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Background STAMPEDE previously reported adding upfront docetaxel improved overall survival for prostate cancer patients starting long-term androgen deprivation therapy. We report long-term results for non-metastatic patients using, as primary outcome, metastatic progression-free survival (mPFS), an externally demonstrated surrogate for overall survival. Methods Standard of care (SOC) was androgen deprivation therapy with or without radical prostate radiotherapy. A total of 460 SOC and 230 SOC plus docetaxel were randomly assigned 2:1. Standard survival methods and intention to treat were used. Treatment effect estimates were summarized from adjusted Cox regression models, switching to restricted mean survival time if non-proportional hazards. mPFS (new metastases, skeletal-related events, or prostate cancer death) had 70% power (α = 0.05) for a hazard ratio (HR) of 0.70. Secondary outcome measures included overall survival, failure-free survival (FFS), and progression-free survival (PFS: mPFS, locoregional progression). Results Median follow-up was 6.5 years with 142 mPFS events on SOC (3 year and 54% increases over previous report). There was no good evidence of an advantage to SOC plus docetaxel on mPFS (HR = 0.89, 95% confidence interval [CI] = 0.66 to 1.19; P = .43); with 5-year mPFS 82% (95% CI = 78% to 87%) SOC plus docetaxel vs 77% (95% CI = 73% to 81%) SOC. Secondary outcomes showed evidence SOC plus docetaxel improved FFS (HR = 0.70, 95% CI = 0.55 to 0.88; P = .002) and PFS (nonproportional P = .03, restricted mean survival time difference = 5.8 months, 95% CI = 0.5 to 11.2; P = .03) but no good evidence of overall survival benefit (125 SOC deaths; HR = 0.88, 95% CI = 0.64 to 1.21; P = .44). There was no evidence SOC plus docetaxel increased late toxicity: post 1 year, 29% SOC and 30% SOC plus docetaxel grade 3-5 toxicity. Conclusions There is robust evidence that SOC plus docetaxel improved FFS and PFS (previously shown to increase quality-adjusted life-years), without excess late toxicity, which did not translate into benefit for longer-term outcomes. This may influence patient management in individual cases.

ObjectiveTo investigate if measured inequalities in cancer survival differ when using individual-based (‘person’) compared with area-based (‘place’) measures of deprivation for three socioeconomic dimensions: income, deprivation and occupation.DesignCohort study.SettingData from the Office for National Statistics Longitudinal Study of England and Wales, UK, linked to the National Cancer Registration Database.ParticipantsPatients diagnosed with cancers of the colorectum, breast, prostate, bladder or with non-Hodgkin’s lymphoma during the period 2008–2016.Primary and secondary outcome measuresDifferentials in net survival between groups defined by individual wage, occupation and education compared with those obtained from corresponding area-level metrics using the English and Welsh Indices of Multiple Deprivation.ResultsSurvival was negatively associated with area-based deprivation irrespective of the type analysed, although a trend from least to most deprived was not always observed. Socioeconomic differences were present according to individually-measured socioeconomic groups although there was an absence of a consistent ‘gradient’ in survival. The magnitude of differentials was similar for area-based and individually-derived measures of deprivation, which was unexpected.ConclusionThese unique data suggest that the socioeconomic influence of ‘person’ is different to that of ‘place’ with respect to cancer outcomes. This has implications for health policy aimed at reducing inequalities. Further research could consider the separate and additional influence of area-based deprivation over individual-level characteristics (contextual effects) as well as investigate the geographic, socioeconomic and healthcare-related characteristics of areas with poor outcomes in order to inform policy intervention.

