Zhu C C, Yamada G, Blum M
Karlsruhe Research Center, Institute of Genetics, Germany.
Biochem Biophys Res Commun. 1997 Jun 27;235(3):748-53. doi: 10.1006/bbrc.1997.6808.
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.
同源框基因gsc在脊椎动物原肠胚胚胎中标记斯佩曼组织者，并在器官发生过程中在颅面部区域、体壁和四肢表达。gsc的小鼠突变体表现出与胚胎中期表达模式相关的多种表型。这些缺陷包括鼓膜环缺失和锤骨畸形，这些表型让人联想到视黄酸（RA）的致畸作用。在此，我们研究了在胚胎第8天+5小时对小鼠胚胎进行体内处理后，gsc基因表达与RA致畸性之间的相关性。我们发现，在E10.5时，gsc在第一和第二鳃弓中受到特异性影响。表达要么降低到背景水平，要么局限于鳃裂区域。gsc基因表达的这种变化与中耳小骨的缺失以及鼓膜环的部分或完全缺失相关，提示gsc在执行RA致畸作用中发挥作用。
