Cold Weather Can Change What Aspect of a Himalayan Rabbit?

This site has a well-written introduction to genetics and to rabbit coat colors at Aurora Rabbits: Raising Rabbits.com

There is likewise an excellent description of rabbit coat color genetics by Laurie Stroupe Of The Nature Trail Rabbitry. Information technology deals with Holland Lops and then skips over a few details that pertain to Rex, but is very thorough with lots of tables and pictures.

Another site full of great pictures & descriptions (with lots of Rex photos) by Pamela Nock

The Three Little Ladies Rabbitry has a neat color chart.

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When it comes to glaze colour, believe it or not, at that place are just two Central Pigments: Blackness (eumelanin) & Yellow(red - phemelanin). The expressed colour is a function of how much blackness or yellow pigment exists in the hair, which can change not only from hair to pilus, simply also along the length of a single hair. In rabbits, at that place can be as many equally v bands of color on a single hair.

In addition, most animals have two types of pilus: 'outer' guard hairs which are stiffer, thicker, and oftentimes straighter than the finer, wavier, and softer undercoat hairs. The outer glaze consisting of guard hairs protects the fauna, while the undercoat provides insulation.

All genes come in pairs. If both genes of a pair are the same, it is said to be homozygous for that trait.

Genotype refers to the gene itself, while phenotype refers to what we can encounter. Sometimes a phenotype volition imply a certain combination of genes just the actual genotype is dissimilar. The all-time way to discover an animal'due south genotype is through test breeding with an animate being whose genotype is known.

At that place are 5 main groups of color genes, each controling a different aspect of the color and markings. The genes inside each grouping are listed in decreasing order of dominance. A Uppercase letter denotes a dominant factor.

A = agouti
a^t = tan (otter)
a = self

The pattern gene controls how the color appears on the hair. The authorization human relationship for these genes is quite simple: each allele is completely ascendant over the ones 'below information technology (equally listed above). This means that the following pairs will all look exactly the same: AA, Aa^t , Aa. They will all wait like agoutis. A tan (or otter) tin can exist a^ta^t or a^ta, and a self can just be aa. Unless you know the genetic make-up of the parents, it is not possible to tell what the second factor is on an agouti or tan without exam breeding.

Agouti is the basic "wild" colour. Hairs on different parts of the torso are colored differently, just will have iii-v unlike colored bands on each pilus. This pattern looks different on a rex considering of the shorter hairs. The bands are smaller and the colors appear more intense. The Castor is the name given to the blackness agouti (the standard wild color). Their hairs should take at least 3 rings: the undercolor should be slate greyness; the intermediate color should be as rich an orange or rufous red every bit possible, and the tips should exist black.

The otter (called tan in most other breeds) should take a solid trunk top color with a lighter undercolor (next to the skin). The underside (from chin through belly to tail) should be white on the surface with a greyness undercolor, and in that location should be a redish line betwixt the torso colour and the undercolor. The insides of the ears, and around the olfactory organ and eyes should besides be red (i.e. red or orange in total concentration [black or chocolate] rabbits and tan or cream in dilute [bluish or lilac] rabbits).

The self rabbits should be exactly the same color all over their bodies right downward to the peel.

There are just two alleles in this group: the "blackness" results in more intense looking colors and the brown changes the black parts of the rabbit to brown. This ways that in the Brush for case, the tips of the hairs go brown instead of black, making the rabbit look much redder.

B = Blackness
b = Chocolate

This gene affects the intensity of melanin production in the coat hairs. The normal or dominant form, C, is what might exist termed 'full color' concentration. In that location are however a number of incompletely ascendant alleles on this locus, with varying effects on color intensity. At least some of these variant forms are temperature sensitive - the higher the temperature, the more effective they are (i.e, the lighter the color).

The dominant form is C- and results in full color concentration.

The outset variant is, c^chd, is (dark) chinchilla. This lightens most or all of the phemelanin with piddling or no effect on eumelanin. E.g. information technology turns black+tan to black+silver.

The side by side variant is shaded (or sable; sometimes likewise chosen light chinchilla) - c^chl. This 1 lightens nigh of all of the phemelanin, and some of the eumelanin. The effect is similar to that of the chinchilla variant, just further lightens the blackness turning it into more of a sepia color.

Second last is the Himalayan (or Californian) allele (c^h).This one has a profoundly temperature sensitive consequence, resulting in hair growing from the warmest parts of the body totally white, and allowing color to develop just on the cooler parts of the torso. This allele is also affected by external temperatures, and then that colors tend to fade in the summer and go more than intense in the winter. Any parts of the rabbit that are exposed to cooler temperatures will abound more colored fur, which tin effect in 'smuttiness', especially around the rear ruff or dewlap.

Finally, the most recessive allele in this series is c, truthful pink-eyed albino. This allele prevents ALL pigment from forming, and must be nowadays in the homozygous country (cc) in order to be expressed..

Another Manner to Look at Information technology

The color concentration cistron controls the corporeality of paint in the hair; relative amounts shown every bit units of black 'B' and yellow( or red) 'Y' color. Imagine that the total amount of pigment in pilus is the aforementioned for all hairs. As a result, shorter hairs announced darker (and also why long-haired varieties look faded). This explains the shading pattern found in seals, sables, torts, and the pointed colors. The color pattern of the chinchilla (C^chd) is essentially the aforementioned as that for the agouti except that is lacks the reddish colour in the mid-band.

