Tritrichomonas foetus: New structures by high-resolution scanning helium ion microscopy

[摘要] Helium ion scanning microscopy (HIM) is a novel high-resolution scanning microscopy technique that uses helium ions instead of electrons to form images of the highest quality and resolution, providing a sub-nanometer resolution sputter uncoated biological cell. Here, we took advantage of HIM to explore the cell surface of Tritrichomonas foetus , a protist parasite of cattle that provokes hard infection and abortion in cows. We describe thin protrusions, like nanotubes described in other cells, with different sizes (27 nm to 81 nm in thickness) and various lengths (from 73 nm to 2 µm), as well bulbous structures either budding from the cell surface or present in the extremities of some protrusions. The flagella also presented these thin protrusions and different protein decoration, similar to those previously described using freeze-fracture techniques. Nanotubes between two cells were also seen, and their role in infection is discussed. The cell surface was also examined and showed several pits indicative of endocytic activity and other types of arrays of particles. These observations were confirmed using Scanning Electron Microscopy (SEM), negative staining, and conventional thin sectioning for observation by transmission electron microscopy. Our findings provide new and relevant information that may contribute to a better understanding of protozoan biology and its interaction with mammalian cells.

[学科分类] 仪器

[关键词] Nanotubes;Microvesicles;Surface specializations