Find research datasets worth reusing
Search datasets from major research repositories and use ShareScore to quickly assess how well each record supports discovery, access, and reuse.
44
datasets available to search
ShareScore release 0.9.0
Dataset results
44 results for “genetic covariation”
Data from: Asymmetry in cross-sex cross-trait genetic covariances and the evolvability of sexual dimorphism
Open the record for dataset details and reuse information.
Positive genetic covariance between male sexual ornamentation and fertilizing capacity
<p>Postcopulatory sexual selection results from variation in competitive fertilization success among males, and comprises powerful evolutionary forces that operate after the onset of mating [1, 2]. Theoretical advances in the field of sexual selection addressing the build-up and co-evolutionary consequences of genetic coupling [3-5], motivate the hypothesis that indirect postcopulatory sexual selection may promote evolution of male secondary sexual traits—those traits traditionally ascribed to mate choice and male fighting [6, 7]. A crucial prediction of this hypothesis is genetic covariance between trait expression and competitive fertilization success, which has been predicted to arise, for example, when traits subject to pre- and postcopulatory sexual selection are under positive correlational selection [8]. We imposed bidirectional artificial selection on male ornament (sex comb) size in <i>Drosophila bipectinata</i>, and demonstrate increased competitive fertilization success as a correlated evolutionary response to increasing ornament size. Transcriptional analyses revealed that levels of specific seminal fluid proteins repeatedly shifted in response to this selection, suggesting that properties of the ejaculate rather than the enlarged sex comb itself contributed fertilizing capacity. We used ultraprecise laser surgery to reduce ornament size of high line males, and found that their fertilizing superiority persisted despite the size reduction, reinforcing the transcriptional results. The data support the existence of positive genetic covariance between a male secondary sexual trait and competitive fertilization success, and suggest the possibility that indirect postcopulatory sexual selection may under certain conditions magnify net selection on ornamental trait expression. </p>
Weak genetic signal for phenotypic integration implicates developmental processes as major regulators of trait covariation
<p>Phenotypic integration is an important metric that describes the degree of covariation among traits in a population, and is hypothesized to arise due to selection for shared functional processes. Our ability to identify the genetic and/or developmental underpinnings of integration is marred by temporally overlapping cell-, tissue-, and structure-level processes that serve to continually 'overwrite' the structure of covariation among traits through ontogeny. Here we examine whether traits that are integrated at the phenotypic level, also exhibit a shared genetic basis (e.g., pleiotropy). We micro-CT scanned two hard tissue traits, and two soft tissue traits (mandible, pectoral girdle, atrium, and ventricle respectively) from an F<sub>5</sub> hybrid population of Lake Malawi cichlids, and used geometric morphometrics to extract 3D shape information from each trait. Given the large degree of asymmetric variation that may reflect developmental instability, we separated symmetric- from asymmetric-components of shape variation. We then performed quantitative trait loci (QTL) analysis to determine the degree of genetic overlap between shapes. While we found ubiquitous associations among traits at the phenotypic level, except for a handful of notable exceptions, our QTL analysis revealed few overlapping genetic regions. Taken together, this indicates developmental interactions can play a large role in determining the degree of phenotypic integration among traits, and likely obfuscate the genotype to phenotype map, limiting our ability to gain a comprehensive picture of the genetic contributors responsible for phenotypic divergence.</p>
Genetic covariance in immune measures and pathogen resistance in decorated crickets (Gryllodes sigillatus) is sex and pathogen specific
<p>Insects are important models for studying immunity in an ecological and evolutionary context. Yet, most empirical work on the insect immune system has come from phenotypic studies meaning we have a limited understanding of the genetic architecture of immune function in the sexes.</p> <p>We use nine highly inbred lines to thoroughly examine the genetic relationships between a suite of commonly used immune assays (haemocyte count, implant encapsulation, total phenoloxidase activity, antibacterial zone of inhibition, pathogen clearance) and resistance to infection by three generalist insect pathogens (the gram-negative bacterium <em>Serratia marcescens</em>, the gram-positive bacterium <em>Bacillus cereus</em> and the fungus <em>Metarhizium robertsii</em>) in male and female <em>Gryllodes sigillatus</em>.</p> <p>There were consistent positive genetic correlations between haemocyte count, antibacterial and phenoloxidase activity and resistance to <em>S. marcescens</em> in both sexes, but these relationships were less consistent for resistance to <em>B. cereus</em> and <em>M. robertsii</em>. In addition, the clearance of <em>S. marcescens</em> was genetically correlated with the resistance to all three pathogens in both sexes. Genetic correlations between resistances to the different pathogen species were inconsistent, indicating that resistance to one pathogen does not necessarily mean resistance to another. Finally, while there is ample genetic (co)variance in immune assays and pathogen resistance, these genetic estimates differed across the sexes and many of these measures were not genetically correlated across the sexes suggesting that these measures could evolve independently in the sexes.</p> <p>Our finding that the genetic architecture of immune function is sex and pathogen specific suggests that the evolution of immune function in male and female <em>G. sigillatus</em> is likely to be complex. Similar quantitative genetic studies that measure a large number of assays and resistance to multiple pathogens in both sexes are needed to ascertain if this complexity extends to other species.</p>
Hormonal pleiotropy structures genetic covariance
Open the record for dataset details and reuse information.
