FIG. 3.—

qRT-PCR confirmed the female-biased expression of X-lined Obp genes of BALB/c mice at 4 weeks of age. The figure shows the expression levels of each X-linked Obp genes and olfactory major protein gene (Omp, a marker gene of matured OSNs) estimated by qRT-PCRs in the two sexes. At least three mice were used in the qRT-PCR assay. The error bars show the standard errors of gene expression levels among all the OE samples tested. The expression levels are significantly different between the two sexes: **P < 0.01, *P < 0.05; the expression levels are not different between the two sexes: ns, P > 0.05.