Increased socially mediated plasticity in gene expression accompanies rapid adaptive evolution

Recent theory predicts that increased phenotypic plasticity can facilitate adaptation as traits respond to selection. When genetic adaptation alters the social environment, socially mediated plasticity could cause co‐evolutionary feedback dynamics that increase adaptive potential. We tested this by asking whether neural gene expression in a recently arisen, adaptive morph of the field cricket Teleogryllus oceanicus is more responsive to the social environment than the ancestral morph. Silent males (flatwings) rapidly spread in a Hawaiian population subject to acoustically orienting parasitoids, changing the population's acoustic environment. Experimental altering crickets’ acoustic environments during rearing revealed broad, plastic changes in gene expression. However, flatwing genotypes showed increased socially mediated plasticity, whereas normal‐wing genotypes exhibited negligible expression plasticity. Increased plasticity in flatwing crickets suggests a coevolutionary process coupling socially flexible gene expression with the abrupt spread of flatwing. Our results support predictions that phenotypic plasticity should rapidly evolve to be more pronounced during early phases of adaptation.     

Ungulates increase forest plant species richness to the benefit of non‐forest specialists

Large wild ungulates are a major biotic factor shaping plant communities. They influence species abundance and occurrence directly by herbivory and plant dispersal, or indirectly by modifying plant‐plant interactions and through soil disturbance. In forest ecosystems, researchers’ attention has been mainly focused on deer overabundance. Far less is known about the effects on understory plant dynamics and diversity of wild ungulates where their abundance is maintained at lower levels to mitigate impacts on tree regeneration. We used vegetation data collected over 10 years on 82 pairs of exclosure (excluding ungulates) and control plots located in a nation‐wide forest monitoring network (Renecofor). We report the effects of ungulate exclusion on (i) plant species richness and ecological characteristics, (ii) and cover percentage of herbaceous and shrub layers. We also analyzed the response of these variables along gradients of ungulate abundance, based on hunting statistics, for wild boar (Sus scrofa), red deer (Cervus elaphus) and roe deer (Capreolus capreolus). Outside the exclosures, forest ungulates maintained higher species richness in the herbaceous layer (+15%), while the shrub layer was 17% less rich, and the plant communities became more light‐demanding. Inside the exclosures, shrub cover increased, often to the benefit of bramble (Rubus fruticosus agg.). Ungulates tend to favour ruderal, hemerobic, epizoochorous and non‐forest species. Among plots, the magnitude of vegetation changes was proportional to deer abundance. We conclude that ungulates, through the control of the shrub layer, indirectly increase herbaceous plant species richness by increasing light reaching the ground. However, this increase is detrimental to the peculiarity of forest plant communities and contributes to a landscape‐level biotic homogenization. Even at population density levels considered to be harmless for overall plant species richness, ungulates remain a conservation issue for plant community composition.     

Modelled biophysical impacts of conservation agriculture on local climates

Including the parameterization of land management practices into Earth System Models has been shown to influence the simulation of regional climates, particularly for temperature extremes. However, recent model development has focused on implementing irrigation where other land management practices such as conservation agriculture (CA) has been limited due to the lack of global spatially explicit datasets describing where this form of management is practiced. Here, we implement a representation of CA into the Community Earth System Model and show that the quality of simulated surface energy fluxes improves when including more information on how agricultural land is managed. We also compare the climate response at the subgrid scale where CA is applied. We find that CA generally contributes to local cooling (~1°C) of hot temperature extremes in mid‐latitude regions where it is practiced, while over tropical locations CA contributes to local warming (~1°C) due to changes in evapotranspiration dominating the effects of enhanced surface albedo. In particular, changes in the partitioning of evapotranspiration between soil evaporation and transpiration are critical for the sign of the temperature change: a cooling occurs only when the soil moisture retention and associated enhanced transpiration is sufficient to offset the warming from reduced soil evaporation. Finally, we examine the climate change mitigation potential of CA by comparing a simulation with present‐day CA extent to a simulation where CA is expanded to all suitable crop areas. Here, our results indicate that while the local temperature response to CA is considerable cooling (>2°C), the grid‐scale changes in climate are counteractive due to negative atmospheric feedbacks. Overall, our results underline that CA has a nonnegligible impact on the local climate and that it should therefore be considered in future climate projections.     

