partial t haplotypes have been recovered which have only the tcs-1 factor (such as the viable t 3 haplotype described in detail by Gluecksohn-Schoenheimer et al (1950) and the partial lethal haplotype t wl8 ) or only the tcs-2 factor (such as the distal haplotypes < A17 and t hl8 described by Lyon & Mason, 1977). In general, the following statement can be made about the effects of the two tcs factors on male fertility.…”

“…Third, males which carry three doses of tcs factors are usually quasisterile (e.g. t 3 /t l described by Gluecksohn-Schoenheimer et al 1950, and t hl8 /t w5 described by Lyon & Mason, 1977). The fertility status of males in this last category ranges from near-fertile to completely sterile, however, no single genotype tested confers complete fertility (Bennett & Dunn, 1971).…”

“…In addition, when the analyses of Gluecksohn-Schoenheimer, Segal & Fitch (1950) and Bennett & Dunn (1971) are interpreted in terms of the partial I haplotype model of Lyon & Meredith (1964a), it is clear that at least two separable factors (proximal and distal) are involved in male sterility effects. Since it now appears possible that the five ' sperm factors' may be independent of each other and of the two ' developmental factors' (tail interaction and lethality), a revised system of nomenclature is crucial.…”

Alleles at a Mutable Locus Found in Populations of Wild House Mice ( Mus Musculus )

“…7 The tests applied to date do not exclude the possi-bility that occasional sperm of t/It' or tl/tw males may be functional as revealed by examination of cleaved eggs in special tests. 8 In summary, then, a sample of one wild population bred for several generations in captivity was found to contain at least two different alleles at locus T which behave like other alleles which had arisen by mutation in laboratory stocks. The mutant alleles, in male heterozygotes, are transmitted in much higher frequency than the normal alleles.…”