Fair Mate Catahoulas
  • Home
  • About us
  • Our Louisiana Catahoula Leopard Dogs
    • Troy
    • Amy
    • Ziva
    • Abby
    • Sally
    • Willow
    • Raine
  • Litters
    • Previous litters >
      • 1st litter July 23, 2011
      • 2nd litter July 4th 2012
      • 3rd litter October 18th 2013
      • 4th litter May 19th 2014
      • 5th litter August 2016 >
        • 6th litter October 26th 2017
      • Litter outside our kennel
      • 7th litter January 22nd 2019
      • 8th litter March 12th 2019
      • 9th litter 12 march 2020
    • Planned litters
    • Available pups
  • Catahoula info
    • Breed standard
    • Original character
    • Health >
      • BAER test
      • Hip Dysplasia
      • Merle gene
  • Contact
  • New Page

Merle Gene

/ A-T  
Genotype is not the same as Phenotype!

The fur color Merle is distinguished by a characteristic look regarding the color pattern. In this case a dog shows larger and smaller areas with diluted pigment and others with full pigment. The gene responsible for the Merle color also causes a color fading of the original fur color. But comparing with other color fading genes, this does not affect the whole fur, just several areas and spots which can be found in different patterns all over the dogs body. Merle also effects the eye color. Merle-colored dogs can have solid brown, blue or mixed colored eyes. They can even have more than one color in one eye.

Cause

Merle is carried by a genetically change in the Silver-Gene. This is a mobile genetically element (Retro  transpose), that lays within the SILV-Gene and deranges its functionality. This for the Merle color responsible defect SILV-Gene is named with M, while the normal SILV-Gene is named with m. The typical Merle fur color originates in dogs which carry the mutant version of the SILV-Gene heterozygous (Mm). The defect SILV-Gene (M) shows an imperfectly dominant heredity.

Health issues

Dogs which carry the heterozygous mutant version of the SILV-Gene (MM, double merle), are mostly colored white, or have great white areas on their body/ head. These kind of ogs can have very severe damage and malformation of the internal ear which can lead to deafness. In addition there can be malformations of the eyesight as well as anomalies of the sexual organs, the skeleton and even the heart. To prevent this defects from happening, you should avoid to breed two Merle looking dogs.

Cryptic  Merle/ A-Typical Merle

Even if it’s rare, but there are dogs which don’t show the merle color, but still carry the Merle gene and when bred they can have merle colored offspring. Such dogs are called cryptic Merle. Its assumed that cryptic Merle dogs carry a specific Merle gene which has a shortened mobile element in the SILV-Gene.


Explanation

MM/Merle Merle = double Merle gene carrier, 2  BIG M’s Often more then 70% white and prone to deafness and vision impairments. Only to be confirmed by a BAER certified Vet ( Brainstem Auditiry Evoked Response)

Mm/ Merle = M- Merle , m-non Merle, so only 1 copy of Merle means Single Merle gene carrier

M/Mc= Dog is Merle color. Merle/Merlecryptic. Cryptic Double Merle which does NOT look like a Double Merle. Dog can have brown eyes and Non white coat but always Merle patern in the color as a normal Leopard.

m/Mc  or m/Ma  = Dog is solid ( no spots) LOOKING. Solid who NOT looks like a Merle gene carrier. The cryptic often is called Ghost or Phantom.  These dogs do carry a Merle gene, these dogs are usually safe to breed to any type of leopard/Merle looking dog


When you have a dog which carry MM genes, he always give 1 M ( Merle gene) to his offspring. So even if a solid colored pup is born out of a parent with MM gene, this pup has a M, big M which means MERLE.

Small m, means NO merle. Single Merle is Mm, Double Merle is MM, true solid is mm. So IF you breed a MM double Merle x to a mm, NON merle, ALL pups carry the  single Merle gene. If you breed a Mm single Merle to a x Mm Single Merle you can have 25% MM, double Merle, 50% Mm Single Merle and 25% mm, true solid.
If you have a cryptic or A-Typical Merle gene carrier, inherted from one of the parents,it is most likely the cryptic gene is forwarded to 50% of the offspring. .

  
We refer to solid coloured dogs and mean they arent Merle, no spots!!

Possible Genotyp-Combinations

Parent  1  mm  = non merle
Parent  2  mm  = non merle
Offspring   = 100% of  these dogs are mm = non merle-  solid ( no spots visible)

Parent 1 mm  = non merle
Parent 2
Mm  = single Merle
Offspring = 50% of  these dogs are Mm = single Merle ,50 % of  these dogs are mm = non merle- solid 
mm  = non merle

Parent 1 MM  = double Merle
Parent 2 mm = non merle
Offspring=
100% of  these dogs are Mm =  single Merle

Parent 1 Mm = single Merle
Parent 2
Mm = single Merle
Offspring = 25% of  these dogs are mm = no merle -solid. 50% of  these dogs are  Mm = single Merle, 25% of  these dogs are MM = double Merle. Attention! Severe health damage can  be caused!

Parent 1
Mm = single Merle
Parent 2 
MM = double Merle
Offspring= 
25% of these dogs are Mm = single Merle. 75% of  these dogs are MM = double Merle . No true solid pups can be born out this combination. All solid pups carry merle gene Attention! Severe health damage can  be caused!

Parent 1
 MM  = double Merle
Parent 2
MM  = double Merle
Offspring = 
 100% of  these dogs are MM = double Merle.  Attention! Severe health damage will be caused!

THE OPTICAL APPEARANCE DOES NOT TELL ANYTHING ABOUT THE GENETICAL SETUP OF A DOG!
 Only with a proper DNA test you can prove what kind of gene each dog carries, and what the safest combination is to breed with! There are 8 different Merle genes found over the past few years. 

Laboratory for testing
Tilia Laboratories Czech Republic

Below a few pictures of cryptic double Merle and cryptic single Merle gene carriers


Plain's Rose. Solid Black. DNA test m/Mc cryptic single Merle gene carrier. Owner K. Atkins United Kingdom
Picture
Windridge's Blue Berry- Nisse. Blue Merle. DNA tested M/Mc
Merle/cryptic  Merle gene carrier. Owner: S. Birkner
Germany
Picture
Fair Mate's Apollo-Appie. DNA test. M/Mc, cryptic double Merle
gene carrier.
Owner: M vd Meer. Netherlands
Picture
Fair Mate's Avery Tallulah Blue. DNA test M/Mc, cryptic double
Merle gene carrier.
Owner:J. Freichmann, Netherlands
Picture
Fair Mate's Arindi- Abby. DNA test Mcm, cryptic single Merle gene
carrier. Owner: D. Janssen-Groesbeek
Picture
Windridge's Aphrodite-Ziva. DNA test m/Mc, cryptic single Merle
gene carrier. Owner: D. Janssen-Groesbeek
Picture
Sunnydog's Cody. Patchwork M/Ma, Merle/ A-Typical Merle. Unilateral
deaf. Owner: J.Kuenen-Vermeulen
Picture
Sumici Kridla Franceska. Red Patchwork. M/Ma, double Merle/a-Typical Merle gene carrier. Owner:
Hana Koutkova, Czech Republik
Picture
Powered by Create your own unique website with customizable templates.