Program of early development in the mammal: Synthesis and intracellular migration of histone H4 during oogenesis in the mouse☆

[摘要] SynthesisofhistoneH4bymouseoocytesandunfertilizedeggshasbeenexaminedbyusingamodifiedhigh-resolutiontwo-dimensionalgelelectrophoresisprocedurecapableofresolvingbasicproteins(M.J.LaMarcaandP.M.Wassarman,1979,Develop.Biol.73,103–119).Histoneswereseparatedonsuchgelsandobservedratesofincorporationof[35S]methionineintohistoneH4wereconvertedintoabsoluteratesofsynthesisbyusingpreviouslydeterminedvaluesfortheabsoluteratesoftotalproteinsynthesisinmouseoocytesandunfertilizedeggs(R.M.Schultz,G.E.Letourneau,andP.M.Wassarman,1979,Develop.Biol.68,341–359;73,120–133).HistoneH4wassynthesizedatallstagesofoogenesisexamined,andaccountedfor0.07,0.05,and0.04%oftotalproteinsynthesisingrowingoocytes,fullygrownoocytes,andunfertilizedeggs,respectively.DuringoocytematurationtheabsoluterateofhistoneH4synthesisdecreasedbyabout40%,ascomparedtoa23%decreaseintherateoftotalproteinsynthesisduringthesameperiod.Thesemeasurementsindicatethatenoughhistoneissynthesizedduringoogenesisinthemousetosupporttwotothreecelldivisions.ExaminationoftheintracellularlocationofnewlysynthesizedproteinsinfullygrownoocytesrevealedthathistoneH4washighlyconcentratedinthenucleus(germinalvesicle),whereastotalproteinandtubulinwerenot.Nearly50%ofthehistoneH4synthesizedduringa5-hrperiodwaslocatedintheoocyte'sgerminalvesicle,ascomparedto1.9and0.9%fortotalproteinandtubulin,respectively.Theseresultsarecomparedwiththoseobtainedusingoocytesandeggsfromnonmammaliananimalspecies.

[学科分类] 生物科学（综合）