The academic disciplines of Science, Technology, Engineering and Mathematics (STEM) have long suffered from a lack of diversity. While in recent years there has been some progress in addressing the underrepresentation of women in STEM subjects, other characteristics that have the potential to impact on equality of opportunity have received less attention. In this study, we surveyed 188 early career scientists (ECRs), defined as within 10 years of completing their PhD, in the fields of ecology, evolutionary biology, behaviour, and related disciplines. We examined associations between ethnicity, age, sexual orientation, sex, socioeconomic background, and disability, with measures of career progression, namely publication record, number of applications made before obtaining a postdoc, type of contract, and number of grant applications made. We also queried respondents on perceived barriers to progression and potential ways of overcoming them. Our key finding was that socioeconomic background and ethnicity were associated with measures of career progression. While there was no difference in the number of reported first‐authored papers on PhD completion, ethnic minority respondents reported fewer other‐authored papers. In addition, ECRs from a lower socioeconomic background were more likely to report being in teaching and research positions, rather than research‐only positions, the latter being perceived as more prestigious by some institutions. We discuss our findings in the context of possible inequality of opportunity. We hope that this study will stimulate wider discussion and help to inform strategies to address the underrepresentation of minority groups in the fields of ecology and evolution, and STEM subjects more widely., This study provides evidence that socioeconomic background and ethnicity can impact negatively on the career progression in early career researchers in the field of ecology and evolution.

Background Abiraterone acetate received licencing for use in only "high-risk" metastatic hormone-naive prostate cancer (mHNPC) following the LATITUDE trial findings. However, a "risk"-related effect was not seen in the STAMPEDE trial. There remains uncertainty as to whether men with LATITUDE "low-risk" M1 disease benefit from androgen deprivation therapy (ADT) combined with abiraterone acetate and prednisolone (AAP). Objective Evaluation of heterogeneity of effect between LATITUDE high- and low-risk M1 prostate cancer patients receiving ADT + AAP in the STAMPEDE trial. Design, setting, and participants A post hoc subgroup analysis of the 2017 STAMPEDE "abiraterone comparison". Staging scans for M1 patients contemporaneously randomised to ADT or ADT + AAP within the STAMPEDE trial were evaluated centrally and blind to treatment assignment. Stratification was by risk according to the criteria set out in the LATITUDE trial. Exploratory subgroup stratification incorporated the CHAARTED criteria. Outcome measurements and statistical analysis The primary outcome measure was overall survival (OS) and the secondary outcome measure was failure-free survival (FFS). Further exploratory analysis evaluated clinical skeletal-related events, progression-free survival (PFS), and prostate cancer-specific death. Standard Cox-regression and Kaplan-Meier survival estimates were employed for analysis. Results and limitations A total of 901 M1 STAMPEDE patients were evaluated after exclusions. Of the patients, 428 (48%) were identified as having a low risk and 473 (52%) a high risk. Patients receiving ADT + AAP had significantly improved OS (low-risk hazard ratio [HR]: 0.66, 95% confidence interval or CI [0.44–0.98]) and FFS (low-risk HR: 0.24, 95% CI [0.17–0.33]) compared with ADT alone. Heterogeneity of effect was not seen between low- and high-risk groups for OS or FFS. For OS benefit in low risk, the number needed to treat was four times greater than that for high risk. However, this was not observed for the other measured endpoints. Conclusions Men with mHNPC gain treatment benefit from ADT + AAP irrespective of risk stratification for "risk" or "volume". Patient summary Coadministration of abiraterone acetate and prednisolone with androgen deprivation therapy (ADT) is associated with prolonged overall survival and disease control, compared with ADT alone, in all men with metastatic disease starting hormone therapy for the first time.

