Worm Breeder's Gazette 12(4): 24 (October 1, 1992)

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.

Narrowing Down fem-2

Petra Jackle, Dave Pilgrim

Figure 1

Dept. of Genetics, Univ. of Alberta, Edmonton, Alberta

The fem-2 gene lies at a branchpoint in the sex determination pathway. Mutations of fem-2 cause somatic feminization of males and feminization of the germline in both sexes. By transformation rescue, the location of fem-2 had been previously localized to a cosmid on the left arm of LG III, T19C3 (Pilgrim, WBG 11#5) using pRF4 ( ROL-6 )as a positive control.

We have been working to narrow down the rescuing region. The overlapping cosmids T19C3 , T22G7 , B0321 and C50E1 rescue the phenotype, and fem-2 is also rescued by a lambda clone ( CB#DP119 )[See Figure] and a plasmid subclone ( DP#DBP003 ).Lambda clone CB#DP120 (as well as other lambda clones from the region) fails to rescue, as do plasmid clones DP#DBP017 ,019 and 023. This determines the location of the gene to a maximum of 11 kbp, and suggests a minimum length for the gene of 5 kbp.

The rescue so far has depended upon the ability to restore spermatogenesis to XX animals of b245ts at 25°C. No integrative transformants have been obtained, but many of our rescued lines have transmitted both the ROL-6 and Fem+ phenotypes for several generations. We have also rescued the q117ts allele, but no non-temperature-sensitive alleles have yet been tested. We have not yet examined the ability of the clones to rescue either of the XO phenotypes of fem-2 .Molecular analysis of the rescuing region is currently underway.

This work was supported by an Alberta Hertiage Fund for Medical Research Summer Studentship.

Figure 1