The characterization of prepro-Insulin-like growth factor-1 Ea-2 expression and Insulin-like growth factor-1 genes (devoid 81 bp) in the zebrafish (Danio rerio)

Chen, M.H., Lin, G., Gong, H., Weng, C., Chang, C., and Wu, J.
Gene   268(1-2): 67-75 (Journal)
Registered Authors
Chen, Mark Hung-Chih, Gong, Hong-Yi, Lin, Gen-Hwa, Weng, Ching-Feng, Wu, Jen-Leih
ProIGF-I; Danio rerio; cDNA; genome
MeSH Terms
  • 3' Untranslated Regions
  • 5' Untranslated Regions
  • Alternative Splicing
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cloning, Molecular
  • Embryo, Nonmammalian
  • Exons
  • Gene Expression Regulation, Developmental*
  • Insulin-Like Growth Factor I/genetics*
  • Insulin-Like Growth Factor I/metabolism
  • Molecular Sequence Data
  • Protein Isoforms/genetics
  • Protein Precursors/genetics*
  • Protein Precursors/metabolism
  • Sequence Analysis
  • Somatomedins/genetics*
  • Zebrafish/embryology
  • Zebrafish/genetics*
  • Zebrafish/growth & development
  • Zebrafish Proteins*
11368902 Full text @ Gene
n this study, we cloned zebrafish (Danio rerio) IGF-1 cDNA and gene from zebrafish brain cDNA library and adult zebrafish genomic library, respectively. Based on two cDNAs sequence with different length of 5'- and 3'-untranslated region (5UTR and 3UTR) and one nucleotide difference at glutamine (A9, CAG) of A domain represented at IGF-1 sequence. One of zebrafish IGF-1 genes named as IGF-1a gene. The zebrafish IGF-1a gene spanned approximately 15 kb and is divided into five exons. The results of IGF-1 cDNA and genomic Southern blotting, all indicated that the zebrafish have more than one IGF-1 gene. The genomic organization of zebrafish IGF-1a gene in an exon is devoid of 81 bp segment which is located at 3' end of exon 3 encoded 27 amino acid of E domain. The segment of 27 amino acid exists in known teleost IGF-1 genes but is absent in zebrafish IGF-1 gene. The E domain of zebrafish IGF-1 Ea-2 is encoded by 3' end of exon 3 (16 amino acid), full of exon 4 (12 amino acid) and exon 5 (19 amino acid). The sequence data revealed the zebrafish IGF-1a gene encoded IGF-1a Ea-2 mRNA. In combination RT-PCR with Southern blotting, zebrafish IGF-1 genes abundantly expressed IGF-1 Ea-2 mRNA in all tested adult tissues and developmental stages of embryo. The IGF-1 Ea-2 mRNA was first detected during embryo development from blastula stage to hatching, during yolk absorption and at feeding. All these findings suggest that the expression of pro-IGF-1 Ea-2 is not controlled by alternative splicing but alternative gene usage in the zebrafish.
Genes / Markers
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Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Engineered Foreign Genes