Office of Undergraduate Biology - SILS VII...SILS VII Summer Institute for Life Sciences Annual Undergraduate Research Symposium August 9, 2017 Warren Hall Room 175 Morning Session

SILSVIISummerInstituteforLifeSciences

AnnualUndergraduateResearchSymposium

August9,2017WarrenHallRoom175

Morning

Session(AM)

8:30-9:00 MorningSessionRegistration,coffeeandbagelsinloungeoutsideRoom173.Registrationwillbeself-serveafterthat.Presenters,pleasestopandgetnametag.

9:00-9:06 Introduction,ColleenKearns,AssociateDirectorofUndergraduateResearch,OfficeofUndergraduateBiology

9:06-9:18 TheEffectofNuclearEnvelopeRuptureonDNADamageinEmery-DreifussMuscularDystrophySushrutaIruvanti1,3,AshleyEarle2,3,GregoryFedorchak2,3,TylerKirby2,3,JanLammerding2,3LammerdingLab,1DepartmentofBiologicalandEnvironmentalEngineering,2DepartmentofBiomedicalEngineering,3WeillInstituteforCellandMolecularBiology

9:18-9:30 TowardModelingandAnalysisofCoagulationandFibrinolysisDynamicsusingReducedOrderEffectiveKineticModelsRoanneYehia,NicholasHorvath,JeffreyD.VarnerVarnerLab,RobertFrederickSmithSchoolofChemical&BiomolecularEngineering

9:30-9:42 DevelopingNovelMethodsandSoftwareToolsforVisualizationofNuclearArchitectureZiningChen,AbdullahOzer,JudhajeetRay,AstraE.Hwang,andJohnT.LisLisLab,DepartmentofMolecularBiologyandGenetics

9:42-9:54 Investigatingtheinvitrosynergisticcytotoxiceffectsofrituximabincombinationwithchemotherapyonhumannon-HodgkinB-celllymphomaBrianLee,TimPierpont,KristyRichardsRichardsLab,DepartmentofBiomedicalSciences

9:54-10:06 InvestigatingtheproductionandmaturationofInterleukin-18inastrocytesinAlzheimer’sDiseaseStephanieBecker,JennyTzeng,DouglasGolenbockGolenbockLab,DepartmentofInfectiousDiseaseandImmunology

10:06-10:18 UsingImmunohistochemistrytoExploreSemilunarValveDevelopmentinMiceforthePrimaryAntibodies:SNAIL,VECadherin,andClathrinBrianKauffman,DucPhamJohnathanT.ButcherLab,NancyE.andPeterC.MeinigSchoolofBiomedicalEngineering

10:18-10:30 ANovelInvivoApproachtoExamineDNADamageResponsePathwaysinMouseSpermatocytesJennyYang,JordanaBloom,JohnC.SchimentiSchimentiLab,DepartmentofBiomedicalSciences

10:30-10:42 Break–coffee,juice,andbagelsinloungeoutsideRoom173

10:42-10:54 Investigatingtheinteractionbetweenadiposestromalcellsandmammaryepithelialcellsina3DspheroidsystemYunxinOuyang,LuLing,ClaudiaFischbachFischbachLab,NancyE.andPeterC.MeinigSchoolofBiomedicalEngineering

10:54-11:06 Impactofstromalcellsand5-azacytidineonBcelldifferentiationfortreatmentofequinecommonvariableimmunodeficiency(CVID)LuriaGreene,Dr.JuliaFelippeEquineImmunologyLaboratory,DepartmentofClinicalSciences

11:06-11:18 InvestigatingBreastCancerStemCellswithstarPEG-HeparinhydrogelsJasonFreedman1,PassantAtallah2,SiyoungChoi1,JanaSievers2,LucasSchirmer2,UweFreudenberg2,CarstenWerner2,ClaudiaFischbach1FischbachLab,MeinigSchoolofBiomedicalEngineering

11:18-11:30 DefiningthemechanismofmelanomainitiationfrommelanocytestemcellsJerryZhu,HyeongsunMoon,LeanneR.Donahue,andAndrewWhiteWhiteLab,DepartmentofBiomedicalSciences

11:30-11:54 ApplicationsandDevelopmentofHomingGeneDriveJoanChung*,ChenLiu*,JacksonChamper,AndrewG.Clark,PhilippMesser*EqualcontributionMesserandClarkLabs,DepartmentofMolecularBiologyandGenetics,DepartmentofBiologicalStatisticsandComputationalBiology

11:54-12:06 NeuralcircuitsunderlyingperformanceevaluationinmiceArchanaPodury,VikramGadagkarandJesseGoldbergGoldbergLab,DepartmentofNeurobiologyandBehavior

12:06-12:18 Investigatingtheidentityofanipsilaterally-projectingexcitatoryinterneuronconnectionintheneonatemousespinalcordDerekNieHarris-WarrickLab,DepartmentofNeurobiologyandBehavior

Afternoonsessionregistrationfrom12:30-1:00PM(self-serveafter1PM).

RefreshmentsinloungeoutsideRoom173.

AfternoonSession(PM)

12:55-1:00 Introduction,ColleenKearns,OfficeofUndergraduateBiology1:00-1:12 ContaminationofExpressedMilkinRealLifeConditions

DainelleAllen1,SarahReyes2,AnthonyHay3,KathleenRasmussen21DepartmentofScienceandTechnologyStudies,2DivisionofNutritionalSciences,3HayLab-DepartmentofMicrobiology

1:12-1:24 UseofplantsmallinterferingRNAsforvirusdiscoveryincultivatedandnaturalplantpopulationsAnnikaGomez,JulianaGonzálezTobón,JoséVargasAsencio,KeithPerryPerryLab,SchoolofIntegrativePlantScience,PlantPathologyandPlant-MicrobeBio.

1:24-1:36 OxyPonicsRahulRambhatla,AshwinViswanathan,YannieMei,RaymondZhangCornelliGEM,BiomedicalEngineering

1:36-1:48 StructuralandfunctionalcharacterizationofbacterialmethyltransferasesYimingNiuChappieLab,DepartmentofMolecularMedicine

1:48-2:00 Cobalt(III)SchiffBaseComplexesasPotentialAnticancerProdrugsA.PadenKing,HendryckGellineau,SamMacMillan,JustinJ.WilsonWilsonGroup,DepartmentofChemistryandChemicalBiology

2:00-2:06 Break–refreshmentsinloungeoutsideofRoom173

2:06-2:18 Geneticanalysisofnewmutationsaffectingthebonemorphogeneticprotein(BMP)signalingpathwayinC.elegansGabrielleVillafanaLiuLab,DepartmentofMolecularBiologyandGenetics

2:18-2:30 AninvestigationontheroleofSMOC-1inthebonemorphogeneticproteinpathwayAliceEastman,MelisaDeGroot,JunLiuMolecularBiologyandGeneticsREULiuLab,DepartmentofMolecularBiologyandGenetics

2:30-2:42 TheEffectofInsulin-likePathwayonCaenorhabditisModelsofHuntingtonDiseaseOanhTran1,2,Cheng-linLi1,SylviaLee2MolecularBiology&GeneticsREULeeLab,1DepartmentofMolecularBiologyandGenetics

2:42-2:54 EffectofRim,CG32834,andbtszonSpermCompetitionandCG32277onEggLayinginDrosophilaMelanogasterHoangV.Bui,SofieY.N.Delbare,andMarianaF.WolfnerMolecularBiologyandGeneticsREUWolfnerLab,DepartmentofMolecularBiology&Genetics

2:54-3:06 SEMINAL:Evolutionary,BiochemicalandGeneticApproachestoExpandingtheSexPeptideNetworkChrisWilson1.2,Dr.AkankshaSingh2,andDr.MarianaWolfner2MolecularBiologyandGeneticsREUWolfnerLab,DepartmentofMolecularBiology&Genetics

3:06-3:18 TheEffectofChromatinStructureonRecombinationBetweenDivergentDNASequencesMarissaBaccas1,2,UjaniChakraborty1,EricAlani1MolecularBiologyandGeneticsREUAlaniLab,DepartmentofMolecularBiologyandGenetics

3:18-3:30 RoleofphospholipasesinthelocalizationoflysosomesGabrielaCasanova,JenniferRoscoe,WilliamJ.BrownMolecularBiologyandGeneticsREUBrownLab,DepartmentofMolecularBiologyandGenetics

3:30-3:42 Functionalstudiesofafamilyofnovellate-GolgiproteinsSaeedRoschdi,LauraThomas,ChrisFrommeMolecularBiologyandGeneticsREUFrommeLab,DepartmentofMolecularBiologyandGenetics

3:42-3:54 ArsenicInducesDegradationofDihydrofolateReductaseAlyssaM.Laffitte1,DeniseM.Stover2,MarthaS.Field2,PatrickJ.Stover2,3MolecularBiologyandGeneticsREUStoverLab,DivisionofNutritionalSciences

3:54-4:06 EmpiricalDeterminationofmicroRNA-targetinteractionsinthe3’UntranslatedRegionAlexanderGirgis1,2,RaviPatel1,CaterinaSchweidenback1,AndrewGrimson1

MolecularBiologyandGeneticsREU1DepartmentofMolecularBiologyandGenetics

4:06-4:18 InvestigatingtheInteractionBetweenProgranulinandClusterin,TwoProteinsInvolvedinNeurodegenerationAlexanderLacrampe,TuanchengFeng,FenghuaHuMolecularBiologyandGeneticsREUHuLab,WeillInstituteforCell&MolecularBiology,DepartmentofMolecularBiology&Genetics

4:18-4:30 UnderstandingthefunctionandregulationofthenuclearreceptorRXRGinneuralcrestcellsRachelYerden,MarcosSimoes-CostaMolecularBiologyandGeneticsREUSimoes-CostaLab,DepartmentofMolecularBiologyandGenetics

