A Gap Junctionally Transmitted Epithelial Cell Signal Regulates Endocytic Yolk Uptake in Oncopeltus fasciatus

Developmental Biology

Karen L. Anderson¹  Richard I. Woodruff¹ 

[1] Department of Biology, West Chester University, West Chester, Pennsylvania, 19383-2130

关键词: vitellogenesis;    endocytosis;    octanol;    EMS;   

DOI  :  10.1006/dbio.2001.0433

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

Forendocyticuptakeofvitellogenins,developingoocytesofOncopeltusrequireasoluble,diffusiblemolecularsignalfromtheirsurroundingepithelialcells,andthissignalmustbetransmittedthroughopengapjunctions.Hormonalstimulationtriggeringsynthesisandprocessingofvitellogeninsintomatureinsectyolksphereshasbeenintenselystudied,andfollicleepithelialcellsareknowninseveralinsectstocontributetothebloodproductswhichareendocytosedalongwithvitellogeninssynthesizedinthefatbodies.However,therehasbeenlittleevidencethatdirectgapjunctionalcommunicationisarequirementforendocyticactivitybyoocytes.Inuntreatedcontrolfollicles,bothelectricalanddyecouplingoccur,andfolliclesincubatedinvitroinphysiologicalsaltsolutioncontainingsmallamountsofbloodandfluorescentdyeproducefluorescentlylabelednascentyolkspheres.Labeledyolksphereswerevisibleinbothsectionedmaterial,and,with(Laser)ConfocalScanning,inlivingmaterial.Dyecouplingwasabolishedbytreatmentwitheither1mMoctanol,0.5mMethylmethanesulfonate(EMS),orcytoplasmicacidification,withcouplingcoefficientsalsobeingaffectedaseachofthesegapjunctionantagonistsdown-regulatedtheconnexons.Witheachofthesetreatments,aftergapjunctionsweredown-regulated,receptor-mediatedendocyticuptakeofblood-bornvitellogeninscametoahalt.Furthermore,Oncopeltusfollicleswithendocyticactivityblockedinthismannercouldberescuedbymicroinjectionofthesolublefractionoflysedepithelialcellcytoplasm,confirmingthattheprocessdependeduponamolecularsignalfromtheepithelialcells.

【 授权许可】

Unknown