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Flagellar morphology

Fumiaki Makino, Dakang Shen, Naoko Kajimura, Akihiro Kawamoto, Panayiota Pissaridou, Henry Oswin, Maria Pain, Isabel Murillo, Keiichi Namba, Ariel J Blocker
Type III secretion systems (T3SSs) are essential devices in the virulence of many Gram-negative bacterial pathogens. They mediate injection of protein effectors of virulence from bacteria into eukaryotic host cells to manipulate them during infection. T3SSs involved in virulence (vT3SSs) are evolutionarily related to bacterial flagellar protein export apparatuses (fT3SSs), which are essential for flagellar assembly and cell motility. The structure of the external and transmembrane parts of both fT3SS and vT3SS is increasingly well-defined...
September 30, 2016: Scientific Reports
Aamir Maqbool, Imtiaz Ahmed
The present study deals with the description of a new piscine trypanosome species found infecting the fresh water fish Schizothorax plagiostomus Heckel from river Jhelum, Srinagar, J&K, India and evaluating the haematological parameters of the infected fish. Haematological examination of S. plagiostomus revealed 61.1 % infection with an intensity of 1-9 trypanosomes/100 RBC's. Small (26.9 ± 1.39 µm) and large (47.17 ± 3.50 µm) forms of the trypanosome were observed in light microscopy investigations, revealing the dimorphic nature of the species...
September 2016: Journal of Parasitic Diseases: Official Organ of the Indian Society for Parasitology
Jun-Hao Zhou, Qi-Zhao Zhou, Jian-Kun Yang, Xiao-Ming Lyu, Jun Bian, Wen-Bin Guo, Zi-Jian Chen, Ming Xia, Hui Xia, Tao Qi, Xin Li, Cun-Dong Liu
Cysteine-rich secretory protein 2 (CRISP2) is an important protein in spermatozoa that plays roles in modulating sperm flagellar motility, the acrosome reaction, and gamete fusion. Spermatozoa lacking CRISP2 exhibit low sperm motility and abnormal morphology. However, the molecular mechanisms underlying the reduction of CRISP2 in asthenoteratozoospermia (ATZ) remain unknown. In this study, low expression of CRISP2 protein rather than its mRNA was observed in the ejaculated spermatozoa from ATZ patients as compared with normozoospermic males...
August 12, 2016: Asian Journal of Andrology
Leandro S Sangenito, Diego S Gonçalves, Sergio H Seabra, Claudia M d'Avila-Levy, André L S Santos, Marta H Branquinha
There is a general lack of effective and non-toxic chemotherapeutic agents against Chagas' disease despite more than a century of research. In this regard, we have verified the impact of human immunodeficiency virus aspartic peptidase inhibitors (HIV-PIs) on the viability and morphology of infective trypomastigote forms of Trypanosoma cruzi as well as on the aspartic peptidase and proteasome activities produced by this parasite. The effects of HIV-PIs on viability were assessed by counting motile parasites in a Neubauer chamber...
October 2016: International Journal of Antimicrobial Agents
Ki Hwan Moon, Xiaowei Zhao, Akarsh Manne, Juyu Wang, Zhou Yu, Jun Liu, Md A Motaleb
Borrelia burgdorferi, the causative agent of Lyme disease, is a highly motile spirochete, and motility, which is provided by its periplasmic flagella, is critical for every part of the spirochete's enzootic life cycle. Unlike externally flagellated bacteria, spirochetes possess a unique periplasmic flagellar structure called the collar. This spirochete-specific novel component is linked to the flagellar basal body; however, nothing is known about the proteins encoding the collar or their function in any spirochete...
July 15, 2016: Molecular Microbiology
Brijesh Kumar, Silvia T Cardona
Burkholderia cenocepacia belongs to the Burkholderia cepacia complex (Bcc), a group of at least 18 distinct species that establish chronic infections in the lung of people with the genetic disease cystic fibrosis (CF). The sputum of CF patients is rich in amino acids and was previously shown to increase flagellar gene expression in B. cenocepacia. We examined flagellin expression and flagellar morphology of B. cenocepacia grown in synthetic cystic fibrosis sputum medium (SCFM) compared to minimal medium. We found that CF nutritional conditions induce increased motility and flagellin expression...
2016: Frontiers in Cellular and Infection Microbiology
Takashi Shiratori, Ken-Ichiro Ishida
We report a new heterotrophic cryptomonad Hemiarma marina n. g., n. sp. that was collected from a seaweed sample from the Republic of Palau. In our molecular phylogenetic analyses using the small subunit ribosomal RNA gene, H. marina formed a clade with two marine environmental sequences, and the clade was placed as a sister lineage of the freshwater cryptomonad environmental clade CRY1. Alternatively, in the concatenated large and small subunit ribosomal RNA gene phylogeny, H. marina was placed as a sister lineage of Goniomonas...
