The role of a “germinal plasm” in the formation of primordial germ cells in Rana pipiens☆
[摘要] UltravioletirradiationofthevegetalhemisphereofRanapipienseggs,beginningthefirstcleavagedivision,withdosesgreaterthan8000ergs/mm2resultedinthecompleteeliminationofprimordialgermcellsin100%ofthelarvaethatwereotherwiseapparentlynormal.IrradiationoftheanimalhemispherewithequivalentdosesofUVhadnoapparenteffectontheformationofprimordialgermcells.TheeffectofUVongermcellformationwasgreatestatthetimeofthefirstdivision.Afterthis,increasinglyfewereggs,whichhadbeenirradiatedatthevegetalhemisphere,developedintolarvaewithoutgermcells.Atthe8-cellstage,completeeliminationofgermcellswasnotobserved.Restitutionofthegermlineinirradiatedeggswasobtainedbyinjectingvegetalhemispherecytoplasmfromunirradiatedeggsintothevegetalhemisphereofirradiatedeggs,butrestitutiondidnotoccurbyinjectionofanimalhemispherecytoplasm.TheUVactionspectrumofgermcellinactivationsuggeststhatthesensitivematerialisanucleicacid.Theseresultsareconsistentwiththehypothesisofaspecificcytoplasmicgerminaldeterminant.Thisdeterminantispresentonlyinthevegetalhemispherecytoplasm;itisprobablyanucleicacid;anditappearsinembryonicdevelopmentpriortothefirstcleavagedivision.
[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]
