Find research datasets worth reusing

opencc-by-4.0May 2019View details →

Engineering gene overlaps to sustain genetic constructs in vivo

Experimental data, simulation data, and code for data analysis and figure production for the paper "Engineering gene overlaps to sustain genetic constructs in vivo" (Decrulle, Frenoy, et al, PloS Computational Biology)

Crossing design shapes patterns of genetic variation in synthetic recombinant populations of Saccharomyces cerevisiae

"Synthetic recombinant" populations have emerged as a useful tool for dissecting the genetics of complex traits. They can be used to derive inbred lines for fine QTL mapping, or the populations themselves can be sampled for experimental evolution. In latter application, investigators generally value maximizing genetic variation in constructed populations. This is because in evolution experiments initiated from such populations, adaptation is primarily fueled by standing genetic variation. Despite this reality, little has been done to systematically evaluate how different methods of constructing synthetic populations shape initial patterns of variation. Here we seek to address this issue by comparing outcomes in synthetic recombinant Saccharomyces cerevisiae populations created using one of two strategies: pairwise crossing of isogenic strains or simple mixing of strains in equal proportion. We also explore the impact of the varying the number of parental strains. We find that more genetic variation is initially present and maintained when population construction includes a round of pairwise crossing. As perhaps expected, we also observe that increasing the number of parental strains typically increases genetic diversity. In summary, we suggest that when constructing populations for use in evolution experiments, simply mixing founder strains in equal proportion may limit the adaptive potential.

Strong population genetic structure and cryptic diversity in the Florida bonneted bat (Eumops floridanus)

Knowledge of genetic structure is essential for the long-term management and conservation of endangered species. We report the results from a genetic examination of the federally endangered Florida bonneted bat (Eumops floridanus) sampled from its range in southern Florida, USA. Bonneted bats are primarily found in four regions separated by approximately 100 to 250 kms, including three western natural areas (BW, PC, and CC) and one urban population on the east coast [Miami-Dade County (MD)]. We used 22 microsatellite loci and cytochrome b sequences to assess the extent of connectivity and levels of genetic diversity. Regional populations were highly differentiated (FST = 0.178) and model-based and multivariate analyses showed that MD was the most distinct among pairwise comparisons. Regional populations are small (i.e., Ne < 100) but demographically stable. Estimates of contemporary migration and historic gene flow suggest that regional populations do not frequently exchange migrants, but simulations suggest that the divergence among western regions is likely a result of recent genetic drift rather than long-term isolation. Significantly, mitochondrial DNA revealed that haplotypes from MD were similar or shared with those recognized as Eumops ferox from Cuba and Jamaica, and divergent (1.5%) from the remainder of bonneted bats in Florida. Our data support the management of each of the four populations as distinct population segments, and that BW, PC and CC combined are on an independent evolutionary trajectory from bats in MD. Critically, bonneted bats in Florida appear to harbor cryptic diversity that will require a reassessment of their taxonomy.

opencc-by-4.0Oct 2021View details →

Juniperus excelsa s. str. in Crimea – differentiation and history inferred from genetic and morphological markers

The file contains Supplementary Data for the paper: Mazur M., Jadwiszczak KA., Bona A., Krasylenko Y., Kukushkin O., Marcysiak K. 2021. Juniperus excelsa s. str. in crimea – differentiation and history inferred from genetic and morphological markers. Folia Forestalia Polonica, vol.63, no.4, pp.276-288. <a href="https://doi.org/10.2478/ffp-2021-0028">https://doi.org/10.2478/ffp-2021-0028</a>

Data from: Genome-wide association studies across environmental and genetic contexts reveal complex genetic architecture of symbiotic extended phenotypes

