title: Adaptive evolution after gene duplication in alpha-KT x 14 subfamily from Buthus martensii Karsch.
abstract: A series of isoforms of alpha-KT x 14 (short chain potassium channel scorpion toxins) were isolated from the venom of Buthus martensii Karsch by RACE and screening cDNA library methods. These isoforms adding BmKK1--3 and BmSKTx1--2 together shared high homology (more than 97%) with each other. The result of genomic sequence analysis showed that a length 79 bp intron is inserted Ala codes between the first and the second base at the 17th amino acid of signal peptide. The introns of these isoforms also share high homology with those of BmKK2 and BmSKT x 1 reported previously. Sequence analysis of many clones of cDNA and genomic DNA showed that a species population or individual polymorphism of alpha-KT x 14 genes took place in scorpion Buthus martensii Karsch and accelerated evolution played an important role in the forming process of alpha-KT x 14 scorpion toxins subfamily. The result of southern hybridization indicated that alpha-KT x 14 toxin genes existed in scorpion chromosome with multicopies. All findings maybe provided an important evidence for an extensive evolutionary process of the scorpion "pharmacological factory": at the early course of evolution, the ancestor toxic gene duplicated into a series of multicopy genes integrated at the different chromosome; at the late course of evolution, subsequent functional divergence of duplicate genes was generated by mutations, deletions and insertion.
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, PR China.
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Cao
authors.forename: Xin
authors.initials: X
authors.lastname: Mao
authors.forename: Xiuling
authors.initials: X
authors.lastname: Xu
authors.forename: Jiqun
authors.initials: J
authors.lastname: Sheng
authors.forename: Chao
authors.initials: C
authors.lastname: Dai
authors.forename: Yingliang
authors.initials: Y
authors.lastname: Wu
authors.forename: Feng
authors.initials: F
authors.lastname: Luo
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Sha
authors.forename: Dahe
authors.initials: D
authors.lastname: Jiang
authors.forename: Wenxin
authors.initials: W
authors.lastname: Li
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002681:China; D019143:Evolution, Molecular; D020440:Gene Duplication; D008969:Molecular Sequence Data; D005810:Multigene Family; D012604:Scorpion Venoms / Q000235:genetics*; D012605:Scorpions / Q000235:genetics*
chemical_list: D012604:Scorpion Venoms