News from CRG
Led by Dr Ben Lehner, group leader at the EMBL-CRG Systems Biology Unit, ICREA and AXA Professor, together with Dr Tanya Vavouri CRG Alumna, the researchers noticed that the impact of environmental change can be passed on in the genes for many generations while studying C. elegans worms carrying a transgene array – a long string of repeated copies of a gene for a fluorescent protein that had been added into the worm genome using genetic engineering techniques.
If the worms were kept at 20 degrees Celsius, the array of transgenes was less active, creating only a small amount of fluorescent protein. But shifting the animals to a warmer climate of 25 degrees significantly increased the activity of the transgenes, making the animals glow brightly under ultraviolet light when viewed down a microscope. When these worms were moved back to the cooler temperature, their transgenes were still highly active, suggesting they were somehow retaining the ‘memory’ of their exposure to warmth. Intriguingly, this high activity level was passed on to their offspring and onwards for 7 subsequent generations kept solely at 20 degrees, even though the original animals only experienced the higher temperature for a brief time. Keeping worms at 25 degrees for five generations led to the increased transgene activity being maintained for at least 14 generations once the animals were returned to cooler conditions.
Although this phenomenon has been seen in a range of animal species it tends to fade after a few generations. These findings, published in the journal Science, represent the longest maintenance of transgenerational environmental ‘memory’ ever observed in animals to date.
Klosin et al. "Transgenerational transmission of environmental information in C. elegans". Science. April 21 2017. DOI: 10.1126/science.aah6412