Temporal and spatial transitions in collagen types during embryonic chick limb development☆

[摘要] Todeterminewhethertransitionsoccurinthetypesofcollagensynthesizedduringembryonicchicklimbdevelopment,theαchaincompositionofthecollagensproducedbywholelimbsandvariousanatomicalregionsoflimbswasanalyzedatdifferentstages(23–24to40).Thetissueswereincubatedinthepresenceof3H-prolineand3H-lysineandtheαchaindistributionofthepurified,labeledcollagenswasdeterminedbychromatographyoncarboxymethylcellulosecolumns.Wefoundthatthestage23–24legmesenchymeisproducingpredominantly,ifnotsolely,an(α1)2α2typecollagen(chaintypeasyetundetermined).Ataboutstage25–26thelimbcorebeginssynthesizingdetectableamountsof(α1)3collagen,whichwepresumetobecartilagetypecollagen,[α1(II)]3,whiletheouterportionofthelimblargelycontinuestoproduce(α1)2α2.Theproductionof(α1)3collageninthecoreprogressivelyincreasesuntil,bystage33itistheonlyspeciesdetectableinthetibialdiaphysis.Shortlythereafter(bystage35+–36)(α1)2α2typecollagenreappearsinthetibialdiaphysissignifyingtheproductionofbonecollagen,[α1(I)]2α2.Duringthenextseveraldaysofincubation,therelativeproportionof(α1)2α2increasesinthebonydiaphysiswhile(α1)3remainsthepredominantspeciessynthesizedinthecartilaginousepiphysis.

[学科分类] 生物科学（综合）