SUMMERINSTITUTEFORLIFESCIENCESSEVENTHANNUALUNDERGRADUATESYMPOSIUM

ABSTRACTSAugust9,2017

PresentationTimeNotedAtEndofAbstractAllTalksWillBeInWarren175UnderlinedAuthorisPresenter

ContaminationofExpressedMilkinRealLifeConditionsDainelleAllen1,SarahReyes2,AnthonyHay3,KathleenRasmussen2

1DepartmentofScienceandTechnologyStudies2DivisionofNutritionalSciences3HayLab-DepartmentofMicrobiology

Recommendationsforhumanmilk(HM)storagearebasedonstudiesconductedundersterileconditions,whichmaynotbeappropriatefor“real-life”conditions.WeconductedarandomizedcontroltrialtocomparebacterialgrowthinHMpumpedwithwomen’sownwithsterilepumps.WefoundthatHMsamplespumpedwithwomen’sownpumpsweremorelikelytobeconsideredunsafe(>104cfu/ml;52%ownvs.11%sterile,p=0.005)andweremorelikelytocontainentericbacteria(65.7%ownvs.5.7%sterile,p=0.008)thanHMpumpedwithasterilepump.Recommendationsshouldconsiderthat,evenbeforestorage,therearemorebacteriainwomen’spumpthansterilepumps.1:00-1:12PM

TheEffectofChromatinStructureonRecombinationBetweenDivergentDNASequencesMarissaBaccas1,2,UjaniChakraborty1,EricAlani1MolecularBiologyandGeneticsREUAlaniLab1CornellUniversity,DepartmentofMolecularBiologyandGenetics,Ithaca,NewYork2DepartmentofChemistryandPhysics,FayettevilleStateUniversity,Fayetteville,NorthCarolinaMismatchrepair(MMR)proteinsdetectandcorrectDNAmisincorporationerrorsthatoccurduringDNAreplication.Asubsetoftheseproteinsisneededforheteroduplexrejection,aprocesswhichpreventsgeneticrecombinationbetweendivergentDNAsequences.HistonedeacetylasescausehistonesthatwraparoundDNAtobeina“closed”conformationwhichIhypothesizesuppressesheteroduplexrejection.WorkintheAlanilabsuggeststhattheinhibitionofSir2histonedeacetylaseincreasesheteroduplexrejectionandthatthedrugnicotinamide(NAM)hasasimilareffect,perhapsbymakingrecombinationsubstratesmoreaccessibletotherejectionmachinery.IhypothesizethatthedeacetylaseinhibitorNAMinhibitstheactivityofSir2oranotherproteininvolvedinthebiochemicalmodificationofhistonesandasaresultimprovesrejection.Toaddressthis,ItreatedonesetofSaccharomycescerevisiaecellswithNAM,anothersetlackedSir2,athirdwastreatedwithNAMandalsolackedSir2(Dsir2),andafourthwasawild-typecontrol.NAMconcentrationsof2mM,10mM,and25mMweretested.Theratesofheteroduplexrejectioninstrainbackgroundsthathaveeitheridentical

ordivergentDNAsubstratesforrecombinationwerecompared.Ifoundthefollowing:1.Inwildtypecells,NAMincreasedtherateofhomologousanddivergentrecombination,butnottheoverallefficiencyofrejection.2.Comparedtowildtype,Dsir2strainsshowedelevatedhomologousrecombinationlevelsandincreasedrejection.3.Curiously,IsawasynergisticincreaseinrejectioninDsir2strainstreatedwith2mMNAM.However,thissynergisticincreasewasnotseenat10mMNAM,andat25mMNAMrejectionwaslowerthanthatseeninDsir2strainsnottreatedwithNAM.Ifoundtheseresultstobeinteresting,andpossiblysuggestthatNAMactsondifferentcellulartargetsatdifferentconcentrationlevels.Futurestudieswillinvolverepeatingtheseexperimentstoconfirmpreliminaryresults,testingdifferentconcentrationsofNAM,andexamininghowandwhytherateofrejectiondecreasesinSir2nullstrainsastheNAMconcentrationincreases.Understandingheteroduplexrejectionmechanismswillallowustobetterunderstandhowdiseasecausingchromosomalrearrangementsoccur.3:06-3:18PMInvestigatingtheproductionandmaturationofInterleukin-18inastrocytesinAlzheimer’sDiseaseStephanieBecker,JennyTzeng,DouglasGolenbockGolenbockLabDepartmentofInfectiousDiseaseandImmunologyUniversityofMassachusettsMedicalSchool,Worcester,MassachusettsAlzheimer’sDisease(AD)isaneurodegenerativediseasethatfeatureschronicinflammationinthebrain.Interleukin-18(IL-18)andinterleukin-1beta(IL-1β),keycytokinesthatareproducedandsecretedtypicallybymonocytesandmacrophagestoinduceinflammation,havebeenimplicatedinADandunpublisheddatashowsthatatanearlystageofAD,IL-18playsaprotectiverole.Insummary,IL-18isanimportantcytokineinADprogressionandseverity.ThecurrentstudysoughttodetermineasourceofIL-18inthebrainbyinvestigatingIL-18productioninastrocytes.PreviouslypublisheddatasuggestsastrocytesareapotentialsourceofIL-18.Therefore,astrocyteIL-18productionandmaturation,aswellastheinflammatorycascadeupstreamIL-18maturationwasobservedbywesternblotandconfocalmicroscopy.DatarevealedthatastrocytesproduceproIL-18butnotmatureIL-18.However,ifastrocytesarecapableofproducingmatureIL-18remainsunknown.Preliminarydatashowsthattheydonotcontainnecessaryinflammatorycascadecomponents,suchasactivecaspase-1,apoptosis-associatedspeck-likeproteincontainingaCARD(ASC),andnod-likereceptorprotein3(NLRP3).FurtherstudyiswarrantedtodetermineifandhowastrocytescanproducematureIL-18inAlzheimer’sDisease.9:54-10:06AMEffectofRim,CG32834,andbtszonSpermCompetitionandCG32277onEggLayinginDrosophilaMelanogasterHoangV.Bui,SofieY.N.Delbare,andMarianaF.WolfnerMolecularBiologyandGeneticsREUWolfnerLabDepartmentofMolecularBiology&GeneticsInDrosophilamelanogaster,reproductionisaffectedbynotjustmaleseminalfluidproteins,butalsobythefemalegenotype,whichislesswellknown.Hereweinvestigatetheeffectoffemalegenotypeonspermcompetitionandegglaying.Tengeneshavebeenidentifiedtoinfluencespermcompetition,thenumberofoffspringsiredbythefirstvs.secondmaletomate,whenknockeddowninfemaleflies.Interestingly,themajorityofthesetengenesareheavilyexpressedinthenervoussystem.Itispossiblethatthesegeneshelpfemalestoactivelyselectforthegenotypeofthefirstorsecondmale.

Alternatively,knockdownmightaffectthesuccessbasedontheorderofmating,independentlyofmalegenotype.Here,wefurtherinvestigatethreegenesoutoftheten(rim,CG32834,andbtsz).Todistinguishthepossibilities,theorderofmatingisbereversed(browneyedmalefirst,whiteeyedmalesecond).Iftheproportionofoffspringofthewhitevs.browneyedmaleremainsthesameasobservedinpreviousexperiments,itislikelythatknockingdownthegenesofinterestaffectsfemalepreferenceforamalegenotype,insteadoffemalepreferenceforthefirstorsecondmaletomate.FunctionsofCG32277,whichcodesforapeptidasethatishighlyexpressedinthesperm-storageorganspermatheca,onegglayingarealsoinvestigated.Thisisdonebyknockingdowngeneexpressionandcomparingthenumberofeggslaidtothecontrolaftermating.2:42-2:54PMRoleofphospholipasesinthelocalizationoflysosomesGabrielaCasanova,JenniferRoscoe,WilliamJ.BrownMolecularBiologyandGeneticsREUBrownLabDepartmentofMolecularBiologyandGeneticsThecellbiologicalmechanismsunderlyingmembraneandorganelletraffickingareincompletelyunderstood.TheBrownlabfocusesoncellularandmolecularmechanismsofintracellularmembranetraffickinginthesecretoryandendocyticpathways.Oneofthemainobjectivesistounderstandtherolethatphospholipid-modifyingenzymes(phospholipasesandlysophospholipidacyltransferases)playintheseprocesses,astheyplayanimportantroleintheformationofmembranetubulesfromtheGolgiandendosomes.Phospholipasesareenzymesthathydrolyzeoneofthebondsinphospholipids.Forexample,phospholipasesA2(PLA2)cleaveofftheSN2fattyacylchain,whichisoftenarachidonicacid,producingalysophospholipidandfreefattyacid.RecentstudiessuggestthatthePLA2enzymecomplexplatelet-activatingfactoracetylhydrolase(PAFAH)Ib,consistingofα1,α2,andLIS1subunits,hasaroleinthedistributionandfunctionoftheGolgicomplexandendosomes.Moreover,earlierlabexperimentshaveshownarelationshipbetweenoverexpressionofα1andα2andLIS1bindingandregulationofdyneininendosomeandlysosometransporttowardsthecentrosome.Also,previousexperiments,withknockedoutPAFAH1bcellsviaCRISPR,showedasimilarphenotype.Althoughtheseresultsseemconsistent,avariablethatcouldhaveaffectedtheseresultsmighthavebeenthelengthoftime(days)fortheexperimentstobecompleted.MyprojectfocusesonthetreatmentofcontrolandPAFAH1bKOcellswithrapidlyactinginhibitorsthathaveaneffectinminutes.Thechangesinlysosomemorphologyandorganizationwillbeobservedviaantibodystainingandimmunofluorescencemicroscopy.Insummary,lysosomalmorphologychangeandorganizationwillbeobservedinPAFAH1bKOcellsastheresultoftheadditionofanantagonistthatwillactwithinashorttimeframe.3:18-3:30PMDevelopingNovelMethodsandSoftwareToolsforVisualizationofNuclearArchitectureZiningChen,AbdullahOzer,JudhajeetRay,AstraE.Hwang,andJohnT.LisLisLabDepartmentofMolecularBiologyandGeneticsNucleararchitectureandgenomeorganizationserveacriticalroleingeneexpressionduringdevelopment,normalphysiologyanddiseasestates.Inrecentyears,variousHi-Cmethodshavebeendevelopedtounderstandgenome-widechromatinorganization.Inaddition,softwaressuchasHiCUP,Juicer,andJuiceboxhavebeendevelopedtoanalyzeandvisualizethedatageneratedbythesemethods.AlthoughHiCmethodsprovideinsightsabouttheoverallorganizationofthegenomeincluding

