It’s in the genes: Worms pass ‘memories’ down through generations - study
A study led by the Centre of Genomic Regulation in Barcelona, Spain, found that environmental ‘memories’ can be passed on in the genes of roundworms for 14 generations — the longest period ever observed in a creature.
The team studied genetically engineered nematode worms that carried a transgene which caused the worm to glow when activated. This allowed scientists to observe the creatures under varying temperatures.
The worms were first kept in a container at 20 degrees Celsius (68 degrees Fahrenheit), resulting in low activity of the transgene and very little glow. When they were moved to a warmer climate of 25 degrees Celsius (77 degrees Fahrenheit), they radiated a stronger glow, signalling activity of the transgene.
When worms were returned to cooler temperatures they continued to glow brightly, suggesting they were retaining an 'environmental memory' of the warmer climate.
Researchers found that descendents of worms and their offspring glowed brightly for seven generations despite not being kept in warmer temperatures.
The team then experimented by putting the worms at a temperature of 25 degrees Celsius for five generations. This resulted in increased transgene activity being maintained for at least 14 generations after the animals were returned to cooler conditions.
“We discovered this phenomenon by chance, but it shows that it’s certainly possible to transmit information about the environment down the generations,” said lead researcher Dr. Ben Lehner.
“We don’t know exactly why this happens, but it might be a form of biological forward-planning," added first author of the study Adam Klosin.
While the phenomenon has been observed in a range of animal species, as well as humans, it normally fades after a few generations. This is the longest transgenerational environmental ‘memory’ ever observed in animals to date, according to the team, who published their results in the journal Science.
"Worms are very short-lived, so perhaps they are transmitting memories of past conditions to help their descendants predict what their environment might be like in the future,” co-leader of the study Tanya Vavouri said.