Chlorarachniophytes are amoeboflagellate algae that acquired photosynthesis secondarily by engulfing a green alga and retaining its plastid (chloroplast). An important consequence of secondary ...endosymbiosis in chlorarachniophytes is that most of the nuclear genes encoding plastid-targeted proteins have moved from the nucleus of the endosymbiont to the host nucleus. We have sequenced and analyzed 83 cDNAs encoding 78 plastid-targeted proteins from the model chlorarachniophyte Bigelowiella natans (formerly Chlorarachnion sp. CCMP621). Phylogenies inferred from the majority of these genes are consistent with a chlorophyte green algal origin. However, a significant number of genes (≈21%) show signs of having been acquired by lateral gene transfer from numerous other sources: streptophyte algae, red algae (or algae with red algal endosymbionts), as well as bacteria. The chlorarachniophyte plastid proteome may therefore be regarded as a mosaic derived from various organisms in addition to the ancestral chlorophyte plastid. In contrast, the homologous genes from the chlorophyte Chlamydomonas reinhardtii do not show any indications of lateral gene transfer. This difference is likely a reflection of the mixotrophic nature of Bigelowiella (i.e., it is photosynthetic and phagotrophic), whereas Chlamydomonas is strictly autotrophic. These results underscore the importance of lateral gene transfer in contributing foreign proteins to eukaryotic cells and their organelles, and also suggest that its impact can vary from lineage to lineage.
The microbiome may be affected by trauma and critical illness. Many studies of the microbiome in critical illness are restricted to a single body site or time point and confounded by preexisting ...conditions. We report temporal and spatial alterations in the microbiome of previously healthy children with severe traumatic brain injury (TBI).
We collected oral, rectal, and skin swabs within 72 hours of admission and then twice weekly until ICU discharge. Samples were analyzed by 16S rRNA gene amplicon sequencing. Children undergoing elective outpatient surgery served as controls. Alpha and beta diversity comparisons were performed with Phyloseq, and differentially abundant taxa were predicted using Analysis of Composition of Microbiomes.
Five quaternary-care PICUs.
Patients less than 18 years with severe TBI requiring placement of an intracranial pressure monitor.
None.
Three hundred twenty-seven samples were analyzed from 23 children with severe TBI and 35 controls. The community composition of initial oral (F = 3.2756, R2 = 0.0535, p = 0.012) and rectal (F = 3.0702, R2 = 0.0649, p = 0.007) samples differed between TBI and control patients. Rectal samples were depleted of commensal bacteria from Ruminococcaceae, Bacteroidaceae, and Lachnospiraceae families and enriched in Staphylococcaceae after TBI (p < 0.05). In exploratory analyses, antibiotic exposure, presence of an endotracheal tube, and occurrence of an infection were associated with greater differences of the rectal and oral microbiomes between TBI patients and healthy controls, whereas enteral nutrition was associated with smaller differences (p < 0.05).
The microbiome of children with severe TBI is characterized by early depletion of commensal bacteria, loss of site specificity, and an enrichment of potential pathogens. Additional studies are needed to determine the impact of these changes on clinical outcomes.
Hydrocephalus is a common disorder caused by the buildup of cerebrospinal fluid (CSF) in the brain. Treatment typically involves the surgical implantation of a pressure-regulated silicone tube ...assembly, known as a shunt. Unfortunately, shunts have extremely high failure rates and diagnosing shunt malfunction is challenging due to a combination of vague symptoms and a lack of a convenient means to monitor flow. Here, we introduce a wireless, wearable device that enables precise measurements of CSF flow, continuously or intermittently, in hospitals, laboratories or even in home settings. The technology exploits measurements of thermal transport through near-surface layers of skin to assess flow, with a soft, flexible, and skin-conformal device that can be constructed using commercially available components. Systematic benchtop studies and numerical simulations highlight all of the key considerations. Measurements on 7 patients establish high levels of functionality, with data that reveal time dependent changes in flow associated with positional and inertial effects on the body. Taken together, the results suggest a significant advance in monitoring capabilities for patients with shunted hydrocephalus, with potential for practical use across a range of settings and circumstances, and additional utility for research purposes in studies of CSF hydrodynamics.
Kolente virus (KOLEV) is a rhabdovirus originally isolated from ticks and a bat in Guinea, West Africa, in 1985. Although tests at the time of isolation suggested that KOLEV is a novel rhabdovirus, ...it has remained largely uncharacterized. We assembled the complete genome sequence of the prototype strain DakAr K7292, which was found to encode the five canonical rhabdovirus structural proteins (N, P, M, G and L) with alternative ORFs (>180 nt) in the P and L genes. Serologically, KOLEV exhibited a weak antigenic relationship with Barur and Fukuoka viruses in the Kern Canyon group. Phylogenetic analysis revealed that KOLEV represents a distinct and divergent lineage that shows no clear relationship to any rhabdovirus except Oita virus, although with limited phylogenetic resolution. In summary, KOLEV represents a novel species in the family Rhabdoviridae.
