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.
132
datasets available to search
ShareScore release 0.7.1
Dataset results
132 results for “eggshell”
Molecular exploration of fossil eggshell uncovers hidden lineage of giant extinct bird
<p>Madagascar's extinct elephant birds are the least studied of the ratites, yet in recent years have proven to be critical for understanding the evolution of all birds. With large spatio-temporal gaps in the fossil record and poor biomolecular preservation of skeletal specimens, the systematics of these flightless giants remains controversial. Here, we overcome these limitations using a comprehensive molecular analysis of 1000-year-old fossil eggshells to provide the first description of elephant bird phylogeography and reveal new insights into the ecology of the world's largest birds. High-throughput sequencing of 21 mitochondrial genomes from across Madagascar reveals genetic variation that is correlated with eggshell morphology, stable isotope composition, and geographic distribution. The elephant bird crown is dated to ca. 30 Mya during the Eocene-Oligocene, a period of marked global cooling when Madagascar's local palaeoclimate is estimated to have become less arid as the island moved northward. High levels of between-clade genetic variation argue for the reclassification of Mullerornis into a new family. Low levels of within-clade genetic variation are unexpected and suggest that there were only two elephant bird genera, with one species per genus existing in southern Madagascar during the Holocene. However, we reveal a newly discovered eggshell collection from Madagascar's far north that is phylogenetically, morphologically, and ecologically distinct, representing a unique lineage of <em>Aepyornis</em>. Furthermore, molecular dating estimates that divergence within <em>Aepyornis</em> coincides with the aridification of Madagascar during the early Pleistocene ca. 1.5 Ma, and is consistent with the fragmentation of populations in the highlands driving diversification, as well as the evolution of extreme gigantism over short timescales. Molecular analysis thus provides the first insight into elephant bird speciation, and we advocate for a revision of their taxonomy that integrates palaeogenomic and palaeoecological perspectives.</p>
Thicker eggshells are not predicted by host egg ejection behaviour in four species of Australian cuckoo
<p>Defences of hosts against brood parasitic cuckoos include detection and ejection of cuckoo eggs from the nest. Ejection behaviour often involves puncturing the cuckoo egg, which is predicted to drive the evolution of thicker eggshells in cuckoos that parasitise such hosts. Here we test this prediction in four Australian cuckoo species and their hosts, using Hall-effect magnetic-inference to directly estimate eggshell thickness in parasitised clutches. In Australia, hosts that build cup-shaped nests are generally adept at ejecting cuckoo eggs, whereas hosts that build dome-shaped nests mostly accept foreign eggs. We analysed two datasets: a small sample of hosts with known egg ejection rates and a broader sample of hosts where egg ejection behaviour was inferred based on nest type (dome or cup). Contrary to predictions, cuckoos that exploit dome-nesting hosts (acceptor hosts) had significantly thicker eggshells relative to their hosts than cuckoos that exploit cup-nesting hosts (ejector hosts). No difference in eggshell thicknesses was observed in the smaller sample of hosts with known egg ejection rates, probably due to lack of power. Overall cuckoo eggshell thickness did not deviate from the expected avian relationship between eggshell thickness and egg length estimated from 74 bird species. Our results do not support the hypothesis that thicker eggshells have evolved in response to host ejection behaviour in Australian cuckoos, but are consistent with the hypothesis that thicker eggshells have evolved to reduce the risk of breakage when eggs are dropped into dome nests.</p>
Heat-induced maternal effects shape avian eggshell traits and embryo development and phenotype at high incubation temperatures
<p>Phenotypic plasticity is an important avenue by which organisms may persist in the face of rapid environmental change. Environmental cues experienced by the mother can also influence the phenotype of offspring, a form of plasticity called maternal effects. Maternal effects can adaptively prepare offspring for the environmental conditions they will experience, however, their ability to buffer offspring against environmental stressors as embryos is understudied. Using captive zebra finches, we performed a maternal-offspring environmental match-mismatch experiment utilizing a 2x2x2 factorial design. Mothers were exposed to a mild heat conditioning (38 °C) or control (22 °C) treatment as juveniles, an acute high heat (42 °C) or control (22 °C) treatment as adults, then paired for breeding. The eggs produced by those females were incubated at a hyperthermic (38.5 °C) or optimal temperature (37.2 °C). We found that when mothers were exposed to a mild heat conditioning as juveniles, their embryos exhibited reduced water loss, longer development times, and produced hatchlings with heavier pectoralis muscles when incubated at high incubation temperatures, compared to embryos from control mothers. Mothers exposed to both the mild heat conditioning as juveniles and a high heat stressor as adults produced eggs with a higher density of shell pores, and embryos with lower heart rates during development. However, there was a cost when there was a mismatch between maternal and embryo environment. Embryos from these conditioned and heat-stressed mothers had reduced survival at control incubation temperatures, indicating the importance of offspring environment when interpreting potential adaptive effects.</p>
High within-clutch repeatability of eggshell phenotype in Barn Swallows (Hirundo rustica erythrogaster) despite less maculated last-laid eggs
Open the record for dataset details and reuse information.
