scholarly journals Assessment of Epigenetic Contributions to Sexually-Dimorphic Kiss1 Expression in the Anteroventral Periventricular Nucleus of Mice

Endocrinology ◽  
2012 ◽  
Vol 153 (4) ◽  
pp. 1875-1886 ◽  
Author(s):  
Sheila J. Semaan ◽  
Sangeeta Dhamija ◽  
Joshua Kim ◽  
Eric C. Ku ◽  
Alexander S. Kauffman
Keyword(s):  
Sex Differences ◽  
Sex Difference ◽  
Cell Number ◽  
Cpg Methylation ◽  
Histone Deacetylation ◽  
Sexually Dimorphic ◽  
Transcriptional Repressors ◽  
Pharmacological Blockade ◽  
In Silico Identification ◽  
Males And Females

The Kiss1 gene, which encodes kisspeptin and is critical for reproduction, is sexually differentiated in the hypothalamic anteroventral periventricular (AVPV)/rostral periventricular (PeN) nuclei. Specifically, female rodents have higher AVPV/PeN Kiss1 expression than males, but how this Kiss1 sex difference is induced in early development is poorly understood. Here, we explored the contribution of epigenetic mechanisms to the establishment of the AVPV/PeN Kiss1 sex difference, focusing on histone deacetylation and DNA methylation. First, we utilized postnatal pharmacological blockade of histone deacetylation and analyzed Kiss1 expression in the AVPV/PeN. Postnatal disruption of histone deacetylase modestly increased AVPV Kiss1 cell number in both sexes but did not alter the Kiss1 sex difference. Next, we assessed whether the level of CpG methylation, which can influence transcription factor binding and gene expression, in the murine Kiss1 gene differs between males and females. We found significant sex differences in methylation at several CpG sites in the putative promoter and first intron of the Kiss1 gene in the AVPV/PeN, but not in the arcuate (which lacks adult Kiss1 sex differences), suggesting that differential methylation of the Kiss1 gene may influence sexually-dimorphic Kiss1 expression in the AVPV/PeN. Transgenic impairment of methyl CpG-binding protein-2 function did not eliminate the Kiss1 sex difference, indicating that other methylation factors are involved. Interestingly, CpG methylation in the AVPV/PeN was lower in males than females, suggesting that transcriptional repressors may contribute to the AVPV/PeN Kiss1 sex difference, a possibility supported by in silico identification of putative repressor binding sites near some of the sexually-dimorphic CpG.

scholarly journals Epigenetic Control of Sexual Differentiation of the Bed Nucleus of the Stria Terminalis

Endocrinology ◽  
2009 ◽  
Vol 150 (9) ◽  
pp. 4241-4247 ◽  
Author(s):  
Elaine K. Murray ◽  
Annie Hien ◽  
Geert J. de Vries ◽  
Nancy G. Forger
Keyword(s):  
Cell Death ◽  
Sex Differences ◽  
Sexual Differentiation ◽  
Cell Number ◽  
Histone Deacetylation ◽  
Postnatal Life ◽  
Sexually Dimorphic ◽  
Stria Terminalis ◽  
Bed Nucleus ◽  
Deacetylase Inhibitor

Abstract The principal nucleus of the bed nucleus of the stria terminalis (BNSTp) is larger in volume and contains more cells in male than female mice. These sex differences depend on testosterone and arise from a higher rate of cell death during early postnatal life in females. There is a delay of several days between the testosterone surge at birth and sexually dimorphic cell death in the BNSTp, suggesting that epigenetic mechanisms may be involved. We tested the hypothesis that chromatin remodeling plays a role in sexual differentiation of the BNSTp by manipulating the balance between histone acetylation and deacetylation using a histone deacetylase inhibitor. In the first experiment, a single injection of valproic acid (VPA) on the day of birth increased acetylation of histone H3 in the brain 24 h later. Next, males, females, and females treated neonatally with testosterone were administered VPA or saline on postnatal d 1 and 2 and killed at 21 d of age. VPA treatment did not influence volume or cell number of the BNSTp in control females but significantly reduced both parameters in males and testosterone-treated females. As a result, the sex differences were eliminated. VPA did not affect volume or cell number in the suprachiasmatic nucleus or the anterodorsal nucleus of the thalamus, which also did not differ between males and females. These findings suggest that a disruption in histone deacetylation may lead to long-term alterations in gene expression that block the masculinizing actions of testosterone in the BNSTp.