People who live in more deprived areas have poorer health outcomes, and this inequality is a major driver of health and social policy. Many interventions targeting these disparities implicitly assume that poorer health is predominantly associated with area-level factors, and that these inequalities are the same for men and women. However, health differentials due to individual socio-economic status (SES) of men and women are less well documented. We used census data linked to the ONS Longitudinal Study to derive individual-level SES in terms of occupation, education and estimated wage, and examined differences in adult mortality and life expectancy. We modelled age-, sex- and SES-specific mortality using Poisson regression, and summarised mortality differences using life expectancy at age 20. We compared the results to those calculated using area-level deprivation metrics. Wide inequalities in life expectancy between SES groups were observed, although differences across SES groups were smaller for women than for men. The widest inequalities were found across men's education (7.2-year (95% CI: 3.0–10.1) difference in life expectancy between groups) and wage (7.0-year (95% CI: 3.5–9.8) difference), and women's education (5.4-year (95% CI: 2.2–8.1) difference). Men with no qualifications had the lowest life expectancy of all groups. In terms of the number of years' difference in life expectancy, the inequalities measured here with individual-level data were of a similar magnitude to inequalities identified previously using area-level deprivation metrics. These data show that health inequalities are as strongly related to individual SES as to area-level deprivation, highlighting the complementary usefulness of these different metrics. Indeed, poor outcomes are likely to be a product of both community and individual influences. Current policy which bases health spending decisions on evidence of inequalities between geographical areas may overlook individual-level SES inequalities for those living in affluent areas, as well as missing important sex differences., Highlights • Health policy to reduce inequalities targets individuals, although often based on area-level data. • We show wide inequalities in health outcomes using individual-level socio-economic data. • Individual-level inequalities are of a similar magnitude to those observed with area-level data. • We find important sex differences in inequalities which are undetectable in area-level analyses. • Both individual and area-level factors should be considered in policy aimed at reducing inequality.

ObjectivesMost research on health inequalities uses aggregated deprivation scores assigned to the small area where the patient lives; however, the concordance between aggregate area-level deprivation measures and personal deprivation experienced by individuals living in the area is poorly understood. Our objective was to examine the agreement between individual and ecological deprivation. We tested the concordance between metrics of income, occupation and education at individual and area levels, and assessed the reliability of area-based deprivation measures to predict individual deprivation circumstances.SettingEngland and Wales.ParticipantsA cancer patient cohort of 9547 individuals extracted from the Office for National Statistics Longitudinal Study.OutcomesWe quantified the concordance between measures of income, occupation and education at individual and area level. In addition, we used ROC (receiver operating characteristic) curves and the area under the curve (AUC) to assess the reliability of area-based deprivation measures to predict individual deprivation circumstances.ResultsWe found low concordance between individual-level and area-level indicators of deprivation (Cramer’s V statistics range between 0.07 and 0.20). The most commonly used indicator in health inequalities research, area-based income deprivation, was a poor predictor of individual income status (AUC between 0.56 and 0.59), whereas education and occupation were slightly better predictors (AUC between 0.62 and 0.65). The results were consistent across sexes and across six major cancer types.ConclusionsOur results indicate that ecological deprivation measures capture only part of the relationship between deprivation and health outcomes, especially with respect to income measurement. This has important implications for our understanding of the relationship between deprivation and health, and, as a consequence, healthcare policy. The results have a wide-reaching impact for the way in which we measure and monitor inequalities, and in turn, fund and organise current UK healthcare policy aimed at reducing them.

The expression of sexually dimorphic phenotypes from a shared genome between males and females is a longstanding puzzle in evolutionary biology. Increasingly, research has made use of transcriptomic technology to examine the molecular basis of sexual dimorphism through gene expression studies, but even this level of detail misses the metabolic processes that ultimately link gene expression with the whole organism phenotype. We use metabolic profi ling in Drosophila melanogaster to complete this missing step, with a view to examining variation in male and female metabolic profi les, or metabolomes, throughout development. We show that the metabolome varies considerably throughout larval, pupal and adult stages. We also fi nd signifi cant sexual dimorphism in the metabolome, although only in pupae and adults, and the extent of dimorphism increases throughout development. We compare this to transcriptomic data from the same population and fi nd that the general pattern of increasing sex differences throughout development is mirrored in RNA expression. We discuss our results in terms of the usefulness of metabolic profi ling in linking genotype and phenotype to more fully understand the basis of sexually dimorphic phenotypes.

