The Sp{sup 4H} deletion may contain a new locus essential for postimplantation development
- MRC Institute of Hearing Research, Nottingham (United Kingdom); and others
Sp{sup 4H} is a semi-dominant mutation that maps to mouse chromosome 1. Heterozygous mice exhibit white spotting of the belly, whereas the fate of the homozygous embryos is unknown. We have previously shown that the entire coding region of the Pax3 gene is deleted in the Sp{sup 4H} mutant. In this study, we have analyzed the fate of the Sp{sup 4H} homozygous embryos. No Sp{sup 4H} homozygotes were detected by Southern blot or PCR analysis in 82 E9-E13-day embryos. We have also documented a significant increase in the number of resorption sites in Sp{sup 4H} heterozygous matings compared to control litters. Sections of the resorption sites (moles) suggest that postimplantation development is arrested prior to gastrulation. We have mapped the extent of the deletion to a maximum of 1.53 {plus_minus} 0.6 cM using markers flanking the Pax3 locus. Four anonymous markers, D1Mit 215, D1Mit253, D1Mit332, and D1McG156, have been shown to be deleted in the Sp{sup 4H} mutation. Further nondeleted markers have been used to extend the linkage map of this region. A total of 22 loci were analyzed in a Splotch intraspecific backcross. As the deletion is large enough to include other genes, and it seems that deletion of Pax3 is not likely to account for the early death of the embryos, we suggest that another developmentally important gene may be deleted in the Sp{sup 4H} mouse mutant and that this may be responsible for the early death of the homozygous mutant embryos. 40 refs., 4 figs., 2 tabs.
- OSTI ID:
- 476776
- Journal Information:
- Genomics, Journal Name: Genomics Journal Issue: 2 Vol. 34; ISSN GNMCEP; ISSN 0888-7543
- Country of Publication:
- United States
- Language:
- English
Similar Records
Evidence for modifier genes that enhance the effect of the Pax-3 mutation, splotch-delayed (Sp{sup d}), on facial morphology: A model for studying the causes of variation of Waardenburg syndrome
Effects of Pax3 modifier genes on craniofacial morphology, pigmentation, and viability: A murine model of Waardenburg syndrome variation