鸭骨形成蛋白4基因的克隆和序列分析

摘要

通过比较基因组学方法,采用RT-PCR技术克隆了鸭骨形成蛋白4(BMP4)基因的1 256 bp cDNA序列,包含44 bp的5'非翻译区和1 212 bp的完整编码序列(编码404个氨基酸);对该基因的结构分析得知鸭BMP4基因包含2个外显子和1个内含子.经同源比对发现该编码序列与鸡的BMP4基因相似性达95.5%,15个物种的该基因成熟肽相似性很高.系统进化分析发现禽类包括鸭和鸡同两栖类、鱼类归为一大类;蛋白质预测结果显示,鸭BMP4基因1~19氨基酸序列为信号肽,与疏水、跨膜区域重合,相对分子质量为46 074,等电点是8.87;二级结构中近1/3为α-螺旋,三级结构由7个α-螺旋和2个卢β-折叠片构成.%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 1212 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.