The septin 7 (CDC10) gene, involved in cellular proliferation, has been previously shown to be expressed at
different levels in the longissimus muscle (LM) between low-marbled and high-marbled steer groups by
differential-display PCR. It is located within the genomic region of a quantitative trait locus for marbling, and
thus was considered as a positional functional candidate gene for marbling. In this study, we showed that the
CDC10 expression levels in the LM were positively correlated with marbling in Japanese Black (JB) steers
(P b 0.0001). Further, an association analysis indicated that a SNP in the promoter region of the CDC10 gene
was associated with marbling using 99 JB sires (P = 0.03) and 542 JB paternal half-sib progeny steers from a
sire homozygous for G allele at the SNP (P b 0.0001). These findings suggest possible effects of the expression
levels in the LM and the SNP of the CDC10 gene on marbling in JB cattle.