Worm Breeder's Gazette 12(5): 50 (February 1, 1993)

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.

Rescue of lin-13 ,a Gene Involved in Vulval Fate Detemination

Gautam Kao, Iva Greenwald

Dept. of Molecular Biology, Princeton University, Princeton NJ 0854

We report here our efforts to extend the analysis of lin-13 which is required for vulval cell fate determination (1, 2). The two previously identified alleles of lin-13 ( n387 & n388 )are heat sensitive reducdon-of-function alleles. lin-13 ( n387 )herrnaphrodites raised at 25-C are multivulva and sterile. lin-13 homozygotes raised at 15°C are fertile and non-Muv but display a zygotically rescuable grandchildless phenotype. Iin-13 / nDfl6 animals raised at 25 C arrest as L2 sized larvae (1).

The deficency result indicates that a null allele of lin-13 might result in a lethal phenotype. We tested several lethal mutations in the region for allelism with lin-13 but so far all the lethals tested complement lin-13 .We have also begun a clonal noncomplementation screen to look for null alleles.

lin-13 maps very close and to the left of mab-5 (Costa & Kenyon, pers. comm.). We therefore tested cosmids near mab-5 for the ability to rescue lin-13 defects. We find that the cosmid K04F4 can rescue both the sterility and the multivula phenotypes of lin-13 .Cosmids C18H2 , C33C3 ,and C41E6 which overlap K04F4 fail to rescue. We are now testing subclones of K04F4 for rescuing ability.

Literature Cited:

l) Ferguson & Horvitz (1985) Genencs 110: 17-72

2) Ferguson et al. (1987) Nature 326: 259-267