Determination of polarity and bilateral asymmetry in palleal and vascular buds of the ascidian Botryllus schlosseri☆
[摘要] ReversalofthebilateralasymmetryofthezooidswasinducedinaseriesofcoloniesofBotryllusschlosseri.Pallealbudsfromcolonieswithnormalorreversedbilateralasymmetrywereisolatedintheearlystagesfromtheparentalzooidsandculturedinthevascularizedtunicofthesamecolonyorofanothercolonywithoppositeasymmetry.Vascularbuddingwasinducedincolonieswitheithertypeofasymmetry.Thebudpolaritywasshowntodependonthevascularization;thetestvesselenteringtheisolatedpallealbudalwayscausestheentrancepointtobecometheposteriorendofthedevelopingzooid.Onthecontrary,thebilateralasymmetrictypeispredeterminedinthebudprimordium;theisolatedpallealbudsdevelopthetypeofasymmetryoftheirparents,evenwhengraftedinthetestofacolonywithoppositeasymmetry.Sincethesamewasalsotrueofthevascularbuds,itisconcludedthattheinformationforthekindofbilateralasymmetrytobedevelopedisconveyedbytheepidermalenvelopeofthebud.Theepidermisoftheparentalzooidsinfluencesthepallealbuds,whereasthewallofthetestvessels,epidermalextrusionsofthezooids,influencesthevascularbuds.
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[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
