FIG. 4.

PERΔ is not fully functional yet maintains partial biological activity. (a) Expression of the wild-type per gene rescues the arrhythmic behavior of the per⁰ mutant, while that of perΔ does not. Expression of the per gene is under the UAS regulatory sequence, which is driven by a panneuronal driver, elav^c155-GAL4 (54). Each panel represents grouped locomotor activity of individual genotypes in constant darkness. Three independent lines of UAS-perΔ are shown here (1A1r, 2Y1, and 2X1); a complete summary is in Table 1. (b) In wild-type-equivalent background (elav^c155-GAL4; UAS-per24), the expression of PERΔ could interfere with the behavioral period. Each panel represents grouped locomotor activity of individual genotypes in constant darkness. Three independent lines of UAS-perΔ are shown here (1A1r, 2Y1, and 2X1); a complete summary is in Table 2. (c) Western blot analysis of PER from fly head extract collected at two time points (ZT 12 and ZT 24). Flies were entrained in 12 h light/12 h dark for at least 3 days prior to the collection. Rabbit anti-PER antibody was used for the detection.