Some gene families are undergoing relatively fast evolution in the domestic pig, with immune genes and (perhaps not surprisingly) olfactory genes quickly expanding. The pig has more unique olfactory genes than humans, mice or dogs, the researchers report.
And while pigs can smell a world of things humans and many other animals can't think truffles their sense of taste is somewhat impaired.
"Pigs have a high tolerance for eating things that have a lot of salt or that we would find repulsive by taste," Schook said.
Pigs have significantly fewer bitter taste receptor genes than humans, for example, and genes involved in perception of sweet and umami (which humans perceive as meaty) flavors are also different in pigs and humans, the researchers found.
"Understanding the genes that shape the characteristics of pigs can point to how and why they were domesticated by humans," Archibald said. "Perhaps it was their ability to eat stuff that is unpalatable to us humans."
The new analysis also supports the use of the pig in studies of human diseases.
"In total, we found 112 positions where the porcine protein has the same amino acid that is implicated in a disease in humans," the researchers wrote.
By also sequencing the genomes of another 48 pigs, "we identified many more gene variants implicated in human disease, further supporting the pig as a valuable biomedical model," Groenen said.
Some of the protein aberrations pigs share with humans are associated with obesity, diabetes, dyslexia, Parkinson's disease and Alzheimer's disease, the researchers report.
The new analysis also has important implications for agriculture, particularly since the domestic pig still has an ancestor-like wild cousin on the loose, the researche
|Contact: Diana Yates|
University of Illinois at Urbana-Champaign