Increasing dietary energy level improves growth performance and lipid metabolism through up-regulating lipogenic gene expression in yak (Bos grunniens)

et al. 2022

Front. Cell Dev. Biol.

Animals have adapted behavioral and physiological strategies to conserve energy during periods of adverse conditions. Hepatic glucose is one such adaptation used by grazing animals. While large vertebrates have been shown to have feed utilization and deposition of nutrients—fluctuations in metabolic rate—little is known about the regulating mechanism that controls hepatic metabolism in yaks under grazing conditions in the cold season. Hence, the objective of this research was to integrate transcriptomic and metabolomic data to better understand how the hepatic responds to chronic nutrient stress. Our analyses indicated that the blood parameters related to energy metabolism (glucose, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, lipoprotein lipase, insulin, and insulin-like growth factor 1) were significantly (p < 0.05) lower in the cold season. The RNA-Seq results showed that malnutrition inhibited lipid synthesis (particularly fatty acid, cholesterol, and steroid synthesis), fatty acid oxidation, and lipid catabolism and promoted gluconeogenesis by inhibiting the peroxisome proliferator-activated receptor (PPAR) and PI3K-Akt signaling pathways. For metabolite profiles, 359 metabolites were significantly altered in two groups. Interestingly, the cold season group remarkably decreased glutathione and phosphatidylcholine (18:2 (2E, 4E)/0:0). Moreover, integrative analysis of the transcriptome and metabolome demonstrated that glycolysis or gluconeogenesis, PPAR signaling pathway, fatty acid biosynthesis, steroid biosynthesis, and glutathione metabolism play an important role in the potential relationship between differential expression genes and metabolites. The reduced lipid synthesis, fatty acid oxidation, and fat catabolism facilitated gluconeogenesis by inhibiting the PPAR and PI3K-Akt signaling pathways to maintain the energy homeostasis of the whole body in the yak, thereby coping with the shortage of forages and adapting to the extreme environment of the Qinghai-Tibetan Plateau (QTP).

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 90%

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Transcriptomic and Metabolomic Analyses Reveal Inhibition of Hepatic Adipogenesis and Fat Catabolism in Yak for Adaptation to Forage Shortage During Cold Season

Zheng

et al. 2022

Front. Cell Dev. Biol.

“…In long-term evolution, yaks developed a unique rumen microecological system with a strong fiber-degrading ability to resist the extreme environment and seasonal forage supply imbalance following synergistic selection [ 3 ]. To date, several studies have found that yak is superior to cattle due to feeding and grazing behavior [ 4 ], digestive organ structure [ 5 , 6 ], nitrogen use efficiency [ 7 ], low rumen methane emission [ 8 ], and interseason energy utilization efficiency [ 9 , 10 ]. Meanwhile, the abundance of uncultured rumen microbial species was higher in the naturally grazing yak compared with house-farmed cattle [ 11 ].…”

Section: Introductionmentioning

confidence: 99%

Fecal Microbiota Dynamics Reveal the Feasibility of Early Weaning of Yak Calves under Conventional Grazing System

Wang

Dingkao

et al. 2021

Biology

Background: The gut microbiota plays an important role in the health and production of animals. However, little information is available on the dynamic variations and comparison of intestinal microbiota in post-weaning yak calves living on the QTP. Methods: We explored the fecal bacterial microbiota succession of yak calves at different months after early weaning (60 d) compared with cattle calves by 16S rRNA gene amplicon sequencing and functional composition prediction. Results: We found no significant difference in blood biochemical parameters related to glucose and lipid metabolism between yaks and calves in different months after weaning. The core fecal bacterial microbiota from both species of calves was dominated by Ruminococcaceae, Rikenellaceae, and Bacteroidaceae. The fecal microbial community has a great alteration within the time after weaning in both cattle and yak calves, but cattle showed a larger change. After five months, the microbiota achieves a stable and concentrated state. This is also similar to the functional profile. Conclusions: Based on the exploration of dynamic changes in the fecal microbiota at an early stage of life, our results illustrated that there were no negative effects of intestinal microbiota succession on yak calves when early weaning was employed.

“…The QTP offers one of the harshest environments for the survival of humans and other mammalian species. It has been found that yak are superior to cattle in feeding and grazing behavior [22], digestive organ structure [23,24], nitrogen use efficiency [25], low rumen methane emission [26], and interseason energy utilization efficiency [27,28]. A whole genome sequencing study has identified potentially functional genes related to the unique adaptation of yak to severe hypoxia condition [29].…”

Section: Introductionmentioning

confidence: 99%

Maternal Gut Microbes Contribute to Rapid Acquisition of Intestinal Microbiota and High-Altitude Adaptation of Pre-Weaning Yak Calves

Zhong

Kao

et al. 2021

Preprint

BackgroundLong time exposure to seasonal forage availability and harsh environment on the Qinghai-Tibetan Plateau (QTP) has resulted in a series of unique adaptation mechanisms following the evolution of yak to cope with nutritional deficiencies and other adverse conditions. This is likely achieved by an unprecedented genetic resource for fibrolytic enzymes of microbial origins that allow the host to efficiently degrade plant polysaccharides. However, to what extent of maternal symbiotic microbial transmission throughout early microbial successions and its adaptation to high-altitude hypoxia in grazing yak driven by the harsh environment and nutritional stress have been far from clear. Understanding the colonization and succession of yak gut microbiota would help to clarify the functional interaction and crosstalk between microorganisms and their hosts. This study explored the succession of intestinal microbiota of yak ( Bos grunniens ) and cattle ( Bos taurus ) kept in the same habitat during pre-weaning period. ResultsThe gut microbiota of yak and cattle calves were dominated by members of the families Ruminococcaceae , Lachnospiraceae , and Bacteroidaceae during pre-weaning. Moreover, source-tracking models revealed that maternal microbiota was critical for the rapid establishment and colonization of initial intestinal microbiota of their calves at development stage and its impact persisted until weaning or even longer. Compared with cattle calves, the gut microbiota of yak calves was rapidly established and reached to a relatively stable status at the 5th week after birth, indicating the evolutionary significance of interaction between the yak and its intestinal microbial community that could facilitate the adaptation of this flagship species to adapt to the harsh environment on the QTP. ConclusionOur results revealed that under natural grazing conditions, the calves raised by their mothers acquire gut microbiota through the contacts with maternal feces and the social learning behavior, which accelerate the establishment of stable intestinal microbiota. In addition, after long-term natural selection, the yak calves acquire a relatively mature and stable intestinal microbiota earlier than the cattle calves, facilitating their strong adaptation to the harsh environment on the QTP.