| First Author | Phillips RJS | Year | 1979 |
| Journal | Mouse News Lett | Volume | 60 |
| Pages | 45-6 | Mgi Jnum | J:13789 |
| Mgi Id | MGI:61968 | Citation | Phillips RJS (1979) sll-1. Mouse News Lett 60:45-6 |
| abstractText | Full text of MNL contribution: 9. Sex-linked lethal tests with In(X)1H. Tests have been continuing using In(X)lH to suppress crossing-over on the X chromosome and so help in scanning for sex-linked recessive lethals. F1(C3H x 101) males have been irradiated with a fractionated dose of 500 + 500 rad x rays 24 hours apart. After the return to fertility the males are mated to In(X)Bpa/In(X)+ or In(X)Ta/In(X)+ females, and Bpa+ or Ta+ F1 daughters are then tested for the presence of a lethal. One sex-linked lethal (sll-1) has been found amongst 103 treated F1 females tested (and none in 118 controls). The males die post-natally (within about a day of birth): they look grossly normal and do suckle. Investigations of the lethal are hampered by the poor breeding performance of the In(X)Ta+/++ sll-1 males. Data have also been obtained treating In(X) males instead of F1 (C3H x 101). No lethals have been found amongst 158 irradiated and 164 control Fl females. It is of interest to note, however, that 7 F1 females (3 treated and 4 control) showed a significant (X2 > 4) shortage of male offspring and 7 (3 treated and 4 control) showed a similar significant shortage of female offspring. The abnormal ratios were not obviously linked with In(X) and were presumably due to chance, and therefore highlight the danger of using sex ratio data to predict the presence of lethals. Another sex-linked recessive lethal; sll-2, has been found in the In(X) breeding stocks (i.e. untreated). 16 daughters of an In(X)Ta male were used in various matings; these females bred as expected except one who produced no weaning age 1n(X)Ta male offspring. Subsequently she proved to carry a post-natal lethal linked to Ta and within the inversion. It is not yet known on which side of Ta the lethal lies. (Phillips) |
