Krox-20 patterns the hindbrain through both cell autonomous and non cell-autonomous mechanisms
Krox-20 patterns the hindbrain through both cell autonomous and non cell-autonomous mechanisms
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DOI：
10.1101/gad.189801
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发表时间：
2001-03-01
影响因子：
10.5
通讯作者：
Gilardi-Hebenstreit, P
中科院分区：
文献类型：
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作者：
Giudicelli, F;Taillebourg, E;Gilardi-Hebenstreit, P
Krox-20基因编码一种锌指转录因子，该因子先前在小鼠中通过靶向失活被证明是分节胚胎后脑中菱形体(r) 3和5发育所必需的。本研究利用电穿孔法在发育中的鸡后脑中异位表达了Krox-20。我们证明，Krox-20的表达足以赋予r2、r4和r6细胞奇数菱形体特征，可能是以细胞自主的方式。因此，Krox-20似乎是后脑内奇数身份的主要决定因素。此外，我们提供的证据表明，存在一种非细胞自主的自激活机制，允许邻近表达krox -20的细胞从偶数区域招募krox -20阳性细胞。在这些观察的基础上，我们提出Krox-20调节了片段模式中多个相互交织的步骤：在少数细胞中初始激活Krox-20会导致分离、均质化，并可能导致领地的扩张，除此之外，Krox-20还会赋予其奇数身份。
The Krox-20 gene encodes a zinc finger transcription factor, which has been shown previously, by targeted inactivation in the mouse, to be required for the development of rhombomeres (r) 3 and 5 in the segmented embryonic hindbrain. In the present work, Krox-20 was expressed ectopically in the developing chick hindbrain by use of electroporation. We demonstrate that Krox-20 expression is sufficient to confer odd-numbered rhombomere characteristics to r2, r4, and r6 cells, presumably in a cell-autonomous manner. Therefore, Krox-20, appears as the major determinant of odd-numbered identity within the hindbrain. In addition, we provide evidence for the existence of a non cell-autonomous autoactivation mechanism allowing recruitment of Krox-20-positive cells from even-numbered territories by neighboring Krox-20-expressing cells. On the basis of these observations, we propose that Krox-20 regulates multiple, intertwined steps in segmental patterning: Initial activation of Krox-20 in a few cells leads to the segregation, homogenization, and possibly expansion of territories to which Krox-20 in addition confers an odd-numbered identity.