The Homeobox Gene mbx Is Involved in Eye and Tectum Development

Developmental Biology

Igor B. Dawid¹  Atsuo Kawahara¹  Chi-Bin Chien¹ 

[1] Laboratory of Molecular Genetics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, 20892

关键词: mbx;    homeobox gene;    eye;    tectum;    midbrain–hindbrain boundary;    morpholino;   

DOI  :  10.1006/dbio.2002.0709

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

Thehomeoboxgenembxisfirstactivatedattheendofgastrulationinzebrafishinthepresumptiveforebrainandmidbrainregion.Duringsomitogenesisstages,theanteriorexpressionofmbx,whichpartlyoverlapsthefutureeyefield,graduallydecreases,whilemidbrainexpressionintensifiesandbecomesrestrictedtothepresumptivetectum.Knockdownofmbxexpressionbymorpholinoantisenseoligonucleotides(mbx-MO)leadstoareductioninthesizeoftheeyesandtectum.Expressiondomainsofrx1andpax6intheeyefieldandofmab21l2intheeyefieldandtectumanlagewerereducedinsizeinmbx-MO-injectedembryosbysomitogenesisstages.Further,inductionofislet1andlim3expressionintheeyeat2dayspostfertilization(dpf)wassuppressedinmbx-MO-injectedembryos.Inmbx-MO-injectedembryosat2–5dpf,thelaminationoftheeyewasdisorganizedandthenumberofretinalaxonswassubstantiallyreduced,butthefewremainingaxonsnavigatedappropriatelytothecontralateraltectum.AchimericproteincomposedoftheMbxDNA-bindingdomainandtheVP16activationdomainaffectedeyeandtectumdevelopmentsimilarlytombx-MOknockdown,suggestingthatMbxactsasatranscriptionalrepressorinthezebrafishembryo.Basedonthesedata,weproposethatthembxhomeoboxgeneisrequiredforthedevelopmentoftheeyesandtectum.

【 授权许可】

Unknown