Nakata K, Koyabu Y, Aruga J, Mikoshiba K
Laboratory for Developmental Neurobiology, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, 351-0198, Saitama, Japan.
Mech Dev. 2000 Dec;99(1-2):83-91. doi: 10.1016/s0925-4773(00)00480-9.
We characterized Xenopus Zic5 which belongs to a novel class of the Zic family. Zic5 is more specifically expressed in the prospective neural crest than other Zic genes. Overexpression of Zic5 in embryos led to ectopic expression of the early neural crest markers, Xsna and Xslu, with the loss of epidermal marker expression. In Zic5-overexpressing animal cap explants, there was marked induction of neural crest markers, without mesodermal and anterior neural markers. This was in contrast to other Xenopus Zic genes, which induce both anterior and the neural crest markers in the same assay. Injection of a dominant-negative form of Zic5 can block neural crest formation in vivo. These results indicate that Zic5 expression converts cells from an epidermal fate to a neural crest cell fate. This is the first evidence for neural crest tissue inductive activity separate from anterior neural tissue inductive activity in a Zic family gene.
我们对非洲爪蟾Zic5进行了特征描述，它属于Zic家族的一个新类别。与其他Zic基因相比，Zic5在预期的神经嵴中表达更为特异性。在胚胎中过表达Zic5会导致早期神经嵴标志物Xsna和Xslu的异位表达，同时表皮标志物表达缺失。在过表达Zic5的动物帽外植体中，神经嵴标志物有明显诱导，而没有中胚层和前神经标志物。这与其他非洲爪蟾Zic基因形成对比，在相同实验中，其他Zic基因会诱导前神经和神经嵴标志物。注射显性负性形式的Zic5可在体内阻断神经嵴形成。这些结果表明，Zic5的表达将细胞从表皮命运转变为神经嵴细胞命运。这是Zic家族基因中神经嵴组织诱导活性与前神经组织诱导活性分离的首个证据。
