Sex differences in physiology and disease in mammals result from the effects of three classes of factors that are inherently unequal in males and females: reversible (activational) effects of gonadal ...hormones, permanent (organizational) effects of gonadal hormones, and cell-autonomous effects of sex chromosomes, as well as genes driven by these classes of factors. Often, these factors act together to cause sex differences in specific phenotypes, but the relative contribution of each and the interactions among them remain unclear. Here, we used the four core genotypes (FCG) mouse model with or without hormone replacement to distinguish the effects of each class of sex-biasing factors on transcriptome regulation in liver and adipose tissues. We found that the activational hormone levels have the strongest influence on gene expression, followed by the organizational gonadal sex effect, and last, sex chromosomal effect, along with interactions among the three factors. Tissue specificity was prominent, with a major impact of estradiol on adipose tissue gene regulation and of testosterone on the liver transcriptome. The networks affected by the three sex-biasing factors include development, immunity and metabolism, and tissue-specific regulators were identified for these networks. Furthermore, the genes affected by individual sex-biasing factors and interactions among factors are associated with human disease traits such as coronary artery disease, diabetes, and inflammatory bowel disease. Our study offers a tissue-specific account of the individual and interactive contributions of major sex-biasing factors to gene regulation that have broad impact on systemic metabolic, endocrine, and immune functions.
Awarded honorable mention for the 2007 Wallace K. Ferguson Prize sponsored by the Canadian Historical Association How were marital and sexual relationships woven into the fabric of late medieval ...society, and what form did these relationships take? Using extensive documentary evidence from both the ecclesiastical court system and the records of city and royal government, as well as advice manuals, chronicles, moral tales, and liturgical texts, Shannon McSheffrey focuses her study on England's largest city in the second half of the fifteenth century. Marriage was a religious union-one of the seven sacraments of the Catholic Church and imbued with deep spiritual significance-but the marital unit of husband and wife was also the fundamental domestic, social, political, and economic unit of medieval society. As such, marriage created political alliances at all levels, from the arena of international politics to local neighborhoods. Sexual relationships outside marriage were even more complicated. McSheffrey notes that medieval Londoners saw them as variously attributable to female seduction or to male lustfulness, as irrelevant or deeply damaging to society and to the body politic, as economically productive or wasteful of resources. Yet, like marriage, sexual relationships were also subject to control and influence from parents, relatives, neighbors, civic officials, parish priests, and ecclesiastical judges. Although by medieval canon law a marriage was irrevocable from the moment a man and a woman exchanged vows of consent before two witnesses, in practice marriage was usually a socially complicated process involving many people. McSheffrey looks more broadly at sex, governance, and civic morality to show how medieval patriarchy extended a far wider reach than a father's governance over his biological offspring. By focusing on a particular time and place, she not only elucidates the culture of England's metropolitan center but also contributes generally to our understanding of the social mechanisms through which premodern European people negotiated their lives.
Once recombination is halted between the X and Y chromosomes, sex chromosomes begin to differentiate and transition to heteromorphism. While there is a remarkable variation across clades in the ...degree of sex chromosome divergence, far less is known about the variation in sex chromosome differentiation within clades. Here, we combined whole-genome and transcriptome sequencing data to characterize the structure and conservation of sex chromosome systems across Poeciliidae, the livebearing clade that includes guppies. We found that the Poecilia reticulata XY system is much older than previously thought, being shared not only with its sister species, Poecilia wingei, but also with Poecilia picta, which diverged roughly 20 million years ago. Despite the shared ancestry, we uncovered an extreme heterogeneity across these species in the proportion of the sex chromosome with suppressed recombination, and the degree of Y chromosome decay. The sex chromosomes in P. reticulata and P. wingei are largely homomorphic, with recombination in the former persisting over a substantial fraction. However, the sex chromosomes in P. picta are completely nonrecombining and strikingly heteromorphic. Remarkably, the profound degradation of the ancestral Y chromosome in P. picta is counterbalanced by the evolution of functional chromosome-wide dosage compensation in this species, which has not been previously observed in teleost fish. Our results offer important insight into the initial stages of sex chromosome evolution and dosage compensation.
Objective
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Chong Xie, Xiangfeng Chen, and Yulin Liu contributed equally to this work.
Genetic defects are identified in nearly 20% of infertile males. Determining the frequency and types of major ...genetic abnormalities in severe male infertility helps inform appropriate genetic counseling before assisted reproductive techniques.
Methods
Cytogenetic results of 912 patients with non-obstructive azoospermia (NOA) and severe oligozoospermia (SOS) in Eastern China were reviewed in this multicenter study from January 2011 to December 2015. Controls were 215 normozoospermic men with offspring.
Results
Among all patients, 22.6% (206/912) had genetic abnormalities, including 27.3% (146/534) of NOA patients and 15.9% (60/378) of SOS patients. Chromosomal abnormalities (all autosomal) were detected in only 1.9% (4 /215) of controls. In NOA patients, sex chromosomal abnormalities were identified in 25.8% (138/534), of which 8% (43/534) had a 47,XXY karyotype or its mosaic; higher than the SOS group prevalence (1.1%; 4/378). The incidence of Y chromosome microdeletions was lower in the SOS group (13.2%; 50/378) than in the NOA group (17.8%; 95/534).
