Tail Membrane Research Articles

The nematode Caenorhabditis elegans enhances tolerance to landfill leachate stress by increasing trehalose synthesis.

The burgeoning issue of landfill leachate, exacerbated by urbanization, necessitates evaluating its biological impact, traditionally overshadowed by physical and chemical assessments. This study harnesses Caenorhabditis elegans, a model organism, to elucidate the physiological toxicity of landfill leachate subjected to different treatment processes: nanofiltration reverse osmosis tail water (NFRO), membrane bioreactor (MBR), and raw leachate (RAW). Our investigation focuses on the modulation of sugar metabolism, particularly trehalose-a disaccharide serving dual functions as an energy source and an anti-adversity molecule in invertebrates. Upon exposure, C. elegans showcased a 60-70% reduction in glucose and glycogen levels alongside a significant trehalose increase, highlighting an adaptive response to environmental stress by augmenting trehalose synthesis. Notably, trehalose-related genes in the NFRO group were up-regulated, contrasting with the MBR and RAW groups, where trehalose synthesis genes outpaced decomposition genes by 20-30 times. These findings suggest that C. elegans predominantly counters landfill leachate-induced stress through trehalose accumulation. This research not only provides insights into the differential impact of leachate treatment methods on C. elegans but also proposes a molecular framework for assessing the environmental repercussions of landfill leachate, contributing to the development of novel strategies for pollution mitigation and environmental preservation.

Elucidating Daptomycin's Antibacterial Efficacy: Insights into the Tripartite Complex with Lipid II and Phospholipids in Bacterial Septum Membrane.

This study elucidated the mechanism of formation of a tripartite complex containing daptomycin (Dap), lipid II, and phospholipid phosphatidylglycerol in the bacterial septum membrane, which was previously reported as the cause of the antibacterial action of Dap against gram-positive bacteria via molecular dynamics and enhanced sampling methods. Others have suggested that this transient complex ushers in the inhibition of cell wall synthesis by obstructing the downstream polymerization and cross-linking processes involving lipid II, which is absent in the presence of cardiolipin lipid in the membrane. In this work, we observed that the complex was stabilized by Ca2+-mediated electrostatic interactions between Dap and lipid head groups, hydrophobic interaction, hydrogen bonds, and salt bridges between the lipopeptide and lipids and was associated with Dap concentration-dependent membrane depolarization, thinning of the bilayer, and increased lipid tail disorder. Residues Orn6 and Kyn13, along with the DXDG motif, made simultaneous contact with constituent lipids, hence playing a crucial role in the formation of the complex. Incorporating cardiolipin into the membrane model led to its competitively displacing lipid II away from the Dap, reducing the lifetime of the complex and the nonexistence of lipid tail disorder and membrane depolarization. No evidence of water permeation inside the membrane hydrophobic interior was noted in all of the systems studied. Additionally, it was shown that using hydrophobic contacts between Dap and lipids as collective variables for enhanced sampling gave rise to a free energy barrier for the translocation of the lipopeptide. A better understanding of Dap's antibacterial mechanism, as studied through this work, will help develop lipopeptide-based antibiotics for rising Dap-resistant bacteria.

Ventral wing hairs provide tactile feedback for aerial prey capture in the big brown bat, Eptesicus fuscus.

Bats rely on their hand-wings to execute agile flight maneuvers, to grasp objects, and cradle young. Embedded in the dorsal and ventral membranes of bat wings are microscopic hairs. Past research findings implicate dorsal wing hairs in airflow sensing for flight control, but the function of ventral wing hairs has not been previously investigated. Here, we test the hypothesis that ventral wing hairs carry mechanosensory signals for flight control, prey capture, and handling. To test this hypothesis, we used synchronized high-speed stereo video and audio recordings to quantify flight and echolocation behaviors of big brown bats (Eptesicus fuscus) engaged in an aerial insect capture task. We analyzed prey-capture strategy and performance, along with flight kinematics, before and after depilation of microscopic hairs from the bat's ventral wing and tail membranes. We found that ventral wing hair depilation significantly impaired the bat's prey-capture performance. Interestingly, ventral wing hair depilation also produced increases in the bat's flight speed, an effect previously attributed exclusively to airflow sensing along the dorsal wing surface. These findings demonstrate that microscopic hairs embedded in the ventral wing and tail membranes of insectivorous bats provide mechanosensory feedback for prey handling and flight control.

