Genetic variation in monoamine oxidase A and analysis of association with behaviour traits in beef cattle

Behavioural Traits in Bos taurus Cattle, Their Heritability, Potential Genetic Markers, and Associations with Production Traits

Simple Summary

Cattle have the potential to seriously injure humans and cause damage to property. The risk of cattle reacting in a dangerous manner can be reduced through genetic selection for cattle which have a better temperament. A literature search was undertaken which returned papers which met the criteria of “Bovine”, “Genetics” and “Behaviour” or terms therein. Behavioural traits were grouped and their heritability, genomic associations and correlations with production traits examined. It was found that heritability estimates were more accurate in studies with large populations (n > 1000). Gene associations with behavioural traits were found on all chromosomes except for chromosome 13, with associated SNPs reported on all chromosomes except 5, 13, 17, 18 and 23. Generally, it was found that correlations between behaviour and production traits were low or negligible, suggesting that genetic improvement can be undertaken without negatively affecting production. There was variation between the results of the studies examined, and this underlines that any genetic study is population specific. Thus, to assess the heritability, genetic associations with production and genomic areas of interest for behavioural traits, a large-scale study of the population of interest would be required.

Abstract

People who work with cattle are at severe risk of serious injury due to the size and strength of the cattle. This risk can be minimised by breeding less dangerous cattle, which have a more favourable reaction to humans. This study provides a systematic review of literature pertaining to cattle genetics relating to behaviour. The review protocol was developed using the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) framework, with Population, Exposure and Outcome components identified as Bovine, Genetics and Behaviour respectively. Forty-nine studies were identified in the sifting and assigned non-exclusively to groups of heritability (22), genomic associations (13) and production traits related to behaviour (24). Behavioural traits were clustered into the following groups: “temperament, disposition and/ or docility”, “aggression”, “chute score”, “flight speed”, “milking temperament”, “non-restrained methods” and “restrained methods”. Fourteen papers reported high accuracy (Standard Error ≤ 0.05) estimates of heritability, the majority (n = 12) of these studies measured over 1000 animals. The heritability estimates were found to vary between studies. Gene associations with behavioural traits were found on all chromosomes except for chromosome 13, with associated SNPs reported on all chromosomes except 5, 13, 17, 18 and 23. Generally, it was found that correlations between behaviour and production traits were low or negligible. These studies suggest that additive improvement of behavioural traits in cattle is possible and would not negatively impact performance. However, the variation between studies demonstrates that the genetic relationships are population specific. Thus, to assess the heritability, genetic associations with production and genomic areas of interest for behavioural traits, a large-scale study of the population of interest would be required.

Aggressive behavior in cattle is associated with a polymorphism in the MAOA gene promoter

Molecular mechanisms underlying aggressive behavior are primitive and similar among the subphylum Vertebrata. In humans, a primary goal in the study of aggression is to determine the neurobehavioral molecular factors triggering violence. Although several species have been used to study agonistic responses, researchers are limited by the difficulty of artificially inducing aggression in animals not selected for it. Conversely, the Lidia cattle breed has been selected since the eighteenth century to display agonistic responses based on traits such as aggressiveness, ferocity and mobility, all of them showing significant heritability values. This intensive selection may have driven shifts in specific allele frequencies. In a previous analysis across the autosomes, we revealed long-term selection regions including genes involved in behavioral development. In the present study, we focus on mapping recent signatures of selection associated with aggressiveness at chromosome X, by comparing Lidia cattle samples with two non-specialized Spanish breeds showing tamed behavior. The most significant markers peaked around the monoamine oxidase A (MAOA) gene, and thus the associations of three functionally important regions located near the promoter of this gene were further investigated. A polymorphism consisting of a variable number of tandem repeats of the nucleotide 'C' (BTX:105,462,494) and displaying lower number of repetitions in the Lidia breed when compared with the tamed breeds was detected. In silico analyses predicted that the g.105,462,494delsinsC variant may code for the Sp1 binding motif, one of the major transcription factors controlling the core promoter and expression of the MAOA gene in humans.

