10.5061/DRYAD.RD465D6
Erickson, Priscilla A
University of Virginia
Weller, Cory A
University of Virginia
Song, Daniel Y
University of Virginia
Schmidt, Paul
University of Pennsylvania
Bergland, Alan O
University of Virginia
Bangerter, Alyssa
University of Virginia
Unique genetic signatures of local adaptation over space and time for
diapause, an ecologically relevant complex trait, in Drosophila
melanogaster
Dryad
dataset
2019
seasonal evolution
photoperiodism
hybrid swarm
ovarian dormancy
clinal evolution
seasonal evolution
photoperiodism
hybrid swarm
ovarian dormancy
clinal evolution
2020-09-15T00:00:00Z
2020-09-15T00:00:00Z
en
https://doi.org/10.1371/journal.pgen.1009110
7624055278 bytes
9
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Organisms living in seasonally variable environments utilize cues such as
light and temperature to induce plastic responses, enabling them to
exploit favorable seasons and avoid unfavorable ones. Local adapation can
result in variation in seasonal responses, but the genetic basis and
evolutionary history of this variation remains elusive. Many insects,
including Drosophila melanogaster, are able to undergo an arrest of
reproductive development (diapause) in response to unfavorable conditions.
In D. melanogaster, the ability to diapause is more common in high
latitude populations, where flies endure harsher winters, and in the
spring, reflecting differential survivorship of overwintering populations.
Using a novel hybrid swarm-based genome wide association study, we
examined the genetic basis and evolutionary history of ovarian diapause.
We exposed outbred females to different temperatures and day lengths,
characterized ovarian development for over 2800 flies, and reconstructed
their full phased genomes. We found that diapause scored at two different
developmental cutoffs has modest heritability, and we identified hundreds
of SNPs associated with each of the two phenotypes. Alleles associated
with one of the diapause phenotypes tend to be more common at higher
latitudes, but these alleles do not show predictable seasonal variation.
The collective signal of many small-effect, clinally varying SNPs can
plausibly explain latitudinal phenotypic variation seen in North America.
SNPs associated with diapause do not exhibit signs of recent selective
sweeps, but most are segregating at relatively high frequencies in Africa,
suggesting that variation in diapause relies on ancestral polymorphisms.
Finally, we utilized outdoor mesocosms to track diapause under natural
conditions. We found that hybrid swarms reared outdoors evolved increased
propensity for diapause in late fall, whereas indoor control populations
experienced no such change. Our results indicate that diapause is a
complex, quantitative trait with different evolutionary patterns across
time and space.
All file names should match the file names found in the code for this
analysis, located at: https://github.com/ericksonp/diapause-scripts-clean