Maternal Stress Affects Fetal Growth but Not Developmental Instability in Rabbits

Abstract

Developmental instability (DI), often measured by fluctuating asymmetry (FA) or the frequency of phenodeviants (fPD), is thought to increase with stress. However, specifically for stressors of maternal origin, evidence of such negative associations with DI is scarce. Whereas effects of maternal stress on DI have predominately been examined retroactively in humans, very little is known from experiments with well-defined stress levels in animal model systems. The aim of this study was to examine the effects of maternal exposure to three doses (plus a control) of a toxic compound affecting maternal condition on DI of their offspring in rabbits. Presence of maternal stress induced by the treatment was confirmed by a decrease in food consumption and weight gain of gravid females in the medium and high dose. Major abnormalities and mortality were unaffected by dose, suggesting the lack of toxic effects of the compound on the offspring. In spite of string maternal stress, offspring FA did not increase with dose. The treatment did lead to elevated fPD, but most were transient, reflecting growth retardation. Furthermore, a consistent association between fPD and FA was absent. These findings indicate that DI is not increased by maternal stress in this animal model.

Early Life Stress (ELS) Effects on Fetal and Adult Bone Development

“…• Rabbit Bots et al [37,38] investigated the role of different levels of maternal stress in developmental instability of fetal skeletal abnormalities. In the first study, authors analyzed the linear patterns of the fluctuating asymmetry of the limbs [37], while in the second one, they also examined the frequency of phenodeviants [38].…”

“…• Rabbit Bots et al [37,38] investigated the role of different levels of maternal stress in developmental instability of fetal skeletal abnormalities. In the first study, authors analyzed the linear patterns of the fluctuating asymmetry of the limbs [37], while in the second one, they also examined the frequency of phenodeviants [38]. Although both studies used gravid rabbits with a control, exposed to toxic treatments from GD6-19 and sacrificed on day 28, just before natural delivery, two different toxicological frameworks were reproduced.…”

“…Although both studies used gravid rabbits with a control, exposed to toxic treatments from GD6-19 and sacrificed on day 28, just before natural delivery, two different toxicological frameworks were reproduced. Specifically, in [37] the toxic compound was an antiprotozoal agent daily administered in three dose groups (80, 320, and 1280 mg/kg), mainly affecting fetal condition more than maternal, while in [38] hydroxy-propyl methylcellulose was used, a non-fermentable semi-synthetic dietary fiber, at different levels (100, 500, and 1500 mg/kg), known to reduce food consumption and cause weight loss in dams without toxic effects in the offspring. In the first study, authors found a higher fluctuating asymmetry of the hind limbs in the low treatment than in the control, detecting abnormalities in the high dose only [37], which was coherent with the so-called hypothesis of the "early warning system", which states that fluctuating asymmetry could serve as a predictor of changes in fitness and health [55].…”

Peer Review #1 of "No relationship between vertebral column shifts and limb fluctuating asymmetry in human foetuses (v0.2)"

“…Phenodeviants are less often used as measure of DI and associations with FA are not always present (e.g. Bots et al (2016)), suggesting that both measures of DI do not necessarily reflect similar aspects of DI.…”

No relationship between vertebral column shifts and limb fluctuating asymmetry in human foetuses

“…The occurrence or frequency of morphological abnormalities—the so-called phenodeviants, a term first coined by Lerner (1954) —were proposed as a measure of DI by Rasmuson (1960) . Phenodeviants are less often used as measure of DI and associations with FA are not always present (e.g., Bots et al, 2016 ), suggesting that both measures of DI do not necessarily reflect similar aspects of DI. Although FA is commonly used in evolutionary studies to measure DI, to date it remains an unpredictable risk marker in the sense that it does not ubiquitously relate to either environmental or genetic stress (e.g., Møller, 1997 ; Lens et al, 2002 ; Van Dongen & Gangestad, 2011 ).…”