BrownPaintHorseJournal0410.pdf

Courtesy Karen Banister

Jessica Hein

APHA File PHoto

there’s no denying that seal brown exists—even if this equine chameleon

could easily pass for a dark bay, liver chestnut or sun-bleached black.

s any horse-crazy 5-year-old girl

will tell you, the brown crayon

don’t last very long in a box of

Crayolas ® . But as she grows older and

wiser, and her artistic endeavors turn

to drawing bays and blacks, sorrels and

palominos, that poor brown crayon

is forgotten. Her equine vocabulary

expands to include buckskins and blue

roans, until one day, she stops using

brown altogether—brown no longer

exists in her mind.

If you too believe there is no such

thing as a brown horse, you’re not alone.

It’s a widely-accepted myth that there

are no brown horses—only dark bays,

liver chestnuts and faded blacks.

The truth is, brown existed long before

the irst Paint Horse was registered, and it

is genetically distinct from bay and black.

And while only 4.6 percent of registered

Paints are classiied as brown, there are

certainly more—some mis-registered,

others further disguised with a dilution

gene or extensive white spotting.

In fact, brown genetics run deeper

in the Paint Horse breed than many

realize, as a signiicant number of sor-

rels, chestnuts and bays carry the gene

but don’t express it. That could have a

major impact if you are breeding for a

speciic color, say buckskin. Curious?

Read on. What you’ll learn will turn

you into a brown believer.

If anyone can explain seal brown

genetics in layman’s terms, it’s Joycelyn

Kasmir. With her husband Jeff, she

owns Diamond J Farms in Needville,

Texas. They stand a 1985 brown son

of Secretariat, Country Side JC, and

his Paint son, Country Picasso, a 2002

sorrel tobiano. Over the years, she’s seen

her share of seal browns.

“A brown horse is going to look very

close to a black horse,” said Kasmir.

But even with her experience spotting

a seal brown, she says she’s been fooled

occasionally. “It’s really hard to tell the

difference between a sooty dark bay and

a seal brown.”

In some cases, only genetic test-

ing can differentiate between the two

colors, which are determined by the

Agouti gene.

“There are two categories of horses—

the black-based horses and the red-

based horses,” explained Kasmir. “The

Extension gene is the black gene. If the

horse has an E , then it has the ability to

make black hair.

“Then you need to look at the Ago-

uti gene to see how much the black is

restricted,” she said. Unlike the Exten-

sion gene—which has two alleles— E for

black hair and e for red hair—the Ago-

uti gene has multiple alleles. “The A is

bay. We use At to designate seal brown.

And a is black,” said Kasmir.

“ A is the most dominant. It has the

most restriction on the body. It restricts

the black hair to the points. If a horse

is AA , AAt or Aa , it is going to be bay

because it has the most dominant allele.

“With AtAt or Ata , you’ll get a brown.

At restricts black hair, but not as much

as a bay. You’ll see a little red showing

through. It is dominant over a , which is

the most recessive. But At is recessive to

the true bay, or A .

“If the horse is aa , he’s true black. The

a allele doesn’t restrict the black at all.”

If you have a red-based horse—a sor-

rel, chestnut, palomino, red dun or

cremello—it can’t make black hair.

Genetic testing is the only way to deter-

mine its Agouti status, searching for all

three alleles— A , At and a .

Most foal owners, however, don’t

have time for genetic testing before

Ordinary brown?

Among registered Paints, the

brown breakdown is:

36%

sorrel

20%

15%

bay

black

4.6%

brown

“We get a lot of brown foals with

‘Country.’ I’ve got a lot of Thorough-

breds in my herd, so there are a lot

of brown genes loating around.” said

Kasmir. “For a very long time, back in

England, the Thoroughbred was pre-

dominantly dark bay or brown, and

every once in a while a black would

show up. The fashion was dark bay or

brown.”

And those brown genes were injected

into the Western stock horse breeds

when they were out-crossed with

Thoroughbreds.

The brown spectrum

The terms “brown” and “seal brown”

are used fairly interchangeably for this

equine coat color described as a very

dark brown or a natural black, with

brown/tan highlights—similar to an

adult seal. According to APHA, a brown

horse has a brown or black body, with

light areas at muzzle, eyes, lank and

inside upper legs. The mane and tail are

usually black.

Paint Horse Journal u aPril 2010 u 59

The seal brown color can be modiied by

other genes. Dusted With Gold (above)

is a seal brown and cream, and Champs

Guthrie AQHA (right) expresses seal

brown and silver. Cute Black Buttons

(below, right) is an example of seal

brown, registered as brown.

they submit registration applications.

And foal coats can be very deceiving, as

Kasmir can attest.

“Most often, if it’s born bay or black-

looking, it’s actually a brown,” she said.

“The true black babies, they have more

of a gray tinge on them—it looks like

pewter. If they look dark, then often

they’re actually brown.”

Most bay foals are born with light-

colored legs—not the black you would

expect. And most brown foals—who

look bay—often have black legs. They

don’t turn brown until they shed. So

it’s easy to understand why sometimes

those browns that are registered early

are misclassiied as bays.

Add a dilution gene, and the situa-

tion gets even more complicated.

“Now that seal brown has been iden-

tiied and proven as a real color, the

problem is registries don’t have names

for brown dilutes,” said Kasmir.

Take the cream gene for example.

On a sorrel base coat, one cream allele

will give you a palomino. Add cream to

bay, and you get a buckskin. Add cream

to black, and you have a smoky black.

But what do you call a seal brown with

cream? The jury is still out. They have

been called brown buckskins, smoky

browns or sooty buckskins.