117 Evaluation of Semen Production and Biomarkers Produced by Boars Fed Microfused Essential Oil Technology in Their Diet

Abstract Two experiments were conducted to evaluate the effect of feeding Microfused Essential Oil Technology (MEOT, Ralco Nutrition, Inc.) to mature boars on their semen production and semen quality biomarkers. In Experiment 1, boars (n = 21) housed at a commercial boar stud were fed MEOT in their diet. These boars were collected in their normal collection routine of twice per week. Total motile sperm count was measured for each collection over a 10-month period (December to September). A baseline motile sperm count was determined for each boar during the 2 months before the beginning of the MEOT feeding in February. Repeated measures analysis was conducted to evaluate the effects of sperm production over time. Feeding MEOT to boars resulted in greater motile sperm count (P < 0.0001) and greater (P < 0.0001) economic revenue per collection. In Exp. 2, the objective was to determine if the increased semen production measured had any impact on semen quality biomarkers. Semen samples were collected from the same boar stud used in Exp. 1 after MEOT feeding. Control samples were collected from a boar stud using similar boar genotypes, environmental condition, semen extender, and time from collection. One 75 mL extended semen dose from 8 to 10 boars across 3 weeks was collected and sent to the laboratory for semen quality analysis. The traits and biomarkers that were analyzed for each sample included morphology, zinc signature, plasma membrane integrity (detected by propidium iodide; PI), lectin PNA acrosome health, lectin LCA membrane health, reactive oxygen species status (ROS; detected by H2DCFDA), aggresome (AGG), and DNA fragmentation (dected by acridine orange). No differences in morphology (P > 0.05) were detected. For the MEOT-fed boars, a greater portion (P < 0.001) of the sperm population was in the zinc signature 2 category indicating more live, non-capacitated sperm and a lesser portion (P < 0.0003) in the zinc signature 4 category indicating less dead, fully capacitated sperm. In addition, for PI, a greater portion (P < 0.03) of the sperm were live with good plasma membrane integrity for boars fed MEOT versus the controls. A greater portion of the sperm from the MEOT-fed boars had better acrosome integrity (P < 0.001) as well as tail membrane health (P < 0.01). No differences (P > 0.05) were observed for ROS. Semen from MEOT-fed boars had less AGG misfolded proteins (P < 0.0001) and a tendency (P < 0.07) for less DNA fragmentation. These data indicate that feeding MEOT to boars resulted in greater motile sperm production and that did not result in a negative impact on semen quality with many semen biomarkers being improved in MEOT-fed boars.

Lipid composition of the stratum corneum in different regions of the body of Kuhl's pipistrelle from the Negev Desert, Israel

The most superficial epidermal layer in endotherms is the stratum corneum (SC), which is composed of dead corneocytes embedded in a lipid matrix with free fatty acids, cholesterol, ceramides, and cerebrosides; the lipid composition of the SC determines its permeability to water vapor. Lipids that are more polar, have longer hydrocarbon chains, and are less bulky are often packed in more ordered phase states to slow cutaneous evaporative water loss (CEWL); these lipids also resist transitions to more disordered phases at high ambient temperatures (Ta). In bats, wing and tail membranes (wing patagia and tail uropatagium, respectively) allow powered flight, but increase surface area, and hence CEWL, with implications for survival in arid environments. We captured Pipistrellus kuhlii from an arid habitat and measured the lipid composition of the SC of the plagiopatagium in the wing, the uropatagium, and the non-membranous region (NMR) of the body using thin layer chromatography and reversed phase high performance liquid chromatography coupled with atmospheric pressure photoionization mass spectrometry. The patagia contained more cholesterol and shorter-chained ceramides, and fewer cerebrosides than the NMR, indicating that the lipid phase transition temperature in the patagia is lower than in the NMR. Thus, at moderate Ta the lipids in the SC in all body regions will remain in an ordered phase state, allowing water conservation; but as Ta increases, the lipids in the SC of the patagia will more easily transition into a disordered phase, resulting in increased CEWL from the patagia facilitating efficient heat dissipation in hot environments.

