Cloning Novel ?-Conotoxins And Genetic Diversity Of Conus Lividus

There are around800species of cone snails living in the world tropical ocean. Venom of each cone snail species consists of up to2000conopeptides or conotoxins. a-Conotoxins are targeting various nAChR isoforms, which are a specific class of short, disulfide-constrained peptides with CC-C-C framework, therefore, they are widely used as pharmacological probe and directly developed drugs. Untill now, a large number of conotoxins have been discovered by native toxin isolation and cDNA cloning, as well as transcriptome sequencing. However, abundant a-conotoxins have yet to be further discovered and utilied.This study identified4a-conotoxins with introns and125a-conotoxins with partial propeptides and mature sequences by3methods.(1)4a-conotoxins were cloned from Genomic DNA of C. Caracteristicus native to Hainan, China, which based on the conserved DNA sequences of signal peptide and3'-UTR (untranslated region) of A-superfamily genes.(2)123a-conotoxins including94genes of a(4,7),9genes of a(4,6) and20genes of a(4,4) were cloned from38genomic DNA from10conus native to Hainan, China, which based on the conserved intron of a-conotoxins by PCR at multiple annealing temperatures. Moreover,12genes with3-Cys framework,13genes with ?? framework,5genes with5-Cys framework,1genes with ??? framework,1genes with ? framework, and1genes with9-Cys framework were also cloned by the method.(3)2?-conotoxins including a(4,7) and ?(4,1) two styles were discovered by transcriptome sequencing of C.lividus native to Hainan, China. Besides the two a-conotoxins, we have got32V-superfamily conotoxins,2O-superfamily conotoxins,1O3-superfamily conotoxin,3M-superfamily conotoxins,4T-superfamily conotoxins,1A-superfamily conotoxin,1Y-superfamily conotoxins, and10unknown superfamily conotoxins.(4)The introns of a-conotoxins shows that the repetition of Microsatellite DNA in introns has an infect on the expression of ?-conotoxins. Further more, introns is associated with conus species and their prey.(5) Analysis of mature region of ?-conotoxins indicated that there was a preference for particular synonymous Cys codon, a conservative proline behind Cys2, and a relationship of various subtype.75CIS genes were cloned from Genomic DNA of15C. lividusnative to Hainan, China, which based on256bp of ?-glutamate carboxylase.According to genetic difference of75CIS genes, variant3alleles in31bases were discovered. It shows genetic diversity of C.lividus.