Fig. 7.

Caffeine treatment inhibits slug migration. a The scheme of experiments for monitoring the effect of caffeine on slug migration. Slugs were formed on a filter. Agar containing 0 mM (control) or 4 mM caffeine was put on the filter during the observation. b Snapshots of migrating slugs with or without 4 mM caffeine treatment. Fluorescent images of slugs expressing Citrine at t = 0 (left) and 30 min (middle) and subtracted images of the two (right) are shown. In the subtracted images, the yellow zones around the tips of the slugs indicate the migration space for 30 min. White circles shown in the t = 0 and 30 min images indicate the positions of the tips of the slugs at t = 0 min. Scale bars, 500 μm. c Comparison of migration rates between no treatment (Control) and caffeine-treated slugs (Caffeine treatment). n = 36 slugs for both groups (mean ± SD). Dots represent original data. *P < 10^–20, Student’s two-tailed t-test