Gender Identity and Adjustment: Understanding the Impact of Individual and Normative Differences in Sex Typing

ERIC Educational Resources Information Center

Lurye, Leah E.; Zosuls, Kristina M.; Ruble, Diane N.

2008-01-01

The relationship among gender identity, sex typing, and adjustment has attracted the attention of social and developmental psychologists for many years. However, they have explored this issue with different assumptions and different approaches. Generally the approaches differ regarding whether sex typing is considered adaptive versus maladaptive,…

A Behavioral Comparison of Male and Female Adults with High Functioning Autism Spectrum Conditions

PubMed Central

Lai, Meng-Chuan; Lombardo, Michael V.; Pasco, Greg; Ruigrok, Amber N. V.; Wheelwright, Sally J.; Sadek, Susan A.; Chakrabarti, Bhismadev; Baron-Cohen, Simon

2011-01-01

Autism spectrum conditions (ASC) affect more males than females in the general population. However, within ASC it is unclear if there are phenotypic sex differences. Testing for similarities and differences between the sexes is important not only for clinical assessment but also has implications for theories of typical sex differences and of autism. Using cognitive and behavioral measures, we investigated similarities and differences between the sexes in age- and IQ-matched adults with ASC (high-functioning autism or Asperger syndrome). Of the 83 (45 males and 38 females) participants, 62 (33 males and 29 females) met Autism Diagnostic Interview-Revised (ADI-R) cut-off criteria for autism in childhood and were included in all subsequent analyses. The severity of childhood core autism symptoms did not differ between the sexes. Males and females also did not differ in self-reported empathy, systemizing, anxiety, depression, and obsessive-compulsive traits/symptoms or mentalizing performance. However, adult females with ASC showed more lifetime sensory symptoms (p = 0.036), fewer current socio-communication difficulties (p = 0.001), and more self-reported autistic traits (p = 0.012) than males. In addition, females with ASC who also had developmental language delay had lower current performance IQ than those without developmental language delay (p<0.001), a pattern not seen in males. The absence of typical sex differences in empathizing-systemizing profiles within the autism spectrum confirms a prediction from the extreme male brain theory. Behavioral sex differences within ASC may also reflect different developmental mechanisms between males and females with ASC. We discuss the importance of the superficially better socio-communication ability in adult females with ASC in terms of why females with ASC may more often go under-recognized, and receive their diagnosis later, than males. PMID:21695147

Sex differences during humor appreciation in child-sibling pairs.

PubMed

Vrticka, Pascal; Neely, Michelle; Walter Shelly, Elizabeth; Black, Jessica M; Reiss, Allan L

2013-01-01

The developmental origin of sex differences in adult brain function is poorly understood. Elucidating neural mechanisms underlying comparable cognitive functionality in both children and adults is required to address this gap. Humor appreciation represents a particularly relevant target for such developmental research because explanatory theories apply across the life span, and underlying neurocircuitry shows sex differences in adults. As a positive mood state, humor is also of interest due to sex differences in rates of depression, a disorder afflicting twice as many women as men. In this study, we employed functional magnetic resonance imaging (fMRI) to investigate brain responses to funny versus positive (and neutral) video clips in 22 children, ages 6-13 years, including eight sibling-pairs. Our data revealed increased activity to funny clips in bilateral temporo-occipital cortex, midbrain, and amygdala in girls. Conversely, we found heightened activation to positive clips in bilateral inferior parietal lobule, fusiform gyrus, inferior frontal gyrus, amygdala, and ventromedial prefrontal cortex in boys. Many of these effects persisted when looking at sibling-pairs only. We interpret such findings as reflecting the presence of early sex divergence in reward saliency or expectation and stimulus relevance attribution. These findings are discussed in the context of evolutionary and developmental theories of humor function.

SEX DIFFERENCES DURING HUMOR APPRECIATION IN CHILD SIBLING-PAIRS

PubMed Central

Vrticka, Pascal; Neely, Michelle; Walter, Elizabeth; Black, Jessica M.; Reiss, Allan L.

2013-01-01

The developmental origin of sex differences in adult brain function is poorly understood. Elucidating neural mechanisms underlying comparable cognitive functionality in both children and adults is required to address this gap. Humor appreciation represents a particularly relevant target for such developmental research because explanatory theories apply across the life span and underlying neurocircuitry shows sex differences in adults. As a positive mood state, humor is also of interest due to sex differences in rates of depression, a disorder afflicting twice as many women as men. In this study, we employed fMRI to investigate brain responses to funny versus positive (and neutral) video clips in 22 children ages 6 to 13 years, including 8 sibling pairs. Our data revealed increased activity to funny clips in bilateral temporo-occipital cortex, midbrain, and amygdala in girls. Conversely, we found heightened activation to positive clips in bilateral inferior parietal lobule, fusiform gyrus, inferior frontal gyrus, amygdala, and ventromedial prefrontal cortex in boys. Many of these effects persisted when looking at sibling-pairs only. We interpret such findings as reflecting the presence of early sex divergence in reward saliency / expectation and stimulus relevance attribution. These findings are discussed in the context of evolutionary and developmental theories of humor function. PMID:23672302

Cognitive ability influences on written expression: Evidence for developmental and sex-based differences in school-age children.

PubMed

Hajovsky, Daniel B; Villeneuve, Ethan F; Reynolds, Matthew R; Niileksela, Christopher R; Mason, Benjamin A; Shudak, Nicholas J

2018-04-01

Some studies have demonstrated that the Cattell-Horn-Carroll (CHC) cognitive abilities influence writing; however, little research has investigated whether CHC cognitive abilities influence writing the same way for males and females across grades. We used multiple group structural equation models to investigate whether CHC cognitive ability influences on written expression differed between grades or sex using the Kaufman Assessment Battery for Children, Second Edition and the Kaufman Tests of Educational Achievement, Second Edition co-normed standardization sample data (N=2117). After testing for consistent measurement of cognitive abilities across grades and sex, we tested whether the cognitive ability influences on written expression were moderated by grade level or sex. An important developmental shift was observed equally across sex groups: Learning Efficiency (Gl) influences decreased whereas Crystallized Ability (Gc) influences increased after fourth grade. Further, Short-Term Memory (Gsm) and Retrieval Fluency (Gr) influences on written expression depended on sex at grades 1-4, with larger Gr influences for females and larger Gsm influences for males. We internally replicated our main findings using two different cognitive explanatory models, adding further support for the developmental and sex-based differential cognitive ability influences on writing. Explanatory cognitive models of writing need to incorporate development, and possibly, sex to provide an expanded understanding of writing development and guard against potential generalizability issues characteristic of special population (i.e., male-female) studies. Copyright © 2017 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Interactions of sex and early life social experiences at two developmental stages shape nonapeptide receptor profiles.

PubMed

Hiura, Lisa C; Ophir, Alexander G

2018-05-31

Early life social experiences are critical to behavioral and cognitive development, and can have a tremendous influence on developing social phenotypes. Most work has focused on outcomes of experiences at a single stage of development (e.g., perinatal, or post-weaning). Few studies have assessed the impact of social experience at multiple developmental stages and across sex. Oxytocin and vasopressin are profoundly important for modulating social behavior and these nonapeptide systems are highly sensitive to developmental social experience, particularly in brain areas important for social behavior. We investigated whether oxytocin receptor (OTR) and vasopressin receptor (V1aR) distributions of prairie voles (Microtus ochrogaster) change as a function of parental composition within the natal nest or social composition after weaning. We raised pups either in the presence or absence of their fathers. At weaning, offspring were housed either individually or with a same-sex sibling. We also examined whether changes in receptor distributions are sexually dimorphic because the impact of the developmental environment on the nonapeptide system could be sex-dependent. We found that differences in nonapeptide receptor expression were region-, sex-, and rearing condition-specific, indicating a high level of complexity in the ways that early life experiences shape the social brain. We found many more differences in V1aR density compared to OTR density, indicating that nonapeptide receptors demonstrate differential levels of neural plasticity and sensitivity to environmental and biological variables. Our data highlight that critical factors including biological sex and multiple experiences across the developmental continuum interact in complex ways to shape the social brain. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

A developmental-psychobiological approach to developmental neuropsychology.

PubMed

Michel, G F

2001-01-01

Although both developmental psychobiology and developmental neuropsychology examine the interface between biological and psychological processes, they differ in conceptual framework. This article argues for the incorporation into developmental neuropsychology of certain aspects of the conceptual framework of developmental psychobiology. Three principles of dynamic psychobiological interaction are described and applied to four issues in neuropsychology (handedness, sex differences in behavior, critical periods, and modularity of structure-function relations). Then, it is proposed that developmental psychobiology can make four direct contributions to developmental neuropsychology. Finally, it is argued that the value of the conceptual framework provided by developmental psychobiology depends, in part, on how well it translates into procedures that can be applied in the clinical settings of the developmental neuropsychologist.

Examination of Sex Differences in a Large Sample of Young Children with Autism Spectrum Disorder and Typical Development

ERIC Educational Resources Information Center

Reinhardt, Vanessa P.; Wetherby, Amy M.; Schatschneider, Christopher; Lord, Catherine

2015-01-01

Despite consistent and substantive research documenting a large male to female ratio in Autism Spectrum Disorder (ASD), only a modest body of research exists examining sex differences in characteristics. This study examined sex differences in developmental functioning and early social communication in children with ASD as compared to children with…

Sex Differences in Latent Cognitive Abilities Ages 6 to 59: Evidence from the Woodcock-Johnson III Tests of Cognitive Abilities

ERIC Educational Resources Information Center

Keith, Timothy Z.; Reynolds, Matthew R.; Patel, Puja G.; Ridley, Kristen P.

2008-01-01

Sex differences in the latent general and broad cognitive abilities underlying the Woodcock-Johnson Tests of Cognitive Abilities were investigated for children, youth, and adults ages 6 through 59. A developmental, multiple indicator-multiple cause, structural equation model was used to investigate sex differences in latent cognitive abilities as…

Developmental patterns of spatial ability: an early sex difference.

PubMed

Johnson, E S; Meade, A C

1987-06-01

Over 1,800 public school students (grades K-12, ages 6-18) took a battery of 7 spatial tests tailored to their respective developmental levels. Analyses of resulting data indicate that it is feasible to measure spatial ability throughout this developmental range with modified versions of adult paper-and-pencil tests, that a male advantage in spatial performance appears reliably by age 10, and that the magnitude of the advantage remains constant through age 18. Analysis of covariance suggests that an early female precocity in language skills may mask a male advantage in spatial ability during the primary school years. There is no indication of a sex difference in kindergarten children.

Sex Differences in Moral Reasoning: Response to Walker's (1984) Conclusion That There Are None.

ERIC Educational Resources Information Center

Baumrind, Diana

1986-01-01

Takes issue with Lawrence Walker's literature review on developmental and individual differences in moral reasoning which found no consistent evidence for sex differences in moral development. Argues instead that the source and specific nature of these differences have yet to be established. (HOD)

Sex-specific mouse liver gene expression: genome-wide analysis of developmental changes from pre-pubertal period to young adulthood

PubMed Central

2012-01-01

Background Early liver development and the transcriptional transitions during hepatogenesis are well characterized. However, gene expression changes during the late postnatal/pre-pubertal to young adulthood period are less well understood, especially with regards to sex-specific gene expression. Methods Microarray analysis of male and female mouse liver was carried out at 3, 4, and 8 wk of age to elucidate developmental changes in gene expression from the late postnatal/pre-pubertal period to young adulthood. Results A large number of sex-biased and sex-independent genes showed significant changes during this developmental period. Notably, sex-independent genes involved in cell cycle, chromosome condensation, and DNA replication were down regulated from 3 wk to 8 wk, while genes associated with metal ion binding, ion transport and kinase activity were up regulated. A majority of genes showing sex differential expression in adult liver did not display sex differences prior to puberty, at which time extensive changes in sex-specific gene expression were seen, primarily in males. Thus, in male liver, 76% of male-specific genes were up regulated and 47% of female-specific genes were down regulated from 3 to 8 wk of age, whereas in female liver 67% of sex-specific genes showed no significant change in expression. In both sexes, genes up regulated from 3 to 8 wk were significantly enriched (p < E-76) in the set of genes positively regulated by the liver transcription factor HNF4α, as determined in a liver-specific HNF4α knockout mouse model, while genes down regulated during this developmental period showed significant enrichment (p < E-65) for negative regulation by HNF4α. Significant enrichment of the developmentally regulated genes in the set of genes subject to positive and negative regulation by pituitary hormone was also observed. Five sex-specific transcriptional regulators showed sex-specific expression at 4 wk (male-specific Ihh; female-specific Cdx4, Cux2, Tox, and Trim24) and may contribute to the developmental changes that lead to global acquisition of liver sex-specificity by 8 wk of age. Conclusions Overall, the observed changes in gene expression during postnatal liver development reflect the deceleration of liver growth and the induction of specialized liver functions, with widespread changes in sex-specific gene expression primarily occurring in male liver. PMID:22475005

Flower development and sex specification in wild grapevine.

PubMed

Ramos, Miguel Jesus Nunes; Coito, João Lucas; Silva, Helena Gomes; Cunha, Jorge; Costa, Maria Manuela Ribeiro; Rocheta, Margarida

2014-12-12

Wild plants of Vitis closely related to the cultivated grapevine (V. v. vinifera) are believed to have been first domesticated 10,000 years BC around the Caspian Sea. V. v. vinifera is hermaphrodite whereas V. v. sylvestris is a dioecious species. Male flowers show a reduced pistil without style or stigma and female flowers present reflexed stamens with infertile pollen. V. vinifera produce perfect flowers with all functional structures. The mechanism for flower sex determination and specification in grapevine is still unknown. To understand which genes are involved during the establishment of male, female and complete flowers, we analysed and compared the transcription profiles of four developmental stages of the three genders. We showed that sex determination is a late event during flower development and that the expression of genes from the ABCDE model is not directly correlated with the establishment of sexual dimorphism. We propose a temporal comprehensive model in which two mutations in two linked genes could be players in sex determination and indirectly establish the Vitis domestication process. Additionally, we also found clusters of genes differentially expressed between genders and between developmental stages that suggest a role involved in sex differentiation. Also, the detection of differentially transcribed regions that extended existing gene models (intergenic regions) between sexes suggests that they may account for some of the variation between the subspecies. There is no evidence of differences of expression levels in genes from the ABCDE model that could explain the shift from hermaphroditism to dioecy. We propose that sex specification occurs after floral organ identity has been established and therefore, sex determination genes might be having an effect downstream of the ABCDE model genes.For the first time a full transcriptomic analysis was performed in different flower developmental stages in the same individual. Our experimental approach enabled us to create a comprehensive catalogue of transcribed genes across developmental stages and genders that will contribute for future work in sex determination in seed plants.

Neonatal testosterone partially organizes sex differences in stress-induced emotionality in mice.

PubMed

Seney, Marianne L; Walsh, Christopher; Stolakis, Ryan; Sibille, Etienne

2012-05-01

Major depressive disorder (MDD) is a debilitating disorder of altered mood regulation. Despite well established sex differences in MDD prevalence, the mechanism underlying the increased female vulnerability remains unknown. Although evidence suggests an influence of adult circulating hormone levels on mood (i.e. activational effects of hormones), MDD prevalence is consistently higher in women across life stages (and therefore hormonal states), suggesting that additional underlying structural or biological differences place women at higher risk. Studies in human subjects and in rodent models suggest a developmental origin for mood disorders, and interestingly, a developmental process also establishes sex differences in the brain. Hence, based on these parallel developmental trajectories, we hypothesized that a proportion of the female higher vulnerability to MDD may originate from the differential organization of mood regulatory neural networks early in life (i.e. organizational effects of hormones). To test this hypothesis in a rodent system, we took advantage of a well-established technique used in the field of sexual differentiation (neonatal injection with testosterone) to masculinize sexually dimorphic brain regions in female mice. We then investigated adult behavioral consequences relating to emotionality by comparing neonatal testosterone-treated females to normal males and females. Under baseline/trait conditions, neonatal testosterone treatment of female mice did not influence adult emotionality, but masculinized adult locomotor activity, as revealed by the activational actions of hormones. Conversely, the increased vulnerability of female mice to develop high emotionality following unpredictable chronic mild stress (UCMS) was partially masculinized by neonatal testosterone exposure, with no effect on post-UCMS locomotion. The elevated female UCMS-induced vulnerability did not differ between adult hormone treated groups. These results demonstrate that sex differences in adult emotionality in mice are partially caused by the organizational effects of sex hormones during development, hence supporting a developmental hypothesis of the human adult female prevalence of MDD. Copyright © 2012 Elsevier Inc. All rights reserved.

Neonatal testosterone partially organizes sex differences in stress-induced emotionality in mice

PubMed Central

Seney, Marianne L.; Walsh, Christopher; Stolakis, Ryan; Sibille, Etienne

2012-01-01

Major depressive disorder (MDD) is a debilitating disorder of altered mood regulation. Despite well established sex differences in MDD prevalence, the mechanism underlying the increased female vulnerability remains unknown. Although evidence suggests an influence of adult circulating hormone levels on mood (i.e. activational effects of hormones), MDD prevalence is consistently higher in women across life stages (and therefore hormonal states), suggesting that additional underlying structural or biological differences place women at higher risk. Studies in human subjects and in rodent models suggest a developmental origin for mood disorders, and interestingly, a developmental process also establishes sex differences in the brain. Hence, based on these parallel developmental trajectories, we hypothesized that a proportion of the female higher vulnerability to MDD may originate from the differential organization of mood regulatory neural networks early in life (i.e. organizational effects of hormones). To test this hypothesis in a rodent system, we took advantage of a well-established technique used in the field of sexual differentiation (neonatal injection with testosterone) to masculinize sexually dimorphic brain regions in female mice. We then investigated adult behavioral consequences relating to emotionality by comparing neonatal testosterone-treated females to normal males and females. Under baseline/trait conditions, neonatal testosterone treatment of female mice did not influence adult emotionality, but masculinized adult locomotor activity, as revealed by the activational actions of hormones. Conversely, the increased vulnerability of female mice to develop high emotionality following unpredictable chronic mild stress (UCMS) was partially masculinized by neonatal testosterone exposure, with no effect on post-UCMS locomotion. The elevated female UCMS-induced vulnerability did not differ between adult hormone treated groups. These results demonstrate that sex differences in adult emotionality in mice are partially caused by the organizational effects of sex hormones during development, hence supporting a developmental hypothesis of the human adult female prevalence of MDD. PMID:22394611

Juvenile Sex Offending Through a Developmental Life Course Criminology Perspective.

PubMed

Lussier, Patrick

2017-02-01

Current American policies and responses to juvenile sex offending have been criticized for being based on myths, misconceptions, and unsubstantiated claims. In spite of the criticism, no organizing framework has been proposed to guide policy development with respect to the prevention of juvenile sex offending. This article proposes a developmental life course (DLC) criminology perspective to investigate the origins, development, and termination of sex offending among youth. It also provides a review of the current state of knowledge regarding various parameters characterizing the development of sex offending (e.g., prevalence, age of onset, frequency, persistence, continuity in adulthood, and versatility). The review highlights some heterogeneity across these developmental parameters suggesting the presence of different sex offending patterns among youth. In fact, it is proposed that, based on the current knowledge, such heterogeneity can be accounted for by a dual taxonomy of adolescents involved in sexual offenses: (a) the adolescent-limited and (b) the high-rate/slow-desister. The DLC criminology approach and the dual taxonomy are proposed as organizing frameworks to conduct prospective longitudinal research to better understand the origins and development of sex offending and to guide policy development and responses to at-risk youth and those who have committed sexual offenses.

Effects of chromosomal sex and hormonal influences on shaping sex differences in brain and behavior: Lessons from cases of disorders of sex development.

PubMed

Bramble, Matthew S; Lipson, Allen; Vashist, Neerja; Vilain, Eric

2017-01-02

Sex differences in brain development and postnatal behavior are determined largely by genetic sex and in utero gonadal hormone secretions. In humans however, determining the weight that each of these factors contributes remains a challenge because social influences should also be considered. Cases of disorders of sex development (DSD) provide unique insight into how mutations in genes responsible for gonadal formation can perturb the subsequent developmental hormonal milieu and elicit changes in normal human brain maturation. Specific forms of DSDs such as complete androgen insensitivity syndrome (CAIS), congenital adrenal hyperplasia (CAH), and 5α-reductase deficiency syndrome have variable effects between males and females, and the developmental outcomes of such conditions are largely dependent on sex chromosome composition. Medical and psychological works focused on CAH, CAIS, and 5α-reductase deficiency have helped form the foundation for understanding the roles of genetic and hormonal factors necessary for guiding human brain development. Here we highlight how the three aforementioned DSDs contribute to brain and behavioral phenotypes that can uniquely affect 46,XY and 46,XX individuals in dramatically different fashions. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Sex differences in the association between infant markers and later autistic traits.

PubMed

Bedford, Rachael; Jones, Emily J H; Johnson, Mark H; Pickles, Andrew; Charman, Tony; Gliga, Teodora

2016-01-01

Although it is well established that the prevalence of autism spectrum disorder (ASD) is higher in males than females, there is relatively little understanding of the underlying mechanisms and their developmental time course. Sex-specific protective or risk factors have often been invoked to explain these differences, but such factors are yet to be identified. We take a developmental approach, using a prospective sample of 104 infants at high and low familial risk for ASD, to characterise sex differences in infant markers known to predict emerging autism symptoms. We examine three markers previously shown to be associated with later autistic social-communication symptoms: the Autism Observation Scale for Infants (AOSI) total score, attention disengagement speed and gaze following behaviour. Our aim was to test whether sex differences were already present in these markers at 1 year of age, which would suggest sex-specific mechanisms of risk or protection. While no sex differences were found in any of the three markers investigated, we found sex differences in their relationship to 3-year autism traits; all three markers significantly predicted later autism traits only in the boys. Previously identified 'early autism markers' were associated with later autism symptoms only in boys. This suggests that there may be additional moderating risk or protective factors which remain to be identified. Our findings have important implications for prospective studies in terms of directly testing for the moderating effect of sex on emerging autistic traits.

Developmental decoupling of alternative phenotypes: insights from the transcriptomes of horn-polyphenic beetles

PubMed Central

Snell-Rood, Emilie C.; Cash, Amy; Han, Mira V.; Kijimoto, Teiya; Andrews, Justen; Moczek, Armin P.

2010-01-01

Developmental mechanisms play an important role in determining the costs, limits, and evolutionary consequences of phenotypic plasticity. One issue central to these claims is the hypothesis of developmental decoupling, where alternate morphs result from evolutionarily independent developmental pathways. We address this assumption through a microarray study that tests whether differences in gene expression between alternate morphs are as divergent as those between sexes, a classic example of developmental decoupling. We then examine whether genes with morph-biased expression are less conserved than genes with shared expression between morphs, as predicted if developmental decoupling relaxes pleiotropic constraints on divergence. We focus on the developing horns and brains of two species of horned beetles with spectacular sexual- and morph-dimorphism in the expression of horns and fighting behavior. We find that patterns of gene expression were as divergent between morphs as they were between sexes. However, overall patterns of gene expression were also highly correlated across morphs and sexes. Morph-biased genes were more evolutionarily divergent, suggesting a role of relaxed pleiotropic constraints or relaxed selection. Together these results suggest that alternate morphs are to some extent developmentally decoupled, and that this decoupling has significant evolutionary consequences. However, alternative morphs may not be as developmentally decoupled as sometimes assumed and such hypotheses of development should be revisited and refined. PMID:20731717

Disruption of Fetal Hormonal Programming (Prenatal Stress) Implicates Shared Risk for Sex Differences in Depression and Cardiovascular Disease

PubMed Central

Goldstein, JM; Handa, RJ; Tobet, SA

2014-01-01

Comorbidity of major depressive disorder (MDD) and cardiovascular disease (CVD) represents the fourth leading cause of morbidity and mortality worldwide, and women have a two times greater risk than men. Thus understanding the pathophysiology has widespread implications for attenuation and prevention of disease burden. We suggest that sex-dependent MDD-CVD comorbidity may result from alterations in fetal programming consequent to the prenatal maternal environments that produce excess glucocorticoids, which then drive sex-dependent developmental alterations of the fetal hypothalamic-pituitary-adrenal (HPA) axis circuitry impacting mood, stress regulation, autonomic nervous system (ANS), and the vasculature in adulthood. Evidence is consistent with the hypothesis that disruptions of pathways associated with gamma aminobutyric acid (GABA) in neuronal and vascular development and growth factors have critical roles in key developmental periods and adult responses to injury in heart and brain. Understanding the potential fetal origins of these sex differences will contribute to development of novel sex-dependent therapeutics. PMID:24355523

Sex differences in visuospatial abilities persist during induced hypogonadism

PubMed Central

Guerrieri, Gioia M.; Wakim, Paul G.; Keenan, P.A.; Schenkel, Linda A; Berlin, Kate; Gibson, Carolyn J.; Rubinow, David R.; Schmidt, Peter J.

2016-01-01

Background Despite well-established sex differences in the performance on tests of several cognitive domains (e.g., visuospatial ability), few studies in humans have evaluated if these sex differences are evident both in the presence of circulating sex hormones and during sex steroid hormonal suppression. Sex differences identified in the relative absence of circulating levels of estradiol and testosterone suggest that differences in brain structure or function exist independent of current hormonal environment and are more likely a reflection of differing developmental exposures and/or genetic substrates. Objective To evaluate cognitive performance in healthy eugonadal men and women before and again during GnRH agonist-induced hypogonadism. Methods Men (n = 16) and women (n = 15) without medical or psychiatric illness were matched for IQ. Cognitive tests were performed at baseline (when eugonadal) and after 68 weeks of GnRH agonist-induced gonadal suppression. The test batteries included measures of verbal and spatial memory, spatial ability, verbal fluency, motor speed/dexterity, and attention/concentration. Data were analyzed using repeated-measures models. Results During both eugonadism and hypogonadism, men performed significantly better than women on several measures of visuospatial performance including mental rotation, line orientation, Money Road Map, Porteus maze, and complex figure drawing. Although some test performances showed an effect of hormone treatment, the majority of these differences reflected an improved performance during hypogonadism compared with baseline (and probably reflected practice effects). Conclusion The well-documented male advantage in visuospatial performance, which we observed during eugonadal conditions, was maintained in the context of short-term suppression of gonadal function in both men and women. These findings suggest that, in humans, sex differences in visuospatial performance are not merely dependent on differences in the current circulating sex steroid environment. Thus sex differences in visuospatial performance in adulthood could reflect early developmental effects of sex steroid exposure or other environmental exposures differing across the sexes as our data confirm that these differences are independent of circulating estradiol or testosterone levels in men and women. PMID:26719236

Sex differences in visuospatial abilities persist during induced hypogonadism.

PubMed

Guerrieri, Gioia M; Wakim, Paul G; Keenan, P A; Schenkel, Linda A; Berlin, Kate; Gibson, Carolyn J; Rubinow, David R; Schmidt, Peter J

2016-01-29

Despite well-established sex differences in the performance on tests of several cognitive domains (e.g., visuospatial ability), few studies in humans have evaluated if these sex differences are evident both in the presence of circulating sex hormones and during sex steroid hormonal suppression. Sex differences identified in the relative absence of circulating levels of estradiol and testosterone suggest that differences in brain structure or function exist independent of current hormonal environment and are more likely a reflection of differing developmental exposures and/or genetic substrates. To evaluate cognitive performance in healthy eugonadal men and women before and again during GnRH agonist-induced hypogonadism. Men (n=16) and women (n=15) without medical or psychiatric illness were matched for IQ. Cognitive tests were performed at baseline (when eugonadal) and after 6-8 weeks of GnRH agonist-induced gonadal suppression. The test batteries included measures of verbal and spatial memory, spatial ability, verbal fluency, motor speed/dexterity, and attention/concentration. Data were analyzed using repeated-measures models. During both eugonadism and hypogonadism, men performed significantly better than women on several measures of visuospatial performance including mental rotation, line orientation, Money Road Map, Porteus maze, and complex figure drawing. Although some test performances showed an effect of hormone treatment, the majority of these differences reflected an improved performance during hypogonadism compared with baseline (and probably reflected practice effects). The well-documented male advantage in visuospatial performance, which we observed during eugonadal conditions, was maintained in the context of short-term suppression of gonadal function in both men and women. These findings suggest that, in humans, sex differences in visuospatial performance are not merely dependent on differences in the current circulating sex steroid environment. Thus sex differences in visuospatial performance in adulthood could reflect early developmental effects of sex steroid exposure or other environmental exposures differing across the sexes as our data confirm that these differences are independent of circulating estradiol or testosterone levels in men and women. Published by Elsevier Ltd.

Sex in the brain: hormones and sex differences.

PubMed

Marrocco, Jordan; McEwen, Bruce S

2016-12-01

Contrary to popular belief, sex hormones act throughout the entire brain of both males and females via both genomic and nongenomic receptors. Many neural and behavioral functions are affected by estrogens, including mood, cognitive function, blood pressure regulation, motor coordination, pain, and opioid sensitivity. Subtle sex differences exist for many of these functions that are developmentally programmed by hormones and by not yet precisely defined genetic factors, including the mitochondrial genome. These sex differences, and responses to sex hormones in brain regions and upon functions not previously regarded as subject to such differences, indicate that we are entering a new era in our ability to understand and appreciate the diversity of gender-related behaviors and brain functions.

Sex Differences in the Experience of Widowhood.

ERIC Educational Resources Information Center

Barrett, Carol J.

Previous writers have presumed that widowhood is more stressful for one sex or the other. Hypotheses derived from demographic considerations and sex role developmental theory compared the needs and resources of 147 widows and 42 widowers, relative to 190 married persons. All subjects were non-institutionalized urban residents aged 62 or over. The…

Influences of somatic donor cell sex on in vitro and in vivo embryo development following somatic cell nuclear transfer in pigs

PubMed Central

Yoo, Jae-Gyu; Kim, Byeong-Woo; Park, Mi-Rung; Kwon, Deug-Nam; Choi, Yun-Jung; Shin, Teak-Soon; Cho, Byung-Wook; Seo, Jakyeom; Kim, Jin-Hoi; Cho, Seong-Keun

2017-01-01

Objective The present study investigates pre- and post-implantation developmental competence of nuclear-transferred porcine embryos derived from male and female fetal fibroblasts. Methods Male and female fetal fibroblasts were transferred to in vitro-matured enucleated oocytes and in vitro and in vivo developmental competence of reconstructed embryos was investigated. And, a total of 6,789 female fibroblast nuclear-transferred embryos were surgically transferred into 41 surrogate gilts and 4,746 male fibroblast nuclear-transferred embryos were surgically transferred into 25 surrogate gilts. Results The competence to develop into blastocysts was not significantly different between the sexes. The mean cell number of female and male cloned blastocysts obtained by in vivo culture (143.8±10.5 to 159.2±14.8) was higher than that of in vitro culture of somatic cell nuclear transfer (SCNT) groups (31.4±8.3 to 33.4±11.1). After embryo transfer, 5 pregnant gilts from each treatment delivered 15 female and 22 male piglets. The average birth weight of the cloned piglets, gestation length, and the postnatal survival rates were not significantly different (p<0.05) between sexes. Conclusion The present study found that the sex difference of the nuclear donor does not affect the developmental rate of porcine SCNT embryos. Furthermore, postnatal survivability of the cloned piglets was not affected by the sex of the donor cell. PMID:27764913

Developmental Sexual Dimorphism of the Oral and Pharyngeal Portions of the Vocal Tract: An Imaging Study

ERIC Educational Resources Information Center

Vorperian, Houri K.; Wang, Shubing; Schimek, E. Michael; Durtschi, Reid B.; Kent, Ray D.; Gentry, Lindell R.; Chung, Moo K.

2011-01-01

Purpose: The anatomic origin for prepubertal vowel acoustic differences between male and female subjects remains unknown. The purpose of this study is to examine developmental sex differences in vocal tract (VT) length and its oral and pharyngeal portions. Method: Nine VT variables were measured from 605 imaging studies (magnetic resonance imaging…

Developmental Sex Differences in the Relation of Neuroanatomical Connectivity to Intelligence

ERIC Educational Resources Information Center

Schmithorst, Vincent J.

2009-01-01

Recent neuroimaging research has shown sex-related differences in the relationship between brain structure and cognitive function. Anatomical studies have shown a greater reliance for cognitive function on white matter structure in adult females, and a greater reliance on gray matter structure in adult males. Functional neuroimaging studies have…

Early Sex Differences in Weighting Geometric Cues

ERIC Educational Resources Information Center

Lourenco, Stella F.; Addy, Dede; Huttenlocher, Janellen; Fabian, Lydia

2011-01-01

When geometric and non-geometric information are both available for specifying location, men have been shown to rely more heavily on geometry compared to women. To shed insight on the nature and developmental origins of this sex difference, we examined how 18- to 24-month-olds represented the geometry of a surrounding (rectangular) space when…

doublesex alters aggressiveness as a function of social context and sex in the polyphenic beetle Onthophagus taurus.

PubMed

Beckers, Oliver M; Kijimoto, Teiya; Moczek, Armin P

2017-10-01

Despite sharing nearly the same genome, individuals within the same species can vary drastically in both morphology and behaviour as a function of developmental stage, sex or developmental plasticity. Thus, regulatory processes must exist that enable the stage-, sex- or environment-specific expression of traits and their integration during ontogeny, yet exactly how trait complexes are co-regulated and integrated is poorly understood. In this study, we explore the developmental genetic basis of the regulation and integration of environment-dependent sexual dimorphism in behaviour and morphology in the horn-polyphenic dung beetle Onthophagus taurus through the experimental manipulation of the transcription factor doublesex (dsx). The gene dsx plays a profound role in the developmental regulation of morphological differences between sexes as well as alternative male morphs by inhibiting horn formation in females but enabling nutrition-responsive horn growth in males. Specifically, we investigated whether experimental downregulation of dsx expression affects male and female aggressive and courtship behaviours in two social contexts: interactions between individuals of the same sex and interactions between males and females. We find that dsx downregulation significantly alters aggressiveness in both males and females, yet does so differently for both sexes as a function of social context: dsx RNAi males exhibited elevated aggression towards males but showed reduced aggression towards females, whereas dsx RNAi females became more aggressive towards males, while their aggressiveness towards other females was unaffected. Moreover, we document unexpectedly high levels of female aggression independent of dsx treatment in both wild-type and control-injected individuals. Lastly, we found no effects of dsx RNAi on courtship and mating behaviours. We discuss the role of dsx in the regulation of sex-specific and plastic behaviours, the unexpectedly high levels of aggression of hornless dsx RNAi males in relation to the well-established description of the hornless sneaker phenotype and the potential ecological function of high female aggression.

Boys and Girls on the Playground: Sex Differences in Social Development Are Not Stable across Early Childhood

PubMed Central

Barbu, Stéphanie; Cabanes, Guénaël; Le Maner-Idrissi, Gaïd

2011-01-01

Sex differences in human social behaviors and abilities have long been a question of public and scientific interest. Females are usually assumed to be more socially oriented and skilful than males. However, despite an extensive literature, the very existence of sex differences remains a matter of discussion while some studies found no sex differences whereas others reported differences that were either congruent or not with gender stereotypes. Moreover, the magnitude, consistency and stability across time of the differences remain an open question, especially during childhood. As play provides an excellent window into children's social development, we investigated whether and how sex differences change in social play across early childhood. Following a cross-sectional design, 164 children aged from 2 to 6 years old, divided into four age groups, were observed during outdoor free play at nursery school. We showed that sex differences are not stable over time evidencing a developmental gap between girls and boys. Social and structured forms of play emerge systematically earlier in girls than in boys leading to subsequent sex differences in favor of girls at some ages, successively in associative play at 3–4 years, cooperative play at 4–5 years, and social interactions with peers at 5–6 years. Preschool boys also display more solitary play than preschool girls, especially when young. Nevertheless, while boys catch up and girls move on towards more complex play, sex differences in social play patterns are reversed in favor of boys at the following ages, such as in associative play at 4–5 years and cooperative play at 5–6 years. This developmental perspective contributes to resolve apparent discrepancies between single-snapshot studies. A better understanding of the dynamics of sex differences in typical social development should also provide insights into atypical social developments which exhibit sex differences in prevalence, such as autism. PMID:21297987

Boys and girls on the playground: sex differences in social development are not stable across early childhood.

PubMed

Barbu, Stéphanie; Cabanes, Guénaël; Le Maner-Idrissi, Gaïd

2011-01-28

Sex differences in human social behaviors and abilities have long been a question of public and scientific interest. Females are usually assumed to be more socially oriented and skillful than males. However, despite an extensive literature, the very existence of sex differences remains a matter of discussion while some studies found no sex differences whereas others reported differences that were either congruent or not with gender stereotypes. Moreover, the magnitude, consistency and stability across time of the differences remain an open question, especially during childhood. As play provides an excellent window into children's social development, we investigated whether and how sex differences change in social play across early childhood. Following a cross-sectional design, 164 children aged from 2 to 6 years old, divided into four age groups, were observed during outdoor free play at nursery school. We showed that sex differences are not stable over time evidencing a developmental gap between girls and boys. Social and structured forms of play emerge systematically earlier in girls than in boys leading to subsequent sex differences in favor of girls at some ages, successively in associative play at 3-4 years, cooperative play at 4-5 years, and social interactions with peers at 5-6 years. Preschool boys also display more solitary play than preschool girls, especially when young. Nevertheless, while boys catch up and girls move on towards more complex play, sex differences in social play patterns are reversed in favor of boys at the following ages, such as in associative play at 4-5 years and cooperative play at 5-6 years. This developmental perspective contributes to resolve apparent discrepancies between single-snapshot studies. A better understanding of the dynamics of sex differences in typical social development should also provide insights into atypical social developments which exhibit sex differences in prevalence, such as autism.

Developmental differences in white matter architecture between boys and girls.

PubMed

Schmithorst, Vincent J; Holland, Scott K; Dardzinski, Bernard J

2008-06-01

Previous studies have found developmental differences between males and females in brain structure. During childhood and adolescence, relative white matter volume increases faster in boys than in girls. Sex differences in the development of white matter microstructure were investigated in a cohort of normal children ages 5-18 in a cross-sectional diffusion tensor imaging (DTI) study. Greater fractional anisotropy (FA) in boys was shown in associative white matter regions (including the frontal lobes), while greater FA in girls was shown in the splenium of the corpus callosum. Greater mean diffusivity (MD) in boys was shown in the corticospinal tract and in frontal white matter in the right hemisphere; greater MD in girls was shown in occipito-parietal regions and the most superior aspect of the corticospinal tract in the right hemisphere. Significant sex-age interactions on FA and MD were also shown. Girls displayed a greater rate of fiber density increase with age when compared with boys in associative regions (reflected in MD values). However, girls displayed a trend toward increased organization with age (reflected in FA values) only in the right hemisphere, while boys displayed this trend only in the left hemisphere. These results indicate differing developmental trajectories in white matter for boys and girls and the importance of taking sex into account in developmental DTI studies. The results also may have implications for the study of the relationship of brain architecture with intelligence. Copyright 2007 Wiley-Liss, Inc.

Sex Differences in Internalizing Problems during Adolescence in Autism Spectrum Disorder

ERIC Educational Resources Information Center

Oswald, Tasha M.; Winter-Messiers, Mary Ann; Gibson, Brandon; Schmidt, Alexandra M.; Herr, Cynthia M.; Solomon, Marjorie

2016-01-01

We hypothesized that the double hit conferred by sex and diagnosis increases the risk for internalizing disorders in adolescent females with autism spectrum disorder (ASD). In a sample of 32 adolescents with ASD and 32 controls, we examined the effects of sex, diagnostic factors, and developmental stages on depression and anxiety. A 3-way…

Resolving Ethical Dilemmas: Exploring the Role of Moral Principles

DTIC Science & Technology

2008-08-01

deontological class of moral philosophies. A second major approach is represented by the cognitive - developmental models of moral development ...extent sex, as predictors of individual differences in moral philosophy. 1.3.1 Age The approach of Kohlberg’s (1969) cognitive developmental ...associated with cognitive and developmental gains that can only occur with maturation. For instance, Kohlberg posited the stages 1 and 2 with their

Sex/Gender Differences and Autism: Setting the Scene for Future Research

PubMed Central

Lai, Meng-Chuan; Lombardo, Michael V.; Auyeung, Bonnie; Chakrabarti, Bhismadev; Baron-Cohen, Simon

2015-01-01

Objective The relationship between sex/gender differences and autism has attracted a variety of research ranging from clinical and neurobiological to etiological, stimulated by the male bias in autism prevalence. Findings are complex and do not always relate to each other in a straightforward manner. Distinct but interlinked questions on the relationship between sex/gender differences and autism remain underaddressed. To better understand the implications from existing research and to help design future studies, we propose a 4-level conceptual framework to clarify the embedded themes. Method We searched PubMed for publications before September 2014 using search terms “‘sex OR gender OR females’ AND autism.” A total of 1,906 articles were screened for relevance, along with publications identified via additional literature reviews, resulting in 329 articles that were reviewed. Results Level 1, “Nosological and diagnostic challenges,” concerns the question, “How should autism be defined and diagnosed in males and females?” Level 2, “Sex/gender-independent and sex/gender-dependent characteristics,” addresses the question, “What are the similarities and differences between males and females with autism?” Level 3, “General models of etiology: liability and threshold,” asks the question, “How is the liability for developing autism linked to sex/gender?” Level 4, “Specific etiological–developmental mechanisms,” focuses on the question, “What etiological–developmental mechanisms of autism are implicated by sex/gender and/or sexual/gender differentiation?” Conclusions Using this conceptual framework, findings can be more clearly summarized, and the implications of the links between findings from different levels can become clearer. Based on this 4-level framework, we suggest future research directions, methodology, and specific topics in sex/gender differences and autism. PMID:25524786

How Sex Attitudes Develop

ERIC Educational Resources Information Center

Arnstein, Helene S.

1976-01-01

Excerpt from "The Roots of Love" (Helene S. Arnstein, 1975). Book is concerned with feelings that are part of child's developmental stages. Included in excerpt are: genital self-discovery, masturbation, discovery of sex differences, and birth fantasies. Stresses importance of parent's feelings which are communicated to child.

Race Differences on the Developmental Test of Visual Motor Integration, the Slosson Intelligence Test, and the ABC Inventory.

ERIC Educational Resources Information Center

Schooler, Douglas L.; Anderson, Robert L.

1979-01-01

Analyzes preschoolers' scores on the Developmental Test of Visual Motor Integration (VMI), the Slosson Intelligence Test (SIT), and the ABC Inventory (ABCI). Separate ANOVAs reveal no race effect on the VMI. Race differences favoring Whites are found for SIT and ABCI. There were no effects for sex on any measure. (Author)

Tissue Specificity and Dynamics of Sex-Biased Gene Expression in a Common Frog Population with Differentiated, Yet Homomorphic, Sex Chromosomes.

PubMed

Ma, Wen-Juan; Veltsos, Paris; Toups, Melissa A; Rodrigues, Nicolas; Sermier, Roberto; Jeffries, Daniel L; Perrin, Nicolas

2018-06-12

Sex-biased genes are central to the study of sexual selection, sexual antagonism, and sex chromosome evolution. We describe a comprehensive de novo assembled transcriptome in the common frog Rana temporaria based on five developmental stages and three adult tissues from both sexes, obtained from a population with karyotypically homomorphic but genetically differentiated sex chromosomes. This allows the study of sex-biased gene expression throughout development, and its effect on the rate of gene evolution while accounting for pleiotropic expression, which is known to negatively correlate with the evolutionary rate. Overall, sex-biased genes had little overlap among developmental stages and adult tissues. Late developmental stages and gonad tissues had the highest numbers of stage- or tissue-specific genes. We find that pleiotropic gene expression is a better predictor than sex bias for the evolutionary rate of genes, though it often interacts with sex bias. Although genetically differentiated, the sex chromosomes were not enriched in sex-biased genes, possibly due to a very recent arrest of XY recombination. These results extend our understanding of the developmental dynamics, tissue specificity, and genomic localization of sex-biased genes.

Examination of Sex Differences in a Large Sample of Young Children with Autism Spectrum Disorder and Typical Development

PubMed Central

Reinhardt, Vanessa P.; Wetherby, Amy M.; Schatschneider, Christopher

2014-01-01

Despite consistent and substantive research documenting a large male to female ratio in Autism Spectrum Disorder (ASD), only a modest body of research exists examining sex differences in characteristics. This study examined sex differences in developmental functioning and early social communication in children with ASD as compared to children with typical development. Sex differences in adaptive behavior and autism symptoms were also examined in children with ASD. Participants (n = 511) were recruited from the Florida State University FIRST WORDS® Project and University of Michigan Autism and Communication Disorders Center. Analyses did not reveal significant effects of sex or a diagnostic group by sex interaction, suggesting a similar phenotype in males and females early in development. Further research is needed to examine sex differences across development. PMID:25189824

Fruit flies may face a nutrient-dependent life-history trade-off between secondary sexual trait quality, survival and developmental rate.

PubMed

Gray, Lindsey J; Simpson, Stephen J; Polak, Michal

2018-01-01

Optimal life-history strategies are those that best allocate finite environmental resources to competing traits. We used the geometric framework for nutrition to evaluate life-history strategies followed by Drosophila melanogaster by measuring the condition-dependent performance of life-history traits, including the morphology of male secondary sexual characters, sex combs. We found that depending on their rearing environment flies faced different forms of trait trade-offs and accordingly followed different life-history strategies. High-energy, high-carbohydrate, low-protein diets supported development of the largest and most symmetrical sex combs, however, consistent with handicap models of sexual selection these foods were associated with reduced fly survival and developmental rate. Expressing the highest quality sex combs may have required secondary sexual trait quality to be traded-off with developmental rate, and our results indicated that flies unable to slow development died. As larval nutritional environments are predominantly determined by female oviposition substrate choice, we tested where mated female flies laid the most eggs. Mothers chose high-energy, high-protein foods associated with rapid larval development. Mothers avoided high-carbohydrate foods associated with maximal sex comb expression, showing they may avoid producing fewer 'sexy' sons in favour of producing offspring that develop rapidly. Copyright © 2017 Elsevier Ltd. All rights reserved.

Handedness is a biomarker of variation in anal sex role behavior and Recalled Childhood Gender Nonconformity among gay men.

PubMed

Swift-Gallant, Ashlyn; Coome, Lindsay A; Monks, D Ashley; VanderLaan, Doug P

2017-01-01

Developmental theories of the biological basis of sexual orientation suggest that sexually differentiated psychological and behavioural traits should be linked with sexual orientation. Subgroups of gay men delineated by anal sex roles differ according to at least one such trait: gender expression. The present study assessed the hypothesis that handedness, a biologically determined sexually differentiated trait, corresponds to differences in subgroups of gay men based on anal sex role. Furthermore, it assessed whether handedness mediates the association between gender nonconformity and male sexual orientation. Straight and gay men (N = 333) completed the Edinburgh Inventory of Handedness and the Recalled Childhood Gender Nonconformity Scale. Gay men also completed measures of anal sex role preference. As in previous studies, gay men showed greater non-right-handedness and gender nonconformity than straight men. Also, among gay men, bottoms/versatiles (i.e., gay men who take a receptive anal sex role, or who take on both a receptive and insertive anal sex role) were more gender-nonconforming than tops (i.e., gay men who take an insertive anal sex role). In support of the hypothesis, bottoms/versatiles were more non-right-handed than tops and handedness mediated the male sexual orientation and anal sex role differences in Recalled Childhood Gender Nonconformity. Together, these findings suggest that developmental processes linked to handedness underpin variation among men in sexual orientation and gender nonconformity as well as variation among subgroups of gay men that are delineated by anal sex roles.

Maternal Prenatal Stress and Other Developmental Risk Factors for Adolescent Depression: Spotlight on Sex Differences.

PubMed

Maxwell, Seth D; Fineberg, Anna M; Drabick, Deborah A; Murphy, Shannon K; Ellman, Lauren M

2018-02-01

Maternal stress during pregnancy has been linked to premorbid abnormalities associated with depression (e.g., difficult temperament, cognitive deficits) in offspring. However, few studies have looked across developmental periods to examine maternal stress during pregnancy and offspring depression during adolescence and whether these associations differ by sex. The current study used data from 1711 mother-offspring dyads (offspring sex: 49.8% male) in a longitudinal birth cohort study. Maternal narratives collected during pregnancy were qualitatively coded for stress-related themes by independent raters. Latent class analysis (LCA) identified distinct subgroups of offspring based on exposure to maternal prenatal stress and other developmental factors from the prenatal, childhood, and adolescent periods that have been associated with depression and/or maternal prenatal stress. LCA identified subgroups that were compared to determine whether and to what extent they differed on adolescent depressive symptoms. LCA revealed a subgroup of "high-risk" individuals, characterized by maternal factors during pregnancy (higher ambivalence/negativity and lower positivity towards the pregnancy, higher levels of hassles, lower maternal education and higher maternal age at birth, higher pre-pregnancy BMI) and offspring developmental factors (decreased cognitive functioning during childhood and adolescence, lower perceived parental support during adolescence, and higher levels of maternal depression during adolescence). High-risk females exhibited elevated conduct symptoms and higher birth order, while high-risk males exhibited decreased internalizing symptoms and lower birth order. Both high-risk males and females reported elevated depressive symptoms during adolescence relative to their "low-risk" counterparts.

Male Adolescent Birth Control Behavior: The Importance of Developmental Factors and Sex Differences.

ERIC Educational Resources Information Center

Cohen, Donald D.; Rose, Ryda D.

1984-01-01

A survey of sex and birth control behavior of 51 male adolescents aged 15-17 was conducted using structured interviews. Based on research with teenage females, three social influences were examined for their possible impact on male birth control behavior. (Author/BW)

Maternal nationality and developmental delays in young children: Analysis of the data from the national registry in Taiwan.

PubMed

Tseng, Yen-Cheng; Guo, How-Ran; Lai, Der-Chung

2016-01-01

With globalization, transnational marriages become more and more common around the world. Children born to immigrant mothers might be more likely to have developmental delays, but studies on this topic are limited and with inconsistent results. To determine whether children born to immigrant mothers are more likely to have developmental delays. We analyzed the data from the national registry of children with developmental delays from 2009 to 2013 and compared the incidence of developmental delays between children born to immigrant mothers and native mothers. We also performed stratified analyses by age, sex, and geographic area. From 2009 to 2013, 78,946 new cases of developmental delays under 6 years of age were registered, including 5619 (7.1%) born to immigrant mothers. The incidence was higher in children born to native mothers in every year with rate ratios ranging from 1.32 to 1.48, and the differences reached statistical significance even after stratification by age, sex, and geographic area. Children born to immigrant mothers had lower incidence of developmental delays in Taiwan. The result may help reduce the discrimination of foreign spouses and their children. Copyright © 2016 Elsevier Ltd. All rights reserved.

Influence of gender constancy and social power on sex-linked modeling.

PubMed

Bussey, K; Bandura, A

1984-12-01

Competing predictions derived from cognitive-developmental theory and social learning theory concerning sex-linked modeling were tested. In cognitive-developmental theory, gender constancy is considered a necessary prerequisite for the emulation of same-sex models, whereas according to social learning theory, sex-role development is promoted through a vast system of social influences with modeling serving as a major conveyor of sex role information. In accord with social learning theory, even children at a lower level of gender conception emulated same-sex models in preference to opposite-sex ones. Level of gender constancy was associated with higher emulation of both male and female models rather than operating as a selective determinant of modeling. This finding corroborates modeling as a basic mechanism in the sex-typing process. In a second experiment we explored the limits of same-sex modeling by pitting social power against the force of collective modeling of different patterns of behavior by male and female models. Social power over activities and rewarding resources produced cross-sex modeling in boys, but not in girls. This unexpected pattern of cross-sex modeling is explained by the differential sex-typing pressures that exist for boys and girls and socialization experiences that heighten the attractiveness of social power for boys.

Handedness is a biomarker of variation in anal sex role behavior and Recalled Childhood Gender Nonconformity among gay men

PubMed Central

Swift-Gallant, Ashlyn; Coome, Lindsay A.; Monks, D. Ashley; VanderLaan, Doug P.

2017-01-01

Developmental theories of the biological basis of sexual orientation suggest that sexually differentiated psychological and behavioural traits should be linked with sexual orientation. Subgroups of gay men delineated by anal sex roles differ according to at least one such trait: gender expression. The present study assessed the hypothesis that handedness, a biologically determined sexually differentiated trait, corresponds to differences in subgroups of gay men based on anal sex role. Furthermore, it assessed whether handedness mediates the association between gender nonconformity and male sexual orientation. Straight and gay men (N = 333) completed the Edinburgh Inventory of Handedness and the Recalled Childhood Gender Nonconformity Scale. Gay men also completed measures of anal sex role preference. As in previous studies, gay men showed greater non-right-handedness and gender nonconformity than straight men. Also, among gay men, bottoms/versatiles (i.e., gay men who take a receptive anal sex role, or who take on both a receptive and insertive anal sex role) were more gender-nonconforming than tops (i.e., gay men who take an insertive anal sex role). In support of the hypothesis, bottoms/versatiles were more non-right-handed than tops and handedness mediated the male sexual orientation and anal sex role differences in Recalled Childhood Gender Nonconformity. Together, these findings suggest that developmental processes linked to handedness underpin variation among men in sexual orientation and gender nonconformity as well as variation among subgroups of gay men that are delineated by anal sex roles. PMID:28234947

Developmental trend of children with Down's syndrome - How do sex and neonatal conditions influence their developmental patterns?

PubMed

Aoki, Sayaka; Yamauchi, Yuko; Hashimoto, Keiji

2018-03-01

This study investigated factors that would influence developmental trend of children with Down's syndrome (DS) in three different domains (motor, cognitive, language), specifically focusing on the effect of sex and neonatal conditions, including preterm birth, low birth weight, and congenital heart disease (CHD). The participants were 158 children with DS (mean age at the initial test = 25.5 months) receiving clinical service at a rehabilitation center in Yokohama, Japan. Kyoto Scale of Psychological Development was used to measure developmental level, which derive total developmental age (DA), Posture-motor DA, Cognitive-adaptive DA, and Language-social DA. For the analyses, a multilevel model for change was adopted, as the model allowed us to investigate intrapersonal growth and the between-personal factors that are associated with individual differences in the pattern of growth. The developmental speed of children with DS was found to be slower than that of typical children in all the three developmental domains assessed (i.e., the estimated coefficient of the slope for chronological age on DA was less than 1). DS Girls developed significantly faster than boys in non-verbal cognitive and language abilities. Low birth weight and CHD had a significant negative impact on development of non-verbal cognitive abilities for boys, but had a somewhat positive effect for girls. As was shown in previous studies, the result of this study indicated that the children with DS develop slower than non-disabled children. Low birth weight and CHD were found to influence developmental trend of children with DS, differently for boys and girls. Copyright © 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Sexual dimorphism in mammalian autosomal gene regulation is determined not only by Sry but by sex chromosome complement as well.

PubMed

Wijchers, Patrick J; Yandim, Cihangir; Panousopoulou, Eleni; Ahmad, Mushfika; Harker, Nicky; Saveliev, Alexander; Burgoyne, Paul S; Festenstein, Richard

2010-09-14

Differences between males and females are normally attributed to developmental and hormonal differences between the sexes. Here, we demonstrate differences between males and females in gene silencing using a heterochromatin-sensitive reporter gene. Using "sex-reversal" mouse models with varying sex chromosome complements, we found that this differential gene silencing was determined by X chromosome complement, rather than sex. Genome-wide transcription profiling showed that the expression of hundreds of autosomal genes was also sensitive to sex chromosome complement. These genome-wide analyses also uncovered a role for Sry in modulating autosomal gene expression in a sex chromosome complement-specific manner. The identification of this additional layer in the establishment of sexual dimorphisms has implications for understanding sexual dimorphisms in physiology and disease. Copyright © 2010 Elsevier Inc. All rights reserved.

Evidence of sex-bias in gene expression in the brain transcriptome of two populations of rainbow trout (Oncorhynchus mykiss) with divergent life histories.

PubMed

Hale, Matthew C; McKinney, Garrett J; Thrower, Frank P; Nichols, Krista M

2018-01-01

Sex-bias in gene expression is a mechanism that can generate phenotypic variance between the sexes, however, relatively little is known about how patterns of sex-bias vary during development, and how variable sex-bias is between different populations. To that end, we measured sex-bias in gene expression in the brain transcriptome of rainbow trout (Oncorhynchus mykiss) during the first two years of development. Our sampling included from the fry stage through to when O. mykiss either migrate to the ocean or remain resident and undergo sexual maturation. Samples came from two F1 lines: One from migratory steelhead trout and one from resident rainbow trout. All samples were reared in a common garden environment and RNA sequencing (RNA-seq) was used to estimate patterns of gene expression. A total of 1,716 (4.6% of total) genes showed evidence of sex-bias in gene expression in at least one time point. The majority (96.7%) of sex-biased genes were differentially expressed during the second year of development, indicating that patterns of sex-bias in expression are tied to key developmental events, such as migration and sexual maturation. Mapping of differentially expressed genes to the O. mykiss genome revealed that the X chromosome is enriched for female upregulated genes, and this may indicate a lack of dosage compensation in rainbow trout. There were many more sex-biased genes in the migratory line than the resident line suggesting differences in patterns of gene expression in the brain between populations subjected to different forces of selection. Overall, our results suggest that there is considerable variation in the extent and identity of genes exhibiting sex-bias during the first two years of life. These differentially expressed genes may be connected to developmental differences between the sexes, and/or between adopting a resident or migratory life history.

[The gender debate from the pedagogic perspective].

PubMed

Forster, Johanna

2004-09-01

The question of form and extent of biological and/or cultural influences on female and male behaviour and performance is marking a major focus in present scientific research. Accordingly, a broad spectrum of approaches in research and interpretations of results is available. The recent debate on sex and gender is offering two basic objectives for research in education science: First, the critical review of the data and results on sex specifics presented in respect to the articulation of educational aims, topics and methods. Second, the intensified research focus on the developmental consequences of gender and gender roles for boys and girls, women and men. The pedagogical focus is discussed regarding the following three objectives: 1. developmental conditions in early ontogeny, 2. the question of sex specific differences in cognitive abilities in respect to school performance of adolescents, and 3. teaching knowledge on "sex" and "gender" in schools.

Effects of Estrogen in Gender-dependent Fetal Programming of Adult Cardiovascular Dysfunction.

PubMed

Chen, Zewen; Wang, Lei; Ke, Jun; Xiao, DaLiao

2018-03-01

Epidemiological studies and experimental studies have demonstrated that intrauterine adverse environment increases the risk of cardiovascular disease (CVD) in adulthood. However, whether an individual develops a cardiovascular dysfunctional phenotype may depend on genetic background, age, and sex. In this review, we summarize some of the recent experimental animal studies in the developmental programming of adult CVD with an emphasis on sex differences and the potential role of estrogen in mediating sexual dimorphism. Few epidemiological studies report the effect of sex on the developmental programming of CVD. However, numerous experimental animal studies have shown a sex difference in fetal programming of adult cardiovascular dysfunction. Most of the animal studies indicate that male offspring develop cardiovascular dysfunction and CVD in adulthood, whereas adult females appear to be protected. Estrogen is one of the key factors that contributes to the sex difference of adult CVD. Estrogen/its receptor (ER) may interact with the RAS system by changes of DNA methylation patterns at the target gene promoter, serve as an antioxidant to counteract the prenatal insults-induced heightened ROS, and function as an eNOS activator to increase vasodilation, resulting in the protection of female offspring from the development of hypertension and other CVDs. These studies suggest that estrogen/ER may contribute to sex differences in cardiovascular response to an adverse intrauterine environment and play a significant role in modulating the cardiovascular response in adulthood. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Sex and Age Differences in Achievement Goal Orientations in Turkish Adolescents

ERIC Educational Resources Information Center

Sahin, Ertugrul; Topkaya, Nursel; Kürkçü, Recep

2016-01-01

Culture plays an important role in the achievement goal orientations of students, which may vary as they progress through their lifespan. However, research examining achievement goal orientations in the Turkish cultural context is scarce. Based on contextual and developmental theories, the aim of this study was to examine sex and age differences…

What's "Verbil" Sex? An Analysis of Adolescents' Questions about Sex.

ERIC Educational Resources Information Center

Campbell, Toni A.; Campbell, David E.

Although many studies have described adolescents' sexual behavior and attitudes, there are little data available on the nature of the questions that occur to adolescents as they move toward maturity. A study was conducted to determine whether the questions children and adolescents ask reflect developmental differences in cognitive abilities and…

Sex differences in voice onset time: A developmental study of phonetic context effects in British English

NASA Astrophysics Data System (ADS)

Whiteside, Sandra P.; Henry, Luisa; Dobbin, Rachel

2004-08-01

Voice onset time (VOT) data for the plosives /p b t d k g/ in two vowel contexts (eye opena) for 5 groups of 46 boys and girls aged 5; 8 (5 years, 8 months) to 13;2 years were investigated to examine patterns of sex differences. Results indicated that there was some evidence of females displaying longer VOT values than the males. In addition, these were found to be most marked for the data of the 13;2-year olds. Furthermore, the sex differences in the VOT values displayed phonetic context effects. For example, the greatest sex differences were observed for the voiceless plosives, and within the context of the vowel /i/.

Improvement of vitrification of in vitro produced buffalo embryos with special reference to sex ratio following vitrification

PubMed Central

Mahmoud, K. Gh. M; Scholkamy, T. H; Darwish, S. F

2015-01-01

Cryopreservation and sexing of embryos are integrated into commercial embryo transfer technologies. To improve the effectiveness of vitrification of in vitro produced buffalo embryos, two experiments were conducted. The first evaluated the effect of exposure time (2 and 3 min) and developmental stage (morula and blastocysts) on the viability and development of vitrified buffalo embryos. Morphologically normal embryos and survival rates (re-expansion) significantly increased when vitrified morulae were exposed for 2 min compared to 3 min (P<0.001). On the other hand, morphologically normal and survival rates of blastocysts significantly increased when exposed for 3 min compared to 2 min (P<0.001). However, there were no significant differences between the two developmental stages (morulae and blastocystes) in the percentages of morphologically normal embryos and re-expansion rates after a 24 h culture. The second experiment aimed to evaluate the effect of viability on the sex ratio of buffalo embryos after vitrification and whether male and female embryos survived vitrification differently. A total number of 61 blastocysts were vitrified for 3 min with the same cryoprotectant as experiment 1. Higher percentages of males were recorded for live as compared to dead embryos; however, this difference was not significant. In conclusion, the post-thaw survival and development of in vitro produced morulae and blastocysts were found to be affected by exposure time rather than developmental stage. Survivability had no significant effect on the sex ratio of vitrified blastocysts; nevertheless, the number of surviving males was higher than dead male embryos. PMID:27175197

Developmental differences between boys and girls result in sex-specific physical fitness changes from fourth to fifth grade.

PubMed

Flanagan, Shawn D; Dunn-Lewis, Courtenay; Hatfield, Disa L; Distefano, Lindsay J; Fragala, Maren S; Shoap, Mark; Gotwald, Mary; Trail, John; Gomez, Ana L; Volek, Jeff S; Cortis, Cristina; Comstock, Brett A; Hooper, David R; Szivak, Tunde K; Looney, David P; DuPont, William H; McDermott, Danielle M; Gaudiose, Michael C; Kraemer, William J

2015-01-01

To better understand how developmental differences impact performance on a broad selection of common physical fitness measures, we examined changes in boys and girls from fourth to fifth grade. Subjects included 273 boys (age, 9.5 ± 0.6 years; height, 139.86 ± 7.52 cm; mass, 38.00 ± 9.55 kg) and 295 girls (age, 9.6 ± 0.5 years; height, 139.30 ± 7.19 cm; weight, 37.44 ± 9.35 kg). We compared anthropometrics, cardiorespiratory and local muscular endurance, flexibility, power, and strength. A mixed-method analysis of variance was used to compare boys and girls at the 2 time points. Pearson correlation coefficients were used to examine relationships between anthropometric and fitness measurements. Significance was set at p ≤ 0.05. Weight increased significantly (>10%) in both sexes, and girls became significantly taller than boys after growing 4.9% by fifth grade (vs. 3.5%). Both groups improved cardiorespiratory endurance and power, although boys performed better than girls at both time points. Boys were stronger in fourth grade, but girls improved more, leading to similar fifth-grade values. Girls were more flexible in fourth grade, but their significant decreases (∼32.4%) coupled with large improvements in boys (∼105%) resulted in similar fifth-grade scores. Body mass index (BMI) was positively correlated with run time regardless of grade or sex. Power was negatively correlated with BMI and run time in fourth grade. In conclusion, sex-specific differences in physical fitness are apparent before pubescence. Furthermore, this selection of measures reveals sexually dimorphic changes, which likely reflect the onset of puberty in girls. Coaches and teachers should account these developmental differences and their effects on anthropometrics and fitness in boys and girls.

Fetal Sex Modulates Developmental Response to Maternal Malnutrition

PubMed Central

Gonzalez-Bulnes, Antonio; Torres-Rovira, Laura; Astiz, Susana; Ovilo, Cristina; Sanchez-Sanchez, Raul; Gomez-Fidalgo, Ernesto; Perez-Solana, Mariluz; Martin-Lluch, Mercedes; Garcia-Contreras, Consuelo; Vazquez-Gomez, Marta

2015-01-01

The incidence of obesity and metabolic diseases is dramatically high in rapidly developing countries. Causes have been related to intrinsic ethnic features with development of a thrifty genotype for adapting to food scarcity, prenatal programming by undernutrition, and postnatal exposure to obesogenic lifestyle. Observational studies in humans and experimental studies in animal models evidence that the adaptive responses of the offspring may be modulated by their sex. In the contemporary context of world globalization, the new question arising is the existence and extent of sex-related differences in developmental and metabolic traits in case of mixed-race. Hence, in the current study, using a swine model, we compared male and female fetuses that were crossbred from mothers with thrifty genotype and fathers without thrifty genotype. Female conceptuses evidence stronger protective strategies for their adequate growth and postnatal survival. In brief, both male and female fetuses developed a brain-sparing effect but female fetuses were still able to maintain the development of other viscerae than the brain (mainly liver, intestine and kidneys) at the expense of carcass development. Furthermore, these morphometric differences were reinforced by differences in nutrient availability (glucose and cholesterol) favoring female fetuses with severe developmental predicament. These findings set the basis for further studies aiming to increase the knowledge on the interaction between genetic and environmental factors in the determination of adult phenotype PMID:26544862

Developmental changes in spatial learning in the Morris water-maze in young meadow voles, Microtus pennsylvanicus.

PubMed

Galea, L A; Ossenkopp, K P; Kavaliers, M

1994-01-31

Spatial learning in pre- and postweaning meadow voles, (Microtus pennsylvanicus) was examined in a Morris water-maze task. The learning performance of 10-day-old (preweaning) and 15-, 20- and 25-day-old (postweaning) male and female voles was assessed by measuring the latency to reach a hidden platform by each animal twice a day for 5 days. Voles of all age groups were able to learn the spatial task with Day 10 and Day 15 voles acquiring the task more slowly than did Day 20 and Day 25 voles. There were no significant sex differences in task acquisition in any of the four age groups. In addition, although swimming speed was related to age, with older animals swimming faster than younger ones, differences in swim speed did not account for the faster acquisition by the older animals. These results show that both preweaning and postweaning voles can successfully learn a spatial task. This is in contrast to preweaning laboratory rats which cannot successfully acquire a similar spatial task. These findings indicate that there are species differences in the ontogeny of spatial learning, which are likely related to the ecological and behavioural developmental characteristics of the species. Furthermore, in contrast to the sex difference in water-maze performance obtained in adult, breeding meadow voles who demonstrate a sex difference, there were no significant sex differences in the spatial performance of the juvenile voles. This suggests that sex differences in spatial learning in the meadow vole do not appear until voles reach reproductive adulthood.

Developmental-Genetic Effects on Level and Change in Childhood Fears of Twins during Adolescence

ERIC Educational Resources Information Center

Eaves, Lindon J.; Silberg, Judy L.

2008-01-01

Background: If the adaptive significance of specific fears changes with age, the genetic contribution to individual differences may be lowest at the age of greatest salience. The roles of genes and environment in the developmental-genetic trajectory of five common childhood fears are explored in 1094 like-sex pairs of male and female monozygotic…

Australian black field crickets show changes in neural gene expression associated with socially-induced morphological, life-history, and behavioral plasticity.

PubMed

Kasumovic, Michael M; Chen, Zhiliang; Wilkins, Marc R

2016-10-24

Ecological and evolutionary model organisms have provided extensive insight into the ecological triggers, adaptive benefits, and evolution of life-history driven developmental plasticity. Despite this, we still have a poor understanding of the underlying genetic changes that occur during shifts towards different developmental trajectories. The goal of this study is to determine whether we can identify underlying gene expression patterns that can describe the different life-history trajectories individuals follow in response to social cues of competition. To do this, we use the Australian black field cricket (Teleogryllus commodus), a species with sex-specific developmental trajectories moderated by the density and quality of calls heard during immaturity. In this study, we manipulated the social information males and females could hear by rearing individuals in either calling or silent treatments. We next used RNA-Seq to develop a reference transcriptome to study changes in brain gene expression at two points prior to sexual maturation. We show accelerated development in both sexes when exposed to calling; changes were also seen in growth, lifespan, and reproductive effort. Functional relationships between genes and phenotypes were apparent from ontological enrichment analysis. We demonstrate that increased investment towards traits such as growth and reproductive effort were often associated with the expression of a greater number of genes with similar effect, thus providing a suite of candidate genes for future research in this and other invertebrate organisms. Our results provide interesting insight into the genomic underpinnings of developmental plasticity and highlight the potential of a genomic exploration of other evolutionary theories such as condition dependence and sex-specific developmental strategies.

Developmental Differences in Young Children's Sex-Typing: Automatic versus Reflective Processing.

ERIC Educational Resources Information Center

Perry, Louise C.; Sung, Hung-yen A.

To investigate social cognitive factors in early sex-role development, this study examined young children's gender-related judgments of toy appropriateness under speeded and delayed response conditions. Subjects were 55 boys and 59 girls, aged 3, 5, and 7. Ninety-two photographs of common toys were independently rated as mainly for girls, mainly…

The Influence of Age, Sex, and School Size Upon the Development of Formal Operational Thought.

ERIC Educational Resources Information Center

Lewis, William Roedolph

School size, age and sex of students as related to scores on the six Piagetian Developmental Thought Processes Tasks were investigated. Five hundred seventy-four students from seventh through twelfth grades were randomly selected from 25 different schools classified as small, medium, or large. Data were treated through factorial analysis of…

Sex determination in insects: a binary decision based on alternative splicing.

PubMed

Salz, Helen K

2011-08-01

The gene regulatory networks that control sex determination vary between species. Despite these differences, comparative studies in insects have found that alternative splicing is reiteratively used in evolution to control expression of the key sex-determining genes. Sex determination is best understood in Drosophila where activation of the RNA binding protein-encoding gene Sex-lethal is the central female-determining event. Sex-lethal serves as a genetic switch because once activated it controls its own expression by a positive feedback splicing mechanism. Sex fate choice in is also maintained by self-sustaining positive feedback splicing mechanisms in other dipteran and hymenopteran insects, although different RNA binding protein-encoding genes function as the binary switch. Studies exploring the mechanisms of sex-specific splicing have revealed the extent to which sex determination is integrated with other developmental regulatory networks. Copyright © 2011 Elsevier Ltd. All rights reserved.

Embryonic transcription factor expression in mice predicts medial amygdala neuronal identity and sex-specific responses to innate behavioral cues

PubMed Central

Lischinsky, Julieta E; Sokolowski, Katie; Li, Peijun; Esumi, Shigeyuki; Kamal, Yasmin; Goodrich, Meredith; Oboti, Livio; Hammond, Timothy R; Krishnamoorthy, Meera; Feldman, Daniel; Huntsman, Molly; Liu, Judy; Corbin, Joshua G

2017-01-01

The medial subnucleus of the amygdala (MeA) plays a central role in processing sensory cues required for innate behaviors. However, whether there is a link between developmental programs and the emergence of inborn behaviors remains unknown. Our previous studies revealed that the telencephalic preoptic area (POA) embryonic niche is a novel source of MeA destined progenitors. Here, we show that the POA is comprised of distinct progenitor pools complementarily marked by the transcription factors Dbx1 and Foxp2. As determined by molecular and electrophysiological criteria this embryonic parcellation predicts postnatal MeA inhibitory neuronal subtype identity. We further find that Dbx1-derived and Foxp2+ cells in the MeA are differentially activated in response to innate behavioral cues in a sex-specific manner. Thus, developmental transcription factor expression is predictive of MeA neuronal identity and sex-specific neuronal responses, providing a potential developmental logic for how innate behaviors could be processed by different MeA neuronal subtypes. DOI: http://dx.doi.org/10.7554/eLife.21012.001 PMID:28244870

A Research Note on Time With Children in Different- and Same-Sex Two-Parent Families.

PubMed

Prickett, Kate C; Martin-Storey, Alexa; Crosnoe, Robert

2015-06-01

Public debate on same-sex marriage often focuses on the disadvantages that children raised by same-sex couples may face. On one hand, little evidence suggests any difference in the outcomes of children raised by same-sex parents and different-sex parents. On the other hand, most studies are limited by problems of sample selection and size, and few directly measure the parenting practices thought to influence child development. This research note demonstrates how the 2003-2013 American Time Use Survey (n=44,188) may help to address these limitations. Two-tier Cragg's Tobit alternative models estimated the amount of time that parents in different-sex and same-sex couples engaged in child-focused time. Women in same-sex couples were more likely than either women or men in different-sex couples to spend such time with children. Overall, women (regardless of the gender of their partners) and men coupled with other men spent significantly more time with children than men coupled with women, conditional on spending any child-focused time. These results support prior research that different-sex couples do not invest in children at appreciably different levels than same-sex couples. We highlight the potential for existing nationally representative data sets to provide preliminary insights into the developmental experiences of children in nontraditional families.

Sex Differences in the Development of Social Relationships in Rhesus Macaques (Macaca mulatta).

PubMed

Kulik, Lars; Amici, Federica; Langos, Doreen; Widdig, Anja

2015-04-01

Several studies have documented the importance of social bonding for the enhancement of individual fitness. However, little is known about how social relationships develop through ontogeny, and whether their development follows the same trajectory in males and females. Here we analyzed affiliative interactions (proximity, social grooming, play) combined with demographic and genetic data in semi-free-ranging rhesus macaques ( Macaca mulatta ) on Cayo Santiago over their first 4 yr of life (from birth to sexual maturation) to understand how these interactions change through development in both sexes. Generalized linear mixed models revealed that social behaviors mostly followed different developmental trajectories in males and females and were highly dependent on the social context. In particular, sex differences in social behavior varied through development depending on the partner's sex and age. Females engaged in more social interactions than males, especially with other females, and were more involved in grooming around the time of maturation. In contrast, males interacted more with males and age peers, especially around maturation. Sex differences in social behavior varied through development, but also depended on rank, partner's rank, and kin line, although not consistently. High-ranking individuals, especially older females, were generally preferred as social partners. Moreover, both male and female individuals interacted mostly with maternal kin, although males also preferred paternal kin over nonkin. Importantly, most developmental changes in sociality happened when individuals were ca . 2 yr old, suggesting that this might be a milestone in the development of sociality in rhesus macaques. The only notable exception to this pattern was play, which was more pronounced in males from the beginning of their lives. We propose that play might serve as a trigger of sex differences in social behavior, with sex differences emerging early in development and increasing through time as males and females gradually grow into their adult social roles.