Macro- and microelements in serum and seminal plasma as biomarkers for bull sperm cryotolerance

ABSTRACTBackgroundWide variation in fertility rates is observed when using frozen bull semen, even when the bulls have met quality standards for semen production. Therefore, a simple and reliable test to assess the freezing potential of bull semen based on the analysis of fresh semen or blood would be of great value. Attention is now turning to assessment of seminal plasma components such as proteins and elements. In the present study, the concentrations of macro- and microelements in fresh bull semen plasma and in serum and their correlation with quality characteristics of fresh semen and with semen quality after freezing and thawing were determined. Ejaculates were collected from 30 mature bulls, and semen volume, concentration, sperm motility, morphology, tail membrane integrity, plasma membrane permeability and DNA fragmentation were determined on the day of collection and after freezing and thawing. The concentrations of macroelements (Na, Mg, K and Ca) and microelements (Cu, Fe, Zn and Se) were determined in the seminal plasma and serum. The semen samples were classified into satisfactory and unsatisfactory groups according to the fresh semen quality.ResultsZinc and Se levels measured in serum were associated with almost all fresh and frozen-thawed semen quality characteristics, while Fe levels were associated only with acrosomal defects in fresh semen. Zinc and Fe levels in fresh seminal plasma were associated with various quality characteristics of fresh and frozen-thawed semen, while Se level in fresh seminal plasma was not associated with any of the semen quality characteristics.ConclusionsMicroelements were shown to be useful as biomarkers involved in the analysis of bull sperm quality and could be used as an additional tool to predict bull semen quality after freezing and thawing. Our results confirm that the analysis of Zn and Se levels in serum and Zn, Cu and Fe levels in fresh seminal plasma can provide information to discriminate between bull semen samples with spermatozoa with high or low cryotolerance.

Unexpected genomic, biosynthetic and species diversity of Streptomyces bacteria from bats in Arizona and New Mexico, USA

BackgroundAntibiotic-producing Streptomyces bacteria are ubiquitous in nature, yet most studies of its diversity have focused on free-living strains inhabiting diverse soil environments and those in symbiotic relationship with invertebrates.ResultsWe studied the draft genomes of 73 Streptomyces isolates sampled from the skin (wing and tail membranes) and fur surfaces of bats collected in Arizona and New Mexico. We uncovered large genomic variation and biosynthetic potential, even among closely related strains. The isolates, which were initially identified as three distinct species based on sequence variation in the 16S rRNA locus, could be distinguished as 41 different species based on genome-wide average nucleotide identity. Of the 32 biosynthetic gene cluster (BGC) classes detected, non-ribosomal peptide synthetases, siderophores, and terpenes were present in all genomes. On average, Streptomyces genomes carried 14 distinct classes of BGCs (range = 9–20). Results also revealed large inter- and intra-species variation in gene content (single nucleotide polymorphisms, accessory genes and singletons) and BGCs, further contributing to the overall genetic diversity present in bat-associated Streptomyces. Finally, we show that genome-wide recombination has partly contributed to the large genomic variation among strains of the same species.ConclusionsOur study provides an initial genomic assessment of bat-associated Streptomyces that will be critical to prioritizing those strains with the greatest ability to produce novel antibiotics. It also highlights the need to recognize within-species variation as an important factor in genetic manipulation studies, diversity estimates and drug discovery efforts in Streptomyces.

