Collagen and mucopolysaccharide biosynthesis in mass cultures and clones of chick corneal fibroblasts in vitro☆

[摘要] Collagenandmucopolysaccharidebiosynthesisbycellpopulationsofthechickcorneahavebeenstudiedinvitro.Stromalfibroblastsfrom14-dayembryosweregrownasmassculturesandclones;cornealepitheliumwasisolatedasintactsheetsofcellsfromembryosofthesameage.Cultureswereincubatedwithradioactiveprecursorsofcollagenormucopolysaccharides.Cornealepitheliumhydroxylatedaportionoftheadministeredprolineandthereforeappearedtosynthesizecollagen.Massculturesofstromalfibroblastswereincubatedwiththelabeledprecursorsatvarioustimesduringculturecycles.Low-andhighlysulfatedchondroitinsulfate,keratosulfate,andcollagen,endproductsofdifferentiationinthecorneainvivo,weresynthesizedduringbothlogarithmicandsaturationphasesofgrowth.Changesintherateofsulfateincorporationintoindividualpolysaccharidesduringtheculturecycledidnotparallelthoseofglucosamineincorporation,suggestingachangeinthedegreeofsulfationofthepolysaccharidessynthesizedasthecelldensityofculturesincreased.Analysisof68clonesofstromalfibroblasts,eachdouble-labeledwithproline-3,4-3H+Na235SO4orproline-14C(uniformlylabeled)+glucosamine-6-3H,showedthatindirectproportiontotheirsize49oftheseclonescouldmakeallthreecornealpolysaccharidesandcollagen.Inallbutoneoftheremainingsmallerclones,allthreepolysaccharidesweredetected.Theclonalanalysisthereforesuggestedthateachcellofthistissue-specificpopulationoffibroblastsisspecializedfortheproductionofmorethanoneendproductofdifferentiation.

[学科分类] 生物科学（综合）