Adult-specific neurons in the nervous system of the moth, Manduca sexta: selective chemical ablation using hydroxyurea.
The segmental ganglia of adults of the moth, Manduca sexta, are constructed both from remodeled larval neurons and from adult-specific cells. The latter are produced by identified stem cells (neuroblasts) during larval life and then differentiate to form functional neurons during metamorphosis. The mitotic activity of the larval neuroblasts could be irreversibly blocked by the DNA-synthesis inhibitor hydroxyurea (HU). Treatment on day 1 of the third larval stage resulted in 80-90% of the neuroblasts being blocked before they produced any progeny while leaving the functional larval neurons unaffected. Treated larvae finished growth, underwent metamorphosis, and produced an adult CNS that contained the normal set of remodeled larval neurons but lacked most of the new adult-specific cells. When HU treatment was delayed until the start of the fourth or fifth larval stage, the neuroblasts produced the early portions of their respective lineages before they were blocked. The immature neurons that were generated prior to treatment survived to contribute adult-specific neurons to the moth CNS, but the remainder of each lineage was missing. This technique therefore enables one to produce adult nervous systems containing the basic set of remodeled larval cells plus defined sets of adult-specific neurons.
D000818:Animals; D002452:Cell Count / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002490:Central Nervous System / Q000187:drug effects; D003561:Cytarabine / Q000494:pharmacology; D006918:Hydroxyurea / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D007915:Lepidoptera / Q000033:anatomy & histology*; D008675:Metamorphosis, Biological / Q000187:drug effects; D016685:Mitomycin; D008937:Mitomycins / Q000494:pharmacology; D009036:Moths / Q000033:anatomy & histology* / Q000187:drug effects; D009410:Nerve Degeneration / Q000187:drug effects; D009473:Neuronal Plasticity / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects*; D013234:Stem Cells / Q000187:drug effects
D008937:Mitomycins; D003561:Cytarabine; D016685:Mitomycin; D006918:Hydroxyurea