Mother's Genes May Be Key in Jet Lag

W A S H I N G T O N, July 14, 2000 -- The reason jet lag plagues some travelers and barely affects others could lie in our mothers’ genes, Science magazine reported on Thursday.

A study on circadian clocks, a subtle biological system that regulates the body’s daily cycles, found that female zebra fish “set” the clocks in their young before birth.

Researchers who conducted the study at the Ecole Normale Superieure in France said a key component of the clock starts “ticking” in zebra fish eggs even before they are fertilized. The gene’s activity keeps the same rhythm as the animal develops.

Scientists had assumed that the circadian clock did not start working until after or around the time of birth. The study showed variations in certain maternal genes that may affect how easily the body’s time-keeping system adjusts to changes in the day/night cycle.

Researchers said it was unclear how closely related the study was to humans.

Resetting the Biological Clock

“The possibility remains open that there is also a direct inheritance as we described in zebra fish,” said Vincent Laudet, one of the study’s researchers.

Laudet said a better understanding of how the clock is run and regulated could lead to a better understanding and treatment of jet lag problems.

Other institutions participating in the study included the Centre National de la Recherche Scientifique, Institut de Genetique et de Biologie Moleculaire et Cellulaire, Institut National de la Sante et de la Recherche Medicale and the Universite Louis Pasteur.