Project description:Heat stress has a detrimental impact on cattle health, welfare and productivity by affecting gene expression, metabolism and immune response, but little is known on the epigenetic mechanisms mediating the effect of temperatureat the cellular and organism level. In this study, we investigated genome-wide DNA methylation in blood samples collected from 5 bulls of the heat stress resilient Nellore breed and 5 bulls of the Angus that are more heat stress susceptible, exposed to the sun and high temperature-high humidity during the summer season of the Brazilian South-East region. The methylomes were analyzed during and after the exposure by Reduced Representation Bisulfite Sequencing, which provided genome-wide single-base resolution methylation profiles. Significant methylation changes between stressful and recovery periods were observed in 822 genes. Among these, 352 were only seen in Angus, 367 were specific to Nellore, and 103 showed significant changes in methylation patterns in both breeds. KEGG and Gene Ontology (GO) enrichment analyses showed that responses were breed-specific. Interestingly, in Nellore significant genes and pathways were mainly involved in stress responses and cellular defense and were undermethylated during heat stress. Whereas in Angus the response was less focused. These preliminary results suggest that heat challenge induces changes in methylation patterns in specific loci, which should be further scrutinized to assess their role in heat tolerance.
Project description:This study aimed to investigate the heat tolerance and inheritance patterns of leukocyte transcriptomics in F1 hybrid cattle (AN♂ × DR♀) and their parents Red Angus (AN) and Droughtmaster (DR) under heat stress.
Project description:Using whole-genome bisulfite sequencing (WGBS), we profiled the DNA methylome of cattle sperms through comparison with three bovine somatic tissues (mammary grand, brain and blood). Large differences between cattle sperms and somatic tissues were observed in the methylation patterns.
Project description:Copy number variations (CNVs) have been demonstrated as crucial substrates for evolution, adaptation and breed formation. Chinese indigenous cattle breeds exhibit a broad geographical distribution and diverse environmental adaptability. Here, we analyzed the population structure and adaptation to high altitude of Chinese indigenous cattle based on genome-wide CNVs derived from the high-density BovineHD SNP array. We successfully detected the genome-wide CNVs of 318 individuals from 24 Chinese indigenous cattle breeds and 37 yaks as outgroups. A total of 5,818 autosomal CNV regions (683 bp - 4,477,860 bp in size), covering ~14.34% of the bovine genome (UMD3.1), were identified, showing abundant CNV resources. Neighbor-joining clustering, principal component analysis (PCA), and population admixture analysis based on these CNVs support that most Chinese cattle breeds are hybrids of Bos taurus taurus (hereinafter to be referred as Bos taurus) and Bos taurus indicus (Bos indicus). The distribution patterns of the CNVs could to some extent be related to the geographical backgrounds of the habitat of the breeds, and admixture among cattle breeds from different districts. We analyzed the selective signatures of CNVs positively involved in high-altitude adaptation using pairwise Fst analysis within breeds with a strong Bos taurus background (taurine-type breeds) and within Bos taurus×Bos indicus hybrids, respectively. CNV-overlapping genes with strong selection signatures (at top 0.5% of Fst value), including LETM1 (Fst = 0.490), TXNRD2 (Fst=0.440) and STUB1 (Fst=0.420) within taurine-type breeds, and NOXA1 (Fst = 0.233), RUVBL1 (Fst=0.222) and SLC4A3 (Fst=0.154) within hybrids, were potentially involved in the adaptation to hypoxia. Thus, we provide a new profile of population structure from the CNV aspects of Chinese indigenous cattle and new insights into high-altitude adaptation in cattle.
Project description:Creatine pyruvate (CrPyr) is a new multifunctional nutrient that can provide both pyruvate and creatine. It has been shown to relieve the heat stress of beef cattle by improving antioxidant activity and rumen microbial protein synthesis, but the mechanism of CrPyr influencing rumen fermentation remains unclear. This study aimed to use metaproteomics technologies to investigate the bacterial protein function in rumen fluid samples taken from heat-stressed beef cattle treated with or without 60 g/d CrPyr.
Project description:Enhancing climate resilience and sustainable production for animals in harsh environments are important goals for the livestock industry given the predicted impacts of climate change. Rapid adaptation to extreme climatic conditions has already been imposed on livestock species, including those exported after Columbus’ arrival in the Americas. We compared the methylomes of two Creole cattle breeds living in tropical environments with their putative Spanish ancestors to understand the epigenetic mechanisms underlying rapid adaptation of a domestic species to a new and more physiologically challenging environment. Reduced representation bisulfite sequencing (RRBS) was used to assess differences in methylation in Creole and Spanish samples and revealed 334 differentially methylated regions (DMRs) using high stringency parameters (p-value < 0.01, 4 CpGs within a distance of 200 bp, mean methylation difference > 25%), annotated to 263 unique features. Gene ontology analysis revealed candidates involved in tropical adaptation processes, including genes differentially hyper- or hypomethylated above 80% in Creole samples displaying biological functions related to immune response (IRF6, PRGDR, FAM19A5, PRLYRP1), nervous system (GBX2, NKX2-8, RPGR), energy management (BTD), heat resistance (CYB561) and skin and coat attributes (LGR6). Our results entail that major environmental changes imposed on Creole cattle has had an impact on their methylomes measurable today, which affects genes implicated in important pathways for adaptation. Although further work is needed, this first characterization of methylation patterns driven by profound environmental change provides a valuable pointer for the identification of biomarkers of resilience for improved cattle performance and welfare under predicted climatic change models.
Project description:This study aims to use omics data to understand the genetic pathways involved in heat stress adaptation. Heat stress is one of the main limiting performance factors in the pig industry, and its importance is expected to grow with the consequences of warming climate. Different solutions to temper the influence of heat stress on the performance and well-being of pigs have been studied, and the genetic selection appear as a potential solution. Genetic mechanisms behind heat tolerance are still not well understood, but some differences between breeds have been shown, as well as an interaction between genetic and environment.
Project description:This study aims to use omics data to understand the genetic pathways involved in heat stress adaptation. Heat stress is one of the main limiting performance factors in the pig industry, and its importance is expected to grow with the consequences of warming climate. Different solutions to temper the influence of heat stress on the performance and well-being of pigs have been studied, and the genetic selection appear as a potential solution. Genetic mechanisms behind heat tolerance are still not well understood, but some differences between breeds have been shown, as well as an interaction between genetic and environment.