TopologicallyAssociatedDomains(TADs),long-rangeloops,andproximityofDNAfragments,theyrelyonasinglecrosslinker;formaldehyde(FA).Thisresultsinalackofdistanceinformationandsensitivitytodetectenhancer-promoterinteractions.ToovercometheselimitationsandtobetterunderstandtheHi-Cprotocol,theLisLabisdevelopingalternativeHi-CmethodswithasetofnewDNA-DNAcrosslinkerswithpredefinedlinkerlengths,aswellasmodificationstoFA-basedHiCmethods.UsingtheheatshockresponseasamodelsystemofanalteredcellconditionwithFA-crosslinking,wefoundnosignificantchangesinthechromatinorganizationcomparedtonon-heatshockconditionsinDrosophilaMelanogasterdespiteanearlierpublicationwithcontradictingconclusion.We’vealsoanalyzedthenatureofcrosslinkedchromatinmaterialusedforvariousHiCmethods,andspecificallylookedathowtimeandamountofsonicationaffectedsizeofnuclearchunksandthesizeofDNAfragmentsusingChromatinImmunoprecipitation(ChIP)technique.Wefoundthatthewidthofthepeaksboundbythetargetprotein(i.e.,HSF)wasinverselyproportionaltosonicationtime;narrowerpeakswithmoresonicatedmaterial.Moreover,sincetheavailablesoftwaretoolsweredevelopedspecificallyforexistingHiCmethodsandmanyareincompatiblewithoneanother,adaptingthesetonewmethodsrequiredevelopmentofnewtoolsorrepurposingexistingones.Forexample,IwroteacodethatconvertsaHiCUPgenerated.bamfiletoa.hicfilesothatJuiceboxprogramcanbeusedforvisualizationofHiCUPanalyzedHiCdata.Oncetheaforementionedmethodsandsoftwaretoolsareinplace,wewillthenbeabletostudytheeffectsofvariouschangestocellularconditiononthenuclearstructurewithbettersensitivityandhigherresolution.9:30-9:42AMApplicationsandDevelopmentofHomingGeneDriveJoanChung*,ChenLiu*,JacksonChamper,AndrewG.Clark,PhilippMesser*EqualcontributionMesserandClarkLabsDepartmentofMolecularBiologyandGeneticsDepartmentofBiologicalStatisticsandComputationalBiologyDuringnormalsexualreproduction,aparenthasa50%chanceofpassingonacertainalleletoitsoffspring.However,genedrivesystemsallowustoovercomethistraditionalrule,increasingtheoddsofaspecificgenedriveallelebeingpassedontotheoffspring.Successfullyengineeredgenedrivescaneithercauseapopulationcrashinthetargetspeciesormodifyittogiveitamoredesirabletrait,suchastheabilitytofightmalaria.Becauseofthis,genedrivesystemshavethepotentialtorevolutionizeourstrategiesforissuessuchasthepreventionofvector-bornediseasesandthecontrolofcroppests.SignificantstrideshavebeenmadetowardsthisgoalwiththediscoveryofCRISPR/Cas9.WedesigneddifferentCRISPR/Cas9hominggenedriveconstructsandstudiedtheirperformanceinthemodelorganismDrosophilamelanogaster.Fromtheexperiment,wedeterminedthemechanismofourgenedrivesandhowtheyformresistancealleles,whichpreventsthegenedrivefromfunctioning.Theseresistanceallelesarethemainobstaclethatmustbeovercometobeeffective.Additionally,welearnedthatagenedrivewithtwogRNAsperformsmoreefficientlyandreducestheformationofresistancealleles.Wephenotypedseverallinesofgenedriveflieswithdiversebackgrounds,andfoundsignificantdifferencesintheirefficiency,whichisanimportantconsiderationwhendetermininghowagenedrivewillperforminanaturalpopulation.11:30-11:54AM

AninvestigationontheroleofSMOC-1inthebonemorphogeneticproteinpathwayAliceEastman,MelisaDeGroot,JunLiuMolecularBiologyandGeneticsREULiuLabDepartmentofMolecularBiologyandGenetics,CornellUniversity,Ithaca,NYThebonemorphogeneticprotein(BMP)pathwayisahighlyconservedsignalingpathwaywithmanyimportantfunctions.Mutationsinthegenesfunctioninginthispathwaycangiverisetoheartandskeletalproblemsaswellascertaincancersinhumans.InC.elegans,theBMPpathwayregulatesseveralsystemsincludingbodysize.whichisthemetricIamusingtodeterminehowanewlyidentifiedsecretedprotein,SMOC-1,functionsintheBMPpathway.smoc-1nullmutants(smoc-1(0))aresmaller,whilewormsover-expressingsmoc-1(smoc-1(OE))arelonger,thanwild-typeworms.Ihavegenerateddoublemutantsbetweensmoc-1(OE)andnullmutationsingenesdbl-1,sma-3,lon-2andlon-1,whichencodetheligand,acytoplasmictransducerR-Smadprotein,anegativeregulatorglypicanandatargetofthepathway,respectively.Ihavemeasuredthebodylengthsofthedoublemutantsandcomparedtheirlengthswiththecorrespondingsinglemutantsandwithwildtypeanimals.MyresultssuggestthatSMOC-1functionsupstreamoftheligandDBL-1andthenegativemodulatorLON-2intheBMPpathway.TodetermineifSMOC-1isspecificallyinvolvedinmodulatingtheBMPpathway,IamalsotestingwhetherSMOC-1isinvolvedinapathwaycloselyrelatedtotheBMPpathway,thedauerTGF-βpathway.Thisisachievedbygeneratingdoublemutantsbetweensmoc-1(0)mutantandnullmutantsindaf-7anddaf-1,whichencodetheligandandtypeIreceptorofthedauerpathway,respectively,andassessingthedauerphenotypeoftheresultingdoublemutants.ResultsfrommyexperimentswillhelpcontributetoourunderstandingofthefunctionsofSMOC-1invivo.2:18-2:30PMInvestigatingBreastCancerStemCellswithstarPEG-HeparinhydrogelsJasonFreedman1,PassantAtallah2,SiyoungChoi1,JanaSievers2,LucasSchirmer2,UweFreudenberg2,CarstenWerner2,ClaudiaFischbach11FischbachLab,MeinigSchoolofBiomedicalEngineering,CornellUniversity,Ithaca,NewYork2MaxBergmannCenterforBiomaterials,Leibniz-InstitutfürPolymerforschung,Dresden,GermanyIn2017,anestimated250,000womenwillbediagnosedwithbreastcancer,andanestimated40,000willdiefromthedisease,intheUSalone.While89%ofwomensurvivethedisease5yearsafterdiagnosis,andtheoddsofremissionarehigh,survivalratesdropdramaticallyiftheyexperiencearelapse.Relapses,oftenmoreresilientandaggressivethantheinitialcancer,arethoughttobedrivenbyasubsetofcancerouscellscalledCancerStemCells(CSCs).CSChallmarksincludenotonlyregenerationofheterogenic,treatment-resistanttumors,butalsoproliferation,progressionandmetastasisofbreastcanceroverall.Twomicro-environmentalfactorsthathavebeenimplicatedinanupregulationofCSCpropertieshavebeenraisedlevelsoftheinflammatorycytokineIL-8,andthestiffnessofthesurroundingextra-cellularmatrix(ECM).TheseinturnupregulateexpressionofthetranscriptionalfactorNANOG,whichisheavilyinvolvedintherenewalofstemnessproperties.NANOGisthusconsideredaCSCmarker.Inordertostudystemnesslevelsinresponsetothesemicro-environmentalfactors,starPEG-HeparinhydrogelsthatallowfortheindependenttuningoflocalIL-8concentrationandstiffnessareutilized.LocalIL-8concentrationisadjustedbyvaryingthesulfationdegreeofHeparin,whilestiffnessismodulatedbyvaryingthemolaramountsofPEGineachgel.Thebindingabilitiesofgelswillbeassessed

bymeasuringIL-8levelsintumorconditionedmedia(TCM)beforeandaftergelincubation,andstoragemoduliofthegelsaredeterminedviarheology.CellstemnesswillbemeasuredbyculturingNANOG-GFPMDA-MB-231cellsongelsandmeasuringfluorescencefromNANOGexpression.ItisourcurrentgoaltocharacterizeandoptimizethebiochemicalandbiochemicalpropertiesofthesegelsforthefuturestudyofCSCs.11:06-11:18AMCobalt(III)SchiffBaseComplexesasPotentialAnticancerProdrugsA.PadenKing,HendryckGellineau,SamMacMillan,JustinJ.WilsonWilsonGroupDepartmentofChemistryandChemicalBiology

