Uterine suppression of biochemical and morphogenetic events in Rana pipiens☆

[摘要] TheinductionofmaturationinR.pipiensoocytes,eitherinvivoorinvitro,stimulateseventswhichoccuratthesamerateinbothbeyondthetimeofovulation(firstmeioticmetaphase).Whenoocytesaremaintainedinvitro,theyproceedtothesecondmeioticmetaphaseandbeyond,uninterrupted,tothelimitsoftheirpotential.Giventheproperinvitroenvironment,thispotentialincludesgastrulalikemorphogeneticmovements(pseudo-gastrulation)andacharacteristicdecreasingrateofproteinsynthesis.Whenmaturingoocytesaremaintainedinvivo,however,thepatternisinterruptedatsomepointaftertheoocytesentertheoviductal-uterineenvironment.Thisinterruptionincludesachangeinenvironmentsufficienttohaltpseudo-gastrulationandmayalsoincludeamarkeddecreaseintherateofproteinsynthesistoalevelsufficienttomaintainmatureeggsforseveraldaysinstorage.Atsomepointsoonafterexpulsionfromtheuterineenvironment,proteinsynthesisincreasestoanelevatedlevel.Wehavesuggestedthatthis“second”stimulationisbroughtaboutbytheenvironmentalchange,notbyfertilizationorartificialactivationassuch.

[学科分类] 生物科学（综合）