Characterization of Adelphocoris suturalis (Hemiptera: Miridae) Transcriptome from Different Developmental Stages

NASA Astrophysics Data System (ADS)

Tian, Caihong; Tek Tay, Wee; Feng, Hongqiang; Wang, Ying; Hu, Yongmin; Li, Guoping

2015-06-01

Adelphocoris suturalis is one of the most serious pest insects of Bt cotton in China, however its molecular genetics, biochemistry and physiology are poorly understood. We used high throughput sequencing platform to perform de novo transcriptome assembly and gene expression analyses across different developmental stages (eggs, 2nd and 5th instar nymphs, female and male adults). We obtained 20 GB of clean data and revealed 88,614 unigenes, including 23,830 clusters and 64,784 singletons. These unigene sequences were annotated and classified by Gene Ontology, Clusters of Orthologous Groups, and Kyoto Encyclopedia of Genes and Genomes databases. A large number of differentially expressed genes were discovered through pairwise comparisons between these developmental stages. Gene expression profiles were dramatically different between life stage transitions, with some of these most differentially expressed genes being associated with sex difference, metabolism and development. Quantitative real-time PCR results confirm deep-sequencing findings based on relative expression levels of nine randomly selected genes. Furthermore, over 791,390 single nucleotide polymorphisms and 2,682 potential simple sequence repeats were identified. Our study provided comprehensive transcriptional gene expression information for A. suturalis that will form the basis to better understanding of development pathways, hormone biosynthesis, sex differences and wing formation in mirid bugs.

Characterization of Adelphocoris suturalis (Hemiptera: Miridae) Transcriptome from Different Developmental Stages

PubMed Central

Tian, Caihong; Tek Tay, Wee; Feng, Hongqiang; Wang, Ying; Hu, Yongmin; Li, Guoping

2015-01-01

Adelphocoris suturalis is one of the most serious pest insects of Bt cotton in China, however its molecular genetics, biochemistry and physiology are poorly understood. We used high throughput sequencing platform to perform de novo transcriptome assembly and gene expression analyses across different developmental stages (eggs, 2nd and 5th instar nymphs, female and male adults). We obtained 20 GB of clean data and revealed 88,614 unigenes, including 23,830 clusters and 64,784 singletons. These unigene sequences were annotated and classified by Gene Ontology, Clusters of Orthologous Groups, and Kyoto Encyclopedia of Genes and Genomes databases. A large number of differentially expressed genes were discovered through pairwise comparisons between these developmental stages. Gene expression profiles were dramatically different between life stage transitions, with some of these most differentially expressed genes being associated with sex difference, metabolism and development. Quantitative real-time PCR results confirm deep-sequencing findings based on relative expression levels of nine randomly selected genes. Furthermore, over 791,390 single nucleotide polymorphisms and 2,682 potential simple sequence repeats were identified. Our study provided comprehensive transcriptional gene expression information for A. suturalis that will form the basis to better understanding of development pathways, hormone biosynthesis, sex differences and wing formation in mirid bugs. PMID:26047353

Developmental stages and sex differences of white matter and behavioral development through adolescence: a longitudinal diffusion tensor imaging (DTI) study.

PubMed

Simmonds, Daniel J; Hallquist, Michael N; Asato, Miya; Luna, Beatriz

2014-05-15

White matter (WM) continues to mature through adolescence in parallel with gains in cognitive ability. To date, developmental changes in human WM microstructure have been inferred using analyses of cross-sectional or two time-point follow-up studies, limiting our understanding of individual developmental trajectories. The aims of the present longitudinal study were to characterize the timing of WM growth and investigate how sex and behavior are associated with different developmental trajectories. We utilized diffusion tensor imaging (DTI) in 128 individuals aged 8-28, who received annual scans for up to 5 years and completed motor and cognitive tasks. Flexible nonlinear growth curves indicated a hierarchical pattern of WM development. By late childhood, posterior cortical-subcortical connections were similar to adults. During adolescence, WM microstructure reached adult levels, including frontocortical, frontosubcortical and cerebellar connections. Later to mature in adulthood were major corticolimbic association tracts and connections at terminal gray matter sites in cortical and basal ganglia regions. These patterns may reflect adolescent maturation of frontal connectivity supporting cognitive abilities, particularly the protracted refinement of corticolimbic connectivity underlying cognition-emotion interactions. Sex and behavior also played a large role. Males showed continuous WM growth from childhood through early adulthood, whereas females mainly showed growth during mid-adolescence. Further, earlier WM growth in adolescence was associated with faster and more efficient responding and better inhibitory control whereas later growth in adulthood was associated with poorer performance, suggesting that the timing of WM growth is important for cognitive development. Copyright © 2013 Elsevier Inc. All rights reserved.

The aquaglyceroporin AQP9 contributes to the sex-specific effects of in utero arsenic exposure on placental gene expression.

PubMed

Winterbottom, Emily F; Koestler, Devin C; Fei, Dennis Liang; Wika, Eric; Capobianco, Anthony J; Marsit, Carmen J; Karagas, Margaret R; Robbins, David J

2017-06-14

Sex-specific factors play a major role in human health and disease, including responses to environmental stresses such as toxicant exposure. Increasing evidence suggests that such sex differences also exist during fetal development. In a previous report using the resources of the New Hampshire Birth Cohort Study (NHBCS), we found that low-to-moderate in utero exposure to arsenic, a highly toxic and widespread pollutant, was associated with altered expression of several key developmental genes in the fetal portion of the placenta. These associations were sex-dependent, suggesting that in utero arsenic exposure differentially impacts male and female fetuses. In the present study, we investigated the molecular basis for these sex-specific responses to arsenic. Using NanoString technology, we further analyzed the fetal placenta samples from the NHBCS for the expression of genes encoding arsenic transporters and metabolic enzymes. Multivariable linear regression analysis was used to examine their relationship with arsenic exposure and with key developmental genes, after stratification by fetal sex. We found that maternal arsenic exposure was strongly associated with expression of the AQP9 gene, encoding an aquaglyceroporin transporter, in female but not male fetal placenta. Moreover, AQP9 expression associated with that of a subset of female-specific arsenic-responsive genes. Our results suggest that AQP9 is upregulated in response to arsenic exposure in female, but not male, fetal placenta. Based on these results and prior studies, increased AQP9 expression may lead to increased arsenic transport in the female fetal placenta, which in turn may alter the expression patterns of key developmental genes that we have previously shown to be associated with arsenic exposure. Thus, this study suggests that AQP9 may play a role in the sex-specific effects of in utero arsenic exposure.

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

PubMed Central

Huddy, Timothy F.; Ogawa-Okada, Maya; Adkins, Jamie L.

2018-01-01

Recent studies in mice have demonstrated a sexual dimorphism in circadian entrainment to scheduled feeding. On a time restricted diet, males tend to develop food anticipatory activity (FAA) sooner than females and with a higher amplitude of activity. The underlying cause of this sex difference remains unknown. One study suggests that sex hormones, both androgens and estrogens, modulate food anticipatory activity in mice. Here we present results suggesting that the sex difference in FAA is unrelated to gonadal sex hormones. While a sex difference between males and females in FAA on a timed, calorie restricted diet was observed there were no differences between intact and gonadectomized mice in the onset or magnitude of FAA. To test other sources of the sex difference in circadian entrainment to scheduled feeding, we used sex chromosome copy number mutants, but there was no difference in FAA when comparing XX, XY-, XY-;Sry Tg, and XX;Sry Tg mice, demonstrating that gene dosage of sex chromosomes does not mediate the sex difference in FAA. Next, we masculinized female mice by treating them with 17-beta estradiol during the neonatal period; yet again, we saw no difference in FAA between control and masculinized females. Finally, we observed that there was no longer a sex difference in FAA for older mice, suggesting that the sex difference in FAA is age-dependent. Thus, our study demonstrates that singular manipulations of gonadal hormones, sex chromosomes, or developmental patterning are not able to explain the difference in FAA between young male and female mice. PMID:29385171

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

PubMed

Aguayo, Antonio; Martin, Camille S; Huddy, Timothy F; Ogawa-Okada, Maya; Adkins, Jamie L; Steele, Andrew D

2018-01-01

Recent studies in mice have demonstrated a sexual dimorphism in circadian entrainment to scheduled feeding. On a time restricted diet, males tend to develop food anticipatory activity (FAA) sooner than females and with a higher amplitude of activity. The underlying cause of this sex difference remains unknown. One study suggests that sex hormones, both androgens and estrogens, modulate food anticipatory activity in mice. Here we present results suggesting that the sex difference in FAA is unrelated to gonadal sex hormones. While a sex difference between males and females in FAA on a timed, calorie restricted diet was observed there were no differences between intact and gonadectomized mice in the onset or magnitude of FAA. To test other sources of the sex difference in circadian entrainment to scheduled feeding, we used sex chromosome copy number mutants, but there was no difference in FAA when comparing XX, XY-, XY-;Sry Tg, and XX;Sry Tg mice, demonstrating that gene dosage of sex chromosomes does not mediate the sex difference in FAA. Next, we masculinized female mice by treating them with 17-beta estradiol during the neonatal period; yet again, we saw no difference in FAA between control and masculinized females. Finally, we observed that there was no longer a sex difference in FAA for older mice, suggesting that the sex difference in FAA is age-dependent. Thus, our study demonstrates that singular manipulations of gonadal hormones, sex chromosomes, or developmental patterning are not able to explain the difference in FAA between young male and female mice.

The Developmental Influence of Sex Composition in Preschool Classrooms: Boys Fare Worse in Preschool Classrooms with More Boys

ERIC Educational Resources Information Center

Moller, Arlen C.; Forbes-Jones, Emma; Hightower, A. Dirk; Friedman, Ron

2008-01-01

A multilevel modeling approach was employed to investigate the relation between sex composition and developmental change in 70 urban preschool classrooms. The research represents a unique contribution as (1) few studies have examined the influence of sex composition during the preschool years, (2) it represents the first research to use a…

THE IMPACT OF COGNITIVE MATURITY ON THE DEVELOPMENT OF SEX-ROLE ATTITUDES IN THE YEARS 4 TO 8.

ERIC Educational Resources Information Center

KOHLBERG, LAWRENCE; ZIGLER, EDWARD

A SERIES OF STUDIES WAS CONDUCTED TO CLARIFY THE ROLE OF INTELLIGENCE IN PERSONALITY ORGANIZATION AND TO ASSESS A COGNITIVE-DEVELOPMENTAL INTERPRETATION OF IQ-PERSONALITY CORRELATIONS. THE SPECIFIC FOCUS OF THE STUDY WAS THE RELATIONSHIP OF INTELLECTUAL MATURITY TO THE DEVELOPMENT OF SEX-ROLE ATTITUDES. AGE-DEVELOPMENTAL TRENDS IN SEX-ROLE…

Two-hit model of schizophrenia induced by neonatal immune activation and peripubertal stress in rats: Study of sex differences and brain oxidative alterations.

PubMed

Monte, Aline Santos; Mello, Bruna Stefânia Ferreira; Borella, Vládia Célia Moreira; da Silva Araujo, Tatiane; da Silva, Francisco Eliclécio Rodrigues; Sousa, Francisca Cléa F de; de Oliveira, Antônio Carlos Pinheiro; Gama, Clarissa Severino; Seeman, Mary V; Vasconcelos, Silvânia Maria Mendes; Lucena, David Freitas De; Macêdo, Danielle

2017-07-28

Schizophrenia is considered to be a developmental disorder with distinctive sex differences. Aiming to simulate the vulnerability of the third trimester of human pregnancy to the developmental course of schizophrenia, an animal model was developed, using neonatal poly(I:C) as a first-hit, and peripubertal stress as a second-hit, i.e. a two-hit model. Since, to date, there have been no references to sex differences in the two-hit model, our study sought to determine sex influences on the development of behavior and brain oxidative change in adult rats submitted to neonatal exposure to poly(I:C) on postnatal days 5-7 as well as peripubertal unpredictable stress (PUS). Our results showed that adult two-hit rats present sex-specific behavioral alterations, with females showing more pronounced deficits in prepulse inhibition of the startle reflex and hyperlocomotion, while males showing more deficits in social interaction. Male and female animals exhibited similar working memory deficits. The levels of the endogenous antioxidant, reduced glutathione, were decreased in the prefrontal cortex (PFC) of both male and female animals exposed to both poly(I:C) and poly(I:C)+PUS. Only females presented decrements in GSH levels in the striatum. Nitrite levels were increased in the PFC of male and in the striatum of female poly(I:C)+PUS rats. Increased lipid peroxidation was observed in the PFC of females and in the striatum of males and females exposed to poly(I:C) and poly(I:C)+PUS. Thus, the present study presents evidence for sex differences in behavior and oxidative brain change induced by a two-hit model of schizophrenia. Copyright © 2017 Elsevier B.V. All rights reserved.

Sex and Age Differences in the Risk Threshold for Delinquency

PubMed Central

Loeber, Rolf; Slotboom, Anne-Marie; Bijleveld, Catrien C. J. H.; Hipwell, Alison E.; Stepp, Stephanie D.; Koot, Hans M.

2015-01-01

This study examines sex differences in the risk threshold for adolescent delinquency. Analyses were based on longitudinal data from the Pittsburgh Youth Study (n = 503) and the Pittsburgh Girls Study (n = 856). The study identified risk factors, promotive factors, and accumulated levels of risks as predictors of delinquency and nondelinquency, respectively. The risk thresholds for boys and girls were established at two developmental stages (late childhood: ages 10–12 years, and adolescence: ages 13–16 years) and compared between boys and girls. Sex similarities as well as differences existed in risk and promotive factors for delinquency. ROC analyses revealed only small sex differences in delinquency thresholds, that varied by age. Accumulative risk level had a linear relationship with boys’ delinquency and a quadratic relationship with girls’ delinquency, indicating stronger effects for girls at higher levels of risk. PMID:23183920

Developmental and Individual Differences in Girls' Sex-Typed Activities in Middle Childhood and Adolescence

ERIC Educational Resources Information Center

McHale, Susan M.; Shanahan, Lilly; Updegraff, Kimberly A.; Crouter, Ann C.; Booth, Alan

2004-01-01

Girls' time in sex-typed leisure activities was studied across 2 years in middle childhood (n=98, M=8.2 years in Year 1), early adolescence (n=106, M=11.7 years), and middle adolescence (n=86, M=14.9 years). In annual home interviews, White middle-class girls, mothers, and fathers rated their gendered attitudes, interests, and personality…

The structure of evaluative anxiety among children differing in socioeconomic status, ethnicity, and sex.

PubMed

Rhine, W R; Spaner, S D

1983-11-01

Following Anastasi and Thurstone, the factor structure of evaluative anxiety was examined among six groups of primary age boys and girls (N = 8064). A factor matching technique was used to study hypotheses about the effects of group differences in socioeconomic status (SES), ethnicity, and sex on the pattern of the children's responses to the Test Anxiety Scale for Children (TASC). Hypotheses about the congruence of factor patterns were based on both demographic differences and results of developmental research. The hypothesis of an SES X ethnicity X sex interaction was strongly supported. Implications for comparing factor structures, measuring evaluative anxiety, and future research of evaluative anxiety are discussed.

Similarities and differences in physical self-concept of males and females during late adolescence and early adulthood.

PubMed

Cağlar, Emine

2009-01-01

The purpose of this study was to examine age and sex differences in physical self-concept of Turkish late adolescents and early adults. A total of 715 high school and 1,125 university students voluntarily participated and were administered the Physical Self-Description Questionnaire. The findings indicate significant sex and age differences on multiple dimensions of physical self, and that males and high school students scored higher on almost all subscales of physical self. However, analysis did not reveal any significant age and sex interactions on physical self. In conclusion, males and females differ from each other on how they perceived themselves on the multiple dimensions of physical self, and developmental age changes were evident in physical self.

Plasticity of gene-regulatory networks controlling sex determination: of masters, slaves, usual suspects, newcomers, and usurpators.

PubMed

Herpin, Amaury; Schartl, Manfred

2015-10-01

Sexual dimorphism is one of the most pervasive and diverse features of animal morphology, physiology, and behavior. Despite the generality of the phenomenon itself, the mechanisms controlling how sex is determined differ considerably among various organismic groups, have evolved repeatedly and independently, and the underlying molecular pathways can change quickly during evolution. Even within closely related groups of organisms for which the development of gonads on the morphological, histological, and cell biological level is undistinguishable, the molecular control and the regulation of the factors involved in sex determination and gonad differentiation can be substantially different. The biological meaning of the high molecular plasticity of an otherwise common developmental program is unknown. While comparative studies suggest that the downstream effectors of sex-determining pathways tend to be more stable than the triggering mechanisms at the top, it is still unclear how conserved the downstream networks are and how all components work together. After many years of stasis, when the molecular basis of sex determination was amenable only in the few classical model organisms (fly, worm, mouse), recently, sex-determining genes from several animal species have been identified and new studies have elucidated some novel regulatory interactions and biological functions of the downstream network, particularly in vertebrates. These data have considerably changed our classical perception of a simple linear developmental cascade that makes the decision for the embryo to develop as male or female, and how it evolves. © 2015 The Authors.

Sex differences in the developmental trajectories of impulse control and sensation-seeking from early adolescence to early adulthood.

PubMed

Shulman, Elizabeth P; Harden, K Paige; Chein, Jason M; Steinberg, Laurence

2015-01-01

It has been proposed that high rates of risk-taking in adolescence are partly attributable to patterns of neurobiological development that promote an increase in sensation-seeking tendencies at a time when impulse control is still developing. It is not known, however, whether this pattern is the same for males and females. The present study investigates sex differences in the developmental trajectories of self-reported impulse control and sensation-seeking between the ages of 10 and 25 using longitudinal data from the National Longitudinal Study of Youth 1979 Child and Young Adult Survey (N = 8,270; 49% female; 33% Black, 22% Hispanic, 45% Non-Black, Non-Hispanic). Prior work has found that, consistent with the dual-systems model of adolescent neurobiological development, sensation-seeking rises and falls across this age span, whereas impulse control increases into the 20s. In the present study, we find that this same general pattern holds for both males and females, but with some key differences. As expected, males exhibit higher levels of sensation-seeking and lower levels of impulse control than females. Differences also emerged in the shapes of the developmental trajectories. Females reach peak levels of sensation-seeking earlier than males (consistent with the idea that sensation-seeking is linked to pubertal development) and decline in sensation-seeking more rapidly thereafter. Also, males increase in impulse control more gradually than females. Consequently, sex differences in both impulse control and sensation-seeking increase with age. The findings suggest that the window of heightened vulnerability to risk-taking during adolescence may be greater in magnitude and more protracted for males than for females.

Decreased head circumference velocity as related to developmental deficit in infancy.

PubMed

Tal, Galit; Cohen, Ayala; Habib, Sonia; Tirosh, Emanuel

2012-11-01

We evaluated the significance of head circumference growth velocity as related to developmental deficits during infancy. Head circumferences, lengths, and developmental diagnoses were retrieved in a standard manner at ≥ 2 time points from 437 infants with developmental deficits, and 3909 normally developing infants. Infants' ages ranged from 1-24 months, with final diagnoses ascertained at age 24 months. Increased velocity during the first 2 months in typical infants was evident in the study group during the period 2-4 months. A differential head circumference growth velocity was observed, and infants diagnosed with motor delay presented decreased velocity between ages 2-4 months, compared with infants receiving other nonmotor developmental diagnoses. These differences remained after controlling for birth weight and length. No significant sex effect was evident. Infants with developmental deficits demonstrate delayed acceleration of head circumference velocity, compared with typical infants in the first 2 months. Infants with motor delay manifest decreased velocity, compared with infants presenting other developmental deficits. These differences may be related to delayed white matter maturation. Copyright © 2012 Elsevier Inc. All rights reserved.

Heterogeneity in development of adolescent anxiety disorder symptoms in an 8-year longitudinal community study.

PubMed

Nelemans, Stefanie A; Hale, William W; Branje, Susan J T; Raaijmakers, Quinten A W; Frijns, Tom; van Lier, Pol A C; Meeus, Wim H J

2014-02-01

In this study, we prospectively examined developmental trajectories of five anxiety disorder symptom dimensions (generalized anxiety disorder, panic disorder, school anxiety, separation anxiety disorder, and social anxiety disorder) from early to late adolescence in a community sample of 239 adolescents, assessed annually over 8 years. Latent growth modeling indicated different developmental trajectories from early into late adolescence for the different anxiety disorder symptoms, with some symptoms decreasing and other symptoms increasing over time. Sex differences in developmental trajectories were found for some symptoms, but not all. Furthermore, latent class growth analysis identified a normal developmental profile (including a majority of adolescents reporting persistent low anxiety disorder symptoms over 8 years) and an at-risk developmental profile (including a minority of adolescents reporting persistent high anxiety disorder symptoms over 8 years) for all of the anxiety disorder symptom dimensions except panic disorder. Additional analyses longitudinally supported the validity of these normal and at-risk developmental profiles and suggested differential associations between different anxiety disorder symptom dimensions and developmental trajectories of substance use, parenting, and identity development. Taken together, our results emphasize the importance of examining separate dimensions of anxiety disorder symptoms in contrast to a using a global, one-dimensional approach to anxiety.

Linking social anxiety and adolescent romantic relationship functioning: indirect effects and the importance of peers.

PubMed

Hebert, Karen R; Fales, Jessica; Nangle, Douglas W; Papadakis, Alison A; Grover, Rachel L

2013-11-01

Peer relationships undergo dramatic shifts in form and function during adolescence, at the same time the incidence of socially evaluative fears sharply rises. Despite well-established links between social anxiety and broader interpersonal functioning, there is a dearth of research evaluating the impact of social anxiety on functioning in close relationships during this developmental stage. The present study examines the impact of social anxiety on functioning in close friendships and romantic relationships during adolescence. From a developmental psychopathology perspective, it was expected that social anxiety would influence functioning (quality, length, satisfaction) in romantic relationships through its influence on functioning in same- and other-sex friendships. Participants included 314 adolescents (60.5% female, 14-19 years of age) with a prior or current history of romantic relationship involvement. Structural equation modeling was used to test a mediation model positing an indirect pathway from social anxiety to romantic relationship functioning through functioning in close same- and other-sex friendships. Given known gender differences in social anxiety and relationship functioning, gender also was explored as a potential moderator. Results supported the hypothesized indirect pathway whereby social anxiety was associated with impairment in same-sex friendships; functioning in same-sex friendships was associated with functioning in other-sex friendships, which was associated, in turn, with functioning in romantic relationships. While the hypothesized indirect pathway was significant among both boys and girls, there was greater continuity of functioning between same- and other-sex friendships for girls. These findings highlight the importance of examining the multiple downstream effects of social anxiety on perceived social functioning in adolescence, and suggest that continuity may exist for maladaptive patterns of socialization, particularly across developmentally salient close relationships.

Sexual identity trajectories among sexual-minority youths: gender comparisons.

PubMed

Savin-Williams, R C; Diamond, L M

2000-12-01

The present investigation explored gender differences in sexual identity development--first same-sex attractions, self-labeling, same-sex sexual contact, and disclosure--among 164 sexual-minority young adults. Based on interviews, results indicated the value of assessing gender differences in the context, timing, spacing, and sequencing of sexual identity milestones. Adolescent males had an earlier onset of all milestones except disclosure. The context for sexual identity milestones were likely to be emotionally oriented for young women and sexually oriented for young men. The gap from first same-sex attractions (8-9 years of age) to first disclosure (around 18 years) averaged 10 years for both sexes. Young women followed label-first developmental trajectories; men were more likely to pursue sex before identifying themselves as gay. In terms of achieving sexual identity milestones, gender mattered, but it was not everything.

Sex differences in moral reasoning: response to Walker's (1984) conclusion that there are none.

PubMed

Baumrind, D

1986-04-01

Data from the Family Socialization and Developmental Competence Project are used to probe Walker's conclusion that there are no sex differences in moral reasoning. Ordinal and nominal nonparametric statistics result in a complex but theoretically meaningful network of relationships among sex, educational level, and Kohlberg stage score level, with the presence and direction of sex differences in stage score level dependent on educational level. The effects on stage score level of educational level and working status are also shown to differ for men and women. Reasons are considered for not accepting Walker's dismissal of studies that use (a) a pre-1983 scoring manual, or (b) fail to control for education. The problems presented to Kohlberg's theory by the significant relationship between educational and stage score levels in the general population are discussed, particularly as these apply to the postconventional level of moral reasoning.

Affect and sexual behavior in the transition to university.

PubMed

Dalton, Andrea L; Galambos, Nancy L

2009-10-01

This research applied a lifespan developmental framework to the study of sexual behavior among late adolescents by examining monthly covariations of penetrative and oral sex with positive and negative affect across the first year of university. Participants were 177 Canadian students who completed baseline questionnaires, followed by six monthly, web-based questionnaires assessing sexual behaviors and affect. Multilevel analyses revealed an average positive relation between oral sex and positive affect. Of six variables, five predicted individual differences in covariation between sex and affect: psychosocial maturity (immature and semi-mature status), attitudes toward sex, prior sexual experience, and living situation. During months when participants reported sexual behavior, psychosocially mature students reported more positive affect than did less mature students; students with more permissive attitudes reported more positive affect than did students with less permissive attitudes; students with no penetrative sexual experience reported more positive affect than students who had penetrative sexual experience; and living away from parents was associated with less negative affect. Implications for further study of sexual behavior from a developmental perspective are discussed.

Effects of age and sex on voice onset time: Evidence from Mandarin voiceless stops.

PubMed

Ma, Junzhou; Chen, Xiaoxiang; Wu, Yezhou; Zhang, Linjie

2018-07-01

Considerable studies have addressed effects of age and sex on voice onset time (VOT) in English. However, few studies have examined these effects on Mandarin stops. This study attempts to examine effects of age and sex on VOT in Mandarin. A total of 85 Mandarin-speaking children, aged 4-18 years old, and 13 adults as reference participated in a production experiment. Productions were elicited by reading target words in carrier phrases. Results showed that children aged 6-7 years old had longer VOTs than older ones for highly aspirated stops, and the same tendency was not observed for unaspirated stops. However, no linear developmental trend was observed for both highly aspirated and unaspirated stops. In addition, females displayed longer VOTs for highly aspirated stops and shorter for unaspirated stops, whereas significant sex differences in VOTs existed from 14 years old to adulthood for highly aspirated stops, and no significant sex differences in VOTs were found for unaspirated stops in each group, indicating that sex differences in VOTs varied with age and aspiration. The findings suggest that physiological changes in and differences between males and females provide account for some, but not all differences in VOTs across age and sex.

Framework for sex differences in adolescent neurobiology: A focus on cannabinoids

PubMed Central

Viveros, Maria-Paz; Marco-López, Eva María; López-Gallardo, Meritxell; Garcia-Segura, Luis Miguel; Wagner, Edward J.

2017-01-01

This review highlights the salient findings that have furthered our understanding of how sex differences are initiated during development and maintained throughout life. First we discuss how gonadal steroid hormones organize the framework for sex differences within critical periods of development—namely, during those exposures which occur in utero and post-partum, as well as those which occur during puberty. Given the extensive precedence of sex differences in cannabinoid-regulated biology, we then focus on the disparities within the endogenous cannabinoid system, as well as those observed with exogenously administered cannabinoids. We start with how the expression of cannabinoid CB1 receptors is regulated throughout development. This is followed by a discussion of differential vulnerability to the pathological sequelae stemming from cannabinoid exposure during adolescence. Next we talk about sex differences in the interactions between cannabinoids and other drugs of abuse, followed by the organizational and activational roles of gonadal steroids in establishing and maintaining the sex dependence in the biological actions of cannabinoids. Finally, we discuss ways to utilize this knowledge to strategically target critical developmental windows of vulnerability/susceptibility and thereby implement more effective therapeutic interventions for afflictions that may be more prevalent in one sex vs. the other. PMID:20869396

Developmental Change in the Effects of Sexual Partner and Relationship Characteristics on Sexual Risk Behavior in Young Men Who Have Sex with Men.

PubMed

Newcomb, Michael E; Mustanski, Brian

2016-06-01

Young men who have sex with men are substantially impacted by HIV/AIDS, and most new infections occur in serious romantic dyads. Young people experience substantial psychosocial and neurocognitive change between adolescence and emerging adulthood which impacts engagement in risk behaviors. We aimed to examine developmental change in the association between sexual partnership characteristics and condomless anal intercourse (CAI). Data were taken from an analytic sample of 114 young adult MSM from a longitudinal study of lesbian, gay, bisexual and transgender youth with 4-year follow-up. Rates of CAI were approximately 12 times higher in serious compared to casual partnerships, but this effect diminished in size over time. Partner age differences and violence were associated with more CAI, and these associations strengthened across development. Characteristics of serious relationships (e.g., power dynamics) were also examined. We discuss the need for HIV prevention strategies that address dyadic influences on CAI during this critical developmental period.

Developmental Change in the Effects of Sexual Partner and Relationship Characteristics on Sexual Risk Behavior in Young Men Who Have Sex with Men

PubMed Central

Newcomb, Michael E.; Mustanski, Brian

2015-01-01

Young men who have sex with men (MSM) are substantially impacted by HIV/AIDS, and most new infections occur in serious romantic dyads. Young people experience substantial psychosocial and neurocognitive change between adolescence and emerging adulthood which impacts engagement in risk behaviors. We aimed to examine developmental change in the association between sexual partnership characteristics and condomless anal intercourse (CAI). Data were taken from an analytic sample of 114 YMSM from a longitudinal study of lesbian, gay, bisexual and transgender youth with 4-year follow-up. Rates of CAI were approximately 12 times higher in serious compared to casual partnerships, but this effect diminished in size over time. Partner age differences and violence were associated with more CAI, and these associations strengthened across development. Characteristics of serious relationships (e.g., power dynamics) were also examined. We discuss the need for HIV prevention strategies that address dyadic influences on CAI during this critical developmental period. PMID:25861731

Replications and Extensions in Arousal Assessment for Sex Offenders with Developmental Disabilities

ERIC Educational Resources Information Center

Reyes, Jorge R.; Vollmer, Timothy R.; Hall, Astrid

2011-01-01

Three adult male sex offenders with developmental disabilities participated in phallometric assessments that involved repeated measures of arousal when exposed to various stimuli. Arousal assessment outcomes were similar to those obtained by Reyes et al. (2006). Additional data-analysis methods provided further information about sexual…

Developmental Risk Factors for Sexual Offending.

ERIC Educational Resources Information Center

Lee, Joseph K. P.; Jackson, Henry J.; Pattison, Pip; Ward, Tony

2002-01-01

A study involving 64 Australian sex offenders and 33 non-sex offenders found childhood emotional abuse and family dysfunction, childhood behavior problems, and childhood sexual abuse were developmental risk factors for paraphilia. Emotional abuse and family dysfunction was found to be a risk factor for pedophilia, exhibitionism, rape, or multiple…

Assessment of Deviant Arousal in Adult Male Sex Offenders with Developmental Disabilities

ERIC Educational Resources Information Center

Reyes, Jorge R.; Vollmer, Timothy R.; Sloman, Kimberly N.; Hall, Astrid; Reed, Robert; Jansen, Greg; Carr, Sam; Jackson, Kevin; Stoutimore, Michael

2006-01-01

Ten individuals, residing in a treatment facility specializing in the rehabilitation of sex offenders with developmental disabilities, participated in an arousal assessment involving the use of the penile plethysmograph. The arousal assessments involved measuring change in penile circumference to various categories of stimuli both appropriate…

Host-feeding sources and habitats jointly affect wing developmental stability depending on sex in the major Chagas disease vector Triatoma infestans.

PubMed

Nattero, Julieta; Dujardin, Jean-Pierre; Del Pilar Fernández, María; Gürtler, Ricardo E

2015-12-01

Fluctuating asymmetry (FA), a slight and random departure from bilateral symmetry that is normally distributed around a 0 mean, has been widely used to infer developmental instability. We investigated whether habitats (ecotopes) and host-feeding sources influenced wing FA of the hematophagous bug Triatoma infestans. Because bug populations occupying distinct habitats differed substantially and consistently in various aspects such as feeding rates, engorgement status and the proportion of gravid females, we predicted that bugs from more open peridomestic habitats (i.e., goat corrals) were more likely to exhibit higher FA than bugs from domiciles. We examined patterns of asymmetry and the amount of wing size and shape FA in 196 adult T. infestans collected across a gradient of habitat suitability and stability that decreased from domiciles, storerooms, kitchens, chicken coops, pig corrals, to goat corrals in a well-defined area of Figueroa, northwestern Argentina. The bugs had unmixed blood meals on human, chicken, pig and goat depending on the bug collection ecotope. We documented the occurrence of FA in wing shape for bugs fed on all host-feeding sources and in all ecotopes except for females from domiciles or fed on humans. FA indices for wing shape differed significantly among host-feeding sources, ecotopes and sexes. The patterns of wing asymmetry in females from domiciles and from goat corrals were significantly different; differences in male FA were congruent with evidence showing that they had higher mobility than females across habitats. The host-feeding sources and habitats of T. infestans affected wing developmental stability depending on sex. Copyright © 2015 Elsevier B.V. All rights reserved.

Developmental link between sex and nutrition; doublesex regulates sex-specific mandible growth via juvenile hormone signaling in stag beetles.

PubMed

Gotoh, Hiroki; Miyakawa, Hitoshi; Ishikawa, Asano; Ishikawa, Yuki; Sugime, Yasuhiro; Emlen, Douglas J; Lavine, Laura C; Miura, Toru

2014-01-01

Sexual dimorphisms in trait expression are widespread among animals and are especially pronounced in ornaments and weapons of sexual selection, which can attain exaggerated sizes. Expression of exaggerated traits is usually male-specific and nutrition sensitive. Consequently, the developmental mechanisms generating sexually dimorphic growth and nutrition-dependent phenotypic plasticity are each likely to regulate the expression of extreme structures. Yet we know little about how either of these mechanisms work, much less how they might interact with each other. We investigated the developmental mechanisms of sex-specific mandible growth in the stag beetle Cyclommatus metallifer, focusing on doublesex gene function and its interaction with juvenile hormone (JH) signaling. doublesex genes encode transcription factors that orchestrate male and female specific trait development, and JH acts as a mediator between nutrition and mandible growth. We found that the Cmdsx gene regulates sex differentiation in the stag beetle. Knockdown of Cmdsx by RNA-interference in both males and females produced intersex phenotypes, indicating a role for Cmdsx in sex-specific trait growth. By combining knockdown of Cmdsx with JH treatment, we showed that female-specific splice variants of Cmdsx contribute to the insensitivity of female mandibles to JH: knockdown of Cmdsx reversed this pattern, so that mandibles in knockdown females were stimulated to grow by JH treatment. In contrast, mandibles in knockdown males retained some sensitivity to JH, though mandibles in these individuals did not attain the full sizes of wild type males. We suggest that moderate JH sensitivity of mandibular cells may be the default developmental state for both sexes, with sex-specific Dsx protein decreasing sensitivity in females, and increasing it in males. This study is the first to demonstrate a causal link between the sex determination and JH signaling pathways, which clearly interact to determine the developmental fates and final sizes of nutrition-dependent secondary-sexual characters.

Developmental Link between Sex and Nutrition; doublesex Regulates Sex-Specific Mandible Growth via Juvenile Hormone Signaling in Stag Beetles

PubMed Central

Gotoh, Hiroki; Miyakawa, Hitoshi; Ishikawa, Asano; Ishikawa, Yuki; Sugime, Yasuhiro; Emlen, Douglas J.; Lavine, Laura C.; Miura, Toru

2014-01-01

Sexual dimorphisms in trait expression are widespread among animals and are especially pronounced in ornaments and weapons of sexual selection, which can attain exaggerated sizes. Expression of exaggerated traits is usually male-specific and nutrition sensitive. Consequently, the developmental mechanisms generating sexually dimorphic growth and nutrition-dependent phenotypic plasticity are each likely to regulate the expression of extreme structures. Yet we know little about how either of these mechanisms work, much less how they might interact with each other. We investigated the developmental mechanisms of sex-specific mandible growth in the stag beetle Cyclommatus metallifer, focusing on doublesex gene function and its interaction with juvenile hormone (JH) signaling. doublesex genes encode transcription factors that orchestrate male and female specific trait development, and JH acts as a mediator between nutrition and mandible growth. We found that the Cmdsx gene regulates sex differentiation in the stag beetle. Knockdown of Cmdsx by RNA-interference in both males and females produced intersex phenotypes, indicating a role for Cmdsx in sex-specific trait growth. By combining knockdown of Cmdsx with JH treatment, we showed that female-specific splice variants of Cmdsx contribute to the insensitivity of female mandibles to JH: knockdown of Cmdsx reversed this pattern, so that mandibles in knockdown females were stimulated to grow by JH treatment. In contrast, mandibles in knockdown males retained some sensitivity to JH, though mandibles in these individuals did not attain the full sizes of wild type males. We suggest that moderate JH sensitivity of mandibular cells may be the default developmental state for both sexes, with sex-specific Dsx protein decreasing sensitivity in females, and increasing it in males. This study is the first to demonstrate a causal link between the sex determination and JH signaling pathways, which clearly interact to determine the developmental fates and final sizes of nutrition-dependent secondary-sexual characters. PMID:24453990

Prenatal Testosterone Programming of Insulin Resistance in the Female Sheep.

PubMed

Puttabyatappa, Muraly; Padmanabhan, Vasantha

2017-01-01

Insulin resistance, a common feature of metabolic disorders such as obesity, nonalcoholic fatty liver disease, metabolic syndrome, and polycystic ovary syndrome, is a risk factor for development of diabetes. Because sex hormones orchestrate the establishment of sex-specific behavioral, reproductive, and metabolic differences, a role for them in the developmental origin of insulin resistance is also to be expected. Female sheep exposed to male levels of testosterone during fetal life serve as an excellent translational model for delineating programming of insulin resistance. This chapter summarizes the ontogeny of insulin resistance, the tissue-specific changes in insulin sensitivity, and the various factors that are involved in the programming and maintenance of the insulin resistance in adult female sheep that were developmentally exposed to fetal male levels of testosterone during the sexual-differentiation window.

Sex-dimorphic effects of gestational exposure to the organophosphate insecticide chlorpyrifos on social investigation in mice.

PubMed

De Felice, Alessia; Venerosi, Aldina; Ricceri, Laura; Sabbioni, Mara; Scattoni, Maria Luisa; Chiarotti, Flavia; Calamandrei, Gemma

2014-01-01

Several pieces of evidence from animal and human studies indicate that the organophosphate insecticide chlorpyrifos (CPF) acts as a developmental neurotoxicant at environmentally relevant doses, and it is possibly endowed with endocrine-disrupting activity. Data collected in rodent models show that developmental exposure to CPF at sub-toxic doses induces long-lasting and sex-dimorphic changes in social and investigative responses in exposed offspring. The aim of this study was to evaluate the effects of gestational CPF treatment on social and olfactory discrimination in adult mice of both sexes. Pregnant CD1 out-bred mice were exposed to CPF per os on gestational days (GD) 14-17 at the sub-toxic dose of 6 mg/kg/bw. At adulthood, male and female offspring underwent the same experimental paradigms, namely i) a social discrimination test where mice were presented with a simultaneous binary choice between a novel conspecific and a familiar one, and ii) an olfactory habituation/dishabituation test to evaluate their capability to discriminate between odors with different eco-ethological salience (non-social vs. social odors). Results showed that in the social discrimination test prenatal CPF primarily affected the female sex by raising the investigation time in females to the same levels as found in vehicle- and CPF-exposed males. The ability to discriminate between a familiar and a novel social mate was not affected by CPF in either sex. In the olfactory habituation/dishabituation test, mice of both sexes successfully discriminated non-social from social odors regardless of the prenatal treatment received. These results confirm previous evidence indicating that developmental exposure to CPF causes long-lasting and sex-dimorphic changes in responsiveness to social cues, in the absence of significant impairment of social and olfactory discrimination capacity. These findings are discussed within the framework of recent data pointing to the limbic/hypothalamic circuitry and steroid hormonal regulations as possible targets for CPF neurotoxicity. Copyright © 2014. Published by Elsevier Inc.

Special Education Teachers Attitudes toward Teaching Sex Education to Students with Developmental Disabilities

ERIC Educational Resources Information Center

Hampton, Carolann

2017-01-01

The attitudes and opinions of special education teachers may potentially reveal insight as to how and why teachers choose to include sex education in their curriculum for self-contained special education classrooms designed to serve students with developmental disabilities. The main objective in developing this study was to gather information…

Conditioned pain modulation (CPM) in children and adolescents: Effects of sex and age

PubMed Central

Tsao, Jennie C. I.; Seidman, Laura C.; Evans, Subhadra; Lung, Kirsten C.; Zeltzer, Lonnie K.; Naliboff, Bruce D.

2013-01-01

Conditioned pain modulation (CPM) refers to the diminution of perceived pain intensity for a test stimulus following application of a conditioning stimulus to a remote area of the body, and is thought to reflect the descending inhibition of nociceptive signals. Studying CPM in children may inform interventions to enhance central pain inhibition within a developmental framework. We assessed CPM in 133 healthy children (mean age = 13 years; 52.6% girls) and tested the effects of sex and age. Participants were exposed to four trials of a pressure test stimulus before, during, and after the application of a cold water conditioning stimulus. CPM was documented by a reduction in pressure pain ratings during cold water administration. Older children (12–17 years) exhibited greater CPM than younger (8–11 years) children. No sex differences in CPM were found. Lower heart rate variability (HRV) at baseline and after pain induction was associated with less CPM controlling for child age. The findings of greater CPM in the older age cohort suggest a developmental improvement in central pain inhibitory mechanisms. The results highlight the need to examine developmental and contributory factors in central pain inhibitory mechanisms in children to guide effective, age appropriate, pain interventions. PMID:23541066

The differential effects of Autism and Down's syndrome on sexual behavior.

PubMed

Ginevra, Maria Cristina; Nota, Laura; Stokes, Mark A

2016-01-01

Although sexuality plays a major role in the socialization of people, few studies have examined the sexual behaviors of individuals with developmental disabilities. Because of this, we decided to investigate sexuality in adolescents with autism spectrum disorder (ASD) and Down's syndrome (Ds) and to compare them with typically developing adolescents, by surveying their parents. Specifically, it was hypothesized that young people with ASD would display lower levels over five domains: social behavior, privacy, sex education, sexual behavior, and parental concerns, than peers with Ds and typically developing young people. In addition, we sought to verify developmental trends in five domains with age for each group. Overall, 269 parents participated; 94 parents of typically developing adolescents, 93 parents of adolescents diagnosed with Ds, and 82 parents of adolescents diagnosed with ASD. Participants were surveyed with a Sexual Behavior Scale developed by Stokes and Kaur [] that assesses parents' reports of their child's: social behavior, privacy awareness, sex education, sexual behavior and parental concerns about the child's behaviors. It was found that three groups were significantly different on all five domains, adolescents with ASD reportedly displaying lower levels than other groups. Moreover, there was a significant improvement in knowledge of privacy and parental concerns with age for adolescents with ASD and a decline in sex education for adolescents with Ds. The results obtained emphasize the need to train adolescents with developmental disability, and especially for adolescents with ASD through sex education programs. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.

Insights into the mechanisms and the emergence of sex-differences in pain.

PubMed

Melchior, Meggane; Poisbeau, Pierrick; Gaumond, Isabelle; Marchand, Serge

2016-12-03

Recent studies describe sex and gender as critical factors conditioning the experience of pain and the strategies to respond to it. It is now clear that men and women have different physiological and behavioral responses to pain. Some pathological pain states are also highly sex-specific. This clinical observation has been often verified with animal studies which helped to decipher the mechanisms underlying the observed female hyper-reactivity and hyper-sensitivity to pain states. The role of gonadal hormones in the modulation of pain responses has been a straightforward hypothesis but, if pertinent in many cases, cannot fully account for this complex sensation, which includes an important cognitive component. Clinical and fundamental data are reviewed here with a special emphasis on possible developmental processes giving rise to sex-differences in pain processing. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Sex differences in the developing brain as a source of inherent risk.

PubMed

McCarthy, Margaret M

2016-12-01

Brain development diverges in males and females in response to androgen production by the fetal testis. This sexual differentiation of the brain occurs during a sensitive window and induces enduring neuroanatomical and physiological changes that profoundly impact behavior. What we know about the contribution of sex chromosomes is still emerging, highlighting the need to integrate multiple factors into understanding sex differences, including the importance of context. The cellular mechanisms are best modeled in rodents and have provided both unifying principles and surprising specifics. Markedly distinct signaling pathways direct differentiation in specific brain regions, resulting in mosaicism of relative maleness, femaleness, and sameness through-out the brain, while canalization both exaggerates and constrains sex differences. Non-neuronal cells and inflammatory mediators are found in greater number and at higher levels in parts of male brains. This higher baseline of inflammation is speculated to increase male vulnerability to developmental neuropsychiatric disorders that are triggered by inflammation.

Sex and the development of Alzheimer’s disease

PubMed Central

Pike, Christian J.

2016-01-01

Men and women exhibit differences in the development and progression of Alzheimer’s disease (AD). The factors underlying the sex differences in AD are not well understood. This review emphasizes the contributions of sex steroid hormones to the relationship between sex and AD. In women, events that decrease lifetime exposure to estrogens are generally associated with increased AD risk, whereas estrogen-based hormone therapy administered near the time of menopause may reduce AD risk. In men, estrogens do not exhibit age-related reduction and are not significantly associated with AD risk. Rather, normal age-related depletions of testosterone in plasma and brain predict enhanced vulnerability to AD. Both estrogens and androgens exert numerous protective actions in the adult brain that increase neural functioning and resilience as well as specifically attenuate multiple aspects of AD-related neuropathology. Aging diminishes the activational effects of sex hormones in sex-specific manners, which is hypothesized to contribute to the relationship between aging and AD. Sex steroid hormones may also drive sex differences in AD through their organizational effects during developmental sexual differentiation of the brain. Specifically, sex hormone actions during early development may confer inherent vulnerability of the female brain to development of AD in advanced age. The combined effects of organizational and activational effects of sex steroids yield distinct sex differences in AD pathogenesis, a significant variable that must be more rigorously considered in future research. PMID:27870425

Patterns and Mechanisms of Evolutionary Transitions between Genetic Sex-Determining Systems

PubMed Central

Sander van Doorn, G.

2014-01-01

The diversity and patchy phylogenetic distribution of genetic sex-determining mechanisms observed in some taxa is thought to have arisen by the addition, modification, or replacement of regulators at the upstream end of the sex-determining pathway. Here, I review the various evolutionary forces acting on upstream regulators of sexual development that can cause transitions between sex-determining systems. These include sex-ratio selection and pleiotropic benefits, as well as indirect selection mechanisms involving sex-linked sexually antagonistic loci or recessive deleterious mutations. Most of the current theory concentrates on the population–genetic aspects of sex-determination transitions, using models that do not reflect the developmental mechanisms involved in sex determination. However, the increasing availability of molecular data creates opportunities for the development of mechanistic models that can clarify how selection and developmental architecture interact to direct the evolution of sex-determination genes. PMID:24993578

Sex differences in the neural substrates of spatial working memory during adolescence are not mediated by endogenous testosterone

PubMed Central

Alarcón, Gabriela; Cservenka, Anita; Fair, Damien A.; Nagel, Bonnie J.

2014-01-01

Adolescence is a developmental period characterized by notable changes in behavior, physical attributes, and an increase in endogenous sex steroid hormones, which may impact cognitive functioning. Moreover, sex differences in brain structure are present, leading to differences in neural function and cognition. Here, we examine sex differences in performance and blood oxygen level-dependent (BOLD) activation in a sample of adolescents during a spatial working memory (SWM) task. We also examine whether endogenous testosterone levels mediate differential brain activity between the sexes. Adolescents between ages 10 and 16 completed a SWM functional magnetic resonance imaging (fMRI) task, and serum hormone levels were assessed within seven days of scanning. While there were no sex differences in task performance (accuracy and reaction time), differences in BOLD response between girls and boys emerged, with girls deactivating brain regions in the default mode network and boys showing increased response in SWM-related brain regions of the frontal cortex. These results suggest that adolescent boys and girls adopted distinct neural strategies, while maintaining spatial cognitive strategies that facilitated comparable cognitive performance of a SWM task. A nonparametric bootstrapping procedure revealed that testosterone did not mediate sex-specific brain activity, suggesting that sex differences in BOLD activation during SWM may be better explained by other factors, such as early organizational effects of sex steroids or environmental influences. Elucidating sex differences in neural function and the influence of gonadal hormones can serve as a basis of comparison for understanding sexually dimorphic neurodevelopment and inform sex-specific psychopathology that emerges in adolescence. PMID:25312831

Thyroid hormone modulates offspring sex ratio in a turtle with temperature-dependent sex determination

PubMed Central

Li, Teng; Mu, Yi; McGlashan, Jessica K.; Georges, Arthur

2016-01-01

The adaptive significance of temperature-dependent sex determination (TSD) has attracted a great deal of research, but the underlying mechanisms by which temperature determines the sex of a developing embryo remain poorly understood. Here, we manipulated the level of a thyroid hormone (TH), triiodothyronine (T3), during embryonic development (by adding excess T3 to the eggs of the red-eared slider turtle Trachemys scripta, a reptile with TSD), to test two competing hypotheses on the proximate basis for TSD: the developmental rate hypothesis versus the hormone hypothesis. Exogenous TH accelerated embryonic heart rate (and hence metabolic rate), developmental rate, and rates of early post-hatching growth. More importantly, hyperthyroid conditions depressed expression of Cyp19a1 (the gene encoding for aromatase) and levels of oestradiol, and induced more male offspring. This result is contrary to the direction of sex-ratio shift predicted by the developmental rate hypothesis, but consistent with that predicted by the hormone hypothesis. Our results suggest an important role for THs in regulating sex steroid hormones, and therefore, in affecting gonadal sex differentiation in TSD reptiles. Our study has implications for the conservation of TSD reptiles in the context of global change because environmental contaminants may disrupt the activity of THs, and thereby affect offspring sex in TSD reptiles. PMID:27798296

The development of sex typing in middle childhood.

PubMed

Serbin, L A; Powlishta, K K; Gulko, J

1993-01-01

The present study examined the development of sex typing during middle childhood, using a sample of 558 children aged 5-12 years. The purpose of the study was to provide information about the developmental course and stability of various aspects of sex typing during this period and to examine the relative contributions of cognitive and environmental factors to sex-role development. Multiple measures of sex typing were obtained, including indices of personal preference, knowledge of stereotypes, and flexibility in the domains of activities, occupations, and traits. We also collected information about the child's cognitive maturity, exposure to sex-typed models at home, and socioeconomic status. Results supported the need for an integrative theory of sex-role development, incorporating factors emphasized by cognitive-developmental, schematic-processing, and social learning theories. Knowledge of stereotypes, flexibility, and sex-typed personal preferences all increased with age during middle childhood. There were also individual differences in sex typing that were stable over a 1-year period. Distinct "cognitive" and "affective" aspects of sex typing were identified using a principal components analysis. Cognitive elements (flexibility and knowledge of stereotypes) were largely a function of the child's cognitive maturity level, although social-environmental factors such as father's presence in the home also had some effect. Affective elements (sex-typed preferences for activities, occupations, and peers), on the other hand, were related more consistently to sex typing of the home environment. Children whose mothers frequently modeled "reversed" sex-role behaviors (i.e., traditionally "masculine" household and child-care tasks) were less sex typed in their own preferences. However, cognitive factors were also important, in that children who believed gender stereotypes to be flexible were less sex typed in their choices of activities, occupations, and peers. In sum, both cognitive maturation and socialization experiences contribute to the development of sex typing during middle childhood. Potential practical implications of these findings, as well as implications for stereotyping in other social domains such as race and ethnicity, are discussed.

Random sex determination: When developmental noise tips the sex balance.

PubMed

Perrin, Nicolas

2016-12-01

Sex-determining factors are usually assumed to be either genetic or environmental. The present paper aims at drawing attention to the potential contribution of developmental noise, an important but often-neglected component of phenotypic variance. Mutual inhibitions between male and female pathways make sex a bistable equilibrium, such that random fluctuations in the expression of genes at the top of the cascade are sufficient to drive individual development toward one or the other stable state. Evolutionary modeling shows that stochastic sex determinants should resist elimination by genetic or environmental sex determinants under ecologically meaningful settings. On the empirical side, many sex-determination systems traditionally considered as environmental or polygenic actually provide evidence for large components of stochasticity. In reviewing the field, I argue that sex-determination systems should be considered within a three-ends continuum, rather than the classical two-ends continuum. © 2016 WILEY Periodicals, Inc.

Aerobic capacity of Peruvian Quechua: a test of the developmental adaptation hypothesis.

PubMed

Kiyamu, Melisa; Rivera-Chira, María; Brutsaert, Tom D

2015-03-01

High altitude natives are reported to have outstanding work capacity in spite of the challenge of oxygen transport and delivery in hypoxia. To evaluate the developmental effect of lifelong exposure to hypoxia on aerobic capacity, VO2peak was measured on two groups of Peruvian Quechua subjects (18-35 years), who differed in their developmental exposure to altitude. Male and female volunteers were recruited in Lima, Peru (150 m), and were divided in two groups, based on their developmental exposure to hypoxia, those: a) Born at sea-level individuals (BSL), with no developmental exposure to hypoxia (n = 34) and b) Born at high-altitude individuals (BHA) with full developmental exposure to hypoxia (n = 32), but who migrated to sea-level as adults (>16-years-old). Tests were conducted both in normoxia (BP = 750 mm Hg) and normobaric hypoxia at sea-level (BP = 750 mm Hg, FiO2  = 0.12, equivalent to 4,449 m), after a 2-month training period (in order to control for initial differences in physical fitness) at sea-level. BHA had a significantly higher VO2peak at hypoxia (40.31 ± 1.0 ml/min/kg) as compared to BSL (35.78 ± 0.96 ml/min/kg, P = 0.001), adjusting for sex. The decrease of VO2peak at HA relative to SL (ΔVO2peak ) was not different between groups, controlling for baseline levels (VO2peak at sea-level) and sex (BHA = 0.35 ± 0.04 l/min, BSL = 0.44 ± 0.04 l/min; P = 0.12). Forced vital capacity (controlling for height) and the residuals of VO2peak (controlling for weight) had a significant association in the BHA group only (r = 0.155; P = 0.031). In sum, results indicate that developmental exposure to altitude constitutes an important factor to determine superior exercise performance. © 2014 Wiley Periodicals, Inc.

Machiavellianism in Japan: A Longitudinal Study.

ERIC Educational Resources Information Center

Dien, Dora Shu-Fang; Fujisawa, Hitoshi

1979-01-01

Middle class Japanese children whose willingness to cheat in a game had been observed at age four were administered a version of a Machiavellianism scale seven years later. Developmental changes in Machiavellianism, sex differences, and belief behavior congruency were considered in the Japanese cultural context. (Author/GC)

Evolution of Courtship Songs in Xenopus : Vocal Pattern Generation and Sound Production.

PubMed

Leininger, Elizabeth C; Kelley, Darcy B

2015-01-01

The extant species of African clawed frogs (Xenopus and Silurana) provide an opportunity to link the evolution of vocal characters to changes in the responsible cellular and molecular mechanisms. In this review, we integrate several robust lines of research: evolutionary trajectories of Xenopus vocalizations, cellular and circuit-level mechanisms of vocalization in selected Xenopus model species, and Xenopus evolutionary history and speciation mechanisms. Integrating recent findings allows us to generate and test specific hypotheses about the evolution of Xenopus vocal circuits. We propose that reduced vocal sex differences in some Xenopus species result from species-specific losses of sexually differentiated neural and neuromuscular features. Modification of sex-hormone-regulated developmental mechanisms is a strong candidate mechanism for reduced vocal sex differences.

Patterns of gender development.

PubMed

Martin, Carol Lynn; Ruble, Diane N

2010-01-01

A comprehensive theory of gender development must describe and explain long-term developmental patterning and changes and how gender is experienced in the short term. This review considers multiple views on gender patterning, illustrated with contemporary research. First, because developmental research involves understanding normative patterns of change with age, several theoretically important topics illustrate gender development: how children come to recognize gender distinctions and understand stereotypes, and the emergence of prejudice and sexism. Second, developmental researchers study the stability of individual differences over time, which elucidates developmental processes. We review stability in two domains-sex segregation and activities/interests. Finally, a new approach advances understanding of developmental patterns, based on dynamic systems theory. Dynamic systems theory is a metatheoretical framework for studying stability and change, which developed from the study of complex and nonlinear systems in physics and mathematics. Some major features and examples show how dynamic approaches have been and could be applied in studying gender development.

Patterns of Gender Development

PubMed Central

Martin, Carol Lynn; Ruble, Diane N.

2013-01-01

A comprehensive theory of gender development must describe and explain long-term developmental patterning and changes and how gender is experienced in the short term. This review considers multiple views on gender patterning, illustrated with contemporary research. First, because developmental research involves understanding normative patterns of change with age, several theoretically important topics illustrate gender development: how children come to recognize gender distinctions and understand stereotypes, and the emergence of prejudice and sexism. Second, developmental researchers study the stability of individual differences over time, which elucidates developmental processes. We review stability in two domains—sex segregation and activities/interests. Finally, a new approach advances understanding of developmental patterns, based on dynamic systems theory. Dynamic systems theory is a metatheoretical framework for studying stability and change, which developed from the study of complex and nonlinear systems in physics and mathematics. Some major features and examples show how dynamic approaches have been and could be applied in studying gender development. PMID:19575615

Sex Differences in Developmental Trends of Suicide Ideation, Plans, and Attempts among European American Adolescents

ERIC Educational Resources Information Center

Boeninger, Daria K.; Masyn, Katherine E.; Feldman, Betsy J.; Conger, Rand D.

2010-01-01

Although suicide ideation, plans, and attempts increase during adolescence, it remains unclear whether boys' and girls' risk for these outcomes peaks at different ages. We used longitudinal categorical data ("never," "once," "2+ times") from the Family Transitions Project (N = 1,248 rural European Americans, ages 11-19) to investigate whether…

Correlation between chronological age and third molar developmental stages in an Iranian population (Demirjian method)

PubMed Central

Khosronejad, Aria; Navabi, Manijeh; Sakhdari, Shirin; Rakhshan, Vahid

2017-01-01

Background: Third molar development is the only available tool for estimating the age of individuals after puberty. Since this tooth has very high interethnic variability, formulas calculated to estimate the age from its development stages cannot be generalized to other populations and should be adjusted for each region. Therefore, this study was conducted to evaluate this method in a sample of Tehran individuals for the first time, and also to compare the development of third molars across sexes and arches, and to estimate cutoff developmental stages for legal minor/major identification. Materials and Methods: A total of 150 dental patients aged between 15 and 25 years old were prospectively enrolled, and their Demirjian stages were recorded. The associations between chronological age and Demirjian stages were evaluated. Dental formation was compared between sexes and jaws. Cutoff stages were determined to identify legal minor/major cases (above or below 18 years old). Age estimation formula was found for this population. Results: Of the 150 included patients, 56 were males. The difference between the ages of males and females at each given developmental stage was nonsignificant (P > 0.05), except for the H stage. Age difference between same stage teeth of the maxilla and mandible was nonsignificant. Each of the G and H stages was significantly above 18 years old (P < 0.001). Furthermore, E and F stages were below 18 years old (P < 0.001). All the correlations between Demirjian stages and age were above 90% (all P < 0.001). Third molar development was positively affected by the chronological age (P = 0.000) and being maxillary (P = 0.000) but not sex (P = 0.113). Regression formula for age estimation was: age = 6.52+ (0.64 × sex) + (0.32 × arch) + (1.86 × Demirjian stage). Conclusion: Development of third molar might complete after the age 22. Iranian individuals with third molars at the G and H stages are likely above 18 while those at E and F are likely below 18. Pace of molar development differs for jaws, but intergender differences are open to further investigations. PMID:28584539

Correlation between chronological age and third molar developmental stages in an Iranian population (Demirjian method).

PubMed

Khosronejad, Aria; Navabi, Manijeh; Sakhdari, Shirin; Rakhshan, Vahid

2017-01-01

Third molar development is the only available tool for estimating the age of individuals after puberty. Since this tooth has very high interethnic variability, formulas calculated to estimate the age from its development stages cannot be generalized to other populations and should be adjusted for each region. Therefore, this study was conducted to evaluate this method in a sample of Tehran individuals for the first time, and also to compare the development of third molars across sexes and arches, and to estimate cutoff developmental stages for legal minor/major identification. A total of 150 dental patients aged between 15 and 25 years old were prospectively enrolled, and their Demirjian stages were recorded. The associations between chronological age and Demirjian stages were evaluated. Dental formation was compared between sexes and jaws. Cutoff stages were determined to identify legal minor/major cases (above or below 18 years old). Age estimation formula was found for this population. Of the 150 included patients, 56 were males. The difference between the ages of males and females at each given developmental stage was nonsignificant ( P > 0.05), except for the H stage. Age difference between same stage teeth of the maxilla and mandible was nonsignificant. Each of the G and H stages was significantly above 18 years old ( P < 0.001). Furthermore, E and F stages were below 18 years old ( P < 0.001). All the correlations between Demirjian stages and age were above 90% (all P < 0.001). Third molar development was positively affected by the chronological age ( P = 0.000) and being maxillary ( P = 0.000) but not sex ( P = 0.113). Regression formula for age estimation was: age = 6.52+ (0.64 × sex) + (0.32 × arch) + (1.86 × Demirjian stage). Development of third molar might complete after the age 22. Iranian individuals with third molars at the G and H stages are likely above 18 while those at E and F are likely below 18. Pace of molar development differs for jaws, but intergender differences are open to further investigations.

Temperament in the developmental course: a longitudinal comparison of New York Longitudinal Study-derived dimensions with the Junior Temperament and Character Inventory.

PubMed

Pitzer, Martina; Esser, Guenter; Schmidt, Martin H; Laucht, Manfred

2007-01-01

Despite theoretical discrepancies between different concepts of temperament, some core dimensions are thought to be common to the various models. We compared temperamental traits derived from the New York Longitudinal Study (NYLS) model and the Cloninger dimensions in the developmental course and investigated the associations of temperament with sex as well as with obstetric risks or psychosocial risks present at birth. Participants were 151 boys and 157 girls born at differing degrees of obstetric and psychosocial risk from a longitudinal study on a high-risk community sample. In infancy and childhood, NYLS-derived temperamental characteristics were assessed by a highly structured parent interview and standardized behavioral observations. At age 15 years, the Junior Temperament and Character Inventory/12-18 was administered. Moderate correlations were found between Junior Temperament and Character Inventory scales in adolescence and NYLS-derived factors in childhood. The psychosocial risk load seemed to influence the expression of novelty seeking or corresponding NYLS-derived factors, whereas the obstetric risks did not contribute to variation in temperament. Our findings further support highly sex-specific gene x environment interactions on temperament in the developmental course. The content of our NYLS-derived factors and the specific type of association across different temperament constructs fit into the increasing consensus regarding a small number of higher-order temperamental traits.

Beyond sex differences: new approaches for thinking about variation in brain structure and function

PubMed Central

Joel, Daphna; Fausto-Sterling, Anne

2016-01-01

In the study of variation in brain structure and function that might relate to sex and gender, language matters because it frames our research questions and methods. In this article, we offer an approach to thinking about variation in brain structure and function that pulls us outside the sex differences formulation. We argue that the existence of differences between the brains of males and females does not unravel the relations between sex and the brain nor is it sufficient to characterize a population of brains. Such characterization is necessary for studying sex effects on the brain as well as for studying brain structure and function in general. Animal studies show that sex interacts with environmental, developmental and genetic factors to affect the brain. Studies of humans further suggest that human brains are better described as belonging to a single heterogeneous population rather than two distinct populations. We discuss the implications of these observations for studies of brain and behaviour in humans and in laboratory animals. We believe that studying sex effects in context and developing or adopting analytical methods that take into account the heterogeneity of the brain are crucial for the advancement of human health and well-being. PMID:26833844

Understanding the broad influence of sex hormones and sex differences in the brain.

PubMed

McEwen, Bruce S; Milner, Teresa A

2017-01-02

Sex hormones act throughout the entire brain of both males and females via both genomic and nongenomic receptors. Sex hormones can act through many cellular and molecular processes that alter structure and function of neural systems and influence behavior as well as providing neuroprotection. Within neurons, sex hormone receptors are found in nuclei and are also located near membranes, where they are associated with presynaptic terminals, mitochondria, spine apparatus, and postsynaptic densities. Sex hormone receptors also are found in glial cells. Hormonal regulation of a variety of signaling pathways as well as direct and indirect effects on gene expression induce spine synapses, up- or downregulate and alter the distribution of neurotransmitter receptors, and regulate neuropeptide expression and cholinergic and GABAergic activity as well as calcium sequestration and oxidative stress. Many neural and behavioral functions are affected, including mood, cognitive function, blood pressure regulation, motor coordination, pain, and opioid sensitivity. Subtle sex differences exist for many of these functions that are developmentally programmed by hormones and by not yet precisely defined genetic factors, including the mitochondrial genome. These sex differences and responses to sex hormones in brain regions, which influence functions not previously regarded as subject to such differences, indicate that we are entering a new era of our ability to understand and appreciate the diversity of gender-related behaviors and brain functions. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Understanding the Broad Influence of Sex Hormones and Sex Differences in the Brain

PubMed Central

McEwen, Bruce S.; Milner, Teresa A.

2016-01-01

Sex hormones act throughout the entire brain of both males and females via both genomic and non-genomic receptors. Sex hormones can act through many cellular and molecular processes that alter structure and function of neural systems and influence behavior as well as providing neuroprotection. Within neurons, sex hormone receptors are found in nuclei and are also located near membranes where they are associated with presynaptic terminals, mitochondria, spine apparatus, post-synaptic densities. Sex hormone receptors also are found in glial cells. Hormonal regulation of a variety of signaling pathways as well as direct and indirect effects upon gene expression induce spine synapses, up- or down-regulate and alter the distribution of neurotransmitter receptors, regulate neuropeptide expression and cholinergic and GABAergic activity as well as calcium sequestration and oxidative stress. Many neural and behavioral functions are affected, including mood, cognitive function, blood pressure regulation, motor coordination, pain and opioid sensitivity. Subtle sex differences exist for many of these functions that are developmentally programmed by hormones and by not-yet-precisely-defined genetic factors including the mitochondrial genome. These sex differences and responses to sex hormones in brain regions, and upon functions not previously regarded as subject to such differences, indicates that we are entering a new era of our ability to understand and appreciate the diversity of gender-related behaviors and brain functions. PMID:27870427

Sex differences in the neural substrates of spatial working memory during adolescence are not mediated by endogenous testosterone.

PubMed

Alarcón, Gabriela; Cservenka, Anita; Fair, Damien A; Nagel, Bonnie J

2014-12-17

Adolescence is a developmental period characterized by notable changes in behavior, physical attributes, and an increase in endogenous sex steroid hormones, which may impact cognitive functioning. Moreover, sex differences in brain structure are present, leading to differences in neural function and cognition. Here, we examine sex differences in performance and blood oxygen level-dependent (BOLD) activation in a sample of adolescents during a spatial working memory (SWM) task. We also examine whether endogenous testosterone levels mediate differential brain activity between the sexes. Adolescents between ages 10 and 16 years completed a SWM functional magnetic resonance imaging (fMRI) task, and serum hormone levels were assessed within seven days of scanning. While there were no sex differences in task performance (accuracy and reaction time), differences in BOLD response between girls and boys emerged, with girls deactivating brain regions in the default mode network and boys showing increased response in SWM-related brain regions of the frontal cortex. These results suggest that adolescent boys and girls adopted distinct neural strategies, while maintaining spatial cognitive strategies that facilitated comparable cognitive performance of a SWM task. A nonparametric bootstrapping procedure revealed that testosterone did not mediate sex-specific brain activity, suggesting that sex differences in BOLD activation during SWM may be better explained by other factors, such as early organizational effects of sex steroids or environmental influences. Elucidating sex differences in neural function and the influence of gonadal hormones can serve as a basis of comparison for understanding sexually dimorphic neurodevelopment and inform sex-specific psychopathology that emerges in adolescence. Copyright © 2014 Elsevier B.V. All rights reserved.

Vertebrate sex-determining genes play musical chairs

PubMed Central

Pan, Qiaowei; Anderson, Jennifer; Bertho, Sylvain; Herpin, Amaury; Wilson, Catherine; Postlethwait, John H.; Schartl, Manfred; Guiguen, Yann

2017-01-01

Sexual reproduction is one of the most highly conserved processes in evolution. However, the genetic and cellular mechanisms making the decision of whether the undifferentiated gonad of animal embryos develops either towards male or female are manifold and quite diverse. In vertebrates, sex-determining mechanisms range from environmental to simple or complex genetic mechanisms and different mechanisms have evolved repeatedly and independently. In species with simple genetic sex-determination, master sex-determining genes lying on sex chromosomes drive the gonadal differentiation process by switching on a developmental program, which ultimately leads to testicular or ovarian differentiation. So far, very few sex-determining genes have been identified in vertebrates and apart from mammals and birds, these genes are apparently not conserved over a larger number of related orders, families, genera, or even species. To fill this knowledge gap and to better explore genetic sex-determination, we propose a strategy (RAD-Sex) that makes use of next-generation sequencing technology to identify genetic markers that define sex-specific segments of the male or female genome. PMID:27291506

The evolution of environmental and genetic sex determination in fluctuating environments.

PubMed

Van Dooren, Tom J M; Leimar, Olof

2003-12-01

Twenty years ago, Bulmer and Bull suggested that disruptive selection, produced by environmental fluctuations, can result in an evolutionary transition from environmental sex determination (ESD) to genetic sex determination (GSD). We investigated the feasibility of such a process, using mutation-limited adaptive dynamics and individual-based computer simulations. Our model describes the evolution of a reaction norm for sex determination in a metapopulation setting with partial migration and variation in an environmental variable both within and between local patches. The reaction norm represents the probability of becoming a female as a function of environmental state and was modeled as a sigmoid function with two parameters, one giving the location (i.e., the value of the environmental variable for which an individual has equal chance of becoming either sex) and the other giving the slope of the reaction norm for that environment. The slope can be interpreted as being set by the level of developmental noise in morph determination, with less noise giving a steeper slope and a more switchlike reaction norm. We found convergence stable reaction norms with intermediate to large amounts of developmental noise for conditions characterized by low migration rates, small differential competitive advantages between the sexes over environments, and little variation between individual environments within patches compared to variation between patches. We also considered reaction norms with the slope parameter constrained to a high value, corresponding to little developmental noise. For these we found evolutionary branching in the location parameter and a transition from ESD toward GSD, analogous to the original analysis by Bulmer and Bull. Further evolutionary change, including dominance evolution, produced a polymorphism acting as a GSD system with heterogamety. Our results point to the role of developmental noise in the evolution of sex determination.

Developmental and sex-specific differences in expression of neuropeptides derived from allatotropin gene in the silkmoth Bombyx mori.

PubMed

Bednár, Branislav; Roller, Ladislav; Čižmár, Daniel; Mitrová, Diana; Žitňan, Dušan

2017-05-01

Allatotropin (AT) and related neuropeptides are widespread bioactive molecules that regulate development, food intake and muscle contractions in insects and other invertebrates. In moths, alternative splicing of the at gene generates three mRNA precursors encoding AT with different combinations of three structurally similar AT-like peptides (ATLI-III). We used in situ hybridization and immunohistochemistry to map the differential expression of these transcripts during the postembryonic development of Bombyx mori. Transcript encoding AT alone was expressed in numerous neurons of the central nervous system and frontal ganglion, whereas transcripts encoding AT with ATLs were produced by smaller specific subgroups of neurons in larval stages. Metamorphosis was associated with considerable developmental changes and sex-specific differences in the expression of all transcripts. The most notable was the appearance of AT/ATL transcripts (1) in the brain lateral neurosecretory cells producing prothoracicotropic hormone; (2) in the male-specific cluster of about 20 neurons in the posterior region of the terminal abdominal ganglion; (3) in the female-specific medial neurons in the abdominal ganglia AG2-7. Immunohistochemical staining showed that these neurons produced a mixture of various neuropeptides and innervated diverse peripheral organs. Our data suggest that AT/ATL neuropeptides are involved in multiple stage- and sex-specific functions during the development of B. mori.

Sex-Specific Pathways to Early Puberty, Sexual Debut, and Sexual Risk Taking: Tests of an Integrated Evolutionary-Developmental Model

ERIC Educational Resources Information Center

James, Jenee; Ellis, Bruce J.; Schlomer, Gabriel L.; Garber, Judy

2012-01-01

The current study tested sex-specific pathways to early puberty, sexual debut, and sexual risk taking, as specified by an integrated evolutionary-developmental model of adolescent sexual development and behavior. In a prospective study of 238 adolescents (n = 129 girls and n = 109 boys) followed from approximately 12-18 years of age, we tested for…

The organizing actions of adolescent gonadal steroid hormones on brain and behavioral development.

PubMed

Schulz, Kalynn M; Sisk, Cheryl L

2016-11-01

Adolescence is a developmental period characterized by dramatic changes in cognition, risk-taking and social behavior. Although gonadal steroid hormones are well-known mediators of these behaviors in adulthood, the role gonadal steroid hormones play in shaping the adolescent brain and behavioral development has only come to light in recent years. Here we discuss the sex-specific impact of gonadal steroid hormones on the developing adolescent brain. Indeed, the effects of gonadal steroid hormones during adolescence on brain structure and behavioral outcomes differs markedly between the sexes. Research findings suggest that adolescence, like the perinatal period, is a sensitive period for the sex-specific effects of gonadal steroid hormones on brain and behavioral development. Furthermore, evidence from studies on male sexual behavior suggests that adolescence is part of a protracted postnatal sensitive period that begins perinatally and ends following adolescence. As such, the perinatal and peripubertal periods of brain and behavioral organization likely do not represent two discrete sensitive periods, but instead are the consequence of normative developmental timing of gonadal hormone secretions in males and females. Copyright © 2016 Elsevier Ltd. All rights reserved.

The organizing actions of adolescent gonadal steroid hormones on brain and behavioral development

PubMed Central

Schulz, Kalynn M.; Sisk, Cheryl L.

2016-01-01

Adolescence is a developmental period characterized by dramatic changes in cognition, risk-taking and social behavior. Although gonadal steroid hormones are well-known mediators of these behaviors in adulthood, the role gonadal steroid hormones play in shaping the adolescent brain and behavioral development has only come to light in recent years. Here we discuss the sex-specific impact of gonadal steroid hormones on the developing adolescent brain. Indeed, the effects of gonadal steroid hormones during adolescence on brain structure and behavioral outcomes differs markedly between the sexes. Research findings suggest that adolescence, like the perinatal period, is a sensitive period for the sex-specific effects of gonadal steroid hormones on brain and behavioral development. Furthermore, evidence from studies on male sexual behavior suggests that adolescence is part of a protracted postnatal sensitive period that begins perinatally and ends following adolescence. As such, the perinatal and peripubertal periods of brain and behavioral organization likely do not represent two discrete sensitive periods, but instead are the consequence of normative developmental timing of gonadal hormone secretions in males and females. PMID:27497718

Socio-cultural Differences and Developmental Changes in Continuing Motivation, Evaluation Anxiety, and Attributions of Success and Failure.

