Genetic diversity in threatened Posidonia australis seagrass meadows

Recognising patterns of genetic diversity and connectivity is integral to understanding the mechanisms behind population declines and formulating management plans for the conservation of threatened or endangered species. This is particularly important for clonal organisms such as seagrasses, which are experiencing rapid global decline. This study quantifies genetic diversity within 12 naturally fragmented Posidonia australis meadows on the east coast of Australia, using a set of eight microsatellite DNA markers. Genetic diversity increased with latitude, moving away from the range-edge, and was significantly lower in six mid-range endangered meadows and the two northernmost meadows. These meadows also showed evidence of shared multilocus genotypes despite significant geographic separation. The four southernmost meadows were genetically differentiated from all other meadows further north, and all multilocus genotypes identified were unique to their sample locations. We conclude that patterns of low diversity in the endangered and northern meadows are likely due to a population bottleneck caused by a range-edge effect. A common ancestral source meadow existing prior to historical sea level changes may explain the sharing of multilocus genotypes, as contemporary gene flow between these geographically isolated meadows is unlikely. Our findings have important implications for conservation, highlighting the endangered and range-edge populations as those potentially most at risk of extinction should environmental conditions change. These results can be utilised for the location of suitable donor populations for transplanting purposes as a means of mitigating further declines.     

GO Explorer: A gene-ontology tool to aid in the interpretation of shotgun proteomics data

Background  

Spectral counting is a shotgun proteomics approach comprising the identification and relative quantitation of thousands of proteins in complex mixtures. However, this strategy generates bewildering amounts of data whose biological interpretation is a challenge.     

Direct and indirect effects of ocean acidification and warming on a marine plant–herbivore interaction

The impacts of climatic change on organisms depend on the interaction of multiple stressors and how these may affect the interactions among species. Consumer–prey relationships may be altered by changes to the abundance of either species, or by changes to the per capita interaction strength among species. To examine the effects of multiple stressors on a species interaction, we test the direct, interactive effects of ocean warming and lowered pH on an abundant marine herbivore (the amphipod Peramphithoe parmerong), and whether this herbivore is affected indirectly by these stressors altering the palatability of its algal food (Sargassum linearifolium). Both increased temperature and lowered pH independently reduced amphipod survival and growth, with the impacts of temperature outweighing those associated with reduced pH. Amphipods were further affected indirectly by changes to the palatability of their food source. The temperature and pH conditions in which algae were grown interacted to affect algal palatability, with acidified conditions only affecting feeding rates when algae were also grown at elevated temperatures. Feeding rates were largely unaffected by the conditions faced by the herbivore while feeding. These results indicate that, in addition to the direct effects on herbivore abundance, climatic stressors will affect the strength of plant–herbivore interactions by changes to the susceptibility of plant tissues to herbivory.     

Generation of a GLO-2 deficient mouse reveals its effects on liver carbonyl and glutathione levels

ObjectiveHydroxyacylglutathione hydrolase (aka as GLO-2) is a component of the glyoxalase pathway involved in the detoxification of the reactive oxoaldehydes, glyoxal and methylglyoxal. These reactive metabolites have been linked to a variety of pathological conditions, including diabetes, cancer and heart disease and may be involved in the aging process. The objective of this study was to generate a mouse model deficient in GLO-2 to provide insight into the function of GLO-2 and to determine if it is potentially linked to endogenous oxalate synthesis which could influence urinary oxalate excretion.MethodsA GLO-2 knock out mouse was generated using CRISPR/Cas 9 techniques. Tissue and 24-h urine samples were collected under baseline conditions from adult male and female animals for biochemical analyses, including chromatographic measurement of glycolate, oxalate, glyoxal, methylglyoxal, D-lactate, ascorbic acid and glutathione levels.ResultsThe GLO-2 KO animals developed normally and there were no changes in 24-h urinary oxalate excretion, liver levels of methylglyoxal, glyoxal, ascorbic acid and glutathione, or plasma d-lactate levels. GLO-2 deficient males had lower plasma glycolate levels than wild type males while this relationship was not observed in females.ConclusionsThe lack of a unique phenotype in a GLO-2 KO mouse model under baseline conditions is consistent with recent evidence, suggesting a functional glyoxalase pathway is not required for optimal health. A lower plasma glycolate in male GLO-2 KO animals suggests glyoxal production may be a significant contributor to circulating glycolate levels, but not to endogenous oxalate synthesis.     

