title: Changes in glutathione redox cycle during diapause determination and termination in the bivoltine silkworm, Bombyx mori.
abstract: To explore whether glutathione regulates diapause determination and termination in the bivoltine silkworm Bombyx mori, we monitored the changes in glutathione redox cycle in the ovary of both diapause- and nondiapause-egg producers, as well as those in diapause eggs incubated at different temperatures. The activity of thioredoxin reductase (TrxR) was detected in ovaries but not in eggs, while neither ovaries nor eggs showed activity of glutathione peroxidase. A lower reduced glutathione/oxidized glutathione (GSH/GSSG) ratio was observed in the ovary of diapause-egg producers, due to weaker reduction of oxidized glutathione (GSSG) to the reduced glutathione (GSH) catalyzed by glutathione reductase (GR) and TrxR. This indicates an oxidative shift in the glutathione redox cycle during diapause determination. Compared with the 25°C-treated diapause eggs, the 5°C-treated diapause eggs showed lower GSH/GSSG ratio, a result of stronger oxidation of GSH catalyzed by thioredoxin peroxidase and weaker reduction of GSSG catalyzed by GR. Our study demonstrated the important regulatory role of glutathione in diapause determination and termination of the bivoltine silkworm.
authors: College of Biological and Basic Medicine Sciences, Soochow University, Suzhou, Jiangsu Province, China.
authors: Lin-Chuan
authors: LC
authors: Zhao
authors: Yi-Sheng
authors: YS
authors: Hou
authors: Yang-Hu
authors: YH
authors: Sima
mesh_terms: D000818:Animals; D012831:Bombyx / Q000201:enzymology / Q000254:growth & development* / Q000378:metabolism*; D005260:Female; D005978:Glutathione / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000378:metabolism; D019476:Insect Proteins / Q000378:metabolism; D008675:Metamorphosis, Biological; D010053:Ovary / Q000166:cytology / Q000201:enzymology / Q000378:metabolism; D010063:Ovum / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism; D010084:Oxidation-Reduction; D013880:Thioredoxin-Disulfide Reductase / Q000378:metabolism
chemical_list: D019476:Insect Proteins; D005979:Glutathione Peroxidase; D013880:Thioredoxin-Disulfide Reductase; D005978:Glutathione
keywords: Bombyx mori; determination; diapause; glutathione redox cycle; termination