Journal
REGULATORY PEPTIDES
Volume 118, Issue 1-2, Pages 25-31Publisher
ELSEVIER
DOI: 10.1016/j.regpep.2003.10.024
Keywords
suboesophageal ganglion neuropeptide I; pupal diapause; diapause termination hormone; Helicoverpa assulta
Categories
Ask authors/readers for more resources
Helicoverpa assulta suboesophageal ganglion neuropeptide I (Has-SGNP I) is a 24-amino acids peptide amide, which shows 62.5% similarity with the diapause hormone of Bombyx mori (Bom-DH). It has been demonstrated that embryonic diapause is induced by DH in B. mori. Injection of synthetic amidated Has-SGNP I terminated pupal diapause in a dose-dependent manner. Therefore, Has-SGNP I might be referred to a diapause termination hormone in H. assulta (Has-DTH). The maximal dose of Has-DTH for diapause termination was 1.0 mug and the half-maximal dose 0.4 mug. The time required for diapause termination of Has-DTH was 2-3 days longer than that of 20-hydroxyecdysone. During the pupal stage, DTH mRNA content in the SGs of nondiapausing pupae was always higher than in diapausing pupae using the combined method of quantitative RT-PCR and Southern blot. DTH gene also expressed at a low level while diapausing pupae were chilled at 4 degreesC, but increased rapidly and largely after being transferred to 25 degreesC. Using a competitive ELISA, Has-DTH-like immunoreactivity in the haemolymph showed the same pattern as that of Has-DTH gene expression. Those results indicated that Has-DTH gene expression was related to diapause development and could be activated by low temperature. Has-DTH might be useful to elucidate the mechanism of diapause termination in pupal diapause species. (C) 2003 Elsevier B.V All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available