Fig. 7

Normal cardiogenesis and myofibrillogenesis in the absence of all Xirps.

(A) Neither cardiac nor skeletal muscle sarcomeric organization of myofibrils is affected in 48 hpf xirp1^sa0046 mutants. Green: α-Actinin or Myosin; red: Actin. Red scale bars: 10 μm, white scale bars: 5 μm. (B) Sectioned adult cardiac tissue reveals that neither Xirp2a nor Xirp2b are expressed to compensate for the loss of Xirp1. Also, the xirp1^sa0046 mutant lacks all three Xirp1 isoforms. Therefore, Xirps are not required for development or maintenance of cardiac tissue. Green: Xirp1; red: Actin. Scale bar: 10 μm. (C) Complete absence of all Xirps within skeletal muscle prior to 24 hpf in xirp1^sa0046/xirp2aMO mutant/morphants. Localization of Xirp1 is not affected in xirp2a morphants and, conversely, Xirp2a localization is normal in xirp1^sa0046 mutants. Scale bar: 50 μm. (D) Complete loss of Xirps in xirp1^sa0046/xirp2aMO mutant/morphants does not impair early cardiogenesis (at 21 hpf) or myofibrillogenesis (at 32 hpf). Green: Xirp1 or Myosin; red: Actin. Red scale bar: 50 μm, white scale bar: 5 μm, yellow scale bar: 20 μm.