Figure 4.

Suppression of up¹⁰¹ by D53. (A-C) Polarized light microscopy of IFMs. Each thorax is shown with anterior-posterior axis running left to right. Bar = 0.125 mm. (A) In up¹⁰¹/Y birefringence is seen only at the muscle ends. The dorso-longitudinal (DLM) flight muscles are most readily seen, but the opposing dorso-ventral (DVM) muscles are visible. (B) The more complete DLMs typical of partial suppression in up¹⁰¹/Y; D53/+ males. (C) Age effects on walking ability of up¹⁰¹ (▪), up¹⁰¹; D53/+ (▴), and wild-type (♦) flies.