为了揭示猪杂种优势的分子机理,利用mRNA差异显示技术研究梅山猪,大白猪和梅大杂交猪背最长肌中基因表达的差异,分离14条在杂种与纯种背最长肌中差异表达的表达序列标签(EST),并用半定量RT-PCR鉴定.核苷酸序列分析表明,这14个EST与已知的基因或表达序列标签没有明显的同源性,随后这14条EST被提交到GenBank数据库.组织表达谱分析揭示了这些EST在心、脾、肝、肾、小肠、卵巢、肺等绝大多数组织中表达,说明这些基因对生命过程很重要.这些研究结果表明梅山×大白杂交组合的杂种与纯种之间的不同基因差异表达的方向存在巨大差异,猪杂种优势可能是在一定阶段有诸多不同的必不可少的基因向各种方向差异表达共同作用的结果.%In order to detect the molecular mechanism of the heterosis in pigs, mRNA differential display (DD) technique was performed to investigate the differences in gene expression in the Longissimus dorsi muscle tissues from Meishan, Meishan×Large White cross and Large White pigs. Fourteen expressed sequence tags (ESTs), differentially expressed between the hybrids and purebreds, were isolated and identified through semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). The nucleotide sequence analysis revealed that the 14 ESTs were not homologous to any of the known genes or ESTs. These novel ESTs were then deposited into GenBank database. Tissue expression profile analysis showed that the ESTs were expressed in most of tissues including heart, spleen, liver, kidney, small intestine, ovary and lung, and this also implied that these genes might be important for the life process. Our results indicate the diversity of differential display directions of genes between the hybrids and purebreds in the Meishan ×Large White cross combination. Results also suggest that the heterosis in pigs might be derived from the differential expression of many indispensable genes towards different directions in the specific phase of life.
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