Differential Requirements for Shh in Mammary Tissue and Hair Follicle Morphogenesis

Developmental Biology

Lothar Hennighausen¹  Philip A. Beachy¹  Gertraud W. Robinson¹  Marta I. Gallego¹ 

[1] Laboratory of Genetics and Physiology, National Institute of Diabetes, and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, 20892

关键词: hedgehog;    mammary gland;    tissue interaction;   

DOI  :  10.1006/dbio.2002.0761

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

SonicHedgehog(Shh)isasecretedmorphogenthatdirectspatterningandcellulardifferentiationthroughbindingtoitsreceptorPatched(Ptc).Itisrequiredforthedevelopmentofskin-derivedorgans,suchashair,whiskers,andteeth.Themammaryglandisaskin-derivedorganthatdevelopsmainlyduringadultlifeinwhichShhisexpressedfrompubertytolactation.WehaveinvestigatedtheroleofShhinmammaryglandmorphogenesisanddifferentiationbytwotransplantationapproaches.SinceShh-nullfetusesdieatlateembryogenesis,wetransplantedShh-nullmammaryanlagenintoclearedfatpadsandundertherenalcapsuleofwildtypehostmice.Pregnancy-mediatedfunctionaldifferentiationofShh-nullmammaryepitheliumwasindistinguishablefromwildtypetransplants,whilehairfolliclesderivedfromcotransplantedskinonlydevelopedinwildtypetransplants.TransplantsofIhh-nullanlagenalsodevelopednormally.ToassessthemolecularconsequencesofShhdeletioninmammarytissue,wecomparedmRNAlevelsofpatched1,atargetgeneofHedgehogsignaling,inShh-nullandwildtypemammaryepithelialtransplants.NoreductionofPtc1transcriptswasobservedinShh-nullmammarytissues.OurresultsdemonstratethatneitherShhnorIhhisrequiredformammaryglandmorphogenesisandfunctionaldifferentiation,suggestingthatthetwomembersoftheHedgehogfamilymayhaveredundantfunctioninactivatingthePtc1signalingpathwayduringmammaryglanddevelopment.

【 授权许可】

Unknown