Table 5_Transcriptomics characteristics and differentiation of subcutaneous adipose tissue among Huainan pigs and its hybrid genetic populations.xlsx

IntroductionThe Huainan pig (HN) is known for its impressive litter size and exquisite meat quality. However, it also exhibits certain drawbacks such as excessive fat deposition, a relatively low percentage of lean meat percentage, and a slower growth rate. Crossbreeding with lean-type breeds, such as Large White, Landrace, and Berkshire can enhance offspring traits, and increase genetic diversity.
MethodsIn this study we employed RNA-seq technology to identify differentially expressed genes (DEGs) in subcutaneous adipose tissue (SAT) samples from HN pigs and their crosses with multiple breeds (with three replicates per group).
ResultsIn the SAT of Huainan × Berkshire pigs (BH), Huainan × Yorkshire pigs (YH), and Huainan × Landrace pigs (LH), numerous key functional genes were identified, including LIPG, PLIN2, CPT1A, KLF9, CCND1, LDLR, ACSL1, ACLY and ANGPTL4. Functional enrichment analysis revealed that DEGs were primarily involved in several key pathways in BH, including the peroxisome proliferator-activated receptor (PPAR) signaling, metabolic pathways, arachidonic acid metabolism, and arginine/proline metabolism. Similarly, in LH, DEGs were associated with PPAR, cyclic adenosine monophosphate (cAMP) signaling, mitogen-activated protein kinase (MAPK), and the arginine/proline pathway. In contrast, the main pathways in YH were slightly different, including MAPK, fatty acid elongation, arginine/proline metabolism, and glycine/serine/threonine metabolism. Compared to HN, the differential genes in BH, LH, and YH showed a reduced fat deposition. However, in comparison, LH has a stronger subcutaneous fat deposition ability. Notably, LH exhibited a stronger tendency for subcutaneous fat deposition than the other two groups, while YH had the lowest fat deposition capacity.
ConclusionIn conclusion, these findings offer valuable insights and provide a foundation for future research on the molecular mechanisms underlying fat deposition in pigs.

引言
淮猪（Huainan pig, HN）以产仔性能优异、肉质细嫩见长，但亦存在脂肪沉积过度、瘦肉率偏低及生长速度较慢等不足。通过与大白猪（Large White）、长白猪（Landrace）、巴克夏猪（Berkshire）等瘦肉型品种杂交，可优化后代性状并提升遗传多样性。

方法
本研究采用RNA测序（RNA-seq）技术，对淮猪及其多品种杂交后代的皮下脂肪组织（subcutaneous adipose tissue, SAT）样本进行差异表达基因（differentially expressed genes, DEGs）筛选，每组设置3个生物学重复。

结果
本研究在淮猪×巴克夏猪杂交群体（BH）、淮猪×约克夏猪杂交群体（YH）及淮猪×长白猪杂交群体（LH）的皮下脂肪组织中，鉴定得到多个关键功能基因，包括LIPG、PLIN2、CPT1A、KLF9、CCND1、LDLR、ACSL1、ACLY及ANGPTL4。功能富集分析显示，BH群体中的差异表达基因主要富集于过氧化物酶体增殖物激活受体（peroxisome proliferator-activated receptor, PPAR）信号通路、代谢通路、花生四烯酸代谢通路以及精氨酸/脯氨酸代谢通路。同样地，LH群体的差异表达基因与PPAR信号通路、环磷酸腺苷（cyclic adenosine monophosphate, cAMP）信号通路、丝裂原活化蛋白激酶（mitogen-activated protein kinase, MAPK）通路及精氨酸/脯氨酸代谢通路显著相关。与之相比，YH群体的主要富集通路略有差异，涵盖MAPK通路、脂肪酸延长通路、精氨酸/脯氨酸代谢通路以及甘氨酸/丝氨酸/苏氨酸代谢通路。与淮猪亲本相比，BH、LH及YH群体的差异表达基因均与脂肪沉积降低相关。但进一步比较发现，LH群体的皮下脂肪沉积能力更强，其皮下脂肪沉积倾向显著高于另外两个杂交群体，而YH群体的脂肪沉积能力最低。

结论
综上，本研究结果为解析猪脂肪沉积的分子调控机制提供了重要参考与研究基础。