Oxidative stress on the male reproductive organs of wild mice collected from an area contaminated by radioactive materials in Fukushima.

The Fukushima Daiichi Nuclear Power Plant accident caused the release of large amounts of radioactive material into the environment. Radiation from radionuclides cause DNA lesions, mainly via oxidation, which adversely affect wild organisms by damaging their germ cells. Here, we investigated the effects of radiation on the reproductive organs of Japanese field mice (Apodemus speciosus) by estimating the dose rate of radiation exposure, the accumulation of DNA lesions, and the expression of DNA repair enzymes.

Optimization of inhaled anesthesia for Octodon degus using electroencephalography.

Physiological responses to inhaled anesthetics vary among species. Therefore, a precise anesthetic technique is important for each individual species. In this study, we focused on the degu (Octodon degus), a small herbivorous rodent.

Diversity and Evolution of Highly Repetitive DNA Sequences Constituting Chromosome Site-Specific Heterochromatin in Two Gerbillinae Species.

Constitutive heterochromatin, consisting of repetitive sequences, diverges very rapidly; therefore, its nucleotide sequences and chromosomal distributions are often largely different, even between closely related species. The chromosome C-banding patterns of two Gerbillinae species, Meriones unguiculatus and Gerbillus perpallidus, vary greatly, even though they belong to the same subfamily. To understand the evolution of C-positive heterochromatin in these species, we isolated highly repetitive sequences, determined their nucleotide sequences, and characterized them using chromosomal and filter hybridization.

Long-term behavioral effects of social separation during early life in a social mammal, Octodon degus.

Social separation is thought to induce a strong stress response in social juvenile mammals, but little is known about how this response might vary throughout the development. The present study examines the long-term effects of early-life stress (ELS) induced by social separation on individual behaviors later in life using the social and precocious species Octodon degus. Four experimental groups were established a positive control group of mothers and siblings from six litters comprised the socially housed (SH) group, while pups from seven litters were randomly assigned to three treatments: pups experiencing no separation (NS) treatment while their siblings did; repeated bouts of consecutive separation (CS); intermittent separation (IS).

Message to researchers: the characteristic absence of a posterior communicating artery is easily lost in the gerbil.

The Mongolian gerbil has historically been useful for brain ischemia experiments, owing to the gerbil's uniquely underdeveloped circle of Willis (CoW). This led to a gerbil model of cochlear ischemia being generated in our unit. However, we have found that the usual severe hearing loss seen in this model was not being induced consistently in recent experiments using the MON/Jms/GbsSlc gerbil (the sole commercially available gerbil in Japan).

Comparison of Ovarian Morphology and Follicular Disturbances between Two Inbred Strains of Cotton Rats ().

Most mammalian ovarian follicles contain only a single oocyte having a single nucleus. However, two or more oocytes and nuclei are observed within one follicle and one oocyte, respectively, in several species, including cotton rat (CR, ). The present study compared ovarian histology, focusing on folliculogenesis, between two inbred CR strains, HIS/Hiph and HIS/Mz.

Myoglobin primary structure reveals multiple convergent transitions to semi-aquatic life in the world's smallest mammalian divers.

The speciose mammalian order Eulipotyphla (moles, shrews, hedgehogs, solenodons) combines an unusual diversity of semi-aquatic, semi-fossorial, and fossorial forms that arose from terrestrial forbearers. However, our understanding of the ecomorphological pathways leading to these lifestyles has been confounded by a fragmentary fossil record, unresolved phylogenetic relationships, and potential morphological convergence, calling for novel approaches. The net surface charge of the oxygen-storing muscle protein myoglobin (Z), which can be readily determined from its primary structure, provides an objective target to address this question due to mechanistic linkages with myoglobin concentration.

Testosterone interrupts binding of Neurexin and Neuroligin that are expressed in a highly socialized rodent, Octodon degus.

Octodon degus is said to be one of the most human-like rodents because of its improved cognitive function. Focusing on its high sociality, we cloned and characterized some sociality-related genes of degus, in order to establish degus as a highly socialized animal model in molecular biology. We cloned degus Neurexin and Neuroligin as sociality-related genes, which are genetically related to autism spectrum disorder in human.

Influence of Quaternary environmental changes on mole populations inferred from mitochondrial sequences and evolutionary rate estimation.

Quaternary environmental changes fundamentally influenced the genetic diversity of temperate-zone terrestrial animals, including those in the Japanese Archipelago. The genetic diversity of present-day populations is taxon- and region-specific, but its determinants are poorly understood. Here, we analyzed cytochrome b gene (Cytb) sequences (1140 bp) of mitochondrial DNA (mtDNA) to elucidate the factors determining the genetic variation in three species of large moles: Mogera imaizumii and Mogera wogura, which occur in central and southern mainland Japan (Honshu, Shikoku, and Kyushu), and Mogera robusta, which occurs on the nearby Asian continent.

Individual differences in torpor expression in adult mice are related to relative birth mass.

Daily torpor is a physiological adaptation in small mammals and birds, characterised by drastic reductions in metabolism and body temperature. Energy-constraining conditions, such as cold and starvation, are known to cause the expression of daily torpor. However, the reason for high degrees of inter- and intra-individual variation in torpor expression (TE) in similar situations is not clear.

Cotton rats (Sigmodon hispidus) possess pharyngeal pouch remnants originating from different primordia.

Pharyngeal pouches in mammals develop into specific derivatives. If the differentiation of the pharyngeal pouches is anomalous, their remnants can result in cysts, sinuses, and fistulae in the differentiated organs or around the neck. In the present study, we found several pharyngeal pouch remnants, such as cystic structures in thymus and parathyroid gland and fossulae extended from the piriform fossa, in the inbred cotton rats maintained at Hokkaido Institute of Public Health (HIS/Hiph) and University of Miyazaki (HIS/Mz).

