Signaling through the G-protein-coupled receptor Rickets is important for polarity, detachment, and migration of the border cells in Drosophila

摘要

Cellmigrationplayscrucialrolesduringdevelopment.AnexcellentmodeltostudycoordinatedcellmovementsisprovidedbythemigrationofbordercellclusterswithinadevelopingemDrosophila/emeggchamber.Inamutagenesisscreen,weisolatedtwoallelesofthegeneemrickets/em(emrk/em)encodingaG-protein-coupledreceptor.Theemrk/emallelesresultinbordercellmigrationdefectsinasignificantfractionofeggchambers.Inemrk/emmutants,bordercellsareproperlyspecifiedandexpressthemarkerSlbo.Yet,analysisofbothfixedaswellaslivesamplesrevealedthatsomesinglebordercellslagbehindthemainbordercellclusterduringmigration,or,inothercases,theentirebordercellclustercanremaintetheredtotheanteriorepitheliumasitmigrates.Thesedefectsareobservedsignificantlymoreofteninmosaicbordercellclusters,thaninfullmutantclusters.ReductionoftheRkligand,Bursicon,inthebordercellclusteralsoresultedinmigrationdefects,stronglysuggestingthatRksignalingisutilizedforcommunicationwithinthebordercellclusteritself.ThemutantbordercellclustersshowdefectsinlocalizationoftheadhesionproteinE-cadherin,andapicalpolarityproteinsduringmigration.E-cadherinmislocalizationoccursinmosaicclusters,butnotinfullmutantclusters,correlatingwellwiththeemrk/embordercellmigrationphenotype.Ourworkhasidentifiedareceptorwithapreviouslyunknownroleinbordercellmigrationthatappearstoregulatedetachmentandpolarityofthebordercellclustercoordinatingprocesseswithinthecellsoftheclusterthemselves./p/div