Time-series metagenomic analysis reveals robustness of soil microbiome against chemical disturbance

Soil microbial communities have great potential for bioremediation of recalcitrant aromatic compounds. However, it is unclear which taxa and genes in the communities, and how they contribute to the bioremediation in the polluted soils. To get clues about this fundamental question here, time-course (up to 24 weeks) metagenomic analysis of microbial community in a closed soil microcosm artificially polluted with four aromatic compounds, including phenanthrene, was conducted to investigate the changes in the community structures and gene pools. The pollution led to drastic changes in the community structures and the gene sets for pollutant degradation. Complete degradation of phenanthrene was strongly suggested to occur by the syntrophic metabolism by Mycobacterium and the most proliferating genus, Burkholderia. The community structure at Week 24 (∼12 weeks after disappearance of the pollutants) returned to the structure similar to that before pollution. Our time-course metagenomic analysis of phage genes strongly suggested the involvement of the ‘kill-the-winner’ phenomenon (i.e. phage predation of Burkholderia cells) for the returning of the microbial community structure. The pollution resulted in a decrease in taxonomic diversity and a drastic increase in diversity of gene pools in the communities, showing the functional redundancy and robustness of the communities against chemical disturbance.     

Occurrence of Cicadulina bipunctata (Hemiptera: Cicadellidae) in southwestern Shikoku,Japan and comparisons of gall-inducing ability between Kyushu and Shikoku populations

The maize orange leafhopper Cicadulina bipunctata (Melichar) is an insect pest of cereal crops in tropical and subtropical regions of the Old World. This leafhopper induces gall symptoms characterized by stunted growth and swollen leaf veins on various Poaceae. Damage by C. bipunctata has been reported from Australia, the Philippines, China, Taiwan, and Japan. In Japan, C. bipunctata occurs in the central and southern parts of Kyushu. Because the leafhopper is a potential pest of various cereal crops, we conducted field surveys in Shikoku and the southern part of the Kii Peninsula (a part of Honshu), where the climate seems to be suitable for the establishment of C. bipunctata. As a result, we found C. bipunctata at some localities in Ehime and Kochi Prefectures. This is the first record of this leafhopper from Shikoku. Our laboratory experiment revealed that a Kochi population of C. bipunctata had a gall inducing ability similar to the Kumamoto population. More attention should be paid to assessing the risk of further expansion of C. bipunctata populations in Shikoku.     

Genetic population structure of Hemigrammocypris rasborella (Cyprinidae) inferred from mtDNA sequences

The genetic population structure of the small cyprinid Hemigrammocypris rasborella, distributed widely in lowlands of western Japan, was examined using partial sequence data of mitochondrial DNA (mtDNA). Molecular phylogenetic analysis revealed that the populations of the western Kyushu region were markedly differentiated from all eastern populations, such that the groups would be comparable to different species; their divergence was inferred to have occurred in the Late Miocene–Pliocene. Also, a largely divergent mtDNA group (with divergence in the early Pleistocene) was found in the Sanyo and northeastern Shikoku regions, forming a secondary contact zone in the western Kinki with the eastern mtDNA group. To date, these aspects of the population structure of H. rasborella appear to be unique among lowland fishes in western Japan. Deeper understanding of the formation processes of freshwater faunas in western Japan will require further comparisons of the phylogeographic patterns and ecological traits of constituent species.     

Association between equine temperament and polymorphisms in dopamine D4 receptor gene

The variable number of tandem repeats (VNTR) polymorphism of the dopamine D4 receptor (DRD4) gene has been reported to be associated with the personality trait of novelty-seeking in humans. In the genus Equus, this region includes an 18-bp repeat unit and there are inter- and intraspecies differences in the number of repetitions. Because horses are unique among livestock species in that their temperament is considered important, we investigated the possible role of this region on equine temperament in thoroughbred horses. We simultaneously determined the sequences of this polymorphic region and administered a questionnaire survey to horse caretakers with questions about 20 different traits of their horses’ temperament. Although there was no difference in the number of repeats among the 136 thoroughbred horses studied, two single nucleotide polymorphisms (SNPs), one of which might cause an amino acid change (A-G substitution), existed. By analyzing the association between these SNPs and temperament scores, a significant association was revealed between two temperament traits (Curiosity and Vigilance) and the A-G substitution. Horses without the A allele had significantly higher Curiosity and lower Vigilance scores than those with the A allele at the A-G substitution. In addition, similar associations between both temperament scores and each genotype of the A-G substitution were observed in two subgroups divided according to the time of their introduction to the farm. These results suggested that the SNP in the VNTR region of the equine DRD4 gene might be related to individual differences in equine temperament.     

