Economic Importance of Virus. and applied virology.pdf

This presentation offers a bird' s-eye view of the domain of applied virology. The economic importance of viruses has been widely explained, with special emphasis on their use in vaccine production, gene therapy, cancer therapy, application in nanotechnology, and design of bio-weapons. It also explains the role of viruses in plant diseases and human diseases. It also highlights the role of viruses in medical diagnosis and modern vaccine production.

1. Economic importance of viruses with reference to vaccine
production, role in research, medicine and diagnostics
and more.
By
Dr. N. Sannigrahi, Associate Professor,
Department of Botany,
Nistarini College, Purulia (W.B.) India.

3. Viruses(LatinVenum–poisonousfluid)aresimplestformsoflife.They
arenotcells,buttheirstudyhasprovidedagreatdealofinformationabout
cells.StudyofvirusesisabranchofbiologycalledVirology.
Viruses,thebiologistpuzzlearecellularparasites.Theyaresmallerthan
bacteriaandhaveamuchmoresimplifiedorganization.
RussianBotanistIwanowsky(1892)wasfirsttogiveclearcutevidenceof
virus.Hedemonstratedtheiroccurrenceintobaccoleavessufferingfrom
mosaicdisease.Mayer(1886),Beijerinck(1898)andLoeffler&Frosch
(1898)establishedtheexistenceofvirusesbydiscoveringmanyviral
diseasesinplantsandanimals.
Schlesinger(1933)wasfirsttodeterminethechemicalcompositionof
virus.W.M.Stanley,anAmericanmicrobiologistcrystallizedtobacco
mosaicvirus(TMV)afterisolatingfrominfectedtobaccoleafjuice.He
thusshowedthatvirusesarenotliketypicalcells.Stanleywasawarded
Nobelprizeforthiswork.

5. Onthewholevirusesaremuchsmallerthanbacteria.Mostanimaland
plantvirusesareinvisibleunderthelightmicroscope.Someofsmaller
virusesareonly200Åindiameter.Variable.Mostvirusesaremuchsmaller
thanbacteria.
Thesizerangesinbetween100Ato250mu.Somevirusesarelargerthan
bacteria,forexamplethepsittacosisavirusmeasuring0.75muindiameter
Virusescannotmultiplyoutsidealivingcell.
Novirushasbeencultivatedinacell-freemedium.Virusesdonothavean
independentmetabolism.Theyaremetabolicallyinactiveoutsidethehost
cellbecausetheydonotpossessenzymesystemsandproteinsynthesis
machinery.
Thusvirusesareobligatoryintracellularparasites.
Viruseshaveaverysimplestructure.Theyconsistofanucleicacidcore
surroundedbyaproteincoat.

6. Inthisrespecttheydifferfromtypicalcellswhicharemadeupofproteins,
carbohydrates,lipidsandnucleicacids.Myxoviruseshaveamembranous
envelopeconsistingofproteins,carbohydrateandlipidoutsidetheusual
proteincoat,butthisenvelopeisderivedfromthehostcell.
Virusesusuallyhaveonlyonenucleicacid,eitherDNAorRNA.Typical
cellshavebothDNAandRNA.RousSarcomavirus(RSV),producing
certaincancer,istheonlyvirushavingbothDNAandRNA.
SSDNA------------------phIx174
DSDNA-----------------Poxvirus,Herpes,Adeno
SSRNA-------------------TMV,Influenza
DSRNA-----------------Retrovirusofanimals,Ricedwarfvirus
DNA-RNA-------------Leukovirus,Roussarcomavirus

7. Thecommonanimalvirusesaresmallpoxvirus,influenzavirus,mumps
virus,poliovirusandherpesvirus.Inmanyanimalvirusesanextra
envelopesurroundstheirproteincoat.
Themembraneconsistsofproteins,lipidsandcarbohydratesandis
derivedfromthehostplasmamembrane.Animalvirusesmayentercellsby
attachingtothesurface.Somearethenengulfedbythecellthrough
pinocytosisorphagocytosis.Insuchcases,uncoatingoftheviralnucleic
acidmightoccurwithinthecell.
Insidethehostcelltheymaymultiplyandformnumerousnewviral
particles.Usually,animalvirusesreleasefromthehostcellsbythe
rupturingandsubsequentdeathofthehostcells.
Thedifferentdiseasesofanimalsingeneralandhumanbeingsinparticular
arecausedbythisbiologistpuzzleelementandtheunfortunateCOVID19
isthedreadfulviralpandemicthatbecomesnightmaretothewholeworld.

