Christen B, Bienz M
Zoological Institute, University of Zürich, Switzerland.
Mech Dev. 1992 Nov;39(1-2):73-80. doi: 10.1016/0925-4773(92)90027-h.
We dissected an upstream control region (a BXD fragment) from the homeotic gene Ultrabithorax (Ubx) of Drosophila which confers a Ubx-like expression pattern in the embryonic ectoderm. We found several distinct enhancer elements spread through the whole BXD fragment each of which is active in transformed embryos, mediating a different pattern of beta-galactosidase expression in the ventral nerve cord. The strongest of these patterns mimics Ubx expression within the Ubx domain. This pattern is strictly dependent on Ubx function. Thus, the BXD control region contains a Ubx response element, suggesting that positive autoregulation of Ubx may occur in the central nervous system of the developing embryo.
我们从果蝇的同源异型基因超双胸（Ubx）中分离出一个上游控制区域（一个BXD片段），该区域在胚胎外胚层中赋予类似Ubx的表达模式。我们发现几个不同的增强子元件分布在整个BXD片段中，每个元件在转化胚胎中都是活跃的，介导腹侧神经索中β-半乳糖苷酶表达的不同模式。这些模式中最强的一种模仿了Ubx结构域内的Ubx表达。这种模式严格依赖于Ubx功能。因此，BXD控制区域包含一个Ubx反应元件，这表明Ubx的正向自动调节可能发生在发育中胚胎的中枢神经系统。
