広島県西条盆地のコウホネ属植物の生育地

[論文] Articl

Seed production and germination in endangered Nuphar（Nymphaeaceae）of western Japan

Populations of both Nuphar pumila subsp. oguraensis and the partially fertile hybrid N．×saijoensis are rare throughout their range. In an aim to identify factors that might influence conservation strategies, seed produc-tion and viability were evaluated in these two imperiled taxa and the more common N . japonica within the Saijô Basin, western Japan. Seed production was significantly higher per fruit in N. japonica and the lowest in N． ×saijoensis. Seed germination did not differ significantly between taxa, however the overall seed viability of the three Japanese taxa was low in comparison to other Nuphar taxa. Our findings suggest that seed viability is not a factor contributing greatly to the rarity of the Nuphar in the Saijô Basin. Fruit and seed harvesting techniques offer potential for propagation efforts

2D Visualization of the Psoriasis Transcriptome Fails to Support the Existence of Dual-Secreting IL-17A/IL-22 Th17 T Cells.

The present paradigm of psoriasis pathogenesis revolves around the IL-23/IL-17A axis. Dual-secreting Th17 T cells presumably are the predominant sources of the psoriasis phenotype-driving cytokines, IL-17A and IL-22. We thus conducted a meta-analysis of independently acquired RNA-seq psoriasis datasets to explore the relationship between the expression of IL17A and IL22. This analysis failed to support the existence of dual secreting IL-17A/IL-22 Th17 cells as a major source of these cytokines. However, variable relationships amongst the expression of psoriasis susceptibility genes and of IL17A, IL22, and IL23A were identified. Additionally, to shed light on gene expression relationships in psoriasis, we applied a machine learning nonlinear dimensionality reduction strategy (t-SNE) to display the entire psoriasis transcriptome as a 2-dimensonal image. This analysis revealed a variety of gene clusters, relevant to psoriasis pathophysiology but failed to support a relationship between IL17A and IL22. These results support existing theories on alternative sources of IL-17A and IL-22 in psoriasis such as a Th22 cells and non-T cell populations

ミズニラ池(仮称)の植生と水質の変化

[論文] Articl

韓国南部の農村地帯の水草相、および水草相と土地利用・水質との関係

We carried out field research in the southern Korean Peninsula and Jeju Island, South Korea to describe the aquatic flora and its habitat of the Korean rural areas, including 32 sites in the peninsula and 16 sites on the island. The sites of the peninsula are irrigation ponds and reservoirs for rice fields. The sites of the island are ponds for the drinking water of domestic animals, and irrigation and washing of local people. The study sites with agriculturally intensive watersheds had high values of electric conductivity （EC） > 40 mS/m. We found 8 free-floating taxa, 9 floating-leaved taxa and 14 submerged taxa. Eleven taxa （e.g. Trapa japonica） were found in both areas. Thirteen taxa （e.g. Euryale ferox） were restricted to the peninsula. Seven taxa （e.g. Potamogeton natans） were restricted to the island. Although most of the taxa were found in waters with various EC values, several species （e.g. Nymphoides indica） were confined to waters with EC < 30 mS/m. Most of the confirmed taxa in this study are found in Japan. The abundant species （e.g. T. japonica） commonly dominate in nutrient-rich ponds in Japan. The aquatic flora of the study area was characterized by species characteristic of a wide distribution and/or eutrophic water. The aquatic flora includes seven species regarded as threatened in Korea. It also includes 15 Japanese threatened species, and 9 of them are rice weeds. Our study shows that ponds of Korean rural areas support diverse aquatic plants including rare and threatened species.韓国の農村地帯の水草相と水草の生育環境を把握することを目的に、朝鮮半島南部32か所と済州島16か所、計48か所において植物と水質の調査を行った。朝鮮半島の調査地は水田灌漑用のため池であり、済州島の調査地は家畜の飲料用と灌漑や洗い物用の池である。調査地のうち、農地に囲まれた池は、電気伝導度（EC）が40mS/m以上の高い値を示した。両地域で浮遊植物8種、浮葉植物9種、沈水植物14種を確認した。このうちヒシなど11種は朝鮮半島と済州島に共通であったが、オニバスなど13種は朝鮮半島、オヒルムシロなど7種は済州島のみに分布し、両地域の植物相に違いがあった。広範囲のEC値に分布する種が多かったが、ガガブタなどの数種はECが30mS/m以下の水域に分布が限られていた。ヒシなどの確認地点が多い種は、日本の富栄養な水域に繁茂する水草であった。調査地の水草相は、生育範囲の広い種と富栄養な水域の種で特徴づけられた。確認種には7種の韓国の絶滅危惧種が含まれていた。また15種の日本の絶滅危惧種も含まれ、そのうちの9種が水田雑草であった。今回の調査結果は、韓国の農村地帯のため池が、稀少種や絶滅危惧種を含む多様な水草の生育地として貴重な存在であることを示している

Relaxed Negative Selection in Germinal Centers and Impaired Affinity Maturation in bcl-xL Transgenic Mice

The role of apoptosis in affinity maturation was investigated by determining the affinity of (4-hydroxy-3-nitrophenyl)acetyl (NP)-specific antibody-forming cells (AFCs) and serum antibody in transgenic mice that overexpress a suppressor of apoptosis, Bcl-xL, in the B cell compartment. Although transgenic animals briefly expressed higher numbers of splenic AFCs after immunization, the bcl-xL transgene did not increase the number or size of germinal centers (GCs), alter the levels of serum antibody, or change the frequency of NP-specific, long-lived AFCs. Nonetheless, the bcl-xL transgene product, in addition to endogenous Bcl-xL, reduced apoptosis in GC B cells and resulted in the expansion of B lymphocytes bearing VDJ rearrangements that are usually rare in primary anti-NP responses. Long-lived AFCs bearing these noncanonical rearrangements were frequent in the bone marrow and secreted immunoglobulin G1 antibodies with low affinity for NP. The abundance of noncanonical cells lowered the average affinity of long-lived AFCs and serum antibody, demonstrating that Bcl-xL and apoptosis influence clonal selection/maintenance for affinity maturation