Currentcancertreatmentslackbiologicalspecificityandleadtoadversesideeffects.Targetingspecificenvironmentsorsystems,suchastumorhypoxia,yieldsmoreselectivetreatmentsandminimizessideeffects.Tumorhypoxiaisalackofoxygenintheinteriorofsolidtumors,whichcreatesanacidic,reductiveenvironment.Wehavesynthesized(bis)ethylenediaminetrifluoroacetylacetone(tfac(en))complexesofcobaltIIIfortheirpotentialashypoxiaactiveredoxprodrugs.ThestructuresofeachcomplexhavebeenanalyzedbyNMRandtheirreductionpotentialsanalyzedbyCyclicVoltammetry.Theirstabilityinsolutionandtheirbiologicalactivitywillsoonbeevaluated.Selectivityforcancerousandhypoxiccellswillbedetermined.Intandem,cellularuptakeandmembranepermeabilitywillalsobestudied.1:48-2:00PM

EmpiricalDeterminationofmicroRNA-targetinteractionsinthe3’UntranslatedRegionAlexanderGirgis1,2,RaviPatel1,CaterinaSchweidenback1,AndrewGrimson1

MolecularBiologyandGeneticsREU1DepartmentofMolecularBiologyandGenetics,CornellUniversity,IthacaNY2DepartmentofBiomedicalEngineering,UniversityofMichigan,AnnArbor,MI

microRNAs(miRNAs)are~22nucleotidesequencesthatinfluencegeneexpressionbyrecruitingsuppressivecomplexestositeswithinthetargetmRNAtranscript.Mostoftentheseregulatorysitesarefounddownstreamofthecodingsequencewithinthe3’untranslatedregion(3’UTR).ComputationalmodelssuchasTargetScanusedeterminantsofmiRNA-targetinteractionsuchassequencecomplementarityandsitecontexttopredictmiRNAtargetsites.ThroughacomparativeanalysisofthetranscriptomeincellswithandwithoutmiR-1induction,theGrimsonlabhasexperimentallyidentifiedmiR-1regulated,post-transcriptionallyrepressedgenetranscripts.ThisnovelmethodcombinedcelltranscriptionalactivitywithtranscriptomeprofilingtodifferentiatedirectlytargetedmiR-1transcriptsfromindirecttargetgenes.Surprisingly,severalidentifiedtargettranscriptsdonotcorrelatewithpredictivemodels.Falsepositivetargets,forwhichmiR-1interactionswerepredictedbutnotdemonstrated,andunpredictedtargetsrepressedbymiR-1haveeachbeenidentified.Iaimtovalidatetargetsofeachtypeusingaluciferasereporterassay.Luciferasewasencodedundertheregulationofeachtarget3’UTRofinterestinareporterconstruct,andsubsequentluciferaseexpressionmeasuredinthepresenceorabsenceofmiR-1toempiricallyidentifymiR-1interactions.TocontrolforunanticipatedmiR-1bindingelsewherewithineach3’UTR,targetsitesofinterestweremutatedusingsite-directedmutagenesisandtheassayrepeated.Shouldexpressiondatabeconsistentwithpreviousresults,themodelingalgorithmswhichhaveincorrectlyclassifiedmultiplemiR-1targetswillrequirerestructuring.3:54-4:06PM

UseofplantsmallinterferingRNAsforvirusdiscoveryincultivatedandnaturalplantpopulationsAnnikaGomez,JulianaGonzálezTobón,JoséVargasAsencio,KeithPerry

PerryLabSchoolofIntegrativePlantScience,PlantPathologyandPlantMicrobeBiologySectionGrapevine(Vitisvinifera)hostsamultitudeofvirusesduetothewayitiscultivated;ithasbeenvegetativelypropagatedformillennia.Thereare64virusesknowntoinfectgrapevine,morethananyothercultivatedplant.Althoughrelatedgrapes(Vitissp.)growwildacrossNorthAmerica,littleisknownaboutvirusesinthesenaturalplantpopulations.Inordertodetectemerginggrapevinevirusesandtotrackthespreadofcommonviruses,avirusnon-specificdiagnostictechnologyisrequired.Virus-specificsmallinterferingRNAs(siRNAs)rangingfrom20-25bpinlengthareproducedbythehostinresponsetovirusinfection.Inplants,theyarepartoftheRNAinterference(RNAi)pathwaythatdefendstheplantagainstviralinfectionbyinhibitingexpressionofviralgenes.PreviousstudieshavedemonstratedthatsequencingofsiRNAsisapowerfultoolforthedetectionanddiscoveryofvirusesinplants,includinggrapevines.Virus-derivedsiRNAsfrommembersofthegeneraFoveavirus,Maculavirus,Marafivirus,Closterovirus,AmpelovirusandNepovirushavebeenshowntobederivedfromeitherthegenomicorantigenomicstrandsofviralRNA.Additionally,thedenovoreconstructionofcompleteviralgenomesfromsiRNAshasbeendescribedformembersofthefamiliesCaulimoviridaeandGeminiviridae.siRNAsequencinggeneratesseveralmillionreads,onlyafractionofwhicharevirus-derived.ThepipelineVirusDetectcanbeusedtoidentifysequencesderivedfromknownandnovelviruses.BLASTNandBLASTXlocaldatabasesearchesareusedtoidentifyknownvirussequences,andsizeprofileanalysisofunmappedreadsisusedtoidentifyputativenovelvirussequences.FollowinganalysisusingVirusDetect,wehaveperformedconservedencodedproteindomainsearchesinanattempttoidentifymoredistantlyrelatedviruses.Inaddition,weareabletomapreadstomoredistantlyrelatedviralgenomes,whichwillaidinthecharacterizationofnovelviruses.Wehavesuccessfullyappliedthesetechniquestodatasetsofbothcultivatedandwildvinesandhaveidentifiedknownandputativenovelvirusesfromthesedatasets.Futureworkwillaimtoconfirmthepresenceandidentityofnovelvirusesandtoanalyzeadditionaldatasetstobegeneratedfromlibrarypreparationsthatarecurrentlybeingprepared.Thesedatasetswillallowforacomparisonofvirusespresentinwildversuscultivatedgrapevines.1:12-1:24PMImpactofstromalcellsand5-azacytidineonBcelldifferentiationfortreatmentofequinecommonvariableimmunodeficiency(CVID)LuriaGreene,Dr.JuliaFelippeEquineImmunologyLaboratoryDepartmentofClinicalSciencesCommonvariableimmunodeficiency(CVID)isaheterogeneous,lateonsetdisordercharacterizedbyspontaneousfaultyBcelldevelopmentinthebonemarrowandhypogammaglobulinemia.Humanandhorsepatientshaverecurrentbacterialinfectionssuchaspneumonia,sinusitis,hepatitis,andmeningitis.ThereisnocureforCVID,andthecauseofCVIDisunknowninmostcases.Horsesaretheonlymodelorganismforthisdisease.TheobjectivesofthisresearcharetodeterminetheimpactofstromalcellsonBcelldevelopmentandtodeterminetheimpactofusing5-azacytidineexvivoasaDNAdemethylatingagenttomodulateBlymphocytedifferentiationofhematopoieticprecursorcellsfromhorseswithCVID.Intheinitialphaseoftheresearchproject,toquantifytheimpactofstromalcellsonBcelldevelopment,hematopoieticstemcells(HSC,CD34+)fromarchiveequinebonemarrowaspirates

weresortedandculturedwithandwithoutequinestromalcellsinαminimumessentialmediumwithcytokines.Inthesecondphaseoftheresearch,HSCsco-culturedwithstromalcellsandtreatedwith5-azacytidinewerecomparedtocontrolsampleswithout5-azacytidine.FlowcytometrywasusedforcellphenotypingandtocountthenumberofCD19+Bcellsproduced.Theresultsindicatedthatwithstromalcells,HSCorganizeintonichesbasedoncelllineage.Withoutstromalcells,HSCdonotorganizeandBcelldifferentiationdoesnotoccur.Additionaltrialsareneededtodetermineifusing5-azacytidineresultsinastatisticallysignificantdifferenceinBcellproduction.10:54-11:06AMTheEffectofNuclearEnvelopeRuptureonDNADamageinEmery-DreifussMuscularDystrophySushrutaIruvanti1,3,AshleyEarle2,3,GregoryFedorchak2,3,TylerKirby2,3,JanLammerding2,3

LammerdingLab1DepartmentofBiologicalandEnvironmentalEngineering2DepartmentofBiomedicalEngineering3WeillInstituteforCellandMolecularBiology

Thenuclearlaminaisafibrillarnetworkofintermediatefilaments,locatedprimarilyontheinnerfaceofnuclearenvelope(NE).Therearetwotypesoflaminproteins,A-typeandB-type,howevermutationsinA-typelaminsaretheprimarycauseofdiseasesinhumans.A-typelaminshavestructuralandfunctionalrolessuchasprovidingmechanicalsupporttothenuclearenvelope,participatinginchromatinorganization,andassistinginDNAreplicationandtranscription.MutationsinLMNAhavebeenshowntocauseseveraldifferentdiseases(laminopathies)suchasHutchinson-Gilfordprogeriasyndrome,dilatedcardiomyopathy,andEmery-DreifussMuscularDystrophy(EDMD)thatpreferentiallyeffectmechanicallyactivetissues.

