biostudies-literatureUnknown11Coceres VMConselho Nacional de Desenvolvimento Científico e TecnológicoAgencia Nacional de Promoción Científica y Tecnológica<i>Trichomonas vaginalis</i> and <i>Tritrichomonas foetus</i> are extracellular flagellated parasites that inhabit humans and other mammals, respectively. In addition to motility, flagella act in a variety of biological processes in different cell types, and extra-axonemal structures (EASs) have been described as fibrillar structures that provide mechanical support and act as metabolic, homeostatic, and sensory platforms in many organisms. It has been assumed that <i>T. vaginalis</i> and <i>T. foetus</i> do not have EASs. However, here, we used complementary electron microscopy techniques to reveal the ultrastructure of EASs in both parasites. Such EASs are thin filaments (3-5 nm diameter) running longitudinally along the axonemes and surrounded by the flagellar membrane, forming prominentFrontiers in cellular and infection microbiology757185https://www.ebi.ac.uk/biostudies/studies/S-EPMC8630684biostudies-literatureUltrastructural and Functional Analysis of a Novel Extra-Axonemal Structure in Parasitic Trichomonads.PMC8630684Pereira-Neves Ade Miguel NIriarte LSMiranda-Magalhaes ACoceres VMSantos de Andrade TAfalseUltrastructural and Functional Analysis of a Novel Extra-Axonemal Structure in Parasitic Trichomonads.<i>Trichomonas vaginalis</i> and <i>Tritrichomonas foetus</i> are extracellular flagellated parasites that inhabit humans and other mammals, respectively. In addition to motility, flagella act in a variety of biological processes in different cell types, and extra-axonemal structures (EASs) have been described as fibrillar structures that provide mechanical support and act as metabolic, homeostatic, and sensory platforms in many organisms. It has been assumed that <i>T. vaginalis</i> and <i>T. foetus</i> do not have EASs. However, here, we used complementary electron microscopy techniques to reveal the ultrastructure of EASs in both parasites. Such EASs are thin filaments (3-5 nm diameter) running longitudinally along the axonemes and surrounded by the flagellar membrane, forming prominent2021-01-01T00:00:00Z20212026-07-14T13:45:59.39Z2025-06-01T00:05:20.197ZS-EPMC86306843485887510.3389/fcimb.2021.757185