Data from: Pollution breaks down the genetic architecture of life history traits in Caenorhabditis elegans

When pollution occurs in an environment, populations present suffer
numerous negative and immediate effects on their life history traits.
Their evolutionary potential to live in a highly stressful environment
will depend on the selection pressure strengths and on the genetic
structure, the trait heritability, and the genetic correlations between
them. If expression of this structure changes in a stressful environment,
it becomes necessary to quantify these changes to estimate the
evolutionary potential of the population in this new environment. We
studied the genetic structure for survival, fecundity, and early and late
growth in isogenic lines of a Caenorhabditis elegans population subject to
three different environments: a control environment, an environment
polluted with uranium, and a high salt concentration environment. We found
a heritability decrease in the polluted environments for fecundity and
early growth, two traits that were the most heritable in the control
environment. The genetic structure of the traits was particularly affected
in the uranium polluted environment, probably due to generally low
heritability in this environment. This could prevent selection from acting
on traits despite the strong selection pressures exerted on them.
Moreover, phenotypic traits were more strongly affected in the salt than
in the uranium environment and the heritabilities were also lower in the
latter environment. Consequently the decrease in heritability was not
proportional to the population fitness reduction in the polluted
environments. Our results suggest that pollution can alter the genetic
structure of a C. elegans population, and thus modify its evolutionary
potential.

当环境发生污染时，种群的生活史性状会受到诸多即时且负面的影响。种群在高胁迫环境中存活的进化潜力，取决于选择压力强度、遗传结构、性状遗传力以及性状间的遗传相关。若该遗传结构在胁迫环境中发生改变，则需对这些变化进行量化，以评估种群在新环境中的进化潜力。本研究以暴露于三种不同环境的秀丽隐杆线虫（Caenorhabditis elegans）同基因品系种群为对象，分析其存活、繁殖力、早期生长与晚期生长的遗传结构。三种实验环境分别为对照环境、铀污染环境以及高盐浓度环境。研究发现，在污染环境中，繁殖力与早期生长这两个在对照环境中遗传力最高的性状，其遗传力均出现下降。性状的遗传结构在铀污染环境中受到的影响尤为显著，这可能与该环境下整体遗传力偏低有关。即便此类性状面临较强的选择压力，这一情况也可能阻碍选择对其发挥作用。此外，盐环境下的表型性状受影响程度高于铀污染环境，且后者的遗传力也更低。因此，污染环境中遗传力的下降幅度与种群适合度的降低幅度并不成正比。本研究结果表明，污染可改变秀丽隐杆线虫种群的遗传结构，进而改变其进化潜力。