JUVENILE-HORMONE REGULATES THE EXPRESSION OF THE GENE ENCODING CERATOTOXIN-A, AN ANTIBACTERIAL PEPTIDE FROM THE FEMALE REPRODUCTIVE ACCESSORY-GLANDS OF THE MEDFLY CERATITIS-CAPITATA

Ceratotoxin A is an antibacterial peptide produced by the reproductive female accessory glands of the medfly Ceratitis capitata. To investig ate whether ceratotoxin A gene expression was affected by juvenile hor mone, which has gonadotropic functions in adult insects, newly emerged female medflies were treated with precocene II, an antiallotropin com pound capable of inhibiting juvenile hormone biosynthesis. Daily treat ment of newly emerged flies with precocene II blocked ceratotoxin A ge ne expression in a dose-dependent manner. Ceratotoxin A gene expressio n could be recovered after withdrawl of precocene II treatment. Moreov er, the effect of precocene II on ceratotoxin A gene expression could be countered by simultaneous treatment with methoprene, a juvenile hor mone analogue. The effects of precocene II and methoprene treatments o n the growth of both ovaries and accessory glands was also investigate d. Our data suggest that ceratotoxin A gene expression is modulated by juvenile hormone. (C) 1997 Elsevier Science Ltd. All rights reserved.