Onthemacroscopiclevel,EDMDischaracterizedbymuscularatrophyandlossoffunction.EDMDwasmodeledwithanA-typeLaminknockoutLmna–/–,andalsousingpointmutationsLmnaH222P/H222PandLmnaN195K/N195K.Primarymyoblastswereharvestedfrommiceandgrownanddifferentiatedtomaturityat10days.WeobservedweakenedandrupturednuclearlaminawithevidenceofprotrusionofchromatinacrosstheNEandintothecytoplasm.WehypothesizethatweakenedlaminsbreakdownandruptureundermechanicalstresscausingthereleaseofDNA,subsequentDNAdamageandultimatelyapoptosisleadingtomuscleloss.γH2AXisoneoftheearliestcellularresponsestodouble-strandedDNAdamage,andactsasacoordinatorforthedamageresponsesignalingpathway.TotestourhypothesisthatDNAdamageiscausedbyrupture,Ievaluatedthepresenceandintensityofdamageindifferentiatedmusclefibersinvitroatmid-andlate-stagesofdifferentiationinallthreeEDMDmodels.Toconfirmthesefindingsinvivo,IisolatedsinglefibersfromhindlimbmusclesandinvestigatedtheincidenceofruptureandDNAdamage.InvitrodatashowsincreasedlevelsofDNAdamageandprotrusionatlaterdifferentiationtimepointsinallthreegenotypes.InvivodatashowsγH2AXconcentratedaroundrupturesites,providingalinkagebetweenruptureandDNAdamage.Additionalstudiestolookatotherdownstreamapoptoticsigning,suchas53BP1stainingandactivationareneededtoconfirmthatdamageisleadingtoapoptosis,howeverinitialresultsarepromisingthatrupturemaybeacontributortothediseasemechanism.9:06-9:18AM

UsingImmunohistochemistrytoExploreSemilunarValveDevelopmentinMiceforthePrimaryAntibodies:SNAIL,VECadherin,andClathrin

BrianKauffman,DucPhamJonathanT.ButcherLabNancyE.andPeterC.MeinigSchoolofBiomedicalEngineeringUsingimmunohistochemistry,weexaminedsemilunarvalvedevelopmentwithinmiceheartembryos.Thesignificanceofstudyingaorticandpulmonaryvalveformationistohelpunderstandandtreatcongenitalheartdisease,oneofthemostcommontypesofbirthdefectsinpeople.Itwasrecentlythoughtthatapoptosisorprogrammedcelldeathplayedasignificantroleininitiatingthesepre-valvularstructurestomoldfrombulboustissueintosemilunarshapesviaspecificchemicalexpressionalongthearterialside.However,ourdatasuggestsnotonlythatEMTorepithelialtomesenchymaltransitionismoresoafactorintheformationoftheaorticandpulmonaryvalve,italsosimilarlycorrelatestheolderfindingsinthatthearterialsideoftheendocardialcushionsexpressesmorechemicaltransition,ratherthantheventricularside.Inaddition,EMTisalsowidelyshownthroughoutexcavationwhereasbeforeitwasthoughttostopprior.Ourmethodsinvolvedbindingtheantibodies:Snail,VECadherin,andClathrinatthepeakofexcavation,usingafluorescentstainingtag.TheresultsshowedthatSnailwassuccessfullyexpressedonthearterialsideoftheendocardialcushionandClathrinwasexpectedlypresentbutnotoversaturated.However,VECadherin,acellbridgeprotein,wasexpressedinsidethecushionasopposedtotheendocardialbarrieronly.Thecurrentmechanismforepithelialtomesenchymaltransitionisnotfullyunderstoodinsemilunarvalvedevelopment.Therefore,ongoingresearchmustbemaintained.Uponapplicationinclinicalresearch,understandingthechemicalprocessesofsemilunarvalvedevelopmentcanhelppreventheartvalvedisease. 10:06-10:18AM InvestigatingtheInteractionBetweenProgranulinandClusterin,TwoProteinsInvolvedinNeurodegenerationAlexanderLacrampe,TuanchengFeng,FenghuaHuHuLabWeillInstituteforCell&MolecularBiology,DepartmentofMolecularBiology&Genetics,CornellUniversity,Ithaca,NewYorkMutationsintheprogranulin(PGRN)gene,whichencodesasecretedgrowthfactorandregulatoroflysosomefunction,arealeadingcauseoffrontotemporallobardegeneration(FTLD).Mutationsintheclusterin(CLU)gene,whichencodesasecretedchaperoneprotein,areassociatedwithAlzheimer’sdisease.AlthoughalargeamountofresearchhasinvestigatedtherolesofPGRNandCLUindividuallyinthesediseases,littleresearchhasinvestigatedpossibleinteractionsbetweenthesetwoproteins.RecentdatacollectedintheHulab,however,suggeststhatCLUcanbindtoPGRN.InordertounderstandtheeffectCLUhasonPGRNproteinlevelsandfunction,weusedCRISPR-Cas9geneeditingtoproduceaHelaCLUknockoutcellline.GuideRNAstargetednearthestartcodonintheCLUgeneswereclonedintoalentiviralvectorexpressingCas9,andlentiviruseswereproducedtoinfectHelacells.Stablecelllineswereselectedusingpuromycin.

WesternblottingconfirmedthesuccessofCLUablationwithoneoftheguideRNAs.Inongoingandfutureexperiments,westernblotsandimmunostainingwillbeusedtodetermineiftheCLUablationhasaneffectonPGRNlevelsandtrafficking,aswellasonlysosomemorphology.ThisresearchwillprovideinsightintofunctionalrelationshipbetweenPGRNandCLUandthemolecularmechanismsofFTLDwithPGRNmutations.4:06-4:18PMArsenicInducesDegradationofDihydrofolateReductaseAlyssaM.Laffitte1,DeniseM.Stover2,MarthaS.Field2,PatrickJ.Stover2,3MolecularBiologyandGeneticsREUStoverLab1DepartmentofBiology,UniversityofMiami,Miami,FL331242DivisionofNutritionalSciences,CornellUniversity,Ithaca,NY148533GraduateFieldofBiochemistry,MolecularandCellBiology,CornellUniversity,Ithaca,NY

Folicacidsupplementationpreventsneuraltubedefects(NTDs),aspecifictypeofbirthdefectthatresultsfromfailureofneuraltubeclosureduringdevelopment.EnvironmentalarsenicexposurecausesNTDs,butrecentstudiesinmiceindicatethatarsenic-inducedNTDsarenotfolicacid-responsive.Folicacidisasynthetic,oxidizedformoffolatethatmustbeconvertedtoabiologicallyactiveformoffolatewithinthecell.Thisconversionrequirestheenzymedihydrofolatereductase(DHFR),whichpreliminarydatasuggestsmayalsobesensitivetoarsenic-induceddegradation.

Thisprojectfocusesontheeffectofarsenicexposureinmouseembryonicfibroblast(MEF)celllinesculturedinmediumcontainingeitherfolicacidorreducedfolate.WehypothesizethatifarsenicdegradesDHFR,thecellsculturedinfolicacid-containingmediumwillbesensitizedtoarsenicexposure,whereasMEFsculturedinreducedfolatewillbeprotected.Totestthishypothesis,MEFsculturedineachconditionwillbetreatedwitharsenic-containingmedium.Then,DHFRlevelswillbequantifiedusingWesternBlot.Furthermore,wewilldeterminewhetherthereisadose-responserelationshipbetweenarsenic(0,1uM,5uM,and10uM)exposureandcellviability,andwhetherviabilityisaffectedbythetypeoffolate(folicacidversusreducedfolate)inwhichMEFcellsareculturedusinganMTTassaytomeasurecellviability.3:42-3:54PMInvestigatingtheinvitrosynergisticcytotoxiceffectsofrituximabincombinationwithchemotherapyonhumannon-HodgkinB-celllymphomaBrianLee,TimPierpont,KristyRichardsRichardsLabDepartmentofBiomedicalSciences

Non-Hodgkinlymphoma(NHL)isaheterogenousgroupofdisordersthatranksseventhincancerincidenceandmortality.Rituximab,aCD20monoclonalantibody,bindstoB-cellsandhasimprovedsurvivalinmanyNHLsubtypes.Ithasbeenshowntopotentiatetheapoptoticresponseformanychemotherapeutics.TheadditionofrituximabtotheCHOPchemotherapyregimen(cyclophosphamide,doxorubicin,vincristine,prednisolone)resultsinahighercompleteresponserateinpatientscomparedtothatfromCHOPalone.Despitethismarkedimprovementintreatmentoutcomes,littleisknownaboutthesynergybetweenRituximabandCHOP.Furthermore,themechanismofrituximab-mediatedcelldeathinvivohasnotbeenfullyelucidated.Therefore,identifyingcooperationofanyofthesefourdrugswithrituximabwouldshedlightonthemechanismofactionofthiscombination

immunochemotherapy.Rituximabcaninducecelldeaththroughthreemainmechanisms:(1)directapoptosis,(2)antibodydependentcellularcytotoxicity(ADCC),and(3)celldependentcytotoxicity(CDC).Inthisproject,dose-responsecurveswereestablishedwiththeindividualconstituentsofCHOPwithorwithoutrituximab-inducedapoptosistoinvestigatethecooperationbetweenrituximabandCHOP.Ourfindingsindicatethatrituximab-inducedapoptosisdoesnotpotentiateCHOPcytotoxicity(cyclophosphamidehasnotbeentestedyet).Therefore,rituximabmaysynergizewithCHOPthroughdifferentconcentrationratios,throughcyclophosphamideonly,throughtheADCCorCDCpathway,orthroughacombinationoftheagentsinCHOP.9:42-9:54AM