A goal of modern biology is to develop the genotype-phenotype (G→P) map, a predictive understanding of how genomic information generates trait variation that forms the basis of both natural and managed communities. As microbiome research advances, however, it has become clear that many of these traits are symbiotic extended phenotypes, being governed by genetic variation encoded not only by the host's own genome, but also by the genomes of myriad cryptic symbionts. Building a reliable G→P map therefore requires accounting for the multitude of interacting genes and even genomes involved in symbiosis. Here we use naturally-occurring genetic variation in 191 strains of the model microbial symbiont Sinorhizobium meliloti paired with two genotypes of the host Medicago truncatula in four genome-wide association studies (GWAS) to determine the genomic architecture of a key symbiotic extended phenotype – partner quality, or the fitness benefit conferred to a host by a particular symbiont genotype, within and across environmental contexts and host genotypes. We define three novel categories of loci in rhizobium genomes that must be accounted for if we want to build a reliable G→P map of partner quality; namely, 1) loci whose identities depend on the environment, 2) those that depend on the host genotype with which rhizobia interact, and 3) universal loci that are likely important in all or most environments. IMPORTANCE: Given the rapid rise of research on how microbiomes can be harnessed to improve host health, understanding the contribution of microbial genetic variation to host phenotypic variation is pressing, and will better enable us to predict the evolution of (and select more precisely for) symbiotic extended phenotypes that impact host health. We uncover extensive context-dependency in both the identity and functions of symbiont loci that control host growth, which makes predicting the genes and pathways important for determining symbiotic outcomes under different conditions more challenging. Despite this context-dependency, we also resolve a core set of universal loci that are likely important in all or most environments, and thus, serve as excellent targets both for genetic engineering and future coevolutionary studies of symbiosis.

opencc-zeroJul 2022View details →

Asimina triloba genetic data

Dispersal and colonization are among the most important ecological processes for species persistence as they allow species to track changing environmental conditions. During the last glacial maximum (LGM), many cold-intolerant Northern Hemisphere plants retreated to southern glacial refugia. During subsequent warming periods, these species expanded their ranges northward. Interestingly, some tree species with limited seed dispersal migrated considerable distances after the LGM ~19,000 year before present (YBP). It has been hypothesized that indigenous peoples may have dispersed valued species, in some cases beyond the southern limits of the Laurentide Ice Sheet. To investigate this question we employed a molecular genetics approach on a widespread North American understory tree species whose fruit was valued by indigenous peoples. Twenty putative anthropogenic (near pre-Columbian habitations) and 62 wild populations of Asimina triloba (pawpaw), which produces the largest edible fruit of any North American tree, were genetically assayed with nine microsatellite loci. Putative anthropogenic populations were characterized by reduced genetic diversity and greater excess heterozygosity relative to wild populations. Anthropogenic populations in regions that were glaciated during the LGM had profiles consistent with founder effects and reduced gene flow, and shared rare alleles with wild populations hundreds of kilometers away (mean = 723.1 km). Some of the most compelling evidence for human-mediated dispersal is that putative anthropogenic and wild populations sharing rare alleles were separated by significantly greater distances (mean = 695.3 km) than wild populations sharing rare alleles (mean = 607.1 km; p = 0.014). Collectively the genetic data suggest that long-distance dispersal played an important role in the distribution of pawpaw and is consistent with the hypothesized role of indigenous peoples.

Seascape genetics of the Atlantic spotted dolphin (Stenella frontalis) based on mitochondrial DNA

The Atlantic spotted dolphin (Stenella frontalis) is endemic to tropical, subtropical, and warm temperate waters of the Atlantic Ocean. Throughout its distribution, both geographic distance and environmental variation may contribute to population structure of the species. In this study we follow a seascape genetics approach to investigate population differentiation of Atlantic spotted dolphins based on a large worldwide dataset and the relationship with marine environmental variables. The results revealed that the Atlantic spotted dolphin exhibits population genetic structure across its distribution based on mitochondrial DNA control region (mtDNA-CR) data. Analyses based on the contemporary landscape suggested, at both the individual and population-level, that the population genetic structure is consistent with the isolation-by-distance model. However, because geography and environmental matrices were correlated, and because in some, but not all analyses, we found a significant effect for the environment, we cannot rule out the addition contribution of environmental factors in structuring genetic variation. Future analyses based on nuclear data are needed to evaluate whether local processes, such as social structure and some level of philopatry within populations, may be contributing to the associations among genetic structure, geographic, and environmental distance.

opencc-by-4.0Oct 2021View details →

Fraxinus excelsior genotype data for "Genetic resources of common ash (Fraxinus excelsior L.) in Poland"

The data set contains microsatellite genotypes (3 chloroplast + 10 nuclear loci) of Fraxinus excelsior trees, together with the information about sampling sites.

