Wing discs do not exhibit any laccase activity.

<p>Laccase is one of the enzymes in insects that may also oxidize phenol to produce melanin materials. Cell lysates of wing discs (W) and epidermis (E) from larvae on V-3 and cell lysates of mushroom (M) and plasma (P) were assayed by Western blot and native gel staining for laccase detection. For each lane, approximately 15 µg proteins were loaded. (A) No laccase was detected in wing discs using a denatured Western blot. PPO in the lysates was detected with a primary antibody against silkworm PPO. Laccase, however, was detected in epidermis as the arrowhead indicates. (B) No active laccase in the wing discs. Laccase activity was detected in the mushroom lysate that served as a positive control. After native gel separation, the gel was stained to show PPO activity (a) by incubating it with dopamine or to show laccase activity by incubating it with ABTS (c) after being activated by ethanol. One native gel was further assayed by Western blot to detect PPO protein (b). The arrows indicate PPO in wing discs and plasma. The arrowhead points to active laccase in the mushroom lysate. No active laccase in the wing discs or plasma was observed. W: wing discs; P: plasma; E: epidermis; M: mushroom.