Exposure during embryonic development to Roundup® Power 2.0 affects lateralization, level of activity and growth, but not defensive behaviour of marsh frog tadpoles

As glyphosate-based herbicides, sold under the commercial name Roundup®, represent the most used herbicides in the world, contamination of the freshwater environment by glyphosate has become a widespread issue. In Italy, glyphosate was detected in half of the surface waters monitoring sites and its concentrations were higher than environmental quality standards in 24.5% of them. It can last from days to months in water, leading to exposure for aquatic organisms and specifically to amphibians’ larvae that develop in shallow water bodies with proven effects to development and behaviour. In this study, we tested the effects of a 96 h exposure during embryonic development of marsh frog’s tadpoles to three ecologically relevant Roundup® Power 2.0 concentrations. As expected, given the low concentrations tested, no mortality was observed. Morphological measurements highlighted a reduction in the total length in tadpoles exposed to 7.6 mg a.e./L, while an increase was observed at lower concentrations of 0.7 and 3.1 mg a.e./L compared to control group. Tadpoles raised in 7.6 mg a.e./L also showed a smaller tail membrane than those raised in the control solution. Regarding behaviour, we tested tadpoles in two different sessions (Gosner stages 25 and 28/29) for lateralization, antipredator response and basal activity. Lower intensity of lateralization was detected in tadpoles raised at the highest Roundup® concentration in the first session of observation, while no significant difference among treatments was observed in the second one. In both sessions, effects of Roundup® Power 2.0 embryonic exposure on antipredator response, measured as the proportional change in activity after the injection of tadpole-fed predator (Anax imperator) cue, were not detected. Tadpoles exposed during embryonic development to Roundup® exhibited lower basal activity than the control group, with the strongest reduction for the 7.6 mg a.e./L treatment. Our results reinforce the concern of Roundup® contamination impact on amphibians.

Investigation of blood cells of Miniopterus schreibersii (Mammalia: Chiroptera) in Turkey

This research was based on some characteristics of the erythrocyte and leukocyte cells of 9 Miniopterus schreibersii (♀♀) samples collected from Balikesir Province in Turkey between July 2015 and September 2016. Bats were caught from an artificial cave using special nets. Blood was taken in heparinized hematocrit tubes from the forearm or tail membrane in the laboratory and the blood smears were prepared. The erythrocyte and leukocyte counts, hemoglobin concentration, and hematocrit values in the blood were determined. In M. schreibersii, the number of erythrocytes in 1 mm3 of blood was between 7.5 and 10 million, and the mean value was 8.8 million. The diameter values of the erythrocyte, monocyte, lymphocyte, eosinophil, neutrophil, and basophil cells were measured as 5.65, 9.66, 8.4, 8.66, 10, and 8.5 µm, respectively. Blood values of M. schreibersii were recorded for the first time in this study in Anatolia.

Frequent or scarce? Damage to flight-enabling body parts in bats (Chiroptera).

Bat wings are characterized by high endurance, and these mammals have developed a number of adaptations that protect them from falling into obstacles and potential injuries. However, in bat populations, there are individuals with visible fresh or healed injuries to the flight–enabling body parts. The aim of this research was to determine the differences in the occurrence of wing membrane damages among species of bats that differ in ecology and behavior. The study was conducted in southern and western Poland in the years 2000–2016 and included 3,525 individuals of six species: lesser horseshoe bat Rhinolopus hipposideros, Daubenton’s bat Myotis daubentonii, Natterer’s bat Myotis nattereri, greater mouse–eared bat Myotis myotis, western barbastelle Barbastella barbastellus, and brown long–eared bat Plecotus auritus. In all, 2.9% of the bats studied showed damage to the flight–enabling body parts. Natterer’s bat was the species with the highest number of injured individuals (21.74%). The lowest number of injured individuals (0.3%) was found in the brown long–eared bat. The most frequently observed type of damage was loss of an edge of the wing membrane (29.3%). The bat species studied differed significantly in the occurrence and location of flight enabling body parts damages. Certain behavioral and ecological factors like foraging mode, foraging habitats and habitat types of bat species determine the number of wing and tail membrane damages.