8. Sr. No.Name of the viral
disease
Organ
affected
Nature of
genetic
material
Incubation
Period
1. Influenza Nose, throat,
lungs
ssRNA 1-2 days
2. Dengue Blood, MusclesssRNA 5-8
3. Poliomyelitis Muscles ssRNA 5-20
4. Measles Respiratory
tract
ssRNA 9-12
5. Hepatitis A
Hepatitis B
Liver ssRNA 16-20
6. Rabies Brain, spinal
cord
ssRNA 30-100
7. Papilloma Skin, genial
area
dsDNA 50-150
8. HIV Lymph ssRNA 1-10 years
9. COVID Respiratory
parts
ssRNA 2-5 days

9. PlantViruses:Theyareparasitesofplantcells.Theirgeneticmaterialis
RNAwhichremainsenclosedintheproteincoat.Themostimportantplant
virusesaretobaccomosaicvirus(TMV),tobaccorattlevirus(TRV),potato
virus(PV),southernbeanmosaicvirus(SBMV),beetyellowvirus(BYV)
andturnipyellowvirus(TYV).
AnimalandHumanViruses:Theanimalandthehumanbeingsalso
affectedbythevirusbymaintaininghost-specificity.Thedifferenthuman
diseaseslikeHIV,influenza,smallpoxandchickenpox,mumps,Polio,
Hydrophobia,HepatitiseventherecentlyoutbrokenCOVID19aresome
ofthetypicalexamplesoftheviraldiseasesofthehumanbeings.
Bacterialvirus:Theyareparasiticonbacteriaandsoalsocalled
bacteriophages.Therearemanyvarietiesofbacteriophages.Theirsizeand
shapevariesfromspeciestospecies.Somephagesarespherical,some
comma-shapedwhereasmajorityofthemhavetadpole-likeappearance.

10. Vaccines and viruses in vaccine production,
New vaccines with use of virus,
Production of vaccines and the growing trend,
Viruses in diagnosis and research,
Viruses in pest control,
Viruses to control Rabbits,
Viruses in Gene Therapy
Viruses in Cancer Therapy,
Bacteriophages Therapy,
Viruses in Plant diseases
Viruses in Biotechnology, Nanotechnology and Material Science
Viruses in aquatic ecosystem management,
Viruses in Bio-weapons,
Viruses in Neurosciences

11. Preventionisbetterthancure”.Vaccine(L.vacca=cow)isa
preparation/suspensionorextractofdead/attenuated(weakened)germsofa
diseasewhichoninoculation(injection)intoahealthypersonprovides
temporary/permanentactive/passiveimmunitybyinducingantibodies
formation.Thusantibodyprovokingagentsarecalledvaccines.Whenthe
vaccineentersintothebody,iteithertotallypreventsorreducestheeffect
ofthedisease.Thistypeofimmunitydevelopediscalledacquired
immunity.SincethediscoveryofvaccinebyEdwardJenner(1796),several
vaccineshavebeendevelopedtoprovideimmunityagainstthedifferent
typeofdiseases.Eitherbacterialorviralvaccines,itmaybetwotypes-
Attenuatedlivevirusvaccine
Inactivatedorkilledvirusvaccine

13. Thelivevirusactivitiesandvirulencehavebeenattenuatedthrough
differenttreatments.Mostoftheviralvaccinesareattenuatedandthe
advantagesofthisvaccinesare-
Requiressingledose,
Noneedofadjuvant,
Durationofimmunityislonger,
ProducebothIgAandIgGtypeofantibodies,
Nomucosalimmunity,
Cellmediatedimmunitygreaterbutthemostimportantproblemisthe
presenceofundesirablecomponentsremainandhighcoldchainand
difficultproductionlevel,
Vaccinesofmeasles.Mumps,yellowfever,rubellaetc.