Sex differences in melanotic encapsulation responses (immunocompetence) in the damselfly Lestes forcipatus Rambur

2002 ◽  
Vol 80 (9) ◽  
pp. 1578-1583 ◽  
Author(s):  
Christopher P Yourth ◽  
Mark R Forbes ◽  
Robert L Baker
Keyword(s):  
Sex Differences ◽  
Immune Responses ◽  
Life Histories ◽  
Mass Gain ◽  
Sexually Dimorphic ◽  
Foreign Objects ◽  
Males And Females ◽  
And Gender ◽  
Parasitic Mites ◽  
Melanotic Encapsulation

A few studies have shown that male and female invertebrates differ in immunity and that these differences appear related to differences in sexual dimorphism and gender differences in life histories. Melanotic encapsulation of foreign objects in insects is one form of immunity. The damselfly Lestes forcipatus Rambur is moderately sexually dimorphic, and much is known about patterns of mass gain in congeners relating to differences in life history between males and females. In this study, females were more immunoresponsive than males under controlled temperatures, following emergence, and at a time when parasitic mites were challenging these hosts. However, males and females that overlapped in mass at emergence did not differ in their immune responses. Males in better condition at emergence were more immunoresponsive than lighter males, but this relation was not found in females. Sex differences in immune expression may have implications for how females versus males are able to deal with challenges from parasites, under varying environmental conditions.

Abstract 302: Sex Differences In Nonlinear Dynamics And Their Circadian Variation In Control Dogs And In A New Arrhythmogenic Canine Model Of Heart Failure

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Yujie Zhu ◽  
Steven M Pogwizd
Keyword(s):  
Nonlinear Dynamics ◽  
Heart Failure ◽  
Sex Differences ◽  
Sex Difference ◽  
Circadian Variation ◽  
Holter Monitoring ◽  
Canine Model ◽  
Nonlinear Parameters ◽  
Arrhythmogenic Substrate ◽  
Males And Females

Introduction: Females can be more arrhythmogenic than males, and this sex difference can persist with development of chronic heart failure (CHF). The aim of this study was to investigate sex differences in the arrhythmogenic substrate in control dogs and in a new arrhythmogenic canine model of CHF. Methods: CHF was induced in 30 dogs by aortic insufficiency and aortic constriction. Holter monitoring assessed VT and PVCs from 30 dogs, as well as traditional HRV measures and nonlinear dynamics (including correlation dimension (CD), detrended fluctuations analysis α1 (DFAα1), and Shannon entropy (SE)) at baseline, 240 days (240d) and 720 days (720d) after CHF induction. Results: At baseline, females had lower LF/HF (0.27±0.03 vs 0.33±0.02, p=0.04), CD (1.60±0.17 vs 2.21±0.15, p=0.01), DFAα1 (0.62±0.03 vs 0.72±0.03, p=0.03), and SE (2.99±0.02 vs 3.10±0.03, p=0.03 vs males). Females lacked circadian variation in LF/HF, DFAα1, and SE while males had circadian variation in all of these. Of 11 dogs with frequent runs of VT and PVCs, 95% and 91% of total VT runs and total PVCs, respectively, were in females. With CHF, all these linear and nonlinear parameters progressively declined in males and females. CHF females had less decline in LF/HF than males so that by 720 days there was no more sex difference (0.24±0.06, 0.17±0.03 in females vs 0.22±0.05, 0.18±0.01 in males at 240d, 720d). However, for nonlinear parameters of CD, DFAα1, and SE, CHF females had lower values than males (CD: 1.56±0.21, 0.99±0.32 vs 1.87±0.24, 1.50±0.34; DFAα1: 0.51±0.05, 0.43±0.04 vs 0.54±0.07, 0.48±0.04; and SE 2.93±0.08, 2.76±0.08 vs 3.01±0.11, 2.91±0.04 in females vs males at 240d, 720d). With CHF, circadian variation in CD, DFAα1, and SE were lost in both males and females. Conclusions: There are sex differences in the arrhythmogenic substrate in control dogs and in this new arrhythmogenic canine model of moderate CHF. At baseline, females have lower sympathetic stimulation, reduced cardiac chaos, and loss of circadian variation in nonlinear dynamics. With CHF, sex differences in nonlinear dynamics persist; this reflects a loss of complexity and fractal properties that could contribute to increased arrhythmias in female CHF dogs.

