小柯机器人

近日，荷兰乌得勒支大学Tzviya Zeev-Ben-Mordehai等研究人员合作揭示精子尾巴的结构特化。相关论文于2023年6月15日在线发表在《细胞》杂志上。

研究人员展示了来自海胆和牛精子的原生轴丝微管二联体（DMT）的高分辨率结构，代表了体外和体内的受精者。研究人员确定了超过60种装饰精子DMT的蛋白质；至少有15种与精子有关，16种与不孕症有关。通过比较不同物种和细胞类型的DMT，研究人员定义了核心微管内蛋白（MIP），并分析了tektin束的演变。研究人员发现保守的轴突微管相关蛋白（MAP）具有独特的微管蛋白结合模式。此外，研究人员确定了一种睾丸特异性的丝氨酸/苏氨酸激酶，它将哺乳动物精子中的DMT与外部致密纤维联系起来。这项研究为在分子水平上理解精子的演化、运动性和功能障碍提供了结构基础。

据悉，精子的运动能力对于有性生殖的生物体的生殖成功至关重要。精子运动受损导致男性不育，这种情况在全球范围内不断增加。精子由一个基于微管的分子机器（轴丝）提供动力，但目前还不清楚轴丝微管是如何在不同的受精环境中被装饰以支持运动的。

附：英文原文

Title: Structural specializations of the sperm tail

Author: Miguel Ricardo Leung, Jianwei Zeng, Xiangli Wang, Marc C. Roelofs, Wei Huang, Riccardo Zenezini Chiozzi, Johannes F. Hevler, Albert J.R. Heck, Susan K. Dutcher, Alan Brown, Rui Zhang, Tzviya Zeev-Ben-Mordehai

Issue&Volume: 2023-06-15

Abstract: Sperm motility is crucial to reproductive success in sexually reproducing organisms. Impaired sperm movement causes male infertility, which is increasing globally. Sperm are powered by a microtubule-based molecular machine—the axoneme—but it is unclear how axonemal microtubules are ornamented to support motility in diverse fertilization environments. Here, we present high-resolution structures of native axonemal doublet microtubules (DMTs) from sea urchin and bovine sperm, representing external and internal fertilizers. We identify >60 proteins decorating sperm DMTs; at least 15 are sperm associated and 16 are linked to infertility. By comparing DMTs across species and cell types, we define core microtubule inner proteins (MIPs) and analyze evolution of the tektin bundle. We identify conserved axonemal microtubule-associated proteins (MAPs) with unique tubulin-binding modes. Additionally, we identify a testis-specific serine/threonine kinase that links DMTs to outer dense fibers in mammalian sperm. Our study provides structural foundations for understanding sperm evolution, motility, and dysfunction at a molecular level.

DOI: 10.1016/j.cell.2023.05.026

Source: https://www.cell.com/cell/fulltext/S0092-8674(23)00576-7