Institute of Anatomy I, Friedrich Schiller University of Jena, Germany.
Neuroscience. 2010 Jan 13;165(1):168-78. doi: 10.1016/j.neuroscience.2009.10.032. Epub 2009 Oct 20.
We cloned chicken cadherin-19 that demonstrates high similarity to human and rat cadherin-19. Chicken cadherin-19 is a type II classic cadherin that is located on the long arm of chicken chromosome 2 and is composed of 13 exons and 12 introns. The expression profile of cadherin-19 was analyzed by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and in situ hybridization during chicken embryonic development. Its expression starts at E2.5, then gradually increases to reach a peak at E20. In contrast to previous results obtained in rat, chicken cadherin-19 is expressed both in Schwann cells and oligodendrocytes, also at late stages of development. We found no other cell type positive for cadherin-19 in the chicken embryo throughout development, suggesting that cadherin-19 is selectively expressed by myelin-forming cells and might play a role in myelin formation. The sequence of cadherin-19 shares high similarity with that of cadherin-7 and cadherin-20, and the three genes form a cluster on chromosome 2. Their expression patterns, however, are rather distinct although partial overlap is observed. For example, cadherin-19 and cadherin-7 are co-expressed by Schwann cells but not by oligodendrocytes. Moreover, a subset of interneurons express cadherin-7 but not cadherin-19 or cadherin-20. Despite their close genetic relation, the three cadherins have acquired functions in rather different cell types during nervous system development.
我们克隆了鸡钙黏蛋白-19，它与人和大鼠钙黏蛋白-19具有高度相似性。鸡钙黏蛋白-19是一种 II 型经典钙黏蛋白，位于鸡染色体 2 的长臂上，由 13 个外显子和 12 个内含子组成。通过半定量逆转录-聚合酶链反应（RT-PCR）和胚胎发育过程中的原位杂交分析钙黏蛋白-19的表达谱。其表达始于 E2.5，然后逐渐增加，在 E20 时达到峰值。与大鼠之前的结果相反，鸡钙黏蛋白-19在 Schwann 细胞和少突胶质细胞中表达，也在发育后期表达。我们在整个胚胎发育过程中没有发现鸡胚胎中其他细胞类型对钙黏蛋白-19呈阳性，这表明钙黏蛋白-19是由髓鞘形成细胞选择性表达的，可能在髓鞘形成中发挥作用。钙黏蛋白-19的序列与钙黏蛋白-7 和钙黏蛋白-20 的序列高度相似，这三个基因在染色体 2 上形成一个簇。然而，它们的表达模式相当不同，尽管存在部分重叠。例如，钙黏蛋白-19和钙黏蛋白-7 由 Schwann 细胞共表达，但不被少突胶质细胞表达。此外，一部分中间神经元表达钙黏蛋白-7，但不表达钙黏蛋白-19 或钙黏蛋白-20。尽管它们具有密切的遗传关系，但这三种钙黏蛋白在神经系统发育过程中已经在相当不同的细胞类型中获得了功能。
