Fig. 4. Tyrosine hydroxylase protein and activity profiles in yw, EH-KO, CCAP-KO, burs^Z1091 and rk⁴ flies following puparium formation. Times are measured from pupariation. (A) Western blot of epidermal tyrosine hydroxylase (TH) from yw flies. An actin loading control is shown below the TH blot in this and subsequent figures. (B) TH activity in yw organisms. TH activity in this and subsequent figures is expressed as a percentage of the yw white pre-pupae (WPP) value. (C) Western blots of epidermal TH from EH-KO, CCAP-KO, burs^Z1091 and rk⁴ flies. (D) TH activity in the same organisms as C. In B and D, black circles represent organisms within the pupal case, white circles represent adult flies. Values are means±s.e.m. of a minimum of three separate experiments.