Cells that control animals’ seasonal body clock have been identified for the first time by Edinburgh researchers.
Scientists say specialised cells in the pituitary gland respond according to how much daylight there is, and help animals’ bodies adapt to the changing seasons.
The findings increase understanding of how the environment affects animals and could also be relevant to humans.
The activity of the cells changes dramatically throughout the year, with different proteins being produced during winter and summer months.
The study shows that switching between proteins drives the seasonal body clock in sheep and other mammals.
Researchers say animals need to alter their physiology to cope with changing environments and increase their chances for survival.
Until now, it was not known how animals changed the genetic make-up of their bodies to suit the seasons.
The findings provide researchers with a greater understanding of how animals’ seasonal body clock regulates this process.
The study took place over three years and involved analysis of how sheep respond to seasonal changes in day length.
Researchers say a similar body clock can be found in most animals, including humans.
It was previously thought that humans did not show seasonal adaptations, but more recent research has found this may not be the case and that there is seasonal variation in protection against infectious disease.
The study, published in the journal Current Biology, was carried out in collaboration with the University of Manchester. The research was funded by the Biotechnology and Biological Sciences Research Council.
The seasonal clock found in sheep is likely to be the same in all vertebrates, or at least, contains the same parts list. The next step is to understand how our cells record the passage of time.