Cytoplasmic glutamine synthetase gene expression regulates larval development in Bactrocera dorsalis (Hendel)

• Published in: Archives of insect biochemistry and physiology Vol. 97; no. 4
• Main Authors: Zhang, Meng‐Yi, Wei, Dong, Li, Ran, Jia, Hong‐Ting, Liu, Yu‐Wei, Taning, Clauvis Nji Tizi, Wang, Jin‐Jun, Smagghe, Guy
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.04.2018
• Subjects: Amino Acid Sequence; Animals; Aquatic insects; Bactrocera dorsalis; Cytosol; Delay; Embryogenesis; Embryonic growth stage; Fecundity; Female; Fruit flies; Gene expression; Genes; Glutamate-ammonia ligase; Glutamate-Ammonia Ligase - genetics; Glutamate-Ammonia Ligase - metabolism; Glutamine; glutamine synthetase; Heat shock; Herbivores; Homology; Insect Proteins - metabolism; Insects; Larva - enzymology; Larva - growth & development; Larval development; Lethality; L‐methionine S‐sulfoximine; Methionine; Methionine Sulfoximine; Mitochondria; Mosquitoes; oriental fruit fly; Pest control; Phylogeny; Pupation; Ribonucleic acid; RNA; RNA Interference; RNA-mediated interference; Synthesis; Tephritidae - enzymology; Tephritidae - genetics; Tephritidae - growth & development; Weight loss; L-methionine S-sulfoximine; pupation; RNA interference; glutamine synthetase; oriental fruit fly
• ISSN: 0739-4462; 1520-6327
• DOI: 10.1002/arch.21447

In insects, glutamine synthetase (GS), a key enzyme in the synthesis of glutamine, has been reported to be associated with embryonic development, heat shock response, and fecundity regulation. However, little is known about the influence of GS on postembryonic development. In this study, we demonstrate that blocking the activity of GS in the oriental fruit fly (Bactrocera dorsalis) with use of a GS‐specific inhibitor (L‐methionine S‐sulfoximine), led to a significant delay in larval development, pupal weight loss, and inhibition of pupation. We further identify cloned and characterized two GS genes (BdGS‐c and BdGS‐m) from B. dorsalis. The two GS genes identified in B. dorsalis were predicted to be located in the cytosol (BdGS‐c) and mitochondria (BdGS‐m), and homology analysis indicated that both genes were similar to homologs from other Dipterans, such as Drosophila melanogaster and Aedes aegypti. BdGS‐c was highly expressed in the larval stages, suggesting that cytosolic GS plays a predominant role in larval development. Furthermore, RNA interference experiments against BdGS‐c, to specifically decrease the expression of cytosolic GS, resulted in delay in larval development as well as pupal weight loss. This study presents the prominent role played by BdGS‐c in regulating larval development and suggests that the observed effect could have been modulated through ecdysteroid synthesis, agreeing with the reduced expression of the halloween gene spook. Also, the direct effects of BdGS‐c silencing on B. dorsalis, such as larval lethality, delayed pupation, and late emergence, can be further exploited as novel insecticide target in the context of pest management.