A Gene Built for the Embryo Turns Out to Run the Adult Body Too

Researchers at the Weizmann Institute found that a gene called Orthopedia, or Otp, keeps working throughout adult life rather than switching off after it helps build the embryonic brain, which is what scientists had assumed until now. Professor Gil Levkowitz, Dr Yael Kuperman and Professor Alon Chen used genetic engineering to selectively disable the gene in adult male mice only after they had reached full maturity, isolating what the gene does later in life from what it does earlier.

Mice without a working Otp gene developed elevated levels of corticosterone, the stress hormone, alongside depression like behaviour and weakened resilience to stress. The same mice also developed higher cholesterol and blood sugar, a higher body fat percentage despite eating normally, and significantly reduced thyroid hormone, a combination that points to the gene regulating metabolism and mood through the same mechanism rather than two separate ones.

It's not just building the system, Levkowitz said, it keeps it running. Published in the journal Endocrinology, the finding reframes Otp from a developmental gene with a fixed job at birth into an ongoing regulator the body keeps relying on. Hebrew University's Professor Danny Ben-Zvi, who was not involved in the research, offered independent commentary on the result.

The next step is testing whether the same pattern holds in female mice, since a treatment built on a male only result risks failing the sex it was never tested on. If the finding holds up, the researchers say it could point toward new treatments for anxiety, stress and metabolic disorders that currently get treated as unrelated conditions rather than as symptoms of the same underlying switch.