Interactions of rumen microbiota and metabolites with meat quality-related genes to regulate meat quality and flavor of Tibetan sheep under nutrient stress in the cold season.

AIM: The meat of Tibetan sheep has a unique flavor, delicious taste, and superior nutritional value. However, the change of grass will lead to a change in meat quality. This study aimed to explore the potential regulatory mechanisms of microbial metabolites with respect to meat quality traits of Tibetan sheep under nutrient stress in the cold season. METHODS AND RESULTS: We determined and analyzed the longissimus dorsi quality, fatty acid composition, expression of genes, and rumen microbial metabolites of Tibetan sheep in cold and warm seasons. The shear force was decreased (P < .05), the meat color a*24 h value was increased (P < .05), and the contents of crude fat (EE) and protein (CP) were decreased in the cold season. Polyunsaturated fatty acids (PUFAs)-linoleic acid and docosahexaenoic acid increased significantly in the cold season (P < .05). The expressions of meat quality genes MC4R, CAPN1, H-FABP, and LPL were significantly higher in the warm season (P < .05), and the CAST gene was significantly expressed in the cold season (P < .01). The different microbial metabolites of Tibetan sheep in the cold and warm seasons were mainly involved in amino acid metabolism, lipid metabolism, and digestive system pathway, and there was some correlation between microbiota and meat quality traits. There are similarities between microbial metabolites enriched in the lipid metabolism pathway and muscle metabolites. CONCLUSION: Under nutritional stress in the cold season, the muscle tenderness of Tibetan sheep was improved, and the fat deposition capacity was weakened, but the levels of beneficial fatty acids were higher than those in the warm season, which was more conducive to healthy eating.

Astragalus additive in feed improved serum immune function, rumen fermentation and the microbiota structure of early-weaned lambs.

AIM: The purpose of this study was to determine the mechanism of Astragalus activity on the immune function, rumen microbiota structure, and rumen fermentation of early-weaned lambs. METHODS AND RESULTS: Thirty healthy early-weaned lambs with similar body weights (17.42 ± 2.02 kg) were selected for the feeding experiment. The control group (KB) was fed a basal diet, and the Astragalus group (HQ) was fed 0.3% Astragalus additive on the basis of a basic diet. The formal trial period was 60 days. The results showed that the concentrations of blood immunoglobulin A (IgA) and immunoglobulin M (IgM) in the HQ group were significantly higher than those in the KB group (P < 0.05). Compared with the KB group, the concentrations of acetic acid, butyric acid, and total volatile fatty acids (VFAs) in the HQ group were higher (P < 0.01). The expression levels of the rumen epithelial-related genes MCT1, MCT4, NHE2, and ZO1 in the Astragalus group were significantly higher than those in the KB group (P < 0.05). 16S rRNA analysis showed that at the phylum level, Bacteroidetes in the HQ group significantly increased (P < 0.01); at the genus level, Prevotella (P < 0.01) and Succiniclasticum (P < 0.01) in the HQ group were found at significantly higher abundances than those in the KB group, and the results of microbiota gene and function prediction showed that "energy metabolism," "glycan biosynthesis and metabolic" pathways were significantly enriched in the HQ group (P < 0.05). CONCLUSION: As a feed additive, Astragalus can improve the immunity of early-weaned lambs, the structure of the rumen microbiota of lambs, and the fermentation capacity of the rumen.

Coevolution of Rumen Epithelial circRNAs with Their Microbiota and Metabolites in Response to Cold-Season Nutritional Stress in Tibetan Sheep.

