As a member of the Iroquois homeobox gene family, the IRX3 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 IRX3 gene was highly expressed in lung, kidney, heart, subcutaneous fat and longissimus dorsi muscle. We cloned the full-length sequence of the bovine IRX3 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 IRX3 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 IRX3 transcription. These results lay an important theoretical foundation for exploring the molecular regulation mechanism of the IRX3 gene in bovine fat deposition.

中文翻译：

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牛IRX3基因启动子区域的特征：SREBF2和PPARG的作用。

作为易洛魁人同源异型盒基因家族的成员，IRX3基因在调节和弦的生长，发育和脂肪沉积中起着重要作用。在本研究中，我们发现，使用实时PCR，牛IRX3基因在肺，肾，心脏，皮下脂肪和背最长肌中高表达。我们克隆了牛IRX3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，然后将它们转染到3T3-L1和C2C12细胞系中以检测其核心启动子区域。结果表明，牛IRX3的核心启动子相对于转录起始位点位于-292 / -42 bp区域内。此外，序列分析鉴定了启动子区域中的八个CpG岛。染色质免疫沉淀试验结合定点突变和siRNA干扰表明SREBF2和PPARG结合发生在-292 / -42区，在牛IRX3转录中至关重要。这些结果为探索IRX3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。