| | |
Summary: vol. 174, no. 6 the american naturalist december 2009
Selection, Epistasis, and Parent-of-Origin Effects on Deleterious
Mutations across Environments in Drosophila melanogaster
Alethea D. Wang,* Nathaniel P. Sharp, Christine C. Spencer, Katherine Tedman-Aucoin,
and Aneil F. Agrawal
Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada
Submitted April 13, 2009; Accepted July 23, 2009; Electronically published October 23, 2009
abstract: Understanding the nature of selection against deleterious
alleles is central to determining how populations are affected by the
constant influx of new mutations. Important progress has been made
in estimating basic attributes of the distribution of selection coeffi-
cients and gene interaction effects (epistasis). Although most aspects
of selection are likely to be context dependent, little is known about
the effect of stress on selection and epistasis at the level of individual
genes, especially in multicellular organisms. Using Drosophila melano-
gaster, we measure how selection on 20 mutant alleles is affected by
direct and indirect genetic factors across two environments. We find
that environmental stress increases selection against individual mu-
tations but reduces selection against combinations of mutations (i.e.,
epistasis becomes more positive). In addition, we find a high inci-
|
