Davis C A, Holmyard D P, Millen K J, Joyner A L
Division of Molecular and Developmental Biology, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Canada.
Development. 1991 Feb;111(2):287-98. doi: 10.1242/dev.111.2.287.
We have raised an antiserum, designated alpha Enhb-1, to a portion of the mouse En-2 protein containing the homeodomain. The antiserum detects both the En-1 and En-2 proteins in mouse, chick and Xenopus embryos by Western blot analysis. Using whole-mount immunohistochemistry, combined in some cases with scanning electron microscopy, we have examined the distribution of the proteins in the early embryos of these species. The major features of expression were similar. The initial production of En protein occurred, just before or during the formation of the first somites, in a band of the anterior neural plate in the prospective mid/hindbrain region. Later in development En-1 protein accumulated in the ventral ectoderm of the developing mouse and chick limb buds, indicating that a dorsal-ventral polarity is present as soon as any limb bud swelling is apparent and that, at least in the mouse, this polarity is established independently of the apical ectodermal ridge. In all three species, alpha Enhb-1 bound to a subset of ventro-lateral differentiating neurons in the spinal cord and hindbrain and their pattern of birth in the mouse reflected the division of the hindbrain into rhombomeres. En-1 protein also accumulated in a lateral stripe of dermatome in the mouse and chick, indicating a dorsal-ventral subdivision of this tissue. The results show that En expression is a good marker for pattern formation in a variety of tissues and will be useful in experimental studies designed to characterize further these processes.
我们制备了一种抗血清，命名为αEnhb - 1，针对小鼠En - 2蛋白中包含同源异型结构域的部分。通过蛋白质免疫印迹分析，该抗血清能检测小鼠、鸡和非洲爪蟾胚胎中的En - 1和En - 2蛋白。利用整体免疫组织化学技术，在某些情况下结合扫描电子显微镜，我们研究了这些物种早期胚胎中这些蛋白的分布。表达的主要特征相似。En蛋白最初的产生发生在第一批体节形成之前或期间，在前脑/后脑区域预期的前神经板带中。在发育后期，En - 1蛋白在发育中的小鼠和鸡肢体芽的腹侧外胚层中积累，这表明一旦肢体芽出现肿胀，背腹极性就存在，并且至少在小鼠中，这种极性的建立独立于顶端外胚层嵴。在所有这三个物种中，αEnhb - 1与脊髓和后脑腹外侧分化神经元的一个亚群结合，并且其在小鼠中的出生模式反映了后脑向菱脑节的划分。En - 1蛋白也在小鼠和鸡的皮节外侧条带中积累，表明该组织存在背腹分区。结果表明，En表达是多种组织模式形成的良好标记，将有助于旨在进一步表征这些过程的实验研究。
