Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin 150030, China; Key Laboratory of Animal Genetics, Breeding and Reproduction, Education Department of Heilongjiang Province, Harbin 150030, China; College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China.
Key Laboratory of Chicken Genetics and Breeding, Ministry of Agriculture and Rural Affairs, Harbin 150030, China; Key Laboratory of Animal Genetics, Breeding and Reproduction, Education Department of Heilongjiang Province, Harbin 150030, China; College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China.
Poult Sci. 2022 Dec;101(12):102169. doi: 10.1016/j.psj.2022.102169. Epub 2022 Sep 10.
Transforming growth factor beta receptor Ⅱ (TGFBR2), a core member of the transforming growth factor-β (TGF-β) signaling pathway. To date, chicken TGFBR2 (cTGFBR2) genomic structure has not been fully explored. Here, the complete sequences of cTGFBR2 transcript isoforms were determined by 5' and 3' rapid amplification of cDNA ends (5' & 3' RACE) and reverse transcription polymerase chain reaction (RT-PCR); the tissue expression profiling of cTGFBR2 transcript isoforms was performed using quantitative real-time polymerase chain reaction (qRT-PCR). The results showed that cTGFBR2 gene produced 3 transcript isoforms though alternative transcription initiation, splicing, and polyadenylation, which were designated as cTGFBR2-1, cTGFBR2-2, and cTGFBR2-3, respectively. These 3 cTGFBR2 transcript isoforms encoded 3 protein isoforms: cTGFBR2-1, cTGFBR2-2, and cTGFBR2-3. Duplication analysis revealed that, unlike other animal species, cTGFBR2 gene harbored a 5.5-kb intragenic tandem duplication. Tissue expression profiling in the 4-wk-old Arbor Acres (AA) broiler chickens showed that cTGFBR2-1 was ubiquitously expressed, with high expression in abdominal fat, subcutaneous fat, lung, gizzard, and muscle; cTGFBR2-2 was highly expressed in heart, kidney, gizzard, and muscle; cTGFBR2-3 was weakly expressed in all the tested chicken tissues. Tissue expression profiling in the 7-wk-old broiler chickens of the fat and lean lines of Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF) showed that cTGFBR2-1 was significantly differentially expressed in all the tested tissues except heart, cTGFBR2-2 was significantly differentially expressed in all the tested tissues except subcutaneous fat and liver, and cTGFBR2-3 was significantly differentially expressed in all the tested tissues between the lean and fat lines. Intriguingly, in the fat line, the 3 cTGFBR2 transcript isoforms were expressed to varying degrees in all the 3 tested fat tissues, while in the lean line, only cTGFBR2-1 was expressed in all the 3 tested fat tissues. This is the first report of intragenic tandem duplication within TGFBR2 gene. Our findings pave the way for further studies on the functions and regulation of cTGFBR2 gene.
转化生长因子-β（TGF-β）信号通路的核心成员是转化生长因子β受体Ⅱ（TGFBR2）。迄今为止，鸡 TGFBR2（cTGFBR2）的基因组结构尚未完全被探索。在此，我们通过 5' 和 3' 快速扩增 cDNA 末端（5' & 3' RACE）和反转录聚合酶链反应（RT-PCR）确定了 cTGFBR2 转录本异构体的完整序列；并通过实时定量聚合酶链反应（qRT-PCR）对 cTGFBR2 转录本异构体的组织表达谱进行了分析。结果表明，cTGFBR2 基因通过转录起始、剪接和多聚腺苷酸化的选择性发生，产生了 3 种转录本异构体，分别命名为 cTGFBR2-1、cTGFBR2-2 和 cTGFBR2-3。这 3 种 cTGFBR2 转录本异构体编码 3 种蛋白异构体：cTGFBR2-1、cTGFBR2-2 和 cTGFBR2-3。复制分析显示，与其他动物物种不同，cTGFBR2 基因内存在一个 5.5kb 的基因内串联重复。4 周龄 Arbor Acres（AA）肉鸡的组织表达谱分析表明，cTGFBR2-1 在各组织中广泛表达，在腹部脂肪、皮下脂肪、肺、肌胃和肌肉中表达量较高；cTGFBR2-2 在心脏、肾脏、肌胃和肌肉中高表达；cTGFBR2-3 在所有检测的鸡组织中弱表达。东北农业大学肉鸡选育系脂肪和瘦肉系（NEAUHLF）7 周龄肉鸡的组织表达谱分析表明，cTGFBR2-1 在除心脏外的所有检测组织中均有显著差异表达，cTGFBR2-2 在除皮下脂肪和肝脏外的所有检测组织中均有显著差异表达，cTGFBR2-3 在瘦肉系和脂肪系之间的所有检测组织中均有显著差异表达。有趣的是，在脂肪系中，3 种 cTGFBR2 转录本异构体在所有 3 种测试脂肪组织中均有不同程度的表达，而在瘦肉系中，只有 cTGFBR2-1 在所有 3 种测试脂肪组织中表达。这是首次在 TGFBR2 基因内报道基因内串联重复。我们的研究结果为进一步研究 cTGFBR2 基因的功能和调控奠定了基础。