Positive genetic covariance between male sexual ornamentation and fertilizing capacity
Open the record for dataset details and reuse information.
Genetic covariance in immune measures and pathogen resistance in decorated crickets (Gryllodes sigillatus) is sex and pathogen specific
Open the record for dataset details and reuse information.
Weak genetic signal for phenotypic integration implicates developmental processes as major regulators of trait covariation
Open the record for dataset details and reuse information.
Environmentally triggered variability in the genetic variance-covariance of herbivory resistance of an exotic plant Solidago altissima
Open the record for dataset details and reuse information.
Data from Koch et al. 2020 Evolution: Genetic variance in fitness and its cross-sex covariance predict adaptation during experimental evolution.
<p><strong>Abstract</strong></p> <p>In presence of rapid environmental changes, it is of particular importance to assess the adaptive potential of populations, which is mostly determined by the additive genetic variation (V<sub>A</sub>) in fitness. In this study we used <em>Tribolium castaneum </em>(red flour beetles) to investigate its adaptive potential in three new environmental conditions (Dry, Hot, Hot-Dry). We tested for potential constraints that might limit adaptation, including negative genetic covariance between female and male fitness. Based on V<sub>A</sub> estimates for fitness, we expected the highest relative fitness increase in the most stressful condition Hot-Dry and similar increases in single stress conditions Dry and Hot. High adaptive potential in females in Hot was reduced by a negative covariance with male fitness. We tested adaptation to the three conditions after 20 generations of experimental evolution and found that observed adaptation mainly matched our predictions. Given that body size is commonly used as a proxy for fitness, we also tested how this trait and its genetic variance (including non-additive genetic variance) were impacted by environmental stress. In both traits, variances were sex and condition dependent, but they differed in their variance composition, cross-sex and cross-environment genetic covariances, as well as in the environmental impact on V<sub>A</sub>.</p> <p> </p> <p><strong>Method</strong></p> <p><em>Strain and environmental conditions</em></p> <p>We used the <em>Tribolium castaneum</em> Cro1 strain collected from a wild population in 2010 and adapted to lab standard conditions (33°C, 70% relative humidity) for more than 20 generations. Beetles were kept in 24h darkness on organic wheat flour mixed with 10% organic baker's yeast. We sterilized flour and yeast by heating them for 12h at 80°C before use. To test for adaptation to new environmental conditions we used replicate lines and exposed them to three treatments and Control conditions. The conditions in the treatments were: Dry: 33°C and 30% relative humidity; Hot: 37°C and 70% r. h.; Hot-Dry: 37°C and 30% r. h.</p> <p> </p> <p><em>Crossing, fitness assay and measurement of body size</em></p> <p>In order to be able to estimate genetic variances, we applied a split-brood paternal half-sib breeding design. We produced 147 half-sib families by mating virgin males to three virgin females. Half- as well as full-sib families were split across all conditions. Male and female offspring (four females and two males per full-sib family and condition) were separated at the pupal stage and transferred to 10 mL tubes with 1 g of medium and remained there until they were used for the fitness assay eight weeks later.</p> <p>To estimate fitness, we mated each virgin male with two unrelated virgin females from the same condition in 15mL tube with 1g medium. The male was removed after 24h and females transferred into two separate tubes. Females were removed from the tubes after one week of egg laying, and 9g medium was added to provide food for the developing offspring. After five weeks the number of adult offspring was counted. While we conducted the matings for the fitness assay, we followed a specific crossing design and always crossed two pairs of full-sib families. Individuals resulting from these crosses (the F2 genaration) were double first cousins.</p> <p>Body size was measured in the F2, i.e. in the offspring of beetles that were used for the fitness assay. To estimate body size, we used the centroid size of the abdominal segment IV as proxy for total size since it can be measured more accurately than dry weight in very small insects and shows a high correlation with body mass.</p> <p> </p> <p><em>Experimental evolution</em></p> <p>We used ten replicate lines per condition originating from the same ancestral population (Cro1) and let them adapt for 20 generations. Each new generation was set up by randomly selecting 120 pupae and placing them into a new vial with 70g medium. One selection line in Dry became extinct. Adult beetles of generation 20 from all selection lines were transferred to control conditions, in which they stayed for one week to mate and lay eggs. After removal of the adults, we waited until their offspring had reached the pupal stage and separated males and females. These individuals (generation 21) developed completely in control conditions. When they had reached the adult stage, each virgin male was mated with a virgin female of the same selection line and their offspring was transferred to all four conditions in the egg stage, resulting in full-sib families split across all conditions . As soon as these offspring (generation 22) had reached the pupal stage, males and females were separated. To compare fitness of different selection lines and test for adaptation, a virgin male and a virgin female of the same selection line in the same condition, but from different families were mated and the number of adult offspring produced within four days of mating and egg laying was used as a fitness estimate.