Environmental effects on the genetic architecture of fitness components in a simultaneous hermaphrodite

Understanding how environmental change affects genetic variances and covariances of reproductive traits is key to formulate firm predictions on evolutionary responses. This is particularly true for sex-specific variance in reproductive success, which has been argued to affect how populations can adapt to environmental change. Our current knowledge on the impact of environmental stress on sex-specific genetic architecture of fitness components is still limited and restricted to separate-sexed organisms. However, hermaphroditism is widespread across animals and may entail interesting peculiarities with respect to genetic constraints imposed on the evolution of male and female reproduction. We explored how food restriction affects the genetic variance-covariance (G) matrix of body size and reproductive success of the simultaneously hermaphroditic freshwater snail Physa acuta. Our results provide strong evidence that the imposed environmental stress elevated the opportunity for selection in both sex functions. However, the G matrix remained largely stable across the tested food treatments. Importantly, our results provide no support for cross-sex genetic correlations suggesting no strong evolutionary coupling of male and female reproductive traits. We discuss potential implications for the adaptation to changing environments and highlight the need for more quantitative genetic studies on male and female fitness components in simultaneous hermaphrodites.

Population genetics under the Massenerhebung effect: the influence of topography on the demography of Acer morrisonense (Sapindaceae)

Aim: The Massenerhebung effect (Mass elevation effect) refers to heat or wind-driven altitudinal distribution patterns of temperature-dependent parameters among massifs with narrower range and lower elevation around peripheral and isolated mountains compared to core and continuous ones. Although common in ecology, this effect is rarely discussed in population genetics. Here, we use genetic markers to reveal population genetic patterns and also test the mountain- and sky-barrier hypotheses relevant to the Massenerhebung distribution pattern of Acer morrisonense in Taiwan's rugged topography and varied local climates. Location: The alpine and cloud forest of Taiwan. Taxon: Acer morrisonense Hayata Methods: Two chloroplast DNA (cpDNA) fragments and 17 expressed sequence tag-simple sequence repeat (EST-SSR) loci respectively from 200 and 286 individuals were used to elucidate the phylogeographic pattern of pollen and seed dispersal of A. morrisonense. These data were combined with ecological niche modeling (ENM) to infer distribution range shifts and refugia. We also correlated the genetic-divergence indices with spatial factors to clarify latitudinal and altitudinal effects on genetic diversity. Results: The incongruent phylogeographic patterns of genetic distributions between nuclear and cpDNA markers indicate unhindered pollen flow but spatially constrained seed dispersal. Taken together with ENM, the genetic pattern further reflects historical colonization from central-mountain refugia to edges since the Holocene. The Massenerhebung reduces the gene flow by the surrounding mountains and also causes lower genetic diversity compared to central alpine populations. Main conclusions: This study is the first to reveal the influence of Massenerhebung effect on cpDNA genetic structure of montane trees and reflect the spatial trends of seed dispersal. This population genetic pattern can also be attributed to the demography-related range shifts with paleoclimate fluctuations under complex mountain topography, supporting the mountain-barrier hypothesis. The results have important implications for conserving the genetic diversity of species with a wide altitudinal distribution range.

Cross-species transcriptomics uncovers genes underlying genetic accommodation of developmental plasticity in spadefoot toads

That hardcoded genomes can manifest as plastic phenotypes responding to environmental perturbations is a fascinating feature of living organisms. How such developmental plasticity is regulated at the molecular level is beginning to be uncovered aided by the development of -omic techniques. Here, we compare the transcriptome-wide responses of two species of spadefoot toads with differing capacity for developmental acceleration of their larvae in the face of a shared environmental risk: pond drying. By comparing gene expression profiles over time and performing cross-species network analyses, we identified orthologues and functional gene pathways whose environmental sensitivity in expression have diverged between species. Genes related to lipid, cholesterol and steroid biosynthesis and metabolism make up most of a module of genes environmentally responsive in one species, but canalized in the other. The evolutionary changes in the regulation of the genes identified through these analyses may have been key in the genetic accommodation of developmental plasticity in this system.

