Veteran Queensland trainer Douglas Gladman investigates the colour of greyhounds:
It would be impossible to understand the reason for colors in greyhound pups without some knowledge of:
- The role of a chromosome in a greyhound:
Chromosomes are tiny thread like structure within the body of all living things. There are 39 of these in a greyhound and they a re responsible for the pups acquiring the individual traits of their parents.
When mating occurs a gene from each parent will attach itself to the chromosome of the pup. One of these genes will dominate the other and the other will stay in the body as a recessive gene. It will occur in all 39 chromosomes and make up all inherited traits of the greyhound.
However for the purpose of this presentation we will concentrate only on genes affecting color.
- Mendel’s theory of genetics:
Anyone who contemplates breeding in any form should avail themselves of the principles of Mendel’s theory of inheritance. Gregor Mendel was an Austrian monk who founded genetics with his work with pea plants in 1865. He was growing tall peas and short peas and tried to cross breed these pea plant’s to attain a medium sized pea plant. To his dismay all plants remained tall. Only when he crossed the plants he had already crossed with each other, he attained an average of four tall and one short. This occurred because mathematically once in every 4 times a recessive (short) gene from each parent would attach to the chromosome.
It should be noted that the one in four is an across-the-board average and would not necessarily occur in order within each litter of the four pups born.
In order to apply Mendel’s theory to the color of pups it would be necessary to ascertain the order of dominance of colors and the relevant genes.
They are in order of dominance:
- Black
- Dun
- Blue
- Brindle
- Fawn.
Black is the most dominate, of all colors, and when a black gene attaches to the chromosome three out of four of the pups will be black (Mendel’s theory). One in four pups could be any colour (dependent on the color of the recessive gene). However, if the recessive gene on the chromosome is also black, all pups will be black (without exception).
Dun is a rare chocolate or liver colour, and estimated to occur once in every 2500 litters.
Blue, when mated to a blue, brindle, or fawn partner will breed only blue, brindle, or fawn pups as a black gene is obviously not present in either parent.
Brindle As with the blue, when mated with a partner lower in dominance, i.e. (fawn) the progeny have to be either brindle or fawn.
Fawn, when mated to a fawn partner, all pups would be fawn. As it is at lowest point of dominance, no other color gene is present on the chromosome.
White. White is not a colour and is in fact an absence of color.
There Is no white gene in a greyhound. Therefore it could never be on the chromosome in any form. However somewhere on the white greyhound will be a patch or stripe of colour, sometimes in a very minute form. This colour will be the dominant colour gene of that greyhound. The greyhound will also have a recessive colour gene.
Whilst white can be used for registration, genetically it exists only as an original absence of colour.
This presentation should not be confused with deoxyribonucleic acid (DNA), which contains unique characteristics of the greyhound, which are passed on and remain unchangeable.
It is pertinent to note that all of the 39 chromosomes in a greyhound are subject to Mendel’s theory. This means that without genetic engineering or cloning, it would be difficult to breed pups that have totally identical traits, including performance. This however, is often influenced by the performance of the recessive gene.
Whilst Mendel had only 12 chromosomes in his peas, by comparison a human has 23 chromosomes, and a greyhound 39.
(About the author: Douglas Gladman has researched and presented a number of papers at forums around Australia and overseas.
He has worked in a number of environments including, anti-social behavior, as well as a number of health issues in disadvantaged groups, including domestic violence in indigenous communities, and children with special needs.
His research in 1997, titled “A study of injury in five cape York communities”, achieved world-wide acclaim, and is currently housed in the archives of the national library in Canberra.
In 2015 he was responsible for bringing awareness to the greyhound industry that greyhounds were colour blind to orange, red and green. He showed that these colors were simply grey to a greyhound. It clearly indicated that a red, or orange lure on a green grass track was all grey to the dog and also that a red, green or orange lure on a grey loam track was also difficult for the greyhound to see.
He has retained a lifetime interest in genetics and in 1994 whilst teaching agricultural science at a tertiary level, coordinated his students to work with the CSIRO in the genetic engineering of cotton plants to attain heliothis moth resistance).