scholarly journals Sex Differences in Exercise-Induced Bronchoconstriction in Athletes: A Systematic Review and Meta-Analysis

2020 ◽  
Vol 17 (19) ◽  
pp. 7270
Author(s):  
Daniel Enrique Rodriguez Bauza ◽  
Patricia Silveyra
Keyword(s):  
Sex Differences ◽  
Female Athletes ◽  
Meta Analysis ◽  
Sexually Dimorphic ◽  
Atopic Status ◽  
Management Plans ◽  
Disease Experience ◽  
Males And Females ◽  
Male Sex ◽  
Exercise Induced

Exercise-induced bronchoconstriction (EIB) is a common complication of athletes and individuals who exercise regularly. It is estimated that about 90% of patients with underlying asthma (a sexually dimorphic disease) experience EIB; however, sex differences in EIB have not been studied extensively. With the goal of better understanding the prevalence of EIB in males and females, and because atopy has been reported to occur at higher rates in athletes, in this study, we investigated sex differences in EIB and atopy in athletes. A systematic literature review identified 60 studies evaluating EIB and/or atopy in post-pubertal adult athletes (n = 7501). Collectively, these studies reported: (1) a 23% prevalence of EIB in athletes; (2) a higher prevalence of atopy in male vs. female athletes; (3) a higher prevalence of atopy in athletes with EIB; (4) a significantly higher rate of atopic EIB in male vs. female athletes. Our analysis indicates that the physiological changes that occur during exercise may differentially affect male and female athletes, and suggest an interaction between male sex, exercise, and atopic status in the course of EIB. Understanding these sex differences is important to provide personalized management plans to athletes with underlying asthma and/or atopy.

Sex Differences in Recognizing the Correct Answer to a Problem

1965 ◽  
Vol 17 (2) ◽  
pp. 532-534 ◽  
Author(s):  
Ronald J. Burke
Keyword(s):  
Sex Differences ◽  
Sex Difference ◽  
Correct Answer ◽  
Males And Females

Previous research has shown the superiority of performance of males over that of females in solving Maier's horse trading problem. This investigation represented an attempt to reduce this sex difference by requiring Ss only to recognize the correct answer and its underlying reason. Consistent with earlier findings, 67.4% of the males and 34.2% of the females correctly solved the problem ( p < .01). Comparison with results of Hoffman and Maier (1961) suggests that the modified version of the problem had little effect on the percentage of males and females correctly solving the problem.

Sex differences in the circadian control of hamster wheel-running activity

1983 ◽  
Vol 244 (1) ◽  
pp. R93-R105 ◽  
Author(s):  
F. C. Davis ◽  
J. M. Darrow ◽  
M. Menaker
Keyword(s):  
Sex Differences ◽  
Sex Difference ◽  
Wheel Running ◽  
Phase Shifts ◽  
Light Cycle ◽  
Dark Cycle ◽  
Running Activity ◽  
Wheel Running Activity ◽  
Activity Onset ◽  
Males And Females

The circadian pacemaker that underlies the wheel-running activity of hamsters was studied in males and females. Sex differences were found in the mechanism by which the pacemaker entrains to light-dark cycles and in the timing of activity onset. When exposed to a light-dark cycle with a period of 24.75 h (with 1 h of light/cycle), males show a greater ability to maintain entrainment than do females. This difference in the upper limit of entrainment appears due to a sex difference in the magnitude of light-induced phase shifts. A small difference in free-running period may also contribute to the sex difference in entrainment. Two weeks after castration of adults, the sex difference in entrainment is not affected, indicating that the difference does not depend on circulating gonadal steroids or on estrous cyclicity of the female. However, castration of females at an early age increases their ability to entrain, whereas long-term castration of males seems to reduce entrainment ability. During entrainment to a 24-h light-dark cycle (LD 14:10), females were found to begin their daily activity before males and before castrated females. This difference is consistent with a sex difference in the magnitude of light-induced phase shifts and in entrainment of the pacemaker. However, evidence is given that the sex difference in activity onset might also be caused by a sex difference in the relationship of locomotor activity to the pacemaker in intact males and females.