The evolution of sexual dimorphism is constrained by a shared genome, leading to ‘sexual antagonism’, in which different alleles at given loci are favoured by selection in males and females. Despite its wide taxonomic incidence, we know little about the identity, genomic location, and evolutionary dynamics of antagonistic genetic variants. To address these deficits, we use sex-specific fitness data from 202 fully sequenced hemiclonal Drosophila melanogaster fly lines to perform a genome-wide association study (GWAS) of sexual antagonism. We identify approximately 230 chromosomal clusters of candidate antagonistic single nucleotide polymorphisms (SNPs). In contradiction to classic theory, we find no clear evidence that the X chromosome is a hot spot for sexually antagonistic variation. Characterising antagonistic SNPs functionally, we find a large excess of missense variants but little enrichment in terms of gene function. We also assess the evolutionary persistence of antagonistic variants by examining extant polymorphism in wild D. melanogaster populations and closely related species. Remarkably, antagonistic variants are associated with multiple signatures of balancing selection across the D. melanogaster distribution range and in their sister species D. simulans, indicating widespread and evolutionarily persistent (about 1 million years) genomic constraints on the evolution of sexual dimorphism. Based on our results, we propose that antagonistic variation accumulates because of constraints on the resolution of sexual conflict over protein coding sequences, thus contributing to the long-term maintenance of heritable fitness variation., This study characterises antagonistic loci across the genome of the fruit fly Drosophila melanogaster, finding them to be preferentially associated with variation in coding sequences and to be selectively maintained across worldwide populations of D. melanogaster, and even its sister species D. simulans.

Lay summaryIn the past decade the scientific community has been trying to tackle the historical underrepresentation of women in science and the fact that gender can constitute a barrier to career success. However, other characteristics, such as being of an ethnic minority or coming from an under-privileged background, have received less attention. In this study we find that ethnicity and socioeconomic status impact detrimentally on career progression in early career scientists, despite the fact that gender is more likely to be reported as a barrier. Our data suggest we need to widen the discussion regarding diversity and equality in science to incorporate potential barriers to career success in addition to gender.AbstractThe academic disciplines of Science Technology Engineering and Mathematics (STEM) have long suffered from a lack of diversity. While in recent years there has been some progress in addressing the underrepresentation of women in STEM subjects, other protected characteristics have received less attention. In this study, we survey early career scientists in the fields of ecology, evolutionary biology, behaviour, and related disciplines. We (i) quantitatively examine the effect of protected characteristics and their intersectionality on career transition, and (ii) provide practical suggestions, based on the qualitative responses of those surveyed, for overcoming some of the barriers we identified. We found that socioeconomic background and ethnicity impacted negatively on the quantitative measures of career progression we examined. Respondents that were female, LGBT, and from a lower socioeconomic background were more likely to report having faced a barrier, and the most frequent barrier named was related to gender. Our results suggest that respondents may have felt more confident discussing the experiences they have had related to their gender, potentially because there is now widespread discourse on this subject. However, respondents were less likely to discuss barriers they have faced in relation to ethnicity and socioeconomic status, despite the fact that the data indicates these are more detrimental to career progression. This may reflect the fact that these characteristics have received less attention, and are therefore deemed more sensitive. We hope that this study will stimulate wider discussion, and help to inform strategies to address the underrepresentation of minority groups in STEM subjects.

International audience; The microbiota is increasingly being recognized as having important impacts on many host biological processes. However, evidence of its effects on animal communication and breeding strategy is lacking. In this three-factorial study, we show that females were more willing to mate with related males, with relatedness likely being assessed through the microbiota. By contrast, male mating investment is concurrently determined by both the relatedness and microbiota status of the female. When the microbiota in female Drosophila melanogaster is altered by an antibiotic, male investment in sperm number increased when mating with unrelated females compared to related ones. Contrastingly, the presence of an intact microbiota in females canceled this male outbreeding strategy. As a consequence, the microbiota, when intact, decreased the fitness of the mating couple. Furthermore, we showed that female sexual signaling (cuticular hydrocarbons), with regards to kin recognition, significantly interacts with microbiota. Interestingly, the interaction is significant for hydrocarbons expressed by both sexes, but not for female-specific compounds. Taken together, our results suggest that microbiota can influence kin recognition by disfavoring male outbreeding strategies, likely by inhibiting key olfactory sexual signaling. This represents the first evidence of a host outbreeding strategy counteracted by their microbiota. © 2018 Heys, Lizé, Colinet, Price, Prescott, Ingleby and Lewis.

