scholarly journals Sexual Dimorphism of the Heart: Genetics, Epigenetics, and Development

2021 ◽  
Vol 8 ◽  
Author(s):  
Daniel F. Deegan ◽  
Priya Nigam ◽  
Nora Engel
Keyword(s):  
Sexual Dimorphism ◽  
Sex Hormones ◽  
Sex Chromosome ◽  
Cardiac Development ◽  
Heart Defects ◽  
Expression Patterns ◽  
Mortality And Morbidity ◽  
Environmental Signals ◽  
Y Chromosomes ◽  
Sex Biases

The democratization of genomic technologies has revealed profound sex biases in expression patterns in every adult tissue, even in organs with no conspicuous differences, such as the heart. With the increasing awareness of the disparities in cardiac pathophysiology between males and females, there are exciting opportunities to explore how sex differences in the heart are established developmentally. Although sexual dimorphism is traditionally attributed to hormonal influence, expression and epigenetic sex biases observed in early cardiac development can only be accounted for by the difference in sex chromosome composition, i.e., XX in females and XY in males. In fact, genes linked to the X and Y chromosomes, many of which encode regulatory factors, are expressed in cardiac progenitor cells and at every subsequent developmental stage. The effect of the sex chromosome composition may explain why many congenital heart defects originating before gonad formation exhibit sex biases in presentation, mortality, and morbidity. Some transcriptional and epigenetic sex biases established soon after fertilization persist in cardiac lineages, suggesting that early epigenetic events are perpetuated beyond early embryogenesis. Importantly, when sex hormones begin to circulate, they encounter a cardiac genome that is already functionally distinct between the sexes. Although there is a wealth of knowledge on the effects of sex hormones on cardiac function, we propose that sex chromosome-linked genes and their downstream targets also contribute to the differences between male and female hearts. Moreover, identifying how hormones influence sex chromosome effects, whether antagonistically or synergistically, will enhance our understanding of how sex disparities are established. We also explore the possibility that sexual dimorphism of the developing heart predicts sex-specific responses to environmental signals and foreshadows sex-biased health-related outcomes after birth.

scholarly journals Y-chromosome haplotypes of varying differentiation to the X are not associated with male fitness in common frogs

2019 ◽  
Author(s):  
Paris Veltsos ◽  
Nicolas Rodrigues ◽  
Tania Studer ◽  
Wen-Juan Ma ◽  
Roberto Sermier ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Y Chromosome ◽  
Sex Chromosomes ◽  
Chromosome Evolution ◽  
Sex Chromosome ◽  
Sex Chromosome Evolution ◽  
Chromosome Differentiation ◽  
Y Chromosomes ◽  
Male Phenotype ◽  
Xx Males

AbstractThe canonical model of sex-chromosome evolution assigns a key role to sexually antagonistic (SA) genes on the arrest of recombination and ensuing degeneration of Y chromosomes. This assumption cannot be tested in organisms with highly differentiated sex chromosomes, such as mammals or birds, owing to the lack of polymorphism. Fixation of SA alleles, furthermore, might be the consequence rather than the cause of recombination arrest. Here we focus on a population of common frogs (Rana temporaria) where XY males with genetically differentiated Y chromosomes (non-recombinant Y haplotypes) coexist with both XY° males with proto-Y chromosomes (only differentiated from X chromosomes in the immediate vicinity of the candidate sex-determining locus Dmrt1) and XX males with undifferentiated sex chromosomes (genetically identical to XX females). Our study shows no effect of sex-chromosome differentiation on male phenotype, mating success or fathering success. Our conclusions rejoin genomic studies that found no differences in gene expression between XY, XY° and XX males. Sexual dimorphism in common frogs seems to result from the differential expression of autosomal genes rather than sex-linked SA genes. Among-male variance in sex-chromosome differentiation is better explained by a polymorphism in the penetrance of alleles at the sex locus, resulting in variable levels of sex reversal (and thus of X-Y recombination in XY females), independent of sex-linked SA genes.Impact SummaryHumans, like other mammals, present highly differentiated sex chromosomes, with a large, gene-rich X chromosome contrasting with a small, gene-poor Y chromosome. This differentiation results from a process that started approximately 160 Mya, when the Y first stopped recombining with the X. How and why this happened, however, remain controversial. According to the canonical model, the process was initiated by sexually antagonistic selection; namely, selection on the proto-Y chromosome for alleles that were beneficial to males but detrimental to females. The arrest of XY recombination then allowed such alleles to be only transmitted to sons, not to daughters. Although appealing and elegant, this model can no longer be tested in mammals, as it requires a sex-chromosome system at an incipient stage of evolution. Here we focus on a frog that displays within-population polymorphism is sex-chromosome differentiation, where XY males with differentiated chromosomes coexist with XX males lacking Y chromosomes. We find no effect of sex-chromosome differentiation on male phenotype or mating success, opposing expectations from the standard model. Sex linked genes do not seem to have a disproportionate effect on sexual dimorphism. From our results, sexually antagonistic genes show no association with sex-chromosome differentiation in frogs, which calls for alternative models of sex-chromosome evolution.

