title: Molecular and bioinformatical characterization of a novel superfamily of cysteine-rich peptides from arthropods.
abstract: The full-length cDNA sequences of two novel cysteine-rich peptides (referred to as HsVx1 and MmKTx1) were obtained from scorpions. The two peptides represent a novel class of cysteine-rich peptides with a unique cysteine pattern. The genomic sequence of HsVx1 is composed of three exons interrupted by two introns that are localized in the mature peptide encoding region and inserted in phase 1 and phase 2, respectively. Such a genomic organization markedly differs from those of other peptides from scorpions described previously. Genome-wide search for the orthologs of HsVx1 identified 59 novel cysteine-rich peptides from arthropods. These peptides share a consistent cysteine pattern with HsVx1. Genomic comparison revealed extensive intron length differences and intronic number and position polymorphisms among the genes of these peptides. Further analysis identified 30 cases of intron sliding, 1 case of intron gain and 22 cases of intron loss occurred with the genes of the HsVx1 and HsVx1-like peptides. It is interesting to see that three HsVx1-like peptides XP_001658928, XP_001658929 and XP_001658930 were derived from a single gene (XP gene): the former two were generated from alternative splicing; the third one was encoded by a DNA region in the reverse complementary strand of the third intron of the XP gene. These findings strongly suggest that the genes of these cysteine-rich peptides were evolved by intron sliding, intron gain/loss, gene recombination and alternative splicing events in response to selective forces without changing their cysteine pattern. The evolution of these genes is dominated by intron sliding and intron loss.
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Wuhan 430074, People's Republic of China. xianchun.zeng@gmail.com
authors.forename: Xian-Chun
authors.initials: XC
authors.lastname: Zeng
authors.forename: Yao
authors.initials: Y
authors.lastname: Nie
authors.forename: Xuesong
authors.initials: X
authors.lastname: Luo
authors.forename: Shifen
authors.initials: S
authors.lastname: Wu
authors.forename: Wanxia
authors.initials: W
authors.lastname: Shi
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Yichen
authors.initials: Y
authors.lastname: Liu
authors.forename: Hanjun
authors.initials: H
authors.lastname: Cao
authors.forename: Ye
authors.initials: Y
authors.lastname: Yang
authors.forename: Jianping
authors.initials: J
authors.lastname: Zhou
mesh_terms: D020121:5' Untranslated Regions; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019295:Computational Biology; D017124:Conserved Sequence; D003545:Cysteine / Q000737:chemistry*; D019143:Evolution, Molecular; D019476:Insect Proteins / Q000737:chemistry* / Q000235:genetics; D007438:Introns; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000235:genetics; D010802:Phylogeny; D011110:Polymorphism, Genetic; D012605:Scorpions / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
chemical_list: D020121:5' Untranslated Regions; D019476:Insect Proteins; D010455:Peptides; D003545:Cysteine