STRUCTURAL ANALYSIS OF ETS-RELATED GENES IN LOWER EUKARYOTES

低等真核生物ets家族基因的研究主要集中在：1）可能的 面包酵母（Saccharomyces cerevisiae）中的ets序列; 2）一种erg 海胆中的同源物; 3）在禽白血病病毒E26中发现的倒位 v-ets; 4）整个ets家族的系统发育分析。 (1)低 严格杂交S.酿酒酵母DNA被四种不同的 一组酶对放射性标记的海胆ets探针显示， 每组酶大约有四个主要条带。 三个独特 分离与ETS序列杂交的噬菌体λ克隆 通过筛选S.酿酒酵母基因组文库。 (2)来自海胆Lytechinus variegatus的基因组克隆被发现， 是ets家族基因ERG和Fli-1的同源物。 它包含一个 开放阅读框，其173个氨基酸的编码区开始于 剪接受体位点。 这些氨基酸中的前84个与 所有的ets家族基因，而序列的其余部分代表一个 高度保守的erg-specific结构域。 (3)E26基因组的片段 在p135 gag-myb-ets的末端附近发现开放阅读框 以包含鸡ETS-1序列的倒位。 反演 包含至少41 bp，并且可以大至46 bp。 这导致 将鸡ETS-1的13个氨基酸替换为16个氨基酸， 衍生自正常ETS-1编码链的反向互补序列，或 通读到E26 env序列中。 改变的羧基末端 序列可能是负责不同的致癌潜力的v- 与鸡ETS-1相比， (4)对32个物种进行系统发育分析 ets序列分析表明，该基因家族可分为11个基因， 分组。 对这些集群的分析可以让我们了解 在后生动物的背景下进行检查的ets基因家族 辐射 在三个门中发现了与Homelets-related基因 （脊索动物门、棘皮动物门和节肢动物门）。 在10个分组中，有4个分组 代表在一个以上的门，这意味着几个基因， 重复发生在这些门的分歧超过500 百万年前

Studies of ets family genes in lower eukaryotes focused on: 1) possible ets sequences in the baker's yeast (Saccharomyces cerevisiae); 2) an erg homolog in a sea urchin; 3) an inversion found in avian leukemia virus E26 v-ets; 4) a phylogenetic analysis of the entire ets family. (1) Low stringency hybridization of S. cerevisiae DNA digested by four different sets of enzymes to a radiolabeled sea urchin ets probe revealed approximately four major bands for each set of enzymes. Three unique bacteriophage lambda clones that hybridize to ets sequences were isolated by screening a S. cerevisiae genomic library under the same conditions. (2) A genomic clone from the sea urchin Lytechinus variegatus was found to be the homolog of the ets family genes, ERG and Fli-1. It contains an open reading frame, of which the 173 amino acid coding region begins at a splice acceptor site. The first 84 of these amino acids are homologous to all ets family genes, while the remainder of the sequence represents a highly-conserved erg-specific domain. (3) The segment of the E26 genome near the termination of the p135gag-myb-ets open reading frame was found to contain an inversion of the chicken ets-1 sequence. The inversion contains at least 41 bp, and may be as large as 46 bp. This results in the replacement of 13 amino acids of chicken ets-1, with 16 amino acids derived from the reverse complement of the normal ets-1 coding strand or read-through into E26 env sequences. The altered carboxy terminal sequences may be responsible for the different oncogenic potential of v- ets, as contrasted to chicken ets-1. (4) A phylogenetic analysis of 32 ets sequences revealed that this family of genes may be divided into 11 subgroups. Analysis of these clusters allows the history of the evolution of the ets gene family to be examined in the context of metazoan radiation. Homologous ets-related genes have been found in three phyla (Chordata, Echinodermata, and Arthropoda). Of the 10 subgroups, 4 have representatives in more than one phyla, implying that several gene duplications occurred prior to the divergence of these phyla over 500 million years ago.