Atomic-Resolution Simulations Show Two Sequential Fusion Peptide Mechanisms in Influenza Membrane Fusion

Influenza viral membrane fusion is mediated by the hemagglutinin protein, and membrane-inserted fusion peptides are critical to the success of this process. However, the field lacks a mechanistic understanding of how fusion peptides act to cause fusion that can fully explain experimental phenotypes of fusion peptide mutants. We have performed the first atomic-resolution simulations of influenza membrane fusion, which demonstrate lipid tail protrusion and membrane bending as two sequential activities of the fusion peptides that are critical to fusion. Each of these is supported by previous experimental data and mechanistic hypotheses, but our simulations now place these, in sequence, as co-existing mechanistic requirements for fusion. A striking new finding is that the membrane-bending activity of fusion peptides is dependent on their N-terminal protonation state, which can in turn control the helical kink or hairpin that modulates fusion activity. These simulations thus provide a unified model for influenza membrane fusion capable of explaining how N-terminal fusion peptide mutations exert their effects. Furthermore, our model by which fusion peptides promote lipid tail protrusion and then membrane bending as sequential requirements may be generalized to explain the fusion behavior of other enveloped viruses.

Structural Insights into Phylloquinone (Vitamin K1), Menaquinone (MK4, MK7), and Menadione (Vitamin K3) Binding to VKORC1.

Vitamin K family molecules—phylloquinone (K1), menaquinone (K2), and menadione (K3)—act as γ-glutamyl carboxylase (GGCX)-exclusive cofactors in their hydroquinone state, activating proteins of main importance for blood coagulation in the liver and for arterial calcification prevention and energy metabolism in extrahepatic tissues. Once GGCX is activated, vitamin K is found in the epoxide state, which is then recycled to quinone and hydroquinone states by vitamin K epoxide reductase (VKORC1). Nevertheless, little information is available concerning vitamin K1, K2, or K3 tissue distribution and preferential interactions towards VKORC1. Here we present a molecular modeling study of vitamin K1, menaquinones 4, 7 (MK4, MK7), and K3 structural interactions with VKORC1. VKORC1 was shown to tightly bind vitamins K1 and MK4 in the epoxide and quinone states, but not in the hydroquinone state; five VKORC1 residues were identified as crucial for vitamin K stabilization, and two other ones were essential for hydrogen bond formation. However, vitamin MK7 revealed shaky binding towards VKORC1, induced by hydrophobic tail interactions with the membrane. Vitamin K3 exhibited the lowest affinity with VKORC1 because of the absence of a hydrophobic tail, preventing structural stabilization by the enzyme. Enzymatic activity towards vitamins K1, MK4, MK7, and K3 was also evaluated by in vitro assays, validating our in silico predictions: VKORC1 presented equivalent activities towards vitamins K1 and MK4, but much lower activity with respect to vitamin MK7, and no activity towards vitamin K3. Our results revealed VKORC1’s ability to recycle both phylloquinone and some menaquinones, and also highlighted the importance of vitamin K’s hydrophobic tail size and membrane interactions.

