Molecular analysis of Angelman syndrome critical region for detection of new related gene

天使人综合征（Angelman syndrome， AS）是一种以智力低下、癫痫发作、运动不稳和不适当的笑声为特征的异常综合征。此前，我们发现位于15q11-q13的UBE3A （E6-AP泛素蛋白连接酶基因）是AS的候选基因。然而，由于AS症状与UBE3A功能相关性不明确，且存在未发生UBE3A突变的患者，提示可能有多个基因参与了AS的发病过程。在本研究中，我们试图寻找位于AS区的未知基因。为了简化AS区域的遗传分析，我们采用了河豚的基因组，其大小是人类基因组的七分之一。从河豚基因组文库中分离到UBE3A和一个新的家族基因。此外，我们还尝试分离河豚鱼的SNRPN、IPW、PAR4等UBE3A邻近基因。我们还描述了一种新的简单的方法，通过PCR扩增分离YAC等巨大基因组克隆的插入端，并构建了一种新的高效的基因捕获载体。

Angelman syndrome (AS) is one of anomaly syndromes characterized by mental retardation, seizure, jerky movement and inappropriate laughter. Previously, we revealed that UBE3A (E6-AP ubiquitin-protein ligase gene) located in 15q11-q13 is a candidate gene of AS. However, the unclear relevance of AS symptoms and UBE3A function and the existence of patients without UBE3A mutation suggested that ff more than one gene might participate in pathogenesis of AS. In this study, we attempted to find unknown genes located in the AS region. In order to simplify genetic analysis of the AS region, we adopted puffer fish genome whose size was one-seventh of the human genome. Puffer fish UBE3A and a novel family gene were isolated from puffer fish genomic libraries. In addition, puffer fish SNRPN, IPW, PAR4, and other neighbor genes of UBE3A were also attempted to isolate, We also describe a new simple method to isolate insert ends of huge genomic clone such as YAC using PCR amplification and construction of a new efficient vector for gene trapping.