A structural basis for variegating position effects
A structural basis for variegating position effects
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DOI：
10.1016/0092-8674(84)90422-7
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发表时间：
1984-07
期刊：
影响因子：
64.5
通讯作者：
K. Tartof;C. Hobbs;Marilyn Jones
中科院分区：
文献类型：
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作者：
K. Tartof;C. Hobbs;Marilyn Jones
果蝇中的位置变异效应是由于染色体重排，其中正常基因被置于异染色质旁边，在一些细胞中失活，但在另一些细胞中却不失活，从而产生了杂色组织。我们已经确定，常染色质断裂点的三个variegating白色突变体的聚集和谎言约25 kb的下游的白色结构基因。在每种情况下，白色基因座在异染色质中与移动的遗传元件邻接。卫星序列不涉及。我们还表明，变异突变体的回复体，ti4，是回复，离开初始的w“4-异染色质连接完整，使一些异染色质衍生的序列仍然加入到白色在其新的位置。这些结果提出了一个简单的模型，用于了解异染色质结构域的结构和如何variegating位置的影响可能会出现。
Variegating position effects in Drosophila result from chromosome rearrangements where normal genes, having been placed next to heterochromatin, are inactivated in some cells but not in others, thereby producing a variegated tissue. We have determined that the euchromatic breakpoints for three variegating white mutants are clustered and lie approximately 25 kb downstream of the white structural gene. In each case the white locus is adjoined in the heterochromatin to a mobile genetic element. Satellite sequences are not involved. We also demonstrate that revertants of the variegating mutant, ti4, are reinversions that leave the initial w’“4-heterochromatic junction intact so that some heterochromatin-derived sequences remain joined to white at its new location. These results suggest a simple model for understanding the structure of heterochromatic domains and how variegating position effects may arise.