23 Viability staining techniques for cryopreserved spermatozoa in 3 caudata species

Salamanders are the most threatened vertebrate taxa; thus, conservation-based research including spermatozoa cryopreservation and other assisted reproductive technologies is essential to their survival. To determine the effectiveness of sperm cryopreservation, methods for evaluating sperm quality are necessary but underdeveloped in caudate research. Evaluating motility has been the primary analysis for sperm viability but is difficult to perform due to the scythe-like morphology, slow rotating progression, and minute undulations of the tail membrane. Estimating apoptosis is a new approach to evaluating caudate spermatozoa survival through cryostress. Fluorescent dyes, such as SYBR-14, annexin-V, and propidium iodide (PI), are valuable tools for identifying degrees of cell viability, apoptosis, and necrosis. Annexin-V marks the externalization of phosphatidylserine on the cell membrane indicating early steps in the apoptosis signalling cascade. Compromised membranes allow PI, a nucleic acid stain, access to DNA, marking cellular necrosis. The SYBR-14 is a nucleic acid stain that permeatesssss intact membranes, labelling live cells. These fluorescent stains were assessed for marking viability and stages of cell death in post-thaw spermatozoa across 3 caudate species: the Eastern tiger salamander (Ambystoma tigrinum), Kweichow Emperor newt (Tylototriton kweichowensis), and black-spotted newt (Notophthalmus meridionalis). For each species, spermic urine samples were acquired by hormone treatment and frozen based on protocols developed in A. tigrinum, yielding an average of 18.2% relative motility recovered at thaw. Straws were thawed for 5min at 20°C. Viability was tested by staining 5μL 1:1 with a 1:50 dilution of SYBR-14 and 2μL of PI. Stages of cell death were evaluated by staining 10μL with 2μL of annexin-V and 2μL of PI. Cell viability was assessed immediately under a fluorescence microscope. For each of the 3 species, 2 samples were stained with both assays in triplicate. Sperm stained with SYBR-14 alone were considered viable, and sperm stained with any annexin-V or PI were considered not viable. Visible dynamic shifting from SYBR-14 to PI staining was observed in real time, indicating rapid necrosis. Morphological abnormalities, not observed in unstained samples, were prevalent across all species following staining, signifying a possible cytotoxic effect of the dyes. High mortality and abnormality rates suggest that fluorescent dyes have elevated toxicity and permeability in caudate sperm. Caudate spermic urine has a very low osmolality, implying high permeability, which could lead to rapid staining and toxicity effects. Shorter incubation times may be required for accurate staining. Results may also indicate that cryopreservation protocols need to be species specific and do not transfer well across taxa. This is one of the earliest studies to evaluate the use of fluorescent stain protocols on measuring cell viability in caudate sperm and indicates that further refinement is required.

MUC1 deficiency mediates corticosteroid resistance in chronic obstructive pulmonary disease

BackgroundLung inflammation in COPD is poorly controlled by inhaled corticosteroids (ICS). Strategies to improve ICS efficacy or the search of biomarkers who may select those patients candidates to receive ICS in COPD are needed. Recent data indicate that MUC1 cytoplasmic tail (CT) membrane mucin can mediate corticosteroid efficacy in chronic rhinosinusitis. The objective of this work was to analyze the previously unexplored role of MUC1 on corticosteroid efficacy in COPD in vitro and in vivo models.MethodsMUC1-CT expression was measured by real time PCR, western blot, immunohistochemistry and immunofluorescence. The inflammatory mediators IL-8, MMP9, GM-CSF and MIP3α were measured by ELISA. The effect of MUC1 on inflammation and corticosteroid anti-inflammatory effects was measured using cell siRNA in vitro and Muc1-KO in vivo animal models.ResultsMUC1-CT expression was downregulated in lung tissue, bronchial epithelial cells and lung neutrophils from smokers (n = 11) and COPD (n = 11) patients compared with healthy subjects (n = 10). MUC1 was correlated with FEV1% (ρ = 0.7479; p < 0.0001) in smokers and COPD patients. Cigarette smoke extract (CSE) decreased the expression of MUC1 and induced corticosteroid resistance in human primary bronchial epithelial cells and human neutrophils. MUC1 Gene silencing using siRNA-MUC1 impaired the anti-inflammatory effects of dexamethasone and reduced glucocorticoid response element activation. Dexamethasone promoted glucocorticoid receptor alpha (GRα) and MUC1-CT nuclear translocation and co-localization that was inhibited by CSE. Lung function decline and inflammation induced by lipopolysaccharide and cigarette smoke in Muc1 KO mice was resistant to dexamethasone.ConclusionsThese results confirm a role for MUC1-CT mediating corticosteroid efficacy in COPD.

