Page 77 - Aussie Magazine - 2024 Issue 3

The origins of the word cryptic come from “crypticus”, a Latin word meaning
“hidden” or "to hide." The terminology of “cryptic Merle” has been used for

decades to mean exactly that - a dog who is a “hidden Merle”. You’ll most
often find the word cryptic also used in conjunction with words such as
“hidden”, “masked”, “ghost” and “phantom”. All the same descriptive words
with the same meaning - a dog who was assumed by phenotype to be non-

Merle and then bred as a Merle producing visibly Merle patterned offspring.

It is very important to note In 2015 a paper was published different breeds.
that the word “cryptic” in this officially naming the “Cryptic
sense has been used only as Merle” allele - Mc. However My choice for the allele would
a general “descriptive” word this research was done still have been Mt - Truncated
and not in a true “genetic” using the old testing method Merle. “Truncated” meaning
manner. Used to describe and based only on phenotype, “shortened”, “curtailed”,
something we could not not on breeding outcomes. This “cut short” which describes
understand as we did not resulted in an Mc allele that the Mc allele perfectly. I
yet have the technology was much too long in length. mentioned earlier that setting
available to us in order to This length encompasses the boundaries for each
discern the precise genetics the “langevin et al” alleles allele was an immense task
of Merle’s poly-A tail. NOTE: of Mc, Mc+ and Ma which that came with an immense
in some breeds cryptic is are all “Non-Expressing” as responsibility. The base pair
also used to describe a dog heterozygous but do not breed numbers for the Mc allele were
who is Minimal Merle. This the same. by far the most important.
expression has 2 distinct We need to ensure for every
Merle genotypes, one It was unfortunate that this breeder that when a dog
which has been covered paper named the allele Mc testing as Mc 200 - 230 bp is
in the previous section on - Cryptic Merle as the term bred to M, there is no deletion
Mosaicism using Astrid as “cryptic” has become so of pigment to white due to the
an example. The second convoluted over the years; combination of both alleles
genotype will be discussed used in such general form to and therefore no risk of vision
in the Mh - Harlequin Merle mean so many different things and/or hearing impairments
section. to different people and in caused due to Merle.

DEFINING MC - CRYPTIC MERLE 200 - 230 BP

Any dog tested as m/Mc or Mc/Mc can safely be bred to M with the Mc allele acting the same as
non-Merle. A dog who is Mc/M will have no pigment deleted to white due the allele combination.

A Worldwide Magazine for the Aussie • Issue 3/2024 | 77