猪肌肉糖原磷酸化酶基因的多态性及其与胴体和肉质性状的相关分析

Genetic Polymorphism and Correlation Analysis with Meat Quality and Carcass Traits of Porcine PYGM Gene

试验旨在寻找不同品种猪的差异表达基因,并对其遗传效应进行初步分析。应用抑制消减杂交技术获得了在梅山猪、长白猪和大白猪中差异表达的肌肉糖原磷酸化酶(glycogen phosphorylase,muscle form,PYGM)基因及其全长cDNA序列,序列分析结果表明,猪PYGM基因编码842个氨基酸,与人、牛、狗、小鼠、大鼠和羊的氨基酸序列具有96%、97%、96%、96%、96%和97%的相似性,而且该基因在各组织中表达量均很高。通过序列比对发现,在3′非翻译区(3′UTR)125 bp处存在1个突变。利用PCR-RFLP方法,在大白猪、梅山猪、长白纯种猪和170头大白×梅山F2代资源家系中检测了该突变位点的多态性并进行性状关联分析,结果表明,该位点的多态性与瘦肉率、骨率、肥肉率、平均背膘厚、眼肌面积、胴体长显著相关,尤其是活体瘦肉率AA基因型(大白猪、长白猪优势基因)比BB基因型(梅山猪优势基因)高3%,肥肉率低5%,与外来猪种瘦肉率显著高于本地猪的性状表现是一致的。因此,猪PYGM基因125 bp位点可能是一个潜在的分子标记辅助常规育种位点。

To search for differentially expressed genes and analysis its genetic effections,in this study,glycogen phosphorylase,muscle form（PYGM）gene was found differentially expressed between Meishan×Large White F1 hybrids and their parents Meishan pigs,and its full-length cDNA sequence was obtained from Yorkshire,Landrace and Meishan pig.Translation of the mRNA transcript revealed an open reading frame（ORF） of 842 amino acid residues,Alignment analysis revealed that the deduced protein sequence exhibit 96%,97%,96%,96%,96%and 97% identity with that of human,cattle,dog,rat,mouse and sheep,respectively.The tissue expression analysis indicated that the porcine PYGM gene was highly expressed in muscle,fat,heart,liver,spleen,lung,kidney,stomach,small intestine,uterus,ovary and testis.One SNP was detected by sequence comparison in 3′untranslated region.The SNP was detected with PCR-RFLP among Yorkshire,Landrace,Meishan and 170 Meishan×Yorkshire F2 progeny.With statistical analysis,it was found the polymorphism was significant associated with lean meat percentage,bone percentage,fat meat percentage,average backfat thickness,loin eye area and carcass length,espessly the lean meat percentage of AA genotype in Yorkshire and Landrace was 3% more than BB genotype in Meishan pigs,but the fat meat percentage was 5% less than Meishan pig.The results was consistent with the performance among lean and local pigs.Therefore,the SNP might be a marker-assistant selection.