Title of article :
The Kinetoplast of Trypanosomatids: From Early Studies of Electron Microscopy to Recent Advances in Atomic Force Microscopy
Author/Authors :
Souza, Wanderley de InstitutoNacionaldeCiênciaeTecnologiadeBiologiaEstruturaleBioimagemandCentroNacionaldeBiologiaEstruturaleBioimagem(CENABIO) - UniversidadeFederaldoRiodeJaneiro - RiodeJaneiro - RJ, Brazil , Cavalcanti, Danielle Pereira InstitutoNacionaldeCiênciaeTecnologiadeBiologiaEstruturaleBioimagemandCentroNacionaldeBiologiaEstruturaleBioimagem(CENABIO) - UniversidadeFederaldoRiodeJaneiro - RiodeJaneiro - RJ, Brazil
Abstract :
ThekinetoplastisaspecializedregionofthemitochondriaoftrypanosomatidsthatharborsthemostcomplexandunusualmitochondrialDNAfoundinnature.KinetoplastDNA(kDNA)iscomposedofthousandsofcircularmoleculestopologicallyinterlockedtoformasinglenetwork.TwotypesofDNAcirclesarepresentinthekinetoplast:minicircles(0.5–10kb)andmaxicircles(20–40kb).KnowledgeofkinetoplastarchitectureiscrucialtounderstandingthereplicationandsegregationofkDNAcirclesbecausethemoleculesinvolvedintheseprocessesarepreciselypositionedinfunctionaldomainsthroughoutthekinetoplast.Thefinestructureofthekinetoplastwasrevealedinearlyelectronmicroscopy(EM)studies.However,anunderstandingofthetopologicalorganizationofkDNAwasonlydemonstratedafterthedevelopmentofprotocolstoseparatekDNAfromnuclearDNA,followedbyEMobservations.Electronmicroscopyanalysisofthinsectionsoftrypanosomatids,spreadingofisolatedkDNAnetworksontoEMgrids,deep-etchingstudies,andcytochemicalandimmunocytochemicalapproachesareexamplesoftechniquesthatwereusefulforelucidatingthestructureandreplicationofthekinetoplast.Recently,atomicforcemicroscopyhasjoinedthissetoftechniquesandimprovedourknowledgeaboutthekDNAnetworkandrevealednewdetailsaboutkDNAtopologyintrypanosomatids.
Keywords :
Kinetoplast , Trypanosomatids , Early Studies , Electron Microscopy , Recent Advances , Atomic Force Microscopy , DNA (kDNA)