Molecular exploration of fossil eggshell uncovers hidden lineage of giant extinct bird
Open the record for dataset details and reuse information.
Data from: Biogenic origin of secondary eggshell units in dinosaur eggshells elucidates lost biomineralization process in maniraptoran dinosaurs
Open the record for dataset details and reuse information.
Heat-induced maternal effects shape avian eggshell traits and embryo development and phenotype at high incubation temperatures
Open the record for dataset details and reuse information.
Microstructural and crystallographic evolution of palaeognath (Aves) eggshells
Open the record for dataset details and reuse information.
DNA sequence data generated using non-invasive feather and eggshell samples from the Grenada Dove for two gene regions: Cyt b and ND2
Open the record for dataset details and reuse information.
Thicker eggshells are not predicted by host egg ejection behaviour in four species of Australian cuckoo
Open the record for dataset details and reuse information.
Data from: The shape of avian eggs: assessment of a novel metric for quantifying eggshell conicality
Open the record for dataset details and reuse information.
Data from: Great spotted cuckoo eggshell microstructure characteristics can make eggs stronger
Obligate avian brood parasites lay stronger eggs than their hosts or non-parasitic relatives because they are rounder and have a thicker eggshell. Additionally, some other characteristics of the brood parasitic eggshells related to their microstructure such as size and orientation of calcite crystal units could also contribute to generating even stronger shells. An eggshell microstructure formed by small randomly oriented calcite crystal units can increase the robustness of the eggshells of birds. Here, the eggshell microstructure of avian brood parasites as well as their hosts have been characterized in detail, using X-ray diffraction analyses to estimate the size and degree of orientation of calcite crystal units making the eggshell. Specifically, the brood parasitic great spotted cuckoo (Clamator glandarius) and two hosts (jackdaws, Corvus monedula and magpie, Pica pica) and one non-host species (the pigeon, Columba livia domestica) were considered. Calcite crystal of the eggshell of the brood parasitic species was smaller and more randomly oriented than those of the eggshells of non-parasitic species, which suggest that eggshell microstructure would contribute to explain why parasitic eggs are more resistant to breakage than those of their hosts.
Genetic barcoding of museum eggshell improves data integrity of avian biological collections
<p>Natural history collections are often plagued by missing or inaccurate metadata for collection items, particularly for specimens that are difficult to verify or rare. Avian eggshell in particular can be challenging to identify due to extensive morphological ambiguity among taxa. Species identifications can be improved using DNA extracted from museum eggshell; however, the suitability of current methods for use on small museum eggshell specimens has not been rigorously tested, hindering uptake. In this study, we compare three sampling methodologies to genetically identify 45 data-poor eggshell specimens, including a putatively extinct bird's egg. Using an optimised drilling technique to retrieve eggshell powder, we demonstrate that sufficient DNA for molecular identification can be obtained from even the tiniest eggshells without significant alteration to the specimen's appearance or integrity. This method proved superior to swabbing the external surface or sampling the interior; however, we also show that these methods can be viable alternatives. We then applied our drilling method to confirm that a purported clutch of Paradise Parrot eggs collected 40 years after the species' accepted extinction date were falsely identified, laying to rest a 53-year-old ornithological controversy. Thus, even the smallest museum eggshells can offer new insights into old questions.</p>
Plumage and eggshell colouration covary with the level of sex-specific parental contributions to nest building in birds
<p>Interspecific variation in sex-specific contributions to prenatal parental care, including avian nest building, remain poorly understood. Here, we examined whether the colouration of the parents and of their eggs covary with sex-specific nest building contributions in 521 species of Western Palearctic birds. Having colourful plumages and laying colourful eggs are both costly because of the deposition of pigments (in feathers and eggs) and/or forming costly nanostructural substrates (in feathers), and so it is expected that those costs are traded-off against the costs of nest building. We therefore tested two predictions of this trade-off hypothesis, namely that species in which females alone build nests (1) exhibit sexual plumage dichromatism in that females are less colourful than males and (2) lay less colourful eggs. Using a phylogenetically-informed comparative approach, we found support for the first prediction so that species in which females build nests alone or together with males are more likely to be dichromatic in plumage. Meanwhile, regarding the second prediction, contrary to our expectation, we found that species in which females build nests alone or together with males are more likely to lay colourfully pigmented eggs relative to species in which only males build nests. This suggests that sex differences in plumage colouration and egg colouration covary in a complex manner with female pre-copulatory investment in reproduction at the interspecific level.</p>