ERIC Educational Resources Information Center

Fyans, Leslie J., Jr.

Students' reported reasons for academic success or failure (categorized as ability, effort, task difficulty, or luck) were studied simultaneously in over 1,000 students in grades 4, 8, and 11. Differences between 16 attributional groups (4 success x 4 failure) were reported by discriminant analysis, according to grade, sex, and ethnic…

Oral vs. Vaginal Sex Experiences and Consequences Among First-Year College Students

PubMed Central

Lefkowitz, Eva S.; Vasilenko, Sara A.; Leavitt, Chelom E.

2015-01-01

To fully understand late adolescents’ experiences of oral sex, we must consider both risk and normative developmental perspectives. Sexual experiences include a range of behaviors, but research on sexual behaviors and consequences focuses primarily on vaginal sex. Oral sex occurs at rates similar to vaginal sex, and carries some, though less, risk than vaginal sex. The current study examined the event-level prevalence and consequences of oral sex compared to vaginal sex with other-sex partners in first year college students. Daily data were from recently sexually active first year college students (N = 253 people, 834 days; M age, 18.4 years; SD = 0.4; 56% female; 31% Hispanic/Latino; 17% African American, 14% Asian American/Pacific Islander, 25% European American, 12% multiracial) who reported on sexual behaviors and consequences. Both positive (intimacy, physical satisfaction) and negative (worrying about health, guilt) consequences were less common for oral than vaginal sex. Gender differences suggested that female adolescents may find vaginal sex more rewarding than oral sex whereas male adolescents may find them equally rewarding. PMID:26597646

Oral vs. Vaginal Sex Experiences and Consequences Among First-Year College Students.

PubMed

Lefkowitz, Eva S; Vasilenko, Sara A; Leavitt, Chelom E

2016-02-01

To fully understand late adolescents' experiences of oral sex, we must consider both risk and normative developmental perspectives. Sexual experiences include a range of behaviors, but research on sexual behaviors and consequences focuses primarily on vaginal sex. Oral sex occurs at rates similar to vaginal sex, and carries some, though less, risk than vaginal sex. The current study examined the event-level prevalence and consequences of oral sex compared to vaginal sex with other-sex partners in first-year college students. Daily data were from recently sexually active first-year college students (N = 253 people, 834 days; M age, 18.4 years; SD = 0.4; 56% female; 31% Hispanic/Latino; 17% African American, 14% Asian American/Pacific Islander, 25% European American, 12% multiracial) who reported on sexual behaviors and consequences. Both positive (intimacy, physical satisfaction) and negative (worrying about health, guilt) consequences were less common for oral than vaginal sex. Gender differences suggested that female adolescents may find vaginal sex more rewarding than oral sex, whereas male adolescents may find them equally rewarding.

Adolescents' Orientation Toward the Future: Sex Role Differentiation in a Sociocultural Context.

ERIC Educational Resources Information Center

Seginer, Rachel

1988-01-01

Tested the future orientation of 228 Jewish and Arab adolescents. Results supported the hypothesized instrumental-expressive division between Jewish males and females and the primacy of higher education for Arab females; these gender differences are sustained by the developmental settings of Jewish and Arab adolescents. (Author/BJV)

Ambivalence in Adult Sibling Relationships.

ERIC Educational Resources Information Center

Bedford, Victoria H.

1989-01-01

Examined gender and developmental differences in awareness of underlying feelings about subjects' age-near, same-sex sibling in 60 child-rearing and empty nest subjects. Found that women seemed to be more aware of their underlying feelings toward sisters than were men toward brothers, but valence of feelings was life phase-specific. (TE)

Sex differences in the developing brain as a source of inherent risk

PubMed Central

McCarthy, Margaret M.

2016-01-01

Brain development diverges in males and females in response to androgen production by the fetal testis. This sexual differentiation of the brain occurs during a sensitive window and induces enduring neuroanatomical and physiological changes that profoundly impact behavior. What we know about the contribution of sex chromosomes is still emerging, highlighting the need to integrate multiple factors into understanding sex differences, including the importance of context. The cellular mechanisms are best modeled in rodents and have provided both unifying principles and surprising specifics. Markedly distinct signaling pathways direct differentiation in specific brain regions, resulting in mosaicism of relative maleness, femaleness, and sameness through-out the brain, while canalization both exaggerates and constrains sex differences. Non-neuronal cells and inflammatory mediators are found in greater number and at higher levels in parts of male brains. This higher baseline of inflammation is speculated to increase male vulnerability to developmental neuropsychiatric disorders that are triggered by inflammation. PMID:28179808

Sex differences in the structural connectome of the human brain.

PubMed

Ingalhalikar, Madhura; Smith, Alex; Parker, Drew; Satterthwaite, Theodore D; Elliott, Mark A; Ruparel, Kosha; Hakonarson, Hakon; Gur, Raquel E; Gur, Ruben C; Verma, Ragini

2014-01-14

Sex differences in human behavior show adaptive complementarity: Males have better motor and spatial abilities, whereas females have superior memory and social cognition skills. Studies also show sex differences in human brains but do not explain this complementarity. In this work, we modeled the structural connectome using diffusion tensor imaging in a sample of 949 youths (aged 8-22 y, 428 males and 521 females) and discovered unique sex differences in brain connectivity during the course of development. Connection-wise statistical analysis, as well as analysis of regional and global network measures, presented a comprehensive description of network characteristics. In all supratentorial regions, males had greater within-hemispheric connectivity, as well as enhanced modularity and transitivity, whereas between-hemispheric connectivity and cross-module participation predominated in females. However, this effect was reversed in the cerebellar connections. Analysis of these changes developmentally demonstrated differences in trajectory between males and females mainly in adolescence and in adulthood. Overall, the results suggest that male brains are structured to facilitate connectivity between perception and coordinated action, whereas female brains are designed to facilitate communication between analytical and intuitive processing modes.

The Emergence of Sex Differences in Risk for Disordered Eating Attitudes During Puberty: A Role for Prenatal Testosterone Exposure

PubMed Central

Culbert, Kristen M.; Breedlove, S. Marc; Sisk, Cheryl L.; Burt, S. Alexandra; Klump, Kelly L.

2014-01-01

Research suggests that prenatal testosterone exposure may masculinize (i.e., lower) disordered eating (DE) attitudes and behaviors and influence the lower prevalence of eating disorders in males versus females. How or when these effects become prominent remains unknown, although puberty may be a critical developmental period. In animals, the masculinizing effects of early testosterone exposure become expressed during puberty when gonadal hormones activate sex-typical behaviors, including eating behaviors. This study examined whether the masculinizing effects of prenatal testosterone exposure on DE attitudes emerge during puberty in 394 twins from opposite-sex and same-sex pairs. Twin type (opposite sex vs. same sex) was used as a proxy for level of prenatal testosterone exposure because females from opposite-sex twin pairs are thought to be exposed to testosterone in utero from their male co-twin. Consistent with animal data, there were no differences in levels of DE attitudes between opposite-sex and same-sex twins during pre-early puberty. However, during mid-late puberty, females from opposite-sex twin pairs (i.e., females with a male co-twin) exhibited more masculinized (i.e., lower) DE attitudes than females from same-sex twin pairs (i.e., females with a female co-twin), independent of several “third variables” (e.g., body mass index [BMI], anxiety). Findings suggest that prenatal testosterone exposure may decrease DE attitudes and at least partially underlie sex differences in risk for DE attitudes after mid-puberty. PMID:23713501

Age Differences in Prenatal Testosterone's Protective Effects on Disordered Eating Symptoms: Developmental Windows of Expression?

PubMed Central

Culbert, Kristen M.; Breedlove, S. Marc; Sisk, Cheryl L.; Keel, Pamela K.; Neale, Michael C.; Boker, Steven M.; Burt, S. Alexandra; Klump, Kelly L.

2015-01-01

Prenatal testosterone exposure may be protective against disordered eating. However, prior studies have produced mixed results. Developmental differences in prenatal testosterone's protective effects on disordered eating may explain these discrepancies. Indeed, studies have differed in the age of participants assessed, with data supporting prenatal testosterone effects on disordered eating in early adolescent and young adult samples but not in late adolescence. The present series of studies are the first to investigate age differences in prenatal testosterone's protective effects on disordered eating. Two indirect markers of higher prenatal testosterone were examined: 1) lower finger-length ratios [index (2D)/ring (4D) finger] (Study 1), and 2) lower disordered eating in females from opposite-sex twin pairs (who are thought to be exposed to higher prenatal testosterone from their male co-twin) relative to female controls (Study 2). Participants were twins from the Michigan State University Twin Registry (Study 1: n = 409; Study 2: n = 1,538) in early adolescence, late adolescence, or young adulthood. Disordered eating was assessed with well-validated questionnaires. Finger-length ratios were measured from hand scans, using electronic computer calipers. Findings were consistent across both studies. Higher prenatal testosterone (lower 2D:4D; females from opposite-sex twin pairs vs. controls) predicted lower disordered eating in early adolescence and young adulthood only. Prenatal testosterone-disordered eating associations were not observed during late adolescence. Results point to the possibility of developmental windows of expression for prenatal testosterone's protective effects on disordered eating and suggest that prior discrepant results may reflect age differences across samples. PMID:25621790

Sex Roles and Career Decision-Making Process in Young Women.

ERIC Educational Resources Information Center

Sola, Janet L.

During the heightened self-consciousness of adolescence, reevaluation and modifications in self-perceptions and sex-role orientations generally take place. Therefore, a developmental perspective is needed to investigate the adoption of sex-typed, cross sex-typed, or non sex-typed attitudes and behaviors. Young women (N=226) responded to a…

Bidirectional Associations Among Sensitive Parenting, Language Development, and Social Competence

PubMed Central

Barnett, Melissa A.; Gustafsson, Hanna; Deng, Min; Mills-Koonce, W. Roger; Cox, Martha

2014-01-01

Rapid changes in language skills and social competence, both of which are linked to sensitive parenting, characterize early childhood. The present study examines bidirectional associations among mothers’ sensitive parenting and children’s language skills and social competence from 24 to 36 months in a community sample of 174 families. In addition, this study examines how these developmental pathways vary by child sex. Findings indicate stability across time in sensitive parenting, expressive language skills, and social competence, as well as positive main effects of sensitive parenting on expressive and receptive language skills for girls and boys. We find mixed evidence over time of reciprocal links between social competence and sensitive parenting. Further, boys’ receptive language skills at 24 months uniquely contribute to increases in mothers’ observed sensitive parenting from 24 to 36 months. These findings highlight the utility of applying transactional frameworks to the study of sex-based differences in early developmental processes. PMID:25126021

Attachment in Middle Childhood: An Evolutionary-Developmental Perspective.

PubMed

Del Giudice, Marco

2015-01-01

Middle childhood is a key transitional stage in the development of attachment processes and representations. Here I discuss the middle childhood transition from an evolutionary-developmental perspective and show how this approach offers fresh insight into the function and organization of attachment in this life stage. I begin by presenting an integrated biological model of middle childhood and discussing the neurobiological mechanisms that support the middle childhood transition. I examine the potential role of adrenal androgens, focusing on their activational effects in interaction with early exposure to sex hormones. I then discuss three insights arising from the integrated model and apply them to the development of attachment in middle childhood. I consider the changing functions of attachment in light of social competition, the emergence of sex differences in attachment, and the model's implications for the genetics of attachment in middle childhood. © 2015 Wiley Periodicals, Inc.

Analysis of the Effect of Cyclophosphamide and Methotrexate on Chrysomya megacephala (Diptera: Calliphoridae).

PubMed

Trivia, Ana Letícia; de Carvalho Pinto, Carlos José

2018-01-19

Forensic entomotoxicology investigates the effects of chemical substances in the development of scavenger insects and the reflection on estimating the minimum postmortem interval (PMI). To evaluate the impact of the chemotherapeutic drugs cyclophosphamide (CF) and methotrexate (MTX) on the postembryonic development of Chrysomya megacephala, controlled experiments were performed by rearing the larvae on spiked minced beef with different concentrations of these drugs. The results indicated that CF significantly decreased their developmental rate up to 28 h but had no significant effect on larval and adult sizes, survival rate, and sex ratio, whereas MTX decreased larval and adult sizes, survival rate, and there was a deviation in the expected sex ratio toward females in MTX-exposed larvae but had no significant impact on developmental rate. These negative interference factors should be considered in cases of suspected death of people that have undergone chemotherapy. © 2018 American Academy of Forensic Sciences.

The Role of Facial Attractiveness and Facial Masculinity/Femininity in Sex Classification of Faces

PubMed Central

Hoss, Rebecca A.; Ramsey, Jennifer L.; Griffin, Angela M.; Langlois, Judith H.

2005-01-01

We tested whether adults (Experiment 1) and 4–5-year-old children (Experiment 2) identify the sex of high attractive faces faster and more accurately than low attractive faces in a reaction time task. We also assessed whether facial masculinity/femininity facilitated identification of sex. Results showed that attractiveness facilitated adults’ sex classification of both female and male faces and children’s sex classification of female, but not male, faces. Moreover, attractiveness affected the speed and accuracy of sex classification independent of masculinity/femininity. High masculinity in male faces, but not high femininity in female faces, also facilitated sex classification for both adults and children. These findings provide important new data on how the facial cues of attractiveness and masculinity/femininity contribute to the task of sex classification and provide evidence for developmental differences in how adults and children use these cues. Additionally, these findings provide support for Langlois and Roggman’s (1990) averageness theory of attractiveness. PMID:16457167

Gender constancy and the effects of sex-typed televised toy commercials.

PubMed

Ruble, D N; Balaban, T; Cooper, J

1981-06-01

The present study represented a cognitive-developmental analysis of the effects of televised, sex-stereotypic information on children's behavior and attitudes toward toy play. The subjects were 50 male and 50 female 4-6-year-olds divided into high and low gender-constancy levels. As the children watched a cartoon, they either saw a commercial of a gender-neutral toy that showed 2 boys or 2 girls playing with the toy, or they saw no commercial (control). As predicted, only the high gender-constant children were differentially affected by the sex-role information in the different commercial conditions. Children at this stage who saw opposite-sex children playing with the toy avoided spending time with the toy and stated verbally that the toy was more appropriate for an opposite-sex sibling, relative to children in the 2 other conditions. The results are discussed in terms of their implications for theories of sex-role development and in terms of the role that television may play in maintaining sex stereotypes and sex-typed behavior.

Evolution of Drosophila sex comb length illustrates the inextricable interplay between selection and variation.

PubMed

Malagón, Juan N; Ahuja, Abha; Sivapatham, Gabilan; Hung, Julian; Lee, Jiwon; Muñoz-Gómez, Sergio A; Atallah, Joel; Singh, Rama S; Larsen, Ellen

2014-09-30

In spite of the diversity of possible biological forms observed in nature, a limited range of morphospace is frequently occupied for a given trait. Several mechanisms have been proposed to explain this bias in the distribution of phenotypes including selection, drift, and developmental constraints. Despite extensive work on phenotypic bias, the underlying developmental mechanisms explaining why particular regions of morphological space remain unoccupied are poorly understood. To address this issue, we studied the sex comb, a group of modified bristles used in courtship that shows marked morphological diversity among Drosophila species. In many Drosophila species including Drosophila melanogaster, the sex comb rotates 90° to a vertical position during development. Here we analyze the effect of changing D. melanogaster sex comb length on the process of rotation. We find that artificial selection changes the number of bristles per comb without a proportional change in the space available for rotation. As a result, when increasing sex comb length, rather than displaying a similar straight vertical shape observed in other Drosophila species, long sex combs bend because rotation is blocked by a neighboring row of bristles. Our results show ways in which morphologies that would be favored by natural selection are apparently impossible to achieve developmentally. These findings highlight the potential role of development in modifying selectable variation in the evolution of Drosophila sex comb length.

Evolution of Drosophila sex comb length illustrates the inextricable interplay between selection and variation

PubMed Central

Malagón, Juan N.; Ahuja, Abha; Sivapatham, Gabilan; Hung, Julian; Lee, Jiwon; Muñoz-Gómez, Sergio A.; Atallah, Joel; Singh, Rama S.; Larsen, Ellen

2014-01-01

In spite of the diversity of possible biological forms observed in nature, a limited range of morphospace is frequently occupied for a given trait. Several mechanisms have been proposed to explain this bias in the distribution of phenotypes including selection, drift, and developmental constraints. Despite extensive work on phenotypic bias, the underlying developmental mechanisms explaining why particular regions of morphological space remain unoccupied are poorly understood. To address this issue, we studied the sex comb, a group of modified bristles used in courtship that shows marked morphological diversity among Drosophila species. In many Drosophila species including Drosophila melanogaster, the sex comb rotates 90° to a vertical position during development. Here we analyze the effect of changing D. melanogaster sex comb length on the process of rotation. We find that artificial selection changes the number of bristles per comb without a proportional change in the space available for rotation. As a result, when increasing sex comb length, rather than displaying a similar straight vertical shape observed in other Drosophila species, long sex combs bend because rotation is blocked by a neighboring row of bristles. Our results show ways in which morphologies that would be favored by natural selection are apparently impossible to achieve developmentally. These findings highlight the potential role of development in modifying selectable variation in the evolution of Drosophila sex comb length. PMID:25197080

Bending Genders: The Biology of Natural Sex Change in Fish.

PubMed

Todd, Erica V; Liu, Hui; Muncaster, Simon; Gemmell, Neil J

2016-01-01

Sexual fate is no longer seen as an irreversible deterministic switch set during early embryonic development but as an ongoing battle for primacy between male and female developmental trajectories. That sexual fate is not final and must be actively maintained via continuous suppression of the opposing sexual network creates the potential for flexibility into adulthood. In many fishes, sexuality is not only extremely plastic, but sex change is a usual and adaptive part of the life cycle. Sequential hermaphrodites begin life as one sex, changing sometime later to the other, and include species capable of protandrous (male-to-female), protogynous (female-to-male), or serial (bidirectional) sex change. Natural sex change involves coordinated transformations across multiple biological systems, including behavioural, anatomical, neuroendocrine, and molecular axes. We here review the biological processes underlying this amazing transformation, focussing particularly on its molecular basis, which remains poorly understood, but where new genomic technologies are significantly advancing our understanding of how sex change is initiated and progressed at the molecular level. Knowledge of how a usually committed developmental process remains plastic in sequentially hermaphroditic fishes is relevant to understanding the evolution and functioning of sexual developmental systems in vertebrates generally, as well as pathologies of sexual development in humans. © 2016 S. Karger AG, Basel.

The developmental course of gender differentiation: conceptualizing, measuring, and evaluating constructs and pathways.

PubMed

Liben, Lynn S; Bigler, Rebecca S

2002-01-01

Gender differentiation is pervasive, and understanding how and why it develops is important for both theoretical and practical reasons. The work described here is rooted in constructivist accounts of gender differentiation. Past research provides considerable support for constructivist predictions concerning (a) developmental changes in gender attitudes and (b) the relation between gender attitudes and information processing. Little work, however, has addressed the more fundamental question of how children's developing gender attitudes about others are related to developing gender characterizations of self. The focus of the current Monograph is on this other-self relation during middle childhood. A brief review of past theory and empirical work on gender differentiation is provided. It is argued that a major explanation of the limitations and inconsistencies evident in earlier work may be traced to restrictions in the measures available to assess key constructs. A conceptual analysis of the specific limitations of past measures is presented. The Monograph then offers alternative models of the developmental relation between attitudes toward others and characterization of self (the attitudinal and the personal pathway models), and identifies conditions expected to influence the strength of the observed other-self relation. Four studies establish the reliability and validity of a suite of measures that provides comparable methods for assessing attitudes toward others (attitude measures, or AM) and sex typing of self (personal measures, or PM) in three domains: occupations, activities, and traits (or OAT). Parallel forms are provided for adults (the OAT-AM and OAT-PM) and for children of middle-school age, roughly 11-13 years old (the COAT-AM and COAT-PM). A fifth study provides longitudinal data from children tested at four times, beginning at the start of grade 6 (approximately age 11 years) and ending at the close of grade 7 (approximately age 13 years). These data are used to examine the developmental relation between children's sex typing of others and sex typing of the self, and to test the predictions concerning the factors hypothesized to affect the strength of the relation between the two types of sex typing. Overall, the data supported the conceptual distinctions among individuals' (a) gender attitudes toward others, (b) feminine self, and (c) masculine self, and, additionally, revealed some intriguing differences across domains. Interestingly, the data concerning the other-self relation differed by sex of participant. Among girls, analyses of concurrent relations showed that those girls who held fewer stereotypes of masculine activities for others showed greater endorsement of masculine items for self, a finding compatible with both the other-to-self attitudinal pathway model and the self-to-other personal pathway model. The prospective regression analyses, however, showed no effects. That is, preadolescent girls' gender attitudes about others did not predict their later self-endorsements, nor did self-endorsements predict later attitudes. Data from boys showed a strikingly different pattern, one consistent with the self-to-other personal pathway model: There was no evidence of concurrent other-self relations, but prospective analyses indicated that preadolescent boys who endorsed greater numbers of feminine traits as self-descriptive early in grade 6 developed increasingly egalitarian gender attitudes by the end of grade 7. The Monograph closes with discussions of additional implications of the empirical data, of preliminary work on developing parallel measures for younger children, and of the need to design research that illuminates the cognitive-developmental mechanisms underlying age-related changes in sex typing.

Kisspeptin Expression in the Human Infundibular Nucleus in Relation to Sex, Gender Identity, and Sexual Orientation.

PubMed

Taziaux, Melanie; Staphorsius, Annemieke S; Ghatei, Mohammad A; Bloom, Stephen R; Swaab, Dick F; Bakker, Julie

2016-06-01

Since the discovery of its central role in reproduction, our functional neuroanatomical knowledge of the hypothalamic kisspeptin system is predominantly based on animal studies. Although sex differences in kisspeptin expression have been shown in humans in adulthood, the developmental origin of this sex difference is unknown. Our objectives were to determine the following: 1) when during development the sex difference in kisspeptin expression in the infundibular nucleus would emerge and 2) whether this sex difference is related to sexual orientation or transsexuality. Postmortem hypothalamic tissues were collected by The Netherlands Brain Bank, and sections were stained for kisspeptin by immunohistochemistry. Hypothalami of 43 control subjects were categorized into three periods: infant/prepubertal (six girls, seven boys), adult (11 women, seven men), and elderly (six aged women, six aged men). Eight male-to-female (MTF) transsexuals, three HIV(+) heterosexual men, and five HIV(+) homosexual men were also analyzed. We estimated the total number of kisspeptin-immunoreactive neurons within the infundibular nucleus. Quantitative analysis confirmed that the human infundibular kisspeptin system exhibits a female-dominant sex difference. The number of kisspeptin neurons is significantly greater in the infant/prepubertal and elderly periods compared with the adult period. Finally, in MTF transsexuals, but not homosexual men, a female-typical kisspeptin expression was observed. These findings suggest that infundibular kisspeptin neurons are sensitive to circulating sex steroid hormones throughout life and that the sex reversal observed in MTF transsexuals might reflect, at least partially, an atypical brain sexual differentiation.

Sex in an Evolutionary Perspective: Just Another Reaction Norm

PubMed Central

Nylin, Sören

2010-01-01

It is common to refer to all sorts of clear-cut differences between the sexes as something that is biologically almost inevitable. Although this does not reflect the status of evolutionary theory on sex determination and sexual dimorphism, it is probably a common view among evolutionary biologists as well, because of the impact of sexual selection theory. To get away from thinking about biological sex and traits associated with a particular sex as something static, it should be recognized that in an evolutionary perspective sex can be viewed as a reaction norm, with sex attributes being phenotypically plastic. Sex determination itself is fundamentally plastic, even when it is termed “genetic”. The phenotypic expression of traits that are statistically associated with a particular sex always has a plastic component. This plasticity allows for much more variation in the expression of traits according to sex and more overlap between the sexes than is typically acknowledged. Here we review the variation and frequency of evolutionary changes in sex, sex determination and sex roles and conclude that sex in an evolutionary time-frame is extremely variable. We draw on recent findings in sex determination mechanisms, empirical findings of morphology and behaviour as well as genetic and developmental models to explore the concept of sex as a reaction norm. From this point of view, sexual differences are not expected to generally fall into neat, discrete, pre-determined classes. It is important to acknowledge this variability in order to increase objectivity in evolutionary research. PMID:21170116

Hypothalamic Response to the Chemo-Signal Androstadienone in Gender Dysphoric Children and Adolescents

PubMed Central

Burke, Sarah M.; Cohen-Kettenis, Peggy T.; Veltman, Dick J.; Klink, Daniel T.; Bakker, Julie

2014-01-01

The odorous steroid androstadienone, a putative male chemo-signal, was previously reported to evoke sex differences in hypothalamic activation in adult heterosexual men and women. In order to investigate whether puberty modulated this sex difference in response to androstadienone, we measured the hypothalamic responsiveness to this chemo-signal in 39 pre-pubertal and 41 adolescent boys and girls by means of functional magnetic resonance imaging. We then investigated whether 36 pre-pubertal children and 38 adolescents diagnosed with gender dysphoria (GD; DSM-5) exhibited sex-atypical (in accordance with their experienced gender), rather than sex-typical (in accordance with their natal sex) hypothalamic activations during olfactory stimulation with androstadienone. We found that the sex difference in responsiveness to androstadienone was already present in pre-pubertal control children and thus likely developed during early perinatal development instead of during sexual maturation. Adolescent girls and boys with GD both responded remarkably like their experienced gender, thus sex-atypical. In contrast, pre-pubertal girls with GD showed neither a typically male nor female hypothalamic activation pattern and pre-pubertal boys with GD had hypothalamic activations in response to androstadienone that were similar to control boys, thus sex-typical. We present here a unique data set of boys and girls diagnosed with GD at two different developmental stages, showing that these children possess certain sex-atypical functional brain characteristics and may have undergone atypical sexual differentiation of the brain. PMID:24904525

Adolescent Major Depressive Disorder: Neuroimaging Evidence of Sex Difference during an Affective Go/No-Go Task.

PubMed

Chuang, Jie-Yu; Hagan, Cindy C; Murray, Graham K; Graham, Julia M E; Ooi, Cinly; Tait, Roger; Holt, Rosemary J; Elliott, Rebecca; van Nieuwenhuizen, Adrienne O; Bullmore, Edward T; Lennox, Belinda R; Sahakian, Barbara J; Goodyer, Ian M; Suckling, John

2017-01-01

Compared to female major depressive disorder (MDD), male MDD often receives less attention. However, research is warranted since there are significant sex differences in the clinical presentation of MDD and a higher rate of suicide in depressed men. To the best of our knowledge, this is the first functional magnetic resonance imaging (fMRI) study with a large sample addressing putative sex differences in MDD during adolescence, a period when one of the most robust findings in psychiatric epidemiology emerges; that females are twice as likely to suffer from MDD than males. Twenty-four depressed and 10 healthy male adolescents, together with 82 depressed and 24 healthy female adolescents, aged 11-18 years, undertook an affective go/no-go task during fMRI acquisition. In response to sad relative to neutral distractors, significant sex differences (in the supramarginal gyrus) and group-by-sex interactions (in the supramarginal gyrus and the posterior cingulate cortex) were found. Furthermore, in contrast to the healthy male adolescents, depressed male adolescents showed decreased activation in the cerebellum with a significant group-by-age interaction in connectivity. Future research may consider altered developmental trajectories and the possible implications of sex-specific treatment and prevention strategies for MDD.

Composition and emission dynamics of migratory locust volatiles in response to changes in developmental stages and population density.

PubMed

Wei, Jianing; Shao, Wenbo; Wang, Xianhui; Ge, Jin; Chen, Xiangyong; Yu, Dan; Kang, Le

2017-02-01

Chemical communication plays an important role in density-dependent phase change in locusts. However, the volatile components and emission patterns of the migratory locust, Locusta migratoria, are largely unknown. In this study, we identified the chemical compositions and emission dynamics of locust volatiles from the body and feces and associated them with developmental stages, sexes and phase changes. The migratory locust shares a number of volatile components with the desert locust (Schistocerca gregaria), but the emission dynamics of the two locust species are significantly different. The body odors of the gregarious nymphs in the migratory locust consisted of phenylacetonitrile (PAN), benzaldehyde, guaiacol, phenol, aliphatic acids and 2,3-butanediol, and PAN was the dominant volatile. Volatiles from the fecal pellets of the nymphs primarily consist of guaiacol and phenol. Principal component analysis (PCA) showed significant differences in the volatile profiles between gregarious and solitary locusts. PAN and 4-vinylanisole concentrations were significantly higher in gregarious individuals than in solitary locusts. Gregarious mature males released significantly higher amounts of PAN and 4-vinylanisole during adulthood than mature females and immature adults of both sexes. Furthermore, PAN and 4-vinylanisole were completely lost in gregarious nymphs during the solitarization process, but were obtained by solitary nymphs during gregarization. The amounts of benzaldehyde, guaiacol and phenol only unidirectionally decreased from solitary to crowded treatment. Aliphatic aldehydes (C7 to C10), which were previously reported as locust volatiles, are now identified as environmental contaminants. Therefore, our results illustrate the precise odor profiles of migratory locusts during developmental stages, sexes and phase change. However, the function and role of PAN and other aromatic compounds during phase transition need further investigation. © 2016 Institute of Zoology, Chinese Academy of Sciences.

Sex differences in impulsivity: a meta-analysis.

PubMed

Cross, Catharine P; Copping, Lee T; Campbell, Anne

2011-01-01

Men are overrepresented in socially problematic behaviors, such as aggression and criminal behavior, which have been linked to impulsivity. Our review of impulsivity is organized around the tripartite theoretical distinction between reward hypersensitivity, punishment hyposensitivity, and inadequate effortful control. Drawing on evolutionary, criminological, developmental, and personality theories, we predicted that sex differences would be most pronounced in risky activities with men demonstrating greater sensation seeking, greater reward sensitivity, and lower punishment sensitivity. We predicted a small female advantage in effortful control. We analyzed 741 effect sizes from 277 studies, including psychometric and behavioral measures. Women were consistently more punishment sensitive (d = -0.33), but men did not show greater reward sensitivity (d = 0.01). Men showed significantly higher sensation seeking on questionnaire measures (d = 0.41) and on a behavioral risk-taking task (d = 0.36). Questionnaire measures of deficits in effortful control showed a very modest effect size in the male direction (d = 0.08). Sex differences were not found on delay discounting or executive function tasks. The results indicate a stronger sex difference in motivational rather than effortful or executive forms of behavior control. Specifically, they support evolutionary and biological theories of risk taking predicated on sex differences in punishment sensitivity. A clearer understanding of sex differences in impulsivity depends upon recognizing important distinctions between sensation seeking and impulsivity, between executive and effortful forms of control, and between impulsivity as a deficit and as a trait.

Beyond sex differences: new approaches for thinking about variation in brain structure and function.

PubMed

Joel, Daphna; Fausto-Sterling, Anne

2016-02-19

In the study of variation in brain structure and function that might relate to sex and gender, language matters because it frames our research questions and methods. In this article, we offer an approach to thinking about variation in brain structure and function that pulls us outside the sex differences formulation. We argue that the existence of differences between the brains of males and females does not unravel the relations between sex and the brain nor is it sufficient to characterize a population of brains. Such characterization is necessary for studying sex effects on the brain as well as for studying brain structure and function in general. Animal studies show that sex interacts with environmental, developmental and genetic factors to affect the brain. Studies of humans further suggest that human brains are better described as belonging to a single heterogeneous population rather than two distinct populations. We discuss the implications of these observations for studies of brain and behaviour in humans and in laboratory animals. We believe that studying sex effects in context and developing or adopting analytical methods that take into account the heterogeneity of the brain are crucial for the advancement of human health and well-being. © 2016 The Author(s).

Adolescent Sex and Mass Media: A Developmental Approach.

ERIC Educational Resources Information Center

Chapin, John R.

2000-01-01

Media critics point to adolescents' exposure to "sexy" television and popular music. Developmental transitions lead to increased information seeking, and developmental tasks force adolescents to find information sources other than their parents, implying a link between sexy media and adolescent development. Media research informed by knowledge of…

Neuronal composition of the magnocellular division of the medial preoptic nucleus (MPN mag) is sex specific in the Syrian hamster (Mesocricetus auratus).

PubMed

Richendrfer, Holly A; Swann, Jennifer M

2010-09-10

The magnocellular division of the medial Preoptic nucleus (MPN mag) plays a critical role in the regulation of male sexual behavior in the hamster. Results from previous studies indicated that the number of neurons in the MPN mag is greater in males than females but failed to find significant differences in the volume of the nucleus suggesting that other elements in the nucleus may be greater in the female. The results of the present study, using NeuN to identify neurons, are in line with this hypothesis. The data show that (1) neurons in the MPN mag display two distinct phenotypes, those with a single nucleolus and those with multiple nucleoli; (2) the percentage of each phenotype is sex specific, differing over the course of development and (3) there is no sex difference in the number of glial cells at any age. Sex differences in the numbers of each type are correlated with developmental milestones and suggest that morphological changes are influenced by changes in circulating gonadal steroids during development. 2010 Elsevier B.V. All rights reserved.

Correcting a Longstanding Misconception about Social Roles and Personality: A Case Study in the Psychology of Science.

PubMed

Johnson, John A

2018-06-04

Psychologists often argue that sex roles direct different types of socializing behaviors toward males and females and that this differential treatment, in turn, leads to sex differences in personality. Widely cited in support of this thesis has been the Fels longitudinal study finding that dependency and passivity are stable from childhood to adulthood for females only and aggressiveness and sexuality for males only. The present article explains why the type of sex differences in personality stability cited by Fels researchers actually contradicts the view that sex role expectations cause these differences. The report suggests ways in which social learning theory, the dominant developmental paradigm of the 1960s, may have contributed to the misinterpretation of the Fels data and how the rise of social constructivism maintained this misinterpretation for decades. The article concludes by correcting misconceptions about biology and personality stability and by explaining why theories that incorporate biology are not only more adequate than social constructivism but also more effective in bringing about the changes in society that constructivists desire.

Sex differences in brain and behavior in adolescence: Findings from the Philadelphia Neurodevelopmental Cohort.

PubMed

Gur, Raquel E; Gur, Ruben C

2016-11-01

Sex differences in brain and behavior were investigated across the lifespan. Parameters include neurobehavioral measures linkable to neuroanatomic and neurophysiologic indicators of brain structure and function. Sexual differentiation of behavior has been related to organizational factors during sensitive periods of development, with adolescence and puberty gaining increased attention. Adolescence is a critical developmental period where transition to adulthood is impacted by multiple factors that can enhance vulnerability to brain dysfunction. Here we highlight sex differences in neurobehavioral measures in adolescence that are linked to brain function. We summarize neuroimaging studies examining brain structure, connectivity and perfusion, underscoring the relationship to sex differences in behavioral measures and commenting on hormonal findings. We focus on relevant data from the Philadelphia Neurodevelopmental Cohort (PNC), a community-based sample of nearly 10,000 clinically and neurocognitively phenotyped youths age 8-21 of whom 1600 have received multimodal neuroimaging. These data indicate early and pervasive sexual differentiation in neurocognitive measures that is linkable to brain parameters. We conclude by describing possible clinical implications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sex differences in brain and behavior in adolescence: Findings from the Philadelphia Neurodevelopmental Cohort

PubMed Central

Gur, Raquel E.; Gur, Ruben C.

2016-01-01

Sex differences in brain and behavior were investigated across the lifespan. Parameters include neurobehavioral measures linkable to neuroanatomic and neurophysiologic indicators of brain structure and function. Sexual differentiation of behavior has been related to organizational factors during sensitive periods of development, with adolescence and puberty gaining increased attention. Adolescence is a critical developmental period where transition to adulthood is impacted by multiple factors that can enhance vulnerability to brain dysfunction. Here we highlight sex differences in neurobehavioral measures in adolescence that are linked to brain function. We summarize neuroimaging studies examining brain structure, connectivity and perfusion, underscoring the relationship to sex differences in behavioral measures and commenting on hormonal findings. We focus on relevant data from the Philadelphia Neurodevelopmental Cohort (PNC), a community-based sample of nearly 10,000 clinically and neurocognitively phenotyped youths age 8–21 of whom 1600 have received multimodal neuroimaging. These data indicate early and pervasive sexual differentiation in neurocognitive measures that is linkable to brain parameters. We conclude by describing possible clinical implications. PMID:27498084

Six Myths About Spatial Thinking

NASA Astrophysics Data System (ADS)

Newcombe, Nora S.; Stieff, Mike

2012-04-01

Visualizations are an increasingly important part of scientific education and discovery. However, users often do not gain knowledge from them in a complete or efficient way. This article aims to direct research on visualizations in science education in productive directions by reviewing the evidence for widespread assumptions that learning styles, sex differences, developmental stages, and spatial language determine the impact of visualizations on science learning. First, we examine the assumption that people differ in their verbal versus visual learning style. Due to the lack of rigorous evaluation, there is no current support for this distinction. Future research should distinguish between two different kinds of visual learning style. Second, we consider the belief that there are large and intractable sex differences in spatial ability resultant from immutable biological reasons. Although there are some spatial sex differences (in some types of spatial tests although not all), there is actually only very mixed support for biological causation. Most important, there is conclusive evidence that spatial skills can be improved through training and education. Third, we explore educators' use of Piaget's ideas about spatial development to draw conclusions about 'developmental appropriateness'. However, recent research on spatial development has focused on identifying sequences that begin with early starting points of skill, and spatial education is possible in some form at all ages. Fourth, although spatial language does not determine spatial thought, it does frame attention in a way that can have impact on learning and understanding. We examine the empirical support for each assumption and its relevance to future research on visualizations in science education.

Developmental exposure to low-dose estrogenic endocrine disruptors alters sex differences in exploration and emotional responses in mice.

PubMed

Gioiosa, Laura; Fissore, Elena; Ghirardelli, Giorgia; Parmigiani, Stefano; Palanza, Paola

2007-09-01

Estrogenic endocrine disruptors (EEDs) are naturally occurring or man-made compounds present in the environment that are able to bind to estrogen receptors and interfere with normal cellular development in target organs and tissues. There is mounting evidence that EEDs can interfere with the processes of sexual differentiation of brain and behavior in different animal models. We investigated the effects of maternal exposure to EEDs, at concentrations within the range of human exposure and not patently teratogenic, on behavioral responses of male and female house mice (Mus musculus domesticus) before and after puberty. Pregnant dams were trained to spontaneously drink daily doses of corn oil with or without the estrogenic plastic derivative, bisphenol A (BPA 10 microg/kg), or the estrogenic insecticide methoxychlor (MXC 20 microg/kg) from gestation day 11 to postpartum day 8. Their male and female offspring were examined at different ages to examine several components of explorative and emotional behaviors in 3 experimental paradigms: a novelty test before puberty and, as adults, a free-exploratory open-field test and the elevated plus maze test. The main results are sex differences in control mice on a number of behavioral responses at both ages and in all experimental paradigms, while perinatal exposure to BPA or MXC decreased or eliminated such sex differences. The present findings are evidence of long-term consequences of developmental exposure to BPA and MXC on neurobehavioral development and suggest a differential effect of low-dose exposure to these estrogenic chemicals in males and females.

Maternal prenatal cortisol predicts infant negative emotionality in a sex-dependent manner.

PubMed

Braithwaite, Elizabeth C; Pickles, Andrew; Sharp, Helen; Glover, Vivette; O'Donnell, Kieran J; Tibu, Florin; Hill, Jonathan

2017-06-01

Prenatal stress influences fetal developmental trajectories, which may implicate glucocorticoid mechanisms. There is also emerging evidence that effects of prenatal stress on offspring development are sex-dependent. However, little is known about the prospective relationship between maternal prenatal cortisol levels and infant behaviour, and whether it may be different in male and female infants. We sought to address this question using data from a prospective longitudinal cohort, stratified by risk. The Wirral Child Health and Development Study (WCHADS) cohort (n=1233) included a stratified random sub-sample (n=216) who provided maternal saliva samples, assayed for cortisol, at home over two days at 32weeks of pregnancy (on waking, 30-min post-waking and during the evening) and a measure of infant negative emotionality from the Neonatal Behavioural Assessment Scale (NBAS) at five weeks-of-age. General population estimates of associations among measures were obtained using inverse probability weights. Maternal prenatal cortisol sampled on waking predicted infant negative emotionality in a sex-dependent manner (interaction term, p=0.005); female infants exposed to high levels of prenatal cortisol were more negative (Beta=0.440, p=0.042), whereas male infants were less negative (Beta=-0.407, p=0.045). There was no effect of the 30-min post-waking measure or evening cortisol. Our findings add to an emerging body of work that has highlighted sex differences in fetal programming, whereby females become more reactive following prenatal stress, and males less reactive. A more complete understanding of sex-specific developmental trajectories in the context of prenatal stress is essential for the development of targeted prevention strategies. Copyright © 2017. Published by Elsevier Inc.

Does MAOA increase susceptibility to prenatal stress in young children?

PubMed

Massey, Suena H; Hatcher, Amalia E; Clark, Caron A C; Burns, James L; Pine, Daniel S; Skol, Andrew D; Mroczek, Daniel K; Espy, Kimberly A; Goldman, David; Cook, Edwin; Wakschlag, Lauren S

2017-05-01

We previously demonstrated a gene-by-prenatal-environment interaction whereby the monoamine oxidase A gene (MAOA) modified the impact of prenatal tobacco exposure (PTE) on adolescent disruptive behavior (DB), with the MAOA risk genotype varying by sex. We extend this work by examining whether this mechanism is evident with another common adversity, prenatal stress exposure (PSE), and whether sex differences are present earlier in development in closer proximity to exposure. Participants were 281 mothers and their 285 children derived from a prenatal cohort with in-depth prospective measures of PSE and PTE. We assessed DB at age 5 via dimensional developmentally-sensitive measurement. Analyses were stratified by sex based on prior evidence for sex differences. Concurrent stress exposure predicted DB in children (β=0.310, p=0.001), while main effects of prenatal exposures were seen only in boys. We found a three-way interaction of MAOA×PSE×sex on DB (β=0.813, p=0.022). Boys with MAOA-H had more DB as a function of PSE, controlling for PTE (β=0.774, p=0.015), and as a function of PTE, controlling for PSE (β=0.362, p=0.037). Boys with MAOA-L did not show this susceptibility. MAOA did not interact with PSE (β=-0.133, p=0.561) nor PTE (β=-0.144; p=0.505) in predicting DB in girls. Examination of gene-environment correlation (rGE) showed a correlation between paternal MAOA-L and daughters' concurrent stress exposure (r=-0.240, p=0.013). Findings underscore complex mechanisms linking genetic susceptibility and early adverse exposures. Replication in larger cohorts followed from the pregnancy through adolescence is suggested to elucidate mechanisms that appear to have varying developmental expression. Copyright © 2017 Elsevier Inc. All rights reserved.

Cooler butterflies lay larger eggs: developmental plasticity versus acclimation.

PubMed Central

Fischer, Klaus; Eenhoorn, Evelien; Bot, Adriane N M; Brakefield, Paul M; Zwaan, Bas J

2003-01-01

We use a full factorial design to investigate the effects of maternal and paternal developmental temperature, as well as female oviposition temperature, on egg size in the butterfly Bicyclus anynana. Butterflies were raised at two different temperatures and mated in four possible sex-by-parental-temperature crosses. The mated females were randomly divided between high and low oviposition temperatures. On the first day after assigning the females to different temperatures, only female developmental temperature affected egg size. Females reared at the lower temperature laid larger eggs than those reared at a higher temperature. When eggs were measured again after an acclimation period of 10 days, egg size was principally determined by the prevailing temperature during oviposition, with females ovipositing at a lower temperature laying larger eggs. In contrast to widely used assumptions, the effects of developmental temperature were largely reversible. Male developmental temperature did not affect egg size in either of the measurements. Overall, developmental plasticity and acclimation in the adult stage resulted in very similar patterns of egg size plasticity. Consequently, we argue that the most important question when testing the significance of acclamatory changes is not at which stage a given plasticity is induced, but rather whether plastic responses to environmental change are adaptive or merely physiological constraints. PMID:14561294

Developmental links between trajectories of physical violence, vandalism, theft, and alcohol-drug use from childhood to adolescence.

PubMed

van Lier, Pol A C; Vitaro, Frank; Barker, Edward D; Koot, Hans M; Tremblay, Richard E

2009-05-01

Differences in developmental trajectories of physical violence, vandalism, theft, and alcohol-drug use from ages 10 to 15 were studied. For females and for males, three trajectories of theft and of alcohol-drug use increased from 10 years to 15 years, while only the high trajectory of vandalism increased from ten to 14. All trajectories of physical violence decreased. Children who engaged in the high trajectories of vandalism, theft, and alcohol-drug use had a high probability of also being high in physical violence. Compared to males, females were less likely to be on the high trajectory of physical violence, and their trajectories of other antisocial behaviors were less strongly associated with high levels of physical violence. The results suggest that physical violence during pre-adolescence and adolescence has a different developmental pattern than other forms of antisocial behavior, and that its relation to these other forms of antisocial behavior differs by sex.

The roles of Dmrt (Double sex/Male-abnormal-3 Related Transcription factor) genes in sex determination and differentiation mechanisms: Ubiquity and diversity across the animal kingdom.

PubMed

Picard, Marion Anne-Lise; Cosseau, Céline; Mouahid, Gabriel; Duval, David; Grunau, Christoph; Toulza, Ève; Allienne, Jean-François; Boissier, Jérôme

2015-07-01

The Dmrt (Double sex/Male-abnormal-3 Related Transcription factor) genes have been intensively studied because they represent major transcription factors in the pathways governing sex determination and differentiation. These genes have been identified in animal groups ranging from cnidarians to mammals, and some of the genes functionally studied. Here, we propose to analyze (i) the presence/absence of various Dmrt gene groups in the different taxa across the animal kingdom; (ii) the relative expression levels of the Dmrt genes in each sex; (iii) the specific spatial (by organ) and temporal (by developmental stage) variations in gene expression. This review considers non-mammalian animals at all levels of study (i.e. no particular importance is given to animal models), and using all types of sexual strategy (hermaphroditic or gonochoric) and means of sex determination (i.e. genetic or environmental). To conclude this global comparison, we offer an analysis of the DM domains conserved among the different DMRT proteins, and propose a general sex-specific pattern for each member of the Dmrt gene family. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Steroid Signaling and Temperature-Dependent Sex Determination – Reviewing the Evidence for Early Action of Estrogen during Ovarian Determination in the Red-Eared Slider Turtle (Trachemys scripta elegans)

PubMed Central

Ramsey, Mary; Crews, David

2009-01-01

The developmental processes underlying gonadal differentiation are conserved across vertebrates, but the triggers initiating these trajectories are extremely variable. The red-eared slider turtle (Trachemys scripta elegans) exhibits temperature-dependent sex determination (TSD), a system where incubation temperature during a temperature-sensitive period of development determines offspring sex. However, gonadal sex is sensitive to both temperature and hormones during this period – particularly estrogen. We present a model for temperature-based differences in aromatase expression as a critical step in ovarian determination. Localized estrogen production facilitates ovarian development while inhibiting male-specific gene expression. At male-producing temperatures aromatase is not upregulated, thereby allowing testis development. PMID:18992835

Body Image Stereotypes: A Developmental Comparison

ERIC Educational Resources Information Center

Kirkpatrick, Sue W.; Sanders, Diane Moody

1978-01-01

Examines the hypothesis that temperament judgments associated with different body types are dependent upon the sex and age of the respondents. Five hundred male and female subjects ranging in age from 6 to 60 years matched 40 temperament or behavior descriptors with one of three body silhouettes representing an ectomorph, an endomorph, and a…

Why We Must Try Same-Sex Instruction

ERIC Educational Resources Information Center

Laster, Carol

2004-01-01

Educators have not been teaching to the learning style of boys, nor have they kept up with recent findings in brain research on the developmental differences between boys and girls. With all the education reform efforts about, with new accountability standards so high, school districts nationwide struggle to balance budgets and increase student…

Developmental constraints and convergent evolution in Drosophila sex comb formation.

PubMed

Atallah, Joel; Liu, Nana Hou; Dennis, Peter; Hon, Andy; Larsen, Ellen W

2009-01-01

The most complex and diverse secondary sexual character in Drosophila is the sex comb (SC), an arrangement of modified bristles on the forelegs of a subclade of male fruit flies. We examined SC formation in six representative nonmodel fruit fly species, in an effort to understand how the variation in comb patterning arises. We first compared SC development in two species with relatively small combs, Drosophila takahashii, where the SCs remain approximately transverse, and Drosophila biarmipes, where two rows of SC teeth rotate and move in an anterior direction relative to other bristle landmarks. We then analyzed comb ontogeny in species with prominent extended SCs parallel to the proximodistal axis, including Drosophila ficusphila and species of the montium subgroup. Our study allowed us to identify two general methods of generating longitudinal combs on the tarsus, and we showed that a montium subgroup species (Drosophila nikananu) with a comb convergently similar in size, orientation and position to the model organism Drosophila melanogaster, forms its SC through a different developmental mechanism. We also found that the protein product of the leg patterning gene, dachshund (dac), is strongly reduced in the SC in all species, but not in other bristles. Our results suggest that an apparent constraint on SC position in the adult may be attributable to at least two different lineage-specific developmental processes, although external forces could also play a role.

Chronic Intranasal Oxytocin Causes Long-term Impairments in Partner Preference Formation in Male Prairie Voles

PubMed Central

Bales, Karen L.; Perkeybile, Allison M.; Conley, Olivia G.; Lee, Meredith H.; Guoynes, Caleigh D.; Downing, Griffin M.; Yun, Catherine R.; Solomon, Marjorie; Jacob, Suma; Mendoza, Sally P.

2012-01-01

Background Oxytocin (OT) is a hormone shown to be involved in social bonding in animal models. Intranasal OT is currently in clinical trials for use in disorders such as autism and schizophrenia. We examined long-term effects of intranasal OT given developmentally in the prairie vole (Microtus ochrogaster), a socially monogamous rodent, often used as an animal model to screen drugs that have therapeutic potential for social disorders. Methods We treated voles with one of three dosages of intranasal OT, or saline, from day 21 (weaning) through day 42 (sexual maturity). We examined both social behavior immediately following administration, as well as long-term changes in social and anxiety behavior after treatment ceased. Group sizes varied from 8 to 15 voles (n = 89 voles total). Results Treatment with OT resulted in acute increases in social behavior in males with familiar partners, as seen in humans. However, long-term developmental treatment with low doses of intranasal OT resulted in a deficit in partner preference behavior (a reduction of contact with a familiar opposite-sex partner, used to index pair-bond formation) by males. Conclusions Long-term developmental treatment with OT may show results different to those predicted by short-term studies, as well as significant sex differences and dosage effects. Further animal study is crucial to determining safe and effective strategies for use of chronic intranasal OT, especially during development. PMID:23079235

Let's Talk about Sex: Recommendations for Educating Adolescents with Developmental Disabilities

ERIC Educational Resources Information Center

Minch, Laura M.

2011-01-01

Individuals with developmental disabilities are vulnerable to sexual abuse, and are often denied access to sexuality education. Public schools have vague curricula regarding sexuality education for general education students, curricula to which adolescents with developmental disabilities do not have access. The current study sought to determine…

The Ultimate Developmental Task in Adolescent Literature.

ERIC Educational Resources Information Center

Abrahamson, Richard F.

The significance of adolescent literature has been judged on the basis of the developmental tasks encountered by the main character. One writer has identified eight developmental tasks that teenagers must undertake as they move toward adulthood: discovering one's sex role in our culture, developing relationships with peers, achieving an easy…

Sex differences and left-right asymmetries in expression of insulin and insulin-like growth factor-1 receptors in developing rat hippocampus.

PubMed

Hami, Javad; Sadr-Nabavi, Ariane; Sankian, Mojtaba; Haghir, Hossein

2012-04-01

Sex differences and laterality of rat hippocampus with respect to insulin-like growth factor-1 receptor (IGF-1R) and insulin receptor (InsR) expression as two important contributors to/regulators of developmental and cognitive functions were examined using real-time PCR and western blot analysis at P0, P7 and P14. Expression of the IGF-1R gene was lowest at P0 in all studied hippocampi. In males, we found the highest expression at P7 in the right hippocampus, and at P14 in the left one. In contrast, the peaked IGF-1R expression occurred at P7 in female hippocampi independent of laterality. Hippocampal InsR expression in males decreased significantly between P0 and P7, followed by a marked upregulation at P14. Conversely, the expression of InsR in females peaked at P7 and then decreased again significantly at P14. We found significant interhemispheric differences in IGF-1R mRNA levels in both male and female hippocampi at different time points. In contrast, we only found significant interhemispheric differences in InsR mRNA expression in P14 male rats, with higher values in the left hippocampus. Interestingly, changes in mRNA expression and in protein levels followed the same developmental pattern, indicating that IGF-1R and InsR transcription is not subject to modulatory effects during the first two weeks of development. These findings indicate that there are prominent interhemispheric and sex differences in IGF-1R and InsR expression in the developing rat hippocampus, suggesting a probable mechanism for the control of gender and laterality differences in development and function of the hippocampus.

Independent degeneration of W and Y sex chromosomes in frog Rana rugosa.

PubMed

Miura, Ikuo; Ohtani, Hiromi; Ogata, Mitsuaki

2012-01-01

The frog Rana rugosa uniquely possesses two different sex-determining systems of XX/XY and ZZ/ZW, separately in the geographic populations. The sex chromosomes of both types share the same origin at chromosome 7, and the structural differences between X and Y or Z and W were evolved through two inversions. In order to ascertain the mechanisms of degeneration of W and Y chromosomes, we gynogenetically produced homozygous diploids WW and YY and examined their viability. Tadpoles from geographic group N (W(N)W(N)) containing three populations died of edema at an early developmental stage within 10 days after hatching, while tadpoles from the geographic group K (W(K)W(K)) that contained two populations died of underdeveloped growth at a much later stage, 40-50 days after fertilization. On the contrary, W(N)W(K) and W(K)W(N) hybrid embryos were viable, successfully passed the two lethal stages, and survived till the attainment of adulthood. The observed survival implies that the lethal genes of the W chromosomes are not shared by the two groups and thus demonstrates their independent degeneration histories between the local groups. In sharp contrast, a sex-linked gene of androgen receptor gene (AR) from the W chromosome was down-regulated in expression in both the groups, suggesting that inactivation of the W-AR allele preceded divergence of the two groups and appearance of the lethal genes. Besides, the YY embryos died of cardiac edema immediately after hatching. The symptom of lethality and the stage of developmental arrest differed from those for either of WW lethal embryos. We therefore conclude that the W and Y chromosomes involve no evolutionary common scenario for degeneration.

Morphological and histomorphological structures of testes and ovaries in early developmental stages of the silkworm, Bombyx mori.

PubMed

Sakai, Hiroki; Kirino, Yohei; Katsuma, Susumu; Aoki, Fugaku; Suzuki, Masataka G

2016-01-01

The gonad develops as a testis in male or an ovary in female. In the silkworm, B. mori , little is known about testis and ovary in the embryonic stages and early larval stages. In this study, we performed morphological and histomorphological observations of ovaries and testes from the late embryonic stage to the 1st instar larval stage. Results obtained with lack of accurate information on sex of examined individuals may be misleading, thus we performed phenotypic observations of gonads by utilizing sex-limited strain that enables us to easily discriminate female embryos from male ones based on those egg colors. In testis, four testicular follicles were clearly observed in the testis at the first instar larval stage, and boundary layers were formed between the testicular follicles. At the late embryonic stage, the testis consisted of four testicular follicles, while the boundary layers were still obscure. In ovary, four ovarioles were easily recognizable in the ovary at the first instar larval stage, and boundary layers were formed between the ovarioles. However, in the late embryonic stage, it was quite difficult to identify four ovarioles. Morphological characteristics were almost similar between testis and ovary in early developmental stages. Our present study demonstrates that the most reliable difference between testis and ovary in early developmental stages is the attaching point of the duct. Formation and development of the duct may be sensitive to the sex-determining signal and display sexual dimorphism in early embryonic stages.

Can We Distinguish Juvenile Violent Sex Offenders, Violent Non-Sex Offenders, and Versatile Violent Sex Offenders Based on Childhood Risk Factors?

ERIC Educational Resources Information Center

Wanklyn, Sonya G.; Ward, Ashley K.; Cormier, Nicole S.; Day, David M.; Newman, Jennifer E.

2012-01-01

Understanding the developmental precursors of juvenile violent sex offending can contribute to the promotion of effective early intervention and prevention programs for high-risk children and youth. However, there is currently a lack of research on the early characteristics of adolescents who commit violent sex offenses. Drawing on the literature…

The Effects of Sex Steroids on Spatial Performance: A Review and an Experimental Clinical Investigation.

ERIC Educational Resources Information Center

Liben, Lynn S.; Susman, Elizabeth J.; Finkelstein, Jordan W.; Chinchilli, Vernon M.; Kunselman, Susan; Schwab, Jacqueline; Dubas, Judith Semon; Demers, Laurence M.; Lookingbill, Georgia; D'Arcangelo, M. Rose; Krogh, Holleen R.; Kulin, Howard E.

2002-01-01

Investigated the relationship between sex hormones and spatial performance among adolescents treated with sex steroids for delayed puberty. Found that spatial performance varied according to gender but did not vary with levels of actively circulating sex steroids. Reviewed physiological mechanisms, developmental periods, and past empirical work…

Sex Role Socialization/Sex Discrimination: A Bibliography. Volume II.

ERIC Educational Resources Information Center

Safilios-Rothschild, Constantina

The bibliography presents a comprehensive list of literature on sex role socialization and sex discrimination published between 1960 and 1974. It is designed to provide researchers with an interdisciplinary bibliography on the subject and with a sense of the developmental trends in this area over the last two decades. Over 3,000 entries including…

Vertebrate sex-determining genes play musical chairs.

PubMed

Pan, Qiaowei; Anderson, Jennifer; Bertho, Sylvain; Herpin, Amaury; Wilson, Catherine; Postlethwait, John H; Schartl, Manfred; Guiguen, Yann

2016-01-01

Sexual reproduction is one of the most highly conserved processes in evolution. However, the genetic and cellular mechanisms making the decision of whether the undifferentiated gonad of animal embryos develops either towards male or female are manifold and quite diverse. In vertebrates, sex-determining mechanisms range from environmental to simple or complex genetic mechanisms and different mechanisms have evolved repeatedly and independently. In species with simple genetic sex-determination, master sex-determining genes lying on sex chromosomes drive the gonadal differentiation process by switching on a developmental program, which ultimately leads to testicular or ovarian differentiation. So far, very few sex-determining genes have been identified in vertebrates and apart from mammals and birds, these genes are apparently not conserved over a larger number of related orders, families, genera, or even species. To fill this knowledge gap and to better explore genetic sex-determination, we propose a strategy (RAD-Sex) that makes use of next-generation sequencing technology to identify genetic markers that define sex-specific segments of the male or female genome. Copyright © 2016 Académie des sciences. All rights reserved.

Sex-specific reaction norms to intraspecific larval competition in the mosquito Aedes aegypti.

PubMed

Bedhomme, S; Agnew, P; Sidobre, C; Michalakis, Y

2003-07-01

As the relationship between a given life-history trait and fitness is not necessarily the same for the two sexes, an 'intersexual ontogenetic conflict' may arise. We analysed the phenotypic reaction to intraspecific larval competition of the mosquito, Aedes aegypti, asking: (i) Do both sexes pay the cost of competition with the same life-history traits and are they equal competitors? (ii) Is there a specific cost of competition beyond sharing food resources? We found that competition incurs a specific cost that was expressed differently by the two sexes. Indeed, each sex maintained the more important life-history trait(s) for their fitness (developmental time for males and body weight and size for females) at the expense of other traits, thus minimizing the effects of competition on their fitness. The competition exerted by females was estimated as being more intense, probably linked with the greater importance of body size for their fitness.

Impaired imprinted X chromosome inactivation is responsible for the skewed sex ratio following in vitro fertilization

PubMed Central

Tan, Kun; An, Lei; Miao, Kai; Ren, Likun; Hou, Zhuocheng; Tao, Li; Zhang, Zhenni; Wang, Xiaodong; Xia, Wei; Liu, Jinghao; Wang, Zhuqing; Xi, Guangyin; Gao, Shuai; Sui, Linlin; Zhu, De-Sheng; Wang, Shumin; Wu, Zhonghong; Bach, Ingolf; Chen, Dong-bao; Tian, Jianhui

2016-01-01

Dynamic epigenetic reprogramming occurs during normal embryonic development at the preimplantation stage. Erroneous epigenetic modifications due to environmental perturbations such as manipulation and culture of embryos during in vitro fertilization (IVF) are linked to various short- or long-term consequences. Among these, the skewed sex ratio, an indicator of reproductive hazards, was reported in bovine and porcine embryos and even human IVF newborns. However, since the first case of sex skewing reported in 1991, the underlying mechanisms remain unclear. We reported herein that sex ratio is skewed in mouse IVF offspring, and this was a result of female-biased peri-implantation developmental defects that were originated from impaired imprinted X chromosome inactivation (iXCI) through reduced ring finger protein 12 (Rnf12)/X-inactive specific transcript (Xist) expression. Compensation of impaired iXCI by overexpression of Rnf12 to up-regulate Xist significantly rescued female-biased developmental defects and corrected sex ratio in IVF offspring. Moreover, supplementation of an epigenetic modulator retinoic acid in embryo culture medium up-regulated Rnf12/Xist expression, improved iXCI, and successfully redeemed the skewed sex ratio to nearly 50% in mouse IVF offspring. Thus, our data show that iXCI is one of the major epigenetic barriers for the developmental competence of female embryos during preimplantation stage, and targeting erroneous epigenetic modifications may provide a potential approach for preventing IVF-associated complications. PMID:26951653

A microRNA family exerts maternal control on sex determination in C. elegans

PubMed Central

McJunkin, Katherine; Ambros, Victor

2017-01-01

Gene expression in early animal embryogenesis is in large part controlled post-transcriptionally. Maternally contributed microRNAs may therefore play important roles in early development. We elucidated a major biological role of the nematode mir-35 family of maternally contributed essential microRNAs. We show that this microRNA family regulates the sex determination pathway at multiple levels, acting both upstream of and downstream from her-1 to prevent aberrantly activated male developmental programs in hermaphrodite embryos. Both of the predicted target genes that act downstream from the mir-35 family in this process, suppressor-26 (sup-26) and NHL (NCL-1, HT2A, and LIN-41 repeat) domain-containing-2 (nhl-2), encode RNA-binding proteins, thus delineating a previously unknown post-transcriptional regulatory subnetwork within the well-studied sex determination pathway of Caenorhabditis elegans. Repression of nhl-2 by the mir-35 family is required for not only proper sex determination but also viability, showing that a single microRNA target site can be essential. Since sex determination in C. elegans requires zygotic gene expression to read the sex chromosome karyotype, early embryos must remain gender-naïve; our findings show that the mir-35 family microRNAs act in the early embryo to function as a developmental timer that preserves naïveté and prevents premature deleterious developmental decisions. PMID:28279983

Men's sexual orientation and suicide: evidence for U.S. adolescent-specific risk.

PubMed

Russell, Stephen T; Toomey, Russell B

2012-02-01

There is strong consensus in the research literature that adolescent and adult men who report same-sex sexual orientations, identities, and behaviors are at higher risk for suicide. Recent studies of general adolescent suicide risk have identified developmental trajectories that peak during the teenage years. Because the adolescent years are characterized by the development and heightened awareness of gender roles and sexual scripts closely tied to dominant cultural ideals of masculinity and heterosexuality, an adolescent-focused developmental trajectory for suicide risk might be particularly relevant for males with adolescent same-sex sexual orientations. We provide the first prospective examination of adolescent-specific risk for suicidality based on adolescent same-sex sexual orientation using data from the United States, the National Longitudinal Study of Adolescent Health. Tracing suicide ideation and attempts across four assessments from adolescence (Wave 1 average age 15.3 years) to young adulthood (Wave 4 average age 28.2), we documented that the risk for suicidal thoughts and attempts for adolescent same-sex attracted males is developmental in nature. Specifically, the risk for suicidal thoughts and attempts for males with same-sex attractions is largely limited to the adolescent years. These results offer new insights for suicide prevention and intervention for male adolescents and adults with same-sex sexual orientations. Copyright © 2010 Elsevier Ltd. All rights reserved.

Developmental evidence for obstetric adaptation of the human female pelvis.

PubMed

Huseynov, Alik; Zollikofer, Christoph P E; Coudyzer, Walter; Gascho, Dominic; Kellenberger, Christian; Hinzpeter, Ricarda; Ponce de León, Marcia S

2016-05-10

The bony pelvis of adult humans exhibits marked sexual dimorphism, which is traditionally interpreted in the framework of the "obstetrical dilemma" hypothesis: Giving birth to large-brained/large-bodied babies requires a wide pelvis, whereas efficient bipedal locomotion requires a narrow pelvis. This hypothesis has been challenged recently on biomechanical, metabolic, and biocultural grounds, so that it remains unclear which factors are responsible for sex-specific differences in adult pelvic morphology. Here we address this issue from a developmental perspective. We use methods of biomedical imaging and geometric morphometrics to analyze changes in pelvic morphology from late fetal stages to adulthood in a known-age/known-sex forensic/clinical sample. Results show that, until puberty, female and male pelves exhibit only moderate sexual dimorphism and follow largely similar developmental trajectories. With the onset of puberty, however, the female trajectory diverges substantially from the common course, resulting in rapid expansion of obstetrically relevant pelvic dimensions up to the age of 25-30 y. From 40 y onward females resume a mode of pelvic development similar to males, resulting in significant reduction of obstetric dimensions. This complex developmental trajectory is likely linked to the pubertal rise and premenopausal fall of estradiol levels and results in the obstetrically most adequate pelvic morphology during the time of maximum female fertility. The evidence that hormones mediate female pelvic development and morphology supports the view that solutions of the obstetrical dilemma depend not only on selection and adaptation but also on developmental plasticity as a response to ecological/nutritional factors during a female's lifetime.

Developmental evidence for obstetric adaptation of the human female pelvis

PubMed Central

Huseynov, Alik; Zollikofer, Christoph P. E.; Coudyzer, Walter; Gascho, Dominic; Kellenberger, Christian; Hinzpeter, Ricarda; Ponce de León, Marcia S.

2016-01-01

The bony pelvis of adult humans exhibits marked sexual dimorphism, which is traditionally interpreted in the framework of the “obstetrical dilemma” hypothesis: Giving birth to large-brained/large-bodied babies requires a wide pelvis, whereas efficient bipedal locomotion requires a narrow pelvis. This hypothesis has been challenged recently on biomechanical, metabolic, and biocultural grounds, so that it remains unclear which factors are responsible for sex-specific differences in adult pelvic morphology. Here we address this issue from a developmental perspective. We use methods of biomedical imaging and geometric morphometrics to analyze changes in pelvic morphology from late fetal stages to adulthood in a known-age/known-sex forensic/clinical sample. Results show that, until puberty, female and male pelves exhibit only moderate sexual dimorphism and follow largely similar developmental trajectories. With the onset of puberty, however, the female trajectory diverges substantially from the common course, resulting in rapid expansion of obstetrically relevant pelvic dimensions up to the age of 25–30 y. From 40 y onward females resume a mode of pelvic development similar to males, resulting in significant reduction of obstetric dimensions. This complex developmental trajectory is likely linked to the pubertal rise and premenopausal fall of estradiol levels and results in the obstetrically most adequate pelvic morphology during the time of maximum female fertility. The evidence that hormones mediate female pelvic development and morphology supports the view that solutions of the obstetrical dilemma depend not only on selection and adaptation but also on developmental plasticity as a response to ecological/nutritional factors during a female’s lifetime. PMID:27114515

Sequential Turnovers of Sex Chromosomes in African Clawed Frogs (Xenopus) Suggest Some Genomic Regions Are Good at Sex Determination

PubMed Central

Furman, Benjamin L. S.; Evans, Ben J.

2016-01-01

Sexual differentiation is fundamentally important for reproduction, yet the genetic triggers of this developmental process can vary, even between closely related species. Recent studies have uncovered, for example, variation in the genetic triggers for sexual differentiation within and between species of African clawed frogs (genus Xenopus). Here, we extend these discoveries by demonstrating that yet another sex determination system exists in Xenopus, specifically in the species Xenopus borealis. This system evolved recently in an ancestor of X. borealis that had the same sex determination system as X. laevis, a system which itself is newly evolved. Strikingly, the genomic region carrying the sex determination factor in X. borealis is homologous to that of therian mammals, including humans. Our results offer insights into how the genetic underpinnings of conserved phenotypes evolve, and suggest an important role for cooption of genetic building blocks with conserved developmental roles. PMID:27605520

Antecedents and sex/gender differences in youth suicidal behavior

PubMed Central

Rhodes, Anne E; Boyle, Michael H; Bridge, Jeffrey A; Sinyor, Mark; Links, Paul S; Tonmyr, Lil; Skinner, Robin; Bethell, Jennifer M; Carlisle, Corine; Goodday, Sarah; Hottes, Travis Salway; Newton, Amanda; Bennett, Kathryn; Sundar, Purnima; Cheung, Amy H; Szatmari, Peter

2014-01-01

Suicide is the second leading cause of death in youth globally; however, there is uncertainty about how best to intervene. Suicide rates are typically higher in males than females, while the converse is true for suicide attempts. We review this “gender paradox” in youth, and in particular, the age-dependency of these sex/gender differences and the developmental mechanisms that may explain them. Epidemiologic, genetic, neurodevelopmental and psychopathological research have identified suicidal behaviour risks arising from genetic vulnerabilities and sex/gender differences in early adverse environments, neurodevelopment, mental disorder and their complex interconnections. Further, evolving sex-/gender-defined social expectations and norms have been thought to influence suicide risk. In particular, how youth perceive and cope with threats and losses (including conforming to others’ or one’s own expectations of sex/gender identity) and adapt to pain (through substance use and help-seeking behaviours). Taken together, considering brain plasticity over the lifespan, these proposed antecedents to youth suicide highlight the importance of interventions that alter early environment(s) (e.g., childhood maltreatment) and/or one’s ability to adapt to them. Further, such interventions may have more enduring protective effects, for the individual and for future generations, if implemented in youth. PMID:25540727

The Developmental Course of Supportive Dyadic Coping in Couples

ERIC Educational Resources Information Center

Johnson, Matthew D.; Horne, Rebecca M.; Galovan, Adam M.

2016-01-01

Drawing from a relational developmental systems (RDS) perspective (Lerner, Agans, DeSouza, & Gasca, 2013) and data from 1,427 continuously partnered young adult and midlife mixed-sex couples over the first 5 years of the German Panel Analysis of Intimate Relationships and Family Dynamics (pairfam), this study examined the developmental course…

Different perspectives on the sex-attachment link: towards an emotion-motivational account.

PubMed

Dewitte, Marieke

2012-01-01

Although the link between sex and attachment was made decades ago (Hazan & Shaver, 1987), theories on sexual and attachment functioning have been developed in relative isolation. Recent efforts to integrate both literatures have been complicated by the fact that the sex-attachment link has been approached from very different perspectives, including biological, evolutionary, developmental, cognitive, and social psychology approaches. Also, at the empirical level, research on sex and attachment lacks overarching synthesis. This article gives an overview of the most important theoretical ideas and empirical insights on sex and attachment. It starts with describing general models that approach the sex-attachment link from an evolutionary and neurobiological perspective. Then, it summarizes theoretical and empirical ideas of attachment theory and describes how attachment style differences are manifested in intimate and sexual relationships. Research so far has been limited to studying the predicted link between sex and attachment in terms of broad descriptives, and it would benefit the literature to specify the processes and pathways that mediate the sex-attachment link. After a short discussion of the functional similarities between the sexual and the attachment systems, the article describes some specific--dynamical--models that focus on the emotional and cognitive-motivational processes through which attachment schemas influence sexual experiences. Such an emotion-motivational perspective on sex and attachment can help to organize theoretical ideas and empirical findings and eventually promote an integrative view on how attachment dynamics can interact with sexual experiences.

Developmental Differences in Engagement Style, Locus of Control, and Parent-Adolescent Relationships in African-American Families.

ERIC Educational Resources Information Center

Hill, Nancy E.

A study examined age and sex differences in engagement style and locus of control and their influence on African-American parent-adolescent relationships. The study subjects were 71 students in 9th grade and 57 students in 11th grade from 4 high schools in a large midwestern city; 46 college freshmen attending a large midwestern university; and 46…

Sociodemographic and Psychiatric Diagnostic Predictors of 3-Year Incidence of DSM-IV Substance Use Disorders among Men and Women in the National Epidemiologic Survey on Alcohol and Related Conditions

PubMed Central

Goldstein, Risë B.; Smith, Sharon M.; Dawson, Deborah A.; Grant, Bridget F.

2016-01-01

Incidence rates of alcohol and drug use disorders (AUDs and DUDs) are consistently higher in men than women, but information on whether sociodemographic and psychiatric diagnostic predictors of AUD and DUD incidence differ by sex is limited. Using data from Waves 1 and 2 of the National Epidemiologic Survey on Alcohol and Related Conditions, sex-specific 3-year incidence rates of AUDs and DUDs among United States adults were compared by sociodemographic variables and baseline psychiatric disorders. Sex-specific logistic regression models estimated odds ratios for prediction of incident AUDs and DUDs, adjusting for potentially confounding baseline sociodemographic and diagnostic variables. Few statistically significant sex differences in predictive relationships were identified and those observed were generally modest. Prospective research is needed to identify predictors of incident DSM-5 AUDs and DUDs and their underlying mechanisms, including whether there is sex specificity by developmental phase, in the role of additional comorbidity in etiology and course, and in outcomes of prevention and treatment. PMID:26727008

Selection in a fluctuating environment and the evolution of sexual dimorphism in the seed beetle Callosobruchus maculatus.

PubMed

Hallsson, L R; Björklund, M

2012-08-01

Temperature changes in the environment, which realistically include environmental fluctuations, can create both plastic and evolutionary responses of traits. Sexes might differ in either or both of these responses for homologous traits, which in turn has consequences for sexual dimorphism and its evolution. Here, we investigate both immediate changes in and the evolution of sexual dimorphism in response to a changing environment (with and without fluctuations) using the seed beetle Callosobruchus maculatus. We investigate sex differences in plasticity and also the genetic architecture of body mass and developmental time dimorphism to test two existing hypotheses on sex differences in plasticity (adaptive canalization hypothesis and condition dependence hypothesis). We found a decreased sexual size dimorphism in higher temperature and that females responded more plastically than males, supporting the condition dependence hypothesis. However, selection in a fluctuating environment altered sex-specific patterns of genetic and environmental variation, indicating support for the adaptive canalization hypothesis. Genetic correlations between sexes (r(MF) ) were affected by fluctuating selection, suggesting facilitated independent evolution of the sexes. Thus, the selective past of a population is highly important for the understanding of the evolutionary dynamics of sexual dimorphism. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

An examination of sex differences in the effects of early-life opiate and alcohol exposure

PubMed Central

Terasaki, Laurne S.; Gomez, Julie; Schwarz, Jaclyn M.

