Sex Specificity Research Articles

In pursuit of scientific excellence: sex matters

In pursuit of scientific excellence: sex matters

In pursuit of scientific excellence: sex matters

In pursuit of scientific excellence: sex matters

In pursuit of scientific excellence: sex matters

In pursuit of scientific excellence: sex matters

In pursuit of scientific excellence: sex matters

In pursuit of scientific excellence: sex matters

In pursuit of scientific excellence: sex matters

the year 2012 marks the 125th anniversary of the American Physiological Society (APS). Throughout its history, APS has been a leader in innovation and excellence in scientific technology, discovery, education, and publication. Consistent with this history, APS is leading the scientific publication

SCALE-SPECIFIC SEX-BIASED DISPERSAL IN THE VALAIS SHREW UNVEILED BY GENETIC VARIATION ON THE Y CHROMOSOME, AUTOSOMES, AND MITOCHONDRIAL DNA

We investigated sex specificities in the evolutionary processes shaping Y chromosome, autosomes, and mitochondrial DNA patterns of genetic structure in the Valais shrew (Sorex antinorii), a mountain dwelling species with a hierarchical distribution. Both hierarchical analyses of variance and isolation-by-distance analyses revealed patterns of population structure that were not consistent across maternal, paternal, and biparentally inherited markers. Differentiation on a Y microsatellite was lower than expected from the comparison with autosomal microsatellites and mtDNA, and it was mostly due to genetic variance among populations within valleys, whereas the opposite was observed on other markers. In addition, there was no pattern of isolation by distance for the Y, whereas there was strong isolation by distance on mtDNA and autosomes. We use a hierarchical island model of coancestry dynamics to discuss the relative roles of the microevolutionary forces that may induce such patterns. We conclude that sex-biased dispersal is the most important driver of the observed genetic structure, but with an intriguing twist: it seems that dispersal is strongly male biased at large spatial scale, whereas it is mildly biased in favor of females at local scale. These results add to recent reports of scale-specific sex-biased dispersal patterns, and emphasize the usefulness of the Y chromosome in conjunction with mtDNA and autosomes to infer sex specificities.

Human IgG Fc-glycosylation profiling reveals associations with age, sex, female sex hormones and thyroid cancer

IgG functions rely on interactions of the Fc region with other proteins, which are optimized by tailoring of a conserved N-linked glycosylation at Asn-297. We conducted a study involving 735 control individuals and 138 thyroid cancer patients. Here we demonstrated that previously described age-related change in Fc-glycosylation was further characterized by definite sex specificity. In females, the incidences of most of glycosylated forms began to pose characteristic changes at ages of puberty or menopause. In addition, glycan-glycan relationships existed extensively within Fc glycosylation, which were characterized to be altered upon different states of subjects, such as age, sex and thyroid cancer. In thyroid cancer patients, detailed comparison of glycosylation incidences with control individuals yielded insight into aberrant change in IgG(1) Fc-glycosylation. This aberrant pattern was also featured by remarkable specificities of both age and sex. The receiver operating characteristic curve analysis was used to determine diagnostic values of Fc glycosylation. Finally, clinical measurement of two major female sex hormones estradiol and progesterone was conducted to determine potential associations of hormones with IgG Fc glycosylation. This study provided an important view to the associations of IgG Fc N-linked glycosylation with age, sex, female sex hormones and thyroid cancer. This article is part of a Special Issue entitled: Proteomics: The clinical link.

