School of Agriculture, Ningxia University, Yinchuan, China.
Ningxia Xihaigu High-end Cattle Industry Research Institute, Zhongwei, China.
Physiol Genomics. 2020 Mar 1;52(3):160-167. doi: 10.1152/physiolgenomics.00091.2019. Epub 2020 Feb 10.
As a member of the Iroquois homeobox gene family, the 3 gene plays an important role in regulating the growth, development and fat deposition of chordates. In the present study, we found, using real-time PCR, that the bovine 3 gene was highly expressed in lung, kidney, heart, subcutaneous fat and longissimus dorsi muscle. We cloned the full-length sequence of the bovine 3 gene promoter and constructed eight series of 5' deletion promoter plasmid luciferase reporter assays and then transfected them to 3T3-L1 and C2C12 cell lines to detect its core promoter regions. The results showed that the core promoter of bovine 3 was located within a -292/-42 bp region relative to the transcriptional start site. Furthermore, sequence analysis identified eight CpG islands in the promoter region. A chromatin immunoprecipitation assay in combination with site-directed mutation and siRNA interference demonstrated that SREBF2 and PPARG binding occurs in region -292/-42 and is essential in bovine 3 transcription. These results lay an important theoretical foundation for exploring the molecular regulation mechanism of the 3 gene in bovine fat deposition.
作为同源异型盒基因家族的一员，3 基因在调节脊索动物的生长、发育和脂肪沉积方面发挥着重要作用。在本研究中，我们通过实时 PCR 发现牛 3 基因在肺、肾、心、皮下脂肪和背最长肌中高度表达。我们克隆了牛 3 基因启动子的全长序列，并构建了 8 个系列的 5'缺失启动子质粒荧光素酶报告基因检测，然后转染到 3T3-L1 和 C2C12 细胞系中，以检测其核心启动子区域。结果表明，牛 3 的核心启动子位于转录起始位点上游-292/-42bp 处。此外，序列分析在启动子区域鉴定出 8 个 CpG 岛。染色质免疫沉淀实验与定点突变和 siRNA 干扰相结合的实验表明，SREBF2 和 PPARG 结合发生在-292/-42 区域，对于牛 3 基因的转录是必需的。这些结果为探索牛 3 基因在牛脂肪沉积中的分子调控机制奠定了重要的理论基础。
