Juvenile hormone regulation of HMG-R gene expression in the bark beetle Ips paraconfusus (Coleoptera : Scolytidae): implications for male aggregationpheromone biosynthesis

Juvenile hormone III (JH III) induces acyclic isoprenoid pheromone producti on in male Ips paraconfusus. A likely regulatory enzyme in this process is 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-R). To begin molecular studie s on pheromone production, a 1.16-kb complementary DNA representing approxi mately one-third of I. paraconfusus HMG-R was isolated by polymerase chain reaction and sequenced. The predicted translation product is 59% and 75% id entical to the corresponding portion of HMG-R from the fruit fly, Drosophil a melanogaster, and the German cockroach, Blattella germanica, respectively . Northern blots show that topical application of JH III increases HMG-R tr anscript levels in male thoraces in an apparent dose- and time-dependent ma nner. These data support the model that JH III raises HMG-R transcript leve ls, resulting in increased activity of the isoprenoid pathway and de novo p heromone production.