Melanogenesis in cultures of peripheral nervous tissue: II. Environmental factors determining the fate of pigment-forming cells☆

[摘要] Spinalgangliafrom4-to7-day[Stage23–30;HamburgerandHamilton(1951)J.Morphol.88,49–92]chickenembryoswereculturedinvitrotoinvestigatetheeffectofvariousenvironmentalconditionsoncelldifferentiation.Culturemorphology(i.e.,degreeofdispersionoftheexplantedganglia,survivalofneurons,andoutgrowthofaxons)wasobservedtodependuponseveralfactorsincluding:(1)theageoftheexplantedganglia,(2)thepresenceorabsenceofnervegrowthfactor(NGF),and(3)thenatureofthesubstratumonwhichtheculturedtissueresides.Theseobservationsenabledustodisturbtheassociationofneuronswiththeothercellsinganglionculturesandtherebymodulatethedifferentiationofadventitiousmelanocytes.Thus,inmediumpermissiveformelanogenesis,melanocytesappearwhentheassociationbetweenneuronsandsmallstellatenonneuronalcellsintheganglionisdisrupted.Thisdisruptionismostextensive(1)whenyoung(Stage26–27,5-day)gangliaareexplantedonplasticsubstrata,intheinitialabsenceofNGF,and(2)whencellsfromenzyme-dissociatedgangliaareculturedonplasticsubstrata.Incomparablemedia,pigmentcelldifferentiationisnotobservedwhentheassociationbetweenneuronsandsmallstellatecellsispreserved.Suchassociationstendtoendure(1)indevelopmentallyolder(Stage30+,7-to8-day)gangliaor(2)whengangliaareculturedonagarorfibroblastsubstrata.Weconcludethatlossofassociationbetweenneuronsandthenonneuronalcellsinyounggangliaisnecessaryforthelattertoundergomelanogenesisinvitro.

[学科分类] 生物科学（综合）