Thoroughbred genetics Flashcards
What is the period when the Thoroughbred horse is considered to have been founded?
1600s-1700s
What aspect of genetics does the sire-line track?
Y chromosome
What aspect of genetics does the dam-line track?
mitochondria
Approximately what percent of Thoroughbred horses trace their male line back to the Darley Arabian?
95%
Approximately what percent of the genes in Thoroughbred horses are descended from the Darley Arabian?
6.5%
Which is an accurate description of the modern Thoroughbred breed?
hybrid of native English horses and horses imported from the Mediterranean region
What was Cunningham’s Paradox?
Thoroughbred horses have had limited improvement in race times but the population has lots of variation measured for racing performance
Heritability of race time in Thoroughbred horses is difficult to measure because of which of the following?
there is no single trait we can identify as racing. horses race different distances, at different ages on different surfaces
Which of the following two traits resulted in discovery of the best heritability scores for racing?
log of money earned and handicapping
What was the result of GWAS studies for racing performance in Thoroughbred horses?
lots of ares of interest were identified, but different ones in different studies
Evidence was found for MSTN, PDK4 and COX412 having an impact on racing performance. Why were those particularly significant?
the evidence was confirmed by cross checking the effects in multiple tests for each one of them, sometimes confirming statistical effect by testing a second population
Bruce Lowe numbers measure…
prominent dams in pedigree
dosage measures…
intuitive judgement by using deep pedigrees of sires
nicking measures…
value of mating
Why do heritability values vary between studies?
different distances measured, different populations, different measures of performance
