@article{SchusterLisackSubotaetal.2021, author = {Schuster, Sarah and Lisack, Jaime and Subota, Ines and Zimmermann, Henriette and Reuter, Christian and Mueller, Tobias and Morriswood, Brooke and Engstler, Markus}, title = {Unexpected plasiticty in the life cycle of Trypanosoma brucei}, series = {eLife}, volume = {10}, journal = {eLife}, doi = {10.7554/eLife.66028.sa2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-261744}, year = {2021}, abstract = {African trypanosomes cause sleeping sickness in humans and nagana in cattle. These unicellular parasites are transmitted by the bloodsucking tsetse fly. In the mammalian host's circulation, proliferating slender stage cells differentiate into cell cycle-arrested stumpy stage cells when they reach high population densities. This stage transition is thought to fulfil two main functions: first, it auto-regulates the parasite load in the host; second, the stumpy stage is regarded as the only stage capable of successful vector transmission. Here, we show that proliferating slender stage trypanosomes express the mRNA and protein of a known stumpy stage marker, complete the complex life cycle in the fly as successfully as the stumpy stage, and require only a single parasite for productive infection. These findings suggest a reassessment of the traditional view of the trypanosome life cycle. They may also provide a solution to a long-lasting paradox, namely the successful transmission of parasites in chronic infections, despite low parasitemia.}, language = {en} } @article{AlizadehradKruegerEngstleretal.2015, author = {Alizadehrad, Davod and Kr{\"u}ger, Timothy and Engstler, Markus and Stark, Holger}, title = {Simulating the complex cell design of Trypanosoma brucei and its motility}, series = {PLOS Computational Biology}, volume = {11}, journal = {PLOS Computational Biology}, number = {1}, doi = {10.1371/journal.pcbi.1003967}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-144610}, pages = {e1003967}, year = {2015}, abstract = {The flagellate Trypanosoma brucei, which causes the sleeping sickness when infecting a mammalian host, goes through an intricate life cycle. It has a rather complex propulsion mechanism and swims in diverse microenvironments. These continuously exert selective pressure, to which the trypanosome adjusts with its architecture and behavior. As a result, the trypanosome assumes a diversity of complex morphotypes during its life cycle. However, although cell biology has detailed form and function of most of them, experimental data on the dynamic behavior and development of most morphotypes is lacking. Here we show that simulation science can predict intermediate cell designs by conducting specific and controlled modifications of an accurate, nature-inspired cell model, which we developed using information from live cell analyses. The cell models account for several important characteristics of the real trypanosomal morphotypes, such as the geometry and elastic properties of the cell body, and their swimming mechanism using an eukaryotic flagellum. We introduce an elastic network model for the cell body, including bending rigidity and simulate swimming in a fluid environment, using the mesoscale simulation technique called multi-particle collision dynamics. The in silico trypanosome of the bloodstream form displays the characteristic in vivo rotational and translational motility pattern that is crucial for survival and virulence in the vertebrate host. Moreover, our model accurately simulates the trypanosome's tumbling and backward motion. We show that the distinctive course of the attached flagellum around the cell body is one important aspect to produce the observed swimming behavior in a viscous fluid, and also required to reach the maximal swimming velocity. Changing details of the flagellar attachment generates less efficient swimmers. We also simulate different morphotypes that occur during the parasite's development in the tsetse fly, and predict a flagellar course we have not been able to measure in experiments so far.}, language = {en} } @article{SchusterKruegerSubotaetal.2017, author = {Schuster, Sarah and Kr{\"u}ger, Timothy and Subota, Ines and Thusek, Sina and Rotureau, Brice and Beilhack, Andreas and Engstler, Markus}, title = {Developmental adaptations of trypanosome motility to the tsetse fly host environments unravel a multifaceted in vivo microswimmer system}, series = {eLife}, volume = {6}, journal = {eLife}, doi = {10.7554/eLife.27656}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158662}, pages = {e27656}, year = {2017}, abstract = {The highly motile and versatile protozoan pathogen Trypanosoma brucei undergoes a complex life cycle in the tsetse fly. Here we introduce the host insect as an expedient model environment for microswimmer research, as it allows examination of microbial motion within a diversified, secluded and yet microscopically tractable space. During their week-long journey through the different microenvironments of the fly´s interior organs, the incessantly swimming trypanosomes cross various barriers and confined surroundings, with concurrently occurring major changes of parasite cell architecture. Multicolour light sheet fluorescence microscopy provided information about tsetse tissue topology with unprecedented resolution and allowed the first 3D analysis of the infection process. High-speed fluorescence microscopy illuminated the versatile behaviour of trypanosome developmental stages, ranging from solitary motion and near-wall swimming to collective motility in synchronised swarms and in confinement. We correlate the microenvironments and trypanosome morphologies to high-speed motility data, which paves the way for cross-disciplinary microswimmer research in a naturally evolved environment.}, language = {en} }