Page 105 - JRT Magazine - 2023 Issue 2

SUMMARY
By understanding the responsibility of
genes at each possible locus associated
with color in Jack Russell Terriers/ Russell
Terriers, breeders’ expectations will better
match reality when pups are born. In the
past, the hidden genes (recessive) could
stay hidden for many generations with
Now, that you understand the basics of color genetics in JRTs,
what is wrong with this illustration?
A Worldwide Magazine for the Jack Russell Terrier / Russell Terrier • Issue 2/2023 | 105
breeders unaware of their existence. A
good example was that of our Russtyle's
du Vallon de l'Alba kennel with the birth
of our tricolor boy Picasso, together with
his brother Pegase, aka Gus, that were
quite a surprise when born. We had not
expected any tricolors in this litter, but we
were lucky enough to get two of them.
With later DNA testing, we confirmed
that both parents carried one copy of
recessive Abb (at) gene. That recessive
gene had been carried through about
eight generations without an appearance,
with no tricolored dogs appearing close
up in the pedigree. Without DNA testing,
we might have wondered if an accidental
mating had occurred…thought we had no
tricolors at the time!
Knowledge of color genetics and DNA
testing can be great tools for any JRT
breeder who wants to improve, expand,
control, or just understand possible colors
in our breed. In our kennel today, we use
DNA breed pack proposed through the
French Kennel Club in conjunction with
the Wisdom Panel for JRTs. It includes
12 tests, 7 of which are for color: loci A
(old version), B, K, D, S, Em, and RALY.
Hopefully the new locus A testing will
become more universally available in the
near future. For now, there appears to
only be two labs (one in USA and one in
Russia) who can provide the distinction
between black saddle (fading tri) and
black-back (tri).
We hope that readers of this article will
find it useful. It contains information that
is more up-to-update than most of what
is currently appearing on the internet.
Genetics research is ongoing, and we
look forward to providing future updates.