Li Shuohan, Cheng Xi, Zhang Ke, Wang Yang, Wei Hongyu, Zhi Yihao, Cheng Zhimin, Guo Yulong, Li Hong, Tian Yadong, Liu Xiaojun, Tian Weihua
College of Animal Science and Technology, Henan Agricultural University, Zhengzhou 450046, China.
College of Animal Science and Technology, Henan Agricultural University, Zhengzhou 450046, China; Henan Key Laboratory for Innovation and Utilization of Chicken Germplasm Resources, Zhengzhou 450046, China; International Joint Research Laboratory for Poultry Breeding of Henan, Zhengzhou 450046, China.
Poult Sci. 2025 Aug 16;104(11):105694. doi: 10.1016/j.psj.2025.105694.
Transmembrane protein 38 (TMEM38) gene family, including TMEM38A and TMEM38B, is responsible for facilitating trimeric intracellular cation transport across the membrane and regulating key cellular processes, such as muscle contraction and cell differentiation in mammals. However, a genome-wide analysis of the chicken TMEM38 gene family, as well as investigations into their biological roles and post-transcriptional expression regulation in fat deposition have not yet been conducted. In this study, we investigated the genome-wide characteristics of chicken TMEM38 gene family, elucidated the regulatory roles of the TMEM38B gene in both abdominal and intramuscular adipogenesis, and explored its miRNA-mediated expression regulatory mechanisms. We found that chicken TMEM38A and TMEM38B exhibited notable conservation in gene structure and motifs across diverse species. Principal component analysis based on SNPs showed that genetic variations in the TMEM38B gene contributed to the selective breeding of commercial broilers. Moreover, gene expression profiling demonstrated that TMEM38A and TMEM38B showed the positive expression in chicken abdominal adipose and muscle tissues, and overall increased expression during the proliferation and adipogenic differentiation of both chicken abdominal and intramuscular preadipocytes. Functionally, TMEM38B overexpression significantly enhanced viability, proliferation, cell cycle progression as well as intracellular triglyceride content and lipid droplet accumulation of both chicken abdominal and intramuscular preadipocytes, paralleling with the expression of proliferative and adipogenic marker genes. Target miRNA prediction identified 37 potential miRNAs targeting the TMEM38B gene. Of these, a dual-luciferase reporter system verified that miR-20b-3p could directly bind to the 3'UTR of the TMEM38B gene and thus inhibit its post-transcriptional expression. Gain-of-function assays showed that miR-20b-3p could suppress the viability, proliferation, and cell cycle progression of chicken abdominal and intramuscular preadipocytes, as well as the adipogenic differentiation of chicken abdominal preadipocytes. Collectively, we demonstrated the promotive effects of TMEM38B in regulating abdominal and intramuscular fat deposition, as well as its post-transcriptional expression inhibition mediated by miR-20b-3p. These findings shed novel lights into the functional role and expression regulation of the miR-20b-3p-TMEM38B axis in adipogenesis, and may provide valuable biomarkers for the genetic improvement of fat traits in chickens.
跨膜蛋白38（TMEM38）基因家族，包括TMEM38A和TMEM38B，负责促进三聚体细胞内阳离子跨膜运输并调节关键细胞过程，如哺乳动物的肌肉收缩和细胞分化。然而，尚未对鸡TMEM38基因家族进行全基因组分析，也未对其在脂肪沉积中的生物学作用和转录后表达调控进行研究。在本研究中，我们调查了鸡TMEM38基因家族的全基因组特征，阐明了TMEM38B基因在腹部和肌肉内脂肪生成中的调控作用，并探索了其miRNA介导的表达调控机制。我们发现，鸡TMEM38A和TMEM38B在不同物种的基因结构和基序上表现出显著的保守性。基于单核苷酸多态性（SNP）的主成分分析表明，TMEM38B基因的遗传变异对商业肉鸡的选择性育种有贡献。此外，基因表达谱分析表明，TMEM38A和TMEM38B在鸡腹部脂肪和肌肉组织中呈阳性表达，并且在鸡腹部和肌肉内前脂肪细胞的增殖和脂肪生成分化过程中总体表达增加。在功能上，TMEM38B过表达显著增强了鸡腹部和肌肉内前脂肪细胞的活力、增殖、细胞周期进程以及细胞内甘油三酯含量和脂滴积累，这与增殖和脂肪生成标记基因的表达平行。靶miRNA预测鉴定出37种潜在的靶向TMEM38B基因的miRNA。其中，双荧光素酶报告系统验证了miR-20b-3p可以直接结合TMEM38B基因的3'非翻译区（UTR），从而抑制其转录后表达。功能获得实验表明，miR-20b-3p可以抑制鸡腹部和肌肉内前脂肪细胞的活力、增殖和细胞周期进程，以及鸡腹部前脂肪细胞的脂肪生成分化。总的来说，我们证明了TMEM38B在调节腹部和肌肉内脂肪沉积中的促进作用，以及其由miR-20b-3p介导的转录后表达抑制。这些发现为miR-20b-3p-TMEM38B轴在脂肪生成中的功能作用和表达调控提供了新的线索，并可能为鸡脂肪性状的遗传改良提供有价值的生物标志物。
