DNA variants help bat beat life span rule


From the elephant to the mayfly, biologists say there is a general rule about longevity: the bigger the animal, the longer it lives.

But an intriguing exception is the Brandt’s bat, a native of temperate areas of Europe and Asia.

The insect-munching mammal tips the scales at 5 to 8 grams — less than two teaspoons of sugar — yet can live for more than 40 years, which is as long as a dolphin and more than a horse or a cow.

Eager to learn why, a group of scientists sequenced the bat’s genetic code, highlighting a network of genes that could explain its exceptional lifespan.

They pinpointed genetic variants that, as expected, give the tiny creature its ability to navigate by sonar and to sense dim and ultraviolet light. But they also came across “unique” variants that control cell sensitivity to two growth hormones. One mutation is linked in humans to a form of dwarfism and may be protective against diabetes and cancer.