Use of principal component analysis to evaluate variability in CASA and flow cytometer sperm characteristics

An intact and functional sperm plasmalemma has a major role in sperm motility and fertilizing capacity. Several techniques have been developed to evaluate the integrity of the sperm plasma membrane, but there are still some inconsistencies concerning the methods that are more closely associated with sperm function. In this study, the aim was to: i) evaluate the integrity of the boar sperm plasmalemma during 72 h of semen storage at 17 °C using four techniques: eosin/nigrosin (E/N), propidium iodide/carboxyfluorescein diacetate (PI/CFDA), hypo-osmotic swelling test (HOST), and combined HOST with eosin staining (HOST/E), ii) assess the correlations and the limits of consistency among these techniques, iii) and estimate the relationships with the acrosomal status and sperm kinetics. Results indicate that the integrity of the sperm plasmalemma decreases during 72 h of storage, although significant differences were found only using the HOST and HOST/E techniques. Moreover, use of E/N and PI/CFDA results in greater values relative to the undamaged sperm membrane than use of HOST and HOST/E at any incubation time. Overall, results using all techniques were consistent and correlate except for findings with PI/CFDA and HOST, which was slightly below 95%. Moreover, values using the techniques for the evaluation of the integrity of the sperm head and tail membranes are positively associated with the acrosomal status and different kinetic variables with the tail integrity being related to rapid linear trajectories and the head integrity to rapid curvilinear trajectories. The results of this study provide new insights into the relevance of evaluating the boar sperm plasmalemma in the routine spermiogram.

Night-Roosting Behaviors for the Northern Long-Eared Myotis (Myotis septentrionalis) Under a Bridge Revealed by Time-Lapse Photography

The northern long-eared myotis (Myotis septentrionalis) occurs across much of eastern North America and is listed as federally threatened in the United States due to pervasive population declines. Limited data are available about roosting behaviors for this imperiled species. We report on night-roosting behaviors for the northern long-eared myotis under a bridge in northwestern Nebraska. Grooming, short visits, and feeding were the most frequently observed behaviors. Grooming, inactivity, and nursing had the longest durations, albeit all averaged <15 min per event. We also documented movement and urination infrequently. Prey manipulation associated with feeding was a frequent behavior and consisted of individuals facing upward or downward, culling wings, elytra, and legs of large prey items. When facing upward wing and tail membranes formed a cup against the abutment wall that likely limited loss of prey. Individuals used the bridge throughout the night but roosted most frequently at 4 and 8 h after sunset (00:15 and 04:15 h, respectively), with early morning activity dominated by feeding/prey manipulation. Our study showed night roosts were used frequently for many reasons, especially for grooming and consumption of large prey. Our observations represent the first description of night-roosting behaviors for the northern long-eared myotis.

TYPE VB AND VI SECRETION SYSTEMS AS COMPETITION AGENTS OF GRAM-NEGATIVE BACTERIA

Abstract Bacterial competition, defined as a local neighbour interactions, can lead to competitors coexistence, bacterial community self-organization or as travelling waves of species dominance in ecological niches. Bacteria have developed many mechanisms to communicate and compete. Kin discrimination mechanisms in bacterial populations allow species to distinguish a friend from a foe in bacterial environment. Type Vb and VI secretion systems (TVIbSS and TVISS) play crucial role in this phenomenon. A contact-dependent growth inhibition (CDI), primarily found in Escherichia coli strains, utilities CdiB/CdiA protein of type Vb secretion system, described also as two-partner secretion (TPS) system, to inhibit growth of non-kin strains, where cell contact is required. Presence of an intracellular small immunity protein (CdiI) protects E. coli cells from autoinhibition. Other bacterial competition system, primarily found in nodulation process of Rhizobium leguminosarum bv. Trifolii strain, engages type VI secretion system. The structure of TVISS is more complicated and comprises the series of proteins with structural homology to bacteriophage tail proteins and membrane proteins which builds the core of the system (Tss proteins). Meanwhile, other proteins of the TVISS was described as associated proteins (Tag proteins). Important proteins for TVISS are haemolysin coregulated protein (Hcp) which has hexameric, tubular structure and VgrG protein (valine-glycine repeat G) which play a dual role in the process: as a chaperone protein in secretion of effector toxin or/and as a secreted toxin itself. Despite the structural differences of both secretion systems they show functional homology in competition phenomenon and govern the social life of bacterial community. 1. Introduction. 2. Contact-dependent growth inhibition. 2.1. Structure o CDI machinery. 2.2. Effectors of CDI system. 3. Type VI secretion system. 3.1. Structure of type VI secretion system. 3.2. Effectors of type VI secretion system. 4. Membership to polymorphic toxins system. 5. Role of the systems in bacterial biology. 6. Conclusions

