Border Collies are mostly known for being black with the white markings, but in reality, they come in many colors & patterns.
To avoid confusion, you must understand some information out there is incorrect, making it impossible to understand the basics. This has caused much confusion when registering border collies due to no option for a particular coat color or pattern, so many border collies are registered under the wrong color or pattern making it difficult for the breeders & owners alike. The result is a fog of confusion.
A word about color standards, In Australia there is a stubbornness about the color and the standard only allows for Black/White, Chocolate/White, Red/White, Blue/White, Blue Merle & Black Tricolour(Black, Tan & White)...Whereas the rest of the world acknowledges all the colours a Border Collie can be... overseas registries simply state: Any color is permissible, but white shouldn't predominate, even in the UK where the Border Collie originates there standard accepts any colour.
The Colours of Border Collies that can be found around the world and are being seen more and more in Australia but not limited to are, Black/White, Chocolate/White, Blue/White, Lilac/White, ee Red/White. There are many variations and coat patterns of these basic colours, which include Sables, Tricolours, & Merles, there is also Seals
Black/White

Choc Merle

Lilac Tricolour

Choc Sable Merle

ee Red/White

Chocolate/White

Choc Merle Tricolour

Black Tricolour

Blue Merle Tricolour

Blue Merle Sable

Colour Genetics.
It is the purpose of this page to clarify the basics of colour genetics, so it is then possible to go on to more detailed knowledge. So let's have some fun together & find out what all the ruckus is about!
Guide to the Gentics Lingo
1.chromosome: The nuclear structure which houses (contains) the genetic information. Chromosomes exist in pairs and therefore there are always two copies of a given gene.
2. gene: a unit of inheritance
3. locus (-ci): the position of a gene on a chromosome. Every gene has a specific locus
4. genotype: the genetic make-up of an individual
5. phenotype: that part of the physical appearance of an organism which depends on gene action
6. homozygous: the condition when both alleles of a gene pair are identical
7. heterozygous: the condition when both alleles of a gene pair are different
8. dominant: term describing a gene which can produce a phenotype when present only once; also the phenotype which results
9. recessive: term describing a gene which must be present twice to produce a phenotype; also refers to the phenotype which results
10. wild: the "normal" phenotype
11. mutant: the non-normal phenotype; is a relative term (relative to the population from which the organism originates
Different
terms are sometimes used for the same genetic colors,
depending on breed and sometimes country too. In Border Collies, the
dilute brown, is called lilac. A dog that is genetically
'recessive red' ("e/e") is known as yellow in some breeds and
red in others. Brown is called chocolate by many and is also
referred to as red. This can be confusing.
Melanin
is the substance that gives a dog's hair its color. There
are two distinct types of melanin in the dog --- eumelanin and
phaeomelanin.
Phaeomelanin is, in its unmodified form, a yellowish color.
Melanin is produced by cells called melanocytes. These are
found in the skin, hair bulbs (from which the hairs grow) and
other places. Melanocytes within the hair follicles cause
melanin to be added to the hair as it grows. However, melanin
is not added at a constant 'rate'. At the very tip of the hair,
eumelanin production is usually most intense, resulting in
the darker tip.
A protein called the Agouti
protein has a major effect on the amount of melanin injected
into the growing hair. The Agouti protein causes a banding
effect on the hair: it causes a fairly sudden change from the
production of eumelanin (black/brown pigment) to phaeomelanin
(red/yellow pigment). An example of this coloration would be like the
color of a wild rabbit. The term 'Agouti' actually refers to a
South American rodent that exemplifies this type of hair.
The Extension Locus - E
This
refers to the extension of eumelanin over the dog's body. The
