Researchers found that while mice and humans have almost the exact same gene pool, the genes are expressed in very different ways.
A research team analyzed 15 different genes that were expressed in both humans and mice and discovered gene expression was more closely related to species than tissue type, a news release reported.
"[The results] go a little against the grain," bioinformatician Mark Gerstein of Yale University who was not involved in the study told The Scientist. "We might think that humans and mice are very similar [genetically], but when we compare their transcriptomes, they're more different than we thought."
Mice are often used in labs because their genetic makeup and can help us determine how drugs and medical treatments will affect our own bodies. This thought process has proved to be effective in some cases, but not in others. This new research provides insight into why mice sometimes react differently to treatments than humans.
Gene expression is when possessing a certain type of gene leads to distinctive trait. Scientists believed animals' gene expression operated similarly to ours, but this new research suggests otherwise. The team observed gene expression in different types of tissue in mice were more alike than those found around the human body.
An example of this is the fact that gene expression in a mouse's heart tissue was more similar to what was found in the liver tissue than heart tissue in humans. The researchers also observed 4,000 genes that were expressed differently by humans and mice.
Past studies have tended to find gene expression in different species is generally the same, but these new findings dispute the popular idea. The researchers suggest these findings were skewed because they only look at a limited type of tissue samples such as heart, kidney, brain, and liver.
The findings were published in the Proceedings of the National Academy of Sciences.