2016-01-01

Early-life exposure to drugs and alcohol is one of the most preventable causes of developmental, behavioural and learning disorders in children. Thus a significant amount of basic, animal and human research has focused on understanding the behavioural consequences and the associated neural effects of exposure to drugs and alcohol during early brain development. Despite this, much of the previous research that has been done on this topic has used predominantly male subjects or rodents. While many of the findings from these male-specific studies may ultimately apply to females, the purpose of this review is to highlight the research that has also examined sex as a factor and found striking differences between the sexes in their response to early-life opiate and alcohol exposure. Finally, we will also provide a framework for scientists interested in examining sex as a factor in future experiments that specifically examine the consequences of early-life drug and alcohol exposure. PMID:26833841

Sex-related shape dimorphism in the human radiocarpal and midcarpal joints.

PubMed

Kivell, Tracy L; Guimont, Isabelle; Wall, Christine E

2013-01-01

Previous research has revealed significant size differences between human male and female carpal bones but it is unknown if there are significant shape differences as well. This study investigated sex-related shape variation and allometric patterns in five carpal bones that make up the radiocarpal and midcarpal joints in modern humans. We found that many aspects of carpal shape (76% of all variables quantified) were similar between males and females, despite variation in size. However, 10 of the shape ratios were significantly different between males and females, with at least one significant shape difference observed in each carpal bone. Within-sex standard major axis regressions (SMA) of the numerator (i.e., the linear variables) on the denominator (i.e., the geometric mean) for each significantly different shape ratio indicated that most linear variables scaled with positive allometry in both males and females, and that for eight of the shape ratios, sex-related shape variation is associated with statistically similar sex-specific scaling relationships. Only the length of the scaphoid body and the height of the lunate triquetrum facet showed a significantly higher SMA slope in females compared with males. These findings indicate that the significant differences in the majority of the shape ratios are a function of subtle (i.e., not statistically significant) scaling differences between males and females. There are a number of potential developmental, functional, and evolutionary factors that may cause sex-related shape differences in the human carpus. The results highlight the potential for subtle differences in scaling to result in functionally significant differences in shape. Copyright © 2012 Wiley Periodicals, Inc.

At the heart of the problem - A person-centred, developmental perspective on the link between alcohol consumption and cardio-vascular events.

PubMed

Lima Passos, Valéria; Klijn, Sven; van Zandvoort, Kevin; Abidi, Latifa; Lemmens, Paul

2017-04-01

The cardio-protective effect of alcohol has been the subject of a long-standing scientific controversy. Emerging evidence remains equivocal, as the validity of the dose-dependent J-shape association is tainted by conceptual, theoretical and methodological problems. A major impediment for a resolution on the matter is the lack of a life-long developmental approach to pinpoint alcohol's specific impact on the risk for cardio-vascular events (CVE). Using retrospective and prospective individual-level data of alcohol consumption (AC) we applied a model-based clustering technique to uncover life-course trajectories of AC and explored their links to CVE. Data stemmed from a random sub-cohort of a large-scale, longitudinal study conducted in the Netherlands (N=2288). Group Based Trajectory Model (GBTM) was applied to extract distinct progressions of AC over time. Stratified by sex, the association between the developmental trajectories and CVE was examined with multiple logistic regression models, with adjustment for traditional risk factors. GBTM analysis laid bare the heterogeneity of AC dynamics over the life-course, reiterating sex differences in drinking habits and CVE risk. AC temporal behaviors during adolescence and adulthood were diverse, but showed relative stability in in middle-age and elderly years. For males, adjusted odds for CVE differed among the uncovered developmental classes. The findings elicited supportive evidence for a J-shape, but with a new twist. Besides moderation the results indicate that onset, timing, duration and stability of AC over the life-course are major aspects to be accounted for when attempting to elucidate alcohol's cardio-vascular role. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Sex differences in fluctuating asymmetry of body traits in chewing lice Docophorulus coarctatus (Phthiraptera: Ischnocera).

PubMed

Tryjanowski, Piotr; Adamski, Zbigniew

2007-10-01

Fluctuating asymmetry (FA) that reflects randomly directed deviations from bilateral symmetry has been shown to increase in organisms exposed to environmental and/or genetic stress. We studied fluctuating asymmetry in head and prothorax of chewing lice Docophorulus coarctatus, a parasite of the great grey shrike Lanius excubitor, to investigate associations between parasite body size and fluctuating asymmetry. Samples of ten individual lice (five females, five males) were randomly collected for measurements from 32 shrikes. Relative FA (scaled to trait size) was estimated for head and prothorax. Sex and trait differences in FA were very distinct (all differences significant at P<0.001). However, relative FA of head was not a predictor to relative FA of prothorax in either sex. Moreover, relative FA measurements of females and males from the same host were not significantly correlated, contrary to expectation if hosts imposed similar selection pressures on parasites of the two sexes. Relative FA of a trait was negatively related to its size, except for the relationship between relative FA of prothorax and prothorax in females. Differences in FA between traits may be explained by time when host condition affects louse developmental biology, with the head developing in a very short time during larval and nymph stages. The sex difference in asymmetry was probably related to different selection pressures by hosts on the sexes of the parasite, with females generally being under more intense selection.

Developmental Trajectories of Physical and Indirect Aggression from Late Childhood to Adolescence: Sex Differences and Outcomes in Emerging Adulthood

ERIC Educational Resources Information Center

Cleverley, Kristin; Szatmari, Peter; Vaillancourt, Tracy; Boyle, Michael; Lipman, Ellen

2012-01-01

Objective: Two common subtypes of aggression (physical and indirect) have been shown to develop concurrently throughout childhood and to uniquely predict maladjustment. However, nothing is known about psychiatric outcomes of joint trajectories of physical aggression (PA) and indirect aggression (IA) in emerging adulthood. Method: Trajectories of…

Sex Differences in Processing Speed: Developmental Effects in Males and Females

ERIC Educational Resources Information Center

Camarata, Stephen; Woodcock, Richard

2006-01-01

The purpose of this study was to compare the cognitive abilities and selected achievement performance of females and males across the lifespan on standardization samples of broad cognitive abilities in 1987 participants (1102 females, 885 males) from the WJ III, 4253 participants (2014 males, 2239 females) from the WJ-R, and 4225 participants…

The Two Sexes: Growing Up Apart, Coming Together. Family and Public Policy Series.

ERIC Educational Resources Information Center

Maccoby, Eleanor E.

This book seeks to explain how gender affects human development from infancy through adolescence and into adulthood. The book's introduction states the two theses of the book: first, gender differences appear primarily in group, or social, contexts; and second, gender differentiation can be understood only in a developmental context--the sexes…

Quality and developmental rate of embryos produced with sex-sorted and conventional semen from superovulated dairy cattle.

PubMed

Mikkola, M; Taponen, J

2017-01-01

This study investigated the effect of sex-sorted semen compared with conventional semen on the outcome of embryo recovery, placing special emphasis on the quality, and developmental stage of embryos. Data were analyzed for 443 embryo collections with sex-sorted semen (SEX group) and 1528 with conventional semen (CONV group) in superovulated dairy heifers and cows. The insemination protocol for conventional semen included two inseminations, comprising a total dose of 30 million sperm passing into the uterine body. For sex-sorted semen, two (30%) to three (70%) deep uterine inseminations were performed, the total dose ranging from eight to 12 million sperm. The data were analyzed separately for heifers and cows. The total number of recovered structures was similar among the groups. The number of viable embryos decreased in the SEX groups compared with the CONV (with 1.4 and 3.2 fewer embryos in heifers and cows, correspondingly, P < 0.001), and correspondingly the proportions of unfertilized ova and degenerated embryos increased in the SEX groups (P < 0.001). The proportion of unsuccessful collections, yielding no transferable embryos, increased in the SEX groups for both heifers (from 7.2% to 11.2%, P = 0.025) and cows (from 9.0% to 20.7%, P < 0.001). Regarding the quality of viable embryos, the quality grades were superior in the CONV group compared with the SEX group for heifers (P < 0.001) and cows (P < 0.001). The proportion of grade 1 embryos decreased by 6.5 percentage points in heifers and 11.9 percentage points in cows when sex-sorted semen was used. Correspondingly, the proportions of grade 2 and 3 embryos increased in heifers and cows when sexed semen was used. The mean developmental stages of embryo collections were numerically slightly lower in the SEX group. In heifers, the delay in developmental stage was statistically significant (P = 0.001), but in cows, there was only a tendency toward that (P = 0.067). In conclusion, sex-sorted sperm decreased the transferable embryo yield and increased the risk of a recovery yielding no transferable embryos. Furthermore, use of sex-sorted semen decreased the proportion of grade 1 embryos. In addition, it also seemed to delay embryonic development, although the delay in embryonic development was minimal and its biological relevance remains undefined. Despite the compromised embryo production, taken into account the optimization of recipient resources, the use of sex-sorted semen is advantageous, especially in superovulated heifers, which are of most importance in the modern breeding strategies using genomic selection. Copyright © 2016 Elsevier Inc. All rights reserved.

How Early Hormones Shape Gender Development

PubMed Central

Berenbaum, Sheri A.; Beltz, Adriene M.

2015-01-01

Many important psychological characteristics show sex differences, and are influenced by sex hormones at different developmental periods. We focus on the role of sex hormones in early development, particularly the differential effects of prenatal androgens on aspects of gender development. Increasing evidence confirms that prenatal androgens have facilitative effects on male-typed activity interests and engagement (including child toy preferences and adult careers), and spatial abilities, but relatively minimal effects on gender identity. Recent emphasis has been directed to the psychological mechanisms underlying these effects (including sex differences in propulsive movement, and androgen effects on interest in people versus things), and neural substrates of androgen effects (including regional brain volumes, and neural responses to mental rotation, sexually arousing stimuli, emotion, and reward). Ongoing and planned work is focused on understanding the ways in which hormones act jointly with the social environment across time to produce varying trajectories of gender development, and clarifying mechanisms by which androgens affect behaviors. Such work will be facilitated by applying lessons from other species, and by expanding methodology. Understanding hormonal influences on gender development enhances knowledge of psychological development generally, and has important implications for basic and applied questions, including sex differences in psychopathology, women’s underrepresentation in science and math, and clinical care of individuals with variations in gender expression. PMID:26688827

Insect Sex Determination Manipulated by Their Endosymbionts: Incidences, Mechanisms and Implications

PubMed Central

Kageyama, Daisuke; Narita, Satoko; Watanabe, Masaya

2012-01-01

The sex-determining systems of arthropods are surprisingly diverse. Some species have male or female heterogametic sex chromosomes while other species do not have sex chromosomes. Most species are diploids but some species, including wasps, ants, thrips and mites, are haplodiploids (n in males; 2n in females). Many of the sexual aberrations, such as sexual mosaics, sex-specific lethality and conversion of sexuality, can be explained by developmental defects including double fertilization of a binucleate egg, loss of a sex chromosome or perturbation of sex-determining gene expression, which occur accidentally or are induced by certain environmental conditions. However, recent studies have revealed that such sexual aberrations can be caused by various groups of vertically-transmitted endosymbiotic microbes such as bacteria of the genera Wolbachia, Rickettsia, Arsenophonus, Spiroplasma and Cardinium, as well as microsporidian protists. In this review, we first summarize the accumulated data on endosymbiont-induced sexual aberrations, and then discuss how such endosymbionts affect the developmental system of their hosts and what kinds of ecological and evolutionary effects these endosymbionts have on their host populations. PMID:26467955

Insect Sex Determination Manipulated by Their Endosymbionts: Incidences, Mechanisms and Implications.

PubMed

Kageyama, Daisuke; Narita, Satoko; Watanabe, Masaya

2012-02-10

The sex-determining systems of arthropods are surprisingly diverse. Some species have male or female heterogametic sex chromosomes while other species do not have sex chromosomes. Most species are diploids but some species, including wasps, ants, thrips and mites, are haplodiploids (n in males; 2n in females). Many of the sexual aberrations, such as sexual mosaics, sex-specific lethality and conversion of sexuality, can be explained by developmental defects including double fertilization of a binucleate egg, loss of a sex chromosome or perturbation of sex-determining gene expression, which occur accidentally or are induced by certain environmental conditions. However, recent studies have revealed that such sexual aberrations can be caused by various groups of vertically-transmitted endosymbiotic microbes such as bacteria of the genera Wolbachia, Rickettsia, Arsenophonus, Spiroplasma and Cardinium, as well as microsporidian protists. In this review, we first summarize the accumulated data on endosymbiont-induced sexual aberrations, and then discuss how such endosymbionts affect the developmental system of their hosts and what kinds of ecological and evolutionary effects these endosymbionts have on their host populations.

Sex Determination: Separate Sexes Are a Double Turnoff in Melons.

PubMed

Ma, Wen-Juan; Pannell, John R

2016-02-22

Flowers with only one sexual function typically result from the developmental suppression of the other. A recent study that shows how this is achieved has important implications for models of the evolution of separate sexes in plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

REPLICATIONS AND EXTENSIONS IN AROUSAL ASSESSMENT FOR SEX OFFENDERS WITH DEVELOPMENTAL DISABILITIES

PubMed Central

Reyes, Jorge R; Vollmer, Timothy R; Hall, Astrid

2011-01-01

Three adult male sex offenders with developmental disabilities participated in phallometric assessments that involved repeated measures of arousal when exposed to various stimuli. Arousal assessment outcomes were similar to those obtained by Reyes et al. (2006). Additional data-analysis methods provided further information about sexual preferences, thus replicating and extending previous research. The results provide preliminary data for establishing a preference gradient by age. Implications for the use of repeated measures and preference gradients in arousal assessments are discussed. PMID:21709795

THE INFLUENCE OF PRESESSION FACTORS IN THE ASSESSMENT OF DEVIANT AROUSAL

PubMed Central

Reyes, Jorge R; Vollmer, Timothy R; Hall, Astrid

2011-01-01

Three adult male sex offenders with developmental disabilities participated in an evaluation of presession factors that may influence levels of sexual arousal measured with a penile plethysmograph. We evaluated the effects of presession masturbation (1 participant) and arousal-suppression strategies (2 participants). Results showed that presession masturbation lowered arousal levels and both participants suppressed arousal to varying degrees. These outcomes suggest the potential for consideration and manipulation of presession factors as treatment components for sex offenders with developmental disabilities. PMID:22219524

Sex differences in thickness, and folding developments throughout the cortex.

PubMed

Mutlu, A Kadir; Schneider, Maude; Debbané, Martin; Badoud, Deborah; Eliez, Stephan; Schaer, Marie

2013-11-15

While significant differences in male and female brain structures have commonly been reported, only a few studies have focused on the sex differences in the way the cortex matures over time. Here, we investigated cortical thickness maturation between the age of 6 to 30 years, using 209 longitudinally-acquired brain MRI scans. Significant sex differences in the trajectories of cortical thickness change with age were evidenced using non-linear mixed effects models. Similar statistical analyses were computed to quantify the differences between cortical gyrification changes with age in males and females. During adolescence, we observed a statistically significant higher rate of cortical thinning in females compared to males in the right temporal regions, the left temporoparietal junction and the left orbitofrontal cortex. This finding is interpreted as a faster maturation of the social brain areas in females. Concomitantly, statistically significant sex differences in cortical folding changes with age were observed only in one cluster of the right prefrontal regions, suggesting that the mechanisms underlying cortical thickness and gyrification changes with age are quite distinct. Sexual dimorphism in the developmental course of the cortical maturation may be associated with the different age of onset and clinical presentation of many psychiatric disorders between males and females. Copyright © 2013 Elsevier Inc. All rights reserved.

Developmental Education and Its Relationship to Academic Success in College Level Courses at a Suburban Community College in Kansas

ERIC Educational Resources Information Center

Cole, Lisa M.

2014-01-01

This study evaluated the effectiveness of developmental math, English, and reading courses by evaluating the success of students in the corresponding college-level math, English, and reading course. This study analyzed select student characteristics (sex, ethnicity, age, socioeconomic status) or student developmental education status as predictors…

Developmental exposure of zebrafish (Danio rerio) to 17α-ethinylestradiol affects non-reproductive behavior and fertility as adults, and increases anxiety in unexposed progeny.

PubMed

Volkova, Kristina; Reyhanian Caspillo, Nasim; Porseryd, Tove; Hallgren, Stefan; Dinnétz, Patrik; Porsch-Hällström, Inger

2015-07-01

Exposure to estrogenic endocrine disruptors (EDCs) during development affects fertility, reproductive and non-reproductive behavior in mammals and fish. These effects can also be transferred to coming generations. In fish, the effects of developmental EDC exposure on non-reproductive behavior are less well studied. Here, we analyze the effects of 17α-ethinylestradiol (EE2) on anxiety, shoaling behavior and fertility in zebrafish after developmental treatment and remediation in clean water until adulthood. Zebrafish embryos were exposed from day 1 to day 80 post fertilization to actual concentrations of 1.2 and 1.6ng/L EE2. After remediation for 82days non-reproductive behavior and fertilization success were analyzed in both sexes. Males and females from the 1.2ng/L group, as well as control males and females, were bred, and behavior of the untreated F1 offspring was tested as adults. Developmental treatment with 1.2 and 1.6ng/L EE2 significantly increased anxiety in the novel tank test and increased shoaling intensity in both sexes. Fertilization success was significantly reduced by EE2 in both sexes when mated with untreated fish of opposite sex. Progeny of fish treated with 1.2ng/L EE2 showed increased anxiety in the novel tank test and increased light avoidance in the scototaxis test compared to control offspring. In conclusion, developmental exposure of zebrafish to low doses of EE2 resulted in persistent changes in behavior and fertility. The behavior of unexposed progeny was affected by their parents' exposure, which might suggest transgenerational effects. Copyright © 2015. Published by Elsevier Inc.

Effects of developmental exposure to bisphenol A and ethinyl estradiol on spatial navigational learning and memory in painted turtles (Chrysemys picta).

PubMed

Manshack, Lindsey K; Conard, Caroline M; Johnson, Sarah A; Alex, Jorden M; Bryan, Sara J; Deem, Sharon L; Holliday, Dawn K; Ellersieck, Mark R; Rosenfeld, Cheryl S

2016-09-01

Developmental exposure of turtles and other reptiles to endocrine disrupting chemicals (EDCs), including bisphenol A (BPA) and ethinyl estradiol (EE2, estrogen present in birth control pills), can induce partial to full gonadal sex-reversal in males. No prior studies have considered whether in ovo exposure to EDCs disrupts normal brain sexual differentiation. Yet, rodent model studies indicate early exposure to these chemicals disturbs sexually selected behavioral traits, including spatial navigational learning and memory. Thus, we sought to determine whether developmental exposure of painted turtles (Chrysemys picta) to BPA and EE2 results in sex-dependent behavioral changes. At developmental stage 17, turtles incubated at 26⁰C (male-inducing temperature) were treated with 1) BPA High (100μg /mL), 2) BPA Low (0.01μg/mL), 3) EE2 (0.2μg/mL), or 4) vehicle or no vehicle control groups. Five months after hatching, turtles were tested with a spatial navigational test that included four food containers, only one of which was baited with food. Each turtle was randomly assigned one container that did not change over the trial period. Each individual was tested for 14 consecutive days. Results show developmental exposure to BPA High and EE2 improved spatial navigational learning and memory, as evidenced by increased number of times spent in the correct target zone and greater likelihood of solving the maze compared to control turtles. This study is the first to show that in addition to overriding temperature sex determination (TSD) of the male gonad, these EDCs may induce sex-dependent behavioral changes in turtles. Copyright © 2016 Elsevier Inc. All rights reserved.

FUNDAMENTAL MOVEMENT SKILLS OF PRESCHOOL CHILDREN IN NORTHWEST ENGLAND.

PubMed

Foulkes, J D; Knowles, Z; Fairclough, S J; Stratton, G; O'Dwyer, M; Ridgers, N D; Foweather, L

2015-08-01

This cross-sectional study examined fundamental movement skill competency among deprived preschool children in Northwest England and explored sex differences. A total of 168 preschool children (ages 3-5 yr.) were included in the study. Twelve skills were assessed using the Children's Activity and Movement in Preschool Motor Skills Protocol and video analysis. Sex differences were explored at the subtest, skill, and component levels. Overall competence was found to be low among both sexes, although it was higher for locomotor skills than for object-control skills. Similar patterns were observed at the component level. Boys had significantly better object-control skills than girls, with greater competence observed for the kick and overarm throw, while girls were more competent at the run, hop, and gallop. The findings of low competency suggest that developmentally appropriate interventions should be implemented in preschool settings to promote movement skills, with targeted activities for boys and girls.

Developmental changes in the skull morphology of common minke whales Balaenoptera acutorostrata.

PubMed

Nakamura, Gen; Kato, Hidehiro

2014-10-01

We investigated growth-related and sex-related morphological changes in the skulls of 144 North Pacific common minke whales Balaenoptera acutorostrata. Measurement was conducted at 39 points on the skull and mandible to extract individual allometric equations relating the length and zygomatic width of the skull. The results revealed no significant differences in skull morphology by sex except for width of occipital bone. The size relative to the skull of the anatomical parts involved in feeding, such as the rostrum and mandible, increased after birth. In contrast, the sensory organs and the anatomical regions involved in neurological function, such as the orbit, tympanic bullae, and foramen magnum, were fully developed at birth, and their relative size reduced over the course of development. This is the first study to investigate developmental changes in the skull morphology using more than 100 baleen whale specimens, and we believe the results of this study will contribute greatly to multiple areas of baleen whale research, including taxonomy and paleontology. © 2014 Wiley Periodicals, Inc.

Immunocompetence of the red turpentine beetle, Dendroctonus valens LeConte (Coleoptera: Curculionidae, Scolytinae): variation between developmental stages and sexes in populations in China.

PubMed

Shi, Zhang-Hong; Sun, Jiang-Hua

2010-11-01

Immune defense imposes fitness costs as well as benefits, so organisms should optimize, not maximize, their immune function through their life cycle. We investigated this issue in the red turpentine beetle, Dendroctonus valens LeConte (Coleoptera: Curculionidae, Scolytinae), which is a pine-killing invasive beetle in China, though it is usually considered as a secondary pest in its native range of North America. We hypothesized that pathogen pressure may affect these beetles differently throughout their life history. We measured the insect's immunocompetence throughout life, determining encapsulation ability and phenoloxidase activity in larval stages, pupae and adults. Pupae had the highest encapsulation ability, but encapsulation was not different between final instar larvae and adults. Phenoloxidase (PO) activity was highest in final instar larvae and pupae, followed by the second instar larvae and adults. Total phenoloxidase activity increased significantly from the second instar larval stage to pupae, and then decreased in adults. Although the second instar larvae had the lowest phenoloxidase activity, more than 90% of total PO existed in the hemolymph in the form of the active enzyme, as compared with pupae, in which over 60% of PO occurred as a proenzyme. Both active PO and total PO were much higher in females than in males, though no significant differences were detected between the encapsulation ability of male and female adults. This result suggests the existence of a sexual dimorphism of immunocompetence in D. valens adults. Variations in immunocompetence across developmental stages suggest that D. valens adopts diverse investment strategies in immunocompetence during different stages. Potential reasons for variation in immunocompetence among developmental stages and between the sexes of D. valens are discussed. Copyright 2010 Elsevier Ltd. All rights reserved.

Early sex differences in weighting geometric cues.

PubMed

Lourenco, Stella F; Addy, Dede; Huttenlocher, Janellen; Fabian, Lydia

2011-11-01

When geometric and non-geometric information are both available for specifying location, men have been shown to rely more heavily on geometry compared to women. To shed insight on the nature and developmental origins of this sex difference, we examined how 18- to 24-month-olds represented the geometry of a surrounding (rectangular) space when direct non-geometric information (i.e. a beacon) was also available for localizing a hidden object. Children were tested on a disorientation task with multiple phases. Across experiments, boys relied more heavily than girls on geometry to guide localization, as indicated by their errors during the initial phase of the task, and by their search choices following transformations that left only geometry available, or that, under limited conditions, created a conflict between beacon and geometry. Analyses of search times suggested that girls, like boys, had encoded geometry, and testing in a square space ruled out explanations concerned with motivational and methodological variables. Taken together, the findings provide evidence for an early sex difference in the weighting of geometry. This sex difference, we suggest, reflects subtle variation in how boys and girls approach the problem of combining multiple sources of location information. 2011 Blackwell Publishing Ltd.

Guidelines for Comprehensive Sexuality Education: Kindergarten-12th Grade.

ERIC Educational Resources Information Center

Sex Information and Education Council of the United States, Inc., New York, NY.

The National Guidelines for Comprehensive Sexuality Education were developed by a Sex Information and Education Council of the United States (SIECUS) task force made up of health, education, and sex education professionals. The group was tasked with formulating sex education concepts and guidelines within four developmental levels, from…

Obsessive-compulsive symptoms and related sex differences in brain structure: an MRI study in Dutch twins.

PubMed

den Braber, Anouk; de Geus, Eco J C; Boomsma, Dorret I; van 't Ent, Dennis

2013-04-01

Neuroimaging studies have indicated abnormalities in cortico-striato-thalamo-cortical circuits in obsessive-compulsive disorder patients, but results have not been consistent. Since there are significant sex differences in human brain anatomy and obsessive-compulsive symptomatology and its developmental trajectories tend to be distinct in males and females, we investigated whether sex is a potential source of heterogeneity in neuroimaging studies on obsessive-compulsive symptoms. We selected male and female twin pairs who were concordant for scoring either high or low for obsessive-compulsive symptoms and a group of discordant pairs where one twin scored high and the co-twin scored low. The design included 24 opposite-sex twin pairs. Magnetic resonance imaging scans of 31 males scoring high for obsessive-compulsive symptoms, 41 low-scoring males, 58 high-scoring females, and 73 low-scoring females were analyzed and the interaction of obsessive-compulsive symptoms by sex on gray matter volume was assessed using voxel-based morphometry. An obsessive-compulsive symptom by sex interaction was observed for the left middle temporal gyrus, the right middle temporal gyrus, and the right precuneus. These interactions acted to reduce or hide a main effect in our study and illustrate the importance of taking sex into account when investigating the neurobiology of obsessive-compulsive symptoms.

A strategy to apply quantitative epistasis analysis on developmental traits.

PubMed

Labocha, Marta K; Yuan, Wang; Aleman-Meza, Boanerges; Zhong, Weiwei

2017-05-15

Genetic interactions are keys to understand complex traits and evolution. Epistasis analysis is an effective method to map genetic interactions. Large-scale quantitative epistasis analysis has been well established for single cells. However, there is a substantial lack of such studies in multicellular organisms and their complex phenotypes such as development. Here we present a method to extend quantitative epistasis analysis to developmental traits. In the nematode Caenorhabditis elegans, we applied RNA interference on mutants to inactivate two genes, used an imaging system to quantitatively measure phenotypes, and developed a set of statistical methods to extract genetic interactions from phenotypic measurement. Using two different C. elegans developmental phenotypes, body length and sex ratio, as examples, we showed that this method could accommodate various metazoan phenotypes with performances comparable to those methods in single cell growth studies. Comparing with qualitative observations, this method of quantitative epistasis enabled detection of new interactions involving subtle phenotypes. For example, several sex-ratio genes were found to interact with brc-1 and brd-1, the orthologs of the human breast cancer genes BRCA1 and BARD1, respectively. We confirmed the brc-1 interactions with the following genes in DNA damage response: C34F6.1, him-3 (ortholog of HORMAD1, HORMAD2), sdc-1, and set-2 (ortholog of SETD1A, SETD1B, KMT2C, KMT2D), validating the effectiveness of our method in detecting genetic interactions. We developed a reliable, high-throughput method for quantitative epistasis analysis of developmental phenotypes.

Time with Peers from Middle Childhood to Late Adolescence: Developmental Course and Adjustment Correlates

PubMed Central

Lam, Chun Bun; McHale, Susan M.; Crouter, Ann C.

2014-01-01

This study examined the developmental course and adjustment correlates of time with peers from age 8 to 18. On 7 occasions over 8 years, the two eldest siblings from 201 European American, working- and middle-class families provided questionnaire and/or phone diary data. Multilevel models revealed that girls’ time with mixed/opposite-sex peers increased beginning in middle childhood, but boys’ time increased beginning in early adolescence. For both girls and boys, time with same-sex peers peaked in mid-adolescence. At the within-person level, unsupervised time with mixed/opposite-sex peers longitudinally predicted problem behaviors and depressive symptoms, and supervised time with mixed/opposite-sex peers longitudinally predicted better school performance. Findings highlight the importance of social context in understanding peer involvement and its implications for youth development. PMID:24673293

A microRNA family exerts maternal control on sex determination in C. elegans.

PubMed

McJunkin, Katherine; Ambros, Victor

2017-02-15

Gene expression in early animal embryogenesis is in large part controlled post-transcriptionally. Maternally contributed microRNAs may therefore play important roles in early development. We elucidated a major biological role of the nematode mir-35 family of maternally contributed essential microRNAs. We show that this microRNA family regulates the sex determination pathway at multiple levels, acting both upstream of and downstream from her-1 to prevent aberrantly activated male developmental programs in hermaphrodite embryos. Both of the predicted target genes that act downstream from the mir-35 family in this process, suppressor-26 ( sup-26 ) and NHL (NCL-1, HT2A, and LIN-41 repeat) domain-containing-2 ( nhl-2 ), encode RNA-binding proteins, thus delineating a previously unknown post-transcriptional regulatory subnetwork within the well-studied sex determination pathway of Caenorhabditis elegans Repression of nhl-2 by the mir-35 family is required for not only proper sex determination but also viability, showing that a single microRNA target site can be essential. Since sex determination in C. elegans requires zygotic gene expression to read the sex chromosome karyotype, early embryos must remain gender-naïve; our findings show that the mir-35 family microRNAs act in the early embryo to function as a developmental timer that preserves naïveté and prevents premature deleterious developmental decisions. © 2017 McJunkin and Ambros; Published by Cold Spring Harbor Laboratory Press.

Beginning Awareness-Rigidity-Flexibility: A Longitudinal Analysis of Sex-Role Stereotyping in 4- to 10-Year-Old Children (Langsschnittliche Analyse von Entwicklungsmerkmalen der Geschlechtstypisierung im Kindersalter. Arbeiten aud dem Forschungsprojekt Nr. 5. 1989/1).

ERIC Educational Resources Information Center

Trautner, Hanns Martin; And Others

A three-phase developmental model of sex-role stereotyping that viewed the acquisition of sex-role stereotypes as part of the broader process of the development of social understanding was proposed. Phases in the model included: (1) beginning awareness of sex-role differentiation; (2) rigid sex-role stereotyping; and (3) flexible sex-role…

Sexuality and the Developmentally Handicapped: Health Education Strategies.

ERIC Educational Resources Information Center

Martin, Mary-Lou; Forchuk, Cheryl

1987-01-01

The article describes a sex education program for small groups of developmentally handicapped adolescents and young adults which includes information on and discussion of body parts, acceptable social behavior, assertiveness, birth control, and sexually transmitted diseases. (Author/JW)

Sex-dependent effects of developmental exposure to different pesticides on spatial learning. The role of induced neuroinflammation in the hippocampus.

PubMed

Gómez-Giménez, Belén; Llansola, Marta; Hernández-Rabaza, Vicente; Cabrera-Pastor, Andrea; Malaguarnera, Michele; Agusti, Ana; Felipo, Vicente

2017-01-01

The use of pesticides has been associated with impaired neurodevelopment in children. The aims of this work were to assess: 1) the effects on spatial learning of developmental exposure to pesticides 2) if the effects are sex-dependent and 3) if hippocampal neuroinflammation is associated with the impairment of spatial learning. We analyzed the effects of developmental exposure to four pesticides: chlorpyrifos, carbaryl, endosulfan and cypermethrin. Exposure was from gestational day 7 to post-natal day 21 and spatial learning and memory was assessed when the rats were young adults. The effects of pesticides on spatial learning were pesticide and gender-dependent. Carbaryl did not affect spatial learning in males or females. Endosulfan and chlorpyrifos impaired learning in males but not in females. Cypermethrin improved spatial learning in the Morris water maze both in males and females while impaired learning in the radial maze only in males. Spatial learning ability was lower in control female rats than in males. All pesticides induced neuroinflammation, increasing IL-1b content in the hippocampus and there is a negative correlation between IL-1b levels in the hippocampus and spatial learning. Neuroinflammation would contribute to the effects of pesticides on spatial learning. Copyright © 2016 Elsevier Ltd. All rights reserved.

Developmental trajectories of aggressive behavior in children from ages 8 to 10: The role of sex and hormones.

PubMed

Azurmendi, Aitziber; Pascual-Sagastizabal, Eider; Vergara, Ana I; Muñoz, Jose M; Braza, Paloma; Carreras, Rosario; Braza, Francisco; Sánchez-Martín, José R

2016-01-01

This study explored the developmental trajectory of aggressive behavior from age 8 to age 10 in school-aged children, taking into account possible sex differences, as well as the involvement of certain hormones. Participants were 90 children (49 boys and 41 girls) from four schools. At the beginning of the study, the children were 8-year old and were in 3rd grade of primary school. The second data collection phase was carried out two years later (at age 10) when the children were in 5th grade (primary). Their aggressive behavior was measured by the Direct and Indirect Aggression Scale, an instrument which uses peer rating. Hormone levels, testosterone, cortisol and estradiol were analyzed using an enzymoimmunoassay technique in saliva samples. The results revealed a difference in aggressive behavior between the ages of 8 and 10, in boys only, who were found to be more aggressive at age 10. A regression analysis revealed that cortisol and estradiol contributed to explaining the changes observed in aggressive behavior in boys. Boys whose cortisol levels rose most between the ages of 8 and 10 were also those whose aggressive behavior increased most during the same timeframe. Moreover, boys whose estradiol levels rose most between the ages of 8 and 10 were also those whose aggressive behavior decreased most during the same timeframe. Our results highlight the importance of studying aggressive behavior from a longitudinal perspective, taking into account sex differences and biological measures. © 2015 Wiley Periodicals, Inc.

Integration of Spectral Reflectance across the Plumage: Implications for Mating Patterns

PubMed Central

Laczi, Miklós; Török, János; Rosivall, Balázs; Hegyi, Gergely

2011-01-01

Background In complex sexual signaling systems such as plumage color, developmental or genetic links may occur among seemingly distinct traits. However, the interrelations of such traits and the functional significance of their integration rarely have been examined. Methodology/Principal Findings We investigated the parallel variation of two reflectance descriptors (brightness and UV chroma) across depigmented and melanized plumage areas of collared flycatchers (Ficedula albicollis), and the possible role of integrated color signals in mate acquisition. We found moderate integration in brightness and UV chroma across the plumage, with similar correlation structures in the two sexes despite the strong sexual dichromatism. Patterns of parallel color change across the plumage were largely unrelated to ornamental white patch sizes, but they all showed strong assortative mating between the sexes. Comparing different types of assortative mating patterns for individual spectral variables suggested a distinct role for plumage-level color axes in mate acquisition. Conclusions/Significance Our results indicate that the plumage-level, parallel variation of coloration might play a role in mate acquisition. This study underlines the importance of considering potential developmental and functional integration among apparently different ornaments in studies of sexual selection. PMID:21853088

Metabolism of 2,2′,3,3′,6,6′-Hexachlorobiphenyl (PCB 136) Atropisomers in Tissue Slices from Phenobarbital or Dexamethasone-Induced Rats is Sex-Dependent

PubMed Central

Wu, Xianai; Kania-Korwel, Izabela; Chen, Hao; Stamou, Marianna; Dammanahalli, Karigowda J.; Duffel, Michael; Lein, Pamela J.; Lehmler, Hans-Joachim

2013-01-01

Chiral polychlorinated biphenyls (PCBs) such as PCB 136 enantioselectively sensitize the ryanodine receptor (RyR). In light of recent evidence that PCBs cause developmental neurotoxicity via RyR-dependent mechanisms, this suggests that enantioselective PCB metabolism may influence the developmental neurotoxicity of chiral PCBs. However, enantioselective disposition of PCBs has not been fully characterized.The effect of sex and cytochrome P450 (P450) enzyme induction on the enantioselective metabolism of PCB 136 was studied using liver tissue slices prepared from naïve control (CTL), phenobarbital (PB; CYP2B inducer) or dexamethasone (DEX; CYP3A inducer) pretreated adult Sprague-Dawley rats. PCB 136 metabolism was also examined in hippocampal slices derived from untreated rat pups.In liver tissue slices, hydroxylated PCB (OH-PCB) profiles depended on sex and inducer pretreatment, and OH-PCB levels followed the rank orders male > female and PB > DEX > CTL. In contrast, the enantiomeric enrichment of PCB 136 and its metabolites was independent of sex and inducer pretreatment. Only small amounts of PCB 136 partitioned into hippocampal tissue slices and no OH-PCB metabolites were detected.Our results suggest that enantioselective metabolism, sex and induction status of P450 enzymes in the liver may modulate the neurotoxic outcomes of developmental exposure to chiral PCBs. PMID:23581876

Does MAOA Increase Susceptibility to Prenatal Stress in Young Children?

PubMed Central

Massey, Suena H.; Hatcher, Amalia E.; Clark, Caron A.C.; Burns, James L.; Pine, Daniel S.; Skol, Andrew D.; Mroczek, Daniel K.; Espy, Kimberly A.; Goldman, David; Cook, Edwin; Wakschlag, Lauren S.

2017-01-01

Background We previously demonstrated a gene-by-prenatal-environment interaction whereby the monoamine oxidase A gene (MAOA) modified the impact of prenatal tobacco exposure (PTE) on adolescent disruptive behavior (DB), with the MAOA risk genotype varying by sex. We extend this work by examining whether this mechanism is evident with another common adversity, prenatal stress exposure (PSE), and whether sex differences are present earlier in development in closer proximity to exposure. Methods Participants were 281 mothers and their 285 children derived from a prenatal cohort with in-depth prospective measures of PSE and PTE. We assessed DB at age 5 via dimensional developmentally-sensitive measurement. Analyses were stratified by sex based on prior evidence for sex differences. Results Concurrent stress exposure predicted DB in children (β=.310, p=.001), while main effects of prenatal exposures were seen only in boys. We found a three-way interaction of MAOAxPSExsex on DB (β=.813, p=.022). Boys with MAOA-H had more DB as a function of PSE, controlling for PTE (β=.774, p=.015), and as a function of PTE, controlling for PSE (β=.362, p=.037). Boys with MAOA-L did not show this susceptibility. MAOA did not interact with PSE (β=−.133, p=.561) nor PTE (β= −.144; p=.505) in predicting DB in girls. Examination of gene-environment correlation (rGE) showed a correlation between paternal MAOA-L and daughters’ concurrent stress exposure (r=−.240, p=.013). Discussion Findings underscore complex mechanisms linking genetic susceptibility and early adverse exposures. Replication in larger cohorts followed from the pregnancy through adolescence is suggested to elucidate mechanisms that appear to have varying developmental expression. PMID:28163169

Impact of Low-Dose Oral Exposure to Bisphenol A (BPA) on Juvenile and Adult Rat Exploratory and Anxiety Behavior: A CLARITY-BPA Consortium Study

PubMed Central

Rebuli, Meghan E.; Camacho, Luísa; Adonay, Maria E.; Reif, David M.; Aylor, David L.; Patisaul, Heather B.

2015-01-01

Bisphenol A (BPA) is a high volume production chemical and has been identified as an endocrine disruptor, prompting concern that developmental exposure could impact brain development and behavior. Rodent and human studies suggest that early life BPA exposure may result in an anxious, hyperactive phenotype but results are conflicting and data from studies using multiple doses below the no-observed-adverse-effect level are limited. To address this, the present studies were conducted as part of the CLARITY-BPA (Consortium Linking Academic and Regulatory Insights on BPA Toxicity) program. The impact of perinatal BPA exposure (2.5, 25, or 2500 µg/kg body weight (bw)/day) on behaviors related to anxiety and exploratory activity was assessed in juvenile (prepubertal) and adult NCTR Sprague-Dawley rats of both sexes. Ethinyl estradiol (0.5 µg/kg bw/day) was used as a reference estrogen. Exposure spanned gestation and lactation with dams gavaged from gestational day 6 until birth and then the offspring gavaged directly through weaning (n = 12/sex/group). Behavioral assessments included open field, elevated plus maze, and zero maze. Anticipated sex differences in behavior were statistically identified or suggested in most cases. No consistent effects of BPA were observed for any endpoint, in either sex, at either age compared to vehicle controls; however, significant differences between BPA-exposed and ethinyl estradiol-exposed groups were identified for some endpoints. Limitations of this study are discussed and include suboptimal statistical power and low concordance across behavioral tasks. These data do not indicate BPA-related effects on anxiety or exploratory activity in these developmentally exposed rats. PMID:26209558

Other-Sex Friendships in Late Adolescence: Risky Associations for Substance Use and Sexual Debut?

ERIC Educational Resources Information Center

Mrug, Sylvie; Borch, Casey; Cillessen, Antonius H. N.

2011-01-01

Adolescents' friendships with other-sex peers serve important developmental functions, but they may also facilitate engagement in problem behavior. This study examines the unique contributions of other-sex friendships and friends' behavior to alcohol use, smoking, and initiation of sexual intercourse among late adolescent girls and boys. A total…

Androgen Modulation of Foxp1 and Foxp2 in the Developing Rat Brain: Impact on Sex Specific Vocalization

PubMed Central

Perez-Pouchoulen, Miguel; Roby, Clinton R.; Ryan, Timothy E.; McCarthy, Margaret M.

2014-01-01

Sex differences in vocal communication are prevalent in both the animals and humans. The mechanism(s) mediating gender differences in human language are unknown, although, sex hormones, principally androgens, play a central role in the development of vocalizations in a wide variety of animal species. The discovery of FOXP2 has added an additional avenue for exploring the origins of language and animal communication. The FOXP2 gene is a member of the forkhead box P (FOXP) family of transcription factors. Prior to the prenatal androgen surge in male fetuses, we observed no sex difference for Foxp2 protein levels in cultured cells. In contrast, 24 hours after the onset of the androgen surge, we found a sex difference for Foxp2 protein levels in cultured cortical cells with males having higher levels than females. Furthermore, we observed the potent nonaromatizable androgen dihydrotestosterone altered not only Foxp2 mRNA and protein levels but also Foxp1. Androgen effects on both Foxp2 and Foxp1 were found to occur in the striatum, cerebellar vermis, and cortex. Immunofluorescence microscopy and coimmunoprecipitation demonstrate Foxp2 and the androgen receptor protein interact. Databases for transcription factor binding sites predict a consensus binding motif for androgen receptor on the Foxp2 promoter regions. We also observed a sex difference in rat pup vocalization with males vocalizing more than females and treatment of females with dihydrotestosterone eliminated the sex difference. We propose that androgens might be an upstream regulator of both Foxp2 and Foxp1 expression and signaling. This has important implications for language and communication as well as neuropsychiatric developmental disorders involving impairments in communication. PMID:25247470

Androgen modulation of Foxp1 and Foxp2 in the developing rat brain: impact on sex specific vocalization.

PubMed

Bowers, J Michael; Perez-Pouchoulen, Miguel; Roby, Clinton R; Ryan, Timothy E; McCarthy, Margaret M

2014-12-01

Sex differences in vocal communication are prevalent in both the animals and humans. The mechanism(s) mediating gender differences in human language are unknown, although, sex hormones, principally androgens, play a central role in the development of vocalizations in a wide variety of animal species. The discovery of FOXP2 has added an additional avenue for exploring the origins of language and animal communication. The FOXP2 gene is a member of the forkhead box P (FOXP) family of transcription factors. Prior to the prenatal androgen surge in male fetuses, we observed no sex difference for Foxp2 protein levels in cultured cells. In contrast, 24 hours after the onset of the androgen surge, we found a sex difference for Foxp2 protein levels in cultured cortical cells with males having higher levels than females. Furthermore, we observed the potent nonaromatizable androgen dihydrotestosterone altered not only Foxp2 mRNA and protein levels but also Foxp1. Androgen effects on both Foxp2 and Foxp1 were found to occur in the striatum, cerebellar vermis, and cortex. Immunofluorescence microscopy and coimmunoprecipitation demonstrate Foxp2 and the androgen receptor protein interact. Databases for transcription factor binding sites predict a consensus binding motif for androgen receptor on the Foxp2 promoter regions. We also observed a sex difference in rat pup vocalization with males vocalizing more than females and treatment of females with dihydrotestosterone eliminated the sex difference. We propose that androgens might be an upstream regulator of both Foxp2 and Foxp1 expression and signaling. This has important implications for language and communication as well as neuropsychiatric developmental disorders involving impairments in communication.

Incubation history prior to the canonical thermosensitive period determines sex in the American alligator.

PubMed

McCoy, Jessica A; Parrott, Benjamin B; Rainwater, Thomas R; Wilkinson, Phillip M; Guillette, Louis J

2015-10-01

Despite the widespread occurrence of environmental sex determination (ESD) among vertebrates, our knowledge of the temporal dynamics by which environmental factors act on this process remains limited. In many reptiles, incubation temperature determines sex during a discrete developmental window just prior to and coincident with the differentiation of the gonads. Yet, there is substantial variation in sex ratios among different clutches of eggs incubated at identical temperatures during this period. Here, we test the hypothesis that temperatures experienced prior to the reported thermosensitive period for alligators (Alligator mississippiensis) can impact how the sex determination system responds to thermal cues later in development. Temperature shift experiments on eggs collected from the field within 24  h of oviposition were employed to decouple various maternal influences from thermal effects, and results demonstrate a previously undefined window of thermosensitivity occurring by stage 15 of embryonic development, six stages earlier than previously reported. We also examine the intrasexual expression of several male- and female-biased genes and show that while male-biased genes display no intrasexual differences, ovarian CYP19A1 (aromatase) transcript abundance differs by approximately twofold depending on thermal exposures experienced at early stages of embryonic development. These findings expand our understanding of the ESD in the alligator and provide the rationale for reevaluation of the temporal dynamics of sex determination in other crocodilians. © 2015 Society for Reproduction and Fertility.

Sex differences in the pathways to major depression: a study of opposite-sex twin pairs.

PubMed

Kendler, Kenneth S; Gardner, Charles O

2014-04-01

The authors sought to clarify the nature of sex differences in the etiologic pathways to major depression. Retrospective and prospective assessments of 20 developmentally organized risk factors and the occurrence of past-year major depression were conducted at two waves of personal interviews at least 12 months apart in 1,057 opposite-sex dizygotic twin pairs from a population-based register. Analyses were conducted by structural modeling, examining within-pair differences. Sixty percent of all paths in the best-fit model exhibited sex differences. Eleven of the 20 risk factors differed across sexes in their impact on liability to major depression. Five had a greater impact in women: parental warmth, neuroticism, divorce, social support, and marital satisfaction. Six had a greater impact in men: childhood sexual abuse, conduct disorder, drug abuse, prior history of major depression, and distal and dependent proximal stressful life events. The life event categories responsible for the stronger effect in males were financial, occupational, and legal in nature. In a co-twin control design, which matches sisters and brothers on genetic and familial-environmental background, personality and failures in interpersonal relationships played a stronger etiologic role in major depression for women than for men. Externalizing psychopathology, prior depression, and specific "instrumental" classes of acute stressors were more important in the etiologic pathway to major depression for men. The results are consistent with previously proposed typologies of major depression that suggest two subtypes that differ in prevalence in women (deficiencies in caring relationships and interpersonal loss) and men (failures to achieve expected goals, with lowered self-worth).

Sex differences in the physiology of eating

PubMed Central

Asarian, Lori

2013-01-01

Hypothalamic-pituitary-gonadal (HPG) axis function fundamentally affects the physiology of eating. We review sex differences in the physiological and pathophysiological controls of amounts eaten in rats, mice, monkeys, and humans. These controls result from interactions among genetic effects, organizational effects of reproductive hormones (i.e., permanent early developmental effects), and activational effects of these hormones (i.e., effects dependent on hormone levels). Male-female sex differences in the physiology of eating involve both organizational and activational effects of androgens and estrogens. An activational effect of estrogens decreases eating 1) during the periovulatory period of the ovarian cycle in rats, mice, monkeys, and women and 2) tonically between puberty and reproductive senescence or ovariectomy in rats and monkeys, sometimes in mice, and possibly in women. Estrogens acting on estrogen receptor-α (ERα) in the caudal medial nucleus of the solitary tract appear to mediate these effects in rats. Androgens, prolactin, and other reproductive hormones also affect eating in rats. Sex differences in eating are mediated by alterations in orosensory capacity and hedonics, gastric mechanoreception, ghrelin, CCK, glucagon-like peptide-1 (GLP-1), glucagon, insulin, amylin, apolipoprotein A-IV, fatty-acid oxidation, and leptin. The control of eating by central neurochemical signaling via serotonin, MSH, neuropeptide Y, Agouti-related peptide (AgRP), melanin-concentrating hormone, and dopamine is modulated by HPG function. Finally, sex differences in the physiology of eating may contribute to human obesity, anorexia nervosa, and binge eating. The variety and physiological importance of what has been learned so far warrant intensifying basic, translational, and clinical research on sex differences in eating. PMID:23904103

Developmental Cognitive Neuroscience of Adolescent Sexual Risk and Alcohol Use

PubMed Central

Ryman, Sephira G.; Gillman, Arielle S.; Weiland, Barbara J.; Thayer, Rachel E.; Bryan, Angela D.

2018-01-01

Human adolescents engage in very high rates of unprotected sex. This behavior has a high potential for unintended, serious, and sustained health consequences including HIV/AIDS. Despite these serious health consequences, we know little about the neural and cognitive factors that influence adolescents’ decision-making around sex, and their potential overlap with behaviorally co-occurring risk behaviors, including alcohol use. Thus, in this review, we evaluate the developmental neuroscience of sexual risk and alcohol use for human adolescents with an eye to relevant prevention and intervention implications. PMID:26290051

Variation and evolution of male sex combs in Drosophila: nature of selection response and theories of genetic variation for sexual traits.

PubMed

Ahuja, Abha; Singh, Rama S

2008-05-01

We investigated the genetic architecture of variation in male sex comb bristle number, a rapidly evolving secondary sexual character of Drosophila. Twenty-four generations of divergent artificial selection for sex comb bristle number in a heterogeneous population of Drosophila melanogaster resulted in a significant response that was more pronounced in the direction of low bristle numbers. We observed a strong positive correlated response to selection in the corresponding female transverse bristle row. The correlated response in male abdominal and sternopleural bristle numbers, on the other hand, did not follow the same pattern as sex comb bristle number differences between selection lines. Relaxation-of-selection experiments along with mate choice and fecundity assays using the selection lines developed demonstrated the action of stabilizing selection on sex comb bristle number. Our results show (1) substantial genetic variation underlying sex comb bristle number variation; (2) a weak relationship between the sex comb and developmentally related, non-sex bristle systems; and (3) that sexual selection may be a driving force in sex comb evolution, indicating the potential of sex combs to diversify rapidly during population differentiation and speciation. We discuss the implications of these results for theories of genetic variation in display and nondisplay male sex traits.

Child development and pediatric sport and recreational injuries by age.

PubMed

Schwebel, David C; Brezausek, Carl M

2014-01-01

In 2010, 8.6 million children were treated for unintentional injuries in American emergency departments. Child engagement in sports and recreation offers many health benefits but also exposure to injury risks. In this analysis, we consider possible developmental risk factors in a review of age, sex, and incidence of 39 sport and recreational injuries. To assess (1) how the incidence of 39 sport and recreational injuries changed through each year of child and adolescent development, ages 1 to 18 years, and (2) sex differences. Design : Descriptive epidemiology study. Emergency department visits across the United States, as reported in the 2001-2008 National Electronic Injury Surveillance System database. Data represent population-wide emergency department visits in the United States. Main Outcome Measure(s) : Pediatric sport- and recreation-related injuries requiring treatment in hospital emergency departments. Almost 37 pediatric sport or recreational injuries are treated hourly in the United States. The incidence of sport- and recreation-related injuries peaks at widely different ages. Team-sport injuries tend to peak in the middle teen years, playground injuries peak in the early elementary ages and then drop off slowly, and bicycling injuries peak in the preteen years but are a common cause of injury throughout childhood and adolescence. Bowling injuries peaked at the earliest age (4 years), and injuries linked to camping and personal watercraft peaked at the oldest age (18 years). The 5 most common causes of sport and recreational injuries across development, in order, were basketball, football, bicycling, playgrounds, and soccer. Sex disparities were common in the incidence of pediatric sport and recreational injuries. Both biological and sociocultural factors likely influence the developmental aspects of pediatric sport and recreational injury risk. Biologically, changes in perception, cognition, and motor control might influence injury risk. Socioculturally, decisions must be made about which sport and recreational activities to engage in and how much risk taking occurs while engaging in those activities. Understanding the developmental aspects of injury data trends allows preventionists to target education at specific groups.

Epigenetic impacts of endocrine disruptors in the brain☆

PubMed Central

Walker, Deena M.; Gore, Andrea C.

2017-01-01

The acquisition of reproductive competence is organized and activated by steroid hormones acting upon the hypothalamus during critical windows of development. This review describes the potential role of epigenetic processes, particularly DNA methylation, in the regulation of sexual differentiation of the hypothalamus by hormones. We examine disruption of these processes by endocrine-disrupting chemicals (EDCs) in an age-, sex-, and region-specific manner, focusing on how perinatal EDCs act through epigenetic mechanisms to reprogram DNA methylation and sex steroid hormone receptor expression throughout life. These receptors are necessary for brain sexual differentiation and their altered expression may underlie disrupted reproductive physiology and behavior. Finally, we review the literature on histone modifications and non-coding RNA involvement in brain sexual differentiation and their perturbation by EDCs. By putting these data into a sex and developmental context we conclude that perinatal EDC exposure alters the developmental trajectory of reproductive neuroendocrine systems in a sex-specific manner. PMID:27663243

Sex, stress, and mood disorders: at the intersection of adrenal and gonadal hormones.

PubMed

Fernández-Guasti, A; Fiedler, J L; Herrera, L; Handa, R J

2012-07-01

The risk for neuropsychiatric illnesses has a strong sex bias, and for major depressive disorder (MDD), females show a more than 2-fold greater risk compared to males. Such mood disorders are commonly associated with a dysregulation of the hypothalamo-pituitary-adrenal (HPA) axis. Thus, sex differences in the incidence of MDD may be related with the levels of gonadal steroid hormone in adulthood or during early development as well as with the sex differences in HPA axis function. In rodents, organizational and activational effects of gonadal steroid hormones have been described for the regulation of HPA axis function and, if consistent with humans, this may underlie the increased risk of mood disorders in women. Other developmental factors, such as prenatal stress and prenatal overexposure to glucocorticoids can also impact behaviors and neuroendocrine responses to stress in adulthood and these effects are also reported to occur with sex differences. Similarly, in humans, the clinical benefits of antidepressants are associated with the normalization of the dysregulated HPA axis, and genetic polymorphisms have been found in some genes involved in controlling the stress response. This review examines some potential factors contributing to the sex difference in the risk of affective disorders with a focus on adrenal and gonadal hormones as potential modulators. Genetic and environmental factors that contribute to individual risk for affective disorders are also described. Ultimately, future treatment strategies for depression should consider all of these biological elements in their design. © Georg Thieme Verlag KG Stuttgart · New York.

The Influence of Sex and Fly Species on the Development of Trypanosomes in Tsetse Flies

PubMed Central

Peacock, Lori; Ferris, Vanessa; Bailey, Mick; Gibson, Wendy

2012-01-01

Unlike other dipteran disease vectors, tsetse flies of both sexes feed on blood and transmit pathogenic African trypanosomes. During transmission, Trypanosoma brucei undergoes a complex cycle of proliferation and development inside the tsetse vector, culminating in production of infective forms in the saliva. The insect manifests robust immune defences throughout the alimentary tract, which eliminate many trypanosome infections. Previous work has shown that fly sex influences susceptibility to trypanosome infection as males show higher rates of salivary gland (SG) infection with T. brucei than females. To investigate sex-linked differences in the progression of infection, we compared midgut (MG), proventriculus, foregut and SG infections in male and female Glossina morsitans morsitans. Initially, infections developed in the same way in both sexes: no difference was observed in numbers of MG or proventriculus infections, or in the number and type of developmental forms produced. Female flies tended to produce foregut migratory forms later than males, but this had no detectable impact on the number of SG infections. The sex difference was not apparent until the final stage of SG invasion and colonisation, showing that the SG environment differs between male and female flies. Comparison of G. m. morsitans with G. pallidipes showed a similar, though less pronounced, sex difference in susceptibility, but additionally revealed very different levels of trypanosome resistance in the MG and SG. While G. pallidipes was more refractory to MG infection, a very high proportion of MG infections led to SG infection in both sexes. It appears that the two fly species use different strategies to block trypanosome infection: G. pallidipes heavily defends against initial establishment in the MG, while G. m. morsitans has additional measures to prevent trypanosomes colonising the SG, particularly in female flies. We conclude that the tsetse-trypanosome interface works differently in G. m. morsitans and G. pallidipes. PMID:22348165

Protective effects of middle school comprehensive sex education with family involvement.

PubMed

Grossman, Jennifer M; Tracy, Allison J; Charmaraman, Linda; Ceder, Ineke; Erkut, Sumru

2014-11-01

School-based comprehensive sex education programs can reduce early adolescents' risky sexual behavior. The purpose of this study was to assess the effectiveness of a 3-year comprehensive sex education program in delaying vaginal sex for middle school students and whether the family component of the intervention contributes to its effectiveness. This longitudinal evaluation followed a cohort of 6th graders (N = 2453) through the end of 8th grade. The design used random assignment of 24 schools into treatment and comparison conditions. The analysis included multiple-group logistic regression to assess differences in delay of sex between intervention and comparison groups. In schools where the program was taught, 16% fewer boys and 15% fewer girls had had sex by the end of 8th grade compared to boys and girls at comparison schools. Completing family activities during the first year of the program predicted delayed sexual debut for boys. Theory-based, developmentally appropriate, comprehensive sex education programs that include parent involvement can be effective in delaying vaginal sex for middle school students. Parent involvement is particularly important for boys, as family activities may encourage parents to talk with their sons earlier and more frequently. © 2014, American School Health Association.

The birds and the bees and the flowers and the trees: lessons from genetic mapping of sex determination in plants and animals.

PubMed

Charlesworth, Deborah; Mank, Judith E

2010-09-01

The ability to identify genetic markers in nonmodel systems has allowed geneticists to construct linkage maps for a diversity of species, and the sex-determining locus is often among the first to be mapped. Sex determination is an important area of study in developmental and evolutionary biology, as well as ecology. Its importance for organisms might suggest that sex determination is highly conserved. However, genetic studies have shown that sex determination mechanisms, and the genes involved, are surprisingly labile. We review studies using genetic mapping and phylogenetic inferences, which can help reveal evolutionary pattern within this lability and potentially identify the changes that have occurred among different sex determination systems. We define some of the terminology, particularly where confusion arises in writing about such a diverse range of organisms, and highlight some major differences between plants and animals, and some important similarities. We stress the importance of studying taxa suitable for testing hypotheses, and the need for phylogenetic studies directed to taxa where the patterns of changes can be most reliably inferred, if the ultimate goal of testing hypotheses regarding the selective forces that have led to changes in such an essential trait is to become feasible.

Sex differences in the acute in vivo effects of different human SP-A variants on the mouse alveolar macrophage proteome

PubMed Central

Phelps, David S.; Umstead, Todd M.; Floros, Joanna

2014-01-01

Surfactant protein A (SP-A) is involved in lung innate immunity. Humans have two SP-A genes, SFTPA1 and SFTPA2, each with several variants. We examined the in vivo effects of treatment with specific SP-A variants on the alveolar macrophage (AM) proteome from SP-A knockout (KO) mice. KO mice received either SP-A1, SP-A2, or both. AM were collected and their proteomes examined with 2D-DIGE. We identified 90 proteins and categorized them as related to actin/cytoskeleton, oxidative stress, protease balance/chaperones, regulation of inflammation, and regulatory/developmental processes. SP-A1 and SP-A2 had different effects on the AM proteome and these effects differed between sexes. In males more changes occurred in the oxidative stress, protease/chaperones, and inflammation groups with SP-A2 treatment than with SP-A1. In females most SP-A1-induced changes were in the actin/cytoskeletal and oxidative stress groups. We conclude that after acute SP-A1 and SP-A2 treatment, sex-specific differences were observed in the AM proteomes from KO mice, and that these sex differences differ in response to SP-A1 and SP-A2. Females are more responsive to SP-A1, whereas the gene-specific differences in males were minimal. These observations not only demonstrate the therapeutic potential of exogenous SP-A, but also illustrate sex- and gene-specific differences in the response to it. PMID:24954098

Assessment of sex specific endocrine disrupting effects in the prenatal and pre-pubertal rodent brain.

PubMed

Rebuli, Meghan E; Patisaul, Heather B

2016-06-01

Brain sex differences are found in nearly every region of the brain and fundamental to sexually dimorphic behaviors as well as disorders of the brain and behavior. These differences are organized during gestation and early adolescence and detectable prior to puberty. Endocrine disrupting compounds (EDCs) interfere with hormone action and are thus prenatal exposure is hypothesized to disrupt the formation of sex differences, and contribute to the increased prevalence of pediatric neuropsychiatric disorders that present with a sex bias. Available evidence for the ability of EDCs to impact the emergence of brain sex differences in the rodent brain was reviewed here, with a focus on effects detected at or before puberty. The peer-reviewed literature was searched using PubMed, and all relevant papers published by January 31, 2015 were incorporated. Endpoints of interest included molecular cellular and neuroanatomical effects. Studies on behavioral endpoints were not included because numerous reviews of that literature are available. The hypothalamus was found to be particularly affected by estrogenic EDCs in a sex, time, and exposure dependent manner. The hippocampus also appears vulnerable to endocrine disruption by BPA and PCBs although there is little evidence from the pre-pubertal literature to make any conclusions about sex-specific effects. Gestational EDC exposure can alter fetal neurogenesis and gene expression throughout the brain including the cortex and cerebellum. The available literature primarily focuses on a few, well characterized EDCs, but little data is available for emerging contaminants. The developmental EDC exposure literature demonstrates evidence of altered neurodevelopment as early as fetal life, with sex specific effects observed throughout the brain even before puberty. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sex-specific modulation of juvenile social play by vasopressin.

PubMed

Veenema, Alexa H; Bredewold, Remco; De Vries, Geert J

2013-11-01

Social play activities among juveniles are thought to contribute to the development of social and emotional skills in humans and animals. Conversely, social play deficits are observed in developmental neuropsychiatric disorders. Importantly, many of these disorders show sex differences in incidence, course of the disease, and severity of symptoms. We hypothesized that sex differences in the neural systems controlling social behavior can contribute to these differences. We therefore studied the involvement of the sexually dimorphic vasopressin and oxytocin systems, which have been implicated in these disorders, in juvenile social play behavior. Single-housed 5-week-old juvenile male and female rats were exposed in their home cage to an age-and sex-matched novel conspecific for 10 min, and social play behaviors were recorded. We found no consistent sex differences in duration or elements of social play in vehicle-treated rats. However, intracerebroventricular injection of the specific vasopressin 1a receptor (V1aR) antagonist (CH2)5Tyr(Me(2))AVP significantly reduced social play behaviors in males while increasing them in females. Intracerebroventricular injection of the specific oxytocin receptor antagonist des-Gly-NH2,d(CH2)5[Tyr(Me)(2),Thr(4)]OVT did not alter social play in either sex. To locate the effects of V1aR blockade on social play, we targeted the lateral septum, a sexually dimorphic brain region showing denser vasopressin fibers in males than in females and an abundant expression of V1aR in both sexes. Surprisingly, blockade of V1aR in the lateral septum increased social play behaviors in males, but decreased them in females. These findings suggest sex- and brain region-specific roles for vasopressin in the regulation of social play behavior in juvenile rats. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sex-specific modulation of juvenile social play by vasopressin

PubMed Central

Veenema, Alexa H.; Bredewold, Remco; De Vries, Geert J.

2013-01-01

SUMMARY Social play activities among juveniles are thought to contribute to the development of social and emotional skills in humans and animals. Conversely, social play deficits are observed in developmental neuropsychiatric disorders. Importantly, many of these disorders show sex differences in incidence, course of the disease, and severity of symptoms. We hypothesized that sex differences in the neural systems controlling social behavior can contribute to these differences. We therefore studied the involvement of the sexually dimorphic vasopressin and oxytocin systems, which have been implicated in these disorders, in juvenile social play behavior. Single-housed 5-week-old juvenile male and female rats were exposed to an unknown age-and sex-matched conspecific for 10 min in their home cage and social play behaviors were recorded. We found no consistent sex differences in level or elements of social play in vehicle-treated rats. However, intracerebroventricular injection of the specific vasopressin 1a receptor (V1aR) antagonist (CH2)5Tyr(Me2) AVP significantly reduced social play behaviors in males, while increasing them in females. Intracerebroventricular injection of the specific oxytocin receptor antagonist des-Gly-NH2,d(CH2)5[Tyr(Me)2,Thr4]OVT did not alter social play in either sex. To locate the effects of V1aR blockade on social play, we targeted the lateral septum, a sexually dimorphic brain region showing denser vasopressin fibers in males than in females and abundant expression of V1aR in both sexes. Surprisingly, blockade of V1aR in the lateral septum increased social play behaviors in males, but decreased them in females. These findings suggest sex- and brain region-specific roles for vasopressin in the regulation of social play behavior in juvenile rats. PMID:23838102

Lessons Learnt from a Secondary School Sex Education Program in Portugal

ERIC Educational Resources Information Center

Sousa, Ana Paula; Soares, Isabel; Vilar, Duarte

2007-01-01

Based on a developmental framework, a study was conducted in Portugal in two groups of youth in terms of relevant aspects related to adolescent psychosexual development: one group participated in an Experimental Project of Sex Education and Health Promotion during high school, whereas the other did not receive any formal sex education in school.…

Prolonged Exposure Treatment of Chronic PTSD in Juvenile Sex Offenders: Promising Results from Two Case Studies

ERIC Educational Resources Information Center

Hunter, John A.

2010-01-01

Prolonged exposure (PE) was used to treat chronic PTSD secondary to severe developmental trauma in two adolescent male sex offenders referred for residential sex offender treatment. Both youth were treatment resistant prior to initiation of PE and showed evidence of long-standing irritability and depression/anxiety. Clinical observation and…

Sex, gender, and age: contributions to laboratory pain responding in children and adolescents.

PubMed

Myers, Cynthia D; Tsao, Jennie C I; Glover, Dorie A; Kim, Su C; Turk, Norman; Zeltzer, Lonnie K

2006-08-01

A cross-sectional design across late childhood and adolescence examined the influence of sex, gender socialization, and age on responses to controlled laboratory pain tasks. Healthy children and adolescents (n = 240, 50% female, age 8 to 18 years) completed the Child Sex Role Inventory, a self-report measure of identification with stereotypically masculine and feminine personality traits, as an index of gender socialization and participated in pressure, cold pressor, and heat pain tasks. Pain tolerance, pain intensity, and bothersomeness of each pain task were assessed. Masculinity correlated with lower heat pain ratings in boys but not girls. Logistic regression indicated cold pain intensity ratings were predicted by sex, gender score, and the age-by-gender score interaction. Heat pain intensity was predicted by age, gender score, age-by-gender score interaction, and sex-by-gender score. The current findings support closer examination of the influence of gender socialization on young people's pain responses and highlight the importance of a multifactorial, developmental approach to studying the impact of gender socialization on the emergence of sex differences in pain responses after puberty.

The acquisition of gender labels in infancy: Implications for sex-typed play

PubMed Central

Zosuls, Kristina M.; Ruble, Diane N.; Tamis-LeMonda, Catherine S.; Shrout, Patrick E.; Bornstein, Marc H.; Greulich, Faith K.

2009-01-01

Two aspects of children’s early gender development - the spontaneous production of gender labels and sex-typed play - were examined longitudinally in a sample of 82 children. Survival analysis, a statistical technique well suited to questions involving developmental transitions, was used to investigate the timing of the onset of children’s gender labeling as based on mothers’ biweekly reports on their children’s language from 9 through 21 months. Videotapes of children’s play both alone and with mother at 17 and 21 months were independently analyzed for play with gender stereotyped and neutral toys. Finally, the relation between gender labeling and sex-typed play was examined. Children transitioned to using gender labels at approximately 19 months on average. Although girls and boys showed similar patterns in the development of gender labeling, girls began labeling significantly earlier than boys. Modest sex differences in play were present at 17 months and increased at 21 months. Gender labeling predicted increases in sex-typed play, suggesting that knowledge of gender categories might influence sex-typing before the age of 2. PMID:19413425

Long-Term Aripiprazole in Youth with Developmental Disabilities Including Autism

ERIC Educational Resources Information Center

Hellings, Jessica A.; Boehm, Danna; Yeh, Hung Wen; Butler, Merlin G.; Schroeder, Stephen R.

2011-01-01

We retrospectively reviewed clinic charts of 21 children and adolescents with developmental disabilities including autism spectrum disorders (ASD) treated consecutively with aripiprazole (ARI) for irritability and severe challenging behaviors. Data extracted include age, sex, and race; level of intellectual disability (ID); "Diagnostic and…

Extremely preterm birth affects boys more and socio-economic and neonatal variables pose sex-specific risks.

PubMed

Månsson, Johanna; Fellman, Vineta; Stjernqvist, Karin

2015-05-01

The early identification of at-risk extremely preterm (EPT) children could improve long-term outcomes. This study sought to investigate sex differences in developmental outcomes and to identify sex-specific predictors at two and a half years of age. We assessed 217 boys and 181 girls born before 27-week gestation using the Bayley Scales of Infant and Toddler Development, third edition (Bayley-III), as a part of the Extremely Preterm Infants in Sweden Study. Sex-specific differences were calculated. Socio-economic, birth and neonatal factors were calculated separately for boys and girls using regression models. Girls scored significantly higher than boys on all Bayley-III indices. In both sexes, brain injury, long-term ventilator treatment and foreign-born mothers predicted lower scores. Receiving breast milk by hospital discharge predicted higher scores. Severe retinopathy of prematurity was the strongest predictor of cognitive and language deficits in boys. High parental education predicted higher cognitive and language scores in girls, whereas severe bronchopulmonary dysplasia was the strongest predictor of motor deficits. Extreme prematurity seems to affect boys more than girls. Socio-economic and neonatal factors confer similar risks or protections on both sexes, but some variables pose sex-specific risks. An awareness of risk factors may provide the basis for treatment and follow-up guidelines. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Prenatal exposure to a common organophosphate insecticide delays motor development in a mouse model of idiopathic autism.

PubMed

De Felice, Alessia; Scattoni, Maria Luisa; Ricceri, Laura; Calamandrei, Gemma

2015-01-01

Autism spectrum disorders are characterized by impaired social and communicative skills and repetitive behaviors. Emerging evidence supported the hypothesis that these neurodevelopmental disorders may result from a combination of genetic susceptibility and exposure to environmental toxins in early developmental phases. This study assessed the effects of prenatal exposure to chlorpyrifos (CPF), a widely diffused organophosphate insecticide endowed with developmental neurotoxicity at sub-toxic doses, in the BTBR T+tf/J mouse strain, a validated model of idiopathic autism that displays several behavioral traits relevant to the autism spectrum. To this aim, pregnant BTBR mice were administered from gestational day 14 to 17 with either vehicle or CPF at a dose of 6 mg/kg/bw by oral gavages. Offspring of both sexes underwent assessment of early developmental milestones, including somatic growth, motor behavior and ultrasound vocalization. To evaluate the potential long-term effects of CPF, two different social behavior patterns typically altered in the BTBR strain (free social interaction with a same-sex companion in females, or interaction with a sexually receptive female in males) were also examined in the two sexes at adulthood. Our findings indicate significant effects of CPF on somatic growth and neonatal motor patterns. CPF treated pups showed reduced weight gain, delayed motor maturation (i.e., persistency of immature patterns such as pivoting at the expenses of coordinated locomotion) and a trend to enhanced ultrasound vocalization. At adulthood, CPF associated alterations were found in males only: the altered pattern of investigation of a sexual partner, previously described in BTBR mice, was enhanced in CPF males, and associated to increased ultrasonic vocalization rate. These findings strengthen the need of future studies to evaluate the role of environmental chemicals in the etiology of neurodevelopment disorders.

BISPHENOL A EXPOSURE DURING EARLY DEVELOPMENT INDUCES SEX-SPECIFIC CHANGES IN ADULT ZEBRAFISH SOCIAL INTERACTIONS

PubMed Central

Weber, Daniel N.; Hoffmann, Raymond G.; Hoke, Elizabeth S.; Tanguay, Robert L.

2014-01-01

Developmental bisphenol A (BPA) exposure is associated with adverse behavioral effects, although underlying modes of action remain unclear. Because BPA is a suspected xenoestrogen, the objective was to identify sex-based changes in adult zebrafish social behavior developmentally exposed to BPA (0.0, 0.1 or 1 μM) or one of two control compounds (0.1μM 17β-estradiol [E2], and 0.1 μM GSK4716, a synthetic estrogen-related receptor γ ligand). A test chamber was divided lengthwise so each arena held one fish unable to detect the presence of the other fish. A mirror was inserted at one end of each arena; baseline activity levels were determined without mirror. Arenas were divided into 3, computer-generated zones to represent different distances from mirror image. Circadian rhythm patterns were evaluated at 1–3 (= AM) and 5–8 (= PM) hr postprandial. Adult zebrafish were placed into arenas and monitored by digital camera for 5 min. Total distance traveled, % time spent at mirror image, and number of attacks on mirror image were quantified. E2, GSK4716, and all BPA treatments dampened male activity and altered male circadian activity patterns; there was no marked effect on female activity. BPA induced non-monotonic effects (response curve changes direction within range of concentrations examined) on male % time at mirror only in AM. All treatments produced increased % time at the mirror during PM. Male attacks on the mirror were reduced by BPA exposure only during AM. There were sex-specific effects of developmental BPA on social interactions and time-of-day of observation affected results. PMID:25424546

Developmental Trajectories of Sex-Typed Behavior in Boys and Girls: A Longitudinal General Population Study of Children Aged 2.5-8 Years

ERIC Educational Resources Information Center

Golombok, Susan; Rust, John; Zervoulis, Karyofyllis; Croudace, Tim; Golding, Jean; Hines, Melissa

2008-01-01

The stability of sex-typed behavior from the preschool to the middle school years was examined. The Preschool Activities Inventory, a measure of within-sex variation in sex-typed behavior, was completed by the primary caregiver when the child was 2.5, 3.5, and 5 years, and a modified version, the Child Activities Inventory, was completed by the…

Biological sex and the risk of cerebral palsy in Victoria, Australia.

