Canine Genetics

Question 1

Genetic theory

Answer 1

• same as with other animals
• diploid number = 78
• 38 pairs of autosomes
• 1 pair of sex chromosomes
• some things are speculative

Question 2

Coat genetics: is short and long hair dominant or recessive

Answer 2

Short: dominant
Long: recessive

Question 3

Coat genetics: is wiry hair and smooth hair recessive or dominant?

Answer 3

Wiry: incomplete dominant
Smooth: maybe

Question 4

Coat genetics of hairlessness?

Answer 4

prolly homozygous lethal

Question 5

pigments of dogs?

Answer 5

Eumelanin: black – grey
Phaeomelanin: red, orange, yellow

Question 6

Eumelanin

Answer 6

black, grey, …

Question 7

Phaeomelanin

Answer 7

red, orange, yellow

Question 8

Associated problems with Merle

Answer 8

• often blind and deaf
• malformed, small eyes
• pups often die
• homozygous semi-lethal

Question 9

Genetics of homozygous lethal?

Answer 9

hairlessness

Question 10

genetics of homozygous semi-lethal?

Answer 10

merle

Question 11

Pleiotropy

Answer 11

One gene affecting many traits

Ex: affects fur coat, sterile reproduction, etc…

Question 12

Deafness is common in which breed?

Answer 12

dalmatians

Question 13

Uric acid production is common in which breed?

Answer 13

dalmatians

Question 14

Hip dysplasia

Answer 14

• Fairly common problem in many breeds
• Hip joint breaks down
  – Very painful to walk
• Can be diagnosed by X-ray
• OFA certification
• Afflicted should not be used as breeders

Question 15

“Breeder-induced” problems

Answer 15

• collie eye anomaly
• respiratory
• reproductive
• back problems (dachshunds, boxers)
• skin

Question 16

other breed-related issues

Answer 16

• Nearly every breed has some problems
  that have been found in that breed
• Check into these when deciding on a breed, and then discuss with breeder
• Several genetic tests available now

Question 17

Is inbreeding in dogs good or bad?

Answer 17

XXXX

Question 18

Inbreeding increases what?

Answer 18

Homozygosity

YAY: increase predictability/purity breed formation (line-breeding)
NAY: can increase incidence of deleterious/”bad” recessive traits

To be used properly, must be willing to remove problems from gene pool

Question 19

To use inbreeding properly, must do what?

Answer 19

be willing to remove problems from gene pool

Question 20

If the goal is to produce a Dalmatian that doesn’t produce uric acid, what to do?

Answer 20

1. Cross a Dalmatian with a Pointer
2. backcross
3. “inbreed”

Question 21

Quantitative traits

Answer 21

• measurable, can be expressed in numbers
• Ex; height, weight litter size

Question 22

Qualitative traits

Answer 22

• descriptive, categorized
• often influenced by a single or few genes
• Ex: coat color, ear shape, temperment

Question 23

Interesting research: domestication of foxes

Answer 23

40-50 years

tameness

Question 24

Interesting research: associated changes

Answer 24

colors, ears, tails, skull measurements, development behaviors