Eva's Rat Colour Genetics Page - Marked

Eva's Home Page Eva's Cavy Page Eva's Natal Rat Page Eva's Mouse Page Eva's Hamster Page Eva's Gerbil Page Eva's Rat Page Eva's Rat Colour Genetics Page

The Marked Group consists of several different markings made from different genes. Here I only list the genetics of the black varieties of each marking. These markings are possible to combine with any of the common colours, but looks best on the darker colours.

  1. European Irish
    To be a white, equilateral triangle on the chest, with the tip of the triangle pointing towards the tail. White front paws, and white hind feet halfway to the hock. Triangle to be even and occupy all space between the front legs, without extending on the legs or in a streak down the belly.
    Other names: English Irish.
    Known since: 1837 (Rattus rattus), in standards 1907.

  2. European Berkshire
    To be a white, symmetrical rektangle on the belly. The rektangle to be as large as possible. Markings not to extend up on the sides or touch the feet markings. Edges to be as straight as possible and no coloured hairs or spots is allowed inside the rektangle. Front legs to be white halfway up the leg (e.g. halfway to the elbow). Hind feet to be white to, and just including, the hocks. Tail to be white from tailtip and halfway to the base of the tail.
    Genetics: aaHh or aahihi?
    Known since: 1957.

  3. American Berkshire (No photos yet.)
    To be a totally white underside. Markings to extend up on the inner sides of the feet markings. Edges to be as straight as possible and no coloured hairs or spots is allowed inside the white underside. Legs to be coloured on the outsides. Tail to be white from tailtip and halfway to the base of the tail.
    Genetics: - aahihn?
    Known since: ?

  4. Hooded
    Hood to be even and cover head, throat, chest and shoulders. Hood to continue in a saddle that follows the spine all the way out on the tail. The saddle to be even, unbroken and circa 2 cm wide going as far out as possible on the tail. The white markings to be clean and without tinges and spots.
    Genetics: hh.
    Known since: 1840, in NFRS standards 1901 as Even Marked. In standards as Hooded in 1976.

  5. Capped
    Head to be covered by a cap that precisely passes the ears and follow the line of the lower jaw bone. The colour not to extend behind the ears or under the lower jaw bone. Blaze or spot wanted and should not be open between the ears. The rest of the body to be cleanly white without tinges or patches.
    Known since: 1915 (not verified 1860). In NFRS standards 1981.

  6. Masked
    Head to be covered by a mask over the eyes. The rest of the body to be cleanly white without tinges or patches.
    Known since: ?

  7. Variegated
    Head and shoulders to be covered by a coloured hood with a blaze. The back to be covered by evenly distributed patches that also shall be on the tail and the sides of the body. Belly and feet white.
    Other name: Broken Marked.
    Genetics:
    Known since: 1900, in standards 1909 to 1935. Disappeared, and came then back 1977 to disappear again and return 1981. Again in standards 1984.

  8. Bareback
    Head, neck, and shoulders to be covered by an even coloured hood. Reminder of body to be white. White parts to becleanly white without tinges, patches or coloured hairs. Belly and feet white.
    Known since: Imported to Sweden in 1986 from the US.

  9. Collared
    Overall description: Coloured rat with a collar of white around its neck.
    Genetics: ??
    Known since: At least before the Husky came to Sweden.

  10. Husky
    Overall impression: A mix of coloured and white hairs, including hairs that are partly coloured and partly white. The impression reminds about silvering but is a lot stronger. The mix of white and coloured hairs to be even and seem to be half white hairs and half coloured hairs. (It is really mostly the guard hairs that are white, giving the effect due to the properties of the fur of the rat.)
    The Husky ought to be based on a dark colour in order for the Huskyeffect to be clearly seen.
    Marking: American Berkshire. Blaze, spot or streak (on forehead) allowed. Eyecolour: To conform with eyecolour of the base colour. (Se standardized colours.)
    Faults: The bleaching effect of the Husky gene on the base colour not to be too strong.
    Genetics: A marking gene similar to W on the mouse.
    Known since: 1994 in Sweden. May be in standards as Silver Black in the USA. The variety is called Husky in Holland, and several other countries.

  11. Husky Hooded
    Overall impression, eyecolour, faults: as for Husky.
    Marking: Two to three cm wide band from nose to tail. It is preferred that the marking continues as far out on the tail as possible. Blaze, spot or streak is allowed, but as little white in the face is preferred to give the impression of a band all over the rat.
    Other name/s: "Striped".
    Genetics: A marking gene similar to W on the mouse, probably also hh.
    Known since: Soon after normal Husky.

  12. Husky Collared
    A new variety.

  13. Dalmation (No photo yet.)
    Overall impression: To be covered with evenly distributed spots, also on the tail, sides, head and shoulders. Spots to be smaller than the spots on the variety Varigated. Shall not resemble Hooded in any way.
    Belly colour: White.
    Feet: White.
    Eye colour: Conforming with body colour.
    Genetics: Husky variety (may be a combination of Husky and Variegated).
    Known since: 1997 (Åkello - Swedish wholesale rat breeder that sells to pet shops).

  14. Broken (No photos yet.)
    Overall impression: Few and assymetrical big spots on the head and body.
    Belly colour: White.
    Feet: White.
    Eye colour: Conforming with body colour.
    Genetics: Husky variety.
    Known since: 1997 (Åkello).

  15. Chinchilla (No photos yet.)
    Overall impression: To have a white band and black ticking, reminding of the chinchilla. This colour to be evenly distributed over the body, without tinges, white hairs or spots.
    Undercolour: To be black.
    Band colour: To be white.
    Ticking: Has to be black as raven.
    Belly colour: To be white.
    Feet: To conform with body colour.
    Eye colour: Black.
    Genetics: (Husky variety).
    Known since: In Sweden around 1996. In 1998 another Chinchilla-looking gene was imported from the US.

The marked rats seem to be the most common rats among pet owners and breeders in Sweden.

I do not breed marked rats myself but I have read "An extreme allele of Hooded spotting in the Norway rat" by Roy Robinson, Genetica, 79: 139 - 141, 1989.

Last update: 13th of February 2003.