DOI: 10.5061/dryad.cg872
title: Data from: Experimental evolution of the Caenorhabditis elegans sex determination pathway

description: Sex determination is a critical developmental decision with major
 ecological and evolutionary consequences, yet a large variety of sex
 determination mechanisms exist and we have a poor understanding of how
 they evolve. Theoretical and empirical work suggest that compensatory
 adaptations to mutations in genes involved in sex determination may play a
 role in the evolution of these pathways. Here, we directly address this
 problem using experimental evolution in Caenorhabditis elegans lines fixed
 for a pair of mutations in two key sex-determining genes that jointly
 render sex determination temperature-sensitive and cause intersexual (but
 still weakly to moderately fertile) phenotypes at intermediate
 temperatures. After fifty generations, evolved lines clearly recovered
 towards wild-type phenotypes. However, changes in transcript levels of key
 sex-determining genes in evolved lines cannot explain their partially (or
 in some cases, nearly completely) rescued phenotypes, implying that
 wild-type phenotypes can be restored independently of the transcriptional
 effects of these mutations. Our findings highlight the microevolutionary
 flexibility of sex determination pathways, and suggest that compensatory
 adaptation to mutations can elicit novel and unpredictable evolutionary
 trajectories in these pathways, mirroring the phylogenetic diversity and
 macroevolutionary dynamics of sex determination mechanisms.
description: Cel_EE_geneexpression_masterContains gene expression data derived from qRT-PCR. See publication for methodological details. sample: The strain/line and biological replicate (e.g., 16EE1b is from strain 16EE1, replicate b; AB1 3 is from strain AB1, replicate 3). gene: The gene in which expression was assayed. plate: The reaction plate in which RT-PCR was performed; the experiment was performed on a total of five 96-well plates. ct: The threshold cycle (CT-value) for each sample. ctcontrol: The threshold cycle (CT-value) for reference gene using the same biological sample (template RNA) from the same reaction plate. deltact: The difference between the experimental and reference CT-values (experimental - reference)EEPhenotypeDataContains tail scores for individual worms of each strain reared at six temperatures. See publication for methodological details. ID: ID number for individual worm. Strain: Strain/line of each worm. Temp: Temperature at which each worm was raised (degrees C). Tail: Tail score (see Chandler, 2010, Heredity, 105, 473-482 for scoring details).EEFitnessDataContains tail scores and gonad phenotypes for individual worms of each strain reared at six temperatures. See publication for methodological details. ID: ID number for individual worm. Strain: Strain/line of each worm. Temp: Temperature at which each worm was raised (degrees C). Tail: Tail score (see Chandler, 2010, Heredity, 105, 473-482 for scoring details). Gonad: Gonad score for each worm, -1 = unscorable, 0 = hermaphrodite with obvious eggs, 1 = hermaphrodite carrying no visible eggs, 2 = looks like a hermaphrodite gonad, but abnormal with no eggs (categories 1 & 2 were pooled together for analyses in the publication), 3 = male.