This study was conducted to analyze the specific genes associated with sex-determination in Korean native cow. The highly organized spermatogenesis requires accurate spatial and temporal regulation of gene expression, which is governed by transcriptional, post-transcriptional, and epigenetic processes. Recently, farmers have been interested in determining the sexual identity of the calves in their farm. We analyzed the sperm of Korean native and Holstein cows, which were supplied from Hanwoo Improvement Center. We evaluated sperm motility and expression of sperm-specific genes after treating semen with both male- and female reagents. Sperm motility in Korean native cows decreased by approximately 10% in the first 30 minutes after treatment with sex-determination reagent. However, sperm motility of Holstein cows decreased to 60-70% after 15 minutes and to 20-30% after 30 minutes. We selected six specific genes expressing in the spermatozoa to analysis the gene expression level. The Real-time PCR results suggest that the selected genes (Gimap4, Tmeff1, Rac2, Abi2, Rac1, and Clu) were highly expressed in the group treated with the male reagent compared to the group treated the female reagent and to the untreated-group (control). In the present study, we suggest that the selected genes play a pivotal role in sex-determination.

This study was conducted to analyze the specific genes associated with sex-determination in semen of Korean Native cow. Male fertility is dependent upon the successful perpetuation of spermatogenesis that is a highly organized process of germ cell differentiation occurring within the seminiferous tubules in the testis. The highly organized spermatogenesis requires accurate, spatial and temporal regulation of gene expression governed by transcriptional, post-transcriptional and epigenetic processes. Recently, the farmers have been interesting in the male or female of calves in the their farm. In first, we analyzed the semen supplied from Hanwoo Improvement Center, NongHyup. The sperm motility in Hanwoo was decreased approximately 10 % in the 30 min after sex-determinant reagent. However, Holstein' sperm motility was decreased to 60-70% after 15 min and the motility was considerably decreased to 20-30 % after 30 min. Next, we analyzed the sperm specific expression genes both male- and female reagents treated-group. The real-time PCR results suggest that the selected genes (GIMP4, TMEFF1, RAC2, ABI2, RAC1, and CLUS) were highly expressed in the group treated with the male reagent compared to female reagent treated group and untreated-group. In the present study, although X or Y gene is play a key role in the sex-determination of mammalian, we suggest that the selected genes may be involved in the sex-determination.