The effects of selection for early and late reproduction on metabolite pools in Acanthoscelides obtectus Say

Abstract

The present study was aimed at revealing the responses of metabolite pools to selection for alternative reproductive schedules in the seed beetle, Acanthoscelides obtectus Say (Coleoptera: Chrysomelidae: Bruchinae). The levels of metabolites (free sugars, glycogen, lipids, soluble and hydrophobic proteins) that were determined in virgin females and males at three ages from adult eclosion onwards were compared among the base population (B) and two derived lines that were selected for either early (Y) or late (O) reproduction. The results showed differences in the accumulation of metabolites during pre‐adult development, as well as in the pattern of their changes during adult ageing. Generally, in comparison to the B population, the short‐lived beetles from the Y line showed increased protein content and reduced carbohydrate and lipid content, whereas the opposite was true for the long‐lived beetles from the O line. Females from the O line exhibited slower utilization of energy reserves and a slower increase in protein contents than females from the Y line. Females contained higher levels of free sugars, glycogen and hydrophobic proteins and lower levels of lipids and soluble proteins than males, although the sexual dimorphism was not evenly expressed among lines. Age‐specific changes in metabolite contents were slower in females than males. Our findings suggest that trade‐offs among capital resources are a physiological basis of early/late fitness trade‐offs and point to a conservation of resources that can be used for somatic maintenance.

Sex-specific mitonuclear epistasis and the evolution of mitochondrial bioenergetics, ageing, and life history in seed beetles

“…Increased complex III activity could also be beneficial if metabolic reprogramming of L beetles toward accumulation of lipids and carbohydrates (Lazarević et al. ) involves higher entrance of electrons to the respiratory chain through FAD‐linked dehydrogenases that bypass complex I (Lenaz et al. ).…”

“…), and metabolite content (Lazarević et al. ). We found this to be true for ETC activity as well, as sexual dimorphism in LL lines were higher than in EE lines for all complexes (Storer's SD index; ETC I: −0.14 vs. −0.12; ETC II: −0.22 vs. −0.12; ETC III: −0.04 vs. 0.02; ETC IV: −0.19 vs. 0.08).…”

Intergenomic Interactions in Hybrids Between Short-Lived and Long-Lived Lines of a Seed Beetle: Analyses of Life History Traits

“…These E and L populations have been used in previous studies to investigate various aspects of life history evolution, such as demographic and physiological aspects of ageing and reproductive behaviour (Tucić et al 1996(Tucić et al , 1997Š ešlija et al 1999;Maklakov et al 2005;Šešlija et al 2009;Lazarević et al 2012;Stojković et al 2011Stojković et al , 2014. It has been repeatedly demonstrated that individuals from the L populations live substantially longer, have higher egg-to-adult viability, longer developmental time, higher body weight and total fecundity relative to the E beetles.…”

The pace‐of‐life: A sex‐specific link between metabolic rate and life history in bean beetles

“…In line with this interpretation, Lazarević et al. () showed that the consumption of metabolite resources is retarded during adult ageing in bean beetles from L lines. Here, we confirm that bean beetles selected for early reproduction have indeed evolved a markedly higher MR. Below, we discuss some more specific insights gained by our experiments.…”

“…These differences in sex‐ and age‐specific MR are well matched by the sex‐ and age‐specific availability of primary metabolic substrates (i.e. lipids), which is higher in males than in females but decreases with age more rapidly in L line males than in L line females (Lazarević et al., ). We note that the costs of mating and mate searching to males are substantial in this group of insects (Berger et al., ; Immonen, Liljestrand‐Rönn, et al., ; Paukku & Kotiaho, ; Salehialavi, Fritzsche, & Arnqvist, ) and male investment in costly ejaculates decreases with age (Fox, Hickman, Raleigh, & Mousseau, ; Immonen, Collet, Goenaga, & Arnqvist, ).…”