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 /nDfl6animals 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.