not the one doing the studies! Ask the scientists! OKAY I'll look! Why DO we use mice?!

A lot of the time, when we're reporting on science here at DNews, the studies we're reading

are done with mice. Mice have been used for more than 100 years in tons of scientific

research. Today, the laboratory mouse or Mus Musculus is used as a human analog in everything

from brain disease studies to social interaction studies, cancer, smoking, obesity, genetics

… so many things.

Scientists use mice because they are small, easy to care for, have a high reproduction

rate, and their genome has been sequenced. According to the National Center for Biotechnology

Information, there are over 450 inbred strains of white lab mice which can be selected and

customized for specific studies. Mice have similar immune systems and metabolisms, have

been inbred to minimize genetic differences for different mice, and can be (or have been)

genetically mutated so their DNA more closely mimics humans. Overall, researchers generally

accept mice as good stand-ins for us. But, as medicine drills deeper into the genetic

code, they've discovered even though we look the same on the surface, mice are still very

different.

It’s already known that humans and mice share 70 percent of the same protein-coding

gene sequences, and about HALF of their DNA overall. But new study in a series of papers

in Nature, Science, and Genome Research found some key variances in the way mouse and human

genes are regulated. More specifically, they found that a mouse’s immune, metabolic and

stress response systems behaved differently than a human’s at the genetic level.

Scientists had been operating under the assumption that mouse genes and human genes would express

the same way, but even though the genes appear to accomplish the same tasks, they did those

tasks in a slightly different way. Like taking a different road to the same destination…

and in science, that little detail matters… a lot.

Now, let's not all start laughing at science, or assume that all the studies ever done are

now invalid lies. That's simply not the case. Mice and humans are still similar enough to

go along with, but as medicine probes deeper and gets more person-to-person specific, the

gene expression of each person is going to affect how they're treated. And knowing the

key differences in how mice and human genes work is going to affect HOW they'll create

that treatment.

As the researchers say, "the mouse continues to be a very good model [for humans]." Now

they just need to fine tune their experimentation.

Because 95 percent of ALL medical experiments use these genetically modified lab mice, more

research is needed to see which studies will have to be re-done (if any) using this new

information. And, luckily for us, the researchers promise there will be more than a dozen studies

on the mus musculus in the coming years. This is going to be super interesting.

How do you feel about science using mice?