PubMed

Reid, Susan M; Meehan, Elaine; Gibson, Catherine S; Scott, Heather; Delacy, Michael J

2016-02-01

Males typically outnumber females in cerebral palsy (CP) cohorts. To better understand this 'male disadvantage' and provide insight into causal pathways to CP, this study used 1983 to 2009 Australian CP and population birth cohorts to identify associations and trends with respect to biological sex and CP. Within birth gestation groups, sex ratios were calculated to evaluate any male excess in the CP cohort compared with livebirths, neonatal deaths, neonatal mortality and survival rates, neonatal survivors, and CP rates in survivors. Sex- and gestation-specific trends in neonatal mortality, CP rates, and CP sex ratios were assessed by plotting their annual frequencies and fitting quadratic curves. Over-representation of males in preterm live births partly explained the male excess in the CP cohort after preterm birth, especially at 28 to 31 weeks. Higher CP rates in male neonatal survivors also contributed to the male excess in CP, particularly at <28 and 37+ weeks. Higher neonatal mortality rates in males at all gestations had little impact on the CP sex ratio. There was no clearly discernible change over time in the CP sex ratio. Gestation-specific associations between sex and CP provide insight into causal pathways to CP and suggest sex-specific differences in response to neuroprotective strategies. © 2016 The Authors. Developmental Medicine & Child Neurology © 2016 Mac Keith Press.

Developmental changes in the facial morphology of the Borneo orangutan (Pongo pygmaeus): possible signals in visual communication.

PubMed

Kuze, Noko; Malim, Titol Peter; Kohshima, Shiro

2005-04-01

Orangutans display remarkable developmental changes and sexual differences in facial morphology, such as the flanges or cheek-pads that develop only on the face of dominant adult males. These changes suggest that facial morphology is an important factor in visual communication. However, developmental changes in facial morphology have not been examined in detail. We studied developmental changes in the facial morphology of the Borneo orangutan (Pongo pygmaeus) by observing 79 individuals of various ages living in the Sepilok Orangutan Rehabilitation Centre (SORC) in Malaysia and in Japanese zoos. We also analyzed photographs of one captive male that were taken over a period of more than 16 years. There were clear morphological changes that occurred with growth, and we identified previously unreported sexual and developmental differences in facial morphology. Light-colored skin around the eyes and mouth is most prominent in animals younger than 3 years, and rapidly decreases in area through the age of approximately 7 years. At the same time, the scattered, erect hairs on the head (infant hair) become thick, dense hairs lying on the head (adult hair) in both sexes. The results suggest that these features are infant signals, and that adult signals may include darkened face color, adult hair, whiskers, and a beard, which begin to develop after the age of approximately 7 years in both sexes. In females, the eyelids remain white even after 10 years, and turn black at around the age of 20; in males, the eyelids turn black before the age of 10. The whiskers and beards of adults are thicker in males than in females, and are fully developed before the age of 10 in males, while they begin to develop in females only after approximately 20 years. White eyelids and undeveloped whiskers and beards may be visual signals that are indicative of young adult females. Our results also show that the facial morphology of the unflanged male is similar to that of the adult female, although it has also been pointed out that unflanged males resemble younger individuals. Copyright 2005 Wiley-Liss, Inc

Trajectories of cognitive development during adolescence among youth at-risk for schizophrenia.

PubMed

Dickson, Hannah; Cullen, Alexis E; Jones, Rebecca; Reichenberg, Abraham; Roberts, Ruth E; Hodgins, Sheilagh; Morris, Robin G; Laurens, Kristin R

2018-04-23

Among adults with schizophrenia, evidence suggests that premorbid deficits in different cognitive domains follow distinct developmental courses during childhood and adolescence. The aim of this study was to delineate trajectories of adolescent cognitive functions prospectively among different groups of youth at-risk for schizophrenia, relative to their typically developing (TD) peers. Using linear mixed models adjusted for sex, ethnicity, parental occupation and practice effects, cognitive development between ages 9 and 16 years was compared for youth characterised by a triad of well-replicated developmental antecedents of schizophrenia (ASz; N = 32) and youth with a least one affected relative with schizophrenia or schizoaffective disorder (FHx; N = 29), relative to TD youth (N = 45). Participants completed measures of IQ, scholastic achievement, memory and executive function at three time-points, separated by approximately 24-month intervals. Compared to TD youth, both ASz and FHx youth displayed stable developmental deficits in verbal working memory and inhibition/switching executive functions. ASz youth additionally presented with stable deficits in measures of vocabulary (IQ), word reading, numerical operations, and category fluency executive function, and a slower rate of growth (developmental lag) on spelling from 9 to 16 years than TD peers. Conversely, faster rates of growth relative to TD peers (developmental delay) were observed on visual and verbal memory, and on category fluency executive function (ASz youth only) and on matrix reasoning (IQ) and word reading (FHx youth only). These differential patterns of deviation from normative adolescent cognitive development among at-risk youth imply potential for cognitive rehabilitation targeting of specific cognitive deficits at different developmental phases. © 2018 The Authors. Journal of Child Psychology and Psychiatry published by John Wiley & Sons Ltd on behalf of Association for Child and Adolescent Mental Health.

Testosterone-related cortical maturation across childhood and adolescence.

PubMed

Nguyen, Tuong-Vi; McCracken, James; Ducharme, Simon; Botteron, Kelly N; Mahabir, Megan; Johnson, Wendy; Israel, Mimi; Evans, Alan C; Karama, Sherif

2013-06-01

Neuroendocrine theories of brain development hold testosterone as the predominant factor mediating sex-specific cortical growth and the ensuing lateralization of hemispheric function. However, studies to date have focussed on prenatal testosterone rather than pubertal changes in testosterone. Yet, animal studies have shown a high density of androgen-sensitive receptors in multiple key cortical areas, and puberty is known to coincide with both a significant rise in testosterone and the emergence of behavioral sex differences, suggesting peripubertal influences of testosterone on brain development. Here, we used linear mixed models to examine sex-specific cortical maturation associated with changes in testosterone levels in a longitudinal sample of developmentally healthy children and adolescents. A significant "sex by age by testosterone" interaction on cortical thickness (CTh) involving widespread areas of the developing brain was found. Testosterone levels were associated with CTh changes in regions of the left hemisphere in males and of the right hemisphere in females. In both sexes, the relationship between testosterone and CTh varied across the age span. These findings show the association between testosterone and CTh to be complex, highly dynamic, and to vary, depending on sex and age; they also suggest sex-related hemispheric lateralization effects of testosterone in humans.

Sex differences in audiovisual discrimination learning by Bengalese finches (Lonchura striata var. domestica).

PubMed

Seki, Yoshimasa; Okanoya, Kazuo

2008-02-01

Both visual and auditory information are important for songbirds, especially in developmental and sexual contexts. To investigate bimodal cognition in songbirds, the authors conducted audiovisual discrimination training in Bengalese finches. The authors used two types of stimulus: an "artificial stimulus," which is a combination of simple figures and sound, and a "biological stimulus," consisting of video images of singing males along with their songs. The authors found that while both sexes predominantly used visual cues in the discrimination tasks, males tended to be more dependent on auditory information for the biological stimulus. Female responses were always dependent on the visual stimulus for both stimulus types. Only males changed their discrimination strategy according to stimulus type. Although males used both visual and auditory cues for the biological stimulus, they responded to the artificial stimulus depending only on visual information, as the females did. These findings suggest a sex difference in innate auditory sensitivity. (c) 2008 APA.

Mapping temporal dynamics in social interactions with unified structural equation modeling: A description and demonstration revealing time-dependent sex differences in play behavior

PubMed Central

Beltz, Adriene M.; Beekman, Charles; Molenaar, Peter C. M.; Buss, Kristin A.

2013-01-01

Developmental science is rich with observations of social interactions, but few available methodological and statistical approaches take full advantage of the information provided by these data. The authors propose implementation of the unified structural equation model (uSEM), a network analysis technique, for observational data coded repeatedly across time; uSEM captures the temporal dynamics underlying changes in behavior at the individual level by revealing the ways in which a single person influences – concurrently and in the future – other people. To demonstrate the utility of uSEM, the authors applied it to ratings of positive affect and vigor of activity during children’s unstructured laboratory play with unfamiliar, same-sex peers. Results revealed the time-dependent nature of sex differences in play behavior. For girls more than boys, positive affect was dependent upon peers’ prior positive affect. For boys more than girls, vigor of activity was dependent upon peers’ current vigor of activity. PMID:24039386

Neuroimmune mechanisms of stress: sex differences, developmental plasticity, and implications for pharmacotherapy of stress-related disease

PubMed Central

Deak, Terrence; Quinn, Matt; Cidlowski, John A.; Victoria, Nicole C.; Murphy, Anne Z.; Sheridan, John F.

2016-01-01

The last decade has witnessed profound growth in studies examining the role of fundamental neuroimmune processes as key mechanisms that might form a natural bridge between normal physiology and pathological outcomes. Rooted in core concepts from psychoneuroimmunology, this review utilizes a succinct, exemplar-driven approach of several model systems that contribute significantly to our knowledge of the mechanisms by which neuroimmune processes interact with stress physiology. Specifically, we review recent evidence showing that (i) stress challenges produce time-dependent and stressor-specific patterns of cytokine/chemokine expression in the CNS; (ii) inflammation-related genes exhibit unique expression profiles in males and females depending upon individual, cooperative, or antagonistic interactions between steroid hormone receptors (Estrogen and Glucocorticoid receptors); (iii) adverse social experiences incurred through repeated social defeat engage a dynamic process of immune cell migration from the bone marrow to brain and prime neuroimmune function; and (iv) early developmental exposure to an inflammatory stimulus (carageenin injection into the hindpaw) has a lasting influence on stress reactivity across the lifespan. As such, the present review provides a theoretical framework for understanding the role that neuroimmune mechanisms might play in stress plasticity and pathological outcomes, while at the same time pointing toward features of the individual (sex, developmental experience, stress history) that might ultimately be used for the development of personalized strategies for therapeutic intervention in stress-related pathologies. PMID:26176590

Neuroimmune mechanisms of stress: sex differences, developmental plasticity, and implications for pharmacotherapy of stress-related disease.

PubMed

Deak, Terrence; Quinn, Matt; Cidlowski, John A; Victoria, Nicole C; Murphy, Anne Z; Sheridan, John F

2015-01-01

The last decade has witnessed profound growth in studies examining the role of fundamental neuroimmune processes as key mechanisms that might form a natural bridge between normal physiology and pathological outcomes. Rooted in core concepts from psychoneuroimmunology, this review utilizes a succinct, exemplar-driven approach of several model systems that contribute significantly to our knowledge of the mechanisms by which neuroimmune processes interact with stress physiology. Specifically, we review recent evidence showing that (i) stress challenges produce time-dependent and stressor-specific patterns of cytokine/chemokine expression in the CNS; (ii) inflammation-related genes exhibit unique expression profiles in males and females depending upon individual, cooperative or antagonistic interactions between steroid hormone receptors (estrogen and glucocorticoid receptors); (iii) adverse social experiences incurred through repeated social defeat engage a dynamic process of immune cell migration from the bone marrow to brain and prime neuroimmune function and (iv) early developmental exposure to an inflammatory stimulus (carageenin injection into the hindpaw) has a lasting influence on stress reactivity across the lifespan. As such, the present review provides a theoretical framework for understanding the role that neuroimmune mechanisms might play in stress plasticity and pathological outcomes, while at the same time pointing toward features of the individual (sex, developmental experience, stress history) that might ultimately be used for the development of personalized strategies for therapeutic intervention in stress-related pathologies.

Genetic identification of female Cannabis sativa plants at early developmental stage.

PubMed

Techen, Natascha; Chandra, Suman; Lata, Hemant; Elsohly, Mahmoud A; Khan, Ikhlas A

2010-11-01

Sequence-characterized amplified region (SCAR) markers were used to identify female plants at an early developmental stage in four different varieties of Cannabis sativa. Using the cetyl trimethylammonium bromide (CTAB) method, DNA was isolated from two-week-old plants of three drug-type varieties (Terbag W1, Terbag K2, and Terbag MX) and one fiber-type variety (Terbag Fedora A7) of C. sativa grown under controlled environmental conditions through seeds. Attempts to use MADC2 (male-associated DNA from Cannabis sativa) primers as a marker to identify the sex of Cannabis sativa plants were successful. Amplification of genomic DNA using MADC2-F and MADC2-R primers produced two distinct fragments, one with a size of approximately 450 bp for female plants and one for male plants with a size of approximately 300 bp. After harvesting the tissues for DNA extraction, plants were subjected to a flowering photoperiod (i.e., 12-h light cycle), and the appearance of flowers was compared with the DNA analysis. The results of the molecular analysis were found to be concordant with the appearance of male or female flowers. The results of this study represent a quick and reliable technique for the identification of sex in Cannabis plants using SCAR markers at a very early developmental stage. © Georg Thieme Verlag KG Stuttgart · New York.

Gender Constancy and the Effects of Sex-typed Televised Toy Commercials.

ERIC Educational Resources Information Center

Ruble, Diane N.; And Others

1981-01-01

Presents a cognitive-developmental analysis of the effects of televised, sex-stereotypic information on children's behavior and attitudes towards toy play. Subjects were 100 children, ages four to six divided into groups exhibiting high and low gender-constancy. (Author/CM)

Whither Sex Education? Excellence in Comprehensive Program Development.

ERIC Educational Resources Information Center

Southern, Stephen

A review of recent sex education literature is presented in an attempt to integrate observations and recommendations related to both program development and innovation acceptance. A Developmental Research and Utilization Model is employed to systematically guide planning, implementation, evaluation, advocacy, and institutionalization. Curriculum…

Examining the Development and Sexual Behavior of Adolescent Males

PubMed Central

Ott, Mary A.

2010-01-01

A careful examination of young men's sexuality by health professionals in pediatrics, primary care and reproductive health is foundational to adolescent male sexual health and healthy development. Through a review of existing literature, this article provides background and a developmental framework for sexual health services for adolescent boys. The article first defines and provides an overview of adolescent boys’ sexual health, and then discusses developmentally focused research on the following topics: (1) early romantic relationships and the evolution of power and influence within these relationships; (2) developmental “readiness” for sex and curiosity; (3) boys’ need for closeness and intimacy; (4) adopting codes of masculinity; (5) boys’ communicating about sex; and (6) contextual influences from peers, families, and providers. This article concludes by examining the implications of these data for sexual health promotion efforts for adolescent males, including HPV vaccination. PMID:20307842

Examining the development and sexual behavior of adolescent males.

PubMed

Ott, Mary A

2010-04-01

A careful examination of young men's sexuality by health professionals in pediatrics, primary care, and reproductive health is foundational to adolescent male sexual health and healthy development. Through a review of existing published data, this article provides background and a developmental framework for sexual health services for adolescent boys. The article first defines and provides an overview of adolescent boys' sexual health, and then discusses developmentally focused research on the following topics: (1) early romantic relationships and the evolution of power and influence within these relationships; (2) developmental "readiness" for sex and curiosity; (3) boys' need for closeness and intimacy; (4) adopting codes of masculinity; (5) boys' communicating about sex; and (6) contextual influences from peers, families, and providers. This article concludes by examining the implications of these data for sexual health promotion efforts for adolescent males, including human papillomavirus vaccination.

Overcoming Barriers to the Sexual Expression of Women with Developmental Disabilities.

ERIC Educational Resources Information Center

Stinson, Jennifer; Christian, LeeAnn; Dotson, Lori Ann

2002-01-01

This article discusses barriers to sexual fulfillment faced by women with developmental disabilities, including: access to gynecological healthcare, limited choices regarding reproductive issues, lack of sex education, and prevailing negative stereotypes that affect the way women are viewed by others and the way they view themselves.…

The Effects of Feminist Scholarship on Developmental Psychology.

ERIC Educational Resources Information Center

Jacklin, Carol Nagy; McBride-Chang, Catherine

1991-01-01

Feminism has helped shape developmental psychology, and feminist scholarship has made its primary contributions to the study of child development in the following major areas: (1) weakening the "male as norm" concept; (2) changing "mother blaming" for children's problems; and (3) theory and research on sex role socialization.…

Gonad development in Midas cichlids and the evolution of sex change in fishes.

PubMed

Oldfield, Ronald G

2011-01-01

Some fishes mature and function as one sex and later transform to the other sex in response to social interactions. Previous evidence suggested that a change in developmental timing may be involved in the evolution of adult sex change in fishes. The most recent support for this idea came from reports that sex in the Midas cichlid, Amphilophus citrinellus, was determined by social conditions experienced at the juvenile stage. Differentiation as a male was reported to be dependent on large body size relative to group-mates, and thought to be mediated through aggressive interactions. Here I demonstrate that socially controlled sex determination does not occur as was originally reported. Previously, I found that sex was not associated with body size in juveniles either in nature or in captivity. Similarly, I found no association between aggressive behavior and sex in juveniles. I later demonstrated that socially controlled sex determination does not typically occur in the Midas cichlid and closely related species and supported an alternative mechanism to explain large body size in adult males. Finally, in the current study I analyze gonad histology of fish from the same population used by the original authors and lay to rest the idea of socially controlled sex determination in this species. Recent observations of socially controlled sex determination in juveniles of species that typically change sex at the adult stage are examples of phenotypic plasticity, not genetic variation. Therefore, juvenile socially controlled sex determination does not support a theory that a change in developmental timing is involved in the evolution of adult sex change in fishes. © 2011 Wiley Periodicals, Inc.

Cranium asymmetry in a modern Greek population sample of known age and sex.

PubMed

Chovalopoulou, Maria-Eleni; Papageorgopoulou, Christina; Bertsatos, Andreas

2017-05-01

The aim of this paper is to evaluate and quantify cranium asymmetry, sexual differences in the set of individual asymmetry scores, and the relationship between fluctuating asymmetry and age, in a modern Greek population sample. In addition, we test for the developmental origins of health and disease hypothesis by assessing the correlation between fluctuating asymmetry and cause of death. The study sample consisted of 173 crania of known sex and adult age (92 males, 81 females) belonging to individuals who lived in Greece during the twentieth century. The three-dimensional coordinates of 77 ectocranial landmarks were digitized using a Microscribe 3DX contact digitizer and landmark configurations were analyzed using the generalized least-squares Procrustes method. Regarding directional asymmetry, the results show that the human skull has a tendency for a left-side excess for the Greek population. No significant directional asymmetry differences between the sexes are found. The highest levels of fluctuating asymmetry for both sexes are located on the skull base. The levels of fluctuating asymmetry in all cranial regions appear higher for males than females. Nevertheless, these differences do not present any statistical significance between sexes. Additionally, there is no relationship between fluctuating asymmetry scores and age for both males and females. Finally, the results of this study could not confirm that early development has a significant impact on adult health outcomes.

Pathways From Depressive Symptoms to Low Social Status

PubMed Central

Agoston, Anna M.; Rudolph, Karen D.

2012-01-01

This research examined two pathways through which depressive symptoms contribute to low social status (i.e., neglect and rejection) within the peer group over time: (a) depressive symptoms promote socially helpless behavior and consequent neglect by peers; and (b) depressive symptoms promote aggressive behavior and consequent rejection by peers. These pathways were investigated in independent samples of youth at two developmental stages: middle childhood (2nd – 4th grade) and early adolescence (5th – 7th grade). In both Study 1 (M age = 7.97, SD = .37; 338 girls, 298 boys) and Study 2 (M age = 11.74, SD = .68; 305 girls, 300 boys), youth and their teachers completed questionnaires at three waves. Multi-group comparison path analyses were conducted to examine sex differences in the models. Consistent with expectations, two pathways emerged through which depressive symptoms undermined subsequent social status. Support was not found for the reverse direction of effect nor for developmental or sex differences in the pathways with one exception: In early adolescence, neglect directly predicted depressive symptoms. These findings suggest specificity but also heterogeneity in the effects of depressive symptoms on social status, and identify behaviors that may be targeted for preventing the persistence of depression and its interpersonal consequences. PMID:22945342

Pathways from depressive symptoms to low social status.

PubMed

Agoston, Anna M; Rudolph, Karen D

2013-02-01

This research examined two pathways through which depressive symptoms contribute to low social status (i.e., neglect and rejection) within the peer group over time: (a) depressive symptoms promote socially helpless behavior and consequent neglect by peers; and (b) depressive symptoms promote aggressive behavior and consequent rejection by peers. These pathways were investigated in independent samples of youth at two developmental stages: middle childhood (2nd-4th grade) and early adolescence (5th-7th grade). In both Study 1 (M age = 7.97, SD = 0.37; 338 girls, 298 boys) and Study 2 (M age = 11.74, SD = 0.68; 305 girls, 300 boys), youth and their teachers completed questionnaires at three waves. Multi-group comparison path analyses were conducted to examine sex differences in the models. Consistent with expectations, two pathways emerged through which depressive symptoms undermined subsequent social status. Support was not found for the reverse direction of effect nor for developmental or sex differences in the pathways with one exception: In early adolescence, neglect directly predicted depressive symptoms. These findings suggest specificity but also heterogeneity in the effects of depressive symptoms on social status, and identify behaviors that may be targeted for preventing the persistence of depression and its interpersonal consequences.

Androgens trigger different growth responses in genetically identical human hair follicles in organ culture that reflect their epigenetic diversity in life.

PubMed

Miranda, Benjamin H; Charlesworth, Matthew R; Tobin, Desmond J; Sharpe, David T; Randall, Valerie A

2018-02-01

Male sex hormones-androgens-regulate male physique development. Without androgen signaling, genetic males appear female. During puberty, increasing androgens harness the hair follicle's unique regenerative ability to replace many tiny vellus hairs with larger, darker terminal hairs ( e.g., beard). Follicle response is epigenetically varied: some remain unaffected ( e.g., eyelashes) or are inhibited, causing balding. How sex steroid hormones alter such developmental processes is unclear, despite high incidences of hormone-driven cancer, hirsutism, and alopecia. Unfortunately, existing development models are not androgen sensitive. Here, we use hair follicles to establish an androgen-responsive human organ culture model. We show that women's intermediate facial follicles respond to men's higher androgen levels by synthesizing more hair over several days, unlike donor-matched, androgen-insensitive, terminal follicles. We demonstrate that androgen receptors-androgen-activated gene transcription regulators-are required and are present in vivo within these follicles. This is the first human organ that involves multiple cell types that responds appropriately to hormones in prolonged culture, in a way which mirrors its natural behavior. Thus, intermediate hair follicles offer a hormone-switchable human model with exceptional, unique availability of genetically identical, but epigenetically hormone-insensitive, terminal follicles. This should enable advances in understanding sex steroid hormone signaling, gene regulation, and developmental and regenerative systems and facilitate better therapies for hormone-dependent disorders.-Miranda, B. H., Charlesworth, M. R., Tobin, D. J., Sharpe, D. T., Randall, V. A. Androgens trigger different growth responses in genetically identical human hair follicles in organ culture that reflect their epigenetic diversity in life.

Developmental programming of energy balance regulation: is physical activity more 'programmable' than food intake?

PubMed

Zhu, Shaoyu; Eclarinal, Jesse; Baker, Maria S; Li, Ge; Waterland, Robert A

2016-02-01

Extensive human and animal model data show that environmental influences during critical periods of prenatal and early postnatal development can cause persistent alterations in energy balance regulation. Although a potentially important factor in the worldwide obesity epidemic, the fundamental mechanisms underlying such developmental programming of energy balance are poorly understood, limiting our ability to intervene. Most studies of developmental programming of energy balance have focused on persistent alterations in the regulation of energy intake; energy expenditure has been relatively underemphasised. In particular, very few studies have evaluated developmental programming of physical activity. The aim of this review is to summarise recent evidence that early environment may have a profound impact on establishment of individual propensity for physical activity. Recently, we characterised two different mouse models of developmental programming of obesity; one models fetal growth restriction followed by catch-up growth, and the other models early postnatal overnutrition. In both studies, we observed alterations in body-weight regulation that persisted to adulthood, but no group differences in food intake. Rather, in both cases, programming of energy balance appeared to be due to persistent alterations in energy expenditure and spontaneous physical activity (SPA). These effects were stronger in female offspring. We are currently exploring the hypothesis that developmental programming of SPA occurs via induced sex-specific alterations in epigenetic regulation in the hypothalamus and other regions of the central nervous system. We will summarise the current progress towards testing this hypothesis. Early environmental influences on establishment of physical activity are likely an important factor in developmental programming of energy balance. Understanding the fundamental underlying mechanisms in appropriate animal models will help determine whether early life interventions may be a practical approach to promote physical activity in man.

Developmental trajectories of children's symbolic numerical magnitude processing skills and associated cognitive competencies.

PubMed

Vanbinst, Kiran; Ceulemans, Eva; Peters, Lien; Ghesquière, Pol; De Smedt, Bert

2018-02-01

Although symbolic numerical magnitude processing skills are key for learning arithmetic, their developmental trajectories remain unknown. Therefore, we delineated during the first 3years of primary education (5-8years of age) groups with distinguishable developmental trajectories of symbolic numerical magnitude processing skills using a model-based clustering approach. Three clusters were identified and were labeled as inaccurate, accurate but slow, and accurate and fast. The clusters did not differ in age, sex, socioeconomic status, or IQ. We also tested whether these clusters differed in domain-specific (nonsymbolic magnitude processing and digit identification) and domain-general (visuospatial short-term memory, verbal working memory, and processing speed) cognitive competencies that might contribute to children's ability to (efficiently) process the numerical meaning of Arabic numerical symbols. We observed minor differences between clusters in these cognitive competencies except for verbal working memory for which no differences were observed. Follow-up analyses further revealed that the above-mentioned cognitive competencies did not merely account for the cluster differences in children's development of symbolic numerical magnitude processing skills, suggesting that other factors account for these individual differences. On the other hand, the three trajectories of symbolic numerical magnitude processing revealed remarkable and stable differences in children's arithmetic fact retrieval, which stresses the importance of symbolic numerical magnitude processing for learning arithmetic. Copyright © 2017 Elsevier Inc. All rights reserved.

Transcriptome Profile Analysis from Different Sex Types of Ginkgo biloba L.

PubMed

Du, Shuhui; Sang, Yalin; Liu, Xiaojing; Xing, Shiyan; Li, Jihong; Tang, Haixia; Sun, Limin

2016-01-01

In plants, sex determination is a comprehensive process of correlated events, which involves genes that are differentially and/or specifically expressed in distinct developmental phases. Exploring gene expression profiles from different sex types will contribute to fully understanding sex determination in plants. In this study, we conducted RNA-sequencing of female and male buds (FB and MB) as well as ovulate strobilus and staminate strobilus (OS and SS) of Ginkgo biloba to gain insights into the genes potentially related to sex determination in this species. Approximately 60 Gb of clean reads were obtained from eight cDNA libraries. De novo assembly of the clean reads generated 108,307 unigenes with an average length of 796 bp. Among these unigenes, 51,953 (47.97%) had at least one significant match with a gene sequence in the public databases searched. A total of 4709 and 9802 differentially expressed genes (DEGs) were identified in MB vs. FB and SS vs. OS, respectively. Genes involved in plant hormone signal and transduction as well as those encoding DNA methyltransferase were found to be differentially expressed between different sex types. Their potential roles in sex determination of G. biloba were discussed. Pistil-related genes were expressed in male buds while anther-specific genes were identified in female buds, suggesting that dioecism in G. biloba was resulted from the selective arrest of reproductive primordia. High correlation of expression level was found between the RNA-Seq and quantitative real-time PCR results. The transcriptome resources that we generated allowed us to characterize gene expression profiles and examine differential expression profiles, which provided foundations for identifying functional genes associated with sex determination in G. biloba.

Transcriptome Profile Analysis from Different Sex Types of Ginkgo biloba L.

PubMed Central

Du, Shuhui; Sang, Yalin; Liu, Xiaojing; Xing, Shiyan; Li, Jihong; Tang, Haixia; Sun, Limin

2016-01-01

In plants, sex determination is a comprehensive process of correlated events, which involves genes that are differentially and/or specifically expressed in distinct developmental phases. Exploring gene expression profiles from different sex types will contribute to fully understanding sex determination in plants. In this study, we conducted RNA-sequencing of female and male buds (FB and MB) as well as ovulate strobilus and staminate strobilus (OS and SS) of Ginkgo biloba to gain insights into the genes potentially related to sex determination in this species. Approximately 60 Gb of clean reads were obtained from eight cDNA libraries. De novo assembly of the clean reads generated 108,307 unigenes with an average length of 796 bp. Among these unigenes, 51,953 (47.97%) had at least one significant match with a gene sequence in the public databases searched. A total of 4709 and 9802 differentially expressed genes (DEGs) were identified in MB vs. FB and SS vs. OS, respectively. Genes involved in plant hormone signal and transduction as well as those encoding DNA methyltransferase were found to be differentially expressed between different sex types. Their potential roles in sex determination of G. biloba were discussed. Pistil-related genes were expressed in male buds while anther-specific genes were identified in female buds, suggesting that dioecism in G. biloba was resulted from the selective arrest of reproductive primordia. High correlation of expression level was found between the RNA-Seq and quantitative real-time PCR results. The transcriptome resources that we generated allowed us to characterize gene expression profiles and examine differential expression profiles, which provided foundations for identifying functional genes associated with sex determination in G. biloba. PMID:27379148

X chromosome regulation: diverse patterns in development, tissues and disease

PubMed Central

Deng, Xinxian; Berletch, Joel B.; Nguyen, Di K.; Disteche, Christine M.

2014-01-01

Genes on the mammalian X chromosome are present in one copy in males and two copies in females. The complex mechanisms that regulate the X chromosome lead to evolutionary and physiological variability in gene expression between species, the sexes, individuals, developmental stages, tissues and cell types. In early development, delayed and incomplete X chromosome inactivation (XCI) in some species causes variability in gene expression. Additional diversity stems from escape from XCI and from mosaicism or XCI skewing in females. This causes sex-specific differences that manifest as differential gene expression and associated phenotypes. Furthermore, the complexity and diversity of X dosage regulation affect the severity of diseases caused by X-linked mutations. PMID:24733023

Age- and sex-related emotional and behavioral problems in children with autism spectrum disorders: comparison with control children.

PubMed

Horiuchi, Fumie; Oka, Yasunori; Uno, Hiroyuki; Kawabe, Kentaro; Okada, Fumi; Saito, Isao; Tanigawa, Takeshi; Ueno, Shu-ichi

2014-07-01

Children with autism spectrum disorders (ASD) often present with emotional and behavioral problems, which could change the clinical course, especially during childhood, and affect future quality of life. The aim of this study was to clarify the age- and sex-related differences of these problems in ASD. The study subjects were 173 patients with ASD (age: 4-16 years) and 173 age- and sex-matched community children (control group). The parent version of the Strengths and Difficulties Questionnaire was used for comparison of the emotional and behavioral problems between the two groups. The Strengths and Difficulties Questionnaire scores were significantly higher in children with ASD than controls at all ages. The score of total difficulties was significantly higher in girls with ASD than in boys, while the score in male controls was significantly higher than in female controls. Age-related differences in emotional and behavioral problems were observed both in children with ASD and controls, but the characteristics were different: in children with ASD, emotional symptoms and peer problems in both sexes and conduct problems in girls increased significantly with age, while none of the problems in the controls changed with age except for a decrease in the score of hyperactivity/inattention developmentally in both sexes. Prosocial behaviors of children with ASD and controls showed small changes with age. Emotional and behavioral problems are common in children with ASD and showed age- and sex-related differences. Our study emphasizes the importance of recognizing those differences among children with ASD for early intervention. © 2014 The Authors. Psychiatry and Clinical Neurosciences © 2014 Japanese Society of Psychiatry and Neurology.

Impacts of stress and sex hormones on dopamine neurotransmission in the adolescent brain.

PubMed

Sinclair, Duncan; Purves-Tyson, Tertia D; Allen, Katherine M; Weickert, Cynthia Shannon

2014-04-01

Adolescence is a developmental period of complex neurobiological change and heightened vulnerability to psychiatric illness. As a result, understanding factors such as sex and stress hormones which drive brain changes in adolescence, and how these factors may influence key neurotransmitter systems implicated in psychiatric illness, is paramount. In this review, we outline the impact of sex and stress hormones at adolescence on dopamine neurotransmission, a signaling pathway which is critical to healthy brain function and has been implicated in psychiatric illness. We review normative developmental changes in dopamine, sex hormone, and stress hormone signaling during adolescence and throughout postnatal life, then highlight the interaction of sex and stress hormones and review their impacts on dopamine neurotransmission in the adolescent brain. Adolescence is a time of increased responsiveness to sex and stress hormones, during which the maturing dopaminergic neural circuitry is profoundly influenced by these factors. Testosterone, estrogen, and glucocorticoids interact with each other and have distinct, brain region-specific impacts on dopamine neurotransmission in the adolescent brain, shaping brain maturation and cognitive function in adolescence and adulthood. Some effects of stress/sex hormones on cortical and subcortical dopamine parameters bear similarities with dopaminergic abnormalities seen in schizophrenia, suggesting a possible role for sex/stress hormones at adolescence in influencing risk for psychiatric illness via modulation of dopamine neurotransmission. Stress and sex hormones may prove useful targets in future strategies for modifying risk for psychiatric illness.

Assessment of upper-limb capacity, performance, and developmental disregard in children with cerebral palsy: validity and reliability of the revised Video-Observation Aarts and Aarts module: Determine Developmental Disregard (VOAA-DDD-R).

PubMed

Houwink, Annemieke; Geerdink, Yvonne A; Steenbergen, Bert; Geurts, Alexander C H; Aarts, Pauline B M

2013-01-01

To investigate the validity and reliability of the revised Video-Observation Aarts and Aarts module: Determine Developmental Disregard (VOAA-DDD-R). Upper-limb capacity and performance were assessed in children with unilateral spastic cerebral palsy (CP) by measuring overall duration of affected upper-limb use and the frequency of specific behaviours during a task in which bimanual activity was demanded ('stringing beads') and stimulated ('decorating a muffin'). Developmental disregard was defined as the difference in duration of affected upper-limb use between both tasks. Raters were two occupational and one physical therapist who received 3 hours of training. Construct validity was determined by comparing children with CP with typically developing children. Intrarater, interrater, and test-retest reliability were determined using the intraclass correlation coefficient. Standard errors of measurement and smallest detectable differences were also calculated. Twenty-five children with CP (15 females, 10 males; mean age 4 y 9 mo [SD 1 y 7 mo], range 2 y 9 mo-8 y; Manual Ability Classification System levels I-III) scored lower on capacity (p=0.052) and performance (p<0.001), and higher on developmental disregard (p<0.001) than 46 age- and sex-matched typically developing children (23 males; mean age 5 y 3 mo [SD 1 y 5 mo], range 2 y 6 mo-8 y). The intraclass correlation coefficients (0.79-1.00) indicated good reliability. Absolute agreement was high, standard errors of measurement ranged from 4.5 to 6.8%, and smallest detectable differences ranged from 12.5 to 19.0%. The VOAA-DDD-R can be reliably and validly used by occupational and physical therapists to assess upper-limb capacity, performance, and developmental disregard in children (2 y 6 mo-8 y) with CP. © The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.

Overweight and Obesity among Children with Developmental Disabilities

ERIC Educational Resources Information Center

De, Sukanya; Small, Jacqueline; Baur, Louise A.

2008-01-01

Background: The aim of this study was to determine the prevalence of overweight and obesity in children with developmental disabilities attending a metropolitan Diagnosis and Assessment Service. Method: A retrospective chart review was carried out for 98 children (67 male) aged 2-18 years. Data on age, sex, weight, height, and severity of…

Cognitive Intervention in the Normal Developmental Problems of Young Adults

ERIC Educational Resources Information Center

Wilson, Stephen B.

1978-01-01

The common developmental problems of young adults--career focus, sex confidence, clarification of beliefs, and separation from parents--provide themes of interest to young adults. Using these themes and the human tendency to problem solve, specific information can be given to improve personal problem-solving skills without psychological games.…

Environmental factors, epigenetics, and developmental origin of reproductive disorders.

PubMed

Ho, Shuk-Mei; Cheong, Ana; Adgent, Margaret A; Veevers, Jennifer; Suen, Alisa A; Tam, Neville N C; Leung, Yuet-Kin; Jefferson, Wendy N; Williams, Carmen J

2017-03-01

Sex-specific differentiation, development, and function of the reproductive system are largely dependent on steroid hormones. For this reason, developmental exposure to estrogenic and anti-androgenic endocrine disrupting chemicals (EDCs) is associated with reproductive dysfunction in adulthood. Human data in support of "Developmental Origins of Health and Disease" (DOHaD) comes from multigenerational studies on offspring of diethylstilbestrol-exposed mothers/grandmothers. Animal data indicate that ovarian reserve, female cycling, adult uterine abnormalities, sperm quality, prostate disease, and mating behavior are susceptible to DOHaD effects induced by EDCs such as bisphenol A, genistein, diethylstilbestrol, p,p'-dichlorodiphenyl-dichloroethylene, phthalates, and polyaromatic hydrocarbons. Mechanisms underlying these EDC effects include direct mimicry of sex steroids or morphogens and interference with epigenomic sculpting during cell and tissue differentiation. Exposure to EDCs is associated with abnormal DNA methylation and other epigenetic modifications, as well as altered expression of genes important for development and function of reproductive tissues. Here we review the literature exploring the connections between developmental exposure to EDCs and adult reproductive dysfunction, and the mechanisms underlying these effects. Copyright © 2016 Elsevier Inc. All rights reserved.

Phenotypic plasticity in sex pheromone production in Bicyclus anynana butterflies.

PubMed

Dion, Emilie; Monteiro, Antónia; Yew, Joanne Y

2016-12-14

Phenotypic plasticity refers to the environmental control of phenotypes. Cues experienced during development (developmental plasticity) or during adulthood (acclimatization) can both affect adult phenotypes. Phenotypic plasticity has been described in many traits but examples of developmental plasticity in physiological traits, in particular, remain scarce. We examined developmental plasticity and acclimatization in pheromone production in the butterfly Bicyclus anynana in response to rearing temperature. B. anynana lives in the African tropics where warm rearing temperatures of the wet season produce active males that court and females that choose, whereas cooler temperatures of the dry season lead to choosy less active males and courting females. We hypothesized that if male pheromone production is costly, it should be reduced in the dry season form. After describing the ultrastructure of pheromone producing cells, we showed that dry season males produced significantly less sex pheromones than wet season males, partly due to acclimatization and partly due to developmental plasticity. Variation in levels of one of the compounds is associated with differential regulation of a pheromone biosynthetic enzyme gene. This plasticity might be an adaptation to minimize pheromone production costs during the stressful dry season.

Environmental Factors, Epigenetics, and Developmental Origin of Reproductive Disorders

PubMed Central

Ho, Shuk-Mei; Cheong, Ana; Adgent, Margaret A.; Veevers, Jennifer; Suen, Alisa A.; Tam, Neville N.C.; Leung, Yuet-Kin; Jefferson, Wendy N.; Williams, Carmen J.

2016-01-01

Sex-specific differentiation, development, and function of the reproductive system are largely dependent on steroid hormones. For this reason, developmental exposure to estrogenic and anti-androgenic endocrine disrupting chemicals (EDCs) is associated with reproductive dysfunction in adulthood. Human data in support of “Developmental Origins of Health and Disease” (DOHaD) comes from multigenerational studies on offspring of diethylstilbestrol-exposed mothers/grandmothers. Animal data indicate that ovarian reserve, female cycling, adult uterine abnormalities, sperm quality, prostate disease, and mating behavior are susceptible to DOHaD effects induced by EDCs such as bisphenol A, genistein, diethylstilbestrol, p,p′-dichlorodiphenyl-dichloroethylene, phthalates, and polyaromatic hydrocarbons. Mechanisms underlying these EDC effects include direct mimicry of sex steroids or morphogens and interference with epigenomic sculpting during cell and tissue differentiation. Exposure to EDCs is associated with abnormal DNA methylation and other epigenetic modifications, as well as altered expression of genes important for development and function of reproductive tissues. Here we review the literature exploring the connections between developmental exposure to EDCs and adult reproductive dysfunction, and the mechanisms underlying these effects. PMID:27421580

Sex Differences in Ethanol's Anxiolytic Effect and Chronic Ethanol Withdrawal Severity in Mice with a Null Mutation of the 5α-Reductase Type 1 Gene.

PubMed

Tanchuck-Nipper, Michelle A; Ford, Matthew M; Hertzberg, Anna; Beadles-Bohling, Amy; Cozzoli, Debra K; Finn, Deborah A

2015-05-01

Manipulation of endogenous levels of the GABAergic neurosteroid allopregnanolone alters sensitivity to some effects of ethanol. Chronic ethanol withdrawal decreases activity and expression of 5α-reductase-1, an important enzyme in allopregnanolone biosynthesis encoded by the 5α-reductase-1 gene (Srd5a1). The present studies examined the impact of Srd5a1 deletion in male and female mice on several acute effects of ethanol and on chronic ethanol withdrawal severity. Genotype and sex did not differentially alter ethanol-induced hypothermia, ataxia, hypnosis, or metabolism, but ethanol withdrawal was significantly lower in female versus male mice. On the elevated plus maze, deletion of the Srd5a1 gene significantly decreased ethanol's effect on total entries versus wildtype (WT) mice and significantly decreased ethanol's anxiolytic effect in female knockout (KO) versus WT mice. The limited sex differences in the ability of Srd5a1 genotype to modulate select ethanol effects may reflect an interaction between developmental compensations to deletion of the Srd5a1 gene with sex hormones and levels of endogenous neurosteroids.

Sex Differences in Ethanol’s Anxiolytic Effect and Chronic Ethanol Withdrawal Severity in Mice With a Null Mutation of the 5α-Reductase Type 1 Gene

PubMed Central

Tanchuck-Nipper, Michelle A.; Ford, Matthew M.; Hertzberg, Anna; Beadles-Bohling, Amy; Cozzoli, Debra K.; Finn, Deborah A.

2015-01-01

Manipulation of endogenous levels of the GABAergic neurosteroid allopregnanolone alters sensitivity to some effects of ethanol. Chronic ethanol withdrawal decreases activity and expression of 5α-reductase-1, an important enzyme in allopregnanolone biosynthesis encoded by the 5α-reductase-1 gene (Srd5a1). The present studies examined the impact of Srd5a1 deletion in male and female mice on several acute effects of ethanol and on chronic ethanol withdrawal severity. Genotype and sex did not differentially alter ethanol-induced hypothermia, ataxia, hypnosis, or metabolism, but ethanol withdrawal was significantly lower in female versus male mice. On the elevated plus maze, deletion of the Srd5a1 gene significantly decreased ethanol’s effect on total entries versus wildtype (WT) mice and significantly decreased ethanol’s anxiolytic effect in female knockout (KO) versus WT mice. The limited sex differences in the ability of Srd5a1 genotype to modulate select ethanol effects may reflect an interaction between developmental compensations to deletion of the Srd5a1 gene with sex hormones and levels of endogenous neurosteroids. PMID:25355320

Sex, Glia, and Development: interactions in health and disease

PubMed Central

Schwarz, Jaclyn M.; Bilbo, Staci D.

2012-01-01

Microglia and astrocytes are the primary immune cells within the central nervous system. Microglia influence processes including neural development, synaptic plasticity and cognition; while their activation and production of immune molecules can induce stereotyped sickness behaviors or pathologies including cognitive dysfunction. Given their role in health and disease, we propose that glia may be also be a critical link in understanding the etiology of many neuropsychiatric disorders that present with a strong sex-bias in their symptoms or prevalence. Specifically, males are more likely to be diagnosed with disorders that have distinct developmental origins such as autism or schizophrenia. In contrast, females are more likely to be diagnosed with disorders that present later in life, after the onset of adolescence, such as depression and anxiety disorders. In this review we will summarize the evidence suggesting that sex differences in the colonization and function of glia within the normal developing brain may contribute to distinct windows of vulnerability between males and females. We will also highlight the current gaps in our knowledge as well as the future directions and considerations of research aimed at understanding the link between neuroimmune function and sex differences in mental health disorders. PMID:22387107

Sex steroid hormones and sex hormone binding globulin levels, CYP17 MSP AI (-34T:C) and CYP19 codon 39 (Trp:Arg) variants in children with developmental stuttering.

PubMed

Mohammadi, Hiwa; Joghataei, Mohammad Taghi; Rahimi, Zohreh; Faghihi, Faezeh; Khazaie, Habibolah; Farhangdoost, Hashem; Mehrpour, Masoud

2017-12-01

Developmental stuttering is known to be a sexually dimorphic and male-biased speech motor control disorder. In the present case-control study, we investigated the relationship between developmental stuttering and steroid hormones. Serum levels of testosterone, dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA), oestradiol, progesterone, cortisol, and sex hormone binding globulin (SHBG), as well as the 2nd/4th digit ratio (2D:4D), an indicator of prenatal testosterone level, were compared between children who stutter (CWS) and children who do not stutter (CWNS). Moreover, two SNPs (CYP17 -34 T:C (MSP AI) and CYP19 T:C (Trp:Arg)) of cytochrome P450, which is involved in steroid metabolism pathways, were analysed between the groups. Our results showed significantly higher levels of testosterone, DHT, and oestradiol in CWS in comparison with CWNS. The severity of stuttering was positively correlated with the serum levels of testosterone, DHEA, and cortisol, whereas no association was seen between the stuttering and digit ratio, progesterone, or SHBG. The CYP17CC genotype was significantly associated with the disorder. Copyright © 2017 Elsevier Inc. All rights reserved.

Untangling the Contributions of Sex-Specific Gene Regulation and X-Chromosome Dosage to Sex-Biased Gene Expression in Caenorhabditis elegans

PubMed Central

Kramer, Maxwell; Rao, Prashant; Ercan, Sevinc

2016-01-01

Dosage compensation mechanisms equalize the level of X chromosome expression between sexes. Yet the X chromosome is often enriched for genes exhibiting sex-biased, i.e., imbalanced expression. The relationship between X chromosome dosage compensation and sex-biased gene expression remains largely unexplored. Most studies determine sex-biased gene expression without distinguishing between contributions from X chromosome copy number (dose) and the animal’s sex. Here, we uncoupled X chromosome dose from sex-specific gene regulation in Caenorhabditis elegans to determine the effect of each on X expression. In early embryogenesis, when dosage compensation is not yet fully active, X chromosome dose drives the hermaphrodite-biased expression of many X-linked genes, including several genes that were shown to be responsible for hermaphrodite fate. A similar effect is seen in the C. elegans germline, where X chromosome dose contributes to higher hermaphrodite X expression, suggesting that lack of dosage compensation in the germline may have a role in supporting higher expression of X chromosomal genes with female-biased functions in the gonad. In the soma, dosage compensation effectively balances X expression between the sexes. As a result, somatic sex-biased expression is almost entirely due to sex-specific gene regulation. These results suggest that lack of dosage compensation in different tissues and developmental stages allow X chromosome copy number to contribute to sex-biased gene expression and function. PMID:27356611

Transcriptome architecture across tissues in the pig

PubMed Central

Ferraz, André LJ; Ojeda, Ana; López-Béjar, Manel; Fernandes, Lana T; Castelló, Anna; Folch, Josep M; Pérez-Enciso, Miguel

2008-01-01

Background Artificial selection has resulted in animal breeds with extreme phenotypes. As an organism is made up of many different tissues and organs, each with its own genetic programme, it is pertinent to ask: How relevant is tissue in terms of total transcriptome variability? Which are the genes most distinctly expressed between tissues? Does breed or sex equally affect the transcriptome across tissues? Results In order to gain insight on these issues, we conducted microarray expression profiling of 16 different tissues from four animals of two extreme pig breeds, Large White and Iberian, two males and two females. Mixed model analysis and neighbor – joining trees showed that tissues with similar developmental origin clustered closer than those with different embryonic origins. Often a sound biological interpretation was possible for overrepresented gene ontology categories within differentially expressed genes between groups of tissues. For instance, an excess of nervous system or muscle development genes were found among tissues of ectoderm or mesoderm origins, respectively. Tissue accounted for ~11 times more variability than sex or breed. Nevertheless, we were able to confidently identify genes with differential expression across tissues between breeds (33 genes) and between sexes (19 genes). The genes primarily affected by sex were overall different than those affected by breed or tissue. Interaction with tissue can be important for differentially expressed genes between breeds but not so much for genes whose expression differ between sexes. Conclusion Embryonic development leaves an enduring footprint on the transcriptome. The interaction in gene × tissue for differentially expressed genes between breeds suggests that animal breeding has targeted differentially each tissue's transcriptome. PMID:18416811

The Neuroendocrine Control of the Circadian System: Adolescent Chronotype

PubMed Central

Hagenauer, Megan Hastings; Lee, Theresa M.

2012-01-01

Scientists, public health and school officials are paying growing attention to the mechanism underlying the delayed sleep patterns common in human adolescents. Data suggest that a propensity towards evening chronotype develops during puberty, and may be caused by developmental alterations in internal daily timekeeping. New support for this theory has emerged from recent studies which show that pubertal changes in chronotype occur in many laboratory species similar to human adolescents. Using these species as models, we find that pubertal changes in chronotype differ by sex, are internally generated, and driven by reproductive hormones. These chronotype changes are accompanied by alterations in the fundamental properties of the circadian timekeeping system, including endogenous rhythm period and sensitivity to environmental time cues. After comparing the developmental progression of chronotype in different species, we propose a theory regarding the ecological relevance of adolescent chronotype, and provide suggestions for improving the sleep of human adolescents. PMID:22634481

Prenatal nicotine alters the developmental neurotoxicity of postnatal chlorpyrifos directed toward cholinergic systems: better, worse, or just "different?".

PubMed

Slotkin, Theodore A; Seidler, Frederic J

2015-01-01

This study examines whether prenatal nicotine exposure sensitizes the developing brain to subsequent developmental neurotoxicity evoked by chlorpyrifos, a commonly-used insecticide. We gave nicotine to pregnant rats throughout gestation at a dose (3mg/kg/day) producing plasma levels typical of smokers; offspring were then given chlorpyrifos on postnatal days 1-4, at a dose (1mg/kg) that produces minimally-detectable inhibition of brain cholinesterase activity. We evaluated indices for acetylcholine (ACh) synaptic function throughout adolescence, young adulthood and later adulthood, in brain regions possessing the majority of ACh projections and cell bodies; we measured nicotinic ACh receptor binding, hemicholinium-3 binding to the presynaptic choline transporter and choline acetyltransferase activity, all known targets for the adverse developmental effects of nicotine and chlorpyrifos given individually. By itself nicotine elicited overall upregulation of the ACh markers, albeit with selective differences by sex, region and age. Likewise, chlorpyrifos alone had highly sex-selective effects. Importantly, all the effects showed temporal progression between adolescence and adulthood, pointing to ongoing synaptic changes rather than just persistence after an initial injury. Prenatal nicotine administration altered the responses to chlorpyrifos in a consistent pattern for all three markers, lowering values relative to those of the individual treatments or to those expected from simple additive effects of nicotine and chlorpyrifos. The combination produced global interference with emergence of the ACh phenotype, an effect not seen with nicotine or chlorpyrifos alone. Given that human exposures to nicotine and chlorpyrifos are widespread, our results point to the creation of a subpopulation with heightened vulnerability. Copyright © 2014 Elsevier Inc. All rights reserved.

Prenatal Nicotine Alters the Developmental Neurotoxicity of Postnatal Chlorpyrifos Directed Toward Cholinergic Systems: Better, Worse, or Just “Different?”

PubMed Central

Slotkin, Theodore A.; Seidler, Frederic J.

2014-01-01

This study examines whether prenatal nicotine exposure sensitizes the developing brain to subsequent developmental neurotoxicity evoked by chlorpyrifos, a commonly-used insecticide. We gave nicotine to pregnant rats throughout gestation at a dose (3 mg/kg/day) producing plasma levels typical of smokers; offspring were then given chlorpyrifos on postnatal days 1–4, at a dose (1 mg/kg) that produces minimally-detectable inhibition of brain cholinesterase activity. We evaluated indices for acetylcholine (ACh) synaptic function throughout adolescence, young adulthood and later adulthood, in brain regions possessing the majority of ACh projections and cell bodies; we measured nicotinic ACh receptor binding, hemicholinium-3 binding to the presynaptic choline transporter and choline acetyltransferase activity, all known targets for the adverse developmental effects of nicotine and chlorpyrifos given individually. By itself nicotine elicited overall upregulation of the ACh markers, albeit with selective differences by sex, region and age. Likewise, chlorpyrifos alone had highly sex-selective effects. Importantly, all the effects showed temporal progression between adolescence and adulthood, pointing to ongoing synaptic changes rather than just persistence after an initial injury. Prenatal nicotine administration altered the responses to chlorpyrifos in a consistent pattern for all three markers, lowering values relative to those of the individual treatments or to those expected from simple additive effects of nicotine and chlorpyrifos. The combination produced global interference with emergence of the ACh phenotype, an effect not seen with nicotine or chlorpyrifos alone. Given that human exposures to nicotine and chlorpyrifos are widespread, our results point to the creation of a subpopulation with heightened vulnerability. PMID:25510202

A Comparative, Developmental, and Clinical Perspective of Neurobehavioral Sexual Dimorphisms

PubMed Central

Viveros, Maria-Paz; Mendrek, Adriana; Paus, Tomáš; López-Rodríguez, Ana Belén; Marco, Eva Maria; Yehuda, Rachel; Cohen, Hagit; Lehrner, Amy; Wagner, Edward J.

2012-01-01

Women and men differ in a wide variety of behavioral traits and in their vulnerability to developing certain mental disorders. This review endeavors to explore how recent preclinical and clinical research findings have enhanced our understanding of the factors that underlie these disparities. We start with a brief overview of some of the important genetic, molecular, and hormonal determinants that contribute to the process of sexual differentiation. We then discuss the importance of animal models in studying the mechanisms responsible for sex differences in neuropsychiatric disorders (e.g., drug dependence) – with a special emphasis on experimental models based on the neurodevelopmental and “three hits” hypotheses. Next, we describe the most common brain phenotypes observed in vivo with magnetic resonance imaging. We discuss the challenges in interpreting these phenotypes vis-à-vis the underlying neurobiology and revisit the known sex differences in brain structure from birth, through adolescence, and into adulthood. This is followed by a presentation of pertinent clinical and epidemiological data that point to important sex differences in the prevalence, course, and expression of psychopathologies such as schizophrenia, and mood disorders including major depression and posttraumatic stress disorder. Recent evidence implies that mood disorders and psychosis share some common genetic predispositions and neurobiological bases. Therefore, modern research is emphasizing dimensional representation of mental disorders and conceptualization of schizophrenia and major depression as a continuum of cognitive deficits and neurobiological abnormalities. Herein, we examine available evidence on cerebral sexual dimorphism to verify if sex differences vary quantitatively and/or qualitatively along the psychoses-depression continuum. Finally, sex differences in the prevalence of posttraumatic disorder and drug abuse have been described, and we consider the genomic and molecular data supporting these differences. PMID:22701400

Great ape origins of personality maturation and sex differences: a study of orangutans and chimpanzees.

PubMed

Weiss, Alexander; King, James E

2015-04-01

Human personality development evinces increased emotional stability, prosocial tendencies, and responsibility. One hypothesis offered to explain this pattern is Social-Investment Theory, which posits that culturally defined social roles, including marriage and employment, are responsible for the increased maturity. Alternatively, Five-Factor Theory emphasizes the role of biological factors, such as those governing physical development, which may predate the emergence of humans. Five-Factor Theory, unlike Social-Investment Theory, predicts that all or some of the human personality developmental trends should be present in great apes, our closest evolutionary relatives. To test this prediction and to better understand the evolutionary origins of sex differences, we examined age and sex differences in the chimpanzee and orangutan personality domains Extraversion, Dominance, Neuroticism, and Agreeableness. We also examined the Activity and Gregariousness facets of Extraversion and the orangutan Intellect domain. Extraversion and Neuroticism declined across age groups in both species, in common with humans. A significant interaction indicated that Agreeableness declined in orangutans but increased in chimpanzees, as it does in humans, though this may reflect differences in how Agreeableness was defined in each species. Significant interactions indicated that male chimpanzees, unlike male orangutans, displayed higher Neuroticism scores than females and maintained higher levels of Activity and Dominance into old age than female chimpanzees, male orangutans, and female orangutans. Personality-age correlations were comparable across orangutans and chimpanzees and were similar to those reported in human studies. Sex differences were stronger in chimpanzees than in humans or orangutans. These findings support Five-Factor Theory, suggest the role of gene-culture coevolution in shaping personality development, and suggest that sex differences evolved independently in different species. (c) 2015 APA, all rights reserved).

tasselseed1 is a lipoxygenase affecting jasmonic acid signaling in sex determination of maize

USDA-ARS?s Scientific Manuscript database

Sex determination in maize is controlled by a developmental cascade leading to the formation of unisexual florets derived from an initially bisexual floral meristem. Abortion of pistil primordia in staminate florets is controlled by a tasselseed-mediated cell death process. Here, we describe the pos...

Life-History and Developmental Antecedents of Female Vocational Preferences.

ERIC Educational Resources Information Center

Reichel, Laura S.; Muchinsky, Paul M.

1995-01-01

A group of 296 female undergraduates completed the Strong Interest Inventory, Biographical Questionnaire, Bem Sex-Role Inventory, and Self-Esteem Inventory. Life history was a better predictor of vocational interests than either sex-role orientation or self-esteem. The only significant exception was that Femininity correlated with interest in…

The Effect of Sex Labels on Adults' Knowledge of Infant Development.

ERIC Educational Resources Information Center

Paludi, Michele, A.; Gullo, Dominic F.

1987-01-01

Adults indicated on questionnaires the age at which they believed infants were first able to perform various developmental skills. Some questionnaires asked about "boys," some about "girls," and some about "babies." Contrary to previous findings, sex labels did not affect adults' rating of behaviors. (Author/LHW)

Why Go There? Evolution of Mobility and Spatial Cognition in Women and Men : An Introduction to the Special Issue.

PubMed

Cashdan, Elizabeth; Gaulin, Steven J C

2016-03-01

Males in many non-monogamous species have larger ranges than females do, a sex difference that has been well documented for decades and seems to be an aspect of male mating competition. Until recently, parallel data for humans have been mostly anecdotal and qualitative, but this is now changing as human behavioral ecologists turn their attention to matters of individual mobility. Sex differences in spatial cognition were among the first accepted psychological sex differences and, like differences in ranging behavior, are documented for a growing set of species. This special issue is dedicated to exploring the possible adaptive links between these cognitive and ranging traits. Multiple hypotheses, at various levels of analysis, are considered. At the functional (ultimate) level, a mating-competition hypothesis suggests that range expansion may augment mating opportunities, and a fertility-and-parental-care hypothesis suggests that range contraction may facilitate offspring provisioning. At a more mechanistic (proximate) level, differences in cue availability may support or inhibit particular sex-specific navigation strategies, and spatial anxiety may usefully inhibit travel that would not justify its costs. Studies in four different cultures-Twe, Tsimane, Yucatec Maya, and Faroese-as well as an experimental study using virtual reality tools are the venue for testing these hypotheses. Our hope is to stimulate more research on the evolutionary and developmental processes responsible for this suite of linked behavioral and cognitive traits.

Effects of age and sex on developmental neural networks of visual-spatial attention allocation.

PubMed

Rubia, Katya; Hyde, Zoe; Halari, Rozmin; Giampietro, Vincent; Smith, Anna

2010-06-01

Compared to our understanding of the functional maturation of brain networks underlying complex cognitive abilities, hardly anything is known of the neurofunctional development of simpler cognitive abilities such as visuo-spatial attention allocation. Furthermore, nothing is known on the effect of gender on the functional development of attention allocation. This study employed event related functional magnetic resonance imaging to investigate effects of age, sex, and sex by age interactions on the brain activation of 63 males and females, between 13 to 38years, during a visual-spatial oddball task. Behaviourally, with increasing age, speed was traded for accuracy, indicative of a less impulsive performance style in older subjects. Increasing age was associated with progressively increased activation in typical areas of selective attention of lateral fronto-striatal and temporo-parietal brain regions. Sex difference analysis showed enhanced activation in right-hemispheric inferior frontal and superior temporal regions in females, and in left-hemispheric inferior temporo-parietal regions in males. Importantly, the age by sex interaction findings showed that these sex-dimorphic patterns of brain activation may be the result of underlying sex differences in the functional maturation of these brain regions, as females had sex-specific progressive age-correlations in the same right inferior fronto-striato-temporal areas, while male-specific age-correlations were in left medial temporal and parietal areas. The findings demonstrate progressive functional maturation of fronto-striato-parieto-temporal networks of the relatively simple function of attention allocation between early adolescence and mid-adulthood. They furthermore show that sex-dimorphic patterns of enhanced reliance on right inferior frontal, striatal and superior temporal regions in females and of left temporo-parietal regions in males during attention allocation may be the result of underlying sex differences in the functional maturation of these brain regions. Copyright 2010 Elsevier Inc. All rights reserved.

Molecular cloning and functional characterization of the sex-determination gene doublesex in the sexually dimorphic broad-horned beetle Gnatocerus cornutus (Coleoptera, Tenebrionidae)

PubMed Central

Gotoh, Hiroki; Ishiguro, Mai; Nishikawa, Hideto; Morita, Shinichi; Okada, Kensuke; Miyatake, Takahisa; Yaginuma, Toshinobu; Niimi, Teruyuki

2016-01-01

Various types of weapon traits found in insect order Coleoptera are known as outstanding examples of sexually selected exaggerated characters. It is known that the sex determination gene doublesex (dsx) plays a significant role in sex-specific expression of weapon traits in various beetles belonging to the superfamily Scarabaeoidea. Although sex-specific weapon traits have evolved independently in various Coleopteran groups, developmental mechanisms of sex-specific expression have not been studied outside of the Scarabaeoidea. In order to test the hypothesis that dsx-dependent sex-specific expression of weapon traits is a general mechanism among the Coleoptera, we have characterized the dsx in the sexually dimorphic broad-horned beetle Gnatocerus cornutus (Tenebrionidea, Tenebirionidae). By using molecular cloning, we identified five splicing variants of Gnatocerus cornutus dsx (Gcdsx), which are predicted to code four different isoforms. We found one male-specific variant (GcDsx-M), two female-specific variants (GcDsx-FL and GcDsx-FS) and two non-sex-specific variants (correspond to a single isoform, GcDsx-C). Knockdown of all Dsx isoforms resulted in intersex phenotype both in male and female. Also, knockdown of all female-specific isoforms transformed females to intersex phenotype, while did not affect male phenotype. Our results clearly illustrate the important function of Gcdsx in determining sex-specific trait expression in both sexes. PMID:27404087

Impact of Low-Dose Oral Exposure to Bisphenol A (BPA) on Juvenile and Adult Rat Exploratory and Anxiety Behavior: A CLARITY-BPA Consortium Study.

PubMed

Rebuli, Meghan E; Camacho, Luísa; Adonay, Maria E; Reif, David M; Aylor, David L; Patisaul, Heather B

2015-12-01

Bisphenol A (BPA) is a high volume production chemical and has been identified as an endocrine disruptor, prompting concern that developmental exposure could impact brain development and behavior. Rodent and human studies suggest that early life BPA exposure may result in an anxious, hyperactive phenotype but results are conflicting and data from studies using multiple doses below the no-observed-adverse-effect level are limited. To address this, the present studies were conducted as part of the CLARITY-BPA (Consortium Linking Academic and Regulatory Insights on BPA Toxicity) program. The impact of perinatal BPA exposure (2.5, 25, or 2500 µg/kg body weight (bw)/day) on behaviors related to anxiety and exploratory activity was assessed in juvenile (prepubertal) and adult NCTR Sprague-Dawley rats of both sexes. Ethinyl estradiol (0.5 µg/kg bw/day) was used as a reference estrogen. Exposure spanned gestation and lactation with dams gavaged from gestational day 6 until birth and then the offspring gavaged directly through weaning (n = 12/sex/group). Behavioral assessments included open field, elevated plus maze, and zero maze. Anticipated sex differences in behavior were statistically identified or suggested in most cases. No consistent effects of BPA were observed for any endpoint, in either sex, at either age compared to vehicle controls; however, significant differences between BPA-exposed and ethinyl estradiol-exposed groups were identified for some endpoints. Limitations of this study are discussed and include suboptimal statistical power and low concordance across behavioral tasks. These data do not indicate BPA-related effects on anxiety or exploratory activity in these developmentally exposed rats. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Child Development and Pediatric Sport and Recreational Injuries by Age

PubMed Central

Schwebel, David C.; Brezausek, Carl M.

2014-01-01

Context: In 2010, 8.6 million children were treated for unintentional injuries in American emergency departments. Child engagement in sports and recreation offers many health benefits but also exposure to injury risks. In this analysis, we consider possible developmental risk factors in a review of age, sex, and incidence of 39 sport and recreational injuries. Objective: To assess (1) how the incidence of 39 sport and recreational injuries changed through each year of child and adolescent development, ages 1 to 18 years, and (2) sex differences. Design Descriptive epidemiology study. Setting: Emergency department visits across the United States, as reported in the 2001–2008 National Electronic Injury Surveillance System database. Patients or Other Participants: Data represent population-wide emergency department visits in the United States. Main Outcome Measure(s) Pediatric sport- and recreation-related injuries requiring treatment in hospital emergency departments. Results: Almost 37 pediatric sport or recreational injuries are treated hourly in the United States. The incidence of sport- and recreation-related injuries peaks at widely different ages. Team-sport injuries tend to peak in the middle teen years, playground injuries peak in the early elementary ages and then drop off slowly, and bicycling injuries peak in the preteen years but are a common cause of injury throughout childhood and adolescence. Bowling injuries peaked at the earliest age (4 years), and injuries linked to camping and personal watercraft peaked at the oldest age (18 years). The 5 most common causes of sport and recreational injuries across development, in order, were basketball, football, bicycling, playgrounds, and soccer. Sex disparities were common in the incidence of pediatric sport and recreational injuries. Conclusions: Both biological and sociocultural factors likely influence the developmental aspects of pediatric sport and recreational injury risk. Biologically, changes in perception, cognition, and motor control might influence injury risk. Socioculturally, decisions must be made about which sport and recreational activities to engage in and how much risk taking occurs while engaging in those activities. Understanding the developmental aspects of injury data trends allows preventionists to target education at specific groups. PMID:25162780

Imaging and examination strategies of normal male and female sex development and anatomy.

PubMed

Wünsch, Lutz; Schober, Justine M

2007-09-01

Over recent years a variety of new details on the developmental biology of sexual differentiation has been discovered. Moreover, important advances have been made in imaging and examination strategies for urogenital organs, and these have added new knowledge to our understanding of the 'normal' anatomy of the sexes. Both aspects contribute to the comprehension of phenotypic sex development, but they are not commonly presented in the same context. This will be attempted in this chapter, which aims to link discoveries in developmental biology to anatomical details shown by modern examination techniques. A review of the literature concerning the link between sexual development and imaging of urogenital organs was performed. Genes, proteins and pathways related to sexual differentiation were related to some organotypic features revealed by clinical examination techniques. Early 'organotypic' patterns can be identified in prostatic, urethral and genital development and followed into postnatal life. New imaging and endoscopy techniques allow for detailed descriptive anatomical studies, hopefully resulting in a broader understanding of sex development and a better genotype-phenotype correlation in defined disorders. Clinical description relying on imaging techniques should be related to knowledge of the genetic and endocrine factors influencing sex development in a specific and stepwise manner.

Similarities and differences in child development from birth to age 3 years by sex and across four countries: a cross-sectional, observational study.

PubMed

Ertem, Ilgi Ozturk; Krishnamurthy, Vibha; Mulaudzi, Mphelekedzeni C; Sguassero, Yanina; Balta, Hakan; Gulumser, Ozlem; Bilik, Burcu; Srinivasan, Roopa; Johnson, Benjamin; Gan, Geliang; Calvocoressi, Lisa; Shabanova, Veronika; Forsyth, Brian W C

2018-03-01

Knowledge about typical development is of fundamental importance for understanding and promoting child health and development. We aimed to ascertain when healthy children in four culturally and linguistically different countries attain developmental milestones and to identify similarities and differences across sexes and countries. In this cross-sectional, observational study, we recruited children aged 0-42 months and their caregivers between March 3, 2011, and May 18, 2015, at 22 health clinics in Argentina, India, South Africa, and Turkey. We obtained a healthy subsample, which excluded children with a low birthweight, perinatal complications, chronic illness, undernutrition, or anaemia, and children with missing health data. Using the Guide for Monitoring Child Development, caregivers described their child's development in seven domains: expressive and receptive language, gross and fine motor, play, relating, and self-help. Clinicians examining the children also completed a checklist about the child's health status. We used logit and probit regression models based on the lowest deviance information criterion to generate Bayesian point estimates and 95% credible intervals for the 50th percentile ages of attainment of 106 milestones. We assessed the significance of differences between sexes and countries using predefined criteria and regions of practical equivalence. Of 10 246 children recruited, 4949 children (48·3%) were included in the healthy subsample. For the 106 milestones assessed, the median age of attainment was equivalent for 102 (96%) milestones across sexes and 81 (76%) milestones across the four countries. Across countries, median ages of attainment were equivalent for all play milestones, 20 (77%) of 26 expressive language milestones, ten (67%) of 15 receptive language milestones, nine (82%) of 11 fine motor milestones, 14 (88%) of 16 gross motor milestones, and eight (73%) of 11 relating milestones. However, across the four countries the median age of attainment was equivalent for only two (22%) of nine milestones in the self-help domain. The ages of attainment of developmental milestones in healthy children, and the similarities and differences across sexes and country samples might aid the development of international tools to guide policy, service delivery, and intervention research, particularly in low-income and middle-income countries. Eunice Kennedy Shriver National Institute of Child Health and Human Development. Copyright © 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.

Sex dimorphic behaviors as markers of neuroendocrine disruption by environmental chemicals: the case of chlorpyrifos.

PubMed

Venerosi, A; Ricceri, L; Tait, S; Calamandrei, G

2012-12-01

The complexity of the neuroendocrine level of investigation requires the assessment of behavioral patterns that extend beyond the reproductive functions, which are age- and sex-specific in rodents, described by defined clusters of behavioral items regulated by genetic, hormonal, and epigenetic factors. The study of social behavior in laboratory rodents reveals sex-dimorphic effects of environmental chemicals that may be undetected either by a traditional neurotoxicological approach or referring to the classical definition of endocrine disrupting chemicals. Here we review data on the neurobehavioral effects of developmental exposure to the non-persistent organophosphorus insecticide chlorpyrifos, whose neurotoxic activity at low doses is currently a matter of concern for children's health. In mice exposed to chlorpyrifos in utero and/or in early development social/emotional responses are differently affected in the two sexes in parallel with sex-dependent interference on hypothalamic neuroendocrine pathways regulating social behaviors (vasopressin, oxytocin, and steroid regulated systems). Through the analysis of complex sex-dimorphic behavioral patterns we show that neurotoxic and endocrine disrupting activities of CPF overlap. This widely diffused organophosphorus pesticide might thus be considered as a neuroendocrine disruptor possibly representing a risk factor for sex-biased neurodevelopmental disorders in children. Copyright © 2012 Elsevier Inc. All rights reserved.

Sex chromosome aneuploidies and copy-number variants: a further explanation for neurodevelopmental prognosis variability?

PubMed

Le Gall, Jessica; Nizon, Mathilde; Pichon, Olivier; Andrieux, Joris; Audebert-Bellanger, Séverine; Baron, Sabine; Beneteau, Claire; Bilan, Frédéric; Boute, Odile; Busa, Tiffany; Cormier-Daire, Valérie; Ferec, Claude; Fradin, Mélanie; Gilbert-Dussardier, Brigitte; Jaillard, Sylvie; Jønch, Aia; Martin-Coignard, Dominique; Mercier, Sandra; Moutton, Sébastien; Rooryck, Caroline; Schaefer, Elise; Vincent, Marie; Sanlaville, Damien; Le Caignec, Cédric; Jacquemont, Sébastien; David, Albert; Isidor, Bertrand

2017-08-01

Sex chromosome aneuploidies (SCA) is a group of conditions in which individuals have an abnormal number of sex chromosomes. SCA, such as Klinefelter's syndrome, XYY syndrome, and Triple X syndrome are associated with a large range of neurological outcome. Another genetic event such as another cytogenetic abnormality may explain a part of this variable expressivity. In this study, we have recruited fourteen patients with intellectual disability or developmental delay carrying SCA associated with a copy-number variant (CNV). In our cohort (four patients 47,XXY, four patients 47,XXX, and six patients 47,XYY), seven patients were carrying a pathogenic CNV, two a likely pathogenic CNV and five a variant of uncertain significance. Our analysis suggests that CNV might be considered as an additional independent genetic factor for intellectual disability and developmental delay for patients with SCA and neurodevelopmental disorder.

Anatomy of female puberty: The clinical relevance of developmental changes in the reproductive system.

PubMed

Colvin, Caroline Wingo; Abdullatif, Hussein

2013-01-01

Puberty is the period of biologic transition from childhood to adulthood. The changes that occur at this time are related to the increasing concentrations of sex steroid hormones. In females, most pubertal changes are caused by estrogen stimulation that results from the onset of central puberty. Significant development occurs in the organs of the female reproductive system and results in anatomic changes that characterize reproductive maturity. Adrenal and ovarian androgens also increase during puberty, affecting change that includes the promotion of certain secondary sex characteristics. The ability to recognize normal pubertal anatomy and distinguish between estrogen and androgen effects is important in the ability to diagnose and treat disorders of sex development, precocious puberty, pubertal delay, and menstrual irregularities in children and adolescents. An understanding of this developmental process can also help clinicians identify and treat reproductive pathology in adults and across all female life stages. Copyright © 2012 Wiley-Liss, Inc.

Chinese adolescents' attitudes toward sexual relationships and premarital sex: implications for promoting sexual health.

PubMed

Chang, Yu-Ting; Hayter, Mark; Lin, Mei-Ling

2014-12-01

This study was designed to explore Taiwanese school students' attitudes toward sexual relationships and premarital sex. This was an exploratory descriptive, qualitative study. Focus groups (N = 8) were conducted with 47 adolescents from three high schools in Taiwan. Transcripts were transcribed and thematically analyzed using Atlas V 5.0. Adolescent attitudes toward sexual relationships and premarital sexual behavior comprise the following three dimensions: (1) external incentives, (2) the developmental process, and (3) internal control. External incentives include the normalization of sexual behavior between peers, the desire to feel included in a group, parental influence, and media influence. The developmental process includes imagining the sexual experience and onset of sexual activity. Internal control includes the fear of pregnancy, the fear of parental rejection, and the fear of being judged. These findings can provide a reference for designing future sex education curricula and counseling programs for adolescents. © The Author(s) 2014.

What Is Nonconsensual Sex? Young Women Identify Sources of Coerced Sex.

PubMed

French, Bryana H; Neville, Helen A

2016-04-12

Extending the American Psychological Association (APA) report on the Sexualization of Girls, this study investigated how young women identified sources of coerced sex. Findings from three focus groups with 25 Black and White adolescent women uncovered a perceived overarching force that "pushed" them to have sex before they felt ready. Participants identified four domains of coerced sex: (a) Sociocultural Context, (b) Internalized Sexual Scripts, (c) Partner Manipulation of Sexual Scripts, and (d) Developmental Status. Coerced sex was a complex system consisting of cultural, peer, and internal messages that create pressures to engage in sexual activities. Future implications for research and practice are presented. © The Author(s) 2016.

Developmental neurotoxicity elicited by prenatal or postnatal chlorpyrifos exposure: effects on neurospecific proteins indicate changing vulnerabilities.

