title: Embryonic Pax7-expressing progenitors contribute multiple cell types to the postnatal olfactory epithelium.
abstract: Prolonged neurogenesis driven by stem/progenitor cells is a hallmark of the olfactory epithelium (OE), beginning at the placodal stages in the embryo and continuing throughout adult life. Despite the progress made to identify and study the regulation of adult OE progenitors, our knowledge of embryonic OE precursors and their cellular contributions to the adult OE has been stalled by the lack of markers able to distinguish individual candidate progenitors. Here we identify embryonic OE Pax7+ progenitors, detected at embryonic day 10.5 (E10.5) in the olfactory pit with an antigen profile and location previously assigned to presumptive OE stem cells. Using Cre-loxP technology (Pax7-cre/ROSA YFP mice), we expose a wide range of derivatives, including CNS and olfactory neurons, non-neuronal cells, and olfactory ensheathing glia, all made from embryonic Pax7+ cells. Importantly, the expression of Pax7 in the embryonic OE is downregulated from E15.5, such that after birth, no Pax7+ cells are found in the OE, and thus the progenitor population here identified is restricted to embryonic stages. Our results provide the first evidence for a population of Pax7-expressing embryonic progenitors that contribute to multiple OE lineages and demonstrate novel insights into the unique spatiotemporal patterning of the postnatal OE.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520-8103, USA. barbara.murdoch@yale.edu
authors.forename: Barbara
authors.initials: B
authors.lastname: Murdoch
authors.forename: Casey
authors.initials: C
authors.lastname: DelConte
authors.forename: Martín I
authors.initials: MI
authors.lastname: García-Castro
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000502:physiology; D002452:Cell Count; D019070:Cell Lineage / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D007150:Immunohistochemistry; D051379:Mice; D008822:Mice, Transgenic; D055495:Neurogenesis / Q000502:physiology*; D009457:Neuroglia / Q000378:metabolism; D009831:Olfactory Mucosa / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D018034:Olfactory Receptor Neurons / Q000196:embryology / Q000378:metabolism*; D051763:PAX7 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000378:metabolism
chemical_list: D051763:PAX7 Transcription Factor; C497322:Pax7 protein, mouse