Retinoic acid receptor isoform β2 is an early marker for alimentary tract and central nervous system positional specification in the chicken
Retinoic acid receptor isoform β2 is an early marker for alimentary tract and central nervous system positional specification in the chicken
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DOI：
10.1002/aja.1002000103
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发表时间：
1994-05
影响因子：
2.5
通讯作者：
Susan M. Smith
中科院分区：
文献类型：
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作者：
Susan M. Smith
在这项研究中，我描述了维甲酸受体-β（RAR-β）的一种变体，RAR-β2亚型，在鸡胚器官发生前的阶段的分布。与较老胚胎的情况不同，在这些阶段，它的分布与所有RAR-β转录本的分布没有质的差异。在前体节头折叠阶段，RAR-β2转录本在两个不同的位置同时上调。这些位置定义了鸡消化道原基内和中枢神经系统（CNS）内的位置标识。随着发育的进行，转录本表达在这两个区域内保持其空间限制。在前体阶段，RAR-β2转录本在原羊膜中富集，原羊膜包含假定的前肠和心前细胞;稍后，它存在于前肠内胚层中，在前肠和侧心囊泡融合形成体腔和心管的部位。随着前肠继续向尾部延伸，RAR-β2表达在消化道内的咽水平上定义了前后边界。RAR-β2 mRNA的第二个表达位点首先出现在后神经板内，在亨森结开始其尾侧消退的水平。这个边界位于后脑内未来的第5和第6菱形之间的边界。RAR-β2转录本的表达在某些迁移的颅神经嵴细胞中也受到空间限制。RAR-β2在颅神经嵴细胞中的表达与已知的决定颅神经嵴细胞命运的机制一致。这些数据支持的假设，维甲酸可能有助于前后体轴的位置规格，也许也发展消化道和心管的形成和身份。© 1994 Wiley利斯公司
In this study I describe the distribution of one variant of retinoic acid receptor‐β (RAR‐β), the RAR‐β2 isoform, during the stages before organogenesis of the chick embryo. Unlike the situation in older embryos, at these stages its distribution does not differ qualitatively from that of all RAR‐β transcripts. During the presomite headfold stage, RAR‐β2 transcripts are simultaneously upregulated in two different locations. These locations define positional identities within the anlage of the chick alimentary tract and within the central nervous system (CNS). As development proceeds the transcript expression maintains its spatial restriction within those two regions. At presomite stages RAR‐β2 transcripts are enriched within the proamnion, which contains the presumptive foregut and precardiac cells; somewhat later it is present within the foregut endoderm at the site where foregut and the lateral amniocardiac vesicles fuse to form the coelom and cardiac tube. As the foregut continues its caudal extension, RAR‐β2 expression defines an anteroposterior boundary at the level of the pharynx within the alimentary tract. The second expression site of RAR‐β2 mRNA first appears within the posterior neural plate at the level where Hensen's node commences its caudal regression. This boundary lies at the border between the future rhombomeres 5 and 6 within the hindbrain. Expression of RAR‐β2 transcripts is also spatially restricted within some migrating cranial neural crest cells. The expression of RAR‐β2 in cranial neural crest cells is consistent with what is known about the mechanisms by which cranial neural crest cell fate is determined. These data support the hypothesis that retinoids may contribute to positional specification of anteroposterior body axis, and perhaps also to the formation and identity of the developing alimentary tract and heart tube. © 1994 Wiley‐Liss, Inc.