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1,696 results for “DNA sequence”
Data from: PCR-Free enrichment of mitochondrial DNA from human blood and cell lines for high quality next-generation DNA sequencing
Recent advances in sequencing technology allow for accurate detection of mitochondrial sequence variants, even those in low abundance at heteroplasmic sites. Considerable sequencing cost savings can be achieved by enriching samples for mitochondrial (relative to nuclear) DNA. Reduction in nuclear DNA (nDNA) content can also help to avoid false positive variants resulting from nuclear mitochondrial sequences (numts). We isolate intact mitochondrial organelles from both human cell lines and blood components using two separate methods: a magnetic bead binding protocol and differential centrifugation. DNA is extracted and further enriched for mitochondrial DNA (mtDNA) by an enzyme digest. Only 1 ng of the purified DNA is necessary for library preparation and next generation sequence (NGS) analysis. Enrichment methods are assessed and compared using mtDNA (versus nDNA) content as a metric, measured by using real-time quantitative PCR and NGS read analysis. Among the various strategies examined, the optimal is differential centrifugation isolation followed by exonuclease digest. This strategy yields >35% mtDNA reads in blood and cell lines, which corresponds to hundreds-fold enrichment over baseline. The strategy also avoids false variant calls that, as we show, can be induced by the long-range PCR approaches that are the current standard in enrichment procedures. This optimization procedure allows mtDNA enrichment for efficient and accurate massively parallel sequencing, enabling NGS from samples with small amounts of starting material. This will decrease costs by increasing the number of samples that may be multiplexed, ultimately facilitating efforts to better understand mitochondria-related diseases.
Data from: Survey sequencing reveals elevated DNA transposon activity, novel elements, and variation in repetitive landscapes among vesper bats
The repetitive landscapes of mammalian genomes typically display high Class I (retrotransposon) transposable element (TE) content, usually around half of the genome. In contrast, the Class II (DNA transposon) contribution is typically small (<3% in model mammals). Most mammalian genomes also exhibit a precipitous decline in Class II activity beginning roughly 40 million years ago (Ma). The first signs of more recently active mammalian Class II TEs were obtained from the little brown bat, Myotis lucifugus and are reflected by higher genome content (~5%). To aid in determining taxonomic limits and potential impacts of this elevated Class II activity, we performed 454 survey sequencing of a second Myotis species as well as four additional taxa within the family Vespertilionidae and an outgroup species from Phyllostomidae. Graph-based clustering methods were used to reconstruct the major repeat families present in each species and novel elements were identified in several taxa. Retrotransposons remained the dominant group with regard to overall genome mass. Elevated Class II TE composition (3-4%) was observed in all five vesper bats while less than 0.5% of the phyllostomid reads were identified as Class II derived. Differences in satellite DNA and Class I TE content are also described among vespertilionid taxa. These analyses present the first cohesive description of TE evolution across closely related mammals, revealing genome-scale differences in TE content within a single family.
Data from: Phylogenetic Relationships of Fig Wasps Pollinating Functionally Dioecious Ficus Based on Mitochondrial DNA Sequences and Morphology
The obligate mutualism between pollinating fig wasps in the family Agaonidae (Hymenoptera: Chalcidoidea) and Ficus species (Moraceae) is often regarded as an example of coevolution but little is known about the history of the interaction and understanding the origin of functionally dioecious fig pollination has been especially difficult. The phylogenetic relationships of fig wasps pollinating functionally dioecious Ficus were inferred from mitochondrial cytochrome oxidase gene sequences (mtDNA) and morphology. Separate and combined analyses indicated that the pollinators of functionally dioecious figs are not monophyletic. However, pollinator relationships were generally congruent with host phylogeny and support a revised classification of Ficus. Ancestral changes in pollinator ovipositor length were also correlated with changes in fig breeding system. In particular, the relative elongation of the ovipositor was associated with the repeated loss of functionally dioecious pollination. The concerted evolution of interacting morphologies may bias estimates of phylogeny based on female head characters but homoplasy is not so concerted in other morphological traits. The lesser phylogenetic utility of morphology compared to mtDNA is not due to rampant convergence in morphology but rather to the greater number of potentially informative characters in DNA sequence data and patterns of nucleotide substitution also limit the utility of mtDNA. None the less, inferring the ancestral associations of fig pollinators from the best-supported phylogeny provided strong evidence of host conservatism in this highly specialized mutualism.
