New species of freshwater Ulva, Ulva limnetica (Ulvales, Ulvophyceae) from the Ryukyu Islands, Japan

Ulva limnetica Ichihara et Shimada, sp. nov. (Ulvales, Ulvophyceae) is described from the Ryukyu Islands, Japan, and is characterized by thalli that are: (i) branched, tubular, fragile and wrinkled; (ii) up to 80 cm in height and up to 2 cm in diameter; (iii) light to yellowish green in color; and (iv) having an asexual reproduction by means of quadriflagellate swarmers. Rhizoidal cells bear tubular extensions on the outside of the cell layer in the stipe. Ulva limnetica is distinguished from species with similar thalli by chloroplast disposition, branching pattern, number of pyrenoids per cell and gross morphology. It is also distinguished by sequences of the nuclear-encoded 18S ribosomal RNA gene, internal transcribed spacer 2 region and the plastid-encoded large subunit of ribulose-1,5-bisphosphate carboxylase/oxgenase gene ( rbc L). Ulva limnetica was clustered with other Ulva species in an early diverging lineage within the genus.     

Discovery of three new species of Drosophila obscura species group (Diptera: Drosophilidae) from Mount Kinabalu in Borneo

We describe three new species of the Drosophila obscura species group, D. hypercephala , D. hideakii and D. quadrangula Gao & Toda, spp. nov., all discovered from high altitudes (>1500 m) on Mt Kinabalu, Sabah, Malaysia. These are the southernmost distribution records of the D. obscura group in the Oriental Region. The three new species are each morphologically similar to different species of the Old World D. obscura species subgroup. This suggests that they are descendants of different founder species that independently colonized the tropics from the subtropical or temperate zones during the glacial ages. The new species D. hypercephala is hypercephalic not only in males but also, although less distinct, in females, unlike other hypercephalic drosophilid species in which only males are hypercephalic. This new finding of a hypercephalic species from the subgenus Sophophora , of which species are relatively easy to culture in the laboratory and include the model species such as D. melanogaster and D. pseudoobscura , will promote genetic analyses on the development and the evolution of hypercephaly.     

Effects of docosahexaenoic acid on in vitro amyloid beta peptide 25–35 fibrillation

Amyloid β peptide_25–35 (Aβ_25–35) encompasses one of the neurotoxic domains of full length Aβ_1–40/42, the major proteinaceous component of amyloid deposits in Alzheimer's disease (AD). We investigated the effect of docosahexaenoic acid (DHA, 22:6, n-3), an essential brain polyunsaturated fatty acid, on the in vitro fibrillation of Aβ_25–35 and found that it significantly reduced the degree of fibrillation, as shown by a decrease in the intensity of both the thioflavin T and green fluorescence in confocal microscopy. Transmission electron microscopy revealed that DHA-incubated samples were virtually devoid of structured fibrils but had an amorphous-like consistency, whereas the controls contained structured fibers of various widths and lengths. The in vitro fibrillation of Aβ_25–35 appeared to be pH-dependent, with the strongest effect seen at pH 5.0. DHA inhibited fibrillation at all pHs, with the strongest effect at pH 7.4. It also significantly decreased the levels of Aβ_25–35 oligomers. Nonreductive gradient gel electrophoresis revealed that the molecular size of the oligomers of Aβ_25–35 was 10 kDa (equivalent to decamers of Aβ_25–35) and that DHA dose-dependently reduced these decamers. These results suggest that DHA decreases the in vitro fibrillation of Aβ_25–35 by inhibiting the oligomeric amyloid species and, therefore, Aβ_25–35-related neurotoxicity or behavioral impairment could be restrained by DHA.     

A novel carborane analog, BE360, with a carbon-containing polyhedral boron-cluster is a new selective estrogen receptor modulator for bone

Carboranes are a class of carbon-containing polyhedral boron-cluster compounds with globular geometry and hydrophobic surface that interact with hormone receptors. Estrogen deficiency results in marked bone loss due to increased osteoclastic bone resorption in females, but estrogen replacement therapy is not generally used for postmenopausal osteoporosis due to the risk of uterine cancer. We synthesized a novel carborane compound BE360 to clarify its anti-osteoporosis activity. BE360 showed a high binding affinity to estrogen receptors (ER), ERα and ERβ. In ovariectomized (OVX) mice, femoral bone volume was markedly reduced and BE360 dose-dependently restored bone loss in OVX mice. However, BE360 did not exhibit any estrogenic activity in the uterus. BE360 also restored bone loss in orchidectomized mice without androgenic action in the sex organs. Therefore, BE360 is a novel selective estrogen receptor modulator (SERM) that may offer a new therapy option for osteoporosis.     

Net release of dissolved organic matter by the scleractinian coral Acropora pulchra

The net production of dissolved organic matter (DOM) and dissolved combined and free amino acids (DCAA and DFAA, respectively) by the hermatypic coral Acropora pulchra was measured in the submerged condition, and the production rates were normalized to the coral surface area, tissue biomass, and net photosynthetic rates by zooxanthellae. When normalized to the unit surface area, the production rates of dissolved organic carbon and nitrogen (DOC and DON, respectively) were 37 and 4.4 nmol cm^− 2 h^− 1, respectively. Comparing with the photosynthetic rate by zooxanthellae, which was measured by ¹³C-tracer accumulation in the soft tissue of the coral colony, the release rate of DOC corresponded to 5.4% of the daily net photosynthetic production. The tissue biomass of the coral colony was 178 µmol C cm^− 2 and 23 µmol N cm^− 2, indicating that the release of DOC and DON accounted for 0.021% h^− 1 and 0.019% h^− 1 of the tissue C and N, respectively. The C:N ratios of the released DOM (average 8.4) were not significantly different from those of the soft tissue of the coral colonies (average 7.7). While DFAA did almost not accumulate in the incubated seawater, DCAA was considerably released by the coral colonies at the rate of 2.1 nmol cm^− 2 h^− 1 on average. Calculating C and N contents of the hydrolyzable DCAA, it was revealed that about 20% and 50%–60% of the released bulk DOC and DON, respectively, were composed of DCAA.     

Genome-wide investigation of in vivo EGR-1 binding sites in monocytic differentiation

Background  

Immediate early genes are considered to play important roles in dynamic gene regulatory networks following exposure to appropriate stimuli. One of the immediate early genes, early growth response gene 1 (EGR-1), has been implicated in differentiation of human monoblastoma cells along the monocytic commitment following treatment with phorbol ester. EGR-1 has been thought to work as a modifier of monopoiesis, but the precise function of EGR-1 in monocytic differentiation has not been fully elucidated.