Xenopus NIK/MSN family kinases in planar polarity and convergent extension

胚胎发育代表新生命的第一步。在胚胎发生过程中，一个单细胞，即卵子，重组成一个类似于成年动物的复杂结构。在胚胎发育结束时，动物的头、眼睛、脊柱、胳膊和腿都清晰可辨。因此，正是在胚胎发育期间，我们的身体计划被确定了。这个过程的最初阶段需要细胞运动，产生三个基本的组织层，产生皮肤、神经系统和大脑，产生肌肉和骨骼，最后产生内部器官，如肺、胃和肠。胚胎发生的这一最早阶段受到精确控制，以便将一层组织精确地置于另一层组织之上。要做到这一点，每个组织层都必须准确地了解另一层在做什么，这是通过在层之间传递信号分子来实现的。我们正试图确切地了解这些信号分子是如何被接收的，以及它们是如何改变每个组织层中细胞的运动的。接收这些信号的错误会导致重要的畸形，通常会影响神经管的闭合（打开后）。这种被称为脊柱裂和无脑畸形的畸形是人类最常见的出生缺陷之一，占1‰。因此，我们正在进行的胚胎发生早期阶段的研究将对我们理解为什么会发生如此严重的出生缺陷产生影响。

Embryonic development represents the first steps of new life. During embryogenesis a single cell, the egg, reorganizes into a complex structure resembling the adult animal. By the end of embryogenesis the head, eyes, vertebral column and arms and legs of the animals are all clearly discernable. It is, then, during embryogenesis that our body plan is defined. The earliest stage of this process requires cell movements that produce three fundamental tissue layers, that giving rise to the skin, nervous system and brain, thoat giving rise to the muscles and the skeleton, and finally that giving the internal organs such as the lungs, stomach and intestines. This earliest stage of embryogenesis is precisely controlled in order to exactly position one layer of tissue over the other. To do this, each tissue layer must understand exactly what the other is doing and this is achieved by signaling molecules that pass between the layers. We are trying to understand exactly how these signaling molecules are received and how they change the movement of cells within each tissue layer. Errors in the reception of these signals lead to important malformations, often affecting closing of the neural tube (open back). Such malformations known as Spina bifida and Anencephaly are among the most common birth defects in humans, accounting for 1 birth in a 1000. The studies we are making of the early stages of embryogenesis will, therefore, have repercussions on our understanding of why such serious birth defects occur.