Description
Typically in the heterozygous
state, the Sabino coat pattern usually involves a horse having two
or more white feet or legs. The white color will often extend up
the legs of the horse to the belly in irregular or fragmented patches.
These jagged white patches are commonly referred to as barrel spots
or belly spots. The head of a Sabino horse is moderately white.
It commonly has a blaze or white patch that expands the length of
the face. The white areas of a Sabino horse lack pigment, both in
the hair and skin.
Same horse as on left but mature
Courtesy of Joanne Abramson |
nSb1
Foal
Courtesy of Joanne Abramson |
Many Sabinos are characterized by flecks, patches, and roan areas.
Roaning (interspersed white hairs throughout the coat) is generally
seen around the midsection of the horse. The roaned areas on a Sabino
horse can be minimal and only see at the edges of the white pattern
to extensive roaning throughout the entire body of the horse. Cases
where a Sabino horse exhibits extensive roaning can sometimes be
confused with classic roan. However, Classic Roan does not involve
the splashy white markings of a Sabino and the head and legs are
usually darker than the body.
In the homozygous state, the white often covers greater than 90%
of the horse's body. This is referred to as a maximum white sabino.
There are instances where a heterozygous horse appears all white
but they usually carry another pattern such as Tobiano or Frame
Overo. A horse with both Tobiano and Sabino is referred to as a
Tovero.
Another distinguishing trait amongst sabinos is their eye color.
They commonly have blue eyes or partially blue and brown eyes.
This chart shows the possibilities of offspring
when mating two horses.
|
- |
nn |
nSb1 |
Sb1Sb1 |
|
nn |
100% nn |
50% nn
50% nSb1 |
100% nSb1 |
|
nSb1 |
50% nn
50% nSb1 |
25% nn
50% nSb1
25% Sb1Sb1 |
50% nSb1
50% Sb1Sb1 |
|
Sb1Sb1 |
100% nSb1 |
50% nSb1
50% Sb1Sb1 |
100% Sb1Sb1 |
nSb1
- one normal/one Sabino1- probable Sabino pattern
nn
- Sabino1 mutation not present.
Sb1Sb1
- Maximum Sabino
Reference:
Brooks SA, Bailey E. Exon skipping in the KIT
gene causes a Sabino spotting pattern in horses.
Mamm Genome. 2005 Nov;16(11):893-902. Epub 2005 Nov 11.
Sabino
1 Testing
Animal Genetics offers
DNA testing and detection of the gene mutation responsible for the
Sabino 1 coat pattern.
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:
|
Sb1Sb1 |
Tested homozygous
positive (two copies) for the Sabino1 gene mutation. Maximum white sabino. |
|
nSb1 |
Both normal and
Sabino1 alleles detected. Horse tested heterozygous for Sabino1
and carries one copy of the Sabino1 gene mutation. |
|
nn |
Tested negative
for the Sabino1 gene mutation. |
|