Prothoracicotropic hormone (PTTH), a neuropeptide hormone stimulating the prothoracic glands to synthesize ecdysone, plays an important role in regulating postembryonic development in insects. The cDNA encoding PTTH w...Prothoracicotropic hormone (PTTH), a neuropeptide hormone stimulating the prothoracic glands to synthesize ecdysone, plays an important role in regulating postembryonic development in insects. The cDNA encoding PTTH was isolated and sequenced from the beet armyworm, Spodoptera exigua (Spe). The deduced a?mino acid sequence is composed of a signal peptide, a peptide (65 amino acids) of un-known function, and a mature PTTH molecule (111 amino acids). The Spe-PTTH shows similarities (45.5%―70.3%) to other known PTTHs reported in Lepidoptera species, but 7 cysteine r?esidues and the hydrophobic regions were conserved. Whole-mount immunocytochemistry by using an antiserum against recombinant Helicoverpa armigera PTTH showed that Spe-PTTH was synthesized in two pairs of neurosecretory cells in the S. exigua brain. Northern blot analysis demonstrates the presence of a 1.2-kb transcript in the brain. The Spe-PTTH mRNA is detectable at high levels at the wandering larval stage, early pupal stage, and pharate adult stage, suggesting that the Spe-PTTH gene might be corre-lated with molting, metamorphosis, and reproduction.展开更多
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 immunosorbe...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 be-tween 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.展开更多
基金Supported by the National Basic Research Program of the Ministry of Science and Technology, People’s Republic of China (Grant No. 2006CB102001)The nucleotide sequence data reported in this article have been submitted to Gen-Bank and have been assigned the accession number AY628763
文摘Prothoracicotropic hormone (PTTH), a neuropeptide hormone stimulating the prothoracic glands to synthesize ecdysone, plays an important role in regulating postembryonic development in insects. The cDNA encoding PTTH was isolated and sequenced from the beet armyworm, Spodoptera exigua (Spe). The deduced a?mino acid sequence is composed of a signal peptide, a peptide (65 amino acids) of un-known function, and a mature PTTH molecule (111 amino acids). The Spe-PTTH shows similarities (45.5%―70.3%) to other known PTTHs reported in Lepidoptera species, but 7 cysteine r?esidues and the hydrophobic regions were conserved. Whole-mount immunocytochemistry by using an antiserum against recombinant Helicoverpa armigera PTTH showed that Spe-PTTH was synthesized in two pairs of neurosecretory cells in the S. exigua brain. Northern blot analysis demonstrates the presence of a 1.2-kb transcript in the brain. The Spe-PTTH mRNA is detectable at high levels at the wandering larval stage, early pupal stage, and pharate adult stage, suggesting that the Spe-PTTH gene might be corre-lated with molting, metamorphosis, and reproduction.
基金the National Basic Research Program of the Ministry of Science and Technology,People’s Republic of China (Grant No.2006CB102001)the Na-tional Natural Science Foundation of China (Grant No. 30370198)
文摘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 be-tween 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.