The evolution of sexual dimorphism is constrained by a shared genome, leading to ‘sexual antagonism’ where different alleles at given loci are favoured by selection in males and females. Despite its wide taxonomic incidence, we know little about the identity, genomic location and evolutionary dynamics of antagonistic genetic variants. To address these deficits, we use sex-specific fitness data from 202 fully sequenced hemiclonalD. melanogasterfly lines to perform a genome-wide association study of sexual antagonism. We identify ~230 chromosomal clusters of candidate antagonistic SNPs. In contradiction to classic theory, we find no clear evidence that the X chromosome is a hotspot for sexually antagonistic variation. Characterising antagonistic SNPs functionally, we find a large excess of missense variants but little enrichment in terms of gene function. We also assess the evolutionary persistence of antagonistic variants by examining extant polymorphism in wildD. melanogasterpopulations. Remarkably, antagonistic variants are associated with multiple signatures of balancing selection across theD. melanogasterdistribution range, indicating widespread and evolutionarily persistent (>10,000 years) genomic constraints. Based on our results, we propose that antagonistic variation accumulates due to constraints on the resolution of sexual conflict over protein coding sequences, thus contributing to the long-term maintenance of heritable fitness variation.

Males from different populations of the same species often differ in their sexually selected traits. Variation in sexually selected traits can be attributed to sexual selection if phenotypic divergence matches the direction of sexual selection gradients among populations. However, phenotypic divergence of sexually selected traits may also be influenced by other factors, such as natural selection and genetic constraints. Here, we document differences in male sexual traits among six introduced Australian populations of guppies and untangle the forces driving divergence in these sexually selected traits.\ud Using an experimental approach, we found that male size, area of orange coloration, number of sperm per ejaculate and linear sexual selection gradients for male traits differed among populations. Within populations, a large mismatch between the direction of selection and male traits suggests that constraints may be important in preventing male traits from evolving in the direction of selection. Among populations, however, variation in sexual selection explained more than half of the differences in trait variation, suggesting that, despite within-population constraints, sexual selection has contributed to population divergence of male traits. Differences in sexual traits\ud were also associated with predation risk and neutral genetic distance. Our study highlights the importance of sexual selection in trait divergence in introduced populations, despite the presence of constraining factors such as predation risk and evolutionary history.

Nuclear transfer techniques (a.k.a. mitochondrial replacement therapies) are currently under development to provide a route to eliminating particular instances of mitochondrial disease from the germline. Before these kinds of techniques are implemented clinically it is of primary concern that their safety and efficacy is established. In a recent paper, Hyslop et al (2016) utilized a specific version of pronuclear transfer (PNT) to investigate the consequences for gene expression in the developing embryo, which may indicate whether or not developmental pathways have been perturbed. However, the study was only able to include a small number of blastocysts within each treatment group, although a larger number of single cell expression profiles from each blastocyst were acquired. Using simulated datasets we show that the size and experimental design of this study cannot provide conclusive evidence that expression profiles of manipulated or control samples are indistinguishable from one another due to low power.

The expression of sexually dimorphic phenotypes from a shared genome between males and females is a longstanding puzzle in evolutionary biology. Increasingly, research has made use of transcriptomic technology to examine the molecular basis of sexual dimorphism through gene expression studies, but even this level of detail misses the metabolic processes that ultimately link gene expression with the whole organism phenotype. We use metabolic profiling in Drosophila melanogaster to complete this missing step, with a view to examining variation in male and female metabolic profiles, or metabolomes, throughout development. We show that the metabolome varies considerably throughout larval, pupal and adult stages. We also find significant sexual dimorphism in the metabolome, although only in pupae and adults, and the extent of dimorphism tends to increase throughout development. We compare this to transcriptomic data from the same population and find that the general pattern of increasing sex differences throughout development is mirrored in RNA expression. We discuss our results in terms of the usefulness of metabolic profiling in linking genotype and phenotype to more fully understand the basis of sexually dimorphic phenotypes.

