The metamorphosis of Drosophila melanogaster, including an accurately timed account of the principal morphological changes

Abstract

FOUR PLATES (THIRTY FIGURES) AUTHOR'S ABSTRACTDuring the quiescent fourth larval instar the larva of Drosophillc becomes loosened from the puparium and takes on the form of a pupa . A large gas bubble is formed within the b2dAt the end of this stadmm. which lasts 111 hours a t 25 d it upates shedding the prepupal cuticle . The gas bubble is used as a meqhanistn to separ;te txe cutiile from its hypodermis . Practically all of the tissues undergo hlstolysls and are replaced by imaginal structures derived from specialized cells . Some of the muscles persist longer than the general mass and perform special functions in the pupa . The sequence of histolytic and histogenetic changes is accurately timed at a constant temperature . during this prepupal period .

The timing of Drosophila salivary gland apoptosis displays an l(2)gl-dose response

“…In wild-type prepupae the disintegration of the salivary glands occurs relatively suddenly, 12 ± 13 h after the onset of pupariation 11,12,20,61,87 and cell death takes place in a nearly synchronous manner in all larval cells. Our investigations show that this process can be studied in vivo with the analytical achievement of a tissue culture system while maintaining the physiological relevance of an intact organism.…”

Autophagic programmed cell death in Drosophila

“…37,38 This cell death is preceded by markers of apoptosis including DNA fragmentation and nuclear acridine orange staining. 39 While these data suggest that salivary glands die by apoptosis, their morphology indicates that they die by autophagy (Figure 2).…”

Steroid regulation of programmed cell death during Drosophila development

“…Imaginal discs undergo morphogenesis to form future adult appendages, and adult flight muscles appear in the anterior region of the prepupa. 23,24 While these changes in adult structures occur, several tissues are destroyed including the anterior larval muscles and the larval midgut. 23,24 Similarly, numerous cell and tissue changes are also induced when the ecdysone titer rises at the prepupal-to-pupal transition.…”