</p> <p> </p> <p> </p> <p><strong>Files</strong></p> <p>This data publication contains the following files:</p> <p>Fitness_data.txt: Fitness data (offspring number) of the first generation in new environmental conditions.</p> <p>ANIMAL: ID of female individuals; male: ID of mating partner, father of the offspring; fitness: number of adult offspring per female produced within one week of egg laying; condition: condition under which the individuals grew up, mated, reproduced (CTL: control, D: dry, H: hot, HD: hot-dry, see Methods for details); MOTHER: mother of the female; Batch: samples where fitness assay was started on the same day</p> <p> </p> <p>Size_data.txt: Centroid size of abdominal segment IV.</p> <p>ANIMAL: ID of measured individuals; condition: condition under which the individuals grew up (CT: control, D: dry, H: hot, HD: hot-dry, see Methods for details); sex: sex of individuals (f: female, m: male); AS: centroid size [Pixel] of abdominal segment IV; Mother: ID of their mother; batch: Batches represent individuals that grew up at the same time, and thus accounts for variations in the medium or lab temperature</p> <p> </p> <p>Pedigree.txt: Pedigree of measured individuals.</p> <p>ANIMAL: individual ID ; MOTHER: mother ID; FATHER: father ID</p> <p> </p> <p>Transplant_data.txt: Offspring number of different selection lines under different conditions after 20 generations of experimental evolution.</p> <p>Line: Selection-line ID; Selection: condition, in which the selection-line spent 20 generations (CT: Control; D: Dry; Hot; HD: Hot-Dry); Fam: each selection line consisted of several families; Treatment: condition, in which offspring number was measured; offspring: number of adult offspring that a female produced within four days of egg-laying</p>
Rapid reversal of a potentially constraining genetic covariance between leaf and flower traits in Silene latifolia
Genetic covariance between two traits generates correlated responses to selection, and may either enhance or constrain adaptation. Silene latifolia exhibits potentially constraining genetic covariance between specific leaf area and flower number in males. Flower number is likely to increase via fecundity selection but the correlated increase in specific leaf area increases mortality, and specific leaf area is under selection to decrease in dry habitats. We selected on trait combinations in two selection lines for four generations to test whether genetic covariance could be reduced without significantly altering trait means. In one selection line, the genetic covariance changed sign and eigenstructure changed significantly, while in the other selection line eigenstructure remained similar to the control line. Changes in genetic variance-covariance structure are therefore possible without the introduction of new alleles, and the responses we observed suggest that founder effects and changes in frequency of alleles of major effect may be acting to produce the changes.
Data from: Genetic covariance between components of male reproductive success: within-pair versus extra-pair paternity in song sparrows
The evolutionary trajectories of reproductive systems, including both male and female multiple mating and hence polygyny and polyandry, are expected to depend on the additive genetic variances and covariances in and among components of male reproductive success achieved through different reproductive tactics. However, genetic covariances among key components of male reproductive success have not been estimated in wild populations. We used comprehensive paternity data from socially monogamous but genetically polygynandrous song sparrows (Melospiza melodia) to estimate additive genetic variance and covariance in the total number of offspring a male sired per year outside his social pairings (i.e. his total extra-pair reproductive success achieved through multiple mating) and his liability to sire offspring produced by his socially paired female (i.e. his success in defending within-pair paternity). Both components of male fitness showed nonzero additive genetic variance, and the estimated genetic covariance was positive, implying that males with high additive genetic value for extra-pair reproduction also have high additive genetic propensity to sire their socially paired female's offspring. There was consequently no evidence of a genetic or phenotypic trade-off between male within-pair paternity success and extra-pair reproductive success. Such positive genetic covariance might be expected to facilitate ongoing evolution of polygyny and could also shape the ongoing evolution of polyandry through indirect selection.
