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Abstract Background Mongolian cattle are local breeds in northern China with excellent adaptability to harsh environmental conditions. Adipose tissues play essential roles in tolerance to cold and disease, but the associated cellular and molecular mechanisms are unclear. Methods Single-nucleus RNA sequencing (snRNA-seq) was performed on the adipose tissues from the subcutaneous (SAT), greater omentum (OAT) and perirenal (PAT) of 3 healthy cattle. The adipogenic trajectory was analyzed, and the functional roles of gene of interest were verified in vitro. Results There were different cell subpopulations in adipose tissues. The lipid-deposition adipocytes identified by the PTGER3 marker exhibited outstanding characteristics in SAT. In PAT and OAT, aldosterone was expressed to provide clues for the differential brown adipocytes. Among the DEGs by comparing OAT with SAT and PAT with OAT, C3 was significantly expressed in most of the cell populations in SAT. G0S2, LIPE, LPIN1, PTGER3 and RGCC took part in the adipogenic trajectory from preadipocyte commitment to mature adipocytes. S100A4 expression affected Ca2+ signaling and the expression of UCP1 ~ 3, FABP4 and PTGER3. Conclusion The cell heterogeneity and genes expressed in adipose tissues of Mongolian cattle not only determine the endocrine and energy storage, but contribute to adapt to cold and disease resistance.

IntroductionIncreases in plant species diversity may increase the community diversity effect and produce community over-yielding. Epichloë endophytes, as symbiotic microorganisms, are also capable of regulating plant communities, but their effects on community diversity effects are often overlooked.MethodsIn this experiment, we investigated the effects of endophytes on the diversity effects of host plant community biomass by constructing artificial communities with 1-species monocultures and 2- and 4-species mixtures of endophyte-infected (E+) and endophyte-free (E-) Achnatherum sibiricum and three common plants in its native habitat, which were potted in live and sterilized soil.Results and discussionThe results showed that endophyte infection significantly increased the belowground biomass and abundance of Cleistogenes squarrosa, marginally significantly increased the abundance of Stipa grandis and significantly increased the community diversity (evenness) of the 4-species mixtures. Endophyte infection also significantly increased the over-yielding effects on belowground biomass of the 4-species mixtures in the live soil, and the increase in diversity effects on belowground biomass was mainly due to the endophyte significantly increasing the complementary effects on belowground biomass. The effects of soil microorganisms on the diversity effects on belowground biomass of the 4-species mixtures were mainly derived from their influences on the complementary effects. The effects of endophytes and soil microorganisms on the diversity effects on belowground biomass of the 4-species communities were independent, and both contributed similarly to the complementary effects on belowground biomass. The finding that endophyte infection promotes belowground over-yielding in live soil at higher levels of species diversity suggests that endophytes may be one of the factors contributing to the positive relationship between species diversity and productivity and explains the stable co-existence of endophyte-infected Achnatherum sibiricum with a variety of plants in the Inner Mongolian grasslands.

In order to study the seepage process of rainwater on granite residual soil cut slopes, a numerical model for seepage analysis of granite residual soil cut slopes was established. Then, by applying the rainfall boundary condition, the seepage path of rainwater on the slope was analyzed under the condition of rainfall infiltration. Finally, during rainwater seepage, the volumetric water content and pore-water pressure change characteristics inside the slope were analyzed, and the seepage mechanism of rainwater in the granite residual soil slope was revealed. The results show that, under the condition of rainfall infiltration, the surface area of the slope gradually forms a saturated area in a temporary stable state. As the saturated area in the temporary stable state gradually extends to the inside of the slope, the area gradually increases and a groundwater level recharge area is gradually formed at the foot of the slope. Rainwater infiltration changes the original stable state of the slope, causing the granite residual soil slope to change from the two original distribution states of the unsaturated area and saturated area to the three distribution states of the temporarily stable saturated area, unsaturated area, and saturated area from top to bottom. The volumetric moisture content of slope-monitoring points increased gradually with an increase in the duration, and the overall distribution showed an “S” shape. The infiltration of rainwater causes the pore-water pressure of the granite residual soil to increase gradually, and matric suction gradually disappears. In particular, the disappearance of the matric suction at the foot of the slope will lead to the gradual weakening of the shear strength of the slope soil, thus affecting the slope stability.