PubMed

Garcia, Stephanie J; Seidler, Frederic J; Slotkin, Theodore A

2003-03-01

The developmental neurotoxicity of the organophosphate pesticide chlorpyrifos (CPF) is thought to involve both neurons and glia, thus producing a prolonged window of vulnerability. To characterize the cell types and brain regions involved in these effects, we administered CPF to developing rats and examined neuroprotein markers for oligodendrocytes (myelin basic protein, MBP), for neuronal cell bodies (neurofilament 68 kDa, NF68), and for developing axons (neurofilament 200 kDa, NF200). Prenatal CPF administration on gestational days (GDs) 17-20 elicited an immediate (GD21) enhancement of MBP and NF68; by postnatal day (PN) 30, however, there were deficits in all three biomarkers, with the effect restricted to females. Exposure in the early postnatal period, PN1-4, did not evoke significant short-term or long-term changes in the neuroproteins. However, with treatment on PN11-14, we found reductions in MBP in the immediate posttreatment period (PN15, PN20) throughout the brain, and deficiencies across all three proteins emerged by PN30. With this regimen, males were targeted preferentially. The sex-selective effects seen here for the GD17-20 and PN11-14 regimens match those reported earlier for subsequent behavioral performance. These results indicate a shift in the populations of neural cells targeted by CPF, dependent upon the period of exposure. Similarly, developmental differences in the sex selectivity of the biochemical mechanisms underlying neurotoxicant actions are likely to contribute to discrete behavioral outcomes.

Graphic Representation of Organs and Organ Systems: Psychological View and Developmental Patterns

ERIC Educational Resources Information Center

Bartoszeck, Amauri Betini; Machado, Danielle Zagonel; Amann-Gainotti, Merete

2011-01-01

The objective of this exploratory study is to characterize by means of drawings if the developmental patterns in the graphic representation of organ and organ systems progresses related to age of participants. Secondly, whether there is an integration of sex organs into the internal body image. The drawings representing the inside of the body in…

Genetic influences on alcohol use behaviors have diverging developmental trajectories: a prospective study among male and female twins.

PubMed

Meyers, Jacquelyn L; Salvatore, Jessica E; Vuoksimaa, Eero; Korhonen, Tellervo; Pulkkinen, Lea; Rose, Richard J; Kaprio, Jaakko; Dick, Danielle M

2014-11-01

Both alcohol-specific genetic factors and genetic factors related to externalizing behavior influence problematic alcohol use. Little is known, however, about the etiologic role of these 2 components of genetic risk on alcohol-related behaviors across development. Prior studies conducted in a male cohort of twins suggest that externalizing genetic factors are important for predicting heavy alcohol use in adolescence, whereas alcohol-specific genetic factors increase in importance during the transition to adulthood. In this report, we studied twin brothers and sisters and brother-sister twin pairs to examine such developmental trajectories and investigate whether sex and cotwin sex effects modify these genetic influences. We used prospective, longitudinal twin data collected between ages 12 and 22 within the population-based FinnTwin12 cohort study (analytic n = 1,864). Our dependent measures of alcohol use behaviors included alcohol initiation (age 12), intoxication frequency (ages 14 and 17), and alcohol dependence criteria (age 22). Each individual's genetic risk of alcohol use disorders (AUD-GR) was indexed by his/her parents' and cotwin's DSM-IV Alcohol Dependence (AD) criterion counts. Likewise, each individual's genetic risk of externalizing disorders (EXT-GR) was indexed with a composite measure of parents' and cotwin's DSM-IV Conduct Disorder and Antisocial Personality Disorder criterion counts. EXT-GR was most strongly related to alcohol use behaviors during adolescence, while AUD-GR was most strongly related to alcohol problems in young adulthood. Further, sex of the twin and sex of the cotwin significantly moderated the associations between genetic risk and alcohol use behaviors across development: AUD-GR influenced early adolescent alcohol use behaviors in females more than in males, and EXT-GR influenced age 22 AD more in males than in females. In addition, the associations of AUD-GR and EXT-GR with intoxication frequency were greater among 14- and 17-year-old females with twin brothers. We found divergent developmental trajectories for alcohol-specific and externalizing behavior-related genetic influences on alcohol use behaviors; in early adolescence, genetic influences on alcohol use behaviors are largely nonspecific, and later in adolescence and young adulthood, alcohol-specific genetic influences on alcohol use are more influential. Importantly, within these overall trajectories, several interesting sex differences emerged. We found that the relationship between genetic risk and problematic drinking across development is moderated by the individual's sex and his/her cotwin's sex. AUD-GR influenced adolescent alcohol outcomes in females more than in males and by age 22, EXT-GR influenced AD criteria more for males than females. In addition, the association between genetic risk and intoxication frequency was greater among 14- and 17-year-old females with male cotwins. Copyright © 2014 by the Research Society on Alcoholism.

Aping humans: age and sex effects in chimpanzee (Pan troglodytes) and human (Homo sapiens) personality.

PubMed

King, James E; Weiss, Alexander; Sisco, Melissa M

2008-11-01

Ratings of 202 chimpanzees on 43 personality descriptor adjectives were used to calculate scores on five domains analogous to the human Five-Factor Model and a chimpanzee-specific Dominance domain. Male and female chimpanzees were divided into five age groups ranging from juvenile to old adult. Internal consistencies and interrater reliabilities of factors were stable across age groups and approximately 6.8 year retest reliabilities were high. Age-related declines in Extraversion and Openness and increases in Agreeableness and Conscientiousness paralleled human age differences. The mean change in absolute standardized units for all five factors was virtually identical in humans and chimpanzees after adjustment for different developmental rates. Consistent with their aggressive behavior in the wild, male chimpanzees were rated as more aggressive, emotional, and impulsive than females. Chimpanzee sex differences in personality were greater than comparable human gender differences. These findings suggest that chimpanzee and human personality develop via an unfolding maturational process. (PsycINFO Database Record (c) 2008 APA, all rights reserved).

Sex differences in fingerprint ridge density in the Mataco-Mataguayo population.

PubMed

Gutiérrez-Redomero, E; Alonso, M C; Dipierri, J E

2011-12-01

Ridge density (RD), the number of digital ridges per unit area, varies according to sex, age, and population origin. The main objective of this study was to determine the extent of sexual dimorphism in RD and to set the age at which it appears, in an Amerindian sample from the Mataco-Mataguayo population. The sample studied for this research consisted of 99 males and 110 females, between 6 and 25 years old, which amounts to a total of 2090 fingerprints. Ridge count was carried out on distal radial and distal ulnar and on proximal regions of each finger to explore the RD patterns in order to identify similarities and differences among samples, areas, age groups, and sexes. RD decreased with age and, at all ages, RD was higher on the distal (radial and ulnar) areas, followed by the proximal sides. Females were found to have higher RD than males when older than 12 years, but not when younger. In the radial area, the Mataco-Mataguayo population, in both sexes, presented the RD similar to Spanish samples, but higher than all other populations analysed to date using this method. Variations in RD in the Amerindian population based on sex, age, and topology were confirmed in this work, and it is postulated that these variations are due to developmental differences among individuals and populations. A comparison between the Mataco-Mataguayo and Spanish populations is presented. Copyright © 2011 Elsevier GmbH. All rights reserved.

Examining the intersection of sex and stress in modelling neuropsychiatric disorders.

PubMed

Goel, N; Bale, T L

2009-03-01

Sex-biased neuropsychiatric disorders, including major depressive disorder and schizophrenia, are the major cause of disability in the developed world. Elevated stress sensitivity has been proposed as a key underlying factor in disease onset. Sex differences in stress sensitivity are associated with corticotrophin-releasing factor (CRF) and serotonin neurotransmission, which are important central regulators of mood and coping responses. To elucidate the underlying neurobiology of stress-related disease predisposition, it is critical to develop appropriate animal models of stress pathway dysregulation. Furthermore, the inclusion of sex difference comparisons in stress responsive behaviours, physiology and central stress pathway maturation in these models is essential. Recent studies by our laboratory and others have begun to investigate the intersection of stress and sex where the development of mouse models of stress pathway dysregulation via prenatal stress experience or early-life manipulations has provided insight into points of developmental vulnerability. In addition, examination of the maturation of these pathways, including the functional importance of the organisational and activational effects of gonadal hormones on stress responsivity, is essential for determination of when sex differences in stress sensitivity may begin. In such studies, we have detected distinct sex differences in stress coping strategies where activational effects of testosterone produced females that displayed male-like strategies in tests of passive coping, but were similar to females in tests of active coping. In a second model of elevated stress sensitivity, male mice experiencing prenatal stress early in gestation showed feminised physiological and behavioural stress responses, and were highly sensitive to a low dose of selective serotonin reuptake inhibitors. Analyses of expression and epigenetic patterns revealed changes in CRF and glucocorticoid receptor genes in these mice. Mechanistically, stress early in pregnancy produced a significant sex-dependent effect on placental gene expression that was supportive of altered foetal transport of key growth factors and nutrients. These mouse models examining alterations and hormonal effects on development of stress pathways provide necessary insight into how specific stress responses can be reprogrammed early in development resulting in sex differences in stress sensitivity and neuropsychiatric disease vulnerability.

Examining the intersection of sex and stress in modeling neuropsychiatric disorders

PubMed Central

Goel, Nirupa; Bale, Tracy L.

2009-01-01

Sex-biased neuropsychiatric disorders, including major depressive disorder and schizophrenia, are the major cause of disability in the developed world. Elevated stress sensitivity has been proposed as a key underlying factor in disease onset. Sex differences in stress sensitivity are associated with CRF and serotonin neurotransmission, important central regulators of mood and coping responses. To elucidate the underlying neurobiology of stress-related disease predisposition, it is critical to develop appropriate animal models of stress pathway dysregulation. Further, the inclusion of sex difference comparisons in stress responsive behaviors, physiology, and central stress pathway maturation in these models is essential. Recent studies by our lab and others have begun to investigate the intersection of stress and sex where the development of mouse models of stress pathway dysregulation via prenatal stress experience or early life manipulations has provided insight into points of developmental vulnerability. In addition, examination of the maturation of these pathways including the functional importance of the organizational and activational effects of gonadal hormones on stress responsivity is essential for determination of when sex differences in stress sensitivity may begin. In such studies, we have detected distinct sex differences in stress coping strategies where activational effects of testosterone produced females that displayed male-like strategies in tests of passive coping, but were similar to females in tests of active coping. In a second model of elevated stress sensitivity, male mice experiencing prenatal stress early in gestation showed feminized physiological and behavioral stress responses, and were highly sensitive to a low dose of SSRI. Analyses of expression and epigenetic patterns revealed changes in CRF and glucocorticoid receptor genes in these mice. Mechanistically, stress early in pregnancy produced a significant sex-dependent effect on placental gene expression supportive of altered fetal transport of key growth factors and nutrients. These mouse models examining alterations and hormonal effects on development of stress pathways provide necessary insight into how specific stress responses can be reprogrammed early in development resulting in sex differences in stress sensitivity and neuropsychiatric disease vulnerability. PMID:19187468

Jurisdictional, socioeconomic and gender inequalities in child health and development: analysis of a national census of 5-year-olds in Australia

PubMed Central

Brinkman, Sally A; Gialamas, Angela; Rahman, Azizur; Mittinty, Murthy N; Gregory, Tess A; Silburn, Sven; Goldfeld, Sharon; Zubrick, Stephen R; Carr, Vaughan; Janus, Magdalena; Hertzman, Clyde; Lynch, John W

2012-01-01

Objectives Early child development may have important consequences for inequalities in health and well-being. This paper explores population level patterns of child development across Australian jurisdictions, considering socioeconomic and demographic characteristics. Design Census of child development across Australia. Setting and participants Teachers complete a developmental checklist, the Australian Early Development Index (AEDI), for all children in their first year of full-time schooling. Between May and July 2009, the AEDI was collected by 14 628 teachers in primary schools (government and non-government) across Australia, providing information on 261 147 children (approximately 97.5% of the estimated 5-year-old population). Outcome measures Level of developmental vulnerability in Australian children for five developmental domains: physical well-being, social competence, emotional maturity, language and cognitive skills and communication skills and general knowledge. Results The results show demographic and socioeconomic inequalities in child development as well as within and between jurisdiction inequalities. The magnitude of the overall level of inequality in child development and the impact of covariates varies considerably both between and within jurisdiction by sex. For example, the difference in overall developmental vulnerability between the best-performing and worst-performing jurisdiction is 12.5% for males and 7.1% for females. Levels of absolute social inequality within jurisdictions range from 8.2% for females to 12.7% for males. Conclusions The different mix of universal and targeted services provided within jurisdictions from pregnancy to age 5 may contribute to inequality across the country. These results illustrate the potential utility of a developmental census to shed light on the impact of differences in universal and targeted services to support child development by school entry. PMID:22952161

Perinatal lead (Pb) exposure results in sex-specific effects on food intake, fat, weight, and insulin response across the murine life-course.

PubMed

Faulk, Christopher; Barks, Amanda; Sánchez, Brisa N; Zhang, Zhenzhen; Anderson, Olivia S; Peterson, Karen E; Dolinoy, Dana C

2014-01-01

Developmental lead (Pb) exposure has been associated with lower body weight in human infants and late onset obesity in mice. We determined the association of perinatal Pb exposure in mice with changes in obesity-related phenotypes into adulthood. Mice underwent exposure via maternal drinking water supplemented with 0 (control), 2.1 (low), 16 (medium), or 32 (high) ppm Pb-acetate two weeks prior to mating through lactation. Offspring were phenotyped at ages 3, 6, and 9 months for energy expenditure, spontaneous activity, food intake, body weight, body composition, and at age 10 months for glucose tolerance. Data analyses were stratified by sex and adjusted for litter effects. Exposed females and males exhibited increased energy expenditure as compared to controls (p<0.0001 for both). In females, horizontal activity differed significantly from controls (p = 0.02) over the life-course. Overall, food intake increased in exposed females and males (p<0.0008 and p<0.0001, respectively) with significant linear trends at 9 months in females (p = 0.01) and 6 months in males (p<0.01). Body weight was significantly increased in males at the medium and high exposures (p = 0.001 and p = 0.006). Total body fat differed among exposed females and males (p<0.0001 and p<0.0001, respectively). Insulin response was significantly increased in medium exposure males (p<0.05). Perinatal Pb exposure at blood lead levels between 4.1 µg/dL and 32 µg/dL is associated with increased food intake, body weight, total body fat, energy expenditure, activity, and insulin response in mice. Physiological effects of developmental Pb exposure persist and vary according to sex and age.

Perinatal Lead (Pb) Exposure Results in Sex-Specific Effects on Food Intake, Fat, Weight, and Insulin Response across the Murine Life-Course

PubMed Central

Sánchez, Brisa N.; Zhang, Zhenzhen; Anderson, Olivia S.; Peterson, Karen E.; Dolinoy, Dana C.

2014-01-01

Developmental lead (Pb) exposure has been associated with lower body weight in human infants and late onset obesity in mice. We determined the association of perinatal Pb exposure in mice with changes in obesity-related phenotypes into adulthood. Mice underwent exposure via maternal drinking water supplemented with 0 (control), 2.1 (low), 16 (medium), or 32 (high) ppm Pb-acetate two weeks prior to mating through lactation. Offspring were phenotyped at ages 3, 6, and 9 months for energy expenditure, spontaneous activity, food intake, body weight, body composition, and at age 10 months for glucose tolerance. Data analyses were stratified by sex and adjusted for litter effects. Exposed females and males exhibited increased energy expenditure as compared to controls (p<0.0001 for both). In females, horizontal activity differed significantly from controls (p = 0.02) over the life-course. Overall, food intake increased in exposed females and males (p<0.0008 and p<0.0001, respectively) with significant linear trends at 9 months in females (p = 0.01) and 6 months in males (p<0.01). Body weight was significantly increased in males at the medium and high exposures (p = 0.001 and p = 0.006). Total body fat differed among exposed females and males (p<0.0001 and p<0.0001, respectively). Insulin response was significantly increased in medium exposure males (p<0.05). Perinatal Pb exposure at blood lead levels between 4.1 µg/dL and 32 µg/dL is associated with increased food intake, body weight, total body fat, energy expenditure, activity, and insulin response in mice. Physiological effects of developmental Pb exposure persist and vary according to sex and age. PMID:25105421

The Composite Regulatory Basis of the Large X-Effect in Mouse Speciation.

PubMed

Larson, Erica L; Keeble, Sara; Vanderpool, Dan; Dean, Matthew D; Good, Jeffrey M

2017-02-01

The disruption of meiotic sex chromosome inactivation (MSCI) has been proposed to be a major developmental mechanism underlying the rapid evolution of hybrid male sterility. We tested this idea by analyzing cell-specific gene expression across spermatogenesis in two lineages of house mice and their sterile and fertile reciprocal hybrids. We found pervasive disruption of sex chromosome gene expression in sterile hybrids at every stage of spermatogenesis. Failure of MSCI was developmentally preceded by increased silencing of autosomal genes, supporting the hypothesis that divergence at the hybrid incompatibility gene, Prdm9, results in increased rates of autosomal asynapsis which in turn triggers widespread silencing of unsynapsed chromatin. We also detected opposite patterns of postmeiotic overexpression or hyper-repression of the sex chromosomes in reciprocal hybrids, supporting the hypothesis that genomic conflict has driven functional divergence that leads to deleterious X-Y dosage imbalances in hybrids. Our developmental timeline also exposed more subtle patterns of mitotic misregulation on the X chromosome, a previously undocumented stage of spermatogenic disruption in this cross. These results indicate that multiple hybrid incompatibilities have converged on a common regulatory phenotype, the disrupted expression of the sex chromosomes during spermatogenesis. Collectively, these data reveal a composite regulatory basis to hybrid male sterility in mice that helps resolve the mechanistic underpinnings of the well-documented large X-effect in mice speciation. We propose that the inherent sensitivity of spermatogenesis to X-linked regulatory disruption has the potential to be a major driver of reproductive isolation in species with chromosomal sex determination. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Estrogenic exposure affects metamorphosis and alters sex ratios in the northern leopard frog (Rana pipiens): identifying critically vulnerable periods of development.

PubMed

Hogan, Natacha S; Duarte, Paula; Wade, Michael G; Lean, David R S; Trudeau, Vance L

2008-05-01

During the transformation from larval tadpole to juvenile frog, there are critical periods of metamorphic development and sex differentiation that may be particularly sensitive to endocrine disruption. The aim of the present study was to identify sensitive developmental periods for estrogenic endocrine disruption in the northern leopard frog (Rana pipiens) using short, targeted exposures to the synthetic estrogen, ethinylestradiol (EE2). Post-hatch tadpoles (Gosner stage 27) were exposed over five distinct periods of metamorphosis: early (stage 27-30), mid (stage 30-36), early and mid (stage 27-36), late (stage 36-42), and the entire metamorphic period (chronic; stage 27-42). For each period, animals were sampled immediately following the EE2 exposure and at metamorphic climax (stage 42). The effects of EE2 on metamorphic development and sex differentiation were assessed through measures of length, weight, developmental stage, days to metamorphosis, sex ratios and incidence of gonadal intersex. Our results show that tadpoles exposed to EE2 during mid-metamorphosis were developmentally delayed immediately following exposure and took 2 weeks longer to reach metamorphic climax. In the unexposed groups, there was low proportion (0.15) of intersex tadpoles at stage 30 and gonads appeared to be morphologically distinct (male and female) in all individuals by stage 36. Tadpoles exposed early in development displayed a strong female-biased sex ratio compared to the controls. Moreover, these effects were also seen at metamorphic climax, approximately 2-3 months after the exposure period, demonstrating that transient early life-stage exposure to estrogen can induce effects on the reproductive organs that persist into the beginning of adult life-stages.

MPK-1 ERK controls membrane organization in C. elegans oogenesis via a sex-determination module.

PubMed

Arur, Swathi; Ohmachi, Mitsue; Berkseth, Matt; Nayak, Sudhir; Hansen, David; Zarkower, David; Schedl, Tim

2011-05-17

Tissues that generate specialized cell types in a production line must coordinate developmental mechanisms with physiological demand, although how this occurs is largely unknown. In the Caenorhabditis elegans hermaphrodite, the developmental sex-determination cascade specifies gamete sex in the distal germline, while physiological sperm signaling activates MPK-1/ERK in the proximal germline to control plasma membrane biogenesis and organization during oogenesis. We discovered repeated utilization of a self-contained negative regulatory module, consisting of NOS-3 translational repressor, FEM-CUL-2 (E3 ubiquitin ligase), and TRA-1 (Gli transcriptional repressor), which acts both in sex determination and in physiological demand control of oogenesis, coordinating these processes. In the distal germline, where MPK-1 is not activated, TRA-1 represses the male fate as NOS-3 functions in translational repression leading to inactivation of the FEM-CUL-2 ubiquitin ligase. In the proximal germline, sperm-dependent physiological MPK-1 activation results in phosphorylation-based inactivation of NOS-3, FEM-CUL-2-mediated degradation of TRA-1 and the promotion of membrane organization during oogenesis. Copyright © 2011 Elsevier Inc. All rights reserved.

Developmental assessment of infants with biliary atresia: differences between boys and girls.

PubMed

Caudle, Susan E; Katzenstein, Jennifer M; Karpen, Saul; McLin, Valérie

2012-10-01

The aim of the present study was to investigate whether male and female infants with biliary atresia (BA) differ cognitively and to confirm previously documented developmental lags in infants with BA before liver transplantation. With the Mullen Scales of Early Learning, we examined 21 female and 12 male infants (ages 3-20 months) with BA, comparing scores across indices by sex and correlating Mullen Scales of Early Learning scores with standard clinical and biochemical parameters. Overall, both boys and girls were found to be vulnerable to developmental lags in the areas of expressive language (EL) and gross motor skills. In comparison with their male peers, girls were found to be weaker in the area of visual reception skills (P=0.05) with a trend found for EL (P=0.08). Girls were also found to have higher C-bilirubin levels and to be of shorter length. Growth parameters were found to be correlated with EL scores. International normalized ratio was found to be correlated with gross motor performance and with a trend also noted for fine motor skills. Age at Kasai predicted receptive language skills. As has been shown, infants with BA appear to be vulnerable to developmental lags before transplantation. In particular, female infants appear to be vulnerable to cognitive and skill delays in comparison with their male peers. C-bilirubin levels may play a role in this increased vulnerability for females.

Demographic and genetic consequences of disturbed sex determination.

PubMed

Wedekind, Claus

2017-09-19

During sex determination, genetic and/or environmental factors determine the cascade of processes of gonad development. Many organisms, therefore, have a developmental window in which their sex determination can be sensitive to, for example, unusual temperatures or chemical pollutants. Disturbed environments can distort population sex ratios and may even cause sex reversal in species with genetic sex determination. The resulting genotype-phenotype mismatches can have long-lasting effects on population demography and genetics. I review the theoretical and empirical work in this context and explore in a simple population model the role of the fitness v yy of chromosomally aberrant YY genotypes that are a consequence of environmentally induced feminization. Low v yy is mostly beneficial for population growth. During feminization, low v yy reduces the proportion of genetic males and hence accelerates population growth, especially at low rates of feminization and at high fitness costs of the feminization itself (i.e. when feminization would otherwise not affect population dynamics much). When sex reversal ceases, low v yy mitigates the negative effects of feminization and can even prevent population extinction. Little is known about v yy in natural populations. The available models now need to be parametrized in order to better predict the long-term consequences of disturbed sex determination.This article is part of the themed issue 'Adult sex ratios and reproductive decisions: a critical re-examination of sex differences in human and animal societies'. © 2017 The Author(s).

Maternal Touch Moderates Sex Differences in Juvenile Social Play Behavior

PubMed Central

Edelmann, Michelle N.; Demers, Catherine H.; Auger, Anthony P.

2013-01-01

Additional somatosensory contact of preterm human infants improves a variety of developmental assessment scores, but less is known about its lasting consequences. In rodents, maternal contact may influence the programming of juvenile social play behavior. Therefore, we used a paradigm where we can control the levels of somatosensory contact associated with maternal care. We find that additional somatosensory contact of offspring can have lasting consequences on juvenile social play behavior in a sex-dependent manner. Specifically, additional somatosensory stimuli reduced male social play behavior, but did not change female play behavior. We then examined if this additional infant contact altered some neurobiological substrates associated with play within the juvenile amygdala. Control males had lower levels of 5HT2a receptor mRNA levels contrasted to females; however, similar to its sex-dependent effect on juvenile social play, males that received additional somatosensory contact had higher serotonin 5HT2a receptor mRNA levels than control males. No difference was found in females. As serotonin signaling typically opposes juvenile play behavior, these data suggest that maternal touch can program lasting differences in juvenile social play and 5HT2a receptors mRNA levels within the juvenile amygdala. PMID:23460849

Developmental trajectories of the fronto-temporal lobes from infancy to early adulthood in healthy individuals.

PubMed

Tanaka, Chiaki; Matsui, Mie; Uematsu, Akiko; Noguchi, Kyo; Miyawaki, Toshio

2012-01-01

Brain development during early life in healthy individuals is rapid and dynamic, indicating that this period plays a very important role in neural and functional development. The frontal and temporal lobes are known to play a particularly important role in cognition. The study of healthy frontal and temporal lobe development in children is therefore of considerable importance. A better understanding of how these brain regions develop could also aid in the diagnosis and treatment of neurodevelopmental disorders. Some developmental studies have used magnetic resonance imaging (MRI) to examine infant brains, but it remains the case that relatively little is known about cortical brain development in the first few years of life. In the present study we examined whole brain, temporal lobe and frontal lobe developmental trajectories from infancy to early adulthood in healthy individuals, considering gender and brain hemisphere differences. We performed a cross-sectional, longitudinal morphometric MRI study of 114 healthy individuals (54 females and 60 males) aged 1 month to 25 years old (mean age ± SD 8.8 ± 6.9). We measured whole brain, temporal and frontal lobe gray matter (GM)/white matter (WM) volumes, following previously used protocols. There were significant non-linear age-related volume changes in all regions. Peak ages of whole brain, temporal lobe and frontal lobe development occurred around pre-adolescence (9-12 years old). GM volumes for all regions increased significantly as a function of age. Peak age was nevertheless lobe specific, with a pattern of earlier peak ages for females in both temporal and frontal lobes. Growth change in whole brain GM volume was larger in males than in females. However, GM volume growth changes for the temporal and frontal lobes showed a somewhat different pattern. GM volume for both temporal and frontal lobes showed a greater increase in females until around 5-6 years old, at which point this tendency reversed (GM volume changes in males became greater), with male GM volume increasing for a longer time than that of females. WM volume growth changes were similar across regions, all increasing rapidly until early childhood but slowing down thereafter. All regions displayed significant rightward volumetric asymmetry regardless of sex. Furthermore, the right temporal and frontal lobes showed a greater volumetric increase than the left for the first several years, with this tendency reversing at around 6 years of age. In addition, the left frontal and temporal lobes increased in volume for a longer period of time. Taken together, these findings indicated that brain developmental trajectories differ depending on brain region, sex and brain hemisphere. Gender-related factors such as sex hormones and functional laterality may affect brain development. Copyright © 2012 S. Karger AG, Basel.

Embryo-larval exposure to atrazine reduces viability and alters oxidative stress parameters in Drosophila melanogaster.

PubMed

Figueira, Fernanda Hernandes; Aguiar, Lais Mattos de; Rosa, Carlos Eduardo da

2017-01-01

The herbicide atrazine has been used worldwide with subsequent residual contamination of water and food, which may cause adverse effects on non-target organisms. Animal exposure to this herbicide may affect development, reproduction and energy metabolism. Here, the effects of atrazine regarding survival and redox metabolism were assessed in the fruit fly D. melanogaster exposed during embryonic and larval development. The embryos (newly fertilized eggs) were exposed to different atrazine concentrations (10μM and 100μM) in the diet until the adult fly emerged. Pupation and emergence rates, developmental time and sex ratio were determined as well as oxidative stress parameters and gene expression of the antioxidant defence system were evaluated in newly emerged male and female flies. Atrazine exposure reduced pupation and emergence rates in fruit flies without alterations to developmental time and sex ratio. Different redox imbalance patterns were observed between males and females exposed to atrazine. Atrazine caused an increase in oxidative damage, reactive oxygen species generation and antioxidant capacity and decreased thiol-containing molecules. Further, atrazine exposure altered the mRNA expression of antioxidant genes (keap1, sod, sod2, cat, irc, gss, gclm, gclc, trxt, trxr-1 and trxr-2). Reductions in fruit fly larval and pupal viability observed here are likely consequences of the oxidative stress induced by atrazine exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

Prediction of Toddlers’ Expressive Language From Maternal Sensitivity And Toddlers’ Anger Expressions: A Developmental Perspective

PubMed Central

Nozadi, Sara S; Spinrad, Tracy L; Eisenberg, Nancy; Bolnick, Rebecca; Eggum-Wilkens, Natalie. D; Smith, Cynthia L; Gaertner, Bridget; Kupfer, Anne; Sallquist, Julie

2013-01-01

Despite evidence for the importance of individual differences in expressive language during toddlerhood in predicting later literacy skills, few researchers have examined individual and contextual factors related to language abilities across the toddler years. Furthermore, a gap remains in the literature about the extent to which the relations of negative emotions and parenting to language skills may differ for girls and boys. The purpose of this longitudinal study was to investigate the associations among maternal sensitivity, children’s observed anger reactivity, and expressive language when children were 18 (T1; n = 247) and 30 (T2; n = 216) months. At each age, mothers reported on their toddlers’ expressive language, and mothers’ sensitive parenting behavior was observed during an unstructured free-play task. Toddlers’ anger expressions were observed during an emotion-eliciting task. Using path modeling, results showed few relations at T1. At T2, maternal sensitivity was negatively related to anger, and in turn, anger was associated with lower language skills. However, moderation analyses showed that these findings were significant for boys but not for girls. In addition, T1 maternal sensitivity and anger positively predicted expressive language longitudinally for both sexes. Findings suggest that the relations between maternal sensitivity, anger reactivity and expressive language may vary depending on the child’s developmental stage and sex. PMID:23911594

Developmental pathways in infants from 4 to 24 months.

PubMed

Valla, L; Birkeland, M S; Hofoss, D; Slinning, K

2017-07-01

There has been limited epidemiological research describing population-based samples regarding developmental pathways throughout infancy, and the research that exists has revealed substantial diversity. Identifying predictors for developmental pathways can inform early intervention services. The Ages and Stages Questionnaire was used to measure communication, gross motor, fine motor, problem-solving and personal-social skills longitudinally in a large, population-based sample of 1555 infants recruited from well-baby clinics in five municipalities in southeast Norway. We conducted latent class analyses to identify common pathways within the five developmental areas. Our results indicated that most classes of infants showed generally positive and stable normative developmental pathways. However, for communication and gross motor areas, more heterogeneity was found. For gross motor development, a class of 10% followed a U-shaped curve. A class of 8% had a declining communication pathway and did not reach the level of the high stable communication class at 24 months. Low gestational age, low Apgar score, male sex, maternal depression symptoms, non-Scandinavian maternal ethnicity and high maternal education significantly predict less beneficial communication pathways. The results suggest that infants with low gestational age, low Apgar score, male sex and a mother with depression symptoms or non-Scandinavian ethnicity may be at risk of developing less beneficial developmental pathways, especially within the communication area. Targeting these infants for surveillance and support might be protective against delayed development in several areas during a critical window of development. © 2017 John Wiley & Sons Ltd.

The Impact of Parents, Child Care Providers, Teachers, and Peers on Early Externalizing Trajectories

PubMed Central

Silver, Rebecca B.; Measelle, Jeffrey R.; Armstrong, Jeffrey M.; Essex, Marilyn J.

2010-01-01

This study utilized growth mixture modeling to examine the impact of parents, child care providers, teachers, and peers on the prediction of distinct developmental patterns of classroom externalizing behavior in elementary school. Among 241 children, three groups were identified. 84.6% of children exhibited consistently low externalizing behavior. The externalizing behavior of the Chronic High group (5.8%) remained elevated throughout elementary school; it increased over time in the Low Increasing group (9.5%). Negative relationships with teachers and peers in the kindergarten classroom increased the odds of having chronically high externalizing behavior. Teacher–child conflict increased the likelihood of a developmental pattern of escalating externalizing behavior. Boys were overrepresented in the behaviorally risky groups, and no sex differences in trajectory types were found. PMID:21094398

Genome-Wide Analysis Reveals Novel Regulators of Growth in Drosophila melanogaster

PubMed Central

Vonesch, Sibylle Chantal; Lamparter, David; Mackay, Trudy F. C.; Bergmann, Sven; Hafen, Ernst

2016-01-01

Organismal size depends on the interplay between genetic and environmental factors. Genome-wide association (GWA) analyses in humans have implied many genes in the control of height but suffer from the inability to control the environment. Genetic analyses in Drosophila have identified conserved signaling pathways controlling size; however, how these pathways control phenotypic diversity is unclear. We performed GWA of size traits using the Drosophila Genetic Reference Panel of inbred, sequenced lines. We find that the top associated variants differ between traits and sexes; do not map to canonical growth pathway genes, but can be linked to these by epistasis analysis; and are enriched for genes and putative enhancers. Performing GWA on well-studied developmental traits under controlled conditions expands our understanding of developmental processes underlying phenotypic diversity. PMID:26751788

Genetics and Epigenetics of Mating Type Determination in Paramecium and Tetrahymena.

PubMed

Orias, Eduardo; Singh, Deepankar Pratap; Meyer, Eric

2017-09-08

While sex is an ancient and highly conserved eukaryotic invention, self-incompatibility systems such as mating types or sexes appear to be derived limitations that show considerable evolutionary plasticity. Within a single class of ciliates, Paramecium and Tetrahymena species have long been known to present a wide variety of mating type numbers and modes of inheritance, but only recently have the genes involved been identified. Although similar transmembrane proteins mediate self/nonself recognition in both ciliates, the mechanisms of mating type determination differ widely, ranging from Mendelian systems to developmental nuclear differentiation, either stochastic or maternally inherited. The non-Mendelian systems rely on programmed editing of the germline genome that occurs during differentiation of the somatic nucleus, and they have co-opted different DNA recombination mechanisms-some previously unknown. Here we review the recent molecular advances and some remaining unsolved questions and discuss the possible implications of these diverse mechanisms for inbreeding/outbreeding balance regulation.

Effect of Sex of Embryo on Developmental Competence, Epigenetic Status, and Gene Expression in Buffalo (Bubalus bubalis) Embryos Produced by Hand-Made Cloning.

PubMed

Sandhu, Anjit; Mohapatra, Sushil K; Agrawal, Himanshu; Singh, Manoj K; Palta, Prabhat; Singla, Suresh K; Chauhan, Manmohan S; Manik, Radhey S

2016-10-01

Buffalo embryos were produced by hand-made cloning using skin fibroblasts from male and female buffaloes (n = 4 each) as donor cells for examining the effect of sex. Although the rate of blastocyst formation (43.8% ± 1.31% vs. 42.2% ± 1.22%) was similar, the total cell number (333 ± 10.4 vs. 270 ± 10.9) was higher (p < 0.05) whereas the apoptotic index (6.39 ± 0.25 vs. 8.52 ± 0.38) was lower (p < 0.05) for male than for female blastocysts. In the blastocysts, the global level of H3K18ac was found to be in the following order: male>female>IVF (in vitro fertilization) blastocysts (p < 0.05). The global level of H3K9me2 was not significantly different between male and female blastocysts and was higher (p < 0.05) compared with that in their IVF counterparts. The relative mRNA abundance of X-chromosome-linked (XIST, HPRT, PGK, and G6PD), apoptosis- (CASPASE3) and pregnancy-related genes (IFN-τ) was significantly higher (p < 0.05) whereas that of DNMT1 was significantly lower (p < 0.05) in female than in male blastocysts; however, in the case of apoptosis- (BCL-XL) and developmental competence-related genes (IGF1R and OCT4), the expression level was similar between the two groups. The gene expression level of OCT4 and IFN-τ but not of IGF1R was significantly lower (p < 0.05) in cloned than in IVF blastocysts. This study demonstrates that the epigenetic status, quality, and expression level of several genes but not the developmental competence are affected by the sex of cloned embryos.

No Evidence of Association between Childhood Urban Environment and Cortical Thinning in Psychotic Disorder.

PubMed

Frissen, Aleida; van Os, Jim; Habets, Petra; Gronenschild, Ed; Marcelis, Machteld

2017-01-01

The alterations in cortical morphology, such as cortical thinning, observed in psychotic disorder, may be the outcome of interacting genetic and environmental effects. It has been suggested that urban upbringing may represent a proxy environmental effect impacting cortical thickness (CT). Therefore, the current study examined whether the association between group as a proxy genetic variable (patients with psychotic disorder [high genetic risk], healthy siblings of patients [intermediate risk] and healthy control subjects [average risk]) and CT was conditional on different levels of the childhood urban environment and whether this was sex-dependent. T1-weighted MRI scans were acquired from 89 patients with a psychotic disorder, 95 non-psychotic siblings of patients with psychotic disorder and 87 healthy control subjects. Freesurfer software was used to measure CT. Developmental urban exposure was classified as low, medium, and high, reflecting the population density and the number of moves between birth and the 15th birthday, using data from the Dutch Central Bureau of Statistics and the equivalent database in Belgium. Multilevel regression analyses were used to examine the association between group, sex, and urban upbringing (as well as their interactions) and cortical CT as the dependent variable. CT was significantly smaller in the patient group compared to the controls (B = -0.043, p <0.001), but not in the siblings compared to the controls (B = -0.013, p = 0.31). There was no main effect of developmental urbanicity on CT (B = 0.001, p = 0.91). Neither the three-way group × urbanicity × sex interaction (χ2 = 3.73, p = 0.16), nor the two-way group × urbanicity interaction was significant (χ2 = 0.51, p = 0.77). The negative association between (familial risk for) psychotic disorder and CT was not moderated by developmental urbanicity, suggesting that reduced CT is not the outcome of familial sensitivity to the proxy environmental factor 'urban upbringing'.

The Microgenetic Emergence of Cooperative Play in 6-Year-Olds Developmentally At-Risk

ERIC Educational Resources Information Center

van der Aalsvoort, Geerdina M.; van der Leeden, Rien

2009-01-01

Cooperative play was investigated by a controlled pre/post-test intervention design with 28 dyads of 6-year-old students developmentally at-risk. Selection was based upon cut-off scores on a language development test and a nonverbal IQ test, and same-sex pairs were matched within classrooms. Co-variables were: socio economic status, free play time…

Carer Reports of Health Status among Adults with Intellectual/Developmental Disabilities in Taiwan Living at Home and in Institutions

ERIC Educational Resources Information Center

Wang, K.-Y.; Hsieh, K.; Heller, T.; Davidson, P. W.; Janicki, M. P.

2007-01-01

Background: The aim of the present study was to assess the health status of a cohort of adults with intellectual/developmental disabilities (I/DD) residing in family homes or institutions in Taiwan and to examine whether morbidity varied with age, sex, existing diagnosis [Down syndrome (DS), seizures, cerebral palsy (CP), intellectual disability…

Phenotypic plasticity in sex pheromone production in Bicyclus anynana butterflies

PubMed Central

Dion, Emilie; Monteiro, Antónia; Yew, Joanne Y.

2016-01-01

Phenotypic plasticity refers to the environmental control of phenotypes. Cues experienced during development (developmental plasticity) or during adulthood (acclimatization) can both affect adult phenotypes. Phenotypic plasticity has been described in many traits but examples of developmental plasticity in physiological traits, in particular, remain scarce. We examined developmental plasticity and acclimatization in pheromone production in the butterfly Bicyclus anynana in response to rearing temperature. B. anynana lives in the African tropics where warm rearing temperatures of the wet season produce active males that court and females that choose, whereas cooler temperatures of the dry season lead to choosy less active males and courting females. We hypothesized that if male pheromone production is costly, it should be reduced in the dry season form. After describing the ultrastructure of pheromone producing cells, we showed that dry season males produced significantly less sex pheromones than wet season males, partly due to acclimatization and partly due to developmental plasticity. Variation in levels of one of the compounds is associated with differential regulation of a pheromone biosynthetic enzyme gene. This plasticity might be an adaptation to minimize pheromone production costs during the stressful dry season. PMID:27966579

Reproductive strategy, sexual development and attraction to facial characteristics

PubMed Central

Cornwell, R. Elisabeth; Law Smith, Miriam J; Boothroyd, Lynda G; Moore, Fhionna R; Davis, Hasker P; Stirrat, Michael; Tiddeman, Bernard; Perrett, David I

2006-01-01

Sexual reproduction strategies vary both between and within species in the level of investment in offspring. Life-history theories suggest that the rate of sexual maturation is critically linked to reproductive strategy, with high investment being associated with few offspring and delayed maturation. For humans, age of puberty and age of first sex are two developmental milestones that have been associated with reproductive strategies. Stress during early development can retard or accelerate sexual maturation and reproduction. Early age of menarche is associated with absence of younger siblings, absence of a father figure during early life and increased weight. Father absence during early life is also associated with early marriage, pregnancy and divorce. Choice of partner characteristics is critical to successful implementation of sexual strategies. It has been suggested that sexually dimorphic traits (including those evident in the face) signal high-quality immune function and reproductive status. Masculinity in males has also been associated with low investment in mate and offspring. Thus, women's reproductive strategy should be matched to the probability of male investment, hence to male masculinity. Our review leads us to predict associations between the rate of sexual maturation and adult preferences for facial characteristics (enhanced sexual dimorphism and attractiveness). We find for men, engaging in sex at an early age is related to an increased preference for feminized female faces. Similarly, for women, the earlier the age of first sex the greater the preference for masculinity in opposite-sex faces. When we controlled sexual dimorphism in male faces, the speed of sexual development in women was not associated with differences in preference for male facial attractiveness. These developmental influences on partner choice were not mediated by self-rated attractiveness or parental relationships. We conclude that individuals assort in preferences based on the rapidity of their sexual development. Fast developing individuals prefer opposite-sex partners with an increased level of sexually dimorphic facial characteristics. PMID:17118929

Reproductive strategy, sexual development and attraction to facial characteristics.

PubMed

Cornwell, R Elisabeth; Law Smith, Miriam J; Boothroyd, Lynda G; Moore, Fhionna R; Davis, Hasker P; Stirrat, Michael; Tiddeman, Bernard; Perrett, David I

2006-12-29

Sexual reproduction strategies vary both between and within species in the level of investment in offspring. Life-history theories suggest that the rate of sexual maturation is critically linked to reproductive strategy, with high investment being associated with few offspring and delayed maturation. For humans, age of puberty and age of first sex are two developmental milestones that have been associated with reproductive strategies. Stress during early development can retard or accelerate sexual maturation and reproduction. Early age of menarche is associated with absence of younger siblings, absence of a father figure during early life and increased weight. Father absence during early life is also associated with early marriage, pregnancy and divorce. Choice of partner characteristics is critical to successful implementation of sexual strategies. It has been suggested that sexually dimorphic traits (including those evident in the face) signal high-quality immune function and reproductive status. Masculinity in males has also been associated with low investment in mate and offspring. Thus, women's reproductive strategy should be matched to the probability of male investment, hence to male masculinity. Our review leads us to predict associations between the rate of sexual maturation and adult preferences for facial characteristics (enhanced sexual dimorphism and attractiveness). We find for men, engaging in sex at an early age is related to an increased preference for feminized female faces. Similarly, for women, the earlier the age of first sex the greater the preference for masculinity in opposite-sex faces. When we controlled sexual dimorphism in male faces, the speed of sexual development in women was not associated with differences in preference for male facial attractiveness. These developmental influences on partner choice were not mediated by self-rated attractiveness or parental relationships. We conclude that individuals assort in preferences based on the rapidity of their sexual development. Fast developing individuals prefer opposite-sex partners with an increased level of sexually dimorphic facial characteristics.

Epigenetics of sex determination and gonadogenesis.

PubMed

Piferrer, Francesc

2013-04-01

Epigenetics is commonly defined as the study of heritable changes in gene function that cannot be explained by changes in DNA sequence. The three major epigenetic mechanisms for gene expression regulation include DNA methylation, histone modifications, and non-coding RNAs. Epigenetic mechanisms provide organisms with the ability to integrate genomic and environmental information to modify the activity of their genes for generating a particular phenotype. During development, cells differentiate, acquire, and maintain identity through changes in gene expression. This is crucial for sex determination and differentiation, which are among the most important developmental processes for the proper functioning and perpetuation of species. This review summarizes studies showing how epigenetic regulatory mechanisms contribute to sex determination and reproductive organ formation in plants, invertebrates, and vertebrates. Further progress will be made by integrating several approaches, including genomics and Next Generation Sequencing to create epigenetic maps related to different aspects of sex determination and gonadogenesis. Epigenetics will also contribute to understand the etiology of several disorders of sexual development. It also might play a significant role in the control of reproduction in animal farm production and will aid in recognizing the environmental versus genetic influences on sex determination of sensitive species in a global change scenario. Copyright © 2013 Wiley Periodicals, Inc.

The ‘male escape hypothesis’: sex-biased metamorphosis in response to climatic drivers in a facultatively paedomorphic amphibian

PubMed Central

Mathiron, Anthony G. E.; Lena, Jean-Paul; Baouch, Sarah

2017-01-01

Paedomorphosis is a major evolutionary process that bypasses metamorphosis and allows reproduction in larvae. In newts and salamanders, it can be facultative with paedomorphs retaining gills and metamorphs dispersing. The evolution of these developmental processes is thought to have been driven by the costs and benefits of inhabiting aquatic versus terrestrial habitats. In this context, we aimed at testing the hypothesis that climatic drivers affect phenotypic transition and the difference across sexes because sex-ratio is biased in natural populations. Through a replicated laboratory experiment, we showed that paedomorphic palmate newts (Lissotriton helveticus) metamorphosed at a higher frequency when water availability decreased and metamorphosed earlier when temperature increased in these conditions. All responses were sex-biased, and males were more prone to change phenotype than females. Our work shows how climatic variables can affect facultative paedomorphosis and support theoretical models predicting life on land instead of in water. Moreover, because males metamorphose and leave water more often and earlier than females, these results, for the first time, give an experimental explanation for the rarity of male paedomorphosis (the ‘male escape hypothesis’) and suggest the importance of sex in the evolution of paedomorphosis versus metamorphosis. PMID:28424346

Isolation and Molecular Characterization of the Transformer Gene From Bactrocera cucurbitae (Diptera: Tephritidae)

PubMed Central

Luo, Ya; Zhao, Santao; Li, Jiahui; Li, Peizheng

2017-01-01

transformer (tra) is a switch gene of sex determination in many insects, particularly in Dipterans. However, the sex determination pathway in Bactrocera cucurbitae (Coquillett), a very destructive pest on earth, remains largely uncharacterized. In this study, we have isolated and characterized one female-specific and two male-specific transcripts of the tra gene (Bcutra) of B. cucurbitae. The genomic structure of Bcutra has been determined and the presence of multiple conserved Transformer (TRA)/TRA-2 binding sites in Bcutra has been found. BcuTRA is highly conservative with its homologues in other tephritid fruit flies. Gene expression analysis of Bcutra at different developmental stages demonstrates that the female transcript of Bcutra appears earlier than the male counterparts, indicating that the maternal TRA is inherited in eggs and might play a role in the regulation of TRA expression. The conservation of protein sequence and sex-specific splicing of Bcutra and its expression patterns during development suggest that Bcutra is probably the master gene of sex determination of B. cucurbitae. Isolation of Bcutra will facilitate the development of a genetic sexing strain for its biological control. PMID:28931159

Isolation and Molecular Characterization of the Transformer Gene From Bactrocera cucurbitae (Diptera: Tephritidae).

PubMed

Luo, Ya; Zhao, Santao; Li, Jiahui; Li, Peizheng; Yan, Rihui

2017-01-01

transformer (tra) is a switch gene of sex determination in many insects, particularly in Dipterans. However, the sex determination pathway in Bactrocera cucurbitae (Coquillett), a very destructive pest on earth, remains largely uncharacterized. In this study, we have isolated and characterized one female-specific and two male-specific transcripts of the tra gene (Bcutra) of B. cucurbitae. The genomic structure of Bcutra has been determined and the presence of multiple conserved Transformer (TRA)/TRA-2 binding sites in Bcutra has been found. BcuTRA is highly conservative with its homologues in other tephritid fruit flies. Gene expression analysis of Bcutra at different developmental stages demonstrates that the female transcript of Bcutra appears earlier than the male counterparts, indicating that the maternal TRA is inherited in eggs and might play a role in the regulation of TRA expression. The conservation of protein sequence and sex-specific splicing of Bcutra and its expression patterns during development suggest that Bcutra is probably the master gene of sex determination of B. cucurbitae. Isolation of Bcutra will facilitate the development of a genetic sexing strain for its biological control. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

Sex differences in body composition, fat storage, and gene expression profile in Caenorhabditis elegans in response to dietary restriction.

PubMed

Miersch, Claudia; Döring, Frank

2013-07-02

The metabolic and health-promoting effects of dietary restriction (DR) have been extensively studied in several species. The response to DR with respect to sex is essentially unknown. To address this question, we used the model organism Caenorhabditis elegans to analyze body composition and gene expression in males and hermaphrodites in response to DR. Unexpectedly, DR increased the fat-to-fat-free mass ratio and enlarged lipid droplets in both sexes to a similar extent. These effects were linked to a downregulation of the lipase-like 5 (lipl-5) gene in both sexes at two developmental stages. By contrast, the reductions in body size, protein content, and total RNA content in response to DR were more pronounced in hermaphrodites than in males. Functional enrichment analysis of gene expression data showed a DR-induced downregulation of several embryogenesis-associated genes concomitant with an ongoing expression of sperm-associated genes in hermaphrodites. In conclusion, DR increases fat stores in both sexes of C. elegans in the form of large and possibly lipolysis-resistant lipid droplets and markedly alters the reproductive program in hermaphrodites but not in males.

Hormonal interactions and gene regulation can link monoecy and environmental plasticity to the evolution of dioecy in plants.

PubMed

Golenberg, Edward M; West, Nicholas W

2013-06-01

Most models for dioecy in flowering plants assume that dioecy arises directly from hermaphroditism through a series of independent feminizing and masculinizing mutations that become chromosomally linked. However, dioecy appears to evolve most frequently through monoecious grades. The major genetic models do not explain the evolution of unisexual flowers in monoecious and submonoecious populations, nor do they account for environmentally induced sexual plasticity. In this review, we explore the roles of environmental stress and hormones on sex determination, and propose a model that can explain the evolution of dioecy through monoecy, and the mechanisms of environmental sex determination. Environmental stresses elicit hormones that allow plants to mediate the negative effects of the stresses. Many of these same hormones are involved in the regulation of floral developmental genes. Recent studies have elucidated the mechanisms whereby these hormones interact and can act as switchpoints in regulatory pathways. Consequently, differential concentrations of plant hormones can regulate whole developmental pathways, providing a mechanism for differential development within isogenic individuals such as seen in monoecious plants. Sex-determining genes in such systems will evolve to generate clusters of coexpressed suites. Coexpression rather than coinheritance of gender-specific genes will define the sexual developmental fate. Therefore, selection for gender type will drive evolution of the regulatory sequences of such genes rather than their synteny. Subsequent mutations to hyper- or hyposensitive alleles within the hormone response pathway can result in segregating dioecious populations. Simultaneously, such developmental systems will remain sensitive to external stimuli that modify hormone responses.

Effects of developmental lead exposure on the hippocampal methylome: Influences of sex and timing and level of exposure.

PubMed

Singh, G; Singh, V; Wang, Zi-Xuan; Voisin, G; Lefebvre, F; Navenot, J-M; Evans, B; Verma, M; Anderson, D W; Schneider, J S

2018-06-15

Developmental lead (Pb) exposure results in persistent cognitive/behavioral impairments as well as an elevated risk for developing a variety of diseases in later life. Environmental exposures during development can result in a variety of epigenetic changes, including alterations in DNA methylation, that can influence gene expression patterns and affect the function and development of the nervous system. The present promoter-based methylation microarray profiling study explored the extent to which developmental Pb exposure may modify the methylome of a brain region, hippocampus, known to be sensitive to the effects of Pb exposure. Male and female Long Evans rats were exposed to 0 ppm, 150 ppm, 375 ppm, or 750 ppm Pb through perinatal exposures (gestation through lactation), early postnatal exposures (birth through weaning), or long-term postnatal exposures (birth through postnatal day 55). Results showed a significant contribution of sex to the hippocampal methylome and effects of Pb exposure level, with non-linear dose response effects on methylation. Surprisingly, the developmental period of exposure contributed only a small amount of variance to the overall data and gene ontology (GO) analysis revealed the largest number of overrepresented GO terms in the groups with the lowest level of exposure. The highest number of significant differentially methylated regions was found in females exposed to Pb at the lowest exposure level. Our data reinforce the significant effect that low level Pb exposure may have on gene-specific DNA methylation patterns in brain and that this occurs in a sex-dependent manner. Copyright © 2018 Elsevier B.V. All rights reserved.

Developmental trajectory of contextual learning and 24-h acetylcholine release in the hippocampus

PubMed Central

Takase, Kenkichi; Sakimoto, Yuya; Kimura, Fukuko; Mitsushima, Dai

2014-01-01

To determine the developmental trajectory of hippocampal function in rats, we examined 24-h changes in extracellular acetylcholine (ACh) levels and contextual learning performance. Extracellular ACh significantly correlated with spontaneous behavior, exhibiting a 24-h rhythm in juvenile (4-week-old), pubertal (6-week-old), and adult (9- to 12-week-old) rats. Although juveniles of both sexes exhibited low ACh levels, adult males had higher ACh levels than adult females. Moreover, juveniles exhibited much more spontaneous activity than adults when they showed equivalent ACh levels. Similarly, juveniles of both sexes exhibited relatively low contextual learning performance. Because contextual learning performance was significantly increased only in males, adult males exhibited better performance than adult females. We also observed a developmental relationship between contextual learning and ACh levels. Scopolamine pretreatment blocked contextual learning and interrupted the correlation. Since long-term scopolamine treatment after weaning impaired contextual learning in juveniles, the cholinergic input may participate in the development of hippocampus. PMID:24435246

Bombyx mori histone methyltransferase BmAsh2 is essential for silkworm piRNA-mediated sex determination.

PubMed

Li, Zhiqian; You, Lang; Yan, Dong; James, Anthony A; Huang, Yongping; Tan, Anjiang

2018-02-01

Sex determination is a hierarchically-regulated process with high diversity in different organisms including insects. The W chromosome-derived Fem piRNA has been identified as the primary sex determination factor in the lepidopteran insect, Bombyx mori, revealing a distinctive piRNA-mediated sex determination pathway. However, the comprehensive mechanism of silkworm sex determination is still poorly understood. We show here that the silkworm PIWI protein BmSiwi, but not BmAgo3, is essential for silkworm sex determination. CRISPR/Cas9-mediated depletion of BmSiwi results in developmental arrest in oogenesis and partial female sexual reversal, while BmAgo3 depletion only affects oogenesis. We identify three histone methyltransferases (HMTs) that are significantly down-regulated in BmSiwi mutant moths. Disruption one of these, BmAsh2, causes dysregulation of piRNAs and transposable elements (TEs), supporting a role for it in the piRNA signaling pathway. More importantly, we find that BmAsh2 mutagenesis results in oogenesis arrest and partial female-to-male sexual reversal as well as dysregulation of the sex determination genes, Bmdsx and BmMasc. Mutagenesis of other two HMTs, BmSETD2 and BmEggless, does not affect piRNA-mediated sex determination. Histological analysis and immunoprecipitation results support a functional interaction between the BmAsh2 and BmSiwi proteins. Our data provide the first evidence that the HMT, BmAsh2, plays key roles in silkworm piRNA-mediated sex determination.

Sex determination strategies in 2012: towards a common regulatory model?

PubMed Central

2012-01-01

Sex determination is a complicated process involving large-scale modifications in gene expression affecting virtually every tissue in the body. Although the evolutionary origin of sex remains controversial, there is little doubt that it has developed as a process of optimizing metabolic control, as well as developmental and reproductive functions within a given setting of limited resources and environmental pressure. Evidence from various model organisms supports the view that sex determination may occur as a result of direct environmental induction or genetic regulation. The first process has been well documented in reptiles and fish, while the second is the classic case for avian species and mammals. Both of the latter have developed a variety of sex-specific/sex-related genes, which ultimately form a complete chromosome pair (sex chromosomes/gonosomes). Interestingly, combinations of environmental and genetic mechanisms have been described among different classes of animals, thus rendering the possibility of a unidirectional continuous evolutionary process from the one type of mechanism to the other unlikely. On the other hand, common elements appear throughout the animal kingdom, with regard to a) conserved key genes and b) a central role of sex steroid control as a prerequisite for ultimately normal sex differentiation. Studies in invertebrates also indicate a role of epigenetic chromatin modification, particularly with regard to alternative splicing options. This review summarizes current evidence from research in this hot field and signifies the need for further study of both normal hormonal regulators of sexual phenotype and patterns of environmental disruption. PMID:22357269

Sex differences and structural brain maturation from childhood to early adulthood.

PubMed

Koolschijn, P Cédric M P; Crone, Eveline A

2013-07-01

Recent advances in structural brain imaging have demonstrated that brain development continues through childhood and adolescence. In the present cross-sectional study, structural MRI data from 442 typically developing individuals (range 8-30) were analyzed to examine and replicate the relationship between age, sex, brain volumes, cortical thickness and surface area. Our findings show differential patterns for subcortical and cortical areas. Analysis of subcortical volumes showed that putamen volume decreased with age and thalamus volume increased with age. Independent of age, males demonstrated larger amygdala and thalamus volumes compared to females. Cerebral white matter increased linearly with age, at a faster pace for females than males. Gray matter showed nonlinear decreases with age. Sex-by-age interactions were primarily found in lobar surface area measurements, with males demonstrating a larger cortical surface up to age 15, while cortical surface in females remained relatively stable with increasing age. The current findings replicate some, but not all prior reports on structural brain development, which calls for more studies with large samples, replications, and specific tests for brain structural changes. In addition, the results point toward an important role for sex differences in brain development, specifically during the heterogeneous developmental phase of puberty. Copyright © 2013 Elsevier Ltd. All rights reserved.

Quality of Life and Relationships in Sex Offenders with Intellectual Disability

ERIC Educational Resources Information Center

Steptoe, Lesley; Lindsay, William R.; Forrest, Diane; Power, Mick

2006-01-01

Background: Hayes (1991) and Day (1994) have developed hypotheses about the importance of social and developmental variables in the aetiology of sexual offences in offenders with intellectual disability. The present study is the first of its kind to investigate the perceived quality of life and relationships of sex offenders in comparison to an…

Internalizing behavior in adolescent girls affects parental emotional overinvolvement: a cross-lagged twin study.

PubMed

Moberg, Therese; Lichtenstein, Paul; Forsman, Mats; Larsson, Henrik

2011-03-01

The aim of this study was to examine the direction and the etiology of the association between different parenting styles (parental emotional overinvolvement [EOI] and parental criticism) and internalizing behavior from adolescence to early adulthood. A longitudinal genetically informative cross-lagged design was applied to a population-based sample of Swedish twins contacted at age 16-17 (n = 2369) and at age 19-20 (n = 1705). Sex-limitation modelling revealed different effects for boys and girls. For girls, genetic influences on internalizing problems at age 16-17 independently explained 2.7% of the heritability in parental EOI at age 19-20. These results suggest that emotionally overinvolved and self-sacrificing parental behavior stems in part from daughters (but not sons) genetic predisposition for internalizing behavior. These findings highlight the importance of genetically influenced child-driven effects underlying the parenting-internalizing association, and clarify that the role of such effects may differ depending on sex, type of parenting and developmental period.

Intrinsic aspirations and personal meaning across adulthood: conceptual interrelations and age/sex differences.

PubMed

Morgan, Jessica; Robinson, Oliver

2013-05-01

The present study examined adult age and sex differences in self-reported aspirations and personal meaning. Young, midlife, and older adults (N = 2,557) from the United Kingdom or United States completed an online survey of their aspiration striving, aspiration importance, and personal meaning (subscales of Purposeful Life, Exciting Life, Accomplished Life, Principled Life, Valued Life). Predictions were made in line with humanistic and gerontology theories, which suggest that sources of personal meaning consolidate across the life span toward intrinsically motivated pursuits. Findings supported these predictions, showing that although there was a tendency for aspirations to decline with age, the proportion of intrinsically motivated aspirations increased, as did total meaning and the interrelationship between meaning and intrinsic aspirations. There were also gender differences in personal meaning and aspirations, which suggested a more pronounced midlife dip in intrinsic and purposive goal striving for men, and a greater focus on intrinsic aspirations in women. Developmental and cohort interpretations of these findings and directions for further research are discussed.

DNA Damage Analysis in Children with Non-syndromic Developmental Delay by Comet Assay.

PubMed

Susai, Surraj; Chand, Parkash; Ballambattu, Vishnu Bhat; Hanumanthappa, Nandeesha; Veeramani, Raveendranath

2016-05-01

Majority of the developmental delays in children are non-syndromic and they are believed to have an underlying DNA damage, though not well substantiated. Hence the present study was carried out to find out if there is any increased DNA damage in children with non-syndromic developmental delay by using the comet assay. The present case-control study was undertaken to assess the level of DNA damage in children with non syndromic developmental delay and compare the same with that of age and sex matched controls using submarine gel electrophoresis (Comet Assay). The blood from clinically diagnosed children with non syndromic developmental delay and controls were subjected for alkaline version of comet assay - Single cell gel electrophoresis using lymphocytes isolated from the peripheral blood. The comets were observed under a bright field microscope; photocaptured and scored using the Image J image quantification software. Comet parameters were compared between the cases and controls and statistical analysis and interpretation of results was done using the statistical software SPSS version 20. The mean comet tail length in cases and control was 20.77+7.659μm and 08.97+4.398μm respectively which was statistically significant (p<0.001). Other comet parameters like total comet length and % DNA in tail also showed a statistically significant difference (p < 0.001) between cases and controls. The current investigation unraveled increased levels of DNA damage in children with non syndromic developmental delay when compared to the controls.

Developmental trajectories of paediatric headache - sex-specific analyses and predictors.

PubMed

Isensee, Corinna; Fernandez Castelao, Carolin; Kröner-Herwig, Birgit

2016-01-01

Headache is the most common pain disorder in children and adolescents and is associated with diverse dysfunctions and psychological symptoms. Several studies evidenced sex-specific differences in headache frequency. Until now no study exists that examined sex-specific patterns of change in paediatric headache across time and included pain-related somatic and (socio-)psychological predictors. Latent Class Growth Analysis (LCGA) was used in order to identify different trajectory classes of headache across four annual time points in a population-based sample (n = 3 227; mean age 11.34 years; 51.2 % girls). In multinomial logistic regression analyses the influence of several predictors on the class membership was examined. For girls, a four-class model was identified as the best fitting model. While the majority of girls reported no (30.5 %) or moderate headache frequencies (32.5 %) across time, one class with a high level of headache days (20.8 %) and a class with an increasing headache frequency across time (16.2 %) were identified. For boys a two class model with a 'no headache class' (48.6 %) and 'moderate headache class' (51.4 %) showed the best model fit. Regarding logistic regression analyses, migraine and parental headache proved to be stable predictors across sexes. Depression/anxiety was a significant predictor for all pain classes in girls. Life events, dysfunctional stress coping and school burden were also able to differentiate at least between some classes in both sexes. The identified trajectories reflect sex-specific differences in paediatric headache, as seen in the number and type of classes extracted. The documented risk factors can deliver ideas for preventive actions and considerations for treatment programmes.

Design, Utility, and History of the Colorado Adoption Project: Examples Involving Adjustment Interactions1

PubMed Central

Rhea, Sally Ann; Bricker, Josh B.; Corley, Robin P.; DeFries, John C.; Wadsworth, Sally J.

2013-01-01

This paper describes the Colorado Adoption Project (CAP), a longitudinal study in behavioral development, and discusses how adoption studies may be used to assess genetic and environmental etiologies of individual differences for important developmental outcomes. Previous CAP research on adjustment outcomes in childhood and adolescence which found significant interactions, including gene-environment interactions, is reviewed. New research suggests mediating effects of menarche and religiosity on age at first sex in this predominantly middle-class, Caucasian sample. PMID:23833552

Parent-of-origin Effect in Schizophrenia and Non-affective Psychoses: Evidence from Dermatoglyphics

PubMed Central

Divakaran, Anjith; Narayanaswamy, Janardhanan C.; Kalmadi, Sunil V.; Narayan, Vidya; Rao, Naren P.; Venkatasubramanian, Ganesan

2013-01-01

Objective: This study aims at examining “parent-of-origin effect” (POE) in dermatoglyphic patterns among patients with schizophrenia and non-affective psychoses. Materials and Methods: Dermatoglyphic comparison was carried out for schizophrenia patients (n=200) and healthy controls (HC) (n=100). In addition, the effect of family history and POE was examined in the dermatoglyphic pattern. Results: Schizophrenia patients compared to HC had significantly lower left total finger ridge count (LTFRC) (t=3.63, P<0.001), right total finger ridge count (RTFRC) (t=4.86, P<0.001), and absolute finger ridge count (ATFRC) (t=4.80, P<0.001) compared to HC. It was also noted that patient group had significantly higher average number of arches (t=2.20, P=0.03). The comparison between the same sex POE group and the opposite sex POE group revealed that significant differences exist in LTFRC (t=2.91, P<0.01) and ATFRC (t=2.30, P=0.02). The same sex group also had lesser number of whorls compared to opposite sex group (t=2.04, P=0.04). Conclusions: The same sex parental inheritance group seem to be more developmentally compromised than the opposite sex parental inheritance group indicating a significant POE. Complex epigenetic mechanisms along with hormonal modulation could explain the sex specific disease phenotype expression, which is a plausible explanation as in the present study. PMID:24249928

Parent-of-origin Effect in Schizophrenia and Non-affective Psychoses: Evidence from Dermatoglyphics.

PubMed

Divakaran, Anjith; Narayanaswamy, Janardhanan C; Kalmadi, Sunil V; Narayan, Vidya; Rao, Naren P; Venkatasubramanian, Ganesan

2013-07-01

This study aims at examining "parent-of-origin effect" (POE) in dermatoglyphic patterns among patients with schizophrenia and non-affective psychoses. Dermatoglyphic comparison was carried out for schizophrenia patients (n=200) and healthy controls (HC) (n=100). In addition, the effect of family history and POE was examined in the dermatoglyphic pattern. Schizophrenia patients compared to HC had significantly lower left total finger ridge count (LTFRC) (t=3.63, P<0.001), right total finger ridge count (RTFRC) (t=4.86, P<0.001), and absolute finger ridge count (ATFRC) (t=4.80, P<0.001) compared to HC. It was also noted that patient group had significantly higher average number of arches (t=2.20, P=0.03). The comparison between the same sex POE group and the opposite sex POE group revealed that significant differences exist in LTFRC (t=2.91, P<0.01) and ATFRC (t=2.30, P=0.02). The same sex group also had lesser number of whorls compared to opposite sex group (t=2.04, P=0.04). The same sex parental inheritance group seem to be more developmentally compromised than the opposite sex parental inheritance group indicating a significant POE. Complex epigenetic mechanisms along with hormonal modulation could explain the sex specific disease phenotype expression, which is a plausible explanation as in the present study.

Interpreting sex differences in enamel hypoplasia in human and non-human primates: Developmental, environmental, and cultural considerations.

PubMed

Guatelli-Steinberg, D; Lukacs, J R

1999-01-01

The purpose of this review is to provide a synoptic, critical evaluation of the evidence of, and potential etiological factors contributing to, sex differences in the expression of enamel hypoplasia (EH). Specifically, this review considers theoretical expectations and empirical evidence bearing on two central issues. The first of these is the impact of a theorized inherent male vulnerability to physiological stress on sex differences in EH. The second issue is the potential contribution to sex differences in EH of intrinsic differences in male and female enamel composition and development. To address this first issue, EH frequencies by sex are examined in samples subject to a high degree of physiological stress. Based on the concept of inherent male vulnerability (or female buffering), males in stressful environments would be expected to exhibit higher EH frequencies than females. This expectation is evaluated in light of cultural practices of sex-biased investment that mediate the relationship between environmental stress and EH expression. Defects forming prenatally afford an opportunity to study this relationship without the confounding effects of sex-biased postnatal investment. Data bearing on this issue derive from previously conducted studies of EH in permanent and deciduous teeth in both modern and archaeological samples as well as from new data on Indian schoolchildren. To address the second issue, fundamental male-female enamel differences are evaluated for their potential impact on EH expression. A large sex difference in the duration of canine crown formation in non-human primates suggests that male canines may have greater opportunity to record stress events than those of females. This expectation is examined in great apes, whose canines often record multiple episodes of stress and are sexually dimorphic in crown formation times. With respect to the first issue, in most studies, sex differences in EH prevalence are statistically nonsignificant. However, when sex differences are significant, there is a slight trend for them to be greater in males than in females, suggesting a weak influence of greater male vulnerability. Cultural practices of sex-biased investment in children appear to have greater impact on EH expression than does male vulnerability/female buffering. With respect to the second issue, sex differences in the composition and development of enamel were reviewed and determined to have limited or unknown impact on EH expression. Of these factors, only the duration of crown formation was expected to affect EH expression by sex within the great apes. The data support an association between higher defect counts in the canines of great ape males relative to those of females that may be the result of longer crown formation times in the canines of great ape males. This review concludes with an assessment of the nature of the evidence currently available to examine these issues and suggests future avenues for research focused on elucidating them.

Stress, sex, and plague: Patterns of developmental stress and survival in pre- and post-Black Death London.

PubMed

DeWitte, Sharon N

2018-01-01

Previous research revealed declines in survivorship in London before the Black Death (c. 1346-1353), and improvements in survivorship following the epidemic. These trends indicate that there were declines in general levels of health before the Black Death and improvements thereof afterwards. This study expands on previous research by examining whether changes in survivorship were consistent between the sexes, and how patterns of developmental stress markers changed before and after the Black Death. This study uses samples from London cemeteries dated to one of three periods: Early Pre-Black Death (1000-1200 AD, n = 255), Late Pre-Black Death (1200-1250 AD, n = 247), or Post-Black Death (1350-1540 AD n = 329). Temporal trends in survivorship are assessed via Kaplan-Meier survival analysis, and trends in tibial length (as a proxy for stature) and linear enamel hypoplasia (LEH) are assessed using t-tests and Chi-square tests, respectively. Survivorship for both sexes decreased before the Black Death and increased afterwards. For males, LEH frequencies increased and stature decreased before the epidemic, and LEH declined and stature increased after the Black Death. For females, the only significant change with respect to developmental stress markers was a decrease in stature after the Black Death. These results might reflect variation between the sexes in sensitivity to stressors, the effects of nutrition on pubertal timing, disproportionate access to dietary resources for males in the aftermath of the Black Death, the disproportionate deaths of frail individuals during the epidemic, or some combination of these factors. © 2017 Wiley Periodicals, Inc.

Developmental Coordination Disorder, Sex, and Activity Deficit over Time: A Longitudinal Analysis of Participation Trajectories in Children with and without Coordination Difficulties

ERIC Educational Resources Information Center

Cairney, John; Hay, John A.; Veldhuizen, Scott; Missiuna, Cheryl; Faught, Brent E.

2010-01-01

Aim: Children with developmental coordination disorder (DCD) are known to participate in active play less than typically developing children. However, it is not known whether the activity deficit between children with and without DCD widens or diminishes over time. Method: Data were obtained from a large, prospective cohort study of children…

Developmental, Familial and Educational Characteristics of a Sample of Children with Autism Spectrum Disorders in Greece

ERIC Educational Resources Information Center

Stampoltzis, Aglaia; Papatrecha, Virginia; Polychronopoulou, Stavroula; Mavronas, Dimitris

2012-01-01

The aim of this study is to describe the developmental, familial and educational characteristics of 91 children with a clinical diagnosis of autism spectrum disorders (ASDs), from one educational district of Athens, Greece. Records of the 91 children, aged 4-14 years old, were examined with respect to sex, age of diagnosis, type of ASDs, school…

Effects of blocking developmental cell death on sexually dimorphic calbindin cell groups in the preoptic area and bed nucleus of the stria terminalis

PubMed Central

2012-01-01

Background Calbindin-D28 has been used as a marker for the sexually dimorphic nucleus of the preoptic area (SDN-POA). Males have a distinct cluster of calbindin-immunoreactive (ir) cells in the medial preoptic area (CALB-SDN) that is reduced or absent in females. However, it is not clear whether the sex difference is due to the absolute number of calbindin-ir cells or to cell position (that is, spread), and the cellular mechanisms underlying the sex difference are not known. We examined the number of cells in the CALB-SDN and surrounding regions of C57Bl/6 mice and used mice lacking the pro-death gene, Bax, to test the hypothesis that observed sex differences are due to cell death. Methods Experiment 1 compared the number of cells in the CALB-SDN and surrounding regions in adult males, females, and females injected with estradiol benzoate on the day of birth. In experiment 2, cell number in the CALB-SDN and adjacent regions were compared in wild-type and Bax knockout mice of both sexes. In addition, calbindin-ir cells were quantified within the principal nucleus of the bed nucleus of the stria terminalis (BNSTp), a nearby region that is larger in males due to Bax-dependent cell death. Results Males had more cells in the CALB-SDN as well as in surrounding regions than did females, and estradiol treatment of females at birth masculinized both measures. Bax deletion had no effect on cell number in the CALB-SDN or surrounding regions but increased calbindin-ir cell number in the BNSTp. Conclusions The sex difference in the CALB-SDN of mice results from an estrogen-dependent difference in cell number with no evidence found for greater spread of cells in females. Blocking Bax-dependent cell death does not prevent sex differences in calbindin-ir cell number in the BNST or CALB-SDN but increases calbindin-ir cell number in the BNSTp of both sexes. PMID:22336348

Effects of blocking developmental cell death on sexually dimorphic calbindin cell groups in the preoptic area and bed nucleus of the stria terminalis.

PubMed

Gilmore, Richard F; Varnum, Megan M; Forger, Nancy G

2012-02-15

Calbindin-D28 has been used as a marker for the sexually dimorphic nucleus of the preoptic area (SDN-POA). Males have a distinct cluster of calbindin-immunoreactive (ir) cells in the medial preoptic area (CALB-SDN) that is reduced or absent in females. However, it is not clear whether the sex difference is due to the absolute number of calbindin-ir cells or to cell position (that is, spread), and the cellular mechanisms underlying the sex difference are not known. We examined the number of cells in the CALB-SDN and surrounding regions of C57Bl/6 mice and used mice lacking the pro-death gene, Bax, to test the hypothesis that observed sex differences are due to cell death. Experiment 1 compared the number of cells in the CALB-SDN and surrounding regions in adult males, females, and females injected with estradiol benzoate on the day of birth. In experiment 2, cell number in the CALB-SDN and adjacent regions were compared in wild-type and Bax knockout mice of both sexes. In addition, calbindin-ir cells were quantified within the principal nucleus of the bed nucleus of the stria terminalis (BNSTp), a nearby region that is larger in males due to Bax-dependent cell death. Males had more cells in the CALB-SDN as well as in surrounding regions than did females, and estradiol treatment of females at birth masculinized both measures. Bax deletion had no effect on cell number in the CALB-SDN or surrounding regions but increased calbindin-ir cell number in the BNSTp. The sex difference in the CALB-SDN of mice results from an estrogen-dependent difference in cell number with no evidence found for greater spread of cells in females. Blocking Bax-dependent cell death does not prevent sex differences in calbindin-ir cell number in the BNST or CALB-SDN but increases calbindin-ir cell number in the BNSTp of both sexes.