C = Normal [BBBBYYY]
C^chd = Dark Chinchilla [BBBBY–]
C^chl = Light Chinchilla [shaded : seal & sable] [BB—–]
C^h = Himalayan [BB—–] (with an added temperature-sensitive feature that prevents pigment from forming on the hairs when the follicles are warmest.
c = White [Albino : absenteeism of color] [——-]

Dark chinchilla removes most of the yellow band. It makes the skin expect brown but takes the carmine color out of the hairs. Note that a chocolate chin retains the brown hue in the tipping but has completely lost information technology from the midband.

Controls the "intensity" of the color: a diluted black is a blue, and a diluted brown is a lilac. The dilution affects the whole rabbit, non just the pilus colour. This includes the pigmentation in the peel and the eye color.

D = Total Forcefulness
d = Diluted

We can look at the colour (black vs brown) and the dilution genes together:
– B- – D- – = Blackness (where the – represent A, C, and E)
– B- – dd – = Blue
– bb – D- – = Chocolate
– bb – dd – = Lilac

Together, these 2 genes account for the 4 main color variations of all the other shades and patterns. For example in the agouti grouping we have: brush (black), opal (blue), amber (chocolate), lynx (lilac).

These alleles control the presence, and extent of black on tips of hair and in undercolor. More extension causes the tipping to extend further down the shaft of each hair, and less extension keeps it at the tips. Non-extension gets rid of the tipping altogether, and the Japanese allele causes the black to announced in patches rather than on each hair, similar to the calico blueprint of cats.

E^d = Dominant [non accepted in King]
Eastward^{due south} = Steel [ non accepted in REX; causes the black on the hair to be extended, often covering the middle band with dark.]
Due east = Normal
due east^j = Japanese [ not accepted in REX [excpet for tri-colour]; responsible for harlequin patterns]
e = Non-Extension [helpfulfor Ruddy]

The E-series has some partial dominances which tin can crusade the second due east-gene of a heterogygous pair to evidence through.

The Dominant Blackness (Eastward^d ) makes agoutis look like blacks. For this reason it is only 'useful' in solid colored rabbits (selfs).

The Steel (E^south ) causes the darker undercolor to be extended. The ticking may too appear longer. This turns the short-haired areas nighttime and makes an agouti rabbit look like the top coat is too heavy. It as well tends to plow the underside (belly) dark.

Next is normal extension (East) which allows the banding and colors to prove through 'naturally'.)

The japanese extension (e^j ) has a randomizing result on the distribution of color. In a solid rabbit, it is responsible for the harlequins. It is the only east-serial gene that is adequate in harlequin rabbits. The black-orange and blue-foam carry C for full color concentration, and the magpies (black-white and chocolate-white) bear the chinchilla gene (c^chd ). An agouti or otter with 1 full extension (E) and ane japanese factor (e^j ) will always show the randomizing event which is about notable inside the ears and around the eyes.

In Rex, a self (no white: enen) harlequin and a broken (En-) is a tri-color and will show the night parts equally actual spots on an orange groundwork. The full colors will take either black or chocolate spots on an orange background and the dilutes are like only with blue or lilac and cream. Black spots on a cream background is undesirable.

The final allele is the non-extension gene (due east) and is recessive to all of them. It eliminates all banding. On a self colored rabbit (aa) it volition appear every bit a tortoiseshell (tort) and on an agouti (A-) information technology will eliminate the ticking which is necessary for reds and creams.

White markings are called "cleaved" in rabbits (en = english spot). This allele is influenced by various modifiers that can crusade the white markings to vary from tiny amounts under the mentum and on the breast to the markings on finds in a Hotot which has only a fine colored line effectually the optics. In Rex, the ideal cleaved pattern allows for 10-50% color. It can exist a blanket blueprint or spots, only the ears must be colored and in that location should be color on either side of the nose. When the nose marker straddles the olfactory organ, information technology's called a butterfly marking. Spots on either side are besides OK. Markings that await like they have single white hairs scattered through the colored parts are Not desirable.

There's also a good article here (Nature Trail, Laurie Stroupe)

En = Cleaved Blueprint
en = Self [Normal]
{there are others but they are not meaning in Male monarch}

White markings fall into 3 categories:

enen	=	solid colored; no white
Enen	=	Cleaved, ordinarily ten-90% colour
EnEn	=	"Charlie", usually < ten% color, typically effectually the eyes, ears, and down the center back

It is non ordinarily possible to distinguish betwixt an "undermarked" broken and a true (genetic) charlie. The only definitive ways is through test-mating. If a cross between the undermarked broken and a self (solid colored) rabbit produces even a unmarried self baby, then the broken is not a charlie.

Judith Graf, 1991, Colour Basics (self-published booklet)

Glenna Chiliad.Huffmon, 1995, Rabbit Coat Color Genetics (I accept the 1995 third edition)

Bobby Schott, 1989, Color Genetics of the Netherland Dwarf Rabbit, Xavier Reference Publications, Douglasville Georgia

cortescrourt.blogspot.com

Source: http://minkhollow.ca/rabbits/doku.php?id=genetics_into