Researchers discover health similarities between humans and pigs

An international scientific collaboration that includes two Kansas State University researchers is bringing home the bacon when it comes to potential animal and human health advancements, thanks to successfully mapping the genome of the domestic pig.

The sequenced genome gives researchers a genetic blueprint of the pig. It includes a complete list of DNA and genes that give pigs their traits like height and color. Once all of the genetic information is understood, scientists anticipate improvements to the animal's health as well as human health, as pigs and humans share similar physiologies.

"With the sequenced genome we have a better blueprint than we had before about the pig's genetics and how those genetic mechanisms work together to create, such as the unique merits in disease resistance," said Yongming Sang, research assistant professor of anatomy and physiology at Kansas State University.

For three years, Sang worked on the genome sequencing project with Frank Blecha, associate dean for the College of Veterinary Medicine and university distinguished professor of anatomy and physiology.

A report of the international study appears as the cover story for the Nov. 15 issue of the journal Nature.

The sequencing effort was led by the Swine Genome Sequencing Consortium. Researchers with the consortium invited Sang and Blecha to work on the project because of their expertise and published studies on the antimicrobial peptides and interferons that pigs use to genetically defend themselves against disease.

Sang and Blecha focused on these two families of immune genes, looking for gene duplications and gene-family expansions throughout the pig's 21,640 protein-coding genes, in an effort to help scientists with future pig-related research.

Sang also completed much of the genome annotation for Kansas State University's contributions. Genome annotation involves identifying, categorizing and recording the potential functions of thousands of individual genes and gene cluster locations in the pig genome.

Analysis revealed that the olfactory and cathelicidin gene families in pigs are more evolutionarily evolved than those in humans and many other animals. Pigs have a better sense of smell, which makes them experts at finding truffles, for example. Pigs also have twice as many interferon genes as humans, possibly indicating some unique immune mechanisms against viral infection, Sang said.

Researchers also discovered several health similarities between humans and pigs. Pigs share some of the same protein abnormalities as humans with obesity, diabetes, dyslexia, Parkinson's disease and Alzheimer's disease.

Similarly, researchers found that pigs have fewer endogenous retroviruses than many other animals, making pigs an important ally for more complex medical procedures like organ transplants.

"The pig genome is very important, maybe even more important than we once thought," Sang said. "It is very good for biomedical research advancements and it also looks to be a good resource for comparative studies of many other diseases."

At Kansas State University the sequenced pig genome stands to benefit agricultural, food animal and veterinary medicine research.

"For many years the pig has been one of the best models for human physiology and has been used extensively because of that," Blecha said. "While this is a blueprint for the health of the pig, it is also a blueprint for the expression of genes and how to modify them for perhaps better animal models and improved health across all species. This moves agricultural and biomedical science forward for the good of everyone."