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Horse Color Basics
updated
Saturday, April 26, 2008
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Genes
All characteristics, including color, are inherited through GENES, which are
located on structures called CHROMOSOMES. They are found in the nucleus of
every cell, and made up of strands of DNA. Genes exist in pairs.
However, the nuclei of egg and sperm cells only have one of each gene from
the individual producing them. So horses, like all mammals, get one of
each gene from the mother, and one of each gene from the father, ending up with
a pair for every possible characteristic.
Horses may have two kinds of pigment in their coats, manes and tails;
RED (e) and/or BLACK (E). Red is called CHESTNUT or SORREL.
GENE WARS?
So, what if a horse gets a red-hair gene (e) from its father (sire), and a
black-hair gene (E) from its mother (dam)? Will it be a reddish-black
horse if it is Ee?
No, because in horse color BLACK is a DOMINANT gene, which means it will
always show itself, whether there are one or two of them. It will be a
black horse!
But what about that red gene (e)? RED is RECESSIVE in horse color, which
means that it can only show up if there is nothing else at that "spot"
(the red-black spot).
So, the only horses that will be RED are ones that get a red gene from BOTH
parents. Two red genes are needed to make a red horse. (ee)
These two make black-based horses: EE or Ee.
Modifiers 101: Bay
Though horses have may two kinds of pigments in their coats, manes and
tails, red and/or black, most horses also carry an AGOUTI modifier (A), that
confines any BLACK to the mane, tail and legs of the horse. This is why
solid black horses (aa) are so rare. The agouti gene cannot be seen on a
horse without the black color (red).
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(ee) Red (chestnut or sorrel). May or may not carry Agouti (bay)
gene.
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(EE or Ee) Bay. Expressing black and agouti (bay) genes. (AA or Aa)
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(EE or Ee) Black. Expressing black gene without any agouti (bay)
genes (aa).
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Bay (agouti) is also a dominant gene, so if a horse carries it, it shows up
... and most horses, as we said, do carry the gene.
Enter the Champagne Gene!
The Champagne gene dilutes red to a golden color, and black to a brown or
taupe color.
The Champagne gene is also dominant. So if a horse has even one
Champagne in the pair, it will be a Champagne horse. If CH is Champagne
and ch is non-, then:
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Ch+Ch = Champagne horse
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Ch+ch = Champagne horse
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ch+ ch = non-Champagne horse
Now we get into something that begins to look like algebra, but if you are
calm and take it slowly, you will understand it. J
We are going to look at COMBINATIONS of these three or four genes. The
red/black, the agouti, and the Champagne genes.
EEAAChCh
This horse has two black genes, two bay genes, and two Champagne
genes. So it will have black, but only on the points (bay) and that black
will be diluted to dark brown (Champagne). The body will be made red by
the bay gene, so the Champagne gene will make the body a deep golden
color. This horse will be an Amber Champagne! It may be mistaken for
a buckskin, but it will have brown points, not black, and pinkish skin with
freckles.
EeAaChch
This horse has one each of these dominant genes, so it will be the same as
the one above, because a dominant gene always shows!
ee(A?)Chch
This horse has no black expressing (ee is red) so we cannot tell whether it
has the bay gene or not (A or a). It does have a Champagne gene, so the red will
be diluted to gold. This horse will be a Gold Champagne. Often
mistaken for Palominos, these horses may or may not have flaxen (white) manes
& tails.
More coming....
*We do not have the rights to this picture at this time. If anyone knows
where it's from, maybe we can get them. I'm sorry, it was so long ago, I
forget.
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