Male Traits Research Articles

Potential candidate genes and pathways related to cytoplasmic male sterility in Dianthus spiculifolius as revealed by transcriptome analysis.

We introduced the candidate gene DsHSP70 into Arabidopsis thaliana, resulting in male gametophyte sterility and abnormal degeneration of sepals and petals. Cytoplasmic male sterility (CMS) is a useful tool for hybrid production. However, the regulatory mechanism of CMS in Dianthus spiculifolius remains unclear. In this study, we investigated whether male-sterile line of D. spiculifolius has a malformed tapetum and fails to produce normal fertile pollen. RNA sequencing technology was used to compare the gene expression patterns of the D. spiculifolius male-sterile line and its male fertility maintainer line during anther development. A total of 12,365 differentially expressed genes (DEGs) were identified, among which 1765 were commonly expressed in the S1, S2 and S3 stages. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that these DEGs were mainly involved in oxidation-reduction processes, signal transduction and programmed cell death. Additionally, weighted correlation network analysis (WGCNA) showed that three modules may be related to male sterility. A putative regulatory pathway for the male sterility traits was constructed based on the reproductive development network. After introducing the candidate DsHSP70 gene into Arabidopsis thaliana, we found that overexpressing plants showed anther abortion and shorter filaments, and accompanied by abnormal degeneration of sepals and petals. In summary, our results identified potential candidate genes and pathways related to CMS in D. spiculifolius, providing new insights for further research on the mechanism of male sterility.

Adherence to the Mediterranean Diet in Preventing Major Cardiovascular Events in Patients with Ischemic Heart Disease: The EVA Study.

Adherence to healthy dietary patterns, such as the Mediterranean diet (Med-diet), is recommended for the maintenance of cardiovascular health. The determinants for adherence to Med-diet and its importance in secondary cardiovascular disease prevention are still unclear. The aim of the study was to evaluate the influence of sex- and psycho-socio-cultural (i.e., gender-related) factors on Med-diet adherence and its role in preventing major cardiovascular events (MACEs) in patients with ischemic heart disease (IHD). Med-diet adherence was evaluated among 503 consecutive adults with IHD. MACEs were collected during a long-term follow-up. Male Bem Sex-Role Inventory score (i.e., male personality traits) and physical functional capacity were associated with higher adherence, while cohabitation with a smoker and physical inactivity with poorer adherence. During a median follow-up of 22 months, 48 participants experienced MACEs (17.5%, 8.1%, and 3.9% of patients with low, medium, and high adherence, respectively; p = 0.016). At multivariate Cox--regression analysis, a greater adherence remained inversely associated with MACEs (HR: 0.49; 95% CI: 0.29-0.82; p = 0.006) after adjusting for confounding factors. The study suggests that gender-related factors have a role in maintaining a healthy dietary pattern. Improving Med-diet adherence may lower the risk of recurring cardiovascular events.

Sex differences in placenta-derived markers and later autistic traits in children

Autism is more prevalent in males and males on average score higher on measures of autistic traits. Placental function is affected significantly by the sex of the fetus. It is unclear if sex differences in placental function are associated with sex differences in the occurrence of autistic traits postnatally. To assess this, concentrations of angiogenesis-related markers, placental growth factor (PlGF) and soluble fms-like tyrosine kinase (sFlt-1) were assessed in maternal plasma of expectant women in the late 1st (mean= 13.5 [SD = 2.0] weeks gestation) and 2nd trimesters (mean=20.6 [SD = 1.2] weeks gestation), as part of the Generation R Study, Rotterdam, the Netherlands. Subsequent assessment of autistic traits in the offspring at age 6 was performed with the 18-item version of the Social Responsiveness Scale (SRS). Associations of placental protein concentrations with autistic traits were tested in sex-stratified and cohort-wide regression models. Cases with pregnancy complications or a later autism diagnosis (n = 64) were also assessed for differences in placenta-derived markers. sFlt-1 levels were significantly lower in males in both trimesters but showed no association with autistic traits. PlGF was significantly lower in male pregnancies in the 1st trimester, and significantly higher in the 2nd trimester, compared to female pregnancies. Higher PlGF levels in the 2nd trimester and the rate of PlGF increase were both associated with the occurrence of higher autistic traits (PlGF-2nd: n = 3469,b = 0.24 [SE = 0.11], p = 0.03) in both unadjusted and adjusted linear regression models that controlled for age, sex, placental weight and maternal characteristics. Mediation analyses showed that higher autistic traits in males compared to females were partly explained by higher PlGF or a faster rate of PlGF increase in the second trimester (PlGF-2nd: n = 3469, ACME: b = 0.005, [SE = 0.002], p = 0.004). In conclusion, higher PlGF levels in the 2nd trimester and a higher rate of PlGF increase are associated with both being male, and with a higher number of autistic traits in the general population.

