Current Research Projects
View projects COBRA is currently involved in below.
Molecular Basis of Genotypic/Phenotypic Plasticity
Harold II. Garner, Ph.D.; John W. Fondon III
This study will test the hypothesis that much of the morphological variation between individuals is due to a specific type of mutation that involves repeated sequences in genes. To test this
hypothesis, we will sequence repetitive regions from ~ 80 genes suspected to be involved in various diseases affecting craniofacial morphology. Purebred dogs are the only system for undertaking this
study for a large number of reasons, including low within-breed genetic diversity, high between-breed morphological diversity, and similarity to humans. A licensed veterinarian will collect 3cc's of
whole blood from breeder-owned, volunteer animals, using standard veterinary techniques. DNA will be extracted from these samples, the regions of interested PCR-amplified and sequenced. Sequences
from dogs representing 60 different morphological distinct breeds will be compared to each other and correlated to measurements of skull morphology taken from dry purebred dog skulls on loan from the
Smithsonian Museum and the Museum of Natural History in Berne, Switzerland.
The morphologic measurements being collected on the Louisiana Catahoula Leopard Dog will serve several purposes. The object is to compile a database of measurements on mature members of the breed,
both male and female, and their offspring when they reach maturity at 2 years of age. After a database has been compiled, ranges and averages can be established. Measurements taken from mature
offspring from known breedings whose sire and dam's measurements are known will be used in an attempt to establish a familial correlation between the morphologic parameters being studied. This data
should provide a better understanding of the inheritance of certain morphologic traits or physical characteristics.
Form: 1/04 Morph
Merle Expression and Its Relation to Deafness Within the Catahoula Leopard Dog
COBRA was initially founded to include supporting research specifically on the health and genetic issues of the Catahoula Leopard Dog. With this in mind, I would like to inform the members of a
research project that many COBRA members have been involved in for the last 2 or more years. I have been collecting and analyzing the genetic makeup of the Catahoula in relation to merle expression
and deafness within merle to merle breedings for over 3 years; and have been studying their more general coat color genetics and health issues for 6 years now. The fruit of all this labor has finally
been able to be catalogued and is almost ready for proper scientific validation among some of the experts in the field. This has only been made possible with the help of some breeders who have been
willing to share their breeding program, health test results, and litter results and who have kept exceptional records for validation of all data supplied.
DNA and Merle What you should know!
For many years the Catahoula has been grouped with Australian Shepherd, Collie, Great Dane, Beauceron, Shetland Sheepdog, Dachshund, and other breeds, and it was believed that the gene acted the same in all breeds. A recent DNA study performed at Texas A&M by Leigh Anne Clark, Ph.D., suggests that there may be a modifier gene having an effect on the merle gene within the Catahoula.
Prevalence of Deafness in Dogs Heterozygous or Homozygous
for the Merle Allele
George Strain, PhD.
Congenital hereditary deafness in most dog breeds is associated with 1 of 2 classical pigmentation genes responsible for white or light skin and fur coloration: piebald and merle.1 The pigment locus S has 3 recessive alleles: Irish spotting, piebald, and extreme piebald; dogs with the dominant allele have solid color. Dogs homozygous for 1 of the recessive alleles have white coloration. Dogs with any of the recessive alleles may have congenital hereditary deafness. The prevalence varies by breed, and can be as high as 30% (unilateral and bilateral deafness combined).
Research Donations For the Catahoula Leopard Dog
We are aligning ourselves with Merle Research Studies as they pertain to the Catahoula Leopard Dog.