Before exploring the wonderful world of genetics, it is important to understand some common terms. Below I have compiled a list of simple terminology to be familiar with before further reading.
Dominant: When used in connection with genetics, Dominant refers to a gene that overrides any other gene in the allele, preventing those characteristics from affecting the rabbit’s color. Dominant genes are usually signified by an upper case letter. For example, in the A-Locus, the A gene will override the a and a(t) genes.
Recessive: Similar to the term dominant, when recessive is applied to genetics, it describes genes that are not automatically expressed. Often times, the most recessive gene is expressed by a lower case letter. In the C-locus for example, the ‘c’ is used to mark the most recessive gene.
Incomplete Dominance: A gene that is incompletely dominant is only dominant over certain genes. The ‘E(s)’ steel gene for example, only causes correct steeling when it is paired with the ‘E’ gene. If steel is paired with harlequin (‘e(j)’), non-extension (‘e’), or another steel gene it could produce steel, a faded self coloration (no ticking whatsoever), or an odd hybrid of ticking and non-ticking when paired with the harlequin gene.
Homozygous: When a rabbit has inherited the same gene from the sire and the dam, such as a rabbit that received a ‘C’ from the father and a ‘C’ from the mother, that pairing of genes is said to be homozygous, or the same.
Heterogenous: Another term referring to a set of genes on the same locus, Heterogenous refers to a rabbit that carries two different genes. For example, a bunny may have inherited a ‘C’ from the sire and a ‘c(chl)’ from the dam, this is notated as ‘Cc(chl)’ and is said to be heterogenous.
Genotype: A genotype is the set of genes a rabbit (or any creature) carries. A genotype is notated as a string of letters with two letters for every locus. For rabbit colors, the list starts at A and proceeds to E, the most dominant gene in each locus is listed first. If there are any color modifiers, they are listed after the main genotype with a space between. For example, here is the genotype of an opal from my rabbitry: AaBbCc(chl)ddEE.
Phenotype: Like the Genotype, the phenotype describes the genes a rabbit carries. Unlike genotypes, phenotypes refer to only what can be seen. In most cases, when predicting colors, you will have to work with a phenotype because every gene a rabbit carries will not be identifiable just by looking at them. With phenotypes, every gene that is unknown is marked by an underscore. Here is an example of a typical chocolate chinchilla rabbit’s phenotype: A_bbc(chd)_D_E_.
With these terms in hand, it’s time to dive into the Big Five Rabbit color loci.