Latitudinal cline in reproductive traits in the red flour beetle Tribolium castaneum

Several previous studies have reported geographic variation and/or latitudinal clines of morphological sexual characteristics, but there are few studies that consider reproductive traits that are not morphological. Here, we measured the proportion of females fertilized by males, frequency of reproductive failure in males, and number of female copulations of the red flour beetle Tribolium castaneum collected from fields in Japan to investigate the relationship between reproductive traits and latitude. Our results show substantial differences in the reproductive traits of both sexes among field populations. We identified latitudinal clines for reproductive traits in males, but not females. Moreover, female, but not male, reproductive traits were correlated with body size. Our study suggests that selection for male reproductive traits varies with latitude in T. castaneum.Significance statementIt has been established that latitudinal gradients are frequently observed in the traits of numerous animal species, of which body size is a prime example. Analogously, latitudinal gradients have been documented in the reproductive traits of several animal species, indicating that sexual selection may be influenced by latitude, although the specific understanding thereof remains elusive. In this study, we quantified the male and female reproductive traits and analyzed their relationship with latitude in the red flour beetle Tribolium castaneum. Our findings indicate that male mating efficacy was superior at lower than at higher latitudes, but no discernible latitudinal gradient was observed in female mating frequency. These results imply that selective pressure on males of this species is stronger at lower than at higher latitudes.

Humidity stress and its consequences for male pre‐ and post‐copulatory fitness traits in an insect

AbstractGlobal declines in insect abundance are of significant concern. While there is evidence that climate change is contributing to insect declines, we know little of the direct mechanisms responsible for these declines. Male fertility is compromised by increasing temperatures, and the thermal limit to fertility has been implicated as an important factor in the response of insects to climate change. However, climate change is affecting both temperature and hydric conditions, and the effects of water availability on male fertility have rarely been considered. Here we exposed male crickets Teleogryllus oceanicus to either low or high‐humidity environments while holding temperature constant. We measured water loss and the expression of both pre‐ and postmating reproductive traits. Males exposed to a low‐humidity environment lost more water than males exposed to a high‐humidity environment. A male's cuticular hydrocarbon profile (CHC) did not affect the amount of water lost, and males did not adjust the composition of their CHC profiles in response to hydric conditions. Males exposed to a low‐humidity environment were less likely to produce courtship song or produced songs of low quality. Their spermatophores failed to evacuate and their ejaculates contained sperm of reduced viability. The detrimental effects of low‐humidity on male reproductive traits will compromise male fertility and population persistence. We argue that limits to insect fertility based on temperature alone are likely to underestimate the true effects of climate change on insect persistence and that the explicit incorporation of water regulation into our modeling will yield more accurate predictions of the effects of climate change on insect declines.

Drought and temperature stresses impact pollen production and autonomous selfing in a California wildflower, Collinsia heterophylla

