Sperm solute carrier family 9 regulator 1 is correlated with boar fertility

Predicting male fertility is extremely important for artificial insemination and profitable farm management. Conventional semen assessment together with computer-assisted sperm analysis is widely used to predict male fertility under field conditions. However, the clinical validation and sensitivity of these methods remain unclear. Therefore, a new approach is needed to predict male fertility. Here, we investigated the use of a transcriptomic marker (solute carrier family 9, subfamily A, member 3, regulator 1; SLC9A3R1) together with sperm motility parameters and capacitation status to predict fertility/infertility in boars at the commercial level. Our data showed that among motility parameters and the capacitation status, hyperactivation (HYP) differed between high- and low-litter size boars. HYP showed a significant positive correlation (R = 0.468) with boar litter size. Simultaneously, the expression of SLC9A3R1, a gene important in sperm ion channel regulation, was significantly negatively correlated (R = -0.523) with boar litter size. Quality assessment revealed that both HYP and SLC9A3R1 showed considerable sensitivity (71.43 vs. 100%), specificity (100 vs. 71.43%), and overall accuracy (90%) for predicting male fertility. Interestingly, the potential of SLC9A3R1 expression to increase the average piglet number per breeding was higher (0.7 piglets) than that of HYP (0.5 piglets). Thus, measuring SLC9A3R1 expression in spermatozoa may be a more accurate marker for evaluating male fertility/infertility than conventionally used motility parameters and capacitation status.