Sex-Specific Response to Caloric Restriction After Reproductive Investment in Microcebus murinus: An Integrative Approach

Abstract

In seasonal environments, males and females usually maintain high metabolic activity during the whole summer season, exhausting their energy reserves. In the global warming context, unpredictability of food availability during summer could dramatically challenge the energy budget of individuals. Therefore, one can predict that resilience to environmental stress would be dramatically endangered during summer. Here, we hypothesized that females could have greater capacity to survive harsh conditions than males, considering the temporal shift in their respective reproductive energy investment, which can challenge them differently, as well as enhanced flexibility in females' physiological regulation. We tackled this question on the gray mouse lemur (Microcebus murinus), focusing on the late summer period, after the reproductive effort. We monitored six males and six females before and after a 2-weeks 60% caloric restriction (CR), measuring different physiological and cellular parameters in an integrative and comparative multiscale approach. Before CR, females were heavier than males and mostly characterized by high levels of energy expenditure, a more energetic mitochondrial profile and a downregulation of blood antioxidants. We observed a similar energy balance between sexes due to CR, with a decrease in metabolic activity over time only in males. Oxidative damage to DNA was also reduced by different pathways between sexes, which may reflect variability in their physiological status and life-history traits at the end of summer. Finally, females' mitochondria seemed to exhibit greater flexibility and greater metabolic potential than males in response to CR. Our results showed strong differences between males and females in response to food shortage during late summer, underlining the necessity to consider sex as a factor for population dynamics in climate change models.

Survival is reduced when endogenous period deviates from 24 h in a non-human primate, supporting the circadian resonance theory

“…However it is known that female mouse lemurs deal with seasonal transitions and metabolic costs differently than males, particularly during aging 26 . Facing an environmental metabolic stress, female mouse lemurs seem to better manage their energy expenditure and exhibit more flexible physiological response [44][45][46] . During aging, males body weight variations collapse whereas females keep displaying clear seasonal mass variations, suggesting a better management of resources 21,47 .…”

The Torpid State: Recent Advances in Metabolic Adaptations and Protective Mechanisms†

“…Indeed, although hibernation episodes have never been observed in captivity, captive female mouse lemurs are capable of using torpor during gestation and lactation when facing food shortage ( Canale et al, 2012 ), whereas the male response to a comparable stress shows a relative inefficiency to maintain body mass by using torpor ( Giroud et al, 2008 ; Villain et al, 2016 ). In addition, female mouse lemurs show enhanced mitochondrial and antioxidant capacities ( Noiret et al, 2020 ).…”

An organism-wide atlas of hormonal signaling based on the mouse lemur single-cell transcriptome

“…P -values were calculated by 2-sample t -test. Data were collected from literature and unpublished work: estradiol (Noiret et al, 2020; Perret and Aujard, 2005), testosterone (Dal-Pan et al, 2011; Petter-Rousseaux and Picon, 1981; Schilling and Perret, 1993), thyroxine ((Noiret et al, 2020; Petter-Rousseaux, 1984) and unpublished data), DHEA (Perret and Aujard, 2005), cortisol ((Perret and Predine, 1984) and unpublished data), IGF1 (Aujard et al, 2010), melatonin (Aujard et al, 2001), and gut hormones (GIP, PPY, insulin, PYY, and GLP-1) (Dal-Pan et al, 2010; Giroud et al, 2009). B.…”