AbstractOngoing climatic changes have altered growing conditions for plants by limiting water availability and inducing unprecedented temperature increases, eliciting plant functional responses that compromise floral trait expression, reduce pollen production and promote early self‐pollination. In a controlled greenhouse study, plants of Collinsia heterophylla, an annual mixed‐mated hermaphrodite, were grown under temperature and water stresses. Floral trait responses and related effects on plant reproductive success were recorded. Plants grown under temperature and water stresses were shorter and had fewer leaves at flowering than control plants. Temperature‐stressed plants flowered earlier and had smaller flowers that produced fewer per capita pollen grains than control and water‐stressed plants. While lifetime flower production in plants experiencing temperature stress alone or water stress alone was similar to control plants, those receiving combined temperature and water stresses had significantly lower lifetime flower production. Abiotic stress did not affect investment in female traits such as ovule number per flower, but impacted male traits seen as fewer pollen grains per flower. In plants experiencing abiotic stress, an increase in autonomous self‐pollination was facilitated through a compromise in herkogamy, a sexual interference mechanism that promotes cross‐pollination. Spatial separation between stigma and anther, a measure of herkogamy was zero or negative in stressed plants. Thus, abiotic stress responses in plants did not compromise plant reproductive success as autonomous selfing was augmented. In nature, such responses will likely reduce available nutrition for pollinators through decreased flower and pollen production.

The Mediating Role of Dark Triad Personality Traits in the Relationship Between Childhood Traumas and Obsessive Beliefs

This study aims to investigate the relationship between childhood traumas, dark triad personality traits, and obsessive beliefs. Personal Information Form, Childhood Trauma Questionnaire, Short Dark Triad Scale, and Obsessive Beliefs Questionnaire were used to collect data in the study. A total of 480 volunteers, of which 306 were female and 174 were male, participated in the study. Pearson Correlation Analysis, independent samples t-test, and Parallel Multiple Mediator Variable analysis were used for the analysis of the obtained data. The correlation analysis results showed that childhood traumas were significantly and positively associated with both dark triad personality traits and obsessive beliefs. Male participants' psychopathic personality traits mean scores were found to be significantly higher than those of females. Mediation analysis results show that the psychopathic personality traits had a mediating effect on the relationship between the physical and emotional neglect and abuse sub-dimensions of childhood traumas and obsessive beliefs. The findings were discussed vis-à-vis the available relevant literature and suggestions were presented.

Association of A51703G and G51656T loci polymorphism in luteinizing hormone receptor (LHR) gene with sperm traits in Holstein bulls

Today, there is an increasing desire to use Candidate genes as molecular markers to improve reproductive traits. The luteinizing hormone receptor is expressed on the Leydig cells and plays a crucial role in gametogenesis initiation and maintenance. This study aimed to study the effects of luteinizing hormone receptor (LHR) gene polymorphisms (A51703G and G51656T) on bull sperm traits. Genomic DNA was extracted from the semen, blood, and samples of 150 AI Iranian Holstein bulls according to the established protocol [10] with minor modifications. Semen traits were routinely collected at bull semen collection centers from each animal between 1992 and 2015. The bull fertility traits include semen concentration (SC 108 per ml) sperm volume (SV ml), fresh sperm motility (FSM %), and post-tallow sperm motility (PTSM %). The mutation was detected with A PCR-RFLP method. The digestion of amplicons was also carried out with BfaI and HinfI restriction enzymes in A51703G and G51656T loci, respectively. The restriction profiles of PCR products indicated two alleles in each locus (A and G for A51703G and G and T for G51656T). The frequency of the A and T alleles were 0.6647 and 0.606, respectively. Analysis of variance showed that LHR loci had a significant effect on sperm characteristics in Iranian Holstein bulls (P < 0.05). Bulls with GG genotype surpassed those with GA and AA genotypes regarding SP, FSM, and PTSM in the A51703G locus. In the G51656T locus, the association result showed that bulls with AG genotype had higher than others in all traits (P < 0.05). In conclusion, these data suggest that LHR polymorphisms are an excellent genetic marker for breeding programs in male reproductive traits in the Iranian bull population.

The coevolutionary dynamics of cryptic female choice.

