Corticosterone in Lizard Egg Yolk Is Reduced by Maternal Diet Restriction but Unaltered by Maternal Exercise

When females face adverse environmental conditions, physiological changes, such as elevated corticosterone levels, to cope with the stressors may also impact their offspring. Such maternal effects are often considered adaptive and may "prime" the offspring for the same adverse environment, but maternal corticosterone levels do not always match that of the eggs produced. We examined how diet restriction and increased locomotor activity, via exercise training, affected steroid hormone levels of female green anole lizards, as well as the hormone levels in the yolk of their eggs. Diet restriction did not affect female hormone levels, but training increased corticosterone levels. Despite this, training did not affect yolk steroid levels, but eggs from females with diet restriction had lower corticosterone levels in yolk. This suggests that two common stressors, food shortage and increased locomotor activity, impact female physiology in a way that is not translated to her offspring.