CollegeofAnimalScienceandTechnology專題知識講座

JlliangZhang(Ph.D)PROTISTACollegeofAnimalScienceandTechnology

Ifyoulookatadropofpondwaterunderamicroscope,allthe"littlecreatures"youseeswimmingaroundare

protists.Allprotistshaveanucleusandaretherefore

eukaryotic.Protistsareeitherplant-like,animal-likeorfungus-like.

PROTISTSVerydiversegroup>60,000knownspeciesMostareunicellularSomearecolonialSomearemulticellularNot“simple”atthecellularlevelRemember,aunicellularorganismmustcarryoutallbasicfunctionsoflifewithinasinglecellCellswithinamulticellularorganismcanbecomespecialized,andneednotcarryoutallsuchfunctionsKingdomProtistaPlantaeFungiAnimaliaProtistaMonera(原核生物)prokaryoticeukaryoticPrincipalcharacterUnicellularMicroscopicNogermlayersAlltypesofsymmetry團藻空球藻實球藻Structure&OrganellesShells&Skeletons:nakedsecretedshellcomposedoforganicorinorganicmaterials(i.e.CaCO3,SiO2)shellcomposedofsmallparticlescementedtogetherStructure&OrganellesCellmembrane=Plasmamembrane=PlasmalemmaCytoplasm(protoplasm):ectoplasm=outersemi-solidregionendoplasm=innerfluidregion(granular)Nucleus/nuclei:*Macronucleus=largenucleusinvolvedincontrollingmetabolicactivities*Micronucleus=smallnucleusinvolvedinreproductiveactivities*NotallprotistshavebothtypesofnucleusAlltypesofnutrition/feeding1.Autotrophic:capableofmakingtheirownfoodhavechloroplastsforphotosynthesis2.Heterotrophic:incapableofmakingtheirownfoodandmustingestpre-formedorganicmaterialsAlltypesofnutrition/feedingFeeding:Phagocytosis（吞噬作用）

Foodvacuole-intracellulardigestivecavityAlltypesofnutrition/feedingFeeding:intakefoodthroughacytostome(cellular“mouth”)eliminatewastethroughacytoproct(cellular“anus”)Cytoproct（胞肛）Cytostome（胞口）Osmoregulation&ExcretionContractilevacuoles（伸縮泡）:involvedinwaterregulationpumpsexcesswateroutofthecytoplasmExcretionisviadiffusionLocomotionPseudopodia“false”“foot”FlagellaCiliacytoplasmicstreamingAsexualReproduction“fission”:whenanindividualsplitsinto2identicalindividuals,itiscalled“binaryfission”(二分裂)if>2progeny,itiscalled“multiplefission”(多分裂)whenasmallerindividualbudsoffofthelargerparent,itiscalled“budding”(出芽生殖)Plasmotomy（質(zhì)裂）Thedivisionofamultinucleateprotozanintomultinucleateduaghterindividualsbycytoplasmicdivisionbutwithoutnucleardivisionaliscalled-Plasmotomyeg:Opalina（蛙片蟲）SexualReproductionconjugation=when2individualsexchangemicronucleiresultsingeneticmixingand“new”genotypes4daughters(geneticallydifferentfromparents)exchangeofmicronuclei-fusionofthe“exchanged”micronuclei-degenerationofoldmicronucleiParameciumreproduction1.Individualsfuse2.Micronucleusproduces4haploidnucleiParameciumreproduction4.Matesswapmicronuclei3.Onedividesbymitosis,3disintegrateParameciumreproduction5.Syngamyoccurs,micronucleifuse6.Micronucleiundergomitosisandform8micronucleiParameciumreproduction7.Originalmacronucleusdisintegrates;4micronucleidevintonewmacronuclei8.After2celldivisionsw/outnucleardivision,thenewmacroandmicronucleiareparceledoutinto4newindividualsGamogenesis（配子生殖）：

PhylumSarcomastigophora（肉鞭亞門）SubphylumSarcodina(肉足綱)SubphylumMastigophora（鞭毛綱）PhylumCiliophora（纖毛亞門）PhylumSporozoa(Apicomplexa)（頂復(fù)亞門）**NotethatyourtextbookhasdifferenttaxonomicgroupingsbutwewillfollowthelabKingdomProtista已命名旳原生動物超出64000種，其中半數(shù)以上為化石種類（Ⅰ）、Mastigophora（鞭毛蟲綱）1、Symbolanimal—Euglena(眼蟲)Lightdetector:swellingnearthebaseofthelongflagellum;detectslightthatisnotblockedbytheeyespot;asaresult,Euglenamovestowardlightofappropriateintensity,animportantadaptationthatenhancesphotosynthesisLongflagellumShortflagellumNucleusPlasmamembraneParamylongranuleChloroplastContractilevacuoleEyespot:pigmentedorganellethatfunctionsasalightshield,allowinglightfromonlyacertaindirectiontostrikethelightdetector

