Insertion of mNeonGreen into the variable domain of DRP-1 permits visualization of functional endogenous protein.

We used CRISPR-Cas9 editing of the genomic drp-1 locus in C. elegans to test whether the mitochondrial fission function of DRP-1 was retained following insertion of mNeonGreen into the variable domain. We found that DRP-1 activity remains largely intact despite this large internal insertion. Furthermore, in living cells, the internally tagged protein is readily detectable as discrete puncta associated with mitochondria, which presumably represent prospective mitochondrial scission sites. The internally tagged DRP-1 protein represents a powerful new tool for real time in vivo analyses of mitochondrial fission and DRP-1 function.