A histological and ultrastructural study of dedifferentiation and redifferentiation of digestive and gland cells in Hydra viridis☆
[摘要] TheisolatedgastrodermisofthegreenHydraiscapableofregeneratingintoanormalanimalcontainingepidermis,mesoglea,andgastrodermis.Sincethegastricregionoftheisolatedgastrodermiscontainsonlytwocelltypes,namely,digestivecellsandglandcells,ourprimaryinterestwastoobservethecellularchangesduringdedifferentiationandredifferentiationintoothercelltypes.Digestivecellsattheperipheryoftheexplantdifferentiatedirectlyintoepitheliomuscularcells,whilesomeofthedigestivecellsintheinteriorofthemassaredestroyedduringtheformationoftheenteron.Theperipheralglandcellsundergoacomplexcellulartransformation.Thegranularendoplasmicreticulumisbrokendown;insomeareasfragmentsoftheendoplasmicreticulumareisolatedinvacuolesassociatedwiththeGolgiapparatusandallsecretorydropletsarevoided.Theglandcelldedifferentiatesintoaninterstitialcell,thecytoplasmofwhichischaracteristicallypackedwithfreeribosomesandwithoutendoplasmicreticulum.Theinterstitialcellssubsequentlydivideandredifferentiateintocnidoblasts.Themechanismbywhichtheendoplasmicreticulumoftheglandcellsisbrokendownisnotknown.Also,itisnotknownwhethernewribosomesaresynthesizedduringtheredifferentiationofinterstitialcellsintocnidoblastsorthattheribosomesfromtheoriginalglandcellsarecapableoftheproteinsynthesisinvolvedinnematocystformation.Thedigestivecellsandglandcellsoftheexplantremaindiscretelylocatedastheyareinthenormalanimal.Forthisreasononlyperipheralglandanddigestivecellsundergocellulartransformation;while,exceptfortheformationoftheenteron,thecellsintheinteriorofthemassbecomethefuturegastrodermisoftheregenerate.
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[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
