Vitellogenin synthesis and characterisation of the liver estrogen receptor in the neotenous salamander Ambystoma mexicanum☆
[摘要] TheneotenoussalamanderAmbystomamexicanumreachessexualmaturitywithoutcompletingmetamorphosis.Femalesmust,therefore,synthesizevitellogenin,theprecursoroftheegg-yolkproteins.WeshowthatliversoffemaleaxolotlssynthesizeandsecreteaphosphoproteinwhichmigrateswithXenopusvitellogeninonSDS-gelsandisprecipitatedbyantibodypreparedagainstXenopusvitellogenin.Theliversofmaleaxolotlsdonotnormallysynthesizethisproteinbutcanbeinducedtodosobytreatmentinvivowithestradiol.Areceptorwithahighaffinityforestradiol(Kd=0.3×10−9M)wasfoundinthenucleipreparedfromliversofmaleandfemaleaxolotls.Itsedimentsat3.7Sat0°Cinsucrosegradientscontaining0.5MKCl.Eachnucleuscontainsabout1300bindingsitesforestradiol,13timesthenumberfoundinnormalmaleXenopusnuclei,butasaxolotlnucleiareabout12timeslarger,theconcentrationsofbindingsitesaresimilar.IncontrasttoXenopus,thereisnodetectableincreaseinthenumberofnuclearbindingsitesfollowingestrogentreatment.WeconcludethatthecontrolsaffectingboththeappearanceofvitellogenininducibilityandtheinductionofvitellogeninsynthesisdifferbetweenthetwospeciesA.mexicanumandXenopuslaevis.
[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]