scholarly journals Sex differences in gene expression and proliferation are dependent on the epigenetic modifier HP1γ

2019 ◽  
Author(s):  
Pui-Pik Law ◽  
Ping-Kei Chan ◽  
Kirsten McEwen ◽  
Huihan Zhi ◽  
Bing Liang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sex Differences ◽  
Sex Chromosome ◽  
Chromosome Complement ◽  
Autosomal Gene ◽  
Sexually Dimorphic ◽  
Heterochromatin Protein 1 ◽  
Epigenetic Modifier ◽  
Early Embryos ◽  
Males And Females

SummarySex differences in growth rate in very early embryos have been recognized in a variety of mammals and attributed to sex-chromosome complement effects as they occur before overt sexual differentiation. We previously found that sex-chromosome complement, rather than sex hormones regulates heterochromatin-mediated silencing of a transgene and autosomal gene expression in mice. Here, sex dimorphism in proliferation was investigated. We confirm that male embryonic fibroblasts proliferate faster than female fibroblasts and show that this proliferation advantage is completely dependent upon heterochromatin protein 1 gamma (HP1γ). To determine whether this sex-regulatory effect of HP1γ was a more general phenomenon, we performed RNA sequencing on MEFs derived from males and females, with or without HP1γ. Strikingly, HP1γ was found to be crucial for regulating nearly all sexually dimorphic autosomal gene expression because deletion of the HP1γ gene in males abolished sex differences in autosomal gene expression. The identification of a key epigenetic modifier as central in defining gene expression differences between males and females has important implications for understanding physiological sex differences and sex bias in disease.

Abstract P787: Sexually Dimorphic Gene Expression Molecular Correlates of Improvement in Human Ischemic Stroke

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Hajar Amini ◽  
Bodie Knepp ◽  
Heather Hull ◽  
Paulina Carmona-Mora ◽  
Marisa Hakoupian ◽  
...  
Keyword(s):  
Gene Expression ◽  
Risk Factors ◽  
Protein Synthesis ◽  
Sex Differences ◽  
Ischemic Stroke ◽  
Major Protein ◽  
Sexually Dimorphic ◽  
Stroke Outcome ◽  
Males And Females ◽  
Dimorphic Gene Expression

Objective: Ischemic stroke (IS) is sexually dimorphic for risk factors, age, heritability, causes, treatment, and outcome. We identified transcriptional correlates with 90-day outcome that differed between male and female IS subjects. Methods: RNA from 72 samples from 2 peripheral blood draws (at ≤3 and 24h post IS onset) was analyzed on Affymetrix U133 Plus 2 microarrays. These represented samples from 36 CLEAR trial IS patients treated with tPA with or without eptifibatide after the first blood sample within 3 hours of stroke onset. Changes in gene expression levels (deltaGE) between 3h and 24h were calculated and the association with percent NIH Stroke Scale (NIHSS) improvement from 3h to 90 days (% Improvement) examined. We used mixed-effects linear regression, including Treatment, Age, Sex, Vascular Risk Factors, 3h NIHSS, % Improvement, and a Sex * % Improvement interaction. Sex differences in association of gene expression with % Improvement were determined by examining the Sex * % Improvement interaction term, p<0.005 was considered statistically significant. Results: 577 genes correlated differently with % Improvement in IS males and females. These included matrix metalloproteinases (MMPs), which play a major role in BBB dysfunction and outcomes post IS. MMP11 , MMP14 and MM17 correlated with % Improvement in opposite direction in males and females. Inflammatory genes like IL-27 , implicated in infarct volume and stroke outcome, and ABC transporters ( ABCC9 ) also had opposite correlation with % Improvement in males and females. Calmodulin 1 ( CAML1 ) was also sexually dimorphic, and a SNP in CALM1 has been implicated in IS risk and blood coagulation in female IS patients. EIF2 signaling, a major protein synthesis pathway was activated in males (adj. p = 1e-8), while suppressed in females (adj. p value = 1e-9). Protein synthesis and associated unfolded protein response cascade have previously been implicated in stroke outcome. Conclusions: The identified sexually dimorphic gene expression associated with 90-day improvement might relate to sex differences in blood immune and clotting pathways. The findings expand our understanding of the genomic underpinnings associated with stroke outcome and may serve as potential sex-specific treatment targets.

