An integrated analysis of second- and third-generation transcriptome sequencing technologies reveals the DAZAP1 function in pig testis

The quality of pig sperm is one of the crucial determinants of reproductive ability, and sperm defects can shorten the reproductive life of boars and affect the production of offspring. During transcription and translation, the <i>DAZAP1</i> gene exerts regulatory control over alternative splicing, thereby exerting influence on vital cellular processes including cell growth, development, and spermatogenesis. In this study, we employed second- and third-generation transcriptome sequencing techniques to isolate and identify the <i>DAZAP1</i> gene and its transcripts using Banna mini-pig inbred line (BMI) testicular cDNA as a template. We identified three splice variants of the <i>DAZAP1</i> gene, including ENSSSCT00000023438.4 (DAZAP1_X1), ENSSSCT00000051975.3 (DAZAP1_X2), and ENSSSCT00000074738.2 (DAZAP1_X3). Furthermore, the transcript DAZAP1_X2, was subjected to comprehensive analysis. The DAZAP1_X2 variant comprises 13 exons, with a coding sequence (CDS) length of 1254 bp (417 aa). Subsequently, enrichment analyses based on GO and KEGG pathways revealed that DAZAP1_X2 primarily participated in pathways associated with spermatogenesis, movement of the 9+2 cilium structure, germ cell development, gamete generation, and sexual reproduction. The ceRNA analysis identified three miRNAs interacting with DAZAP1_X2: ssc-miR-107, ssc-miR-127, and ssc-miR-1343, which were primarily linked to spermatogenesis. Both the testis and urethral bulb had significant levels of <i>DAZAP1</i> expression, according to multi-tissue expression analysis. Subcellular localization indicated that the DAZAP1 was mainly distributed in the cell nucleus. <i>DAZAP1</i> was critical for sperm formation and was essential for reproductive. These results shed light on the biological roles of <i>DAZAP1</i> in pigs.