Some more cat alleles
Calico
X^O/X^ob
tri-colour cats
calico only occurs in females
males are black or orange (unless klienfelders)
they have variation in?
Coat colour
Coat type
Head shape
Ear shape
tail length
coat types of dogs? (2 types)
Double and single
Sizes of dogs
Giant = ~100lbs, 22-42 inches, bread for protection and work, grow rapidly, common problem are hip dysplasia
Standard = large breed - akita, mid size - border collie, small size - cocker spaniel
Miniature - Proportional size decrease, 8-12 inches, bred to decrease size, have hydrocephalus, protruding eyes, bit problems, cryptorchidism
Dwarf = shortened limbs but normal torso and head
Dwarfism
Shortened limbs
Achondroplastic dwarfism
short legged condition
gene is autosomal dominant and homozygous lethal
Tabby pattern types
Mackerel tabby - eumelanin line, stripes branching off
Blotched tabby - also called classic tabby, whorls of darker colour
Types of cat hairs
Guard hairs
awn hair
down hairs
Length of dog hair - L Locus
Short hair is dominant, long hair is recessive
fibroblast growth factor mutation
The three skull types are? breeds associated with them
Dolichocephalic - whippet, sight hounds
Mesaticephalic - retreivers, labs
Brachycephalic - bulldogs, boxers
Cats that have tail length defects
Manx - homozygous lethal - skeletal disorders associated = mm - tail, Mm - pixie bob, MM - die in utero
Japanese bobtail - dominant = characteristic kinked tail (homozygous have slightly shorter tail than heterozygous
Ticked
Thought to be caused by mutation in gene DKK4
ticked allele is dominant to non-ticked
ticked is epistatic to tabby
it is fixed in the abyssinian breed
Long coat type
long hair is recessive in cats
four FGF5 mutations in breeds of long hair cats
Coat texture - W locus
Smooth hair is wildtype
Wirehair furnishings
dominant inheritance
RSPO2 gene
insertion of 167 bp at 3' noncoding region
ear set of dogs
inheritance is not straightforward mendelian trait
floppy ears found in foxes selected for tameness
possible mutation involvement in cartilage enzyme methionine sulfoxide reductase B3
long floppy ear more prone to infection and mites
Ear shapes and deformities?
Tufted, curled, folded
Scottish fold = apex of the ear is bent forward because of a defect in cartilage development, cartilage defect occurs throughout the body, dominant inheritance
Bengal
came from crosses of domestic cat and the leopard cat
first generation males are frequently infertile
mentioned in 1889 publication
Curly coat type
In Devon rex = autosomal recessive, KRT71 gene is responsible for devon rex, caused by a complex genetic rearrangement, shortened guard hair
in selkirk rex = a dominant mutation, originated in montana after a rescue cat had kittens, all selkrik rex can trace back to the og female
In cornish rex - LPAR6 gene, 4bp del = premature stop, G protein-coupled receptor essential for maintaining the hair shaft, a mutation in humans causes a wooly phenotype
Curly coat
Incomplete dominant - CC = curly, Cc = wavy, cc = straight
Mutation in KRT71 found in rexoid cats
mice with curly hair already identified to have mutation in KRT71
Tail docking and ear cropping
Controversial
Cropping = banned in some countries now, cropping involves surgical removal of section of ear about 9-12 weeks of age, ears must be bandaged in splints for weeks after
docking = cut at 2 days without anesthetic, some European countries do not allow docked dogs in showring
Burmese head defect
Traditional head conformation of burmese cat becomes brachycephalic with one copy of the mutation
kittens with the defect do not survive very long if born alive
Mutation in 5.7% of population
ALX1 gene - 4 amino acid deletion
Inhibitor = I locus
inhibitor locus causes paleness in hairs, due to decreased pigment granules
gene not yet known, but on chromosome D2
dominant
colour is called silver
Hairless coat types
Hypotrichosis
KRT71 splice site mutation
autosomal recessive trait
Hairless coat type
Chinese crested and Xoloitzcuintle
Hair missing on much of body, dominant mutation, FOXI3 mutation (premature stop resulting in 95% of gene missing)
pp = powder puff
Pp = show quality
PP = lethal
Natural bob tails
T-box transcription factor T mutation present in most dogs with natural bob tails
mutation found in 18 of 24 breeds studied
homozygous lethal mutation
Polydactyly
Normally 5 toes on fore paws, 4 on hind paws
May occur on 1-4 feet but normally occurs on fore paws
twisty phenotype - polydactyly with other skeletal deformities