| First Author | Cattanach BM | Year | 1984 |
| Journal | Mouse News Lett | Volume | 70 |
| Pages | 80-81 | Mgi Jnum | J:13961 |
| Mgi Id | MGI:62139 | Citation | Cattanach BM, et al. (1984) A further new X-linked gene. Mouse News Lett 70:80-81 |
| abstractText | Full text of MNL contribution: 7. A further new X-linked gene. A new X-linked gene has been found and given the name lined (Li). It was first discovered among the third generation descendants of an X-irradiated male but it is not known whether the mutation was induced by the irradiation or was of spontaneous origin. Li is a pre-natal lethal in the male. Li+ females appear to be fully viable although there is a slight shortage of this class at weaning relative to their + sibs (0.75:l). This could be caused by some pre-natal loss or by a failure to recognise all Li+ females. The Li+ phenotype is that of a very fine striping which is often seen on only parts of the dorsal area body and can be difficult to detect. The predominance of + coat appears to be due to a non-random X-chromosome expression because the phenotypes of Li+/+Blo, Li+/+Ta and Li+/+Hq double heterozygotes very closely resemble those of Blo, Ta and Hq hemizygotes. Moreover, electrophoretic studies upon brain, liver and kidney (representing ectoderm, endoderm and mesoderm, respectively) from LiPgk-lb/+Pgk-1a females, showed the presence of only the PGK-1A isozyme which suggests that the Li X-chromosome is inactive in at least 90% of cells. Linkage tests have been carried out with Blo and Hq. Crosses of Li+/+Blo females x ++/Y males produced 47 Blo+ females, 69 phenotypically Li+ females, 57 BloY males, 30 +/+ females and 24 +/Y males. Tests on a sample of 10 phenotypically Li+ females showed that a proportion were in fact genotypically Li Blo/+ +, thus again demonstrating the non-random X-chromosome expression. Based on the male data the Li-Blo RF is 29.63 +/- 5.07%. Crosses of Li+/+Hq females x ++/Y have produced so far, 48 "striped" females, 21 of which appeared Li+ and 27 Hq+, and also 12 Hq/Y males, 18 +/+ females and 16 ++/Y males. 12 of the "striped" females are under test to determine their genotypes but, based on the male data, there is little indication of linkage between Li and Hq (RF - 57.14%). Li must therefore be located distally on the chromosome. Linkage tests with Hyp are in progress. (Cattanach, A.J.M. Crocker, Department of Medical Genetics, Churchill Hospital, Oxon and Peters) |
