Mangile's Pigeon Pages

Dominant & Recessive

It bears restating that every gene in every chromosome of the Rock Dove is accepted as a standard issue!  Each of the thousands of genes combine to produce the rock dove.  Until a mutation is identified all genes are declared wildtype genes; and are labeled with  "+", the symbol for wildtype.

When a characteristic is identified that is not found in the wild type, a tentative symbol is assigned to that variation (mutation).   Breeding tests are necessary to determine if the characteristic is a dominant, a recessive, or a combination affect of more that one genes actions.

The concept of a dominant gene is - one that has some control over the actions of the opposing wildtype gene (allele) on the adjoining chromosome - therefore, altering the outward appearance (phenotype) of the wild type.

Conversely, a  recessive gene  - has no control over the actions of the opposing wildtype gene (allele) on the adjoining chromosome - therefore, the outward appearance (phenotype) of the wild type remains unchanged.

For a cartoon grapic depicting dominance and recessiveness, click here.

Generally, a mutant gene (one that has changed from wildtype) is either a dominant gene or a recessive gene.   Excepting for sex-linked genes, if the action of a single gene is detectable in wildtype it is considered a dominant; and if it is not detectable it is considered a recessive.  It must be well understood that dominant and recessive are terms used primarily to describe a single genes expression on  wildtype.  Although they are often used to compare one mutant to another, at a given locus; (e.g., checker is dominant to barless).

Both almond  and faded are dominant genes; (dominant to wildtype).  Though almond may be described as being dominant to faded; and faded as being recessive to almond, it has no bearing on their classification on wildtype.  Wildtype (+) is neutral or standard; neither dominant or recessive to other genes.   Instead, other genes are dominant or recessive to wildtype.  A classification of "dominant" or "recessive" is based on the action of a gene when opposed by a wildtype gene; and not the action of a mutant gene when opposed by another mutant geneOnly when opposed by a wildtype allele are the terms "dominant" and "recessive" used to classify mutant genes.

All dominant gene symbols begin with capital, or upper case letters, (A, B, C, etc.); and all recessive gene symbols begin with lower case letters, (a, b, c, etc.).  (Figure 1.)

Gene ChartFigure 1.

-- Symbols for dominant genes - almond, faded, qualmond and ash-red - begin with upper case letters.  Symbols for recessive genes - dilute, dilute-pale, reduced, web-lethal and brown - begin with lower case letters.

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