Analysis of Pax6 expression using a BAC transgene reveals the presence of a paired-less isoform of Pax6 in the eye and olfactory bulb
Analysis of Pax6 expression using a BAC transgene reveals the presence of a paired-less isoform of Pax6 in the eye and olfactory bulb
复制标题
DOI：
10.1016/j.ydbio.2005.12.041
复制
发表时间：
2006-04-15
影响因子：
2.7
通讯作者：
Lauderdale, JD
中科院分区：
文献类型：
--
作者：
Kim, J;Lauderdale, JD
Pax6 是转录因子配对家族的成员，在发育中的眼睛、嗅觉系统、中枢神经系统和胰腺中表现出有限的表达和基本功能。 Pax6 的功能主要取决于发育过程中适当表达水平的诱导，为了了解 Pax6 的功能，有必要阐明控制 Pax6 转录的分子机制。尽管之前使用经典转基因方法的研究提供了有关 Pax6 调节所涉及的调节元件的分布和类型的大量信息，但对人类和小鼠的遗传学研究表明，仅这些增强子不足以完全调节 Pax6 表达。我们在这里报告我们对 160 kb 小鼠 Pax6 BAC 转基因小鼠的分析，该转基因小鼠是测试体内 Pax6 表达的远程控制必要的第一步。我们证明这种 BAC 转基因在眼睛中复制了 Pax6 表达。这是报告基因转基因首次在眼睛的所有组织中以正常的 Pax6 样模式表达，并在 Pax6 下游调节区 (DRR) 内定义了一个眼睛调节区。其次，我们证明该 BAC 转基因包含发育中胚胎内正常 Pax6 表达所需的所有顺式调控元件（间脑和嗅球内除外）。第三，我们证明该转基因受到 Pax6 自身调节的影响。最后，我们首次在哺乳动物中鉴定出缺乏配对结构域的 Pax6 蛋白亚型。这种异构体在发育中的嗅球和眼睛中表达。 Pax6 Delta PD 的过度表达会导致 Pax6(+/+) 小鼠和 Pax6(+/-) 小鼠出现小眼表型。这些结果证明了 Pax6 Delta PD 在眼睛发育中的作用，这似乎与典型的 Pax6 或 Pax6(5a) 的作用不同。 (c) 2006 Elsevier Inc. 保留所有权利。
Pax6, a member of the paired-family of transcription factors, exhibits restricted expression and essential functions in the developing eye, olfactory system, central nervous system, and pancreas. To understand Pax6 function, which critically depends on induction of proper expression levels during development, it is necessary to elucidate the molecular mechanisms governing Pax6 transcription. Although previous studies using classic transgenic approaches have provided a wealth of information about the distribution and types of regulatory elements involved in Pax6 regulation, genetic studies in both humans and mice indicate that these enhancers alone are not sufficient for fully regulated Pax6 expression. We report here our analysis of mice transgenic for a 160 kb mouse Pax6 BAC transgene, which was generated as a necessary first step towards testing the long-range control of Pax6 expression in vivo. We show that this BAC transgenc replicates Pax6 expression in the eye. This is the first time that a reporter transgene has been expressed in a normal Pax6-like pattern in all of the tissues of the eye and defines an eye regulatory region within the Pax6 downstream regulatory region (DRR). Second, we show that this BAC transgene contains all of the cis regulatory elements required for normal Pax6 expression within the developing embryo, except for within the diencephalon and olfactory bulb. Third, we show that this transgene is subject to Pax6 autoregulation Lastly, we identify, for the first time in mammals, an isoform of the Pax6 protein lacking the paired domain. This isoform is expressed in the developing olfactory bulb and eye. Over-expression of Pax6 Delta PD causes a microphthalmic phenotype in both Pax6(+/+) mice and Pax6(+/-) mice. These results demonstrate a role for Pax6 Delta PD in eye development, which appears to be different than that ascribed to either canonical Pax6 or Pax6(5a). (c) 2006 Elsevier Inc. All rights reserved.