B1 SOX coordinate cell specification with patterning and morphogenesis in the early zebrafish embryo.
B1 SOX coordinate cell specification with patterning and morphogenesis in the early zebrafish embryo.
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DOI：
10.1371/journal.pgen.1000936
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发表时间：
2010-05-06
期刊：
影响因子：
4.5
通讯作者：
Kamachi Y
中科院分区：
文献类型：
--
作者：
Okuda Y;Ogura E;Kondoh H;Kamachi Y
B1Sox转录因子SOX1/2/3/19参与了早期胚胎发育的各种过程。然而，它们在从囊胚到早期神经元阶段的调节功能仍然很大程度上是未知的，主要是因为到目前为止，功能丧失的研究还没有提供足够的信息。在我们目前的研究中，我们系统地敲除了斑马鱼中的B1 Sox基因。只有4个B1Sox基因sox2/3/19a/19b的四重敲除导致了非常严重的发育异常，证实了B1Sox基因在功能上是多余的。我们通过原位杂交、RT-PCR和基因芯片分析来检测基因表达的变化，从而对Sox2/3/19a/19b四重敲除胚胎进行了详细的表征。重要的是，这些表型分析揭示了B1Sox蛋白调控下列不同的过程：(1)通过控制bmp2b/7来调控早期的背腹模式；(2)通过调控pcdh18a/18b和wnt11(一个非规范的Wnt配体基因)来调控原肠的运动；(3)通过调控Hes类bHLH基因HER3和原神经类bHLH基因neg1(正)和ascl1a(负)以及区域转录因子基因，如hex1、zic1和rx3来调控神经分化；以及(4)通过调控信号通路基因cyp26a1来调控神经模式，其中cyp26a1是RA信号通路，P是Nodal信号、shh和mdkb。染色质免疫沉淀分析HER3、hex1、urog1、pcdh18a和cyp26a1基因进一步表明这些基因受到B1 Sox的直接调控。我们还发现B1 Sox四重敲除胚胎的早期表型与缺乏Pou5f1活性的母体受精卵spg胚胎之间存在有趣的重叠。这些发现表明，B1Sox蛋白通过与Pou5f1部分配对以及可能与其他因素配对，控制着早期胚胎中广泛的发育调节因子，并表明B1Sox功能是协调细胞命运指定与早期胚胎中发生的图案化和形态发生过程的核心。在发育中的胚胎中，细胞命运指定、胚胎构型和形态发生等各种过程同时发生。胚胎必须控制基因表达，以协调这些过程，从而使其结构得到适当的组织。以“干细胞基因”sox2为代表的B1Sox转录因子基因，被认为在从胚胎期到神经期的这些胚胎过程中发挥着关键作用。然而，由于缺乏功能丧失的研究，这些基因的确切调控功能在很大程度上是未知的。在我们目前的研究中，我们利用斑马鱼系统并使用反义基因敲除技术成功地耗尽了早期胚胎中的B1 Sox活性。这一方法使我们能够进一步揭示B1Sox在早期胚胎中的调节功能。我们发现，B1Sox基因的活性是一系列发育调节因子表达所必需的，包括转录因子、信号通路组件和细胞黏附分子。这些发现表明，B1Sox的功能对于协调不同的胚胎过程是至关重要的，特别是发生在中枢神经系统原基发育期间的那些过程。
The B1 SOX transcription factors SOX1/2/3/19 have been implicated in various processes of early embryogenesis. However, their regulatory functions in stages from the blastula to early neurula remain largely unknown, primarily because loss-of-function studies have not been informative to date. In our present study, we systematically knocked down the B1 sox genes in zebrafish. Only the quadruple knockdown of the four B1 sox genes sox2/3/19a/19b resulted in very severe developmental abnormalities, confirming that the B1 sox genes are functionally redundant. We characterized the sox2/3/19a/19b quadruple knockdown embryos in detail by examining the changes in gene expression through in situ hybridization, RT–PCR, and microarray analyses. Importantly, these phenotypic analyses revealed that the B1 SOX proteins regulate the following distinct processes: (1) early dorsoventral patterning by controlling bmp2b/7; (2) gastrulation movements via the regulation of pcdh18a/18b and wnt11, a non-canonical Wnt ligand gene; (3) neural differentiation by regulating the Hes-class bHLH gene her3 and the proneural-class bHLH genes neurog1 (positively) and ascl1a (negatively), and regional transcription factor genes, e.g., hesx1, zic1, and rx3; and (4) neural patterning by regulating signaling pathway genes, cyp26a1 in RA signaling, oep in Nodal signaling, shh, and mdkb. Chromatin immunoprecipitation analysis of the her3, hesx1, neurog1, pcdh18a, and cyp26a1 genes further suggests a direct regulation of these genes by B1 SOX. We also found an interesting overlap between the early phenotypes of the B1 sox quadruple knockdown embryos and the maternal-zygotic spg embryos that are devoid of pou5f1 activity. These findings indicate that the B1 SOX proteins control a wide range of developmental regulators in the early embryo through partnering in part with Pou5f1 and possibly with other factors, and suggest that the B1 sox functions are central to coordinating cell fate specification with patterning and morphogenetic processes occurring in the early embryo. In the developing embryo, various processes such as cell fate specification, embryo patterning, and morphogenesis take place concurrently. The embryo must control gene expression in order to coordinate these processes and thereby enable the proper organization of its structures. The B1 sox transcription factor genes, exemplified by the “stem cell gene” sox2, are thought to play a key role in these embryonic processes from the blastoderm stage to the neural stage. However, the precise regulatory functions of these genes are largely unknown due to the lack of loss-of-function studies. In our current study, we took advantage of the zebrafish system and successfully depleted B1 sox activity from the early embryo using antisense knockdown technology. This approach enabled us to further uncover the regulatory functions of B1 sox in early embryos. We found that the activity of the B1 sox genes is required for the expression of a wide range of developmental regulators including transcription factors, signaling pathway components, and cell adhesion molecules. These findings suggest that the B1 sox functions are central to coordinating diverse embryonic processes, particularly those that occur during the development of the primordium of the central nervous system.
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DOI：
10.1016/j.gep.2008.12.010
发表时间：
2009-04
期刊：
Gene expression patterns : GEP
影响因子：
--
作者：
Burzynski GM;Delalande JM;Shepherd I
通讯作者：
Shepherd I
影响因子：
64.5
作者：
Ballas, N;Grunseich, C;Mandel, G
通讯作者：
Mandel, G
影响因子：
25
作者：
Favaro, Rebecca;Valotta, Menella;Nicolis, Silvia K.
通讯作者：
Nicolis, Silvia K.
影响因子：
10.5
作者：
Kamachi, Y;Uchikawa, M;Kondoh, H
通讯作者：
Kondoh, H
影响因子：
4.6
作者：
Andoniadou, Cynthia L.;Signore, Massimo;Martinez-Barbera, Juan Pedro
通讯作者：
Martinez-Barbera, Juan Pedro