dominant form, "E", is normal extension. The recessive form,
"e", is non-extension. When a dog is homozygous for
non-extension (e/e), its coat will be entirely red/yellow
(phaeomelanin based). All dogs that have a brown (chocolate) coat will
have at least one "E" allele, because of the production of
eumelanin.
The way to tell the difference
between an Agouti red/yellow and an Extension (e/e) red/yellow
dog -- is the Agouti red/yellow almost always have some
black/brown hair in the coat (usually around the ears and tail)
and the Extension (e/e) dog won't. Another way is the Agouti
red/yellow must have at least one ("A^y") allele and can carry at most
one other agouti allele, the Extension (e/e) can carry any two
Agouti alleles (not necessarily "A^y").
DOMINANT BLACK -- "K"
The
dominant form of black: completely dominates all formation of
phaeomelanin pigment. In the past, dominant black had been
placed at the head of the Agouti series (symbol "A^s"). Now, it
has been proven to be part of a separate series, the "K"
series, and not at the Agouti locus at all.
Dominant black (K) is epistatic to whatever is found at the Agouti locus
(simply means that it causes the Agouti allele to act
differently from what it normally would), however; "e/e" is
dominant to "K" at the E
locus.
When "K" is in the dominant form, "K/K" or "K/k", there would be
no expression from the A Locus and the color is dependant on
what is at the E Locus.
When "K" is
in the homozygous recessive form "k/k", the coat color will
depend on what is located on the "E" and "A" Locus.
Dominant "K" codes for both dominant black and brindle in decreasing order of dominance:
K -- dominant black (does not allow the A Locus alleles to be expressed)
br^k -- brindle (expressed when A Locus alleles are expressed)
k -- normal (allows the A Locus alleles to be expressed)
A dog that is:
"K/K" or "K/k" -- dominant black; dominant black carrying recessive black
"K^br" -- dominant black, carrying brindle
"br^br" -- brindled
"br^k" -- brindled, carrying recessive black
"k/k" -- 'normal' (recessive black)
Brindling is
'stripes' of eumelanin-based (can be modified by the genes at the B
and D Locus, so the color could be black, blue, chocolate or
lilac) hairs in areas that are otherwise phaeomelanin based.
In order to produce the brindle color, at least one parent
MUST be a brindle. Brindle is dominant to its absence, so only
one copy is needed. If a person has a brindle colored pup
for sale and there are no brindle colors anywhere in the
pedigree, then the sire that is reported on the registration
papers --- genetically can not be the (true) sire. There is
an exception to this if the dog is "e/e" or "K", he can be a carrier
of brindle.
It is thought that the three loci E, K and A act together as follows:
If the dog is "e/e" at the E locus, and at the K
locus, it is "K", "br" or "k", its coat will be entirely
red/yellow (phaeomelanin based);
If the dog is E/E or E/e at the E locus, and at the K locus,
it is "K", its coat will be entirely dominant black (eumelanin
based) [**NOTE: the phenotypic color will depend on what is at the B, D, C and M Locus];
If
the dog is E/E or E/e at the E locus, and at the K locus, it is
"br^br" or "br^k" it will be brindled with the color of the
phaeomelanin part of the brindling affected by the Agouti
alleles present;
If the dog is E/E or E/e at
the E locus, and at the K locus, it is "k/k" the distribution
of eumelanin and phaeomelanin will be determined solely by the
Agouti alleles present.
The Agouti Locus - A
Simply, this is how the pigment is distributed on the dog's body and hair shaft.
The Agouti locus controls the formation of the Agouti protein,
that in turn is one of the mechanisms that controls the
replacement of eumelanin with phaeomelanin in the growing hair.
The alleles of the Agouti locus can affect not just whether
or not the eumelanin -- phaeomelanin shift occurs, but also
where on the dog's body this happens.
Two promoters are generally associated with the "wild type" version of the agouti gene.
- Cycling Promoter
- Ventral Promoter
The
Cycling Promoter produces a banded hair with a black tip and
yellow middle over the entire body. If only the action of this
