| First Author | Evans EP | Year | 1978 |
| Journal | Mouse News Lett | Volume | 58 |
| Pages | 44-45 | Mgi Jnum | J:13742 |
| Mgi Id | MGI:61921 | Citation | Evans EP, et al. (1978) Inversion on Chromosome 2. Mouse News Lett 58:44-45 |
| abstractText | Full text of MNL contribution: Dr. E.P. Evans (Dunn School of Pathology, Oxford) using G-banding, has now demonstrated the presence of an inversion of chromosome 2 with breakpoints in the region of D (or possibly El) and H1; i.e. about 40% of the chromosome is involved. He has also studied meiosis in As + and found a frequency of only about 1/500 inversion bivalents at metaphase I, 1 possible dicentric at metaphase II and no bridges in more than 100 anaphase IÕs from orcein squashes. At pachytene, chromosome 2's seem to pair all along their length with no signs of a loop, but with a possible sign of "straining" in the central region which he suggests indicates a lack of true homology so that chiasmata could rarely form within the inversion and would be forced to form proximally and/or distally to it. This is possibly reflected in the increased crossing-over which occurs between a and bp in the presence of As (MNL 39:25). The linkage data support the cytological length of the inverted segment:- Recombination Values: A. In the presence of In(2)2H (As) a - As; 0.6%; * As - pa; 0%; As - fi; 16% (40/245 recombinants from B.C.'s); B. Without In(2)2H (As) pa - fi; 26% (BLM2); pa - T7Ca; 8.5% (Carter, Lyon and Phillips, 1956) *eg. Of 38/1076 crossovers between bp and pa from bp + pa/+As+ I.C.'s, 30 were fully tested and proved to be between bp and As. These data suggest that the inversion extends from about the T7Ca breakpoint proximally to the a-locus distally, which, from work with translocations, corresponds to bands D and H1 respectively (Searle, personal communication). (Evans and Phillips). |
