Synthesis of macromolecules in early mouse embryos cultured in vitro: RNA, DNA, and a polysaccharide component☆
[摘要] Theproductsofincorporationofuridine-5-3Hinembryosfromthe8-cellstagetothehatchedblastocyst(day5)wereanalyzedbysedimentationinsucrosegradients.RibosomalRNAisamajorproductofRNAsynthesisduringthisperiod.HeterodisperseRNA,includingagiant-sizelabileRNA,and4SRNAarealsosynthesized.Pulselabelingandactinomycinchaseexperimentshaveledtotheidentificationofarapidlylabeled39SRNAspeciesasaprecursorof28Sand18SrRNA.LowconcentrationsofdactinomycininhibitrRNAsynthesisselectivelyandtoanextentproportionatetodose.Uniformlylabeledthymidine-14CisincorporatedintoDNA,RNA,andpolysaccharide.ThesecomponentshavebeenseparatedandanalyzedinCsClandethidiumbromide-CsCldensitygradients.TheDNAsynthesizedisnuclearandlabeledtoaveryhighspecificactivity.TheevidencesuggeststhatnoextensivereplicationofmitochondrialDNAtakesplaceduringcleavage.Amajorportionofuniformlylabeledthymidine-14Cisincorporatedintoapolysaccharidecomponentduringtheblastocyststage(day4–5).Somepropertiesofthispolysaccharidearedescribed.
[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] tRNA;transfer RNA;rRNA;ribosomal RNA;r-pre-RNA;ribosomal precursor RNA;dRNA;RNA with DNA-like base composition;mRNA;messenger RNA;HnRNA;high-molecular-weight heterodisperse nuclear RNA [时效性]
