What is in this article?:
- Pig genome offers window into human health
- Shedding pig light
- Genomic analysis reveals unexpected and potentially beneficial similarities between pigs and humans.
- New analysis helps understand the genetic mechanisms that enable high-quality pork production, feed efficiency and resistance to disease.
Shedding pig light
“This understanding of the genetic origins of modern pigs is important as we breed pigs to meet growing demand more efficiently and to resist old and emerging diseases,” said Alan Archibald, a professor at The Roslin Institute at the University of Edinburgh and a principal investigator on the study.
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 researchers said. Unlike the domestic cow, whose ancestors, the aurochs, are now extinct, the porcine lineage has a lot of genetic diversity remaining.
“We can easily go find genes that might be still in the wild that we could use for breeding purposes today,” said Schook, who is the Gutgsell Professor of Animal Sciences, Bioengineering, Pathobiology, Nutritional Sciences, Pathology and Surgery at Illinois.
“This study demonstrates the benefits of basic genomic research on agricultural animals and their closest living relatives,” said U. of I. President Bob Easter, who helped secure funding for the pig genome sequencing effort when he was the dean of the College of Agricultural, Consumer and Environmental Sciences at Illinois.
“This work has important implications for agriculture, contributes to our understanding of evolution and will aid in human medicine,” said Easter, who also is an emeritus professor of animal sciences and of nutritional sciences.
The USDA National Institute of Food and Agriculture supported this research.