Laboratory for Bio-feed and Molecular Nutrition, College of Animal Science and Technology, Southwest University, Chongqing, China.
State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, China.
J Anim Sci. 2024 Jan 3;102. doi: 10.1093/jas/skae264.
Pork is an important high-value protein source that fulfills the nutritional requirements for normal growth development, repair, and metabolism. Tryptophan (Trp), a crucial amino acid for piglet growth performance and muscle development, has an essential yet unclear regulatory mechanism. To investigate the biological basis of Trp regulation of piglet muscle development and identify the related regulatory pathways, we studied 20 weaned piglets. The piglets were divided into control (CON, 0.14% Trp) and high Trp (HT, 0.35% Trp) groups. They were fed with different Trp concentrations for 28 d, after which we collected the longissimus dorsi (LD) muscle for histomorphometric analysis and RNA extraction. Our results showed that the HT diet significantly increased the average daily weight gain, myocyte number, and muscle fiber density in weaned piglets. We then analyzed the differentially expressed (DE) genes in the LD muscle through RNA sequencing (RNA-seq). We identified 253 lncRNAs and 1,055 mRNAs mainly involved in myoblast proliferation and myofiber formation, particularly through the FoxO and AMPK signaling pathways and metabolism. Further analysis of the DE lncRNA targeting relationship and construction of a protein-protein interaction network resulted in the discovery of a novel lncRNA, XLOC_021675, or FRPMD, and elucidated its role in regulating piglet muscle development. Finally, we confirmed the RNA-seq results by reverse transcription polymerase chain reaction (RT-PCR). This study provides valuable insights into the regulatory mechanism of lncRNA-mediated Trp regulation of muscle development in weaned piglets offering a theoretical basis for optimizing piglet dietary ratios and enhancing pork production.
猪肉是一种重要的高价值蛋白质来源，可满足正常生长发育、修复和代谢的营养需求。色氨酸（Trp）是仔猪生长性能和肌肉发育的关键氨基酸，其具有重要但尚未明确的调节机制。为了研究 Trp 调节仔猪肌肉发育的生物学基础并确定相关的调节途径，我们研究了 20 头断奶仔猪。仔猪分为对照组（CON，0.14%Trp）和高 Trp 组（HT，0.35%Trp）。它们分别用不同 Trp 浓度喂养 28 天，之后采集背最长肌（LD）进行组织形态学分析和 RNA 提取。结果表明，HT 饮食显著增加了断奶仔猪的平均日增重、肌细胞数量和肌纤维密度。然后，我们通过 RNA 测序（RNA-seq）分析 LD 肌肉中的差异表达（DE）基因。我们鉴定了 253 个 lncRNA 和 1055 个 mRNAs，它们主要参与肌细胞增殖和肌纤维形成，特别是通过 FoxO 和 AMPK 信号通路和代谢。进一步分析 DE lncRNA 的靶向关系并构建蛋白质-蛋白质相互作用网络，发现了一个新的 lncRNA，XLOC_021675 或 FRPMD，并阐明了其在调节仔猪肌肉发育中的作用。最后，我们通过逆转录聚合酶链反应（RT-PCR）验证了 RNA-seq 结果。该研究提供了有关 lncRNA 介导的 Trp 调节断奶仔猪肌肉发育的调节机制的有价值的见解，为优化仔猪日粮比例和提高猪肉产量提供了理论依据。
