Abstract
Background Shank3 is a scaffolding protein essential for the organization and function of the glutamatergic postsynapse. Monogenic mutations in SHANK3 gene are among the leading genetic causes of Autism Spectrum Disorders (ASD). The multiplicity of Shank3 isoforms seems to generate as much functional diversity and yet, there are no tools to study endogenous Shank3 proteins in an isoform-specific manner. Methods In this study, we created a novel transgenic mouse line, the Shank3 Venus/Venus knock in mouse, which allows to monitor the endogenous expression of the major Shank3 isoform in the brain, the full-length Shank3a isoform. Results We show that the endogenous Venus-Shank3a protein is localized in spines and is mainly expressed in the striatum, hippocampus and cortex of the developing and adult brain. We show that Shank3 Venus/+ and Shank3 Venus/Venus mice have no behavioral deficiency. We further crossed Shank3 Venus/Venus mice with Shank3 ΔC/ΔC mice, a model of ASD, to track the Venus-tagged wild-type copy of Shank3a in physiological (Shank3 Venus/+ ) and pathological (Shank3 Venus/ΔC ) conditions. We report a developmental delay in brain expression of the Venus-Shank3a isoform in Shank3 Venus/ΔC mice, compared to Shank3 Venus/+ control mice. Conclusion Altogether, our results show that the Shank3 Venus/Venus mouse line is a powerful tool to study endogenous Shank3a expression, in physiological conditions and in ASD.