The study of hybrid zones offers important insights into speciation. Earlier studies on hybrid populations of the marine mussel species Mytilus edulis and Mytilus galloprovincialis in SW England provided evidence of admixture but were constrained by the limited number of molecular markers available. We use 57 ancestry-informative SNPs, most of which have been mapped genetically, to provide evidence of distinctive differences between admixed populations in SW England and asymmetrical introgression from M.
View Article and Find Full Text PDFProteomic analysis was carried out on the Crab (upper-shore) and Wave (lower-shore) ecotypes of from a hybrid zone at Silleiro Cape, Spain. Proteome profiles of individual snails were obtained. Protein expression in F hybrid snails bred in the laboratory and snails with intermediate shell phenotypes collected from the mid-shore were compared with Crab and Wave ecotypes using analytical approaches used to study dominance.
View Article and Find Full Text PDFMislabeling samples or data with the wrong participant information can affect study integrity and lead investigators to draw inaccurate conclusions. Quality control to prevent these types of errors is commonly embedded into the analysis of genomic datasets, but a similar identification strategy is not standard for cytometric data. Here, we present a method for detecting sample identification errors in cytometric data using expression of human leukocyte antigen (HLA) class I alleles.
View Article and Find Full Text PDFBACKGROUNDDespite a rapidly growing body of literature on coronavirus disease 2019 (COVID-19), our understanding of the immune correlates of disease severity, course, and outcome remains poor.METHODSUsing mass cytometry, we assessed the immune landscape in longitudinal whole-blood specimens from 59 patients presenting with acute COVID-19 and classified based on maximal disease severity. Hospitalized patients negative for SARS-CoV-2 were used as controls.
View Article and Find Full Text PDFEvolution has direct and indirect consequences on species-species interactions and the environment. However, Earth systems models describing planktonic activity invariably fail to explicitly consider organism evolution. Here we simulate the evolution of the single most important physiological characteristic of any organism as described in models-its maximum growth rate (μ).
View Article and Find Full Text PDFDysregulated cholesterol metabolism is implicated in a number of neurological disorders. Many sterols, including cholesterol and its precursors and metabolites, are biologically active and important for proper brain function. However, spatial cholesterol metabolism in brain and the resulting sterol distributions are poorly defined.
View Article and Find Full Text PDFThe clinical diagnosis of new-onset type 1 diabetes has, for many years, been considered relatively straightforward. Recently, however, there is increasing awareness that within this single clinical phenotype exists considerable heterogeneity: disease onset spans the complete age range; genetic susceptibility is complex; rates of progression differ markedly, as does insulin secretory capacity; and complication rates, glycemic control, and therapeutic intervention efficacy vary widely. Mechanistic and immunopathological studies typically show considerable patchiness across subjects, undermining conclusions regarding disease pathways.
View Article and Find Full Text PDFCell mediated immunity plays a vital role in defense against influenza infection in humans. Less is known about the role of vaccine-induced cell mediated immunity and the cytokine responses elicited. We measured CD4 and CD8 T-cell reactivity in human subjects following vaccination with licensed trivalent influenza vaccine and a novel virus-like particle based vaccine.
View Article and Find Full Text PDFThe mussels and are marine organisms with external fertilization able to hybridize where their distributions overlap allowing the study of reproductive isolation mechanisms in nature. We provide raw data of a transcriptomic analysis of mature male gonads from these two spp. using NGS (Illumina) technology and a preliminary list of transcript that were functionally annotated showing species-specific differential expression.
View Article and Find Full Text PDFSpeciation mechanisms in marine organisms have attracted great interest because of the apparent lack of substantial barriers to genetic exchange in marine ecosystems. Marine mussels of the Mytilus edulis species complex provide a good model to study mechanisms underlying species formation. They hybridise extensively at many localities and both pre- and postzygotic isolating mechanisms may be operating.
View Article and Find Full Text PDFNutrient acquisition is a critical determinant for the competitive advantage for auto- and osmohetero- trophs alike. Nutrient limited growth is commonly described on a whole cell basis through reference to a maximum growth rate (Gmax) and a half-saturation constant (KG). This empirical application of a Michaelis-Menten like description ignores the multiple underlying feedbacks between physiology contributing to growth, cell size, elemental stoichiometry and cell motion.
View Article and Find Full Text PDFMany bivalve species have two types of mitochondrial DNA passed independently through the female line (F genome) and male line (M genome). Here we study the cytochrome oxidase I protein in such bivalve species and provide evidence for differences between the F and M proteins in amino acid property values, particularly relating to hydrophobicity and helicity. The magnitude of these differences varies between different regions of the protein and the change from the ancestor is most marked in the M protein.
View Article and Find Full Text PDFAim: Expression of PD-L1 in the tumor is associated with more favorable responses to anti-PD-1 therapy in multiple cancers. However, obtaining tumor biopsies for PD-L1 interrogation is an invasive procedure and challenging to assess repeatedly as the disease progresses.
