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Description
Basic coat colors (bay, black, brown, and chestnut)
are controlled by the Extension gene (E) which controls the production
of red and black pigment. This is also referred to as red factor
and has been linked to a single nucleotide polymorphism or SNP (SNP
is simply a change in a single nucleotide). Red Factor is recessive
(e) and non-red factor or black factor is dominant (E). This means
that horses testing heterozygous (Ee) and homozygous black factor
(EE) will have a black pigmented base coat color. Only horses testing
homozygous for red factor (ee) will have a red pigmented base coat
color. The shade and pattern of colors will be determined by many
other genes some of which have genetic markers within those genes
already identified (cream dilution, agouti, etc).
Red Factor Testing
Animal Genetics offers DNA testing for the Extension
gene.
Why test for Red Factor?
Often breeders of black horses will want to test
for Red Factor to determine if the horse is homozygous for black
(EE). Homozygous black horses will always throw black as a base
coat. Thus, the resulting offspring will be black unless modified
by other color modifying genes. Other reasons to test for Red Factor
would be to verify that a horse has a chestnut or sorrel base. Cremello
and Palomino horses are homozygous for Red Factor (ee).
Cost
$25.00
US per sample.
Sample Collection
Collect sample by pulling (not cutting) 20-30
mane or tail hairs with roots attached. It is important that you
pull the hairs and confirm that the actual root of the hair is being
collected. The root contains the genetic material of your horse
that is needed for DNA testing. Therefore, cut hairs do not provide
an adequate sample of your horse. Place the collected hairs of each
horse in a separate zip-lock bag labeling the bags accordingly with
the horses name or identification number. Download and complete
a submission form for each sample and send along with payment to
Animal Genetics for testing.
Results
Results are given using the following symbolic
notation:
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ee
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Only the red factor
detected. The horse tested homozygous for red pigment. The basic
color is chestnut or sorrel unless modified by other color modifying
genes. |
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Ee
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Both black and red
factors detected. The horse tested heterozygous for the red
factor. It can transmit either E or e to its offspring. The
basic color of the horse will be black, bay or brown unless
modified by other color modifying genes. |
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EE
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Only the black factor
detected. The horse tested homozygous for black pigment. It
cannot have red foals regardless of the color of the mate. The
basic color of the horse will be black, bay or brown unless
modified by other color modifying genes. |
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Offspring Coat
