Chinchilla Genetics

There are two other chinchilla genetics documents on ChinNet too, at Mike Thurston's and Jim Jensen's pages.

Most chinchilla colours found at the moment are in colour groups which can depend on a dominant gene, but some colours can be carried by a recessive gene. Unfortunately the number of different coloured chinchillas that are available in the United Kingdom is not as great as those in the United States, but recently some new animals have entered the country.

I have not used genetic symbols to work out the combinations, but words to make it simpler and easier to understand.

Some colours are not possible to breed, like a homozygous white which has a lethal factor. If this is so, if you crossed two whites an average of 1/4 of the eggs fertilised would not develop into young. Of the 3/4 of the young that survive 1/4 of those would be standard in colour, and the other 2/4 of the young would be heterozygous, like their parents.

Punnet Squares

One of the best ways of showing genetic information is by using a 'Punnet Square'. The genes of one parent are placed down one side and the genes of the other parent are placed across the top of the square, then the offspring colours can be worked out. The genes of the parents are bold and the colours of the young are written in italics to avoid confusion.

Example of Punnet Square

Standard mated to Standard

	Standard	Standard
Standard	Standard Standard	Standard Standard
Standard	Standard Standard	Standard Standard

All the young will be standard grey in colour.

Beige mated to Black velvet (both heterozygous) :

	Black	Standard
Beige	Black Beige	Standard Beige
Standard	Black Standard	Standard Standard

The combinations above show that from this mating you could expect :

1 Brown velvet (Black and beige).
1 Heterozygous Beige (Standard and beige. The beige is dominant so the chin is beige)
1 Black velvet (Black and Standard. The Black is dominant.)
1 Standard (Standard-Standard)

One last, complex example you may want to cross a Pink White and a Brown Velvet.

On both sides of the chart you must include all the expected colour combinations you would get if you crossed each parent with a standard.

		Pink White
		White	Beige	White Beige	Standard
B r o w n V e l v e t	Black	White Black	Beige Black	White Beige Black	Standard Black
	Beige	White Beige	Beige Beige	White Beige Beige	Standard Beige
	Black Beige	White Black Beige	Beige Black Beige	White Beige Black Beige	Standard Black Beige
	Standard	White Standard	Beige Standard	White Beige Standard	Standard Standard

When two Beige characteristics appear together, the offspring will be homozygous for this colour. The average results from these combinations would be :

1 Black/White cross
2 Pink Whites
2 Black/Beige/White combined
1 White
2 Brown Velvet
1 homozygous beige
1 homozygous beige combined with black
2 heterozygous beige's
1 homozygous beige combined with white
1 homozygous beige combined with both black and white
1 Black velvet
1 Standard

Standard mated to Violet

	Standard	Standard
Violet	Standard Violet	Standard Violet
Violet	Standard Violet	Standard Violet

All of the young will be standard with a recessive violet gene.

Heterozygous Beige

	Standard	Standard
Beige	Standard Beige	Standard Beige
Standard	Standard Standard	Standard Standard

On average half of the young would be heterozygous beige and the other half would be standard.

Black velvet

	Standard	Standard
Black	Standard Black	Standard Black
Standard	Standard Standard	Standard Standard

On average half of the young would be Black velvet and the other half would be standard.

Brown Velvet

	Black	Beige	Black Beige	Standard
Standard	Black Standard	Beige Standard	Black Beige Standard	Standard Standard
Standard	Black Standard	Beige Standard	Black Beige Standard	Standard Standard

On average 1 quarter would be Black velvet, 1 quarter would be heterozygous beige, 1 quarter would be brown velvet and 1 quarter would be standard.

White

	White	Standard
Standard	White Standard	Standard Standard
Standard	White Standard	Standard Standard

On average half the young would be white and the other half would be standard.

Pink White

	Beige	White	White Beige	Standard
Standard	Beige Standard	White Standard	White Beige Standard	Standard Standard
Standard	Beige Standard	White Standard	White Beige Standard	Standard Standard

On average 1 quarter would be Heterozygous beige, 1 quarter would be White, 1 quarter would be Pink White and 1 quarter standard.

Black/White cross

	Standard	Black Beige	White Standard	Black White
Standard	Standard Standard	Beige Black Standard	White Standard Standard	Black White Standard
Standard	Standard Standard	Black Beige Standard	White Standard Standard	Black White Standard

On average 1 quarter would be standard, 1 quarter would be Brown velvet, 1 quarter would be white and one quarter would be Black/white crosses.

Charcoal

	Charcoal	Charcoal
Standard	Charcoal Standard	Charcoal Standard
Standard	Charcoal Standard	Charcoal Standard

All the young would be Standard with a recessive charcoal gene.

Charblack

	Charcoal	Black
Standard	Charcoal Standard	Black Standard
Standard	Charcoal Standard	Black Standard

On average half of the young would be Standard with a recessive charcoal gene and the other half would be Black velvet.

Ebony

	Ebony	Ebony
Standard	Ebony Standard	Ebony Standard
Standard	Ebony Standard	Ebony Standard

All the young would be Ebony because this is the dominant gene.

Sapphire

	Sapphire	Sapphire
Standard	Sapphire Standard	Sapphire Standard
Standard	Sapphire Standard	Sapphire Standard

All the young would be standard with recessive sapphire gene.

Dark Pastel

	Charcoal	Charcoal	Beige
Standard	Charcoal Standard	Charcoal Standard	Beige Standard
Standard	Charcoal Standard	Charcoal Standard	Beige Standard

On average, half the babies would be standard with a recessive charcoal gene, and the other half would be heterozygous Beige in colour.

Light Pastel

	Charcoal	Charcoal	Beige	Beige
Standard	Charcoal Standard	Charcoal Standard	Beige Beige	Beige Beige
Standard	Charcoal Standard	Charcoal Standard	Beige Beige	Beige Beige

Brown/White cross

	Standard	Standard
Standard	Standard Standard	Standard Standard
Beige Standard	Standard Beige Standard	Standard Beige Standard
Black Standard	Standard Black Standard	Standard Black Standard
White Standard	Standard White Standard	Standard White Standard
Black Beige	Standard Black Beige	Standard Black Beige
Black Beige White	Standard Black Beige White	Standard Black Beige White
Beige White	Standard Beige White	Standard Beige White
Black White	Standard Black White	Standard Black White

The average results of this combination are as follows :

2 Standards
2 Beiges
2 Black velvets
2 Whites
2 Brown velvets
2 Brown/white crosses
2 Pink Whites
2 Black/White crosses

You can reach me by email :

Michael Dewhurst (Chris.Dewhurst@btinternet.com)