Fitness decline in spontaneous mutation accumulation lines of Caenorhabditis elegans with varying effective population sizes

Vaishali Katju, Lucille B. Packard, Lijing Bu, Peter D. Keightley, Ulfar Bergthorsson

Research output: Contribution to journalArticlepeer-review

Abstract

The rate and fitness effects of new mutations have been investigated by mutation accumulation (MA) experiments in which organisms are maintained at a constant minimal population size to facilitate the accumulation of mutations with minimal efficacy of selection. We evolved 35 MA lines of Caenorhabditis elegans in parallel for 409 generations at three population sizes (N = 1, 10, and 100), representing the first spontaneous long-term MA experiment at varying population sizes with corresponding differences in the efficacy of selection. Productivity and survivorship in the N = 1 lines declined by 44% and 12%, respectively. The average effects of deleterious mutations in N = 1 lines are estimated to be 16.4% for productivity and 11.8% for survivorship. Larger populations (N = 10 and 100) did not suffer a significant decline in fitness traits despite a lengthy and sustained regime of consecutive bottlenecks exceeding 400 generations. Together, these results suggest that fitness decline in very small populations is dominated by mutations with large deleterious effects. It is possible that the MA lines at larger population sizes contain a load of cryptic deleterious mutations of small to moderate effects that would be revealed in more challenging environments.

Original languageEnglish
Pages (from-to)104-116
Number of pages13
JournalEvolution
Volume69
Issue number1
DOIs
Publication statusPublished - 1 Jan 2015

Keywords

  • deleterious mutation
  • epistasis
  • fitness
  • genome-wide mutation rate
  • productivity
  • survivorship to adulthood

Fingerprint

Dive into the research topics of 'Fitness decline in spontaneous mutation accumulation lines of Caenorhabditis elegans with varying effective population sizes'. Together they form a unique fingerprint.

Cite this