Modification of the Drosophila heterochromatic mutation brownDominant by linkage alterations.
Modification of the Drosophila heterochromatic mutation brownDominant by linkage alterations.
复制标题
通过连锁改变对果蝇异染色质突变棕色显性进行修饰。
DOI：
10.1093/genetics/136.2.559
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发表时间：
1994
期刊：
影响因子：
3.3
通讯作者：
Henikoff,S
中科院分区：
文献类型：
--
作者：
Talbert,PB;LeCiel,CD;Henikoff,S
果蝇棕色优势基因(BWD)与异染色质插入到染色体臂2R的59E位有关。诱变产生了150个BWD杂化的显性抑制因子。它们分为两类：非连锁抑制子，它也抑制其他杂色突变；以及连锁染色体重排，它只抑制BWD。一些重排在59E处被破坏，因此可能直接干扰该位置的异色插入引起的杂色。然而，大多数重排是在2R的52D-57D区域内BW近端断裂的易位。X染色体上的易位断裂点散布在X常染色质上，而3号染色体上的易位断裂点仅限于顶端。这表明，X染色体的一种特殊性质抑制了BWD的变异，就像常染色体末端的位置一样。相反，BWD的两个增强子是由2R的同一部分移位到近端异染色质引起的，使BWD异染色质插入接近其强烈相关的染色质中心。这些结果支持这样的观点，即一个遗传位点上异染色质的形成取决于它在细胞核内的位置。
The variegating mutation brownDominant (bwD) of Drosophila melanogaster is associated with an insertion of heterochromatin into chromosome arm 2R at 59E, the site of the bw gene. Mutagenesis produced 150 dominant suppressors of bwD variegation. These fall into two classes: unlinked suppressors, which also suppress other variegating mutations; and linked chromosome rearrangements, which suppress only bwD. Some rearrangements are broken at 59E, and so might directly interfere with variegation caused by the heterochromatic insertion at that site. However, most rearrangements are translocations broken proximal to bw within the 52D-57D region of 2R. Translocation breakpoints on the X chromosome are scattered throughout the X euchromatin, while those on chromosome 3 are confined to the tips. This suggests that a special property of the X chromosome suppresses bwD variegation, as does a distal autosomal location. Conversely, two enhancers of bwD are caused by translocations from the same part of 2R to proximal heterochromatin, bringing the bwD heterochromatic insertion close to the chromocenter with which it strongly associates. These results support the notion that heterochromatin formation at a genetic locus depends on its location within the nucleus.