SHANK3 (ProSAP2) is among the most common genes mutated in autism spectrum disorders (ASD) and is the causative gene in Phelan-McDermid syndrome (PMS). We performed genetic rescue of Shank3 mutant phenotypes in adult mice expressing a Shank3 exon 21 insertion mutation (Shank3G ). We used a tamoxifen-inducible Cre/loxP system (CreTam ) to revert Shank3G to wild-type (WT) Shank3+/+ We found that tamoxifen treatment in adult Shank3GCreTam+ mice resulted in complete rescue of SHANK3 protein expression in the brain and appeared to rescue synaptic transmission and some behavioral differences compared to Shank3+/+CreTam+ controls. However, follow-up comparisons between vehicle-treated, WT Cre-negative mice (Shank3+/+CreTam- and Shank3+/+CreTam+) demonstrated clear effects of CreTam on baseline synaptic transmission and some behaviors, making apparently positive genetic reversal effects difficult to interpret. Thus, while the CreTam tamoxifen-inducible system is a powerful tool that successfully rescues Shank3 expression in our Shank3G/G reversible mutants, one must exercise caution and use appropriate control comparisons to ensure sound interpretation.
Keywords: Cre-recombinase; Shank3; autism; reversal; tamoxifen.
Copyright © 2019 Speed et al.