Sex-based memory advantages and cognitive aging: a challenge to the cognitive reserve construct?

PubMed

Caselli, Richard J; Dueck, Amylou C; Locke, Dona E C; Baxter, Leslie C; Woodruff, Bryan K; Geda, Yonas E

2015-02-01

Education and related proxies for cognitive reserve (CR) are confounded by associations with environmental factors that correlate with cerebrovascular disease possibly explaining discrepancies between studies examining their relationships to cognitive aging and dementia. In contrast, sex-related memory differences may be a better proxy. Since they arise developmentally, they are less likely to reflect environmental confounds. Women outperform men on verbal and men generally outperform women on visuospatial memory tasks. Furthermore, memory declines during the preclinical stage of AD, when it is clinically indistinguishable from normal aging. To determine whether CR mitigates age-related memory decline, we examined the effects of gender and APOE genotype on longitudinal memory performances. Memory decline was assessed in a cohort of healthy men and women enriched for APOE ɛ4 who completed two verbal [Rey Auditory Verbal Learning Test (AVLT), Buschke Selective Reminding Test (SRT)] and two visuospatial [Rey-Osterrieth Complex Figure Test (CFT), and Benton Visual Retention Test (VRT)] memory tests, as well as in a separate larger and older cohort [National Alzheimer's Coordinating Center (NACC)] who completed a verbal memory test (Logical Memory). Age-related memory decline was accelerated in APOE ɛ4 carriers on all verbal memory measures (AVLT, p=.03; SRT p<.001; logical memory p<.001) and on the VRT p=.006. Baseline sex associated differences were retained over time, but no sex differences in rate of decline were found for any measure in either cohort. Sex-based memory advantage does not mitigate age-related memory decline in either APOE ɛ4 carriers or non-carriers.

Chronic Stress Modulates Regional Cerebral Glucose Transporter Expression in an Age-Specific and Sexually-Dimorphic Manner

PubMed Central

Kelly, Sean D.; Harrell, Constance S.; Neigh, Gretchen N.

2014-01-01

Facilitative glucose transporters (GLUT) mediate glucose uptake across the blood-brain-barrier into neurons and glia. Deficits in specific cerebral GLUT isoforms are linked to developmental and neurological dysfunction, but less is known about the range of variation in cerebral GLUT expression in normal conditions and the effects of environmental influences on cerebral GLUT expression. Knowing that puberty is a time of increased cerebral plasticity, metabolic demand, and shifts in hormonal balance for males and females, we first assessed gene expression of five GLUT subtypes in four brain regions in male and female adolescent and adult Wistar rats. The data indicated that sex differences in GLUT expression were most profound in the hypothalamus, and the transition from adolescence to adulthood had the most profound effect on GLUT expression in the hippocampus. Next, given the substantial energetic demands during adolescence and prior demonstrations of the adverse effects of adolescent stress, we determined the extent to which chronic stress altered GLUT expression in males and females in both adolescence and adulthood. Chronic stress significantly altered cerebral GLUT expression in males and females throughout both developmental stages but in a sexually dimorphic and brain region-specific manner. Collectively, our data demonstrate that cerebral GLUTs are expressed differentially based on brain region, sex, age, and stress exposure. These results suggest that developmental and environmental factors influence GLUT expression in multiple brain regions. Given the importance of appropriate metabolic balance within the brain, further assessment of the functional implications of life stage and environmentally-induced changes in GLUTs are warranted. PMID:24382486

Topological Organization of Functional Brain Networks in Healthy Children: Differences in Relation to Age, Sex, and Intelligence

PubMed Central

Wu, Kai; Taki, Yasuyuki; Sato, Kazunori; Hashizume, Hiroshi; Sassa, Yuko; Takeuchi, Hikaru; Thyreau, Benjamin; He, Yong; Evans, Alan C.; Li, Xiaobo; Kawashima, Ryuta; Fukuda, Hiroshi

2013-01-01

Recent studies have demonstrated developmental changes of functional brain networks derived from functional connectivity using graph theoretical analysis, which has been rapidly translated to studies of brain network organization. However, little is known about sex- and IQ-related differences in the topological organization of functional brain networks during development. In this study, resting-state fMRI (rs-fMRI) was used to map the functional brain networks in 51 healthy children. We then investigated the effects of age, sex, and IQ on economic small-world properties and regional nodal properties of the functional brain networks. At a global level of whole networks, we found significant age-related increases in the small-worldness and local efficiency, significant higher values of the global efficiency in boys compared with girls, and no significant IQ-related difference. Age-related increases in the regional nodal properties were found predominately in the frontal brain regions, whereas the parietal, temporal, and occipital brain regions showed age-related decreases. Significant sex-related differences in the regional nodal properties were found in various brain regions, primarily related to the default mode, language, and vision systems. Positive correlations between IQ and the regional nodal properties were found in several brain regions related to the attention system, whereas negative correlations were found in various brain regions primarily involved in the default mode, emotion, and language systems. Together, our findings of the network topology of the functional brain networks in healthy children and its relationship with age, sex, and IQ bring new insights into the understanding of brain maturation and cognitive development during childhood and adolescence. PMID:23390528

Sex-Related Differences in the Developmental Morphology of the Atlas: A Computed Tomography Study.

PubMed

Asukai, Mitsuru; Fujita, Tomotada; Suzuki, Daisuke; Nishida, Tatsuya; Ohishi, Tsuyoshi; Matsuyama, Yukihiro

2018-05-15

A retrospective study. To elucidate sex-related differences in the age at synchondroses closure, the normative size of the atlas, and the ossification patterns of the atlas in Japanese children. The atlas develops from three ossification centers during childhood. The anterior and posterior synchondroses, which are separate ossification centers, mimic fracture lines on computed tomography (CT). Sex-related differences of age dependent morphological changes of the atlas in a large sample size have not been reported. This study analyzed data of 688 subjects (449 boys) between 0 and 18 years old who underwent CT examination of the head and/or neck between January 2010 and July 2016. The age at synchondroses closure, anteroposterior outer, inner, and spinal canal widths of the atlas, and variations of the ossification centers were examined. Anterior synchondroses closed by 10 years in boys and by 7 years in girls. Significant earlier closure of anterior synchondroses was observed in girls than in boys (P < 0.05 at 4 and 5 years old). Posterior synchondrosis closed by 6 years in boys and by 5 years in girls. The outer, inner, and spinal canal widths increased up to 10 to 15 years in both sexes, although all three parameters in girls peaked 3 years earlier than those in boys. All parameters in boys were significantly larger than those in girls, except in the 10- to 12-year-old age category. Two or more ossification centers in the anterior arch were observed in 18.3% subjects, and 6% had midline ossification centers in the posterior arch of the atlas. Distinct sex-related differences in the age at anterior synchondroses closure and the size of the atlas were observed in Japanese children. Knowledge of morphological features of the atlas could help distinguish fractures from synchondroses. 3.

Topological organization of functional brain networks in healthy children: differences in relation to age, sex, and intelligence.

PubMed

Wu, Kai; Taki, Yasuyuki; Sato, Kazunori; Hashizume, Hiroshi; Sassa, Yuko; Takeuchi, Hikaru; Thyreau, Benjamin; He, Yong; Evans, Alan C; Li, Xiaobo; Kawashima, Ryuta; Fukuda, Hiroshi

2013-01-01

Recent studies have demonstrated developmental changes of functional brain networks derived from functional connectivity using graph theoretical analysis, which has been rapidly translated to studies of brain network organization. However, little is known about sex- and IQ-related differences in the topological organization of functional brain networks during development. In this study, resting-state fMRI (rs-fMRI) was used to map the functional brain networks in 51 healthy children. We then investigated the effects of age, sex, and IQ on economic small-world properties and regional nodal properties of the functional brain networks. At a global level of whole networks, we found significant age-related increases in the small-worldness and local efficiency, significant higher values of the global efficiency in boys compared with girls, and no significant IQ-related difference. Age-related increases in the regional nodal properties were found predominately in the frontal brain regions, whereas the parietal, temporal, and occipital brain regions showed age-related decreases. Significant sex-related differences in the regional nodal properties were found in various brain regions, primarily related to the default mode, language, and vision systems. Positive correlations between IQ and the regional nodal properties were found in several brain regions related to the attention system, whereas negative correlations were found in various brain regions primarily involved in the default mode, emotion, and language systems. Together, our findings of the network topology of the functional brain networks in healthy children and its relationship with age, sex, and IQ bring new insights into the understanding of brain maturation and cognitive development during childhood and adolescence.

Disorders of sex development and gender identity outcome in adolescence and adulthood: understanding gender identity development and its clinical implications.

PubMed

de Vries, Annelou L C; Doreleijers, Theo A H; Cohen-Kettenis, Peggy T

2007-06-01

This article reviews studies on gender identity outcome in individuals with disorders of sex development (DSD). It appears that a high percentage of affected individuals suffer from gender dysphoria. However, these figures differ substantially among the various DSD and they never reach 100%. From the studies it also becomes clear that a distinction should be made between gender role behavior and gender identity. Put in a broader theoretical framework, there is now more evidence that biological factors influence the development of gender role behavior than gender identity. Developmental psychology studies add evidence that social and psychological factors play a role as well in gender development. Clinicians should be aware of, but not overestimate the influences of neurobiological factors in gender development.

Effect of Sex Education Programme on at-risk sexual behaviour of school-going adolescents in Ilorin, Nigeria.

PubMed

Esere, Mary Ogechi

2008-06-01

Adolescents display sexual behaviours and developmental characteristics that place them at risk for Sexually Transmitted Diseases (STDs). Because young people experiment sexually and because of the consequences of indiscriminate sexual activities on the youth, there is the need to mount sex education programmes that are geared towards enlightenment and appropriate education about sex and sexuality. To determine whether Sex Education Intervention Programme would reduce at-risk sexual behaviours of school-going adolescents. Pre-test, post-test control group quasi-experimental design. A randomly selected co-educational school in Ilorin Metropolis, Nigeria. 24 school-going adolescents aged 13-19 years. Sex Education Programme (treatment group) versus Control programme (placebo). Self-reported exposure to sexually transmitted diseases, multiple sex partners, anal sex, oral sex, non use of condom. When the treatment (intervention) group was compared with the control group in an intention to treat analysis, there were significant differences in at-risk sexual behaviours of the two groups. Those in the intervention group reported less at-risk sexual behaviours than their counterparts in the control group. The treatment group evaluated the intervention programme positively and their knowledge of sexual health improved. Lack of behavioural effect on the control group could be linked to differential quality of delivery of intervention. Compared with the control group, this specially designed intervention sex education programme reduced at-risk sexual behaviour in adolescents. Based on this finding, it was recommended that sex education be introduced into the curriculum of secondary school education in Nigeria.

apterous A specifies dorsal wing patterns and sexual traits in butterflies

PubMed Central

2018-01-01

Butterflies have evolved different colour patterns on their dorsal and ventral wing surfaces to serve different signalling functions, yet the developmental mechanisms controlling surface-specific patterning are still unknown. Here, we mutate both copies of the transcription factor apterous in Bicyclus anynana butterflies using CRISPR/Cas9 and show that apterous A, expressed dorsally, functions both as a repressor and modifier of ventral wing colour patterns, as well as a promoter of dorsal sexual ornaments in males. We propose that the surface-specific diversification of wing patterns in butterflies proceeded via the co-option of apterous A or its downstream effectors into various gene regulatory networks involved in the differentiation of discrete wing traits. Further, interactions between apterous and sex-specific factors such as doublesex may have contributed to the origin of sexually dimorphic surface-specific patterns. Finally, we discuss the evolution of eyespot number diversity in the family Nymphalidae within the context of developmental constraints due to apterous regulation. PMID:29467265

Bone Marrow Adipocyte Developmental Origin and Biology.

PubMed

Bukowska, Joanna; Frazier, Trivia; Smith, Stanley; Brown, Theodore; Bender, Robert; McCarthy, Michelle; Wu, Xiying; Bunnell, Bruce A; Gimble, Jeffrey M

2018-06-01

This review explores how the relationships between bone marrow adipose tissue (BMAT) adipogenesis with advancing age, obesity, and/or bone diseases (osteopenia or osteoporosis) contribute to mechanisms underlying musculoskeletal pathophysiology. Recent studies have re-defined adipose tissue as a dynamic, vital organ with functions extending beyond its historic identity restricted solely to that of an energy reservoir or sink. "State of the art" methodologies provide novel insights into the developmental origin, physiology, and function of different adipose tissue depots. These include genetic tracking of adipose progenitors, viral vectors application, and sophisticated non-invasive imaging modalities. While constricted within the rigid bone cavity, BMAT vigorously contributes to local and systemic metabolic processes including hematopoiesis, osteogenesis, and energy metabolism and undergoes dynamic changes as a function of age, diet, bone topography, or sex. These insights will impact future research and therapies relating to osteoporosis.

Plant Sex Determination.

PubMed

Pannell, John R

2017-03-06

Sex determination is as important for the fitness of plants as it is for animals, but its mechanisms appear to vary much more among plants than among animals, and the expression of gender in plants differs in important respects from that in most animals. In this Minireview, I provide an overview of the broad variety of ways in which plants determine sex. I suggest that several important peculiarities of plant sex determination can be understood by recognising that: plants show an alternation of generations between sporophytic and gametophytic phases (either of which may take control of sex determination); plants are modular in structure and lack a germ line (allowing for a quantitative expression of gender that is not common in animals); and separate sexes in plants have ultimately evolved from hermaphroditic ancestors. Most theorising about sex determination in plants has focused on dioecious species, but we have much to learn from monecious or hermaphroditic species, where sex is determined at the level of modules, tissues or cells. Because of the fundamental modularity of plant development and potentially important evolutionary links between monoecy and dioecy, it may be useful to relax the distinction often made between 'developmental sex determination' (which underpins the development of male versus female flowers in monoecious species) and 'genetic sex determination' (which underpins the separation of males and females in dioecious species, often mediated by a genetic polymorphism and sex chromosomes). I also argue for relaxing the distinction between sex determination involving a genetic polymorphism and that involving responses to environmental or hormonal cues, because non-genetic cues might easily be converted into genetic switches. Copyright © 2017 Elsevier Ltd. All rights reserved.

"What a Girl Wants, What a Girl Needs:" Responding to Sex, Gender, and Sexuality in the Early Childhood Classroom

ERIC Educational Resources Information Center

Blaise, Mindy

2009-01-01

This paper is based on data generated from a qualitative study of gender and sexuality in a kindergarten classroom. Post-developmental perspectives of sex, gender, and sexuality are used to show how young children are constructing gender and heterosexual discourses in the early childhood classroom. Drawing from feminist post-structuralism and…

Sex-specific gray matter volume differences in females with developmental dyslexia.

PubMed

Evans, Tanya M; Flowers, D Lynn; Napoliello, Eileen M; Eden, Guinevere F

2014-05-01

Developmental dyslexia, characterized by unexpected reading difficulty, is associated with anomalous brain anatomy and function. Previous structural neuroimaging studies have converged in reports of less gray matter volume (GMV) in dyslexics within left hemisphere regions known to subserve language. Due to the higher prevalence of dyslexia in males, these studies are heavily weighted towards males, raising the question whether studies of dyslexia in females only and using the same techniques, would generate the same findings. In a replication study of men, we obtained the same findings of less GMV in dyslexics in left middle/inferior temporal gyri and right postcentral/supramarginal gyri as reported in the literature. However, comparisons in women with and without dyslexia did not yield left hemisphere differences, and instead, we found less GMV in right precuneus and paracentral lobule/medial frontal gyrus. In boys, we found less GMV in left inferior parietal cortex (supramarginal/angular gyri), again consistent with previous work, while in girls differences were within right central sulcus, spanning adjacent gyri, and left primary visual cortex. Our investigation into anatomical variants in dyslexia replicates existing studies in males, but at the same time shows that dyslexia in females is not characterized by involvement of left hemisphere language regions but rather early sensory and motor cortices (i.e., motor and premotor cortex, primary visual cortex). Our findings suggest that models on the brain basis of dyslexia, primarily developed through the study of males, may not be appropriate for females and suggest a need for more sex-specific investigations into dyslexia.

Sex-specific Gray Matter Volume Differences in Females with Developmental Dyslexia

PubMed Central

Evans, Tanya M.; Flowers, D. Lynn; Napoliello, Eileen M.; Eden, Guinevere F.

2013-01-01

Developmental dyslexia, characterized by unexpected reading difficulty, is associated with anomalous brain anatomy and function. Previous structural neuroimaging studies have converged in reports of less gray matter volume (GMV) in dyslexics within left hemisphere regions known to subserve language. Due to the higher prevalence of dyslexia in males, these studies are heavily weighted towards males, raising the question whether studies of dyslexia in females only and using the same techniques, would generate the same findings. In a replication study of men we obtained the same findings of less GMV in dyslexics in left middle/inferior temporal gyri and right postcentral/supramarginal gyri as reported in the literature. However, comparisons in women with and without dyslexia did not yield left hemisphere differences and instead we found less GMV in right precuneus and paracentral lobule/medial frontal gyrus. In boys, we found less GMV in left inferior parietal cortex (supramarginal/angular gyri), again consistent with previous work, while in girls differences were within right central sulcus, spanning adjacent gyri, and left primary visual cortex. Our investigation into anatomical variants in dyslexia replicates existing studies in males, but at the same time shows that dyslexia in females is not characterized by involvement of left hemisphere language regions but rather early sensory and motor cortices (i.e. motor and premotor cortex, primary visual cortex). Our findings suggest that models on the brain basis of dyslexia, primarily developed through the study of males, may not be appropriate for females and suggest a need for more sex-specific investigations into dyslexia. PMID:23625146

Drosophila sex combs as a model of evolutionary innovations.

PubMed

Kopp, Artyom

2011-01-01

The diversity of animal and plant forms is shaped by nested evolutionary innovations. Understanding the genetic and molecular changes responsible for these innovations is therefore one of the key goals of evolutionary biology. From the genetic point of view, the origin of novel traits implies the origin of new regulatory pathways to control their development. To understand how these new pathways are assembled in the course of evolution, we need model systems that combine relatively recent innovations with a powerful set of genetic and molecular tools. One such model is provided by the Drosophila sex comb-a male-specific morphological structure that evolved in a relatively small lineage related to the model species D. melanogaster. Our extensive knowledge of sex comb development in D. melanogaster provides the basis for investigating the genetic changes responsible for sex comb origin and diversification. At the same time, sex combs can change on microevolutionary timescales and differ spectacularly among closely related species, providing opportunities for direct genetic analysis and for integrating developmental and population-genetic approaches. Sex comb evolution is associated with the origin of novel interactions between Hox and sex determination genes. Activity of the sex determination pathway was brought under the control of the Hox code to become segment-specific, while Hox gene expression became sexually dimorphic. At the same time, both Hox and sex determination genes were integrated into the intrasegmental spatial patterning network, and acquired new joint downstream targets. Phylogenetic analysis shows that similar sex comb morphologies evolved independently in different lineages. Convergent evolution at the phenotypic level reflects convergent changes in the expression of Hox and sex determination genes, involving both independent gains and losses of regulatory interactions. However, the downstream cell-differentiation programs have diverged between species, and in some lineages, similar adult morphologies are produced by different morphogenetic mechanisms. These features make the sex comb an excellent model for examining not only the genetic changes responsible for its evolution, but also the cellular processes that translate DNA sequence changes into morphological diversity. The origin and diversification of sex combs provides insights into the roles of modularity, cooption, and regulatory changes in evolutionary innovations, and can serve as a model for understanding the origin of the more drastic novelties that define higher order taxa. © 2011 Wiley Periodicals, Inc.

Drosophila Sex Combs as a Model of Evolutionary Innovations

PubMed Central

Kopp, Artyom

2011-01-01

The diversity of animal and plant forms is shaped by nested evolutionary innovations. Understanding the genetic and molecular changes responsible for these innovations is therefore one of the key goals of evolutionary biology. From the genetic point of view, the origin of novel traits implies the origin of new regulatory pathways to control their development. To understand how these new pathways are assembled in the course of evolution, we need model systems that combine relatively recent innovations with a powerful set of genetic and molecular tools. One such model is provided by the Drosophila sex comb – a male-specific morphological structure that evolved in a relatively small lineage related to the model species D. melanogaster. Our extensive knowledge of sex comb development in D. melanogaster provides the basis for investigating the genetic changes responsible for sex comb origin and diversification. At the same time, sex combs can change on microevolutionary timescales and differ spectacularly among closely related species, providing opportunities for direct genetic analysis and for integrating developmental and population-genetic approaches. Sex comb evolution is associated with the origin of novel interactions between HOX and sex determination genes. Activity of the sex determination pathway was brought under the control of the HOX code to become segment-specific, while HOX gene expression became sexually dimorphic. At the same time, both HOX and sex determination genes were integrated into the intrasegmental spatial patterning network, and acquired new joint downstream targets. Phylogenetic analysis shows that similar sex comb morphologies evolved independently in different lineages. Convergent evolution at the phenotypic level reflects convergent changes in the expression of HOX and sex determination genes, involving both independent gains and losses of regulatory interactions. However, the downstream cell differentiation programs have diverged between species, and in some lineages similar adult morphologies are produced by different morphogenetic mechanisms. These features make the sex comb an excellent model for examining not only the genetic changes responsible for its evolution, but also the cellular processes that translate DNA sequence changes into morphological diversity. The origin and diversification of sex combs provides insights into the roles of modularity, cooption, and regulatory changes in evolutionary innovations, and can serve as a model for understanding the origin of the more drastic novelties that define higher-order taxa. PMID:23016935

Interpersonal identity formation in conversations with close friends about dating relationships.

PubMed

Morgan, Elizabeth M; Korobov, Neill

2012-12-01

The present study explores how close same-sex friendship groups participate in the co-construction of identities in the interpersonal domain during young adulthood. Participants included 24 same-sex college student friendship triads (12 male and 12 female; 72 total participants) who took part in semi-structured group interviews that elicited stories about conversations with their friends about dating relationship problems. Qualitative thematic analysis revealed five common responses to dating problems evidencing identity work in the context of friends' conversations. These responses included relating the issue to one's own experiences, providing validation and encouragement, joking about the problem, offering advice, and providing concrete instrumental support. Results are interpreted with regard to gender differences and similarities as well as the social context of college and developmental context of emerging adulthood. The findings identify ways in which young adults are actively co-constructing and re-evaluating their interpersonal identities within conversations with close same-sex friends. Copyright © 2011 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Impact of Fetal Versus Perinatal Hypoxia on Sex Differences in Childhood Outcomes: Developmental Timing Matters

PubMed Central

Anastario, Michael; Salafia, Carolyn M.; Fitzmaurice, Garrett; Goldstein, Jill M.

2013-01-01

Purpose To examine how the timing of hypoxic exposure results in specific childhood outcomes and whether there is a differential effect by sex. Methods A sample of 10,879 prospectively followed pregnancies was drawn from the Boston and Providence sites (New England-NE) of the National Collaborative Perinatal Project. Based on placental pathology, we developed and validated a measure of probable chronic fetal hypoxia (CHP) and contrasted the effects of acute perinatal hypoxia on age 7 emotional, behavioral, and cognitive outcomes. Results Perinatal hypoxia had a significant impact on multiple behavioral and cognitive outcomes in boys and girls by age 7, in contrast to probable CHP which had a differential effect on girls and boys such that there was decreased verbal IQ and increased inhibition in females alone. Conclusions Findings underscore the importance of considering the timing of obstetric complications and offspring sex in investigations of the impact of fetal and perinatal hypoxia on offspring’s outcomes throughout the life course. PMID:21327969

Recommendations for sex/gender neuroimaging research: key principles and implications for research design, analysis, and interpretation

PubMed Central

Rippon, Gina; Jordan-Young, Rebecca; Kaiser, Anelis; Fine, Cordelia

2014-01-01

Neuroimaging (NI) technologies are having increasing impact in the study of complex cognitive and social processes. In this emerging field of social cognitive neuroscience, a central goal should be to increase the understanding of the interaction between the neurobiology of the individual and the environment in which humans develop and function. The study of sex/gender is often a focus for NI research, and may be motivated by a desire to better understand general developmental principles, mental health problems that show female-male disparities, and gendered differences in society. In order to ensure the maximum possible contribution of NI research to these goals, we draw attention to four key principles—overlap, mosaicism, contingency and entanglement—that have emerged from sex/gender research and that should inform NI research design, analysis and interpretation. We discuss the implications of these principles in the form of constructive guidelines and suggestions for researchers, editors, reviewers and science communicators. PMID:25221493

Sex-Specific Effect of Recalled Parenting on Affective and Cognitive Empathy in Adulthood.

PubMed

Lyons, Minna T; Brewer, Gayle; Bethell, Emily J

2017-01-01

Previous research has demonstrated the influence of parenting on the development of children's empathy. However, few studies have considered the impact of parents on empathy in adulthood, specific components of empathy, or the importance of parent and child biological sex. In the present study, 226 participants (71 men) completed online versions of the Parental Bonding Instrument (Parker et al. British Journal of Medical Psychology, 52, 1-10 1979), Empathy Quotient (Baron-Cohen and Wheelwright Journal of Autism and Developmental Disorders, 34, 163-175 2004), and Interpersonal Reactivity Index (Davis JSAS Catalog of Selected Documents in Psychology, 10, 85 1980). Paternal care and overprotection influenced affective empathy in men, whilst maternal overprotection predicted affective empathy in women. Further, maternal care related to cognitive empathy in men, whilst none of the parental care variables related to cognitive empathy in women. Findings are discussed in relation to sex differences in childhood parenting experiences on adult cognitive and affective empathy.

Recommendations for sex/gender neuroimaging research: key principles and implications for research design, analysis, and interpretation.

PubMed

Rippon, Gina; Jordan-Young, Rebecca; Kaiser, Anelis; Fine, Cordelia

2014-01-01

Neuroimaging (NI) technologies are having increasing impact in the study of complex cognitive and social processes. In this emerging field of social cognitive neuroscience, a central goal should be to increase the understanding of the interaction between the neurobiology of the individual and the environment in which humans develop and function. The study of sex/gender is often a focus for NI research, and may be motivated by a desire to better understand general developmental principles, mental health problems that show female-male disparities, and gendered differences in society. In order to ensure the maximum possible contribution of NI research to these goals, we draw attention to four key principles-overlap, mosaicism, contingency and entanglement-that have emerged from sex/gender research and that should inform NI research design, analysis and interpretation. We discuss the implications of these principles in the form of constructive guidelines and suggestions for researchers, editors, reviewers and science communicators.

Morphological variation in Homo erectus and the origins of developmental plasticity

PubMed Central

Antón, Susan C.; Taboada, Hannah G.; Middleton, Emily R.; Rainwater, Christopher W.; Taylor, Andrea B.; Turner, Trudy R.; Turnquist, Jean E.; Weinstein, Karen J.; Williams, Scott A.

2016-01-01

Homo erectus was the first hominin to exhibit extensive range expansion. This extraordinary departure from Africa, especially into more temperate climates of Eurasia, has been variously related to technological, energetic and foraging shifts. The temporal and regional anatomical variation in H. erectus suggests that a high level of developmental plasticity, a key factor in the ability of H. sapiens to occupy a variety of habitats, may also have been present in H. erectus. Developmental plasticity, the ability to modify development in response to environmental conditions, results in differences in size, shape and dimorphism across populations that relate in part to levels of resource sufficiency and extrinsic mortality. These differences predict not only regional variations but also overall smaller adult sizes and lower levels of dimorphism in instances of resource scarcity and high predator load. We consider the metric variation in 35 human and non-human primate ‘populations’ from known environmental contexts and 14 time- and space-restricted paleodemes of H. erectus and other fossil Homo. Human and non-human primates exhibit more similar patterns of variation than expected, with plasticity evident, but in differing patterns by sex across populations. The fossil samples show less evidence of variation than expected, although H. erectus varies more than Neandertals. This article is part of the themed issue ‘Major transitions in human evolution’. PMID:27298467

Comprehensive Transcriptome Analysis of Phytohormone Biosynthesis and Signaling Genes in the Flowers of Chinese Chinquapin (Castanea henryi).

PubMed

Fan, Xiaoming; Yuan, Deyi; Tian, Xiaoming; Zhu, Zhoujun; Liu, Meilan; Cao, Heping

2017-11-29

Chinese chinquapin (Castanea henryi) nut provides a rich source of starch and nutrients as food and feed, but its yield is restricted by a low ratio of female to male flowers. Little is known about the developmental programs underlying sex differentiation of the flowers. To investigate the involvement of phytohormones during sex differentiation, we described the morphology of male and female floral organs and the cytology of flower sex differentiation, analyzed endogenous levels of indole-3-acetic acid (IAA), gibberellins (GAs), cytokinins (CKs), and abscisic acid (ABA) in the flowers, investigated the effects of exogenous hormones on flower development, and evaluated the expression profiles of genes related to biosyntheses and signaling pathways of these four hormones using RNA-Seq combined with qPCR. Morphological results showed that the flowers consisted of unisexual and bisexual catkins, and could be divided into four developmental stages. HPLC results showed that CK accumulated much more in the female flowers than that in the male flowers, GA and ABA showed the opposite results, while IAA did not show a tendency. The effects of exogenous hormones on sex differentiation were consistent with those of endogenous hormones. RNA-Seq combined with qPCR analyses suggest that several genes may play key roles in hormone biosynthesis and sex differentiation. This study presents the first comprehensive report of phytohormone biosynthesis and signaling during sex differentiation of C. henryi, which should provide a foundation for further mechanistic studies of sex differentiation in Castanea Miller species and other nonmodel plants.

The Development of the Basal Ganglia in Capuchin Monkeys (Cebus apella)

PubMed Central

Phillips, Kimberley A.; Sobieski, Courtney A.; Gilbert, Valerie R.; Chiappini-Williamson, Christine; Sherwood, Chet C.; Strick, Peter L.

2010-01-01

The basal ganglia are subcortical structures involved in the planning, initiation and regulation of movement as well as a variety of non-motor, cognitive and affective functions. Capuchin monkeys share several important characteristics of development with humans, including a prolonged infancy and juvenile period, a long lifespan, and complex manipulative abilities. This makes capuchins important comparative models for understanding age-related neuroanatomical changes in these structures. Here we report developmental volumetric data on the three subdivisions of the basal ganglia, the caudate, putamen and globus pallidus in brown capuchin monkeys (Cebus apella). Based on a cross-sectional sample, we describe brain development in 28 brown capuchin monkeys (male n = 17, female n = 11; age range = 2 months – 20 years) using high-resolution structural MRI. We found that the raw volumes of the putamen and caudate varied significantly with age, decreasing in volume from birth through early adulthood. Notably, developmental changes did not differ between sexes. Because these observed developmental patterns are similar to humans, our results suggest that capuchin monkeys may be useful animal models for investigating neurodevelopmental disorders of the basal ganglia. PMID:20227397

Developmental Perspectives on Oxytocin and Vasopressin

PubMed Central

Hammock, Elizabeth A D

2015-01-01

The related neuropeptides oxytocin and vasopressin are involved in species-typical behavior, including social recognition behavior, maternal behavior, social bonding, communication, and aggression. A wealth of evidence from animal models demonstrates significant modulation of adult social behavior by both of these neuropeptides and their receptors. Over the last decade, there has been a flood of studies in humans also implicating a role for these neuropeptides in human social behavior. Despite popular assumptions that oxytocin is a molecule of social bonding in the infant brain, less mechanistic research emphasis has been placed on the potential role of these neuropeptides in the developmental emergence of the neural substrates of behavior. This review summarizes what is known and assumed about the developmental influence of these neuropeptides and outlines the important unanswered questions and testable hypotheses. There is tremendous translational need to understand the functions of these neuropeptides in mammalian experience-dependent development of the social brain. The activity of oxytocin and vasopressin during development should inform our understanding of individual, sex, and species differences in social behavior later in life. PMID:24863032

Regulation of Sex Determination in Mice by a Non-coding Genomic Region

PubMed Central

Arboleda, Valerie A.; Fleming, Alice; Barseghyan, Hayk; Délot, Emmanuèle; Sinsheimer, Janet S.; Vilain, Eric

2014-01-01

To identify novel genomic regions that regulate sex determination, we utilized the powerful C57BL/6J-YPOS (B6-YPOS) model of XY sex reversal where mice with autosomes from the B6 strain and a Y chromosome from a wild-derived strain, Mus domesticus poschiavinus (YPOS), show complete sex reversal. In B6-YPOS, the presence of a 55-Mb congenic region on chromosome 11 protects from sex reversal in a dose-dependent manner. Using mouse genetic backcross designs and high-density SNP arrays, we narrowed the congenic region to a 1.62-Mb genomic region on chromosome 11 that confers 80% protection from B6-YPOS sex reversal when one copy is present and complete protection when two copies are present. It was previously believed that the protective congenic region originated from the 129S1/SviMJ (129) strain. However, genomic analysis revealed that this region is not derived from 129 and most likely is derived from the semi-inbred strain POSA. We show that the small 1.62-Mb congenic region that protects against B6-YPOS sex reversal is located within the Sox9 promoter and promotes the expression of Sox9, thereby driving testis development within the B6-YPOS background. Through 30 years of backcrossing, this congenic region was maintained, as it promoted male sex determination and fertility despite the female-promoting B6-YPOS genetic background. Our findings demonstrate that long-range enhancer regions are critical to developmental processes and can be used to identify the complex interplay between genome variants, epigenetics, and developmental gene regulation. PMID:24793290

Developmental sex-specific change in auditory-vocal integration: ERP evidence in children.

PubMed

Liu, Peng; Chen, Zhaocong; Jones, Jeffery A; Wang, Emily Q; Chen, Shaozhen; Huang, Dongfeng; Liu, Hanjun

2013-03-01

The present event-related potential (ERP) study examined the developmental mechanisms of auditory-vocal integration in normally developing children. Neurophysiological responses to altered auditory feedback were recorded to determine whether they are affected by age and sex. Forty-two children were pairwise matched for sex and were divided into a group of younger (10-12years) and a group of older (13-15years) children. Twenty healthy young adults (20-25years) also participated in the experiment. ERPs were recorded from the participants who heard their voice pitch feedback unexpectedly shifted -50, -100, or -200 cents during sustained vocalization. P1 amplitudes became smaller as subjects increased in age from childhood to adulthood, and males produced larger N1 amplitudes than females. An age-related decrease in the P1-N1 latencies was also found: latencies were shorter in young adults than in school children. A complex age-by-sex interaction was found for the P2 component, where an age-related increase in P2 amplitudes existed only in girls, and boys produced longer P2 latencies than girls but only in the older children. These findings demonstrate that neurophysiological responses to pitch errors in voice auditory feedback depend on age and sex in normally developing children. The present study provides evidence that there is a sex-specific development of the neural mechanisms involved in auditory-vocal integration. Copyright © 2012 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

The role of sex and gender socialization in stress reactivity.

PubMed

Dedovic, Katarina; Wadiwalla, Mehereen; Engert, Veronika; Pruessner, Jens C

2009-01-01

Individual health is determined by a myriad of factors. Interestingly, simply being male or female is one such factor that carries profound implications for one's well-being. Intriguing differences between men and women have been observed with respect to vulnerability to and prevalence of particular illnesses. The activity of the major stress hormone axis in humans, the hypothalamus-pituitary-adrenal axis, is directly and indirectly associated with the onset and propagation of these conditions. Previous studies have shown differences between men and women at the level of stress hormone regulation, suggesting that the metabolic effects of stress may be related to susceptibility for stress-related disease. While the majority of studies have suggested that biological differences are responsible, few have also considered the role of gender socialization. In this selective review, the authors summarize evidence on sex differences and highlight some recent results from endocrinological, developmental, and neuroimaging studies that suggest an important role of gender socialization on the metabolic effects of stress. Finally, a model is proposed that integrates these specific findings, highlighting gender socialization and stress responsivity.

Age and sex differences in perceptions of networks of personal relationships.

PubMed

Furman, W; Buhrmester, D

1992-02-01

In this study, 549 youths in the fourth grade, seventh grade, tenth grade, and college completed Network of Relationship Inventories assessing their perceptions of their relationships with significant others. The findings were largely consistent with 7 propositions derived from major theories of the developmental courses of personal relationships. In particular, mothers and fathers were seen as the most frequent providers of support in the fourth grade. Same-sex friends were perceived to be as supportive as parents in the seventh grade, and were the most frequent providers of support in the tenth grade. Romantic partners moved up in rank with age until college, where they, along with friends and mothers, received the highest ratings for support. Age differences were also observed in perceptions of relationships with grandparents, teachers, and siblings. Finally, age differences in perceived conflict, punishment, and relative power suggested that there was a peak in tension in parent-child relationships in early and middle adolescence. Discussion centers around the role various relationships are perceived as playing at different points in development.

A Factorial Analysis of Variance and Resulting Norm Tables for Tennessee Head Start Children Based on the Developmental Test of Visual-Motor Integration.

ERIC Educational Resources Information Center

Nye, Barbara A.

Data from a statewide screening of Tennessee Head Start children on the Developmental Test of Visual-Motor Integration (VMI) are analyzed in this report for two purposes: to determine whether sex, race, and residence have a significant influence on visual motor development as measured by the VMI, and to develop VMI norms for the Tennessee Head…

Sex-specific differences in effect of prenatal exposure to dioxin-like compounds on neurodevelopment in Japanese children: Sapporo cohort study.

PubMed

Nakajima, Sonomi; Saijo, Yasuaki; Miyashita, Chihiro; Ikeno, Tamiko; Sasaki, Seiko; Kajiwara, Junboku; Kishi, Reiko

2017-11-01

Consistent reports are not available on the effects of dioxin-like polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins (PCDD)/ polychlorinated dibenzofurans (PCDF) (dioxin-like compounds [DLCs]) on child neurodevelopment. Further, the effect of background-level exposure to individual DLC isomers is not known. We carried out the Sapporo cohort study to evaluate the effect of prenatal exposure to each DLC isomer on child neurodevelopment at 6 and 18 months of age, and assessed sex-specific differences in these effects. The levels of all and each individual DLC isomers were estimated in maternal peripheral blood. Neurodevelopment was evaluated using the Bayley Scales of Infant Development-2nd Edition for 6-month-old infants (n = 190) and 18-month-old children (n = 121). In male children, levels of 10 DLC isomers were significantly negatively associated with the Psychomotor Developmental Index (PDI) at 6 months of age after adjustment for potential confounding variables. However, at 18 months of age, these associations were absent. In female children, the level of only one DLC isomer was significantly negatively associated with PDI at 6 months of age. However, in contrast to the male children, the levels of six DLC isomers in 18-month-old female children were significantly positively associated with the Mental Developmental Index. These findings indicate that adverse neurodevelopmental effects of prenatal background-level exposure to DLCs may be stronger in male children. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect on embryos of injection of phosphorothioate-modified oligonucleotides into pregnant mice.

PubMed

Gaudette, M F; Hampikian, G; Metelev, V; Agrawal, S; Crain, W R

1993-01-01

Phosphorothioate-modified oligonucleotides were injected into pregnant female mice to assess the effect on developing embryos. Injections were carried out during two different time periods, one when embryos were in preimplantation stages of development (about 3.5 days of development) and the other after implantation, when both a fetus and placenta are present (from days 9.5 to 11.5 of development). Three different phosphorothioate-modified oligonucleotides were injected. One, which had a sequence not present in the mouse genome, was used to ask whether nonspecific toxic or teratogenic effects on embryos result from treatment of the mother. A second was complementary to the mRNA of the testis-determining factor gene Sry and was used to ask whether a specific developmental pathway (i.e., sex determination) could be disrupted in embryos in vivo. The third was the complement of the anti-Sry sequence. None of these oligonucleotides reduced the frequency of successful pregnancy after mating or the average litter size from that observed in controls animals. Furthermore, examination of 291 pups or fetuses from all oligonucleotide-injected pregnant females revealed no developmental defects regardless of which sequence was used. It is concluded that injection of phosphorothioate-modified oligonucleotides into pregnant females according to the protocols described here is not toxic or teratogenic to embryos in a nonspecific way. Also, anti-Sry oligonucleotides did not influence sex determination in embryos, although there are several possible explanations for this.

Conduct disorder in adolescent females: current state of research and study design of the FemNAT-CD consortium.

PubMed

Freitag, Christine M; Konrad, Kerstin; Stadler, Christina; De Brito, Stephane A; Popma, Arne; Herpertz, Sabine C; Herpertz-Dahlmann, Beate; Neumann, Inga; Kieser, Meinhard; Chiocchetti, Andreas G; Schwenck, Christina; Fairchild, Graeme

2018-06-09

Conduct disorder (CD) is a common and highly impairing psychiatric disorder of childhood and adolescence that frequently leads to poor physical and mental health outcomes in adulthood. The prevalence of CD is substantially higher in males than females, and partly due to this, most research on this condition has used all-male or predominantly male samples. Although the number of females exhibiting CD has increased in recent decades, the majority of studies on neurobiological measures, neurocognitive phenotypes, and treatments for CD have focused on male subjects only, despite strong evidence for sex differences in the aetiology and neurobiology of CD. Here, we selectively review the existing literature on CD and related phenotypes in females, focusing in particular on sex differences in CD symptoms, patterns of psychiatric comorbidity, and callous-unemotional personality traits. We also consider studies investigating the neurobiology of CD in females, with a focus on studies using genetic, structural and functional neuroimaging, psychophysiological, and neuroendocrinological methods. We end the article by providing an overview of the study design of the FemNAT-CD consortium, an interdisciplinary, multi-level and multi-site study that explicitly focuses on CD in females, but which is also investigating sex differences in the causes, developmental course, and neurobiological correlates of CD.

Sex differences in white matter development during adolescence: a DTI study.

PubMed

Wang, Yingying; Adamson, Chris; Yuan, Weihong; Altaye, Mekibib; Rajagopal, Akila; Byars, Anna W; Holland, Scott K

2012-10-10

Adolescence is a complex transitional period in human development, composing physical maturation, cognitive and social behavioral changes. The objective of this study is to investigate sex differences in white matter development and the associations between intelligence and white matter microstructure in the adolescent brain using diffusion tensor imaging (DTI) and tract-based spatial statistics (TBSS). In a cohort of 16 typically-developing adolescents aged 13 to 17 years, longitudinal DTI data were recorded from each subject at two time points that were one year apart. We used TBSS to analyze the diffusion indices including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD). Our results suggest that boys (13-18 years) continued to demonstrate white matter maturation, whereas girls appeared to reach mature levels earlier. In addition, we identified significant positive correlations between FA and full-scale intelligence quotient (IQ) in the right inferior fronto-occipital fasciculus when both sexes were looked at together. Only girls showed significant positive correlations between FA and verbal IQ in the left cortico-spinal tract and superior longitudinal fasciculus. The preliminary evidence presented in this study supports that boys and girls have different developmental trajectories in white matter microstructure. Copyright © 2012 Elsevier B.V. All rights reserved.

Changes in developmental contexts as predictors of transitions in HIV-risk behaviors among young men who have sex with men (YMSM).

PubMed

Wong, Carolyn F; Schrager, Sheree M; Chou, Chih-Ping; Weiss, George; Kipke, Michele D

2013-06-01

Emerging adulthood is a transitional time often marked by instability in many areas of life, including residential status, work, school, and romantic relationships. The purpose of this study is to examine transitions in HIV-risk related behaviors among a cohort of ethnically-diverse young men who have sex with men (YMSM) and to reveal how changes in developmental contexts during emerging adulthood might be associated with these behavioral changes. Hidden Markov models were used to examine movement across different stages of behavioral risk-taking over time. Semi-annual surveys were administered across 2 years; analyses included those with at least three of the five waves of data. Results indicated substantial movement at the individual-level transitions. Additionally, high variability in sexual risk, alcohol misuse, and illicit drug-risk behaviors was predicted by age, ethnicity, and correlates of emerging adulthood, such as residential status, work, post-secondary school enrollment, and primary-relationship status. Findings provide evidence of great change in risky behaviors among YMSM during this pivotal time, particularly among those who actively experiment in varying levels of risk-taking. In order to prevent experimental behaviors from evolving into more serious risk, interventions must consider ways to assist YMSM to adjust to life changes brought on by emerging adulthood.

Post-GWAS in Psychiatric Genetics: A Developmental Perspective on the "Other" Next Steps.

PubMed

Dick, Danielle M; Barr, Peter B; Cho, Seung Bin; Cooke, Megan E; Kuo, Sally I-Chun; Lewis, Tenesha J; Neale, Zoe; Salvatore, Jessica E; Savage, Jeanne; Su, Jinni

2018-03-01

As psychiatric genetics enters an era where gene identification is finally yielding robust, replicable genetic associations and polygenic risk scores, it is important to consider next steps and delineate how that knowledge will be applied to ultimately ameliorate suffering associated with substance use and psychiatric disorders. Much of the post-genome-wide association study discussion has focused on the potential of genetic information to elucidate the underlying biology and use this information for the development of more effective pharmaceutical treatments. In this review we focus on additional areas of research that should follow gene identification. By taking genetic findings into longitudinal, developmental studies, we can map the pathways by which genetic risk manifests across development, elucidating the early behavioral manifestations of risk, and studying how various environments and interventions moderate that risk across developmental stages. The delineation of risk across development will advance our understanding of mechanism, sex differences and risk and resilience processes in different racial/ethnic groups. Here, we review how the extant twin study literature can be used to guide these efforts. Together, these new lines of research will enable us to develop more informed, tailored prevention and intervention efforts. © 2017 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Developmental changes in hippocampal shape among preadolescent children.

PubMed

Lin, Muqing; Fwu, Peter T; Buss, Claudia; Davis, Elysia P; Head, Kevin; Muftuler, L Tugan; Sandman, Curt A; Su, Min-Ying

2013-11-01

It is known that the largest developmental changes in the hippocampus take place during the prenatal period and during the first two years of postnatal life. Few studies have been conducted to address the normal developmental trajectory of the hippocampus during childhood. In this study shape analysis was applied to study the normal developing hippocampus in a group of 103 typically developing 6- to 10-year-old preadolescent children. The individual brain was normalized to a template, and then the hippocampus was manually segmented and further divided into the head, body, and tail sub-regions. Three different methods were applied for hippocampal shape analysis: radial distance mapping, surface-based template registration using the robust point matching (RPM) algorithm, and volume-based template registration using the Demons algorithm. All three methods show that the older children have bilateral expanded head segments compared to the younger children. The results analyzed based on radial distance to the centerline were consistent with those analyzed using template-based registration methods. In analyses stratified by sex, it was found that the age-associated anatomical changes were similar in boys and girls, but the age-association was strongest in girls. Total hippocampal volume and sub-regional volumes analyzed using manual segmentation did not show a significant age-association. Our results suggest that shape analysis is sensitive to detect sub-regional differences that are not revealed in volumetric analysis. The three methods presented in this study may be applied in future studies to investigate the normal developmental trajectory of the hippocampus in children. They may be further applied to detect early deviations from the normal developmental trajectory in young children for evaluating susceptibility for psychopathological disorders involving hippocampus. Copyright © 2013 ISDN. Published by Elsevier Ltd. All rights reserved.

BDE-47 causes developmental retardation with down-regulated expression profiles of ecdysteroid signaling pathway-involved nuclear receptor (NR) genes in the copepod Tigriopus japonicus.

PubMed

Hwang, Dae-Sik; Han, Jeonghoon; Won, Eun-Ji; Kim, Duck-Hyun; Jeong, Chang-Bum; Hwang, Un-Ki; Zhou, Bingsheng; Choe, Joonho; Lee, Jae-Seong

2016-08-01

2,2',4,4'-Tetrabromodiphenyl ether (BDE-47) is a persistent organic pollutant (POP) in marine environments. Despite its adverse effects (e.g. developmental retardation) in ecdysozoa, the effects of BDE-47 on transcription of ecdysteroid signaling pathway-involved-nuclear receptor (NR) genes and metamorphosis-related genes have not been examined in copepods. To examine the deleterious effect of BDE-47 on copepod molting and metamorphosis, BDE-47 was exposed to the harpacticoid copepod Tigriopus japonicus, followed by monitoring developmental retardation and transcriptional alteration of NR genes. The developmental rate was significantly inhibited (P<0.05) in response to BDE-47 and the agricultural insecticide gamma-hexachlorocyclohexane. Conversely, the ecdysteroid agonist ponasterone A (PoA) led to decreased molting and metamorphosis time (P<0.05) from the nauplius stage to the adult stage. In particular, expression profiles of all NR genes were the highest at naupliar stages 5-6 except for SVP, FTZ-F1, and HR96 genes. Nuclear receptor USP, HR96, and FTZ-F1 genes also showed significant sex differences (P<0.05) in gene expression levels over different developmental stages, indicating that these genes may be involved in vitellogenesis. NR gene expression patterns showed significant decreases (P<0.05) in response to BDE-47 exposure, implying that molting and metamorphosis retardation is likely associated with NR gene expression. In summary, BDE-47 leads to molting and metamorphosis retardation and suppresses transcription of NR genes. This information will be helpful in understanding the molting and metamorphosis delay mechanism in response to BDE-47 exposure. Copyright © 2016 Elsevier B.V. All rights reserved.

Feasibility and validity of the structured attention module among economically disadvantaged preschool-age children.

PubMed

Bush, Hillary H; Eisenhower, Abbey; Briggs-Gowan, Margaret; Carter, Alice S

2015-01-01

Rooted in the theory of attention put forth by Mirsky, Anthony, Duncan, Ahearn, and Kellam (1991), the Structured Attention Module (SAM) is a developmentally sensitive, computer-based performance task designed specifically to assess sustained selective attention among 3- to 6-year-old children. The current study addressed the feasibility and validity of the SAM among 64 economically disadvantaged preschool-age children (mean age = 58 months; 55% female); a population known to be at risk for attention problems and adverse math performance outcomes. Feasibility was demonstrated by high completion rates and strong associations between SAM performance and age. Principal Factor Analysis with rotation produced robust support for a three-factor model (Accuracy, Speed, and Endurance) of SAM performance, which largely corresponded with existing theorized models of selective and sustained attention. Construct validity was evidenced by positive correlations between SAM Composite scores and all three SAM factors and IQ, and between SAM Accuracy and sequential memory. Value-added predictive validity was not confirmed through main effects of SAM on math performance above and beyond age and IQ; however, significant interactions by child sex were observed: Accuracy and Endurance both interacted with child sex to predict math performance. In both cases, the SAM factors predicted math performance more strongly for girls than for boys. There were no overall sex differences in SAM performance. In sum, the current findings suggest that interindividual variation in sustained selective attention, and potentially other aspects of attention and executive function, among young, high-risk children can be captured validly with developmentally sensitive measures.

Transsexualism: a review of etiology, diagnosis and treatment.

PubMed

Cohen-Kettenis, P T; Gooren, L J

1999-04-01

Transsexualism is considered to be the extreme end of the spectrum of gender identity disorders characterized by, among other things, a pursuit of sex reassignment surgery (SRS). The origins of transsexualism are still largely unclear. A first indication of anatomic brain differences between transsexuals and nontranssexuals has been found. Also, certain parental (rearing) factors seem to be associated with transsexualism. Some contradictory findings regarding etiology, psychopathology and success of SRS seem to be related to the fact that certain subtypes of transsexuals follow different developmental routes. The observations that psychotherapy is not helpful in altering a crystallized cross-gender identity and that certain transsexuals do not show severe psychopathology has led clinicians to adopt sex reassignment as a treatment option. In many countries, transsexuals are now treated according to the Standards of Care of the Harry Benjamin International Gender Dysphoria Association, a professional organization in the field of transsexualism. Research on postoperative functioning of transsexuals does not allow for unequivocal conclusions, but there is little doubt that sex reassignment substantially alleviates the suffering of transsexuals. However, SRS is no panacea. Psychotherapy may be needed to help transsexuals in adapting to the new situation or in dealing with issues that could not be addressed before treatment.

Sex education changes for the worse, say sexual health organisations.

PubMed

1993-01-01

Amendments to the Education Bill, which was part of the Education act of 1993, included some changes for sex education in Great Britain. These changes included 1) removing from the science curriculum all mention of sexually transmitted diseases (STDs) including HIV infections, 2) giving parents the right to withdraw their children from sex education classes in primary and secondary schools, and 3) placing the responsibility for sex education, including HIV/AIDS and STDs, in "maintained" secondary schools with governors. Family planning and sexual health educators were opposed to the amendment. Over 30 different organizations grouped under the Sex Education Forum also expressed concern about the changes. The UK has not had a compulsory and comprehensive sex education program; compulsory sex education has been a component only within the science curriculum, mostly reproductive biology. The thinking was that this amendment would not strengthen effective sex education. Sex education advocates want a broad-based curriculum, that covers more than reproductive biology and is provided throughout the developmental stages of a young person's schooling. Critics of this amendment have proposed that the parental right to withdraw their children from sex education classes deprives children of potentially life-saving information. There would also appear to be a conflict with the Children Act of 1989 and the UN Convention on the Rights of Children, which assures the rights of children to information. These changes would add to the existing difficulties and create new ones. Implementation is in the hands of the Department of Education. Draft guidelines are expected in the Fall 1993; sex education circulars would be distributed in the Spring 1994, and curriculum changes would be fully implemented in August 1994.

Transcriptome display during tilapia sex determination and differentiation as revealed by RNA-Seq analysis.

PubMed

Tao, Wenjing; Chen, Jinlin; Tan, Dejie; Yang, Jing; Sun, Lina; Wei, Jing; Conte, Matthew A; Kocher, Thomas D; Wang, Deshou

2018-05-15

The factors determining sex in teleosts are diverse. Great efforts have been made to characterize the underlying genetic network in various species. However, only seven master sex-determining genes have been identified in teleosts. While the function of a few genes involved in sex determination and differentiation has been studied, we are far from fully understanding how genes interact to coordinate in this process. To enable systematic insights into fish sexual differentiation, we generated a dynamic co-expression network from tilapia gonadal transcriptomes at 5, 20, 30, 40, 90, and 180 dah (days after hatching), plus 45 and 90 dat (days after treatment) and linked gene expression profiles to both development and sexual differentiation. Transcriptomic profiles of female and male gonads at 5 and 20 dah exhibited high similarities except for a small number of genes that were involved in sex determination, while drastic changes were observed from 90 to 180 dah, with a group of differently expressed genes which were involved in gonadal differentiation and gametogenesis. Weighted gene correlation network analysis identified changes in the expression of Borealin, Gtsf1, tesk1, Zar1, Cdn15, and Rpl that were correlated with the expression of genes previously known to be involved in sex differentiation, such as Foxl2, Cyp19a1a, Gsdf, Dmrt1, and Amh. Global gonadal gene expression kinetics during sex determination and differentiation have been extensively profiled in tilapia. These findings provide insights into the genetic framework underlying sex determination and sexual differentiation, and expand our current understanding of developmental pathways during teleost sex determination.

Sex determination strategies in 2012: towards a common regulatory model?

PubMed

Angelopoulou, Roxani; Lavranos, Giagkos; Manolakou, Panagiota

2012-02-22

Sex determination is a complicated process involving large-scale modifications in gene expression affecting virtually every tissue in the body. Although the evolutionary origin of sex remains controversial, there is little doubt that it has developed as a process of optimizing metabolic control, as well as developmental and reproductive functions within a given setting of limited resources and environmental pressure. Evidence from various model organisms supports the view that sex determination may occur as a result of direct environmental induction or genetic regulation. The first process has been well documented in reptiles and fish, while the second is the classic case for avian species and mammals. Both of the latter have developed a variety of sex-specific/sex-related genes, which ultimately form a complete chromosome pair (sex chromosomes/gonosomes). Interestingly, combinations of environmental and genetic mechanisms have been described among different classes of animals, thus rendering the possibility of a unidirectional continuous evolutionary process from the one type of mechanism to the other unlikely. On the other hand, common elements appear throughout the animal kingdom, with regard to a) conserved key genes and b) a central role of sex steroid control as a prerequisite for ultimately normal sex differentiation. Studies in invertebrates also indicate a role of epigenetic chromatin modification, particularly with regard to alternative splicing options. This review summarizes current evidence from research in this hot field and signifies the need for further study of both normal hormonal regulators of sexual phenotype and patterns of environmental disruption. © 2012 Angelopoulou et al; licensee BioMed Central Ltd.

Developmental Neurogenetics and Multimodal Neuroimaging of Sex Differences in Autism

PubMed Central

Chen, Christina; Van Horn, John Darrell

2016-01-01

Examining sex differences in the brain has been contentious but is nonetheless important for advancing mental health for both girls and boys. Unfortunately, females in biomedical research remain underrepresented in most mental health conditions including autism spectrum disorders (ASD), even though equal inclusion of females would improve treatment for girls and yield benefits to boys. This review examines sex differences in the relationship between neuroanatomy and neurogenetics of ASD. Recent findings reveal that girls diagnosed with ASD exhibit more intellectual and behavioral problems compared to their male counterparts, suggesting that girls may be less likely diagnosed in the absence of such problems or that they require a higher mutational load to meet the diagnostic criteria. Thus far, the female biased effect of chromosome 4, 5p15.33, 8p, 9p24.1, 11p12-13, 15q, and Xp22.3 and the male biased effect of 1p31.3, 5q12.3, 7q, 9q33.3, 11q13.4, 13q33.3, 16p11.2, 17q11-21, Xp22.33/Yp11.31, DRD1, NLGN3, MAOA, and SHANK1 deletion have been discovered in ASD. The SNPs of genes such as RYR2, UPP2, and the androgen receptor gene have been shown to have sex-biasing factors in both girls and boys diagnosed with ASD. These sex-related genetic factors may drive sex differences in the neuroanatomy of these girls and boys, including abnormal enlargement in temporal gray and white matter volumes, and atypical reduction in cerebellar gray matter volumes and corpus callosum fibers projecting to the anterior frontal cortex in ASD girls relative to boys. Such factors may also be responsible for the attenuation of brain sexual differentiation in adult men and women with ASD; however, much remains to be uncovered or replicated. Future research should leverage further the association between neuroanatomy and genetics in girls for an integrated and interdisciplinary understanding of ASD. PMID:26781567

Developmental neurogenetics and multimodal neuroimaging of sex differences in autism.

PubMed

Chen, Christina; Van Horn, John Darrell

2017-02-01

Examining sex differences in the brain has been historically contentious but is nonetheless important for advancing mental health for both girls and boys. Unfortunately, females in biomedical research remain underrepresented in most mental health conditions including autism spectrum disorders (ASD), even though equal inclusion of females would improve treatment for girls and yield benefits to boys. This review examines sex differences in the relationship between neuroanatomy and neurogenetics of ASD. Recent findings reveal that girls diagnosed with ASD exhibit more intellectual and behavioral problems compared to their male counterparts, suggesting that girls may be less likely diagnosed in the absence of such problems or that they require a higher mutational load to meet the diagnostic criteria. Thus far, the female biased effect of chromosome 4, 5p15.33, 8p, 9p24.1, 11p12-13, 15q, and Xp22.3 and the male biased effect of 1p31.3, 5q12.3, 7q, 9q33.3, 11q13.4, 13q33.3, 16p11.2, 17q11-21, Xp22.33/Yp11.31, DRD1, NLGN3, MAOA, and SHANK1 deletion have been discovered in ASD. The SNPs of genes such as RYR2, UPP2, and the androgen receptor gene have been shown to have sex-biasing factors in both girls and boys diagnosed with ASD. These sex-related genetic factors may drive sex differences in the neuroanatomy of these girls and boys, including abnormal enlargement in temporal gray and white matter volumes, and atypical reduction in cerebellar gray matter volumes and corpus callosum fibers projecting to the anterior frontal cortex in ASD girls relative to boys. Such factors may also be responsible for the attenuation of brain sexual differentiation in adult men and women with ASD; however, much remains to be uncovered or replicated. Future research should leverage further the association between neuroanatomy and genetics in girls for an integrated and interdisciplinary understanding of ASD.

Developmental Exposure to Concentrated Ambient Ultrafine Particulate Matter Air Pollution in Mice Results in Persistent and Sex-Dependent Behavioral Neurotoxicity and Glial Activation

PubMed Central

Allen, Joshua L.; Liu, Xiufang; Weston, Douglas; Prince, Lisa; Oberdörster, Günter; Finkelstein, Jacob N.; Johnston, Carl J.; Cory-Slechta, Deborah A.

2014-01-01

The brain appears to be a target of air pollution. This study aimed to further ascertain behavioral and neurobiological mechanisms of our previously observed preference for immediate reward (Allen, J. L., Conrad, K., Oberdorster, G., Johnston, C. J., Sleezer, B., and Cory-Slechta, D. A. (2013). Developmental exposure to concentrated ambient particles and preference for immediate reward in mice. Environ. Health Perspect. 121, 32–38), a phenotype consistent with impulsivity, in mice developmentally exposed to inhaled ultrafine particles. It examined the impact of postnatal and/or adult concentrated ambient ultrafine particles (CAPS) or filtered air on another behavior thought to reflect impulsivity, Fixed interval (FI) schedule-controlled performance, and extended the assessment to learning/memory (novel object recognition (NOR)), and locomotor activity to assist in understanding behavioral mechanisms of action. In addition, levels of brain monoamines and amino acids, and markers of glial presence and activation (GFAP, IBA-1) were assessed in mesocorticolimbic brain regions mediating these cognitive functions. This design produced four treatment groups/sex of postnatal/adult exposure: Air/Air, Air/CAPS, CAPS/Air, and CAPS/CAPS. FI performance was adversely influenced by CAPS/Air in males, but by Air/CAPS in females, effects that appeared to reflect corresponding changes in brain mesocorticolimbic dopamine/glutamate systems that mediate FI performance. Both sexes showed impaired short-term memory on the NOR. Mechanistically, cortical and hippocampal changes in amino acids raised the potential for excitotoxicity, and persistent glial activation was seen in frontal cortex and corpus callosum of both sexes. Collectively, neurodevelopment and/or adulthood CAPS can produce enduring and sex-dependent neurotoxicity. Although mechanisms of these effects remain to be fully elucidated, findings suggest that neurodevelopment and/or adulthood air pollution exposure may represent a significant underexplored risk factor for central nervous system diseases/disorders and thus a significant public health threat even beyond current appreciation. PMID:24690596

Autosomal gsdf acts as a male sex initiator in the fish medaka

PubMed Central

Zhang, Xi; Guan, Guijun; Li, Mingyou; Zhu, Feng; Liu, Qizhi; Naruse, Kiyoshi; Herpin, Amaury; Nagahama, Yoshitaka; Li, Jiale; Hong, Yunhan

2016-01-01

Sex is pivotal for reproduction, healthcare and evolution. In the fish medaka, the Y-chromosomal dmy (also dmrt1bY) serves the sex determiner, which activates dmrt1 for male sex maintenance. However, how dmy makes the male decision via initiating testicular differentiation has remained unknown. Here we report that autosomal gsdf serves a male sex initiator. Gene addition and deletion revealed that gsdf was necessary and sufficient for maleness via initiating testicular differentiation. We show that gsdf transcription is activated directly by dmy. These results establish the autosomal gsdf as the first male sex initiator. We propose that dmy determines maleness through activating gsdf and dmrt1 without its own participation in developmental processes of sex initiation and maintenance. gsdf may easily become a sex determiner or other autosomal genes can be recruited as new sex determiners to initiate gsdf expression. Our findings offer new insights into molecular mechanisms underlying sex development and evolution of sex-controlling genes in vertebrates. PMID:26813267

Associations between biological markers of prenatal stress and infant negative emotionality are specific to sex.

PubMed

Braithwaite, Elizabeth C; Murphy, Susannah E; Ramchandani, Paul G; Hill, Jonathan

2017-12-01

Fetal programming is the idea that environmental stimuli can alter the development of the fetus, which may have a long-term effect on the child. We have recently reported that maternal prenatal cortisol predicts infant negative emotionality in a sex-dependent manner: high prenatal cortisol was associated with increased negative emotionality in females, and decreased negative emotionality in males. This study aims to test for this sex-specific effect in a different cohort, and investigate whether sex differences in fetal programming may be specific to glucocorticoid mechanisms by also examining a maternal salivary alpha-amylase (sAA) by sex interaction. 88 pregnant women (mean gestational age=27.4 weeks, SD=7.4) collected saliva samples at home over two working days to be assayed for the hormone cortisol (range=0.13-88.22nmol/l) and the enzyme alpha-amylase (range=4.57-554.8units/ml). Samples were collected at waking, 30-min post-waking and 12h post-waking. Two months after birth participants reported infant negative emotionality using the distress to limits subscale of the Infant Behavior Questionnaire. The interaction between maternal prenatal cortisol and infant sex to predict distress to limits approached significance (p=0.067). In line with our previous finding there was a positive association between prenatal cortisol and negative emotionality in females, and a negative association in males. The interaction between sAA and sex to predict distress was significant (p=0.025), and the direction of effect was the same as for the cortisol data; high sAA associated with increased negative emotionality in females and reduced negative emotionality in males. In line with our previous findings, this research adds to an emerging body of literature, which suggests that fetal programming mechanisms may be sex-dependent. This is the first study to demonstrate that maternal prenatal sAA may be an important biomarker for infant behavior, and the findings have implications for understanding sex differences in developmental psychopathology. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

The Effect of Interpersonal Touch during Childhood on Adult Attachment and Depression: A Neglected Area of Family and Developmental Psychology?

ERIC Educational Resources Information Center

Takeuchi, Mika S.; Miyaoka, Hitoshi; Tomoda, Atsuko; Suzuki, Masao; Liu, Qingbo; Kitamura, Toshinori

2010-01-01

Interpersonal touch has been little studied empirically as an indicator of parent- and peer-child intimacy. Undergraduate students (n = 390) were studied using a questionnaire survey regarding the frequencies of interpersonal touch by father, mother, same-sex peers, and opposite-sex peers during preschool ages, grades 1-3, grades 4-6, and grades…

Encoding Processes and Sex-Role Preferences. Developmental Program Report No. 48.

ERIC Educational Resources Information Center

Kail, Robert V., Jr.; Levine, Laura

A total of 240, 7- and 10-year-olds were tested on memory and sex-role preference tasks. The memory task was the Wickens release from proactive inhibition paradigm in which short-term recall of words is tested on successive trials. On trials 1-4 words were selected from 1 of 2 categories, either words with masculine or feminine connotations. On…

Sleep and Cognitive Functioning in Childhood: Ethnicity, Socioeconomic Status, and Sex as Moderators

ERIC Educational Resources Information Center

Philbrook, Lauren E.; Hinnant, J. Benjamin; Elmore-Staton, Lori; Buckhalt, Joseph A.; El-Sheikh, Mona

2017-01-01

We examined children's sleep at age 9 as a predictor of developmental trajectories of cognitive performance from ages 9 to 11 years. The effects of sleep on cognition are not uniform and thus we tested race/ethnicity, socioeconomic status (SES), and sex as moderators of these associations. At the first assessment, 282 children aged 9.44 years (52%…

Language Use, Language Ability, and Language Development: Abstracts of Doctoral Dissertations Published in "Dissertation Abstracts International," January through June 1979 (Vol. 39 Nos. 7 through 12).

ERIC Educational Resources Information Center

ERIC Clearinghouse on Reading and Communication Skills, Urbana, IL.

This collection of abstracts is part of a continuing series providing information on recent doctoral dissertations. The 23 titles deal with the following topics: sex appropriate and sex inappropriate language; lexical retrieval and perceptual errors; naming deficits in anomia and aphasia; developmental discourse; pragmatic information and…

Developmental delay in moderately preterm-born children with low socioeconomic status: risks multiply.

PubMed

Potijk, Marieke R; Kerstjens, Jorien M; Bos, Arend F; Reijneveld, Sijmen A; de Winter, Andrea F

2013-11-01

To assess separate and joint effects of low socioeconomic status (SES) and moderate prematurity on preschool developmental delay. Prospective cohort study with a community-based sample of preterm- and term-born children (Longitudinal Preterm Outcome Project). We assessed SES on the basis of education, occupation, and family income. The Ages and Stages Questionnaire was used to assess developmental delay at age 4 years. We determined scores for overall development, and domains fine motor, gross motor, communication, problem-solving, and personal-social of 926 moderately preterm-born (MP) (32-36 weeks gestation) and 544 term-born children. In multivariable logistic regression analyses, we used standardized values for SES and gestational age (GA). Prevalence rates for overall developmental delay were 12.5%, 7.8%, and 5.6% in MP children with low, intermediate, and high SES, respectively, and 7.2%, 4.0%, and 2.8% in term-born children, respectively. The risk for overall developmental delay increased more with decreasing SES than with decreasing GA, but the difference was not statistically significant: OR (95% CI) for a 1 standard deviation decrease were: 1.62 (1.30-2.03) and 1.34 (1.05-1.69), respectively, after adjustment for sex, number of siblings, and maternal age. No interaction was found except for communication, showing that effects of SES and GA are mostly multiplicative. Low SES and moderate prematurity are separate risk factors with multiplicative effects on developmental delay. The double jeopardy of MP children with low SES needs special attention in pediatric care. Copyright © 2013 Mosby, Inc. All rights reserved.

Effect of rearing temperatures during embryonic development on the phenotypic sex in zebrafish (Danio rerio).

PubMed

Abozaid, H; Wessels, S; Hörstgen-Schwark, G

2011-01-01

In zebrafish, Danio rerio, a polygenic pattern of sex determination or a female heterogamety with possible influences of environmental factors is assumed. The present study focuses on the effects of an elevated water temperature (35° C) during the embryonic development on sex determination in zebrafish. Eggs derived from 3 golden females were fertilized by the same mitotic gynogenetic male and exposed to a water temperature of 35° C, applied from 5 to 10 h post fertilization (hpf), from 5 to 24 hpf, and from 5 to 48 hpf, which correspond to the following developmental stages: gastrula, gastrula to segmentation, and gastrula to pharyngula stage, respectively. Hatching and survival rates decreased with increasing exposure to high water temperatures. Reductions in the hatching and survival rates were not responsible for differences in sex ratios. Accordingly, exposition of the fertilized eggs to a high temperature (35° C) leads to an increase of the male proportion from 22.0% in the controls to a balanced sex ratio (48.3, 47.5, and 52.6%) in the gastrula, segmentation, and pharyngula groups, respectively. These results prove the possibility to change the pathway of sexual determination during early embryonic stages in zebrafish by exposure to a high water temperature. Copyright © 2011 S. Karger AG, Basel.

The 'male escape hypothesis': sex-biased metamorphosis in response to climatic drivers in a facultatively paedomorphic amphibian.

PubMed

Mathiron, Anthony G E; Lena, Jean-Paul; Baouch, Sarah; Denoël, Mathieu

2017-04-26

Paedomorphosis is a major evolutionary process that bypasses metamorphosis and allows reproduction in larvae. In newts and salamanders, it can be facultative with paedomorphs retaining gills and metamorphs dispersing. The evolution of these developmental processes is thought to have been driven by the costs and benefits of inhabiting aquatic versus terrestrial habitats. In this context, we aimed at testing the hypothesis that climatic drivers affect phenotypic transition and the difference across sexes because sex-ratio is biased in natural populations. Through a replicated laboratory experiment, we showed that paedomorphic palmate newts ( Lissotriton helveticus ) metamorphosed at a higher frequency when water availability decreased and metamorphosed earlier when temperature increased in these conditions. All responses were sex-biased, and males were more prone to change phenotype than females. Our work shows how climatic variables can affect facultative paedomorphosis and support theoretical models predicting life on land instead of in water. Moreover, because males metamorphose and leave water more often and earlier than females, these results, for the first time, give an experimental explanation for the rarity of male paedomorphosis (the 'male escape hypothesis') and suggest the importance of sex in the evolution of paedomorphosis versus metamorphosis. © 2017 The Author(s).

FOXL2 is a female sex-determining gene in the goat.

PubMed

Boulanger, Laurent; Pannetier, Maëlle; Gall, Laurence; Allais-Bonnet, Aurélie; Elzaiat, Maëva; Le Bourhis, Daniel; Daniel, Nathalie; Richard, Christophe; Cotinot, Corinne; Ghyselinck, Norbert B; Pailhoux, Eric

2014-02-17

The origin of sex reversal in XX goats homozygous for the polled intersex syndrome (PIS) mutation was unclear because of the complexity of the mutation that affects the transcription of both FOXL2 and several long noncoding RNAs (lncRNAs). Accumulating evidence suggested that FOXL2 could be the sole gene of the PIS locus responsible for XX sex reversal, the lncRNAs being involved in transcriptional regulation of FOXL2. In this study, using zinc-finger nuclease-directed mutagenesis, we generated several fetuses, of which one XX individual bears biallelic mutations of FOXL2. Our analysis demonstrates that FOXL2 loss of function dissociated from loss of lncRNA expression is sufficient to cause an XX female-to-male sex reversal in the goat model and, as in the mouse model, an agenesis of eyelids. Both developmental defects were reproduced in two newborn animals cloned from the XX FOXL2(-/-) fibroblasts. These results therefore identify FOXL2 as a bona fide female sex-determining gene in the goat. They also highlight a stage-dependent role of FOXL2 in the ovary, different between goats and mice, being important for fetal development in the former but for postnatal maintenance in the latter. Copyright © 2014 Elsevier Ltd. All rights reserved.

A New Z Score Curve of the Coronary Arterial Internal Diameter Using the Lambda-Mu-Sigma Method in a Pediatric Population.

PubMed

Kobayashi, Tohru; Fuse, Shigeto; Sakamoto, Naoko; Mikami, Masashi; Ogawa, Shunichi; Hamaoka, Kenji; Arakaki, Yoshio; Nakamura, Tsuneyuki; Nagasawa, Hiroyuki; Kato, Taichi; Jibiki, Toshiaki; Iwashima, Satoru; Yamakawa, Masaru; Ohkubo, Takashi; Shimoyama, Shinya; Aso, Kentaro; Sato, Seiichi; Saji, Tsutomu

2016-08-01

Several coronary artery Z score models have been developed. However, a Z score model derived by the lambda-mu-sigma (LMS) method has not been established. Echocardiographic measurements of the proximal right coronary artery, left main coronary artery, proximal left anterior descending coronary artery, and proximal left circumflex artery were prospectively collected in 3,851 healthy children ≤18 years of age and divided into developmental and validation data sets. In the developmental data set, smooth curves were fitted for each coronary artery using linear, logarithmic, square-root, and LMS methods for both sexes. The relative goodness of fit of these models was compared using the Bayesian information criterion. The best-fitting model was tested for reproducibility using the validation data set. The goodness of fit of the selected model was visually compared with that of the previously reported regression models using a Q-Q plot. Because the internal diameter of each coronary artery was not similar between sexes, sex-specific Z score models were developed. The LMS model with body surface area as the independent variable showed the best goodness of fit; therefore, the internal diameter of each coronary artery was transformed into a sex-specific Z score on the basis of body surface area using the LMS method. In the validation data set, a Q-Q plot of each model indicated that the distribution of Z scores in the LMS models was closer to the normal distribution compared with previously reported regression models. Finally, the final models for each coronary artery in both sexes were developed using the developmental and validation data sets. A Microsoft Excel-based Z score calculator was also created, which is freely available online (http://raise.umin.jp/zsp/calculator/). Novel LMS models with which to estimate the sex-specific Z score of each internal coronary artery diameter were generated and validated using a large pediatric population. Copyright © 2016 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

Female turtles from hot nests: is it duration of incubation or proportion of development at high temperatures that matters?

