Biosynthesis of glycosaminoglycans in the developing retina☆
[摘要] Theglycosaminoglycansofneuralretinasfrom5-,7-,10-,and14-daychickembryoswerelabeledinculturewith[3H]glucosamineand35SO4,extracted,andisolatedbygelfiltration.Theincorporationoflabelperretinaintoglycosaminoglycansincreasedwithembryonicage,butthatpercellandperunitweightofuronicaciddecreased.Specificenzymemethodscoupledwithgelfiltrationandpaperchromatographydemonstratedthat[3H]glucosamineincorporationintochondroitinsulfateincreasedbetween5and14daysfrom7to34%ofthetotalincorporationintoglycosaminoglycans.Duringthisperiod,incorporationintochondroitin-4-sulfateincreasedrelativetothatintochondroitin-6-sulfate.Between5and10days,incorporationintoheparansulfateshowedarelativedeclinefrom89to61%.Incorporationintohyaluronicacidalwaysrepresentedlessthan2%ofthetotal.Atwofoldgreaterincreaseingalactosamineconcentrationthaninglucosamineconcentrationintheglycosaminoglycanfractionbetween7and14dayssupportstheconclusionthatchondroitinsulfatewasthemostrapidlyaccumulatingglycosaminoglycan.ECTEOLA-cellulosechromatographyrevealedaheterogeneityinthesizeand/ornetchargeofchondroitinsulfateandheparansulfate.Weconcludethatincorporationofexogenousprecursorsintoglycosaminoglycansinthechickretinadecreasesrelativetocellnumberasdifferentiationprogressesfromaperiodofhighmitoticactivitytooneoftissuespecialization,andthatitisaccompaniedbyanetaccumulationofglycosaminoglycanandachangeinthepatternofitssynthesis.
[发布日期] [发布机构]
[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
