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Flagellar morphology

Yong-Qiang Zhao, Dan-Li Mu, Di Wang, Ying-Li Han, Cong-Cong Hou, Jun-Quan Zhu
Spermatogenesis represents one of the most complicated morphological transformation procedures. During this process, the assembly and maintenance of the flagella and intracellular transport of membrane-bound organelles required KIF3A and KIF3B. Our main goal was to test KIF3A and KIF3B location during spermatogenesis of Boleophthalmus pectinirostris. We cloned complete cDNA of KIF3A/3B from the testis of B. pectinirostris by PCR and rapid amplification of cDNA ends (RACE). The predicted secondary and tertiary structures of B...
March 6, 2018: Fish Physiology and Biochemistry
Daria Tashyreva, Galina Prokopchuk, Jan Votýpka, Akinori Yabuki, Aleš Horák, Julius Lukeš
Diplonemids represent a hyperdiverse and abundant yet poorly studied group of marine protists. Here we describe two new members of the genus Diplonema (Diplonemea, Euglenozoa), Diplonema japonicum sp. nov. and Diplonema aggregatum sp. nov., based on life cycle, morphology, and 18S rRNA gene sequences. Along with euglenozoan apomorphies, they contain several unique features. Their life cycle is complex, consisting of a trophic stage that is, following the depletion of nutrients, transformed into a sessile stage and subsequently into a swimming stage...
March 6, 2018: MBio
Charles Coutton, Alexandra S Vargas, Amir Amiri-Yekta, Zine-Eddine Kherraf, Selima Fourati Ben Mustapha, Pauline Le Tanno, Clémentine Wambergue-Legrand, Thomas Karaouzène, Guillaume Martinez, Serge Crouzy, Abbas Daneshipour, Seyedeh Hanieh Hosseini, Valérie Mitchell, Lazhar Halouani, Ouafi Marrakchi, Mounir Makni, Habib Latrous, Mahmoud Kharouf, Jean-François Deleuze, Anne Boland, Sylviane Hennebicq, Véronique Satre, Pierre-Simon Jouk, Nicolas Thierry-Mieg, Beatrice Conne, Denis Dacheux, Nicolas Landrein, Alain Schmitt, Laurence Stouvenel, Patrick Lorès, Elma El Khouri, Serge P Bottari, Julien Fauré, Jean-Philippe Wolf, Karin Pernet-Gallay, Jessica Escoffier, Hamid Gourabi, Derrick R Robinson, Serge Nef, Emmanuel Dulioust, Raoudha Zouari, Mélanie Bonhivers, Aminata Touré, Christophe Arnoult, Pierre F Ray
Spermatogenesis defects concern millions of men worldwide, yet the vast majority remains undiagnosed. Here we report men with primary infertility due to multiple morphological abnormalities of the sperm flagella with severe disorganization of the sperm axoneme, a microtubule-based structure highly conserved throughout evolution. Whole-exome sequencing was performed on 78 patients allowing the identification of 22 men with bi-allelic mutations in DNAH1 (n = 6), CFAP43 (n = 10), and CFAP44 (n = 6). CRISPR/Cas9 created homozygous CFAP43/44 male mice that were infertile and presented severe flagellar defects confirming the human genetic results...
February 15, 2018: Nature Communications
Yoshihiro Mouri, Moon-Sun Jang, Kenji Konishi, Aiko Hirata, Takeaki Tezuka, Yasuo Ohnishi
The rare actinomycete Actinoplanes missouriensis forms terminal sporangia containing a few hundred flagellated spores, which can swim in aquatic environments after release from sporangium. However, gene regulation for its characteristic morphological development is largely unknown. Here, we report the functional analysis of an orphan response regulator, TcrA, which is encoded next to the chemotaxis-flagellar gene cluster. The tcrA null (ΔtcrA) mutant formed sporangium, in which sporulation proceeded. However, many distorted spores were produced and some spores ectopically germinated in the mutant sporangia...
January 24, 2018: Molecular Microbiology
J X Wang, X Y Yang, H B Cheng, L Y Shen, G G Wang, Y C Shi, H Li, S M Yang
Objective: To analyze the sperm morphological characteristics of multiple morphological abnormalities of the sperm flagella (MMAF), and to analyze their common features and subtypes. Methods: Twenty-eight patients with abnormal morphology of flagella were analyzed by semen analysis. The morphological characteristics were analyzed by scanning electron microscopy and transmission electron microscopy. Histological observation of one case of testicular tissue was performed. Results: Of the 28 patients, only 13 patients (46...
December 26, 2017: Zhonghua Yi Xue za Zhi [Chinese medical journal]
E Sabaneyeva, M Castelli, F Szokoli, K Benken, N Lebedeva, A Salvetti, M Schweikert, S Fokin, G Petroni
Newly isolated strains of the ciliate Paramecium calkinsi and their cytoplasmic bacterial endosymbionts were characterized by a multidisciplinary approach, including live observation, ultrastructural investigation, and molecular analysis. Despite morphological resemblance, the characterized P. calkinsi strains showed a significant molecular divergence compared to conspecifics, possibly hinting for a cryptic speciation. The endosymbionts were clearly found to be affiliated to the species "Candidatus Trichorickettsia mobilis" (Rickettsiales, Rickettsiaceae), currently encompassing only bacteria retrieved in an obligate intracellular association with other ciliates...
