Production in vitro by spinal cord of growth factor(s) acting on newt limb regeneration: influence of regeneration of the nerve fibers.
In order to approach the problem of regulation of growth factor(s) production during limb regeneration in newt, we co-cultivated spinal cord segments and blastemas. First we showed that, like the sensory supply, the spinal cord possesses size-dependent mitogenic capacities for limb blastemas. A 5-mm long spinal segment enhances radiolabelled thymidine incorporation to the same extent as spinal ganglia (1.6-fold). Second, we co-cultivated blastemas with spinal segments, the nerve fibers of which were previously stimulated to regenerate (= stimulated spinal segment) or not (= non-stimulated spinal segment). Only after a 24-h coculture, do stimulated spinal segments enhance thymidine incorporation in blastemas 2-fold more than non-stimulated spinal segments. Our results suggest that during limb regeneration brachial nerves produce more growth factor(s) when regrowing, inducing the proliferation of blastema cells which in return deliver a neuronotrophic factor acting on these nerves.
Boilly
B
B
Laboratoire de Morphogenèse Animale, Université des Sciences et Techniques de Lille, Villeneuve d'Ascq, France.
Bauduin
B
B
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D005121:Extremities / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D008934:Mitogens / Q000494:pharmacology; D009414:Nerve Growth Factors / Q000378:metabolism / Q000494:pharmacology*; D009416:Nerve Regeneration / Q000187:drug effects*; D012038:Regeneration / Q000187:drug effects*; D012455:Salamandridae / Q000502:physiology*; D013116:Spinal Cord / Q000378:metabolism*; D013936:Thymidine
D008934:Mitogens; D009414:Nerve Growth Factors; D013936:Thymidine