猪ESR基因一个外显子片段的克隆与序列分析

参考人、鸡、鼠的ESR基因序列，设计一对引物，采用PCR技术扩增出猪ESR基因一段DNA片段，将该片段克隆到pGEM-T Easy质粒中，重组质粒用PCR扩增和酶切分析进行阳性克隆鉴定，然后测定核苷酸序列，并推导其氨基酸序列。将测定的猪ESR基因的部分序列（332bp)与人、鼠、鸡的序列进行比较，结果表明：猪的核苷酸和氨基酸序列与人、鼠、鸡相比，同源性分别为90．06％和86．36％，85．54％和88．18％，74．10％和71．82％，显示了强的保守性，猪的核苷酸序列与人、鼠、鸡相比存在着4处特有变异，氨基酸序列aa25-30存在高变异区。

CLONING AND SEQUENCEANALYSIS OF THE DNA FRAGMENT OF A EXON OF THE PIG ESE GENE

According to the data of the human，chicken and rat ESR sequence，a pair of primer is designed．One DNA fragment of the pig ESR gene was amplified successfully by PCR，and was cloned into pGEM-T Easy vector．The fragment was further identified by PCR，restriction enzymes analysis and sequence analysis．The peptide sequence of this fragment was deduced．The comparison of the fragment sequence with those of human，rat and chicken ESR gene shows：The homologies of the nucleotide sequence and peptide sequence of the fragment with human，rat and chicken’s are 90.06％ and 86.36％，85.54％ and 88.18％，74.10％ and 71.82％，respectively，which indicates the ESR gene is highly conserved．The pig nucleotide sequence exits 4 special variation and the peptide sequence in amino acid 25～30 is poorly conserved．