| First Author | Cattanach BM | Year | 1997 |
| Journal | Mouse Genome | Volume | 95 |
| Pages | 484-5 | Mgi Jnum | J:44592 |
| Mgi Id | MGI:1100476 | Citation | Cattanach BM, et al. (1997) A further Sl mutation associated with a Chromosome 10 translocation. Mouse Genome 95:484-5 |
| abstractText | Full text of Mouse Genome contribution: Research News: 1. A further Sl mutation associated with a chromosome 10 translocation. A female showing a standard steel (Sl) phenotype and detected in a homozygous T(6;7)51H translocation stock has proved to be associated with a Chr 10 reciprocal translocation. On being crossed with a 3H1 (C3H/HeH x 101/H F1) male, her litter size was low (2.9) and half of her progeny which survived to classification (7/14) showed the Sl phenotype. The same characteristics were shown by all her tested progeny, the litter size however also being reduced by the obligate heterozygosity for the T51H translocation. G band analysis of the original female demonstrated that she carried a reciprocal 10;11 translocation in addition to T51H, with breakpoints in bands 10D1 and 11D respectively. As the chromosome 10 breakpoint lies within the same band as a range of Sl deletions of varying sizes (Cattanach et al Proc 10th ICRR Vol. 2, pp 531-534, 1996) it may be deduced that the translocation is the cause of the mutant phenotype. In addition to the deletions, four other reciprocal translocations with breakpoints in band 10D and a Sl phenotype have been described (Cachiero & Russell, Genet. Res. 25:193-195, 1975). Band D though represents one quarter of the total chromosome length and although the deletions have further narrowed the position of the locus to band D1, this band is wide and dark staining so even this siting is imprecise. The new translocation, however, clearly splits 10D1 so that two-thirds of the band is translocated to a pale staining segment of Chr 11, leaving the proximal one-third on Chr 10. The site of the Sl locus can therefore be assigned to a proximal position in band 10D1. On the basis of the Sl deletions and the five translocations it may be deduced that the region is not only haplo-sufficient but liable to breakage, with the Sl locus additionally being prone to translocation inactivation. The new 10;11 translocation, which is co-inherited with the Sl phenotype, has been named T(10;11)Sl(34H)75H and has now been separated from the T51H translocation. On socring 100 cells at the M1/diakinesis stages of meiosis, quadrivalent frequencies comprising 60RIV, 36 CIV, 2 CIII+I and 2 with 20II were seen. Intercrosses of T75H heterozygotes failed to generate anaemic young suggesting that the homozygote is a prenatal lethal. Anaemic offspring were also not detected pre-natally suggesting that the translocation homozygote dies either before implantation or very soon thereafter. The fate of homozygotes for the other known Sl translocations has not been reported. (Cattanach, Rasberry, Woodward and Evans). |
