Chromatin proteins of sea urchin embryos: Dual origin from an oogenetic reservoir and new synthesis☆

[摘要] Thechromatinproteinsofdifferentembryonicstages,rangingfrom16celltogastrula,oftheseaurchinStrongylocentrotuspurpuratuswerelabeled,invivo,with14Candwerelabeled,invitro,with3H.Theproteinsthuslabeledwereseparatedbyhighresolutiontwo-dimensionalelectrophoresis.Theextentofpossiblecytoplasmiccontaminationhasbeenexaminedwithreconstructionexperiments.Gastrulachromatincontainsover200separablenonhistoneproteins,andabout90%ofthemarealsodetectedatthe60-cellstage;cleavagestageshaveoverallproteingelpatternsdisplayingnumerousdifferenceswiththepatternshownbychromatinfromlaterstages.Differencesintheproportionofhistonetononhistoneproteinsthataresynthesizedareobservableatthedifferentembryonicstages,withhistonespredominatinginmidcleavage.Abouthalfofthenonhistoneproteinsofthedevelopingembryothatcanbelabeledwith3H,invitro,arenotlabeledwith14C,invivo,andhence,mustoriginatefromareservoirofnonhistoneproteinsassembledduringoogenesis.

[学科分类] 生物科学（综合）