Heritability and recursive influence of host genetics on the rumen microbiota drive body weight variance in male Hu sheep lambs.

BACKGROUND: Heritable rumen microbiota is an important modulator of ruminant growth performance. However, no information exists to date on host genetics-rumen microbiota interactions and their association with phenotype in sheep. To solve this, we curated and analyzed whole-genome resequencing genotypes, 16S rumen-microbiota data, and longitudinal body weight (BW) phenotypes from 1150 sheep. RESULTS: A variance component model indicated significant heritability of rumen microbial community diversity. Genome-wide association studies (GWAS) using microbial features as traits identified 411 loci-taxon significant associations (P < 10-8). We found a heritability of 39% for 180-day-old BW, while also the rumen microbiota likely played a significant role, explaining that 20% of the phenotypic variation. Microbiota-wide association studies (MWAS) and GWAS identified four marker genera (Bonferroni corrected P < 0.05) and five novel genetic variants (P < 10-8) that were significantly associated with BW. Integrative analysis identified the mediating role of marker genera in genotype influencing phenotype and unravelled that the same genetic markers have direct and indirect effects on sheep weight. CONCLUSIONS: This study reveals a reciprocal interplay among host genetic variations, the rumen microbiota and the body weight traits of sheep. The information obtained provide insights into the diverse microbiota characteristics of rumen and may help in designing precision microbiota management strategies for controlling and manipulating sheep rumen microbiota to increase productivity. Video Abstract.

Molecular identification of Theileria equi, Babesia caballi, and Rickettsia in adult ticks from North of Xinjiang, China.

BACKGROUND: Ticks in Xinjiang distribute widely and account for one third of China. Ticks can carry and transmit bacteria, virus, and parasite. However, the research of tick-borne pathogens in Xinjiang is rather little. OBJECTIVE: To understand the situation of hard tick carry Theileria equi, Babesia caballi and Rickettsia spp. of Zhaosu and Altay in Xinjiang. METHODS: In this study, 119 tick samples were obtained from horses in Xinjiang, China, Ticks were identified morphologically to determine species and PCR was used to investigate the situation of pathogens by hard ticks. RESULTS: One hundred and seven belong to Dermacentor marginatus, five belong to D. niveus, and seven belong to D. silvarum. Theileria equi and Babesia caballi were detected in one tick and 18 ticks, respectively. However, the carrying rate of Rickettsia spp. was 51.26% (61/119). Among these, the mixed carriage rate of T. equi and Rickettsia spp. was 0.8% (1/119). The mixed carriage rate of B. caballi and Rickettsia spp. was 10.1% (12/119). CONCLUSION: Our results revealed that hard tick can carry not only haeimoparasite but also many important zoonotic pathogens in Xinjiang, and this situation was worth heeding.

Molecular detection of tick-borne pathogens harbored by ticks collected from livestock in the Xinjiang Uygur Autonomous Region, China.

Ticks carry and transmit a wide range of pathogens (bacteria, viruses, and protozoa) that are of importance to humans and animals globally. However, information about the tick-borne pathogens harbored by ticks in the Xinjiang Uygur Autonomous Region (XUAR), northwestern China, is scarce. This study investigated the occurrence of tick species of domestic animals and tick-borne pathogens by using morphological molecular identification and sequence analysis in Turpan, Qitai, Altay, Hejing, Nileke, and Zhaosu counties (XUAR). A total of 5822 adult ticks (females and males) from 12 tick species were identified from 5 animal species (cattle, goats, sheep, camels, and horses) in 6 counties in the XUAR. Collected tick species included Dermacentor marginatus (24.7 %), Dermacentor nuttalli (20.8 %), Hyalomma anatolicum (13.7 %), Dermacentor niveus (13.1 %), Haemaphysalis punctata (10.7 %), Dermacentor silvarum (7.1 %), Dermacentor pavlovskyi (3.9 %), Hyalomma asiaticum (2.2 %), Rhipicephalus pumilio (1.9 %), Rhipicephalus sanguineus sensu lato (0.7 %), Rhipicephalus turanicus (0.6 %), and Hyalomma asiaticum kozlovi (0.6 %). Furthermore, 750 partially engorged adult ticks (females and males), including H. anatolicum (250), D. nuttalli (250), and D. marginatus (250), were individually separated according to species and sampling site, used for DNA extraction, and then screened for tick-borne pathogens. The most common pathogen was Rickettsia raoultii (36.80 %), followed by Brucella sp. (26.2 %), Anaplasma ovis (22.4 %), Babesia caballi (14.8 %), Theileria equi (8.7 %), and Theileria ovis (8.5 %). The sequencing of 6 genes showed a 96-100 % nucleotide identity between the sequences in this study and those deposited in GenBank. This study provides a scientific reference for the prevention and control of tick-borne diseases in the XUAR.