mRNA expression of porcine SPP1 in fetal longissimus dorsi muscle according to the genotype at the SNP g.3836A>G. (A) Results of the across-stage analysis of pooled data of each 12 Duroc fetuses per stage 49, 63, 77 and 91 days post conception (dpc). (B) Results of an independent analysis of 7 Duroc fetuses (91 dpc) per genotype class. Each bar shows the least square means ± standard error for a genotype class. The number of individuals per genotype class is indicated above the corresponding bar.