In contrast to sexual selection on traits that affect interactions between the sexes before mating, little theoretical research has focused on the coevolution of postmating traits via cryptic female choice (when females bias fertilization toward specific males). We used simulation models to ask (a) whether and, if so, how nondirectional cryptic female choice (female-by-male interactions in fertilization success) causes deviations from models that focus exclusively on male-mediated postmating processes, and (b) how the risk of sperm competition, the strength of cryptic female choice, and tradeoffs between sperm number and sperm traits interact to influence the coevolutionary dynamics between cryptic female choice and sperm traits. We found that incorporating cryptic female choice can result in males investing much less in their ejaculates than predicted by models with sperm competition only. We also found that cryptic female choice resulted in the evolution of genetic correlations between cryptic female choice and sperm traits, even when the strength of cryptic female choice was weak, and the risk of sperm competition was low. This suggests that cryptic female choice may be important even in systems with low multiple mating. These genetic correlations increased with the risk of sperm competition and as the strength of cryptic female choice increased. When the strength of cryptic female choice and risk of sperm competition was high, extreme codivergence of sperm traits and cryptic female choice preference occurred even when the sperm trait traded off with sperm number. We also found that male traits lagged behind the evolution of female traits; this lag decreased with increasing strength of cryptic female choice and risk of sperm competition. Overall, our results suggest that cryptic female choice deserves more attention theoretically and may be driving trait evolution in ways just beginning to be explored.

Eighty million years of rapid evolution of the primate Y chromosome.

The Y chromosome usually plays a critical role in determining male sex and comprises sequence classes that have experienced unique evolutionary trajectories. Here we generated 19 new primate sex chromosome assemblies, analysed them with 10 existing assemblies and report rapid evolution of the Y chromosome across primates. The pseudoautosomal boundary has shifted at least six times during primate evolution, leading to the formation of a Simiiformes-specific evolutionary stratum and to the independent start of young strata in Catarrhini and Platyrrhini. Different primate lineages experienced different rates of gene loss and structural and chromatin change on their Y chromosomes. Selection on several Y-linked genes has contributed to the evolution of male developmental traits across the primates. Additionally, lineage-specific expansions of ampliconic regions have further increased the diversification of the structure and gene composition of the Y chromosome. Overall, our comprehensive analysis has broadened our knowledge of the evolution of the primate Y chromosome.

Remodeling male coercion and the evolution of sexual autonomy by mate choice.

Models of sexual conflict over mating, including conflict over indirect benefits of mate choice, have generally presumed that female resistance to male coercion must involve direct confrontation, which can lead to sexually antagonistic coevolutionary arms-races. We built a quantitative model examining the largely ignored possibility that females may evolve new, additional mate preferences for new male traits that undermine male capacity to coerce. Thus, females may "remodel" the coercive capacity of the male phenotype in order to enhance their own sexual autonomy-a novel alternative mechanism by which females may avoid arms-races. We demonstrate that evolutionary "remodeling" is possible, in spite of costs to males, because females that prefer males with protective, autonomy-enhancing traits (traits correlated with lower coercion effectiveness) are likelier to gain indirect benefits of having attractive mates. Our analysis reveals new possibilities for the evolution of systems of sexual conflict over indirect benefits, showing that autonomy-enhancing male traits can act as a "public good," benefiting all females regardless of mating preferences, leading to oscillatory dynamics; and that preferences for more protective male traits will often be favored relative to preferences for less protective traits, potentially leading to an evolutionary "snowball" of expanding sexual autonomy.

Differential masculinization of the chelipeds in two simultaneously hermaphroditic Apseudes tanaidaceans (Crustacea: Malacostraca)

Simultaneous hermaphrodites are uncommon in Malacostraca, having been reported only in Decapoda, Isopoda, and Tanaidacea. Sexual traits not directly related to reproduction, such as masculinization of chelipeds, have received little attention. This study demonstrated that the tanaidacean Apseudes nipponicus Shiino is simultaneously hermaphroditic; and investigated the allometry of chelipeds in two simultaneously hermaphroditic tanaidaceans, A. nipponicus and Apseudes sp. The two species show differential masculinization of the chelipeds. In A. nipponicus, increase in the widths of the chelipedal carpus and chela relative to body size is diphasic, with a higher growth rate in larger individuals. Large individuals also develop ventral spiniform processes on the carpus and a dorsal triangular process on the fixed finger. In Apseudes sp., increase in the widths of the chelipedal carpus and chela relative to body size is monophasic; large individuals fail to develop ventral processes on the carpus but do produce a dorsal process on the fixed finger. The most masculinized state of cheliped development in Apseudes sp. resembles the state in A. nipponicus individuals at an early stage of chelipedal masculinization. Apseudes sp. is smaller in size than A. nipponicus, suggesting that the former might be a progenetic simultaneously hermaphroditic species, achieving earlier maturation as a female by reducing resource allocation to male secondary traits and growth.

