The cuticle of Caenorhabditis elegans: II. Stage-specific changes in ultrastructure and protein composition during postembryonic development☆
[摘要] Thecuticleofthefree-livingnematodeCaenorhabditiselegansisaproteinaceousextracellularstructurethatisreplacedateachoffourpostembryonicmoltsbytheunderlyinghypodermis.Thecuticlesoftheadultandthreejuvenilestages(L1,Dauerlarva,L4)havebeencomparedultrastructurallyandbiochemically.Eachcuticlehasanannulatedsurfaceandcomprisestwomainlayers,aninnerbasallayerandanoutercorticallayer.Theadultcuticlehasanadditionalclearlayerwhichseparatesthebasalandcorticallayersandistraversedbyregularlyarrangedcolumnsofelectron-densematerial.Thefinestructureofthecorticallayerissimilarincuticlesfromdifferentstageswhilethatofthebasallayerisstagespecific.Purifiedcuticleswereobtainedbysonicationandtreatmentwithsodiumdodecylsulfate(SDS)andtheircomponentproteinssolubilizedwithasulfhydrylreducingagent.Thedegreeofcuticlesolubilityisstagespecificandtheinsolublestructuresforeachcuticlewerelocalizedbyelectronmicroscopy.Analysisof35S-labeledsolublecuticleproteinsbySDS-polyacrylamidegelelectrophoresisyieldsuniquebandingpatternsforeachstage.Mostproteinsareofhighmolecularweight(100–200K)andarerestrictedtoparticularstages.Sixteenofthenineteenmajorproteinscharacterizedarespecificallydegradedbybacterialcollagenase.Theresultsindicatethatthedifferentmoltsarenotreiterative,butrequiretheintegrationofbothuniqueandsharedgenefunctions.Thepotentialuseofstage-specificcuticledifferencestoidentifyandcharacterizeregulatorygenescontrollingcuticle-typeswitchingduringdevelopmentisdiscussed.
[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]
