Maternal stress alters the phenotype of the mother, her eggs, and her offspring in a wild caught lizard
- While biomedical researchers have long appreciated the influence of maternal stress on offspring phenotype, ecologists have only recently explored its impact in wild animals. Interpreting biomedical findings within an ecological context has posited that maternal stress may play an adaptive role preparing offspring for a stressful or rigorous environment. However, such an adaptive potential of maternal stress has been poorly studied in wild animals. 2. We tested the hypothesis that maternal stress may adaptively alter offspring phenotypes in a wild reptile, the eastern fence lizard (Sceloporus undulatus). In addition to visual predators, this lizard has frequent non-lethal interactions with a key invasive predator, the invasive red imported fire ant (Solenopsis invicta), which elevate the lizards’ glucocorticoid (stress) hormone levels. 3. Using a non-invasive transdermal application of glucocorticoids we experimentally mimicked fire ant-induced increases in maternal stress hormones. We examined the effects of this maternal stress on fitness-relevant traits of the mother, her eggs, and her subsequent offspring. 4. We found maternal glucocorticoid application increased mother’s antipredator-relevant behaviours and post-laying glucose levels. Maternal glucocorticoid application had no effect on egg morphology or caloric value, but altered yolk hormone (elevated glucocorticoid) and nutrient content (higher protein and decreased lipid). Glucocorticoid-dosed mothers had offspring with altered phenotypes including stress-relevant physiology (lower baseline plasma glucocorticoid and a greater glucocorticoid response to ACTH), morphology (longer body and tail), and behaviour (more time under a refuge and less responsiveness to mimicked fire ant attack). 5. These findings reveal that elevated glucocorticoids during gestation can have significant impacts on the mother and her eggs and offspring; changes which may be adaptive to prevalent stressors, such as visual predators. These data contribute to our growing knowledge that maternal glucocorticoids can have potentially beneficial impacts on offspring phenotype, and that stress-induced phenotypes must be viewed within an ecologically relevant framework.
|Work Title||Maternal stress alters the phenotype of the mother, her eggs, and her offspring in a wild caught lizard|
|License||Public Domain Mark 1.0|
|Deposited||July 26, 2018|
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