Semiochemical responsive olfactory sensory neurons are sexually dimorphic and plastic [pS6-IP-Seq of whole olfactory mucosa]

Understanding how genes and experiences work in concert to generate phenotypic variability will provide a better understanding of individuality. Here, we considered this in the context of the main olfactory epithelium, a chemosensory structure with over a thousand distinct cell types, in mice. We identified a subpopulation of at least three types of olfactory sensory neurons, defined by receptor expression, whose abundances were sexually dimorphic. This subpopulation of olfactory sensory neurons was over-represented in sex-separated female mice and responded robustly to the male-specific semiochemicals 2-sec-butyl-4,5-dihydrothiazole and (methylthio)methanethiol. Sex-combined housing led to a robust attenuation of the female over-representation. Testing of Bax-/- mice revealed a Bax-dependence in generating the sexual dimorphism in sex-separated mice. Altogether, our results suggest a profound role of experience and activity in influencing homeostatic mechanisms to generate a robust sexually dimorphic phenotype in the main olfactory epithelium. Overall design: Phosphorylated S6 ribosomal subunit capture and associated mRNA profiling (pS6-IP-Seq) on whole olfactory mucosa after odorant exposure.