14. Vaccinesaredesignedbytheinactivationofviralinfectivitybythe
treatmentofdifferentchemicalslikemildformalin,ethyleminesetc,heat,
radiationsorantibioticsbyensuringthepurityandpotencyduring
inactivation.
VaccinesofCholera,rabies,polio,influenza,bubonicplague,hepatitisA
etcarebelongedtothiscategory.Killedvaccinesareavailableintwo
forms-wholevirusvaccinesorsub-unitvaccines.
Sub-unitvaccinesareseparatedfrompurifiedvirusbydetergent,then
centrifugedkeepingthecomponentstostimulateprotectiveantibody.
VaccinesforeHepatitisB,HumanPapilolomavirus(HPV)belongtothis
group.
Toxoidvaccinesarealsobelongedtothisgroupasitcontaintoxic
compoundsratherthanpathogen.Itrequiresinmultipledoses,need
adjuvantforbettereffectively,shorttermimmunity,produceonlyIgG.

15. Molecularbiologyandmoderntechnologiesoffersnovelapproachesof
vaccineproductionasfollows:
Syntheticpeptides-throughgeneticengineering,nucleicacidcanbe
designedtoproduceshortpeptidescorrespondtoantigenicdeterminantson
aviralproteinalthoughitisweakerthanthatinducedbyintactprotein.
RecombinantVacciniavirusasvaccines-Importantviralantigenslike
HepatitisBsurfaceantigen,influenzavirushemagglutineproteins,rabies
virusGproteinetchavebeenproducedandvaccinesaredesigned.
DNAVaccines-GeneticallyengineeredDNAinjectedintotheorganismso
thatcellsdirectlyproduceantigenresultingimmunologicalresponseas
protection.Here,aplasmidpreparationwithgenesofthepathogenvirus
andastrongviralpromoterareinjectedintothemuscleofthehost.SV40,
RousSarcomavirus(RSV)likepromoterareusedduringthesame.Itis
mostlyusedinveterinarypurposesbutpromisestodomore.

16. Antibodywithnarrowrangeofapplication.etcarealsousedtopreventthe
infectionRecentlysyntheticvaccines,Recombinantvacciniavirus,DNA
vaccinesarealsobeingusedbytheapplicationofgeneticengineering.
Productionofvaccineneedsthefollowingsteps-generationofantigen,
isolationandpurification,formulationandpacking.Thenewtrendsin
vaccineproductionare-
Developmentofvaccinefordifferentagegroups,
Productionofcombinationvaccinestoreducethequantitiesofantigen,
Focusonmammaliancellculturesratherthanconventionalchickenegg
embryosculture,
Newmethodofadministration,
Developmentofediblevaccines.

17. Viruscanbeextensivelyuseinthedifferentfieldslikemicrobiology,
molecularbiology,immunology,geneticengineeringandothers.
USEDASPROBES:Probesareshortoligonucleotidessequences(10-30
bases)ofDNAorRNAusedtodetectcomplementarysequencespresent
inunknowngeneticmaterial.Southernblotting,Northernblotting,dot
blots,DNA/RNAsequencing,constructionofgenomiclibraryetcusethe
differenttypesofprobesforidentificationofgeneticmaterials.Theprobes
arenothingbutdsDNAorSSDNAorssRNAstrandsandlabeledwith
radioactiveornon-radioactivesubstancesfordetection.Theshort
sequencesofprobesaregenerallyobtainedfromviralgenomes.
ComplementaryDNA(cDNA)artepreparedusingmRNAwhichcanbe
clonedinE.coliusingbacteriophage.

