A clonal approach to the problem of neural crest determination☆

[摘要] Afundamentalquestionregardingneuralcrestdevelopmentisthepossiblepluripotentialnatureofthisembryonictissue.Asafirststepinexaminingthisproblem,clonaltechniquesareusedtoproducehomogeneouspopulationsofcrestcells.PrimaryculturesofthesecellsareobtainedbyexplantingneuraltubesfromJapanesequailinvitroandallowingcrestcellstomigrateaway.Theexplantisremoved,theoutgrowthisisolated,dissociatedwithtrypsin,andthecellsplatedatclonaldensity.Coloniesderivedinthismannerfallintothefollowingcategories:allcellsofthecolonypigmented;noneofthecellspigmented;andsomeofthecellspigmented,theremainderunpigmented.Pigmentedcoloniesgenerallyarisefromsmall,roundcellswhereasthenon-pigmentedcoloniesusuallyoriginatefromlarge,flattenedpolymorphouscells.Differentiationofmelanocytesdoesnotprecludetheircontinuedproliferation.Thepigmentphenotype,inaddition,isstablethroughatleast25generations.Thatthemixedcolonies,infact,areclonallyderivedisshownbyphysicallyisolatingsinglecells.Theidentityofthenon-pigmentcellswasnotestablishedinthepresentwork.Apossibleneuralfateissuggested,however,sincenerve-likecellsdevelopafterthepetriplatesbecomeovergrown.Neuralclonesdidnotformeventhoughnervegrowthfactoractivityispresentasanormalconstituentoftheculturemediumandwasaddedasasupplementinsomeinstances.Thesetechniquespermitthepreparationoflarge,homogeneouspopulationsofneuralcrestcellsandaffordanopportunitytoexamineaspectsofcrestdeterminationheretoforeimpossibletostudy.

[学科分类] 生物科学（综合）