199 research outputs found

    Nemertean and phoronid genomes reveal lophotrochozoan evolution and the origin of bilaterian heads

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    Nemerteans (ribbon worms) and phoronids (horseshoe worms) are closely related lophotrochozoans—a group of animals including leeches, snails and other invertebrates. Lophotrochozoans represent a superphylum that is crucial to our understanding of bilaterian evolution. However, given the inconsistency of molecular and morphological data for these groups, their origins have been unclear. Here, we present draft genomes of the nemertean Notospermus geniculatus and the phoronid Phoronis australis, together with transcriptomes along the adult bodies. Our genome-based phylogenetic analyses place Nemertea sister to the group containing Phoronida and Brachiopoda. We show that lophotrochozoans share many gene families with deuterostomes, suggesting that these two groups retain a core bilaterian gene repertoire that ecdysozoans (for example, flies and nematodes) and platyzoans (for example, flatworms and rotifers) do not. Comparative transcriptomics demonstrates that lophophores of phoronids and brachiopods are similar not only morphologically, but also at the molecular level. Despite dissimilar head structures, lophophores express vertebrate head and neuronal marker genes. This finding suggests a common origin of bilaterian head patterning, although different heads evolved independently in each lineage. Furthermore, we observe lineage-specific expansions of innate immunity and toxin-related genes. Together, our study reveals a dual nature of lophotrochozoans, where conserved and lineage-specific features shape their evolution

    Hyper-expansion of large DNA segments in the genome of kuruma shrimp, Marsupenaeus japonicus

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    <p>Abstract</p> <p>Background</p> <p>Higher crustaceans (class Malacostraca) represent the most species-rich and morphologically diverse group of non-insect arthropods and many of its members are commercially important. Although the crustacean DNA sequence information is growing exponentially, little is known about the genome organization of Malacostraca. Here, we constructed a bacterial artificial chromosome (BAC) library and performed BAC-end sequencing to provide genomic information for kuruma shrimp (<it>Marsupenaeus japonicus</it>), one of the most widely cultured species among crustaceans, and found the presence of a redundant sequence in the BAC library. We examined the BAC clone that includes the redundant sequence to further analyze its length, copy number and location in the kuruma shrimp genome.</p> <p>Results</p> <p>Mj024A04 BAC clone, which includes one redundant sequence, contained 27 putative genes and seemed to display a normal genomic DNA structure. Notably, of the putative genes, 3 genes encode homologous proteins to the inhibitor of apoptosis protein and 7 genes encode homologous proteins to white spot syndrome virus, a virulent pathogen known to affect crustaceans. Colony hybridization and PCR analysis of 381 BAC clones showed that almost half of the BAC clones maintain DNA segments whose sequences are homologous to the representative BAC clone Mj024A04. The Mj024A04 partial sequence was detected multiple times in the kuruma shrimp nuclear genome with a calculated copy number of at least 100. Microsatellites based BAC genotyping clearly showed that Mj024A04 homologous sequences were cloned from at least 48 different chromosomal loci. The absence of micro-syntenic relationships with the available genomic sequences of <it>Daphnia </it>and <it>Drosophila </it>suggests the uniqueness of these fragments in kuruma shrimp from current arthropod genome sequences.</p> <p>Conclusions</p> <p>Our results demonstrate that hyper-expansion of large DNA segments took place in the kuruma shrimp genome. Although we analyzed only a part of the duplicated DNA segments, our result suggested that it is difficult to analyze the shrimp genome following normal analytical methodology. Hence, it is necessary to avoid repetitive sequence (such as segmental duplications) when studying the other unique structures in the shrimp genome.</p

    幼児・中学生の脂肪酸摂取と生活習慣病のリスクに関する研究

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    生活習慣病の発現が若年層に見られるようになった。われわれは4歳~5歳の幼児48名と12歳の中学生37名を対象に生活習慣病のリスク保有者を研究の対象とした。検討の指標には肥満とコレステロール値を用い、同時に食物摂取状況調査をして栄養素の算出は第五次日本食品成分表により算出した。肥満群や高コレステロール値群と栄養素摂取量、特に脂肪と脂肪酸の摂取を検討した。肥満の出現率は4歳~5歳の群に多く、高コレステロール値、低HDLコレステロール値は12歳の群に多く見られた。12歳の食品摂取の特徴は脂肪や脂肪酸の摂取が高く、抗酸化性のあるビタミンC、ビタミンA、の摂取が低かった。4~5歳の肥満群ではほとんどの栄養素摂取量と肥満度の間に正の相関を示し、過食を示している。The incidence rate of the life style related diseases has been increasing in early age group. We observed the age of 4 to 5 (48) and 12 (37) who have risks life related disease. As for health observations we used obese ratio and cholesterol levels, and the same time we investigated food intake status and calculated nutrients intakes using food composition table. We investigated the relation between the children who was obese or high cholesterol groups and nutrients intake, especially fat and fatty acid intakes. Incidence rate of obese was observed higher in 4 and 5 years old groups but high cholesterol level and low HDL-cholesterol were found in 12 years old group. The characteristics of the food intake in high cholesterol in 12 years old group were shown high intake of fat and fatty acids and low in Vitamin C and vitamin A that contain anti oxidant substances. Obese group was shown positive correlation bretween the most of the nutrients intabe and obese rate. This indicated obese group was over eating