18. PRODUCTION OFENZYMES:Theenzymereversetranscriptase
producedbyretrovirushasbeenextensivelyusedinthegenerationof
cDNAwhichisfrequentlyusedforresearchworksandchemical
diagnosis.T4phagevirusalsoproduceenzymeligaseswhichisusedin
recombinantDNAtechnologyaswellasinligaseschainreaction.
BACTERIOPHAGE TYPING:Theparticularviruscaninfecta
particularbacteria.Thistechniqueisusedinidentifyingthebacteria
speciesandthisisusedinclinicalsamplesinanalysisandresearch.The
pathogenicbacteriumtobeidentifiedincultured.
Theplateisthenmarkedintosquaresandeachsquareisinoculatedwitha
particularphageandplateisincubatedfor24hours.
Afterthestipulatedtime,theplaqueformationisobservedandphage
typingisrecordedtothephagesensitivityofthebacterium.

20. VIRUSASVECTORS:
Virushastheabilityinserttheircontentintothehostcells.Vectorsare
automaticallyreplicatingDNAfragmentstowhichgenesofinterestcanbe
integratedforcloning.
Besides,thevectorDNAshouldbecapableofmanipulation,easily
isolatedandinsertedintothehost,carrysitesforrestrictionendonuclease
enzymesandpossessselectablemarkersforeasyidentification.
ThelamdaphageandM13phagesaremostlyusedasvectors.Sincephage
vectorsarenaturallyinfective,canaccommodatelargeDNAfragmentsfor
cloningandidentificationofrecombinantviralvectors,itiscomparatively
easy.Theyaremostlypreferredasplasmidvectors.
LambdabacteriophagesareusedinDNAcloningresearch.Thisphage
virusisatemperatephageandcanperformbothLyticandlysogenycycle
whichinfecthost.Thelinearlamdaphagegenomebecomescircularon
enteringthehostbacteriumE.coli8andcanaccommodatelarge

22. Transgenicinvolvetheartandscienceofthecombinationoftwonon-
identicalgeneticelements,
DNAinsertandgeneratedifferenttypesoflamdavectors.
M13vectorsareusedtogetsinglestrandsofclonedDNAwhichhaveuses
inDNAsequencing.SeveralmodifiedvectorslikeM13,mp1mmp8,mp9
etcarethemodifiedvectorsproducedfromM13genome.Differentcosmid
vectors(withcossite),phagmidvectorsalsousedinrecDNAtechnology.
TRANSGENIC PLANTS&ANIMALS:Virusesareregularlyusedfor
thedesigningofgeneticmodifiedorganisms.Duringthisprocess,viruses
areusedasshuttlevectorsthroughwhichdesiredgenesenterintothe
bacterialhostandthentothetargetorganism.Baculovirusesareusedto
designvectorsforproductionofrecombinantproteinininsectcellline.
Forbio-pesticidesdesigning,ingenetherapy,virotherapyincancerand
bacteriophagetherapy,virusplayaverycrucialroleinmedicalscience

24. Bio-pesticidesmainlyderivedfromthebacterialsourcesandmostly
profuselyusedbacteriaBacillusthuringenesistodesignandharvestBt-
toxinforkillingdifferentpestsbytransgenicmethod.
Virusalsousedtokillinsectandpestsbyactingastheirpathogens.
MostcommonlyusedvirusesareBaculoviruses,Oryctesrhinoceros(OrV),
Entomoxvirus,Polyhedronsvirusesetc.
Baculovirusesformthickproteinshells,occlusionbodies(OBs)aroundthe
nucleocapsidestructurethatcannotbedegradedanimalsWhenthe
bacuovirusesareeateninsectlarvae,theyinfectthecellsofgutand
multiply.Thistype[eofinfectionfoundinbutterfliesandmoths.
Baculovirusesmaybetwotypes-Nucleopolyhedroviruses(NPV)and
granuloviruses(GVs).SomeexamplesareAnagraphafalciferaNPVthat
killCelerylooper,HelicoverpazeaNPVagainstcottonbullworm,tobacco
budworm,tomatofruitwormetc.

