scholarly journals Sexual antagonism drives the displacement of polymorphism across gene regulatory cascades

2018 ◽  
Author(s):  
Mark Hill ◽  
Max Reuter ◽  
Alexander J. Stewart
Keyword(s):  
Sexual Dimorphism ◽  
Evolutionary Dynamics ◽  
Sexual Antagonism ◽  
Antagonistic Selection ◽  
Regulatory Cascade ◽  
Regulatory Architecture ◽  
Regulatory Cascades ◽  
Males And Females ◽  
Intermediate Expression ◽  
Upstream Regulators

Males and females have different reproductive roles and are often subject to contrasting selection pressures. This sexual antagonism can lead, at a given locus, to different alleles being favoured in each sex and, consequently, to genetic variation being maintained in a population. Although the presence of antagonistic polymorphisms has been documented across a range of species, their evolutionary dynamics remain poorly understood. Here we study antagonistic selection on gene expression, which is fundamental to sexual dimorphism, via the evolution of regulatory binding sites. We show that for sites longer than 1 nucleotide, polymorphism is maintained only when intermediate expression levels are deleterious to both sexes. We then show that, in a regulatory cascade, polymorphism tends to become displaced over evolutionary time from the target of antagonistic selection to upstream regulators. Our results have consequences for understanding the evolution of sexual dimorphism, and provide specific empirical predictions for the regulatory architecture of genes under antagonistic selection

scholarly journals Sexual antagonism drives the displacement of polymorphism across gene regulatory cascades

2019 ◽  
Vol 286 (1904) ◽  
pp. 20190660 ◽  
Author(s):  
Mark S. Hill ◽  
Max Reuter ◽  
Alexander J. Stewart
Keyword(s):  
Sexual Dimorphism ◽  
Evolutionary Dynamics ◽  
Sexual Antagonism ◽  
Regulatory Cascade ◽  
Regulatory Architecture ◽  
Regulatory Cascades ◽  
Males And Females ◽  
Intermediate Expression ◽  
Upstream Regulators ◽  
Expression Polymorphism

Males and females have different reproductive roles and are often subject to contrasting selection pressures. This sexual antagonism can lead, at a given locus, to different alleles being favoured in each sex and, consequently, to genetic variation being maintained in a population. Although the presence of sexually antagonistic (SA) polymorphisms has been documented across a range of species, their evolutionary dynamics remain poorly understood. Here, we study SA selection on gene expression, which is fundamental to sexual dimorphism, via the evolution of regulatory binding sites. We show that for sites longer than 1 nucleotide, expression polymorphism is maintained only when intermediate expression levels are deleterious to both sexes. We then show that, in a regulatory cascade, expression polymorphism tends to become displaced over evolutionary time from the target of SA selection to upstream regulators. Our results have consequences for understanding the evolution of sexual dimorphism, and provide specific empirical predictions for the regulatory architecture of genes under SA selection.

scholarly journals Genome-wide sexually antagonistic variants reveal longstanding constraints on sexual dimorphism in the fruitfly

2017 ◽  
Author(s):  
Filip Ruzicka ◽  
Mark S. Hill ◽  
Tanya M. Pennell ◽  
Ilona Flis ◽  
Fiona C. Ingleby ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Evolutionary Dynamics ◽  
Genome Wide Association Study ◽  
Balancing Selection ◽  
Sexual Antagonism ◽  
Protein Coding ◽  
Genome Wide ◽  
Genomic Location ◽  
Classic Theory ◽  
A Genome

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 hemiclonal D. melanogaster fly 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 wild D. melanogaster populations. Remarkably, antagonistic variants are associated with multiple signatures of balancing selection across the D. melanogaster distribution 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.

