The Dynamic Expression Pattern of frzb-1 Suggests Multiple Roles in Chick Development

Developmental Biology

Michelle Baranski¹  James S. Sandler¹  Diana K. Darnell¹  Eli Berdougo¹  Laura W. Burrus¹ 

[1]Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, California, 94132

关键词: chick;    chondrogenesis;    development;    embryo;    Frizzled;    Frzb;    gastrulation;    Hensen's node;    HNK-1;    limb;    neural crest;    neurulation;    Sarp;    Sfrp;    whole-mount in situ hybridization;    Wnt;   

DOI  :  10.1006/dbio.1999.9516

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

TheWntfamilyofsecretedproteinshasbeenshowntohavemultiplerolesinembryonicdevelopment.Wntsignalsarethoughttobepropagatedbybindingtothecysteine-richextracellulardomain(CRD)ofFrizzled,aseven-transmembrane-domaincellsurfacereceptor.SecretedFrizzled-relatedproteins(generallydenotedFrzborSfrp)possessadomainwithahighdegreeofsequenceidentityandstructuralsimilaritywiththeCRDofFrizzled.Currentdataindicatethatthecysteine-richdomainofsecretedFrzbproteinscanbindWntproteins,suggestingthepossibilitythatFrzbscompetewithmembrane-boundFrizzledforWntbindingandconsequentlyactascompetitiveinhibitorsofWntsignaling.InordertogainabetterunderstandingofthepotentialrolesofFrzb-1inchickdevelopment,weutilizedthepolymerasechainreactiontoisolateapartialcDNAofthechickorthologueoffrzb-1,cfrzb-1,andcompareditsexpressionpatterntothatofWnt-1,Wnt-3a,Wnt-5a,Wnt-7a,andWnt-8c.Whole-mountinsituhybridizationshaverevealedthreemajorphasesofexpressionforcfrzb-1inthedevelopingchick.Theearliestexpressionofcfrzb-1isincellsfatedtobecomeneuralectoderminstreak-stageembryos.Expressionofcfrzb-1intheneuralectodermcontinuesupthroughstage8.Afterstage8,cfrzb-1expressionisgraduallyattenuatedintheclosingneuraltubeofthetrunkandisconcomitantlyup-regulatedinneuralcrestcells.Finally,cfrzb-1appearsinthecondensingmesenchymeofthebonesinboththelimbandthetrunkinstage25+embryos.Comparativeanalysisofthecfrzb-1andtheWntgeneexpressionpatternssuggestspossibleinteractionsbetweencFrzb-1andalloftheWntfamilymembersexamined.

【 授权许可】

Unknown