Radial axis differentiation in a globular embryo is marked by HAZ1, a PHD-finger homeobox gene of rice.
Radial axis differentiation in a globular embryo is marked by HAZ1, a PHD-finger homeobox gene of rice.
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DOI：
10.1016/j.gene.2004.02.040
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发表时间：
2004-04
期刊：
影响因子：
3.5
通讯作者：
Yukihiro Ito;Atsushi Chujo;M. Eiguchi;N. Kurata
中科院分区：
文献类型：
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作者：
Yukihiro Ito;Atsushi Chujo;M. Eiguchi;N. Kurata
同源盒基因编码转录因子，在植物和动物系统的发育和分化中都起着重要的作用。从授粉后3天（DAP）水稻胚cDNA文库中克隆出一个编码具有博士指结构域和同源结构域的蛋白的HAZ1 cDNA。数据库检索结果显示，HAZ1与玉米博士手指家族同源结构域蛋白Zmhox1a（同源性52%）和Zmhox1b（同源性50%）的全氨基酸序列最为相似。与Zmhox1不同的是，过表达HAZ1在烟草和水稻中均未引起形态变化。原位杂交表明，在3 DAP时，HAZ1在发育胚胎外层的表达水平高于胚胎内部。在4和5 DAPs时，HAZ1的表达集中在胚胎的腹侧。这些结果表明，在球形胚胎发生任何形态分化之前，HAZ1标记了其外层细胞。由HAZ1标记的径向轴分化随着胚胎形态发生而动态瓦解，随后HAZ1标记胚胎腹面。
Homeobox genes that encode transcription factors play important roles in development and differentiation of both plant and animal systems. From a cDNA library of 3-day after-pollination (DAP) rice embryos we cloned a HAZ1 cDNA that encodes a protein with a PHD-finger domain and a homeodomain. A database search showed that HAZ1 was most similar in its entire amino acid sequence to Zmhox1a (52% identity) and Zmhox1b (50%), PHD-finger family homeodomain proteins of maize. Differing from Zmhox1, overexpression of HAZ1 brought no morphological change either in tobacco or in rice. In situ hybridization showed that HAZ1 was expressed at a higher level in the outer layers of a developing embryo than in the inner parts of the embryo at 3 DAP. At 4 and 5 DAPs, the expression of HAZ1 was concentrated at the ventral part of an embryo. These results indicate that HAZ1 marks outer layer cells of a globular embryo before any morphological differentiation is discerned in it. Radial axis differentiation marked by HAZ1 is then collapsed dynamically along with embryo morphogenesis, and HAZ1 later marks the ventral surface of the embryo.