Investigatingtheidentityofanipsilaterally-projectingexcitatoryinterneuronconnectionintheneonatemousespinalcordDerekNieHarris-WarrickLabDepartmentofNeurobiologyandBehaviorCentralpatterngenerators(CPGs)arerelativelysimpleneuralnetworksthatcoordinatethemusclecontractionsbehindrepetitivebehaviors,suchaswalking.Addingneurotransmitters,suchasNMDA,serotoninanddopamine,toanisolatedneonatemousespinalcordcaninduce“fictivelocomotion,”therhythmicburstingofCPGs,invitro.Intheintactspinalcord,thisischaracterizedbyalternatingburstingofflexorandextensorventralmotorrootsononesideofthecord.Byperformingextracellularrecordingsofactionpotentialsofthesemotorroots,itispossibletoidentifyandrecordfictivelocomotion.Previousresearchhasshownthattheadditionofstrychnineandpicrotoxin,antagonistsoftheinhibitoryneurotransmittersGABAandglycine,inducessynchronousinsteadofalternatingburstingpatternsinipsilateralflexorandextensorventralmotorroots.Bytestingfictivelocomotionusinglongitudinally-bisectedspinalcords,orhemicords,theeffectofipsilaterally-projectinginterneuronscanbeisolatedbecauseinputfromcontralateralcommissuralinhibitoryinterneurons,whichprojectfromtheothersideofthespinalcord,aredisrupted.Ihavefoundthatstrychnineandpicrotoxin,appliedtoahemicordlocomotingpreparation,canevokesynchronousrhythmicburstingbetweentheflexorandextensorventralroots.Ihavealsonoticedchangingphaseshiftsbetweenflexorandextensorrootbursts,whichdriftmodestlyfrompuresynchrony.Thisprovesthatcontralateralcommissuralinputisnotnecessarytogeneratethissynchronousactivity,andimplicatestheexistenceofacurrentlyunknownexcitatoryconnectionbetweenflexorsandextensors.Inowseektoidentifytheipsilaterally-projectinginterneuronsthatgeneratethissynchronousactivity.TheV2aneuronsarethemajorclassofipsilaterallyprojectingexcitatoryinterneurons,andareidentifiedbyembryonicexpressionofthetranscriptionfactor,Chx10.Forfutureexperiments,IwilluseChx10::DTAmice,inwhichtheV2ainterneuronsarekilledduringtheembryonicstage.Previousstudieshaveshownthatthesemicearestillviableforsuchanapproach.Fortheseexperiments,Iwillrepeatthehemicordpreparationwithstrychnineandpicrotoxin;iftheflexorandextensorrootsarenotsynchronouslyactive,oriftheirburstingpatternsdriftmarkedly,thisresultwouldsupportmyhypothesisthatV2ainterneuronsmediatetheexcitatoryconnectionbetweenipsilateralflexorandextensornetworks.12:06-12:18PM

StructuralandfunctionalcharacterizationofbacterialmethyltransferasesYimingNiuChappieLabDepartmentofMolecularMedicineDNAmethyltransferases(MTases)catalyzetheadditionofmethylgroupstoDNAbases.DNAmethylationiscriticalformodulatinggeneexpressionandmediatingtheepigeneticlandscapeofprokaryotesandeukaryotes.Inprokaryotes,DNAmethylationisalsoimportantindistinguishinghostDNAfromforeignDNA,whichensuresproperandefficientactivityofrestrictionendonucleasesandotherbacterialdefensesystems.AlthoughMTasesshareaconservedstructuralcore,differentenzymeshaveevolveddistinctspecificitiesthattargeteitheradeninesattheN6positionorcytosinesattheN4orC5position.UnderstandinghowaMTaserecognizesitssubstrateandexertsiscatalyticfunctioniscriticalforunderstandinghowitfunctionsinagivenbiologicalcontext.SeveralpoorlycharacterizedbacterialMTasesareassociatedwiththeatypicalrestrictionsystemsLlaJIandLlaI.LlaJIcontainstwocytosineMTases(LlaJI.M1andLlaJI.M2)thatregulatetheexpressionofthecleavagemachinery(LlaJI.R1andLlaJI.R2).TheR1andR2proteinsaredistanthomologsofMcrBandMcrCrespectively,whichtogetherformaprototypicalmodification-dependentrestrictionsystem.TheLlaIoperon,incontrast,consistsofacontrolprotein(LlaI.C),aMTase(LlaI.M),andthreeproteins(LlaI.1,LlaI.2,andLlaI.3)presumedtoformarestrictioncomplex.Togaininsightintothemolecularmechanismsofthesesystems,IhaveendeavoredtoexpressinE.coliandpurifytheLlaJI.R1,LlaJI.R2,andLlaI.MproteinsfromLactococcuslactisforstructuralandbiochemicalstudies.PreliminaryeffortsshowlowexpressionyieldsforeachMTaseandunfavorableinteractionswithnumerouspurificationtags.LlaI.M,however,demonstratedpromisingpurificationresults:theproteincouldbeisolatedandremainedsolubletoafinalconcentrationwas2.0mg/mL.Futureeffortswillbeaimedatscalingupthisproceduretoobtainenoughmaterialforcrystallizationtrialsaswellasoptimizingexpressionoftheotherproteins.Oncepurified,Iwillalsodevelopanassaytotesttheactivityandspecificityofeachenzymeinvitro.1:36-1:48PMInvestigatingtheinteractionbetweenadiposestromalcellsandmammaryepithelialcellsina3DspheroidsystemYunxinOuyang,LuLing,ClaudiaFischbachFischbachLabNancyE.andPeterC.MeinigSchoolofBiomedicalEngineering,CornellUniversity,Ithaca,NY

Themicroenvironmentofbreastcancer,aheterogeneousgroupofmalignanciesderivedfromtheductalepithelium,comprisesofextracellularmatrixandnumerousstromalcelltypes,includingfibroblasts,adipocytes,immunecells,etc.andisnowconsideredasanimportantprognosticfactorintumorprogression.Previousstudiesinourlabshowedthatobesitycanpromoteadiposestromalcells(ASCs)todepositstifferextracellularmatrixandcontributetoincreasedlevelsoffibroticremodeling,therebymimictumorassociatedstromaandpromotingcarcinogenesis(Seoetal.,2015).However,howthedifferenttypesofASCsinteractwithbreastepithelialcellswithvariousdegreesofmalignancyremainsunclearandhasyettobeelucidated.Therefore,thegoalofthisstudyistocharacterizethegrowthsandinteractionsbetweenmammaryepithelialcellsandASCcells,andtoinvestigatehowASCcellsmaypromotetumormigration.

Weutilizeda3Dinvitroplatforminwhichcellsformamulticellularspheroidtomimictumormicroenvironment.ASCsfromlean(wildtype,WT)andobese(ob/ob)micewereculturedindividuallyorco-culturedwithMCF10A(normalepithelialcells)andMCF10AT1cells(pre-malignantepithelialcells)toformspheroids.TheproliferationandgrowthrateofspheroidsfromeachconditionweretrackedbyDNAquantificationandbright-fieldimaginganalysis.Inaddition,spheroidswerefixed,cryosectionedandimmunofluorescenceimagedonday1,3,and5.MCF10AandMCF10AT1mono-culturesbecomemoredenselypackedovertime,whileinterestingly,boththeirco-cultureswithASCcellsdevelopirregularshapeswithprotrudedstructures.Inaddition,duringtheirnaturalintegration,theepithelialcellstendtoformalayerandenveloptheASCcellsinthecoreregionofthespheroids.Toevaluatetheirmigratorybehaviors,spheroidsfromeachconditionwereimbeddedintocollagengelandtheirspreadingweretackedbybrightfieldimagesaswellasimmunofluorescenceimaging.Resultsindicatedthatspheroidscontainingonlyepithelialcellswerenotabletomigrateatall,buttheyrequireASCcellstoexhibitsproutingbehaviors.Furthermore,theimbeddedco-culturespheroidsformhollow-cagestructureswithathickringofsproutingcellsandasmall,densecore.

Inconclusion,ASCcellsmightpromotetheproliferative,andinvasivecapacitiesofmammaryepithelialcellsandprovideguidancecuesfortheirmigration.OngoingstudiesevaluatethefunctionalconnectionsandcellularregulationsofASCsandmammaryepithelialcellsintheirrolesduringtumordevelopmentandprogression.10:42-10:54AM

NeuralcircuitsunderlyingperformanceevaluationinmiceArchanaPodury,VikramGadagkarandJesseGoldbergGoldbergLabDepartmentofNeurobiologyandBehavior

Virtuallyallhumanbehaviorsarelearnedthroughatrial-and-errorprocessofexplorationfollowedbypruningofvariability.Forinstance,withenoughrepetition,atennisplayerlearnstodirectaninconsistentforehandintoareliableregionofthecourt.Whileweknowthatpracticeleadstostereotypedmovementpatterns,theneuralcircuitrythatdrivesthislearningremainsunclear.Behavioralmodelsshowthatexternalrewards,suchasfoodandjuice,candriveanimalstolearncomplexmotorsequences.Innature,however,mostmotorlearningoccursintheabsenceofanyexternalreward;areward-independentinternalevaluationcircuitmustthereforedrivemotorlearning.Werecentlyshowedthatsongbirdsinternallyevaluatetheirsongperformanceduringpractice,andtheirongoingevaluationdrivesthemtowardsasuccessful,stereotypedsequenceofnotes.Thismechanismofperformanceevaluationisanalogoustothepresenceorabsenceofanexternalreward:hittingthecorrectnoteevokesthesamedopaminergic(DA)responseasamonkeythatreceivesjuice,whilemissingthenotedrivesthesameDApausethatisobservedwhenthejuiceiswithheldfromthemonkey.Thus,theinternalevaluatorcircuitmodulateslearningjustasanexternalrewardwould.Tobettercharacterizetheroleofperformanceevaluationinmotorlearning,weaimtouncoverthemammaliananalogtothisevaluationcircuit.