Data from: The genetic variance but not the genetic covariance of life-history traits changes towards the north in a time-constrained insect
Seasonal time constraints are usually stronger at higher than lower latitudes and can exert strong selection on life history traits and the correlations among these traits. To predict the response of life history traits to environmental change along a latitudinal gradient, information must be obtained about genetic variance in traits and also genetic correlation between traits, i.e., the genetic variance-covariance matrix, G. Here, we estimated G for key life history traits in an obligate univoltine damselfly that faces seasonal time constraints. We exposed populations to simulated native temperatures and photoperiods and common garden environmental conditions in a laboratory setup. Despite differences in genetic variance in these traits between populations (lower variance at northern latitudes), there was no evidence for latitude-specific covariance of the life history traits. At simulated native conditions, all populations showed strong genetic and phenotypic correlations between traits that shaped growth and development. The variance-covariance matrix changed considerably when populations were exposed to common garden conditions compared with the simulated natural conditions, showing the importance of environmentally induced changes in multivariate genetic structure. Our results highlight the importance of estimating variance-covariance matrixes in environments that mimic selection pressures and not only trait variances or mean trait values in common garden conditions for understanding the trait evolution across populations and environments.
Data from: The evolutionary stability of cross-sex, cross-trait genetic covariances
Although knowledge of the selective agents behind the evolution of sexual dimorphism has advanced considerably in recent years, we still lack a clear understanding of the evolutionary durability of cross-sex genetic covariances that often constrain its evolution. We tested the relative stability of cross-sex genetic covariances for a suite of homologous contact pheromones of the fruit fly Drosophila serrata, along a latitudinal gradient that these traits have diverged in mean. Using a Bayesian framework, which allowed us to account for uncertainty in all parameter estimates, we compared divergence in the total amounts and orientations of genetic variance across populations, finding divergence in orientation but not total variance. We then statistically compared orientation divergence of within-sex (G) to cross-sex (B) covariance matrices. In line with a previous theoretical prediction, we find that the cross-sex covariance matrix, B, is more variable than either male or female within-sex covariance matrix. Decomposition of B matrices into their symmetrical and non-symmetrical components revealed that instability is linked to the degree of asymmetry. We also find that the degree of asymmetry correlates with latitude suggesting a role for spatially varying natural selection in shaping genetic constraints on the evolution of sexual dimorphism.
Positive genetic covariance and limited thermal tolerance constrain tropical insect responses to global warming
<p>Tropical ectotherms are particularly vulnerable to global warming because their physiologies are assumed to be adapted to narrow temperature ranges. This study explores three mechanisms potentially constraining thermal adaptation to global warming in tropical insects: 1. tradeoffs in genotypic performance at different temperatures (the jack-of-all-trades hypothesis) 2. positive genetic covariance in performance, with some genotypes performing better than others at viable temperatures (the 'winner and 'loser genotypes hypothesis) or 3. limited genetic variation as the potential result of relaxed selection and the loss of genes associated with responses to extreme temperatures (the gene decay hypothesis). We estimated changes in growth and survival rates at multiple temperatures for three tropical rain forest insect herbivores (<i>Cephaloleia</i> rolled-leaf beetles, Chrysomelidae). We reared 2746 individuals in a full-sibling experimental design, at temperatures known to be experienced by this genus of beetles in nature (<i>i.e.</i>, 10-35°C). Significant genetic covariance was positive for 16 traits, supporting the 'winner and 'loser genotypes hypothesis. Only two traits displayed negative cross-temperature performance correlations. We detected a substantial contribution of genetic variance in traits associated with size and mass (0-44%), but low heritability in plastic traits such as development time (0-6%) or survival (0-4%). Lowland insect populations will most likely decline if current temperatures increase beyond 2°C. It is concerning that local adaption is already lagging behind current temperatures. The consequences of maintaining the current global warming trajectory would be devastating for tropical insects. However, if humans can limit or slow warming, many tropical ectotherms might persist in their current locations, and potentially adapt to warmer temperatures.</p>
Data from: The genetic variance but not the genetic covariance of life-history traits changes towards the north in a time-constrained insect
Open the record for dataset details and reuse information.
Data from: Genetic covariance between components of male reproductive success: within-pair versus extra-pair paternity in song sparrows
Open the record for dataset details and reuse information.
Data from: The evolutionary stability of cross-sex, cross-trait genetic covariances
Open the record for dataset details and reuse information.
Data from: Population divergence along lines of genetic variance and covariance in the invasive plant Lythrum salicaria in eastern North America
Open the record for dataset details and reuse information.
Positive genetic covariance and limited thermal tolerance constrain tropical insect responses to global warming
Open the record for dataset details and reuse information.
ScienceDex guides
Understand access before you commit
These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.