This study explores the effects of the coevolution of the host genome (the first genome) and gut microbiome (the second genome) on nutrition stress in Tibetan sheep during the cold season. The rumen epithelial tissue of six Tibetan sheep (Oula-type) was collected as experimental samples during the cold and warm seasons and the study lasted for half a year. The cDNA library was constructed and subjected to high-throughput sequencing. The circRNAs with significant differential expression were identified through bioinformatics analysis and functional prediction, and verified by real-time quantitative PCR (qRT-PCR). The results showed that a total of 56 differentially expressed (DE) circRNAs of rumen epithelial tissue were identified using RNA-seq technology, among which 29 were significantly upregulated in the cold season. The circRNA-miRNA regulatory network showed that DE circRNAs promoted the adaptation of Tibetan sheep in the cold season by targeting miR-150 and oar-miR-370-3p. The results of correlation analysis among circRNAs, microbiota, and metabolites showed that the circRNA NC_040275.1:28680890|28683112 had a very significant positive correlation with acetate, propionate, butyrate, and total volatile fatty acid (VFA) (p < 0.01), and had a significant positive correlation with Ruminococcus-1 (p < 0.05). In addition, circRNA NC_040256.1:78451819|78454934 and metabolites were enriched in the same KEGG pathway biosynthesis of amino acids (ko01230). In conclusion, the host genome and rumen microbiome of Tibetan sheep co-encoded a certain glycoside hydrolase (ß-glucosidase) and coevolved efficient VFA transport functions and amino acid anabolic processes; thus, helping Tibetan sheep adapt to nutrient stress in the cold season in high-altitude areas.

Blood leukocyte count as a systemic inflammatory biomarker associated with a more rapid spirometric decline in a large cohort of iron and steel industry workers.

OBJECTIVE: Iron and steel industry workers are exposed to high levels of inhalable dust particles that contain various elements, including metals, and cause occupational lung diseases. We aim to assess the relationship between occupational dust exposure, systemic inflammation, and spirometric decline in a cohort of Chinese iron and steel workers. METHODS: We studied 7513 workers who participated in a Health Surveillance program at Wugang Institute for Occupational Health between 2008 and 2017. Time-weighted exposure intensity (TWEI) of dust was quantified based on self-reported dust exposure history, the experience of occupational hygienists, and historical data of dust exposure for workers with certain job titles. A linear mixed-effects model was used for association analyses. RESULTS: The average annual change of lung function was - 50.78 ml/year in forced expiratory volume in 1 s (FEV1) and - 34.36 ml/year in forced vital capacity (FVC) in males, and - 39.06 ml/year in FEV1 and - 26.66 ml/year in FVC in females. Higher TWEI prior to baseline was associated with lower longitudinal measurements of FEV1 and FVC but not with their decline rates. Higher WBC and its differential at baseline were associated with lower longitudinal measurements and a more rapid decline of FEV1 and FVC in a dose-dependent monotonically increasing manner. Moreover, the increase of WBC and its differential post-baseline was also associated with a more rapid decline of FEV1 and FVC. CONCLUSIONS: Our findings support the important role of systemic inflammation in affecting the temporal change of lung function in iron and steel industry workers.

[Association between single nucleotides polymorphism of catalase gene and susceptibility to noise-induced hearing loss in occupational population].

OBJECTIVE: To investigate the relationship between single nucleotides polymorphism of catalase(CAT) gene and susceptibility to noise-induced hearing loss(NIHL) in occupational noise exposed population. METHODS: A case-control study of 1∶1 was conducted to select 286 workers with binaural high frequency average hearing threshold ≥40 dB(HL), from 2006 to 2015 in a cohort study of occupational noise exposure workers in Henan Province. According to the type of work, the age difference was not more than 5 years and the length of exposure to noise was not more than 2 years. The polymorphism of 8 single nucleotides in CAT gene was detected by medium SNPscanTM, and the relationship between 8 single nucleotides polymorphism of CAT gene and NIHL susceptibility was analyzed by multivariate conditional logistic regression. RESULTS: Under the dominant model of rs208679 locus of CAT gene [(GA GG)/AA], the risk of NIHL in individuals carrying GA or GG genotype was 1. 431 times higher than that in individuals carrying AA genotype(95%CI 1. 020-2. 009), and P=0. 038. CONCLUSION: G, a mutant at rs208679 site of CAT gene, may be one of the risk factors for NIHL susceptibility.

Effects of Spirulina algae as a feed supplement on nutritional value and flavour components of silkie hens eggs.

