Characteristics of the TDRD1 gene promoter in chickens

Tudor domain containing 1 (TDRD1) is a member of the TDRD family and plays an important role in embryogenesis and gametogenesis. A detailed study of the characteristics of chicken TDRD1 can lay a foundation for the study of chicken spermatogonia stem cell formation and spermatogenesis. We cloned 2117 bp upstream fragment of TDRD1 promoter and constructed a series of recombinant vectors with different length deletions. The dual-luciferase experiments reveal that the upstream region of - 161 to 0 bp was its core transcription promoter region. Bioinformatics analysis predicted the possible binding of Transcription Factor 7 Like 2 (TCF7L2) and Zinc Finger E-Box-Binding Homeobox 1(ZEB1) transcription factors in the core region. The transcriptional activity of TDRD1 was significantly decreased after mutation of TCF7L2-binding site, while that of TDRD1 was significantly increased after mutation of ZEB1-binding site. Further, ChIP experiments verified that TCF7L2 enriched in the TDRD1 core transcriptional initiation region, suggesting that TCF7L2 and ZEB1 play an important role in the regulation of TDRD1. In summary, the region from - 161 to 0 bp is the core promoter region of TDRD1; ZEB1 and TCF7L2 bind to the TDRD1 promoter region and TCF7L2 activates the transcription of TDRD1 gene.