Clements D, Taylor H C, Herrmann B G, Stott D
Department of Biological Sciences, University of Warwick, Coventry, UK.
Mech Dev. 1996 May;56(1-2):139-49. doi: 10.1016/0925-4773(96)00520-5.
Brachyury is required for the normal extension of the anteroposterior axis during mouse embryogenesis. A transgene comprising sequences from -500 to +150 relative to the start of Brachyury transcription, and the reporter gene lacZ, recapitulates some, but not all elements of Brachyury expression. Beta-Galactosidase expression is seen in the primitive streak from 6.5 d.p.c. but there is no detectable reporter expression in the node or notochord. Thus, the regulatory sequences required for the expression of Brachyury in the cells traversing the primitive streak are distinct from those required for the initiation of expression in the node. This suggests that different or additional signals are involved in activation of Brachyury in the node and notochord than those inducing Brachyury in the primitive streak. Additionally, the data suggest the possibility that axial and non-axial mesoderm are distinct from the earliest stages of Brachyury expression.
在小鼠胚胎发育过程中，短尾基因（Brachyury）对于前后轴的正常延伸是必需的。一个转基因包含相对于Brachyury转录起始位点从-500到+150的序列以及报告基因lacZ，它重现了Brachyury表达的一些但不是所有元件。在6.5天胚胎龄（d.p.c.）时，在原条中可见β-半乳糖苷酶表达，但在节点或脊索中未检测到报告基因表达。因此，在穿过原条的细胞中Brachyury表达所需的调控序列与在节点中启动表达所需的调控序列不同。这表明，与在原条中诱导Brachyury表达的信号不同，在节点和脊索中激活Brachyury涉及不同或额外的信号。此外，数据表明轴向和非轴向中胚层从Brachyury表达的最早阶段就有所不同的可能性。
