Fig. 4.

Drosha is required for effective homologous recombination and non-homologous end joining. a Cartoon depicting the quantitative HR reporter assay. Incompatible DNA ends are generated after digestion of the chromosomally integrated reporter with I-SceI endonuclease. Gene conversion after HR repair reconstitutes an active GFP gene, measured by FACS. b Quantitation of HR repair efficiency in U2OS cells using the reporter system described in a. In all cases, error bars = SD, Wilcoxon signed rank non-parametric test, ***p ≤ 0.001, N = 3. c NHEJ reporter schematic. An adenovirus exon results in a non-functional GFP product; following cleavage by I-SceI, this is excised and NHEJ repair ligates introns 1 and 2 together. Splicing of the NHEJ-repaired product results in an active GFP which can be measured by FACS. d Quantitation of NHEJ repair efficiency in U2OS cells using the reporter system described in c. Mean of 3 biological replicates, error bars = SD, Wilcoxon signed rank non-parametric test, *p ≤ 0.05, ***p ≤ 0.001