Estimation of Fish Biomass Using Environmental DNA

Environmental DNA (eDNA) from aquatic vertebrates has recently been used to estimate the presence of a species. We hypothesized that fish release DNA into the water at a rate commensurate with their biomass. Thus, the concentration of eDNA of a target species may be used to estimate the species biomass. We developed an eDNA method to estimate the biomass of common carp (Cyprinus carpio L.) using laboratory and field experiments. In the aquarium, the concentration of eDNA changed initially, but reached an equilibrium after 6 days. Temperature had no effect on eDNA concentrations in aquaria. The concentration of eDNA was positively correlated with carp biomass in both aquaria and experimental ponds. We used this method to estimate the biomass and distribution of carp in a natural freshwater lagoon. We demonstrated that the distribution of carp eDNA concentration was explained by water temperature. Our results suggest that biomass data estimated from eDNA concentration reflects the potential distribution of common carp in the natural environment. Measuring eDNA concentration offers a non-invasive, simple, and rapid method for estimating biomass. This method could inform management plans for the conservation of ecosystems

Efficient Test Set Modification for Capture Power Reduction

The occurrence of high switching activity when the response to a test vector is captured by flipflops in scan testing may cause excessive IR drop, resulting in significant test-induced yield loss. This paper addresses the problem with a novel method based on test set modification, featuring (1) a new constrained X-identification technique that turns a properly selected set of bits in a fullyspecified test set into X-bits without fault coverage loss, and (2) a new LCP (low capture power) X-filling technique that optimally assigns 0’s and 1’s to the X-bits for the purpose of reducing the switching activity of the resulting test set in capture mode. This method can be readily applied in any test generation flow for capture power reduction without any impact on area, timing, test set size, and fault coverage

Environmental DNA preserved in marine sediment for detecting jellyfish blooms after a tsunami

堆積物の環境DNAで探る過去の出来事 --津波直後のクラゲ大発生を検知--. 京都大学プレスリリース. 2021-08-23.Environmental DNA (eDNA) can be a powerful tool for detecting the distribution and abundance of target species. This study aimed to test the longevity of eDNA in marine sediment through a tank experiment and to use this information to reconstruct past faunal occurrence. In the tank experiment, juvenile jack mackerel (Trachurus japonicus) were kept in flow-through tanks with marine sediment for two weeks. Water and sediment samples from the tanks were collected after the removal of fish. In the field trial, sediment cores were collected in Moune Bay, northeast Japan, where unusual blooms of jellyfish (Aurelia sp.) occurred after a tsunami. The samples were analyzed by layers to detect the eDNA of jellyfish. The tank experiment revealed that after fish were removed, eDNA was not present in the water the next day, or subsequently, whereas eDNA was detectable in the sediment for 12 months. In the sediment core samples, jellyfish eDNA was detected at high concentrations above the layer with the highest content of polycyclic aromatic hydrocarbons, reflecting tsunami-induced oil spills. Thus, marine sediment eDNA preserves a record of target species for at least one year and can be used to reconstruct past faunal occurrence

The fecal microbiome in dogs with acute diarrhea and idiopathic inflammatory bowel disease.

Recent molecular studies have revealed a highly complex bacterial assembly in the canine intestinal tract. There is mounting evidence that microbes play an important role in the pathogenesis of acute and chronic enteropathies of dogs, including idiopathic inflammatory bowel disease (IBD). The aim of this study was to characterize the bacterial microbiota in dogs with various gastrointestinal disorders. Fecal samples from healthy dogs (n = 32), dogs with acute non-hemorrhagic diarrhea (NHD; n = 12), dogs with acute hemorrhagic diarrhea (AHD; n = 13), and dogs with active (n = 9) and therapeutically controlled idiopathic IBD (n = 10) were analyzed by 454-pyrosequencing of the 16S rRNA gene and qPCR assays. Dogs with acute diarrhea, especially those with AHD, had the most profound alterations in their microbiome, as significant separations were observed on PCoA plots of unweighted Unifrac distances. Dogs with AHD had significant decreases in Blautia, Ruminococcaceae including Faecalibacterium, and Turicibacter spp., and significant increases in genus Sutterella and Clostridium perfringens when compared to healthy dogs. No significant separation on PCoA plots was observed for the dogs with IBD. Faecalibacterium spp. and Fusobacteria were, however, decreased in the dogs with clinically active IBD, but increased during time periods of clinically insignificant IBD, as defined by a clinical IBD activity index (CIBDAI). Results of this study revealed a bacterial dysbiosis in fecal samples of dogs with various GI disorders. The observed changes in the microbiome differed between acute and chronic disease states. The bacterial groups that were commonly decreased during diarrhea are considered to be important short-chain fatty acid producers and may be important for canine intestinal health. Future studies should correlate these observed phylogenetic differences with functional changes in the intestinal microbiome of dogs with defined disease phenotypes

