| First Author | Beechey CV | Year | 1983 |
| Journal | Mouse News Lett | Volume | 69 |
| Pages | 55 | Mgi Jnum | J:23567 |
| Mgi Id | MGI:71511 | Citation | Beechey CV, et al. (1983) How a pericentric inversion carrying stock was converted into a stock with a deficiency for at least the terminal band of Chr. 15 and the centric heterochromatin of Chr. 6. Mouse News Lett 69:55 |
| abstractText | Full text of MNL contribution: Research News: How a pericentric inversion carrying stock was converted into a stock with a deficiency for at least the terminal band of Chr. 15 and the centric heterochromatin of Chr. 6. In MNL 60 (p. 77) Nijhoff reported the recovery of a pericentric inversion in Rb(6.15) 1Ald after irradiation of post meiotic stages in males of the MRCH stock homozygous for Rb(ll.l3)4Bnr, Rb(9.19)163H and Rb(6.15)1A1d. The breakpoints were allocated in bands 6A2 and 15F2. The stock was propagated through male carriers that were semi-sterile as the original male was characterized by 57% post-implantation loss. When after 9 generations of outcrossing to Swiss random-bred a meiotic analysis of the descendants was conducted, it appeared that the original chromosome mutant had been replaced by its recombination product with chromosome 15. Thus this stock now has a karyotype of 39 acrocentric chromosomes, with a large 15<6> chromosome deficient for the small segments of Chr. 6 proximal to the breakpoint and for chr. 15 distal to the breakpoint. Testis weights and sperm counts seem to be normal to near normal. At pachytene (electron microscope whole mount spreads) the two acrocentrics pair in a tandem fashion along the 15<6> long marker chromosome with usually non-homologous pairing between the two "deficiency" regions of the chromosomes 6 and 15. At anaphase of meiosis 1, the two 15 centromeres of the trivalent almost always coorientate. Relative litter sizes suggest the karyotype described is not prone to prenatal selection (Beechey and de Boer). |
