利用功能分类基因芯片研究不同品种猪脂肪中特定基因的发育性变化

Developmental Expression Changes of Specific Genes in Adipose Tissue for Different Pig Breeds by Using Pathway- Focused Microarray

摘要:

利用Oligo功能分类基因芯片检测了瘦肉型的长白猪和脂肪型的太湖猪在1、2、3、4和5月龄间背部皮下脂肪中脂肪沉积代谢和细胞生长调控相关基因的动态表达变化。差异表达分析结果显示1~5月龄的品种间分别有10、6、11、8和19个基因的表达差异倍数大于2倍, 且长白猪有25个基因在不同月龄间的表达差异达显著水平(P<0.05)。其中血管生成素样蛋白4 (ANGPTL4)、组织蛋白酶K (CTSK) 、异柠檬酸脱氢酶2(NADP+) (IDH2)、脂蛋白脂酶 (LPL)、苹果酸酶1 (ME1)、 硬酯酰辅酶A去饱和酶 (SCD)和解藕联蛋白2 (UCP2)这7个基因不仅在同月龄的品种间和品种内的不同月龄间差异表达, 主成分分析结果也显示其表达模式明显偏离其他基因, 提示受到了特殊的调控。聚类分析结果显示1~5月龄间长白猪中正调控脂肪酸代谢基因的表达量逐渐上调, 太湖猪中参与细胞生长调控基因的表达量平缓波动且变化幅度相对较小。另外, 5个差异表达基因的荧光定量RT-PCR验证结果均与芯片结果呈正相关趋势。结果成功筛选出了对猪胴体和肉质性状可能具有重要影响并值得深入研究的一些候选基因, 初步揭示了相关基因的表达变化规律, 为了解生长发育过程中脂肪酸合成与水解的动态平衡过程提供了基础数据。

Abstract:

The expression changes of genes associated with adipose metabolism and regulation of cell growth in backfat tissue at five growth stages (1, 2, 3, 4 and 5 months) of Landrace (a leaner Western breed) and Taihu pigs (a fatty indigenous Chinese breed) were measured by using pathway-focused Oligo microarray. The comparative results between two pig breeds of change ratios showed that the fold changes of 10, 6, 11, 8 and 19 genes were over two times at same month from 1 to 5 months respectively. Variance analysis (ANOVA) revealed that 25 genes in Landrace pigs showed significantly altered in expression among five growth stages (P<0.05). Principal components analysis (PCA) revealed that angiopoietin-like 4 (ANGPTL4), cathepsin K (CTSK), isocitrate dehydrogenase 2(NADP+) (IDH2), lipoprotein lipase (LPL), malic enzyme 1 (ME1), stearoyl-CoA desaturase (SCD) and uncoupling protein 2 (UCP2) displayed distinctive expression patterns from other genes, which suggested that these genes may be subject to special regulation during the period from 1 to 5 months. K-means clustering analysis revealed that genes in Landrace pigs which showed up-regulation were mainly related to the positive regulation of fatty acid metabolism and genes in Taihu pigs which showed slight fluctuation were mainly related to the regulation of cell growth. Quantitative real-time RT-PCR was used to verify the microarray data for five modulated genes, and a good positive correlation between the two measures of expression was observed for both two pig breeds at different growth stages. These results highlight some possible candidate genes for porcine carcass and meat quality traits, reveal the expressional disciplinarian of correlative genes and provide some data on which to base further study of the dynamic balance process for fatty acid biogynthesis and hydrolyzation.