Marsagan Labradors

Coat Colour Genetics

In diploid organisms (humans, dogs...), chromosomes go in duplicated pairs. Both chromosomes of a given pair contain the same genes in the same locations. The same gene can have different types which are called alleles. Genes are said to be either dominant or recessive, but what this really means is that the alleles of a given gene are either dominant or recessive. If an allele is dominant (eg. brown eyes) it only needs to be expressed once (ie. on one of two chromosomes of a given pair) for that trait to be expressed. If it is recessive (eg. 'blue eyes') it needs to be expressed twice (in both chromosomes of one pair) for the trait to be expressed. The genetic coding of an organism is called its genotype, the physical expression of this genotype is called the phenotype (in this case, 'having brown/blue eyes').

In Labradors, two genes code for the coat colour. In other words there are two chromosomes coding for coat colours, and as there are two copies of each chromosome, four chromosomes from two different pairs affect coat colour. Each of the two genes coding for the coat colour has two alleles.
The first gene is the coat colour gene and determines the dark coat colour: black is dominant ('B') and brown is recessive ('b'). The second gene is the expression gene and determines the ability to express the dark colour: the 'ability to express a dark coat' is dominant ('E') and the 'inability to express a dark coat' ('e') is recessive ('e'). Hence there are only two coat colours: black and brown. Yellow dogs are the result of the inability to express a dark coat colour.
Puppies inherit one coat colour gene (B or b) and one expression gene (E or e) from each parent. So... a coat colour gene on a dog can be BB, Bb or bb. An expression gene can be EE, Ee or ee. The combination of these two genes gives the puppies' phentoype.

