Cloning and sequence analysis of duck BMP4 gene.

With the aid of comparative genomics,the cDNA sequence of duck BMP4 gene was cloned by the method of RT-PCR.The cloned 1 256 bp cDNA of duck BMP4 gene included a partial 5′UTR of 44 bps and the complete coding sequence of 1 212 bp,which encoded 404 amino acid residues.And the duck BMP4 gene contained two exons and one intron.Duck BMP4 CDS sequence shared a 95.5% homologous identity with that of chicken.Duck BMP4 mature peptide also expressed high homologue among 15 species.The result of phylogenetic analysis of BMP4 revealed that Aves(including duck and chicken) resided into the same cluster with amphibians and fish.The results of the protein structure prediction showed that first 19 amino acids formed signal peptide,which coincided with hydrophobic and transmembrane region.The relative molecular mass of duck BMP4 protein was 46 074 and the isoelectric focus point was 8.87.The secondary structure included α-helics accounting for one third,and the tertiary structure contained seven α-helicses and two β-sheets.The results will provide data for the investigation of duck BMP4 gene mechanism and function.