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.
72
datasets available to search
ShareScore release 0.9.0
Dataset results
72 results for “sex reversal”
Data from: Variation in nuptial colour in relation to sex, individual quality and mating success in the sex-role reversed red phalarope (Phalaropus fulicarius)
<p>In most bird species, males are more ornamented and compete for females, who contribute more to offspring care. In a minority of species this pattern is reversed, with more colourful females competing for mates and males taking care of parental duties. In such sex-role reversed species, the links between colourful ornamentation, individual quality and mating success are not well established. The red phalarope (<em>Phalaropus fulicarius</em>) is a colourful sex-role reversed migratory shorebird with regular social polyandry, in which both sexes show considerable colour variation. Here, we describe sex differences in colour and quantify associations between colour variation and indicators of quality and mating success in both sexes. Using a large sample of photos collected across three consecutive years on the Arctic breeding grounds, we scored colour variation for four body parts (bill, crown, cheek and breast), and analysed scores separately and combined into an overall colour score. Females were more colourful and larger than males, and individuals could be unambiguously sexed by crown colour. Nevertheless, there was substantial variation within sexes and some overlap between males and females in bill, cheek, breast, and overall colour scores. Assortative mating by colour was only found for the bill. Colour variation did not correlate with plasma testosterone levels, except for male cheek colour. Females in better body condition had yellower bills and higher overall colour scores, while early-arriving birds had higher breast and overall scores. Phalaropes that bred locally were heavier than those that did not, but they did not have higher colour scores. Female colour variation did not predict the probability of local social polyandry nor variation in clutch size, and male coloration did not predict the probability of nest predation. In conclusion, phalarope colour variation showed modest correlations with individual quality and was unrelated to variation in local reproductive success. </p>
Data from: Evolutionary divergence via sexual selection acting on females in a species with sex role reversal
<p>1. There is much evidence that sexual selection drives the evolutionary divergence of male sexual traits, but little is known of females.</p> <p>2. Comparisons between neutral genetic divergence (FST) and phenotypic divergence (PST) among populations can reveal evolutionary responses to selection.</p> <p>3. In the bushcricket <em>Kawanaphila nartee</em>, changes in floral food availability cause sex roles to shift from competitive females and choosy males to choosy females and competitive males midway through the breeding season. Males call to attract females, and female auditory spiracle size is under sexual selection. We ask whether selection on females can drive an evolutionary divergence in auditory spiracle size among populations.</p> <p>4. We sampled 188 individuals from nine geographic locations and analysed 9,478 neutral SNP loci and two phenotypic characters to estimate FST and PST, respectively.</p> <p>5. We found that PST for female auditory spiracle size far exceeded the global FST, suggesting that female auditory spiracle size is subject to strong directional selection. We relate differences in phenotypic traits to differences in geological and floristic characteristics among the sites.</p> <p>6. Our data suggest that variation in sexual selection driven by variation in the floristic community on which this species feeds may contribute to the strength of directional selection acting on female <em>K. nartee</em> among populations.</p> <p>7. Together, these findings indicate that divergence among populations can be driven by sexual selection acting on females, even when that selection is temporary and circumscribed.</p>
Data from: Population genomics reveals multiple drivers of population differentiation in a sex-role-reversed pipefish
Open the record for dataset details and reuse information.
Sex-role-reversal and the Bateman gradient in coucals – females benefit from mating with multiple partners
Open the record for dataset details and reuse information.
Data from: Evolutionary stability inferred for a free ranging lizard with sex-reversal
Open the record for dataset details and reuse information.
Data from: Evolutionary divergence via sexual selection acting on females in a species with sex role reversal
Open the record for dataset details and reuse information.
Data from: Variation in nuptial colour in relation to sex, individual quality and mating success in the sex-role reversed red phalarope (Phalaropus fulicarius)
Open the record for dataset details and reuse information.
