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==Basic Color Genetics==
== Basic Color Genetics ==


The five base Alle's that effects the base coat color of the Domestic rabbit.( DISCRIPE THE BASIC DEFEINTION OF EACH, LINK TO NEW PAGE FOR INDEPTH DISCUSSION.)
This page covers the five base alleles that affect the coat color of domestic rabbits. This article focuses strictly on '''genotype''' (the genetic makeup), not '''phenotype''' (how the color appears).


===A- Agouti===
*'''Genotype'''* = the black-and-white formula on the gene that produces a color. 
*'''Phenotype'''* = the observable color, often used in breed standards. 


The Agouti gene has three variable Alles.
Understanding genotype is crucial for predicting offspring color in breeding.
Agouti is the most dominate followed by Tan , and then Self is the most recessive.


=== A – Agouti ===


The Agouti gene has three alleles: 


* '''A''' – Agouti (most dominant) 
* '''at''' – Tan 
* '''a''' – Self (most recessive) 


[[File:Geneiticx3-01.jpg|thumb|Agouti]]
The Agouti locus expresses the “wild color” banding along each hair shaft. Agouti hairs have alternating bands of eumelanin (dark pigment) and pheomelanin (yellow/red), producing a “ringed” appearance. Standard Agouti colors include Chestnut (Castor), Sandy, Copper, and Chinchilla (Squirrel). Other Agouti-based patterns modified by additional genes include Red, Steel, Harlequin, and Ermine.


===B-Black/Brown===
* '''Tan (at)''' – Eumelanin on top, pheomelanin on the bottom; expressed across the back, ears, face, belly, and inside the ears. Dominant over '''a''' (Self), recessive to '''A'''. Examples: Tan, Marten, Otter. 
The B marker has 2 Alle's , Black is Dominate  to Brown.


[[File:Black-2.jpeg|thumb|Black and Chocolate]]
* '''Self (aa)''' – Requires homozygous recessive alleles. Produces solid-colored hair shafts, typically expressing the base color at the B locus and sometimes modified by the D and E loci. Examples: Black, Chocolate, Lilac, Blue, Tort.


===C-Color Coverage===
Summary Table:
there are four alles on the color concentration marker.
* '''A''' = Agouti (banded hair shaft) 
Full Color, Chinchilla, Shaded/light chinchilla, Himalayan, and Albino.
* '''at''' = Tan (solid color on top, pheomelanin on bottom) 
* '''aa''' = Self (solid hair shaft)


=== B – Base Color ===


[[File:Geneiticx3-27.png|thumb|B Locus]] 


[[File:Wiki.png|thumb|Caption]]
The B locus controls the type of eumelanin expressed:


===D-Density===
* '''B''' – Black (dominant) 
Density Gene has two Alle's, Full Density is dominate, and Dilute is recessive. The representation of The Dominate full Darkness marker is usually defined as " D". While the Dilute , is a higher "brightness" marker is usually defined as "d".
* '''b''' – Brown/Chocolate (recessive)
This gene can be thought of like the brightness slider under the hue/saturation adjuster in photoshop. Your default image (D) is set to 0, while the Dilute is akin to +50 brightness.


example :
Base color forms the foundation for many rabbit colors (e.g., Black, Chestnut, Chinchilla, Harlequin, Torts) and can be masked by other genes (white or pheomelanin-only expression).
[[[Brown-02.jpeg]]]
Black


Blue
=== C – Color Coverage ===
[[[inset image]]]


[[File:Geneiticx3_C_loci.jpg|thumb|C Locus]] 


The C locus affects color intensity and coverage. Four primary alleles: 


* '''C''' – Full Color (dominant). Expresses complete eumelanin over the body; modified by at, d, e, and En loci. Examples: Solid Blacks, Chocolates, Blues, Lilacs, Chestnuts, Steels, Harlequins. 
* '''chd''' – Dark Chinchilla. Strips most pheomelanin while leaving eumelanin intact; affects Agouti most. Produces Martin, Fox, Ermine, Chinchilla, Silver-Tipped Steel, Magpies. 
* '''chl''' – Light Chinchilla. Co-dominant; partially strips pheomelanin. Agouti rabbits with chl- are Siamese; self and tan rabbits with chl- are Sable. Homozygous chlchl = Seal. 
* '''ch''' – Himalayan / Californian. Temperature-sensitive; color restricted to cooler points (ears, nose, feet, tail). Recessive to C, chd, chl; dominant over c. 
* '''c''' – Albino. Most recessive; masks all other loci when homozygous (cc), producing red-eyed white rabbits.


=== D – Density ===


[[File:Wiki.png|thumb|Caption]]
[[File:Geneiticx3-28.png|thumb|D Locus]]


===E-Extension===
The D locus controls pigment density: 


* '''D''' – Full Density (dominant) 
* '''d''' – Dilute (recessive) 


Dilution affects eumelanin: Black → Blue, Chocolate → Lilac. Think of it as a “brightness slider” for color intensity.


[[File:Wiki.png|thumb|Caption]]
*Reference:* [A frameshift mutation in the melanophilin gene causes the dilute coat colour in rabbit (PMC)](https://pubmed.ncbi.nlm.nih.gov/24320228/)
The Extension  gene has five separate markers that control the extend of the band of an Agouti rabbit. Ed dominate black the rabbit will appear self as it will extend the color at B to entire hair follicle,  Es steel is the second most dominate color, this extends the color at  the B loci almost to the tip on an agouti rabbit, so the follicle will be soil 3/4 of the way to the tip with just the tip showing a red/yellow/white coloring.  , E-regular extension, this will preset the hair as it is, and Agouti rabbit will have banded color along the hair shaft, and a self or tan rabbit will have a soil hair coloration. ej-Japanese harliqe is a co-dominate recessive gene that  expresses patches of alternating color, or Bridling on Agouti coats. ee-is non-extention, it is the oposite of dominate black and  hide the color at B on Agouti rabbit extending the tip color to the base . and  blocking out all Eumelnion.


