Discovery of two potential DAZL gene markers for sperm quality in boars by population association studies.

The Deleted in AZoospermia Like (DAZL) gene is a member of the DAZ (deleted in azoospermia) gene family which are critical for successful germ cell development in diverse animals. In previous research, we discovered two SNPs (DAZL c.570+385 A>G, DAZL c.735+150 C>A) associated with litter size traits in sows. Here we selected DAZL gene as a candidate gene for boar sperm quality traits based on its function on the formation of germ cells during spermatogenesis, and then analyzed the associations of the two SNPs with sperm quality traits in Duroc (n=185), Large White (n=87) and Landrace (n=49) pig populations. The results showed DAZL c.570+385 AG boars had significantly higher motility (MOT) than GG boars (P<0.05) in Large White and Landrace pigs; Duroc DAZL c.735+150 CA boars had significantly lower MOT and lower sperm concentration (SCON) than CC and AA boars (P<0.05), respectively; Large White DAZL c.735+150 CC boars produced lower abnormal sperm rate (ASR) than CA and AA boars (P<0.05), with favorable allelic C substitution effect -0.94% (P<0.05). Our research indicated that DAZL c.570+385 A>G and DAZL c.735+150 C>A locus were the potential molecular markers for improving the sperm quality traits in pigs.