title: Correlation between loss of middle ear bones and altered goosecoid gene expression in the branchial region following retinoic acid treatment of mouse embryos in vivo.
abstract: The homeobox gene goosecoid marks the Spemann organizer in vertebrate gastrula embryos, and is expressed in the craniofacial region, body wall and limbs during organogenesis. Mouse mutants of goosecoid displayed a variety of phenotypes related to the expression pattern at mid-embryogenesis. These defects included loss of the tympanic ring and malformation of the malleus, phenotypes which were reminiscent of the teratogenic effects of retinoic acid (RA). Here we investigated the correlation of goosecoid gene expression and RA-teratogenicity following treatment of mouse embryos in vivo at embryonic day (E) 8 + 5 h. We found that goosecoid was specifically affected at E10.5 in branchial arches I and II. Expression was either reduced to background levels or restricted to the branchial cleft region. This change in goosecoid gene expression correlated with a loss of middle ear ossicles and a partial or complete deletion of the tympanic ring, suggesting a role for goosecoid in executing the RA teratogenic effects.
authors.affiliation: Karlsruhe Research Center, Institute of Genetics, Germany.
authors.forename: C C
authors.initials: CC
authors.lastname: Zhu
authors.forename: G
authors.initials: G
authors.lastname: Yamada
authors.forename: M
authors.initials: M
authors.lastname: Blum
mesh_terms: D000818:Animals; D002356:Cartilage / Q000187:drug effects / Q000196:embryology / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000096:biosynthesis*; D004429:Ear Ossicles / Q000002:abnormalities* / Q000187:drug effects / Q000196:embryology; D005314:Embryonic and Fetal Development; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D051956:Goosecoid Protein; D018398:Homeodomain Proteins; D017403:In Situ Hybridization; D051379:Mice; D008810:Mice, Inbred C57BL; D010012:Osteogenesis / Q000187:drug effects*; D011247:Pregnancy; D012097:Repressor Proteins; D013723:Teratogens; D014157:Transcription Factors; D014212:Tretinoin / Q000494:pharmacology*
chemical_list: D004268:DNA-Binding Proteins; D051956:Goosecoid Protein; C497993:Gsc protein, mouse; D018398:Homeodomain Proteins; D012097:Repressor Proteins; D013723:Teratogens; D014157:Transcription Factors; D014212:Tretinoin