Conclusions
The high prevalence of genetic abnormalities in our study indicates the importance of routine genetic testing in severe male infertility diagnosis. This may help determine the choice of assisted reproductive technique and allow specific pre-implantation genetic testing to minimize the risk of transmitting genetic defects.
A central element of interdependence theory is that people have standards against which they compare their current outcomes, and one ubiquitous standard in the mating domain is the preference for ...particular attributes in a partner (ideal partner preferences). This article reviews research on the predictive validity of ideal partner preferences and presents a new integrative model that highlights when and why ideals succeed or fail to predict relational outcomes. Section 1 examines predictive validity by reviewing research on sex differences in the preference for physical attractiveness and earning prospects. Men and women reliably differ in the extent to which these qualities affect their romantic evaluations of hypothetical targets. Yet a new meta-analysis spanning the attraction and relationships literatures (k = 97) revealed that physical attractiveness predicted romantic evaluations with a moderate-to-strong effect size (r = ∼.40) for both sexes, and earning prospects predicted romantic evaluations with a small effect size (r = ∼.10) for both sexes. Sex differences in the correlations were small (rdifference = .03) and uniformly nonsignificant. Section 2 reviews research on individual differences in ideal partner preferences, drawing from several theoretical traditions to explain why ideals predict relational evaluations at different relationship stages. Furthermore, this literature also identifies alternative measures of ideal partner preferences that have stronger predictive validity in certain theoretically sensible contexts. Finally, a discussion highlights a new framework for conceptualizing the appeal of traits, the difference between live and hypothetical interactions, and the productive interplay between mating research and broader psychological theories.
The sex of a host affects the intensity, prevalence, and severity of helminth infection. In many cases, one sex has been found to be more susceptible than the other, with the prevalence and intensity ...of helminth infections being generally higher among male than female hosts; however, many exceptions exist. This observed sex bias in parasitism results primarily from ecological, behavioural, and physiological differences between males and females. Complex interactions between these influences modulate the risk of infection. Indeed, an interplay among sex hormones, sex chromosomes, the microbiome and the immune system significantly contributes to the generation of sex bias among helminth-infected hosts. However, sex hormones not only can modulate the course of infection but also can be exploited by the parasites, and helminths appear to have developed molecules and pathways for this purpose. Furthermore, host sex may influence the efficacy of anti-helminth vaccines; however, although little data exist regarding this sex-dependent efficacy, host sex is known to influence the response to vaccines. Despite its importance, host sex is frequently overlooked in parasitological studies. This review focuses on the key contributors to sex bias in the case of helminth infection. The precise nature of the mechanisms/factors determining these sex-specific differences generally remains largely unknown, and this represents an obstacle in the development of control methods. There is an urgent need to identify any protective elements that could be targeted in future therapies to provide optimal disease management with regard to host sex. Hence, more research is needed into the impact of host sex on immunity and protection.
A major reason for studying plant sex chromosomes is that they may often be ‘young’ systems. There is considerable evidence for the independent evolution of separate sexes within plant families or ...genera, in some cases showing that the maximum possible time during which their sex-determining genes have existed must be much shorter than those of several animal taxa. Consequently, their sex-linked regions could either have evolved soon after genetic sex determination arose or considerably later. Plants, therefore, include species with both young and old systems. I review several questions about the evolution of sex-determining systems and sex chromosomes that require studies of young systems, including: the kinds of mutations involved in the transition to unisexual reproduction from hermaphroditism or monoecy (a form of functional hermaphroditism); the times when they arose; and the extent to which the properties of sex-linked regions of genomes reflect responses to new selective situations created by the presence of a sex-determining locus. I also evaluate which questions are best studied in plants, vs other suitable candidate organisms. Studies of young plant systems can help understand general evolutionary processes that are shared with the sex chromosomes of other organisms.
The authors analyzed experiences, characteristics, and risks of adult women who trade sex in Minneapolis, MN (n = 117), and found significant differences between women who first traded sex as a ...juvenile compared with those who first traded sex as an adult. Adult starters were 3.44 times more likely to use drugs prior to their first sex trade. They were also more likely to have children. Juvenile starters were more likely to trade sex prior to their first instance of drug use and they had worse outcomes in most other domains that were measured. The study findings showed that they can be useful in shaping prevention of prostitution and methods to be used for its intervention.
Obesity is associated with many adverse health effects, such as an increased cardiometabolic risk. Despite higher adiposity for a given BMI, premenopausal women are at lower risk of cardiometabolic ...disease than men of the same age. This cardiometabolic advantage in women seems to disappear after the menopause or when type 2 diabetes mellitus develops. Sexual dimorphism in substrate supply and utilization, deposition of excess lipids and mobilization of stored lipids in various key metabolic organs (such as adipose tissue, skeletal muscle and the liver) are associated with differences in tissue-specific insulin sensitivity and cardiometabolic risk profiles between men and women. Moreover, lifestyle-related factors and epigenetic and genetic mechanisms seem to affect metabolic complications and disease risk in a sex-specific manner. This Review provides insight into sexual dimorphism in adipose tissue distribution, adipose tissue, skeletal muscle and liver substrate metabolism and tissue-specific insulin sensitivity in humans, as well as the underlying mechanisms, and addresses the effect of these sex differences on cardiometabolic health. Additionally, this Review highlights the implications of sexual dimorphism in the pathophysiology of obesity-related cardiometabolic risk for the development of sex-specific prevention and treatment strategies.
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