Studies on intercellular adhesive selectivity☆☆☆

[摘要] Theprobabilitythattwocellswillformandmaintainanadhesionaftercollisionoccursinsuspensionisassumedtoindicatetheadhesivestabilitybetweenthecellsinquestion.Unlabeledcellaggregatesarecirculatedintritiatedthymidine-labeledcellsuspensionswhereallextraneousfactorswhichmighthaveaffectedcollisionareheldconstant.Aftercirculating,theaggregatesarecollected,sectionedandexaminedradioautographicallyforlabeledcells.Experimentsarecarriedoutwithcellsandaggregatesfromchickenembryoneuralretinae,livers,sterna,heartventriclesandpectoralmusclesandwithmouseembryoneuralretinaeandheartventricles.Isotypicaggregates(sametissuetypeasthecellsinthesuspension)alwayscollectmorelabeledcellsthansimilar-sizedheterotypicaggregates(differenttissuetype).Collectionsoflabeledchickenembryolivercellsbyunlabeledliveraggregatesisdecreasedbylowtemperatures(0°and22°C)andbypuromycinbutnotbyactinomycinD.“Conditioned”mediumincreasesthecollectionandcounteractstheinhibitoryeffectsoflowtemperaturesandpuromycin.Somedegreeofadhesiveselectivityisshownbyneuralretinaandlivercellsandaggregateswhichwerekilledwithglutaraldehyde.Becausethepresenceofunlabeledcellsaltersthecollectionoflabeledcellsofanothertypebyiso-andheterotypicaggregates,itisconcludedthatnonselectiveadhesionsoccurredbetweenfreshlydissociatedcellsofdifferenttypesmorereadilythanbetweencellsandheterotypicaggregates.Ahypothesisisdescribedwhichassumesthatthereareatleasttwodifferentmolecularmoietiesonthecellsurfacewhichareresponsibleforintercellularadhesion.Oneofthesecausesselectiveandtheothernonselectiveadhesions.Experimentstotestpredictionsofthehypothesisarediscussed.

[学科分类] 生物科学（综合）