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Rapid growth reduces cold resistance: evidence from latitudinal variation in growth rate, cold resistance and stress proteins.

Stoks R, De Block M - PLoS ONE (2011)

Bottom Line: Yet, individual variation in Hsp70 levels did not explain variation in cold resistance.WE PROVIDE EVIDENCE FOR A NOVEL COST OF RAPID GROWTH: reduced cold resistance.Our results indicate that the reduced cold resistance in southern populations of animals that change voltinism along the latitudinal gradient may not entirely be explained by thermal selection per se but also by the costs of time constraint-induced higher growth rates.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Aquatic Ecology and Evolutionary Biology, University of Leuven, Leuven, Belgium. robby.stoks@bio.kuleuven.be

ABSTRACT

Background: Physiological costs of rapid growth may contribute to the observation that organisms typically grow at submaximal rates. Although, it has been hypothesized that faster growing individuals would do worse in dealing with suboptimal temperatures, this type of cost has never been explored empirically. Furthermore, the mechanistic basis of the physiological costs of rapid growth is largely unexplored.

Methodology/principal finding: Larvae of the damselfly Ischnura elegans from two univoltine northern and two multivoltine southern populations were reared at three temperatures and after emergence given a cold shock. Cold resistance, measured by chill coma recovery times in the adult stage, was lower in the southern populations. The faster larval growth rates in the southern populations contributed to this latitudinal pattern in cold resistance. In accordance with their assumed role in cold resistance, Hsp70 levels were lower in the southern populations, and faster growing larvae had lower Hsp70 levels. Yet, individual variation in Hsp70 levels did not explain variation in cold resistance.

Conclusions/significance: WE PROVIDE EVIDENCE FOR A NOVEL COST OF RAPID GROWTH: reduced cold resistance. Our results indicate that the reduced cold resistance in southern populations of animals that change voltinism along the latitudinal gradient may not entirely be explained by thermal selection per se but also by the costs of time constraint-induced higher growth rates. This also illustrates that stressors imposed in the larval stage may carry over and shape fitness in the adult stage and highlights the importance of physiological costs in the evolution of life-histories at macro-scales.

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Related in: MedlinePlus

Differences in growth rate, Hsp70 level and chill coma recovery time                        between latitudes across temperatures.Mean (±1 SE) larval growth rate (A), and Hsp70 level (B) and chill                        coma recovery time (C) in the adult stage of Ischnura                            elegans from two northern and two southern populations at three                        rearing temperatures. Means are slightly offset to aid visualization. Hsp70                        levels and chill coma recovery times are quantified after a cold shock                        treatment (1.5 h exposure to 4°C) given to the freshly emerged                        adults.
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pone-0016935-g001: Differences in growth rate, Hsp70 level and chill coma recovery time between latitudes across temperatures.Mean (±1 SE) larval growth rate (A), and Hsp70 level (B) and chill coma recovery time (C) in the adult stage of Ischnura elegans from two northern and two southern populations at three rearing temperatures. Means are slightly offset to aid visualization. Hsp70 levels and chill coma recovery times are quantified after a cold shock treatment (1.5 h exposure to 4°C) given to the freshly emerged adults.

Mentions: Southern larvae had much higher growth rates than northern larvae (F1,1.81 = 123.13, P = 0.011; Fig. 1A). With increasing temperature growth rate increased (F2,248 = 54.67, P<0.0001). This temperature-induced plasticity in growth rate was less pronounced in southern larvae (Latitude × Temperature, F2,248 = 5.66, P = 0.0039).


Rapid growth reduces cold resistance: evidence from latitudinal variation in growth rate, cold resistance and stress proteins.

Stoks R, De Block M - PLoS ONE (2011)

Differences in growth rate, Hsp70 level and chill coma recovery time                        between latitudes across temperatures.Mean (±1 SE) larval growth rate (A), and Hsp70 level (B) and chill                        coma recovery time (C) in the adult stage of Ischnura                            elegans from two northern and two southern populations at three                        rearing temperatures. Means are slightly offset to aid visualization. Hsp70                        levels and chill coma recovery times are quantified after a cold shock                        treatment (1.5 h exposure to 4°C) given to the freshly emerged                        adults.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3044720&req=5

pone-0016935-g001: Differences in growth rate, Hsp70 level and chill coma recovery time between latitudes across temperatures.Mean (±1 SE) larval growth rate (A), and Hsp70 level (B) and chill coma recovery time (C) in the adult stage of Ischnura elegans from two northern and two southern populations at three rearing temperatures. Means are slightly offset to aid visualization. Hsp70 levels and chill coma recovery times are quantified after a cold shock treatment (1.5 h exposure to 4°C) given to the freshly emerged adults.
Mentions: Southern larvae had much higher growth rates than northern larvae (F1,1.81 = 123.13, P = 0.011; Fig. 1A). With increasing temperature growth rate increased (F2,248 = 54.67, P<0.0001). This temperature-induced plasticity in growth rate was less pronounced in southern larvae (Latitude × Temperature, F2,248 = 5.66, P = 0.0039).

Bottom Line: Yet, individual variation in Hsp70 levels did not explain variation in cold resistance.WE PROVIDE EVIDENCE FOR A NOVEL COST OF RAPID GROWTH: reduced cold resistance.Our results indicate that the reduced cold resistance in southern populations of animals that change voltinism along the latitudinal gradient may not entirely be explained by thermal selection per se but also by the costs of time constraint-induced higher growth rates.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Aquatic Ecology and Evolutionary Biology, University of Leuven, Leuven, Belgium. robby.stoks@bio.kuleuven.be

ABSTRACT

Background: Physiological costs of rapid growth may contribute to the observation that organisms typically grow at submaximal rates. Although, it has been hypothesized that faster growing individuals would do worse in dealing with suboptimal temperatures, this type of cost has never been explored empirically. Furthermore, the mechanistic basis of the physiological costs of rapid growth is largely unexplored.

Methodology/principal finding: Larvae of the damselfly Ischnura elegans from two univoltine northern and two multivoltine southern populations were reared at three temperatures and after emergence given a cold shock. Cold resistance, measured by chill coma recovery times in the adult stage, was lower in the southern populations. The faster larval growth rates in the southern populations contributed to this latitudinal pattern in cold resistance. In accordance with their assumed role in cold resistance, Hsp70 levels were lower in the southern populations, and faster growing larvae had lower Hsp70 levels. Yet, individual variation in Hsp70 levels did not explain variation in cold resistance.

Conclusions/significance: WE PROVIDE EVIDENCE FOR A NOVEL COST OF RAPID GROWTH: reduced cold resistance. Our results indicate that the reduced cold resistance in southern populations of animals that change voltinism along the latitudinal gradient may not entirely be explained by thermal selection per se but also by the costs of time constraint-induced higher growth rates. This also illustrates that stressors imposed in the larval stage may carry over and shape fitness in the adult stage and highlights the importance of physiological costs in the evolution of life-histories at macro-scales.

Show MeSH
Related in: MedlinePlus