scholarly journals BAX-Dependent and BAX-Independent Regulation of Kiss1 Neuron Development in Mice

Endocrinology ◽  
2010 ◽  
Vol 151 (12) ◽  
pp. 5807-5817 ◽  
Author(s):  
Sheila J. Semaan ◽  
Elaine K. Murray ◽  
Matthew C. Poling ◽  
Sangeeta Dhamija ◽  
Nancy G. Forger ◽  
...  
Keyword(s):  
Sex Difference ◽  
Cell Number ◽  
Sexually Dimorphic ◽  
Neuron Development ◽  
Wild Type ◽  
Th Cell ◽  
Double Label ◽  
D 12 ◽  
Th Mrna

The Kiss1 gene and its product kisspeptin are important regulators of reproduction. In rodents, Kiss1 is expressed in the hypothalamic arcuate (ARC) and anteroventral periventricular (AVPV)/rostral periventricular (PeN) nuclei. In the AVPV/PeN, females have more Kiss1 and tyrosine hydroxylase (TH) neurons than males. We explored the ontogeny of the Kiss1 sex difference, and the role of cell death in establishing Kiss1 and TH cell number. We also determined whether Kiss1 cells in AVPV/PeN coexpress TH. AVPV/PeN Kiss1 neurons were first detected in both sexes on postnatal d 10, but the Kiss1 sex difference did not emerge until postnatal d 12. The role of BAX-mediated apoptosis in generating this sex difference was tested in adult Bax knockout (KO) and wild-type mice. Deletion of Bax did not diminish the sex difference in Kiss1 expression in the AVPV/PeN. TH expression was sexually dimorphic in the AVPV of both wild-type and Bax KO mice but, unlike Kiss1, was not sexually dimorphic in the PeN of either genotype. Double-label analysis determined that most Kiss1 neurons coexpress TH mRNA, but many TH neurons do not coexpress Kiss1, especially in the PeN. These findings suggest that several subpopulations of TH cells reside within the AVPV/PeN, only one of which coexpresses Kiss1. In the ARC, Kiss1 cell number was markedly increased in Bax KO mice of both sexes, indicating that although BAX-dependent apoptosis does not generate the sex difference in either Kiss1 or TH expression in AVPV/PeN, BAX does importantly regulate Kiss1 cell number in the ARC.

Some reflections on sex differences in aggression and violence

1999 ◽  
Vol 22 (2) ◽  
pp. 232-233
Author(s):  
Stephen C. Maxson
Keyword(s):  
Sex Differences ◽  
Sex Difference ◽  
Evolutionary Explanation ◽  
Men And Women ◽  
Human Aggression ◽  
Intrasexual Aggression ◽  
Males And Females ◽  
Evolutionary Explanations

Four issues relevant to sex differences in human aggression and violence are considered. (1) The motivation for play and serious aggression in children and juvenile animals is different. Consequently, the evolutionary explanations for each may be different. (2) Sex differences in intrasexual aggression may be due to effects of the attacker or the target. There is evidence that both males and females are more physically aggressive against males and less physically aggressive against females. The evolutionary explanation for each component of the sex difference in intrasexual aggression may be different. (3) Aggression and violence are defined. The former is the attack, and the latter is the consequent injury or death. The evolutionary explanation for each may not be the same. (4) Most men and women are neither physically aggressive nor criminally violent. The evolutionary explanations of sex differences in aggression and violence should take this polymorphism into account.

Sign in / Sign up

Export Citation Format

Share Document