Labrador Dog Colours

genetics

BBEE

BBEe

BBee

BbEE

BbEe

Bbee

geneticschocolate

bbEE

NBP bbee

bbEe

Black (BBEE)	50% Black (EEBB), 50% Black carries Yellow (BBEe)	Black carries Yellow (BBEe)	50% Black (BBEE), 50% Black carries Brown (BbEE)	25% Black (BBEE), 25% Black carries Yellow (BBEe), 25% Black carries Brown (BbEE), 25% Black carries Brown & Yellow (BbEe)	50% Black carries Yellow (BBEe), 50% Black carries Yellow & Brown (BbEe)	Black carries Brown (BbEE)	Black carries Yellow & Brown (BbEe)	50% Black carries Brown (BbEE), 50% Black carries Brown & Yellow (BbEe)
50% Black (EEBB), 50% Black carries Yellow (BBEe)	50% Black carries Yellow (BBEe), 25% Black (BBEE), 25% Yellow (BBee)	50% Black carries Yellow (BBEe), 50% Yellow carries Black (BBee)	50% Yellow carries Black (BBee), 50% Yellow carries Brown (Bbee)	25% Black carries Yellow & Brown (BbEe), 25% Black carries Yellow (BBEe), 12.5% Black (BBEE), 12.5% Black carries Brown (BbEE), 12.5% Yellow carries black (BBee), 12.5% Yellow carries Brown (Bbee)	25% Black carries Yellow (BBEe), 25% Black carries Yellow & Brown (BbEe), 25% Yellow carries Brown (Bbee), 25% Yellow carries Black (BBee)	50% Black carries Brown (BbEE), 50% Black carries Brown & Yellow (BbEe)	50% Black carries Brown & Yellow (BbEe), 50% Yellow carries Brown (Bbee)	33.3% Black carries Brown (BbEE), 33.3% Black carries Brown & Yellow (BbEe), 33.3% Yellow carries
Black carries Yellow (BBEe)	50% Black carries Yellow (BBEe), 50% Yellow carries Black (BBee)	Yellow carries Black (BBee)	50% Black carries Yellow (BBEe), 50% Black carries Brown & Yellow (BbEe)	25% Black carries Yellow & Brown (BbEe), 25% Black carries Yellow (BBEe), 25% Yellow carries Black (BBee), 25% Yellow carries Brown (Bbee)	50% Yellow carries Black (BBee), 50% Yellow carries Brown (Bbee)	Black carries Brown & Yellow(BbEe)	50% Yellow carries Black, 50% Yellow carries Brown	50% Black carries Brown & Yellow (BbEe), 50% Yellow carries Brown (Bbee)
50% Black (BBEE), 50% Black carries Brown (BbEE)	25% Black (BBEE), 25% Black carries Yellow (BBEe), 25% Black carries Brown (BbEE), 25% Black carries Brown & Yellow (BbEe)	50% Black carries Yellow (BBEe), 50% Black carries Brown & Yellow (BbEe)	25% Black (BBEE), 25% Brown (bbEE), 50% Black carries Brown (BbEE),	25% Black carries Brown (BbEE), 25% Black carries Brown & Yellow (BbEe), 12.5% Black carries Yellow (BBEe), 12.5% Black (BBEE), 12.5% Brown (bbEE), 12.5% Brown carries Yellow (bbEe)	50% Black carries Brown & Yellow (BbEe), 25% Brown carries Yellow (BbEe), 25% Black carries Yellow (BBEe)	50% Black carries Brown (BbEE), 50% Brown (bbEE)	50% Black carries Brown & Yellow (BbEe), 50% Brown carries Yellow (bbEe)	25% Brown (bbEE), 25% Black carries Brown (BbEE), 25% Brown carries Yellow (bbEe), 25% Black carries Brown & Yellow (BbEe)
25% Black (BBEE), 25% Black carries Yellow (BBEe), 25% Black carries Brown (BbEE), 25% Black carries Brown & Yellow (BbEe)	25% Black carries Yellow & Brown (BbEe), 25% Black carries Yellow (BBEe), 12.5% Black (BBEE), 12.5% Black carries Brown (BbEE), 12.5% Yellow carries black (BBee), 12.5% Yellow carries Brown (Bbee)	25% Black carries Yellow & Brown (BbEe), 25% Black carries Yellow (BBEe), 25% Yellow carries Black (BBee), 25% Yellow carries Brown (Bbee)	25% Black carries Brown (BbEE), 25% Black carries Brown & Yellow (BbEe), 12.5% Black carries Yellow (BBEe), 12.5% Black (BBEE), 12.5% Brown (bbEE), 12.5% Brown carries Yellow (bbEe)	6.25% Br, 6.25% B, 25% B carries Y&Br, 12.5% B carries Y, 12.5% B carries Br, 12.5% Br carries Y, 12.5% Y carries Br, 12.5% carries Y	25% Black carries Brown & Yellow (BbEe), 25% Yellow carries Brown (bbee), 12.5% Black carries Yellow (BBEe), 12.5% Brown carries Yellow (bbEe), 12.5% Yellow carries Black (BBee), 12.5% Yellow NBP (bbee)	25% Black carries Brown & Yellow (BbEe), 25% Brown (bbEE), 25% Black carries Brown (BbEE), 25% Brown carries Yellow (bbEe)	25% Black with Brown & Yellow (BbEe), 25% Brown carries Yellow (bbEe), 25% Yellow carries Brown (Bbee), 25% Yellow NBP (bbee)	25% Black carries Brown & Yellow (BbEe), 25% Brown carries Yellow (bbEe), 12.5% Black carries Brown (BbEE), 12.5% Yellow carries Brown (Bbee), 12.5% Yellow NBP (bbee), 12.5% Chocolate (bbEE)
50% Black carries Yellow (BBEe), 50% Black carries Yellow & Brown (BbEe)	25% Black carries Yellow (BBEe), 25% Black carries Yellow & Brown (BbEe), 25% Yellow carries Brown (Bbee), 25% Yellow carries Black (BBee)	50% Yellow carries Black (BBee), 50% Yellow carries Brown (Bbee)	50% Black carries Brown & Yellow (BbEe), 25% Brown carries Yellow (BbEe), 25% Black carries Yellow (BBEe)	25% Black carries Brown & Yellow (BbEe), 25% Yellow carries Brown (bbee), 12.5% Black carries Yellow (BBEe), 12.5% Brown carries Yellow (bbEe), 12.5% Yellow carries Black (BBee), 12.5% Yellow NBP (bbee)	50% Yellow carries Brown (Bbee), 25% Yellow carries Black (BBee). 25% Yellow NBP (bbee)	50% Black carries Brown & Yellow (BbEe), 50% Brown carries Yellow (bbEe)	50% Yellow NBP (bbee), 50% Yellow carries Brown (Bbee)	25% Yellow carries Brown (Bbee), 25% Black carries Brown & Yellow (BbEe), 25% Yellow NBP (bbee), 25% Brown carries Yellow (bbEe)
Black carries Brown (BbEE)	50% Black carries Brown (BbEE), 50% Black carries Brown & Yellow (BbEe)	Black carries Brown & Yellow(BbEe)	50% Black carries Brown (BbEE), 50% Brown (bbEE)	25% Black carries Brown & Yellow (BbEe), 25% Brown (bbEE), 25% Black carries Brown (BbEE), 25% Brown carries Yellow (bbEe)	50% Black carries Brown & Yellow (BbEe), 50% Brown carries Yellow (bbEe)	Brown (bbEE)	Brown carries Yellow (bbEe)	50% Brown (bbEE), 50% Brown carries Yellow (bbEe)
Black carries Yellow & Brown (BbEe)	50% Black carries Brown & Yellow (BbEe), 50% Yellow carries Brown (Bbee)	50% Yellow carries Black, 50% Yellow carries Brown	50% Black carries Brown & Yellow (BbEe), 50% Brown carries Yellow (bbEe)	25% Black with Brown & Yellow (BbEe), 25% Brown carries Yellow (bbEe), 25% Yellow carries Brown (Bbee), 25% Yellow NBP (bbee)	50% Yellow NBP (bbee), 50% Yellow carries Brown (Bbee)	Brown carries Yellow (bbEe)	Yellow carries Brown (bbee)	50% Yellow NBP (bbee), 50% Brown carries Yellow (bbEe)
50% Black carries Brown (BbEE), 50% Black carries Brown & Yellow (BbEe)	33.3% Black carries Brown (BbEE), 33.3% Black carries Brown & Yellow (BbEe), 33.3% Yellow carries Brown (Bbee)	50% Black carries Brown & Yellow (BbEe), 50% Yellow carries Brown (Bbee)	25% Brown (bbEE), 25% Black carries Brown (BbEE), 25% Brown carries Yellow (bbEe), 25% Black carries Brown & Yellow (BbEe)	25% Black carries Brown & Yellow (BbEe), 25% Brown carries Yellow (bbEe), 12.5% Black carries Brown (BbEE), 12.5% Yellow carries Brown (Bbee), 12.5% Yellow NBP (bbee), 12.5% Chocolate (bbEE	25% Yellow carries Brown (Bbee), 25% Black carries Brown & Yellow (BbEe), 25% Yellow NBP (bbee), 25% Brown carries Yellow (bbEe)	50% Brown (bbEE), 50% Brown carries Yellow (bbEe)	50% Yellow NBP (bbee), 50% Brown carries Yellow (bbEe)	50% Chocolate caries yellow (bbEe) 25% Chocolate (bbEE) 25% Yellow carries chocolate (bbee)