The goal of this exploratory research is to generate mice with tissue- specific expression of the Cre gene in the non-neuronal cells of the olfactory mucosa. These mice will be valuable for subsequent studies to specifically disrupt a given gene in the Cre-expressing olfactory mucosal cells in order to demonstrate its biological function in vivo. The non- neuronal cells play essential roles in olfactory chemoreception by participating in "perireceptor events". Therefore, the ability to specifically modulate molecular events in these cells will be an important contribution to olfactory chemosensory research. Two different approaches will be used to generate mice with tissue-specific expression of the Cre gene in the non-neuronal cells of the olfactory mucosa. One will use a transgenic approach and the other will use a "knock-in" approach. Both will utilizes the Cyp2g1 gene, which encodes a cytochrome P450 enzyme and is the only well-characterized gene with abundant, tissue-specific expression in the supporting cells and Bowman's glands in the olfactory mucosa. The specific aims are: Aim 1. To generate and characterize transgenic mice with a Cyp2g1-Cre fusion gene construct; Aim 2. To generate and characterize knock-in mice with an IRES-Cre expression cassette at the Cyp2g1 locus. The use of these two different approaches will increase the likelihood of achieving the goal. Additionally, the two mouse models may have differences in the temporal or spatial expression of the Cre gene which can be useful for future studies. These mice, which will be essential for the PI's attempts to study the biological functions of olfactory mucosal biotransformation enzymes, will also be made available to the research community; they will have a broad impact because of their ability to disrupt essentially any gene that is flanked by the loxP sequences, therefore providing great opportunities for olfactory chemoreception science.