Toxoplasma gondii is a protozoan apicomplexan parasite that uses an adhesion-dependent mode of motility termed gliding to access host cells and disseminate into tissues. Previous studies on Apicomplexa motile morphotypes, including the T. gondii tachyzoite, have identified a cortical actin–myosin motor system that drives the rearward translocation of transmembrane adhesins, thus powering forward movement. However, this model is currently questioned. Here, combining micropatterning and tunable surface chemistry (to edit parasite surface ligands) with flow force and live or super-resolution imaging, we show that tachyzoites build only one apical anchoring contact with the substrate, over which it slides. Furthermore, we show that glycosaminoglycan–parasite interactions are sufficient to promote such force-productive contact and find that the apicobasal flow is set up independent of adhesin release and surface interactions. These findings should enable further characterization of the molecular functions at the T. gondii–substrate mechanosensitive interface and their comparison across apicomplexans.

弓形虫是一种原生动物顶复门寄生虫，它使用一种称为滑动的粘附依赖性运动模式来进入宿主细胞并扩散到组织中。先前对 Apicomplexa 运动形态型的研究，包括 T. gondii 速殖子，已经确定了一种皮质肌动蛋白-肌球蛋白运动系统，该系统驱动跨膜粘附素的向后易位，从而推动向前运动。然而，这种模式目前受到质疑。在这里，将微图案化和可调表面化学（以编辑寄生虫表面配体）与流力和实时或超分辨率成像相结合，我们表明速殖子只与基材建立一个顶端锚定接触，并在其上滑动。此外，我们表明糖胺聚糖-寄生虫相互作用足以促进这种力-产生接触，并发现顶基底流的建立独立于粘附蛋白释放和表面相互作用。这些发现应该能够进一步表征刚地弓形虫-底物机械敏感界面的分子功能以及它们在顶复体之间的比较。