Changes in glutathione redox cycle during diapause determination and termination in the bivoltine silkworm, Bombyx moil

• Published in: 中国昆虫科学：英文版 2014 (1), p.39-46
• Main Author: Lin-Chuan Zhao Yi-Sheng Hou Yang-Hu Sima
• Format: Article
• Language: English
• Subjects: GSSG; 家蚕; 氧化还原循环; 滞育卵; 硫氧还蛋白; 谷胱甘肽过氧化物酶; 谷胱甘肽还原酶; 还原型谷胱甘肽
• ISSN: 1672-9609; 1744-7917

To explore whether glutathione regulates diapause determination and termina tion in the bivoltine silkworm Bombyx mori, we monitored the changes in glutathione redox cycle in the ovary of both diapanse and nondiapauseegg producers, as well as those in dia pause eggs incubated at different temperatures. The activity ofthioredoxin 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 diapauseegg 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 cy cle during diapause determination. Compared with the 25℃treated diapause eggs, the 5℃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.