Cat coat colour genetics

Question 1

ASIP- A locus

Answer 1

-wild types ((hunting advantage)
-dominant A can be banded

Question 2

black

Answer 2

-mutation in ASIP
-recessive a/a
-simular in horses and herding dogs

Question 3

TYRP1- B locus

Answer 3

-B - not brown
-b/b modifies black eumelanin to black
-b is rare allele seen in a few cat breeds
-called chocolate

Question 4

TYRP1-b1 allele

Answer 4

-called cinnamon of b1/b1
-b/b1 is more chocolate in colour

Question 5

D locus - melanophilin

Answer 5

-d/d cats are dilute color
-melanophilin (MLPH) deletion

Question 6

E locus=MC1R
ea- amber

Answer 6

-amino acid change causes a recessive allele
-eumelanin replaced with phaeomelanin (born black/brown tabby)
-areas that would typically be cream are “redder”
-mutation only found in Norwegian cats so far

Question 7

MC1R- er

Answer 7

-three pair deletion causes a recessive allele
-results in a “russet” cat
-mutation found only in Burmese cats

Question 8

O locus

Answer 8

-orange
-controlled by an unknown gene located on the X chromosome and is a sex-linked trait

Question 9

TYR= C Locus

Answer 9

-full colour: C
-siamese: Cs
-Burmese: Cb
-albino c
-C>cs=cb>c

Question 10

colour point patterns

Answer 10

-tyrosinase TYR gene
-dark points in several colours
-white/pale body
-coloured on extremities
-mutation is temp sensitive
-closer to the body is warmer so no colour

Question 11

colour point allele Cs

Answer 11

-siamese
-cs/cs light body and dark extremities
-cs allele makes a temp-sensitive tyrosinase enzyme that is non-functional at cat core body temperature
-recessive mutation

Question 12

Burmese allele

Answer 12

-cb is less tempratue sensitive than the cs allele
-body is dark brown, with darker extremities

Question 13

cs/cb genotype

Answer 13

-cs/cb genotype causes colouration midway between siamese and burmese
-tonkinese cats have this genotype

Question 14

albino cats

Answer 14

-c/c cats are albino
-frameshift mutation results in a premature stop codon
-no pigments in hair or iris

Question 15

W locus= white dominant

Answer 15

-an insertion in intron of the KIT gene believed to be cause of dominant white
-caused by an insertion- feline endogenous retrovirus disrupting the gene
-causes cats to be completely white

Question 16

white cats and deafness

Answer 16

-white cats are prone to deafness
-blue eyes are more likely
-odd eyed white cats may be deaf on the blue-eyed side

Question 17

white spotting and markings

Answer 17

-white marking with white paws and underside common
-insertion in KIT gene is thought to be the cause of white spotting
-codominance and variable expression
-Ws/Ws= mostly white
-W+/Ws= some white
-W+/W+=completely pigmented

Question 18

white feet in Birman cats

Answer 18

-called gloving
-results from recessive mutation in KIT gene
-genotypes
-GG=no gloving
-Gg=no gloving
-gg= gloving