Vasa unveils a common origin of germ cells and of somatic stem cells from the posterior growth zone in the polychaete Platynereis dumerilii
Vasa unveils a common origin of germ cells and of somatic stem cells from the posterior growth zone in the polychaete Platynereis dumerilii
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DOI：
10.1016/j.ydbio.2007.03.521
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发表时间：
2007-06-15
影响因子：
2.7
通讯作者：
Arendt, D.
中科院分区：
文献类型：
--
作者：
Rebscher, N.;Zelada-Gonzalez, F.;Arendt, D.
为了阐明后生动物生殖细胞规格的进化，最近的比较研究集中在祖先动物群体上。在这里，我们通过结合谱系追踪实验，通过检测Vasa和其他种系特异性因子的mRNA和蛋白表达，在多毛类环节动物Platynereis umerilii的整个生命周期中跟踪种系。在受精卵中，母体Vasa蛋白定位于动物极处的无卵黄细胞质。然后，它不对称地首先分离到微粒中，然后进入中胚层后生长区(MPGZ)的创始细胞。VASA转录最初显示无处不在的分布，但后来逐渐局限于MPGZ。BrdU脉冲标记实验证明，MPGZ的细胞高度增殖。除了Vasa，它们还表达Nanos以及干细胞特有的基因piwi和pl10。在发育4天时，四个原始生殖细胞从MPGZ内被挑选出来，并迁移到前段，在新发现的“原生性腺”上定居。我们的数据表明生殖细胞和体细胞的共同起源，类似于在脊椎动物和脊椎动物中发现的情况，这可能构成后生动物生殖细胞指定的祖先模式。(C)2007 Elsevier Inc.保留所有权利。
To elucidate the evolution of germ cell specification in Metazoa, recent comparative studies focus on ancestral animal groups. Here, we followed the germline throughout the life cycle of the polychaete annelid Platynereis dumerilii, by examining mRNA and protein expression of vasa and other germline-specific factors in combination with lineage tracing experiments. In the fertilised egg, maternal Vasa protein localises to the yolk-free cytoplasm at the animal pole. It then asymmetrically segregates first into the micromeres, then into the founder cells of the mesodermal posterior growth zone (MPGZ). Vasa transcripts initially show ubiquitous distribution, but then become progressively restricted to the MPGZ. The cells of the MPGZ are highly proliferative, as evidenced by BrdU pulse labelling experiments. Besides vasa, they express nanos along with the stem cell-specific genes piwi, and PL10. At 4 days of development, four primordial germ cells are singled out from within the MPGZ, and migrate into the anterior segments to colonise a newly discovered 'primary gonad'. Our data suggest a common origin of germ cells and of somatic stem cells, similar to the situation found in planarians and cnidarians, which may constitute the ancestral mode of germ cell specification in Metazoa. (C) 2007 Elsevier Inc. All rights reserved.