Molecular Genetics of a New Tumor Suppressor Gene in Drosophila

我们对一种新发现的 肿瘤抑制基因（疣，缩写wts）在果蝇。 所述基因是 通过有丝分裂重组的肿瘤表型鉴定 克隆是纯合的小染色体缺陷的， wts基因。 缺乏wts基因从成虫盘细胞的原因 细胞过度增殖，可能会导致克隆变圆， 干扰定向细胞分裂的控制， 角质层被分泌细胞之间以及在他们的顶端 表面。 从细胞遗传学作图中已知wts基因是 存在于已经被克隆的DNA中。 我们将分离新的 WTS和其他未知肿瘤抑制基因的突变 用一种新的方法揭示了 有丝分裂重组克隆中的隐性突变。 我们将 鉴定对应于克隆的 通过定位DNA上的缺陷断点和wts突变 水平 我们将分离对应于wts的cDNA并确定 它们的核苷酸序列来预测 基因产物的序列和可能的功能。 抗体 将针对细菌中产生的融合基因产物， 抗体将用于定位基因产物， 光学和电子显微镜水平。 我们将标记wts克隆在 未分化的胚盘，以进一步检查 突变对克隆生长的影响和对 细胞骨架和细胞表面蛋白。 %%% 新型抑癌基因的鉴定与鉴定 在这个简单的果蝇模型系统中， 人类新肿瘤抑制基因鉴定。

We propose a molecular genetic analysis of a newly discovered tumor-suppressor gene (warts,abb.wts) in Drosophila. The gene is identified by the tumorous phenotype of mitotic-recombination clones that are homozygous for small chromosome deficiencies of the wts gene. Absence of the wts gene from imaginal disc cells causes excess cell proliferation, causes clone rounding presumably by interfering with control of oriented cell divisions, and allows cuticle to be secreted between cells as well as over their apical surfaces. The wts gene is known, from cytogenetic mapping, to be present in DNA that has already been cloned. We will isolate new mutations in wts and other unidentified tumor suppressor genes using a new method for revealing the homozygous phenotype of recessive mutations in mitotic recombination clones. We will identify the transcription unit corresponding to wts in the cloned DNA by mapping deficiency breakpoints and wts mutations at the DNA level. We will isolate cDNAs corresponding to wts and determine their nucleotide sequence in order to predict the amino acid sequence and possible function of the gene product. Antibodies will be raised against a fusion gene product made in bacteria, and the antibodies will be used to localize the gene product at both light and electron microscopic levels. We will mark wts clones in the undifferentiated imaginal disc in order to further examine the effects of the mutation on clone growth and on the distribution of cytoskeletal and cell-surface proteins. %%% The identification and characterization of novel tumor-suppressor genes in this simple model system of the fruit fly may lead to the identification of new tumor-suppressor genes in man.