Fig. 1

Beta-actin (ACTB), prohibitin (PHB), heat shock protein family D member 1 (HSPD1), and arginine vasopressin receptor 2 (AVPR2) mRNA expression in high- and low-litter size boar spermatozoa. Differences in marker candidate gene expression in the high-litter size (n = 3) and low-litter size (n = 3) spermatozoa groups based on the average litter sizes. A AVPR2 mRNA expression in boar spermatozoa with high- and low-litter sizes. B ACTB mRNA expression in boar spermatozoa with high- and low-litter sizes. C PHB mRNA expression in boar spermatozoa with high- and low-litter sizes. D HSPD1 mRNA expression in boar spermatozoa with high- and low-litter sizes. Relative expression was normalised to GAPDH expression. The data are expressed as the mean ± standard error of the mean (SEM); ^*P < 0.05