December 9, 2017: European Journal of Protistology
Lucrecia Iruzubieta Villagra, Inés Ramos, Susana Cisint, Claudia A Crespo, Silvia N Fernández
Scanning and transmission electron microscopy were used to investigate the fine structure of the testis and spermatozoa of toad Leptodactylus chaquensis. Our observations indicate that germinal compartment contains Sertoli (SC) and germ cells. The tight junctions and desmosomes among SC indicate the existence of an hematotesticular barrier in charge of maintaining the differences in the composition of the germinal and interstitial compartments. During spermatogenesis, SC acts as a structural support for germ cells...
February 2018: Micron: the International Research and Review Journal for Microscopy
Jenna A Perry, Amy N Sinclair-Davis, Michael R McAllaster, Christopher L de Graffenried
Trypanosoma brucei uses multiple mechanisms to evade detection by its insect and mammalian hosts. The flagellar pocket (FP) is the exclusive site of uptake from the environment in trypanosomes and shields receptors from exposure to the host. The FP neck is tightly associated with the flagellum via a series of cytoskeletal structures that include the hook complex (HC) and the centrin arm. These structures are implicated in facilitating macromolecule entry into the FP and nucleating the flagellum attachment zone (FAZ), which adheres the flagellum to the cell surface...
February 2018: Molecular Microbiology
Alejandra C Schoijet, Kildare Miranda, Tamara Sternlieb, Nadia M Barrera, Wendell Girard-Dias, Wanderley de Souza, Guillermo D Alonso
The class III phosphatidylinositol 3-kinase (PI3K) Vps34 is an important regulator of key cellular functions, including cell growth, survival, intracellular trafficking, autophagy and nutrient sensing. In yeast, Vps34 is associated with the putative serine/threonine protein kinase Vps15, however, its role in signaling has not been deeply evaluated. Here, we have identified the Vps15 orthologue in Trypanosoma brucei, named TbVps15. Knockdown of TbVps15 expression by interference RNA resulted in inhibition of cell growth and blockage of cytokinesis...
January 2018: Molecular and Biochemical Parasitology
Aline Beatriz Reis Santos, José Lino-Neto
The sperm morphology of two predatory bugs Amphiareus constrictus and Blaptostethus pallescens, representing the tribes Dufouriellini and Blasptostethini, respectively, was described using light and transmission electron microscopy. The spermatozoa of Amphiareus constrictus and Blaptostethus pallescens are fine and long, each measuring 216.6μm and 181.0μm in length, of which 37.0μm and 11.6μm, respectively, comprise the nuclei. When stained with DAPI (for DNA), the posterior half of the nucleus in B. pallescens exhibited low fluorescence, while in A...
November 11, 2017: Micron: the International Research and Review Journal for Microscopy
Anna Albisetti, Célia Florimond, Nicolas Landrein, Keni Vidilaseris, Marie Eggenspieler, Johannes Lesigang, Gang Dong, Derrick Roy Robinson, Mélanie Bonhivers
Trypanosoma brucei belongs to a group of unicellular, flagellated parasites that are responsible for human African trypanosomiasis. An essential aspect of parasite pathogenicity is cytoskeleton remodelling, which occurs during the life cycle of the parasite and is accompanied by major changes in morphology and organelle positioning. The flagellum originates from the basal bodies and exits the cell body through the flagellar pocket (FP) but remains attached to the cell body via the flagellum attachment zone (FAZ)...
November 2017: PLoS Pathogens
Tomáš Skalický, Eva Dobáková, Richard J Wheeler, Martina Tesařová, Pavel Flegontov, Dagmar Jirsová, Jan Votýpka, Vyacheslav Yurchenko, Francisco J Ayala, Julius Lukeš
Paratrypanosoma confusum is a monoxenous kinetoplastid flagellate that constitutes the most basal branch of the highly diverse parasitic trypanosomatids, which include human pathogens Trypanosoma and Leishmania This makes Paratrypanosoma uniquely informative for the evolution of obligatory parasitism from free-living lifestyle and the evolution of human parasitism in some trypanosomatid lineages. It has typical promastigote morphology but also forms surface-attached haptomonads and amastigotes. Haptomonads form by attachment to a surface via a large bulge at the base of the flagellum, which is then remodeled into a thin attachment pad associated with flagellum shortening...
October 31, 2017: Proceedings of the National Academy of Sciences of the United States of America
Pernille Vængebjerg Boutrup, Øjvind Moestrup, Urban Tillmann, Niels Daugbjerg
A gymnodinioid photosynthetic dinoflagellate was isolated from Argentina and examined by light and electron microscopy and analysis of nuclear-encoded LSU rDNA. Kirithra asteri gen. et sp. nov. was proposed as morphology and molecular phylogeny separated this dinoflagellate from others within the family Ceratoperidiniaceae. Cells were surrounded by a hyaline amphiesma comprising polygonal vesicles. Each vesicle contained a honeycomb and a trilaminar structure. An anterior sulcal extension ending in a complete circle formed the apical structure complex (ASC), which characterizes Ceratoperidiniaceae...