Data from: Experimental evidence of rapid heritable adaptation in the absence of initial standing genetic variation

The success of genetically depauperate populations in the face of environmental change is contrary to the expectation that high genetic diversity is required for rapid adaptation. Alternative pathways such as environmentally induced genetic modifications and non-genetic heritable phenotypes have been proposed mechanisms for heritable adaptation within an ecologically relevant timeframe. However, experimental evidence is currently lacking to establish if, and to what extent, these sources of phenotypic variation can produce a response. To test if adaptation can rapidly occur in the absence of initial standing genetic variation and recombination in small populations, we (i) exposed replicate monoclonal populations of the microzooplankton Brachionus calyciflorus to a culturing regime that selected for phenotypic variants with elevated population growth with either high or low phosphorus food for a period of 55 days and (ii) examined population-level response in two fully factorial common garden experiments at day 15 and 35 of the exposure experiment. Within six generations, we observed heritable local adaptation to nutrient limitation. More specifically, populations with a history of exposure to P-limited food exhibited higher population growth rates under low P food conditions than populations with a high P exposure history. However, the capacity for such a response was found to vary among clones. Our study finds that although standing genetic variation is considered essential for rapid heritable adaptation, the rapid emergence of de novo genetic variation or alternative sources of phenotypic variation could aid in the establishment and persistence of low diversity populations.

opencc-by-4.0Dec 2018View details →

Differential Role of a persistent Seed Bank for genetic Variation in early vs. late successional Stages

The file contains data of AFLP analyses of the perennial plant Viola elatior, collected in populations in Germany and the Czech Republic. The first sheet contains a read-me describing the data that reads as follows: "Presence/absence matrix (1/0) of AFLP markers. The first column provides the sample ID (R - Upper Rhine region; T - Thaya/Morava region; M - meadow habitat; W - woodland habitat; sb - seedbank sample) and second and third column provides coordinates used for analyses of small-scale spatial genetic structure. Note that for SB cohorts, only samples originating from soil pools with a maximum distance of 4 m between the two soil sampling sites (cf. SB sampling strategy in M&M) were considered, using the corresponding midpoint coordinates, respectively. The first row provides the marker ID (selective primer combination + fragment size in bp). Selective Primer Combinations: F1 - FAM_AAC-CTA; F2 - FAM_ACT-CAA; V1 - VIC_ACA-CAA; V2 - VIC_ACA-CTC; N1 - NED_AAG-CAC; N2 - NED_AAG-CTC; P1 - PET_AGC-CAA; P2 - PET_AGG-CTC". We used the data to compare genetic variation of aboveground and seed bank cohorts in 15 populations of the partially cleistogamous Viola elatior in two contrasting early and late successional habitats characterized by strong differences in light-availability and declining population size. Using AFLP markers, we found significantly higher aboveground than seed bank genetic diversity in early successional meadow but not in late successional woodland habitats.

Dataset 2 for Large‐ and small‐scale geographic structures affecting genetic patterns across populations of an Alpine butterfly

Understanding factors influencing patterns of genetic diversity and the population genetic structure of species is of particular importance in the current era of global climate change and habitat loss. These factors include the evolutionary history of a species as well as heterogeneity in the environment it occupies, which in turn can change across time. Most studies investigating spatio-temporal genetic patterns have focused on patterns across wide geographical areas rather than local variation, but the latter can nevertheless be important particularly in topographically complex areas. Here we consider these issues in the Sooty Copper butterfly (Lycaena tityrus) from the European Alps, using genome-wide SNPs identified through RADseq. We found strong genetic differentiation within the Alps with four genetic clusters, indicating western, central, and eastern refuges, and a strong reduction of genetic diversity from west to east. This reduction in diversity may suggest that the southwestern refuge was the largest one in comparison to other refuges. Also, the high genetic diversity in the West may result from (1) admixture of different western refuges, (2) more recent demographic changes, or (3) introgression of lowland L. tityrus populations. At small spatial scales, populations were structured by several landscape features and especially by high mountain ridges and large river valleys. We detected 36 outlier loci likely under altitudinal selection, including several loci related to membranes and cellular processes. We suggest that efforts to preserve alpine L. tityrus should focus on the genetically diverse populations in the western Alps, and that the dolomite populations should be treated as genetically distinct management units, since they appear to be currently more threatened than others. This study demonstrates the usefulness of SNP-based approaches for understanding patterns of genetic diversity, gene flow and selection in a region that is expected to be particularly vulnerable to climate change.

