Fig. 4. Body wall muscle cells of UNC-89 PK2 KtoA mutants have fragmented mitochondria.

a Confocal images of body wall muscle stained with antibodies to ATP5A to reveal the morphology of mitochondria. Note that wild type has mitochondria organized as long wavy lines running parallel to the A- and I-bands, described as “tubular”. In contrast, unc-89(sf22) which carries the PK2 KtoA mutation, and unc-89(tm752) which lacks expression of all kinase-containing isoforms have mitochondria that appear as dots or can be described as fragmented. By comparison, unc-89(e1460) which maintains expression of all kinase-containing isoforms, and unc-89(su75) which lacks expression of all giant isoforms but still expresses small kinase-containing isoforms have mitochondria that appear more tubular or more like wild type. b 3D rendering of SIM images of muscle mitochondria of the indicated strains. Note the presence of linear or tubular mitochondria in wild type and unc-89(e1460) and fragmented mitochondria in unc-89(sf22) and unc-89(tm752). c, d Three additional independently isolated PK2 KtoA mutants (sf24, syb1195, and syb1360) show fragmented mitochondria. Scale bars, 10 μm in (a and c); 5 μm in (b and d).