Localization of “transcriptively active” cells during odontogenesis using acridine orange ultrastructural cytochemistry☆

[摘要] Acridineorange(AO)wasshowntobeaneffectiveprobefortheultrastructurallocalizationofgeneexpressioninembryonicepithelialandectomesenchymalcellsduringrabbitincisortoothorganogenesis.Aconcentrationof10−2MAOprovidedhigh-resolutionlocalizationofintranuclearbindingsitesindicativeof“transcriptivelyactive”euchromatinportionsofthecellnucleus.ThismethodwascombinedwithananalysisofthedistributionofsilvergrainsresultingfromtheincorporationoflabeleduridineintoribonucleicacidmoleculesasevaluatedbyRNAseT1andactinomycinDsensitivity.Comparisonsofthespatialdistributionpatternsof(1)electron-densereactionproductsresultingfromAObindingtoeuchromatin,and(2)silvergrainsresultingfromtheincorporationofuridineintonewlysynthesizedRNAmolecules,localizedseveraldiscrete“transcriptivelyactive”regionsinthecervicalloopofprogenitorectomesenchymalandadjacentepithelialcellpriortoovertcelldifferentiation.Theresultsjustifyfurtherinvestigationsofacridineorangeandotherrelatedmoleculesasultrastructuralprobesforgeneexpressionduringembryonicepithelial-mesenchymalinteractionsassociatedwithepidermalorganogenesis.

[学科分类] 生物科学（综合）