Disrupted-in-Schizophrenia (DISC-1) is a promising candidate gene for schizophrenia. Disruption of the DISC1 gene associated with familial psychosis, including schizophrenia, in a Scottish pedigree could lead to a C-terminal truncated DISC1 protein (mutDISC1). Our previous studies indicate that DISC1 forms a protein complex together with NUDEL and LIS1 (Kamiya et al, SFN abstract 2004) and that overexpression of mutDISC1 inhibits neurite outgrowth in PC12 cells (Ozeki et al, PNAS 2003). Here we report an expression study of DISC1, NUDEL, and their associated proteins in transgenic mice expressing mutDISC1 under the CaMKII promoter. We compared expression of exogenous mutDISC1 among lines, and most of them expressed mutDISC1 in neurons in the olfactory bulb and the frontal cortex. The effects of exogenous mutDISC1 on endogenous DISC1, NUDEL, and their associated proteins have been studied. This study together with a study using the same transgenic mice with behavioral assays and anatomical studies with MRI ...