Questions
Fire regime alterations are pushing open ecosystems worldwide past tipping points where alternative steady states characterized by woody dominance prevail. This reduces the frequency and ...intensity of surface fires, further limiting their effectiveness for controlling cover of woody plants. In addition, grazing pressure (exotic or native grazers) can reinforce woody encroachment by potentially reducing fine‐fuel loads. We investigated the effects of different fire energies on the herbaceous plant community, together with mammalian wildlife herbivory (exotic and native combined) exclusion, to inform best management practices.
Location
Texas semi‐arid savanna, southern Great Plains, USA.
Methods
We conducted an experiment in which we manipulated fire intensity and herbivore access to herbaceous biomass in a split‐plot design. We altered fire energy via fuel addition rather than applying fire under different environmental conditions to control for differences in standing biomass and composition attributable to differential plant physiological status and fire season.
Results
High‐energy fire did not reduce herbaceous biomass or alter plant community composition, although it did increase among‐plot variability in composition and forb biomass relative to low‐energy fire and non‐burned controls. Grazing pressure from native and non‐native mammalian herbivores reduced above‐ground herbaceous biomass regardless of fire treatments, but did not alter community composition.
Conclusions
Managers seeking to apply high‐intensity prescribed fire to reduce woody encroachment will not negatively impact herbaceous plant productivity or alter community composition. However, they should be cognizant that repeated fires necessary for greatly reducing woody plants in heavily invaded areas might be difficult to accomplish due to fine‐fuel reduction from wild herbivores. High fencing to restrict access by wildlife herbivores or culling might be necessary to build fuels sufficient to conduct high‐intensity burns for woody‐plant reduction.
We conducted an experiment manipulating fire energy and herbivore access to herbaceous biomass in a well‐replicated, split‐plot design. Managers seeking to apply high‐intensity prescribed fire to reduce woody encroachment will not negatively impact herbaceous plant productivity or alter community compositional trajectories. However, exotic herbivores greatly reduce fine fuels.
Since 1998, cyclic mortality events in common eiders (Somateria mollissima), numbering in the hundreds to thousands of dead birds, have been documented along the coast of Cape Cod, MA, USA. Although ...longitudinal disease investigations have uncovered potential contributing factors responsible for these outbreaks, detecting a primary etiological agent has proven enigmatic. Here, we identify a novel orthomyxovirus, tentatively named Wellfleet Bay virus (WFBV), as a potential causative agent of these outbreaks. Genomic analysis of WFBV revealed that it is most closely related to members of the Quaranjavirus genus within the family Orthomyxoviridae. Similar to other members of the genus, WFBV contains an alphabaculovirus gp64-like glycoprotein that was demonstrated to have fusion activity; this also tentatively suggests that ticks (and/or insects) may vector the virus in nature. However, in addition to the six RNA segments encoding the prototypical structural proteins identified in other quaranjaviruses, a previously unknown RNA segment (segment 7) encoding a novel protein designated VP7 was discovered in WFBV. Although WFBV shows low to moderate levels of sequence similarity to Quaranfil virus and Johnston Atoll virus, the original members of the Quaranjavirus genus, additional antigenic and genetic analyses demonstrated that it is closely related to the recently identified Cygnet River virus (CyRV) from South Australia, suggesting that WFBV and CyRV may be geographic variants of the same virus. Although the identification of WFBV in part may resolve the enigma of these mass mortality events, the details of the ecology and epidemiology of the virus remain to be determined.
The emergence or reemergence of viral pathogens resulting in large-scale outbreaks of disease in humans and/or animals is one of the most important challenges facing biomedicine. For example, understanding how orthomyxoviruses such as novel influenza A virus reassortants and/or mutants emerge to cause epidemic or pandemic disease is at the forefront of current global health concerns. Here, we describe the emergence of a novel orthomyxovirus, Wellfleet Bay virus (WFBV), which has been associated with cyclic large-scale bird die-offs in the northeastern United States. This initial characterization study provides a foundation for further research into the evolution, epidemiology, and ecology of newly emerging orthomyxoviruses, such as WFBV, and their potential impacts on animal and/or human health.
•Insertion of a recognition site for a microRNA (miRNA) reduces reporter gene expression in Brugia malayi.•Mutation of the seed and 5′ end sequences of the miRNA recognition site partially restore ...expression.•miRNA target prediction algorithms developed for other organisms can predict miRNA targets in B. malayi.•Transient transfection of B. malayi embryos can be used to functionally assay miRNA recognition sites.
The complement of the Brugia malayi microRNA-71 was inserted into the 3′ untranslated region of a reporter plasmid, resulting in a decrease in reporter activity. Mutation of the seed sequence restored activity. Insertion of the 3′ untranslated regions from two algorithm-predicted putative target genes into the reporter resulted in a similar decrease in activity; mutation of the predicted target sequences restored activity. These experiments demonstrate that B. malayi microRNA targets may be predicted using current algorithms and describe a functional assay to confirm predicted targets.
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