Flagellar Research Articles

A pilot sero-survey for surra in livestock in Karnataka by ELISA using flagellar antigen of Trypanosoma evansi

Background: Trypanosoma evansi causes trypanosomosis or ‘surra’ in domestic and wild animals and is transmittedby haematophagus tabanid fly. For successful control of the disease, it is important to detect the carrier animalsfollowed by successive treatment. For this purpose a reliable serological test is useful for mass screening of theanimals. Methodology: In the present study, emphasis was given to address the need for the development of a massscreening serological test by using purified flagellar antigen of T. evansi for the detection of antibody against surra.Also a pilot sero-epidemiological study for trypanosomosis in different species using purified flagellar (FLA) antigenbased indirect enzyme linked immunosorbant assay (I-ELISA) was conducted and compared with standard CATT/T.evansi test. The diagnostic potentiality of purified FLA antigen based I-ELISA (FLA-I-ELISA) was evaluated using197 sera samples from field animals including cattle, buffaloes, horses and donkeys. Results: The test showed anoverall 14.72% sero positivity (S.P). Among cattle, S.P was found to be 18.03%, in buffalo 25%, in horse 6.25% andin donkeys 5.5%. Conclusion: Thus, epidemiological survey were done with purified FLA antigen based I-ELISAtest in Karnataka reveals that, buffalo samples showed the maximum sero positivity for trypanosomosis.

Eshelby Twist as a Possible Source of Lattice Rotation in a Perfectly Ordered Protein/Silica Structure Grown by a Simple Organism.

The formation mechanism of a perfectly ordered protein/silica structure in the axial filament of the anchor spicule of the silica sponge Monorhaphis chuni is suggested. Experimental evidence shows that the growth of this architecture is realized by a thermodynamically driven dislocation-mediated spiral growth mechanism, resulting in a specific rotation of the mesoscopic crystal lattice (Eshelby twist).

The relationship between segmentation failure and spermatozoa motility characteristics

Dynamics of sperm motility (sperm velocity, percentage of motility and flagellar beat frequency) and monthly variations of semen characteristics (semen volume and osmolality and sperm concentration and motility) were studied. These criteria were used in the embryology laboratory and reproductive biology in the city of Lattakia, Syria, This study showed that sperm velocity, percentage of motility and beat frequency significantly and rapidly decreased after the activation of sperm motility. To study the dynamics of sperm motility parameters, twenty permeating males were randomly selected and electronically tagged to study the variations of semen characteristics. Specially we focused on the relationship between segmentation failure in cases treated with In Vitro Fertilization (IVF) to define the characteristics using the Computer Assisted Sperm Analysis (CASA). This study compares the reference group (normal) and a group of individuals treated with IVF, who have failed the treatment where segmentation did not occur. The role of the spermatozoon in fertilization expresses itself especially through the motility criterion. Studying the motility characteristics using CASA method seems interesting in clarifying the relationship between some of the motility characteristics and the ability to fertilize in order to determine the notification in cases of IVF. This study based on the acquired information of 85 normal voluntaries as references cases. And 45 patients with segmentation failure in the Embryology-lab of Al-Andalus University for medical Sciences between 2012- 2013. The results were clear, that significant relationship and correlation between segmentation failure and motility of the sperms.

Electron microscope analyses of the bio-silica basal spicule from the Monorhaphis chuni sponge.

We report on a structural analysis of several basal spicules of the deep-sea silica sponge Monorhaphis chuni by electron microscope techniques supported by a precise focused ion beam (FIB) target preparation. To get a deeper understanding of the spicules length growth, we concentrated our investigation onto the apical segments of two selected spicules with apparently different growth states and studied in detail permanent and temporary growth structures in the central compact silica axial cylinder (AC) as well as the structure of the organic axial filament (AF) in its center. The new findings concern the following morphology features: (i) at the tip we could identify thin silica layers, which overgrow as a tongue-like feature the front face of the AC and completely fuse during the subsequent growth state. This basically differs from the radial growth of the surrounding lamellar zone of the spicules made of alternating silica lamellae and organic interlayers. (ii) A newly detected disturbed cylindrical zone in the central region of the AC (diameter about 30 μm) contains vertical and horizontal cavities, channels and agglomerates, which can be interpreted as permanent leftover of a formerly open axial channel, later filled by silica. (iii) The AF consists of a three-dimensional crystal-like arrangement of organic molecules and amorphous silica surrounding these molecules. Similar to an inorganic crystal, this encased protein crystal is typified by crystallographic directions, lattice planes and surface steps. The 〈001〉 growth direction is especially favored, thereby scaffolding the axial cylinders growth and consequently the spicules' morphology.