The relationship between color–object associations and color preference: Further investigation of ecological valence theory

Ecological valence theory (EVT; Palmer & Schloss, Proceedings of the National Academy of Sciences 107:8877-8882, 2010) proposes that color preferences are due to affective responses to color-associated objects: That is, people generally like colors to the degree that they like the objects associated with those colors. Palmer and Schloss found that the average valence of objects associated with a color, when weighted by how well the objects matched the color (weighted affective valence estimates: WAVE) explained 80% of the variation in preference across colors. Here, we replicated and extended Palmer and Schloss's investigation to establish whether color-object associations can account for sex differences in color preference and whether the relationship between associated objects and color preference is equally strong for males and females. We found some degree of sex specificity to the WAVEs, but the relationship between WAVE and color preference was significantly stronger for males than for females (74% shared variance for males, 45% for females). Furthermore, analyses identified a significant inverse relationship between the number of objects associated with a color and preference for the color. Participants generally liked colors associated with few objects and disliked colors associated with many objects. For the sample overall and for females alone, this association was not significantly weaker than the association of the WAVE and preference. The success of the WAVE at capturing color preference was partly due to the relationship between the number of associated objects and color preference. The findings identify constraints of EVT in its current form, but they also provide general support for the link between color preference and color-object associations.

How Are Homicide, Suicide, and Drinking Age Related?

Back to table of contents Previous article Next article Clinical & Research NewsFull AccessHow Are Homicide, Suicide, and Drinking Age Related?Leslie SinclairLeslie SinclairSearch for more papers by this authorPublished Online:3 Feb 2012https://doi.org/10.1176/pn.47.3.psychnews_47_3_26-aAbstractCari Lightner’s legacy may be more far reaching than anyone thought. She was the 13-year-old girl whose death in 1980 caused by a hit-and-run drunk driver spurred her mother, Candace Lightner, to create Mothers Against Drunk Driving (MADD). Candace Lightner’s personal crusade was so successful that only two years after Cari’s death, Lightner was invited by President Ronald Reagan to be a member of the presidential commission that subsequently recommended the minimum legal drinking age (MLDA) be raised to 21.The National Minimum Drinking Age Act of 1984 legislated the withholding of revenue from states that allow the purchase of alcohol by anyone under the age of 21; by 1987, all 50 states had set their MLDA at 21.Raising the minimum legal drinking age may have prevented more deaths than just those caused by drunk drivers.olly/ShutterstockNow, more than 30 years after Lightner founded MADD, proponents say that alcohol-related traffic fatalities in the United States have been cut by 40 percent, and they estimate that MADD and its efforts have saved more than 300,000 lives.But researchers at the Washington University School of Medicine in St. Louis, in a November 15, 2011, online article in Alcoholism: Clinical and Experimental Research, have chronicled another possible result of the change in MLDA that may have added substantially to the number of lives saved: A lower MLDA appears to be associated with a persistent, elevated risk for suicide and homicide among women. These researchers said their data suggest that the national MLDA of 21 may be preventing as many as 600 suicides and 600 homicides annually in the United States.Their findings are based on an analysis of data from the U.S. Multiple Cause of Death files, 1990 to 2004, combined with data on the living population from the U.S. Census and American Community Survey.Richard Grucza, Ph.D., M.P.E., an assistant professor of psychiatry at Washington University in St. Louis, and colleagues found that women who grew up during a time of lower drinking-age laws in some states, particularly women born after 1960, were at higher risk for taking their own life or that of someone else. The databases the researchers examined included records on more than 200,000 suicides and 130,000 homicides for individuals born from 1949 to 1972, who reached adulthood during years when the drinking age was in flux in many states.Why women but not men? “The sex specificity of the MLDA-suicide and MLDA-homicide associations may be related to unique alcohol-related risks faced by women,” wrote Grucza and colleagues. They also theorized that although suicide attempts are more common in women but completions are more prevalent in men, alcohol problems stemming from lower MLDAs may increase the lethality of suicide attempts by women, as well as elevate rates of partner violence and influence rates of female homicide deaths.They also speculated that the reason suicide and homicide rates were not associated with MLDA for women born prior to 1960 may be that “excessive drinking was simply not part of the culture for women born in earlier years of the cohorts examined here, and changing cultural norms may be a key contributor to MLDA-associated suicide and homicide risk observed for more recent birth years.”Could other factors be involved? “Because we were working with vital-statistics data, there were a limited number of additional factors that could be explicitly modeled, although education was one of them, and it did not influence the association,” Grucza explained to Psychiatric News. “Unless other factors changed at the same times and in the same places as drinking-age laws, they are unlikely to account for the association we saw between MLDA and suicide/homicide.”The study was supported by grants from the National Institutes of Health.An abstract of “The Legacy of Minimum Legal Drinking Age Law Changes: Long-Term Effects on Suicide and Homicide Deaths Among Women” is posted at http://onlinelibrary.wiley.com/doi/10.1111/j.1530-0277.2011.01608.x/abstract. ISSUES NewArchived

