POLYHOMEOTIC REGULATORY SEQUENCES INDUCE DEVELOPMENTAL REGULATOR-DEPENDENT VARIEGATION AND TARGETED P-ELEMENT INSERTIONS IN DROSOPHILA
POLYHOMEOTIC REGULATORY SEQUENCES INDUCE DEVELOPMENTAL REGULATOR-DEPENDENT VARIEGATION AND TARGETED P-ELEMENT INSERTIONS IN DROSOPHILA
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DOI：
10.1101/gad.7.8.1508
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发表时间：
1993-08-01
影响因子：
10.5
通讯作者：
DURA, JM
中科院分区：
文献类型：
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作者：
FAUVARQUE, MO;DURA, JM
在含有P转座子的转座子中，在常染色质背景下观察到miniwhite基因的杂色，所述P转座子包括驻留miniwhite基因（P[ph]）上游的多同源异型（ph）基因的调控序列。这种杂色表型不受大多数异染色质位置效应杂色（PEV）遗传修饰剂的影响，也不受Y染色体去除的影响。有趣的是，它对ph和Polycomb（Pc）突变敏感，已知这些突变会影响同源异型基因调控。ph的调节DNA也可以介导miniwhite基因的转染。这种转染在ph中被消除，但在zeste突变体背景中没有。此外，P[ph]优先插入对应于多线染色体水平定义的PH/PC蛋白质结合位点的位点。这些插入诱导异常高比例的基因突变，影响同源异型基因调控。特别是，一个插入位于tramtrack轨迹内，这被认为是调节fushi tarazu，一种Ultrabithorax激活剂。我们认为，一个多聚体复合物含有PH和PC蛋白，在最低限度，导致本地和克隆遗传的异染色质化，保持抑制状态的同源异型基因的转录。
Variegation of the miniwhite gene is observed in a euchromatic context in transformant lines that contain a P transposon including regulatory sequences of the polyhomeotic (ph) gene upstream of the resident miniwhite gene (P[ph]). This variegated phenotype is not affected by most of the genetic modifiers of heterochromatic position-effect variegation (PEV) nor by removal of the Y chromosome. Interestingly, it is sensitive to ph and Polycomb (Pc) mutations, which are known to affect homeotic gene regulation. Regulatory DNA of ph can also mediate transvection of the miniwhite gene. This transvection is abolished in a ph but not in a zeste mutant background. In addition, P[ph] inserts preferentially in sites corresponding to PH/PC protein-binding sites as defined at the polytene chromosome level. These insertions induce an unusually high proportion of mutations in genes affecting homeotic gene regulation. In particular, one insertion is located within the tramtrack locus, which is thought to regulate fushi tarazu, an Ultrabithorax activator. We suggest that a multimeric complex containing PH and PC proteins, at a minimum, causes a local and clonally inherited heterochromatinization, which maintains the repressed state of transcription of the homeotic genes.