Juvenile hormone inhibition of gene expression for cytochrome P4504C1 in adult females of the cockroach, Blaberus discoidalis

The regulation and pattern of gene expression for cytochrome P4504C1 was me asured in the fat body of adult females of the cockroach, Blaberus discoida lis. The level of CYP4C1-mRNA was high at adult emergence but disappeared a fter 4 days of adult Life. In starved females, CYP4C1-mRNA levels declined by day 4 but increased steadily thereafter; by 25 days, the levels were nea rly twice those observed at eclosion. Both the rapid early disappearance of the transcript and the starvation-related increase failed to occur followi ng decapitation. Allatectomy also prevented the disappearance of CYP4C1-mRN A at day 4, and treatment of decapitated females with methoprene (JHA) stim ulated a 70% decrease in transcript within 24 h. Injection of synthetic Bla berus hypertrehalosemic hormone (HTH) increased CYP4C1-mRNA by six-fold in the fat body of both intact and decapitated females. CYP4C1-mRNA in the fat body of males did not respond to JHA treatment. The dynamics of CYP4C1-mRN A in the fat body of females could be explained based on an inhibition of C YP4C1 expression by JH that was overcome by HTH. (C) 1999 Elsevier Science Ltd. All rights reserved.