Protein restriction does not affect body temperature pattern in female mice.

Daily torpor is a physiological adaptation in mammals and birds characterized by a controlled reduction of metabolic rate and body temperature during the resting phase of circadian rhythms. In laboratory mice, daily torpor is induced by dietary caloric restriction. However, it is not known which nutrients are related to daily torpor expression.

Comparative Morphology of the Penis and Clitoris in Four Species of Moles (Talpidae).

The penile and clitoral anatomy of four species of Talpid moles (broad-footed, star-nosed, hairy-tailed, and Japanese shrew moles) were investigated to define penile and clitoral anatomy and to examine the relationship of the clitoral anatomy with the presence or absence of ovotestes. The ovotestis contains ovarian tissue and glandular tissue resembling fetal testicular tissue and can produce androgens. The ovotestis is present in star-nosed and hairy-tailed moles, but not in broad-footed and Japanese shrew moles.

Talpid Mole Phylogeny Unites Shrew Moles and Illuminates Overlooked Cryptic Species Diversity.

The mammalian family Talpidae (moles, shrew moles, desmans) is characterized by diverse ecomorphologies associated with terrestrial, semi-aquatic, semi-fossorial, fossorial, and aquatic-fossorial lifestyles. Prominent specializations involved with these different lifestyles, and the transitions between them, pose outstanding questions regarding the evolutionary history within the family, not only for living but also for fossil taxa. Here, we investigate the phylogenetic relationships, divergence times, and biogeographic history of the family using 19 nuclear and 2 mitochondrial genes (∼16 kb) from ∼60% of described species representing all 17 genera.

Influence of human serum albumin on the bile acid-mediated inhibition of liver microsomal type 1 11β-hydroxysteroid dehydrogenase.

The influence of human serum albumin (HSA) on the bile acid-mediated inhibition of liver microsomal type 1 11β-hydroxysteroid dehydrogenase (11β-HSD1) was studied in vitro. A rat liver microsomal fraction was prepared, and the 11β-HSD1 enzyme activity in the presence of various concentrations of bile acids and HSA was determined using hydrocortisone as the substrate. The products of the reaction were extracted and analyzed using high-performance liquid chromatography.

Susceptibility of muridae cell lines to ecotropic murine leukemia virus and the cationic amino acid transporter 1 viral receptor sequences: implications for evolution of the viral receptor.

Ecotropic murine leukemia viruses (Eco-MLVs) infect mouse and rat, but not other mammalian cells, and gain access for infection through binding the cationic amino acid transporter 1 (CAT1). Glycosylation of the rat and hamster CAT1s inhibits Eco-MLV infection, and treatment of rat and hamster cells with a glycosylation inhibitor, tunicamycin, enhances Eco-MLV infection. Although the mouse CAT1 is also glycosylated, it does not inhibit Eco-MLV infection.

Self-assessment tool of disease activity of rheumatoid arthritis by using a smartphone application.

Objectives: The disease activities of rheumatoid arthritis (RA) tend to fluctuate between visits to doctors, and a self-assessment tool can help patients accommodate to their current status at home. The aim of the present study was to develop a novel modality to assess the disease activity of RA by a smartphone without the need to visit a doctor.

Subjects And Methods: This study included 65 patients with RA, 63.

Multilocus phylogeny of talpine moles (Talpini, Talpidae, Eulipotyphla) and its implications for systematics.

The tribe Talpini is a group of strictly subterranean moles distributed across the Eurasian Continent whose phylogenetic relationships and taxonomy remain unresolved. Here we report a multi-locus nuclear-mitochondrial DNA dataset (9468 bp) from 11 talpine species encompassing all five recognized genera, together with analyses of their divergence times and evolutionary affinities inferred from maximum likelihood and Bayesian approaches. Our results finely resolved all relationships except the root of the four recognized Asian genera, which was placed sister to the genus Talpa.

Development of lifelog sharing system for rheumatoid arthritis patients using smartphone.

In this paper, we report the development of a lifelog sharing system for rheumatoid arthritis patients. Our system can objectively assess patients' condition from day to day via their smartphone use. We conducted a field experiment to investigate the feasibility of lifelog collection and sharing.

Spatial and temporal aspects of occurrence of Mogera species in the Japanese islands inferred from mitochondrial and nuclear gene sequences.

We assessed dispersal and vicariant events in four species of Japanese moles in the genera Mogera and Euroscaptor to better understand the factors shaping intra- and interspecific differentiation in Japanese moles. We used the combined viewpoints of molecular phylogeny and historical geology using nucleotide sequences of mitochondrial (cytochrome b; Cytb) and nuclear (A2ab, Bmp4, Tcf25, vWf) genes. The divergence times estimated from the molecular data were verified with available geological data on the chronology of fluctuations in sea level in the Korea Strait, assuming sequential migration and speciation events.

A quill vibrating mechanism for a sounding apparatus in the streaked tenrec (Hemicentetes semispinosus).

The streaked tenrec (Hemicentetes semispinosus) is equipped with a quill vibrating mechanism on the dorsal side of the caudal trunk that has evolved as an extraordinary sounding apparatus for communication. An arrangement of 15 or 16 light-brown quills was observed. Thickened cutaneous muscles were confirmed beneath quills.

Effects of bile acids on rat hepatic microsomal type I 11beta-hydroxysteroid dehydrogenase.

The aim of this study was to investigate the effect of various bile acids on hepatic type I 11beta-hydroxysteroid dehydrogenase (11beta-HSD1) activity in vitro. The rat liver microsome fraction was prepared and 11beta-HSD1 activity was assayed using cortisol and corticosterone as substrates for the enzyme reaction. The substrate and various concentrations of bile acids were added to the assay mixture.