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Is
it a Cremello, or is it an Albino?
by Lana Sibley
I told my friend that there are no albinos in horses
and he looked at me like I was nuts. “I have
seen them!” he said. I tried to explain that
what he
saw was probably a “cremello” and not an
“albino”. He just shrugged. His basic
stand was this:
I was calling it one thing and he was calling
it another, but it was still the same horse, and in
his book... an albino.
So my point here is to explain why albino and cremello
are not the same thing. I’ll make this
brief without any genetic letter combinations to
confuse and confound. I just want to explain
what an albino actually is, and how it comes to exist.
And then I’ll point out the differences
between it and a cremello horse.
There are several different genes that cause albinism
in the species in which it exists. We say it
does not exist in horses because genetists have never
found a horse that meets the criteria to be
considered an albino, not because it is impossible in
one species while possible in another. In my
understanding, even the genetists don’t know
why it
doesn’t exist in horses. Its existence has just
never been proven.
Albinism is created when an offspring receives two
recessive genes from its parents... one from
each parent. The parents do not exhibit any signs of
albinism... a recessive gene is completely
masked or “overpowered” by the dominant
gene in the
pair. So the parent carries the gene
without being albino. The different types of albinism
all affect pigmentation, and also carry with
them some other genetic problems including eye
problems, blood clotting problems, and hearing
problems.
But the creme gene, which causes a cremello, is
not a
recessive gene. It is what is referred to as
an “incomplete dominant” gene. This
means that it
shows even when there is only one copy in
the gene pair (because it is dominant) but shows more
strongly when the horse carries two
copies! A horse that carries one creme gene is a very
popular animal in today’s horse world! He
is usually either palomino or buckskin. The single
creme gene dilutes the chestnut or sorrel
basecoat to a gold or cream color and the mane and
tail to white. But it does not affect black
pigment, so on a bay basecoat, it creates the same
golden color, but leaves the mane, tail and
points black. There are also horses who have no red
hair on their bodies and the gene can be
hidden there... these are called smoky blacks.
Only on
true blacks is the gene totally masked,
because any brown or red hair will be turned to gold
and give those horses a “glow”.
When the horse receives a copy of the creme gene from
each parent, you have a cremello (on a
chestnut basecoat) perlino (on a bay basecoat) or
smoky creme (on a black basecoat). But, just as
it is not a recessive gene like the albino gene, it
also does not carry the associated genetic
defects. There is no indication that cremellos,
perlinos or smoky blacks have the eye problems,
blood clotting problems, or hearing problems that come
with an albino gene. This is because the
creme gene is a totally different type of gene.
Albino is one thing, caused by one genetic factor.
Cremello is another, caused by a completely
different genetic factor. So you see that it’s
not
just an argument over what we call them! |
