ObjectivesT follicular helper (Tfh) cells are critical in the development and progression of syst... more ObjectivesT follicular helper (Tfh) cells are critical in the development and progression of systemic lupus erythematosus (SLE). To assess the characteristics and mechanisms of differentiation of Tfh cells, we investigated the phenotype of T helper cells in patients with SLE and underlying epigenetic modifications by cytokine-induced signal transducer and activators of transcription (STAT) family factors.MethodsPeripheral blood mononuclear cells from patients and healthy donors were analysed by flow cytometry. CD4+ T cells were isolated and cultured under various stimulations. Expression of characteristic markers and phosphorylation of STATs were analysed by flow cytometry and quantitative PCR. Histone modifications were analysed by chromatin immunoprecipitation (ChIP)-PCR.ResultsDifferentiation of CD4+CXCR5+CXCR3+Bcl-6+T-bet+IL-21+IFN-γ+Tfh-Th1-like cells was induced by interleukin (IL)-12-induced activation of STAT1 and STAT4 simultaneously. The loci of Bcl-6 and T-bet at STAT bin...
Current theories predict that Allee effects should be widespread in nature, but there is little c... more Current theories predict that Allee effects should be widespread in nature, but there is little consistency in empirical findings. We hypothesized that this gap can arise from ignoring spatial contexts (i.e. spatial scale and heterogeneity) that potentially mask an existing fitness–density relationship: a ‘cryptic’ Allee effect. To test this hypothesis, we analysed how spatial contexts interacted with conspecific density to influence the fertilization rate of the freshwater mussel Margaritifera laevis . This sessile organism has a simple fertilization process whereby females filter sperm from the water column; this system enabled us to readily assess the interaction between conspecific density and spatial heterogeneity (e.g. flow conditions) at multiple spatial levels. Our findings were twofold. First, positive density-dependence in fertilization was undetectable at a population scale (approx. less than 50.5 m 2 ), probably reflecting the exponential decay of sperm density with dist...
In a survey of the fish fauna of the Shubuto River system, northern Oshima Peninsula, Hokkaido, 2... more In a survey of the fish fauna of the Shubuto River system, northern Oshima Peninsula, Hokkaido, 29 species belonging to 10 families were recorded from June to October 2010. The species richness and abundance of diadromous species were relatively high. In contrast, fishes requiring lentic habitat were conspicuously absent, and Hucho perryi was not recorded. These results may be attributed to high connectivity from upper river reaches to the ocean due to the absence of dams hindering fish migration and to the lack of floodplain wetland habitats and transverse migratory routes. In terms of the conservation ecology of the region, we strongly recommend the preservation of the current status of longitudinal connectivity as well as the restoration of floodplain habitats along the river channels.
ABSTRACT Population status and physicochemical factors affecting local density of endangered fres... more ABSTRACT Population status and physicochemical factors affecting local density of endangered freshwater pearl mussels, Margaritifera laevis, in Shubuto river basin were investigated through measurements of local density and individual size of M. laevis, and environmental variables at 27 sites (including 324 quadrats: 0.5 × 0.5 m). Proportions of small-sized juveniles were 34–100% depending on the reach, suggesting relatively high recruiting rates. Generalized linear mixed models (GLMMs) revealed that the local density is strongly affected positively by dissolved oxygen, %sand, and current velocity. Quadratic terms are also strong for two physical factors, %sand and water depth. The local density tended to be higher at quadrats with 9.30–10.2 mg/l dissolved oxygen, 10–50% sand proportion, 0.2–0.6 m water depth, and 0.05–0.30 m/s current velocity. There were little differences in the factors affecting local density among three size classes (< 20 mm, 20–50 mm, > 50 mm). Therefore, the local density was significantly higher at the river fringe with a combination of more suitable physical environment factors than middle of the river. These results suggest that artificial alteration of river fringe could have adverse influences on M. laevis population.