May 24, 2016: Journal of Eukaryotic Microbiology
Pablo Sartori, Veikko F Geyer, Andre Scholich, Frank Jülicher, Jonathon Howard
Cilia and flagella are model systems for studying how mechanical forces control morphology. The periodic bending motion of cilia and flagella is thought to arise from mechanical feedback: dynein motors generate sliding forces that bend the flagellum, and bending leads to deformations and stresses, which feed back and regulate the motors. Three alternative feedback mechanisms have been proposed: regulation by the sliding forces, regulation by the curvature of the flagellum, and regulation by the normal forces that deform the cross-section of the flagellum...
2016: ELife
Elsio A Wunder, Cláudio P Figueira, Nadia Benaroudj, Bo Hu, Brian A Tong, Felipe Trajtenberg, Jun Liu, Mitermayer G Reis, Nyles W Charon, Alejandro Buschiazzo, Mathieu Picardeau, Albert I Ko
Leptospira are unique among bacteria based on their helical cell morphology with hook-shaped ends and the presence of periplasmic flagella (PF) with pronounced spontaneous supercoiling. The factors that provoke such supercoiling, as well as the role that PF coiling plays in generating the characteristic hook-end cell morphology and motility, have not been elucidated. We have now identified an abundant protein from the pathogen L. interrogans, exposed on the PF surface, and named it Flagellar-coiling protein A (FcpA)...
August 2016: Molecular Microbiology
Clémentine Wambergue, Raoudha Zouari, Selima Fourati Ben Mustapha, Guillaume Martinez, Françoise Devillard, Sylviane Hennebicq, Véronique Satre, Sophie Brouillet, Lazhar Halouani, Ouafi Marrakchi, Mounir Makni, Habib Latrous, Mahmoud Kharouf, Florence Amblard, Christophe Arnoult, Pierre F Ray, Charles Coutton
STUDY QUESTION: Does DNAH1 status influence intracytoplasmic sperm injection (ICSI) outcomes for patients with multiple morphological abnormalities of the sperm flagella (MMAF)? SUMMARY ANSWER: Despite a highly abnormal morphology, sperm from MMAF patients with DNAH1 mutations have a low aneuploidy rate and good nuclear quality, leading to good embryonic development following ICSI and a high pregnancy rate. WHAT IS KNOWN ALREADY: Teratozoospermia represents a heterogeneous group including a wide range of phenotypes...
June 2016: Human Reproduction
Emmanuel Tetaud, Michèle Lefebvre, Diane-Ethna M'Bang-Benet, Lucien Crobu, Corinne Blancard, Yvon Sterkers, Michel Pages, Patrick Bastien, Gilles Merlin
TbFlabarin is the Trypanosoma brucei orthologue of the Leishmania flagellar protein LdFlabarin but its sequence is 33% shorter than LdFlabarin, as it lacks a C-terminal domain that is indispensable for LdFlabarin to localize to the Leishmania flagellum. TbFlabarin is mainly expressed in the procyclic forms of the parasite and localized to the flagellum, but only when two palmitoylable cysteines at positions 3 and 4 are present. TbFlabarin is more strongly attached to the membrane fraction than its Leishmania counterpart, as it resists complete solubilization with as much as 0...
July 2016: Experimental Parasitology
Célia Fontana, Ambroise Lambert, Nadia Benaroudj, David Gasparini, Olivier Gorgette, Nathalie Cachet, Natalia Bomchil, Mathieu Picardeau
Pathogenic Leptospira strains are responsible for leptospirosis, a worldwide emerging zoonotic disease. These spirochetes are unique amongst bacteria because of their corkscrew-like cell morphology and their periplasmic flagella. Motility is reported as an important virulence determinant, probably favoring entry and dissemination of pathogenic Leptospira in the host. However, proteins constituting the periplasmic flagella and their role in cell shape, motility and virulence remain poorly described. In this study, we characterized a spontaneous L...
2016: PloS One
Helen Pinto Santos, Marcelo Silva Barcellos, Aline Beatriz Reis, Heidi Dolder, José Lino-Neto
Sperm morphology of the parasitoid Muscidifurax uniraptor was investigated under light and transmission electron microscopy. M. uniraptor sperm are filiform, spiraled, approximately 150 μm in length, with a distinctive head, hooded by an extracellular sheath and a flagellum. This extracellular layer, from which many filaments radiate, measures approximately 90 nm in thickness and covers a small acrosome and the anterior nuclear region. The acrosome is composed of an acrosomal vesicle and a perforatorium with its base inserted in the nuclear tip...