Data from: The Strepsiptera Problem: Phylogeny of the Holometabolous Insect Orders Inferred from 18S and 28S Ribosomal DNA Sequences and Morphology
Phylogenetic relationships among the holometabolous insect orders were inferred from cladistic analysis of nucleotide sequences of 18S ribosomal DNA (rDNA) (85 exemplars) and 28S rDNA (52 exemplars) and morphological characters. Exemplar outgroup taxa were Collembola (1 sequence), Archaeognatha (1), Ephemerida (1), Odonata (2), Plecoptera (2), Blattodea (1), Mantodea (1), Dermaptera (1), Orthoptera (1), Phasmatodea (1), Embioptera (1), Psocoptera (1), Phthiraptera (1), Hemiptera (4), and Thysanoptera (1). Exemplar ingroup taxa were Coleoptera: Archostemata (1), Adephaga (2), and Polyphaga (7); Megaloptera (1); Raphidioptera (1); Neuroptera (sensu stricto ;eq Planipennia): Mantispoidea (2), Hemerobioidea (2), and Myrmeleontoidea (2); Hymenoptera: Symphyta (4) and Apocrita (19); Trichoptera: Hydropsychoidea (1) and Limnephiloidea (2); Lepidoptera: Ditrysia (3); Siphonaptera: Pulicoidea (1) and Ceratophylloidea (2); Mecoptera: Meropeidae (1), Boreidae (1), Panorpidae (1), and Bittacidae (2); Diptera: Nematocera (1), Brachycera (2), and Cyclorrhapha (1); and Strepsiptera: Corioxenidae (1), Myrmecolacidae (1), Elenchidae (1), and Stylopidae (3). We analyzed ~1 kilobase of 18S rDNA, starting 398 nucleotides downstream of the 5' end, and ~400 bp of 28S rDNA in expansion segment D3. Multiple alignment of the 18S and 28S sequences resulted in 1,116 nucleotide positions with 24 insert regions and 398 positions with 14 insert regions, respectively. All Strepsiptera and Neuroptera have large insert regions in 18S and 28S. The secondary structure of 18S insert 23 is composed of long stems that are GC rich in the basal Strepsiptera and AT rich in the more derived Strepsiptera. A matrix of 176 morphological characters was analyzed for holometabolous orders. Incongruence length difference tests indicate that the 28S + morphological data sets are incongruent but that 28S + 18S, 18S + morphology, and 28S + 18S + morphology fail to reject the hypothesis of congruence. Phylogenetic trees were generated by parsimony analysis, and clade robustness was evaluated by branch length, Bremer support, percentage of extra steps required to force paraphyly, and sensitivity analysis using the following parameters: gap weights, morphological character weights, methods of data set combination, removal of key taxa, and alignment region. The following are monophyletic under most or all combinations of parameter values: Holometabola, Polyphaga, Megaloptera + Raphidioptera, Neuroptera, Hymenoptera, Trichoptera, Lepidoptera, Amphiesmenoptera (Trichoptera + Lepidoptera), Siphonaptera, Siphonaptera + Mecoptera, Strepsiptera, Diptera, and Strepsiptera + Diptera (Halteria). Antliophora (Mecoptera + Diptera + Siphonaptera + Strepsiptera), Mecopterida (Antliophora + Amphiesmenoptera), and Hymenoptera + Mecopterida are supported in the majority of total evidence analyses. Mecoptera may be paraphyletic because Boreus is often placed as sister group to the fleas; hence, Siphonaptera may be subordinate within Mecoptera. The 18S sequences for Priacma (Coleoptera: Archostemata), Colpocaccus (Coleoptera: Adephaga), Agulla (Raphidioptera), and Corydalus (Megaloptera) are nearly identical, and Neuropterida are monophyletic only when those two beetle sequences are removed from the analysis. Coleoptera are therefore paraphyletic under almost all combinations of parameter values. Halteria and Amphiesmenoptera have high Bremer support values and long branch lengths. The data do not support placement of Strepsiptera outside of Holometabola nor as sister group to Coleoptera. We reject the notion that the monophyly of Halteria is due to long branch attraction because Strepsiptera and Diptera do not have the longest branches and there is phylogenetic congruence between molecules, across the entire parameter space, and between morphological and molecular data.
