Ingestion of radioactively contaminated diets for two generations in the pale grass blue butterfly

Background: The release of radioactive materials due to the Fukushima nuclear accident has raised concern regarding the biological impacts of ingesting radioactively contaminated diets on organisms. We previously performed an internal exposure experiment in which contaminated leaves collected from polluted areas were fed to larvae of the pale grass blue butterfly, Zizeeria maha, from Okinawa, which is one of the least polluted localities in Japan. Using the same experimental system, in the present study, we further examined the effects of low-level-contaminated diets on this butterfly. Leaves were collected from two localities in Tohoku (Motomiya (161 Bq/kg) and Koriyama (117 Bq/kg)); two in Kanto (Kashiwa (47.6 Bq/kg) and Musashino (6.4 Bq/kg)); one in Tokai (Atami (2.5 Bq/kg)); and from Okinawa (0.2 Bq/kg). In addition to the effects on the first generation, we examined the possible transgenerational effects of the diets on the next generation.Results: In the first generation, the Tohoku groups showed higher rates of mortality and abnormalities and a smaller forewing size than the Okinawa group. The mortality rates were largely dependent on the ingested dose of caesium. The survival rates of the Kanto-Tokai groups were greater than 80%, but the rates in the Tohoku groups were much lower. In the next generation, the survival rates in the Tohoku groups were below 20%, whereas those of the Okinawa groups were above 70%. The survival rates in the second generation were independent of the locality of the leaves ingested by the first generation, indicating that the diet in the second generation was the determinant of their survival. Moreover, a smaller forewing size was observed in the Tohoku groups in the second generation. However, the forewing size was inversely correlated with the cumulative caesium dose ingested throughout the first and second generations, indicating that the diet in the first generation also influenced the forewing size of the second generation.Conclusions: Biological effects are detectable under a low ingested dose of radioactivity from a contaminated diet. The effects are transgenerational but can be overcome by ingesting a non-contaminated diet, suggesting that at least some of the observed effects are attributable to non-genetic physiological changes

Development and application of fluorescent SDF-1 derivatives.

Background: SDF-1/CXCR4 signaling plays key roles in directed cell migration under physiological and pathological conditions. To develop agonist-based CXCR4 probes for detection of CXCR4 expression on cell lines and metastatic tumors, SAR analyses of fluorescent SDF-1 derivatives were carried out. Results: Several SDF-1 derivatives with a single fluorescent label were designed and synthesized. Modification of the SDF-1 C-terminus with AlexaFluor® 488 or tetramethylrhodamine provided potent CXCR4 probes. Using a potent probe, a novel binding inhibition assay was established for biological evaluation of potential CXCR4 ligands. Conclusion: SDF-1 derivatives with C-terminal modification exhibit equipotent binding with CXCR4 and an alternative SDF-1 receptor CXCR7 to unlabeled SDF-1. The SDF-1 derivatives are applicable to flow cytometry to detect the receptor expression and identify binding compounds for CXCR4

Effects of causeway construction on environment and biota of subtropical tidal flats in Okinawa, Japan-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

a b s t r a c t Okinawa, Japan is known for its high marine biodiversity, yet little work has been performed on examining impacts of numerous large-scale coastal development projects on its marine ecosystems. Here, we examine apparent impacts of the construction of the Kaichu-Doro causeway, which was built over 40 years ago. The causeway is a 4.75 km long embankment that divides a large tidal flat and has only two points of water exchange along its entire length. We employed quadrats, transects, sampling, visual surveys, and microbial community analyses combined with environmental, water quality data, and 1 m cores, at five stations of two paired sites each (one on each side of Kaichu-Doro) to investigate how the environment and biota have changed since the Kaichu-Doro was built. Results indicate reduction in water flow, and site S1 was particularly heavily impacted by poor water quality, with low diversity and disturbed biotic communities

Paradoxical Downregulation of CXC Chemokine Receptor 4 Induced by Polyphemusin II-Derived Antagonists

CXC chemokine receptor 4 (CXCR4) is a G protein-coupled receptor implicated in cell entry of T-cell line-tropic HIV-1 strains. CXCR4 and its ligand stromal cell derived factor-1 (SDF-1)/CXCL12 play pivotal parts in many physiological processes and pathogenetic conditions (e.g., immune cell-homing and cancer metastasis). We previously developed the potent CXCR4 antagonist T140 from structure–activity relationship studies of the antimicrobial peptide polyphemusin II. T140 and its derivatives have been exploited in biological and biomedical studies for the SDF-1/CXCR4 axis. We investigated receptor localization upon ligand stimulation using fluorescent SDF-1 and T140 derivatives as well as a specific labeling technique for cellular-membrane CXCR4. Fluorescent T140 derivatives induced translocation of CXCR4 into the perinuclear region as observed by treatment with fluorescent SDF-1. T140 derivative-mediated internalization of CXCR4 was also monitored by the coiled-coil tag-probe system. These findings demonstrated that the CXCR4 antagonistic activity and anti-HIV activity of T140 derivatives were derived (at least in part) from antagonist-mediated receptor internalization