Early-life environmental effects on birds: mechanisms underlying long-lasting effects

Suvi Ruuskanen

University of Jyväskylä, Finland

While the long-lasting effects of variation in early life environment have been well documented across organisms, only recently have we started to understand the underlying mechanisms. Yet, understanding the underlying mechanisms of long-lasting effects can help us predict how organisms will respond to changing environments. Birds offer a great system to study developmental plasticity and its underlying mechanisms due to variation in developmental trajectories (from altricial to precocial), large external eggs and extensive parental care, combined with a long tradition of physiological, ecological and evolutionary research. Epigenetic changes (such as DNA methylation) have been suggested as a key mechanism to mediate long-lasting effects of early-life environment across taxa. Even more recently, changes in the early-life gut microbiome have been identified as another potential mediator of developmental plasticity. This talk briefly synthesizes the complexity of the early prenatal and postnatal environment in birds, including recent findings understanding, for example, the role of the microbial environment. I will then discuss and summarize the current evidence on the mediators of avian developmental plasticity, focusing on the role of epigenetics and gut microbiome. I will consider and compare prenatal and postnatal environmental effects and different developmental modes. I hope to identify knowledge gaps and challenges and discuss fruitful future research directions.