Age variation and sexual dimorphism in the sixteen diagnostic clusters of risk factors for the metabolic syndrome

ObjectiveTo document age- and sex-related differences in the 16 phenotypes of risk factors for the metabolic syndrome (MS) among adults in the Fels Longitudinal Study (FLS).MethodsData on risk factors for the MS were analyzed in 471 white men and 503 white women in the FLS. We used the Cochran-Armitage test to compare age- and sex-related differences in the prevalence of the 16 diagnostic clusters of positive risk factors.ResultsOf the 974 subjects, 238 were found to meet diagnostic criteria for 15 of a possible 16 phenotypes of the MS. The prevalence of the MS was four times greater in subjects older than 40 years than in subjects 20–40 years old. Older subjects had more risk factors exceeding criterion values than younger subjects. Among those who met three-to-five criteria for the MS, younger subjects were more likely to have dyslipidemia, less likely to have high blood pressure (HBP), and two times less likely to have impaired fasting plasma glucose (IFG) than subjects 40+ years old. Older men were more likely than older women to have HBP and IFG. . We found that if one of the five risk factors reaches a criterion value, the values for the other four risk factors move closer to their own diagnostic criterion values in apparent synchrony.ConclusionsSubjects 40+ years old are four times likelier to have the MS than younger subjects, and older men are at higher risk than older women. The mean values for each of the five risk factors get progressively worse as the number of risk factors meeting diagnostic criteria increases. Therefore, when one factor is found to meet its diagnostic criterion, levels of the other four risk factors should be measured. The different phenotypic patterns that comprise the MS should prompt clinicians to target specific risk factors for prevention or treatment. Certain phenotypes were found more commonly in women and certain others more commonly in men. Similarly, certain phenotypes were found more commonly in older than in younger age groups. These age- and sex-specific phenotypes should help clinicians to identify subjects at highest risk for certain risk factors and to initiate specifically tailored preventive and therapeutic interventions. Our observations should also stimulate clinical investigators and epidemiologists to ascertain what factors determine the sex and age specificity of certain phenotypes of the MS.

Short Communication An AFLP-based approach for the identification of sex-linked markers in blunt snout bream, Megalobrama amblycephala (Cyprinidae)

Sex-specific DNA markers are useful for studying sex-determination mechanisms and establishment of monosex populations. Three widely spaced geographical populations (Liangzi, Poyang and Yuni Lakes in China) of blunt snout bream (Megalobrama amblycephala) were screened with AFLPs to search for sex-linked markers. Female and male pools (10 individuals in each pool) from each population were screened using 64 different primer combinations. A total of 4789 genomic fragments were produced, with a mean frequency of 75 bands per primer pair. Three different primer combinations produced putative sex-associated amplifications and were selected for individual screening in the three populations. However, none showed sex specificity when we converted these three markers into sequence characterized amplified region markers and evaluated all the individuals from the three populations.

