Do Not Regulate Mitochondri or Fusion in Caenorhabditis

fission during apoptosis in one study [1] but was found to promote mitochondria fusion in healthy cells in another [2], calling into question of the exact physiological roles of C. elegans Bcl-2 family proteins in regulating mitochondria dynamics. To address the critical issue of whether Bcl-2 proteins regulate normal mitochondrial fission or fusion of mitochondria in N2, drp-1(tm1108), fzo-1(tm1133), egl-1(n3082), and ced-9(n2812); ced-3(n717) blastomeres by generating line intensity plots and calculating the frequency of major TMRE fluorescent spikes (Figure S2; method described in Supplemental Experimental Procedures). In N2 blastomeres, TMRE fluorescent signals varied in frequency, with an average of 0.49 fluorescent spikes/mm (Figure S2). TMRE fluorescent signals were very broad and of low spike frequency in drp-1(tm1108) blastomeres (average frequency of 0.16 fluorescent spikes/mm; Figure S2), consistent with larg