Effect of predator-induced maternal stress during gestation on growth in root voles Microtus oeconomus

We studied the effect of maternal stress evoked by a severe stressor from the cues of predation risk during gestation on the growth of offspring in root volesMicrotus oeconomus Pallas, 1776. Body mass of both male and female offspring was significantly reduced in the period from birth to weaning. Females showed compensatory growth after weaning, whereas males maintained low body mass at weaning into adulthood. Maternal stress led to an elevated plasma corticosterone level in male offspring, but did not affect that of female offspring. Corticosterone levels remained elevated in males from stressed dams into adulthood. Increased levels of plasma corticosterone may have led to the inhibition of pituitary growth hormone and a chronically abnormal energy mobilization, considering the greater energy and metabolic requirements of male offspring, this may account for the sex-specific differences in compensatory growth. We suggest that in the high stress situation, endocrine-based sex-biased effects of maternal stress as a primary factor can lead to long-term physical and ecological consequences for male offspring.