Variation in Courtship Ultrasounds of Three Ostrinia Moths with Different Sex Pheromones

Moths use ultrasounds as well as pheromones for sexual communication. In closely related moth species, variations in ultrasounds and pheromones are likely to profoundly affect mate recognition, reproductive isolation, and speciation. The European corn borer, Ostrinia nubilalis, and its Asian congeners, Ostrinia furnacalis and Ostrinia scapulalis, exhibit within-species and between-species variation in their pheromone communication. Recently, we reported ultrasound communication in O. furnacalis; however, variations in ultrasounds in the three congeners have not been addressed to date. Here we investigated features of ultrasound production and hearing in O. nubilalis and O. scapulalis, and compared them with those of O. furnacalis. As in O. furnacalis, males of O. nubilalis and O. scapulalis produced ultrasounds during courtship by rubbing specialized scales on the wings against scales on the thorax. The covering of these scales with nail polish muffled the sounds and significantly reduced mating success in O. nubilalis, showing the importance of ultrasound signaling in mating. The ultrasounds produced by O. nubilalis and O. scapulalis were similar, consisting of long trains of pairs of pulses with a main energy at 40 kHz, but distinctly different from the ultrasound produced by O. furnacalis, consisting of groups of pulses peaking at 50 kHz and with substantially more energy up to 80 kHz. Despite overall similarities, temporal features and patterns of amplitude modulation differed significantly among the geographic populations of O. nubilalis and O. scapulalis, which differed in pheromone type. In contrast, no significant difference in hearing was found among the three species with regard to the most sensitive frequencies and hearing threshold levels. The patterns of variations in the songs and pheromones well reflected those of the phylogenetic relationships, implying that ultrasound and pheromone communications have diverged concordantly. Our results suggest that concordant evolution in sexual signals such as courtship ultrasounds and sex pheromones occurs in moths.     

Proliferation of both somatic and germ cells is affected in the Drosophila mutants of raf proto-oncogene.

The genomic and cDNA fragments of Drosophila melanogaster, homologous to human c-raf-1, were cloned. The nucleotide sequence predicted the primary structure of a polypeptide of 666 amino acid residues with a highly conserved Ser-Thr kinase domain on its carboxy terminal half. Draf-1 was mapped to the 2F region of the X chromosome. Two newly induced recessive lethals belonging to a complementation group in this region were identified to be defective in Draf-1 by P element-mediated rescue experiments. The mutants die at larval/pupal stages. The mutant larvae are apparently normal, but they harbor serious defects in the organs containing proliferating cells of both somatic and germ line origins. Maternal effects on embryogenesis indicated that Draf-1 is also required in early larval development.     

Prevalence of Mental Illness,Cognitive Disability,and Their Overlap among the Homeless in Nagoya,Japan

Background

While the prevalence of mental illness or cognitive disability is higher among homeless people than the general population in Western countries, few studies have investigated its prevalence in Japan or other Asian countries. The present study conducted a survey to comprehensively assess prevalence of mental illness, cognitive disability, and their overlap among homeless individuals living in Nagoya, Japan.

Methods

Participants were 114 homeless individuals. Mental illness was diagnosed based on semi-structured interviews conducted by psychiatrists. The Wechsler Adult Intelligence Scale-III (WAIS-III, simplified version) was used to diagnose intellectual/ cognitive disability.

Results

Among all participants, 42.1% (95% CI 33.4–51.3%) were diagnosed with a mental illness: 4.4% (95% CI 1.9–9.9%) with schizophrenia or other psychotic disorder, 17.5% (95% CI 11.6–25.6%) with a mood disorder, 2.6% (95% CI 0.9–7.5%) with an anxiety disorder, 14.0% (95% CI 8.8–21.6%) with a substance-related disorder, and 3.5% (95% CI 1.4–8.8%) with a personality disorder. Additionally, 34.2% (95% CI 26.1–43.3%) demonstrated cognitive disability: 20.2% (95% CI 13.8–28.5%) had mild and 14.0% (95% CI 8.8–21.6%) had moderate or severe disability. The percent overlap between mental illness and cognitive disability was 15.8% (95% CI 10.2–23.6%). Only 39.5% (95% CI 26.1–43.3%) of the participants were considered to have no psychological or cognitive dysfunction. Participants were divided into four groups based on the presence or absence of mental illness and/or cognitive disability. Only individuals with a cognitive disability reported a significant tendency toward not wanting to leave their homeless life.

Conclusion

This is the first report showing that the prevalence of mental illness and/or cognitive disability among homeless individuals is much higher than in the general Japanese population. Appropriate support strategies should be devised and executed based on the specificities of an individual’s psychological and cognitive condition.