Meeting Abstract

90.5  Friday, Jan. 7  Stress begets stress: elevated yolk corticosterone impacts oxidative stress in chicks HAUSSMANN, M.F.*; BOWDEN, R.M.; Bucknell Univ.; Illinois State Univ. mfh008@bucknell.edu

Early embryonic exposure to maternal glucocorticoids (GCs) can broadly impact physiology and behavior across phylogenetically diverse taxa. The transfer of maternal GCs to offspring may be an inevitable cost associated with poor environmental conditions, but may also serve as a maternally mediated cue that alters offspring phenotype in preparation for a stressful environment. Maternal GCs are likely to have both costs and benefits that are paid and collected over different developmental times. To date, the majority of work has focused on the short-term effects of maternal GCs on offspring phenotype. But, a recent link between elevated GCs and accelerated cellular aging in humans suggests that increased embryonic exposure to maternal GCs may also have long-term survival costs. Here, we manipulated yolk corticosterone (CORT) in domestic chickens (Gallus domesticus) to investigate the link between yolk CORT and cellular aging. Eggs were assigned to three groups balanced for mass: control (C, n = 15), low CORT (5 ng/ml CORT, n = 15), and high CORT (10 ng/ml CORT, n = 15). Upon hatch, chicks were weighed daily and at 25 days of age we measured activity of the HPA axis through a stress series. CORT injection successfully elevated yolk CORT levels. High CORT birds were the lightest at hatch, but this difference disappeared by 4 days of age and thereafter growth rate did not differ among treatments. High CORT birds had an over-representation of short telomeres compared to the control and low CORT birds, which may be due to altered responsiveness of the HPA axis and its impact on oxidative stress. In wild birds and humans, individuals with the shortest telomeres have the poorest survival prospects. Thus, the long-term costs of maternal GCs may be accelerated aging and increased mortality.