Changes in the Intestinal Microbiota of Gibel Carp (Carassius gibelio) Associated with Cyprinid herpesvirus 2 (CyHV-2) Infection.

Gut microbiota are integral to the host, and have received increased attention in recent years. However, information regarding the intestinal microbiota of many aquaculture animals is insufficient; elucidating the dynamics of the intestinal microbiota can be beneficial for nutrition, immunity, and disease control. In this study, we used 16S rRNA sequencing to observe changes in the intestinal microbiota of gibel carp (Carassius auratus gibelio) associated with cyprinid herpesvirus 2 (CyHV-2) infection. Our results indicate that the diversity of the intestinal microbiota was strongly reduced, and the composition was dramatically altered following CyHV-2 infection. The most dominant species in healthy fish were Cetobacterium, Rhodobacter, and Crenothrix; meanwhile, Cetobacterium, Plesiomonas, Bacteroides, and Flavobacterium were the most abundant species in sick fish. Plesiomonas was highly abundant in infected samples, and could be used as a microbial biomarker for CyHV-2 infection. Chemical properties of the aquaculture water were significantly correlated with the microbial community structure; however, it is difficult to determine whether these changes are a cause or consequence of infection. However, it may be possible to use probiotics or prebiotics to restore the richness of the host intestinal microbiota in infected animals to maintain host health.

[Diversity and network features of fungal community in the soils of planted and natural Picea asperata forests.] / äººå·¥ä¸Žå¤©ç„¶äº‘æ‰æž—åœŸå£¤çœŸèŒç¾¤è½å¤šæ ·æ€§åŠèŒç¾¤ç½‘ç»œå ³ç³»ç‰¹å¾.

The diversity and interactions of soil fungal community are the key to maintain the diversity and stability of ecosystem. In this study, we examined the structure, diversity and co-occurrence networks of fungal community in rhizosphere and non-rhizosphere soils of planted and natural Picea asperata forests using high-throughput sequencing technique and bioinformatic methods. The results showed that Inocybaceae and Sebacinaceae were dominant family in soils of planted and natural forests, respectively. At the genus level, Inocybe was dominant one in soils of planted and natural forests. There were significant differences in ß-diversity of fungal communities between rhizosphere and non-rhizosphere soils in both planted and natural forests. There were no significant correlations between environmental variables and the relative abundance and α-diversity of fungal communities. Herb layer coverage, soil water content, total organic carbon concentration, and plant species richness played important roles in explaining the variations of ß-diversity of fungal communities. Results of the network analysis showed that the negative correlations were dominant among soil fungal communities in natural forest, suggesting that the competition of different groups in natural forest. Moreover, there were more negative correlations in non-rhizosphere soils than in rhizosphere soils, which indicated that fungal communities in non-rhizosphere soils comprised more competitive network structure than in the rhizosphere soils. Biomarker species were identified based on differential abundance analysis. Sebacinaceae was the single shared keystone species in the fungal network which had significant differences among rhizosphere and non-rhizosphere soils of planted and natural forests. Therefore, it is suggested that the variation of differential species in the soil fungal communities between the planted and natural forest might had limited influence on the stability of the community of planted and natural forests.

Duodenal-Jejunal Bypass Ameliorates Type 2 Diabetes Mellitus by Activating Insulin Signaling and Improving Glucose Utilization in the Brain.

BACKGROUND: Duodenal-jejunal bypass (DJB) can dramatically improve type 2 diabetes independent of weight loss and food restriction. Increasing evidence has demonstrated that brain insulin signaling plays an important role in the pathophysiology of type 2 diabetes. This study explores whether the antidiabetic effect of DJB is involved in brain insulin signaling activation and brain glucose utilization. METHODS: A diabetic rat model was established by high-fat and high-glucose diet. DJB or sham surgery was performed in diabetic rats. 18F-FDG PET scanning was used to detect glucose uptake in different organs, particularly in the brain. The levels of glucose transporters, glucose utilization-related proteins (HK1 and PFK2), insulin, and insulin signaling pathway-related proteins (InsR, IRS1/2, PI3K, and p-Akt) in the brain tissues were evaluated and analyzed. RESULTS: The results showed that DJB significantly improved basal glycemic parameters and reversed the decreasing glucose uptake in the brains of type 2 diabetic rats. DJB significantly increased not only the expression levels of brain insulin, IRS1/2, PI3K, and p-Akt but also the levels of the glucose utilization enzymes HK1 and PFK2 in the brain. CONCLUSION: These results indicate that enhanced brain insulin signaling transduction and brain glucose utilization play important roles in the antidiabetic effect of DJB.

[Soil methanotrophic community structure and diversity in different vegetation types at elevation gradient of Gongga Mountain, Southwest China]. / è´¡å˜Žå±±æµ·æ‹”æ¢¯åº¦ä¸Šä¸åŒæ¤è¢«ç±»åž‹åœŸå£¤ç”²çƒ·æ°§åŒ–èŒç¾¤è½ç»“æž„åŠå¤šæ ·æ€§.

Methane (CH4) is the second abundant greenhouse gas. Aerobic methane oxidations of topsoil in forest are identified as an important sink of atmosphere methane, playing critical roles in carbon cycle and global warming alleviation. Comparing the community structure and diversity of methane oxidizing bacteria (MOBs) in different vegetation ecosystems could provide new insights into the relationships between vegetation types and community of MOBs. In this study, we collected 92 soil samples from four types of vegetation along the elevation gradient of Gongga Mountain, and further assessed the community structure, diversity and potential drivers of MOBs across the four vegetation types using Miseq sequencing and bioinformatics methods. The result indicated that MOBs community compositions in evergreen and deciduous broad-leaved forest (EDBF) and coniferous and broad-leaved mixed forest (CBMF) was more similar, whereas in dark coniferous forest (DCF) and shrub meadow area (SMA) soils, MOB composition was more similar. In the four types of vegetation, α-diversities of MOBs in EDBF and CBMF were significantly higher than that in the other three vegetation types (P＜0.001), whereas ß-diversities in soils of DCF and SMA were significantly higher than those in EDBF and CBMF (P＜0.001). Spearman analysis indicated that the relative abundance of different MOBs in four types of vegetation showed different responses to environmental change. Factors including soil total nitrogen, conductivity and soil temperature appeared to govern the variation of α-diversity across the four vegetation types. Partial Mantel test and redundancy ana-lysis (RDA) suggested that environmental parameters likely contributed more to diversity variations in soils from EDBF and CBMF, whereas diversity variations in soils from DCF and SAM might be driven by other potential environmental factors or mechanism. Precipitation appeared to drive the ß-diversity variation between vegetation of EDBF and CBMF and vegetation of DCF and SAM. Our study suggested that the community structure and diversity variation of MOBs in different vegetation types might be governed by both soil properties and climate change.