Abstract:

【Objective】 The cDNA sequence of duck liver basic fatty acid-binding protein(Lb-FABP) gene was cloned and the gene tissue patterns and protein structure were analyzed. 【Method】 Based on comparative genomics, the cDNA sequence of duck Lb-FABP gene was obtained by RT-PCR and RACE. The mRNA expressions of the gene in sixteen tissues were detected through semi-quantitative PCR. And the protein structure was analyzed by bioinformatics methods. 【Result】 The cDNA sequence of the gene contained the 5’ untranslated region (5’UTR, 97 bp), the 3’ untranslated region (3’UTR, 69 bp) and the CDS (381 bp, including the stop condon). The gene was composed of 4 exons and 3 introns, which were 991 bp, 292 bp, and 713 bp, respectively. The semi-quantitative RT-PCR results revealed that Lb-FABP mRNA expression was higher in the liver than that in the other fifteen tissues. The physical and chemical properties of duck Lb-FABP indicated that Lb-FABP is a basic protein. And the protein has no clear signal peptide and transmembrane segments. The secondary structure of duck Lb-FABP was mainly made of β sheets and few α helixes and loops. One cytosol fatty acid-binding protein domain was found on the amino acid region from 5 to 22. The speculated amino acids sequence of duck Lb-FABP shared 97% and above 80% homologies with chicken and other nonmanmalian vertebrate species. The results showed that Lb-FABP is not in mammalian species. 【Conclusion】 The full length of the cDNA and genomic sequences were obtained. And the Lb-FABP mRNA expression was the highest in duck liver. One cytosol fatty acid-binding protein domain was found on the amino acid region from 5 to 22.

Key words: duck, Lb-FABP gene, cloning, tissue expression pattern, protein function prediction