23/09/2025
Part 2
Let us explain which genes (C, P, etc.) are responsible for producing these specific guinea pig colors (cream, buff, saffron, red, golden) and how they relate genetically?
Let’s dive into the genetics behind the guinea pig colors in the picture. All of these belong to the Red/Yellow color series (different dilutions of the red pigment, called phaeomelanin).
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🔬 Key Genes Involved
C-locus (Color series/dilution)
C = full color (allows full expression of red pigment → red)
cd = dilute (turns red into buff/golden/cream, depending on intensity)
cr = red-eyed dilute / cream allele (often used in cream lines)
ch = Himalayan (temperature-sensitive pigment)
ca = albino (removes pigment completely, white with pink eyes)
These alleles form a dominance hierarchy:
C > cd > cr > ch > ca
P-locus (Eye color & pigment depth)
P = full pigment (dark eyes, rich color)
pp = pink-eyed dilution (lightens coat + pink eyes)
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🎨 The Colors in the Image
1. Cream (C-dilute + P-)
Genetics: cdch P-
Very pale version of red with dark eyes.
Looks like a soft beige/vanilla shade.
Note: Genetics code information are corrected from cdcd P- to cdch -P (Source: Cavy Genetics: An Exploration
Originally written by Nick Warren, 1999; Revised and updated by Bryan Mayoh, with input from Simon Neesam, 2008 Introduction). It is also possible Cream can be cdcr (cr = ruby eyed dilute aka dark-eyed white dilute).
2. P.E. Cream (C-dilute + pp)
Genetics: cdch pp
Same as Cream but with pink-eye dilution, making the coat even lighter and giving pink eyes.
Note: Genetics code information are corrected from cdcd pp to cdch pp (Source: Cavy Genetics: An Exploration
Originally written by Nick Warren, 1999; Revised and updated by Bryan Mayoh, with input from Simon Neesam, 2008 Introduction)
3. Buff (medium dilution, dark eyes)
Genetics: cdcd P- (slightly deeper expression than cream, same locus effect).
Warm golden-brown color, darker than cream but lighter than red.
4. Saffron (buff + pink eyes)
Genetics: cdcd pp
Pink eyes + lighter coat version of buff.
5. Red (full intensity, dark eyes)
Genetics: CC P-
Strong, rich, deep red coat with dark eyes.
This is the “baseline” color in the red series.
6. P.E. Golden (full intensity + pink eyes)
Genetics: CC pp
Red diluted by pink-eye gene → turns into a golden-orange shade with pink eyes.
✅ So basically:
C-locus controls coat depth (red → buff → cream).
P-locus controls whether the eyes (and coat) stay dark (P) or dilute to pink (pp).
Credit to the Owner (Information and images)
Part 1 ==>https://www.facebook.com/share/p/1BT3DfBaMw/
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Here are the main reference points where this genetic framework comes from:
📚 Published & Academic Sources
Castle, W. E. (1922–1930s) – Early genetic work on guinea pigs (Journal of Experimental Zoology, Carnegie Institution of Washington). He described inheritance of coat color, eye color, and pigment dilution in cavies.
Searle, A. G. (1968) – Comparative Genetics of Coat Colour in Mammals. This text compares coat color genetics across species, including guinea pigs.
Robinson, R. (1976) – Genetics for Cat Breeders (also references guinea pig color loci because many mammal coat genes are conserved).
🐹 Cavy Fancier & Breeder References
British Cavy Council (BCC) Standards – UK standard of points that define official coat colors like Cream, Buff, Saffron, Red, Golden, etc.
American Cavy Breeders Association (ACBA) – US show standards, describing how red series and dilutes are recognized in competition.
Online breeder guides (e.g., Cavy Colours & Guinea Lynx forums) — where fanciers document practical breeding outcomes confirming classical genetics.
🔬 Genetic principles
The C-locus (full color vs. dilute alleles) and P-locus (dark-eyed vs. pink-eyed dilution) are classical Mendelian traits first mapped in guinea pigs by early 20th-century geneticists.
These loci are still used by breeders today when predicting offspring colors.
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