The Tobiano coat pattern usually involves white on all four legs below the hocks and knees and rounded white spots on the body with sharp, clean edges. La cabeza es oscura, con marcas blancas como las de un caballo de color sólido. El blanco en el cuerpo generalmente cruzará la línea superior del caballo. La piel subyacente a las manchas blancas es rosada y debajo de las áreas coloreadas es negra. Los ojos suelen ser marrones, pero uno o ambos pueden ser azules o parcialmente azules. The tail can be two colors, a characteristic seldom seen in horses that are not tobiano. A horse can also carry mutations for other modifying genes which can further affect its coat colour.
The Coat Colour Tobiano test (P903) tests for a genetic factor that affects the function of the KIT gene. Este gen tiene dos variantes (alelos). El alelo dominante TO da como resultado el patrón de Tobiano y el alelo recesivo N no tiene un efecto sobre el color básico.
The Coat Colour Tobiano test encloses the following results, in this scheme the results of the Coat Colour Tobiano test are shown in combination with the possible results for the tests that determine the basic Coat Colour (Coat Colour Chestnut and Coat Colour Agouti test):
|
Result Tobiano |
Result Chestnut + Agouti |
Coat Colour |
Descripción |
|---|---|---|---|
|
N/N |
e/e + A/A, A/a or a/a
|
Chestnut, Sorrel
|
Not Tobiano. The basic colour chestnut/sorrel is not modified unless modified by other colour modifying genes. It can only pass on allele N to its offspring. |
|
N/N |
E/E or E/e + A/A or A/a |
Bay, Brown |
Not Tobiano. The basic colour bay/brown is not modified unless modified by other colour modifying genes. It can only pass on allele N to its offspring. |
|
N/N |
E/E or E/e + a/a |
Black |
Not Tobiano. The basic colour black is not modified unless modified by other colour modifying genes. It can only pass on allele N to its offspring. |
|
N/TO |
e/e + A/A, A/a or a/a
|
Chestnut/sorrel tobiano |
One copy of the dominant TO allele. The colour is chestnut/sorrel tobiano unless modified by other colour modifying genes. It can pass on either allele N or TO to its offspring. |
|
N/TO |
E/E or E/e + A/A or A/a |
Bay/brown tobiano |
One copy of the dominant TO allele. The colour is bay/brown tobiano unless modified by other colour modifying genes. It can pass on either allele N or TO to its offspring. |
|
N/TO |
E/E or E/e + a/a |
Black tobiano |
One copy of the dominant TO allele. The colour is black tobiano unless modified by other colour modifying genes. It can pass on either allele N or TO to its offspring. |
|
TO/TO |
e/e + A/A, A/a or a/a
|
Chestnut/sorrel tobiano |
Two copies of the dominant TO allele. The colour is chestnut/sorrel tobiano unless modified by other colour modifying genes. It can only pass on allele TO to its offspring. |
|
TO/TO |
E/E or E/e + A/A or A/a |
Bay/brown tobiano |
Two copies of the dominant TO allele. The colour is bay/brown tobiano unless modified by other colour modifying genes. It can only pass on allele TO to its offspring. |
|
TO/TO |
E/E or E/e + a/a |
Black tobiano |
Two copies of the dominant TO allele. The colour is black tobiano unless modified by other colour modifying genes. It can only pass on allele TO to its offspring. |