Expression patterns of Brx1 (Rieg gene), Sonic hedgehog, Nkx2.2, Dlx1 and Arx during zona limitans intrathalamica and embryonic ventral lateral geniculate nuclear formation
Expression patterns of Brx1 (Rieg gene), Sonic hedgehog, Nkx2.2, Dlx1 and Arx during zona limitans intrathalamica and embryonic ventral lateral geniculate nuclear formation
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DOI：
10.1016/s0925-4773(97)00110-x
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发表时间：
1997-09-01
影响因子：
2.6
通讯作者：
Kato, K
中科院分区：
文献类型：
--
作者：
Kitamura, K;Miura, H;Kato, K
Brx1同源盒基因已被分离出来，并显示在小鼠胚胎的丘脑内嗜铬细胞（ZLI）中表达。Brx1是Err基因家族的成员，并且包含Brx1a和Brx1b的基因，其在位于同源框的5 ′-末端侧的区域中的序列不同。确定了Brx1a和Brx1b开放阅读框的完整氨基酸序列，发现每个序列都与Rgs（Rieger综合征相关的人RIEG基因（RGS）的小鼠同源物）的序列相似，以至于Rgs的序列已被阐明。Brx1在小鼠胚胎脑的乳头区以及ZLI中强烈表达。Brx1a和Brx1b的同源物在鸡中分离，其中Brx1在腹侧间脑中的表达是保守的。在小鼠胚胎ZLI形成时检测Brx 1沿着Sonic hedgehog（Shh）、Nkx 2.2、Dlx 1和Arx的表达。Shh的表达最初出现在假定ZLI的脑室区，然后在神经上皮细胞径向迁移时被Brx 1所取代。Nkx2.2在假定ZLI的脑室区广泛表达，在外套带也呈窄带。Dlx 1和Arx在假定腹侧丘脑的表达延伸至ZLI，并与Brx 1的表达重叠。Dlx 1和Arx表达细胞在ZLI，延伸到间脑壁的外侧（软膜）表面，不同于那些表达Nkx2.2和Brx 1。胚胎视觉通路中的腹外侧膝状体核最终由这些细胞形成。每个同源异型盒基因也在细胞核中区域性表达，表明细胞核由亚细胞组成。(C)1997 Elsevier Science爱尔兰有限公司
The Brx1 homeobox gene has been isolated and shown to be expressed in the zona limitans intrathalamica (ZLI) of the mouse embryo. Brx1 is a member of the Err gene family and comprises the genes for Brx1a and Brx1b, which differ in the sequence in the region located on the 5'-terminal side of the homeobox. The complete amino acid sequences of the open reading frame of Brx1a and Brx1b were determined and each was found to be similar to that of Rgs, the mouse homologue of the Rieger syndrome associated human RIEG gene (RGS), to the extent that the sequence of Rgs has been clarified. Brx1 was strongly expressed in the mammillary area as well as in the ZLI of the mouse embryonic brain. Homologues of Brx1a and Brx1b were isolated in chick in which the expression of Brx1 in the ventral diencephalon was well conserved. The expression of Brx1 along with that of Sonic hedgehog (Shh), Nkx2.2, Dlx1 and Arx was examined at the time of the formation of ZLI in mouse embryos. The expression of Shh was initially noted in the ventricular zone of the presumptive ZLI and was then replaced by that of Brx1 at the time of radial migration of the neuroepithelial cells. Nkx2.2 was widely expressed in the ventricular zone of presumptive ZLI and also as a narrow band in the mantle zone. The expression of Dlx1 and Arx in the presumptive ventral thalamus extended as far as ZLI and overlapped with that of Brx1. The Dlx1- and Arx-expressing cells in ZLI, which extended towards the lateral (pial) surface of the diencephalic wall, differed from those expressing Nkx2.2 and Brx1. The embryonic ventral lateral geniculate nucleus present in the visual pathway was eventually formed from these cells. Each homeobox gene was also expressed regionally in the nucleus, suggesting that the nucleus is comprised of subdivisions. (C) 1997 Elsevier Science Ireland Ltd.