Finding the Genes that Help Kingfishers Dive without Hurting Their Brains
Published:30 Nov.2023 Source:Field Museum
If you've ever belly-flopped into a pool, then you know: water can be surprisingly hard if you hit it at the wrong angle. But many species of kingfishers dive headfirst into water to catch their fishy prey. Researchers compared the DNA of 30 different kingfisher species to zero in on the genes that might help explain the birds' diet and ability to dive without sustaining brain damage. The type of diving that kingfishers do -- what researchers call "plunge-diving" -- is an aeronautic feat. But it's a behavior that's potentially risky.
For kingfishers to dive headfirst the way they do, they must have evolved other traits to keep them from hurting their brains. In the Field's Pritzker DNA Laboratory, the researchers began the process of sequencing full genomes for each of the species, generating the entire genetic code of each bird. From there, they used software to compare the billions of base pairs making up these genomes to look for genetic variations that the diving kingfishers have in common.
The scientists found that the fish-eating birds had several modified genes associated with diet and brain structure. For instance, they found mutations in the birds' AGT gene, which has been associated with dietary flexibility in other species, and the MAPT gene, which codes for tau proteins that relate to feeding behavior. Tau proteins help stabilize tiny structures inside the brain, but the accumulation of too many tau proteins can be a bad thing. In humans, traumatic brain injuries and Alzheimer's disease are associated with a buildup of tau.