Worm Breeder's Gazette 5(2): 50a
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.
The dominant mutation her-2(e1575) transforms both XX and X0 animals into females, i.e. hermaphrodites that are self-sterile but cross- fertile. A small percentage of the heterozygotes (her-2/+) make a few sperm and therefore have a few self-progeny; homozygotes (her-2/her-2) never make sperm but are still cross-fertile. The mutation has been mapped, and is located between vab-7 and dpy-18 on LGIII. This is similar to the map position of tra-1, and it is therefore possible that her-2 is a mutation causing constitutive expression of the tra-1 gene product. Tests of this hypothesis are in progress. Animals of genotype her-2/tra-1 are female; if they are fertilized by tra-1/tra-1 males, the progeny are all her-2/tra-1 females and tra- 1/tra-1 males, i.e. the same as the parents. Male/female strains of this type can be propagated by crossing for many generations (though in some cases rare wild types (probably recombinants between her-2 and tra-1) have eventually taken over). In such strains, sex is entirely controlled by the state of LGIII, and the X chromosome genotype is irrelevant. If the her-2 chromosome is designated W, and the tra-1 chromosome is designated Z, then these strains have WZ heterogametic females and ZZ homogametic males (like birds and butterflies), in contrast to the sexes of the original N2 strain (XX homogametlc hermaphrodites and X0 heterogametic males). Both tra-2 and tra-3 mutations are suppressed by her-2.