scholarly journals Y recombination arrest and degeneration in the absence of sexual dimorphism

2021 ◽  
Author(s):  
Thomas Lenormand ◽  
Denis Roze
Keyword(s):  
Sexual Dimorphism ◽  
Dosage Compensation ◽  
Chromosome Evolution ◽  
Sex Chromosome ◽  
Current Theory ◽  
Whole Process ◽  
Y Chromosomes ◽  
Regulatory Effects ◽  
Cis And Trans ◽  
Y Chromosome Degeneration

Current theory proposes degenerated sex chromosomes evolve via three successive steps: recombination arrest, which links male-beneficial alleles to the Y chromosome; degeneration of these regions due to the inefficacy of natural selection in the absence of recombination; and lastly, the evolution of dosage compensation to correct the resulting low expression of X-linked genes in males. Here we investigate new models of sex chromosome evolution incorporating the coevolution of cis- and trans-regulators of gene expression. We show that the early emergence of dosage compensation favors the maintenance of Y-linked inversions by creating sex-antagonistic regulatory effects. This is followed by inversion degeneration caused by regulatory divergence between the X and Y chromosomes. In stark contrast to the current theory, the whole process occurs without any selective pressure related to sexual dimorphism.

Abstract 249: Male Mice with XX Sex Chromosome Complement Exhibit Reduced Angiotensin II-Induced Hypertension and Atherosclerosis

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Yasir Alsiraj ◽  
Sean Thatcher ◽  
Lisa A Cassis
Keyword(s):  
Sexual Dimorphism ◽  
Angiotensin Ii ◽  
Surface Area ◽  
Sex Hormones ◽  
Sex Chromosome ◽  
Chromosome Complement ◽  
Atherosclerotic Lesion ◽  
Renin Angiotensin System ◽  
Induced Hypertension ◽  
Xx Males

Objective: Hypertension and atherosclerosis exhibit sexual dimorphism, partially ascribed to effects of sex hormones. However, recent studies suggest that sex chromosome complement may also contribute to sexual dimorphism of these diseases. The renin-angiotensin system has been suggested to contribute to sexual dimorphism of hypertension and atherosclerosis. However, the relative contribution of sex hormones, versus chromosomes, in the regulation of angiotensin II (AngII)-mediated responses is unknown. We hypothesized that the presence of an XX chromosome complement in male hyperlipidemic mice would reduce AngII-induced hypertension and atherosclerosis. Methods and Results: Male Ldlr-/- mice with an Sry mutation but with an Sry transgene on autosomes were bred to Ldlr-/- females to generate XY or XX males. Male XY or XX mice were segregated to sham-operated or orchiectomized (ORC) groups and fed a high fat diet (42% kcal from fat). Two weeks later, mice were infused with AngII (1,000 ng/kg/min) for 4 weeks. In the presence of sex hormones (sham groups), systolic blood pressure (SBP) was significantly lower in AngII-infused XX than XY males (XY, 136 ± 4; XX, 119 ± 4 mmHg, p=0.024). In XY males, ORC had no significant effect on SBP compared to sham (ORC XY, 129 ± 6 mmHg; p=0.48). However, following castration of XX males, SBP significantly increased (ORC XX 135 ± 3 mmHg; p =0.002). In XY males, ORC resulted in a significant increase in atherosclerotic lesion surface area in the aortic arch (sham, 19 ± 4; ORC, 32 ± 7%; p=0.04). In contrast, ORC had no significant effect on lesion surface area in XX males (sham, 17 ± 3; ORC, 15 ± 2%; p=0.53). Moreover, in the absence of sex hormones, lesion surface area was markedly increased in XY compared to XX males (XY, 32 ± 7; XX, 15 ± 2%; p=0.002). Conclusions: These results demonstrate that effects of testosterone to regulate AngII-induced hypertension and atherosclerosis are dependent on sex chromosome complement. In XY males, testosterone protects against AngII-induced atherosclerosis. In XX males, testosterone protects against AngII-induced hypertension. Moreover, there is pronounced effect of XY chromosome complement to promote AngII-induced atherosclerosis in males.

scholarly journals Regulatory Role of Sex Hormones in Cardiovascular Calcification

