Ohuchi H, Tomonari S, Itoh H, Mikawa T, Noji S
Department of Genetic Biochemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan.
Mech Dev. 1999 Jul;85(1-2):193-5. doi: 10.1016/s0925-4773(99)00094-5.
We have isolated chick rax/rx cDNAs, cRaxL (chick Rax/Rx-like) and cRax, (chick Rax) and examined their expression patterns during early eye and brain development. The cRaxL cDNA encodes a 228 amino acid protein that is most closely related to the zebrafish Rx1 and Rx2. The cRax cDNA encodes a 317 amino acid protein, which shares higher homology with the Xenopus Rx. In addition to the homeodomain, the octapeptide and paired tail domains are conserved between the cRax and other vertebrate Rax/Rx, while cRaxL lacks the octapeptide containing N-terminal region which is conserved among all other members of the rax/rx gene family identified so far. The chick rax/rx genes are expressed in overlapping domains in the anterior neural ectoderm which corresponds to the forebrain and retina field, and later in the optic vesicle. cRax mRNA can be detected earlier than cRaxL prior to the formation of the notochord and its expression domain appears broader than that of cRaxL.
我们分离出了鸡的rax/rx cDNA、cRaxL（鸡Rax/Rx样）和cRax，并研究了它们在早期眼和脑发育过程中的表达模式。cRaxL cDNA编码一种228个氨基酸的蛋白质，它与斑马鱼的Rx1和Rx2关系最为密切。cRax cDNA编码一种317个氨基酸的蛋白质，与非洲爪蟾的Rx具有更高的同源性。除了同源异型域外，cRax与其他脊椎动物的Rax/Rx之间八肽和成对尾域是保守的，而cRaxL缺乏在迄今鉴定的rax/rx基因家族所有其他成员中保守的含八肽的N端区域。鸡的rax/rx基因在前神经外胚层的重叠区域表达，该区域对应于前脑和视网膜区域，随后在视泡中表达。在脊索形成之前就能检测到cRax mRNA，且其表达域似乎比cRaxL的更宽。
