在养猪业中, 与脂肪沉积相关的性状如背膘厚、肥肉率等具有重要的经济价值。因此, 研究与脂肪沉积有关的基因具有重要的理论和实践意义。FIT1(Fat-inducing transcript 1)基因, 即脂肪诱导转录基因, 在脂肪滴打包形成过程中具有重要作用。文章以FIT1基因作为脂肪沉积的候选基因, 通过序列比较, 发现该基因在第二外显子590~595 bp处存在CACTCC的插入/缺失突变。对该位点的多态性进行了PCR-SSCP检测, 并在F2“大白×梅山”资源家系中作了性状关联分析。结果表明: 在所检测的所有个体中, 梅山猪均为CACTCC插入, 定为A等位基因, 而在大白猪中主要为CACTCC缺失, 定为B等位基因; 在“大白×梅山”F2资源家系群体中进行的性状关联分析表明该位点与肥肉率、6~7腰椎间膘厚、臀部平均膘厚、板油重、内脂合计、内脂率(%)等脂肪沉积性状的相关性达到极显著水平(P<0.01)。以上结果提示, FIT1基因在脂肪沉积方面可能具有较大的应用价值, 有必要对其进行更深入的功能研究, 为分子标记辅助选择提供理论依据。
In pig industry, fat deposition related traits such as back fat thickness and fat rate are of great economic importance. Thus, research on genes related with fat deposition can offer many useful values theoretically and practically. Gene FIT1 (Fat-inducing transcript 1) plays an important role in packaging lipid droplets. Here, we used FIT1 gene as the candidate gene for fat deposition. Sequence comparison revealed that an insertion/deletion mutation occurred at 590~595 bp of the second exon. We then carried out PCR-SSCP analysis followed by association analysis in F2 “Large white ×Meishan” resource family. In all the individuals tested, all Meishan pigs possessed the insertion, which was designated allele A, while most Large white pigs possessed the deletion and was named as allele B. Association analysis in F2 resource family showed that this site was highly associated with fat percentage (FP), 6-7 rib fat thickness (RFT), buttock fat thickness (BFT), leaf fat weigh (LFW), total internal fat weigh (TFW), and internal fat rate (IFR) (P<0.01). These results indicated that FIT1 gene may have some important values for application. Further and deep research is necessary for revealing more information on this gene in order to provide a new marker for molecular marker-assisted selection breeding.
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