Page 20 - Aussie Magazine - 2023 Issue 2

Informative

Some of the most
exciting test results

which explained so many

previously unexplained
irregularities we often see

in some Merle patterns and

differences in phenotype from FIRE
parent to offspring, were the

mosaic results.

These are important distinctions for a breeder as well as when paired with a different length
who strives to produce Merle patterns that allele. There are 28 possible combinations from
fall within the given guidelines of many breed 7 alleles. 14 of those combinations can delete
standards. There is also the issue of not wanting pigment to white. In this article I cannot include
to produce “Double Merle” offspring in a resulting examples of all combinations so will concentrate
litter. Breeders not only need to know the most on the examples that provide answers to unusual
typical phenotype expression for a given allele phenotypes
and their combinations; but also how that dog
will breed, what patterned offspring this dog can
produce when paired with the alleles from the m Non-Merle Wild Type
mate. These are the most essential questions and Mc Cryptic Merle 200 - 230 bp
the alleles of m, Mc, Mc+, Ma, Ma+, M and Mh Mc+ Cryptic Merle+ 231 - 246 bp
provide those answers.
Ma Atypical Merle 247 - 254 bp
The Merle trait is an “incomplete dominant”, one Ma+ Atypical Merle+ 255 - 264 bp
allele does not completely dominate another.
Depending on which 2 alleles are inherited, it can M Merle 265 - 268 bp
create an intermediate expression or a completely Mh Harlequin Merle 269 - 280 bp
distinct pattern. When the base pair numbers were
set for each allele it was not just a matter of looking We can assume that Mh - Harlequin Merle is the
at the phenotype of each allele as heterozygous, original ancestrally allele as it is the longest. So
each length had to be looked at as homozygous, here have all the other allele lengths come from?

20 | A Worldwide Magazine for the Aussie • Issue 2/2023