Analyses of cell recognition mechanisms by genetic manipulation

我们得到了以下结果：1。我们寻找小说。钙粘蛋白，并鉴定出r -钙粘蛋白。该钙粘蛋白主要表达于神经系统，但表达时间较Ncadherin晚。这些钙粘蛋白的分布模式也很明显。2. 以脑MRNA为模板，通过PCR获得了其他新的钙粘蛋白CDNA片段。我们克隆了其中的两个，并确定了它们的序列。这些dna编码的钙粘蛋白表现出一些独特的特征，将它们与传统的钙粘蛋白区分开来。这些结果表明，钙粘蛋白家族应该被划分。亚科。3. 我们尝试用PCR方法对果蝇的钙粘蛋白进行鉴定，得到了可分为四组的CDNA片段。此外，我们可以克隆一种果蝇同源的脊椎动物（x-连环蛋白）。4. 为了研究钙粘蛋白的形态发生作用，我们将n -钙粘蛋白mRNA注射到爪蟾2细胞期胚胎中。胚胎中N-cadherin的过表达引起表皮增厚和细胞团分离等多种形态异常。n -钙粘蛋白的异位表达也影响了一些形态发生运动。这些发现证实了……的重要性。钙粘蛋白在形态发生中的调控表达。5. 我们证明了catenins，钙粘蛋白相关蛋白，对钙粘蛋白的功能至关重要。我们还克隆了cc-catenin，发现它与vinculin相似。

We obtained the following results : 1. We searched for novel. cadherins, and identified R-cadherin. This cadherin was mainly expressed in the nervous system, but its expression occured at later developmental stages than Ncadherin. The distribution patterns of these cadherins were also distinct. 2. By PCR using brain MRNA as template, we obtained other novel cadherin CDNA fragments. We cloned two of them and determined their sequences. Cadherins encoded by these cDNAs showed some unique features which demarcate them from classical cadherins. These results suggest that the cadherin family should be divided. into subfamilies. 3. We attempted to identify Drosophila cadherins using PCR', and could obtain CDNA fragments which can be divided into four groups. Also, we could clone -a Drosophila homologue of vertebrate (x-catenin. 4. To investigate the morphogenetic role of cadherins, we injected N-cadherin mRNA into Xenopus 2-cell stage embryos. The overexpression of N-cadherin in embryos induced various morphological abnormalities, including thickening of epidermis and separation of cell masses. The ectopic expression of N-cadherin also affected some morphogenetic movements. These findings confirmed the importance of. regulated expression of cadherins in morphogenesis. 5. We demonstrated that catenins, cadherin-associated proteins, are crucial for cadherin function. We also cloned cc-catenin, and found that it is similar to vinculin.