Effects of early nutritional stress on physiology, life-histories and their trade-offs in a model ectothermic vertebrate

Abstract

Early-life experiences can have far-reaching consequences for phenotypes into adulthood. The effect of early-life experiences on fitness, particularly under adverse conditions, is mediated by resource allocation to particular life-history traits. Reptiles exhibit great variation in life histories (e.g. indeterminate growth), thus selective pressures often mitigate the effects of early-life stress, particularly on growth and maturation. We examined the effects of early-life food restriction on growth, adult body size, physiology and reproduction in the checkered garter snake. Animals were placed on one of two early-life diet treatments: normal diet (approximating ad libitum feeding) or low diet (restricted to 20% of body mass in food weekly). At 15 weeks of age, low-diet animals were switched to the normal-diet treatment. Individuals fed a restricted diet showed reduced growth rates, depressed immunocompetence and a heightened glucocorticoid response. Once food restriction was lifted, animals experiencing nutritional stress early in life (low diet) caught up with the normal-diet group by increasing their growth, and were able to recover from the negative effects of nutritional stress on immune function and physiology. Growth restriction and the subsequent allocation of resources into increasing growth rates, however, had a negative effect on fitness. Mating success was reduced in low-diet males, while low-diet females gave birth to smaller offspring. In addition, although not a direct goal of our study, we found a sex-specific effect of early-life nutritional stress on median age of survival. Our study demonstrates both immediate and long-term effects of nutritional stress on physiology and growth, reproduction, and trade-offs among them.

Sex‐specific aging in animals: Perspective and future directions

“…In great skua ( Stercorarius skua ), females are larger than males, and female chicks typically grow faster than males, but poor environmental conditions led to slower growth in female chicks than in male chicks (Kalmbach et al, 2009 ). Sex‐specific effects of development under poor nutrition also have been studied in garter snakes (Holden et al 2019 ) where females, but not males, had significantly lower adult survival when they developed under poor nutrition (despite exhibiting catch‐up growth when switched to a high‐nutrient diet pre‐maturation). In humans, intra‐uterine growth restriction leads to negative outcomes more often in males (reviewed in Cheong et al, 2016 ).…”

“…in garter snakes (Holden et al 2019) where females, but not males, had significantly lower adult survival when they developed under poor nutrition (despite exhibiting catch-up growth when switched to a high-nutrient diet pre-maturation). In humans, intra-uterine growth restriction leads to negative outcomes more often in males (reviewed in Cheong et al, 2016).…”

The early‐life stress induced by oxytocin inhibition in p53 knockout mouse dams increases adulthood tumorigenesis in first and second generations

“…Early life is a critical time period for all species as somatic and germ cells complete development and unfavorable events such as nutrient, 33 heat or oxygen 34 deprivation can have long‐term consequences, possibly inheritable from one generation to the next one 35 . In humans, adverse conditions during early life have been found to favor several disorders including obesity, 36 cognitive dysfunctions, 30 inflammation, 37 and to increase the incidence of life‐threatening cardiovascular diseases and cancer 38 .…”

Clutch may predict growth of hatchling Burmese pythons better than food availability or sex

“…Early developmental conditions and experiences can have strong immediate and long-lasting effects on offspring life-history traits (e.g. Brown and Shine, 2004 ; Holden et al, 2019 ; Shine et al, 1997 ). The eggs from C1 were incubated in the wild for a longer proportion of time than the C2 clutch, and the female pythons that laid these clutches were different sizes and chose different microhabitats for their nesting sites (C1 was laid on the ground surface in some grass, while C2 was laid in a burrow).…”