Early-life immune expression profiles predict later life health and fitness in a wild rodent

Abstract

Individuals differ in the nature of the immune responses they produce, affecting disease susceptibility and ultimately health and fitness. These differences have been hypothesised to have an origin in events experienced early in life that then affect trajectories of immune development and responsiveness. Here we investigate early life influences on immune expression profiles using a natural population of field voles, Microtus agrestis, in which we are able to monitor variation between and within individuals though time by repeat (longitudinal) sampling of individually marked animals. We analysed the co-expression of 20 immune genes in early life to create a correlational network consisting of three main clusters, one of which (containing Gata3, Il10 and Il17) was associated with later life reproductive success and susceptibility to chronic bacterial (Bartonella) infection. More detailed analyses supported associations between early life expression of Il17 and reproductive success later in life, and of increased Il10 expression early in life and later infection with Bartonella. We also found significant association between an Il17 genotype and the early life expression of Il10. Our results demonstrate that immune expression profiles can be manifested during early life with effects that persist through adulthood and that shape the variability among individuals in susceptibility to infection and fitness widely seen in natural populations.

Maternal transmission gives way to social transmission during gut microbiota assembly in wild mice

“…Thus microbiota differences involving this genus early in life could have important knock-on effects on the functioning of the adaptive immune response – a key fitness determinant. Future wild studies that assess links between early-life microbial communities and later life traits associated with health or fitness (similar to [53]) would be useful in this respect. We suggest wild mouse systems, such as that used here, are a tractable system in which to quantify these long-term, and potentially profound, effects of maternal transmission.…”

“…Thus microbiota differences involving this genus early in life could have important knock-on effects on the functioning of the adaptive immune responsea key fitness determinant. Future wild studies that assess links between early-life microbial communities and later life traits associated with health or fitness (similar to [53]) would be useful in this respect.…”