Worm Breeder's Gazette 9(3): 51
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.
Early expression of the her-l gene appears to be both necessary and sufficient to establish the male program of somatic development. Using the temperature-sensitive allele her-l(e1561), Hodgkin observed that a shift to restrictive temperature after embryogenesis has no significant effect on male tail or gonad morphology in the adult (JEEM 83, Supplement, 103-117, 1984). We have used the same allele to ask whether later her-l expression is required to maintain the male differentiated state in the intestine (no vitellogenin synthesis) and the germline (no oocyte production). To determine the temperature- sensitive period for her-l control of vitellogenin synthesis, her-l( e1561);him- 8(e1489) XO animals were raised to early adulthood at 16 C, and the resulting morphologically normal males were then shifted to 25 C. By about 36 hr after the shift, synthesis of the three vitellogenins yp88, yp115, and yp170 was detected by electrophoresis and silver staining of proteins from 45-animal samples on 6% polyacrylamide gels. The germline of these animals was also transformed; approximately 80% had oocytes present by 48 hr after the shift. Control animals left at 16 showed no production of vitellogenins or oocytes for several days, although 9-dayold animals were found to make vitellogenin and oocytes in reduced amounts compared to animals shifted to 25 C. In addition, him- 8(e1489) XO animals were never observed to make either vitellogenin or oocytes at any age whether reared continuously at 16 C or 25 C, or reared to early adulthood at 16 C and then shifted to 25 C. The difference between her-l(e1561);him-8(e1489) and him-8(e1489) XO animals at 16 suggests that the her-l(e1561) gene product is unstable even at the permissive temperature. The results of the temperature-shift experiments indicate that decisions regarding vitellogenin synthesis in the intestine and oocyte production in the germline are not made irreversibly based on the state of the her-l gene during embryogenesis, or even during larval development. Rather, her-l activity is required in adult XO animals to maintain the male differentiated states of these tissues.