Frequency of RBC Alloantibodies in Chinese Surgical Patients

Background: The aim of this study was to evaluate the frequency of red blood cell (RBC) alloantibodies in surgical patients. Methods: Blood samples of 18,980 Chinese surgical patients were collected and tested between January 2009 and September 2010. For patients with RBC alloantibodies, sequences of antibodies were identified with the DiaMed Asia antibody screening system. Data regarding sex, age, transfusion history, pregnancy history, and alloantibody specificity were collected. Results: 39 alloantibodies were identified from 18,980 samples, yielding a prevalence of 0.21%. The most frequently identified alloantibodies were Rhesus system antibodies (28/39, 71.8%), including anti-E (17/39; 1 anti-E accompanied by anti-Fy^b), anti-c (5/39), anti-cE (2/39), anti-C^w (1/39), anti-D (1/39), and anti-e (1/39). Other antibodies included anti-M (5/39), anti-Le^a (2/39), anti-Le^b (1/39), anti-K+S (1/39), anti-JK^a (1/39), and anti-JS^a (1/39). The frequency of alloantibodies was greater in females than in males (31 vs. 8). Conclusion: The results show a higher prevalence of RBC alloantibodies in females than in males. Anti-E was the most common alloantibody identified in this Chinese surgical population and was also more frequent in females compared to males.

The sex specificity of hip-joint muscles offers an explanation for better results in men after total hip arthroplasty

Choosing a surgical approach for total hip arthroplasty (THA) has a patient-specific impact on peri-operative muscle damage as well as postoperative functional outcome. Women and aged patients increasingly benefit from minimally invasive surgical procedures. For this reason, and due to the distinctly different bony anatomy of men and women, the hypothesis of this study is that muscle distribution around the hip joint is dependent on sex and age. The goal of this study was to analyse hip musculature in men and women and to correlate total muscle volume distribution. From 93 computed tomography (CT) scans of the pelvis (45 men, 48 women) volumes of gluteus medius (GMV), gluteus maximus (GXV) and tensor faciae latae (TFL) muscles were measured on both sides of the pelvis. The distribution of muscle volumes was normalised to patient weight and then correlated with sex and age. The measured muscle volumes featured no major differences between the left and the right side. The absolute total volume of the hip-encompassing muscular system (TMV) is bigger in men than in women. Correlations between TMV and collected data were observed in both sexes in relation to body weight and size (men p < .00001; women p 0.001). With increased body weight, the TMV of the male patients increased progressively (women 11.2 cm TMV/kg KG vs. men 17.4 cm TMV/kg KG) (p 0.04). The relative distribution of each muscle volume (GMV, GXV, TFL) around the hip joint showed no major differences with respect to sex and/or age (p 0.986 and 0.996, respectively). The equal relative muscle distribution in men and women around the hip joint reflects neither sex-related differences observed in clinical outcomes after THA nor bony anatomy. Yet men exhibited more muscle reserves (muscle volume; absolute and in relation to body mass) , which could explain the better outcome in men after THA. Furthermore, this suggests the extraordinary importance of muscle-sparing surgical approaches in women. The results represent the rationale for designing and analysing future studies of sex-specific therapies with regard to hip-joint muscles.

Chronic stress induces sex-specific alterations in methylation and expression of corticotropin-releasing factor gene in the rat.

BackgroundAlthough the higher prevalence of depression in women than in men is well known, the neuronal basis of this sex difference is largely elusive.MethodsMale and female rats were exposed to chronic variable mild stress (CVMS) after which immediate early gene products, corticotropin-releasing factor (CRF) mRNA and peptide, various epigenetic-associated enzymes and DNA methylation of the Crf gene were determined in the hypothalamic paraventricular nucleus (PVN), oval (BSTov) and fusiform (BSTfu) parts of the bed nucleus of the stria terminalis, and central amygdala (CeA).ResultsCVMS induced site-specific changes in Crf gene methylation in all brain centers studied in female rats and in the male BST and CeA, whereas the histone acetyltransferase, CREB-binding protein was increased in the female BST and the histone-deacetylase-5 decreased in the male CeA. These changes were accompanied by an increased amount of c-Fos in the PVN, BSTfu and CeA in males, and of FosB in the PVN of both sexes and in the male BSTov and BSTfu. In the PVN, CVMS increased CRF mRNA in males and CRF peptide decreased in females.ConclusionsThe data confirm our hypothesis that chronic stress affects gene expression and CRF transcriptional, translational and secretory activities in the PVN, BSTov, BSTfu and CeA, in a brain center-specific and sex-specific manner. Brain region-specific and sex-specific changes in epigenetic activity and neuronal activation may play, too, an important role in the sex specificity of the stress response and the susceptibility to depression.

