PROGRAMMED CELL-DEATH OF IDENTIFIED PEPTIDERGIC NEURONS INVOLVED IN ECDYSIS BEHAVIOR IN THE MOTH, MANDUCA-SEXTA

The eclosion of the adult Manduca sexta moth is followed by a wave of cell death that eliminates up to 50% of the neurons of the central ner vous system within the first few days of imaginal life. While the iden tity of some of the dying motoneurons has been established, that of mo st doomed neurons is unknown, Here, we show that the dying cells inclu de peptidergic neurons involved in the control of ecdysis behavior. Th ese cells belong to a small population of 50 neurons that express crus tacean cardioactive peptide (CCAP), a potent regulator of the ecdysis motor program, and show increases in cyclic 3',5'-guanosine monophosph ate at each ecdysis, First, we describe new markers for these neurons and show that they are expressed in these CCAP-immunoreactive neurons in a complex temporal pattern during development. We then show that th ese neurons die within 36 h after adult eclosion, the last performance of ecdysis behavior in the life of the animal, via the active, geneti cally determined process of programmed cell death. The death of these neurons supports the hypothesis that outmoded or unused neurons are ac tively eliminated. (C) 1998 John Wiley gr Sons, Inc.