La localisation d'enzymes de déphosphorylation dans les oeufs de quelques Invertébrés☆
[摘要] Thesitesoftheenzymesdephosphorylatingvariousmononucleotideshavebeeninvestigatedintheformalin-fixedeggsofabivalve,anannelid,aseaurchin,andanascidian.Thetechnicalconditions(timesoffixation,washingandincubation,substrateconcentration)whichgiveanoptimalresultareapproximatelythesameforthefourspeciesstudied.Enzyme-bearinginclusionsoriginatemainlyintheyolkplatelets.Theirproductionalreadytakesplace,thoughmoderately,intheunfertilizedegg;itismaintained,oroftenenhanced,duringcleavageanddecreasesatthebeginningofmorphogenesis.Theactivegranulations—whicharenotmitochondria—rangefromthelimitofvisibilityupto2μ.Theysurroundthemitoticfiguresandareabundantneartheinterphasenuclei.Thereactionofthefurrows,whenpresent,isverydiscrete.Theactivityoftheblastomeresisoftenunequal.ThepolarlobeofSabellariaisparticularlyrichinenzyme(s).Centrifugationsedimentstheactivegranulespartlyinthehyalinezone,partlyinthelayerimmediatelyadjacenttothelipidcap.Theenzymesdetectedseeminglyformasystemofthemononucleotide-phosphohydrolasetype.Theyapparentlycomprise:anAMPase,anenzymewhichhydrolyzesbothATPandADP,andoneormoreothersactingontheothertriphosphatesthatwereused.Therelationshipoftheseelementswiththeinvivometachromaticαandβgranules,isdiscussed.Theimportanceoftheenzymaticequipmentoftheeggsaswellasitsspecializationinthedifferentgroupsisemphasized.
[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]
