Selective inhibition of cancer cell migration using a pH-responsive nucleobase-modified DNA aptamer.

Because of the extracellular acidic microenvironment of cancer cells, many pH-responsive molecules have become indispensable materials for bioanalysis and targeted therapy development. pH-Responsive DNA aptamers, which selectively bind to target proteins in cancer cells, have become a key research target in the therapeutic field. However, conventional pH-responsive aptamers have fatal drawbacks, such as complex structures, sequence limitation, and difficulties in mass production, as they require special nucleic acid structures, including the i-motif and DNA triplex.

Study on the relationship between the dispersal of wild boar (Sus scrofa) and the associated variability of Cesium-137 concentrations in its muscle Post-Fukushima Daiichi Nuclear Power Plant accident.

After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011, the wild boar (Sus scrofa) population within the Fukushima Evacuation Zone (FEZ) increased substantially in size and distribution. This growing population and their potential dispersal from the FEZ, where they are exposed to high levels of radionuclides, into the surrounding landscape underscores the need to better understand boar movement patterns in order to establish policies for managing shipping restrictions for boar meat and develop management strategies. In this study, we quantified the genetic population structure of boar in and around Fukushima prefecture using sequence data of the mitochondrial DNA control region and MIG-seq analysis using 348 boar samples to clarify boar dispersal patterns.

Monitoring of radioactive cesium in wild boars captured inside the difficult-to-return zone in Fukushima Prefecture over a 5-year period.

Following the Fukushima Daiichi Nuclear Power Plant accident in 2011, tissue samples from wild boar (Sus scrofa) outside the evacuation zone (difficult-to-return zone, DRZ) tended to show high activity concentrations of cesium-137 (Cs). Understanding the Cs dynamics of wild boar populations inside the DRZ is necessary because they affect Cs dynamics and wild boar management in areas outside the DRZ. Since few detailed, long-term studies have been conducted inside the DRZ, we measured Cs activity concentrations in 221 wild boar muscle samples obtained from wild boar caught inside the DRZ and surrounding areas over a 5-year period.

Genetic Population Structure of Wild Boars () in Fukushima Prefecture.

We aimed to reveal the dispersal and gene flow of the local wild boar () population and find their genetic boundary in Fukushima Prefecture. After the nuclear incident in 2011, the land was considered a difficult-to-return zone, and the increase in the number of wild boars was pronounced. To provide an effective management strategy for the wild boar population, we used multiplexed inter-simple sequence repeat genotyping by sequencing (MIG-seq) and clarified the genetic structure of wild boars.

Unnatural Base Pair Enables Alphabet-Expanded DNA Self-Assembly.

Self-assembly properties and diversity in higher-order structures of DNA enable programmable tools to be used to construct algorithms at the molecular level. However, the utility of DNA-based programmable tools is hampered by the low orthogonality to natural nucleic acids, especially in complex molecular systems. To address this challenge, we report here the orthogonal regulation of DNA self-assembly by using an unnatural base pair (UBP) formation.

Evaluation of DNA damage and stress in wildlife chronically exposed to low-dose, low-dose rate radiation from the Fukushima Dai-ichi Nuclear Power Plant accident.

The health effects associated with chronic low-dose, low-dose rate (LD-LDR) exposures to environmental radiation are uncertain. All dose-effect studies conducted outside controlled laboratory conditions are challenged by inherent complexities of ecological systems and difficulties quantifying dose to free-ranging organisms in natural environments. Consequently, the effects of chronic LD-LDR radiation exposures on wildlife health remain poorly understood and much debated.

Associations between plasma testosterone levels and season, nutritional status, age, and body size in free-ranging male Asian black bears (Ursus thibetanus) in central Honshu, Japan.

Testosterone is an important regulator of male reproduction in terms of spermatogenesis and physiological changes in the accessory reproductive organs. Despite the important role of the testosterone level in male reproduction, testosterone levels vary among male bears even during the breeding season, and the causative underlying factors remain unknown. We postulated that testosterone levels are higher during the breeding season than during other seasons in free-ranging male bears, and that testosterone levels increase with advancing age, larger body size, and better nutritional status.

Effects of Cs contamination after the TEPCO Fukushima Dai-ichi Nuclear Power Station accident on food and habitat of wild boar in Fukushima Prefecture.

After the Tokyo Electric Power Company Fukushima Dai-ichi Nuclear Power Station accident, wild boar was found to have greater radiocesium (Cs) activity concentrations in their bodies than other wild animals in Japan; however, the reason for this remains unknown. To understand the mechanism of Cs transfer from the environment to wild boar, and the factors that affect variation in Cs contamination in wild boar, we sampled muscle and stomach contents from wild boar captured in Fukushima Prefecture and analyzed the relationships among Cs concentrations in muscle tissue and in the stomach contents, Cs ground deposition at capture sites, and wild boar food habits. Significant positive relationships were observed among Cs activity concentrations in muscle and stomach contents, as well as Cs deposition density at capture sites.

Relationship between radiocaesium in muscle and physicochemical fractions of radiocaesium in the stomach of wild boar.

After the accident at the TEPCO Fukushima Daiichi Nuclear Power Plant in 2011, it became important to study radiation dynamics, assess internal radiation exposure and specify factors affecting radionuclide variation in wildlife. Therefore, it is necessary to investigate which physicochemical fractions of radiocaesium (Cs) are absorbed from ingested material in species with high activity concentrations of Cs, such as wild boar. This study analysed the physicochemical fractions of Cs in the stomach contents of wild boar to evaluate the transfer from ingested food to muscle.

Monitoring Cs concentrations in bird species occupying different ecological niches; game birds and raptors in Fukushima Prefecture.

This study was conducted to assess radiocesium accumulation in birds after the accident at Tokyo Electric Power Company's Fukushima Daiichi Nuclear Power Station in 2011, with a particular focus on Cs, which has a long physical half-life. Results of Cs monitoring in four game bird species including two pheasant species and two duck species (copper pheasant, green pheasant, spot-billed duck and mallard) were assessed in Fukushima Prefecture. We also obtained samples from rescued raptors that died during treatment or rehabilitation at the Wildlife Symbiosis Centre in Fukushima Prefecture because of severe injury.

Seasonal variation of Cesium-137 concentration in Asian black bear (Ursus thibetanus) and wild boar (Sus scrofa) in Fukushima Prefecture, Japan.

To elucidate and reduce the risk of radionuclide contamination in wildlife caused by the Tokyo Electric Power Company Fukushima Dai-ichi Nuclear Power Station accident, it is important to understand radionuclide variations in the wild animal population. Here, we used environmental monitoring data and muscle samples collected from Asian black bear (Ursus thibetanus) and wild boar (Sus scrofa) from May 2011 to March 2016 to examine seasonal variation in radiocesium (137Cs) concentrations in muscle tissues (hereafter, muscle 137Cs) of these important game species in Fukushima Prefecture. We measured muscle 137Cs of bears and wild boars killed by hunters or in animal control culls.

The selection by the Asiatic black bear () of spring plant food items according to their nutritional values.

The present study aimed to investigate the nutritional aspects of the bear diet quantitatively, in order to understand plant food selection in spring. Bears were observed directly from April to July in 2013 and 2014, to visually recognize plant species consumed by bears, and to describe the foraging period in the Ashio-Nikko Mountains, central Japan. Leaves were collected from eight dominant tree species, regardless of whether bears fed on them in spring, and their key nutritional components analyzed: crude protein (CP), neutral detergent fiber (NDF), and total energy.