=== E – Extension ===


[[File:Geneiticx3 E loci v002.jpg|thumb|E Locus]] 


The E locus controls how far color extends along the hair shaft in Agouti rabbits: 


* '''Ed''' – Dominant Black. Extends B locus color across entire hair. 
* '''Es''' – Steel. Extends B color most of the way; tips show pheomelanin. 
* '''E''' – Regular Extension. Normal banding along hair shaft. 
* '''ej''' – Japanese / Harlequin. Co-dominant; alternating patches of color. 
* '''ee''' – Non-Extension / Tort. Suppresses eumelanin; tips colored, rest pheomelanin. 


 
*References:* 
in-depth references:
* [Mutations in the melanocortin 1 receptor (MC1R) gene in rabbits](https://pubmed.ncbi.nlm.nih.gov/16978179/) 
 
* [Slc7a11 modulated by POU2F1 and pigmentation in rabbits](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6566412/) 
Slc7a11 Modulated by POU2F1 is Involved in Pigmentation in Rabbit
* [ASIP gene characterization in rabbits](https://www.sciencedirect.com/science/article/pii/S0888754309002559) 
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6566412/
* W.E. Castle, "Who Discovered the Dominant Black Rabbit?", Journal of Heredity, 1939
 
Characterization of the rabbit agouti signaling protein (ASIP) gene: Transcripts and phylogenetic analyses and identification of the causative mutation of the nonagouti black coat colour
https://www.sciencedirect.com/science/article/pii/S0888754309002559

Latest revision as of 18:36, 16 August 2025

Basic Color Genetics[edit | edit source]

This page covers the five base alleles that affect the coat color of domestic rabbits. This article focuses strictly on genotype (the genetic makeup), not phenotype (how the color appears).

  • Genotype* = the black-and-white formula on the gene that produces a color.
  • Phenotype* = the observable color, often used in breed standards.

Understanding genotype is crucial for predicting offspring color in breeding.

A – Agouti[edit | edit source]

The Agouti gene has three alleles:

  • A – Agouti (most dominant)
  • at – Tan
  • a – Self (most recessive)

The Agouti locus expresses the “wild color” banding along each hair shaft. Agouti hairs have alternating bands of eumelanin (dark pigment) and pheomelanin (yellow/red), producing a “ringed” appearance. Standard Agouti colors include Chestnut (Castor), Sandy, Copper, and Chinchilla (Squirrel). Other Agouti-based patterns modified by additional genes include Red, Steel, Harlequin, and Ermine.

  • Tan (at) – Eumelanin on top, pheomelanin on the bottom; expressed across the back, ears, face, belly, and inside the ears. Dominant over a (Self), recessive to A. Examples: Tan, Marten, Otter.
  • Self (aa) – Requires homozygous recessive alleles. Produces solid-colored hair shafts, typically expressing the base color at the B locus and sometimes modified by the D and E loci. Examples: Black, Chocolate, Lilac, Blue, Tort.

Summary Table:

  • A = Agouti (banded hair shaft)
  • at = Tan (solid color on top, pheomelanin on bottom)
  • aa = Self (solid hair shaft)

B – Base Color[edit | edit source]

B Locus

The B locus controls the type of eumelanin expressed:

  • B – Black (dominant)
  • b – Brown/Chocolate (recessive)

Base color forms the foundation for many rabbit colors (e.g., Black, Chestnut, Chinchilla, Harlequin, Torts) and can be masked by other genes (white or pheomelanin-only expression).

C – Color Coverage[edit | edit source]

C Locus

The C locus affects color intensity and coverage. Four primary alleles:

  • C – Full Color (dominant). Expresses complete eumelanin over the body; modified by at, d, e, and En loci. Examples: Solid Blacks, Chocolates, Blues, Lilacs, Chestnuts, Steels, Harlequins.
  • chd – Dark Chinchilla. Strips most pheomelanin while leaving eumelanin intact; affects Agouti most. Produces Martin, Fox, Ermine, Chinchilla, Silver-Tipped Steel, Magpies.
  • chl – Light Chinchilla. Co-dominant; partially strips pheomelanin. Agouti rabbits with chl- are Siamese; self and tan rabbits with chl- are Sable. Homozygous chlchl = Seal.
  • ch – Himalayan / Californian. Temperature-sensitive; color restricted to cooler points (ears, nose, feet, tail). Recessive to C, chd, chl; dominant over c.
  • c – Albino. Most recessive; masks all other loci when homozygous (cc), producing red-eyed white rabbits.

D – Density[edit | edit source]

D Locus

The D locus controls pigment density:

  • D – Full Density (dominant)
  • d – Dilute (recessive)

Dilution affects eumelanin: Black → Blue, Chocolate → Lilac. Think of it as a “brightness slider” for color intensity.

E – Extension[edit | edit source]

E Locus

The E locus controls how far color extends along the hair shaft in Agouti rabbits:

  • Ed – Dominant Black. Extends B locus color across entire hair.
  • Es – Steel. Extends B color most of the way; tips show pheomelanin.
  • E – Regular Extension. Normal banding along hair shaft.
  • ej – Japanese / Harlequin. Co-dominant; alternating patches of color.
  • ee – Non-Extension / Tort. Suppresses eumelanin; tips colored, rest pheomelanin.
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