Groupes sulfhydriles et morphogénèse III. Etude biochimique des effets du mercaptoéthanol sur les embryons de batraciens et l'algue Acetabularia mediterranea

摘要

Thebiochemicaleffectsof?2-mercaptoethanol(whichinhibitsneuraltubeclosureveryeffectively)havebeenstudiedinamphibiangastrulaeandneurulae,andinthealgaAcetabularia.Ithasbeenfoundthat:1.1.Totalandacidsoluble-SHgroupsdefinitelyincreaseinmercaptoethanol-treatedeggs.2.2.S35-MercaptoethanolisincorporatedintotheproteinsofbothamphibianembryosandAcetabularia.Theradioactivityoftheproteinsrepresents25%ofthetotalradioactivityinthetreatedeggsandvariesbetween10and25%,accordingtocultureconditions,inAcetabularia.3.3.AutoradiographyobservationsandworkonhomogenateshaveshownthatS35-mercaptoethanolisincorporatedmainlyintothepigmentgranulesandyolkplateletsoftheanimalhalfand,later,ofthedorsalhalfoftheembryo.InAcetabularia,theincorporationishighestinthenucleusandintheapicalpartofthestem.4.4.Itwasnotpossibletodetectbyelectrophoresistheappearanceofanewsoluble-SH-containingproteininmercaptoethanol-treatedeggs.MostoftheradioactivityisfoundinthebasicproteinfractionaftertreatmentwithS35-mercaptoethanolofamphibianeggs.5.5.Amphibianeggscontainnoecto-ATPase,andmercaptoethanoltreatmenthasnoappreciableeffectontheirendo-ATPase.Thesignificanceoftheseresultsforanexplanationofthemorphostaticeffectsofmercaptoethanolisdiscussed.