Apical movement during interkinetic nuclear migration is a two-step process

摘要

Neuralprogenitorcellsinthepseudostratifiedneuroepitheliuminvertebratesundergointerkineticnuclearmigration,whichresultsinmitoticcellslocalizedtotheapicalsurface.Interphasenucleiaredistributedthroughouttherestoftheepithelium.Howmitosisiscoordinatedwithnuclearmovementisunknown,andthemechanismbywhichthenucleusmigratesapicallyiscontroversial.Usingtime-lapseconfocalmicroscopy,weshowthatnucleimigrateapicallyinG2phaseviamicrotubules.However,lateinG2,centrosomesleavetheapicalsurfaceafterciliaaredisassembled,andmitosisinitiatesawayfromtheapicalsurface.Themitoticcellthenroundsuptotheapicalsurface,whichisanactin-dependentprocess.Thisbehaviorisobservedinbothchickenneural-tube-slicepreparationsandinmousecorticalslices,andthereforeislikelytobeageneralfeatureofinterkineticnuclearmigration.Weproposeanewmodelforinterkineticnuclearmigrationinwhichactinandmicrotubulesareusedtopositionthemitoticcellattheapicalsurface./p/div