Rabinowitz Jeremy S, Chan Xin Yi, Kingsley Evan P, Duan Yingli, Lambert J David
Department of Biology, University of Rochester, Rochester, New York 14627, USA.
Curr Biol. 2008 Mar 11;18(5):331-6. doi: 10.1016/j.cub.2008.01.055. Epub 2008 Feb 28.
During animal development, blast cell lineages are generated by repeated divisions of a mother cell into a series of daughter cells, often with a specific series of distinct fates. Nanos is a translational regulator that is involved in germline development in diverse animals and also involved in somatic patterning in insects. Recently, Nanos was found to be required for maintenance of stem cell divisions in the Drosophila germline. We have found that in the mollusk Ilyanassa, Nanos messenger RNA and protein are specifically localized in the mesendodermal blast cell lineage derived from the strongly conserved 4d cell. Nanos activity is required for differentiation of multiple tissues that are derived from the 4d cell, showing that IoNanos is required for somatic development in this embryo. At the cellular level, we show that IoNanos activity is required for the highly stereotyped cleavage pattern of the 4d lineage, the proliferative capacity of the blast cells, and the marked asymmetry of the blast cell divisions. These results suggest that IoNanos is involved in regulating blast cell behaviors in the 4d lineage.
在动物发育过程中，母细胞通过反复分裂产生一系列子细胞，从而形成胚细胞谱系，这些子细胞通常具有一系列特定的不同命运。Nanos是一种翻译调节因子，参与多种动物的生殖系发育，也参与昆虫的体细胞模式形成。最近发现，Nanos是果蝇生殖系中维持干细胞分裂所必需的。我们发现，在软体动物伊利亚那萨（Ilyanassa）中，Nanos信使核糖核酸（mRNA）和蛋白质特异性定位于源自高度保守的4d细胞的中内胚层胚细胞谱系中。源自4d细胞的多种组织的分化需要Nanos活性，这表明伊利亚那萨Nanos（IoNanos）是该胚胎体细胞发育所必需的。在细胞水平上，我们表明IoNanos活性对于4d谱系高度定型的分裂模式、胚细胞的增殖能力以及胚细胞分裂的明显不对称性是必需的。这些结果表明，IoNanos参与调节4d谱系中的胚细胞行为。
