大型迪庆藏猪不同生长阶段背脂沉积差异基因及其调控通路分析

Differential gene screening and regulation analysis of back fat deposition of large Diqing Tibetan pigs at different growth stages

【目的】筛选大型迪庆藏猪不同生长阶段背脂沉积差异的关键基因并分析其调控途径。【方法】对体重长至40、80、120 kg的大型迪庆藏猪背脂组织进行转录组测序,测序数据进行拼接、比对、注释并进行功能富集分析、STEM趋势分析和互作网络分析。【结果】10~40 kg(S1阶段)与40~80 kg(S2阶段)、S2阶段与80~120 kg(S3阶段)比较分别筛选到845、558个显著差异表达基因(DEGs);差异表达基因STEM趋势分析显示,模块0、模块3和模块4的基因随大型迪庆藏猪体重增加而下调表达,模块14的基因先上调后轻微下调;显著差异基因互作网络显示,在模块0、模块3和模块4的基因互作网络中,PTGER3、CPT1B、LPIN3基因位于核心位置,PTGER3下调抑制脂肪分解、促进脂肪细胞增大,CPT1B下调降低脂肪酸氧化能力、导致甘油三酯增多,LPIN3下调维持脂质稳态;在模块14的基因互作网络中,AACS、SOCS3、AQP3、RPS6KA1位于核心位置,AACS上调促进脂肪细胞分化、脂肪细胞数量增多,SOCS3、RPS6KA1上调促进脂肪生成,AQP3上调促进脂肪细胞内甘油三酯增多,这与大型迪庆藏猪随体重增加背膘厚显著增加,但S1阶段与S2阶段背膘厚的增幅大于S2阶段与S3阶段的结果一致;对PTGER3、AACS等15个差异基因进行qPCR验证,定量结果与转录组结果一致。【结论】本研究筛选到15个调控大型迪庆藏猪背膘厚的潜在候选基因,可为迪庆藏猪的遗传改良提供参考。

【Objective】The present study aimed to screen the key genes regulating back fat deposition of large Diqing Tibetan pigs(TPs)at different growth stages and analyze their regulatory pathway.【Method】Transcriptome sequencing of back fat tissues of TPs with body weight up to 40,80 and 120 kg was performed,and 3 pigs as a group.The sequencing data were spliced,compared,annotated and analyzed.Differential genes related to back fat deposition were screened by functional enrichment analysis,STEM analysis and differential gene interaction network analysis.【Result】There were 845 and 558 significantly differentially expressed genes(DEGs)in 10-40 kg(stage 1)vs.40-80 kg(stage 2),40-80 kg vs.80-120 kg(stage 3),respectively.STEM analysis of differential genes showed that the genes of modules 0,3 and 4 were down-regulated with increasing body weight of TPs,and the genes of modules 14 were up-regulated firstly and then slightly down-regulated.Differential gene interaction network analysis showed that PTGER3,CPT1B and LPIN3 genes were located in the core of the gene interaction network constructed by genes in modules 0,3 and 4.The down-regulation of PTGER3 inhibited lipolysis and promoted adipocyte enlargement,the down-regulation of CPT1B reduced fatty acid oxidation and increased triglycerides,and the down-regulation of LPIN3 maintained lipid homeostasis.AACS,SOCS3,AQP3 and RPS6KA1 were located at the core of gene interaction network constructed by genes in module 14.The up-regulation of AACS promoted adipocyte differentiation and the increase in number of adipocytes,the up-regulation of SOCS3 and RPS6KA1 promoted adipogenesis,and the up-regulation of AQP3 promoted the increase of triglycerides in adipocytes.This was consistent with the result that backfat thickness of TPs increased significantly with the increase of body weight,but the increase of backfat thickness at stage 1 vs.stage 2 was greater than that at stage 2 vs.stage 3.There were 15 differential genes such as PTGER3 and AACS were selected for qPCR verification,and the quantitative verification results of 15 genes were consistent with the transcriptome sequencing results.【Conclusion】In the study,15 potential candidate genes that regulate backfat thickness of TPs are screened to provide reference for the genetic improvement of TPs.