Sex-specific incompatibility generates locus-specific rates of introgression between species.

Disruption of interactions among ensembles of epistatic loci has been shown to contribute to reproductive isolation among various animal and plant species. Under the Bateson–Dobzhansky–Muller model, such interspecific incompatibility arises as a by-product of genetic divergence in each species, and the Orr–Turelli model indicates that the number of loci involved in incompatible interactions may “snowball” over time. We address the combined effect of multiple incompatibility loci on the rate of introgression at neutral marker loci across the genome. Our analysis extends previous work by accommodating sex specificity: differences between the sexes in the expression of incompatibility, in rates of crossing over between neutral markers and incompatibility loci, and in transmission of markers or incompatibility factors. We show that the evolutionary process at neutral markers in a genome subject to incompatibility selection is well approximated by a purely neutral process with migration rates appropriately scaled to reflect the influence of selection targeted to incompatibility factors. We confirm that in the absence of sex specificity and functional epistasis among incompatibility factors, the barrier to introgression induced by multiple incompatibility factors corresponds to the product of the barriers induced by the factors individually. A new finding is that barriers to introgression due to sex-specific incompatibility depart in general from multiplicativity. Our partitioning of variation in relative reproductive rate suggests that such departures derive from associations between sex and incompatibility and between sex and neutral markers. Concordant sex-specific incompatibility (for example, greater impairment of male hybrids or longer map lengths in females) induces lower barriers (higher rates of introgression) than expected under multiplicativity, and discordant sex-specific incompatibility induces higher barriers.

Prenatal programming of the innate immune response following in utero exposure to inflammation: a sexually dimorphic process?

Maternal infection and inflammation are common events during pregnancy. This article documents evidence that suggests such inflammation compromises the development of the fetal innate immune response, in support of an in utero origins hypothesis of neonatal and childhood inflammatory disease. The potential for this response to exhibit sex specificity is also explored, based on evidence of sexually dimorphic placental responses to maternal inflammation.

Model selection procedures for high dimensional genomic data

Many complex diseases are thought to be caused by multiple genetic variants. Recent advances in genotyping technology allowed investigators of a complex disease to obtain data for a massive number of candidate genetic variants. Typically each candidate variant is tested individually for an association with the disease. We approach the problem as one of model selection for high dimensional data. We propose a method whereby penalised maximum likelihood estimation provides a reasonably sized set of variants for inclusion in our model. We then perform stepwise regression on this set of variants to arrive at our model. Penalised maximum likelihood estimation is performed with both the lasso and a more recently developed method known as the hyperlasso, with smoothing parameters chosen by cross-validation. The hyperlasso has a penalty function that favours sparser solutions but with less shrinkage of those variables that are included in the model, when compared to the lasso; however, this comes at extra computational cost. We apply the above method to a large genomic data set from a previously published mice obesity study and use resample model averaging to assess model performance. References Kristin A. Ayers and Heather J. Cordell. SNP selection in genome-wide and candidate gene studies via penalized logistic regression. Genetic Epidemiology, 38:879--891, 2010. doi:10.1002/gepi.20543 David J. Balding. A tutorial on statistical methods for population association studies. Nature Reviews Genetics, 7:781--791, 2006. doi:10.1038/nrg1916 Christopher S. Carlson, Michael A. Eberle, Mark J. Rieder, Qian Yi, Leonid Kruglyak, and Deborah A. Nickerson. Selecting a maximally informative set of single-nucleotide polymorphisms for association analyses using linkage disequilibrium. Am. J. Hum. 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Plasmodium falciparum NIMA-related kinase Pfnek-1: sex specificity and assessment of essentiality for the erythrocytic asexual cycle