25. RabbitsarehighlydestructivepestsmainlyinEuropeandAustralia
Myxomavirus,anumberofpoxviridaecauseswildskindiseaseinrabbits,
Europeanrabbitsarekilledduetotheinfectionbythisviruscausing
myxomatosis,
TheviruseswereintroducesinAustraliatocontrolrabbitpopulation,
Itisanexcellentexampleofthewellpropagatingnatureofeffective
biologicalagent.

26. Genetherapytorectifytheinherentgeneticdisordersisthecallofthetime
.Itneedsthefollowingrequirements:
Limitednumberofgenesorsinglegenetobeintroducedinthecomplex
geneticmachineryofhumans,
Theneedoftheeffectiveversionofdefectivecellulargenes,
Availabilityofthesuitabledeliverysystemforthosegenesintothe
recipientcellsalongwiththedesiredexpression.
Threetypesofgenetherapyproceduresareavailable:
A.Ex-vivosomaticgenetherapy-Defectivecellsareremoved,therapeutic
genesareinsertedandthegeneticmodifiedsomaticcellsarereintroduced,
B.In-vivosomaticgenetherapy-Therapeuticgenesaredirectlyintroduced
intothetargetcellsofthepatient,
C.Germlinegenetherapy-thetherapeuticgenesareintroducedinthegerm
cellsforthesakeofthenextgenerationalthoughtheethicalnormsdonot
allowtoapplyinhumanbeings.

28. Anykindofgenetherapyneedsvectorstodeliverthegenesofinterestinto
thetargetcells,
AmongViralandnon-viraldeliverysystems,viraldeliverysystemsare
effectiveduetheirpotentialatlessaccessibleareasofthebody,
Viralvectorsarehighlyspecifictoinfectspecifictypeofcells,
Thedifferentviruseshavebeenusedforclinicaltrialsforgenetherapylike
Adenovirus(Adenoviridae)-372trials,
Herpessimplexvirus(Herpesviridae)-51trials,
Adeno-associatedvirus(Parvoviridae)-67trials,
Vaccinavirus(Poxviridae)-95trials,
Poxvirus(Poxviridae)-64trials,
Retrovirus(Retroviridae)-326trials,
Multiplevirus-37trials

29. Cancerismostlyuncontrolleddivisionofcellandthismadnessofcellis
treatedbydifferentlineslikeRadiotherapy,Chemotherapy,Chemo-
radiotherapy,
Therecenttrendofcancertherapyistheuseofviruseitheruseofviral
vaccinesoruseofvirusdirectly,popularlyknownasvirotherapy.
Vaccinesagainsthepaticcellularcancerispreventedbytheusesof
HapatititisBvaccinesandCervicalcancerbyHumanpapillomavirus
vaccine,
Bothcases,selectedviralproteins(subunitofvaccine)isusedtostimulate
immunesystemtosynthesizeanti-viralmoleculeforthesame.
Invirotherapy,approachesuseeithernatural,unmodifiedvirusesor
geneticallymodifiedvirusorvirusvectorisusedforselectivekillingof
cancercells.
SeveralRNAviruslikereovirus,vesicularstomatisvirus(VSV),New
Castlediseasevirus(NDV)areusedaspotentialtherapeuticagentsforthe
cells.

31. Theuseofbacterialviruses(bacteriophage)toinfectanddestroybacteria
causingdiseaseoranyeconomiclossoftheeconomicimportantplantsis
usedpopularlycalledbacteriophagetherapy.
Ithasbeenstartedsinethediscoveryofantibiotics(1919,1921)totreat
typhoidinchickenandstaphylococcalskindisease,
Theemergenceofantibioticsresistanceagaindrawtheimportanceofthe
bacteriophagetherapy,
Bacteriophagetherapyisusedtopreventbacterialinfectionoftomatoes
andpeppers,tocontrolbacteriaassociatedwithfoodpoisoningetc,
TheclinicaltrialsforhumanpathogensforEnterococcous,E.coli,
Pseudomonasaeruginosahaveconsulted,
Bacteriophagesinhumantherapyispromisingbutintensivetrialsalong
withethicalissuesmustbeaddressedinthisconsequences.