September 9, 2017: Protist
Shenmin Yang, Liang Gao, Wei Wang, Jie Ding, Yongle Xu, Hong Li
PURPOSE: The purpose of this study is to analyze the sperm morphology of a Chinese man affected with multiple morphological abnormalities of the sperm flagella (MMAF) and observe the intracytoplasmic sperm injection (ICSI) outcome. METHODS: A Chinese man was diagnosed with multiple morphological abnormalities of the sperm flagella by semen analysis and electron microscopy. Testicular spermatozoa were injected intracytoplasmically, and the following ICSI results were observed...
October 2, 2017: Journal of Assisted Reproduction and Genetics
Xiaoyan Zhu, Emiliya Poghosyan, Radhika Gopal, Yi Liu, Kristine S Ciruelas, Yousif Maizy, Dennis R Diener, Stephen M King, Takashi Ishikawa, Pinfen Yang
Nucleoside diphosphate kinases (NDKs) play a central role in diverse cellular processes using the canonical NDK activity or alternative mechanisms that remain poorly defined. Our study of dimeric NDK5 in a flagellar motility control complex, the radial spoke (RS), has revealed new modalities. The flagella in Chlamydomonas ndk5 mutant were paralyzed, albeit only deficient in three RS subunits. RS morphology appeared severely changed in averaged cryo-electron tomograms, suggesting that NDK5 is crucial for the intact spokehead formation as well as RS structural stability...
November 1, 2017: Molecular Biology of the Cell
Fouad El Baidouri, Chris Venditti, Stuart Humphries
Functional morphological adaptation is an implicit assumption across many ecological studies. However, despite a few pioneering attempts to link bacterial form and function, functional morphology is largely unstudied in prokaryotes. One intriguing candidate for analysis is bacterial shape, as multiple lines of theory indicate that cell shape and motility should be strongly correlated. Here we present a large-scale use of modern phylogenetic comparative methods to explore this relationship across 325 species of the phylum Firmicutes...
November 21, 2016: Nature Ecology & Evolution
Yulia Filip'echeva, Andrei Shelud'ko, Alexei Prilipov, Elizaveta Telesheva, Dmitry Mokeev, Andrei Burov, Lilia Petrova, Elena Katsy
Azospirillum brasilense has the ability of swimming and swarming motility owing to the work of a constitutive polar flagellum and inducible lateral flagella, respectively. The interplay between these flagellar systems is poorly understood. One of the key elements of the flagellar export apparatus is the protein FlhB. Two predicted flhB genes are present in the genome of A. brasilense Sp245 (accession nos. HE577327-HE577333). Experimental evidence obtained here indicates that the chromosomal coding sequence (CDS) AZOBR_150177 (flhB1) of Sp245 is essential for the production of both types of flagella...
August 15, 2017: Folia Microbiologica
Emily V W Setton, Logan E March, Erik D Nolan, Tamsin E Jones, Holly Cho, Ward C Wheeler, Cassandra G Extavour, Prashant P Sharma
The deutocerebral (second) head segment is putatively homologous across Arthropoda, in spite of remarkable disparity of form and function of deutocerebral appendages. In Mandibulata this segment bears a pair of sensory antennae, whereas in Chelicerata the same segment bears a pair of feeding appendages called chelicerae. Part of the evidence for the homology of deutocerebral appendages is the conserved function of homothorax (hth), which has been shown to specify antennal or cheliceral fate in the absence of Hox signaling, in both mandibulate and chelicerate exemplars...
October 1, 2017: Developmental Biology
Aaron A Heiss, Alaric W Heiss, Kaleigh Lukacs, Eunsoo Kim
Glaucophytes are a kingdom-scale lineage of unicellular algae with uniquely underived plastids. The genus Cyanophora is of particular interest because it is the only glaucophyte that is a flagellate throughout its life cycle, making its morphology more directly comparable than other glaucophytes to other eukaryote flagellates. The ultrastructure of Cyanophora has already been studied, primarily in the 1960s and 1970s. However, the usefulness of that work has been undermined by its own limitations, subsequent misinterpretations, and a recent taxonomic revision of the genus...
December 2017: Journal of Phycology
Eric R Moore, Briana S Bullington, Alexandra J Weisberg, Yuan Jiang, Jeff Chang, Kimberly H Halsey
The reproductive strategy of diatoms includes asexual and sexual phases, but in many species, including the model centric diatom Thalassiosira pseudonana, sexual reproduction has never been observed. Furthermore, the environmental factors that trigger sexual reproduction in diatoms are not understood. Although genome sequences of a few diatoms are available, little is known about the molecular basis for sexual reproduction. Here we show that ammonium reliably induces the key sexual morphologies, including oogonia, auxospores, and spermatogonia, in two strains of T...
2017: PloS One
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