Maternally derived FILIA-MATER complex localizes asymmetrically in cleavage-stage mouse embryos
Maternally derived FILIA-MATER complex localizes asymmetrically in cleavage-stage mouse embryos
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DOI：
10.1242/dev.011445
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发表时间：
2008-01-15
期刊：
影响因子：
4.6
通讯作者：
Dean, Jurrien
中科院分区：
文献类型：
--
作者：
Ohsugi, Mami;Zheng, Ping;Dean, Jurrien
在胚胎着床前小鼠发育过程中，8个卵裂球致密形成极化的胚泡，形成了预示着内细胞团和胚外滋养外胚层的初始细胞系。FILIA已被鉴定为母体效应基因编码的母体抗原MATER（胚胎所需的母体抗原，也称为NLRP5）的结合伴侣。每个基因的产物都在生长中的卵母细胞中检测到，尽管转录本在受精前被降解，但同源蛋白在早期囊胚中持续存在。这两种蛋白共同定位于排卵卵子的细胞皮层，其中FILIA的稳定性依赖于MATER的存在。受精后，由于在细胞-细胞接触区域中缺失，FILIA-MATER复合物在两细胞胚胎的顶端细胞皮层中不对称地受到限制。这种不对称在二细胞和四细胞胚胎的卵裂球解体后是可逆的。每种蛋白都存在于着床前胚胎的细胞中，但桑葚胚“内部”细胞的连续细胞-细胞接触似乎排除了皮层下细丝- mater复合物的形成，并导致以其存在（“外部”）或不存在（“内部”）为标志的细胞群体。因此，FILIA-MATER复合体提供了胚胎细胞系的分子标记，但尚不清楚首次细胞分裂后建立的分子不对称是否在早期小鼠胚胎中决定细胞命运中起作用。
Initial cell lineages that presage the inner cell mass and extra-embryonic trophectoderm are established when eight blastomeres compact to form polarized morulae in preimplantation mouse development. FILIA has been identified as a binding partner to MATER (maternal antigen that embryos require; also known as NLRP5), which is encoded by a maternal effect gene. Products of each gene are detected in growing oocytes and, although transcripts are degraded before fertilization, the cognate proteins persist in early blastocysts. The two proteins co-localize to the cytocortex of ovulated eggs, where the stability of FILIA is dependent on the presence of MATER. After fertilization, FILIA-MATER complexes become asymmetrically restricted in the apical cytocortex of two-cell embryos due to their absence in regions of cell-cell contact. This asymmetry is reversible upon disaggregation of blastomeres of the two- and four-cell embryo. Each protein persists in cells of the preimplantation embryo, but the continuous cell-cell contact of 'inner' cells of the morulae seemingly precludes formation of the subcortical FILIA-MATER complex and results in cell populations that are marked by its presence ('outer') or absence ('inner'). Thus, the FILIA-MATER complex provides a molecular marker of embryonic cell lineages, but it remains to be determined if the molecular asymmetry established after the first cell division plays a role in cell fate determinations in the early mouse embryo.