Developmental profiles of epidermal mRNAs during the pupal-adult molt of Tenebrio molitor and isolation of a cDNA clone encoding an adult cuticular protein: Effects of a juvenile hormone analogue

摘要

ChangesintranslatablemRNAsfromthewingepidermisoftheColeopteraTenebriomolitorhavebeeninvestigatedduringmetamorphosisbyanalysisofinvitrotranslatedproducts.StrikingdifferencesbetweenthepatternsobtainedfrommRNAsextractedduringpupalandadultcuticlesecretionindicatedthatadrasticchangeingeneexpressionoccursduringthepupal-adulttransition.Inadditiontothesestage-specificmodifications,themRNApatternschangedwithineachcuticularsynthesisprogram(pupaloradult),especiallyatecdysis.Aftertritiatedleucineincorporation,someofthemajorradiolabeledcuticularproteinsshowedsimilarchangessuggestingthatthesequentialappearanceofmRNAscorrespondstosequentialdepositionofcuticularproteins.Insupernumerarypupaeobtainedafterjuvenilehormoneanalogue(JHA)applicationonnewlyecdysedpupae,translatablemRNAwereverysimilartothoseofpharatepupae.TheJHAseemed,therefore,topreventtheexpressionoftheadultprogram.Byimmunoblottinginvitrotranslatedproductswithamonoclonalantibodyrecognizinganadult-specificcuticularprotein,thedevelopmentalprofileofthecorrespondingmRNAwasstudied.ThismRNAwasdetectedinanteriorwingepidermisduringthefirst80hrofthepharateadultstage.Usingthesameantibody,acDNAclonewasisolatedfromepidermalmRNA.ThehybridselectedmRNAcodedforonlyoneproteinwithanapparentMWof22kDawhichwas,furthermore,recognizedbytheantibody.TheNorthernblotanalysisperformedwiththecloneconfirmedtheWesternblotanalysisoftheinvitrotranslationproducts.JHAapplicationatthebeginningofthepupal-adultreprogramingpreventedtheappearanceofthismRNA;however,thistranscriptwaspresentduringthefollowingmoltingcycle.ThisreversibilityoftheJHAactionwasconfirmedbyimmunogoldlabelingofthecuticlesformedintreatedanimals.