Theinsectmidgutepitheliumiscomposedofcolumnar,goblet,andregenerativecells.Columnarepithelialcellsarethemostabundantandhavemembraneprotrusionsthatformthebrushbordermembrane(BBM)ontheirapicalside.Theseincreasesurfaceareaavailableforthetransportofnutrients,butalsoprovideopportunitiesforinteractionwithxenobioticssuchaspathogens,toxinsandhostplantallelochemicals.RecentimprovementsinproteomicandbioinfbrmaticstoolsprovidedanopportunitytodeterminetheproteomeoftheT.niBBMinunprecedenteddetail.ThisstudyreportstheidentificationofproteinsfromBBMvesicles(BBMVs)usingsingledimensionpolyacrylamidegelelec?trophoresiscoupledwithmulti-dimensionalproteinidentificationtechnology.Morethan3000proteinswereassociatedwiththeBBMVofwhich697werepredictedtopossesseitherasignalpeptide,atleastonetransmembranedomainoraGPI-anchorsignal.Ofthese,bioinfbrmaticsanalysisandmanualcurationpredictedthat185maybeassociatedwiththeBBMVorepithelialcellplasmamembrane.Thesearediscussedwithrespecttotheirpredictedfunctions,namelydigestion,nutrientuptake,cellsignaling,development,cell-cellinteractions,andotherfunctions.Webelievethistobethemostdetailedproteomicanalysisofthelepidopteranmidgutepitheliummembranetodate,whichwillprovideinformationtobetterunderstandthebiochemical,physiologicalandpathologicalprocessestakingplaceinthelarvalmidgut.
