Retinoic acid (RA) is a potent morphogen required for embryonic development. RA is formed in a multistep process from vitamin A (retinol); RA acts in a paracrine fashion to shape the developing eye and is essential for normal optic vesicle and anterior segment formation. Perturbation in RA-signaling can result in severe ocular developmental diseases-including microphthalmia, anophthalmia, and coloboma. RA-signaling is also essential for embryonic development and life, as indicated by the significant consequences of mutations in genes involved in RA-signaling. The requirement of RA-signaling for normal development is further supported by the manifestation of severe pathologies in animal models of RA deficiency-such as ventral lens rotation, failure of optic cup formation, and embryonic and postnatal lethality. In this review, we summarize RA-signaling, recent advances in our understanding of this pathway in eye development, and the requirement of RA-signaling for embryonic development (e.g., organogenesis and limb bud development) and life.

中文翻译：

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视黄酸途径的遗传学和功能，特别强调眼睛。

视黄酸 (RA) 是胚胎发育所需的有效形态发生素。RA 是由维生素 A（视黄醇）在多步过程中形成的；RA 以旁分泌方式作用以塑造发育中的眼睛，对于正常的视囊泡和眼前节的形成至关重要。RA 信号的扰动可导致严重的眼部发育疾病，包括小眼症、无眼症和缺损。RA 信号传导对于胚胎发育和生命也是必不可少的，正如参与 RA 信号传导的基因突变的显着后果所表明的那样。RA 缺陷动物模型中严重病理的表现进一步支持了 RA 信号对正常发育的要求，例如腹侧晶状体旋转、视杯形成失败以及胚胎和出生后的致死率。在本次审查中，