Cat coat genetics reference chart
Gene
Genotypes
L
LL
Ll
ll
(hair length)
W
(white)
S
piebald spotting)
D
(dense pigment)
O
(orange)
WW
Ww
ww
SS
Ss
ss
DD
Dd
dd
Phenotypes
short hair
short hair
long hair
completely white hair
completely white hair
some colored hair
some white hair
some white hair
no white hair
black, brown or orange
black, brown or orange
gray, light brown or cream
OO (♀) or O- (♂) orange or cream
orange and black, or cream and gray
Oo (♀)
oo (♀) or o- (♂) black or gray
Long hair - Long hair is recessive, and is indicated by ll. Short hair is
either Ll or LL.
Dominant white – All-white cats, with nonpink eyes (non albino) are
either Ww or WW. The dominant W allele is quite rare; this helps students
understand that a "dominant" allele, in genetics, is one that determines the
phenotype of the heterozygote, not the most common allele in the
population. It is impossible to score any of the other color genes (es.
Orange) in the presence of W. This is an example of epistasis.
Peabald spotting -The amount of white color in cats with the S allele
can range from a few white toes, to white everywhere except for a colored
patch on the forehead or tail. S/s heterozygotes have white on less than 50
percent of the body, while S/S homozygotes have white on more than 50
percent. This is an example of incomplete dominance.
Dense pigment – This gene controls the amount of melanine
(responsible for the density of the hair color) in hair. The recessive
condition (d/d) causes the black pigment to become gray (often with a
bluish tint) and the orange pigment to be diluted to cream.
Orange - The orange locus is sex-linked (it is on the X chromosome).
Allele O, changes black pigment to orange. Because the O gene is on the X
chromosome, males are hemizygous (XY) and are either O or o. Females
can be OO and completely orange, oo and have no orange, or are
heterozygous, Oo, and are mosaics of orange and nonorange fur due to Xinactivation.