promoter is disrupted, the hair color on the dog's back will
be black and its belly and inside of the legs will be yellow.
This produces the black and tan color.
The
Ventral Promoter dictates that there will be only yellow color in
the hair on the belly.The animal will have black banded hair on the
dorsal (back) side andpaler yellow hair on the ventral (belly)
side. If only the action of this promoter is disrupted, the
hair color on the dog will be banded over its entire body. This
is said to be solid agouti color.
If
something inactivates the agouti protein, or if both promoters are
disrupted, the animal will appear to be solid black.
If a mutation occurs at one of these Promoters, this can cause
the yellow to be expressed over most of the body.
NOTE: In part of a series on Dog Coat Color Genetics by Sheila Schmutz, she states that recent
studies show that the agouti signal peptide (ASIP) competes
with melanocyte stimulating hormone (MSH), which produces
eumelanin pigments, to bind on the melanocortin receptor and
must sometimes win. Both the E allele and Em allele are
responsive to agouti or melanocortin binding in dogs. However
dogs that are ee have a mutation in MC1R and produce only phaeomelanin.
The dog's agouti genotype doesn't affect its coat color, which
will be some shade of cream, yellow or red.
To further complicate things, agouti has 2 separate and
somewhat distant promoters. Roughly, one seems to control
ventral or belly color and the other dorsal or back color. The
simplest way to "see" this is on a black and tan dog......the
back is black from eumelanin pigment being made and the belly
is tan or red from phaeomelanin pigment being made.
The agouti gene has been mapped in the dog and DNA studies to
determine which patterns are under the control of this gene in
the dog are in progress. This gene undoubtedly has several
alleles, but how many is still an open question. Some have
been identified using DNA studies and tests for agouti
phenotypes in some breeds may become available soon. Although
several books attempt to state thedominance hierarchy of the
agouti alleles, since no breed has all the alleles, it is not possible
to know this for sure. Most books suggest that it is aw >
ay > at > a. Breeding data and DNA data from our
collaborative study with Dr. Greg Barsh's group at Stanford
supports this. However the data confirm pairwise
dominance/recessive
relationships in different families.......not the entire hierarchy in one family.
Decreasing in order of dominance: (**sable may be dominant over wolf in some breeders)
~~ "a^w", 'wolf' color -
This is like "a^y" but the tan is replaced with a pale
gray/cream color and the hairs usually have several bands of
light and dark color, not just the black tip of sable. Example
would be Keeshond, Siberian and Norwegian Elkhound.
~~ "a^y", 'sable' -
also known as 'dominant yellow' or 'golden sable'. This results in an
essentially red/yellow phenotype, but the hair tips are black
(eumelanin). The extent of the eumelanin tip varies
considerably from lighter sables (where just the ear tips are
black, called "Clear Sables") to darker sables (where much of
the body is dark, called "Shaded Sables").
~~ "a^s", 'saddle'
- Eumelanin is restricted to the back
and side regions, somewhat like the black/tan ("a^t") allele (below).
~~ "a^t", 'tan points' -
This is primarily a solid colored dog with tan (phaeomelanin)
"points" above the eyes, muzzle, chest, stomach and lower
legs. The hue can range from a pale biscuit to a rich ginger
to a golden copper in color. In the Border Collie which has
the Irish spotting, along with tan points, this is known as "tri"
colored .
~~ "a" -
last of the Agouti series is recessive black. When a dog is
homozygous for recessive black (a/a), there will be no
red/yellow (phaeomelanin) in its coat (unless "e/e" is present, which
is epistatic to the Agouti series). Examples of breeds that show
to be recessive black are German Shepherd and Shetland
Sheepdog.
BLACK or BROWN (CHOCOLATE) - B GENE LOCUS: (pigment color)
This gene, when in the homozygous recessive form,
has a lightening effect on eumelanin (black-based
colors) only. It has no effect on phaeomelanin (red-based colors).