Materials & Methods: Here we assess an alternative, minimally invasive approach to analyze blood samples for circulating tumor cells (CTCs) that have broken away from the tumor and entered the periphery.
Small molecule Toll-like receptor 7 (TLR7) agonists have been used as vaccine adjuvants by enhancing innate immune activation to afford better adaptive response. Localized TLR7 agonists without systemic exposure can afford good adjuvanticity, suggesting peripheral innate activation (non-antigen-specific) is not required for immune priming. To enhance colocalization of antigen and adjuvant, benzonaphthyridine (BZN) TLR7 agonists are chemically modified with phosphonates to allow adsorption onto aluminum hydroxide (alum), a formulation commonly used in vaccines for antigen stabilization and injection site deposition.
View Article and Find Full Text PDFDengue disease is a global challenge for healthcare systems particularly during outbreaks, and millions of dollars are spent every year for vector control. An efficient and safe vaccine that is cost-effective could resolve the burden that dengue virus imposes on affected countries. We describe here the immunogenicity of a tetravalent formulation of a recombinant fusion protein consisting of E domain III and the capsid protein of dengue serotypes 1-4 (Tetra DIIIC).
View Article and Find Full Text PDFAdjuvants increase vaccine potency largely by activating innate immunity and promoting inflammation. Limiting the side effects of this inflammation is a major hurdle for adjuvant use in vaccines for humans. It has been difficult to improve on adjuvant safety because of a poor understanding of adjuvant mechanism and the empirical nature of adjuvant discovery and development historically.
View Article and Find Full Text PDFMethods: A novel, fully bacterially produced recombinant virus-like particle (VLP) based influenza vaccine (gH1-Qbeta) against A/California/07/2009(H1N1) was tested in a double-blind, randomized phase I clinical trial at two clinical sites in Singapore. The trial evaluated the immunogenicity and safety of gH1-Qbeta in the presence or absence of alhydrogel adjuvant. Healthy adult volunteers with no or low pre-existing immunity against A/California/07/2009 (H1N1) were randomized to receive two intramuscular injections 21 days apart, with 100μg vaccine, containing 42μg hemagglutinin antigen.
View Article and Find Full Text PDFInfluenza pandemics can spread quickly and cost millions of lives; the 2009 H1N1 pandemic highlighted the shortfall in the current vaccine strategy and the need for an improved global response in terms of shortening the time required to manufacture the vaccine and increasing production capacity. Here we describe the pre-clinical assessment of a novel 2009 H1N1 pandemic influenza vaccine based on the E. coli-produced HA globular head domain covalently linked to virus-like particles derived from the bacteriophage Qβ.
View Article and Find Full Text PDFMany bivalves have an unusual mechanism of mitochondrial DNA (mtDNA) inheritance called doubly uniparental inheritance (DUI) in which distinctly different genomes are inherited through the female (F genome) and male (M genome) lineages. In fertilized eggs that will develop into male embryos, the sperm mitochondria remain in an aggregation, which is believed to be delivered to the primordial germ cells and passed to the next generation through the sperm. In fertilized eggs that will develop into female embryos, the sperm mitochondria are dispersed throughout the developing embryo and make little if any contribution to the next generation.
View Article and Find Full Text PDFDps proteins are found almost ubiquitously in bacterial genomes and there is now an appreciation of their multifaceted roles in various stress responses. Previous studies have shown that this family of proteins assemble into dodecamers and their quaternary structure is entirely critical to their function. Moreover, the numbers of dps genes per bacterial genome is variable; even amongst closely related species - however, for many genera this enigma is yet to be satisfactorily explained.
View Article and Find Full Text PDFMultiple-choice question (MCQ) examinations are increasingly used as the assessment method of theoretical knowledge in large class-size modules in many life science degrees. MCQ-tests can be used to objectively measure factual knowledge, ability and high-level learning outcomes, but may also introduce gender bias in performance dependent on topic, instruction, scoring and difficulty. The 'Single Answer' (SA) test is often used in which students choose one correct answer, in which they are unable to demonstrate partial knowledge.
View Article and Find Full Text PDFProteomic analysis on sperm has been restricted to only a few model organisms. We present here a 2DE PAGE proteome map of sperm cells from a nonmodel organism, the marine mussel Mytilus edulis, a free-spawning marine invertebrate with external fertilization. Ninety-six protein spots showing high expression were selected and of these 77 were successfully identified by nESI-MS analysis.
View Article and Find Full Text PDFAnalytical methods for regulatory tests usually must be defined before testing. To take this into account and to minimise equivocal interpretations, a sequential strategy is recommended. Assay validity must be verified and results then classed as clearly negative, clearly positive, or uncertain based on historical data.
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