The synthesis and degradation of RNA containing polyriboadenylate during sea urchin embryogeny☆

[摘要] Thesynthesisanddegradationofpolyriboadenylate[poly(A)]wasstudiedduringseaurchinembryogenesisinanefforttolearnmoreabouttheroleofpoly(A)inthecellanditsrelationshiptoembryogeny.Midcleavage,midblastula,andmidgastrulaembryoswerelabeledwith3H-adenosine,andthekineticsofincorporationfollowedfor4hrinboththeentirecellandthecytoplasmicfraction.Cleavingembryosshowlinearincorporationofisotope.Attheotherstagesisotopeincorporationfollowssaturationkineticsindicativeofturnover.RNAthatcontainspoly(A)wasshowntoexhibitatypeofincorporationkineticssimilartononadenylylatedRNA,althoughsomewhatmoreoftheRNAthatcontainspoly(A)isexportedtothecytoplasmthanisthenonadenylylatedportion.AconsiderableamountoftheRNAthatcontainspoly(A)isdegradedinthenucleuswithoutexporttothecytoplasm.Thepoly(A)wasisolatedfromthenewlysynthesizedRNAthatcontainspoly(A),anditssizeshowedabroadrangefromabout80to200nucleotidesatallstagesandforalllabelingtimes.Itisconcludedthatpolyadenylylationisveryactivethroughoutembryogenesis,butthatthestabilityofpolyadenylylatedmoleculesmaybedifferentinnucleusandcytoplasm,andfromonedevelopmentalstagetoanother.

[学科分类] 生物科学（综合）