OBJECTIVE: Silkie chicken (Gallus gallus domesticus brisson) is also named Chinese Taihe chicken, characterized by blue comb, green earlobes, black skin, meat and bones. This study aimed to evaluate the effects of spirulina feeding on the nutritive value and flavour of silkie hens eggs. METHODS: A total of 280 Silkie hens of 42 weeks old were fed 4 different diets, including basal diet and basal diet containing 0.1%, 0.3% and 0.5% spirulina. Each diet group was divided into 70 Silkie hens experimentally. The production performance of silkie hens, the nutritional compositions [e.g., amino acids (AAs) and fatty acids] and flavour substances of silkie hens eggs were compared with control. RESULTS: A 0.3% and 0.5% spirulina feeding significantly increased the average egg production rate and average egg weight, while only 0.3% spirulina feeding decreased both the average daily feed intake and feed conversion ratio of silkie hens compared with the controls (p < 0.05). The contents of crude protein, fat, cholesterol and Ca in silkie hens eggs were significantly increased by 0.3% spirulina feeding (p < 0.05). Only fat and cholesterol were significantly increased by 0.5% spirulina but had no significant difference compared with 0.3% spirulina. The flavour, amino acids/total AAs, and saturated fatty acids/unsaturated fatty acids in silkie hens eggs were significantly increased by 0.3% spirulina feeding than other groups (p < 0.05). A total of 46 volatile substances were identified in silkie hens eggs, and the substances of total acids, alkanes and aldehydes were significantly increased by 0.3% spirulina feeding. CONCLUSION: Spirulina feeding at a proportion of 0.3% improved the production performance of silkie hens, and nutritive value and flavour of silkie hens eggs.

Effect of GRM7 polymorphisms on the development of noise-induced hearing loss in Chinese Han workers: a nested case-control study.

BACKGROUND: Noise-induced hearing loss (NIHL) is a complex, irreversible disease caused by the interaction of genetic and environmental factors. In recent years, a great many studies have been done to explore the NIHL susceptibility genes among humans. So far, high powerful detections have been founded that genes of potassium ion channel genes (KCNQ4 and KCNE1), catalase (CAT), protocadherin 15 (PCDH15), myosin 14 (MYH14) and heart shock protein (HSP70) which have been identified in more than one population may be associated with the susceptibility to NIHL. As for metabolic glutamate receptor7 gene (GRM7), a lot of researches mainly focus on age-related hearing loss (ARHL) and the results have shown that the polymorphisms of GRM7 are linked to the development of ARHL. However, little is known about the association of GRM7 and the susceptibility to NIHL. Therefore, the aim of this study was to explore the effect of GRM7 polymorphisms on the susceptibility to NIHL. METHODS: A nested case-control study based on the cohort in a Chinese steel factory was implemented in 292 cases and 584 controls matched with the same sex, the age difference ≤ 5 years old, the same type of work, duration of occupational noise exposure ≤2 years. Five single nucleotide polymorphisms (SNPs) of GRM7 were gained through selecting and genotyping SNPs. Conditional logistic regression analysis was used to assess the main effect of GRM7 polymorphisms on the susceptibility to NIHL and the gene-by-environment interaction. Furthermore, the gene-by-gene interactions were analyzed by generalized multiple dimensionality reduction (GMDR). RESULTS: This research discovered for the first time that the mutant allele C in rs1485175 of the GMR7 may decrease individuals' susceptibility to NIHL. The interaction between rs1485175 and cumulative noise exposure (CNE) at high level was found after the stratification according to CNE (p/p bon = 0.014/0.007, OR = 0.550, 95% CI: 0.340-0.891). Permutation test of GMDR suggested that rs1920109, rs1485175 and rs9826579 in GRM7 might interact with each other in the process of developing NIHL (p = 0.037). CONCLUSIONS: The results suggest that the mutant allele C of rs1485175 in GRM7 may reduce the susceptibility to NIHL in Chinese Han population.

Production, performance, slaughter characteristics, and meat quality of Ziwuling wild crossbred pigs.