Limited seed dispersal shapes fine-scale spatial genetic structure in a Neotropical dioecious large-seeded palm

Seed and pollen dispersal contribute to gene flow and shape the genetic patterns of plants over fine spatial scales. We inferred fine-scale spatial genetic structure (FSGS) and estimated realized dispersal distances in Phytelephas aequatorialis, a Neotropical dioecious large-seeded palm. We aimed to explore how seed and pollen dispersal shape this genetic pattern in a focal population. For this purpose, we genotyped 138 seedlings and 99 adults with 20 newly developed microsatellite markers. We tested if rodent-mediated seed dispersal has a stronger influence than insect-mediated pollen dispersal in shaping FSGS. We also tested if pollen dispersal was influenced by the density of male palms around mother palms in order to further explore this ecological process in large-seeded plants. Rodent-mediated dispersal of these large seeds occurred mostly over short distances (mean 34.76 ± 34.06 m) while pollen dispersal distances were two times higher (mean 67.91 ± 38.29 m). The spatial extent of FSGS up to 35 m and the fact that seed dispersal did not increase the distance at which male alleles disperse suggest that spatially limited seed dispersal is the main factor shaping FSGS and contributes only marginally to gene flow within the population. Pollen dispersal distances depended on the density of male palms, decreasing when individuals show a clumped distribution and increasing when they are scattered. Our results show that limited seed dispersal mediated by rodents shapes FSGS in P. aequatorialis, while more extensive pollen dispersal accounts for a larger contribution to gene flow and may maintain high genetic diversity.

Illumina next generation ddRAD sequencing SNP data from: Contrasting genetic diversity and structure between endemic and widespread damselfishes are related to differing adaptive strategies

Aim: Discerning when, where, and how processes of isolation lead to differing biogeography is especially complex for marine species with similar ecological niches and within the same geographic location. We assessed population genetics of congeneric and ecologically similar damselfishes within their overlapping distributions and across potential barriers to geneflow. Taxon: Dascyllus marginatus (endemic) and Dascyllus abudafur (widespread). Location: Coral reefs from the Red Sea, Djibouti, Yemen, Oman, and Madagascar. Methods: We used RADseq derived SNPs to investigate key differences in population genetics between both species and discuss barriers shaping genetic differentiation (neutral vs. selective) and biogeography. Results: Dascyllus marginatus inhabited the Red Sea, the coasts of Yemen (including Socotra), and the Gulf of Oman. Dascyllus abudafur species was present from the Red Sea to Madagascar but was absent from Yemen and Oman. Populations of D. marginatus had an order of magnitude higher genetic differentiation compared to D. abudafur, as well as several outlier loci (suggesting selective pressure), which were absent in D. abudafur despite equal sampling locations. In both species, specimens from the Red Sea and Djibouti formed one genetic cluster separated from all other locations. Main conclusions: The stronger genetic structure at smaller geographic scale of the endemic species seems associated to faster adaptation to environmental differences; whereas the widespread species only experienced reduced geneflow and neutral differentiation at much larger geographic scales. Restrictive transitions (between the Gulf of Aqaba and the Red Sea or the Red Sea and the Gulf of Aden) did not affect the genetic architecture of either species, while the environmental shift within the Red Sea (at 22°N/20°N) affected the endemic but not the widespread species. Samples from continental Yemen revealed that a genetic break in the Gulf of Aden likely reflects historical colonization processes and not contemporary environmental regimes.

Transitioning from microsatellites to SNP-based microhaplotypes in genetic monitoring programs: lessons from a 20-year time series of paired data.

