Ratte Rosalea, Burmese Harley

Burmese und Wheaten Burmese

Kathrin Guttmann Shades / Shade, Knowledge, Breeding & Genetic

The standard of the Burmese rat

Burmese can theoretically Shade (Shades) appear on each color, wherein it is at its best to bear on dark colors. but only Burmese is standardized to black or agoutifarbenen animals.

The NFRS and AFRMA demand at a Burmese uniform, strong medium brown stains without Silvering or, with darker points of the same color. There should be a strong contrast between the points and the body color. The eyes are black.

In the German standard of color rat is a rich, deep brown required as the base color. Tapering to head- and the tail and feet the color changes into a darker brown (from the end of the hip, facial, in the middle between the front and your, from the feet from the end of the ankle). Missing Points shall be considered defective.

In the standard the NFRS a Wheaten Burmese is described as beige with significantly darker Points, the undercoat may be light gray. The belly should have a bright silver gray, The eyes are black.

The AFRMA has been conducting 2008 Wheaten Burmese under the name Agouti Burmese as a nonstandard variant. The body color should be a not too dark or warm red to brown are, Cinnamon is similar, with a light gray-brown at the base of the hair. The coat should be uniform ticked with mid-brown outer coat. The belly should have a bright silver gray. The points should be considerably darker than the body color.

Russian Blue Burmese are guided by the AFRMA as unrecognized color-shade combination. The color should be a warm medium gray with blue shades without silvering or stains with clearly visible darker points of the same color. A slight mottling and a ticked appearance (Heathering) is very common and no error.

Russian Blue Burmese Agouti are the result AFRMA to have a light sand color with blue ticking, the Poinst to be much darker than the body color. The undercoat should be light blue-gray. The stomach should be of pale silvery-gray. The eyes are black.

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Russian Blue Burmese Harley

The genetics of Burmese rat

Burmese have given great mystery at the beginning of their breeding history breeders in terms of inheritance this Shades. I want to represent the history of the development of the Burmese rat here, to show once, that it is not always easy to determine, how they are inherited certain characteristics.

have the output of the Burmese animals originated in a laboratory line of Edinburgh University Scotland, from albino rats and, which were described as "reddish Cinnamon" Hooded, file. From this line two animal went to a breeder: The Milkman, of a Black Eyed White should be, and Crystal, a reddish Cinnamon Hoddeds.

Various matings and Rückverpaarungen gave the following colors (are not consistent with current common names):

„milky-tea taupe“ (literally: "Tea with milk Mole-color") or "stone" (because it looked like Stone in mice)

and

Black Eyed Cream"Or"Black Eyed Champagne“ (Cream / Champagne with dark eyes)

Image
mole, French "Taupe" (From Didier Descouens - own work, CC BY-SA 4.0, Link)
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Burmese Harley

The C(e)-theory

Die B.E. Champagne developed in shedding Points, However, the later faded. At that time it was thought, Burmese that is transmitted over the C-locus and the allele c(e) responsible is One came from following genotypes, the inheritance of Stone (UK, referred to in the AFRMA with reverse Siamese) meet in mice:

  • c(e)c(e)
  • Taupe/Stone
  • c(e)c
  • or for Black Eyed Cream. Ivory in mice (by AFRMA)
  • c(e)c(h)
  • Color Point Beige

In October 1998 came a trio of Black Eyed Creams to a breeder in London. The three rats were probably F2 animals from Black Eyed Cream F1 animals with "The Milkman" as a father. At the time, many test breeding have been made with the animals, to realize, Genetics which is behind the Shade. After some time, it was found, that the stone animals a slight ticking (Cream and white on beige) showed, which led regarding the genotype to believe, dass Black Eyed Creme und Black Eyed Himalaya Non-Agouti (aa) are based, while Stone Agouti should be based (A-). However, it was possible in any test mating, what B.E. to breed Siamese Cream x or x Stone Pink Eyed White pure agoutis.

In the year 2000 the company was renamed the Farbbezeichnugen:

Stone/Taupe was to Biscuit

Black Eyed Cream was to Milk

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Burmese from the Rendevous Council

The e-Theory

At times, it was assumed, that another locus than the C locus is responsible for the new variant. In mice there is the Extension locus, on the opposite to the wild-type allele recessive e (recessive yellow) ensures, that black pigment is reduced and monochrome yellow hair arises. However, the option of inheriting Biscuit could (formerly Stone / Taupe) and Milk (vormals Black Eyed Cream) be ruled out relatively quickly via a e-locus by trial mating.

