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2004 Fiscal Year Final Research Report Summary

Molecular evolution of secreted phospholipases A2 from venomous snakes

Research Project

Project/Area Number 15570189
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Evolutionary biology
Research InstitutionSophia University

Principal Investigator

TAMIYA Toru  Sophia University, Chemistry, Professor, 理工学部, 教授 (30119135)

Co-Investigator(Kenkyū-buntansha) KANZAWA Nobuyuki  Sophia University, Chemistry, Research Associate, 理工学部, 助手 (40286761)
Project Period (FY) 2003 – 2004
Keywordssnake venom / group IA phospholipase A2 / group IB phospholipase A2 / accelerated evolution / molecular evolution / Elaphe climacophora / Laticauda semifasciata / Trimersurus flavoviridis
Research Abstract

Toxic type PLA2 (IA type) gene expressed in the venom glands and enzymic PLA2 (IB type) gene expressed in pancreas should coexist in the genome of the proteroglyphous snakes such as cobras and sea kraits. Therefore, in the genomes of proteroglyphous snakes, PLA2 genes have been evolved through discarding or maintaining the enzymic function from a common ancestor gene. The aim of this study is to clarify the evolution process of various PLA2 genes expressed in the venomous snakes.
In the academic year 2003, mRNAs were extracted from the L. semifasciata tissues, mRNAs obtained were amplified by RT-PCR. Both type PLA2s (type IB : pancreas type ; type IA : toxin type) were amplified from the heart, pancreas, venom gland, brain, lungs, and muscles. None of the deduced amino acid sequences has pro-sequences which exist in mammalian pancreatic PLA2s. Northern blot analysis and gene quantitative analysis by slot blot Southern hybridization revealed that the expression level of type IB PLA2 was very low.
In the academic year 2004, mRNAs were extracted from the livers of sea snakes (L.colubrine, L.laticaudata), habu snake (Trimeresurus flavoviridis) which has type II PLA2s in the venom and non-toxic snakes (Llaphe climacophora and Llaphe quadriviragata). cDNAs encoding type IB PLA2s were amplified from all the snakes. The size of the cDNAs are about 900 by and the deduced amino acid sequences have no pro-sequences.

  • Research Products

    (3 results)

All 2004 2003

All Journal Article (3 results)

  • [Journal Article] Comparative analysis of gene expression mechanisms between group IA and IB phospholipase A2 gene from sea snake Laticauda semifasciata2004

    • Author(s)
      Fujimi, T., Yasuoka, S., Ogura, E., Tsuchiya, T., Tamiya, T.
    • Journal Title

      Gene 332

      Pages: 179-190

    • Description
      「研究成果報告書概要(和文)」より
  • [Journal Article] Comparative analysis of gene expression mechanisms between group IA and IB phospholipase A2 gene from sea snake Laticauda semifasciata2004

    • Author(s)
      Fujimi, T.J., Yasuoka, S., Ogura, E., Tsuchiya, T., Tamiya, T.
    • Journal Title

      Gene 332

      Pages: 179-190

    • Description
      「研究成果報告書概要(欧文)」より
  • [Journal Article] Molecular evolution and diversification of snake toxin genes, revealed by analysis of intron sequence2003

    • Author(s)
      Fujimi, T.J., Nakajo, T., Nishimura, E., Ogura, E., Tsuchiya, T., Tamiya, T.
    • Journal Title

      Gene 313

      Pages: 111-118

    • Description
      「研究成果報告書概要(和文)」より

URL: 

Published: 2006-07-11  

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