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 nervous system within the first few days of imaginal life. While the identity of some of the dying motoneurons has been established, that of most doomed neurons is unknown. Here, we show that the dying cells include peptidergic neurons involved in the control of ecdysis behavior. These cells belong to a small population of 50 neurons that express crustacean cardioactive peptide (CCAP), a potent regulator of the ecdysis motor program, and show increases in cyclic 3′,5′‐guanosine monophosphate 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 these neurons die within 36 h after adult eclosion, the last performance of ecdysis behavior in the life of the animal, via the active, genetically determined process of programmed cell death. The death of these neurons supports the hypothesis that outmoded or unused neurons are actively eliminated. © 1998 John Wiley & Sons, Inc. J Neurobiol 37: 265–280, 1998

During metamorphosis of the insect brain, the optic lobe anlagen generate the proliferation centers for the visual cortices. We show here that, in the moth Manduca sexta, an 80 kDa Golgi complex protein (Ms-golgin80) is abundantly expressed in the cytoplasm of neuroblasts and ganglion mother cells in the optic lobe anlagen and proliferation centers. The predicted amino acid sequence for Ms-golgin80 is similar to that of several members of the GM130 subfamily of Golgi-associated proteins, including rat GM130 and human golgin-95. Homologs of Ms-golgin80 from Drosophila melanogaster, Caenorhabditis elegans, and Brugia malayi were identified through homology sequence search. Sequence similarities are present in three regions: the N-terminus, an internal domain of 89 amino acids, and another domain of 89 amino acids near the C-terminus. Structural similarities further suggest that these molecules play the same cellular role as GM130. GM130 is involved in the docking and fusion of coatomer (COP I) coated vesicles to the Golgi membranes; it also regulates the fragmentation and subsequent reassembly of the Golgi complex during mitosis. Abundant expression of Ms-golgin80 in neuroblasts and ganglion mother cells and its reduced expression in the neuronal progeny of these cells suggest that this protein may be involved in the maintenance of the proliferative state.BrdU5-bromo-2′-deoxyuridineCOP I, IIcoatomer proteins that coat vesicles and direct protein and membrane trafficking between early compartments of the secretory pathway in eukaryotic cellsGM130Peripheral membrane proteins associated with the Golgi bodies. GMCganglion mother cellMs-golgin80The Manduca sexta homolog of the GM130 protein. Other homologs include Rn-GM130 (Rattus norvegicus); Hs-GM130 (Homo sapiens), Dm-golgin90 (Drosophila melanogaster), Ce-golgin107 (Caenorhabditis elegans) and Bm-golgin (Brugia malayi)PBSphosphate buffered salinePBSTphosphate buffered saline containing 0.05% Tween-20TBSTTris buffered saline containing 0.05% Tween-20