The nuclear distribution of Polycomb during Drosophila melanogaster development shown with a GFP fusion protein
The nuclear distribution of Polycomb during Drosophila melanogaster development shown with a GFP fusion protein
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DOI：
10.1007/s004120050355
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发表时间：
1999-05-01
期刊：
影响因子：
1.6
通讯作者：
Paro, R
中科院分区：
文献类型：
--
作者：
Dietzel, S;Niemann, H;Paro, R
染色质蛋白Polycomb（PC）是保持同源异型基因以永久和可遗传的方式被抑制所必需的。PC是一个大的多聚体复合物（PcG蛋白）的一部分，参与在靶基因产生沉默的染色质结构域，从而防止其不适当的表达。为了评估在不同发育阶段以及在种系中的有丝分裂期间PC的核内分布，我们产生了表达PC-GFP（绿色荧光蛋白）融合蛋白的转基因果蝇品系。发现快速分裂的细胞核显示出相当均匀的PC-GFP分布。然而，随着分化程度的增加，观察到明显的亚核模式。在所有研究的二倍体体细胞组织中，大部分PC-GFP融合蛋白在有丝分裂期间从染色体中耗尽：然而，可检测的部分仍然相关。在精子发生早期的雄性生殖系中，PC-GFP与染色体二价体密切相关，并在后期逐渐丢失。有趣的是，我们发现PC与精母细胞的核仁相关，而不像体细胞核。与不显示PC-GFP信号的成熟精子相反，雌性生殖系将PC保留在生殖囊泡中。
The chromatin protein Polycomb (PC) is necessary for keeping homeotic genes repressed in a permanent and heritable manner. PC is part of a large multimeric complex (PcG proteins) involved in generating silenced chromatin domains at target genes, thus preventing their inappropriate expression. In order to assess the intranuclear distribution of PC during mitosis in different developmental stages as well as in the germ line we generated transgenic fly lines expressing a PC-GFP (Green Fluorescent Protein) fusion protein. Rapidly dividing nuclei were found to display a rather homogeneous PC-GFP distribution. However, with increasing differentiation a pronounced subnuclear pattern was observed. In all investigated diploid somatic tissues the bulk of PC-GFP fusion protein is depleted from the chromosomes during mitosis: however, a detectable fraction remains associated. In the male germ line in early spermatogenesis, PC-GFP was closely associated with the chromosomal bivalents and gradually lost at later stages. Interestingly, we found that PC is associated with the nucleolus in spermatocytes, unlike somatic nuclei. In contrast to mature sperm showing no PC-GFP signal the female germ line retains PC in the germinal vesicle.