Phospholipid metabolism following fertilization in sea urchin eggs and embryos☆
[摘要] PhospholipidmetabolismduringearlydevelopmentwasexaminedintheseaurchinsStronglyocentrotuspurpuratusandLytechinuspictus.Transportof3H-cholinewasstimulatedfivefoldfollowingfertilizationinbothspecies.However,theactualpercentincorporationoflabeledprecursorsintophospholipidsfromtheTCAsolublepooldidnotchangeatfertilization.Therewasaslightincreaseintransportof14C-ethanolamineatfertilizationbutagaintherewasnochangeinitspercentincorporationintophospholipids.Wheneggswerepreloadedwith3H-cholineor14C-ethanolamineandfertilized,theeggsorembryosshowedsimilarpatternsofincorporationintophospholipids.Therewasnosignificantchangeinthepercentphosphorylationofcholineinfertilizedorunfertilizedeggs.Aninvestigationwasmadeoftheactivityofcholinekinase,thefirstenzymeinthebiosynthesisofphosphatidylcholine.Thisenzymewasfoundtohavesimilaractivitiesinfertilizedandunfertilizedeggsusingavarietyofhomogenizationmedia.Theactivityofcholinekinasewasfoundtodecreaseslightlyinactivityatfertilizationandreachamaximumactivitybygastrula.Theseresultsindicatethatthereisnoactivationofphospholipidsynthesisatfertilizationofseaurchineggs.Apparentincreasedincorporationactuallyreflectsincreasedtransportofprecursorsandnotdenovosynthesis.
[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]
