I element distribution in mitotic heterochromatin of Drosophila melanogaster reactive strains:: identification of a specific site which is correlated with the reactivity levels
I element distribution in mitotic heterochromatin of Drosophila melanogaster reactive strains:: identification of a specific site which is correlated with the reactivity levels
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DOI：
10.1159/000084948
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发表时间：
2005-01-01
影响因子：
1.7
通讯作者：
Bucheton, A
中科院分区：
文献类型：
--
作者：
Dimitri, P;Bucheton, A
I因子是一种在I-R杂种发育不全的遗传系统中有效转座的果蝇LINE样元件。研究表明，某些与I相关的序列可能位于D.黑腹动物参与I因子活性的调节。在这项工作中，我们进行了荧光原位杂交（FISH）定位的I元件序列在有丝分裂异染色质的9个差异反应D。黑腹菌菌株。我们的分析结果表明，一个单一的杂交位点映射到区域H28的远端异染色质的X染色体是存在于三个菌株具有低或中等水平的反应性，而它是无法检测到在6个高反应性菌株。总之，这些观察结果表明位于h28的I序列与反应性水平之间存在负相关性。在这方面，有趣的是，弗拉门戈和COM，两个基因座调节D。黑腹果蝇内源性逆转录病毒也定位于X染色体的远端异染色质。我们的数据代表的第一个实验证据，有利于沉默的作用，自然发生的I元件序列位于着丝粒周围异染色质。版权所有（c）2005 S. Karger AG，巴塞尔。
The I factor is a Drosophila melanogaster LINE-like element that efficiently transposes in the genetic system of I-R hybrid dysgenesis. It has been suggested that some of the I-related sequences located in the heterochromatin of D. melanogaster are involved in the regulation of I factor activity. In this work we have performed fluorescent in situ hybridization (FISH) mapping of I element sequences in mitotic heterochromatin of nine differentially reactive D. melanogaster strains. The results of our analysis showed that a single hybridization site mapping to region h28 of the distal heterochromatin of the X chromosome is present in three strains with low or intermediate levels of reactivity, while it is undetectable in six highly reactive strains. Together, these observations suggest a negative correlation between I sequences located at h28 and the level of reactivity. To this regard, it is intriguing that flamenco and COM, two loci that regulate the activity of D. melanogaster endogenous retroviruses also map to the distal heterochromatin of the X chromosome. Our data represent the first experimental evidence in favour of a silencing effect exerted by naturally occurring I element sequences located in pericentromeric heterochromatin. Copyright (c) 2005 S. Karger AG, Basel.