Is DSCAM Overexpression Sufficient for Producing Phenotypical Changes in Mouse Brain Tissue?

Jeffrey Dill, Microbiology

Second Place: Undergraduate Poster

Abstract: The organization of complex layered tissues in animals is regulated mainly by cell adhesion molecules. Down's Syndrome cell adhesion molecule (DSCAM) is a protein found in all mammals that is crucial to neural development. In humans with Down's Syndrome, trisomy 21 leads to over-expression of DSCAM in the brain, as well as other genes. We have obtained a mouse lineage with a euploid chromosome set that solely over-expresses DSCAM. Previous studies in our lab have shown that over-expression of DSCAM leads to observable phenotypic differences in cell mosaics within retinal tissue of mouse models. In this study, we are observing and quantifying differences in axon pathways within brain tissue of mouse models over-expressing DSCAM vs. wild type. The cortex, cerebellum and hippocampus are the primary structures of interest. Based on findings in the retina tissue study, we expect to see histological differences between the gain of function (GOF) genotypes and the wild type brain, particularly in myelination levels, location, and progression at each developmental time point. We hope to gain insight into whether DSCAM alone is sufficient in producing these phenotypical changes.