Takeda Y, Hatano S, Sentoku N, Matsuoka M
Bio Science Center, Nagoya University, Aichi, Japan.
Mol Gen Genet. 1999 Aug;262(1):131-8. doi: 10.1007/s004380051067.
Homologs of the eyes absent (eya) gene in animals function at multiple stages in the development of organs. Their functional roles in the genetic network that regulates eye development in Drosophila have recently been extensively analyzed. A rice homolog of eya was identified from a cDNA library made from embryo RNA. The corresponding gene (OSEya1) encodes a conserved ED1 domain and a short N-terminal peptide. The ED1 domain of OSEya1 shows 25% identity and 36% similarity to the product of Drosophila eya. Mammalian and squid eya homologs show about 35% similarity to OSEya1. Homologous sequences were also found in the alfalfa EST database (53% identity and 65% similarity to OSEya1) and in the Arabidopsis genome sequence (63% identity). Therefore, eya homologs are present in both monocots and dicots. Three regions in the ED1 domain are well conserved in animals and plants. Plant eya products deduced from the nucleotide sequences also have short N-terminal peptides. The OSEya1 gene is located between the wx gene and the telomere on the short arm of chromosome 6. OSEya1 is expressed in the embryo, shoot apex, and caryopsis in rice. Expression in the embryo increases during embryogenesis until 7 days after pollination, with preferential localization in leaf primordia and the shoot apical meristem. Expression in the influorescence was observed in floral meristems. The functions of OSEya1 in higher plants are discussed and compared with those of their animal homologs. OSEya1 might regulate the morphogenesis of lateral organs as a subunit of a transcription factor.
动物中无眼（eya）基因的同源物在器官发育的多个阶段发挥作用。最近对它们在果蝇眼睛发育调控基因网络中的功能作用进行了广泛分析。从由胚胎RNA构建的cDNA文库中鉴定出eya的水稻同源物。相应基因（OSEya1）编码一个保守的ED1结构域和一个短的N端肽。OSEya1的ED1结构域与果蝇eya的产物有25%的同一性和36%的相似性。哺乳动物和鱿鱼的eya同源物与OSEya1有大约35%的相似性。在苜蓿EST数据库中也发现了同源序列（与OSEya1有53%的同一性和65%的相似性）以及在拟南芥基因组序列中（63%的同一性）。因此，eya同源物存在于单子叶植物和双子叶植物中。ED1结构域中的三个区域在动植物中都高度保守。从核苷酸序列推导的植物eya产物也有短的N端肽。OSEya1基因位于6号染色体短臂上的wx基因和端粒之间。OSEya1在水稻的胚胎、茎尖和颖果中表达。在胚胎中的表达在胚胎发生过程中增加，直到授粉后7天，优先定位在叶原基和茎尖分生组织中。在花序中观察到在花分生组织中有表达。讨论了OSEya1在高等植物中的功能，并与它们的动物同源物的功能进行了比较。OSEya1可能作为转录因子的一个亚基调节侧生器官的形态发生。
