Grant sponsor: National Natural Science Foundation of China; Grant number: 31172264; Grant sponsor: National High-Tech R&D Program of China (863 Program); Grant number: 2011AA100306; Grant sponsor: Provincial Key Technology R&D Program of Jiangsu; Grant number: BE2011327-1; Grant sponsor: Priority Academic Program Development of Jiangsu Higher Education Institutions.
CHITIN SYNTHASE B: A MIDGUT-SPECIFIC GENE INDUCED BY INSECT HORMONES AND INVOLVED IN FOOD INTAKE IN Bombyx mori LARVAE
Article first published online: 13 DEC 2013
© 2013 Wiley Periodicals, Inc.
Archives of Insect Biochemistry and Physiology
Volume 85, Issue 1, pages 36–47, January 2014
How to Cite
Zhuo, W., Chu, F., Kong, L., Tao, H., Sima, Y. and Xu, S. (2014), CHITIN SYNTHASE B: A MIDGUT-SPECIFIC GENE INDUCED BY INSECT HORMONES AND INVOLVED IN FOOD INTAKE IN Bombyx mori LARVAE. Arch. Insect Biochem. Physiol., 85: 36–47. doi: 10.1002/arch.21141
Weiwei Zhuo and Feng Chu are co-first authors who contributed equally to this work.
- Issue published online: 15 DEC 2013
- Article first published online: 13 DEC 2013
- National Natural Science Foundation of China. Grant Number: 31172264
- National High-Tech R&D Program of China (863 Program). Grant Number: 2011AA100306
- Provincial Key Technology R&D Program of Jiangsu. Grant Number: BE2011327-1
- Priority Academic Program Development of Jiangsu Higher Education Institutions
- chitin synthase B;
- gene expression;
- exogenous hormone;
- nikkomycin Z;
- Bombyx mori
Chitin synthase (CHS) is the key regulatory enzyme in chitin synthesis and excretion in insects, and a specific target of insecticides. We cloned a CHS B gene of Bombyx mori (BmChsB) and showed it to be midgut specific, highly expressed during the feeding process in the larva. Knockdown of BmChsB expression in the third-instar larvae increased the number of nonmolting and abnormally molting larvae. Exposure to nikkomycin Z, a CHS inhibitor, reduced the amount of chitin in the peritrophic membrane of molted larvae, whereas abnormally elevated BmChsB mRNA levels were readily detected from the end of molting and in the newly molted larvae. Exogenous 20-hydroxyecdysone (20E) and methoprene, a juvenile hormone analogue, significantly upregulated the expression of BmChsB when the levels of endogenous molting hormone (MH) were low and the levels of endogenous juvenile hormone (JH) were high immediately after molting. When levels of endogenous MH were high and those of endogenous JH were low during the molting stage, exogenous 20E did not upregulate BmChsB expression and exogenous methoprene upregulated it negligibly. When the endogenous hormone levels were low during the mulberry-leaf intake process, BmChsB expression was upregulated by exogenous methoprene. We conclude that the expression of BmChsB is regulated by insect hormones, and directly affects the chitin-synthesis-dependent form of the peritrophic membrane and protects the food intake and molting process of silkworm larvae.