The more proximal reciprocal Chr 1 QTL lying between 170 and 173 Mbp was examined in some detail. The interval contains 20 known and predicted genes, several of which are highly expressed in the brain (http://symatlas.gnf.org/SymAtlas/). These include Rgs4 and Rgs5 (regulators of g-protein signaling 4 and 5), Umhk1 (U2AF homology motif [UHM] kinase), and Nos1ap (nitric oxide synthase [neuronal] adaptor protein); variants in each of these genes have been implicated as having a role in schizophrenia (e.g., Bakker et al. 2007; Campbell et al. 2008; Puri et al. 2007; Brzustowicz et al. 2004). To our knowledge, none of these genes has been directly implicated as having a role in ethanol-related behaviors. Indirectly, one could strongly infer a role for Nos1ap. Nos1ap (also known as carboxy-terminal PDZ domain ligand of nNos; neuronal nitric oxide synthase) competes with PSD95 for the nNos PDZ domain and prevents the coupling of nNos activation with NMDA-receptor-mediated calcium influx (Jaffrey et al. 1998). nNos knockout mice have been shown to have an increase in ethanol consumption (Spanagel et al. 2002). Direct sequencing confirmed that a
