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.

A Maintenance Function for her-1 in Control of Vitellogenin Synthesis and Oogenesis in XO Adults

P. Schedin, P. Jonas and W.B. Wood

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.