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Burmese Harley

The C(e)-c(b)-theory

2001 appeared the first Sable on Burmese, the dark and gray were known as the "Biscuit" Animals and black points had. Meanwhile, they had broken away from the idea, that the inheritance of the new Shades alone a c(e)-Allele on the C locus runs, and went analogy of an inheritance for Burmese in cats from. It now adopted the following genotypes:

  • c(b)c(h)
  • Taupe/Stone/Biscuit
  • c(e)
  • Ivory (before Black Eyed Cream or. Milk)
  • c(b)c(h)
  • Sable Burmese
  • unknown
  • Dark Eyed dark Cream

But even with these assumptions, the results of test breeding could not be explained.

Burmese Variegated Farbratte
Burmese Variegated (non-standard)

The C(b)-theory

2005 then the following genetics was proposed:

  • aa c(b)c(b)
  • Sable Burmese
  • aa c(b)c(h) or c aa(b)c
  • Burmese
  • A- c(b)c(b)
  • Wheaten Sable Burmese
  • A- c(b)c(h) or A- c(b)c
  • Wheaten Burmese

But this assumption was refuted by test breeding.

Image

comparison: top Siamese, unten Burmese, Those: Rendevous Rats

The Bu-theory

Today, it is at least in Germany assume, that there is a separate locus, encoded on the Burmese and affects the expression of the alleles on the C-locus. The Burmese allele is dominant or against the non-Burmese allele. the wild-type allele of the. the corresponding animal is allowed to become visible to the effect of Burmese allele carry no wild-type allele on a C-Locus, d.h. it must not be the genotype C- feature. This produces the following genotypes:

  • aa c(h)c(h) BuBu oder aa c(h)c BuBu
  • Sable Burmese mit Points
  • cc aa BuBu
  • Sable Burmese ohne Points
  • aa c(h)c(h) Bubu oder aa c(h)c Bubu
  • Burmese mit Points
  • cc aa Bubu
  • Burmese ohne Points

The inheritance of Wheaten Burmese is analogous with A- Instead of aa on the Agouti locus.

Image
Burmese cub, Those: Rattery of the Walking Rats

Die Be(this)-theory

Some growers argue, that must be present in a Burmese also definitely a Black Eyed allele. This allele is dominant over the non-black-eyed allele, but only in albino, Himalaya, Siam or Devil visible, So in animals, would have the red due to a C-locus allele eyes. In these animals, the Black Eyed provides allele for, that the eyes are black. Another theory says, that Burmese by a third black eyed allele Be(this) (next to the Black Eyed allele Be and the Non-Black-eyed allele be) is caused.

Image
Wheaton Burmese (Those: Rattery of the Walking Rats)

The C(e)-c(i)-theory

To make the whole thing even more complicated, was also suggested, In addition to the already illustrated above allele c(e) to accept a further C-locus allele, the C(i). Therefore, the following alleles could be on the C locus:

  • C
  • Wild form
  • c(e)
  • extreme Dilute
  • c(h)
  • Himalaya
  • c(i)
  • intense Dilute

This implies the following combinations would result:

  • CC
  • Wild form (Black bzw. Agouti)
  • c(e)c(e)
  • Sable Burmese
  • c(e)c(h)
  • Burmese
  • c(e)c(i)
  • Burmese (too bright)
  • c(h)c(i)
  • Black Eyed Siamese
  • c(i)c(i)
  • Black Eyed Himalaya
  • c(e)c
  • Burmese (extreme hell) or. Dark Cream in NFRS
  • c(i)c
  • Ivory

Current view in Germany

Currently it is based on the theory in Germany, that two loci are involved, and that the Burmese allele dominant or. is intermediate to the wild-type. In addition, Burmese shows only, if no non-albino allele C is present, So only cc, cc(h) and c(h)c(h). The genotypes CC or CC Burmese is phenotypically distinct and remains "invisible".

  • Bubu c(h)c(h)
  • Burmese in a normal Braunton, pronounced Point
  • BuBu c(h)c(h)
  • Sable Burmese, Dark brown, pronounced Points
  • Bubu c(h)c
  • Pale Burmese, lighter than normal, weaker Points
  • BuBu c(h)c
  • Pale Sabel Burmese
  • Bubu cc
  • Burmese ohne Points (named in GB also Biscuit Cream)
  • BuBu cc
  • Sable Burmese ohne Points

All information above refer to the genotype aa, so animals, the homozygous for non-agouti (Black) are. Animals with at least one allele Agouti (So Aa or AA) shape from the corresponding Wheaten Burmese phenotype.

Finally it should be noted, that the professional world is currently not quite agree on the inheritance of Burmese. The National Fancy Rat and Mouse Association therefore writes, that genetic background has not been assigned to Burmese and is still under investigation. I recommend, play through various explanations variants at once own matings, because sometimes different explanations fit the same litter.