Boss/Sev Signaling from Germline to Soma Restricts Germline-Stem-Cell-Niche Formation in the Anterior Region of Drosophila Male Gonads

SummaryDrosophila germline stem cells are regulated by the somatic microenvironment, or “niche,” which ensures that the stem cells can both self-renew and produce functional gametes throughout adult life. However, despite its prime importance, little is known about how niche formation is regulated during gonadal development. Here, we demonstrate that a receptor tyrosine kinase, Sevenless (Sev), is required to ensure that the niche develops in the anterior region of the male embryonic gonads. Sev is expressed in somatic cells within the posterior region of the gonads. Sev is activated by a ligand, Bride of sevenless (Boss), which is expressed by the germline, to prevent ectopic niche differentiation in the posterior gonadal somatic cells. Thus, we propose that signal transduction from germline to soma restricts expansion of the germline-stem-cell niche in the gonads

Finding Euroscaptor mizura (Mammalia : Insectivora) and Its Nest from under Hebeloma radicosum (Fungi : Agaricales) in Ashiu, Kyoto, with Data of Possible Contiguous Occurrences of Three Talpine Species in This Region

We examined nests and other traces of moles in Ashiu, Kyoto, beneath fruit bodies of a mushroom species, Hebeloma radicosum, which grows on the underground latrines of small mammals. We also attempted to catch animals at nesting sites which were detected through the fungal fruiting. As a result, an adult specimen of a talpine mole species, Euroscaptor mizura, was collected together with its nest. This is the first record of E. mizura from Ashiu region. Also, this is the first report of the nest of E. mizura, of the mushroom-mole nest association in H. radicosum and E. mizura, and of the capture of a mole at the nesting site under indication of the fungus. Morphological features of the animal and structure of the nest are described. This finding further revealed a contiguousness in the distribution of three talpine species, E. mizura, Mogera wogura and Mogera kobeae in Ashiu

Atomic-scale dents on cellulose nanofibers: the origin of diverse defects in sustainable fibrillar materials

セルロースナノファイバーに生じた原子レベルの欠陥構造を発見 --理想的なバイオポリマー材料の生産にむけて--. 京都大学プレスリリース. 2022-10-07.Atomic-scale dent structures on the surfaces of cellulose nanofibers were detected. These dent parts constituted at least 30–40% of the total length of the dispersed nanofibers, and deep dents induced the kinking and fragmentation of nanofibers

Optical-power-dependent splitting of magnetic resonance in nitrogen-vacancy centers in diamond

Nitrogen-vacancy (NV) centers in diamonds are a powerful tool for accurate magnetic field measurements. The key is precisely estimating the field-dependent splitting width of the optically detected magnetic resonance (ODMR) spectra of the NV centers. In this study, we investigate the optical power dependence of the ODMR spectra using NV ensemble in nanodiamonds (NDs) and a single-crystal bulk diamond. We find that the splitting width exponentially decays and is saturated as the optical power increases. Comparison between NDs and a bulk sample shows that while the decay amplitude is sample-dependent, the optical power at which the decay saturates is almost sample-independent. We propose that this unexpected phenomenon is an intrinsic property of the NV center due to non-axisymmetry deformation or impurities. Our finding indicates that diamonds with less deformation are advantageous for accurate magnetic field measurements.Comment: 9 pages, 7 figure