Data from: The evolutionary history of Xiphophorus fish and their sexually selected sword: a genome-wide approach using restriction site-associated DNA sequencing
Next-generation sequencing (NGS) techniques are now key tools in the detection of population genomic and gene expression differences in a large array of organisms. However, so far few studies have utilized such data for phylogenetic estimations. Here, we use NGS data obtained from genome-wide restriction site-associated DNA (RAD) (∼66000 SNPs) to estimate the phylogenetic relationships among all 26 species of swordtail and platyfish (genus Xiphophorus) from Central America. Past studies, both sequence and morphology-based, have differed in their inferences of the evolutionary relationships within this genus, particularly at the species-level and among monophyletic groupings. We show that using a large number of markers throughout the genome, we are able to infer the phylogenetic relationships with unparalleled resolution for this genus. The relationships among all three major clades and species within each of them are highly resolved and consistent under maximum likelihood, Bayesian inference and maximum parsimony. However, we also highlight the current cautions with this data type and analyses. This genus exhibits a particularly interesting evolutionary history where at least two species may have arisen through hybridization events. Here, we are able to infer the paternal lineages of these putative hybrid species. Using the RAD-marker-based tree we reconstruct the evolutionary history of the sexually selected sword trait and show that it may have been present in the common ancestor of the genus. Together our results highlight the outstanding capacity that RAD sequencing data has for resolving previously problematic phylogenetic relationships, particularly among relatively closely related species.
Data from: Plastome sequencing of ten nonmodel crop species uncovers a large insertion of mitochondrial DNA in cashew
In plant evolution, intracellular gene transfer (IGT) is a prevalent, ongoing process. While nuclear and mitochondrial genomes are known to integrate foreign DNA via IGT and horizontal gene transfer (HGT), plastid genomes (plastomes) have resisted foreign DNA incorporation and only recently has IGT been uncovered in the plastomes of a few land plants. In this study, we completed plastome sequences for l0 crop species and describe a number of structural features including variation in gene and intron content, inversions, and expansion and contraction of the inverted repeat (IR). We identified a putative rpl22 in cinnamon (Cinnamomum verum J. Presl) and other sequenced Lauraceae and an apparent functional transfer of rpl23 to the nucleus of quinoa (Chenopodium quinoa Willd.). In the orchard tree cashew (Anacardium occidentale L.), we report the insertion of an ∼6.7-kb fragment of mitochondrial DNA into the plastome IR. BLASTn analyses returned high identity hits to mitogenome sequences including an intact ccmB open reading frame. Using three plastome markers for five species of Anacardium, we generated a phylogeny to investigate the distribution and timing of the insertion. Four species share the insertion, suggesting that this event occurred <20 million yr ago in a single clade in the genus. Our study extends the observation of mitochondrial to plastome IGT to include long-lived tree species. While previous studies have suggested possible mechanisms facilitating IGT to the plastome, more examples of this phenomenon, along with more complete mitogenome sequences, will be required before a common, or variable, mechanism can be elucidated.
Data from: Phylogeographical patterns of an alpine plant, Rhodiola dumulosa (Crassulaceae), inferred from chloroplast DNA sequences
The phylogeographical patterns of Rhodiola dumulosa, an alpine plant species restrictedly growing in the crevices of rock piles, were investigated based on 4 fragments of the chloroplast genome. To cover the full distribution of R. dumulosa in China, 19 populations from 3 major disjunct distribution areas (northern, central, and northwestern China) were sampled. A total of 5881bp (after alignment) of chloroplast DNA (cpDNA) from 100 individuals were sequenced. The combined cpDNA data set yielded 36 haplotypes. The total genetic diversity of R. dumulosa was remarkably high (H T = 0.981). The interpopulation genetic differentiation was significantly large (F ST = 0.8537, P < 0.001), possibly due to the long-term isolation of the natural populations. N ST was significantly larger than G ST (P < 0.001), indicating the presence of phylogeographical structure among the R. dumulosa populations. We propose 2 migration steps to explain the current distribution of R. dumulosa in China. First, this species migrated from refugia in the Qinghai-Tibetan Plateau to northern areas via the intervening highlands when temperatures increased; second, the highland populations migrated toward the mountaintops when temperatures increased further because R. dumulosa is adapted to cold environments. During the second migration step, the common ancestral haplotypes may have been gradually lost.