Isolation and perfusion of rat inner medullary vasa recta

Outer medullary isolated descending vasa recta have proven to be experimentally tractable, and consequently much has been learned about outer medullary vasa recta endothelial transport, pericyte contractile mechanisms, and tubulovascular interactions. In contrast, inner medullary vasa recta have never been isolated from any species, and therefore isolated vasa recta function has never been subjected to in vitro quantitative evaluation. As we teased out inner medullary thin limbs of Henle's loops from the Munich-Wistar rat, we found that vasa recta could be isolated using similar protocols. We isolated ∼30 inner medullary vasa recta from 23 adult male Munich-Wistar rats and prepared them for brightfield or electron microscopy, gene expression analysis by RT-PCR, or isolated tubule microperfusion. Morphological characteristics include branching and nonbranching segments exhibiting a thin endothelium, axial surface filaments radiating outward giving vessels a hairy appearance, and attached interstitial cells. Electron microscopy shows multiple cells, tight junctions, and either continuous or fenestrated endothelia. Isolated vasa recta express genes encoding the urea transporter UT-B and/or the fenestral protein PV-1, genes expressed in descending or ascending vasa recta, respectively. The transepithelial NaCl permeability (383.3 ± 60.0 × 10(-5) cm/s, mean ± SE, n = 4) was determined in isolated perfused vasa recta. Future quantitative analyses of isolated inner medullary vasa recta should provide structural and functional details important for more fully understanding fluid and solute flows through the inner medulla and their associated regulatory pathways.

Nanomedicine: Controlled In Vivo Swimming of a Swarm of Bacteria‐Like Microrobotic Flagella (Adv. Mater. 19/2015)

Nanomedicine: Controlled In Vivo Swimming of a Swarm of Bacteria‐Like Microrobotic Flagella (Adv. Mater. 19/2015)

PHYSIOLOGICAL AND BIOCHEMICAL CHARACTERISTICS AND MULTILOCUS SEQUENCE ANALYSIS OF BANANA SOFT ROT BACTERIA IN CHINA

Bacterial soft rot is a new disease that, in recent years, has caused significant economic losses to banana production in China. Four bacterial isolates representative of a larger group of bacteria recovered from diseased banana plants located in different regions of China and a strain of Dickeya zeae (Ec1) from rice, used as control, were characterized by morphological, physiological, biochemical, and molecular assays. Results showed that the bacterial isolates from banana were Gram-negative, rod-shaped with multiple flagella, and produced a brown pigment on NGM medium (nutrient agar supplemented with 1% glycerol), indicating that they belong to Dickeya. Physiological and biochemical assays revealed that all bacteria from banana were in fact isolates of D. zeae differing from Dickeya dieffenbachiae and Dickeya paradisiaca. Phylogenetic analysis in comparison with sequences of 14 strains of Dickeya spp. retrieved from GenBank was done using the concatenated partial sequences of the seven housekeeping genes dnaA, dnaJ, dnaX, gyrB, recN, gapA, and mdh. All banana isolates were closely related to D. zeae and distinct from other Dickeya spp. The germination rate of rice seeds soaked with bacterial culture supernatant (crude toxin) and toxin bacteriostatic test results showed that the banana strains were different from D. zeae Ec1 in toxin production.

