308VetPathol36:308–313(1999)DetectionandLocalizationofMycoplasmahyopneumoniaeDNAinLungsfromNaturallyInfectedPigsbyInSituHybridizationUsingaDigoxigenin-labeledProbeD.KWONANDC.CHAEDepartmentofVeterinaryPathology,CollegeofVeterinaryMedicine,SeoulNationalUniversity,Suwon,RepublicofKoreaAbstract.MycoplasmahyopneumoniaeDNAwasdetectedin20naturallyinfectedpigsbyinsituhybrid-izationusinganonradioactivedigoxigenin-labeledDNAprobe.A520-base-pairDNAprobetargetingareit-erativesequenceoftheM.hyopneumoniaegenomewasgeneratedbythepolymerasechainreaction.All20pigsinfectedwithM.hyopneumoniaehaddistinctandpositivehybridizationsignalswithoutbackgroundstain-ing.Astronghybridizationsignalwasdetectedmainlyintheluminalsurfaceofbronchialandbronchiolarliningepithelialcells,whereasnohybridizationsignalwasseeninthecytoplasmofbronchialandbronchiolarliningepithelialcells.Whenhybridizationsignalwasdetectedintheluminalsurfaceofbronchialandbron-chiolarliningepithelialcells,agivenbronchusorbronchiolehadperibronchiolarlymphoidhyperplastictissues.Hybridizationsignalswerenotseenintheperibronchiolarlymphoidhyperplastictissues.Alessintensesignalwasdetectedintheinterstitialandalveolarmacrophagesrandomlyscatteredinthethickenedalveolarseptaandspaces.HybridizationsignalwasrarelydetectedinthetypeIpneumocytes.TheinsituhybridizationtechniquedevelopedinthisstudywasusefulfordetectionofM.hyopneumoniaenucleicacidsintissuestakenfromnaturallyinfectedpigletsandmaybeavaluabletechniqueforstudyingthepathogenesisofM.hyopneumoniaeinfection.Keywords:Enzooticpneumonia;insituhybridization;lungs;Mycoplasmahyopneumoniae;pigs.Mycoplasmaisthecommonnameforagroupofmicroorganismsthathavebeenarrangedinaseparateclass,theMollicutes,becauseofsomeunusualphe-notypiccharacteristics,themostimportantbeingthelackofarigidcellwall.Theypossessthesmallestgenomeofanyfree-livingorganism,andtheG�CcontentoftheirDNAisamongthelowestknown.21,22Thepigishosttoanumberofmycoplasmas,andthemostcommonlyisolatedspeciesareMycoplasmahyopneumoniae,M.hyorhinis,...
