Genesis of olfactory receptor neurons in vitro: regulation of progenitor cell divisions by fibroblast growth factors.
Olfactory receptor neurons are produced continuously in mammalian olfactory epithelium in vivo, but in explant cultures neurogenesis ceases abruptly. We show that in vitro neurogenesis is prolonged by fibroblast growth factors (FGFs), which act in two ways. FGFs increase the likelihood that immediate neuronal precursors (INPs) divide twice, rather than once, before generating neurons; this action requires exposure of INPs to FGFs by early G1. FGFs also cause a distinct subpopulation of explants to generate large numbers of neurons continually for at least several days. The data suggest that FGFs delay differentiation of a committed neuronal transit amplifying cell (the INP) and support proliferation or survival of a rare cell, possibly a stem cell, that acts as a progenitor to INPs.
DeHamer
M K
MK
Department of Biological Sciences, University of Iowa, Iowa City 52242.
Guevara
J L
JL
Hannon
K
K
Olwin
B B
BB
Calof
A L
AL
D000818:Animals; D001483:Base Sequence; D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D017931:DNA Primers / Q000737:chemistry; D005346:Fibroblast Growth Factors / Q000494:pharmacology*; D066298:In Vitro Techniques; D051379:Mice; D008969:Molecular Sequence Data; D009831:Olfactory Mucosa / Q000166:cytology; D018034:Olfactory Receptor Neurons / Q000166:cytology*; D017468:Receptors, Fibroblast Growth Factor / Q000378:metabolism; D011994:Recombinant Proteins; D013234:Stem Cells / Q000166:cytology
D017931:DNA Primers; D017468:Receptors, Fibroblast Growth Factor; D011994:Recombinant Proteins; D005346:Fibroblast Growth Factors