Lack of Female Preference for Nuptial Gifts May Have Led to Loss of the Male Sexual Trait

Lack of Female Preference for Nuptial Gifts May Have Led to Loss of the Male Sexual Trait

Examination of the effects of inbreeding on reproductive capacity in the Pacific oyster, Crassostrea gigas

The Pacific oyster (Crassostrea gigas) has been widely cultured as a commercially important bivalve. Intercrossing of inbred strains is regarded as an efficient method to increase yield (heterosis), so the development of inbred lines is common in the breeding strategies of C. gigas. However, inbreeding usually reduces physiological efficiency or reproductive capacity. The effects of inbreeding on gonadal development and reproductive capacity remain to be explored in oysters. In the present study, the monthly gonadal development of an inbred and a control population was observed. Compared with the control population, the delayed gonadal development in the inbred population may require more time and cost for breeders in the artificial breeding process. We investigated how inbreeding influenced female and male gametic traits, including reproductive effort, egg diameter, fertilization rate, hatching rate, sperm motility, sperm longevity, and sperm curvilinear velocity, as well as sperm competitiveness based on a male's share of paternity. We found no inbreeding depression for egg diameter, fertilization rate, or sperm motility. However, maternal inbreeding decreased reproductive effort and hatching rate, and paternal inbreeding decreased sperm longevity, curvilinear velocity, and competitiveness. Our results show evidence of inbreeding depression in the gonadal development and reproductive capacity of C. gigas, which could help us in a better understanding and management of inbreeding in oyster aquaculture.

Integration of GWAS and eGWAS to screen candidate genes underlying green head traits in male ducks.

Sexually dimorphic plumage coloration is widespread in birds. The male possesses more brightly colored feathers than the female. Dark green head feathers comprise one of the most typical appearance characteristics of the male Ma duck compared with the female. However, there are noticeable individual differences observed in these characteristics. Herein, genome-wide association studies (GWAS) were employed to investigate the genetic basis of individual differences in male duck green head-related traits. Our results showed that 165 significant SNPs were associated with green head traits. Meanwhile, 71 candidate genes were detected near the significant SNPs, including four genes (CACNA1I, WDR59, GNAO1 and CACNA2D4) related to the individual differences in the green head traits of male ducks. Additionally, the eGWAS identified three SNPs located within two candidate genes (LOC101800026 and SYNPO2) associated with TYRP1 gene expression, and might be important regulators affecting the expression level of TYRP1 in the head skin of male ducks. Our data also suggested that transcription factor MXI1 might regulate the expression of TYRP1, thereby causing differences in the green head traits among male ducks. This study provided primary data for further analysis of the genetic regulation of duck feather color.

Female great tits (Parus major) reproduce earlier when paired with a male they prefer

AbstractMate choice is a key component of reproductive biology. Females often prefer certain males but do females modulate their reproductive investment depending on whether they are mated with their preferred partner? We investigated this question in great tits (Parus major) where we subjected 36 females to a six‐choice mate preference test. Male morphological traits and the female's own characteristics did not influence the preference females expressed. We however found that females spent more time near more exploratory males. We then paired females with one of the males in indoor aviaries, and subsequently monitored their reproductive investment (through measurement of plasma 17β‐oestradiol concentrations, first egg date, clutch size and egg size). Females that were mated with a male for which they had a strong preference laid their first clutch significantly earlier in the season than females paired with a male they less preferred. Our results show that mate preference influences reproductive investment in great tits, thereby linking mate choice to bird reproductive decisions.

Male reproductive traits are differentially affected by dietary macronutrient balance but unrelated to adiposity

Dietary factors influence male reproductive function in both experimental and epidemiological studies. However, there are currently no specific dietary guidelines for male preconception health. Here, we use the Nutritional Geometry framework to examine the effects of dietary macronutrient balance on reproductive traits in C57BL/6 J male mice. Dietary effects are observed in a range of morphological, testicular and spermatozoa traits, although the relative influence of protein, fat, carbohydrate, and their interactions differ depending on the trait being examined. Interestingly, dietary fat has a positive influence on sperm motility and antioxidant capacity, differing to typical high fat diet studies where calorie content is not controlled for. Moreover, body adiposity is not significantly correlated with any of the reproductive traits measured in this study. These results demonstrate the importance of macronutrient balance and calorie intake on reproductive function and support the need to develop specific, targeted, preconception dietary guidelines for males.

