The dynamics of DAXX protein distribution in the nucleus of mouse early embryos
The dynamics of DAXX protein distribution in the nucleus of mouse early embryos
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DOI：
10.1016/j.acthis.2019.04.007
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发表时间：
2019-01-01
影响因子：
2.5
通讯作者：
Bogolyubov, Dmitry S.
中科院分区：
文献类型：
--
作者：
Bogolyubova, Irina O.;Sailau, Zhuldyz K.;Bogolyubov, Dmitry S.
用荧光显微镜和电子显微镜研究了小鼠胚胎从受精卵到桑椹胚不同发育阶段死亡相关蛋白6（Daxx）的核分布。Daxx被发现与转录沉默的染色质主要与异染色质边缘周围的核仁前体（NPB）在研究的所有阶段。在受精卵阶段，Daxx只在雄性和雌性原核的NPB的周边检测到。在后期的两个细胞阶段，Daxx不仅定位在异染色质边缘的外周NPB，但也在异染色质区与NPB无关。在桑椹胚阶段，弥漫性分布的Daxx占主导地位。只有在核仁周边的一些胚胎中检测到罕见的Daxx阳性区。因此，Daxx在小鼠胚胎卵裂过程中显著地重新分布，并且在两细胞期结束时观察到Daxx浓度的最明显区域。Daxx与染色质重塑蛋白ATRX仅在两细胞胚胎中共定位，但在此阶段也观察到含有Daxx或ATRX的异染色质区域。然而，大多数含有Daxx和ATRX的区域表现出较低的FRET效率。这表明两个分子没有足够接近以发生分子相互作用。我们的数据表明，Daxx的功能可能不与ATRX合作，至少在小鼠早期发育的某些阶段。
Nuclear distribution of Death-associated protein 6 (Daxx) was studied using fluorescent and electron microscopy in mouse embryos at different stages of development in vivo, from zygote to morula. Daxx was found in association with transcriptionally silent chromatin predominantly with a heterochromatin rim surrounding the nucleolus precursor bodies (NPBs) at all stages studied. At the zygote stage, Daxx was detected only at the periphery of NPBs both in male and female pronuclei. At the late two-cell stage, Daxx was localized not only in the heterochromatin rim at the periphery of NPBs but also in heterochromatin zones not associated with NPBs. At the morula stage, a diffuse distribution of Daxx prevailed. Scarce Daxx-positive zones were detected only in some embryos at the nucleolar periphery. Thus, Daxx is noticeably redistributed during mouse embryo cleavage, and the most conspicuous areas of Daxx concentration are observed at the end of two-cell stage. Daxx is found colocalized with the chromatin-remodeling protein ATRX exclusively in two-cell embryos, but the heterochromatin areas containing either Daxx or ATRX individually are also observed at this stage. However, most zones containing both Daxx and ATRX demonstrated a low FRET-efficiency. This suggest that two molecules are not approached sufficiently close for molecular interactions to occur. Our data suggests that Daxx may function without cooperation with ATRX at least at some stages of early mouse development.