摘要: 采用RT-PCR和RACE技术, 从日本七鳃鳗(Lampetra japonica)口腔腺、肝脏中分离获得了3条Y-box基因序列, 分别命名为Lyb1、Lyb2和Lyb3, 生物信息学分析其编码的蛋白质序列长度分别为331、181和171个氨基酸残基。采用DNAMAN软件, 将七鳃鳗的3个Y-box蛋白氨基酸序列与海鞘、斑马鱼、清鳉、河豚鱼和小鼠Y-box蛋白进行同源性分析, 结果显示他们共有一个保守的冷休克结构域, 其中包含两个RNA结合基序RNP-1和RNP-2, 表明获得的Lyb基因属于Y-box 基因家族成员。此外, 从Swiss-Prot下载了经实验验证过的Y-box蛋白序列数据, 结合实验克隆得到的Lyb基因所编码的氨基酸序列构建系统发育树, 发现Y-box基因在有颌类出现以前只有一种类型, 有颌类出现以后, Y-box基因分化成YB1、YB2和CSDA三种类型。

Abstract: In the present study, three Y-box cDNAs, named as Lyb1, Lyb2, and Lyb3, were cloned from the liver and oral gland of Japanese lamprey (Lampetra japonica) using reverse transcript-PCR (RT-PCR) and rapid amplification of cDNA ends (RACE) techniques. Further bioinformatical analysis indicated that the three Y-box genes of lamprey, i.e., Lyb1, Lyb2, and Lyb3, encoded 331, 181, and 171 amino acids, respectively. The three amino acid sequences were homologically aligned with those from Ciona intestinalis, Danio rerio, Oryzias latipes, Takifugu rubripes, and Mus musculus by DNAMAN software. The Lyb genes were novel members of Y-box gene family containing a conserved cold-shock domain with two RNA binding motifs (RNP-1 and RNP-2). Moreover, phylogenetic analysis revealed that there was only one type of Y-box gene before the emergence of gnathostomata. By contrast, the Y-box gene were divided into three groups, YB1, YB2, and CSDA during evolution of jawed vertebrates.