Analysis of gut microbiota in chinese donkey in different regions using metagenomic sequencing.

BACKGROUND: Gut microbiota plays a significant role in host survival, health, and diseases; however, compared to other livestock, research on the gut microbiome of donkeys is limited. RESULTS: In this study, a total of 30 donkey samples of rectal contents from six regions, including Shigatse, Changdu, Yunnan, Xinjiang, Qinghai, and Dezhou, were collected for metagenomic sequencing. The results of the species annotation revealed that the dominant phyla were Firmicutes and Bacteroidetes, and the dominant genera were Bacteroides, unclassified_o_Clostridiales (short for Clostridiales) and unclassified_f_Lachnospiraceae (short for Lachnospiraceae). The dominant phyla, genera and key discriminators were Bacteroidetes, Clostridiales and Bacteroidetes in Tibet donkeys (Shigatse); Firmicutes, Clostridiales and Clostridiales in Tibet donkeys (Changdu); Firmicutes, Fibrobacter and Tenericutes in Qinghai donkeys; Firmicutes, Clostridiales and Negativicutes in Yunnan donkeys; Firmicutes, Fibrobacter and Fibrobacteres in Xinjiang donkeys; Firmicutes, Clostridiales and Firmicutes in Dezhou donkeys. In the functional annotation, it was mainly enriched in the glycolysis and gluconeogenesis of carbohydrate metabolism, and the abundance was the highest in Dezhou donkeys. These results combined with altitude correlation analysis demonstrated that donkeys in the Dezhou region exhibited strong glucose-conversion ability, those in the Shigatse region exhibited strong glucose metabolism and utilization ability, those in the Changdu region exhibited a strong microbial metabolic function, and those in the Xinjiang region exhibited the strongest ability to decompose cellulose and hemicellulose. CONCLUSION: According to published literature, this is the first study to construct a dataset with multi-regional donkey breeds. Our study revealed the differences in the composition and function of gut microbes in donkeys from different geographic regions and environmental settings and is valuable for donkey gut microbiome research.

Comparison of gut microflora of donkeys in high and low altitude areas.

Donkeys' gut microbe is critical for their health and adaptation to the environment. Little research has been conducted on the donkey gut microbiome compared with other domestic animals. The Tibetan Plateau is an extreme environment. In this study, 6 Qinghai donkeys (QH) from the Tibetan Plateau and 6 Dezhou donkeys (DZ) were investigated, and the contents of 4 parts-stomach, small intestine, cecum, and rectum-were collected. 16S rRNA sequencing and metagenomic sequencing were used to analyze the composition and diversity of gut microbial communities in donkeys. The results showed that the flora diversity and richness of the hindgut were significantly higher than those of the foregut (p < 0.01), with no sex differences, and the community structure and composition of the same or adjacent regions (stomach, small intestine, cecum, and rectum) were similar. Besides, the flora diversity and richness of QH on the Tibetan Plateau were significantly higher than those of DZ (p < 0.05). The major pathways associated with QH were signal transduction mechanisms and carbohydrate transport and metabolism, and Bacteroidales were the major contributors to these functions. Our study provides novel insights into the contribution of microbiomes to the adaptive evolution of donkeys.

Identification of Candidate Genes for Twinning Births in Dezhou Donkeys by Detecting Signatures of Selection in Genomic Data.

Twinning trait in donkeys is an important manifestation of high fecundity, but few reports are available elucidating its genetic mechanism. To explore the genetic mechanism underlying the twin colt trait in Dezhou donkeys, DNA from 21 female Dezhou donkeys that had birthed single or twin colts were collected for whole-genome resequencing. FST, θπ and Tajima's D were used to detect the selective sweeps between single and twin colt fecundity in the Dezhou donkey groups. Another set of 20 female Dezhou donkeys with single or multiple follicles during estrus were selected to compare concentrations of reproductive hormone including follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2) and progesterone (P4). Four candidate genes including ENO2, PTPN11, SOD2 and CD44 were identified in the present study. The CD44 gene had the highest FST value, and ENO2, PTPN11 and SOD2 were screened by two joint analyses (FST and θπ, θπ and Tajima's D). There was no significant difference in the LH, FSH and P4 levels between the two groups (p > 0.05); however, the serum E2 content in the multi-follicle group was significantly higher than that in the single-follicle group (p < 0.05). The identified candidate genes may provide new insights into the genetic mechanism of donkey prolificacy and may be useful targets for further research on high reproductive efficiency.