以色列魏茨曼科学研究所Yonatan Stelzer等研究人员合作揭示兔和小鼠的沙漏型原肠运动模型。2023年5月19日，《细胞》杂志在线发表了这项成果。

研究人员表示，沙漏模型描述了同一门类中的物种在发育过程中向类似的身体计划汇聚；然而，对哺乳动物中这一现象的分子机制仍描述不详。

研究人员比较了兔子和小鼠的时间分辨分化轨迹，从而在单细胞分辨率下重新审视了这一模型。研究人员使用数百个在妊娠6.0天和8.5天之间取样的胚胎建立了原肠运动动态模型，并使用时间分辨的单细胞分化流分析框架对两个物种进行了比较。研究人员发现，尽管周围的滋养细胞和下胚层细胞的信号有差异，但在E7.5时，76个转录因子的定量保守表达支持了向类似的细胞状态组成的汇聚。然而，研究人员观察到一些谱系的特化时间发生了明显的变化，原始生殖细胞程序也发生了分化，在兔子中，这些程序不激活中胚层基因。时间分化模型的比较分析为研究不同哺乳动物的胚胎发育动态演变提供了基础。

附：英文原文

Title: Time-aligned hourglass gastrulation models in rabbit and mouse

Author: Yoav Mayshar, Ofir Raz, Saifeng Cheng, Raz Ben-Yair, Ron Hadas, Netta Reines, Markus Mittnenzweig, Oren Ben-Kiki, Aviezer Lifshitz, Amos Tanay, Yonatan Stelzer

Issue&Volume: 2023-05-19

Abstract: The hourglass model describes the convergence of species within the same phylum to a similar body plan during development; however, the molecular mechanisms underlying this phenomenon in mammals remain poorly described. Here, we compare rabbit and mouse time-resolved differentiation trajectories to revisit this model at single-cell resolution. We modeled gastrulation dynamics using hundreds of embryos sampled between gestation days 6.0 and 8.5 and compared the species using a framework for time-resolved single-cell differentiation-flows analysis. We find convergence toward similar cell-state compositions at E7.5, supported by the quantitatively conserved expression of 76 transcription factors, despite divergence in surrounding trophoblast and hypoblast signaling. However, we observed noticeable changes in specification timing of some lineages and divergence of primordial germ cell programs, which in the rabbit do not activate mesoderm genes. Comparative analysis of temporal differentiation models provides a basis for studying the evolution of gastrulation dynamics across mammals.

DOI: 10.1016/j.cell.2023.04.037

Source: https://www.cell.com/cell/fulltext/S0092-8674(23)00471-3