The Colour Black
Skunk Deodorizing Recipe
The Colours of The
(The Genetic Transmission)
by Pierre Willems
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I AM NOT A GENETICIST!.... but
I am very curious, and as we, poor Frenchmen, dispose of very few popularizing literature
about the subject, a few years ago, being unable to find someone who could help me with
the mystery of colour inheritance, I undertook an investigation in the works of some
writers in your language, and after a lot of reading and investigations, I wrote an
article about the subject, that has been printed - in French, of course - in the Club de
l'Epagneul Breton magazine in 1991.
Since then I went on investigating ... and, as I believe many of you have as little
knowledge as I had, I hope that this article will help you understand how things work for
our specific breed.
Before starting to "teach", a few words more:
For those who do not know yet, the French standard admits five colours, with or without
Orange and white (OW)
Black and white (BW)
Liver and white (LW)
Tricolour black (Black + white + orange: BT)
Tricolour liver (Liver + white + orange: LT)
It is impossible to try and explain genetic transmission without some preliminaries. Even
avoiding the technical or trying not to take myself for a scientist, a minimum of
knowledge is indispensable:
Any dog of any breed, even mongrels, possess the entire panel of the genes existing in the
species. Whether it is physically visible or not in a specific dog is another question,
but the fact that a gene is not physically visible does not mean that it is not present!
Most of the visible characteristics of a dog (the "phenotype") are under
the influence of genes, present in the chromosomes, and so inherited from the parents.
Some are not as they depend much of the way the dog is raised: weight, coat thickness,
occasionally also height, musculature, etc. ....
Genes are always present in pairs, one of the elements of the pair coming from the father,
the other one from the mother, due to the division of the cell at the time the embryo is
created. To give a rough example: If the father's genes are imaged by "PP", and
the mother's genes by "MM", the offspring will carry "PM" genes.
Those genes may exist as several varieties (the alleles) for a same gene, whose
influence varies accordingly in its effect as well as strength. We distinguish DOMINANT
genes, and RECESSIVE ones. (This notion of genetic dominance must not be confused with the
"dominance" of a temperament. "Dominance" is a word for the
genetician, white "domination" involves social characteristics). By convention,
a dominant gene is designated by a capital letter, white a recessive gene is designated by
a small letter.
The existence of a dominant gene is ALWAYS evident, visible; people say that the
gene is expressed. Even if the pair of genes consist for one half by a recessive, and for
the other half by a dominant, it is only the latter that will be in evidence, and not some
intermediate between the two genes! On the contrary, for a recessive gene to be expressed,
this one will have to be present in double ("homozygous"). In short:
Dominant + dominant = evidence of the
Dominant + recessive = evidence of the dominant;
Recessive + recessive = evidence of the recessive.
1. THE "B" GENE (the Black
This is the gene that
gives the black colour, and also the liver one! Both colours are due to the same
pigment (eumelanin) and the size of its particles determines whether it is seen as black
or liver. The gene for black is designated by "B" (=dominant), while the one for
liver is designated by "b" (=recessive). If we have parents ... father=BB
(=black) ... mother = bb (=liver), all their offspring will be uniformly "Bb".
As we explained above, the dominant gene
masks the expression of the recessive, so this first generation offspring will be
uniformly black, all the puppies carrying a "Bb" gene sequence.
If we mated the first generation pups to each other, the offspring in this second
generation would each show one of these combinations:
Bb + Bb = BB
which is black (homozygous)
Bb + Bb = Bb which is
black too (heterozygous)
Bb + Bb = equivalent to the above line
Bb + Bb = bb which is liver (homozygous)
BB and Bb are "phenotypes" (physically black but there is no guarantee of the
genetic combination), while "bb" is a "genotype" (liver is ALWAYS
and ONLY of "bb" type).
Also it should be noted that, statistically, a mating as above (Bb+Bb) will produce 75%
black coated offspring, and 25% liver. However, on a small amount of offspring, it may not
be true, of course! (For another characteristic - tricolour - when I bred together a dog
and a bitch both carrying the tri gene, I had to wait until their third liter to obtain
Hard to understand? Sorry, but if you did not follow, please read again, otherwise the
next steps will be unintelligible.
2. THE "A" GENE (the Agouti series)
There are several forms
of this gene, several "alleles", but we are fortunate in that our breed only
involves two of them: "As" and "at". (Although one expert thinks there
is a possibility for a third allele for "A" in the brittany. Despite my
investigations, I could not find any evidence of this theory, while my conclusions
appeared to be correct, after a check on about 500 brittanys!)
"As" which is
dominant, gives solid colours, while "at", which is recessive, involves the
"tan point" that gives the ticking at the end of the legs, around the anus, on
the eyebrows, and on the cheeks. In short, it qualifies our tricolour dogs, while the
"As" gene concerns the non-tri's.
As seen before, the combination of the two genes give:
As + As = ASAS = plain colour
As + at = Asat = plain colour (heterozygous)
at + at = atat = tricolour (homozygous)
Depending what the "B" gene
allows, we will obtain:
BB/AsAs = black
Bb/AsAs = black
bb/AsAs = liver
BB/Asat = black
bb/Asat = liver
BB/atat = black tricolour
Bb/atat = black tricolour
bb/atat = liver tricolour
3. THE "E" GENE (the Extension
It is the gene that
permits orange (the true name being "fawn"). Or, more exactly, the "E"
(dominant) allows the other genes in the "B" series to express themselves.
The heterozygous recessive form "ee" FORBIDS the evidence of the black (B-) or
the liver (bb) ...The "ee" form is called "epistatic" to
So, an orange and white
brittany is ALWAYS a carrier of "ee", regardless of what he may hide on the
"B" or "A" gene!! ... and so, it is obvious that a mating involving
two OW dogs will only produce OW offspring. On the reverse "other colours" will
give a variety of colour, as very often, they carry a heterozygous "E" gene.
