The origin of heart asymmetry: Right and left contributions to the early chick embryo heart☆
[摘要] Thecontributionsofrightandleftprecardiacmesodermtotheheartsofchickembryosatstages9+to12+havebeendetermined.EmbryosculturedbytheNewtechniquewerelabeledononesidewithtritiatedthymidineatstages5–7.ThelabelwasappliedbymeansofsmallpiecesofMilliporefilter.Twenty-fiveembryoswerestudiedbyserialsections,autoradiography,andgraphicalreconstructions;27embryoswerestudiedbydissectionoftheepimyocardium,whichwastransferredtomicroscopicalslidesandpreparedassquashpreparations.Thesewereautoradiographed,andthenumberofcellsoriginatingfromeachsidewasdetermined.Atstage10−,significantlymorecellshavebeencontributedtotheepimyocardiumfromtherightsidethanfromtheleftside.Thisrelationismaintainedinthecephalicpartofthebulboventricularloopatlaterstages.Inthecaudalpartofthebulboventricularloop,therelationisreversed,withsignificantlymorecellsoriginatingfromtheleftside.Theasymmetryincellnumbersmaybetheexpressionofaprimarydifferencebetweenthedevelopmentalpotenciesofrightandleftheartprimordiathroughwhichthelateralityoftheheartloopformationisdetermined.Thedistributionofendocardiallabeledcellswasfoundtocoincidelargelywiththedistributionofepimyocardiallabeledcells.
[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]
