Mishima N, Tomarev S
Laboratory of Molecular and Developmental Biology, National Eye Institute, Bethesda, MD 20892-2730, USA.
Int J Dev Biol. 1998 Nov;42(8):1109-15.
In all vertebrates studied (human, mouse, chicken), there are at least three genes related to Drosophila eyes absent (eya) gene. The chicken Eyes absent 2 (Eya2) cDNA was isolated from 14 day embryonic chicken lenses, and a complete open reading frame encoding a 59 kDa protein was elucidated. The chicken Eya2 protein is moderately conserved and 78-82% identical to the mouse and human Eya2. The Eya2 gene demonstrated a dynamic expression pattern in different tissues of diverse embryological origin. Expression of Eya2 was first detected at Hamburger and Hamilton stage 9 in the foregut. At later stages of development, Eya2 mRNA was detected in neural crest derivatives (dorsal root ganglia, branchial arches and cranial nerve ganglia). In the cranial placodes, expression of Eya2 was first detected in the nasal pit at stage 13. In the eye, expression of Eya2 was first convincingly detected in neural retina at stage 24 (day 4). The highest level of Eya2 mRNA in the lens was detected around day 9. Eya2 is also expressed in the cornea and iris. Therefore, chicken Eya2, as well as mouse Eya2, is expressed relatively early in the nasal (but not in the lens) placode and may mediate induction of the nasal placode. Expression of Eya2 in the wing and limb buds is consistent with its proposed role in the patterning of limb connective tissues.
在所有已研究的脊椎动物（人类、小鼠、鸡）中，至少有三个基因与果蝇无眼（eya）基因相关。鸡的无眼2（Eya2）cDNA是从14日龄鸡胚胎晶状体中分离出来的，并且阐明了一个编码59 kDa蛋白质的完整开放阅读框。鸡的Eya2蛋白具有中度保守性，与小鼠和人类的Eya2有78 - 82%的同源性。Eya2基因在不同胚胎起源的不同组织中呈现出动态表达模式。Eya2的表达最早在汉伯格和汉密尔顿第9期的前肠中被检测到。在发育后期，Eya2 mRNA在神经嵴衍生物（背根神经节、鳃弓和脑神经节）中被检测到。在颅基板中，Eya2的表达最早在第13期的鼻窝中被检测到。在眼睛中，Eya2的表达最早在第24期（第4天）的神经视网膜中被明确检测到。晶状体中Eya2 mRNA的最高水平在第9天左右被检测到。Eya2也在角膜和虹膜中表达。因此，鸡的Eya2以及小鼠的Eya2在鼻基板中相对较早地表达（但不在晶状体中），并且可能介导鼻基板的诱导。Eya2在翅芽和肢芽中的表达与其在肢体结缔组织模式形成中所提出的作用一致。
