| dc.description | Six genes encoding intracellular lipid-binding proteins (iLBPs), including fatty acid-binding proteins 3 (fabp3) and 7 (fabp7a and fabp7b), cellular retinol-binding protein 1 (rbp1a and rbp1b) and 2 (rbp2) were identified in the zebrafish (Danio rerio) genome. cDNAs for fabp3, fabp7b, rbp1a and rbp1b were cloned by 3' RACE and 5'RLM-RACE and sequenced. The structure of each gene was defined through data mining of the zebrafish genomic DNA database. Transcription start site(s) for each gene were mapped by 5'RLM-RACE. Phylogenetic analysis and synteny with mammalian orthologs confirmed the identity of each gene, and radiation hybrid mapping assigned each gene to a linkage group. Tissue-specific distribution of iLBP gene transcripts in adult zebrafish was investigated by RT-PCR, and by tissue-section in situ hybridization and emulsion autoradiography. Spatio-temporal distribution of the iLBP gene transcripts during development was examined using whole mount in situ hybridization on zebrafish embryos and larvae at different developmental stages. The results showed that the genomic properties of the zebrafish iLBP genes, including gene structure, coding features and syntenic relationship, are conserved when compared with their mammalian orthologs, while both conserved and diverged expression patterns were observed. Gene duplication is common within the zebrafish iLBP multigene family. Genomic analysis of two duplicated iLBP gene pairs showed that the duplicate iLBP genes might arise from chromosomal, or possibly, whole genome duplication. Comparative analysis of the spatio-temporal distribution of mRNA from sister copies of the duplicated iLBP gene pairs provided new insights into the evolution of gene functions and the mechanism for preservation of duplicate genes in the vertebrate genomes. | en_US |
