Advanced Color Genetics

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More Advanced Color Genetics

Broken Locus

  • En – Broken
    Broken

The Broken pattern is dominant over solid. Rabbits homozygous for the Broken gene are called Charlies and should only be carefully bred. Homozygous Broken carries a ~70% probability of producing rabbits with megacolon, a digestive disorder.

Vienna

  • V – Vienna
    Vienna

Vienna is a co-dominant gene. Two copies (vv) produce Blue-Eyed White (BEW) rabbits. Rabbits with one copy (Vv) are carriers, sometimes showing random white markings and blue eye coloration in one, part, or both eyes. BEW is only expressed in homozygous recessive rabbits (vv).

Wideband

  • W – Wideband

Wideband is a trait modifier affecting Agouti-based rabbits. It extends the band coverage, especially in Chestnut, Red, and Chinchilla rabbits:

  • Chestnut → larger area of pheomelanin, less white, more red/yellow on the belly
  • Chinchilla → more white on the coat and belly
  • Red → solid red belly extending from back

Wideband high-rufus Reds and Chestnuts are desirable in New Zealand Red programs.

  • Normal bandwidth: dominant "W"
  • Wideband: homozygous recessive "ww"

Dutch

  • Du – regular color
  • dud – Dutch dark
  • duw – Dutch white

[Reference PDF](https://www.adhrc.com/Forms/Color%20Genetics%20of%20the%20Dwarf%20Hotot.pdf)

Silver

  • Si – Silver

The Silver gene produces hairs that are fully white from root to tip, evenly intermixed with body-color hairs.

Lutino

Lutino Rabbit

The Lutino coloration is a p mutation affecting an integral membrane protein involved in pigmentation. This mutation reduces eumelanin production in both the eyes and coat, creating pink eyes and lighter coat colors.

  • Recessive: P = normal, p = mutation. Homozygous pp expresses pink eyes and coat color change.
  • Genotypes:
 * Basic orange Lutino: A_B_C_D_eepp  
 * Cream Lutino (“Shadow”): A_B_C_D_E_pp

The Lutino gene functions similarly to the non-extension gene but with pink eyes and less effect on pheomelanin. It has been studied extensively in mice (Castle 1909) and rabbits (SoftPawsRabbits, 1985–2014).

References: 1. Rosemblat et al., 1994, PNAS 91:12071–12075 2. Russell, Genetics 34:146, 1949 3. Castle, Science 30(766):313–314, 1909 [SoftPawsRabbits Lutino Gene](https://softpawsrabbits.weebly.com/the-lutino-gene.html)

Modifiers

Modifiers are not genes themselves but affect the extent of coverage or intensity of rabbit coat colors.

Intensity of Red

Intensity
  • Intensity of red (“Rufus”) controls pheomelanin saturation.
  • Low intensity → almost dirty white
  • High intensity → deep mahogany/maroon
  • Rufus also affects pigment saturation in other colors (e.g., rich black vs. dull charcoal)

Extent of Broken Pattern

Extent of Coverage
  • Charlie
  • Broken
  • Blanket
  • Booted

Co-dominant, Cryptic, and Ghost Presentations

Some genes present partially dominant traits, show stronger expression when homozygous, or produce “phantom” colors.

ej – Harlequin

Harlequin Opal
Harlequin Chinchilla
  • Harlequin (ej) can appear in:
 * Self: aa, Eej  
 * Chinchilla: A, chd, Eej  
 * Chestnut: A, Eej
  • Ej paired with Steel (Es) can produce “phantom black” or super steel: subtle barring visible only in sunlight or on the belly.

chl – Chinchilla Light / Shaded

  • chlchl → Seal (intense shaded pattern)
  • chdchl → Intermediate shaded pattern

Es – Steel

  • Genotypes: EsEs, Ese, Esej
  • Can present as solid black in some cases

Ed – Dominant Black

  • Extends eumelanin fully on Agouti rabbits (ABCDEd) → appears self black
  • Can produce cryptic self rabbits
  • Testing: breed suspected Ed rabbits with self-colored rabbits or red rabbits to confirm genotype

References:

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