Lucie Burgers Stichting - The effect of brood size on epigenetically mediated personality in wild great tits (Parus major).

In order to cope with environmental changes, such as habitat destruction, urbanization and
global warming, populations need to behaviourally adapt. Animal personality describes the
consistent differences in how individuals cope with such environmental challenges.
Personality traits have a heritable component and associate with fitness. Recent studies have
shown that early developmental effects also regulate personality traits, even over multiple
generations. Such observations have sparked speculation about an epigenetic regulation of
personality traits. Epigenetic mechanisms, such as DNA methylation, can stably alter gene
expression in response to environmental factors without the need for structural modifications
of the DNA sequence. However, studies linking natural variation in DNA methylation to
evolutionary processes are scarce and ecological research connecting DNA methylation to
behavioural trait variation is almost absent. We have conducted an experiment in which we
have experimentally altered the brood size of great tit (Parus major) nestlings in order to
measure such epigenetic effects on personality. Thanks to a grant funded by the Lucie
Burgers Stichting, we were able to measure DNA methylation in pools of individuals from small
and large broods. We here propose to measure DNA methylation on individual level in the
control group (original brood size) in order to assess whether behavioural changes caused by
the early developmental effects are mediated via DNA methylation.