DNA-dependent cytoplasmic RNA polymerases I and II in insect oocytes☆
[摘要] CytoplasmfrommatureeggsofManducasextawasexaminedforstoredDNA-dependentRNApolymeraseactivity.LargeamountsofeukaryoticRNApolymerasesIandIIwerefoundandidentifiedbytheirsensitivity,orresistance,tothetoxinsα-amanitinandactinomycinD.Usingthebindingof[3H]amanitin,thecontentofRNApolymeraseIIineachmatureeggwasfoundtobeapproximately0.011pmole,fargreaterthannecessaryinsuchatranscriptionallyquiescentcell.Leakageofnuclearpolymeraseintothecytoplasmduringpreparationoftheooplasmicextractwasdiscountedasapossibleexplanationforthisobservationbyinjecting[3H]amanitinintotheeggandlocatingthe[3H]amanitinRNApolymeraseIIcomplexesbyautoradiography.Essentiallyallofthesilvergrainswerefoundovertheooplasm.TheseobservationsindicatethatsignificantamountsofDNA-dependentRNApolymerasesarestoredintheooplasm,possiblyuntilblastodermformationwhentheymaybetransportedintonucleustotakepartinthemassiveincreaseintranscriptionalactivityseenatthattime.
[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]