If your "other
colours" both present an "Ee" structure, they will give you "ee"
(=OW) offspring as well as "EE" or "Ee" (=BW or LW or Tris)... and,
similarly, if mating an OW to any "other colour", provided the later is not
homozygous for "EE", as this would allow BW and LW but FORBID OW!
THE COATS OF THE BRITTANYS
We know enough now to put our dogs' coats in codes, thus allowing us to extrapolate what
colour possibilities any mating will offer:
The minimum formulae
are as follows: ("-" is conventionally used to denote that the gene is
|Orange and white
|Black and white
And it gives the following panel:
||O/W, L/W, LT
||O/W, L/W, LT
||O/W, BT, LT
||O/W, BT, LT
||O/W, L/W, LT
||O/W, BT, LT
4. WHITE, THE "S" GENE (the
The white in the coat
is not easy to understand, as our eye, and subsequently our brain, has the reflex to
"read" a combination of a colour and white as COLOUR ON WHITE, may be due to the
fact that we are used to writing with dark ink on white paper!?
Well, our dogs are not
"white + something", but "something + white".
Do not forget that the
original colour of the "wild" dog was fawn, and it is only due to mutations
along the centuries that black appeared, and then white .
existence or the absence of white IS NOT BOUNDED TO THE SURFACE OF THE COLOUR! Contrary to
what happens in painting, white is not an element of a palette that can be mixed according
to wish, and so accentuating or reducing the pigmentation. That part of white appearing on
the coat of brittanys is dependent on a gene known as "S" (for spotting) - or
"s" for the recessive alleles.
These genes can be present under four declensions:
"S+" giving a coat almost entirely colored, nearly without any white
(e.g. Labrador, Gordon setter).
"si" the "Irish" spotting (because of the origin of the rats who were
used for the study, and not because of the Irish setter!).
"sp" (p = piebald) giving a coat with irregular spotting or ticking (e.g.
cocker, English setter).
"sw" (w = white) concerns coats almost completely white, with
"invading" white spotting (e.g. Westie, Pyrenean Mountain, Dogo Argentina).
Roy Robinson, a geneticist of great reputation, classifies the different
types of spotting in ten grades as below:
"S+" (not shown)
corresponds to "0 white" with 100% coloured,
"1" to "3" corresponds to "si"
"3" to "9" corresponding to "sp"
"9" and "10" being "sw".
Remember that, in what is written above,
white areas are considered in opposition to coloured areas, disregarding any ticking,
flecking, or roan, which are under the influence of another gene that we will explain
As you will notice, the
coats showing white all depend on recessive genes...which means that, to be expressed, the
are supposed to exist in an homozygous form!...and so, if you want to breed dogs with a
lot of white, you will have to "extract" the combination "spsp" from
the parent's genes.
But here we have two
problems to face. As the standard of the brittany allows it since it exists, all this gene
capital has been mixed up along the generations, and, as the domination between the
recessive gene - though being in the order listed (i.e.: S+ - si - sp - sw) - is very
incomplete, there is no "mathematical" way to obtain a given result.
But one thing is sure: the genes "S+" and "sw" do not exist in
our breed. Being dominant, the presence of S+ would be evident in the first generation,
while "swsw" implicates white spots on the ears, eyes in a white area, such characteristics which are FORBIDDEN by the standard, and so they do
not allow brittanys in France to be confirmed. (In France, confirmation by a breed
expert is compulsory to obtain the registration of a pedigree), and so this gene should be
expelled from our breed since the very beginning of its existence!
on ears or eyes, or a coat with no white would indeed imply a crossing with another breed.
And so, it also means that, however dark your brittany's coat may be, it will always show
at the same time Colour+white without risk of deviating to "all colour" or
Of course, a good
knowledge of the appearance of your dog's parents will help you in reaching your goals!
The important thing to understand is that, once again we are not in
possession of a palette that allows us to spread the colour as the painter does!
5. THE "T" GENE (the Ticking series)
Well, we approach the
end of my attempt to explain our dogs' coats. Thank you if you followed me so far! Do not
worry, this one will be short!
Firstly, it could be
useful to remind you that ticking/flecking/and so on concerns the small spots of uniform
colour that appear in the white
parts of the coat, disregarding the true spots, of much larger size, while roan applies
only to an intimate mix of coloured hair and white hair.
The coats with ticking
are under the influence of the "T" gene which is dominant. Conversely, the coats
with no ticking are determined by the recessive allele "t", so the
"tt" type has uniform white between/around the colour spots.
It should be noted that it appears that this dominance of "T:on"tt" is not
total, and also it seems that "tt" is involved in majority of dogs of
"spsp" type, rather than "sisi" ones.
....and roan??? Well, as far as I know, experts are still guessing about the existence of
a "R" gene, or if roan is just an extreme expression of "T".. and I
will not tell you more than they do!
What must be remembered
is that ticking is independent from the extension of the coloured area, and, here too, it
is not a painter's brush spreading the ticking so much that is becomes a spot!!
You are still here?
What patience!! Thank you for having been so attentive to my words!
I hope your knowledge, or better, your understanding about the colours in our breed has
But never forget that a brittany is not just a lovely coat, as it is a working dog, with a
very balanced temper, and this is much more important to the welfare of the breed than any
References: Robinson's "Genetics for dog breeders 1982"
Willis' "Genetics of the dog 1989"
Whitney's "How to breed dogs 1971"
Pr. Denis' "Les couleurs de robe chez le chien 1982"
Printed with the express permission of P. Willems. No unauthorized use,
copying or distribution permitted.
Bill & Kathy Dillon
38548 280th Street, Armour, SD 57313