32. Plantviruses,likeotherviruses,containacoreofeitherDNAorRNA.As
plantviruseshaveacellwalltoprotecttheircells,theirvirusesdonotuse
receptor-mediatedEndocytosistoenterhostcellsasisseenwithanimal
viruses.Formanyplantvirusestobetransferredfromplanttoplant,
damagetosomeoftheplants’cellsmustoccurtoallowthevirustoentera
newhost.Thisdamageisoftencausedbyweather,insects,animals,fire,or
humanactivitiessuchasfarmingorlandscaping.Additionally,plant
offspringmayinheritviraldiseasesfromparentplants.
Plantvirusescanbetransmittedbyavarietyofvectors:throughcontact
withaninfectedplant’ssap,bylivingorganismssuchasinsectsand
nematodes,andthroughpollen.Whenplantvirusesaretransferredbetween
differentplants,

33. thisisknownashorizontaltransmission;whentheyareinheritedfroma
parent,thisiscalledverticaltransmission.
Symptomsofviraldiseasesvaryaccordingtothevirusanditshost.One
commonsymptomishyperplasia:theabnormalproliferationofcellsthat
causestheappearanceofplanttumorsknownasgalls.Othervirusesinduce
hypoplasia,ordecreasedcellgrowth,intheleavesofplants,causingthin,
yellowareastoappear.Stillothervirusesaffecttheplantbydirectlykilling
plantcells;aprocessknownascellnecrosis.Othersymptomsofplant
virusesincludemalformedleaves,blackstreaksonthestemsoftheplants,
alteredgrowthofstems,leaves,orfruits,andringspots,whicharecircular
orlinearareasofdiscolorationfoundinaleaf.

35. Nameof the diseaseName of Virus Genetic materialHost
TobaccoMosaic
Disease
TMV RNA Tobacco, Nicotiana
tabacum(
Solanaceae)
Potato Virus DiseasePVX RNA Potato, Solanum
tuberosum
Cucumber Mosaic
Disease
CMV RNA Cucumber, Cucumis
sativus
(Cucurbitaceae)
Tomato Spotted Wilt
Disease
TSWV ssRNA Tomato, Solanum
lycopersicum(
Solanaceae)
Cauliflower Mosaic
Disease
CaMV dsDNA Brassicaoleracea
var.bottrytis
(Brassicaceae)
RiceTungroDiseaseRTSV dsDNA Oryzasativa (
Poaceae)
Mosaic disease of
sugarcane
SCMV ssRNA Saccharum
officinarum(Poaceae)

36. Researchistheintegralpartofscientificunderstandingandvirusesof
differenttypesareusedinthefieldofmolecularbiologyand
biotechnologyalongwiththedifferentendsofappliedbiologyforthe
developmentofvaccines,cancertherapy,genetherapyandtransgenic
sciences.Someofthefieldsarestatedbelow:
i.asapartofvirusresearch,theabilitytotransfergenesfrombacteriumto
otherthroughtransductionprocessasapartofhorizontalgeetransferin
thedomainofgeneticcode,functionofribosome,recombinantDNAin
biotechnology,
Commonlyusedasvectorstotransfergenestoeukaryoticcells.Viruscan
memultipliedinbacterialhosts,purifiedandgenecloning,
Bacteriophageisusedinphagetyping,
Beforetheadventofantibioticsandafterthehazardsofantibiotics
resistancebybacteria,pathogensarebeingtreatedbytheuseand
manipulationofvirus,
DNAreplication,RNAprocessing,RNAsilencing,proteintransport,
Immunologyandotherfields.

37. Nanotechnologyreferstothebranchofscienceandengineeringdevotedto
designing,producing,andusingstructures,devices,andsystemsby
manipulatingatomsandmoleculesatnanoscale,i.e.havingoneormore
dimensionsoftheorderof100nanometers(100millionthofamillimeter)
orless.
Virusistreatedasorganicnano-particlesasfarasshapeandsizealong
withfunctionalgroups,itcanbeusedatemplatesfororganicmaterialsat
nanoscale.
CowpeaMosaicvirusparticlesusedtoamplifysignalsinDNAmicroarray
basedsensors,
Usedasnanoscalebreadboardofmolecularelectronics,
Canbeusedasgreenandsafevarietiesnano-particles,
Itcanbeusedforthedepositionofspecificmetalsormineralsformass
production.