PubMed

Georges, Arthur

1989-11-01

Mean daily temperature in natural nests of freshwater turtles with temperature-dependent sex determination is known to be a poor predictor of hatchling sex ratios when nest temperatures fluctuate. To account for this, a model was developed on the assumption that females will emerge from eggs when more than half of embryonic development occurs above the threshold temperature for sex determination rather than from eggs that spend more than half their time above the threshold. The model is consistent with previously published data and in particular explains the phenomenon whereby the mean temperature that best distinguishes between male and female nests decreases with increasing variability in nest temperature. The model, if verified by controlled experiments, has important implications for our understanding of temperature-dependent sex determination in natural nests. Both mean nest temperature and "hours spent above the threshold" will be poor predictors of hatchling sex ratios. Studies designed to investigate latitudinal trends and inter-specific differences in the threshold temperature will need to consider latitudinal and inter-specific variation in the magnitude of diel fluctuations in nest temperature, and variation in factors influencing the magnitude of those fluctuations, such as nest depth. Furthermore, any factor that modifies the relationship between developmental rate and temperature can be expected to influence hatchling sex ratios in natural nests, especially when nest temperatures are close to the threshold.

How sex became gender.

PubMed

Nye, Robert A

2010-01-01

This article argues that "sex" which had been commonly assumed in the West to refer to a permanent set of biological and behavioural traits particular to men and women, is gradually being replaced in general usage by "gender." Though feminist theorists attempted to attach a constructivist meaning to gender, a generation of developmental theorists, clinicians and analysts has imbued the term with the determinism and biological qualities formerly ascribed to "sex." The triumph of this materialist conception of gender is not assured, but it threatens our ability to think about gender identity as a historically-constructed category.

Inspiratory Phonation in Baby Voice.

PubMed

Wermke, Kathleen; Haschemi, Asin Ahmad; Hesse, Volker; Robb, Michael P

2018-03-01

This study aimed to evaluate the developmental occurrence of inspiratory phonations (IPs) in the spontaneous cries of healthy infants across the first 10 weeks of life. This is a populational retrospective study. The spontaneous crying of 17 healthy infants (10 were male) was retrospectively investigated. Sound files of spontaneously uttered cries that were repeatedly recorded once per week for across the first 10 weeks of life were retrospectively analyzed. Frequency spectra and waveforms were used to identify the occurrence of IPs and to measure the duration and fundamental frequency (fo) of each instance of IP. A consistent number of IPs were identified across the 10-week period. All infants were observed to produce IPs in their spontaneous cries, although the frequency of occurrence was not consistent across infants. A marked sex difference was observed with female infants producing a higher number of IPs compared to males. The duration and fo of IPs did not differ significantly across the 10 weeks or between sexes. The production of IPs is a regularly occurring phenomenon in healthy, normally developing infants' spontaneous crying. The proportional difference in the production of IPs between female and male infants, observed for the first time here, is postulated to be linked to sex-based differences (including steroidal hormones) in respiratory anatomy and physiology. Copyright © 2018 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Ontogenetic Trajectories of Chimpanzee Social Play: Similarities with Humans

PubMed Central

Cordoni, Giada; Palagi, Elisabetta

2011-01-01

Social play, a widespread phenomenon in mammals, is a multifunctional behavior, which can have many different roles according to species, sex, age, relationship quality between playmates, group membership, context, and habitat. Play joins and cuts across a variety of disciplines leading directly to inquiries relating to individual developmental changes and species adaptation, thus the importance of comparative studies appears evident. Here, we aim at proposing a possible ontogenetic pathway of chimpanzee play (Pan troglodytes) and contrast our data with those of human play. Chimpanzee play shows a number of changes from infancy to juvenility. Particularly, solitary and social play follows different developmental trajectories. While solitary play peaks in infancy, social play does not show any quantitative variation between infancy and juvenility but shows a strong qualitative variation in complexity, asymmetry, and playmate choice. Like laughter in humans, the playful expressions in chimpanzees (at the different age phases) seem to have a role in advertising cooperative dispositions and intentions thus increasing the likelihood of engaging in solid social relationships. In conclusion, in chimpanzees, as in humans, both play behavior and the signals that accompany play serve multiple functions according to the different age phases. PMID:22110630

Ontogenetic trajectories of chimpanzee social play: similarities with humans.

PubMed

Cordoni, Giada; Palagi, Elisabetta

2011-01-01

Social play, a widespread phenomenon in mammals, is a multifunctional behavior, which can have many different roles according to species, sex, age, relationship quality between playmates, group membership, context, and habitat. Play joins and cuts across a variety of disciplines leading directly to inquiries relating to individual developmental changes and species adaptation, thus the importance of comparative studies appears evident. Here, we aim at proposing a possible ontogenetic pathway of chimpanzee play (Pan troglodytes) and contrast our data with those of human play. Chimpanzee play shows a number of changes from infancy to juvenility. Particularly, solitary and social play follows different developmental trajectories. While solitary play peaks in infancy, social play does not show any quantitative variation between infancy and juvenility but shows a strong qualitative variation in complexity, asymmetry, and playmate choice. Like laughter in humans, the playful expressions in chimpanzees (at the different age phases) seem to have a role in advertising cooperative dispositions and intentions thus increasing the likelihood of engaging in solid social relationships. In conclusion, in chimpanzees, as in humans, both play behavior and the signals that accompany play serve multiple functions according to the different age phases.

Does Chernobyl-derived radiation impact the developmental stability of Asellus aquaticus 30years on?

PubMed

Fuller, Neil; Smith, Jim T; Nagorskaya, Liubov L; Gudkov, Dmitri I; Ford, Alex T

2017-01-15

Effects of long-term, environmentally relevant doses of radiation on biota remain unclear due to a lack of studies following chronic exposure in contaminated environments. The 1986 Chernobyl accident dispersed vast amounts of radioactivity into the environment which persists to date. Despite three decades of research, impacts of the incident on non-human organisms continues to be contested within the scientific literature. The present study assessed the impact of chronic radiation exposure from Chernobyl on the developmental stability of the model aquatic isopod, Asellus aquaticus using fluctuating asymmetry (FA) as an indicator. Fluctuating asymmetry, defined as random deviations from the expected perfect bilateral symmetry of an organism, has gained prominence as an indicator of developmental stability in ecotoxicology. Organisms were collected from six lakes along a gradient of radionuclide contamination in Belarus and the Ukraine. Calculated total dose rates ranged from 0.06-27.1μGy/h. Fluctuating asymmetry was assessed in four meristic and one metrical trait. Significant differences in levels of pooled asymmetry were recorded between sample sites independent of sex and specific trait measured. However, there was no correlation of asymmetry with radiation doses, suggesting that differences in asymmetry were not attributed to radionuclide contamination and were driven by elevated asymmetry at a single site. No correlation between FA and measured environmental parameters suggested a biotic factor driving observed FA differences. This study appears to be the first to record no evident increase in developmental stability of biota from the Chernobyl region. These findings will aid in understanding the response of organisms to chronic pollutant exposure and the long term effects of large scale nuclear incidents such as Chernobyl and Fukushima. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

The dynamics of resource allocation and costs of reproduction in a sexually dimorphic, wind-pollinated dioecious plant.

PubMed

Teitel, Z; Pickup, M; Field, D L; Barrett, S C H

2016-01-01

Sexual dimorphism in resource allocation is expected to change during the life cycle of dioecious plants because of temporal differences between the sexes in reproductive investment. Given the potential for sex-specific differences in reproductive costs, resource availability may contribute to variation in reproductive allocation in females and males. Here, we used Rumex hastatulus, a dioecious, wind-pollinated annual plant, to investigate whether sexual dimorphism varies with life-history stage and nutrient availability, and determine whether allocation patterns differ depending on reproductive commitment. To examine if the costs of reproduction varied between the sexes, reproduction was either allowed or prevented through bud removal, and biomass allocation was measured at maturity. In a second experiment to assess variation in sexual dimorphism across the life cycle, and whether this varied with resource availability, plants were grown in high and low nutrients and allocation to roots, aboveground vegetative growth and reproduction were measured at three developmental stages. Males prevented from reproducing compensated with increased above- and belowground allocation to a much larger degree than females, suggesting that male reproductive costs reduce vegetative growth. The proportional allocation to roots, reproductive structures and aboveground vegetative growth varied between the sexes and among life-cycle stages, but not with nutrient treatment. Females allocated proportionally more resources to roots than males at peak flowering, but this pattern was reversed at reproductive maturity under low-nutrient conditions. Our study illustrates the importance of temporal dynamics in sex-specific resource allocation and provides support for high male reproductive costs in wind-pollinated plants. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

Sex differences, learning flexibility, and striatal dopamine D1 and D2 following adolescent drug exposure in rats

PubMed Central

Izquierdo, Alicia; Pozos, Hilda; De La Torre, Adrianna; DeShields, Simone; Cevallos, James; Rodriguez, Jonathan; Stolyarova, Alexandra

2016-01-01

Corticostriatal circuitry supports flexible reward learning and emotional behavior from the critical neurodevelopmental stage of adolescence through adulthood. It is still poorly understood how prescription drug exposure in adolescence may impact these outcomes in the long-term. We studied adolescent methylphenidate (MPH) and fluoxetine (FLX) exposure in rats and their impact on learning and emotion in adulthood. In Experiment 1, male and female rats were administered MPH, FLX, or saline (SAL), and compared with methamphetamine (mAMPH) treatment beginning in postnatal day (PND) 37. The rats were then tested on discrimination and reversal learning in adulthood. In Experiment 2, animals were administered MPH or SAL also beginning in PND 37 and later tested in adulthood for anxiety levels. In Experiment 3, we analyzed striatal dopamine D1 and D2 receptor expression in adulthood following either extensive learning (after Experiment 1) or more brief emotional measures (after Experiment 2). We found sex differences in discrimination learning and attenuated reversal learning after MPH and only sex differences in adulthood anxiety. In learners, there was enhanced striatal D1, but not D2, after either adolescent MPH or mAMPH. Lastly, also in learners, there was a sex x treatment group interaction for D2, but not D1, driven by the MPH-pretreated females, who expressed significantly higher D2 levels compared to SAL. These results show enduring effects of adolescent MPH on reversal learning in rats. Developmental psychostimulant exposure may interact with learning to enhance D1 expression in adulthood, and affect D2 expression in a sex-dependent manner. PMID:27091300

Sex differences, learning flexibility, and striatal dopamine D1 and D2 following adolescent drug exposure in rats.

PubMed

Izquierdo, Alicia; Pozos, Hilda; Torre, Adrianna De La; DeShields, Simone; Cevallos, James; Rodriguez, Jonathan; Stolyarova, Alexandra

2016-07-15

Corticostriatal circuitry supports flexible reward learning and emotional behavior from the critical neurodevelopmental stage of adolescence through adulthood. It is still poorly understood how prescription drug exposure in adolescence may impact these outcomes in the long-term. We studied adolescent methylphenidate (MPH) and fluoxetine (FLX) exposure in rats and their impact on learning and emotion in adulthood. In Experiment 1, male and female rats were administered MPH, FLX, or saline (SAL), and compared with methamphetamine (mAMPH) treatment beginning in postnatal day (PND) 37. The rats were then tested on discrimination and reversal learning in adulthood. In Experiment 2, animals were administered MPH or SAL also beginning in PND 37 and later tested in adulthood for anxiety levels. In Experiment 3, we analyzed striatal dopamine D1 and D2 receptor expression in adulthood following either extensive learning (after Experiment 1) or more brief emotional measures (after Experiment 2). We found sex differences in discrimination learning and attenuated reversal learning after MPH and only sex differences in adulthood anxiety. In learners, there was enhanced striatal D1, but not D2, after either adolescent MPH or mAMPH. Lastly, also in learners, there was a sex x treatment group interaction for D2, but not D1, driven by the MPH-pretreated females, who expressed significantly higher D2 levels compared to SAL. These results show enduring effects of adolescent MPH on reversal learning in rats. Developmental psychostimulant exposure may interact with learning to enhance D1 expression in adulthood, and affect D2 expression in a sex-dependent manner. Copyright © 2016 Elsevier B.V. All rights reserved.

Age Differences in STDs, Sexual Behaviors, and Correlates of Risky Sex Among Sexually Experienced Adolescent African-American Females

PubMed Central

Brown, Jennifer L.; DiClemente, Ralph J.; Davis, Teaniese L.; Kottke, Melissa J.; Rose, Eve S.

2012-01-01

Objective To explore age differences in factors associated with positive sexually transmitted diseases (STD) status among a sample of African-American adolescent females. Methods Data were collected via ACASI from 701 African-American adolescent females (14–20 years) seeking services at reproductive health clinics. Adolescents provided self-collected vaginal swabs assayed using NAAT to assess the prevalence of three STDs. Results Younger adolescents (14–17 years) had significantly higher rates of STDs than older adolescents (18–20 years), but older adolescents had significantly higher levels of STD-associated risk behavior. In controlled analysis, having a casual sex partner was the only variable significantly associated with a positive STD test for younger adolescents, and prior history of STD and higher impulsivity were significantly associated with testing STD positive among older adolescents. Conclusions These findings suggest that developmentally tailored STD/HIV prevention interventions are needed for younger and older subgroups of adolescent females to help reduce their risk of infection. PMID:21933811

Sex differences in performance over 7 years on the Wechsler Intelligence Scale for Children--Revised among adults with intellectual disability.

PubMed

Kittler, P; Krinsky-McHale, S J; Devenny, D A

2004-02-01

The aim of this study was to explore changes related to sex differences on the Wechsler Intelligence Scale for Children - Revised (WISC-R) subtest performance over a 7-year interval in middle-aged adults with intellectual disability (ID). Cognitive sex differences have been extensively studied in the general population, but there are few reports concerning individuals with ID. Sex differences are of current relevance to actively debated issues such as cognitive changes during menopause and risk for Alzheimer's disease. Given that hormonal effects on cognition have been observed in the general population, particularly in areas such as visuospatial processing, and individuals with Down's syndrome (DS) have been reported to be hormonally and reproductively atypical, we analysed our data to allow for the possibility of an aetiology-specific profile of sex differences for these adults. The WISC-R subtests were administered in a longitudinal study, as part of a more comprehensive test battery, at least twice within 7 years. Participants were 18 females with ID without DS [age at first test time (time 1): mean = 40.5; IQ: mean = 59.3], 10 males with ID without DS (age at time 1: mean = 42.4; IQ: mean = 59.4), 21 females with DS (age at time 1: mean = 37.9; IQ: mean = 51.6), and 21 males with DS (age at time 1: mean = 40.3; IQ: mean = 54.3). All participants were in the mild to moderate range of ID and were displaying no changes suggestive of early dementia. Females, regardless of aetiology of ID, exhibited a robust superiority on the coding subtest, which parallels the widely reported difference among adults in the general population. Additionally, there was a decline in overall performance during the 7-year study interval, particularly on the verbal subscale subtests, but there was no evidence of sex-differentiated decline. There were also marginal sex by aetiology interactions on the object assembly and block design subtests, suggesting that males with unspecified ID might perform better than their female peers, but among adults with DS, females might do better than males. This study supports the presence of cognitive sex differences in the population with ID as indicated by female superiority on the WISC-R coding subtest. Extending this observation to adults with ID has implications for explanations of female advantage on this task, which now have to account for its presence among individuals with a broader range of intellectual capabilities, more atypical developmental histories and more varied genotypes than previously considered. Trends towards sex by aetiology interactions on the two visuoconstructive subtests, while marginal, were sufficient to warrant continued consideration of the idea of a distinct profile of sex differences for adults with DS and to justify looking at the effects of sex separately within different aetiologies of ID.

Sex Differences in Early Postnatal Microglial Colonization of the Developing Rat Hippocampus Following a Single-Day Alcohol Exposure.

PubMed

Ruggiero, M J; Boschen, K E; Roth, T L; Klintsova, A Y

2018-06-01

Microglia are involved in various homeostatic processes in the brain, including phagocytosis, apoptosis, and synaptic pruning. Sex differences in microglia colonization of the developing brain have been reported, but have not been established following alcohol insult. Developmental alcohol exposure represents a neuroimmune challenge that may contribute to cognitive dysfunction prevalent in humans with Fetal Alcohol Spectrum Disorders (FASD) and in rodent models of FASD. Most studies have investigated neuroimmune activation following adult alcohol exposure or following multiple exposures. The current study uses a single day binge alcohol exposure model (postnatal day [PD] 4) to examine sex differences in the neuroimmune response in the developing rat hippocampus on PD5 and 8. The neuroimmune response was evaluated through measurement of microglial number and cytokine gene expression at both time points. Male pups had higher microglial number compared to females in many hippocampal subregions on PD5, but this difference disappeared by PD8, unless exposed to alcohol. Expression of pro-inflammatory marker CD11b was higher on PD5 in alcohol-exposed (AE) females compared to AE males. After alcohol exposure, C-C motif chemokine ligand 4 (CCL4) was significantly increased in female AE pups on PD5 and PD8. Tumor necrosis factor-α (TNF-α) levels were also upregulated by AE in males on PD8. The results demonstrate a clear difference between the male and female neuroimmune response to an AE challenge, which also occurs in a time-dependent manner. These findings are significant as they add to our knowledge of specific sex-dependent effects of alcohol exposure on microglia within the developing brain.

Empathy: Gender effects in brain and behavior

PubMed Central

Christov-Moore, Leonardo; Simpson, Elizabeth A.; Coudé, Gino; Grigaityte, Kristina; Iacoboni, Marco; Ferrari, Pier Francesco

2016-01-01

Evidence suggests that there are differences in the capacity for empathy between males and females. However, how deep do these differences go? Stereotypically, females are portrayed as more nurturing and empathetic, while males are portrayed as less emotional and more cognitive. Some authors suggest that observed gender differences might be largely due to cultural expectations about gender roles. However, empathy has both evolutionary and developmental precursors, and can be studied using implicit measures, aspects that can help elucidate the respective roles of culture and biology. This article reviews evidence from ethology, social psychology, economics, and neuroscience to show that there are fundamental differences in implicit measures of empathy, with parallels in development and evolution. Studies in nonhuman animals and younger human populations (infants/children) offer converging evidence that sex differences in empathy have phylogenetic and ontogenetic roots in biology and are not merely cultural byproducts driven by socialization. We review how these differences may have arisen in response to males’ and females’ different roles throughout evolution. Examinations of the neurobiological underpinnings of empathy reveal important quantitative gender differences in the basic networks involved in affective and cognitive forms of empathy, as well as a qualitative divergence between the sexes in how emotional information is integrated to support decision making processes. Finally, the study of gender differences in empathy can be improved by designing studies with greater statistical power and considering variables implicit in gender (e.g., sexual preference, prenatal hormone exposure). These improvements may also help uncover the nature of neurodevelopmental and psychiatric disorders in which one sex is more vulnerable to compromised social competence associated with impaired empathy. PMID:25236781

Sex, Age, and Emotional Valence: Revealing Possible Biases in the 'Reading the Mind in the Eyes' Task.

PubMed

Kynast, Jana; Schroeter, Matthias L

2018-01-01

The 'Reading the Mind in the Eyes' test (RMET) assesses a specific socio-cognitive ability, i.e., the ability to identify mental states from gaze. The development of this ability in a lifespan perspective is of special interest. Whereas former investigations were limited mainly to childhood and adolescence, the focus has been shifted towards aging, and psychiatric and neurodegenerative diseases recently. Although the RMET is frequently applied in developmental psychology and clinical settings, stimulus characteristics have never been investigated with respect to potential effects on test performance. Here, we analyzed the RMET stimulus set with a special focus on interrelations between sex, age and emotional valence. Forty-three persons rated age and emotional valence of the RMET picture set. Differences in emotional valence and age ratings between male and female items were analyzed. The linear relation between age and emotional valence was tested over all items, and separately for male and female items. Male items were rated older and more negative than female stimuli. Regarding male RMET items, age predicted emotional valence: older age was associated with negative emotions. Contrary, age and valence were not linearly related in female pictures. All ratings were independent of rater characteristics. Our results demonstrate a strong confound between sex, age, and emotional valence in the RMET. Male items presented a greater variability in age ratings compared to female items. Age and emotional valence were negatively associated among male items, but no significant association was found among female stimuli. As personal attributes impact social information processing, our results may add a new perspective on the interpretation of previous findings on interindividual differences in RMET accuracy, particularly in the field of developmental psychology, and age-associated neuropsychiatric diseases. A revision of the RMET might be afforded to overcome confounds identified here.

Sex, Age, and Emotional Valence: Revealing Possible Biases in the ‘Reading the Mind in the Eyes’ Task

PubMed Central

Kynast, Jana; Schroeter, Matthias L.

2018-01-01

The ‘Reading the Mind in the Eyes’ test (RMET) assesses a specific socio-cognitive ability, i.e., the ability to identify mental states from gaze. The development of this ability in a lifespan perspective is of special interest. Whereas former investigations were limited mainly to childhood and adolescence, the focus has been shifted towards aging, and psychiatric and neurodegenerative diseases recently. Although the RMET is frequently applied in developmental psychology and clinical settings, stimulus characteristics have never been investigated with respect to potential effects on test performance. Here, we analyzed the RMET stimulus set with a special focus on interrelations between sex, age and emotional valence. Forty-three persons rated age and emotional valence of the RMET picture set. Differences in emotional valence and age ratings between male and female items were analyzed. The linear relation between age and emotional valence was tested over all items, and separately for male and female items. Male items were rated older and more negative than female stimuli. Regarding male RMET items, age predicted emotional valence: older age was associated with negative emotions. Contrary, age and valence were not linearly related in female pictures. All ratings were independent of rater characteristics. Our results demonstrate a strong confound between sex, age, and emotional valence in the RMET. Male items presented a greater variability in age ratings compared to female items. Age and emotional valence were negatively associated among male items, but no significant association was found among female stimuli. As personal attributes impact social information processing, our results may add a new perspective on the interpretation of previous findings on interindividual differences in RMET accuracy, particularly in the field of developmental psychology, and age-associated neuropsychiatric diseases. A revision of the RMET might be afforded to overcome confounds identified here. PMID:29755385

Correlates of Pediatric CPAP Adherence.

PubMed

Hawkins, Stephen M M; Jensen, Emily L; Simon, Stacey L; Friedman, Norman R

2016-06-15

Obstructive sleep apnea (OSA) is a common pediatric condition characterized by recurrent partial or complete cessation of airflow during sleep, typically due to inadequate upper airway patency. Continuous positive airway pressure (CPAP) is a therapeutic option that reduces morbidity. Despite efforts to promote use, CPAP adherence is poor in both pediatric and adult populations. We sought to determine whether demographics, insurance status, OSA severity, therapeutic pressure, or comorbid conditions were associated with pediatric CPAP adherence. A retrospective review of adherence download data was performed on all pediatric patients with initiation or adjustment of CPAP treatment over a one-year period with documented in-laboratory CPAP titration. Patients were grouped as CPAP adherent or non-adherent, where adherence was defined as > 70% nightly use and average usage ≥ 4 hours per night. Differences between the groups were analyzed by χ(2) test. Overall, nearly half of participants were CPAP adherent (49%, 69/140). Of the demographic data collected (age, ethnicity, sex, insurance status), only female sex was associated with better adherence (60.9% vs 39.5% of males adherent; odds ratio [OR] = 2.41, 95%CI = 1.20-4.85; p = 0.01). Severity of OSA (diagnostic apnea-hypopnea index [AHI] and degree of hypoxemia), therapeutic pressure, and residual AHI did not impact CPAP adherence (p > 0.05). Patients with developmental delay (DD) were more likely to be adherent with CPAP than those without a DD diagnosis (OR = 2.55, 95%CI = 1.27-5.13; p = 0.007). Female patients with trisomy 21 tended to be more adherent, but this did not reach significance or account for the overall increased adherence associated with female sex. Our study demonstrates that adherence to CPAP therapy is poor but suggests that female sex and developmental delay are associated with better adherence. These findings support efforts to understand the pathophysiology of and to develop adherence-promoting and alternative interventions for pediatric OSA. © 2016 American Academy of Sleep Medicine.

Emergence of Mixed-Sex Friendship Groups during Adolescence: Developmental Associations with Substance Use and Delinquency

ERIC Educational Resources Information Center

Molloy, Lauren E.; Gest, Scott D.; Feinberg, Mark E.; Osgood, D. Wayne

2014-01-01

Prospective longitudinal data from over 14,000 youth residing in 28 communities in the rural United States were analyzed to examine the emergence of mixed-sex friendship groups in early adolescence. Youth were surveyed on 5 occasions between fall of 6th grade and spring of 9th grade. At each assessment, youth reported the names of up to 7…

"God Made Me Gay for a Reason": Young Men Who Have Sex with Men's Resiliency in Resolving Internalized Homophobia from Religious Sources

ERIC Educational Resources Information Center

Kubicek, Katrina; McDavitt, Bryce; Carpineto, Julie; Weiss, George; Iverson, Ellen F.; Kipke, Michele D.

2009-01-01

Research investigating the role of religion in the lives of young men who have sex with men (YMSM) is limited. Given the unique developmental stage of emerging adults and the fact that most religions have restrictions on homosexual behavior, it is important to understand how YMSM integrate their sexual and religious/spiritual identities. Drawing…

Irritability, Externalizing, and Internalizing Psychopathology in Adolescence: Cross-Sectional and Longitudinal Associations and Moderation by Sex.

PubMed

Humphreys, Kathryn L; Schouboe, Sophie N F; Kircanski, Katharina; Leibenluft, Ellen; Stringaris, Argyris; Gotlib, Ian H

2018-04-18

Irritability is a common feature of many psychiatric disorders, including both externalizing and internalizing disorders. There is little research, however, examining associations between irritability and these symptom domains, particularly during the important developmental period of adolescence, characterized by sex differences in the prevalence of disorders. We examined the cross-sectional associations between irritability, measured with the Affective Reactivity Index, and symptoms of externalizing and internalizing domains of psychopathology, measured with the Youth Self Report, in a volunteer community sample (N = 183) of 9- to 13-year-old (M = 11.39, SD = 1.07) boys and girls (37% White/Caucasian, 8% Asian, 11% Hispanic, 8% African American, 2% Native American, 2% Pacific Islander, 28% Other, and 3% not reported). A subset of the sample (n = 112) provided data at a 2-year follow-up, used to extend these associations. There were no sex differences in levels of irritability; however, the associations between irritability and symptom domains were moderated by sex. Specifically, in girls, irritability was associated equally with externalizing and internalizing symptoms. In contrast, in boys, irritability was associated more strongly with externalizing symptoms than with internalizing symptoms. Thus, across both sexes, irritability was moderately associated with externalizing symptoms, but the association between irritability and internalizing symptoms was stronger in girls than in boys. At follow-up, sex moderated the association between baseline irritability and later externalizing and internalizing symptoms. These findings indicate that irritability is associated with both externalizing and internalizing symptoms in early adolescence and that irritability is associated with internalizing symptoms more strongly in girls than in boys.

Developmental changes of nasal and oral calls in the goitred gazelle Gazella subgutturosa, a nonhuman mammal with a sexually dimorphic and descended larynx

NASA Astrophysics Data System (ADS)

Efremova, Kseniya O.; Volodin, Ilya A.; Volodina, Elena V.; Frey, Roland; Lapshina, Ekaterina N.; Soldatova, Natalia V.

2011-11-01

In goitred gazelles ( Gazella subgutturosa), sexual dimorphism of larynx size and position is reminiscent of the case in humans, suggesting shared features of vocal ontogenesis in both species. This study investigates the ontogeny of nasal and oral calls in 23 (10 male and 13 female) individually identified goitred gazelles from shortly after birth up to adolescence. The fundamental frequency (f0) and formants were measured as the acoustic correlates of the developing sexual dimorphism. Settings for LPC analysis of formants were based on anatomical dissections of 5 specimens. Along ontogenesis, compared to females, male f0 was consistently lower both in oral and nasal calls and male formants were lower in oral calls, whereas the first two formants of nasal calls did not differ between sexes. In goitred gazelles, significant sex differences in f0 and formants appeared as early as the second week of life, while in humans they emerge only before puberty. This result suggests different pathways of vocal ontogenesis in the goitred gazelles and in humans.

I want to hold your hand: abstinence curricula, bioethics, and the silencing of desire.

PubMed

Wilkerson, Abby

2013-06-01

The abstinence approach to sex education remains influential despite its demonstrated ineffectiveness. One bill forbids the "promotion" of "gateway sexual activity," while requiring outright condemnation of "non-abstinence," defined so loosely as to plausibly include handholding. Bioethics seldom (if ever) contributes to sex-ed debates, yet exploring the pivotal role of medical discourse reveals the need for bioethical intervention. Sex-ed debates revolve around a theory of human flourishing based on heteronormative temporality, a developmental teleology ensuring the transmission of various supposed social goods through heterosexual marriage (Halberstam, 2005). Heteronormative temporality also constitutes a moralized discourse in which the values of health and presumed certainties of medicine serve to justify conservative religious dictates that otherwise would appear controversial as the basis for public policy. Overall, this analysis explores how moralized medical discourses compound existing injustices, while suggesting bioethics' potential contributions to moral and political analysis of sex-ed policies.

Phenotypic integration mediated by hormones: associations among digit ratios, body size and testosterone during tadpole development.

PubMed

Lofeu, Leandro; Brandt, Renata; Kohlsdorf, Tiana

2017-08-02

Developmental associations often explain phenotypic integration. The intersected hormonal regulation of ontogenetic processes fosters predictions of steroid-mediated phenotypic integration among sexually dimorphic traits, a statement defied by associations between classical dimorphism predictors (e.g. body size) and traits that apparently lack sex-specific functions (e.g. ratios between the lengths of Digits II and IV - 2D:4D). Developmental bases of female-biased 2D:4D have been identified, but these remain unclear for taxa presenting male-biased 2D:4D (e.g. anura). Here we propose two alternative hypotheses to investigate evolution of male-biased 2D:4D associated with sexually dimorphic body size using Leptodactylus frogs: I)'hypothesis of sex-specific digit responses' - Digit IV would be reactive to testosterone but exhibit responses in the opposite direction of those observed in female-biased 2D:4D lineages, so that Digit IV turns shorter in males; II) 'hypothesis of identity of the dimorphic digit'- Digit II would be the dimorphic digit. We compiled the following databases using Leptodactylus frogs: 1) adults of two species from natural populations and 2) testosterone-treated L. fuscus at post-metamorphic stage. Studied traits seem monomorphic in L. fuscus; L. podicipinus exhibits male-biased 2D:4D. When present, 2D:4D dimorphism was male-biased and associated with dimorphic body size; sex differences resided on Digit II instead of IV, corroborating our 'hypothesis of identity of the dimorphic digit'. Developmental steroid roles were validated: testosterone-treated L. fuscus frogs were smaller and exhibited masculinized 2D:4D, and Digit II was the digit that responded to testosterone. We propose a model where evolution of sexual dimorphism in 2D:4D first originates from the advent, in a given digit, of increased tissue sensitivity to steroids. Phenotypic integration with other sexually dimorphic traits would then occur through multi-trait hormonal effects during development. Such process of phenotypic integration seems fitness-independent in its origin and might explain several cases of steroid-mediated integration among sexually dimorphic traits.

Genetic Diversity Influences the Response of the Brain to Developmental Lead Exposure

PubMed Central

Schneider, Jay S.; Talsania, Keyur; Mettil, William; Anderson, David W.

2014-01-01

Although extrinsic factors, such as nutritional status, and some intrinsic genetic factors may modify susceptibility to developmental lead (Pb) poisoning, no studies have specifically examined the influence of genetic background on outcomes from Pb exposure. In this study, we used gene microarray profiling to identify Pb-responsive genes in rats of different genetic backgrounds, including inbred (Fischer 344 (F344)) and outbred (Long Evans (LE), Sprague Dawley (SD)) strains, to investigate the role that genetic variation may play in influencing outcomes from developmental Pb exposure. Male and female animals received either perinatal (gestation through lactation) or postnatal (birth through weaning) exposure to Pb in food (0, 250, or 750 ppm). RNA was extracted from the hippocampus at day 55 and hybridized to Affymetrix Rat Gene 1.0 ST Arrays. There were significant strain-specific effects of Pb on the hippocampal transcriptome with 978 transcripts differentially expressed in LE rats across all experimental groups, 269 transcripts differentially expressed in F344 rats, and only 179 transcripts differentially expressed in SD rats. These results were not due to strain-related differences in brain accumulation of Pb. Further, no genes were consistently differentially regulated in all experimental conditions. There was no set of “Pb toxicity” genes that are a molecular signature for Pb neurotoxicity that transcended sex, exposure condition, and strain. These results demonstrate the influence that strain and genetic background play in modifying the brain's response to developmental Pb exposure and may have relevance for better understanding the molecular underpinnings of the lack of a neurobehavioral signature in childhood Pb poisoning. PMID:24913800

Decreasing sex bias through education for parenthood or prevention of adolescent pregnancy: a developmental model with integrative strategies.

PubMed

Weinstein, E; Rosen, E

1994-01-01

This paper identifies the need for more research, education, and services for males about adolescent pregnancy and parenthood to augment their social and familial learning experiences. A case is made for more participation by schools in achieving a better balance between males and females in preparing for parenthood or prevention of pregnancy. Developmentally appropriate educational concepts and strategies that are integrated into the curriculum are described.

2D:4D digit ratio is not a biomarker of developmental programming in baboons (Papio hamadryas species).

PubMed

Huber, Hillary F; Li, Cun; Nathanielsz, Peter W

2018-02-01

We hypothesized second-to-fourth hand digit ratio (2D:4D) is a biomarker of developmental programming in 3 baboon groups: intrauterine growth restriction (7 females, 8 males), exposure during fetal life to synthetic glucocorticoids (4 females, 5 males), and controls (66 females, 20 males). 2D:4D was similar between sexes and groups. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Activational effects of sex hormones on cognition in men.

PubMed

Ulubaev, A; Lee, D M; Purandare, N; Pendleton, N; Wu, F C W

2009-11-01

Changing world demographic patterns, such as the increasing number of older people and the growing prevalence of cognitive impairment, present serious obstacles to preserving the quality of life and productivity of individuals. The severity of dementia varies from subclinical, mild cognitive impairment to neurodegenerative diseases such as Alzheimer's. In normally ageing men, these age-related cognitive declines are accompanied by gradual but marked decreases in androgen levels and changes in other hormone profiles. While developmental effects of sex hormones on cognition in the pre- and early postnatal period have been demonstrated, their activational effects in later life are still a focus of contemporary research. Although there is a plethora of published research on the topic, results have been inconsistent with different studies reporting positive, negative or no effects of sex hormones on various aspects of mental agility. This review summarizes the evidence supporting the biological plausibility of the activational effects of sex hormones upon cognition and describes the mechanisms of their actions. It offers a comprehensive summary of the studies of the effects of sex hormones on fluid intelligence in men utilizing elements from the Cochrane Collaboration Guidelines for Reviews. The results of both observational (cross-sectional and longitudinal) and interventional studies published to date are collated in table form and further discussed in the text. Factors contributing to the difficulties in understanding the effects of sex hormones on cognition are also examined. Although there is convincing evidence that steroid sex hormones play an organizational role in brain development in men, the evidence for activational effects of sex hormones affecting cognition in healthy men throughout adult life remains inconsistent. To address this issue, a new multifactorial approach is proposed which takes into account the status of other elements of the sex hormones axis including receptors, enzymes and other hormones.

Developmental loss of effect of a Chromosome 15 QTL on alcohol acceptance.

PubMed

McClearn, G E; Tarantino, L M; Hofer, S M; Jones, B; Plomin, R

1998-12-01

Human alcohol abuse and alcoholism have clear developmental features, suggesting the possibility of changes over time in heritability and in quantitative genetic architecture, and raising prospects of identifying individual genes or quantitative trait loci (QTLs) that display different influence on alcohol-related phenotypes at different ages. The identification of specific loci showing such age-related changes will open up opportunities of focused association studies and of genotype manipulation by various mating procedures. Most animal model research in alcohol assesses the phenotypes of the animals at an early age; developmental studies are rare. Here we report on a QTL on Chromosome (Chr) 15 of the mouse that has been shown in several populations, including BXD recombinant inbred strains, an F2, and genotypically selected lines, to affect a measure of alcohol consumption. In the present study, we measured alcohol acceptance in the genotypically selected animals and in an F4 sample at about 100 days and again at about 300 days of age. In both groups, and in both sexes, significant differences were observed at 100 days between animals that were homozygous for the "increasing" haplotype defining the QTL region and those homozygous for the "decreasing" haplotype. At 300 days of age, the effect is absent in females and has diminished or disappeared in males. The results provide a further confirmation of the Chr 15 QTL in young mice, offer a new perspective on the development of alcohol-related phenotypes, and have strong implications for research design.

Developmental outcome, including setback, in young children with severe visual impairment.

PubMed

Dale, Naomi; Sonksen, Patricia

2002-09-01

This study retrospectively investigated the developmental perspective of 69 children (40 males, 29 females) with 'potentially simple' congenital disorders of the peripheral visual system: development was examined in the context of degree of visual impairment. Developmental and visual assessments were carried out at 10 to 16 months (Time 1) and 27 to 54 months of age (Time 2). Participants were grouped according to (1) visual status: profound visual impairment (PVI), severe visual impairment (SVI); (2) developmental status on the Reynell-Zinkin scales. A majority of the sample showed normal development on all subscales (62% Time 1, 57% Time 2). Those with PVI were more developmentally vulnerable than SVI with a greater incidence of (1) uneven developmental profile at Time 1 (48% PVI, 16% SVI); (2) global learning difficulties at Time 2 (37% PVI, 0% SVI); (3) delay on individual subscales at Time 2 (p<0.02 PVI versus SVI); (4) deceleration (verbal comprehension 74% PVI, 24% SVI, sensorimotor understanding 70% PVI, 27% SVI); and (5) severe developmental setback (33% PVI, 7% SVI). Risk factors of visual level, age, and sex for poor developmental outcome in infants with visual impairment were established.

Transcriptome profile analysis of floral sex determination in cucumber.

PubMed

Wu, Tao; Qin, Zhiwei; Zhou, Xiuyan; Feng, Zhuo; Du, Yalin

2010-07-15

Cucumber has been widely studied as a model for floral sex determination. In this investigation, we performed genome-wide transcriptional profiling of apical tissue of a gynoecious mutant (Csg-G) and the monoecious wild-type (Csg-M) of cucumber in an attempt to isolate genes involved in sex determination, using the Solexa technology. The profiling analysis revealed numerous changes in gene expression attributable to the mutation, which resulted in the down-regulation of 600 genes and the up-regulation of 143 genes. The Solexa data were confirmed by reverse transcription polymerase chain reaction (RT-PCR) and real-time quantitative RT-PCR (qRT-PCR). Gene ontology (GO) analysis revealed that the differentially expressed genes were mainly involved in biogenesis, transport and organization of cellular component, macromolecular and cellular biosynthesis, localization, establishment of localization, translation and other processes. Furthermore, the expression of some of these genes depended upon the tissue and the developmental stage of the flowers of gynoecious mutant. The results of this study suggest two important concepts, which govern sex determination in cucumber. First, the differential expression of genes involved in plant hormone signaling pathways, such as ACS, Asr1, CsIAA2, CS-AUX1 and TLP, indicate that phytohormones and their crosstalk might play a critical role in the sex determination. Second, the regulation of some transcription factors, including EREBP-9, may also be involved in this developmental process. Copyright (c) 2010 Elsevier GmbH. All rights reserved.

Development of hippocampal subfield volumes from 4 to 22 years.

PubMed

Krogsrud, Stine K; Tamnes, Christian K; Fjell, Anders M; Amlien, Inge; Grydeland, Håkon; Sulutvedt, Unni; Due-Tønnessen, Paulina; Bjørnerud, Atle; Sølsnes, Anne E; Håberg, Asta K; Skrane, Jon; Walhovd, Kristine B

2014-11-01

The hippocampus supports several important cognitive functions known to undergo substantial development during childhood and adolescence, for example, encoding and consolidation of vivid personal memories. However, diverging developmental effects on hippocampal volume have been observed across studies. It is possible that the inconsistent findings may attribute to varying developmental processes and functions related to different hippocampal subregions. Most studies to date have measured global hippocampal volume. We aimed to explore early hippocampal development both globally and regionally within subfields. Using cross-sectional 1.5 T magnetic resonance imaging data from 244 healthy participants aged 4-22 years, we performed automated hippocampal segmentation of seven subfield volumes; cornu ammonis (CA) 1, CA2/3, CA4/dentate gyrus (DG), presubiculum, subiculum, fimbria, and hippocampal fissure. For validation purposes, seven subjects were scanned at both 1.5 and 3 T, and all subfields except fimbria showed strong correlations across field strengths. Effects of age, left and right hemisphere, sex and their interactions were explored. Nonparametric local smoothing models (smoothing spline) were used to depict age-trajectories. Results suggested nonlinear age functions for most subfields where volume increases until 13-15 years, followed by little age-related changes during adolescence. Further, the results showed greater right than left hippocampal volumes that seemed to be augmenting in older age. Sex differences were also found for subfields; CA2/3, CA4/DG, presubiculum, subiculum, and CA1, mainly driven by participants under 13 years. These results provide a detailed characterization of hippocampal subfield development from early childhood. Copyright © 2014 Wiley Periodicals, Inc.

Emergence of Sex Differences in the Development of Substance Use and Abuse during Adolescence

PubMed Central

Kuhn, Dr. Cynthia

2015-01-01

Substance use and abuse begins during adolescence. Male and female adolescent humans initiate use at comparable rates, but males increase use faster. In adulthood, more men than women use and abuse addictive drugs. However, some women progress more rapidly from initiation of use to entry into treatment. In animal models, adolescent males and females consume addictive drugs similarly. However, reproductively mature females acquire self-administration faster, and in some models, escalate use more. Sex/gender differences exist in neurobiologic factors mediating both reinforcement (dopamine, opioids) and aversiveness (CRF, dynorphin), as well as intrinsic factors (personality, psychiatric co-morbidities) and extrinsic factors (history of abuse, environment especially peers and family) which influence the progression from initial use to abuse., Many of these important differences emerge during adolescence, and are moderated by sexual differentiation of the brain. Estradiol effects which enhance both dopaminergic and CRF-mediated processes contribute to the female vulnerability to substance use and abuse. Testosterone enhances impulsivity and sensation seeking in both males and females. Several protective factors in females also influence initiation and progression of substance use including hormonal changes of pregnancy as well as greater capacity for self-regulation and lower peak levels of impulsivity/sensation seeking. Same sex peers represent a risk factor more for males than females during adolescence, while romantic partners increase risk for women during this developmental epoch. In summary, biologic factors, psychiatric co-morbidities as well as personality and environment present sex/gender-specific risks as adolescents begin to initiate substance use. PMID:26049025

Emergence of sex differences in the development of substance use and abuse during adolescence.

PubMed

Kuhn, Cynthia

2015-09-01

Substance use and abuse begin during adolescence. Male and female adolescent humans initiate use at comparable rates, but males increase use faster. In adulthood, more men than women use and abuse addictive drugs. However, some women progress more rapidly from initiation of use to entry into treatment. In animal models, adolescent males and females consume addictive drugs similarly. However, reproductively mature females acquire self-administration faster, and in some models, escalate use more. Sex/gender differences exist in neurobiologic factors mediating both reinforcement (dopamine, opioids) and aversiveness (CRF, dynorphin), as well as intrinsic factors (personality, psychiatric co-morbidities) and extrinsic factors (history of abuse, environment especially peers and family) which influence the progression from initial use to abuse. Many of these important differences emerge during adolescence, and are moderated by sexual differentiation of the brain. Estradiol effects which enhance both dopaminergic and CRF-mediated processes contribute to the female vulnerability to substance use and abuse. Testosterone enhances impulsivity and sensation seeking in both males and females. Several protective factors in females also influence initiation and progression of substance use including hormonal changes of pregnancy as well as greater capacity for self-regulation and lower peak levels of impulsivity/sensation seeking. Same sex peers represent a risk factor more for males than females during adolescence, while romantic partners increase risk for women during this developmental epoch. In summary, biologic factors, psychiatric co-morbidities as well as personality and environment present sex/gender-specific risks as adolescents begin to initiate substance use. Copyright © 2015 Elsevier Inc. All rights reserved.

Sexually dimorphic levels of color trait integration and the resolution of sexual conflict in Lake Malawi cichlids.

PubMed

Brzozowski, Frances; Roscoe, Jennifer; Parsons, Kevin; Albertson, Craig

2012-06-01

East African cichlids are renowned for their propensity to radiate, and variation in color patterns accounts for much of endemic cichlid diversity. Sexual dimorphism in color among cichlid species likely represents the outcome of different selective regimes acting on each sex, and is a classic example of sexual conflict. It is generally assumed that this conflict has been mitigated through the evolution of sex-linked color polymorphisms. Here, we propose that the evolution of sex-specific differences in levels of color trait integration may represent an additional mechanism through which sexual conflict has been resolved in this group. Specifically, we predict: (1) that general patterns of integration are influenced by early developmental events and thus conserved across sexes and (2) that male color is less integrated than females, and thus more evolvable in terms of producing an elaborate palette (i.e., in response to sexual selection), whereas female color is more integrated, facilitating wholesale shifts in color for background matching (i.e., in response to natural selection for crypsis). We tested these hypotheses using an F(2) design to compare the segregation of male and female color patterns. Both exploratory methods and hypothesis-driven analyses of integration demonstrate that the covariance structure of color traits in males and females is distinct, and that males are significantly less integrated than females. We suggest that the ability of species to promote different levels, and to a lesser extent patterns, of phenotypic integration between males and females may have contributed to the evolutionary success of this group. © 2012 WILEY PERIODICALS, INC.

Children's gender-typed perceptions of physical activity: consequences and implications.

PubMed

Mead, B J; Ignico, A A

1992-12-01

This paper provides an expanded discussion of issues raised in our 1990 experimental study, with particular focus upon the differential cognitive, affective, and psychomotor consequences to girls and boys of gender-typed, sex-segregated play. Evidence is provided that, as agents of socialization, teachers and schools can enlist practices and provide structure to foster cross-sex interaction and behavior. Nonstereotypical play is advocated so that each sex can enjoy the benefits typically accruing only to the opposite; correspondingly, and in light of a society not yet gender-aschematic, psychological androgyny is invoked as the developmental ideal.

Developmental Outcomes of Preterm Infants With Neonatal Hypoglycemia.

PubMed

Goode, Rachel H; Rettiganti, Mallikarjuna; Li, Jingyun; Lyle, Robert E; Whiteside-Mansell, Leanne; Barrett, Kathleen W; Casey, Patrick H

2016-12-01

Neonatal hypoglycemia has been associated with abnormalities on brain imaging and a spectrum of developmental delays, although historical and recent studies show conflicting results. We compared the cognitive, academic, and behavioral outcomes of preterm infants with neonatal hypoglycemia with those of normoglycemic controls at 3 to 18 years of age. A secondary analysis of data from the Infant Health and Development Program, a national, multisite, randomized controlled longitudinal intervention study of long-term health and developmental outcomes in preterm infants. Of the 985 infants enrolled in the Infant Health and Development Program, 745 infants had glucose levels recorded. Infants were stratified into 4 groups by glucose level. By using standardized cognitive, academic, and behavioral assessments performed at 3, 8, and 18 years of age, we compared groups after adjusting for intervention status, birth weight, gestational age, sex, severity of neonatal course, race, maternal education, and maternal preconception weight. No significant differences were observed in cognitive or academic skills between the control and effected groups at any age. Participants with more severe neonatal hypoglycemia reported fewer problem behaviors at age 18 than those without hypoglycemia. No significant differences in intellectual or academic achievement were found between preterm infants with and without hypoglycemia. A statistical difference was found in behavior at age 18, with hypoglycemic children showing fewer problematic behaviors than normoglycemic children. This difference was not clinically meaningful. Using extended outcomes, our results are consistent with previous studies that found no significant neurodevelopmental outcomes associated with neonatal hypoglycemia in preterm-born children. Copyright © 2016 by the American Academy of Pediatrics.

Developmental Outcomes of Preterm Infants With Neonatal Hypoglycemia

PubMed Central

Rettiganti, Mallikarjuna; Li, Jingyun; Lyle, Robert E.; Whiteside-Mansell, Leanne; Barrett, Kathleen W.; Casey, Patrick H.

2016-01-01

BACKGROUND AND OBJECTIVES: Neonatal hypoglycemia has been associated with abnormalities on brain imaging and a spectrum of developmental delays, although historical and recent studies show conflicting results. We compared the cognitive, academic, and behavioral outcomes of preterm infants with neonatal hypoglycemia with those of normoglycemic controls at 3 to 18 years of age. METHODS: A secondary analysis of data from the Infant Health and Development Program, a national, multisite, randomized controlled longitudinal intervention study of long-term health and developmental outcomes in preterm infants. Of the 985 infants enrolled in the Infant Health and Development Program, 745 infants had glucose levels recorded. Infants were stratified into 4 groups by glucose level. By using standardized cognitive, academic, and behavioral assessments performed at 3, 8, and 18 years of age, we compared groups after adjusting for intervention status, birth weight, gestational age, sex, severity of neonatal course, race, maternal education, and maternal preconception weight. RESULTS: No significant differences were observed in cognitive or academic skills between the control and effected groups at any age. Participants with more severe neonatal hypoglycemia reported fewer problem behaviors at age 18 than those without hypoglycemia. CONCLUSIONS: No significant differences in intellectual or academic achievement were found between preterm infants with and without hypoglycemia. A statistical difference was found in behavior at age 18, with hypoglycemic children showing fewer problematic behaviors than normoglycemic children. This difference was not clinically meaningful. Using extended outcomes, our results are consistent with previous studies that found no significant neurodevelopmental outcomes associated with neonatal hypoglycemia in preterm-born children. PMID:27940690

Autism spectrum disorders: toward a gendered embodiment model.

PubMed

Cheslack-Postava, Keely; Jordan-Young, Rebecca M

2012-06-01

One of the most consistent observations in the epidemiology of autism spectrum disorders (ASD) is the preponderance of male cases. A few hypotheses have been put forth which attempt to explain this divergence in terms of sex-linked biology, with limited success. Feminist epidemiologists suggest the importance of investigating specific mechanisms for male-female differences in health outcomes, which may include sex-linked biology and/or gender relations, as well as complex biosocial interactions. Neither domain has been systematically investigated for autism, and the possible role of gender has been particularly neglected. In this article, we posit hypotheses about how social processes based on perception of persons as male or female, particularly patterns of social and physical interaction in early development, may affect the observed occurrence and diagnosis of ASD. We gesture toward an embodiment model, incorporating hypotheses about initial biological vulnerabilities to autism--which may or may not be differentially distributed in relation to sex biology--and their interactions with gender relations, which are demonstrably different for male and female infants. Toward building such a model, we first review the epidemiology of ASD with an eye toward male-female differences, then present a theory of gender as a "pervasive developmental environment" with relevance for the excess burden of autism among males. Finally, we suggest research strategies to further investigate this issue. Copyright © 2011 Elsevier Ltd. All rights reserved.

Revising the BIS/BAS to Study Development: Measurement Invariance and Normative Effects of Age and Sex from Childhood through Adulthood

PubMed Central

Pagliaccio, David; Luking, Katherine R.; Anokhin, Andrey P.; Gotlib, Ian H.; Hayden, Elizabeth P.; Olino, Thomas M.; Peng, Chun-Zi; Hajcak, Greg; Barch, Deanna M.

2015-01-01

Carver and White's Behavioral Inhibition System/Behavioral Activation System (BIS/BAS) Scale has been a useful tool for studying individual differences in reward/punishment sensitivity; however, its factor structure and invariance across development have not been well tested. In the current study, we examined the factor structure of the BIS/BAS Scale across five age groups: 6-10-year-old children (N=229), 11-13-year-old early adolescents (N=311), 14-16-year-old late adolescents (N=353), 18-22-year-old young adults (N=844), and 30-45-year-old adults (N=471). Given poor fit of the standard four-factor model (BIS, Reward Responsivity, Drive, Fun Seeking) in the literature, we conducted exploratory factor analyses in half of the participants and identified problematic items across age groups. The four-factor model showed poor fit in our sample whereas removing the BAS Fun Seeking subscale and problematic items from the remaining subscales improved fit in confirmatory factor analyses conducted with the second half of the participants. The revised model showed strict invariance across age groups and by sex, indicating consistent factor structure, item loadings, thresholds, and unique/residual variances. Additionally, in our cross-sectional data, we observed non-linear relations between age and subscale scores, where scores tended to be higher in young adulthood than childhood and later adulthood. Furthermore, sex differences emerged across development; adolescent and adult females had higher BIS scores than males in this age range, whereas sex differences were not observed in childhood. These differences may help us to understand the rise in internalizing psychopathology in adolescence, particularly in females. Future developmental studies are warranted to examine the impact of rewording problematic items. PMID:26302106

Neuropsychological features of indigent murder defendants and death row inmates in relation to homicidal aspects of their crimes.

PubMed

Hanlon, Robert E; Rubin, Leah H; Jensen, Marie; Daoust, Sarah

2010-02-01

Neuropsychological features of 77 indigent murder defendants and death row inmates were examined in relation to criminal variables underlying their homicidal acts. Clinically, the sample was characterized by elevated rates of developmental disorders (49%), personality disorders (54%), Axis I psychiatric disorders (45%), substance abuse (86%), and history of violence (43%). By statute, killing more than one person is an aggravating factor in many jurisdictions that renders a murder defendant eligible for the death penalty. Individuals who committed a single murder were characterized by executive dysfunction, lower intelligence, slower speed of information processing, and a higher frequency of developmental disorders (58%), relative to those charged and/or convicted of killing two or more people, who were characterized by a significantly higher rate of personality disorders (79%) and a lower rate of developmental disorders (34%). Additionally, using the FBI criminal classification system for categorizing homicide by motive, a significant difference in the frequency of psychosis was found among subgroups associated with the following motives: Criminal enterprise; personal cause; and sex. The collective neuropsychological profile of the sample revealed that executive functions were significantly decreased, relative to memory functions, with over half of the sample (55%) demonstrating executive dysfunction.

Differences in patterns of physical participation in recreational activities between children with and without intellectual and developmental disability.

PubMed

Chien, Chi-Wen; Rodger, Sylvia; Copley, Jodie

2017-08-01

Children with intellectual and developmental disability (IDD) are at risk of experiencing limited participation in recreational activities, where they may be present but not physically engaged. To compare patterns of physical engagement in recreational activities between children with and without IDD. Fifty children with IDD (26 boys, 24 girls; mean age 8.7 years) were matched for age and sex with 50 typically developing children. Parents completed a questionnaire which captured participation in 11 recreational activities involving hand use as an indication of physical engagement. More than 80% of children in both groups participated physically in eight recreational activities, but fewer children with IDD participated in six activities when compared with typically developing children. Children with IDD also participated less frequently in five activities and required more assistance to participate in all the 11 activities. Parents wanted their child with IDD to participate in 10 recreational activities with less assistance. The difference between the groups related to participation frequency, independence, and parents' desire for changes in their child's participation. Greater efforts are needed to address these differences and to support recreational participation in children with IDD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Relaxed selection is a precursor to the evolution of phenotypic plasticity.

PubMed

Hunt, Brendan G; Ometto, Lino; Wurm, Yannick; Shoemaker, DeWayne; Yi, Soojin V; Keller, Laurent; Goodisman, Michael A D

2011-09-20

Phenotypic plasticity allows organisms to produce alternative phenotypes under different conditions and represents one of the most important ways by which organisms adaptively respond to the environment. However, the relationship between phenotypic plasticity and molecular evolution remains poorly understood. We addressed this issue by investigating the evolution of genes associated with phenotypically plastic castes, sexes, and developmental stages of the fire ant Solenopsis invicta. We first determined if genes associated with phenotypic plasticity in S. invicta evolved at a rapid rate, as predicted under theoretical models. We found that genes differentially expressed between S. invicta castes, sexes, and developmental stages all exhibited elevated rates of evolution compared with ubiquitously expressed genes. We next investigated the evolutionary history of genes associated with the production of castes. Surprisingly, we found that orthologs of caste-biased genes in S. invicta and the social bee Apis mellifera evolved rapidly in lineages without castes. Thus, in contrast to some theoretical predictions, our results suggest that rapid rates of molecular evolution may not arise primarily as a consequence of phenotypic plasticity. Instead, genes evolving under relaxed purifying selection may more readily adopt new forms of biased expression during the evolution of alternate phenotypes. These results suggest that relaxed selective constraint on protein-coding genes is an important and underappreciated element in the evolutionary origin of phenotypic plasticity.

Developmental expression of the neuroligins and neurexins in fragile X mice.

PubMed

Lai, Jonathan K Y; Doering, Laurie C; Foster, Jane A

2016-03-01

Neuroligins and neurexins are transsynaptic proteins involved in the maturation of glutamatergic and GABAergic synapses. Research has identified synaptic proteins and function as primary contributors to the development of fragile X syndrome. Fragile X mental retardation protein (FMRP), the protein that is lacking in fragile X syndrome, binds neuroligin-1 and -3 mRNA. Using in situ hybridization, we examined temporal and spatial expression patterns of neuroligin (NLGN) and neurexin (NRXN) mRNAs in the somatosensory (S1) cortex and hippocampus in wild-type (WT) and fragile X knockout (FMR1-KO) mice during the first 5 weeks of postnatal life. Genotype-based differences in expression included increased NLGN1 mRNA in CA1 and S1 cortex, decreased NLGN2 mRNA in CA1 and dentate gyrus (DG) regions of the hippocampus, and increased NRXN3 mRNA in CA1, DG, and S1 cortex between female WT and FMR1-KO mice. In male mice, decreased expression of NRXN3 mRNA was observed in CA1 and DG regions of FMR1-KO mice. Sex differences in hippocampal expression of NLGN2, NRXN1, NRXN2, and NRXN3 mRNAs and in S1 cortex expression of NRXN3 mRNAs were observed WT mice, whereas sex differences in NLGN3, NRXN1, NRXN2, and NRXN3 mRNA expression in the hippocampus and in NLGN1, NRXN2 and NRXN3 mRNA expression in S1 cortex were detected in FMR1-KO mice. These results provide a neuroanatomical map of NLGN and NRXN expression patterns over postnatal development in WT and FMR1-KO mice. The differences in developmental trajectory of these synaptic proteins could contribute to long-term differences in CNS wiring and synaptic function. © 2015 Wiley Periodicals, Inc.

Age- and sex-related characteristics of tonic GABA currents in the rat substantia nigra pars reticulata.

PubMed

Chudomel, O; Hasson, H; Bojar, M; Moshé, S L; Galanopoulou, A S

2015-04-01

Previous studies have shown that the pharmacologic effects of GABAergic drugs and the postsynaptic phasic GABAAergic inhibitory responses in the anterior part of the rat substantia nigra pars reticulata (SNRA) are age- and sex-specific. Here, we investigate whether there are age- and sex-related differences in the expression of the δ GABAA receptor (GABAAR) subunit and GABAAR mediated tonic currents. We have used δ-specific immunochemistry and whole cell patch clamp to study GABAAR mediated tonic currents in the SNRA of male and female postnatal day (PN) PN5-9, PN11-16, and PN25-32 rats. We observed age-related decline, but no sex-specific changes, in bicuculline (BIM) sensitive GABAAR tonic current density, which correlated with the decline in δ subunit in the SNRA between PN15 and 30. Furthermore, we show that the GABAAR tonic currents can be modified by muscimol (GABAAR agonist; partial GABACR agonist), THIP (4,5,6,7-tetrahydroisoxazolo (5,4-c)pyridin-3-ol: α4β3δ GABAARs agonist and GABACR antagonist), and zolpidem (α1-subunit selective GABAAR agonist) in age- and sex-dependent manner specific for each drug. We propose that the emergence of the GABAAR-sensitive anticonvulsant effects of the rat SNRA during development may depend upon the developmental decline in tonic GABAergic inhibition of the activity of rat SNRA neurons, although other sex-specific factors are also involved.

Expression profiles of amhy and major sex-related genes during gonadal sex differentiation and their relation with genotypic and temperature-dependent sex determination in pejerrey Odontesthes bonariensis.

PubMed

Zhang, Yan; Hattori, Ricardo S; Sarida, Munti; García, Estefany L; Strüssmann, Carlos Augusto; Yamamoto, Yoji

2018-03-15

To shed light on the mechanisms of and interactions of GSD and TSD in pejerrey, we investigated how the transcriptional profiles of amhy and amha are affected by feminizing (17 °C) and masculinizing (29 °C) temperatures during the critical period of sex determination/differentiation and their relation with the expression profiles of AMH receptor type II (amhrII), gonadal aromatase (cyp19a1a), and 11 beta-hydroxysteroid dehydrogenase 2 (hsd11b2). Careful consideration of the results of this study and all information currently available for this species, including similar analyzes for an intermediate, mixed-sex promoting temperature (25 °C), suggests a model for genotypic/temperature-dependent sex determination and gonadal sex differentiation that involves a) cyp19a1a-dependent, developmentally-programmed ovarian development as the default state that becomes self-sustaining in the absence of a potent and timely masculinizing stimulus, b) early, developmentally-programmed amhy expression and high temperature as masculinization signals that antagonize the putative female pathway by suppressing cyp19a1a expression, c) increasing stress response, cortisol, and the synthesis of the masculinizing androgen 11-keto-testosterone via hsd11b2 with increasing temperature that is important for masculinization in both genotypes but particularly so in XX individuals, and d) an endocrine network with positive/negative feedback mechanisms that ensure fidelity of the male/female pathway once started. The proposed model, albeit tentative and non-all inclusive, accounts for the continuum of responses, from all-females at low temperatures to all-males at high temperatures and for the balanced-, genotype-linked sex ratios obtained at intermediate temperatures, and therefore supports the coexistence of TSD and GSD in pejerrey across the range of viable temperatures for this species. Copyright © 2018 Elsevier Inc. All rights reserved.

Sex determination mode does not affect body or genital development of the central bearded dragon (Pogona vitticeps).

PubMed

Whiteley, Sarah L; Holleley, Clare E; Ruscoe, Wendy A; Castelli, Meghan; Whitehead, Darryl L; Lei, Juan; Georges, Arthur; Weisbecker, Vera

2017-01-01

The development of male- or female-specific phenotypes in squamates is typically controlled by either temperature-dependent sex determination (TSD) or chromosome-based genetic sex determination (GSD). However, while sex determination is a major switch in individual phenotypic development, it is unknownhow evolutionary transitions between GSD and TSD might impact on the evolution of squamate phenotypes, particularly the fast-evolving and diverse genitalia. Here, we take the unique opportunity of studying the impact of both sex determination mechanisms on the embryological development of the central bearded dragon ( Pogona vitticeps ). This is possible because of the transitional sex determination system of this species, in which genetically male individuals reverse sex at high incubation temperatures. This can trigger the evolutionary transition of GSD to TSD in a single generation, making P. vitticeps an ideal model organism for comparing the effects of both sex determination processes in the same species. We conducted four incubation experiments on 265 P. vitticeps eggs, covering two temperature regimes ("normal" at 28 °C and "sex reversing" at 36 °C) and the two maternal sexual genotypes (concordant ZW females or sex-reversed ZZ females). From this, we provide the first detailed staging system for the species, with a focus on genital and limb development. This was augmented by a new sex chromosome identification methodology for P. vitticeps that is non-destructive to the embryo. We found a strong correlation between embryo age and embryo stage. Aside from faster growth in 36 °C treatments, body and external genital development was entirely unperturbed by temperature, sex reversal or maternal sexual genotype. Unexpectedly, all females developed hemipenes (the genital phenotype of adult male P. vitticeps ), which regress close to hatching. The tight correlation between embryo age and embryo stage allows the precise targeting of specific developmental periods in the emerging field of molecular research on P. vitticeps . The stability of genital development in all treatments suggests that the two sex-determining mechanisms have little impact on genital evolution, despite their known role in triggering genital development. Hemipenis retention in developing female P. vitticeps , together with frequent occurrences of hemipenis-like structures during development in other squamate species, raises the possibility of a bias towards hemipenis formation in the ancestral developmental programme for squamate genitalia.

Singaporean gifted adolescents under scrutiny: The gender factor

NASA Astrophysics Data System (ADS)

Kwan, Patrick C. F.

1993-05-01

Research on the sex-role problems of gifted adolescents rarely lifts its sight beyond Western developed countries, making generalizations to the Third World suspect. The present study, by exploring the relationship between gender and adjustment among gifted adolescents in Singapore, hopes to extend the consideration of developmental sex-role issues to a society different from the West. Specifically, it reports that Singaporean gifted girls, like some of their Western counterparts, had difficulty in reconciling their giftedness with societal notions of femininity. Conceivably, this conflict placed them on the threshold of stress, leaving them more vulnerable than the gifted boys to adjustment problems. In addition, having internalized the gender stereotypic view that academic excellence was less important to them than to the boys, the gifted girls might inadvertently put ceilings on their own achievements. The paper concludes with several remedies for educators, counsellors, and parents to help gifted girls embark upon their road to self-fulfilment.

Developmental neurogenetics of sexual dimorphism in Aedes aegypti

PubMed Central

Duman-Scheel, Molly; Syed, Zainulabeuddin

2015-01-01

Sexual dimorphism, a poorly understood but crucial aspect of vector mosquito biology, encompasses sex-specific physical, physiological, and behavioral traits related to mosquito reproduction. The study of mosquito sexual dimorphism has largely focused on analysis of the differences between adult female and male mosquitoes, particularly with respect to sex-specific behaviors related to disease transmission. However, sexually dimorphic behaviors are the products of differential gene expression that initiates during development and therefore must also be studied during development. Recent technical advancements are facilitating functional genetic studies in the dengue vector Aedes aegypti, an emerging model for mosquito development. These methodologies, many of which could be extended to other non-model insect species, are facilitating analysis of the development of sexual dimorphism in neural tissues, particularly the olfactory system. These studies are providing insight into the neurodevelopmental genetic basis for sexual dimorphism in vector mosquitoes. PMID:26949699

Differing levels of gender salience in preschool classrooms: effects on children's gender attitudes and intergroup bias.

PubMed

Hilliard, Lacey J; Liben, Lynn S

2010-01-01

Developmental intergroup theory posits that when environments make social-group membership salient, children will be particularly likely to apply categorization processes to social groups, thereby increasing stereotypes and prejudices. To test the predicted impact of environmental gender salience, 3- to 5-year-old children (N = 57) completed gender attitude, intergroup bias, and personal preference measures at the beginning and end of a 2-week period during which teachers either did or did not make gender salient. Observations of peer play were also made at both times. After 2 weeks, children in the high- (but not low-) salience condition showed significantly increased gender stereotypes, less positive ratings of other-sex peers, and decreased play with other-sex peers. Children's own activity and occupational preferences, however, remained unaffected. © 2010 The Authors. Child Development © 2010 Society for Research in Child Development, Inc.

Species and Sex Differences in the Morphogenic Response of Primary Rodent Neurons to 3,3′-Dichlorobiphenyl (PCB 11)

PubMed Central

Sethi, Sunjay; Keil, Kimberly P.

2017-01-01

PCB 11 is an emerging global pollutant that we recently showed promotes axonal and dendritic growth in primary rat neuronal cell cultures. Here, we address the influence of sex and species on neuronal responses to PCB 11. Neuronal morphology was quantified in sex-specific primary hippocampal and cortical neuron-glia co-cultures derived from neonatal C57BL/6J mice and Sprague Dawley rats exposed for 48 h to vehicle (0.1% DMSO) or PCB 11 at concentrations ranging from 1 fM to 1 nM. Total axonal length was quantified in tau-1 immunoreactive neurons at day in vitro (DIV) 2; dendritic arborization was assessed by Sholl analysis at DIV 9 in neurons transfected with MAP2B-FusRed. In mouse cultures, PCB 11 enhanced dendritic arborization in female, but not male, hippocampal neurons and male, but not female, cortical neurons. In rat cultures, PCB 11 promoted dendritic arborization in male and female hippocampal and cortical neurons. PCB 11 also increased axonal growth in mouse and rat neurons of both sexes and neuronal cell types. These data demonstrate that PCB 11 exerts sex-specific effects on neuronal morphogenesis that vary depending on species, neurite type, and neuronal cell type. These findings have significant implications for risk assessment of this emerging developmental neurotoxicant. PMID:29295518

Species and Sex Differences in the Morphogenic Response of Primary Rodent Neurons to 3,3'-Dichlorobiphenyl (PCB 11).

PubMed

Sethi, Sunjay; Keil, Kimberly P; Lein, Pamela J

2017-12-23

PCB 11 is an emerging global pollutant that we recently showed promotes axonal and dendritic growth in primary rat neuronal cell cultures. Here, we address the influence of sex and species on neuronal responses to PCB 11. Neuronal morphology was quantified in sex-specific primary hippocampal and cortical neuron-glia co-cultures derived from neonatal C57BL/6J mice and Sprague Dawley rats exposed for 48 h to vehicle (0.1% DMSO) or PCB 11 at concentrations ranging from 1 fM to 1 nM. Total axonal length was quantified in tau-1 immunoreactive neurons at day in vitro (DIV) 2; dendritic arborization was assessed by Sholl analysis at DIV 9 in neurons transfected with MAP2B-FusRed. In mouse cultures, PCB 11 enhanced dendritic arborization in female, but not male, hippocampal neurons and male, but not female, cortical neurons. In rat cultures, PCB 11 promoted dendritic arborization in male and female hippocampal and cortical neurons. PCB 11 also increased axonal growth in mouse and rat neurons of both sexes and neuronal cell types. These data demonstrate that PCB 11 exerts sex-specific effects on neuronal morphogenesis that vary depending on species, neurite type, and neuronal cell type. These findings have significant implications for risk assessment of this emerging developmental neurotoxicant.

Infant formula supplementation with long-chain polyunsaturated fatty acids has no effect on Bayley developmental scores at 18 months of age--IPD meta-analysis of 4 large clinical trials.

PubMed

Beyerlein, Andreas; Hadders-Algra, Mijna; Kennedy, Katherine; Fewtrell, Mary; Singhal, Atul; Rosenfeld, Eva; Lucas, Alan; Bouwstra, Hylco; Koletzko, Berthold; von Kries, Rüdiger

2010-01-01

To find out whether supplementation of formula milk by long-chain polyunsaturated fatty acids (LCPUFA) affects neurodevelopment at 18 months of age in term or preterm infants by an individual patient data (IPD) meta-analysis. Data of 870 children from 4 large randomised clinical trials for formula milk with and without LCPUFAs allowed for assessing the effect of LCPUFA with adjustment for potential confounders and extensive subgroup analysis on prematurity, LCPUFA source, and dosage. Any additional clinical trials examining the effect of LCPUFA supplementation on Bayley Scales of Infant Development at 18 months were regarded as relevant. Two relevant studies were identified by MEDLINE, but were not available to us. An IPD meta-analysis was performed with subgroup analyses by preterm delivery, very low birth weight (<1500 g), trials with higher amounts of docosahexaenoic acid (DHA) and arachidonic acid (AA), and specific sources of LCPUFA. The sample size of 870 children was sufficient to detect clinically relevant differences in Bayley Scales even in subgroups. There were no significant differences in mental or psychomotor developmental indexes between LCPUFA-supplemented and control groups for all children or in subgroups. This was confirmed with adjustment for the possible confounders: sex, gestational age, birth weight, maternal age, and maternal smoking. The adjusted mean differences in mental developmental index and psychomotor developmental index for all of the children were -0.8 (95% confidence interval -2.8 to 1.2) and -1.0 (-2.7 to 0.7), respectively. These data based on considerable sample size provide substantial evidence that LCPUFA supplementation of infant formula does not have a clinically meaningful effect on the neurodevelopment as assessed by Bayley scores at 18 months. Inclusion of all relevant data should not have led to differing conclusions except, possibly, for very-low-birth-weight infants.

[PLASTIC SURGERY OF THE VULVA AND THEIR CIRCUMSTANCES].

PubMed

Rabinerson, David; Salman, Lina; Gabbay-Benziv, Rinnat

2016-03-01

Plastic surgery of the vulva for aesthetic reasons is recently gaining popularity in the Western world, as well as in Israel. There are different methods of executing these operations with no meaningful difference in the surgical results and the satisfaction of the patients. There are also more complicated plastic operations, in which the vulva is involved. These are performed in cases of pseudohermaphroditism, various states of intersex, sex change operations and developmental defects of the genitor-urinary systems. These are considered successful procedures. Furthermore, the issue of the illegal mutilation surgery of the external female genitalia, on religious or cultural background, is mentioned. All the above-mentioned types of operations involving the vulva are discussed.

Prenatal betamethasone exposure has sex specific effects in reversal learning and attention in juvenile baboons

PubMed Central

RODRIGUEZ, Jesse S.; ZÜRCHER, Nicole R.; KEENAN, Kathryn E.; BARTLETT, Thad Q.; NATHANIELSZ, Peter W.; NIJLAND, Mark J.

2011-01-01

Objective We investigated effects of three weekly courses of fetal betamethasone (βM) exposure on motivation and cognition in juvenile baboon offspring utilizing the Cambridge Neuropsychological Test Automated Battery. Study design Pregnant baboons (Papio sp.) received two injections of saline control (C) or 175 μg/kg βM 24h apart at 0.6, 0.65 and 0.7 gestation. Offspring [Female (FC), n = 7 and Male (MC), n = 6; Female (FβM), n = 7 and Male (MβM), n = 5] were studied at 2.6–3.2 years with a progressive ratio test for motivation, simple discriminations (SD) and reversals (SR) for associative learning and rule change plasticity, and an intra-dimensional/extra-dimensional (IDED) set-shifting test for attention allocation. Results βM exposure decreased motivation in both sexes. In IDED testing, FβM made more errors in the SR [mean difference of errors (FβM minus MβM) = 20.2 ± 9.9; P≤0.05], compound discrimination [mean difference of errors = 36.3 ± 17.4; P≤0.05] and compound reversal [mean difference of errors = 58 ± 23.6; P<0.05] stages as compared to the MβM offspring. Conclusion This central nervous system developmental programming adds growing concerns of long-term effects of repeated fetal synthetic glucocorticoid exposure. In summary, behavioral effects observed show sex specific differences in resilience to multiple fetal βM exposures. PMID:21411054

Gender differences in the perception and utilization of social support: theoretical perspectives and an empirical test.

PubMed

Flaherty, J; Richman, J

1989-01-01

The authors contend that women are the more supportive, nurturing and affectively-connected sex. They argue that these gender differences result from socialization experiences which may be modified by social and occupational roles. Theoretical perspectives and research addressing this proposition are reviewed. Empirical data on support-eliciting and support-providing behaviors in a cohort of medical students are then provided to test their thesis. The data suggest that women have developed a greater sensitivity to the needs of themselves and others, leading to a greater capacity to provide support and a greater dependence upon social support for psychological well-being. Personality and developmental factors that may account for these differences are examined. The implications of these findings for gender differences in mental health are discussed.