First,wearedevelopingabehavioralparadigmtostudyperformanceevaluationindependentofexternalreward.Wewillallowamousetospontaneouslyrunonamotorizedrunningwheelwhileoccasionallyinducingcuedchangesintheresistanceofthewheel.Thechangeinresistancerequiresthemousetoutilizeadifferentmotortemplatetoavoidtripping.Onafractionofcuedtrials,resistancechangeswillnotoccur,causingthemousetotripandengageperformanceevaluationcircuits.During

thetask,wewillrecordfromDAneuronsintheventraltegmentalarea(VTA),amidbrainnucleusimplicatedinreward,usingacalcium-dependentimagingtechniqueknownasfiberphotometry.Cre-dependentexpressionintransgenicmiceallowsforcell-typespecificaccesstoDAneurons;viraltracingwithcalcium-dependentfluorophoresandimplantedopticalfibersallowforin-vivovisualizationofneuronalactivity.WepredictthatproperlycuedtrialswillelicitincreasedactivityofDAneuronsinVTA,whileimproperlycuedtrialswillleadtoaDApause,analogoustotheevaluationmechanisminsongbirds.Elucidatingperformanceevaluationcircuitsinmammalswouldprovideinsightintohowhumanslearncomplexmotorsequences.11:54-12:06PMOxyPonicsRahulRambhatla,AshwinViswanathan,YannieMei,RaymondZhangCornelliGEMBiomedicalEngineering

Hydroponicsisoneofthefastestgrowingareasofagriculture,expectedtobea$400millionmarketby2020.However,hydroponicfarmersstillfacelowcropyieldsduetodiseaseandnutrientimbalances.Onepromisingsolutionfordeep-waterhydroponicsystemsliesinregulatingreactiveoxygenspecies(ROS),whichplaysignificantrolesinprocessesrangingfromtumorangiogenesistoplantgrowthtosignaling.Oxidativestressincontrolledamountsiswell-documentedtoaidcropgrowth,boostplantimmunity,andimprovenutrientuptake.Currently,duetodifficultyinsensingandcontrollingstresslevels,fewsystemsexistthatoptimizeandprovidereal-timemonitoringofoxidativestress.CornelliGEMhopestodevelopanovelself-regulatingbiopathwayinEscherichiacolitooffergreaterversatilityandsensitivityformonitoringoxidativestressinhydroponicsystems.Thepathwaycontainstwoparts:aratiometricbiosensormadebyfusingaredox-sensitivefluorescentprotein(rxRFP)andyeastperoxidase(Tsa2),andalight-sensitivedownstreampathwayknownasthepDawn/pDusksystemthatcontrolstheexpressionofproductstoadjustenvironmentalROSlevelssurroundingthehydroponicplants.TestingwillincludeaccuracyofoxidativestresscontrolandplantbiomassevaluationsinpresenceofthegeneticallymodifiedE.coli.Tocreateacomprehensivesystemanddeliverthebacteriatotheplants,anoptogenetichardwaresystemwasdesignedincollaborationwithRev,ahardwarestartupincubator,usinginputfromhydroponicfarmers.ThesystemhasacamerawhichdetectfluorescenceintensityfromthebacteriainthepresenceofROS.PastaspecifiedROSthreshold,thecameratriggersLEDstoactivatepDawn/pDusklightsensitiveproductionofantioxidantmolecules.Thisfeedbacksystemoptimizesoxidativestresslevelsineachindividualplant’slocalenvironment.Enduserscanoptimizetheirhydroponicsystemsbymanipulatingthethresholdleveloffluorescencewhichtriggerstobiochemicalpathway.Respectivecropyieldcanhencebegreatlyimproved.Inanothercontext,theratiometricoxidativestresspathway,andpDawn/pDuskresponsepeptide,canbeusedinotherapplicationswhereself-containedoxidativestressmonitoringsystemmaybeneeded.1:24-1:36PM

Functionalstudiesofafamilyofnovellate-GolgiproteinsSaeedRoschdi,LauraThomas,ChrisFrommeMolecularBiologyandGeneticsREUFrommeLabDepartmentofMolecularBiologyandGeneticsTheunderstandingoftraffickingwithintheGolgiisessentialtounderstandinghoweukaryoticcellsfunction.ThroughtheuseofmodelsystemssuchasSaccharomycescerevisiae(buddingyeast)wecan

gaininsightintothetraffickingmechanismsofeukaryoticcellswhichisneededforthecellstoproperlyfunction.TheTVPfamilyofproteins,madeupofTVP-15,18,23,and38,wasidentifiedinascreenofproteinsassociatedwithlateGolgi/endosomalcompartmentsinyeast.Thegoalforthissummerwastodeterminethefunction(s)oftheseproteinsbycreatingaquadrupleknockoutofallTVPproteinsinyeast.ThereasonforcreatingthequadrupleknockoutistoseeifthenonessentialTVPproteinsshareanyredundantfunctions.ThefirststepofthisprocesswastocreatethequadrupleknockoutbyreplacingtheTVP’scodingsequenceswithselectablemarkers.Thequadrupleknockoutwasviable,sowetestedwhetherlossofTVPproteinscausedagrowthdefectandsawalessenedgrowthspeedat37degreesCelsiusandabove.IalsousedfluorescencemicroscopywithestablishedGolgimarkerstotestwhetherGolgimorphologyisalteredintheTVPmutant.ThroughtheseexperimentsIsawcolocalizationbetweenSec-7andTvp-23andanincreasedconcentrationofSnc1inthecells.TheseresultsgiveusimportantinsightintopossiblefunctionsoftheTvpproteinsandverifiestheirfunctioningatthelate-Golgi.3:30-3:42PMTheEffectofInsulin-likePathwayonCaenorhabditisModelsofHuntingtonDiseaseOanhTran1,2,Cheng-linLi1,SylviaLee2

1DepartmentofMolecularBiologyandGenetics,CornellUniversity,IthacaNY;2DeptartmentofUndergraduateNaturalScience,UniversityofTexasatAustin,AustinTX

Huntingtondisease(HD)isaneurodegenerativediseasecausedbyglutamineexpansion(polyQ)inthehttgenethatresultsinproteinaggregationsinthenervecells.TounderstandthetoxiceffectsofpolyQaggregation,CaenorhabditiseleganstransgenicmodelsexpressingpolyQ(Q0::yfp,Q40::yfp,andQ67::yfp)andexhibitingprogressivemotilitydefectshavebeenestablished.SinceHDisanage-dependentdisease,manipulationsthatinfluenceagingmayaffectthemotilitydeclineassociatedwithpolyQaggregation.InC.elegans,theinsulin-likepathwayiswellknowntomodulatelongevity,metabolism,anddevelopment.Thus,analysisofthethrashingrate(BBPS)woulddeterminewhetherdownregulatingtheinsulin-likepathway,whichisknowntoprolonglifespan,candelaythemotilitydefectsofpolyQworms.UsingRNAitoknockdownmajorcomponentsoftheinsulin-likepathway(daf-2,age-1,anddaf-16),polyQwormsaretrackedtomonitorthebendingrateofthetreatedworms.BecauseoftheoverlapinmotilityrateinWT,Q0,Q40,andQ67wormsatdifferenttimepoints,theresultdictatesthattheinsulin-likepathwayhasnosignificanteffectonpolyQHDworms.Daf-2deficientQ67wormsshowrelativelyimprovedmotilityrateonday1-2incomparisontootherQ67RNAideficiencyworms.However,thedatadisplaysnosignificantdifferencewhichconcludesthatlongevitydoesnotsignificantlyaffectpolyQHDworms.Thus,thisprojecthelpstobetterunderstandhowlongevitymodulatingimpactpolyQ-mediatedneurodegeneration. 2:30-2:42 PM

Geneticanalysisofnewmutationsaffectingthebonemorphogeneticprotein(BMP)signalingpathwayinC.elegansGabrielleVillafana

LiuLab

DepartmentofMolecularBiologyandGenetics

Thebonemorphogeneticprotein(BMP)signallingpathwayisresponsibleforregulatingmanydifferentdevelopmentalprocesses.Defectsinthispathwaycancausevarioushumandiseases.Thus,thereare

manylevelsofmodulationtoensurethatthispathwayisactivatedintherightwayattherightlevelspatiotemporally.InC.elegansthereisaBMP-likepathwaythatregulatesbodysize,maletailpatterningandmesodermdevelopment.TheLiuLabconductedalargescalegeneticscreeninordertoidentifynewgenesfunctioningintheBMPpathway.Wholegenomesequencingof42mutationsisolatedfromthescreenshowedthatthereare8mutantstrainsthatdidnothavemutationsinthecodingregionsofknownBMPpathwaygenesonchromosomeIII.Ihavebeenconductingpairwisebi-directionalcomplementationtestsforthese8mutationsinordertodeterminethenumberofcomplementationgroupsthattheybelongtoandwhethereachgroupaffectsoneofthefiveknownBMPgenesonchromosomeIII.FromthiswehopetoidentifynewgenesfunctioningintheBMPpathway.2:06-2:18PMSEMINAL:Evolutionary,BiochemicalandGeneticApproachestoExpandingtheSexPeptideNetworkChrisWilson1.2,Dr.AkankshaSingh2,andDr.MarianaWolfner2MolecularBiologyandGeneticsREUWolfnerLabMolecularBiology&GeneticsResearchExperienceforUndergraduates1ReedCollege2DepartmentofMolecularBiology,CornellUniversityTheseminalfluidproteins(Sfp)madebymalefliesareresponsibleforinducingseveralpostmatingresponsesinfemales.OneoftheseSfps,sexpeptide(SP),hasbeenshowntoplayamajorroleinseveralpostmatingresponses,namely–stimulatingegglayinganddecreasingreceptivity(meaningmakingthefemalelesslikelytomateagain).However,ithasbeenshownthatthelong-termfunctionalityofsexpeptideisdependentontheproteinbindingtospermandthatthiseventrequiresacomplexnetworkofSfps,femalereproductivetractproteinsandspermproteins.MygoalforthissummerhasbeentoexpandthecurrentlydefinedSPnetwork.PreviousmembersoftheWolfnerlabhaveperformedevolutionaryrarecovariation(ERC)andmassspectrometrystudies,andhavefound21proteinstobepossibleinvolvedintheSPnetwork.Byknocking-downtheexpressionofeachproteinofinterestusingRNAidrivenbyGAL4/UAS,andmatingmalescarryingthisKDwillwild-typefemales,Ihavebeenabletosubsequentlymonitorwhetherthelong-termpost-matingresponsescorrelatedwithSP-spermbinding(receptivityandegglaying)areconserved,checkforthelong-termretentionofSPinthefemalereproductivetractusingwesternblots,andidentifytheeffectsonproduction,transferandprocessingtheseKDhavebeenonpreviouslyidentifiedmembersoftheSPnetwork(alsousingwesternblots).Boththereceptivityandegglayingassayhavebeendoneoveraperiodof4-5daysinabletoensurethelong-termeffectsofSParebeingtargeted.Ihavefoundthat4ofthe15proteinsIscreenedthroughthissummershowedstatisticallysignificantincreasesinreceptivityincomparisontocontrols(determinedviafisher’sexacttest),indicatingthattheseproteinsmaybeinvolvedintheSPnetwork.TheSPretentionstudiesarestillunderwayandwillhopefullyservetoreinforcetheseresults.Additionally,IhaveperformedwesternblotsonfemalereproductivetractsmatedwithKDmales1hourafterthestartofmatingandprobedtheseblotsformembersoftheSPnetworkthathavebeenpreviouslyidentifiedbymembersoftheWolfnerlab.Sofar,thisworkhasshownthatoneoftheERCcandidates,Spn43Ab,islikelyresponsibleforthetransferorstabilityofseveralmembersoftheSPnetworkinthefemales.2:54-3:06PM