It is believed that the Brown Locus codes for an enzyme,
tyrosinase-related protein 1 (TYRP1), which catalyzes the final
step in eumelanin production, changing the final intermediate
brown pigment (dihydroxyindole) to black pigment. SO, ALL
dogs start as BROWN and after the final step --- this directs
the color to be black.
When brown (b/b) is
expressed, it means that the final step in eumelanin production
has not been completed and the pigment remains brown. The
brown color is not a genetic defect.
When the
alleles are in the homozygous or heterozygous dominant form of
B/B or B/b, the color and pigment (nose, eye rims and lips) remains (or
directs the color to be) black.
When
the alleles are in the homozygous recessive form (b/b), the color
and pigment will be brown. This just means that the final step in
eumelanin production of changing brown to black did not occur.
Phaemelanin (yellow/red [e/e]) is not affected. BUT, in the
e/e colored dog, if the dog is also b/b; they'll be either red
or yellow and will have brown pigment (nose, eye rims and
lips). The pigment
granules produced by "bb" are smaller,
rounder in shape, and appear lighter than pigment granules in
"B" dogs. The iris of the eye is also lightened.
DILUTION - D GENE LOCUS: (dilution of pigment)
This gene has an effect on both eumelanin and phaeomelanin.
When in the dominant form, "D/D" or "D/d", it allows for full color (black or red).
When present in the homozygous recessive form (d/d) it dilutes
black (eumelanin) to blue, chocolate to lilac and red to
cream.
COMBINATIONS OF B AND D IN EUMELANISTIC COATS:
The effects of these 2 genes, when combined, form a range of 4 eumelanistic ('black-based') colors:
The color of the pup/dog (Eumelanistic Color):
B/B D/D or B/b D/d will be black in color
B/B d/d or B/b d/d will be blue in color
b/b D/D or b/b D/d will be brown/chocolate
b/b d/d will be flat or dull diluted brown/chocolate
WHITE SPOTTING - S GENE:
The "S" series alleles appear to be incompletely
dominant. In dogs it is thought there are four alleles that
deal with white spotting:
~~ "S"
- 'solid/self color'. Most dogs that are homozygous
for "S/S" have no white hair at all, or possible a tiny amount,
like a white tail tip.
~~ "s^i" - 'irish spotting'. This involves white spotting on most parts of the coat, but
not crossing the back beyond the withers. This color pattern
is evident on the Border Collie that have the white collar. New research has proven that the white undersides of the Border Collie is dictated by a different gene.
~~ "s^p" -
'piebald'. The white is more extensive than irish spotting, and often
crosses the back. It is sometimes confused with the merle
pattern. This coloration usually has large colored spots on the
body. The white covers approximately 50% of the body.
~~ "s^w" -
'extreme white piebald'. A dog that is homozygous for "s^w" will be
almost entirely white. This allelic pair is also responsible for
the "color headed" white dogs. Often times, along with a
colored head, there will also be a colored spot near the tail.
TICKED - T GENE:
A
dominant mutation that causes the presence of color (flecks
of color) in areas that have been made white by the effect of
alleles in the white spotting (S) series.
Ticked ("T/T") is incompletely dominant to non-ticked ("t/t").
ALBINO - C GENE: (development of pigment)
The
intensity of melanin production in the coat hairs is affected
by this gene. The dominant form, "C", is termed 'full color'.
At this locus, almost all dogs are "C/C", or full color.
The lower series alleles, in order of decreasing dominance:
~~ "c^ch" -
Chinchilla -- It is an incomplete dominant gene. Chinchilla lightens
most or all of the red/yellow (phaeomelanin) with little or no
effect on black/brown (eumelanin). It turns black/tan to
black/silver. In dogs, this gene lightens yellow, tan or
reddish phaeomelanin to cream. Since there is little effect on
the dark eumelanin, phaeomelanin is effected more strongly
than eumelanin and brown.
Dilute eumelanin (blue) is
effected more strongly than dark (black) eumelanin. When
chinchilla is present, it dilutes brown to milk chocolate, blue
to silver and red to a butter cream color.
NOTE: Newer
research indicates a chinchilla-like mutation occurs in dogs,
