Hawthorn Rat Varieties

Most rat markings are created by mutations at the H-locus. The most distinctive is probably the hooded, but the full variety is quite amazing. Opinions on which alleles actually exist in the fancy at the moment differ, but some known alleles include:

H - Wild type, minimum white spotting.
H^e - Quite extensive white spotting
hⁱ - Irish, small amount of spotting confined to the underside
h - Hooded, extensive white spotting confined to the rear end of the animal
Hⁿ - Notched, quite extensive white spotting
H^ro - Robert type, lethal when homozygous, gives a small amount of white spotting with a fading effect

All of these mutations are co-dominant, meaning hetrozygous rats are different varieties from homozygous rats. Not all of these varieties have been bred/confirmed and many are missing, so this chart will no doubt be updated at a later date. Marked varieties are difficult to breed, with most of the offspring produced being mismarked which should be taken into account when trying to decide the marking of a rat.

H/H Self

H/h or H/H^e or H/Hⁿ Berkshire (with varying amounts of white, pictured is a standard H/h)

H/H^ro Essex

H^e/H^e or H^e/Hⁿ or H^e/H^ro Black eyed white

H^e/H^e or H^e/Hⁿ or H^e/H^ro Patched/mismarked/masked

H^e/H^e or H^e/Hⁿ or Hⁿ/Hⁿ Capped/Bareback

H^e/hⁱ or Hⁿ/hⁱ Variegated or "variberk"

hⁱ/hⁱ or H/hⁱ Irish

The downunder gene modifies the pattern of white spotting to leave a saddle (like hooded) but across the stomach. Further modifiers or combinations of H locus alleles can interact with this modifier to give a whole variety of new patterns.

H/h^du Downunder Berkshire

h/h^du Downunder hooded

H/H	Self
H/h or H/H^e or H/Hⁿ	Berkshire (with varying amounts of white, pictured is a standard H/h)
H/H^ro	Essex
H^e/H^e or H^e/Hⁿ or H^e/H^ro	Black eyed white
H^e/H^e or H^e/Hⁿ or H^e/H^ro	Patched/mismarked/masked
H^e/H^e or H^e/Hⁿ or Hⁿ/Hⁿ	Capped/Bareback
H^e/hⁱ or Hⁿ/hⁱ	Variegated or "variberk"
hⁱ/hⁱ or H/hⁱ	Irish