人胸腺素α原cDNA序列多态性分析

Analysis of polymorphism in human cDNA sequence of prothymosin-α

目的：通过对人胸腺素α原（prothymosin-α，ProTa）cDNA测序来分析人胸腺素a原的序列多态性。方法：应用RT—PCR技术从健康人外周血及健康新生儿脐带血中扩增胸腺素α原cDNA，纯化后与克隆载体pMDl8-T连接，进行克隆测序，并与标准序列比对，分析其多态性。结果：序列分析结果表明，克隆的ProTa基因的核苷酸序列并不一致。与已报道的胸腺素Q原基因（NM-002823）进行比较，发现存在2种变异：I类变异包括107位单核苷酸突变（A→G）、110～121位和191～205位的核苷酸片段缺失；Ⅱ类变异为306位单核苷酸（G）缺失，多见于年龄60-80岁者。结论：本研究中Pro Tα cDNA序列存在2种变异，但并未影响其N-端前28个氨基酸。

Objective：To analyze the polymorphism in human cDNA sequence of prothymosin-α （ProTα） by sequencing analysis. Methods： The cDNA of human ProTα was amplified from cells of peripheral blood and cord blood by RT-PCR. The product of RT-PCR was purified and linked with vector pMD18-T. After cloning and sequencing, the sequence of ProTα cDNA was compared with the standard sequence to analyze the polymorphism in the ProTα cDNA sequence. Results： The cloned ProTα cDNA sequence was different from that of the standard. We found 2 kinds of variations： （1） The nucleotide in 107 position was varied and the nucleotides in 110-121 and 191-205 positions were deleted; （2） The nucleotide in 306 position was deleted, mainly in the 60-80 years old group. Conclusion： We have identified 2 kinds of variations in human ProTα cDNA, but the first 28 amino acid in the N-terminal of cDNA of human ProTα are not involved therefore the variations do not affect the function of human ProTα.