Molecular Cloning And Characterization Of Ryanodine Receptors From Chilo Suppressalis And Its Larval Endoparasitoid, Cotesia Chilonis

In this study, we cloned ryanodine receptors from Chilo suppressalis and its larval endoparasitoid Cotesia chilonis. And the amino acid sequence of CsRyR and CcRyR was analyzed for putative regulatory domains. Further by comparing their amino acid sequences, we speculated the reason why diamide insecticide has high toxicity to Chilo suppressalis but nearly no toxicity to Cotesia chilonis. The main content is summarized as follows:1. Molecular cloning and characterization of ryanodine receptors from Chilo suppressalisThe CsRyR cDNA ORF encodes5113amino acids, with molecular mass of578.5kDa. The ORF of CsRyR has a long hydrophilic N-terminal, and its C-terminal with six hydrophobic transmembrane domain (TM1:4460-4482; TM2:4641-4663; TM3:4723-4745; TM4:4865-4887; TM5:4913-4935; TM6:4993-5012), without signal peptide. CsRyR shares the greatest amino acid identity with Cnaphalocrocis medinalis ryanodine receptor, CmRyR(89%).2. Molecular cloning and characterization of ryanodine receptors from Cotesia chilonisThe CcRyR cDNA ORF encodes5121amino acids, with molecular mass of580.0kDa. The ORF of CcRyR has a long hydrophilic N-terminal, and its C-terminal with six hydrophobic transmembrane domain (TM1:4445-4467; TM2:4632-4654; TM3:4726-4748; TM4:4869-4891; TM5:4917-4939; TM6:4997-5016), without signal peptide. CcRyR shares84%amino acid identity with Harpegnathos saltator ryanodine receptor(HsRyR), Bombus terrestris ryanodine receptor(BtRyR) and Apis mellifera ryanodine receptor(AmRyR). But CcRyR shares a relative low amino acid identity with CsRyR(75%).3. By mainly comparing the amino acid sequences of CcRyR and CsRyR, we also found several specific amino acid residues in lepidopteran insects(corresponds to N4963, N4965, N4976, L4991, L5022, N5054and T5105in CsRyR). In addtion, in comparison with CsRyR, CcRyR has a specific amino acids (4700-4708) between the TM2and TM3of CcRyR. These differences might be the reason why diamide insecticide has high toxicity to Chilo suppressalis but nearly no toxicity to Cotesia chilonis.