Sexual signals can be used to attract mates, but to be honest indicators of signaller quality they need to convey information reliably. However, environmental variation and genotype-by-environment (G × E) interactions have the potential to compromise the reliability of sexual signals. Here, we test the reliability of cuticular hydrocarbons (CHCs) as signals of heritable aspects of male attractiveness in Drosophila simulans. We examined the heritability of male attractiveness and a measure of the difference between fathers' and sons' CHC profiles across dietary and temperature environments. Our results show that environmental heterogeneity disrupts the similarity of some components of father and son CHC profile. However, overall male attractiveness is heritable within and across environments, so that sire attractiveness is a good predictor of son attractiveness even with environmental heterogeneity. This suggests that although some male CHC signals are unreliable, attractive genotypes retain their attractiveness across environments on average.

Genotype-by-environment interactions (G × Es) describe genetic variation for phenotypic plasticity. Recent interest in the role of these interactions in sexual selection has identified G × Es across a diverse range of species and sexual traits. Additionally, theoretical work predicts that G × Es in sexual traits could help to maintain genetic variation, but could also disrupt the reliability of these traits as signals of mate quality. However, empirical tests of these theoretical predictions are scarce. We reared iso-female lines of Drosophila simulans across two axes of environmental variation (diet and temperature) in a fully factorial design and tested for G × Es in the expression of cuticular hydrocarbons (CHCs), a multivariate sexual trait in this species. We find sex-specific environmental, genetic and G × E effects on CHC expression, with G × Es for diet in both male and female CHC profile and a G × E for temperature in females. We also find some evidence for ecological crossover in these G × Es, and by quantifying variance components, genetic correlations and heritabilities, we show the potential for these G × Es to help maintain genetic variation and cause sexual signal unreliability in D. simulans CHC profiles.

Genotype-by-environment interactions (GxEs) in naturally selected traits have been extensively studied, but the impact of GxEs on sexual selection has only recently begun to receive attention. Here, we review recent models and consider how GxEs might affect the evolution of sexual traits through influencing sexual signal reliability and also how GxEs may influence variation in sexually selected traits and the process of reproductive isolation. We then assess the current empirical literature on GxEs in sexual selection and conclude by highlighting areas that need additional work. Research on GxEs and sexual selection is an important new area of study for the discipline, which has largely focused on relatively simple mate choice/competition scenarios to date. Investigators now need to apply this knowledge to more complex, but realistic, situations, to more fully explore the evolution of sexual traits, and in this review we suggest potentially useful directions for future research.

The risk and intensity of sperm competition can influence male adaptations that ultimately affect male fertilization success, for example investment in sperm production and strategic sperm allocation patterns. Previous studies have examined male behavioural responses to variation in immediate levels of sperm competition. Here we quantified the evolutionary responses of male adaptations resulting from long-term manipulation of the level of sperm competition. By varying the adult sex ratio of populations of the Indian meal moth, Plodia interpunctella, we successfully altered the frequency of male and female copulations, and thus the level of sperm competition experienced by males. As predicted by theory, males evolving under higher levels of sperm competition increased investment in sperm production and differed in their sperm allocation patterns across matings, compared to males evolving under intermediate and low levels of sperm competition. However, we found no evidence for trade-offs between ejaculate components, or between total sperm production and male body size in this species.

