Genetic Disorders and Physical Traits in Canines

1. Genetic Disorders and Physical Traits in Canines Kate Olson, Stephanie Saris, VivMontony, Amy Phongsa

2. Basics • The nucleus in cells contains all the information to regulate the activity of the cell and ultimately forms the individual animal. • A gene is a portion of a DNA molecule carried on a chromosome. • Dogs have 78 chromosomes in 39 pairs on approximately 100,000 genes • Each gene in a chromosome pair has a partner. Each member of a gene pair is called an allele. • The dominant allele is expressed as a capital (P) and the recessive is expressed in lowercase (p)

4. Sex-Linked Characteristics • Females have a pair of X chromosomes (XX) • Males have 1X and 1Y chromosome(XY) • 1 dose of a recessive X-linked trait will cause the expression of that characteristic in a male(Xy) • A female with only 1 dose will be an unaffected carrier(Xx)

5. Inheritance vs. Spontaneous • A genetic disorder is a result of a mutation in a gene • Some mutations are spontaneous • example-toxins • Some mutations are inherited from one or both parents • Veterinarians will look at many different factors to determine the cause such as • age the condition is present • Are the littermates affected? • Is the condition present in any relative

6. Autosomal Dominance Autosomal Recessive Only one copy of a gene from ether parent is required to produce the trait Parent will pass affected gene to approx. 25% of offspring Most common mode of inheritance To be affected the animal must inherit two copies of the gene-one from each parent As long as carriers of the affected gene are mated with normal animals the offspring will be unaffected, yet some will remain carriers If two carriers are mated there is a 25% chance the offspring will be affected

7. Autosomal Dominant

8. Autosomal Recessive

9. Good breeding practices • Need to find how disease is inherited • Try to identify condition as early as possible • Reduce inheritance by eliminating breeding with affected/carriers of condition • Mate normal(PP) with carriers(Pp)

10. The Spaniel The spaniel has many different

11. Coat Factors to determine coat are similar to human genetics Solid coat spaniels can carry parti-color genes but parti-color cannot carry solid genes Ex: Dark roans are dominant over light roans; 2 light roans cannot produce dark roans; light roans may produce dark roans R = dark roans r = light roans r = light roans r r R r r R R r From this example you can see why two light roan parents cannot make a dark roan pup, however, a light roan parent carrying the dark roan gene and a dark roan parent will most of the time produce dark roan pups though sometimes will produce a parti-color

12. Springer Rage Syndrome “unprovoked attacks” going from stare to full-blown attack with no in-between Not to be compared to rage in people Various forms of aggression were also found in same dogs “glazed look” and dilated pupils (warning signs) is caused by sympathetic nervous stimulation Most severe cases in springer spaniels could be traced back to common bloodline 5 fields of prognosis: age of onset aggression, duration of aggression, severity of the aggression, predictability of aggression, owner/family profile Could be caused by low serotonin metabolites

13. Works Cited • Johnson, L. (May, 2001). http://www.essfta.org/Health_Research/aggression.htm. In An Article concerning the so-called "Rage Syndrome". Retrieved August 16, 2012, from http://www.essfta.org/Health_Research/agression.htm. • . (). Genetics of Color in the English Cocker Spaniel. In A Short Course on Coat Color in Spaniels. Retrieved August 16, 2012, from http://www.stirling-ecs.org/general/color_genes_c.html.

14. Genetic Disorders of the Australian Cattle Dog Specifically, expressed recessive disorders of autosomal alleles through multi-canine breeding.

15. Breeding History M DINGO F COLLIE

16. F DINGO-BLUE MERLE COLLIE M DALMATION

17. F BAGUSTA M KELPIE SHEPHARD

18. AUSTRALIAN CATTLE DOG

19. Genetics of Australian Cattle Dog • Homozygous • These are autosomal recessive alleles or autorecessive genes. This means that two non-sex, recessive chromosomes formed a sequence marker within the DNA. • Commonly two alleles form a dominant/recessive partnership, Rr, called a genotype. With the Cattle dog the gene influence is two recessive genes, rr, now called a phenotype.

20. Phenotypes are what cause a trait to be expressed and the dog to be affected by a recessive disease.

21. Piebald alleles • This is the expression of lack of sufficient melanin in the skin, fur, middle eye and inner ear. This is what causes the Cattle dog to have white skin, multi-colored fur with much white or fare, blue eyes and unfortunately, congenital hereditary deafness and progressive retinal atrophy. • Each of these expressions are an overall influence of the Dalmation, who holds the lowest concentration of melanin. Although each dog, except for Dingo, can be a carrier of the recessive trait.

22. In the phenotype • Deafness- onset can be immediate, but not tested until roughly four weeks old. In a Louisiana University study of 442 Cattle dogs, 2.5%(11) were deaf in one ear and 14.5%(64) in both. • PRA-progressive retinal atrophy-is a degeneration of the retina that occurs slowly often first causing “moon blindness”—the dog not seeing in low light—and ultimately complete blindness. It can also have early onset, but usually presents late in life.

23. There is no cure for either of these inherited diseases. However, many cattle dogs are fitted with cochlear implants allowing full hearing and the opportunity to continue their herding/droving lifestyle. Although there is no aid for sight in dogs there is currently a Cattle Dog Breeding Registry. This allows breeders from around the world to have a simple blood panel done to verify if the recessive allele exists and then register their dog to ensure the halt of double recessive breeding.

24. WORK CITED • Dr. George M. Strain. (June 23, 2010). Breed Specific Deafness, Louisiana University. Retrieved August 17, 2012, from http://www.lsu.edu/deafness/incidenc.htm. • (August 5, 2005). Genetic Advancement. In Optigen. Retrieved August 15, 2012, from http://www.optigen.com/opt9_test_pra_acd.html. • . (). Australian Cattle Dog. In Wikipedia. Retrieved August 16, 2012, from http://en.wikipedia.org/wiki/Australian_Cattle_Dog.

25. . (). Piebald. In Wikipedia. Retrieved August 16, 2012, from http://en.wikipedia.org/wiki/Piebald. • . (). Recessive. In Wikipedia. Retrieved August 16, 2012, from http://en.wikipedia.org/wiki/Autosomal_recessive#Autosomonal_recessive_gene. • . (). Melanocyte. In Wikipedia. Retrieved August 17, 2012, from http://en.wikipedia.org/wiki/Melanocytes.

26. The Siberian Husky • The Siberian Husky was originally bred in Asia, by the Chukchi people. • Siberian Huskies were bred to be work dogs -Herd animals -Watch Dog -Ultimately to pull Sleds • The most important trait of the Siberian Husky to understand is their high energy level. IMG- http://www.dogs-wallpapers.com/user-content/uploads/wall/mid/63/siberian_huskies_wallpaper.jpg INFO- http://www.squidoo.com/siberian-husky-traits

27. Coat • The Coat is made up of two layers. • Undercoat- the hairs are shorter, finer, and softer.It makes up most of the coat • Guard hairs- the hairs are straight, long and bristly, and provides protection for the undercoat. • Siberian Huskies coats are thick due to their heritage of living in the extremely cold weather conditions of Siberia. • The colder the environment, the thicker the coat will get. • Huskies can withstand Artic temp. as low • as -60 degrees C.

28. Claws • Huskies are known for pulling sleds over ice and snow. • They have long, strong, sharp claws due to this. • Their claws are what gives the dog grip and control to pull loads over harsh terrain.