Assessing the veracity of Precambrian ‘sponge’ fossils using in situ nanoscale analytical techniques

Paleontological inferences, molecular clocks, and biomarker fossils indicate sponges evolved in the Cryogenian, but Precambrian sponge fossils are rare, poorly substantiated, and controversial. Spicule-like microstructures (SLMs) hosted in phosphatized fossils from the Ediacaran Doushantuo Formation (∼635–551Ma) at Weng’an of South China have been interpreted as cylindrical siliceous monaxons, and their hosting fossils as the oldest demosponges in the fossil record. In order to assess their veracity as the oldest spiculate demosponges, we utilize a suite of in situ nanoscale analytical techniques—including scanning electron microscopy, synchrotron X-ray fluorescence mapping, X-ray absorption near edge structure (XANES) spectroscopy, focused ion beam electron microscopy, and transmission electron microscopy—to evaluate the ultrastructures and elemental, chemical, and mineralogical compositions of the SLMs. Our data decisively shows that the SLMs are carbonaceous in composition and rectangular in transverse sections, and therefore, are not cylindrical siliceous spicules. Instead, the SLMs may be microbial strands, axial filaments of early hexactinellids, or acicular crystals molded by organic matter. Regardless, our new data invalidate the oldest and only Precambrian demosponges with mineralized spicules. These results indicate that interpretations of Precambrian sponge fossils should be scrutinized with compositional, mineralogical, and ultrastructural data collected using in situ analytical techniques. In addition, our conclusions affirm that no unequivocal biomineralizing sponges occur below the Ediacaran–Cambrian boundary. If hexactinellids and demosponges did diverge in the Cryogenian as suggested by molecular clocks and biomarkers, they either evolved biomineralization long after their divergence or their biomineralized spicules were never preserved until after the Ediacaran–Cambrian boundary. In either case, the dearth of biomineralizing sponge fossils in the Precambrian and their abundance in the early Cambrian must reflect a geobiologically significant aspect of the Precambrian–Phanerozoic transition.

Spermatozoon ultrastructure and semen parameters of Brycon vermelha (Characiformes, Characidae)

This study analyzed semen parameters and the ultrastructure of spermatozoa of Brycon vermelha. The semen was white and viscous, with a mean volume of 5.0±2.6mL/kg body weight and mean spermatozoon concentration of 4.3±0.8×1010 spermatozoa/mL. The estimated motility rate was 90%, with 50% of spermatozoa motile at 35.0±0.1s and 100% immotile by 46.5±0.1s. The spermatozoon of B. vermelha had a distinct head, midpiece, and flagellum. The ovoid head measured 1.9±0.2μm by 1.3±0.1μm, with its volume almost completely occupied by the nucleus, and was enveloped by an irregular nuclear membrane, with no acrosome vesicle. The nuclear fossa held the centriole complex and the initial segment of flagellum. The midpiece was symmetrical and measured 1.3±0.3μm. Mitochondria were scarce and restricted to the anterior region, while vesicles were absent. The posterior region of the midpiece was characterized by the absence of mitochondria and the presence of the cytoplasmic sheath. The flagellum, enclosed by the flagellar membrane, measured 29.6±3.4μm, and possessed an axial filament containing a 9+2 microtubule pattern. The spermatozoa of B. vermelha appeared similar in structure to those of fish that breed through external fertilization, thus classifying them as uniflagellate anacrosomal aquasperm, or Type 1 aquasperm.

Advances on Bacterial Ghost as Novel Vaccine and Delivery Vector

Bacterial ghost(BG) is an empty bacterial envelope of gram-negative bacteria devoid of cytoplasmic content,and produced by controlled expression of bacteriophage PhiX174 lysis gene E.BG keeps intact bacterial outer membrane structure,such as flagella,LPS and outer membrane proteins,making bacterial easy to adherence to the human or animal cell receptors,so it can be used as vaccines without adjuvant to induce strong humoral immune response and cellular immune response.BG has many spaces,such as the outer membrane,the periplasmic space and the inner membrane to load other substance.BG also can be used as DNA,antigen and drugs delivery vector as it exhibits potency with regard to target antigens and large capacity compared to conventional approaches.In addition,BG can be provided with a foreign antigen,nucleic acid or other ingredients to construct combined vaccine for human or animal health services.BG has wide application prospect in the prevention and treatment of disease.

