Figure 1. The Drosophila heart and physiological analysis.

(A) The abdominally located Drosophila heart (Hrt) is a simple linear tube that is divided into an anterior, conical chamber (CC) and three posterior compartments. A1 = abdominal segment 1; A6–A7 = abdominal segments 6 and 7; Os = ostia inflow tracts (modified from [66]). (B–F) Cardiac-restricted expression of wild type human CryAB (HG4>wtCryAB) had no significant effect on any measured parameter of cardiac performance in Drosophila. Several indices of cardiac function were influenced by the expression of mutant CryAB^R120G (HG4>R120GCryAB). The diameter across the heart tubes during (D) diastole and (E) systole were significantly greater, and (F) percent fractional shortening significantly lower relative to HG4>wtCryAB flies. Knockdown of G6PD in CryAB^R120G mutant hearts (HG4>R120GCryAB+G6PDRNAi) substantially improved cardiac performance of the mutant hearts as evidenced by (B) significant decreases in heart period, (C) arrhythmic beating patterns, (E) systolic dimensions and (F) significantly increased fractional shortening relative to HG4>R120GCryAB hearts. * P≤0.05, ** P≤0.01, *** P≤0.001, **** P≤0.0001.