Figure 4. Modulation of the expression of genes related to odorant detection in germfree animals.

Quantitative PCR (qPCR) analysis of cDNAs from olfactory mucosa. Genes are grouped by functions; (A) olfactory receptors sensitive to odorants tested in the EOG experiment; (B) main olfactory transduction pathway components; (C) olfactory binding proteins; (D) detoxifying enzymes. Their expression levels were normalized to that of β-tubIII (A,B) or β-actin (C,D) and are given as mean ± SEM (n = 7). (*) P < 0.05.