Expression of olfactory receptors, G-proteins and AxCAMs during the development and maturation of olfactory sensory neurons in the mouse.
Three mouse olfactory receptors have been cloned and sequenced and were found to be expressed in different zones of the olfactory epithelium. In situ hybridisation (ISH) results showed that each olfactory receptor was expressed at an early stage in development (E12), was not dependent on the maturation of the receptor neurons, and was present long before the onset of odour detection. Cells positive for these same olfactory receptors and the G-protein (Gbeta) were also found in non-neural regions of the nasal epithelium in the earlier stages of development (E12-16). Ncam, and Big-2 expression were, however, restricted to the region of developing olfactory neurons. Ncam expression appeared in advance of the olfactory receptor expression, while Big-2 appeared after olfactory receptor expression and neither were expressed in cells outside the olfactory epithelium. Both showed the highest number of positive cells in the early post-partum period when olfactory detection is functional. Ncam is known to be involved in guidance of the developing olfactory axons and was expressed earlier than any of the olfactory receptors, while Big-2 appears somewhat later (E14) at a time when developing axons reach the olfactory bulb. Moreover the highest periods of expression occur at post-natal day 7 when a proliferation of bulbar glomeruli are observed, suggesting the role of Big-2 to be primarily concerned with synaptogenesis.
Saito
H
H
Sub-Department of Animal Behaviour, Department of Zoology, University of Cambridge, Madingley, Cambridge CB3 8AA, UK.
Mimmack
M
M
Kishimoto
J
J
Keverne
E B
EB
Emson
P C
PC
D000375:Aging / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D015816:Cell Adhesion Molecules, Neuronal / Q000096:biosynthesis / Q000235:genetics*; D017124:Conserved Sequence; D058966:Contactins; D017931:DNA Primers; D005314:Embryonic and Fetal Development; D019204:GTP-Binding Proteins / Q000096:biosynthesis / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009297:Nasal Mucosa / Q000196:embryology / Q000254:growth & development / Q000294:innervation*; D019006:Neural Cell Adhesion Molecules / Q000096:biosynthesis / Q000235:genetics*; D018034:Olfactory Receptor Neurons / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D018035:Receptors, Odorant / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D015816:Cell Adhesion Molecules, Neuronal; C484359:Cntn4 protein, mouse; D058966:Contactins; D017931:DNA Primers; D019006:Neural Cell Adhesion Molecules; D018035:Receptors, Odorant; D019204:GTP-Binding Proteins