Transcript colors of horses

The Wonders of Horse Coat
Color
The colors of
horses
The colors
O
Search the
web for horses
The Genetic
Explanation
Link to horse
Click
classifieds
here after
Internet assign.
Basic Color Determinants
• At #1 loci: 3 alleles
possible, C, c, and cr. The
alleles C and cr are codominant for skin
pigmentation. Where C
codes for solid color and
cr codes for mutated color.
The allele c is recessive
and codes for no pigment
in the skin. However, if
both alleles on this loci are
c the gene becomes lethal.
The horse would have
been a true albino, but it
dies before it is ever born.
• At #2 loci: 2 alleles
possible, B and b. This
loci codes for skin color.
B is black and dominant.
The recessive b codes for
brown.
Regulation of Pigment
• At loci #4: 3 alleles possible, ED, E,
• At #3 loci: 4 Alleles
and e. (Listed in order of dominance.)
possible, A, A+, a+, and
These genes act in conjunction with the
a. (Listed in order of
genes at loci #1and #2, and code for
dominance.) The allele A
pigment intensity. ED raises the
codes for a bay hair coat.
intensity of dark pigment. E produces
The allele A+ is a dun or
normal pigment distribution. The allele
buckskin. The allele a+
e supresses black and brown pigments,
makes the horse have tan
and increase the intensity of the colors
or red points. The allele a
yellow and red.
makes the horse totally
uniform in color.
• At loci #5: 2 alleles possible, D and d.
These genes are dilution genes. D is
dominant and dilutes all colors. The
allele d is recessive and produces a
Main Menu
non-diluted, normal coat color.
Searching the Web for horses
When you get to the internet sight you will want to
run a search. You may then select what type of ad
you are looking for, what state it is from, what
breed of horse you want, what discipline the horse
is in, etc. Be sure to click the list photo ads only
box before you run the search!
Find a horse you like. Look at its picture and
identify its color. Record this information on your
worksheet (#10a).
Web link to horse
classifieds
Internet Extension
• Now that you have information about what
color your “internet horse” is, pick two loci
out of the five and try to determine what
alleles would be present to create your
horse’s coat color (10b and c). If you need
to go back to the loci slides click on the box
below.
Your worksheet should be filled out (keep it until it is collected by the teacher)
You should have learned the colors of horses
You should now understand why coat color occurs
You should have found a horse you like on the web and identified its coat color
You should have also genetically explained the internet horse’s coat color
CREDITS
1. Evans, Warren. Horses. W.H. Freeman and Co., New York, p. 51-4, 580-91.
2. Www.horses-for-sale.net/
3. Www.mcquaystables.com
4. Www.horsesales.com/whitehorse.htm