Inherited Sheep Traits

Question 1

Spider syndrome

Answer 1

Skeletal abnormalities
Lethal/semi-Lethal
Single gene recessive. Fibroblast growth factor receptor.

Question 2

Scrapie

Answer 2

Central nervous system disorder
No cure
Costs US sheep industry $20-25 mil
Diagnosis using necropsy of brain/lymph nodes or examine 3rd eyelid for abnormal prion protein
Codon 136, 154, 171

Question 3

Booroola

Answer 3

Fecdundancy allele
Increased ovulation
Chromosome 6
Large litter size, poor lamb survival, lamb growth, and ewe conception.

Question 4

Callipyge

Answer 4

Muscular hypotrophy
Telomeric region of chromosome 18
Higher dressing percentage, larger loin, though meat, decreases fat, better feed efficiency.
Polar over-dominance: only 1 sure copy allows trait to be expressed
Manifests 1 month after birth