Elimination of Calm1 long 3′-UTR mRNA isoform by CRISPR–Cas9 gene editing impairs dorsal root ganglion development and hippocampal neuron activation in mice

Characterization of Calm1 isoforms in the hippocampus. (A) qRT-PCR analysis revealed no changes in total Calm1 (uni) RNA levels between Calm1^+/+ and Calm1^ΔL/ΔL, while the Calm1-L expression is abolished in Calm1^ΔL/ΔL hippocampus. Significance was determined using a t-test, ns: P > 0.05, (**) P < =0.01, n = 4 mice. (B) Western blot analysis of Calm1^+/+ and Calm1^ΔL/ΔL adult hippocampus showing no change in overall protein levels. Significance was determined using a t-test, P = 0.287; n = 3 mice. (C,D) smFISH analysis in both Calm1^+/+ and Calm1^ΔL/ΔL hippocampal neurons showed that the deletion of Calm1-L did not significantly impair localizing potential of Calm1 mRNAs in hippocampal neurons. Significance was determined using a Wilcoxon test, ns: P > 0.05; n = 19 Calm1^+/+ neurons (739 puncta), n = 26 Calm1^ΔL/ΔL neurons (802 puncta).