Experimental evolution of personality traits : open-field exploration in bank voles from a multidirectional selection experiment

Evolution of complex physiological adaptations could be driven by natural selection acting on behavioral traits. Consequently, animal personality traits and their correlation with physiological traits have become an engaging research area. Here, we applied a unique experimental evolution model - lines of bank voles selected for (A) high exercise-induced aerobic metabolism, (H) ability to cope with low-quality herbivorous diet, and (P) intensity of predatory behavior, that is, traits shaping evolutionary path and diversity of mammals - and asked how the selection affected the voles’ personality traits, assessed in an open field test. The A- and P-line voles were more active, whereas the H-line voles were less active, compared those from unselected control lines (C). H-line voles moved slower but on more meandering trajectories, which indicated a more thorough exploration, whereas the A- and P-line voles moved faster and on straighter trajectories. A-line voles showed also an increased escape propensity, whereas P-line voles tended to be bolder. The remarkable correlated responses to the selection indicate a common genetic underlying mechanism of behavioral and physiological traits, and support the paradigm of evolutionary physiology built around the concept of correlated evolution of behavior and physiology

Evolution of basal metabolic rate in bank voles from a multidirectional selection experiment

A major theme in evolutionary and ecological physiology of terrestrial vertebrates encompasses the factors underlying the evolution of endothermy in birds and mammals and interspecific variation of basal metabolic rate (BMR). Here, we applied the experimental evolution approach and compared BMR in lines of a wild rodent, the bank vole (Myodes glareolus), selected for 11 generations for: high swim-induced aerobic metabolism (A), ability to maintain body mass on a low-quality herbivorous diet (H) and intensity of predatory behaviour towards crickets (P). Four replicate lines were maintained for each of the selection directions and an unselected control (C). In comparison to C lines, A lines achieved a 49% higher maximum rate of oxygen consumption during swimming, H lines lost 1.3 g less mass in the test with low-quality diet and P lines attacked crickets five times more frequently. BMR was significantly higher in A lines than in C or H lines (60.8, 56.6 and 54.4 ml O2/h, respectively), and the values were intermediate in P lines (59.0 ml O2/h). Results of the selection experiment provide support for the hypothesis of a positive association between BMR and aerobic exercise performance, but not for the association of adaptation to herbivorous diet with either a high or low BMR

Data from: Evolution of basal metabolic rate in bank voles from a multidirectional selection experiment

A major theme in evolutionary and ecological physiology of terrestrial vertebrates encompasses the factors underlying the evolution of endothermy in birds and mammals and interspecific variation of basal metabolic rate (BMR). Here, we applied the experimental evolution approach and compared BMR in lines of a wild rodent, the bank vole (Myodes glareolus), selected for 11 generations for: high swim-induced aerobic metabolism (A), ability to maintain body mass on a low-quality herbivorous diet (H) and intensity of predatory behaviour towards crickets (P). Four replicate lines were maintained for each of the selection directions and an unselected control (C). In comparison to C lines, A lines achieved a 49% higher maximum rate of oxygen consumption during swimming, H lines lost 1.3 g less mass in the test with low-quality diet and P lines attacked crickets five times more frequently. BMR was significantly higher in A lines than in C or H lines (60.8, 56.6 and 54.4 ml O2 h−1, respectively), and the values were intermediate in P lines (59.0 ml O2 h−1). Results of the selection experiment provide support for the hypothesis of a positive association between BMR and aerobic exercise performance, but not for the association of adaptation to herbivorous diet with either a high or low BMR

Prenatal Treatment of Mosaic Mice (Atp7a mo-ms) Mouse Model for Menkes Disease, with Copper Combined by Dimethyldithiocarbamate (DMDTC)

<div><p>Menkes disease is a fatal neurodegenerative disorder in infants caused by mutations in the gene <em>ATP7A</em> which encodes a copper (Cu) transporter. Defects in <em>ATP7A</em> lead to accumulated copper in the small intestine and kidneys and to copper deficiencies in the brain and the liver. The copper level in the kidney in postnatal copper-treated Menkes patients may reach toxic levels. The mouse model, <em>mosaic Atp7a </em><b><em>^mo-ms</em></b> recapitulates the Menkes phenotype and die about 15.75±1.5 days of age. In the present study we found that prenatal treatment of <em>mosaic</em> murine fetuses throughout gestation days 7, 11, 15 and 18 with a combination of CuCl₂ (50 mg/kg) and dimethyldithiocarbamate (DMDTC) (280 mg/kg) leads to an increase in survival to about 76±25.3 days, whereas treatment with CuCl₂ alone (50 mg/kg) only leads to survival for about 21 days ±5 days. These copper-DMDTC treated mutants showed an improved locomotor activity performance and a gain in body mass. In contrast to treatment with CuCl₂ alone, a significant increase in the amount of copper was observed in the brain after prenatal copper-DMDTC treatment as well as a decrease in the amount of accumulated copper in the kidney, both leading towards a normalization of the copper level. Although copper-DMDTC prenatal treatment only leads to a small increase in the sub-normal copper concentration in the liver and to an increase of copper in the already overloaded small intestine, the combined results suggest that prenatal copper-DMDTC treatment also should be considered for humans.</p> </div

Copper concentration (g/g wet tissue) in the organs of the 14-day-old progeny of untreated, CuCl₂- or CuCl₂-DMDTC treated heterozygous mothers.

<p>^(a) Significantly different from wild-type animals P<0.01; ^(b) Significantly different from wild-type animals P<0.000; ^(c) Significantly different from untreated mutant animals P<0.01; ^(d) Significantly different from untreated mutants P<0.05; ^(e) Significantly different from untreated mutants P<0.05; ^(f) Significantly different from wild-type animals P<0.001. The number of mice in each group is shown in brackets.</p

The effect of prenatal therapy on the litter size born from untreated, CuCl₂-treated, CuCl₂-DMDTC-treated or DMDTC-treated, wild type (wt) and heterozygous (ms/+) mothers.

<p>Significantly different from the litter size from ^(a) wild-type untreated mothers P<0.05; ^(b) from wild-type CuCl₂-treated mothers P<0.05; ^(c) from untreated heterozygous mothers P<0.05; ^(d) from heterozygous CuCl₂-treated mothers P<0.01; ^(e) from untreated heterozygous mothers P<0.01; ^(f) from heterozygous CuCl₂-treated mothers P<0.001; ^(g) from heterozygous CuCl₂-DMDTC- treated mothers P<0.05. The number of litters in each group is shown in brackets.</p

14-day-old mice; wild-genotype males (grey) and mosaic mutant males (white).

<p>The mice are born of: A) untreated heterozygous female. B) CuCl₂-treated heterozygous female, C) CuCl₂-DMDTC treated heterozygous female. The young mosaic mutant mice are smaller than the wild type mice. D) 8-week-old males, wild-genotype male (grey) and mosaic mutant male (white) born of a CuCl2-DMDTC treated heterozygous female.</p