Data from: A long PCR based approach for DNA enrichment prior to next-generation sequencing for systematic studies
Premise of the study: We present an alternative approach for molecular systematic studies that combines long PCR and next-generation sequencing (NGS). Our approach can be used to generate templates from any DNA source for NGS. Here we test our approach by amplifying complete chloroplast genomes and we present a set of 58 potentially universal primers for angiosperms to do so. Additionally, this approach is likely to be particularly useful for nuclear regions. Methods and Results: Chloroplast genomes of 30 species across angiosperms were amplified to test our approach. Amplification success varied depending on whether PCR conditions were optimized for a given taxon. To further test our approach, some amplicons were sequenced on an Illumina HiSeq 2000. Conclusions: Although here we tested this approach by sequencing plastomes, long PCR amplicons could be generated using DNA from any genome, expanding the possibilities of this approach for molecular systematic studies.
FIGURE 13 in Taxonomy of the African army ant Dorylus gribodoi Emery, 1892 (Hymenoptera, Formicidae) — new insights from DNA sequence data and morphology
FIGURE 13. Dorsal view of the hypopygium of the D. gribodoi queen (HAD 2.53 mm).
FIGURE 7 in Taxonomy of the African army ant Dorylus gribodoi Emery, 1892 (Hymenoptera, Formicidae) — new insights from DNA sequence data and morphology
FIGURE 7. Lateral view of the head of a large D. gribodoi worker (HW 2.79 mm), Taï, Ivory Coast.
FIGURE 6 in Taxonomy of the African army ant Dorylus gribodoi Emery, 1892 (Hymenoptera, Formicidae) — new insights from DNA sequence data and morphology
FIGURE 6. Lateral overview of a large D. emeryi worker from Taï, Ivory Coast.
FIGURE 4 in Taxonomy of the African army ant Dorylus gribodoi Emery, 1892 (Hymenoptera, Formicidae) — new insights from DNA sequence data and morphology
FIGURE 4. Dorylus gribodoi male: genital capsule and subgenital plate.
FIGURE 3 in Taxonomy of the African army ant Dorylus gribodoi Emery, 1892 (Hymenoptera, Formicidae) — new insights from DNA sequence data and morphology
FIGURE 3. Frontal view of the head of a Dorylus gribodoi male from Taï, Ivory Coast.
FIGURE 2 in Taxonomy of the African army ant Dorylus gribodoi Emery, 1892 (Hymenoptera, Formicidae) — new insights from DNA sequence data and morphology
FIGURE 2. Lateral overview of a Dorylus gribodoi male from Taï, Ivory Coast.
FIGURE 5 in Taxonomy of the African army ant Dorylus gribodoi Emery, 1892 (Hymenoptera, Formicidae) — new insights from DNA sequence data and morphology
FIGURE 5. Lateral overview of a large Dorylus gribodoi worker from Taï, Ivory Coast.
FIGURE 1 in Taxonomy of the African army ant Dorylus gribodoi Emery, 1892 (Hymenoptera, Formicidae) — new insights from DNA sequence data and morphology
FIGURE 1. Definition of the subgenital plate measurements.
FIGURE 11 in Taxonomy of the African army ant Dorylus gribodoi Emery, 1892 (Hymenoptera, Formicidae) — new insights from DNA sequence data and morphology
FIGURE 11. Lateral overview of the D. gribodoi queen collected from a nest at Lamto, Ivory Coast.
FIGURE 8 in Taxonomy of the African army ant Dorylus gribodoi Emery, 1892 (Hymenoptera, Formicidae) — new insights from DNA sequence data and morphology
FIGURE 8. Lateral view of the head of a large D. emeryi worker (HW 3.62 mm) from Taï, Ivory Coast.
FIGURE 43 in Stenelmis puberula Reitter (Coleoptera: Elmidae)-description of larva and its association with adults, using DNA sequences
FIGURE 43. Distributional records of Stenelmis puberula Reitter from Slovakia.
FIGURE 2 in The identity of the Javan Krait, Bungarus javanicus Kopstein, 1932 (Squamata: Elapidae): evidence from mitochondrial and nuclear DNA sequence analyses and morphology
FIGURE 2. Dorsal view of the type specimen of Bungarus javanicus (RMNH 9007). Photo by Ulrich Kuch.
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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)
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DANDI Archive for NWB datasets
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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.