The merle coat color lies in basic genetics, where there is a dominant and recessive trait to produce those gorgeous splotches. This is the merle allele (M) and one copy of the non-merle allele (m). The merle (M) allele is a semi-dominant gene, meaning it only takes one copy of the M allele to produce a merle.
An autosomal, incompletely dominant trait, merle coat coloring predisposes dogs to inherited deafness. When inherited in the homozygous state, the merle mutation causes dogs to be white and have an even greater incidence of deafness, blindness and sterility.
Merle cannot be carried, it is a dominant gene (although incompletely dominant). This means that a dog is either Merle or they aren't - it cannot lay hidden and be produced down the line in offspring, from non-Merle parents. However... The Merle gene is not as simple as 'non-merle' and 'merle'.
Merle is a gene found in dogs that may present with a colorful coat pattern, but it's not a breed. It consists of swirled or mottled patches of blues, black, and white or various shades of red and white. Dogs can also carry the merle gene without showing the distinct coat pattern.
The merle gene causes pets to have multicolored coats and striking blue eyes. Having the merle gene is great, but becomes problematic when two dogs with that gene are paired. Birth defects in litters can happen when two dogs with this merle gene are bred together, hence double merle breeding.
The merle pattern can lead to a slew of health problems. The most common is hearing loss in one or both ears. Having even a single M allele actually raises the chance of being deaf, although the chance of an Mm merle being bilaterally deaf is still less than 1 percent.
The quick answer is that a well-bred merle dog with one copy of the merle gene will be as healthy as a solid-colored dog. If a dog is a so-called “double merle” however, he is likely to suffer from vision, hearing and skin problems.
Many people are unaware, but when two merles (of any breed) are bred together, each puppy has a 25% chance of being born as a double merle. These puppies have excessive white coloration – lack of pigment – and this coloration causes loss of hearing, vision, or any combination of the two impairments.
Merle is a distinguishing marking of several breeds, particularly the Australian Shepherd and Catahoula Leopard Dog, and appears in others, including the Miniature American Shepherd, the Koolie in Australia, the Shetland Sheepdog, various collie breeds, the Cardigan Welsh Corgi, the Pyrenean Shepherd and the Bergamasco ...
Yes, but we only register merle dogs in breeds where this type of coat is known to traditionally appear. In these breeds, merle is a long-standing and commonly-occurring colour, and there is a well-established tradition of careful breeding to avoid merle-to-merle matings.
Dogs with cryptic merle (also called phantom or ghost merle) typically display little to no merle pattern and some may be misclassified as non-merles. The cryptic merle alleles occur in the lower end of the range (typically from 200-255, however, this range and designation varies by study).
All merles may have blue or partially blue eyes, and pink or partially pink noses. Merle can be completely hidden by recessive red, as recessive red dogs can't make eumelanin pigment and merle only affects eumelanin.
As you can see each puppy has a 50% chance of being born merle, a 25% of being solid/non merle, and a 25% chance of being a double merle.
If two merle dogs are bred together, each puppy in the litter has a 25% chance of being born a double merle. A double merle inherits the merle gene twice.
Double Merle dogs are highly likely to suffer from hearing and vision impairments and in some cases complete blindness and deafness. Deafness and hearing impairment happens due to lack of hair pigment produced in the inner ear. Double Merles can also be blind or have vision problems due to congenital eye defects.
The M Locus (Merle) coat color test reliably determines if a dog carries the M (merle insertion variant) Allele of the PMEL gene. If present, this test will also determine the approximate size (+/- 1 base pair) of the M allele(s).
Merle is among the most exciting coat color mutations of dogs both phenotypically and genotypically. The autosomal semidominant inheritance of this mutation was described nearly a century ago. Two alleles have been identified and distinguished: the wild “m” allele and the mutant “M” (or merle) allele [8].
A combination of colors may be found in one or both eyes. Colors expressed may range from a pale, light blue to greenish to amber. Unfortunately, the same gene that is responsible for the desirable coat and eye appearance is often responsible for many developmental eye defects.
Merle French Bulldogs have a unique pattern on their coats that combines two or more colors, usually red, blue, black, or fawn. This pattern creates a mottled or patchy look. On the other hand, Brindle French bulldogs have a striped or tiger-like pattern on their coats.
The solid red coat of an Australian shepherd is the rarest color. This Australian shepherd coat color, which ranges from deep reddish to lighter shades of red, is the rarest color. To create a solid red coat, breeders must strategically pair dogs with the ee recessive form of the E gene.
Harlequin causes the grey background on a merle to be diluted to white, leaving dark patches on a white background, and can affect any type of merle (including brindle, sable etc, as well as double merles). It is a dominant embryonic lethal gene, so all HH dogs are reabsorbed into the womb and only Hh dogs are born.
The Merle gene can lighten the color of a dog's coat as well as lead to developmental defects in one or both of his eyes, ranging from minor to significant.
Why are merle dogs so expensive? In a nutshell, merle dogs are expensive because puppy buyers are willing to pay a lot of money for them. The pattern is very sought-after, and the more demand there is, the higher breeders can set their prices. In addition, merle breedings can be quite rare in some breeds.
The merle gene is responsible for creating mottled patches of color in a dog's coat and blue or odd-colored eyes. However, merle is an incompletely dominant gene, so not every merle dog will have blue eyes. And while merle dogs often have blue eyes, they can also have one brown and one blue eye.
A single merle gene can produce results as harmless as fur or eye color and as difficult as loss of eyesight or hearing. However, mating two dogs with the merle gene can produce offspring with a homozygous double merle gene, sometimes known as “lethal white” or “double-blue.”