Sensory projections from normal and homoeotically transformed antennae in Drosophila☆

[摘要] Thesensoryprojectionofhomoeotictarsalneuronsintheantennalmutantspineless-aristapedia(ssa)iscomparedwiththeprojectionsofwild-typeantennaeandtarsi.TheprojectionpatternwasidentifiedbydiffusionofcobaltintothecutperipheralnervesfollowedbyTimm'ssilverintensification.Nosensoryfibersofthehomoeotictarsusextendintothethoraciclegcenters;insteadtheyprojectintonormalantennalcentersofthebrain.Intheposteriorantennalcenterandtheposteriorpartofthesuboesophagealganglion(SOG)theyshowpreciselythesamepatternasdothosefromthewild-typeantenna.Inotherregionsthisisnotthecase:intheantennalglomerulihomoeoticterminalsarerandomlydistributed,andintheanteriorSOGfibersformatractwhichisnotpresentinantennalcobaltfills.Wehavenotfoundanycorrespondencebetweenthoracicandhomoeotictarsalprojections.Theprojectionofhomoeotictarsiinmosaicfliesexhibitinganssaantennaandawild-typebrainissimilartothe“normal”homoeoticpattern.Thissuggeststhatthecentralnervoussystem(cns)isnottransformedbythessagene.Thebehaviorofnormalandectopicsensoryfibersinthecnsisexplainedintermsofbothintrinsicpropertiesofthesensoryaxonsandextrinsicfactorsinthesurroundingnervoustissue.

[学科分类] 生物科学（综合）