Worm Breeder's Gazette 9(3): 50
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.
Mutations which suppress her-l(n695sd)V are likely to be involved in the processes of sex determination or dosage compensation. n695 causes an incomplete masculinization of XX animals; homozygotes are uniformly egg laying defective (Egl) and approximately 30% display further variable sexual transformation of normally hermaphrodite tail structures into male-like structures (C. Trent). We have isolated two extragenic suppressors of n695 (y11 and y12) which result in the following phenotypes: n695; sup animals never display pseudomale tails and less than 10% are Egl. y11 maps to the right arm of chromosome I and has a strong maternal-effect component: y11/+ daughters of y11/y11 mothers are 75% non-Egl while y11/y11 daughters of y11/+ animals are uniformly Egl. y12 maps to the left of unc-32 on chromosome III and is a recessive suppressor of the n695 tail phenotype but a maternal effect suppressor of the egg-laying defect (y12/y12 daughters of y12/+ mothers are 77% Egl, y12/y12 daughters of y12/+ mothers are only 6% Egl). (It is not allelic with sup-26(n1091), a suppressor of n695 identified by C. Trent). y11 and y12 affect XO animals. Although XO animals of n695; sup strains appear to be wildtype, in a her-l+ background a small fraction of y12 XO animals appear intersexual. (In her-l+ strains y11 XX, y12 XX, and y11 XO animals have no apparent phenotype.) This suggests that y12 affects XO animals, but that in the her-l+ background, sufficient her-l activity is present to effectively mask this. Therefore we constructed sup; her-l(e1561) strains to explore the effects of y11 and y12 in XO animals. e1561 is a ts allele of her-l; XO animals are >95% male at 15 and 18 , and hermaphrodite at 20 . y11; e1561 and y12; e1561 XO animals are exclusively hermaphrodite at all three temperatures. Thus, y11 and y12 can result in feminization of both XX and XO animals where her-1 activity is present. We were interested in placing y11 and y12 in the context of the major sex determination pathway. We felt that the interactions between the sups and mutations in the known genes immediately upstream (sdc-1) and downstream (tra-2) of her-l would be especially informative. tra-2( n1106) XX animals are weakly transformed towards a male sexual fate. The resulting sup; n1106 animals are indistinguishable from n1106 alone. We are at present placing the sups in combination with the strong alleles n196 and e1095 of tra-2, and constructing the triple mutant strains sup; n1106; n695. sdc-1(n485)/Df results in XX animals being transformed into pseudomales (Villeneuve and Meyer, Cell, in press). y12; n485/Df animals are suppressed for this transformation. One possibility is that y12, and probably y11, modulate the major sex determination pathway at some point between the genes sdc-1 and tra-2.