Sarcomere length defects are due to disruption of thin filament length.

<p>Distribution of actin across the sarcomere was used to determine sarcomere length, thin filament length and H-zone width. (A) Sample image of a single sarcomere labeled with phalloidin to show actin filaments. Black overlay lines indicate quantified parameters. (B) Sample profile of a sarcomere showing the normalized fluorescent intensities of pixels found along the overlay line labeled ‘Sarcomere’ in A. Measured parameters, “Sarcomere Length”, “Thin Filament Length” and “H-zone Width”, are indicated. (C-E) Quantification of Sarcomere Length, Thin Filament Length, and H-zone width respectively in control and <i>bent</i> RNAi construct-expressing flies. Sarcomere and thin filament length does not significantly change in the control flies, but significantly shortens in the <i>bent</i> RNAi construct-expressing flies over six days. (F-H) Quantification of Sarcomere Length, Thin Filament Length, and H-zone width respectively in control and <i>Mhc</i> RNAi construct-expressing flies. Sarcomere and thin filament does not significantly change in the control flies, but significantly increases in the <i>Mhc</i> RNAi construct-expressing flies over six days. (I-K) Quantification of Sarcomere Length, Thin Filament Length, and H-zone width respectively in control and <i>Mhc</i> RNAi construct-expressing flies. Sarcomere and thin filament length does not significantly change in the control flies, but significantly increases in the <i>Mhc</i> RNAi construct-expressing flies over six days. Representative images of phalloidin stainings can be found in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0099362#pone-0099362-g007" target="_blank">Figure 7D-G</a> For all panels, error bars indicate standard error; n.s. indicates a p-value>0.05, *** indicates a p-value<0.0005. For (C-K) N≥30 sarcomeres from 5 animals at each time-point.