Wild boars, because of their large size and ability to survive adverse conditions, are usually used to cross with domestic breeds to improve the quality of domesticated pigs. This study aimed to investigate the growth performance, slaughter performance, and meat quality of Ziwuling crossbred pigs. Crossbred pigs in four groups (n = 8 per group, 4 boars and 4 sows, all aged 100 days), F1 [wild × B (Bamei)], F1 × B, F1 × Y (Yorkshire), and F1 × F1, were selected at a commercial pig farm. Growth performance, slaughter performance, and meat quality of these crossbred pigs were determined. Characteristics of fatty acids, amino acids, and longissimus muscle fiber in relation to growth, carcass, and meat quality traits were also investigated. Pigs in F1 and F1 × F1 groups had lower average daily weight gain, water and storage loss rates, larger meat color score, higher muscle amino acid levels, larger muscle fiber diameter, and higher ratio of flavor amino acids to unsaturated fatty acids compared to other groups. Crossbred pigs with higher rate of wild boar's consanguinity could improve production performance, slaughter performance, and meat quality. Thus, crossbreeding wild pig with domestic breeds might be an effective method to improve meat quality and flavor.

[Relationship between GRM7 gene polymorphisms and the susceptbility to noise-induced hearing loss].

OBJECTIVE: To investigate the relationship between metabolic glutamate receptor 7 gene( GRM7) polymorphisms and the susceptibility to noise-induced hearing loss( NIHL) in Chinese Han occupational population. METHODS: Using a nested case-control study with a 1 ∶ 1 matching, a total of 277 cases of contacting noise workers were selected from a cohort in a steel factory. According to the matching criteria: the same sex, the same type of work, the age difference ≤ 5 years, contact noise length ≤ 2 years, 277 controls were selected. The 8 single nucleotide polymorphisms( SNPs) of the GRM7 gene, rs3749380, rs11928865, rs9877154, rs3828472, rs9819783, rs11920109, rs1485175 and rs9826579, were detected by SNPscanTMmethod. The 4 gene models, the additive model, dominant model, recessive model, codominant model, were constructed to explore the biological association with NIHL susceptibility. The possible diplotype of each subject was constructed using Phase 2. 0. 2 to analyze its relationship with NIHL. According to the layered cumulative noise exposure( CNE), the interactions between the influencing factor were analyzed. The relationship between the GRM7 gene and NIHL was analyzed by single factor and multivariate factors conditional logistic regression analysis. RESULTS: The comparison of general demographic characteristics between the hearing loss group and control group showed that smoking could increase the risk of developing NIHL by 2. 051 times( 95 % CI 1. 456-2. 891, P< 0. 001). No statistically significant difference was found in the analysis of GRM7 polymorphisms and the susceptibility to NIHL. CONCLUSION: Smoking may increase the risk of NIHL. The relationship between GRM7 polymorphisms and the susceptibility to NIHL has not been found in this study.

Genetic variation in EYA4 on the risk of noise-induced hearing loss in Chinese steelworks firm sample.

OBJECTIVES: Noise-induced hearing loss is one of the most serious occupational diseases worldwide. It is caused by interactions between environmental and genetic factors. The purpose of this study was to examine the association between the genetic susceptibility of the eye absent homolog 4 (EYA4) gene and the risk of developing noise-induced hearing loss in China. METHODS: A case-control association study was carried out with 326 hearing loss cases and 326 controls matched with age and duration of noise exposure, drawn from a cohort of steel workers. Five single nucleotide polymorphisms (SNPs) in the EYA4 were selected and genotyped. Logistic regression was performed to analyse the main effect of genotypes and interactions between genotypes and individual/environmental factors adjusted for confounding factors. Moreover, generalised multiple dimensionality reduction was applied to further detect interaction among the 5 selected SNPs. RESULTS: Analysis revealed that locus polymorphism of rs3813346 was associated with the risk of developing noise-induced hearing loss in the dominance model, the codominance model and the addictive model (p=0.004, 0.009 and 0.003, respectively). A significant interaction between rs9321402 and cumulative noise exposure was found (p=0.002). A significant main effect p value (p=0.006) was obtained in the high-level exposure group (cumulative noise exposure ≥98 dB(A)). Generalised multiple dimensionality reduction indicated that the combined interaction of the 2 loci-rs3813346 and rs9493627-significantly affected the incidence of noise-induced hearing loss. CONCLUSIONS: The research suggests that EYA4 genetic variant and its interaction with noise levels may modify the susceptibility to develop noise-induced hearing loss in Chinese population.