Molecular Characterization of the Insulin-like Growth Factor-I (IGF-I) Gene in Channel Catfish (Ictalurus punctatus)
Document Type
Article
Publication Date
12-20-2005
Department
Biological Sciences
School
Biological, Environmental, and Earth Sciences
Abstract
The insulin-like growth factor I (IGF-I) gene was characterized in channel catfish. Partial cDNA sequence, missing exon 1 and part of exon 2, was obtained in 5′- and 3′-RACE experiments. Direct sequencing of two bacterial artificial chromosome clones revealed gene structure and provided sequence from 640 bp upstream of the initiator methionine to 136 bp beyond the polyadenylation site. Genomic sequence contained a putative TATA box 506 bp upstream of the initiator methionine. The 477-bp reading frame within five exons encoded a 159-amino acid (aa) pre-propeptide highly similar to IGF-I in higher vertebrates. The sequence encoding the signal peptide was unique in catfish and contained 70% G + C content with the potential for a stable stem–loop structure. Full-length cDNA was only maintained in recombination-deficient (DH10B) strain E. coli. Levels of IGF-I mRNA were highest in liver, followed by brain and muscle, then heart and kidney (P < 0.05). A CT/GA dinucleotide microsatellite in intron 1 was highly polymorphic in commercial channel catfish, and permitted placement of the IGF-I gene on the catfish genetic map. However, specific IGF-I alleles were not correlated with differences in growth rate from 100 to 130 days post-hatch in USDA103 line catfish.
Publication Title
Biochimicao et Biophysica Acta (BBA) - Gene Structure and Expression
Volume
1731
Issue
3
First Page
139
Last Page
148
Recommended Citation
Clay, L. A.,
Wang, S. Y.,
Wolters, W. R.,
Peterson, B. C.,
Waldbieser, G. C.
(2005). Molecular Characterization of the Insulin-like Growth Factor-I (IGF-I) Gene in Channel Catfish (Ictalurus punctatus). Biochimicao et Biophysica Acta (BBA) - Gene Structure and Expression, 1731(3), 139-148.
Available at: https://aquila.usm.edu/fac_pubs/8571