Taxonomic and functional adaption of the gastrointestinal microbiome of goats kept at high altitude (4800 m) under intensive or extensive rearing conditions

The gut microbiota composition is influenced by the diet as well as the environment in both wild and domestic animals. We studied the effects of two feeding systems on the rumen and hindgut microbiome of semi-feral Tibetan goats kept at high altitude (∼4800 m) using 16S rRNA gene and metagenomic sequencing. Intensive drylot feeding resulted in significantly higher zootechnical performance, narrower ruminal acetate: propionate ratios and a drop in the average rumen pH at slaughter to ∼5.04. Hindgut microbial adaption appeared to be more diverse in the drylot group suggesting a higher influx of undegraded complex non-starch polysaccharides from the rumen. Despite their higher fiber levels in the diet, grazing goats exhibited lower counts of Methanobrevibacter and genes associated with the hydrogenotrophic methanogenesis pathway, presumably reflecting the scarce dietary conditions (low energy density) when rearing goats on pasture from extreme alpine environments. These conditions appeared to promote a relevant abundance of bacitracin genes. In parallel, we recognized a significant increase in the abundance of antibiotic resistance genes in the digestive tracts of drylot animals. In summary, this study provides a deeper insight into the metataxonomic and functional adaption of the gastrointestinal microbiome of goats subject to intensive drylot and extensive pasture rearing conditions at high altitude.

Phylogenetic and functional adaption of the gastrointestinal microbiome of goats kept at high altitude (4800 m) under intensive or extensive rearing conditions

Background: The gut microbiota composition is influenced by the diet as well as the environment in both wild and domestic animals. Although the rumen microbiome in herbivorous ruminants has been studied intensively, there is a lack of data regarding the simultaneous adaption of the rumen and hindgut metagenome as affected by different feeding systems in extreme environments. Therefore, we studied the effects of two feeding systems, grazing and drylot, on the rumen and hindgut microbiome composition of semi-feral Tibetan goats kept at high altitude (~4800 m). 16S rRNA gene sequencing and metagenomic analysis were conducted on DNA extracts from the contents and mucosal layer of different sections of the gastrointestinal tract (rumen, cecum, and colon).Results: Intensive drylot feeding resulted in significantly higher zootechnical performance, narrower ruminal acetate: propionate ratios and a drop in the average rumen pH at slaughter to ~5.04. In response, the ruminal microbiome of drylot goats expressed a significantly lower diversity compared to the grazing animals. Otherwise, hindgut microbial adaption appeared to more diverse in the drylot group suggesting a higher influx of undegraded complex non-starch polysaccharides from the rumen. Despite their higher fiber levels in the diet, grazing goats exhibited lower counts of Methanobrevibacter and genes associated with the hydrogenotrophic methanogenesis pathway, presumably reflecting the scarce dietary conditions (low energy density) when rearing goats on pasture from extreme alpine environments. These conditions appeared to promote a relevant abundance of bacitracin genes, which potentially benefits the host's adaption to harsh environmental conditions. In parallel, we recognized a significant increase in the abundance of antibiotic resistance genes in the digestive tracts of drylot animals.Conclusion: In summary, this study provides a deeper insight in the phylogenetic and functional adaption of the gastrointestinal microbiome of goats subject to intensive drylot and extensive pasture rearing conditions at high altitude.

MEMS-Based Microballoons Achieving Multidirectional Large-Strain for Cell Mechanics Studies

The influence of mechanical stresses on cells has been a topic of special interest [1]. Attention is being focused on the cell-to-cell and cell-to-surrounding interactions and the mechanical stimuli that could be directly linked with functional adaption and pathological conditions of each cell or cluster of cells [2]. The aim of this research is to understand the biomechanical roles of cellular junctions on epithelial cells, exposed to a large multidirectional and uniform strain, using a microballoon (MB) platform. Quantitative measurement on strain values can be used to determine the necessary strains at which intercellular and cell-to-substrate connections are disassembled. This will provide information for characterizing cell-to-cell and cell-to-substrate adhesions during biological development and/or diseases.

Regional Sweating in Eskimos Compared to Caucasians

After pharmacological stimulation, prints of functioning sweat glands were obtained from 17 skin sites on the face, body, and limbs of 37 adult male Eskimos and 21 Caucasian controls.Eskimos showed greater numbers and greater activity of functioning sweat glands on exposed parts of the face such as nose and cheeks, while responding with significantly less sweat gland activity on all body surfaces that are normally heavily clothed in winter. Trunks, arms, hands, legs, and feet showed a progressive reduction of sweat gland response in the order of one-half on the trunk to one-fifth on feet when comparing mean sweat gland counts per square centimeter in Eskimos and controls. The comparative reduction of sweat gland response in the Eskimos progressed in the same order as the distance of the part from the body core, and as the risk of the part to freezing. Therefore, this reduction of sweat gland activity may represent a morphological and/or functional adaption to environmental conditions including climate and clothing.