Body Type

Genetics terms:      Allele      Gene      Genotype       Phenotype       Dominant Genes- can not be carried, but can be masked. [ex. the dominant Pearl gene will only express itself on a mink rat, therefore a black rat carrying the recessive mink gene could genetically be pearl, while phenetically being black]      Recessive Genes- can be carried from generation to generation and will only express itself when paired with an identical recessive gene making them homozygous recessive. [ex. a/a (black) x a/a (black) will produce all black babies unless other recessivce genes are carried by the parents]      Homozygous -  Having identical alleles for a single trait.                                  ~ homozygous recessive carries two copies of the allele that codes for the recessive trait. [ex. a/a is a rat expressing the recessive trait of black (non-banded) hair]                                  ~ homozygous dominant carries two copies of the allele that codes for the dominant trait. [ex. A/A is a rat expressing the dominant trait of agouti (banded or ticked) hair]      Heterozygous - A rat is heterozygous for a particular gene when two different alleles occupy the gene's position on the homologous chromosomes. Heterozygous genotypes are represented by a capital letter (representing the dominant allele) and a lowercase letter (representing the recessive allele) [ex. A/a is an agouti rat carrying the black gene]      EYE COLORS click on the links below for photos and genetics information  Recessive  Heterozygous  Homozygous Dominant Black Eyes  a red or pink eyed rat This is not the dominant BE (black eye) that changes the normally pink eyed c locus rats (albino, himalayan, siamese) to black  R/r or P/p ([r] for red eye dilute and [p] for pink eye dilute) black eyes carrying RED or PED  R/R or P/P ([r] for red eye dilute and [p] for pink eye dilute) black eyes - does not carry RED or PED  Red Eye Dilute (RED)  r/r [RED] red/ruby eyes - this gene also dilutes the coat  R/r black eyes carrying RED  R/R black eyes - does not carry RED  Pink Eye Dilute (PED)  p/p [PED] pink eyes - this genes dilutes the coat color significantly  P/p black eyes carrying PED  P/P black eyes - does not carry PED  Dominant Black Eye (Be) shows only on the c locus  be/be albino, himalayan, or siamese rat with pink eyes  Be/be this gene causes the normally pink eye of c locus rats to be black - carries the pink eyed gene   Be/Be [BE] this gene causes the normally pink eye of c locus rats to be black - does not carry the pink eyed gene Odd Eyes  one black eye and one red eye OR one red eye and one pink eye odd eyes are a result of both dominant and recessive 'coat' marking genes, less often found on recessives Odd eye standards- RatsPacNW: Not a separate section but will be judged if present. Odd-eyes: Two eyes of different colors.  May be black / ruby or ruby / pink.  The deepest contrast is best.  Can be shown in any recognized color and marking (usually found in American Husky and Dalmatian) AFRMA: Odd-eye rats may be shown in any recognized color. The unique feature is one eye pink and one eye dark ruby or black. The markings, if any, to be judged at the judge’s discrection and may be in a recognized or unrecognized pattern.  one black eye and one red eye OR one red eye and one pink eye odd eyes are a result of both dominant and recessive 'coat' marking genes, most often found on dominants  one black eye and one red eye OR one red eye and one pink eye odd eyes are a result of both dominant and recessive 'coat' marking genes, most often found on dominants     EAR TYPE Recessive  Heterozygous  Homozygous Dominant   Standard Ears  du/du dumbo ears  Du/du tulip shaped ears held erect over the head - carries the dumbo gene  Du/Du tulip shaped ears held erect over the head - carries the dumbo gene  Dumbo Ears  du/du [dumbo]  saucer shaped ears set low on the sides of the head Dumbo Ear Standards- RatsPacNW: Large, roundish ears, set lower on the head.  Round ears should show no prominent point, heavy folds or creases. Poor shape includes "tubular" ears, butterfly or elephant shaped.  The body type on a dumbo may be more stocky.  AFRMA: Dumbo rats to be shown in any recognized color, marking, or variety. The distinguishing feature being their low ear set. The ears are large and round, set low on the sides of the head. Head to form an equilateral triangle when viewed from above.  Du/du standard ears - carries the dumbo gene  Du/Du standard ears - does not carry the dumbo gene   BODY SIZE   Recessive  Heterozygous  Homozygous Dominant  Standard Size  dw/dw dwarf  Dw/dw standard size rat carrying the dwarf gene  Dw/Dw standard size rat - does not carry the dwarf gene  Dwarfism  dw/dw [dwarf] A lack of growth hormone results in a small stature rat around 1/3 the size of a standard size rat many dwarves have large eyes in comparison to their head Dwarf Rat Standards- RatsPacNW: Miniatures: The rat shall conform to color, marking, temperament and condition standards as for regular rats.  May have curious and busy personalities. Body size should be 1/3 size of standard rats.  Feet are smaller in proportion to body.  Tails are short in proportion to body size.  Legs are short.  Eyes should be large.  The facial features of males may be more feminine and this should not be faulted. Faults:  Small standard rat that is not genetically a dwarf rat. Stockys: The rat shall conform to color, marking, temperament and condition standards as for regular rats.  May have curious and busy personalities. Body size should be 1/3 size of standard rats.  Feet are smaller in proportion to body.  Tails are short in proportion to body size. The facial features of males and females are shortened and wider than miniature dwarf rats.  Eyes are very large and out of size proportion.  Legs are short.  Kittens may have thin tails. Faults:   Small standard rat that is not genetically a dwarf rat.  Dw/dw standard size - carries the dwarf gene  Dw/Dw standard size - does not carry the dwarf gene    TAIL Recessive  Heterozygous  Homozygous Dominant   Standard    rat with normal long tail  rat with normal long tail - does not carry the combination of genes for taillessness Tailless (Manx)  Taillessness in rats is very complex and not completely understood as of yet. It does appear to be a recessive gene but not a simple recessive. There needs to be a certain combination of genes at play in order to produce tailless babies. Tailless Standards- RatsPacNW: The tailless rat should not have points taken off for being too small.  When allowed to walk they should sit a little higher in the rear then most rats. Their spine should feel like it ends where the tail would begin (that is quite a bit farther then most people think) there should not be anything sticking out. You should be able to feel the last vertebrae in their spine.  A rat should not be docked for having a small piece of skin sticking out so long as their is no bone.   A tailless rat should be more rounded in body shape, not fat but the whole body should appear more rounded and shortened. Hind legs should be slightly longer then the front legs (not dramatically). The judge should have treats for this class, the rats should be able to stand on their hind legs with ease! Check the rear end for scars, if it looks like the rats tail was CUT off, they should be disqualified!  DQ: deformed or shuffles when walks. AFRMA: Complete absence of a tail, similiar to the Manx cats.