High elevation increases the risk of Y chromosome loss in Alpine skink populations with sex reversal
<p>The view genotypic sex determination (GSD) and environmental sex determination (ESD) are mutually exclusive states has been contradicted by the discovery that chromosomal sex and environmental influences can co-exist within the same species, hinting at a continuum of intermediate states. Systems where genes and the environment interact to determine sex present the opportunity for sex reversal to occur, where the phenotypic sex is the opposite of that predicted by their sex chromosome complement. The skink Bassiana duperreyi has XX:XY sex chromosomes with sex reversal of the XX genotype to a male phenotype in response to exposure to cold incubation temperatures. Here we studied the frequency of sex reversal in B. duperreyi in response to climatic variation, using elevation as a surrogate for environmental temperatures. We demonstrate sex reversal for the first time in free-ranging adults of a reptile species with XX/XY sex determination. The highest frequency of sex reversal occurred at the highest elevation location, Mount Ginini (18.64%) and decreases in frequency with elevation. We model the impact of this under Fisher's frequency dependent selection to show that, only at the highest elevations, populations risk the loss of the Y chromosome and a transition to TSD. This study contributes to our understanding of the risks of extinction from climate change in species subject to sex reversal by temperature, and will provide focus for future research to test on-the-ground management strategies to mitigate the effects of climate in local populations.</p> <div> <div> <div class="msocomtxt"> <p class="MsoCommentText"> </p> </div> </div> </div>
Data from: Androgen-armoured amazons – reversed sex roles in coucals are associated with testosterone in females but not males
<p class="MsoNormal">In some species, sexual selection is stronger in females than males. In classically polyandrous birds, for instance, females compete for mating opportunities and males care for offspring. Sex steroids such as testosterone have been suggested to regulate the behaviours of 'role-reversed' females and males, but comparative studies did not find evidence for a role of testosterone in relation to sex roles. However, the large variability of hormone measurements across laboratories may prevent detecting subtle differences in hormone levels. To circumvent this caveat, I compared sex steroid concentrations of females and males of two closely related and cohabiting species with different mating systems, the classically polyandrous black coucal (<em>Centropus grillii</em>) and the monogamous white-browed coucal (<em>C. superciliosus</em>). Baseline and GnRH-induced testosterone concentrations were twice as high in female black coucals than female white-browed coucals, and the low pre-breeding progesterone concentrations of female black coucals were consistent with progesterone's modulatory role during agonistic interactions in this species. Baseline and GnRH-induced testosterone and progesterone concentrations did not differ between males of both species. This study provides first evidence that elevated testosterone is associated with sex-role reversed traits in females, whereas low levels of testosterone may not be necessary to facilitate sex-role reversal in males.</p>
Data from: Mate quality and the temporal dynamics of breeding in a sex-role-reversed pipefish, S. typhle
Open the record for dataset details and reuse information.
High elevation increases the risk of Y chromosome loss in Alpine skink populations with sex reversal
Open the record for dataset details and reuse information.
Data from: Prevalence and implications of sex reversal in free-living birds
Open the record for dataset details and reuse information.
Data from: Androgen-armoured amazons – reversed sex roles in coucals are associated with testosterone in females but not males
Open the record for dataset details and reuse information.
Data from: Differential introgression of a female competitive trait in a hybrid zone between sex-role reversed species
Open the record for dataset details and reuse information.
Data from: Partner cues and individual variation underlie sex-reversed parental care in poison frogs
Open the record for dataset details and reuse information.
Data from: The effects of synthetic estrogen exposure on pre-mating and post-mating episodes of selection in sex-role-reversed Gulf pipefish
Environmental estrogens have been shown to affect populations of aquatic organisms in devastating ways, including feminization of males, alterations in mating behaviors, and disruption of sexual selection. Studies have shown 17α-ethinylestradiol (EE2) exposure to induce female-like secondary sexual traits in male Gulf pipefish, changing how females perceive affected males. We aimed to understand the effects of EE2 exposure on the sex-role-reversed mating system and the strength of selection in Gulf pipefish. We used artificial Gulf pipefish breeding aggregations and microsatellite-based parentage analysis to determine maternity. We then calculated the opportunity for selection and selection differentials on body size for both sexes during three consecutive episodes of selection. Exposure to EE2 did not affect the strength of selection, likely due to the unusual sex-role-reversed mating system found in this species. With respect to multiply mated females, EE2 exposed females produced more eggs with higher embryo survivorship than non-exposed females. Thus, short-term exposure to low concentrations (2.0 ng/L) of EE2 in Gulf pipefish enhanced female reproductive success. However, higher EE2 concentrations (5.0 ng/L) caused complete reproductive failure in Gulf pipefish males. These results call for more work on the long-term effects of EE2 exposure in Gulf pipefish in artificial and natural populations.
