Mixed support for an alignment between phenotypic plasticity and genetic differentiation in damselfly wing shape

Abstract

The relationship between genetic differentiation and phenotypic plasticity can provide information on whether plasticity generally facilitates or hinders adaptation to environmental change. Here, we studied wing shape variation in a damselfly (Lestes sponsa) across a latitudinal gradient in Europe that differed in time constraints mediated by photoperiod and temperature. We reared damselflies from northern and southern populations in the laboratory using a reciprocal transplant experiment that simulated time-constrained (i.e. northern) and unconstrained (southern) photoperiods and temperatures. After emergence, adult wing shape was analysed using geometric morphometrics. Wings from individuals in the northern and southern populations differed significantly in shape when animals were reared in their respective native environment. Comparing wing shape across environments, we found evidence for phenotypic plasticity in wing shape, and this response differed across populations (i.e. G × E interactions). This interaction was driven by a stronger plastic response by individuals from the northern population and differences in the direction of plastic wing shape changes among populations. The alignment between genetic and plastic responses depended on the specific combination of population and rearing environment. For example, there was an alignment between plasticity and genetic differentiation under time-constrained, but not under non-time-constrained conditions for forewings. We thus find mixed support for the hypothesis that environmental plasticity and genetic population differentiation are aligned. Furthermore, although our laboratory treatments mimicked the natural climatic conditions at northern and southern latitudes, the effects of population differences on wing shape were two to four times stronger than plastic effects. We discuss our results in terms of time constraints and the possibility that natural and sexual selection is acting differently on fore-and hindwings.

Phylogeography and phenotypic wing shape variation in a damselfly across populations in Europe

“…We estimated phenotypic wing shape of wild caught individuals and hence the observed wing shape variation was probably affected by a combination of genetic and environmental effects. In our study species, photoperiod imposes time constraints impacting larval growth, developmental time, and adult morphology [21,23,63,64]. In a recent study, Johansson et al [23] showed that wing shape differences between northern and southern populations of L. sponsa were composed of genetic and plastic responses to photoperiod and temperature in the larval rearing environment.…”

“…In our study species, photoperiod imposes time constraints impacting larval growth, developmental time, and adult morphology [21,23,63,64]. In a recent study, Johansson et al [23] showed that wing shape differences between northern and southern populations of L. sponsa were composed of genetic and plastic responses to photoperiod and temperature in the larval rearing environment. However, that study [23] was only investigating two populations (north and central), which makes it difficult to compare the observed latitudinal patterns of wing shape to the present study.…”

“…In a recent study, Johansson et al [23] showed that wing shape differences between northern and southern populations of L. sponsa were composed of genetic and plastic responses to photoperiod and temperature in the larval rearing environment. However, that study [23] was only investigating two populations (north and central), which makes it difficult to compare the observed latitudinal patterns of wing shape to the present study. Nevertheless, the two major abiotic variables that differ along the latitudinal range and that potentially could affect wing shape in this study are photoperiod and temperature.…”

“…Past studies have shown some evidence for local adaptation in populations along a latitudinal gradient. For example, there is local adaptive variation in wing shape [19] as well as genetic variation in wing shape and life history traits along the latitudinal gradient [21][22][23]. In addition, also body size varies across latitudes and one study has shown a U-shaped latitudinal pattern [16].…”

Antimicrobial resistance in the wild: Insights from epigenetics

“…For example, if an organism contains the genetic machinery to be phenotypically plastic in response to a certain environmental variable, it has a larger mutational target size for changing this phenotype. The empirical evidence for this hypothesis is mixed, with some support (Lind et al., 2015 ) and some contradicting results (Johansson et al., 2023 ). Testing this hypothesis would be interesting in the context of priming and antimicrobial resistance.…”