Neotenic reproductives influence worker caste differentiation in the termite Reticulitermes speratus (Isoptera; Rhinotermitidae)

Division of labor among castes in social insect colonies increases ergonomic efficiency and colony-level fitness, and has played a key role in the ecological success of social insects. Knowledge of the factors that regulate castes is important for understanding adaptive social organization. Our previous study on the termite Reticulitermes speratus demonstrated that the presence of a pair of nymphoid reproductives during development affected offspring caste ratios. In the present study, we investigated further the influence of individual neotenics on offspring caste ratios. Parthenogenetically-produced offspring were reared in worker-tended experimental colonies with the addition of different forms (nymphoid or ergatoid) and numbers of neotenics, and compared the caste ratios of the offspring between the different experimental treatments. We found that all offspring in worker-only tended colonies became nymphs, while a proportion of offspring in colonies with a single neotenic (with the exception of male ergatoids) differentiated into workers. These results show offspring caste ratios are influenced by the presence of single female ergatoids, single female and male nymphoids, while they remain unaffected by the presence of male ergatoids

Phased A-tracts bind to the α subunit of RNA polymerase with increased affinity at low temperature

AbstractPreviously we showed that the expression of a Clostridium perfringens phospholipase C gene (plc) is activated by promoter upstream phased A-tracts in a low temperature-dependent manner. In this paper we characterize the interaction between the α subunit of C. perfringens RNA polymerase and the phased A-tracts. Hydroxyl radical footprinting and fluorescence polarization assaying revealed that the α subunit binds to the minor grooves of the phased A-tracts through its C-terminal domain with increased affinity at low temperature. The result provides a molecular mechanism underlying the activation of the plc promoter by the phased A-tracts

Essential Insight of Direct Electron Transfer-Type Bioelectrocatalysis by Membrane-Bound d-Fructose Dehydrogenase with Structural Bioelectrochemistry

電極を基質認識できる酵素の反応メカニズムを解明 --次世代バイオセンシングにつながる基盤技術--. 京都大学プレスリリース. 2023-10-16.Flavin adenine dinucleotide-dependent d-fructose dehydrogenase (FDH) from Gluconobacter japonicus NBRC3260, a membrane-bound heterotrimeric flavohemoprotein capable of direct electron transfer (DET)-type bioelectrocatalysis, was investigated from the perspective of structural biology, bioelectrochemistry, and protein engineering. DET-type reactions offer several benefits in biomimetics (e.g., biofuel cells, bioreactors, and biosensors) owing to their mediator-less configuration. FDH provides an intense DET-type catalytic signal; therefore, extensive research has been conducted on the fundamental principles and applications of biosensors. Structural analysis using cryo-electron microscopy and single-particle analysis has revealed the entire FDH structures with resolutions of 2.5 and 2.7 Å for the reduced and oxidized forms, respectively. The electron transfer (ET) pathway during the catalytic oxidation of d-fructose was investigated by using both thermodynamic and kinetic approaches. Structural analysis has shown the localization of the electrostatic surface charges around heme 2c in subunit II, and experiments using functionalized electrodes with a controlled surface charge support the notion that heme 2c is the electrode-active site. Furthermore, two aromatic amino acid residues (Trp427 and Phe489) were located in a possible long-range ET pathway between heme 2c and the electrode. Two variants (W427A and F489A) were obtained by site-directed mutagenesis, and their effects on DET-type activity were elucidated. The results have shown that Trp427 plays an essential role in accelerating long-range ET and triples the standard rate constant of heterogeneous ET according to bioelectrochemical analysis

The Atomic and Electronic structure of 0{\deg} and 60{\deg} grain boundaries in MoS2

We have investigated atomic and electronic structure of grain boundaries in monolayer MoS2, where relative angles between two different grains are 0 and 60 degree. The grain boundaries with specific relative angle have been formed with chemical vapor deposition growth on graphite and hexagonal boron nitride flakes; van der Waals interlayer interaction between MoS2 and the flakes restricts the relative angle. Through scanning tunneling microscopy and spectroscopy measurements, we have found that the perfectly stitched structure between two different grains of MoS2 was realized in the case of the 0 degree grain boundary. We also found that even with the perfectly stitched structure, valence band maximum and conduction band minimum shows significant blue shift, which probably arise from lattice strain at the boundary

The MAXI Mission on the ISS: Science and Instruments for Monitoring All Sky X-Ray Images

The MAXI (Monitor of All-sky X-ray Image) mission is the first astronomical payload to be installed on the Japanese Experiment Module-Exposed Facility (JEM-EF) on the ISS. It is scheduled for launch in the middle of 2009 to monitor all-sky X-ray objects on every ISS orbit. MAXI will be more powerful than any previous X-ray All Sky Monitor (ASM) payloads, being able to monitor hundreds of AGN. MAXI will provide all sky images of X-ray sources of about 20 mCrab in the energy band of 2-30 keV from observation on one ISS orbit (90 min), about 4.5 mCrab for one day, and about 1 mCrab for one month. A final detectability of MAXI could be 0.2 mCrab for 2 year observations.Comment: 12 pages, 11 figures, accepted for publication in Publications of the Astronomical Society of Japa

Long-term results of a randomized controlled trial comparing neoadjuvant Adriamycin, cisplatin, and 5-fluorouracil vs docetaxel, cisplatin, and 5-fluorouracil followed by surgery for esophageal cancer (OGSG1003)

Sugimura, K, Yamasaki, M, Yasuda, T, et al. Long‐term results of a randomized controlled trial comparing neoadjuvant Adriamycin, cisplatin, and 5‐fluorouracil vs docetaxel, cisplatin, and 5‐fluorouracil followed by surgery for esophageal cancer (OGSG1003). Ann. Gastroenterol. Surg. 2020; 00: 1– 8. https://doi.org/10.1002/ags3.12388

Variantes genéticas en el locus 9p21 contribuyen al desarrollo de arteriosclerosis a través de la modulación de ANRIL y CDKN2A/B

Registro creado en correspondencia al grado de doctora de Ada Congrains Castillo.Los estudios de asociación de todo el genoma (GWAS) han identificado variantes genéticas que contribuyen al riesgo de enfermedad cardiovascular (ECV) en el locus del cromosoma 9p21. La región asociada a CVD es adyacente a los dos inhibidores de quinasas dependientes de ciclina (CDKN) 2A y 2B y los últimos exones del ARN no codificante, ANRIL. Todavía no está claro cuál de estas transcripciones o cómo están involucradas en la patogénesis de la aterosclerosis.Genome-wide association studies (GWAS) have identified genetic variants contributing to the risk of cardiovascular disease (CVD) at the chromosome 9p21 locus. The CVD-associated region is adjacent to the two cyclin dependent kinase inhibitors (CDKN)2A and 2B and the last exons of the non-coding RNA, ANRIL. It is still not clear which of or how these transcripts are involved in the pathogenesis of atherosclerosis.Japón. Programa de Promoción de Estudios Fundamentales en el Instituto Nacional de Innovación Biomédica de Japón (HR: 22-2-5), el Ministerio de Educación, Cultura, Deportes, Ciencia y Tecnología de Japón (KK: 22510211) y la Fundación NOVARTIS para la Investigación Gerontológica (KK).Tesi