Effects of olfactory-specific Bcl11b overexpression on gene expression in the main olfactory epithelium of neonatal mice.

Individual olfactory sensory neurons (OSNs) express a single odorant receptor (OR) gene from the class I or class II repertoire in mice. The mechanisms that regulate the binary fate specification of OSNs remain unknown. Here we show that the transcription factor Bcl11b, which is expressed in class II OSNs determines the OR class to be expressed in OSNs. Genetic studies provide evidence that class I is a default-fate and Bcl11b permits a class II fate by suppressing a class I-OR enhancer. These findings reveal a unique transcriptional mechanism that serves as a binary switch to select the OR class and is crucial to both the anatomical and functional organization of olfactory system. The mRNA profiles in the main olfactory epithelium (MOE) of neonatal Control and Bcl11b-overexpressing Tg mice were generated by deep sequencing, using an Illumina MiSeq sequencer