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Changes in selection regime cause loss of phenotypic plasticity in planktonic freshwater copepods.

Sereda SV, Wilke T, Schulthei├č R - PLoS ONE (2014)

Bottom Line: Here we use the planktonic freshwater copepod Acanthodiaptomus denticornis from two lakes as model system to study UV stress responses of two phenotypically different populations under laboratory conditions.Our study reveals heritable lake- and sex-specific differences of behaviour, physiological plasticity, and mortality.We discuss specific selective scenarios causing these differences and argue that phenotypic plasticity will be higher when selection pressure is moderate, but will decrease or even be lost under stronger pressure.

View Article: PubMed Central - PubMed

Affiliation: Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany.

ABSTRACT
Rapid phenotypic adaptation is critical for populations facing environmental changes and can be facilitated by phenotypic plasticity in the selected traits. Whereas recurrent environmental fluctuations can favour the maintenance or de novo evolution of plasticity, strong selection is hypothesized to decrease plasticity or even fix the trait (genetic assimilation). Despite advances in the theoretical understanding of the impact of plasticity on diversification processes, comparatively little empirical data of populations undergoing diversification mediated by plasticity are available. Here we use the planktonic freshwater copepod Acanthodiaptomus denticornis from two lakes as model system to study UV stress responses of two phenotypically different populations under laboratory conditions. Our study reveals heritable lake- and sex-specific differences of behaviour, physiological plasticity, and mortality. We discuss specific selective scenarios causing these differences and argue that phenotypic plasticity will be higher when selection pressure is moderate, but will decrease or even be lost under stronger pressure.

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Related in: MedlinePlus

Study system.(A) Specimens of Acanthodiaptomus denticornis populations from the neighbouring lakes Lac Pavin (LP) and Lac de Montcineyre (LM). Both sexes in LM as well as LP females are translucent, whereas LP males bright red. (B) The lakes are situated in the French Massif Central. Grey areas around the lakes are woodland, white areas are mainly agricultural or other areas under human use.
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pone-0090010-g001: Study system.(A) Specimens of Acanthodiaptomus denticornis populations from the neighbouring lakes Lac Pavin (LP) and Lac de Montcineyre (LM). Both sexes in LM as well as LP females are translucent, whereas LP males bright red. (B) The lakes are situated in the French Massif Central. Grey areas around the lakes are woodland, white areas are mainly agricultural or other areas under human use.

Mentions: The present study tests this hypothesized relationship between changes in phenotypic plasticity and selection regime. In particular, we investigated the impact of UV stress on two neighbouring populations of the freshwater copepod Acanthodiaptomus denticornis with differences in carotenoid pigmentation (Fig. 1). We found substantial population- and sex-specificity in physiological plasticity (i.e., changes in carotenoid pigmentation), UV-induced behaviour (i.e., vertical migration), and mortality. Our data indicates that the observed loss of ancestral phenotypic plasticity in one of the studied populations was directly caused by a change in selection regime in its natural habitat.


Changes in selection regime cause loss of phenotypic plasticity in planktonic freshwater copepods.

Sereda SV, Wilke T, Schulthei├č R - PLoS ONE (2014)

Study system.(A) Specimens of Acanthodiaptomus denticornis populations from the neighbouring lakes Lac Pavin (LP) and Lac de Montcineyre (LM). Both sexes in LM as well as LP females are translucent, whereas LP males bright red. (B) The lakes are situated in the French Massif Central. Grey areas around the lakes are woodland, white areas are mainly agricultural or other areas under human use.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3935978&req=5

pone-0090010-g001: Study system.(A) Specimens of Acanthodiaptomus denticornis populations from the neighbouring lakes Lac Pavin (LP) and Lac de Montcineyre (LM). Both sexes in LM as well as LP females are translucent, whereas LP males bright red. (B) The lakes are situated in the French Massif Central. Grey areas around the lakes are woodland, white areas are mainly agricultural or other areas under human use.
Mentions: The present study tests this hypothesized relationship between changes in phenotypic plasticity and selection regime. In particular, we investigated the impact of UV stress on two neighbouring populations of the freshwater copepod Acanthodiaptomus denticornis with differences in carotenoid pigmentation (Fig. 1). We found substantial population- and sex-specificity in physiological plasticity (i.e., changes in carotenoid pigmentation), UV-induced behaviour (i.e., vertical migration), and mortality. Our data indicates that the observed loss of ancestral phenotypic plasticity in one of the studied populations was directly caused by a change in selection regime in its natural habitat.

Bottom Line: Here we use the planktonic freshwater copepod Acanthodiaptomus denticornis from two lakes as model system to study UV stress responses of two phenotypically different populations under laboratory conditions.Our study reveals heritable lake- and sex-specific differences of behaviour, physiological plasticity, and mortality.We discuss specific selective scenarios causing these differences and argue that phenotypic plasticity will be higher when selection pressure is moderate, but will decrease or even be lost under stronger pressure.

View Article: PubMed Central - PubMed

Affiliation: Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Giessen, Germany.

ABSTRACT
Rapid phenotypic adaptation is critical for populations facing environmental changes and can be facilitated by phenotypic plasticity in the selected traits. Whereas recurrent environmental fluctuations can favour the maintenance or de novo evolution of plasticity, strong selection is hypothesized to decrease plasticity or even fix the trait (genetic assimilation). Despite advances in the theoretical understanding of the impact of plasticity on diversification processes, comparatively little empirical data of populations undergoing diversification mediated by plasticity are available. Here we use the planktonic freshwater copepod Acanthodiaptomus denticornis from two lakes as model system to study UV stress responses of two phenotypically different populations under laboratory conditions. Our study reveals heritable lake- and sex-specific differences of behaviour, physiological plasticity, and mortality. We discuss specific selective scenarios causing these differences and argue that phenotypic plasticity will be higher when selection pressure is moderate, but will decrease or even be lost under stronger pressure.

Show MeSH
Related in: MedlinePlus