Regeneration by complementary wing disc fragments of Drosophila melanogaster☆

[摘要] Ifanamphibianorinsectappendageiscutintotwofragmentsandbothareallowedtoundergogrowthandpatternregulation,oftenonefragmentregeneratesstructuresspecifiedbythesecond,whilethesecondformsamirrorduplicate.Thiscomplementarityhasbeencentraltorecentmodelsofpositionalinformationinepimorphicfields.Totestifcomplementaryfragmentsrigorouslyduplicateandregenerate,weculturedavarietyofDrosophilawingdiscfragmentsfor0,3,5,7,or14daysinadultspriortoinjectionintolarvalhostsformetamorphosis.Theresultsconfirmthatcomplementaryfragmentspredominantlyduplicateandregenerate,butalsoshowthat:(1)Regenerationbycomplementaryfragments,sometimesasfarastheoppositediscmargins,iscommonandstatisticallysignificant.(2)Narrowanteriorandventraldiscmarginfragmentsregenerateinabout0.25oftheculturedimplants;equal-sizedposterioranddorsalfragmentsdonot,thusanterior-posteriorandventral-dorsalasymmetriesexist.(3)Alargecentraldiscfragmentanditsperipheralcomplementbothregenerate.(4)Thekineticsofregenerationdiffersindifferentfragments.(5)Duplicationandregenerationarestatisticallyindependenteventsinindividualimplants.Theanterior-posteriorandventral-dorsalasymmetriessuggestpositionalcodinginimaginaldiscsiscarriedinaCartesiancross-gradientsystem.Regenerationbycomplementaryfragmentsimpliesthatsomemechanismenablesnormallyduplicatingfragmentstoregenerate.Thecapacityofbiosyntheticreaction-diffusionsystemstoestablishCartesiancoordinatesandexplainwingdiscpatternregulationisdiscussed.

[学科分类] 生物科学（综合）