The embryonic origin of primordial germ cells in the tardigrade Hypsibius exemplaris
The embryonic origin of primordial germ cells in the tardigrade Hypsibius exemplaris
复制标题
缓步动物原始生殖细胞的胚胎起源
DOI：
10.1016/j.ydbio.2023.02.008
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发表时间：
2023
影响因子：
2.7
通讯作者：
Goldstein, Bob
中科院分区：
文献类型：
--
作者：
Heikes, Kira L.;Game, Mandy;Smith, Frank W.;Goldstein, Bob
原始生殖细胞（PGCs）产生配子-各种生物体繁殖和生育所必需的细胞。目前对PGC发育的了解仅限于少数已被鉴定和研究的PGC生物。将该领域扩展到包括很少研究的分类群和新兴的模式生物，对于理解PGC发展演变的全部广度是重要的。在缓步动物门中，迄今为止还没有使用分子标记鉴定出早期细胞谱系。这包括PGC血统。在这里，我们描述PGC的发展模型tardigradeHypsibius exemplaris。四个最早的内化细胞（EIC）表现出PGC样的行为和核形态。EIC的位置富含保守的PGC标记swiwi 1（水熊虫piwi 1）和vasa的mRNA。在早期阶段，wiwi 1和vasamRNA在胚胎中均能检测到，这表明这些mRNA不作为PGC特化的局部决定因素。只是后来才在EIC中富集。最后，我们追踪了产生四种PGC的细胞。我们的研究结果揭示了PGC的胚胎起源的H. exemplarium，并提供了第一个在缓步动物门的早期细胞谱系的分子特征。我们预计，这些观察结果将作为一个基础，在这种动物的PGC发展的机制进行表征。
Primordial germ cells (PGCs) give rise to gametes – cells necessary for the propagation and fertility of diverse organisms. Current understanding of PGC development is limited to the small number of organisms whose PGCs have been identified and studied. Expanding the field to include little-studied taxa and emerging model organisms is important to understand the full breadth of the evolution of PGC development. In the phylum Tardigrada, no early cell lineages have been identified to date using molecular markers. This includes the PGC lineage. Here, we describe PGC development in the model tardigradeHypsibius exemplaris. The four earliest-internalizing cells (EICs) exhibit PGC-like behavior and nuclear morphology. The location of the EICs is enriched for mRNAs of conserved PGC markerswiwi1(water bearpiwi1) andvasa. At early stages, bothwiwi1andvasamRNAs are detectable uniformly in embryos, which suggests that these mRNAs do not serve as localized determinants for PGC specification. Only later arewiwi1andvasaenriched in the EICs. Finally, we traced the cells that give rise to the four PGCs. Our results reveal the embryonic origin of the PGCs ofH. exemplarisand provide the first molecular characterization of an early cell lineage in the tardigrade phylum. We anticipate that these observations will serve as a basis for characterizing the mechanisms of PGC development in this animal.