“The cream gene only lightens the

non-black hair. And on a seal brown,

there’s not much non-black hair to

lighten. In a brown, which has only a

few reddish areas, it’s almost goldish,”

said Kasmir. “There’s more proit in

calling them a buckskin, but they don’t

necessarily look like a buckskin.”

The same goes for the dun gene. On a

sorrel base coat, a dun allele will give you

a red dun. The typical dun is a bay with a

dun gene. Add dun to black, and you get

a grulla. But what about seal brown?

“There’s no name for brown with the

dun gene,” explained Kasmir. “They

generally fall in the grulla category

because they are almost black. But then

they’ve got that brownish muzzle and

they don’t really look like a grulla.”

Another rare, but legitimate, pos-

sibility is a brown with a silver gene.

This dilution gene is unique because

60 u aPril 2010 u Paint Horse Journal

Mixing brown Paint

Breeding brown? Brush up on your genetics beforehand.

If you do have a diluted seal brown,

perhaps the simplest solution is to

describe the horse using the base color

plus the dilute: brown with cream, for

example.

And while roan is a pattern of white

and not a dilution gene, the situation

is the same.

“There’s no name for brown roan,”

Kasmir continued. “They look more

like a blue roan than a bay roan.”

Until terminology catches up with

technology, the best you can do is reg-

ister the foal as brown and request

that the dilution gene be mentioned in

the remarks, providing genetic testing

results to prove your case.

Q: Can two black horses produce a brown foal?

A: No. Two true black horses—both tested aa —will never make a brown baby.

Neither carries the At allele necessary to make seal brown.

Q: Can a brown horse produce a bay?

A: A brown stallion, bred to a black or brown mare, cannot make a bay foal

as neither parent carries the necessary A allele. But, if you breed a brown

stallion with a red-based mare, unless you know her Agouti status, bay is

one possibility. On the other hand, a bay could produce a brown if the bay

carried both the A and At alleles.

Q: Can a brown horse produce a buckskin?

A: No, a brown horse cannot produce a buckskin, unless you cross it with

one carrying both the cream and bay genes. A palomino, for example, car-

ries cream but because it’s a red-based color, genetic testing is required to

determine the Agouti status.

Finding seal brown

The research leading to the discovery

of the seal brown allele received a major

boost from three Paint Horse owners—

Carolyn Shepard, Joycelyn Kasmir and

Q: Are all Agouti tests the same?

A: No. Most labs test for the recessive a (black) allele. If they ind something

other than a , they report it as dominant A (bay) although it could be At

(seal brown). Only one laboratory looks for the At (seal brown) allele—Pet

DNA Services of AZ ® .

Keyhole Buffy (below, left) has both

seal brown and dun genes. California

Champagne (below) possesses both

the seal brown and champagne genes,

called a sable champagne.

it dilutes only the black pigment in

the hair, leaving the red pigment

untouched. Generally, the mane and

tail are more strongly diluted than the

body, although this varies from a slight

lightening to platinum blond.

“The only registry that has a name

for a brown dilute is the International

Champagne Horse Registry (ICHR),”

Kasmir continued. “They call brown

with a champagne gene a sable.”

Paint Horse Journal u aPril 2010 u 61

Julia Lord. Their efforts led Michal Proc-

hazka, MD, a molecular geneticist and

founder of Pet DNA Services of AZ ® , to

become interested in seal brown genetics

and begin his research in 2005.

Previously, geneticists from the INRA

Centre de Recherche de Jouy, outside

Paris, France, published a study in 2001

showing their discovery of the recessive

a allele at the Agouti locus.

“There were seal brown horses in the

study,” recalled Prochazka, “but they

didn’t ind anything in the Agouti gene

that caused seal brown.”

Prochazka realized the French were

on the right track, but he took the

research a step further.

“They investigated a functionally

most critical part of the gene, but there

are additional parts that we investi-

gated,” he said. “They are called regu-

latory parts of the gene that control

whether the gene is turned on or off,

and in which areas of the body, and

that’s where we found the difference.”

Collecting samples was relatively easy,

as breeders were very interested in the

research, says Prochazka, who inanced

the study himself.

“It took about two years to get some

data that looked like positive evidence

for the brown allele,” he recalled. “We

did it by looking at the gene in seal

brown, bay and black horses. We used

standard laboratory procedures involv-

ing PCR (polymerase chain reaction)

where you can amplify the DNA and

compare the same parts between dif-

ferent colors.

“First, we were looking for any evi-

dence for any change in the DNA

that would correlate with the color,”

Prochazka recalled. “For example, there

could be a change in the DNA which

could be causing the difference in color.

That would be the true mutation that

causes the color. Or it could be some-

thing nearby that lags the mutation,

like a marker. First, we found a marker,

but based on our evidence it wasn’t

likely to cause the color.”

In 2007, Pet DNA Services initially

offered a test using the DNA marker,

while continuing the research.

“Eventually, we discovered a change

in the gene which by all evidence

appears to be causing the differ-

ence in color,” said Prochazka. “We

tested this brown mutation in many

different breeds—Thoroughbreds,

Quarter Horses, Arabians, Miniature

Horses, Appaloosas, Paint Horses,

Mustangs, etc. In every breed where

we found it, it correlated with the

seal brown color. It’s more common

than people think.

“The Agouti gene only has an effect

on the body distribution of black-

pigmented hair, and of course, in a

chestnut- [or sorrel-] based horse, you

don’t see it because it doesn’t have black

hair. However, they can carry it too,

depending on what they inherit from

their parents.”

Since the study began, more than

300 horses have been tested for the seal

brown mutation. Prochazka estimates

Gambling Man (right) is one of the

breed’s most well-known brown stal-

lions. Of his 253 offspring, more than

40 are registered as brown.

62 u aPril 2010 u Paint Horse Journal

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