Hitting all stages of the parasite life cycle

The hemoflagellateTrypanosoma cruziis the causative agent of American trypanosomiasis. Despite the importance of motility in the parasite life cycle, little is known aboutT. cruzimotility, and there is no quantitative description of its flagellar beating. Using video microscopy and quantitative vectorial analysis of epimastigote trajectories, we find a forward parasite motility defined by tip-to-base symmetrical flagellar beats. This motion is occasionally interrupted by base-to-tip highly asymmetric beats, which represent the ciliary beat of trypanosomatid flagella. The switch between flagellar and ciliary beating facilitates the parasite's reorientation, which produces a large variability of movement and trajectories that results in different distance ranges traveled by the cells. An analysis of the distance, speed, and rotational angle indicates that epimastigote movement is not completely random, and the phenomenon is highly dependent on the parasite behavior and is characterized by directed and tumbling parasite motion as well as their combination, resulting in the alternation of rectilinear and intricate motility paths.

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Encounter rate between local populations shapes host selection in complex parasite life cycle

Biological Journal of the Linnean Society ◽

10.1111/j.1095-8312.2006.00661.x ◽

2006 ◽

Vol 89 (1) ◽

pp. 99-106 ◽

Cited By ~ 12

Author(s):

GÉRALDINE LOOT ◽

YOUNG-SEUK PARK ◽

SOVAN LEK ◽

SÉBASTIEN BROSSE

Keyword(s):

Life Cycle ◽

Host Selection ◽

Encounter Rate ◽

Parasite Life Cycle ◽

Local Populations

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Structural, functional and computational studies of membrane recognition by Plasmodium Perforin-Like Proteins 1 and 2.

10.1101/2021.12.16.473088 ◽

2021 ◽

Author(s):

Sophie Williams ◽

Xiulian Yu ◽

Tao Ni ◽

Robert Gilbert ◽

Phillip Stansfeld

Keyword(s):

Life Cycle ◽

Lipid Bilayers ◽

Membrane Binding ◽

Binding Activity ◽

Life Cycles ◽

Site Directed Mutagenesis ◽

Parasite Life Cycle ◽

Dynamics Simulations ◽

Membrane Recognition

Perforin-like proteins (PLPs) play key roles in the mechanisms associated with parasitic disease caused by apicomplexans such as Plasmodium (malaria) and Toxoplasma. The T. gondii PLP1 (TgPLP1) mediates tachyzoite egress from cells, while the five Plasmodium PLPs carry out various roles in the life cycle of the parasite and with respect to the molecular basis of disease. Here we focus on Plasmodium vivax PLP1 and PLP2 (PvPLP1 and PvPLP2) compared to TgPLP1; PvPLP1 is important for invasion of mammalian hosts by the parasite and establishment of a chronic infection, PvPLP2 is important during the symptomatic blood stage of the parasite life cycle. Determination of the crystal structure of the membrane-binding APCβ domain of PvPLP1 reveals notable differences with that of TgPLP1, which are reflected in its inability to bind lipid bilayers in the way that TgPLP1 and PvPLP2 can be shown to. Molecular dynamics simulations combined with site-directed mutagenesis and functional assays allow a dissection of the binding interactions of TgPLP1 and PvPLP2 on lipid bilayers, and reveal a similar tropism for lipids found enriched in the inner leaflet of the mammalian plasma membrane. In addition to this shared mode of membrane binding PvPLP2 displays a secondary synergistic interaction side-on from its principal bilayer interface. This study underlines the substantial differences between the biophysical properties of the APCβ domains of Apicomplexan PLPs, which reflect their significant sequence diversity. Such differences will be important factors in determining the cell targeting and membrane-binding activity of the different proteins, in their different developmental roles within parasite life cycles.

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Furuncular Botfly Myiasis – A Case Report

Serbian Journal of Dermatology and Venerology ◽

10.2478/sjdv-2018-0002 ◽

2018 ◽

Vol 10 (1) ◽

pp. 9-11

Author(s):

Juliana Gao ◽

Vera Tešić ◽

Vesna Petronić Rosić

Keyword(s):

Case Report ◽

Life Cycle ◽

South America ◽

Treatment Options ◽

Local Population ◽

Body Cavity ◽

Parasite Life Cycle ◽

Susceptible Host ◽

Dermatobia Hominis ◽

Blood Sucking

Abstract Botfly myiasis is an infestation of the skin or a body cavity by developing larvae of Dermatobia hominis, one of the most common flies that cause human infestation among the local population, in regions ranging from Mexico into South America and in travelers. The life cycle starts when a female fly glues the eggs to the vector, a blood-sucking arthropod, which carries the unhatched larvae to the susceptible host. A case of furuncular botfly myiasis in an 85 year-old female with recent travel to Belize is presented here to highlight the parasite life cycle and review the different treatment options.

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The Malaria Parasite Cyclic GMP-Dependent Protein Kinase Plays a Central Role in Blood-Stage Schizogony

Eukaryotic Cell ◽

10.1128/ec.00186-09 ◽

2009 ◽

Vol 9 (1) ◽

pp. 37-45 ◽

Cited By ~ 123

Author(s):

Helen M. Taylor ◽

Louisa McRobert ◽

Munira Grainger ◽

Audrey Sicard ◽

Anton R. Dluzewski ◽

...

Keyword(s):

Life Cycle ◽

Protein Kinase ◽

Cyclic Gmp ◽

Malaria Parasite ◽

Kinase Inhibitor ◽

Blood Stage ◽

Parasite Life Cycle ◽

Dependent Protein Kinase ◽

Asexual Blood Stage ◽

Dependent Protein

ABSTRACT A role for the Plasmodium falciparum cyclic GMP (cGMP)-dependent protein kinase (PfPKG) in gametogenesis in the malaria parasite was elucidated previously. In the present study we examined the role of PfPKG in the asexual blood-stage of the parasite life cycle, the stage that causes malaria pathology. A specific PKG inhibitor (compound 1, a trisubstituted pyrrole) prevented the progression of P. falciparum schizonts through to ring stages in erythrocyte invasion assays. Addition of compound 1 to ring-stage parasites allowed normal development up to 30 h postinvasion, and segmented schizonts were able to form. However, synchronized schizonts treated with compound 1 for ≥6 h became large and dysmorphic and were unable to rupture or liberate merozoites. To conclusively demonstrate that the effect of compound 1 on schizogony was due to its selective action on PfPKG, we utilized genetically manipulated P. falciparum parasites expressing a compound 1-insensitive PfPKG. The mutant parasites were able to complete schizogony in the presence of compound 1 but not in the presence of the broad-spectrum protein kinase inhibitor staurosporine. This shows that PfPKG is the primary target of compound 1 during schizogony and provides direct evidence of a role for PfPKG in this process. Discovery of essential roles for the P. falciparum PKG in both asexual and sexual development demonstrates that cGMP signaling is a key regulator of both of these crucial life cycle phases and defines this molecule as an exciting potential drug target for both therapeutic and transmission blocking action against malaria.

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