English (Broken) Pattern Locus - En
The broken genetics are incompletely dominant (Fontanesi, 2021). To get a true broken, you need one solid allele (“en”) and one broken allele (“En”) Two broken alleles (EnEn) gives you a Charlie, whereas two solid alleles (enen) gives you a solid.
En: English spotting
en: Solid
Say you breed a Charlie buck to a solid doe. The Charlie buck HAS to donate on En allele (that is all he has to give), and the solid has to donate a solid allele. Therefore all the kits will be broken.
If you breed a Broken buck to a Broken doe: the broken buck can donate either a broken or a solid allele, and so can the doe. Therefore, some kits will get a broken allele from each parent, making it a Charlie. Some will get a solid allele from each, making it a solid. The majority (usually) get one of each and end up as brokens.
If you breed a solid buck to a solid doe, all you can get is solid because both parents can only donate a solid allele. If you breed a Charlie buck to a Charlie doe, all you can get is Charlies because both parents can only donate a Charlie allele.
A broken x a solid will result in mostly solids. The reason is because they HAVE to get at least one solid allele from the solid parent. The broken parent can donate either a broken or a solid allele. Therefore, about 3/4 of the litter will be solid. (Of course, chance plays its part too.).
Breeding a charlie to a broken has the opposite result, usually 3/4 charlies. Charlies have an increased risk of a potentially deadly issue called megacolon.
Gene involved: KIT (KIT proto-oncogene, receptor tyrosine kinase) gene.
Broken Black
aa B_ C_ D_ E_ Enen
Charlie Black
aa B_ C_ D_ E_ EnEn
Harlequin
A_ B_ C_ D_ eʲ_ EnEn
Harlequin is the solid version of tricolor. Tricolor is the broken version of harlequin.
Tricolor (black/orange)*
aa B_ C_ D_ eʲe Enen
* This rabbit appears to be a torted tricolor. This can occur when a harlequin or tricolor is self-based (aa) and carries non-extension (eje rather than ejej). Notice the tortoiseshell shading in the orange.
Broken pattern can vary quite dramatically. Modifiers work to determine the general pattern. However, there is some randomness involved, due to how the white spotting mutation affects pigment production. An interesting fact is that white spotted animals, if cloned, do not have the exact same pattern! However, they will typically have similar pattern placement and amount of white versus color. Below are various examples of broken patterns.
Booted Broken: Enen
Genotype:
A_ B_ cᶜʰᵈ_ D_ E_ Enen
When a broken rabbit only has a little white around the feet and front, it is called a "booted" pattern.
Photo credit: Bullitt Buns
Blanket Broken: Enen
Genotype:
A_ B_ cᶜʰᵈ_ D_ E_ Enen
When a broken rabbit has move of a solid 'blanket' of color across the body but has more color than a booted broken, it is called a 'blanket broken'.
Broken: Enen
Genotype:
aa B_ C_ D_ E_ Enen
English spots have been selectively bred for very specific broken patterns.
Broken: Enen
Genotype:
aa B_ C_ D_ E_ Enen
Checkered giants have been selectively bred for very specific broken patterns, similar but not identical to English spots.
Broken: Enen
Genotype:
aa B_ C_ D_ E_ Enen
Dalmatian rex in the U.K. have been selectively bred for broken pattern resembling Dalmatian dog spotting.