Retraction: NF-κB activation by Helicobacter pylori requires Akt-mediated phosphorylation of p65

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Developmental genetic bases behind the independent origin of the tympanic membrane in mammals and diapsids

International audienceThe amniote middle ear is a classical example of the evolutionary novelty. Although paleontological evidence supports the view that mammals and diapsids (modern reptiles and birds) independently acquired the middle ear after divergence from their common ancestor, the developmental bases of these transformations remain unknown. Here we show that lower-to-upper jaw transformation induced by inactivation of the Endothelin1-Dlx5/6 cascade involving Goosecoid results in loss of the tympanic membrane in mouse, but causes duplication of the tympanic membrane in chicken. Detailed anatomical analysis indicates that the relative positions of the primary jaw joint and first pharyngeal pouch led to the coupling of tympanic membrane formation with the lower jaw in mammals, but with the upper jaw in diapsids. We propose that differences in connection and release by various pharyngeal skeletal elements resulted in structural diversity, leading to the acquisition of the tympanic membrane in two distinct manners during amniote evolution

Genetic Predisposition to Ischemic Stroke

Background and Purpose—The prediction of genetic predispositions to ischemic stroke (IS) may allow the identification of individuals at elevated risk and thereby prevent IS in clinical practice. Previously developed weighted multilocus genetic risk scores showed limited predictive ability for IS. Here, we investigated the predictive ability of a newer method, polygenic risk score (polyGRS), based on the idea that a few strong signals, as well as several weaker signals, can be collectively informative to determine IS risk.Methods—We genotyped 13 214 Japanese individuals with IS and 26 470 controls (derivation samples) and generated both multilocus genetic risk scores and polyGRS, using the same derivation data set. The predictive abilities of each scoring system were then assessed using 2 independent sets of Japanese samples (KyushuU and JPJM data sets).Results—In both validation data sets, polyGRS was shown to be significantly associated with IS, but weighted multilocus genetic risk scores was not. Comparing the highest with the lowest polyGRS quintile, the odds ratios for IS were 1.75 (95% confidence interval, 1.33–2.31) and 1.99 (95% confidence interval, 1.19–3.33) in the KyushuU and JPJM samples, respectively. Using the KyushuU samples, the addition of polyGRS to a nongenetic risk model resulted in a significant improvement of the predictive ability (net reclassification improvement=0.151; P<0.001).Conclusions—The polyGRS was shown to be superior to weighted multilocus genetic risk scores as an IS prediction model. Thus, together with the nongenetic risk factors, polyGRS will provide valuable information for individual risk assessment and management of modifiable risk factors

日本列島の冷温帯林における30年間の土壌動物相の変化とシカ類の影響の可能性

Feature : Impact on Ashiu forest ecosystem due to deerDeer overabundance affects many taxa and ecosystem functions in both aboveground and belowground systems. We investigated changes in soil macro fauna along a ridge and at the bottom of a slope in Ashiu Experimental Forest, a cool temperate natural forest in central Japan, in which the flora, fauna, microflora, and ecosystem functions were studied before the Sika-deer (Cervus nippon) population increased. The abundance and biomass of soil macrofaunal detritivores (earthworms, isopods, amphipods, and diplopods) and predators (opilionids, Araneae, and chilopods) were adversely affected both along the ridge and at the slope bottom. These results are consistent with prior studies conducted with deer exclosures or natural experiments. The soil organic matter distribution, the carbon-nitrogen ratio in the litter and mineral layers, and soil hardness along the slope also changed. These results suggest that deer overabundance affects ecosystem functions along the slope. The movement of litter and soil along the slope, and the reduction of soil macro fauna associated with decomposition possibly contributed to these changes.温帯におけるシカ類の密度の増大が、広範な植物相と動物相、生態系プロセスに影響することが示されてきた。我々はニホンジカ(Cervus nippon)の増加以前の土壌動物相の知見が蓄積されている京都大学芦生演習林(中部日本)において、斜面の尾根部と谷部において大型土壌動物相を調査して過去のデータと比較した。過去と現在の間の変化は尾根と谷とで類似しており、腐植食者のミミズ類、等脚類、端脚類、倍脚類と、捕食者であるイシムカデ類、ジムカデ類、クモ類、ザトウムシ類が個体数や現存量に負の影響を受けていた。尾根部で地表排徊性甲虫の密度が増加していた。我々の大型土壌動物に関する結果は排除柵や自然の実験を用いた、有蹄類が土壌動物に及ぼす影響に関する先行研究の結果によく一致するものであった。同じ期間に斜面における有機物土壌の分布と、表層リターおよび土壌におけるC/N比、土壌硬度が顕著に変化しており、シカが生態系機能に影響を与えていることが示唆された。斜面上の有機物の移動や分解者としての土壌動物相の減少がこの変化に寄与した可能性がある

Crystallization and preliminary X-ray diffraction study of BchU, a methyltransferase from Chlorobium tepidum involved in bacteriochlorophyll c biosynthesis

Recombinant BchU from C. tepidum has been crystallized. Crystals diffract to 2.27 Å using synchrotron radiation at SPring-8 and belong to space group P6122 or P6522, with unit-cell parameters a = b = 81.5, c = 250.7 Å