    HBOC患者に対するRRSOへの意思決定

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    Hereditary breast and ovarian cancer syndrome(HBOC) has been reported to account for about 10-15% of all ovarian cancers, and risk-reducing salpingo-oophorectomy(RRSO) is regarded as the only preventive measure against the risk of such cancers. It is important for patients with BRCA 1/2 pathogenic variants to undergo RRSO after childbearing, between the ages of 35 to 45, but a multifaceted perspective is needed when considering this procedure, as it may cause physical and psychological problems. This paper discusses factors that influence decision-making regarding RRSO from three perspectives : demographics, medical history, and psychosociology, with reference to previous studies. Accurate insight into the background that led to the decision to undergo RRSO is crucial for support. Above all, it is essential to utilize such insight in healthcare as vital information to prevent death from breast or ovarian cancer among HBOC patients

    Nonmagnetic framboid and associated iron nanoparticles with a space-weathered feature from asteroid Ryugu

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    リュウグウ試料に初期太陽系の新しい磁気記録媒体を発見~太陽系磁場の新たな研究手法の確立に期待~.京都大学プレスリリース. 2024-04-30.Extraterrestrial minerals on the surface of airless Solar System bodies undergo gradual alteration processes known as space weathering over long periods of time. The signatures of space weathering help us understand the phenomena occurring in the Solar System. However, meteorites rarely retain the signatures, making it impossible to study the space weathering processes precisely. Here, we examine samples retrieved from the asteroid Ryugu by the Hayabusa2 spacecraft and discover the presence of nonmagnetic framboids through electron holography measurements that can visualize magnetic flux. Magnetite particles, which normally provide a record of the nebular magnetic field, have lost their magnetic properties by reduction via a high-velocity (>5 km s⁻¹) impact of a micrometeoroid with a diameter ranging from 2 to 20 μm after destruction of the parent body of Ryugu. Around these particles, thousands of metallic-iron nanoparticles with a vortex magnetic domain structure, which could have recorded a magnetic field in the impact event, are found. Through measuring the remanent magnetization of the iron nanoparticles, future studies are expected to elucidate the nature of the nebular/interplanetary magnetic fields after the termination of aqueous alteration in an asteroid

    サービングサイズ オ モチイタ カンイ ショクモツ セッシュリョウ チョウサホウ ノ カイハツ

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    近年,生活習慣病の深刻化に伴い,管理栄養士に高度な専門知識や技能が求められるようになった。対象者の食行動の変容を目的とした栄養教育の過程で,栄養状態や食習慣の十分な把握は重要であり,実際に個人または集団レベルでの食物および栄養摂取量評価のために食事調査が行われている。その方法は多種類あるが,我々は個人および集団を対象とし,簡便かつ調査者および被調査者の負担が軽く,より正確な摂取状況を把握する方法としてサービングサイズを用いた簡易食物摂取量調査法を開発するために,20歳代女子大生に見合った簡易記録法(以下,簡易法)I,IIを作成し,段階的調査を行った。簡易法の摂取栄養量の算出のため,食品群別荷重平均成分表(以下,荷重平均成分表)を作成し,24時間秤量法(以下,秤量法)との整合性をはかり,精度を高める検討をした。秤量法と簡易法の一回目の検討の結果,食品群では調味料類を除いて有意な差は認められなかったが,食品摂取量の間に相違がみられた。栄養素では,ナトリウム(以下,Na)を除いて有意な差は認められなかった。両調査法間の相関関係は,全ての食品群で有意な正の相関がみられた。栄養素では,レチノール当量を除いて有意な正の相関が認められた。しかし,簡易法の摂取量と秤量法のそれとの間の近似をはかるために,1日の目標量を訂正し,両調査法の二度目の検討を行った。調査IIの結果,食品群では嗜好飲料類を除いて有意な差は認めらなかった。両調査法による食品摂取量は,目標量に対する充足率80&acd;120%を示し,近似値が認められた。栄養素では,鉄(以下,Fe),レチノール当量,ビタミンC(以下,VC)を除いて有意な差は認められなかった。両調査法間の相関関係は,嗜好飲料類を除く全ての食品群で有意であった。また,全ての栄養素で有意な正の相関が認められた

    The noble gas and nitrogen relationship between Ryugu and carbonaceous chondrites

