Comprehensive analysis of the critical transcript function of the DAZAP2 gene in porcine testis

The DAZAP2 (Deleted in Azoospermia-associated Protein 2) gene encodes an azoospermia-related protein that plays key roles in spermatogenesis, cell cycle regulation, and transcriptional regulation. Here, we employed transcriptome sequencing to analyze porcine testis tissues using long-read and short-read sequencing and identified the DAZAP2 transcripts via RT-PCR. Protein interaction analysis, GO and KEGG enrichment, and competing endogenous RNA (ceRNA) regulatory network construction were performed to elucidate its functional pathways. Furthermore, we assessed the multi-tissue expression of DAZAP2 and the subcellular localization of the DAZAP2 protein. We identified two spliceosomes of the DAZAP2 gene in Banna mini-pig inbred line (BMI) testicular tissue, namely DAZAP2_X1 and DAZAP2_X2, with DAZAP2_X2 being the predominant transcript. Functional enrichment analysis revealed that DAZAP2_X2 was associated with ubiquitin–protein ligase binding, positive regulation of protein monoubiquitination and Wnt signaling pathway, indicating its involvement in spermatogenesis. Additionally, we identified nine microRNAs (miRNAs) interacting with DAZAP2_X2, including ssc-miR-490-3p, ssc-miR-150, ssc-miR-107, ssc-miR-193a-3p, ssc-miR-497, ssc-miR-192, ssc-miR-383, ssc-miR-129a-5p, and ssc-miR-181a, most of which were associated with spermatogenesis. We found DAZAP2_X2 was highly expressed in the testis and bulbourethral glands and was mainly localized in the cytoplasm. These findings suggest that DAZAP2_X2 played a significant role in spermatogenesis and provide a reference for further research on spermatogenesis-related genes and regulatory pathways.