Synthesis dynamic and developmental profile of prothoracicotropic hormone between diapause- and nondiapause-destined individuals in Helicoverpa arrnigera

Biosynthesis and secretion of prothoracicotropic hormone （PTTH） of diapause- and nondiapausedestined individuals in Helicoverpa armigera were studied using whole-mount immunocytochemistry and enzyme-linked immunosorbent assay （ELISA）. The immunocytochemistry revealed that PTTH is expressed in two pairs of lateral neurosecretory cells of the brain. The presence of immunoreactivity has not significant difference between the brains of the diapause- and nondiapause-destined 6th instar larvae. However, the obvious differences of expressional pattern from day 4 pupae were observed between the two types. PTTH titers in hemolymph from the 6th instar larvae to pharate adults were measured by the ELISA. Although there were similar titer changes between the two types of individuals at the larval stage, a significant difference from developmental expression was detected at the pupal stage, suggesting that the expression and secretion of PTTH does play a crucial role in regulation of pupal diapause of H. armigera.

Synthesis dynamic and developmental profile of prothoracicotropic hormone between diapause- and nondiapause-destined individuals in Helicoverpa armigera

Biosynthesis and secretion of prothoracicotropic hormone (PTTH) of diapause- and nondiapause-destined individuals in Helicoverpa armigera were studied using whole-mount immunocytochemistry and enzyme-linked immunosorbent assay (ELISA). The immunocytochemistry revealed that PTTH is expressed in two pairs of lateral neurosecretory cells of the brain. The presence of immunoreactivity has not significant difference between the brains of the diapause- and nondiapause-destined 6th instar larvae. However, the obvious differences of expressional pattern from day 4 pupae were observed between the two types. PTTH titers in hemolymph from the 6th instar larvae to pharate adults were measured by the ELISA. Although there were similar titer changes between the two types of individuals at the larval stage, a significant difference from developmental expression was detected at the pupal stage, suggesting that the expression and secretion of PTTH does play a crucial role in regulation of pupal diapause of H. armigera. Supported by the National Basic Research Program of the Ministry of Science and Technology, People’s Republic of China (Grant No. 2006CB102001), and the National Natural Science Foundation of China (Grant No. 30370198).