Note: If you have no background in genetics, it would be a good idea to review the Color Genetics Terms and the Sheep Color Genetics Primer before continuing on this page. In basic Shetland (meaning most primitive breeds) color genetics, most wool color is determined by two pairs of genes: Agouti and Black/brown. Shetland Sheep Society colours and markings.
There are eleven main whole colours in Shetland sheep, with many shades and variants in between. This video covers the basic principles of sheep color genetics. A beginners guide to understanding color base, spotting and pattern with real life examples of pairing outcomes from sheep breeding.
Shetland Color Genetics by Theresa Gygi This document is a very brief overview of the patterns and colors expressed which involve Shetland fleece. Each pattern and color can easily warrant. A Summary of Shetland Sheep Color Genetics Phillip Sponenberg, DVM, PhD Sheep color is complicated, and final color and pattern are the result of summing the changes over several different genetic addresses.
Sheltie Coat Color Inheritance Sheltie (Shetland Sheepdog) puppies look like their parents, but not exactly. Sheltie puppies inherit characteristics from their parents. Individuals have an appearance (say a Sheltie with a Golden Sable coat).
Individuals also have genes. Each Sheltie carries two copies of each gene, one from each parent. Here's a quote that gives some idea of the scope of color genetics (about all domesticated animals, not just sheep): "Although to date more than 300 genetic loci and more than 150 coat-colour-associated genes have been discovered, which influence pigmentation in various ways, the genetic pathways influencing coat colouration are still only.
Confused? This is an area of color genetics which is probably the most complex, so don't let it bother you! Finally, there are genes which are fully recessive. These can act only in pairs of the same gene. A solid color black or moorit (brown) Shetland sheep must have the recessive pair Aa/Aa.
Shelties can change colors as they mature due to genetics like the agouti and merle genes. Explore the fascinating world of Sheltie coat color shifts. Wrong! There are thousands of years of breeding color out of sheep behind us, leaving only 'primitive' breeds like Shetland and Icelandic routinely expressing color in their wool.
And research on sheep color genetics is slow because most ewes produce one or two lambs a year, not the several dozen kits a rabbit doe can produce. No wonder sheep color genetics are not well understood, especially.