ANovelInvivoApproachtoExamineDNADamageResponsePathwaysinMouseSpermatocytesJennyYang,JordanaBloom,JohnC.SchimentiSchimentiLabDepartmentofBiomedicalSciencesUndergraduateResearcherDNAdouble-strandedbreaks(DSBs)areacrucialcomponentofmeiosisandtheircorrectrepairensurespropersynapsis,crossover,andchromosomesegregationevents.RepairofDSBsisfacilitatedbyp53-bindingprotein1(53BP1),whichlocalizestoDNADSBsgeneratedeitherendogenouslyorexogenously.Typically,theDNAdamageresponse(DDR)inmeiosisisstudiedusingantibody-basedimmunofluorescencestaining.Thisantibody-basedapproachislimitedtofixedsamplesandmaynotalwaysbeabletocapturecellularmechanismsinvivo.TobettercaptureDNAdamagerepairdynamicsduringmalemeiosisourlabhasgeneratedatransgenicmousemodelthatexpressesthechromatin-bindingdomainof53BP1fusedtoamCherryfluorophore.Iamcurrentlyintheprocessofselectingatransgenicreporterlinethatbestexpressesthereporterconstruct.Preliminaryresultsfrommeioticspreadsofdifferentmouselinesrevealthatsomereportersexpressmorestronglythanothersandthatundernormalconditionsthereporterlocalizestothesexbodyofpachytene-stagespermatocytes.However,ifsubjectedtoexogenousDNAdamageinducedwithirradiation,withinonehouraftertheDNAdamage,distinguishable53BP1fociareobservedthroughoutthenucleiofthespermatocytes.Ihaveconfirmedthattheseobserved53BP1focifromourreporterdoindeedlocalizetositesofDNADSBslesionsbyco-stainingthesecellswithmarkersforDNAdamage,includingγH2AXandRAD51.Inthefuture,weplantousethistransgenicreportertoexamineDNAdamageinnumerousmeioticmutantanimals.Throughthesestudies,wehopetogainabetterunderstandingofhowDNAdamagerepairpathwaysoperateduringmalemeiosisinvivo.10:18-10:30AMTowardModelingandAnalysisofCoagulationandFibrinolysisDynamicsusingReducedOrderEffectiveKineticModelsRoanneYehia,NicholasHorvath,JeffreyD.VarnerVarnerLabRobertFrederickSmithSchoolofChemical&BiomolecularEngineering

TraumaaccountsforoneoftheleadingcausesofdeathintheUnitedStatesandisespeciallyfatalforpeople36andyounger.Itaccountsfor30%oftheyearsoflifelostintheUSandcausesaneconomicburdenof$671billionperyear.Counteractingtraumapresentsachallengewhenitcomestocontrollingahemorrhage,especiallywhentherearecoagulationdisordersinthepatient.Inresponsetothis,theVarnerLabhasdevelopedpharmacokineticmodelswhichcansimulatethebodybasedonphysicalandbiochemicalprinciplesthatdescribetheinjury.Sincethiscanbeverycomplex,theyhavealsodevelopedreduced-orderkineticmodelingtoolswhicharebotheffectiveandsimple.Priortomodelingthehumanbody,itisessentialtobeginwiththeveryessenceofallbeings—thecell.Understandingthebiochemistryatthislevelwillenablesuccessfulmodelingoflargescalesystems,suchasthehumanbody.Inthisstudy,wemodeledasimplebatchcultureexperimenttopredictasyntheticdatasetforsubstrateuptakeandbiomassproduction.Wewrotemolebalancesaroundthesubstrateandbiomass,modeledasasystemofordinarydifferentialequations.UsingtheprogramminglanguageJulia,andEuler’smethodforsolvingdifferentialequations,weimplementedanalgorithmtominimizetheerrorbetweenoursimulationsandthesyntheticdatasetandsolvefortheoptimalparametervalues.Wethenperformedlocalsensitivityanalysisonthefivemodelparameterstodeterminewhichparameter

inducedthelargesteffectonthebiomassproductionandsubstrateintake.Whiletherewasnotoneparameterwhichhadthehighestimpactduringeverytimeintervaltested,themaximumgrowthcoefficienthadthelargestsensitivityimpactoverall.Themaintenanceconstanthadbyfarthesmallesteffectonsensitivity.Thesystemthatwechosetostudyisknownasthe“blackbox”modelofthecell.Theonlyprocessesbeingconsideredaretheonesrelatedtouptakeandgrowth;itdoesnotmodeltheinternalcellularstoichiometry.Tomorethoroughlymodelintracellularprocesses,wewillusefluxbalanceanalysis,amethodthatuseslinearprogrammingtosolveforthefluxesofreactionsoccurringinthecell.Thiswillmakeitpossibleforustostartapplyingpharmacokineticmodelstowholebodysystemstobetterunderstandhemorrhage.9:18-9:30AM

UnderstandingthefunctionandregulationofthenuclearreceptorRXRGinneuralcrestcellsRachelYerden,MarcosSimoes-CostaMolecularBiologyandGeneticsREUSimoes-CostaLabDepartmentofMolecularBiologyandGenetics

Theneuralcrestisatransientstructurelocatedbetweentheepidermisandtheneuralplateofavertebrateembryo,andtheneuralcrestcontainspopulationsofmultipotentcells.Theseprogenitorscangiverisetooverthirtydifferenttypesofcellsthatformfacialstructures,pigmentation,partsofthegut,partsoftheheart,andcartilage.Becausethesecellsaremultipotent,theyhavebeenconsideredforpossibleusesinstemcelltherapies.Inaddition,iftheneuralcrestformsincorrectlyitcanleadtovariouscancersandcongenitalbirthdefects.Therefore,neuralcrestcellsarecrucialtohumanhealth.Manygenesandtranscriptionfactorscontributetotheformationoftheneuralcrest.RXRGisanuclearreceptorexpressedspecificallyintheneuralcrestcells.IthasbeenshownthatRXRGisanessentialpartintheretinoicacidsignalingpathway,whichhasavitalfunctionincraniofacialdevelopment.However,thefunctionofRXRGinneuralcrestdevelopmentisnotknown.IwillemployavarietyoftechniquestobetterunderstandthefunctionoftheRXRGgeneinneuralcrestdevelopment.Iwillusein-situhybridizationtoidentifyneuralcrestcellsinwhichRXRGispresentandtounderstandthetimingofRXRGexpression.TounderstandtheregulationofRXRG,IwillanalyzethechickengenometoidentifyenhancersthatmayregulateexpressionofthisgenebylookingatopenregionsofchromatinthatarepresentpriortotheRXRGsequence.Moreover,byinhibitingthefunctionoftheRXRGgenewithmorpholinos,whichwillblocktranslationofproteins,wewillseetheresultingeffectsofRXRGknockdownonneuralcrestdevelopment.ResultsfromtheseexperimentsshowthatRXRGiscrucialinneuralcrestdevelopment,isregulatedbythechromosomeregions8.957and8.958,andbeginstobeexpressedaround30hourspost-fertilization.Thisdataisimportantinbetterunderstandtheneuralcrestanditsdevelopment.4:18-4:30PM

DefiningthemechanismofmelanomainitiationfrommelanocytestemcellsJerryZhu,HyeongsunMoon,LeanneR.Donahue,andAndrewWhiteWhiteLabDepartmentofBiomedicalSciences

Melanomaisconsideredthedeadliestofskincancersandisresponsibleforthemajorityofskincancerrelateddeathsdespiterepresentingfewerthanfivepercentofskincancercases.Inthepast30years,theannualmortalityrateofmelanomahasincreasedandmelanomaisresponsibleforclaimingapproximately9,000livesintheUSannually.Althoughrecentresearchhasfocusedondeveloping

moleculartargetsagainstestablishedtumors,theaggressivenatureandlowsurvivalrateoflatestagemelanomamakepreventingtumorigenesisacompellinggoal.Therefore,todevelopeffectivepreventativestrategiesinmelanomas,identifyingthecancercelloforiginandelucidatingtumorinitiationfromitscellularoriginsarecritical.

Inourrecentstudy,wefoundmelanocytestemcellsascancercellsoforiginanddelineatetheenvironmentalcausesandcellularconditionsresponsibleinearlystepsofmelanomainitiation.Toachieveouraims,weusedgeneticallyengineeredmousemodelsofmelanomasincombinationwithalineagetracingmethodtoidentifythecellulardynamicsandmolecularmechanismsinherittomelanomainitiation.Ofnote,melanomasarisefromtumor-competentmelanocytestemcellsuponstimulationbyUVBirradiationinducingmelanocytestemcellactivationandtranslocationviaaninflammationdependentprocess.Conversely,wefurtherfoundthatmelanocytestemcelloriginatingmelanomainitiationcanbereducedbysuppressionofacutecutaneousinflammation.Thesefindingsprovideanewframeworkformelanomainitiationandsuggestpotentialmoleculartargetsforpreventativetherapeuticapplicationsformelanoma.11:18-11:30AM