Identification of Selective Small Molecule Inhibitors of the Nucleotide-Binding Oligomerization Domain 1 (NOD1) Signaling Pathway

NOD1 is an intracellular pattern recognition receptor that recognizes diaminopimelic acid (DAP), a peptidoglycan component in gram negative bacteria. Upon ligand binding, NOD1 assembles with receptor-interacting protein (RIP)-2 kinase and initiates a signaling cascade leading to the production of pro-inflammatory cytokines. Increased NOD1 signaling has been associated with a variety of inflammatory disorders suggesting that small-molecule inhibitors of this signaling complex may have therapeutic utility. We utilized a cell-based screening approach with extensive selectivity profiling to search for small molecule inhibitors of the NOD1 signaling pathway. Via this process we identified three distinct chemical series, xanthines (SB711), quinazolininones (GSK223) and aminobenzothiazoles (GSK966) that selectively inhibited iE-DAP-stimulated IL-8 release via the NOD1 signaling pathway. All three of the newly identified compound series failed to block IL-8 secretion in cells following stimulation with ligands for TNF receptor, TLR2 or NOD2 and, in addition, none of the compound series directly inhibited RIP2 kinase activity. Our initial exploration of the structure-activity relationship and physicochemical properties of the three series directed our focus to the quinazolininone biarylsulfonamides (GSK223). Further investigation allowed for the identification of significantly more potent analogs with the largest boost in activity achieved by fluoro to chloro replacement on the central aryl ring. These results indicate that the NOD1 signaling pathway, similarly to activation of NOD2, is amenable to modulation by small molecules that do not target RIP2 kinase. These compounds should prove useful tools to investigate the importance of NOD1 activation in various inflammatory processes and have potential clinical utility in diseases driven by hyperactive NOD1 signaling.     

Managing the horn fly (Diptera: Muscidae) using an electric walk-through fly trap

An electric walk-through fly trap was evaluated for the management of the horn fly, Hematobia irritans (L.), on dairy cattle in North Carolina over 2 yr. The trap relies on black lights and electrocution grids to attract and kill flies that are brushed from the cattle passing through. During the first season, horn fly densities were reduced from >1,400 to <200 flies per animal. Horn fly density averaged 269.2 +/- 25.8 on cattle using the walk-through fly trap twice daily, and 400.2 +/- 43.5 on the control group during the first year. The second year, seasonal mean horn fly density was 177.3 +/- 10.8 on cattle using the walk-through fly trap compared with 321.1 +/- 15.8 on the control group. No insecticides were used to control horn flies during this 2-yr study.     

Many cameras make light work: opportunistic photographs of rare species in iNaturalist complement structured surveys of reef fish to better understand species richness

Biodiversity and Conservation - Citizen science is on the rise, with growing numbers of initiatives, participants and increasing interest from the broader scientific community. iNaturalist is an...     

Effect of stacking method on Salmonella elimination from recycled poultry bedding

Recycled poultry bedding (RPB) is a protein and mineral supplement for cattle. Concerns regarding this product have arisen because of the perceived risk of transmitting potentially pathogenic organisms to cattle. This study's primary objective was to assess survival of Salmonella in RPB stacked to a recommended height (2.13 m-DS-RPB), or a height of 0.76 m (SS-RPB). Dialysis bags containing RPB and Salmonella typhimurium were placed throughout stacks. Temperature was monitored daily using thermocouples attached to sample bags. After 21 days, sample bags were recovered. Ammonia analysis was performed from multiple sites in the stacks. Bag contents were cultured to determine viability of the salmonella inoculates. This trial demonstrated a wide variation of temperature within the stacks. Temperature near the edge of stacks changed with ambient temperature. Ammonia concentration in the RPB was highest at the top of the DS-RPB. Salmonella was eliminated in 98.7% of sites, with at least a 5-log reduction in the Salmonella organisms in sites where it was still viable.