Genetics Flashcards
Why study genetics?
Svartberg and Forkman (2002) support harmonious dog-human partnership
Gazit & Terkel (2003) enhancing abilities of service dogs important for human health
improve welfare
resolve behavioural problems
production traits
Identifying a genetic component
Indirect- sex/breed differences
Direct- calculation of h2
Svartberg (2006)
show dogs bred for looks increase in aggressiveness
McCune (1995)
paternity influences kitten friendliness- friendly fathers produce friendly kittens even when controlled for environment
Important behaviours for cattle
reaction to confinement temperament (safety, handling efficiency) milking temperament feeding behaviours exit from holding area selected for calmness
Scott & Fuller (1965) single gene
barking and struggling demonstrated simple dominant allels in basenji and cocker spaniel
Ilska et al (2017)
h2 of behaviours in labradors all very low
TH gene
close to SNP associated with aggression
TH linked to activity and inattention
Llinamo et al (2007) h2 in dogs for aggression
human- 0.77
dog- 0.81
correlation between these was 0.4
however they used similar litters and kept in similar environments
Staiger et al (2016) horses
anxious, tractable, agnostic, excitable explained 64% of trait variance- strong genetic component
Mills & Redgate horses
predisposition for crib biting, weaving and stall walking
D’Earth et al (2010)
low h2 for lots of behaviours
If not one gene then how?
linkage modern gene tech knock out studies GWAS QTL
Coat colour in cats
black= amicable
orange= aggressive
red/cream/tortoiseshell= less dosile
colour pigments produced by same chemical pathways as some NTs
Wilhelmy et al (2016) found No relationship
Jacobs et al (2016) horses
coat colour may impact behaviour
black mares more self reliant
Bovine neuroreceptor 5 gene (NYPSR)
linked to appetite and feeding
Melanocortin 4 receptor gene (MC4R)
food intake capacity
Epigenetics
DNA methylation changes activity without changing sequence
reversible
therapeutic applications
EG rats licking pups- silencing epigenetic makers on glucocorticoid receptors
licking removes silencing marker thus turns on and enhances future stress coping
Dovc et al (2009) developed a cattle database of gene and genetic markers for milk production
contains 943 genes and genetic markers involved in mammary gland development
44 genes found by multiple independent analysese were suggested as most promising candidates
Sun et al (2013) 14 new genes for meat quality in chicken using GWAS
included genes linked to meat colour brightness and intramuscular fat content in breast muscle
The NHGRI dog genome project
Ostrander’s lab at NIH
Working to find DNA variants associated with disease and reduce their occurence
Suggest since dieases are similar to those of humans likely to provide insight into human research as well
Pritchard et al (1994) physiological influence on benefits of exercise in dogs
- Exercise can provide stimulus for increased production of endothelium relaxing factor (EDRF) and nitric oxide mediated epicardial coronary artery dilation
- Contributing to beneficial effects of exercise on the cardiovascular system
- Gene associated with this is ECNOS and they found mRNA levels for ECNOS significantly higher in exercised dogs
Corbet & Burrow (2000) beef cattle
found low h2 for slight speed in zebu-derived beef cattle
Lim et al (2004) showed enhancing
gene for vassopressin V1a receptor (V1aR) enhances partner preference formation in meadow vole
Although not companion animals, they show that change in expression of a single gene can profoundly alter social behaviour
Ronai et al (2017) linked DRD4 gene to activity-impulsivity in dogs
police german shepherd with at least one 2a allele showed signif. higher scores on A-I dimension of dog ADHD rating scale
Campbell & Marchant (2018) use of chemogenetics in behavioural neuroscience
- Increase in neuroscience technologies allows precise manipulation of neural circuits in awake, behaving animals- can look at the way neural circuit influence behaviour
- Chemogenetics= allows for reversible remote control of specific cell pops/neural circuitry by injection/ micro-infusion
Craft et al (2018)
integration of contact networks and genomic approaches useful
Allows answering complicated Qs about animal behaviour and pathogen transmission
Thompson et al (2017) epigenetic ageing clock in dogs
- DNA methylation represents a form of genome modification that regulates gene expression
- Assessed blood DNA methylations and found age related DNA methylation changes in canids similar to that of humans
- Suggesting this epigenetic mechanism associated with age is an evolutionary conserved mechanism