ObjectivesT follicular helper (Tfh) cells are critical in the development and progression of syst... more ObjectivesT follicular helper (Tfh) cells are critical in the development and progression of systemic lupus erythematosus (SLE). To assess the characteristics and mechanisms of differentiation of Tfh cells, we investigated the phenotype of T helper cells in patients with SLE and underlying epigenetic modifications by cytokine-induced signal transducer and activators of transcription (STAT) family factors.MethodsPeripheral blood mononuclear cells from patients and healthy donors were analysed by flow cytometry. CD4+ T cells were isolated and cultured under various stimulations. Expression of characteristic markers and phosphorylation of STATs were analysed by flow cytometry and quantitative PCR. Histone modifications were analysed by chromatin immunoprecipitation (ChIP)-PCR.ResultsDifferentiation of CD4+CXCR5+CXCR3+Bcl-6+T-bet+IL-21+IFN-γ+Tfh-Th1-like cells was induced by interleukin (IL)-12-induced activation of STAT1 and STAT4 simultaneously. The loci of Bcl-6 and T-bet at STAT bin...
Current theories predict that Allee effects should be widespread in nature, but there is little c... more Current theories predict that Allee effects should be widespread in nature, but there is little consistency in empirical findings. We hypothesized that this gap can arise from ignoring spatial contexts (i.e. spatial scale and heterogeneity) that potentially mask an existing fitness–density relationship: a ‘cryptic’ Allee effect. To test this hypothesis, we analysed how spatial contexts interacted with conspecific density to influence the fertilization rate of the freshwater mussel Margaritifera laevis . This sessile organism has a simple fertilization process whereby females filter sperm from the water column; this system enabled us to readily assess the interaction between conspecific density and spatial heterogeneity (e.g. flow conditions) at multiple spatial levels. Our findings were twofold. First, positive density-dependence in fertilization was undetectable at a population scale (approx. less than 50.5 m 2 ), probably reflecting the exponential decay of sperm density with dist...
In a survey of the fish fauna of the Shubuto River system, northern Oshima Peninsula, Hokkaido, 2... more In a survey of the fish fauna of the Shubuto River system, northern Oshima Peninsula, Hokkaido, 29 species belonging to 10 families were recorded from June to October 2010. The species richness and abundance of diadromous species were relatively high. In contrast, fishes requiring lentic habitat were conspicuously absent, and Hucho perryi was not recorded. These results may be attributed to high connectivity from upper river reaches to the ocean due to the absence of dams hindering fish migration and to the lack of floodplain wetland habitats and transverse migratory routes. In terms of the conservation ecology of the region, we strongly recommend the preservation of the current status of longitudinal connectivity as well as the restoration of floodplain habitats along the river channels.
ABSTRACT Population status and physicochemical factors affecting local density of endangered fres... more ABSTRACT Population status and physicochemical factors affecting local density of endangered freshwater pearl mussels, Margaritifera laevis, in Shubuto river basin were investigated through measurements of local density and individual size of M. laevis, and environmental variables at 27 sites (including 324 quadrats: 0.5 × 0.5 m). Proportions of small-sized juveniles were 34–100% depending on the reach, suggesting relatively high recruiting rates. Generalized linear mixed models (GLMMs) revealed that the local density is strongly affected positively by dissolved oxygen, %sand, and current velocity. Quadratic terms are also strong for two physical factors, %sand and water depth. The local density tended to be higher at quadrats with 9.30–10.2 mg/l dissolved oxygen, 10–50% sand proportion, 0.2–0.6 m water depth, and 0.05–0.30 m/s current velocity. There were little differences in the factors affecting local density among three size classes (< 20 mm, 20–50 mm, > 50 mm). Therefore, the local density was significantly higher at the river fringe with a combination of more suitable physical environment factors than middle of the river. These results suggest that artificial alteration of river fringe could have adverse influences on M. laevis population.
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