CHROMOSOMAL COMPLEMENTATION OF BLOOM SYNDROME CELLS

布卢姆综合征细胞的染色体互补

• 批准号: 2094608
• 负责人: ROGER A. SCHULTZ
• 金额: $ 22.5万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-05-01 至 1997-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2094608
• 关键词: Bloom syndrome; DNA repair; computer assisted sequence analysis; cytogenetics; gene complementation; gene mutation; genetic mapping; genetic markers; human genetic material tag; hybrid cells; ligase; linkage mapping; molecular cloning; northern blottings; nucleic acid sequence; polymerase chain reaction; tissue /cell culture; western blottings

Bloom syndrome (BSx) is an autosomal recessive disorder exhibiting a constellation of clinical features including proportional dwarfing, chronic infections, and a significant predisposition to the development of cancer. cytologically, this disease exhibits a many-fold increase in the occurrence of spontaneous chromosome breakage and sister chromatid exchanges (SCEs), the latter being diagnostic. Subtle biochemical alterations have been detected in BSx cells, but reflect consequences secondary to the elusive primary defect. Genetic analyses clearly demonstrate that BSx is a single gene defect. Linkage mapping has been compromised by rare occurrence, by poor family collections, and by a lack of availability of those limited materials which have been collected. Microcell-mediated chromosome transfer (MMCT) offers an alternative mapping approach in which individual normal human chromosomes are transferred from somatic cell hybrids into defective cells to demonstrate phenotypic complementation. Correction of the elevated SCE and chromosome breakage phenotypes of BSx cells coincides with introduction of human chromosome 15. Somatic cell hybrids possessing deletions of chromosome 15 have refined MMCT mapping to l5q23-q26. These mapping data are supported by recent genetic linkage results of others which map the BSx disease to l5q26.l. This application proposes the cloning and characterization of the BSx gene. Genomic clones (cosmids and YACs) representing this 15q26.1 region will be identified and assessed for their ability to complement BSx cells. Concurrently, several innovative approaches (focusing principally on MMCT of additional chromosome IS deletions) will be used to confirm and further refine mapping of the BSx locus. Identification of the BSx complementing genomic clone will permit isolation of a cDNA. Comparisons of mRNA levels and cDNA sequencing data from normal and BSx alleles should confirm this locus to be the primary defect for this disorder. Characterization of this gene and its protein should provide insights into mechanisms which influence recombination, SCE formation, chromosome breakage, and predilection to neoplasia.

Bloom综合征（BSX）是一种常染色体隐性疾病，表现出 临床特征的星座，包括比例矮人， 慢性感染，以及对发展的重要倾向 癌症。从细胞学上讲，该疾病的增长倍 自发染色体断裂和姐妹染色质的发生 交换（SCES），后者是诊断。微妙的生化 在BSX细胞中已检测到改变，但反映了后果 继发于难以捉摸的主要缺陷。遗传分析清楚 证明BSX是单个基因缺陷。 链接映射已经 由于罕见发生，家庭收藏不良和缺乏 收集的那些有限材料的可用性。 Microcell介导的染色体转移（MMCT）提供了替代方案 单个正常人类染色体的映射方法 从体细胞杂种转移到有缺陷的细胞中以证明 表型互补。校正升高的SCE和染色体 BSX细胞的断裂表型与引入人类一致 染色体15。具有染色体缺失的体细胞杂种15 已将MMCT映射到L5Q23-Q26。这些映射数据得到了支持 通过其他其他人的遗传联系结果，将BSX疾病映射到 L5Q26.L。该应用提出了克隆和表征 BSX基因。 代表此15Q26.1的基因组克隆（宇宙和YAC） 将确定并评估其补充BSX的能力 细胞。 同时，几种创新的方法（主要集中于 关于其他染色体的MMCT，删除）将用于确认和 进一步完善BSX基因座的映射。 识别BSX 补充基因组克隆将允许分离cDNA。比较 来自正常和BSX等位基因的mRNA水平和cDNA测序数据应 确认该基因座是该疾病的主要缺陷。 该基因及其蛋白质的表征应提供见解 影响重组，SCE形成，染色体的机制 破裂，偏爱肿瘤。