Much effort has been devoted to better understanding the effects of land-use and climate changes on biodiversity and ecosystem functions (BEF); however, the mechanistic pathways behind the observed changes remain largely unexplored, especially for grassland arthropod community. Using a 7-year grassland experiment in Inner Mongolian steppe, we examined the relative importance of direct versus indirect (through mediating plant and arthropod biodiversity) effects of four land-use types (growing-season grazing, spring & summer grazing, mowing and enclosure) and precipitation variation in two climatically contrasting years on plant and arthropod productivity. Our results showed that: (1) the variation patterns of species and functional diversity and productivity across land use types were significantly different between plant and arthropod communities, though both plants and arthropods had their community-weighted mean size (i.e., plant height and arthropod body size) decreased under grazing or mowing; (2) moderate grazing and plant growing-season precipitation enhanced plant productivity mainly via indirectly increasing plant functional dispersion and decreasing plant nitrogen concentration associated with the shift in dominant species, but reduced arthropod productivity majorly by direct grazing damage and less importantly by indirect mediation of arthropod body size; (3) grassland management and precipitation-induced variations in plant and arthropod productivity could be well explained by the changes in their functional traits and diversity, but not species richness. Our results indicate the importance of trait-based method in understanding the mechanisms of management and precipitation affecting plant and arthropod productivity, and suggest that biological traits in multiple trophic groups can be used as efficient indicators in the assessment of grassland ecosystem health.

This study was conducted to investigate the effects of different levels of yeast chromium on growth performance, organ index, antioxidant capacity, immune performance and liver health of broilers under high stocking density. A total of 684 1-day-old Arbor Acres broilers were selected and fed a common diet from 1 to 22 days of age. At the end of 22 days, broilers with similar weight were randomly divided into six treatments, with six replications in each treatment. The broilers in control groups were fed with a control diet and raised at low stocking density of broilers (14 broilers/m2, LSD) and high stocking density (20 broilers/m2, HSD). The broilers in treatment groups were fed with diets supplemented with 200, 400, 800 and 1600 µg Cr/kg chromium yeast (Cr-yeast) under HSD, respectively. The experimental period was 23~42 days. Compared with the LSD group, the HSD group significantly decreased the liver index (ratio of liver weight to live weight of broilers) of broilers (p < 0.05), the HSD group significantly increased the content of corticosterone (CORT) and the activities of alanine aminotransferase (ALT) and alkaline phosphatase (ALP) and decreased the prealbumin (PA) level in the serum (p < 0.05). HSD decreased the total antioxidant capacity (T-AOC) contents in the serum, liver and breast, serum glutathione peroxidase (GSH-Px) activities, breast total superoxide dismutase (T-SOD) activities and liver catalase (CAT) activities of broilers (p < 0.05). The HSD group significantly increased the total histopathological score (p < 0.05). Compared with the HSD group, adding 200, 400, and 1600 Cr-yeast significantly increased the liver index of broilers (p < 0.05), all HSD + Cr-yeast groups decreased the ALT activities (p < 0.05), and the HSD + 800 group significantly decreased the CORT contents and the ALP activities of the serum (p < 0.05); the HSD + 400, 800 and 1600 groups increased the PA contents of the serum (p < 0.05); HSD + 800 group significantly reduced the tumor necrosis factor-α (TNF-α) and Interleukin-1β (IL-1β) contents of the serum (p < 0.05); moreover, the HSD + 400 group increased the GSH-Px activities of the serum (p < 0.05), the T-AOC and the T-SOD activities of the breast (p < 0.05) and the T-AOC and CAT activities of the liver (p < 0.05). Adding 800 Cr-yeast significantly decreased the total histopathological score (degree of hepatocyte edema and inflammatory cell infiltration) under HSD (p < 0.05). In summary, Cr-yeast can improve the antioxidant capacity and immune traits, and liver health of broilers under HSD. Based on the results of the linear regression analysis, the optimal supplementation of Cr-yeast in antioxidant capacity, immunity ability and liver health were at the range of 425.00–665.00, 319.30–961.00, and 800.00–1531.60 µg Cr/kg, respectively.

Achnatherum sibiricum can be infected by two species of fungal endophytes, Epichloë gansuensis (Eg) and Epichloë sibirica (Es). In this study, the metabolites of Eg, Es, and their infected plants were studied by GC–MS analysis. The results showed that the metabolic profiles of Eg and Es were similar in general, and only six differential metabolites were detected. The direct effect of endophyte infection on the metabolites in A. sibiricum was that endophyte-infected plants could produce mannitol, which was not present in uninfected plants. Epichloë infection indirectly caused an increase in the soluble sugars in A. sibiricum related to growth and metabolites related to the defense against pathogens and herbivores, such as α-tocopherol, α-linolenic acid and aromatic amino acids. Epichloë infection could regulate galactose metabolism, starch and sucrose metabolism, tyrosine metabolism and phenylalanine metabolism of host grass. In addition, there was a significant positive correlation in the metabolite contents between the endophyte and the host.