Introducing fluorescence resonance energy transfer‐based biosensors for the analysis of cAMP‐PKA signalling in the fungal pathogen Candida glabrata

The cyclic adenosine monophosphate‐protein kinase A (cAMP‐PKA) pathway is central to signal transduction in many organisms. In pathogenic fungi such as Candida albicans, this signalling cascade has proven to be involved in several processes, such as virulence, indicating its potential importance in antifungal drug discovery. Candida glabrata is an upcoming pathogen of the same species, yet information regarding the role of cAMP‐PKA signalling in virulence is largely lacking. To enable efficient monitoring of cAMP‐PKA activity in this pathogen, we here present the usage of two FRET‐based biosensors. Both variations in the activity of PKA and the quantity of cAMP can be detected in a time‐resolved manner, as we exemplify by glucose‐induced activation of the pathway. We also present information on how to adequately process and analyse the data in a mathematically correct and physiologically relevant manner. These sensors will be of great benefit for scientists interested in linking the cAMP‐PKA signalling cascade to downstream processes, such as virulence, possibly in a host environment.     

Adaptation of <Emphasis Type="Italic">Lactobacillus acidophilus</Emphasis> to Thermal Stress Yields a Thermotolerant Variant Which Also Exhibits Improved Survival at pH 2

Loss in probiotic viability upon exposure to stressful storage and transport conditions has plagued the probiotic market worldwide. Lactobacillus acidophilus is an important probiotic that is added to various functional foods. It is known to be fairly labile and susceptible to temperature variations that it encounters during processing and storage which increases production cost. It has been repeatedly demonstrated that pre-exposure to sub-lethal doses of stress, particularly, temperature and pH, leads to improved survival of various probiotics when they subsequently encounter the same stress of a much greater magnitude. Attempts to adapt L. acidophilus to temperatures as high as 65 °C to arrive at a thermotolerant variant have not been reported previously. To improve viability at elevated temperatures, we gradually adapted the L. acidophilus NCFM strain to survival at 65 °C for 40 min. Following adaptation, the variant showed a 2-log greater survival compared to wild-type at 65 °C. Interestingly, this thermotolerant variant also demonstrated a 2-log greater stability compared to wild-type at pH 2.0. The improved pH and temperature stress tolerance exhibited by this variant remained unaltered even when the strain was lyophilized. Moreover, the thermotolerant variant demonstrated improved stability compared to wild-type when stored for up to a week at 37 and 42 °C. Probiotic properties of the variant such as adherence to epithelial cells and antibacterial activity remained unaltered. This strain can potentially help address the issue of significant loss in viable cell counts of L. acidophilus which is typically encountered during probiotic manufacture and storage.     

Electronegative LDL induces MMP-9 and TIMP-1 release in monocytes through CD14 activation: Inhibitory effect of glycosaminoglycan sulodexide

Objective

Electronegative LDL (LDL(?)) is involved in atherosclerosis through the activation of the TLR4/CD14 inflammatory pathway in monocytes. Matrix metalloproteinases (MMP) and their inhibitors (tissue inhibitors of metalloproteinase [TIMP]) are also crucially involved in atherosclerosis, but their modulation by LDL(?) has never been investigated. The aim of this study was to examine the ability of LDL(?) to release MMPs and TIMPs in human monocytes and to determine whether sulodexide (SDX), a glycosaminoglycan-based drug, was able to affect their secretion.

Microbiome Influences Prenatal and Adult Microglia in a Sex-Specific Manner

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Purification and carbohydrate-binding specificity of Agrocybe cylindracea lectin

A lectin was isolated from fruiting bodies of Agrocybe cylindracea by two ion-exchange chromatographies and gel filtration on Toyopearl HW55F. The lectin was homogeneous on polyacrylamide gel electrophoresis and its molecular mass was determined to be 30 000 by gel filtration, and 15 000 by sodium dodecylsulfate polyacrylamide gel electrophoresis, signifying a dimeric protein. Its carbohydrate-binding specificity was investigated both by sugar-hapten inhibition of hemagglutination and by enzyme-linked immunosorbent assay. The inhibition tests showed the affinity of the lectin to be weakly directed toward sialic acid and lactose, and the enhanced affinity toward trisaccharides containing the NeuAcα2,3Galβ-structure. Importantly, the lectin strongly interacted with glycoconjugates containing NeuAcα2,3Galβ1,3GlcNAc-/GalNAc sequences. This revised version was published online in November 2006 with corrections to the Cover Date.