Developmental elimination of ectopic projection sites for the transgenic OR gene that has lost zone specificity in the olfactory epithelium.
In rodents, olfactory receptor (OR) genes are expressed in one of four zones in the olfactory epithelium (OE), and olfactory sensory neurons (OSNs) expressing the same OR project their axons to a specific set of glomeruli on the olfactory bulb (OB). Using the yeast artificial chromosome (YAC) transgenic system, we have analysed the expression of the murine OR gene MOR29A of the MOR28 cluster located on chromosome 14. Although expression of the endogenous MOR29A was restricted to the most dorsomedial zone, the transgenic MOR29A (Tg MOR29A) was expressed in all four zones of the OE. When the OB of the transgenic mouse was analysed, the axons of the OSNs expressing Tg MOR29A were found to project not only to the dorsal side but also to the ventral side of the OB as well. The ectopic projection sites on the ventral side gradually disappear during postnatal development. Naris occlusion prevents this elimination, suggesting that odorant stimulation is involved in eliminating the ectopic projection sites.
Nakatani
Hiroko
H
Department of Biophysics & Biochemistry, Graduate School of Science, CREST and PRESTO Programmes of Japan Science and Technology Corporation, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
Serizawa
Shou
S
Nakajima
Miho
M
Imai
Takeshi
T
Sakano
Hitoshi
H
D000818:Animals; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D051379:Mice; D008822:Mice, Transgenic; D009830:Olfactory Bulb / Q000254:growth & development*; D009831:Olfactory Mucosa / Q000254:growth & development* / Q000378:metabolism*; D009832:Olfactory Nerve / Q000254:growth & development*; D018034:Olfactory Receptor Neurons / Q000254:growth & development / Q000378:metabolism; D018035:Receptors, Odorant / Q000235:genetics / Q000378:metabolism*; D012683:Sensory Deprivation
D018035:Receptors, Odorant