Pellicle:proteinbandsbeneaththeplasmamembranethatprovidestrengthandflexibility(Euglenalacksacellwall)Euglena(LM)5μmbinaryfissionEncystation（包囊形成）2.characteristicspresentinclassmastigophora(鞭毛綱)Oneormorewhiplikeflagellapresentforlocomotionandfoodcapture.Nutritionautotrophicbyphototrophy,orheterotrophicbyosmotrophy,ormixtotrophic.Reproductiontypicallyasexuallybysymmetrogeniclongitudinalbinaryfission;sexualreproductionoccursinsomecases.

Thereareabout2023speciesandseveralorders,whicharegroupedintotwosubclasses:I.ClassPhytomastigophora（植鞭亞綱）II.ClassZoomastigophora（動鞭亞綱）3、ClassificationofmastigophoraA、Phytomastigophora：Membersofthethisclasshavebothchloroplastsandflagella。常見旳有綠眼蟲、團藻蟲、盤藻蟲、鐘罩蟲、夜光蟲等。盤藻Goniumformosum團藻Volvoxcarteri幾種鞭毛蟲裸甲腰鞭蟲夜光蟲溝腰鞭蟲角鞭蟲鐘罩蟲合尾滴蟲尾窩蟲RedTidesEnvironmentalconditionscancausedinoflagellate（腰鞭毛蟲）populationstoexploderesultinginredtidescancausefishkillsinvolvedinparalyticshellfishpoisoningB、ZoomastigophoraItsorganismsareheterotrophicandhaveone-to-manyflagella.代表性旳種類有利什曼原蟲、錐蟲、原海綿蟲等。1）Leishmania（利什曼原蟲）Sandfly

2）Trypansoma（錐蟲）TsetseflyTrypansomasleepingsickness3）Cryptobia（鰓隱鞭蟲）寄生于魚鰓陰道毛滴蟲Trichomonasvaginalis披發(fā)蟲Trichonympha領(lǐng)鞭毛蟲和變形鞭毛蟲變形鞭毛蟲雙領(lǐng)蟲原綿蟲自由生活種類（Ⅱ）Sarcodina1、Symbolanimal—AmoebaproteusPseudopodiaassistphagocytosisandmotionintheorganisms.Thepellicle(orenvelope)isusuallythinandflexible.Theircytoplasmconsistsofclear,outerectoplasmandgranular,innerendoplasm.Asexualreproductionoccursbyfissionofthecell.2、CharacteristicspresentinSarcodina3、ClassificationofSarcodina

1）Rhizopoda偽足為葉狀、指狀、絲狀或根狀特征：代表：大變形蟲、痢疾內(nèi)變形蟲、表殼蟲、有孔蟲Symbolanimal：entamoebahistolyticaMajorpathogenworld-widedistribution(10%)5%insomedevelopedcountries100deathsinChicago1930Trophozoite（滋養(yǎng)體）&Cyst（包囊）oral-faecaltransmission表殼蟲Arcella

sp砂殼蟲Difflugiasp有孔蟲Foraminifer2）Actinopoda特征：具軸偽足，多營漂浮生活代表：太陽蟲、放射蟲太陽蟲Actinophrys放射蟲Radiolarian(Ⅲ)Sporovoa

(孢子綱)1、Symbolanimal—Plasmodiumvivax(間日瘧原蟲)Mosquito&“victim”Africa=kills1millionchildrenperyearThousandsofsporozoitesinjectedAnophelesMosquitoPlasmodiumsporozoitegameteocyte卵囊裂殖子

寄生在人體紅細胞內(nèi)旳瘧原蟲：1-環(huán)狀體；2-滋養(yǎng)體3-裂殖體；4-雄配子；5-雌配子；6-中性粒細胞；7-淋巴細胞2、CharacteristicspresentinSporovoa1）Exclusivelyparasites2）Adultsporozoanshavenostructuresformovement3）Heterotrophic4）Complexlifecycle；Reproductivepatternincludinggamogenesis,merozoitereproduction(裂殖子生殖)andsporogony（孢子生殖）.3、ThecommonkindofSporovoa巴貝斯焦蟲Babesia艾美球蟲Eimeria碘泡蟲Myxobolus(Ⅳ)C