Table 2.
Putative biomarkers for experienced stress or stress susceptibility in livestock obtained by different omics approaches.
| Omics Type | Molecule Type | Molecule Name | Biofluid/Tissue | Description | Reference |
|---|---|---|---|---|---|
| epigenomics | DNA methylation | BCL-2 and RORA PPIEL |
postmortem brains and peripheral blood cells | hypermethylation of BCL-2 and RORA genes in patients with autism; hypomethylation of PPIEL in bipolar disorder; hypermethylation of genes involved in brain development and tryptophan metabolism |
[78] |
| DNA methylation | HTR1A, S-COMT, BDNF1 HTR1E, COMTD1 and MB-COMT |
peripheral blood cells | peripheral epigenetic biomarkers of schizophrenia; hypermethylation of HTR1A, S-COMT, BDNF 1 hypomethylation of HTR1E, COMTD1 and MB-COMT |
[79] | |
| DNA methylation | VWF and LRRC32 | hippocampus | reduced cognition in pigs in response to early life environmental insults (infection with porcine reproductive and respiratory syndrome virus) is associated with differential methylation and differential gene expression. VWF and LRRC32 are implicated in blood brain barrier permeability and regulatory T-cell activation, respectively. | [73] | |
| transcriptomics | miRNA | miR-24-2-5p, miR-27a-3p, miR-30e-5p, miR-3590-3p, miR-362-3p, and miR-532-5p |
blood | pre-challenge circulating miRNAs reflect resilience or vulnerability to chronic social defeat in rats |
[74] |
| miRNA | mir-132 | diverse tissues and fluids | associated with post-traumatic stress disorder in humans and animal models in a systematic review; lack of specificity | [75] | |
| miRNA | miR-19b, miR-27b, and miR-365 | saliva | concentrations greater in pigs that received no anti-inflammatory treatment after tail docking than in pigs that received treatment | [76] | |
| miRNA | range of circulating extra-cellular miRNAs | plasma | after feed deprivation in chicken lines selected for high and low residual feed intake, 23 and 19 miRNAs were found to be differentially expressed between feeding conditions and lines (indicating influence of genetic background), respectively. | [80] | |
| miRNA | range of circulating extra-cellular miRNAs | plasma | miRNA profiles were different between age classes (26 miRNAs) and lines (5 miRNAs) in dairy cattle. Three miRNAs negatively associated with telomere length, but positively with milk fat yield, mastitis and lameness. | [81] | |
| mRNA | profile | dorsal root ganglia | 3000 genes were differentially regulated between docked and undocked pigs | [56] | |
| mRNA | Pyruvate dehydrogenase (PDK4), heat shock (e.g. HSPB1) and oxidative (e.g. COX1) genes | longissimus dorsi muscle | up-regulated in the muscle of pigs under heat stress, reflecting the transition from glycolysis to fatty acid oxidation during chronic exposure to HS | [53] | |
| mRNA | profile | liver | A list of genes dose-dependently regulated by glucocorticoids as biomarkers of stress action | [82] | |
| proteomics | APP | Pig Major Acute Phase protein | serum | 7-fold increase in pigs after road transport | [58] |
| protein | GRP94 | liver | of critical importance at the onset of innate immune response, in pigs under HS. induces an inflammatory response, causing hepatocytes to synthesise haptoglobin (HP) and α-1-antichymotrypsin 2 precursor (SERPINA3) to maintain cell integrity. | [54] | |
| protein | lactate dehydrogenase (LDH) | saliva | significantly increased in the saliva of pigs restrained with a nose snare and in pigs with lameness. (LDH follows adrenaline production) | [57] | |
| protein | haptoglobin protegrin-3 and galectin-1 β-actin |
blood serum | transition of sows from group to individual confined housing caused increase; indicates activation of immune defence and cell damage; indicates synthesis of stress-response hormones | [47] | |
| metabolomics | metabolite | 4,8-dimetil-nonanoyl carnitine | mesenteric adipose tissue | accumulation of 4,8-dimetil-nonanoyl carnitine, an intermediary of fatty acid oxidation, in this tissue of heat stressed pigs | [55] |