Sexual dimorphism is predicted to be constrained by the underlying genetic architecture shared between the sexes and through ontogeny, but whole-transcriptome data for both sexes across genotypes and developmental stages are lacking. Within a quantitative genetic framework, we sequenced RNA from Drosophila melanogaster at different developmental stages to examine sex-biased gene expression and how selection acts upon it. We found evidence that gene expression is constrained by both univariate and multivariate shared genetic variation between genes, sexes and developmental stages, but may be resolved by differential splicing. These results provide a comprehensive picture of how conflict over sexual dimorphism varies through development and clarifies the conditions under which it is predicted to evolve.

Sexual selection is responsible for the evolution of many elaborate traits, but sexual trait evolution could be influenced by opposing natural selection as well as genetic constraints. As such, the evolution of sexual traits could depend heavily on the environment if trait expression and attractiveness vary between environments. Here, male Drosophila simulans were reared across a range of diets and temperatures, and we examined differences between these environments in terms of (i) the expression of male cuticular hydrocarbons (CHCs) and (ii) which male CHC profiles were most attractive to females. Temperature had a strong effect on male CHC expression, whereas the effect of diet was weaker. Male CHCs were subject to complex patterns of directional, quadratic and correlational sexual selection, and we found differences between environments in the combination of male CHCs that were most attractive to females, with clearer differences between diets than between temperatures. We also show that genetic covariance between environments is likely to cause a constraint on independent CHC evolution between environments. Our results demonstrate that even across the narrow range of environmental variation studied here, predicting the outcome of sexual selection can be extremely complicated, suggesting that studies ignoring multiple traits or environments may provide an over-simplified view of the evolution of sexual traits.

Males and females share much of their genome, and as a result, intralocus sexual conflict is generated when selection on a shared trait differs between the sexes. This conflict can be partially or entirely resolved via the evolution of sex-specific genetic variation that allows each sex to approach, or possibly achieve, its optimum phenotype, thereby generating sexual dimorphism. However, shared genetic variation between the sexes can impose constraints on the independent expression of a shared trait in males and females, hindering the evolution of sexual dimorphism. Here, we examine genetic constraints on the evolution of sexual dimorphism in Drosophila melanogaster cuticular hydrocarbon (CHC) expression. We use the extended G matrix, which includes the between-sex genetic covariances that constitute the B matrix, to compare genetic constraints on two sets of CHC traits that differ in the extent of their sexual dimorphism. We find significant genetic constraints on the evolution of further dimorphism in the least dimorphic traits, but no such constraints for the most dimorphic traits. We also show that the genetic constraints on the least dimorphic CHCs are asymmetrical between the sexes. Our results suggest that there is evidence both for resolved and ongoing sexual conflict in D. melanogaster CHC profiles.

Recent research has highlighted the potential importance of environmental and genotype-by-environment (G×E) variation in sexual selection, but most studies have focussed on the expression of male sexual traits. Consequently, our understanding of genetic variation for plasticity in female mate choice is extremely poor. In this study we examine the genetics of female mate choice in Drosophila simulans using isolines reared across two post-eclosion temperatures. There was evidence for G×Es in female choosiness and preference, which suggests that the evolution of female mate choice behaviour could differ across environments. However, the ranked order of preferred males was consistent across females and environments, so the same males are favoured by mate choice in spite of G×Es. Our study highlights the importance of taking cross-environment perspectives in order to gain a more comprehensive understanding of the operation of sexual selection.

Sex-biased gene expression is likely to account for most sexually dimorphic traits because males and females share much of their genome. When fitness optima differ between sexes for a shared trait, sexual dimorphism can allow each sex to express their optimum trait phenotype, and in this way, the evolution of sex-biased gene expression is one mechanism that could help to resolve intralocus sexual conflict. Genome-wide patterns of sex-biased gene expression have been identified in a number of studies, which we review here. However, very little is known about how sex-biased gene expression relates to sex-specific fitness and about how sex-biased gene expression and conflict vary throughout development or across different genotypes, populations, and environments. We discuss the importance of these neglected areas of research and use data from a small-scale experiment on sex-specific expression of genes throughout development to highlight potentially interesting avenues for future research.