Analysis of core promoter and transcription factors screening of porcine DHRS3 gene

Dehydrogenase/Reductase (SDR) Family Member 3 ( DHRS3 , also known as Rsdr1 and retSDR1) is a membrane-bound enzyme with critical roles in embryonic development and animal growth. Studying the porcine DHRS3 gene promoter can provide a foundation for understanding growth, development, and reproduction in pigs. In this study, we first analyzed the promoter region structure of the porcine DHRS3 gene and constructed five promoter region dual-luciferase reporter vectors with sequential deletion fragments. Through dual-luciferase assays, all five truncated promoter reporter constructs exhibited transcriptional activity, with the core promoter region localized between +210 bp and -842 bp. Bioinformatics analysis then predicted key transcription factors in this region. Combining site-directed mutagenesis and RNA interference experiments, we demonstrated that mutation or knockdown of CDX1, MYOD, and MYOG transcription factor binding sites significantly increased transcriptional activity compared to wild-type controls, whereas USF2 site mutation or knockdown resulted in significantly decreased activity ( P< 0.05). These results suggest that CDX1, MYOD, and MYOG negatively regulate the porcine DHRS3 gene, while USF2 acts as a positive regulator. These findings suggest the potential for further genetic and breeding applications aimed at modulating the DHRS3 gene expression in pigs.