Axonal ephrin-As and odorant receptors: coordinate determination of the olfactory sensory map.
Olfactory sensory neurons expressing a given odorant receptor (OR) project with precision to specific glomeruli in the olfactory bulb, generating a topographic map. In this study, we demonstrate that neurons expressing different ORs express different levels of ephrin-A protein on their axons. Moreover, alterations in the level of ephrin-A alter the glomerular map. Deletion of the ephrin-A5 and ephrin-A3 genes posteriorizes the glomerular locations for neurons expressing either the P2 or SR1 receptor, whereas overexpression of ephrin-A5 in P2 neurons results in an anterior shift in their glomeruli. Thus the ephrin-As are differentially expressed in distinct subpopulations of neurons and are likely to participate, along with the ORs, as one of a complement of guidance receptors governing the targeting of like axons to precise locations in the olfactory bulb.
Cutforth
Tyler
T
Howard Hughes Medical Institute and Center for Neurobiology and Behavior, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
Moring
Laurie
L
Mendelsohn
Monica
M
Nemes
Adriana
A
Shah
Nirao M
NM
Kim
Michelle M
MM
Frisén
Jonas
J
Axel
Richard
R
D000818:Animals; D001369:Axons / Q000378:metabolism*; D036384:Ephrin-A3 / Q000235:genetics / Q000378:metabolism*; D036386:Ephrin-A5 / Q000235:genetics / Q000378:metabolism*; D017403:In Situ Hybridization; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009475:Neurons, Afferent / Q000166:cytology / Q000378:metabolism; D009830:Olfactory Bulb / Q000033:anatomy & histology / Q000502:physiology*; D051842:Olfactory Marker Protein; D018035:Receptors, Odorant / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012677:Sensation / Q000502:physiology*
D036384:Ephrin-A3; D036386:Ephrin-A5; D009419:Nerve Tissue Proteins; D051842:Olfactory Marker Protein; C497598:Omp protein, mouse; D018035:Receptors, Odorant; D011993:Recombinant Fusion Proteins