2021 ◽  
Vol 22 (9) ◽  
pp. 4620
Author(s):  
Holly J. Woodward ◽  
Dongxing Zhu ◽  
Patrick W. F. Hadoke ◽  
Victoria E. MacRae
Keyword(s):  
Cardiovascular Disease ◽  
Sex Differences ◽  
Sexual Dimorphism ◽  
Aortic Stenosis ◽  
Sex Hormones ◽  
Sex Hormone ◽  
Increased Risk ◽  
Male Sex ◽  
Primary Male

Sex differences in cardiovascular disease (CVD), including aortic stenosis, atherosclerosis and cardiovascular calcification, are well documented. High levels of testosterone, the primary male sex hormone, are associated with increased risk of cardiovascular calcification, whilst estrogen, the primary female sex hormone, is considered cardioprotective. Current understanding of sexual dimorphism in cardiovascular calcification is still very limited. This review assesses the evidence that the actions of sex hormones influence the development of cardiovascular calcification. We address the current question of whether sex hormones could play a role in the sexual dimorphism seen in cardiovascular calcification, by discussing potential mechanisms of actions of sex hormones and evidence in pre-clinical research. More advanced investigations and understanding of sex hormones in calcification could provide a better translational outcome for those suffering with cardiovascular calcification.

scholarly journals Outflow Tract Formation—Embryonic Origins of Conotruncal Congenital Heart Disease

2021 ◽  
Vol 8 (4) ◽  
pp. 42
Author(s):  
Sonia Stefanovic ◽  
Heather C. Etchevers ◽  
Stéphane Zaffran
Keyword(s):  
Congenital Heart ◽  
Cardiac Development ◽  
Heart Defects ◽  
Dynamic Structure ◽  
Cell Types ◽  
Outflow Tract ◽  
Heart Tube ◽  
Heart Field ◽  
Multiple Cell ◽  
The Many

Anomalies in the cardiac outflow tract (OFT) are among the most frequent congenital heart defects (CHDs). During embryogenesis, the cardiac OFT is a dynamic structure at the arterial pole of the heart. Heart tube elongation occurs by addition of cells from pharyngeal, splanchnic mesoderm to both ends. These progenitor cells, termed the second heart field (SHF), were first identified twenty years ago as essential to the growth of the forming heart tube and major contributors to the OFT. Perturbation of SHF development results in common forms of CHDs, including anomalies of the great arteries. OFT development also depends on paracrine interactions between multiple cell types, including myocardial, endocardial and neural crest lineages. In this publication, dedicated to Professor Andriana Gittenberger-De Groot and her contributions to the field of cardiac development and CHDs, we review some of her pioneering studies of OFT development with particular interest in the diverse origins of the many cell types that contribute to the OFT. We also discuss the clinical implications of selected key findings for our understanding of the etiology of CHDs and particularly OFT malformations.

scholarly journals Sexual Dimorphisms of Adrenal Steroids, Sex Hormones, and Immunological Biomarkers and Possible Risk Factors for Developing Rheumatoid Arthritis

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Alfonse T. Masi ◽  
Azeem A. Rehman ◽  
Laura C. Jorgenson ◽  
Jennifer M. Smith ◽  
Jean C. Aldag
Keyword(s):  
Rheumatoid Arthritis ◽  
Risk Factors ◽  
Sexual Dimorphism ◽  
Sex Hormones ◽  
Inflammatory Diseases ◽  
Interleukin 2 ◽  
Tumor Necrosis Factor Receptor ◽  
Serum Levels ◽  
Amyloid A ◽  
Neuroendocrine Factors

Innate immunity and immunological biomarkers are believed to be interrelated with sex hormones and other neuroendocrine factors. Sexual dimorphism mechanisms may be operating in certain rheumatic and inflammatory diseases which occur more frequently in women than men, as rheumatoid arthritis (RA). Less data have been available on altered interrelations of the combined neuroendocrine and immune (NEI) systems as risk factors for development of certain diseases. In this study, serological interrelations of NEI biomarkers are analyzed before symptomatic onset of RA (pre-RA) versus control (CN) subjects, stratified by sex. Sexual dimorphism was found in serum levels of acute serum amyloid A (ASAA), soluble interleukin-2 receptor alpha (sIL-2Rα), and soluble tumor necrosis factor receptor 1 (sTNF-R1). Multiple steroidal and hormonal (neuroendocrine) factors also showed highly(p<0.001)significant sexual dimorphism in their assayed values, but less for cortisol(p=0.012), and not for 17-hydroxyprogesterone(p=0.176). After stratification by sex and risk of developing RA, differential NEI correlational patterns were observed in the interplay of the NEI systems between the pre-RA and CN groups, which deserve further investigation.

