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Evidence for an endogenous neurocidin in the Manduca sexta ventral nerve cord
Author(s) -
Choi M. K.,
Fahrbach S. E.
Publication year - 1995
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/arch.940280308
Subject(s) - manduca sexta , biology , ventral nerve cord , nervous system , central nervous system , ganglion , neuron , insect , endogeny , anatomy , neuroscience , sensory system , microbiology and biotechnology , endocrinology , botany
Half of the neurons in the abdominal nervous system of the moth Manduca sexta die after adult eclosion. Two physiological signals regulate post‐eclosion neuronal death in adult moths. The first is endocrine: a decline in blood ecdysteroids is necessary for the death of neurons in the segmental ganglia. The second signal, which is highly specific for a pair of motoneurons found at the posterior midline in each of the three unfused abdominal ganglia, originates in the nervous system. It is transmitted from the fused pterothoracic ganglion to abdominal ganglion A3 via the intersegmental connectives. To characterize the signal of neural origin, we have developed an in vitro bioassay for neuron‐killing factors (“neurocidins”). Aqueous extracts of pterothoracic ganglia were prepared and applied to cultured ventral nerve cords. These extracts exhibited concentration‐dependent effectiveness in killing motoneurons. The active component of the extract was heat‐stable and protease‐sensitive. Size fractionation studies suggested that the active component has a molecular mass between 10 and 30 kD. This is the first report of an endogenous neuron‐killing protein from an insect nervous system. © 1995 Wiley‐Liss, Inc.