MU2 and Double Strand Break Repair Figure 2. MU2 marks double strand breaks in the germarium. Immunostaining of Oregon R (A) and mu2a (B) germaria shows cH2Av in red as a mark for DSBs, MU2 in green, and DNA as identified by DAPI in blue. The anterior tip of the germarium is pointing up. MU2 foci co-localize with the cH2Av foci, as shown in the merged image of Oregon R. The small amount of MU2 signal in the mu2a mutant does not co-localize with cH2Av. (C) Plot showing the difference in the number of cH2Av foci in the germaria of Oregon R and mu2a ovaries. cH2Av foci were counted in at least ten germaria showing equal intensity of staining without changing any settings of the instruments. The number of foci is represented as the mean6SD. doi:10.1371/journal.pgen.1000473.g002 PLoS Genetics | www.plosgenetics.org 5 May 2009 | Volume 5 | Issue 5 | e1000473