Bonini N M, Leiserson W M, Benzer S
Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6018, USA.
Dev Biol. 1998 Apr 1;196(1):42-57. doi: 10.1006/dbio.1997.8845.
The eyes absent (eya) gene plays an essential role in the events that lead to formation of the Drosophila eye; without expression of eya in retinal progenitor cells, they undergo programmed cell death just prior to the morphogenetic furrow, leading to an eyeless or reduced eye phenotype. The eya gene has recently been found to be highly conserved to humans, defining a new gene family. Insights into the gene's function in the fly, therefore, are likely to be relevant to the role of its homologs in vertebrates. Detailed studies at the subcellular level indicate that the Eya protein is localized to the nucleoplasm, suggesting a role in control of nuclear events. The eya gene shows expression and roles in tissues other than the eye, including subsets of cells of the adult visual system, brain, and ovary, as well as an elaborate expression pattern in the embryo. Various mutations in the eya gene cause loss of ocelli, female sterility, or lethality. Analysis of the embryonic lethal phenotype indicates that mutant alleles show defects in head morphogenesis. These data indicate that eya has critical roles in morphogenesis of a number of tissues in the animal, in addition to its role in early eye formation. Despite multiple roles at multiple stages of development of the fly, both the type I and type II forms of the protein, when expressed ectopically during larval development, can direct eye formation.
无眼（eya）基因在果蝇眼睛形成过程中起着至关重要的作用；如果视网膜祖细胞中没有eya的表达，它们会在形态发生沟之前经历程序性细胞死亡，导致无眼或小眼表型。最近发现eya基因在人类中高度保守，从而定义了一个新的基因家族。因此，对该基因在果蝇中功能的深入了解可能与其在脊椎动物中的同源物的作用相关。亚细胞水平的详细研究表明，Eya蛋白定位于核质，这表明它在控制核事件中发挥作用。eya基因在眼睛以外的组织中也有表达和作用，包括成年视觉系统、大脑和卵巢的细胞亚群，以及胚胎中的精细表达模式。eya基因的各种突变会导致单眼缺失、雌性不育或致死。对胚胎致死表型的分析表明，突变等位基因在头部形态发生中存在缺陷。这些数据表明，eya除了在早期眼睛形成中发挥作用外，在动物许多组织的形态发生中也起着关键作用。尽管在果蝇发育的多个阶段有多种作用，但该蛋白的I型和II型形式在幼虫发育过程中异位表达时，都能指导眼睛的形成。
