Data from: Circadian rhythms vary over the growing season and correlate with fitness components
Rubin, Matthew J. et al. (2017), Data from: Circadian rhythms vary over the growing season and correlate with fitness components, Dryad, Dataset, https://doi.org/10.5061/dryad.th8b5
Circadian clocks have evolved independently in all three domains of life, suggesting that internal mechanisms of time-keeping are adaptive in contemporary populations. However, the performance consequences of either discrete or quantitative clock variation have rarely been tested in field settings. Clock sensitivity of diverse segregating lines to the environment remains uncharacterized as do the statistical genetic parameters that determine evolutionary potential. In field studies with Arabidopsis thaliana, we found that major perturbations to circadian cycle length (referred to as clock period) via mutation reduce both survival and fecundity. Subtler adjustments via genomic introgression of naturally occurring alleles indicated that clock periods slightly >24 hrs were adaptive, consistent with prior models describing how well the timing of biological processes is adjusted within a diurnal cycle (referred to as phase). In segregating recombinant inbred lines (RILs), circadian phase varied up to two hours across months of the growing season, and both period and phase expressed significant genetic variances. Performance metrics including developmental rate, size, and fruit set were described by principal components (PC) analyses and circadian parameters correlated with the first PC, such that period lengths slightly >24 hrs were associated with improved performance in multiple RIL sets. These experiments translate functional analyses of clock behavior performed in controlled settings to natural ones, demonstrating that quantitative variation in circadian phase is highly responsive to seasonally variable abiotic factors. The results expand upon prior studies in controlled settings, showing that discrete and quantitative variation in clock phenotypes correlate with performance in nature.
National Science Foundation, Award: IOS-0923752, IOS-1025965