The evolutionary demise of a social interaction: experimentally induced loss of traits involved in the supply and demand of care.

Phenotypic plasticity enables animals to adjust their behavior flexibly to their social environment-sometimes through the expression of adaptive traits that have not been exhibited for several generations. We investigated how long social adaptations can usefully persist when they are not routinely expressed, by using experimental evolution to document the loss of social traits associated with the supply and demand of parental care. We allowed populations of burying beetles Nicrophorus vespilloides to evolve in two different social environments for 48 generations in the lab. In "Full Care" populations, traits associated with the supply and demand of parental care were expressed at every generation, whereas in "No Care" populations we prevented expression of these traits experimentally. We then revived trait expression in the No Care populations at generations 24, 43, and 48 by allowing parents to supply post-hatching care and compared these social traits with those expressed by the Full Care populations. We found that offspring demands for care and male provision of care in the No Care populations were lost sooner than female provision of care. We suggest that this reflects differences in the strength of selection for the expression of alternative traits in offspring, males and females, which can enhance fitness when post-hatching care is disrupted.

Relationship of Gaming Disorder with parenting based on low affection-communication and personality trait of neuroticism in adolescents.

Gaming Disorder is increasingly common in adolescents. We aimed to evaluate the relationship between parenting, personality traits, and Gaming Disorder. An observational and cross-sectional study in six secondary schools of Castelló, obtaining a final sample of 397 students. Adolescents with Gaming Disorder had lower scores in Adolescent Affection-Communication (F = 8.201; p < 0.001), Father's Warmth (F = 3.459; p = 0.028), and Father's Acceptance/Involvement (F = 5.467; p = 0.003), and higher scores in Mother's Revoking Privileges (F = 4.277; p = 0.034) and Father's Indifference (F = 7.868; p = 0.002) than healthy participants. Male sex was a risk factor for Gaming Disorder (OR = 12.221; p = 0.004), while Adolescent Affection-Communication (OR = 0.908; p = 0.001) and Agreeableness (OR = 0.903; p = 0.022) were protective factors. Data modeling described the protective effect that Adolescent Affection-Communication had on Gaming Disorder, which was both directly (B = -0.20; p < 0.001) and indirectly mediated by Neuroticism (B = -0.20; p < 0.001), while Neuroticism itself was a risk factor for Gaming Disorder (B = 0.50; p < 0.001). These results reflect that Parental style with low affection and communication was directly and indirectly related to the Gaming Disorder, as well as male sex and personality trait of Neuroticism.

Extra‐pair paternity is not repeatable between years in Pied Flycatchers (Ficedula hypoleuca): a role for social context

Extra‐pair paternity (EPP) is the consequence of the interactions between a social pair and extra‐pair males during the female's fertile phase in a specific social context and ecological environment. Although EPP occurs in many avian species, there is a lack of understanding of how environmental factors may impact its frequency. Accordingly, the relative importance of individual characteristics on the one hand, and of their immediate social environment on the other, may affect EPP repeatability and thereby the capacity of this trait to respond to selection. If EPP is an individual genetically based trait that may respond to selection, we expect it to be repeatable across breeding seasons. To check this possibility, we analysed the within‐individual repeatability in EPP of breeding males and females in two natural populations of Pied Flycatchers Ficedula hypoleuca in central Spain during three field seasons. We then studied the relationship between EPP and individual male and female traits (only some of which were themselves repeatable), as well as key context variables such as breeding synchrony and population density. Our results showed no repeatability for EPP in either sex. We found a positive association with laying date and stronger associations of EPP with male plumage and morphological traits than with female characteristics. We suggest that the variable social environment is an important modulator of EPP patterns, and that differences between field EPP studies in this respect may explain contradictory results in the same species, even in the same populations in different years.