although, tyrosinase activity hasn't been shown to be
connected. Therefore, some other factor may be involved and the
dog chinchilla allele may not belong in this series. Also,
there may be more than one form of the chinchilla gene.
~~
"c^e" - is 'extreme dilution'. It causes tan to become almost
white. It is thought that the white labrador might be "c^e"
with another, lower, "C" series allele. The "c^e" allele may be
responsible for producing white hair, while allowing fullexpression of
dark nose and eye pigment. West Highland Terriers are thought
to be e/e c^e/c^e.
~~ "c^b" -
or blue-eyed albino. This is an entirely white coat with a
very small amount of residual pigment in the eyes, giving pale
blue eyes. It is also called platinum or silver. This allelic
pair could be responsible for the white coated, pink skinned,
blue-eyed Doberman's.
~~ "c^c" - true pink-eyed albino. Has not been seen in dogs.
GRAYING - G GENE:
This
is a dominant mutant gene that causes the dog to gray with
age. The pigmented hairs are progressively replaced with
unpigmented hairs.
MERLE - M GENE:
The only way
a merle colored pup can be produced is if at least one parent
is merle. Some breeders are of the understanding that the
merle gene is a recessive gene and is carried from generation
to generation. This is not correct. The merle gene is not
carried, meaning -- the dog is either a merle or is not a merle.
There are no exceptions to this law of genetics (for now, at least,
until further research
is conducted).
If someone tells you that they have a litter of merled colored
pups and there are no merles for many generations in their
bloodlines --- then these merled pups were not sired by the
sire the owner thinks there were. In fact, he should look for
the hole in the fence!
The merle gene is an
incomplete dominant or a gene with intermediate expression and
is another dilution gene. Instead of diluting the whole coat
it causes a patchy dilution, with a black coat becoming gray
patched with black. Brown becomes dilute brown patched with chocolate,
sienna, brick, and various diluted brown colors. While sable
merles can be distinguished from sables, this is sometimes
very difficult because the merle coloration looks like -- to
just slightly different from -- the sable color. The merling is
clearly visible at birth, but may fade to little more than
mottling of the ear tips as an adult. Merling on the tan points
of a merle black and tan is not immediately obvious, either,
though it does show if the mask factor is present. Eyes of a
merle dog are sometimes blue or marbled (brown
and blue segments in the eye).
A "m/m" (homozygous recessive) dog is normal color (no merling). A "M/m" (heterozygous) dog is a merle. A "M/M" (homozygous dominant) dog, known as a double
merle (from a merle to merle mating), has much more white
than is normal for the breed and may have hearing loss, vision
problems including small or missing eyes, and possible
infertility. The health effects seem worse if a gene for
white markings is also present. In Border Collies all of which normally have
fairly extensive white markings, the "M/M" white has a strong
probability of being deaf or blind. A "M/M", double merle, to
"mm", non-merle black in color breeding, is the only one that
will produce 100% merles.
Cryptic or
phantom (as it's sometimes called) merles are dogs which carry
a merle gene but are phenotypically (look like) tri, bi or self
colored. These dogs will have some small area of merling somewhere,
usually a tiny patch of merle pattern on their ear, tail, top
of head, etc. Keep in mind the tiny patch can be only one hair
and it can be located anywhere on the body. Cryptic merles
are very rare. AGAIN, a cryptic or visible merle can only be
produced when one or both parents are merles.
GENOTYPES AND COLORS:
("-" is either the dominant or recessive allele)
B/- D/- E/- K/- = black
b/b D/- E/- K/- = brown (chocolate)
B/- d/d E/- K/- = blue
b/b d/d E/- K/- = lilac
AGOUTI:
at^at B/- D/- E/- k/k = black with tan points
at^at b/b D/- E/- k/k = chocolate with tan points
at^at B/- d/d E/- k/k = blue with dilute tan points
at^at b/b d/d E/- k/k = lilac with dilute tan points
NON-EXTENSION RED (cream):