Abstract：The main function of establishment of sister chromatid cohesion N-acetyltransferase 2 (ESCO2) is to regulate the aggregation of sister chromatid, thus it plays an important role in the repair of DNA double strand breaks in cells. In this study, dairy goat (Capra hircus) ESCO2 was cloned by RT-PCR, and the sequence was analyzed by modern bioinformatics. Further, the expression pattern of the gene was analyzed through PCR, qRT-PCR, bioinformatics analysis, immunofluorescence staining and related experiments. Moreover, eukaryotic expression vector carrying ESCO2 (pESCO2-IRES2-AcGFP) was also constructed successfully in our work, which was transfected into male germline stem cells of Dairy Goat (mGSCs-I-SB) in the following study. The results showed that, the sequence of dairy goat ESCO2 gene had a length of 1 834 bp and encoded an amino acid sequence with 612 residues (GenBank accession No. KP341998.D), which was highly conservative in evolution, its homology between dairy goat and Bos taurus was up to 97.82%. While widely-expressed throughout the body organs of dairy goat, ESCO2 was expressed highest in heart and lung, followed by testis and liver. The ESCO2 gene began to express after the birth of dairy goat and reached its peak at the age of one-year old, then falled down with the age of the goat in the testis. After being transfected with pESCO2-IRES2-AcGFP, mGSCs-I-SB showed an up-regulation in the expression level of meiosis-related genes, indicating that ESCO2 had a significant effect on the meiosis of spermatogenesis of dairy goat. Our work set a molecular basis for further study of the meiosis and differentiation process of dairy goat's spermatogonium.