Sex, age, or genetic differences related to play behaviors in Japanese Black calves

Play behavior in young animals has been used to evaluate the condition (health) of livestock. We investigated age, sex, and genetic differences of Japanese Black calves in relation to frequency of play behaviors (galloping, leaping, turning, bucking, head butting objects, and head shaking) and examined how these relationships might affect growth during the suckling stage. Locomotor play behaviors (galloping, leaping, turning, and bucking) and head butting objects gradually declined with the age for both sexes. The frequency of head butting was significantly higher in males than females. We found that significant interaction effects (age × MAOA polymorphism) in play behaviors (except head shaking) and the frequencies of locomotor play in calves without the wild-type allele were significantly higher than those in younger calves (2 and 6 weeks of age). Weight gain was significantly correlated with the frequency of locomotor play in females, but not in males. This study suggests that play in Japanese Black calves gradually declines as they mature and that play may be controlled by variations in the MAOA gene. In addition, the frequency of locomotor play may be an indicator of health in female calves.

Early differential gene expression in beef Longissimus thoracis muscles from carcasses with normal (<5.8) and high (>5.9) ultimate pH

The objective of this study was to investigate early postmortem (0.5 h) gene expression in beef Longissimus thoracis (LT) muscles from carcasses with NORMAL (<5.8) and HIGH (>5.9) ultimate pH (pH_u). A total of 53 transcripts were differentially expressed (P-value <.05): 40 showed up-regulation and 13 showed down-regulation in HIGH pH_u carcasses. Four up-regulated (PDK4, GADD45B, MAOA, METTL21C) genes were confirmed (P < .05) by q-PCR. HIGH pH_u samples resulted with lower values in glycolytic potential and AMP-activated protein kinase activity compared to NORMAL at 0.5 and 24 h postmortem (P < .05). Functional pathway analysis showed that calcium transport and GADD45 signaling pathways are associated with the development of HIGH pH meat. Genes involved in stress-related signaling, such as GADD45B, METTL21C and MAOA were overexpressed. These genes are involved in stress signaling that might be affecting Ca²⁺ transport and oxidative metabolism pathways in HIGH pH muscles.

Association of SNPs in dopamine and serotonin pathway genes and their interacting genes with temperament traits in Charolais cows

Cattle temperament is a complex trait, and molecular studies aimed at defining this trait are scarce. We used an interaction networks approach to identify new genes (interacting genes) and to estimate their effects and those of 19 dopamine- and serotonin-related genes on the temperament traits of Charolais cattle. The genes proopiomelanocortin (POMC), neuropeptide Y (NPY), solute carrier family 18, member 2 (SLC18A2) and FBJ murine osteosarcoma viral oncogene homologue (FOSFBJ) were identified as new candidates. Their potential to be associated with temperament was estimated according to their reported biological activities, which included interactions with neural activity, receptor function, targeting or synthesis of neurotransmitters and association with behaviour. Pen score (PS) and exit velocity (EV) measures were determined from 412 Charolais cows to calculate their temperament score (TS). Based on the TS, calm (n = 55; TS, 1.09 ± 0.33) and temperamental (n = 58; TS, 2.27 ± 0.639) cows were selected and genotyped using a 248 single-nucleotide variation (SNV) panel. Of the 248 variations in the panel, only 151 were confirmed to be polymorphic (single-nucleotide polymorphisms; SNPs) in the tested population. Single-marker association analyses between genotypes and temperament measures (EV, PS and/or TS) indicated significant associations of six SNPs from four candidate genes. The markers rs109576799 and rs43696138, located in the DRD3 and HTR2A genes, respectively, were significantly associated with both EV and TS traits. Four markers, rs110365063 and rs137756569 from the POMC gene and rs110365063 and rs135155082 located in SLC18A2 and DRD2, respectively, were associated with PS. The variant rs110365063 located in bovine SLC18A2 causes a change in the amino acid sequence from Ala to Thr. Further studies are needed to confirm the association of genetic profile with cattle temperament; however, our study represents important progress in understanding the regulation of cattle temperament by different genes with divergent functions.

Genetics of cattle temperament and its impact on livestock production and breeding – a review

Abstract. Cattle temperament, which describes individual behaviour differences with regard to a stressor or environmental challenge, is known for its impact on working safety, adaptability to new housing conditions, animal productivity and for evaluation of animal welfare. However, successful use of temperament in animal breeding and husbandry to improve keeping conditions in general or animal welfare in particular, requires the availability of informative and reproducible phenotypes and knowledge about the genetic modulation of these traits. However, the knowledge about genetic influences on cattle temperament is still limited. In this review, an outline is given for the interdependence between production systems and temperament as well as for the phenotyping of cattle temperament based on both behaviour tests and observations of behaviour under production conditions. In addition, the use of temperament as a selection criterion is discussed.