1: Understanding Coat Colour Inheritance
Do you want to know why some Italian Greyhounds are blue, some fawn,
and some black or red, but you freak out as soon as genetics, alleles, A ay d D recessives etc. are mentioned! Well here it is made easy - well, made easier I hope. For these purposes I am not going to be strictly scientific as I should be using the term allele
to denote an alternative form of the gene and using the correct letters for the genetic code. These can be found at the end of the article if you make it that far! You know that you are half your mother and half your father. This is because you inherit one
gene from each parent. All genes come in pairs just like Levis! What you see on the outside is called your phenotype. What you inherit but may not be visible is called your genotype. There are basically two genes for coat colour in IGs. And there is one gene
which modifies the coat colour called the dilute gene. The gene which gives the black coat colour we shall signify by the letters BL The gene which gives the red coat colour we shall signify by the letters rd
The gene which dilutes BLACK to BLUE and red to fawn we shall signify by the letters dil
The gene which does not affect coat colour is the NON DILUTE gene which we shall signify by the letters ND You will notice that BL
and ND are in capital letters And rd and dil are in lower case letters. The reason that BL is in capitals is to show that it is it is a dominant gene.
ND is also a dominant gene. rd and dil are both recessive genes. What does Dominant and Recessive mean? Well it doesn't
mean that one is more likely to be inherited than the other - a common mistaken belief. It simply means that if your IG inherits one dominant gene from one parent and one recessive gene from the other it is the dominant gene that will give the visible coat
One gene from each parent will be for coat colour the other will determine whether the coat will be diluted or NOT DILUTED
dil is a Clear Blue Bitch BLrdND dil is
a seal/black Possible gene combinations their puppies may inherit: 1. BL (from dad) BL (from mum) dil (from dad) ND (from mum) -Black
2. BL (from dad) rd (from mum) dil (from dad) dil (from mum) - Blue
3. BL (from dad) BL (from mum) dil
(from dad) dil (from mum) - Blue
4. BL (from dad) rd
(from mum) dil (from dad ) ND (from mum) - Seal You will see how we got to the colour when you read on.
Examples of colour genetics
- Jack is a BLBLND ND . He has inherited dominant genes from both his parents. He will be BLACK. Because he has all dominant genes all his offspring will be black too as
he can only give them BL for colour and ND for non dilute irrespective of the colour of the mother. This is called a Clear Black. What you see in his coat colour is what he will pass to his offspring.
- James is a BLrdND dil
. He has inherited a mixture of both dominant and recessive genes He will also be BLACK or possibly Seal - but he could pass on his recessive genes to his offspring and depending on the genotype of his mate could produce BLACKS,
BLUESreds or fawns! Unlike Jack his phenotype and genotype are different. That is, what you see is not necessarily what
you will get!
- Jeremy is a BLBLdil dil
. He has inherited the dominant BLACK gene but no dominant ND gene so the dil genes have a chance to work their magic. He will be BLUE. He can only pass on his dominant colour gene and his dil gene so all his offspring will be either BLUE or possibly BLACK
if his mate passes on a ND gene to prevent colour dilution or seal if his mate passes on an rd as well as an ND . He
is known as a Clear Blue. He cannot produce reds or fawns as his dominant BL genes will always overcome the rd gene that gives the red
or fawn coat. N.B. Clear Blacks and Blues are relatively uncommon.
- Justin is BLrddil dil . He will have the diluted coat colour and although he has the rd gene
his BL gene will be dominant. He will also be BLUE but unlike Jack and Jeremy but just like James his phenotype and his genotype are different.
- Jazz is a rdrdND ND .
He has inherited only the recessive red gene and only the dominant non dilute gene. He will be red. His offspring will either be rd or BLACK as his
non dilute gene will prevent dilution of coat colour whatever the genotype of his mate.
- Jonathon is a rdrddil dil . He has inherited only recessive genes. He will be fawn. His offspring
can only inherit recessive genes from him and depending on the genotype of his mate he can produce any colour as a mate with dominant genes will always overcome his.
fawns mated to fawns will always produce fawns. fawns
mated to BLUE can only produce dilutes i.e. fawns or BLUE There are two other variations: BLBLND dil - is a BLACK dog who could pass on his dilute gene. rdrd
ND dil - is a red dog who also has a dilute gene which could be passed on to his offspring.
O.K. so far but how can you tell a red fawn, if you don't know it's parentage from a red? If you know it's parentage you will know that the parents are either fawn
or BLUE i.e .dilutes. Genetically true reds will have black noses and eye rims. You may think your red fawn has a black nose but closer inspection will reveal it isn't truly black. Although it might be a little
tricky to see, the nose on the red fawn in photograph is not black - and that's not due to the result of the camera flash. Paler fawns often have lilac/ light brown noses to match their coat colour. These are colour true pictures
It would appear that BL can be affected by rd in some dogs. Many of us have had litters that
contain deep blues and mucky blues, some verging on the pale chocolate. Hence dogs which have the dominant BL gene and the recessive rd gene can be either a deep blue or a blue fawn in the presence
of two dil genes or a black or a seal in the presence of an ND gene. Possible seals; BLrdND
dil ( which is the same genetic code as James ) or BLrdND ND
Possible blue /fawns BLrddil dil ( which is the same genetic code as Justin )
- 1. Let's mate
James ( lucky dog ) who is BLrdND dil to a beautiful fawn
lady who must be rdrddil dil What possible basic colours might the puppies
- Now Justin who is BLrddil dil meets the same lady next year. What possible colours will this mating produce?
- The following year
it's Jazz's turn. He is rdrdND ND What possible colours will their puppies
be? Now we have a mating that has produced these puppies. All we know is that the dog is blue and the bitch is pied red/white
From the colour of these puppies can you work out the genetic codes for sire and dam?
There is one BLUE,
two fawns, one red and one seal. All answers please to our e- mail address. If you would like to know the correct letters for the genetic codes here
they are; BL = A - this stands for the Agouti black gene rd = ay - this stands for the sable gene* ND = D - this is letter for the non dilute gene
dil = d - is the letter for the dilution gene Strictly speaking we REALLY should be using the term allele instead of gene as it is an alternative form of a gene but....we don't want to confuse you any more!
- Italian Greyhounds do not have the true red coat of say the red setter which is the e gene. Instead they have black tips to the red hair hence it is
called the sable gene.