Environmental detection of eumycetoma pathogens using multiplex real-time PCR for soil DNA in Sennar State, Sudan

Background: Mycetoma is a chronic disease affecting the skin and subcutaneous tissue endemic in the tropical and subtropical regions. Several bacteria and fungi can cause mycetoma, but fungal mycetoma (eumycetoma) is challenging because the treatment requires a combination of a long-term antifungal agent and surgery. Although the transmission route has not yet been elucidated, infection from the soil is a leading hypothesis. However, there are few soil investigation studies, and the geographical distribution of mycetoma pathogens is not well documented. Here, we used multiplex real-time PCR technology to identify three fungal species from soil samples. Methods: In total, 64 DNA samples were extracted from soil collected in seven villages in an endemic area in Sennar State, Sudan, in 2019. Primers and fluorescent probes specifically targeting the ribosomal DNA of Madurella mycetomatis, Falciformispora senegalensis, and F. tompkinsii were designed. Results: Multiplex real-time PCR was performed and identified the major pathogen, M. mycetomatis that existed in most sites (95%). In addition, two other pathogens were identified from some sites. This is the first report on the use of this technique for identifying the eumycetoma causative microorganisms. Conclusions: This study demonstrated that soil DNA investigation can elucidate the risk area of mycetoma-causative agents. The results will contribute to the design of prevention measures, and further large-scale studies may be effective in understanding the natural habitats of mycetoma pathogens.</p

Environmental detection of eumycetoma pathogens using multiplex real-time PCR for soil DNA in Sennar State, Sudan

Background: Mycetoma is a chronic disease affecting the skin and subcutaneous tissue endemic in the tropical and subtropical regions. Several bacteria and fungi can cause mycetoma, but fungal mycetoma (eumycetoma) is challenging because the treatment requires a combination of a long-term antifungal agent and surgery. Although the transmission route has not yet been elucidated, infection from the soil is a leading hypothesis. However, there are few soil investigation studies, and the geographical distribution of mycetoma pathogens is not well documented. Here, we used multiplex real-time PCR technology to identify three fungal species from soil samples. Methods: In total, 64 DNA samples were extracted from soil collected in seven villages in an endemic area in Sennar State, Sudan, in 2019. Primers and fluorescent probes specifically targeting the ribosomal DNA of Madurella mycetomatis, Falciformispora senegalensis, and F. tompkinsii were designed. Results: Multiplex real-time PCR was performed and identified the major pathogen, M. mycetomatis that existed in most sites (95%). In addition, two other pathogens were identified from some sites. This is the first report on the use of this technique for identifying the eumycetoma causative microorganisms. Conclusions: This study demonstrated that soil DNA investigation can elucidate the risk area of mycetoma-causative agents. The results will contribute to the design of prevention measures, and further large-scale studies may be effective in understanding the natural habitats of mycetoma pathogens.</p

Lineage-specific RUNX3 hypomethylation marks the preneoplastic immune component of gastric cancer

Runt domain transcription factor 3 (RUNX3) is widely regarded as a tumour-suppressor gene inactivated by DNA hypermethylation of its canonical CpG (cytidine-phosphate-guanidine) island (CGI) promoter in gastric cancer (GC). Absence of RUNX3 expression from normal gastric epithelial cells (GECs), the progenitors to GC, coupled with frequent RUNX3 overexpression in GC progression, challenge this longstanding paradigm. However, epigenetic models to better describe RUNX3 deregulation in GC have not emerged. Here, we identify lineage-specific DNA methylation at an alternate, non-CGI promoter (P1) as a new mechanism of RUNX3 epigenetic control. In normal GECs, P1 was hypermethylated and repressed, whereas in immune lineages P1 was hypomethylated and widely expressed. In human GC development, we detected aberrant P1 hypomethylation signatures associated with the early inflammatory, preneoplastic and tumour stages. Aberrant P1 hypomethylation was fully recapitulated in mouse models of gastric inflammation and tumorigenesis. Cell sorting showed that P1 hypomethylation reflects altered cell-type composition of the gastric epithelium/tumour microenvironment caused by immune cell recruitment, not methylation loss. Finally, via long-term culture of gastric tumour epithelium, we revealed that de novo methylation of the RUNX3 canonical CGI promoter is a bystander effect of oncogenic immortalization and not likely causal in GC pathogenesis as previously argued. We propose a new model of RUNX3 epigenetic control in cancer, based on immune-specific, non-CGI promoter hypomethylation. This novel epigenetic signature may have utility in early detection of GC and possibly other epithelial cancers with premalignant immune involvement