The Plasmodium falciparum kinome includes a family of four protein kinases (Pfnek-1 to -4) related to the NIMA (never-in-mitosis) family, members of which play important roles in mitosis and meiosis in eukaryotic cells. Only one of these, Pfnek-1, which we previously characterized at the biochemical level, is expressed in asexual parasites. The other three (Pfnek-2, -3 and -4) are expressed predominantly in gametocytes, and a role for nek-2 and nek-4 in meiosis has been documented. Here we show by reverse genetics that Pfnek-1 is required for completion of the asexual cycle in red blood cells and that its expression in gametocytes in detectable by immunofluorescence in male (but not in female) gametocytes, in contrast with Pfnek-2 and Pfnek-4. This indicates that the function of Pfnek-1 is non-redundant with those of the other members of the Pfnek family and identifies Pfnek-1 as a potential target for antimalarial chemotherapy. A medium-throughput screen of a small-molecule library provides proof of concept that recombinant Pfnek-1 can be used as a target in drug discovery.

Sex specificity of the spatiotemporal organization of brain bioelectric potentials in adults and five- to six-year-old children in a state of quiet wakefulness

Correlation and coherence analyses of EEG recordings from 26 children aged five to seven years (12 boys and 14 girls) as compared to 33 adult subjects (18 women and 15 men) has been carried out to study the topical features of the spatial structure of EEG distant interactions. A higher level of EEG intrahemispheric interactions in the posttemporal and frontal areas of the left hemisphere has been found in men as compared to women in whom the prevalence of interhemispheric interactions due to the expressed EEG interactions in the bilaterally symmetric areas of both hemispheres has been found. A different type of sex-related differences in the systemic organization of interregional interactions of cortical potentials, as compared to adults, has been found in preschool children. In particular, a higher prevalence of EEG distant interactions has been found in those areas of the left hemisphere, the EEG interactions of which were higher in adult men. The data show that a distinct sexual dimorphism of interregional interactions of cortex potentials in adult subjects and children is formed due to the topology of the different EEG distant interactions differing in men and women. Investigations of the sex specificity of the spatiotemporal organization of brain bioelectric potentials in children can promote understanding of the sexual identity role in development of human brain systemic activity.

Genetic Variation in Captive Herd of Arabian Oryx Using RAPD and ISSR Markers

According to the international taxonomy of IUCN, the Arabian Oryx (Oryx leucoryx) is considered to be in endangered and included among the animals that may be extinct. Saudi Arabia began an important project of captive breeding of this species in 1986 at the National Wildlife Research Center (NWRC). Therefore, the current captive population of Saudi Arabian Oryx at NWRC may suffer from inbreeding depression due to the population of small sizes. The genetic variation among 10 Arabian Oryx animals was studied using random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) markers. The animals were chosen as a representative sample of NWRC current herd. The objectives of this study were: (1) Establishment of RAPD and ISSR marker sets for the genetic characterization of Saudi Arabian Oryx and (2) application of the RAPD and ISSR markers for the identification and estimation of the genetic variation among the 10 Arabian Oryx animals. The results of the RAPD and ISSR primers used in this study confirmed that there was no sex specificity for any of them. 20 random primers were used for the RAPD experiment that generated 118 fragments with 93.5% polymorphism (110 fragments). Also, 12 ISSR primers were used to detect the polymorphism level among the 10 animals of Arabian Oryx. These primers generated 89 fragments and the number of polymorphic fragment was 65 (71.5%). At the same time, they showed average heterozygosity (variability measurement) of 0.24 among the 89 ISSR loci. The result of the genetic variation of RAPD and ISSR indicated a high level of variation among the 10 genotypes as a representative sample of the animals from the germplasm of NWRC. Finally, it can be recommended that the amount of variations among the NWRC germplasm is enough for selection and breeding improvement without affecting the genetic diversity within the captive herd. Key words: Arabian Oryx, captive herd, National Wildlife Research Center (NWRC),random amplified polymorphic DNA (RAPD), inter simple sequence repeat (ISSR), genetic diversity, Saudi Arabia.