Figure 1. Ebony gene expression is under clock control.

(A) Ebony mRNA cycles in abundance in a light:dark (LD) cycle and in constant darkness (DD). Total RNA samples were prepared from heads of control yw and yw;tim⁰¹ flies collected every 4 hours in LD and DD. Real-time quantitative RT-PCR was performed on RNA samples using primers specific for ebony (see Methods). Relative abundance indicates the amount of ebony transcript normalized to rp49 mRNA abundance which is known to remain constant throughout the cycle. Ebony RNA cycles in yw but not in tim⁰¹(A) flies. (B) Ebony protein abundance changes in a diurnal manner in wild-type (yw) brains. Hand-dissected brains were collected every 4 hours in an LD cycle. Protein blots were immunostained with rabbit anti-MAPK antibodies. Each gel lane contained approximately 5μg protein. The graph shows the ratio of Ebony to MAPK protein as a function of time of day. The horizontal bars in panels A and B indicate the light:dark schedules.