Page 101 - JRT Magazine - 2023 Issue 2

There is a difference in the ticking between Locus I stands for Intensity of pheomelanin.
smooth-coat and broken/rough-coat JRTs. On It is a recently discovered locus that is in its infancy
smooth coats, the ticking appears through in terms of a full understanding by researchers.
both the undercoat and topcoat, whereas with Many questions remain unanswered despite
broken/rough coats, only the undercoat shows many labs already offering a test for this locus.
the ticking because of the different structure of For now, we know that there are two alleles of a
the hairs. gene responsible for the range of intensity of red
pigments on the coat. The range goes from very
deep red to almost white, where the dominant
allele I makes the pigment more intense, and the
recessive allele i less intense.

Ticking is mostly hidden by the topcoat in this rough-coated JRT.

In general, ticking appears first, and is most
heavy, on the extremities of the body (limbs) and
the muzzle. Clipping can lead to fast ‘growth’
and visibility of ticking relevant to a change in
the topcoat structure, as it becomes more like
undercoat.

Phaeomelanin can result in a wide range of shades, with the I
Ticking is most obvious in smooth-coated JRTs. allele potentially affecting the intensity.

A Worldwide Magazine for the Jack Russell Terrier / Russell Terrier • Issue 2/2023 | 101