Biochemical and ultrastructural studies of collagen and proteochondroitin sulfate in normal and nanomelic cartilage☆
[摘要] Biochemicalandultrastructuralanalysisofthesternalcartilageofchickembryoshomozygousfortheautosomalrecessivegenenanomeliasuggestthatthemutantcellsarefunctionalchondrocytesinallrespectsexceptinproteochondroitinsulfatesynthesis.Proteochondroitinsulfatesynthesizedbynormalandmutantsternainvitrowaschromatographedon1%agarose.Twodistinctfractionsofproteochondroitinsulfatewereresolvedfrombothnormalandmutantcartilage.Innormalcartilage,themajorfractionrepresentsapproximately90%ofthetotalmaterial,andinthemutant,thisfractionisreducedto10%,whilethesecondfractionremainsunchanged.Itissuggestedthatattheonsetofchondrogenesisinthemutant,anaugmentationinthesyntheisofthemajorfractiondoesnotoccur.Collagensynthesisinthemutantcartilagewasanalyzedbyhydroxyprolinedetermination,carboxymethylcellulosechromatography,andaminoacidanalysistodeterminethepercentagehydroxylationoflysineresidues.Bytheseprocedures,collagensynthesisinthemutantwasfoundtobebothquantitativelyandqualitativelysimilartonormal.Ultrastructuralstudiesonthemutantsternarevealedthatwhilethemutantchondrocyteswerenormalinappearance,theamountofextracellularmatrixwasdecreased.Inconjunctionwiththisdecrease,thereisaseverereductioninthenumberofproteochondroitinsulfatematrixgranules.Nodifferenceswereobservedinthecollagenfibrils.
[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]