Many long-term genetic monitoring programs began before next-generation sequencing became widely available. Older programs can now transition to new marker systems usually consisting of 1000s of SNP loci, but there are still important questions about comparability, precision, and accuracy of key metrics estimated using SNPs. Ideally, transitioned programs should capitalize on new information without sacrificing continuity of inference across the time series. We combined existing microsatellite-based genetic monitoring information with SNP-based microhaplotypes obtained from archived samples of Rio Grande silvery minnow (Hybognathus amarus) across a 20-year time series to evaluate point estimates and trajectories of key genetic metrics. Demographic and genetic monitoring bracketed multiple collapses of the wild population, and included cases where captive-born repatriates comprised the majority of spawners in the wild. Even with smaller sample sizes, microhaplotypes yielded comparable and in some cases more precise estimates of variance genetic effective population size, multilocus heterozygosity and inbreeding compared to microsatellites because many more microhaplotype loci were available. Microhaplotypes also recorded shifts in allele frequencies associated with population bottlenecks. Trends in microhaplotype-based inbreeding metrics were associated with the fraction of hatchery-reared repatriates to the wild, and should be incorporated into future genomic monitoring. Although differences in accuracy and precision of some metrics were observed between marker types, biological inferences and management recommendations were consistent.

The oceanographic isolation of the Ogasawara Islands and genetic divergence in a reef-building coral

Aim: Due to their spatial isolation, oceanic islands are natural systems to study evolutionary divergence. The Ogasawara Islands belong to the most isolated archipelagos on Earth and are well-known for their high terrestrial endemicity, however, less is known about the marine realm. Here, we analyze the degree of oceanographic isolation of the archipelago based on genetic data of a reef-building coral and a biophysical dispersal model. Location: North-Western Pacific (Ogasawara, Ryukyu, Daito Islands, Guam) Taxon: Galaxea fascicularis L. Method: Three to 15 specimens were sampled at several sites in Ogasawara and its closest potential migration sources in southern Japan and the Mariana Islands (Guam) and RAD-sequenced. 108 specimens from the common Pacific lineages 'L' (Ryukyu- and Daito Islands, Guam) and 'Ogasawara' (Ogasawara) were analyzed with population genetics and demographic modeling. Oceanographic dispersal was investigated by inverse particle tracking using a Lagrangian particle advection simulation based on ROMS and applying biological dispersal parameters of G. fascicularis. Results: The G. fascicularis population in Ogasawara is genetically highly differentiated from the next closest reefs in the region and has diverged from the Ryukyu Islands under very little, asymmetric, eastward migration. Inverse particle tracking confirmed the oceanographic isolation of Ogasawara and showed that the islands are rarely but most likely reached by settlers from the Ryukyu Islands by long-distance-dispersal of exceptionally long-lived larvae (>44 days), with no dispersal vice versa. Main conclusions: Ogasawara is a dispersal sink location and the high degree of genetic differentiation in Galaxea has resulted from strong oceanographic isolation. This research highlights how oceanographic features impact species-level genetic differentiation even in well-dispersed taxa such as broadcast-spawning corals, and they are likely even more pronounced in less vagile organisms. These findings suggest the Ogasawaran Archipelago should be considered an important priority for marine conservation, alongside its high importance for terrestrial conservation.

opencc-by-4.0Sep 2022View details →

Data - Attack of the clones: population genetics reveals clonality of Colletotrichum lupini, the causal agent of lupin anthracnose

Colletotrichum lupini, causing lupin anthracnose, is one of the worst pathogens to lupin cultivation worldwide. Understanding its population structure and evolutionary potential is crucial to design successful disease management strategies. The objective of this study was to employ population genetics to investigate the genetic diversity, evolutionary dynamics and molecular basis of host-speciation of this notorious lupin pathogen. A collection of globally representative C. lupini isolates was genotyped through triple digest restriction-site associated DNA sequencing (3D-RADseq), resulting in a dataset of unparalleled resolution. Phylogenetic and structural analysis could distinguish four (I – IV) independent lineages. The strong population structure, low recombination rate and slow linkage decay strongly indicate that C. lupini reproduces clonally. Different morphologies and virulence patterns on white and Andean lupin were observed between and within clonal lineages. Lineage II  isolates were shown to have a mini chromosome which was also partly present in lineage III and IV, but not in lineage I isolates. Variation in the presence of this mini-chromosome could indicate a function related to virulence or host-speciation. All four lineages were present in the South American Andes region, which is concluded to be the center of origin of this species. Only members of lineage II have been found outside South America since the 1990s, indicating it as the current pandemic population. As a seed-borne pathogen, C. lupini has mainly spread through infected but symptomless seeds, stressing the importance of phytosanitary measures to prevent future outbreaks of strains that are yet confined to South America.