scholarly journals Stable linkage disequilibrium owing to sexual antagonism

2010 ◽  
Vol 278 (1707) ◽  
pp. 855-862 ◽  
Author(s):  
Francisco Úbeda ◽  
David Haig ◽  
Manus M. Patten
Keyword(s):  
Linkage Disequilibrium ◽  
Genomic Structure ◽  
Natural Populations ◽  
Allele Frequencies ◽  
Population Subdivision ◽  
Sexual Antagonism ◽  
Antagonistic Selection ◽  
Sexually Antagonistic Selection ◽  
Males And Females ◽  
Frequent Observation

Linkage disequilibrium (LD) is an association between genetic loci that is typically transient. Here, we identify a previously overlooked cause of stable LD that may be pervasive: sexual antagonism. This form of selection produces unequal allele frequencies in males and females each generation, which upon admixture at fertilization give rise to an excess of haplotypes that couple male-beneficial with male-beneficial and female-beneficial with female-beneficial alleles. Under sexual antagonism, LD is obtained for all recombination frequencies in the absence of epistasis. The extent of LD is highest at low recombination and for stronger selection. We provide a partition of the total LD into distinct components and compare our result for sexual antagonism with Li and Nei's model of LD owing to population subdivision. Given the frequent observation of sexually antagonistic selection in natural populations and the number of traits that are often involved, these results suggest a major contribution of sexual antagonism to genomic structure.

scholarly journals The genetic architecture of sexual dimorphism in the mossCeratodon purpureus

2021 ◽  
Vol 288 (1946) ◽  
pp. 20202908
Author(s):  
Leslie M. Kollar ◽  
Scott Kiel ◽  
Ashley J. James ◽  
Cody T. Carnley ◽  
Danielle N. Scola ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Evolutionary Biology ◽  
Genetic Architecture ◽  
Genetic Correlations ◽  
Natural Populations ◽  
Sexual Antagonism ◽  
Antagonistic Selection ◽  
Genetic Constraints ◽  
Sexually Antagonistic Selection ◽  
The Cross

A central problem in evolutionary biology is to identify the forces that maintain genetic variation for fitness in natural populations. Sexual antagonism, in which selection favours different variants in males and females, can slow the transit of a polymorphism through a population or can actively maintain fitness variation. The amount of sexually antagonistic variation to be expected depends in part on the genetic architecture of sexual dimorphism, about which we know relatively little. Here, we used a multivariate quantitative genetic approach to examine the genetic architecture of sexual dimorphism in a scent-based fertilization syndrome of the mossCeratodon purpureus.We found sexual dimorphism in numerous traits, consistent with a history of sexually antagonistic selection. The cross-sex genetic correlations (rmf) were generally heterogeneous with many values indistinguishable from zero, which typically suggests that genetic constraints do not limit the response to sexually antagonistic selection. However, we detected no differentiation between the female- and male-specific trait (co)variance matrices (GfandGm, respectively), meaning the evolution of sexual dimorphism may be constrained. The cross-sex cross-trait covariance matrixBcontained both symmetric and asymmetric elements, indicating that the response to sexually antagonistic or sexually concordant selection, and the constraint to sexual dimorphism, are highly dependent on the traits experiencing selection. The patterns of genetic variances and covariances among these fitness components is consistent with partly sex-specific genetic architectures having evolved in order to partially resolve multivariate genetic constraints (i.e. sexual conflict), enabling the sexes to evolve towards their sex-specific multivariate trait optima.

Observation on the breeding biology of Polypedates teraiensis (Dubois, 1987) (Amphibia: Rhacophoridae)

2017 ◽  
Vol 17 (1) ◽  
pp. 25-32
Author(s):  
Jacinta Lalchhanhimi ◽  
Lalremsanga H.T.
Keyword(s):  
Sexual Dimorphism ◽  
Breeding Season ◽  
Sound Production ◽  
Reproductive Function ◽  
Breeding Biology ◽  
Tree Frog ◽  
University Campus ◽  
Morphometric Measurements ◽  
Advertisement Calls ◽  
Males And Females

The breeding biology of tree frog, Polypedates teraiensis was studied during the breeding season at Mizoram University Campus. It was found that sound production by male during the breeding season was primarily a reproductive function and advertisement calls attract females to the breeding areas and announce other males that a given territory is occupied. The aim of this study was to provide the detailed information on the breeding behaviour and the advertisement calls of Polypedates teraiensis. The morphometric measurements of the amplecting pairs (males and females) for sexual dimorphism along with clutch sizes were also studied.