Data from: Female ornamentation and the fecundity trade-off in a sex-role reversed pipefish
Sexual ornaments found only in females are a rare occurrence in nature. One explanation for this is that female ornaments are costly to produce and maintain and, therefore, females must trade-off resources related to reproduction to promote ornament expression. Here, we investigate whether a trade-off exists between female ornamentation and fecundity in the sex-role reversed, wide-bodied pipefish, Stigmatopora nigra. We measured two components of the disk-shaped, ventral-striped female ornament, body width and stripe thickness. After controlling for the influence of body size, we found no evidence of a cost of belly width or stripe thickness on female fecundity. Rather, females that have larger ornaments have higher fecundity and thus accurately advertise their reproductive value to males without incurring a cost to fecundity. We also investigated the relationship between female body size and egg size and found that larger females suffered a slight decrease in egg size and fecundity, although this decrease was independent of female ornamentation. More broadly, considered in light of similar findings in other taxa, lack of an apparent fecundity cost of ornamentation in female pipefish underscores the need to revisit theoretical assumptions concerning the evolution of female ornamentation.
Data from: Individual heterogeneity determines sex differences in mortality in a monogamous bird with reversed sexual dimorphism
Sex differences in mortality are pervasive in vertebrates, and usually result in shorter life spans in the larger sex, although the underlying mechanisms are still unclear. On the other hand, differences in frailty among individuals (i.e. individual heterogeneity), can play a major role in shaping demographic trajectories in wild populations. The link between these two processes has seldom been explored. We used Bayesian survival trajectory analysis to study age-specific mortality trajectories in the Eurasian sparrowhawk (Accipiter nisus), a monogamous raptor with reversed sexual size dimorphism. We tested the effect of individual heterogeneity on age-specific mortality, and the extent by which this heterogeneity was determined by average reproductive output and wing length as measures of an individual's frailty. We found that sex differences in age-specific mortality were primarily driven by the differences in individual heterogeneity between the two sexes. Females were more heterogeneous than males in their level of frailty. Thus, a larger number of females with low frailty are able to survive to older ages than males, with life expectancy for the least frail adult females reaching up to 4·23 years, while for the least frail adult males it was of 2·68 years. We found that 50% of this heterogeneity was determined by average reproductive output and wing length in both sexes. For both, individuals with high average reproductive output had also higher chances to survive. However, the effect of wing length was different between the two sexes. While larger females had higher survival, larger males had lower chances to survive. Our results contribute a novel perspective to the ongoing debate about the mechanisms that drive sex differences in vital rates in vertebrates. Although we found that variables that relate to the cost of reproduction and sexual dimorphism are at least partially involved in determining these sex differences, it is through their effect on the level of frailty that they affect age patterns of mortality. Therefore, our results raise the possibility that observed differences in age-specific demographic rates may in fact be driven by differences in individual heterogeneity.
Data from: The contributions of premating and postmating selection episodes to total selection in sex-role-reversed Gulf pipefish
Empirical studies of sexual selection often focus on events occurring either before or after mating but rarely both and consequently may fail to discern the relative magnitudes and interactions of premating and postmating episodes of selection. Here, we simultaneously quantify premating and postmating selection in the sex-role-reversed Gulf pipefish by using a microsatellite-based analysis of parentage in experimental populations. Female pipefish exhibited an opportunity for selection (I) of 1.64, which was higher than that of males (0.35). Decompositions of I and the selection differential on body size showed that over 95% of the selection on females arose from the premating phase. We also found evidence for a trade-off between selection phases, where multiply mating females had significantly lower offspring survivorship compared to singly mated females. In males, variance in relative fitness arose mainly from the number of eggs received per copulation and a small number of males who failed to mate. Overall, our study exemplifies a general approach for the decomposition of total selection into premating and postmating phases to understand the interplay among components of natural and sexual selection that conspire to shape sexually selected traits.
Climate change, sex reversal, and lability of sex determining systems
Sex reversal at high temperatures during embryonic development (e.g. ZZ females) provides the opportunity for new genotypic crosses (e.g. ZZ male x ZZ female). This raises the alarming possibility that climatic warming could lead to the loss of an entire chromosome – one member of the sex chromosome pair (the Y or W) – and the transition of populations to environmental sex determination (ESD). Here we examine the evolutionary dynamics of sex-determining systems exposed to climatic warming using theoretical models. We found that the loss of sex chromosomes is not an inevitable consequence of sex reversal. A large frequency of ZZ sex reversal (50% reversal from male to female) typically divides the outcome between loss of the ZW genotype and the stable persistence of ZZ males, ZW females, and ZZ females. The amount of warming associated with sex chromosome loss depended on several features of wild populations – environmental fluctuation, immigration, heritable variation in temperature sensitivity, and differential fecundity of sex-reversed individuals. Chromosome loss was partially or completely buffered when sex-reversed individuals suffered a reproductive fitness cost, when immigration occurred, or when heritable variation for temperature sensitivity existed. Thus, under certain circumstances, sex chromosomes may persist cryptically in systems where the environment is the predominant influence on sex.
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.