Telomeric Position Effects in Drosophila

果蝇端粒位置效应

• 批准号: 9304866
• 负责人: Robert Levis
• 金额: $ 35.56万
• 依托单位: Fred Hutchinson Cancer Research Center
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-09-01 至 1997-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9304866&HistoricalAwards=false
• 关键词: Telomeric; Position; Effects; Drosophila

Chromosomes of eukaryotes have regions of differing compaction termed heterochromatin and euchromatin. Heterochromatin has a high density of repetitious DNA, few genes and little transcription. Active genes, most of which are found in the euchromatin, are inactivated if they are removed to heterochromatic regions. This effect, called position effect variegation (PEV), has been extensively studied in Drosophila melanogaster, the fruit fly. There is evidence that the telomeric regions at the ends of eukaryotic chromosomes are specialized heterochromatic-like domains. The project proposed uses telomeric PEV in Drosophila to investigate telomeric chromatin by identification of telomeric non- histone proteins and telomeric DNA sequences which bind those proteins. A white eye color gene flanked by telomeric sequences will be integrated at non-telomeric locations and the expression of that gene with and without the telomeric sequences will be compared. A second approach will be to localize the DNA sequences necessary and/or sufficient to bind HP1, a protein characterized in other laboratories, which is implicated in chromatin condensation. %%% The primary objective of this project is to identify telomeric proteins and the DNA sequences to which they bind, but the resulting data will also be relevant to the broader question of how gene expression is regulated by chromosome condensation. Such a mechanism is thought to be critical to normal development of eukaryotic organisms.

真核生物的染色体有不同的区域， 致密化称为异染色质和常染色质。异染色 有高密度的重复DNA，很少的基因和很少的 转录。活性基因，其中大部分是在 常染色质，如果它们被移到异染色质中， 地区这种效应称为位置效应杂色（PEV）， 在黑腹果蝇（Drosophila melanogaster）中得到了广泛的研究。 有证据表明，端粒区的两端， 真核生物的染色体是特化的异染色质样的 域.该项目利用果蝇端粒PEV， 通过鉴定端粒非- 组蛋白和与之结合的端粒DNA序列 proteins.侧接端粒序列的白色眼睛颜色基因 将整合在非端粒位置， 有没有端粒序列的基因 比较了第二种方法是定位DNA序列 必需和/或足以结合HP 1的蛋白质，其特征在于 其他实验室，这是牵连在染色质凝聚。 %%% 本项目的主要目的是鉴定端粒 蛋白质和它们所结合的DNA序列，但 由此产生的数据也将与如何解决更广泛的问题相关 基因表达受染色体浓缩的调节。这样的 机制被认为是至关重要的正常发展， 真核生物