Sexual Dimorphism among the Kathmandu University Students Assessed by Anthropometric Studies

2018 ◽  
Vol 9 (05) ◽  
pp. 20469-20472
Author(s):  
Shakya R ◽  
Bhattacharya SC ◽  
Shrestha R
Keyword(s):  
Young Adults ◽  
Sexual Dimorphism ◽  
Young Adult ◽  
University Students ◽  
Plastic Surgery ◽  
Age Group ◽  
Adult Age ◽  
Clinically Normal ◽  
Crime Detection ◽  
Males And Females

Objectives: To observe the sexual dimorphism among the young adult age group ranging from 18-21 years, of Kathmandu University students by measuring craniofacial circumference and canthal distances. Rationale of the study: These data could be useful for establishing the craniofacial standards and adds an implementation on plastic surgery, crime detection as well as in the industrial field. Method: 300 clinically normal students of Kathmandu University aged between 18-21 years were examined for the study. Fronto-occipital circumference, outer and inner canthal distances were measured. All the parameters were compared between males and females. Result: The cranial circumference as well as the inner and outer canthal distance in males was found to be significantly higher as compared to the females. Conclusion: The results concluded that sexual dimorphism remarkably exists in young adults of Kathmandu University students.

scholarly journals Sexual dimorphism in the long-term stability (10 years) of skeletal Class III treatment

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Natalia Tejedor ◽  
Conchita Martín ◽  
José Antonio Alarcón ◽  
María Dolores Oteo-Calatayud ◽  
Juan Carlos Palma-Fernández
Keyword(s):  
Sexual Dimorphism ◽  
Class Iii ◽  
Class Iii Malocclusion ◽  
Skeletal Class ◽  
Term Stability ◽  
Long Term Stability ◽  
Fixed Appliances ◽  
Males And Females ◽  
Class Iii Treatment

Abstract Background Class III malocclusion is associated with high sexual dimorphism, especially in individuals older than 13 years of age, with significant differences in growth between males and females during the pubertal and postpubertal stages, and in adulthood. The aim of this research was to examine differences between males and females in long-term stability (10 years) of treatment for skeletal Class III malocclusion. Methods Thirty patients (15 males and 15 females) with skeletal Class III malocclusion, who had been treated with rapid maxillary expansion (RME) combined with face mask protraction followed by fixed appliances, were selected sequentially. Thirty patients (15 males and 15 females) with skeletal Class I and mesofacial patterns treated only with fixed appliances for dental problems served as the control group. Differences between groups and sexes were evaluated using lateral cephalograms taken at the start of treatment (T0), immediately after the end of treatment (T1), and after 10 years (T2). The long-term treatment success rate was calculated. Results Ten years after Class III treatment, overjet and overbite relapse occurred similarly in females (− 0.68 ± 0.7 mm; − 0.38 ± 0.75 mm, respectively) and males (− 1.09 ± 1.47 mm; − 0.64 ± 0.9 mm, respectively); the ANB angle and Wits appraisal became significantly more negative in males (− 1.37 ± 1.06°; − 2.7 ± 2.53 mm) than in females (− 0.18 ± 1.26°; − 0.46 ± 1.94 mm). The success rate was 73.3% in males and 80% in females. Conclusions Significant differences in the long-term stability of Class III treatment outcomes have been found between males and females, with a larger skeletal Class III relapse and lower long-term success rates in males.

