(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) > cellular organisms: NE > Eukaryota: NE > Opisthokonta: NE > Metazoa: NE > Eumetazoa: NE > Bilateria: NE > Protostomia: NE > Ecdysozoa: NE > Panarthropoda: NE > Arthropoda: NE > Mandibulata: NE > Pancrustacea: NE > Hexapoda: NE > Insecta: NE > Dicondylia: NE > Pterygota: NE > Neoptera: NE > Paraneoptera: NE > Hemiptera: NE > Sternorrhyncha: NE > Aphidomorpha: NE > Aphidoidea: NE > Aphididae: NE > Aphidinae: NE > Aphidini: NE > Rhopalosiphum: NE > Rhopalosiphum padi complex: NE > Rhopalosiphum padi: NE
LegendThis sequence has been compared to family alignement (MSA) red => minority aminoacid blue => majority aminoacid color intensity => conservation rate title => sequence position(MSA position)aminoacid rate Catalytic site Catalytic site in the MSA MSVDCVYTSAVTLLLCCSAVLGRPSSNGGADGGGGGGSAGGGAGGGGGGG SAVDDTDESPVVVTSTGLVQGYTKIIANREVRVYTGIPFAKPPVGHLRFR RPVPVDPWPGVLNATRLPNTCYQERYEYFPGFVGEDMWNPNTKLSEDCLY LNIWIPRKQRTRHHSNNAHHAKIPVLVWIYGGGYMSGTSTLDIYDGDLLA ATFDVMIASMQYRLGAFGSLYITPELPEDSDDAPGNMGLWDQALAIKWIK ENAAAFGADPETITLFGESAGGGSVSVHLISPETRGMVKRGIIQSGTVNA PWSYMTGERAVDIAKKLLDDCNCNSTSLDSNPIGTMSCMRSVDASTISKK QWNSYSGILGFPSAPTVDGIFLPEHPLDMLAKANFSDIDILIGSNLNEGT YFLLYDFVDFFDRTSATALPREKFVQIVNVIFKDRTQLERDAIIYQYSGW EKKEVDDIYSNQKQLSDVVADYFFVCPTNLFANIVSSRGARVYYYFFTHR TDSHLWGDWMGVLHGDEMQYVFGHPLNMSMPYNARERDLSIRIMEAFTRF SLTGTPVSDDIDWPLYNESKPIYHVWNAAEMHVGYGPRAAECQFWNGFFP KIAQALKETSKTTCEDYPDSMPTTNENCTFTSSFATINPQISFTIIFILV LPAHGLF
References
Title: Mutations in acetylcholinesterase genes of Rhopalosiphum padi resistant to organophosphate and carbamate insecticides Chen MH, Han ZJ, Qiao XF, Qu MJ Ref: Genome, 50:172, 2007 : PubMed
Apple grain aphid, Rhopalosiphum padi (Linnaeus), is an important wheat pest. In China, it has been reported that R. padi has developed high resistance to carbamate and organophosphate insecticides. Previous work cloned from this aphid 2 different genes encoding acetylcholinesterase (AChE), which is the target enzyme for carbamate and organophosphate insecticides, and its insensitive alteration has been proven to be an important mechanism for insecticide resistance in other insects. In this study, both resistant and susceptible strains of R, padi were developed, and their AChEs were compared to determine whether resistance resulted from this mechanism and whether these 2 genes both play a role in resistance. Bioassays showed that the resistant strain used was highly or moderately resistant to pirimicarb, omethoate, and monocrotophos (resistance ratio, 263.8, 53.8, and 17.5, respectively), and showed little resistance to deltamethrin or thiodicarb (resistance ratio, 5.2 and 3.4, respectively). Correspondingly, biochemistry analysis found that AChE from resistant aphids was very insensitive to the first 3 insecticides (I50 increased 43.0-, 15.2-, and 8.8-fold, respectively), but not to thiodicarb (I50 increased 1.1-fold). Enzyme kinetics tests showed that resistant and susceptible strains had different AChEs. Sequence analysis of the 2 AChE genes cloned from resistant and susceptible aphids revealed that 2 mutations in Ace2 and 1 in Ace1 were consistently associated with resistance. Mutation F368(290)L in Ace2 localized at the same position as a previously proven resistance mutation site in other insects. The other 2 mutations, S329(228)P in Ace1 and V435(356)A in Ace2, were also found to affect the enzyme structure. These findings indicate that resistance in this aphid is mainly the result of insensistive AChE alteration, that the 3 mutations found might contribute to resistance, and that the AChEs encoded by both genes could serve as targets of insecticides.
Title: Cloning and sequence analysis of 2 different acetylcholinesterase genes in Rhopalosiphum padi and Sitobion avenae Chen M, Han Z Ref: Genome, 49:239, 2006 : PubMed
Two genes encoding different acetylcholinesterases (AChE) were successfully cloned from 2 species of aphid, Rhopalosiphum padi (L.) and Sitobion avenae (F.). They were named Rp.AChE1 (GenBank accession No. AY707318), Rp.AChE2 (AY667435), Sa.AChE1 (AY707319), and Sa.AChE2 (AY819704), and were 2133, 2363, 2131, and 2362 bp in length and encoded 664, 676, 664, and 676 amino acids, respectively. All of them shared the characteristics of the AChE family: catalytic tiads, 3 intra-chain disulfide bridges, an acyl pocket, and the conservative aromatic residues for the active site of the gorge. Sequence analysis revealed that Rp.AChE1 and Sa.AChE1 showed higher identity to the reported orthologous genes of Drosophila AChE, and Rp.AChE2 and Sa.AChE2 to paralogous genes. However, in each of the aphids, the 2 genes from the same species shared only 29% identity between one another. It was therefore concluded that each of the aphids has 2 different AChE genes, which are either orthologous or paralogous to Drosophila AChE. The high conservation of AChE1 and AChE2 indicated that 2 acetylcholinesterases exist popularly and that both might function in aphids.
