Fig. 4. Jasplakinolide prevents module shortening. Thoraces from 48-hour animals were cultured for 5 hours in the presence or in the absence of jasplakinolide (3 µM), stained with rhodamine-labeled phalloidin and imaged by confocal microscopy. (a) Bundles in control bristles develop the expected gaps owing to actin depolymerization. (b) In contrast, bundles in jasplakinolide-treated bristles failed to undergo normal barbed-end depolymerization and remained smooth.