Genomic organisation of rainbow trout, Oncorhynchus mykiss TGF-beta

G D Daniels, C J Secombes

Research output: Contribution to journalArticle

Abstract

The genomic organisation of Oncorhynchus mykiss TGF-beta has been determined through the generation of contiguous clones by PCR, The O. mykiss TGF-beta gene is approximately 3.4 Kb in length and consists of 7 coding exons with no introns in the 5'-UTR. Whilst this is the same number of exons found in TGF-beta genes of amphibians, birds and mammals, in the O. mykiss gene intron 2 of other vertebrates is absent and an additional intron is present at the 3' end of the molecule, splitting exon 7 of the other known TGF-beta genes into two exons (trout exons 6 and 7). Comparison of exon sizes in the coding region support the suggestion that the Xenopus TGF-beta 5 and trout TGF-beta sequences are the forerunners of TGF-beta 1. Conservation of exons coding for the mature TGF-beta peptide is relatively high (63-73% identity) but other exons show lower identities (37-58%). Comparison of the TGF-beta intron sequences reveals that in general the O. mykiss introns are considerably shorter than the avian homologs. The impact of the teleost TGF-beta gene organisation on theories of the gene evolution of this cytokine family are discussed. (C) 1999 Elsevier Science Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)139-147
Number of pages9
JournalDevelopmental and Comparative Immunology
Volume23
Publication statusPublished - 1999

Keywords

  • TGF-beta
  • cytokine
  • rainbow trout
  • gene organisation
  • splice sites
  • introns
  • exons
  • PCR
  • GROWTH-FACTOR-BETA
  • COMPLEMENTARY-DNA
  • MOUSE CHROMOSOME-7
  • VERTEBRATE GENOME
  • TRANSFORMED-CELLS
  • XENOPUS-LAEVIS
  • GENE FAMILY
  • SEQUENCE
  • SUPERFAMILY
  • EXPRESSION

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