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 language | English |
|---|---|
| Pages (from-to) | 139-147 |
| Number of pages | 9 |
| Journal | Developmental and Comparative Immunology |
| Volume | 23 |
| Publication status | Published - 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