Stage-specific chromosomal association of Drosophila dMBD2/3 during genome activation
Stage-specific chromosomal association of Drosophila dMBD2/3 during genome activation
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DOI：
10.1007/s00412-002-0188-2
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发表时间：
2002-03-01
期刊：
影响因子：
1.6
通讯作者：
Lyko, F
中科院分区：
文献类型：
--
作者：
Marhold, J;Zbylut, M;Lyko, F
果蝇基因dMBD 2/3编码一种与哺乳动物甲基DNA结合蛋白MBD 2和MBD 3具有显着同源性的蛋白质。这些蛋白质是参与表观遗传基因调控的染色质复合物的重要组成部分。由于关于dMBD 2/3的可用体外数据相互矛盾，我们已经开始了dMBD 2/3的体内表征。我们检测到两种亚型的表达，特别是在胚胎发育过程中。染色的整个胚胎结合高分辨率共聚焦显微镜显示了高度调节的空间分布。在合胞胚盘阶段，dMBD 2/3形成定位于细胞质的斑点。不久之后，在细胞胚盘阶段，蛋白质进入细胞核并形成与DNA结合的明亮灶。这种快速转变与胚胎基因组的激活相吻合。在精母细胞基因组激活期间进行了类似的观察，因为dMBD 2/3形成了与激活的Y染色体相关的不同病灶。我们的研究结果表明，dMBD 2/3形成专门的核隔室，以保持某些基因在基因组激活过程中表观遗传沉默。
The Drosophila gene dMBD2/3 encodes a protein with significant homologies to the mammalian methyl-DNA binding proteins MBD2 and MBD3. These proteins are essential components of chromatin complexes involved in epigenetic gene regulation. Because the available in vitro data on dMBD2/3 are conflicting we have started an in vivo characterization of dMBD2/3. We detected expression of two isoforms specifically during embryonic development. Staining of whole embryos combined with high-resolution confocal microscopy revealed a highly regulated spatial distribution. During the syncytial blastoderm stage, dMBD2/3 formed speckles that localized to the cytoplasm. Shortly after, during the cellular blastoderm stage, the protein entered the nucleus and formed bright foci that associated with DNA. This rapid transition coincided with the activation of the embryonic genome. A similar observation was made during activation of the spermatocyte genome as dMBD2/3 formed distinct foci associated with the activated Y chromosome. Our results indicate that dMBD2/3 forms specialized nuclear compartments to keep certain genes epigenetically silenced during genome activation.