麻鸭和樱桃谷鸭的CD3ε、CD4、CD8α基因ORF克隆及序列分析

Cloning and Sequence Analyses of Genes Coding for CD3ε,CD4,CD8α of Sheldrake and Cherry Valley Duck

【目的】分析比较中国部分品种鸭的CD3ε、CD4和CD8α基因ORF序列,为研究CD3ε链、CD4和CD8α链的结构和功能及其抗体的应用提供依据。【方法】利用RT-PCR,对麻鸭、樱桃谷鸭的CD3ε、CD4和CD8α基因ORF序列克隆测定,应用Clustal(X1.83)和DNAstar生物学软件分别与GenBank上公布的北京鸭CD3ε(AF378704)、CD4(AF378701)和CD8α(AF378373)基因ORF序列进行序列分析。【结果】麻鸭、樱桃谷鸭、北京鸭CD3ε和CD4基因ORF序列及所编码的氨基酸同源性为99%;北京鸭和麻鸭CD8α基因ORF序列同源性为99%,与樱桃谷鸭的同源性为95%。麻鸭和北京鸭CD8α基因ORF序基因编码的氨基酸完全一致,与樱桃谷鸭的CD8α存在16处位点差异,其中胞外区有15个氨基酸的差异,使亲水性、抗原性以及此区域位于蛋白质表面的可能性都有明显差异。从遗传发生树得出樱桃谷鸭、北京鸭、麻鸭CD3ε和CD4的ORF序列相互之间的遗传关系近;樱桃谷鸭、麻鸭和北京鸭CD8α基因ORF序列之间的遗传关系较远。【结论】樱桃谷鸭、北京鸭、麻鸭CD3ε和CD4的ORF序列遗传变异性低,樱桃谷鸭与麻鸭和北京鸭CD8α基因ORF之间具有较高遗传变异性。

【Objective】 Comparative analyses were conducted employing the coding sequences of the CD3ε,CD4,and CD8α genes from ducks of certain Chinese domestic breeds,which provide a fundamental basis for the investigation of their structure and function,and potential application of related antibodies.【Method】 The complete coding sequences of CD3ε,CD4,and CD8α of Sheldrake and Cherry Valley ducks were isolated by RT-PCR assay,and sequence alignment was made employing ClustalX（1.83） and DNAstar software by aligned with the corresponding coding sequences of Pekin duck（published in the GenBank,and accession no：AF378704,AF378701 and AF378373）.【Result】 The identities of pair-wise nucleotide and amino acid sequences of CD3ε and CD4 genes have reached to 99% among Pekin duck,Sheldrake and Cherry Valley duck.As for CD8α,the nucleotide sequences similarities between Pekin duck and Sheldrake reached 99%,whereas it was 95% for Pekin duck and Cherry Valley duck.Furthermore,the amino acid sequence of CD8α is the same for both Sheldrake and Cherry Valley duck,whereas the protein sequence of CD8α of Cherry Valley duck contained 16 different amino acids,including 15 amino acids in the extracellular area,which result in the obvious differences in protein hydrophilicity,antigenicity and the possibilities to be exposed on protein surface.The phylogenetic and evolutionary relationships of the nucleic acid sequences of these genes were analysed,the result showed a close relationship among Cherry valley duck ,Sheldrake and Pekin duck in genes coding for CD3ε and CD4,but Cherry valley duck had a remote relationship with Sheldrake and Pekin duck in genes coding for CD8α.【Conclusion】 There is a low diversity among Cherry valley duck ,Sheldrake and Pekin duck in genes coding for CD3ε and CD4,but Cherry valley duck has a considerable diversity with Sheldrake and Pekin duck in genes coding for CD8α.