scholarly journals Sex differences in circadian food anticipatory activity are not altered by individual manipulations of sex hormones or sex chromosome copy number in mice

PLoS ONE ◽  
2018 ◽  
Vol 13 (1) ◽  
pp. e0191373 ◽  
Author(s):  
Antonio Aguayo ◽  
Camille S. Martin ◽  
Timothy F. Huddy ◽  
Maya Ogawa-Okada ◽  
Jamie L. Adkins ◽  
...  
Keyword(s):  
Sex Differences ◽  
Sex Hormones ◽  
Copy Number ◽  
Sex Chromosome ◽  
Chromosome Copy Number ◽  
Food Anticipatory Activity ◽  
Anticipatory Activity

scholarly journals Abnormal Cardiac Development in the Absence of Heart Glycogen

2004 ◽  
Vol 24 (16) ◽  
pp. 7179-7187 ◽  
Author(s):  
Bartholomew A. Pederson ◽  
Hanying Chen ◽  
Jill M. Schroeder ◽  
Weinian Shou ◽  
Anna A. DePaoli-Roach ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Cardiac Muscle ◽  
Heart Development ◽  
Congenital Heart ◽  
Cardiac Development ◽  
Glycogen Synthase ◽  
Heart Defects ◽  
Mendelian Inheritance ◽  
And Function ◽  
Impaired Cardiac Function

ABSTRACT Glycogen serves as a repository of glucose in many mammalian tissues. Mice lacking this glucose reserve in muscle, heart, and several other tissues were generated by disruption of the GYS1 gene, which encodes an isoform of glycogen synthase. Crossing mice heterozygous for the GYS1 disruption resulted in a significant underrepresentation of GYS1-null mice in the offspring. Timed matings established that Mendelian inheritance was followed for up to 18.5 days postcoitum (dpc) and that ∼90% of GYS1-null animals died soon after birth due to impaired cardiac function. Defects in cardiac development began between 11.5 and 14.5 dpc. At 18.5 dpc, the hearts were significantly smaller, with reduced ventricular chamber size and enlarged atria. Consistent with impaired cardiac function, edema, pooling of blood, and hemorrhagic liver were seen. Glycogen synthase and glycogen were undetectable in cardiac muscle and skeletal muscle from the surviving null mice, and the hearts showed normal morphology and function. Congenital heart disease is one of the most common birth defects in humans, at up to 1 in 50 live births. The results provide the first direct evidence that the ability to synthesize glycogen in cardiac muscle is critical for normal heart development and hence that its impairment could be a significant contributor to congenital heart defects.

scholarly journals Telomere-to-telomere assembly of a fish Y chromosome reveals the origin of a young sex chromosome pair

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Lingzhan Xue ◽  
Yu Gao ◽  
Meiying Wu ◽  
Tian Tian ◽  
Haiping Fan ◽  
...  
Keyword(s):  
Y Chromosome ◽  
Sex Chromosomes ◽  
Chromosome Pair ◽  
Sex Chromosome ◽  
Structural Variations ◽  
Recombination Suppression ◽  
Chromosome Differentiation ◽  
Y Chromosomes ◽  
Recent Origin ◽  
Mastacembelus Armatus

Abstract Background The origin of sex chromosomes requires the establishment of recombination suppression between the proto-sex chromosomes. In many fish species, the sex chromosome pair is homomorphic with a recent origin, providing species for studying how and why recombination suppression evolved in the initial stages of sex chromosome differentiation, but this requires accurate sequence assembly of the X and Y (or Z and W) chromosomes, which may be difficult if they are recently diverged. Results Here we produce a haplotype-resolved genome assembly of zig-zag eel (Mastacembelus armatus), an aquaculture fish, at the chromosomal scale. The diploid assembly is nearly gap-free, and in most chromosomes, we resolve the centromeric and subtelomeric heterochromatic sequences. In particular, the Y chromosome, including its highly repetitive short arm, has zero gaps. Using resequencing data, we identify a ~7 Mb fully sex-linked region (SLR), spanning the sex chromosome centromere and almost entirely embedded in the pericentromeric heterochromatin. The SLRs on the X and Y chromosomes are almost identical in sequence and gene content, but both are repetitive and heterochromatic, consistent with zero or low recombination. We further identify an HMG-domain containing gene HMGN6 in the SLR as a candidate sex-determining gene that is expressed at the onset of testis development. Conclusions Our study supports the idea that preexisting regions of low recombination, such as pericentromeric regions, can give rise to SLR in the absence of structural variations between the proto-sex chromosomes.

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