mTn-lacZ/LEU2

TR | Tn3terminalinvertedrepeats |
lacZ | 5"-truncatedlacZgeneencodingbeta-galactosidase |
LEU2 | LEU2genefromS.cerevisiae |
amp | Encodesbeta-lactamase |
loxP | loxsite,targetforCrerecombinase |
Uses:Genedisruption,analysisofgeneexpression,immunodetectionofbeta-galfusionprotein.
Inmoredetail:mTn-lacZ/leu2wasconstructedbySiefertetal.(1986).Itcaneasilybeinsertedatmutiplesitesinagivengene.ThemutagenizedDNAisthentransformedintoyeast,whereitreplacesthechromosomallocusbyhomologousrecombination.Thetransposoninsertionscreateapoolofinsertion/disruptionalleles.Insertionsthatgeneratein-framefusionofthecodingregiontolacZcanbeusedtomonitorandquantifygeneexpression,viaassaysforbeta-galactivity.Thefusionproteincanalsobeimmunodetectedusingantibodiesdirectedagainstbeta-gal.
TheaccessionformTn-lacZ/LEU2isU35112
AkitformutagenesisofayeastgenewithmTn-lacZ/LEU2isavailable.
- Seewhatitcontains
- Orderthekit
Pleasereadthiswholedocumentbeforeyoustart!
Shuttlemutagenesis
- ClonefragmentintovectorpHSS6(fromstrainR1123;mapgivenbelow).
- DeleteasmuchofthepolylinkeraspossIBLeassometimestransposon"hot-spots"intoit.SelecttransformantsonLBKan40.
- TransformthisplasmidintocompetentcellsofR1236/B211.
- TransferF::mTn-lacZ/LEU2intocellsbymatingwithstrainB198
- Growstrainsovernightwithantibioticselection(Amp50forB198).
- Subculture1:100infreshmedium(noantibiotics).Growat37oCtoearlylogphase(whencellswirlsarevisible).Therecipientstrain(B211)canbedenserthanthedonor.
- Mix200ulofeachstrain.Incubateat37oCwithoutagitationfor20minto1hr.Plateas100ulaliquotsontoLBAmp50Kan40Cm34.
- Grow1-2daysat30oC.Nowhavecointegrates.(SetupstrainR1230inSm50overnight).
- MatetostrainR1230toresolvecointegrates
- Elutecoloniesfromplates:put2mlsofLBontheplate,scrapeoffthecolonieswithaspeader.Thisisyoureluate.Youshouldhaveseveralthousandcoloniesatleast.
- DiluteovernightcultureofstrainR12301:100withoutantibiotic.Diluteeluatetoroughlysamedensity.
- Growandmateasbefore.
- Aftermatingfor20minto1hr,plate100ulaliquotsonLBAmp50Kan40Sm50andgrowovernightat37oC.
- DotheControl:Spotthestartingstrainsontothismedia.
- RescueresolvedDNAfromthisstrain
- EluteyourcoloniesoffinLB.Again,youshouldhavethousands.DilutesomeeluateinLBAmp50Kan40togiveanalmostsaturateddensity.Growat37oCforafewhours.
- IsolateDNAbyminiprep.(Wedoastandard1-2-3alkalinelysisbutuse150ulof7.5MNH4AcassolutionIII,and270ulofisopropanoltoprecipitate.Thisremovesmostofprotein(avoidingphenol)andRNA,givingaverysmallcleanpellet.Still,therearenucleasessowekeepeverythingonice).
- Transformabout1/10ofminprepintoaregularrecAendAcloningstrain(egDH5).PlateonLBAmp50Kan40.
- TransformintoyeastselectingforLEU2
- Eluteentirepooloftransformants(again,aimforthousands)andmakeaminiprepasinstep5.(Make-70stockofbacterialpoolforfutureuse).
- TransformNotIdigestofentirepoolintoyeastandlookforlacZfusionsamongtransformants.
Screeningforin-framelacZfusionsinyeast
- TransformantcoloniesarepatchedtoSC-leu.
- CellsarereplicaplatedtoaSC-leuplateandaSC-leuplateonwhichasterilediscofWhatman1Afilterpaperhasbeenplaced,andgrownovernightat30oC.Othermediaorgrowthconditionscanbesubstitutedasdesired.Forade2strains,anytestmediashouldcontain80mg/lofadenine,astheredpigmentcanobscuretheX-galresult.
- Filtersareliftedfromtheplatesandplacedinthelidofa9-cmglasspetridish.Thislidisthenplacedinsideaclosed15-cmglasspetridishcontainingchloroform,for10to30minutes.Theminimumexposuretimenecessaryforaparticularyeaststraincanbedeterminedempirically.
- Filtersareplacedcolony-sideupontoX-Galplates(120ug/ml5-bromo-4-chloro-3-indolyl-b-D-galactopyranoside,0.1MNaPO4[pH7]and1mMMgSO4in1.6%agar)andincubatedat30oCforupto2days.
- TransformantscarryingproductivelacZfusionsarerecoveredfromtheregrownSC-leuplate.ItisadvisabletosubsequentlymaintainselectionforLEU2whereverpossible,assomemutationsaredeleteriousevenintheheterozygousstate.
Bacterialstrainsused(includedinkit):
R1123 | StrainXL1-bluecarryingvectorpHSS6. |
R1236/B211 | StrainRDP146(F-recA"(deltalac-pro)rpsE;spectinomycinresistant)withplasmidpLB101(pACYC184withtnpA;activetransposase,chloramphenicolresistant)(F.Heffron) |
B198 | StrainRDP146withpOX38FfactorderivativecarryingmTn3derivativemTn-lacZ/LEU2(lacZ,LEU2,amp,ampicillinresistant) |
R1230/NS2114Sm | F-recArpsL(Streptomycinresistant,lamBDa-crelysogen) |
Vectorused:

TheaccessionforpHSS6isM84115
Antibioticsused:
Ampicillin,Amp, | 50mg/mlinwater.Useat50ug/ml(Amp50) |
Kanamycin,Kan, | 10mg/mlinwater.Useat40ug/ml(Kan40) |
Chloramphenicol,Cm, | 34mg/mlinethanol.Useat34ug/ml(Cm34) |
Streptomycin,Sm, | 10mg/mlinwater.Useat50ug/ml(Sm50) |
Whenonlyafewplatesofeachtypeareused,it"sconvenienttochopanLBplateupwithasteriletoothpick,putthebitsinasterileflask,andmelttheagarbymicrowave.Addappropriateamountsofantibioticandrepourplates.
================ 蚂蚁淘在线 ================
免责声明:本文仅代表作者个人观点,与本网无关。其创作性以及文中陈述文字和内容未经本站证实,对本文以及其中全部或者部分内容、文字的真实性、完整性、及时性本站不做任何保证或承诺,请读者仅作参考,并请自行核实相关内容
版权声明:未经蚂蚁淘在线授权不得转载、摘编或利用其他方式使用上述作品。已经经本网授权使用作品的,应该授权范围内使用,并注明“来源:蚂蚁淘在线”。违反上述声明者,本网将追究其相关法律责任。