Spicy Snackin’ Shrews

Do our furry friends LOVE to spice it up? 

This is Sandra Tsing Loh with the Loh Down on Science saying, YOU PEPPER BELIEVE IT!

Some of us humans love spicy food! Others don’t. But what’s the story with. . . MAMMALS? Bowen Li from the Kunming Institute of Zoology in China and colleagues wondered. They discovered that common mice say YUCK to spicy peppers. BUT another small rodent, the tree shrew, willingly gobbles them down!

So what gives? 

When the researchers analyzed the tree shrews’ DNA, they found a unique mutated section. Using computer models, they observed how pepper molecules interacted with the mutated DNA.

Results? The models showed that pepper molecules don’t bind as easily with the mutated DNA. This prevents the shrews from feeling that “spice sensation!” 

When they simulated a DNA swap between the mice and shrews, it showed that shrews with mice DNA would experience a FIFTY-FOLD increase in sensitivity! 

The researchers believe shrews evolved their spicy palette to munch on nearby pepper plants. 

As for me? MY DNA tells me . . . . more flamin’ hot cheetos!

Reference: Han, Y., Li, B., et al. Molecular mechanism of the tree shrew’s insensitivity to spiciness. PLOS Biol 16, 7 (2018). https://doi.org/10.1371/journal.pbio.2004921