Fig. 4. Targeted ablation of CCAP neurons causes failures of pupation. (A-D) Early KO pupa (A,B) and corresponding control (C,D). KO animals show defects such as incomplete head eversion, as evidenced by the anterior position of head (white asterisk indicates the position of the eye); retracted posterior cuticle due to failure to transition from pre-ecdysis to ecdysis (arrow in A), and incomplete shedding of tracheal lining (arrowheads in B point to scars left on the larval cuticle). White arrows in D indicate properly everted legs (l) in control animal. (E-H) KO (E-G) and control (H) pharate adults. The failure at pupation in KO animals results in defects in adult head formation and in leg and wing extension. Black asterisk: partial adult head; m, larval mouthooks; p, proboscis of adult. White arrows and black arrowheads in E-H indicate the posterior extent of the wings and prothoracic set of legs, respectively. (I) Timecourse of morphological and behavioral events at pupation. Pharate pupae collected at late stage P4(i) (Bainbridge and Bownes, 1981) were first quiescent (green gradient), then went into pre-ecdysis (yellow), followed by ecdysis (head eversion; red segment), which was specifically absent in KO animals. Ecdysis (in the control) and the extended pre-ecdysis (of KO animals) were followed by a long period of abdominal movements (blue gradient). Records were aligned relative to the onset of pre-ecdysis, and the duration of each interval is indicated as average±s.e.m.; times prior to pre-ecdysis were not tabulated. These data and the statistical significance of the observed differences are tabulated in Table 2.