May 2016: Arthropod Structure & Development
Joel L Bargul, Jamin Jung, Francis A McOdimba, Collins O Omogo, Vincent O Adung'a, Timothy Krüger, Daniel K Masiga, Markus Engstler
African trypanosomes thrive in the bloodstream and tissue spaces of a wide range of mammalian hosts. Infections of cattle cause an enormous socio-economic burden in sub-Saharan Africa. A hallmark of the trypanosome lifestyle is the flagellate's incessant motion. This work details the cell motility behavior of the four livestock-parasites Trypanosoma vivax, T. brucei, T. evansi and T. congolense. The trypanosomes feature distinct swimming patterns, speeds and flagellar wave frequencies, although the basic mechanism of flagellar propulsion is conserved, as is shown by extended single flagellar beat analyses...
February 2016: PLoS Pathogens
Carlo Polidori, Amanda Freitas-Cerqueira, Juli Pujade-Villar, Francesc Oliva, Mar Ferrer-Suay
The antennal sensillar equipment in the parasitic wasp family Figitidae was analyzed to date only in few species, despite some are associated with crop pests and can have an economic importance. It is the case of the genus Alloxysta, which includes hyperparasitoids of aphids which can potentially reduce effectiveness of primary pest parasitoids. Here we analyzed, through scanning electron microscopy, the diversity, morphology, and distribution of the antennal sensilla in males and females of Alloxysta consobrina (Zetterstedt) and Alloxysta victrix (Westwood), two species with overall very similar morphology...
2016: Journal of Insect Science
Glenda Dias, José Lino-Neto, David Mercati, Romano Dallai
The sperm structure and spermiogenesis of the morphologically peculiar heteropteran Coptosoma scutellatum has been examined with electron microscopy. The sperm has a short monolayer acrosome, a cylindrical nucleus, a 9+9+2 axoneme and two mitochondrial derivatives with crystallized matrix. It shows the synapomorphies typical of the group, consisting of (a) two crystallized areas in the mitochondrial derivatives; (b) the presence of two bridges connecting the intertubular material of the flagellar axoneme to the flattened cisterns adhering to the inner sides of the mitochondrial derivatives; (c) the absence of accessory bodies...
March 2016: Micron: the International Research and Review Journal for Microscopy
Justin L Rheubert, David M Sever, Dustin S Siegel, Kevin M Gribbins
Studies on reptilian sperm morphology have shown that variation exists at various taxonomic levels but studies on the ontogeny of variation are rare. Sperm development follows a generalized bauplan that includes acrosome development, nuclear condensation and elongation, and flagellar development. However, minute differences can be observed such as the presence/absence of manchette microtubules, structural organization during nuclear condensation, and presence/absence of a nuclear lacuna. The purpose of this investigation was to examine sperm development within the Sceloporus genus...
February 2016: Micron: the International Research and Review Journal for Microscopy
Rute Pereira, Rosália Sá, Alberto Barros, Mário Sousa
The genetic bases and molecular mechanisms involved in the assembly and function of the flagellum components as well as in the regulation of the flagellar movement are not fully understood, especially in humans. There are several causes for sperm immotility, of which some can be avoided and corrected, whereas other are related to genetic defects and deserve full investigation to give a diagnosis to patients. This review was performed after an extensive literature search on the online databases PubMed, ScienceDirect, and Web of Science...
December 15, 2015: Asian Journal of Andrology
Claude Lemieux, Antony T Vincent, Aurélie Labarre, Christian Otis, Monique Turmel
BACKGROUND: The class Chlorophyceae (Chlorophyta) includes morphologically and ecologically diverse green algae. Most of the documented species belong to the clade formed by the Chlamydomonadales (also called Volvocales) and Sphaeropleales. Although studies based on the nuclear 18S rRNA gene or a few combined genes have shed light on the diversity and phylogenetic structure of the Chlamydomonadales, the positions of many of the monophyletic groups identified remain uncertain. Here, we used a chloroplast phylogenomic approach to delineate the relationships among these lineages...
2015: BMC Evolutionary Biology
Mei Matsuzaki, Shusei Mizushima, Gen Hiyama, Noritaka Hirohashi, Kogiku Shiba, Kazuo Inaba, Tomohiro Suzuki, Hideo Dohra, Toshiyuki Ohnishi, Yoshikatsu Sato, Tetsuya Kohsaka, Yoshinobu Ichikawa, Yusuke Atsumi, Takashi Yoshimura, Tomohiro Sasanami
Although successful fertilization depends on timely encounters between sperm and egg, the decoupling of mating and fertilization often confers reproductive advantages to internally fertilizing animals. In several vertebrate groups, postcopulatory sperm viability is prolonged by storage in specialized organs within the female reproductive tract. In birds, ejaculated sperm can be stored in a quiescent state within oviductal sperm storage tubules (SSTs), thereby retaining fertilizability for up to 15 weeks at body temperature (41°C); however, the mechanism by which motile sperm become quiescent within SSTs is unknown...
2015: Scientific Reports
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