LACZ AND OMP ARE COEXPRESSED DURING ONTOGENY AND REGENERATION IN OLFACTORY RECEPTOR NEURONS OF OMP PROMOTER-LACZ TRANSGENIC MICE

The ontogeny and cellular specificity of expression of beta-galactosid ase activity and olfactory marker protein (OMP) are compared in olfact ory tissue of the H-OMP-lacZ-3 line of transgenic mice. In this line t he expression of lacZ is driven by a 0.3kb fragment of the rat OMP pro moter. During fetal development, lacZ expression is detectable in olfa ctory receptor neurons (ORNs) shortly after the initial appearance of endogenous OMP. The beta-galactosidase marker was observed only in mat ure olfactory receptor neurons where it co-localized with endogenous O MP. It was absent from immature neurons that express the growth associ ated phosphoprotein B50/GAP43. Lesion of the peripheral olfactory path way by intranasal irrigation with Triton X-100 eliminated expression o f both OMP and lacZ in the olfactory neuroepithelium. Subsequent regen eration of the full complement of olfactory receptor neurons was assoc iated with co-expression of both OMP and beta-galactosidase activity. Neither OMP nor beta-galactosidase activity was induced in any other c ell type of the regenerating olfactory mucosa. Thus, as little as 0.3 kb of the OMP promoter has the ability to target lacZ expression to ol factory receptor neurons in a temporally and spatially defined manner. We discuss the potential utility of this transgenic line for future s tudies of the olfactory system. Copyright (C) 1996 ISDN.