Responses to Selection for Cadmium Resistance in the Least Killifish, Heterandria Formosa

Abstract

An artificial selection experiment was conducted for six generations to investigate the responses to selection for cadmium resistance in the least killifish, Heterandria formosa. There was a rapid response to selection. After only one generation of selection, two of the three selection lines had an increased resistance to cadmium, while all three selection lines had an elevated resistance by the next generation. After six generations of selection, fish from the selection lines survived about three times as long as control line fish when exposed to cadmium. Realized heritability for cadmium resistance was estimated to be 0.50. Cross-resistance to copper was studied in the F2, F3, and F6 generations; fish from the cadmium-resistant lines had a longer survival time than those from the control lines. Resistance to heat was investigated in the F2, F3, and F5 generations; the cadmium-resistant lines had a significantly shorter survival time than the control lines. Our results showed that evolution of resistance to cadmium was rapid, that cross-resistance to copper occurred, and that the evolution of resistance to cadmium was accompanied by a trade-off (fitness costs) as evidenced by the reduced heat tolerance.

Adaptation costs to constant and alternating polluted environments

“…To explain the beneficial effects, these researchers assumed that detoxification mechanisms were common to the different pollutants. This could be possible when there is a single major gene or a few genes with effects specific to a class of pollutants or even to more general actions of pollutants (McKenzie, 1996; Xie & Klerks, 2003). Knowledge on biochemical, physiological and molecular mechanisms that are associated with the adaptation to each pollutant would help us predict when populations may be able to adapt to a series of different pollutants and in which combination of pollutants adaptive costs or benefits are expected.…”

“…Adaptive genetic variation should allow populations to quickly adapt to severe and novel stressors, and thus reduce their risk of extinction (Bell & Collins, 2008; Charlesworth & Hughes, 2000; Hoffmann & Parsons, 1991; Reed, Lowe, Briscoe, & Frankham, 2003). For instance, some populations have been shown to evolve rapidly in response to several pollutants, such as xenobiotics or heavy metals (Jansen, Stoks, Coors, van Doorslaer, & de Meester, 2011; Lopes, Sucena, Santos, & Magalhães, 2008; Salice, Anderson, & Roesijadi, 2010; Shirley & Sibly, 1999; Ward & Robinson, 2005; Xie & Klerks, 2003), and there is strong evidence that adaptive changes in response to selection in a given environment can happen over just a few generations (Hoffmann & Parsons, 1991; Morgan, Kille, & Stürzenbaum, 2007). However, such adaptive response is often hypothesized to come with a cost that constrains future evolutionary potential in several ways (Bergelson & Purrington, 1996; Coustau, Chevillon, & ffrench‐Constant, 2000).…”

“…Experimental studies on adaptation costs generally focus on costs induced by a constant stress from a single stressor (Jansen, Stoks, et al., 2011; Ward & Robinson, 2005; Xie & Klerks, 2003) or from a simultaneous combination of stressors (Jansen, de Meester, Cielen, Buser, & Stoks, 2011; Jasmin & Kassen, 2007; Koskella, Lin, Buckling, & Thompson, 2012). Comparatively few studies have examined how populations adapt to a temporally heterogeneous environment and its consequence on adaptation costs (Magalhães, Cailleau, Blanchet, & Olivieri, 2014; Reed et al., 2003; Turner & Elena, 2000), despite the fact that wild populations experience temporal environmental heterogeneity (Hedrick, 1986; Levins, 1968).…”

Adaptive responses and latent costs of multigeneration cadmium exposure in parasite resistant and susceptible strains of a freshwater snail

“…Anthropogenic stressors, including environmental pollutants, are considered among the strongest of current evolutionary forces (Palumbi 2001), and adaptive responses to pollutants have been seen in naturally occurring (Hairston et al 2005;Klerks and Levinton 1989;Thompson 1998) and laboratory populations (Xie and Klerks 2003;Shirley and Sibly 1999;Ward and Robinson 2005) and may be expected in response to strong directional selection.…”

Evolutionary toxicology in an omics world

“…Effects such as (i) genome‐wide changes in diversity, (ii) changes in allelic or genotypic frequencies due to contaminant‐mediated selective pressure, (iii) changes in gene flow between populations, and (iv) increased mutation rates (Bickham, 2011) have been used to describe and search for patterns of differentiation. Studies in this field explore a wide range of selective pressures: metals (Xie & Klerks, 2003), polycyclic aromatic hydrocarbons (Mulvey, Newman, Vogelbein, & Unger, 2002; Ownby et al., 2002), polychlorinated biphenyls (Nacci et al., 1999; Oziolor, Bigorgne, Aguilar, Usenko, & Matson, 2014), dioxins and furans (Yuan, Courtenay, Chambers, & Wirgin, 2006), and in addition a variety of organisms (Oziolor, De Schamphelaere, & Matson, 2016a), but mostly focused on aquatic species. Previous reviews in the field focus on evolutionary research in fish (Wirgin & Waldman, 2004), across stressors (Oziolor & Matson, 2015), and the push toward quantitative genetics to link these processes to heritability and fitness of populations (Klerks, Xie, & Levinton, 2011).…”