Worm Breeder's Gazette 9(2): 73
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
We have utilized a screen for maternal effect lethal mutations ( Preiss, J., Kemphues, K., Wolf, N., and Hirsh, D. (1984) WBG 8(2),5) to search for mutations that may be due to Tc1 transposition. The egg- laying defective mutation, egl-23 (n601) IV, was crossed into strains bearing the mutators mut-2 (r459) or mut-3 (r456) (Phil Anderson, Bonnie Saari, and John Collins (1985) WBG 9(1), 29). New maternal effect mutations that arose during propagation were identified as heterozygotes: 1/4 of their progeny produced dead eggs and were not consumed by larva (they did not 'bag'). In our preliminary screens, we picked 1500 egl-23; and 600 egl-23;mut-3 worms. We identified three maternal effect mutations in the mut-2 background: jb2, jb3, and jb7. Homozygous jb2 hermaphrodites will produce a few progeny (~1-10) inevitably sterile. Early divisions of eggs from which are jb2 hermaphrodites are symmetric and synchronous, reminiscent of mutations in the par loci. Indeed, jb2 fails to complement par-2 (it5) III (Niansheng Cheng, Diane Morton, and Ken Kemphues, this issue). Hermaphrodites homozygous for the mutation jb3 (which maps to chromosome III) produce eggs with variable terminal phenotypes; no clear defect in early divisions can be seen. Strains homozygous for the jb7 mutation produce eggs whose early divisions are far slower than wild type. We've isolated one maternal effect mutation from the mut-3 background, jb6. The jb6 mutants produce eggs whose first observable defects are in gastrulation and/or the timing of the second round of division of the E lineage. Genetic and molecular analysis of these maternal effect alleles and screens to identify additional mutations are in progress.