Isolation and endocrine regulation of an HMG-CoA synthase cDNA from the male Jeffrey pine beetle, Dendroctonus jeffreyi (Coleoptera : Scolytidae)

We have isolated a full length 3-hydroxy-3-methylglutaryl coenzyme A syntha se (HMG-S) cDNA from the male Jeffrey pine beetle, Dendroctonus jeffreyi Ho pkins, and studied the effects of topical applications of juvenile hormone III (JH III) on its expression. The predicted translation product of this a pparently single copy gene has 63% and 58% identity with HMG-S1 and HMG-S2 from Blattella germanica (L.), and 61% identity with Drosophila melanogaste r Hmgs. HMG-S transcript levels remain uniformly low in JH III-treated and control D. jeffreyi females, but are induced approximately 2.5- to 5-fold i n JH III-treated males. JH III causes a dose- and time-dependent increase i n HMG-S transcripts in the male metathoracic-abdominal region. Since monote rpenoid pheromone precursor synthesis and HMG-CoA reductase expression are under the control of JH III in the metathorax of Ips bark beetles, the obse rved HMG-S expression pattern suggests that the isoprenoid pathway is simil arly important for semiochemical production in D. jeffreyi. (C) 2000 Elsevi er Science Ltd. All rights reserved.