Molecular Liver Fingerprint Reflects the Seasonal Physiology of the Grey Mouse Lemur (Microcebus murinus) during Winter

Abstract

Grey mouse lemurs (Microcebus murinus) are primates that respond to environmental energetic constraints through strong physiological seasonality. They notably fatten during early winter (EW), and mobilize their lipid reserves while developing glucose intolerance during late winter (LW), when food availability is low. To decipher how the hepatic mechanisms may support such metabolic flexibility, we analyzed the liver proteome of adult captive male mouse lemurs, whose seasonal regulations are comparable to their wild counterparts. We highlight profound hepatic changes that reflect fat accretion in EW at the whole-body level, without triggering an ectopic storage of fat in the liver, however. Moreover, molecular regulations are consistent with the decrease in liver glucose utilization in LW, and therefore with reduced tolerance to glucose. However, no major regulation was seen in insulin signaling/resistance pathways. Fat mobilization in LW appeared possibly linked to the reactivation of the reproductive system while enhanced liver detoxification may reflect an anticipation to return to summer levels of food intake. Overall, these results show that the physiology of mouse lemurs during winter relies on solid molecular foundations in liver processes to adapt fuel partitioning while opposing the development of a pathological state despite large lipid fluxes.

Mouse lemur transcriptomic atlas informs primate genes, mutations, physiology, and disease

“…provide an appealing model for the study of primate biology and health [7][8][9] . Their physiology has been studied for decades in laboratory colonies, especially their circadian and dramatic seasonal rhythms, metabolism, cognition and ageing [10][11][12][13][14][15][16] .…”

“…Mouse lemurs are also favorably placed phylogenetically for a model organism, roughly half the evolutionary distance between mouse and human [7][8][9] . Their physiology has been studied for decades in laboratory colonies, especially their circadian and dramatic seasonal rhythms, metabolism, cognition and ageing [10][11][12][13][14][15][16] . Likewise, their ecology, behavior, and phylogeny have been investigated through field studies in their native Madagascar [17][18][19][20][21] .…”

“…Mouse lemurs are also favorably placed phylogenetically for a model organism, roughly half the evolutionary distance between mouse and human 7–9 . Their physiology has been studied for decades in laboratory colonies, especially their circadian and dramatic seasonal rhythms, metabolism, cognition and ageing 10–16 . Likewise, their ecology, behavior, and phylogeny have been investigated through field studies in their native Madagascar 17–21 .…”