Data from: Protoporphyrin-based eggshell pigmentation is associated with female plumage colouration and predicts offspring sex ratio in the barn swallow
Inter- and intraspecific variation in eggshell colouration has long fascinated evolutionary biologists. Among species, such variation may accomplish different functions, the most obvious of which is camouflage and background matching. Within species, it has been proposed that inter-female variation in eggshell pigmentation patterns can reflect egg, maternal or paternal traits and hence may provide cues to conspecifics about egg, maternal or paternal phenotypic quality. However, the relationship between protoporphyrin-based eggshell pigmentation and egg or maternal/paternal traits appears to be highly variable among species. We investigated patterns of intraspecific variation in Eurasian barn swallow (Hirundo r. rustica) protoporphyrin-based eggshell pigmentation, and analysed its association with egg and clutch characteristics, maternal/paternal phenotypic traits and parental feeding effort. Eggshell pigmentation pattern significantly varied between breeding colonies, was significantly repeatable in clutches laid by the same females in different years (intraclass correlation coefficient ranging between 0.56 and 0.63), but it was not significantly associated with egg traits, such as position in the laying sequence, egg mass, yolk testosterone concentration and antioxidant capacity. It was weakly or non-significantly associated with female and male traits (sexual ornaments), but females laying darker (higher pigment intensity) first clutches had higher hatching success, suggesting that eggshell pigment intensity may predict fitness. Nevertheless, males did not significantly modulate their parental nestling feeding effort accordingly. In addition, females with darker breast plumage colouration (a melanin-based trait related to fitness) laid highly protoporphyrin-covered eggs, suggesting the presence of a previously unappreciated link between protoporphyrin biosynthesis and plumage melanisation. Moreover, the proportion of male offspring increased in clutches originating from highly protoporphyrin-covered eggs, suggesting that parents could acquire visual cues about their future brood sex composition before egg hatching. Our results support the idea that intraspecific signalling via eggshell pigmentation is a species-specific rather than a general feature of avian taxa.
Data from: Eggshell biliverdin concentration does not sufficiently predict eggshell coloration
Avian eggshell coloration may have arisen due to selection on the biological, chemical, or physical properties of the pigments embedded within the eggshell, or due to selection on the coloration that emerges due to pigment deposition. Within both hypothetical frameworks, pigment-based eggshell coloration would be related to metrics of egg quality; however, no one has evaluated the relative strength of coloration and pigment concentration in predicting egg quality. Here, we examined 66 European starling Sturnus vulgaris eggs and quantified eggshell biliverdin concentration (an antioxidant that produces the eggshell's blue coloration) and used 28 different coloration metrics derived from both photographic and spectrophotometric data. We also measured egg size, eggshell thickness, concentration of carotenoids in the yolk, and concentration of lysozyme in the albumen to capture variation in egg quality. We found that throughout the laying sequence, biliverdin concentration increased while eggshell thickness, yolk carotenoid concentration, and lysozyme concentration in the albumen all decreased, but this variation was not captured by any eggshell coloration metric. Both eggshell coloration and biliverdin concentration were negatively associated with yolk carotenoid concentration, but only eggshell biliverdin concentration was negatively associated with yolk mass. Lastly, biliverdin concentration explained, at most, only 46% of the variation for all eggshell coloration metrics. Our results suggest biliverdin concentration is a better predictor of egg quality than egg coloration in European starlings, supporting the hypothesis that eggshell pigment concentration per se may be the target of selection.
Raw documents of data (eggshell project)
<p>Raw documents of data for eggshell project</p>
MALDI-TOF-MS spectra of archaeological eggshell in Central Asia
<p>Spectral data from archaeological eggshell fragments from four archaeological sites in Central Asia (Paykend, Afrasiab, Bash Tepa, Tashbulak and Burial Mound LCD-HA-K7). Samples were cleaned, bleached, demineralized with acid (HCl), followed by filtration, digestion with trypsin and peptide purification using C18 ZipTips. They were run on a Bruker autoflex MALDI-TOF-MS. MzXML raw data files are provided here along with a csv file providing information about the samples.</p>
Fig. 2 in Turicibacter bilis sp. nov., a novel bacterium isolated from the chicken eggshell and swine ileum
Fig. 2. Whole genome sequence phylogeny of MMM721T, ISU324, PIG517 and all publicly available genomes on the PATRIC genome database as of November 2020. The tree is rooted by Eggerthia catenaformis OT569. Only bootstrap values>50% are noted for branch nodes. The PATRIC genome IDs are noted in parentheses after the strain name.
Fig. 1 in Turicibacter bilis sp. nov., a novel bacterium isolated from the chicken eggshell and swine ileum
Fig. 1. (a) Transmission electron microscope image of MMM721T cells. Bar, 1 Μm. (b) Scanning electron microscope image of MMM721T cells. Bar, 2 Μm. Cells were cultured in BHIGL for 24 h at 42 °C prior to fixation and visualization.
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.