HYPERTREHALOSEMIC HORMONE IN A COCKROACH - MOLECULAR-CLONING AND EXPRESSION

Hypertrehalosemic hormone (HTH) is a neuropeptide in the adipokinetic hormone/red pigment-concentrating hormone (AKH/RPCH) family that stimu lates the synthesis of trehalose, the main blood sugar of many insects . The preproHTH of the cockroach Blaberus discoidalis was cloned from the corpora cardiaca (CC), the endocrine source for HTH, and the deduc ed sequence and organization of preproHTH were compared with other AKH /RPCH precursors. PreproHTH mRNA was determined to be similar to 0.5 k b in length as predicted by DNA. sequence analysis. Northern blot anal ysis of the CC, ventral nerve cord, brain and fat body detected HTH-mR NA only in the CC. Levels of the HTH transcript in the CC were determi ned according to age, gender and mating. The HTH message was most abun dant in the CC during the first several days of adult life in both sex es, then declined by 50% and were stable. HTH-mRNA levels in the CC di d not respond to mating. (C) 1997 Elsevier Science Ireland Ltd.