Types of Antennal Sensilla of Three Pseudacteon Species (Diptera: Phoridae) Females That Parasitize Red Imported Fire Ants (Solenopsis invicta) ( Hymenoptera: Formicidae)

While antenna is the main organ for insect to accept the external chemical signals, the antennal sensilla that are diverse in structure and function form the insect receptors in chemical communication. Since a variety of Pseudacteon species are important natural enemies of the red imported fire ant, Solenopsis invicta Buren (. invicta), to elucidate the types of Pseudacteon sensilla will promote the study and understanding of the selection behavior of Pseudacteon in parasitizing . invicta. This study has used scanning electron microscope (SEM) to observe and investigate the female’s antennal sensilla of three Pseudacteon species, the Pseudacteon (P.) litoralis, P. obtusus, and P. tricuspis, and demonstrated that there are four types of sensilla, the trichoid, basiconic, coeloconic, and chaetic sensilla, on their antennal flagellum. Among them, the former three are common in all three species, with trichoid sensillum as mostly abundant, while the chaetic sensillum exists only in the antennae of P. obtusus. The trichoid sensilla exhibit significant interspecies variations and are further classified into two subtypes based on the presence or absence of protrusions, the surface of which contains different shades of groove-like or irregular punctate structures. The basiconic sensilla resemble short spines with densely porous structures on the surface and are in the length of 7.3-9.8 μm and the width of 1.3-1.6 μm, upright or slightly bent. The coeloconic sensilla are irregularly formed in the middle and base of the flagellum, without surface pores; each coeloconic sensillum has eight finger-like folds in unequal lengths, while the end of the fold resembles a blunt cone. The chaetic sensilla enlarge at the base, possess multiple fold-like structures and fine-tipped ends, and are approximately 5 μm in length.

The Mediterranean Endemic New genusFelicinia(Halymeniales, Rhodophyta) Recognized by a Morphological and Phylogenetic Integrative Approach

Recently, DNA phylogenies resulted in the transfer of some species of the halymeniacean genus Aeodes, namely A. orbitosa and A. ulvoidea, to the genus Pachymenia leaving the former supposedly as a monotypic genus based on the type species, A. nitidissima. Nevertheless, that work overlooked the presence of A. marginata, a red foliaceus alga endemic to the Mediterranean Sea with a convoluted nomenclatural history.In the present study, we provided a thorough description of A. marginata based on both anatomical and molecular data and inferred its phylogenetic relationships among halymeniacean genera using both chloroplastic (rbcL) and nuclear genes (LSU). Based on our data, A. marginata allied with Halymenia, Cryptonemia, and associated genera rather than with the generitype A. nitidissima, and presented a unique set of characters deserving the status of genus within the Halymeniaceae. Therefore, we proposed the new genus Felicinia based on Felicinia marginata comb. nov.A description of the multiaxial vegetative of F. marginata construct was provided, highlighting a unique characteristic among red algae: the presence, in the medulla, of peculiar oblique multicellular filaments connecting periclinal filaments. These filaments are produced secondarily as branches from axial filaments and are possibly homologous to the anticlinal filaments observed in the medulla of Halymenia.

Homogeneous Microscopic Abnormalities in Sperm Morphology and Immotility as A Cause of Male Infertility

Objective To study the identification of the cause of specific sperm abnormalities. Methods Two adult men with specific alterations in sperm morphology causing 100% immobility were included in this study. The study of sperm used: transmission electron microscopy (both patients); apoptotic markers, DNA fragmentation test and fluorescence in-situ hybridization (patient 1) and immunocytochemistry study of sperm flagellum using anti-β tubulin antibodies and ciliary activity test (patient 2). Results Increased DNA fragmentation (52.6%) and apoptosis biomarkers were detected in patient 1, and loss of the central pair of microtubules in patient 2 (‘9+0’ axoneme); the nasal ciliary activity was normal. Conclusion Results suggest an apoptotic origin of the abnormalities in the sperm from patient 1 and dysplasia of the fibrous sheath in patient 2.

