A University of Illinois side-by-side comparison of the human and pig genomes has revealed remarkable similarities.
“We took the human genome, cut it into 173 puzzle pieces and rearranged it to make a pig,” explains animal geneticist Lawrence Schook. “Everything matches up perfectly. The pig is genetically very close to humans.”
When looking at a pig or a human, the difference is seen instantly. “But, in the biological sense, animals aren’t that much different from one another – at least not as different as they appear,” he says.
Animals all have the same basic makeup, as in eyes, ears and stomachs. “But the same gene in the pig may work in combination with other genes to control something very different than it does in a human,” adds animal geneticist Jonathan Beever.
So while all the genes for humans and pigs match up, understanding how they work together is the next step in deciphering what makes a pig a pig and a human a human, he adds.
A genome is the complete set of genes for an organism, similar to an instruction manual. But in this manual the steps aren’t in any particular order. “We don’t know, for instance, when in the development of the animal a certain gene is expressed,” Beever says. “And the same gene may behave very differently in a different animal. That’s the next level of information we’ll be looking at.”
Learning this much about the pig genome is important because the pig is one of the closest large animal species to humans. “We believe a niche the pig has will be in biomedical models to understand and fight human disease. If you study a human genetic disease in a lab mouse, the manifestations of the disease may not be appropriate. But genetic diseases may look the same in a pig as they do in a human, so disease research with pigs will be much more applicable to human medicine,” states Beever.
The pig genome map will be very useful in drug therapy to control or cure a disease. The pig provides the closely related model needed in human therapeutic medicine, notes Schook.
Schook and Beever and other Illinois researchers are in the third year of a five-year study funded by USDA to create comprehensive genome maps of the pig and the cow.
More information is available at www.swinegenomics.com.