中文摘要：

为研究牛精子鞭毛2（SPEF2）基因在中国荷斯坦公牛各组织中的表达调控机制及其与精液品质的相关性,利用RTPCR和克隆测序技术分析SPEF2基因的可变剪切体,同时利用PCR-RFLP（PCR-restriction fragment length polymorphism）技术对中国荷斯坦公牛群体进行基因型检测分析。结果表明：鉴定到1个新转录本,命名为SPEF2-splice variant（SPEF2-SV）,此转录本是从外显子2到外显子5之间缺失459 bp的新序列,预测编码1个含有1 618个氨基酸的蛋白。SPEF2基因的参考转录本在睾丸中高表达,而SPEF2-SV呈现低表达。在SPEF2基因第1内含子（邻近剪切位点附近140 bp）筛选到1个单核苷酸多态（SNP）突变位点（g.11043C＞T）,经ESEfinder 3.0软件预测发现该SNP改变了剪切因子结合蛋白SC35与靶序列的结合,它可能是产生异常转录本的重要原因。此SNP位点与中国荷斯坦公牛精液品质的相关性分析结果表明,其与射精量、精子密度和精子活力无显著相关,而与精子畸形率显著相关（P〈0.05）,其中等位基因对精子畸形的加性效应、显性和替代效应分别是-1.24%、-2.99%、-0.76%。结论：SPEF2基因表达受可变剪切机制的调控,而且其g.11043C＞T突变位点可作为中国荷斯坦公牛精液品质选择的潜在功能性分子标记。

英文摘要：

This paper preliminarily studied the post-transcription regulation mechanism of sperm flagella 2（SPEF2） gene through analyzing gene alternative splicing,and further single nucleotide polymorphism（SNP） was scanned and predicted whether it is the reason producing the SPEF2 gene splice variant or not. Meanwhile,the association between the SNP and semen quality traits was analysed. Using RT-PCR and clone sequencing,we investigated the potentiol splices variant of bovine SPEF2 gene. 50 Chinese Holstein bulls were genotyped by the PCR-RFLP（PCR-restriction fragment length polymorphism）. The results showed that a novel bovine SPEF2 splice variant（SPEF2-SV） was identified in testis tissues using RT-PCR and cloning sequence which deleted a 459 bp sequence and encoded a putative shorten isoform（1 618 aa）; RT-PCR results showed that SPEF2-SV presented lower expression in testis when compared with the reference SPEF2-complete transcript. A SNP（g. 11043C〉T） near the splice sites around 140 bp was found in intron 1 of the bovine SPEF2 gene,which was located within a putative exonic splice enhancer（ESE）. Using ESEfinder 3. 0 software,we predicted that the SNP changed the SC35 combination with the target sequence and it might be the reason for the generation of the aberrant SPEF2-SV transcript. Association between the genotypes of the SNP and sperm quality traits showed that the SNP had a significant effect on the semen deformity rate（P〈0. 05）. However,no significant differences were found for the ejaculate volume,sperm density and sperm motility,of which,the additive,dominance and allele substitution effects of mutant allele on sperm deformity rate were-1. 24%,-2. 99% and-0. 76%,respectively. The result indicated that SPEF2 gene was regulated by alternative splicing mechanism and the SNP（g. 11043C〉T） can be used as a potential novel molecular marker for the selection of fineness semen quality traits in Chinese Holstein bulls.