An alternative minimally invasive technique for genetic sampling of bats: Wing swabs yield species identification

ABSTRACTBat species are traditionally identified morphologically, but in some cases, species can be difficult to differentiate. Wing punches (biopsies) of wing or tail membranes are commonly used to collect tissue for DNA analysis, but less invasive techniques are preferable. As such, DNA acquired using buccal and wing swabs or from fecal pellets are increasingly being employed. We compared a dry swabbing technique with the wing biopsy technique for DNA collection. We compared species identification between tissue biopsies and wing swabs collected from bats in Alberta and British Columbia, Canada, between April and November, 2014, and September and October 2015. Species identification was achieved with varying methods of field collection and lab processing. DNA was extracted, sequenced, and compared with reference sequences and field identifications. We concluded that wing swabs are an effective way to identify bat species genetically and far less invasive than biopsy techniques. These methods should be considered for genetically sampling bats, especially during seasons when wounds from biopsy are slow to heal. © 2017 The Wildlife Society.

Effect of serum antioxidant levels on sperm function in infertile male

Abstract Antioxidant and reactive oxygen species (ROS) has been implicated in male infertility. Antioxidants are compounds which scavenge formation or oppose of the actions ROS. Spermatozoa are particularly vulnerable to ROS because of inherent deficiencies in intracellular antioxidant enzyme protection, thus total body antioxidant capacity become more substantial to protect sperm. In this study to try to evaluate the role of serum total antioxidant capacity, uric acid, glutathione, total thiols, ferritin, albumin and malodialdehyde in male infertility. 66 men included in this study 40 were infertile and 26 were healthy fertile. Results showed a significant decrease in sperm progressive motility and a significant increase in sperm tail abnormality, also there were a significant decrease in serum total antioxidant capacity, uric acid and albumin in infertile group. Because of lack of the intracellular antioxidant enzymes sperm cannot protect plasma membrane that surrounds the tail, the protection depends on the antioxidant defense afforded by the seminal plasma and on the entire body antioxidant capacity. Decrease of serum antioxidant capacity, uric acid and albumin may cause destroy of sperm tail membrane and this may lowering of sperm progressive motility.

Integrity of head and tail plasmalemma is associated with different kinetic variables in boar sperm

An intact and functional sperm plasmalemma has a major role in sperm motility and fertilizing capacity. Several techniques have been developed to evaluate the integrity of the sperm plasma membrane, but there are still some inconsistencies concerning the methods that are more closely associated with sperm function. In this study, the aim was to: i) evaluate the integrity of the boar sperm plasmalemma during 72h of semen storage at 17°C using four techniques: eosin/nigrosin (E/N), propidium iodide/carboxyfluorescein diacetate (PI/CFDA), hypo-osmotic swelling test (HOST), and combined HOST with eosin staining (HOST/E), ii) assess the correlations and the limits of consistency among these techniques, iii) and estimate the relationships with the acrosomal status and sperm kinetics. Results indicate that the integrity of the sperm plasmalemma decreases during 72h of storage, although significant differences were found only using the HOST and HOST/E techniques. Moreover, use of E/N and PI/CFDA results in greater values relative to the undamaged sperm membrane than use of HOST and HOST/E at any incubation time. Overall, results using all techniques were consistent and correlate except for findings with PI/CFDA and HOST, which was slightly below 95%. Moreover, values using the techniques for the evaluation of the integrity of the sperm head and tail membranes are positively associated with the acrosomal status and different kinetic variables with the tail integrity being related to rapid linear trajectories and the head integrity to rapid curvilinear trajectories. The results of this study provide new insights into the relevance of evaluating the boar sperm plasmalemma in the routine spermiogram.