GSE138596
Insights into olfactory ensheathing cell development from a laser-microdissection and transcriptome-profiling approach
Olfactory ensheathing cells (OECs) are neural crest-derived glia that ensheath bundles of olfactory axons from their peripheral origins in the olfactory epithelium to their central targets in the olfactory bulb. We took an unbiased laser microdissection and differential RNA-seq approach, validated by in situ hybridisation, to identify candidate molecular mechanisms underlying mouse OEC development and differences with the neural crest-derived Schwann cells developing on other peripheral nerves. We identified 25 novel markers for developing OECs in the olfactory mucosa and/or the olfactory nerve layer surrounding the olfactory bulb, of which 15 were OEC-specific, i.e., not expressed by Schwann cells. One pan-OEC-specific gene, Ptprz1, encodes a receptor-like tyrosine phosphatase that blocks oligodendrocyte differentiation. Mutant analysis suggests Ptprz1 may also act as a brake on OEC differentiation, and that its loss disrupts olfactory axon targeting. Overall, our results provide new insights into OEC development and the diversification of neural crest-derived glia.  Overall design: Embryonic mouse olfactory nerve regions (at E11.5, E13.5 and E16.5) and trigeminal nerve (at E16.5) were isolated in situ by laser microdissection of 8 µm cryosections of flash-frozen embryos. mRNA profiles were generated by sequencing using the Illumina NextSeq 500 platform (multiplex paired-end). At least 3 replicates were analysed per sample type.