38. Freshwaterandmarineecosystemshavebeensufferingalotdueto
differentanthropogenicissues,
Thedestroyofbacterialpopulationtochecktheissuerofeutrophication
alongwithlargescalewaterpollution,viruscancontributealot,
Viruscanplayroleincarbonrecyclingasbiologicalpumpwherecarbonis
sequestered,
Marineanimalsarenowatthethreatandviruscanbeusedforthesame.

39. Biologicalweaponsdisseminatedisease-causingorganismsortoxinsto
harmorkillhumans,animalsorplants.Theygenerallyconsistoftwoparts
–aweaponizedagentandadeliverymechanism.Biologicalwarfareisthe
deliberateuseofdisease-causingbiologicalagentssuchasbacteria,virus,
rickettsiae,andfungi,ortheirtoxins,tokillorincapacitatehumans,
animals,orplantsasanactofwar.
Theinfectiousnucleicacidcanbedesignedinthelaboratoriesandcanbe
usedbythewarmongerswithoutthesustainabilityandmis-happeningsof
thecommonhumanrace.
Virusesmaybeusedinbiologicalwarfareandonemicrobecancause
multipleissuesinthehumanlife.
Bioweaponsisnotonlydetrimentalforhumanhealthbutalsoitcanraise
concernovertheproductivityoffoodandvegetablecropsthatcanpose
sustainablefoodcrisis.

40. Neuroscientistsfocusonthebrainanditsimpactonbehaviorandcognitive
functions.Notonlyisneuroscienceconcernedwiththenormalfunctioning
ofthenervoussystem,butalsowhathappenstothenervoussystemwhen
peoplehaveneurological,psychiatricandneuro-developmentaldisorders.
Themainfocusofthefieldistostudyvirusescapableofinfectingthe
nervoussystem.Inadditiontothis,thefieldstudiestheuseofvirusesto
traceneuro-anatomicalpathways,forgenetherapy,andtoeliminate
detrimentalpopulationsofneuralcells.
SuidherpesVirus(SuHV1)usedtoanalyzeneuralcircuitsofcentral
nervoussystem(CNS)andhelpinneuralmapping.AttenuatedBartha
SuHV1strainiscommonlyusedasbothretrogradeandintergrades
transneuronaltracer.
SuHV1Barthareleasedatthesynapsesisabletocrossthesynapsesto
infecttheaxonterminalofthesynapticallyconnectedneurons,thereby,
propagatingthevirus

42. Virusesareimportantmicrobialpredatorsthatinfluenceglobal
biogeochemicalcyclesanddrivemicrobialevolution,althoughtheir
impactisoftenunderappreciated.
Virusesreproduceafterattachingandtransferringtheirgenetic
materialintoahostcell.Theidentificationofvirusneedsthe
understandingofmultiplecharacters-potentialinfectiousnature,
shape,size,structureandsymmetry,envelopenatureofgenetic
materialandotherfeatures.
TherecentpandemicofCOVID19hasbroughtthedevastationand
destructionofmillionshasagainraisedatrilliondollarquestions
abouttheacellularentityandthescientistsbecomeverymuch
anxioustomanagethisentityforthebestofthehumancivilization.
Moreresearchesareneededtoexplorethepuzzleofthis
ultramicroscopicentity.Betterlatethannever’-------------

44. References:
Google for images
Microbiology & Phycology -Mishra & Dash
Brook Microbiology of Microorganisms-Madigan, Martinko, Bender,
Buckley & Stahl,
A Textbook of Microbiology-Chakraborty
Microbiology-Pelzer, Chan & Krieg
Disclaimer:This PPT has been designed to enrich the open source of
learning. The author does not claim any kind of financial pleasure.