title: Molecular cloning and mRNA expression of a ryanodine receptor gene in the cotton bollworm, Helicoverpa armigera.
abstract: Ryanodine receptors (RyRs) are the targets of novel diamide insecticides. The cotton bollworm, Helicoverpa armigera, is one of the most important cotton pests in the world. In this study, we report the full-length RyR cDNA sequence (named as HaRyR) of H. armigera. The 16,083-bp contiguous sequence encoded 5, 142 amino acid residues, which shares 80% and 78% overall identities with its homologues in Nilaparvata lugens (NlRyR) and Drosophila melanogaster (DmRyR), respectively. All hallmarks of RyR proteins are conserved in the HaRyR, including the GXRXGGGXGD motif conserved in the Ca(2+) release channels and four copies of RyR domain unique to RyR channels. The previously identified seven lepidopteran-specific RyR residues were also found in HaRyR (N(4977), N(4979), N(4990), L(5005), L(5036), N(5068) and T(5119)). An amino acid sequence alignment showed that the N-terminal region of HaRyR (residues 188-295) shared high sequence identity with NlRyR (94%) and DmRyR (92%), and moderate sequence identity (47-50%) with three rabbit RyR isoforms, while the short segment of the C-terminal transmembrane region of HaRyR (residues 4632-4676) exhibited moderate sequence identity with NlRyR (69%) and DmRyR (67%), and low sequence identity (19-28%) with three rabbit RyR isoforms. In addition, expression analysis of HaRyR revealed that the mRNA expression level in eggs was significantly lower than in third instar larvae, pupae and adults, and anatomical regulation of HaRyR expression was also observed with the highest expression level in head compared with thorax and abdomen. Our results lay a foundation for comprehensive structural and functional characterization of HaRyR and for understanding of the molecular mechanisms of toxicity selectivity of diamide insecticides among different species.
authors.affiliation: College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Yaping
authors.initials: Y
authors.lastname: Liu
authors.forename: Jingkun
authors.initials: J
authors.lastname: Gao
authors.forename: Zhijuan
authors.initials: Z
authors.lastname: Xie
authors.forename: Li
authors.initials: L
authors.lastname: Huang
authors.forename: Wenlong
authors.initials: W
authors.lastname: Wang
authors.forename: Jianjun
authors.initials: J
authors.lastname: Wang
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D009036:Moths; D012333:RNA, Messenger / Q000235:genetics; D019837:Ryanodine Receptor Calcium Release Channel / Q000235:genetics / Q000378:metabolism*
chemical_list: D019476:Insect Proteins; D012333:RNA, Messenger; D019837:Ryanodine Receptor Calcium Release Channel
keywords: Calcium release channel; Cotton bollworm; Diamide insecticides; Helicoverpa armigera; RT-qPCR; Ryanodine receptor