Els Atema defended her thesis at Groningen University on 13 January. She discovered that telomeres of great tits differ from those in other birds species and in humans. It's a discovery that could change our understanding of how ageing works.


Els Atema

Telomeres are pieces of DNA at the end of chromosomes. Their main function is to protect the rest of the DNA from deterioration, or from fusion with neighboring chromosomes.

It's possible to measure variation in the quality and rate of ageing between individuals of a species by looking at telomere length. In many species, telomere length shortens with increasing age. Shortening is accelerated by processes that also lead to a decrease in life expectancy.

Two classes

In her research, Els Atema used shorter telomeres as away to measure ageing in great tits (Parus major). Great tits seem to have two classes of telomeres: relatively short telomeres that become shorter as they get older, but also long telomeres that do not shorten with age.

"We found that the great tits that are most successful in reproduction, also better maintained their telomeres. This suggests that these successful great tits are of better 'quality'."

Increased workload

As part of her research, Atema equipped a number of male great tits with backpacks the size of a transmitter. This increased their workload, but apart from some small, short-term behavioural changes there was no negative impact.

"We found no long term effects of the backpacks on telomere shortening or on fitness parameters", says Atema. "Birds frequently receive equipment such as transmitters, so with our results we show that these could be used without negative consequences in the long term for great tits."

Fundamental insights

It's an effect that had not been observed previously, but why exactly great tits have these groups of ultra-long telomeres still remains a mystery.

More research is needed, believes Atema. Eventually, this may even give us new, "fundamental insights into the nature of ageing."