Expression of a developmentally regulated gene, Mng10, in identified neurosecretory cells in the CNS of Manduca sexta

We are interested in the molecular events underlying the development of the nervous system of Manduca sexta during the final 24 h of the pupal molt. In this article we describe a gene, Mng10, that is expressed in the abdominal nervous system of M. sexta and is developmentally regulated over this 24-h period. In situ hybridization analysis shows that the transcript is localized predominantly to a single pair of uniquely identifiable neurosecretory neurons, the NS-L₁ cells in the abdominal ganglia. Mng10 is a single copy gene encoding a 229 amino acid protein with a predicted molecular mass of 26 kDa. At the amino acid level the protein shows 34% identity to the yeast transcription unit, Yer082. Northern blot analysis shows that the transcript of Mng10 is very rare, comprising about 0.001% of the poly (A)⁺ RNA from the CNS and is detectable at 4 h but not 24 h prior to pupal ecdysis. One of the physiological events that develops over the final 24 h of the pupal molt is the ability of the nervous system to respond to the neuropeptide eclosion hormone. In this context, it is interesting to note that the NS-L₁ cells are members of the group of 50 neurons that show increased cGMP immunoreactivity when the nervous system is exposed to the neuropeptide eclosion hormone.