scholarly journals Safe sex: male–female coalitions and pre-copulatory mate-guarding in a fiddler crab

2009 ◽  
Vol 6 (2) ◽  
pp. 180-182 ◽  
Author(s):  
Richard N. C. Milner ◽  
Michael D. Jennions ◽  
Patricia R. Y. Backwell
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Success ◽  
Observational Data ◽  
Fiddler Crab ◽  
Lower Boundary ◽  
Mate Guarding ◽  
Maintenance Costs ◽  
Boundary Maintenance ◽  
Uca Annulipes ◽  
Males And Females

In fiddler crabs both males and females defend territories that are essential for survival. Given pronounced sexual dimorphism in weaponry, how do weaponless females defend their territory from well-armed males? Using observational data and two simple experiments, we test whether male Uca annulipes protect their female neighbours from conspecific intruders. We show that males defend their female neighbours against male but not female intruders. We also show that females sometimes mate with their immediate neighbours. Male defence of female neighbours appears to represent both pre-copulatory mate-guarding and a territorial coalition. Males who ensure that their neighbour remains female could benefit through increased opportunity for future reproductive success and lower boundary maintenance costs.

Sex differences in white adipose tissue expansion: emerging molecular mechanisms

2021 ◽  
Vol 135 (24) ◽  
pp. 2691-2708
Author(s):  
Simon T. Bond ◽  
Anna C. Calkin ◽  
Brian G. Drew
Keyword(s):  
Sex Differences ◽  
Sexual Dimorphism ◽  
Gene Networks ◽  
Large Scale ◽  
Molecular Mechanisms ◽  
Association Studies ◽  
Tissue Expansion ◽  
Economic Systems ◽  
Genomic Association ◽  
Males And Females

Abstract The escalating prevalence of individuals becoming overweight and obese is a rapidly rising global health problem, placing an enormous burden on health and economic systems worldwide. Whilst obesity has well described lifestyle drivers, there is also a significant and poorly understood component that is regulated by genetics. Furthermore, there is clear evidence for sexual dimorphism in obesity, where overall risk, degree, subtype and potential complications arising from obesity all differ between males and females. The molecular mechanisms that dictate these sex differences remain mostly uncharacterised. Many studies have demonstrated that this dimorphism is unable to be solely explained by changes in hormones and their nuclear receptors alone, and instead manifests from coordinated and highly regulated gene networks, both during development and throughout life. As we acquire more knowledge in this area from approaches such as large-scale genomic association studies, the more we appreciate the true complexity and heterogeneity of obesity. Nevertheless, over the past two decades, researchers have made enormous progress in this field, and some consistent and robust mechanisms continue to be established. In this review, we will discuss some of the proposed mechanisms underlying sexual dimorphism in obesity, and discuss some of the key regulators that influence this phenomenon.

scholarly journals Morphometric characters and their relationship in estuarine catfish

1970 ◽  
Vol 6 (2) ◽  
pp. 349-353 ◽  
Author(s):  
M Begum ◽  
Abdullah Al-Mamun ◽  
ML Islam ◽  
MJ Alam
Keyword(s):  
Sexual Dimorphism ◽  
Linear Relationship ◽  
Standard Length ◽  
Head Length ◽  
Pectoral Fin ◽  
Morphometric Characters ◽  
Total Length ◽  
Length Standard ◽  
Eye Diameter ◽  
Males And Females

The morphometric observations were made on total length, standard length, pre-caudal length, head length, eye diameter and depth of body at pectoral fin base of estuarine catfish M. gulio. Males and females showed homogeneity in characters. A linear relationship was found between total length and morphometric characters. Regression of length and weight did not deviate significantly from cube law indicating isometric growth. The fish exhibited sexual dimorphism. Keywords: Morphometric characters; Estuarine catfish; Mystus gulio DOI: 10.3329/jbau.v6i2.4833 J. Bangladesh Agril. Univ. 6(2): 349-353, 2008

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