Composition and Mechanical Properties of a Protein/Silica Hybrid Material Forming the Micron‐Thick Axial Filament in the Spicules of Marine Sponges

Nearly equal volume fractions of biosilica and proteins are found in the micron-thick axial filament of the anchor spicule of the marine sponge Monorhaphis chuni. Chemical composition and mechanical properties of this unique composite material are characterized by confocal Raman spectroscopy and by nanoindentation and nanoscale elastic modulus mapping, respectively.

Topic 5. Flagella and Pathogenicity

Topic 5. Flagella and Pathogenicity

Bio Focus: Bacteria construct tiny flagella “nanomachines” outside the cell

Bio Focus: Bacteria construct tiny flagella “nanomachines” outside the cell

A Perfectly Periodic Three‐Dimensional Protein/Silica Mesoporous Structure Produced by an Organism

The discovery of perfectly ordered 3D mesoporous protein/silica structure in the axial filament of the marine sponge Monorhaphis chuni is reported. The structure belongs to body-centered tetragonal symmetry system (a=9.88 nm, c=10.83 nm) and comprises interconnecting lattices of protein and silica, templated by the self-assembled, enzymatically active protein-silicatein, whose primary function is the precipitation of silica.

Spicule structure and affinities of the Late Ordovician hexactinellid-like spongeCyathophycus loydellifrom the Llanfawr Mudstones Lagerstätte, Wales

Exceptionally well-preserved specimens of the reticulosan sponge Cyathophycus loydelli from the Sandbian (Late Ordovician) Llanfawr Mudstones Formation of Llandrindod, Waes, UK, have been examined using scanning electron microscopy (SEM). The specimens include exquisitely detailed pyritized spicules, and granular pyritization of surrounding soft tissues. Spicules frequently show axial canals of diameter similar to those of modern siliceous sponges, with hexagonal symmetry typical of modern demosponges rather than hexactinellids. In one case, the axial filament is also preserved. The largest spicules (ray diameter >20 μm) show a complex structure, with a laminar external region similar to that of the extant hexactinellid Monorhaphis. Some spicules preserve sub-micron detail of the spicule surface, resembling the reticulate collagenous sheath of Monorhaphis. The hexagonal symmetry of the canal confirms that at least some Reticulosa are not crown-group hexactinellids, but stem-group Hexactinellida or Demospongea, or stem-group Silicea. This suggests that a square canal is a sufficient diagnostic feature of total-group Hexactinellida, but that hexagonal canals were more widely distributed among Early Silicea and were probably not restricted to demosponges. Alternatively, comparison with the structure of modern verongiid fibres suggests that these may be homologous with the outer layers of Cyathophycus spicules, and Cyathophycus may instead be a stem-group demosponge. The preserved detail of the surface layer shows that pyritization can preserve certain material with extraordinarily fine resolution.

Genes & cells: Flagellum failure lets bacteria steer: Buckling of appendage drives tiny two‐point turn

Genes & cells: Flagellum failure lets bacteria steer: Buckling of appendage drives tiny two‐point turn

PRELIMINARY ELECTRON-MICROSCOPE STUDIES OF FERTILISATION IN TELMATOSCOPUS ALBIPUNCTATUS (WILLISTON) (DIPTERA PSYCHODIDAE)

SUMMARY The results of preliminary studies of fertilisation in Telmatoscopus albipunctatus (Williston) (Diptera Psychodidae) are described. In this species the spermatheca is missing, consequently the sperms are injected deeply into the female apparatus during mating. The sperms are immotile and devoid also of the accessory structure which substitute the flagellar complex; they are even unable to acquire motility after chemical treatment. The eggs are, however, normal; in fact, they are provided with common inclusions, a normally constituted chorion and a micropyle like a corolla of petal-shaped platelets. Probably the sperms reach the micropyle as a results of the activity of the slender filaments present near it.