Metabolic adaptations in a range expanding arthropod

Abstract

Despite an increasing number of studies documenting life-history evolution during range expansions or shifts, we lack a mechanistic understanding of the underlying physiological processes. In this explorative study, we used a metabolomics approach to study physiological changes associated with the recent range expansion of the two-spotted spider mite (Tetranychus urticae). Mite populations were sampled along a latitudinal gradient from range core to edge and reared under benign common garden conditions for two generations. Using gas chromatography-mass spectrometry, we obtained metabolic population profiles, which showed a gradual differentiation along the latitudinal gradient, indicating (epi)genetic changes in the metabolome in association with range expansion. These changes seemed not related with shifts in the mites' energetic metabolism, but rather with differential use of amino acids. Particularly, more dispersive northern populations showed lowered concentrations of several essential and nonessential amino acids, suggesting a potential downregulation of metabolic pathways associated with protein synthesis.

Selecting for invasive tendencies: the evolution of morphological, physiological, and movement behaviour traits associated with dispersal

“…Those at the range edge display substantial upregulation genes involved with metabolism and activity (Rollins et al 2015), which contrasts with findings from metabolomics of invasive spider mites (Tetranychus urticae) that have undergone a range expansion (Van Petegem et al 2016b). Individuals from the expanding range edge potentially downregulate metabolic pathways associated with protein synthesis and also show differential use of amino acids to those individuals from the range core (Van Petegem et al 2016b). These recent findings demonstrate the complexity of evolutionary processes at range edges that remains to be understood, and highlights the importance of integrating advances in metabolomics and epigenetic technologies.…”

“…A recent genetic study on invasive cane toads has found differential expression of genes involved in metabolism and immune function between individuals from range edge and range core populations (Rollins et al 2015). Those at the range edge display substantial upregulation genes involved with metabolism and activity (Rollins et al 2015), which contrasts with findings from metabolomics of invasive spider mites (Tetranychus urticae) that have undergone a range expansion (Van Petegem et al 2016b). Individuals from the expanding range edge potentially downregulate metabolic pathways associated with protein synthesis and also show differential use of amino acids to those individuals from the range core (Van Petegem et al 2016b).…”

“…Resting MR has been previously found to be higher in individuals with greater movement propensity (Niitepõld et al 2009;Myles-Gonzalez et al 2015) and a recent study found that genes underlying metabolic processes are upregulated in dispersive cane toads (Rollins et al 2015). Given the potential involvement of genetic and epigenetic mechanisms, and potential metabolome differences between dispersive and non-dispersive individuals (Rollins et al 2015;Van Petegem et al 2015;2016b), it may be worth exploring the association between MR and movement in other systems. Burton et al 2011;Killen et al 2012;Killen et al 2013;Lebeau et al 2016;Metcalfe et al 2016).…”

“…If differences in these traits are apparent between resident and disperser larvae (which seems highly probable), then it would be insightful to examine the expression of genes involved in metabolic processes and their regulation. Recent studies have found that the genetics, epigenetics, and metabolomics can differ between resident and disperser toads (Rollins et al 2015) and spider mites (Van Petegem et al 2016b). …”

The distinct phenotypic signatures of dispersal and stress in an arthropod model: from physiology to life history

“…Metabolic profile changes in response to stress exposure, and their (putative) functional roles, have been extensively documented, especially in arthropods (Bundy et al, 2008; Steinberg, 2012; Teets and Denlinger, 2013). In contrast, metabolite differences between dispersers and residents even in interaction with the environment- are surprisingly understudied, compared to other phenotypic differences (Cote et al, 2017; Ronce and Clobert, 2012; but see Tung et al, 2018; Van Petegem et al, 2016).…”