Dilution Factor


As we look closer and closer into Tunis color it is quite obvious that a lot of research has been done to figure out “red” hair. The opposite is true on “shades of red hair”. Looking into everything from cattle to mice and even to humans the intensity of red in hair has not been genetically tracked. One idea/ theory is that there could be a dilution gene in Tunis. This would be the first dilution gene in sheep. Dr. Notter of Virginia tech hypothesizes that

“Most Diluter alleles are dominant (so Charolais x Hereford are always yellow), so a dark red face would be a double recessive. If your flock is somewhat line-bred and generally light red, then it would be difficult to get dark red, even with an outcross to a dark red ram. If there were enough sheep, you could outcross to 2 unrelated rams with dark red faces. Offspring in your flock should be mostly light red, and could only be dark red if you had ewes carrying a recessive allele at a Diluter locus. If you then mated offspring out of the dark red sheep, but with light red faces, together, you should get 25% dark red (i.e., mating carriers of a recessive together). That provides a decent hypothesis but hard to test without committing all your sheep to it!!”