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    Carbonaceous chondrites are considered to have originated from C-type asteroids and represent some of the most primitive material in our solar system. Furthermore, since carbonaceous chondrites can contain significant quantities of volatile elements, they may have played a crucial role in supplying volatiles and organic material to Earth and other inner solar system bodies. However, a major challenge of unravelling the volatile composition of chondritic meteorites is distinguishing between which features were inherited from the parent body, and what may be a secondary feature attributable to terrestrial weathering. In December 2020, the Hayabusa2 mission of the Japan Aerospace Exploration Agency (JAXA) successfully returned surface material from the C-type asteroid (162173) Ryugu to Earth. This material has now been classified as closely resembling CI-type chondrites, which are the most chemically pristine meteorites. The analysis of material from the surface of Ryugu therefore provides a unique opportunity to analyse the volatile composition of material that originated from a CI-type asteroid without the complications arising from terrestrial contamination. Given their highly volatile nature, the noble gas and nitrogen inventories of chondrites are highly sensitive to different alteration processes on the asteroid parent body, and to terrestrial contamination. Here, we investigate the nitrogen and noble gas signature of two pelletized grains collected from the first and second touchdown sites (Okazaki et al., 2022a), to provide an insight into the formation and alteration history of Ryugu. The concentration of trapped noble gas in the Ryugu samples is greater than the average composition of previously measured CI chondrites and are primarily derived from phase Q, although a significant contribution of presolar nanodiamond Xe-HL is noted. The large noble gas concentrations coupled with a significant contribution of presolar nanodiamonds suggests that the Ryugu samples may represent some of the most primitive unprocessed material from the early solar system. In contrast to the noble gases, the abundance of nitrogen and δ15N composition of the two Ryugu pellets are lower than the average CI chondrite value. We attribute the lower nitrogen abundances and δ15N measured in this study to the preferential loss of a 15N-rich phase from our samples during aqueous alteration on the parent planetesimal. The analyses of other grains returned from Ryugu have shown large variations in nitrogen concentrations and δ15N indicating that alteration fluids heterogeneously interacted with material now present on the surface of Ryugu. Finally, the ratio of trapped noble gases to nitrogen is higher than CI chondrites, and is closer to refractory phase Q and nanodiamonds. This indicates that Ryugu experienced aqueous alteration that led to the significant and variable loss of nitrogen, likely from soluble organic matter, without modification of the noble gas budget, which is primarily hosted in insoluble organic matter and presolar diamonds and is therefore more resistant to aqueous alteration.ISSN:0016-7037ISSN:1872-953

    北海道産クロテッドクリームの品質に及ぼす冷凍の影響

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    本研究は、クロテッドクリームの品質に及ぼす冷凍ならびに糖類添加による影響について検討した。実験方法は、冷凍および解凍時の温度履歴、色調の測定、示差走査熱量分析、粘度測定、官能検査である。1. クロテッドクリームの冷凍時間は無糖が短く、ソルビトール、グラニュー糖の順に長くなった。解凍時間は糖類添加に比べて無糖が長くなった。2. 色調はクロテッドクリームの解凍後、いずれも冷凍前に比べてグラフは右・下方向に移行し、明るさを示す明度の減少と彩度の増加が認められた。3. 吸熱エンタルピー(ΔH)は無糖が3.5mJ/mg、グラニュー糖添加3.5mJ/mg、ソルビトール添加11.2mJ/mg であった。ソルビトール添加が無糖よりも大きくなり、熱に対する安定性が示唆された。4. 粘度変化率は、無糖が最も大きく、次いで、グラニュー糖添加、ソルビトール添加の順になった。5. 官能検査は冷凍・解凍クロテッドクリームの評点が0.4~0.5点であった。冷凍保存において糖類添加することはクロテッドクリームの品質を保つ有効な手段であることが明らかとなった。This study examined the effects of freezing or the addition of sugar on the quality of clotted cream. The experimental method included the following steps; temperature history with regard to freezing and thawing, measurement of color tone, differential scanning calorimetry, viscometric measurement and sensory inspection. 1. Sugar-free clotted cream froze in the shortest time, followed by sorbitolcontaining cream, and granulated sugar-containing cream. On the other hand, the thawing time for sugar-free cream was longer than that for sugar-containing cream. 2. All graphs of color tone showed a shift to the lower right after thawing compared to before freezing,and a decrease in brightness together with an increase in saturation was observed. 3. Endothermic enthalpy was 3.5mJ/mg for sugar-free cream, 3.5mJ/mg for granulated sugar-containing cream, and 11.2mJ/mg for sorbitol-containing cream. The figure for sorbitol-containing cream was larger than that of sugar-free cream, which suggested that sorbitol-containing cream has thermal stability. 4. The rate of change in viscosity for sugar-free cream was the largest among samples tested, followed by granulated sugar-containing cream, and sorbitolcontaining cream. 5. Sensory inspection revealed a preference for granulated sugar-containing cream. This indicates that the addition of sugar is an effective measure for maintaining the quality of clotted cream in frozen storage
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