Sexually dimorphic effects of NMDA receptor antagonism on brain-pituitary-gonad axis development in the platyfish

NASA Technical Reports Server (NTRS)

Flynn, Katherine M.; Miller, Shelly A.; Sower, Stacia A.; Schreibman, Martin P.

2002-01-01

The N-methyl-D-aspartate glutamate receptor (NMDAR) is found in hypothalamic nuclei involved in the regulation of reproduction in several species of mammals and fishes. NMDAR is believed to affect reproductive development and function by regulating gonadotropin releasing hormone (GnRH)-producing cells. These pathways are likely to be sexually dimorphic, as are several other neurotransmitter systems involved in reproductive function. In this report, male and female platyfish received intraperitoneal injections of 0, 5, 10, 20, 40 or 60 microg/g body wt. of the non-competitive NMDAR antagonist MK-801. Injections began at 6 weeks of age and continued thrice weekly until control animals reached puberty, as evidenced by anal fin maturation. The percent of pubescent animals was significantly affected by sex and treatment, with fewer MK-801-injected females in puberty than control females at each dose (P<0.001), and fewer pubescent females than males at 10, 20 and 40 microg/g (P<0.05). There were no MK-801-related effects in males. Histological analyses revealed typical immature gonads and pituitary glands in treated females, and typical mature morphology in control females and all males. Immunocytochemical distribution of the R1 subunit of the NMDAR within the brain-pituitary-gonad (BPG) axis was limited to GnRH-containing brain cells in all animals; however, NMDAR1 distribution was in an immature pattern in treated females and a mature pattern in all others. Neural concentrations of GnRH were unaffected by MK-801 treatment in both sexes. These data suggest that in the platyfish, NMDAR influence on reproductive development is sexually dimorphic and occurs at, or above, the level of GnRH-containing cells of the BPG axis.

ENDOCRINE DISRUPTERS: A REVIEW OF SOME SOURCES, EFFECTS, AND MECHANISMS OF ACTIONS ON BEHAVIOR AND NEUROENDOCRINE SYSTEMS

PubMed Central

Frye, C.; Bo, E.; Calamandrei, G.; Calzà, L.; Dessì-Fulgheri, F.; Fernández, M.; Fusani, L.; Kah, O.; Kajta, M.; Le Page, Y.; Patisaul, H.B.; Venerosi, A.; Wojtowicz, A.K.; Panzica, G.C.

2011-01-01

Some environmental contaminants interact with hormones and may exert adverse consequences due to their actions as endocrine disrupting chemicals (EDCs). Exposure in people is typically due to contamination of the food chain, inhalation of contaminated house dust, or occupational exposure. EDCs include pesticides and herbicides (such as diphenyl-dichloro-trichloroethane, DDT, or its metabolites), methoxychlor, biocides, heat stabilizers and chemical catalysts (such as tributyltin, TBT), plastic contaminants (e.g. bisphenol A, BPA), pharmaceuticals (i.e. diethylstilbestrol, DES; 17alpha-ethynilestradiol, EE2), or dietary components (such as phytoestrogens). The goal of this review is to address sources, effects and actions of EDCs, with an emphasis on topics discussed at the International Congress on Steroids and the Nervous System. EDCs may alter reproductively-relevant or non-reproductive, sexually-dimorphic behaviors. In addition, EDCs may have significant effects on neurodevelopmental processes, influencing morphology of sexually-dimorphic cerebral circuits. Exposure to EDCs is more dangerous if it occurs during specific “critical periods” of life, such as intrauterine, perinatal, juvenile or puberty periods, when organisms are more sensitive to hormonal disruption, than in other periods. However, exposure to EDCs in adulthood also can alter physiology. Several EDCs are xenoestrogens, may alter serum lipid concentrations, or metabolism enzymes that are necessary for converting cholesterol to steroid hormones, ultimately altering production of E2 and/or other steroids. Finally, many EDCs may have actions via, or independent of, classic actions at cognate steroid receptors. EDCs may have effects through numerous other substrates, such as the aryl hydrocarbon receptor (AhR), the peroxisome proliferator-activated receptor (PPAR) and retinoid X receptor (RXR), signal transduction pathways, calcium influx, and/or neurotransmitter receptors. Thus, EDCs, from varied sources, may have organizational effects during development, and/or activational effects in adulthood, that influence sexually-dimorphic, reproductively-relevant processes or other functions, by mimicking, antagonizing, or altering steroidal actions. PMID:21951193

Sex differences in the effects of androgens acting in the central nervous system on metabolism

PubMed Central

Morford, Jamie; Mauvais-Jarvis, Franck

2016-01-01

One of the most sexually dimorphic aspects of metabolic regulation is the bidirectional modulation of glucose and energy homeostasis by testosterone in males and females. Testosterone deficiency predisposes men to metabolic dysfunction, with excess adiposity, insulin resistance, and type 2 diabetes, whereas androgen excess predisposes women to insulin resistance, adiposity, and type 2 diabetes. This review discusses how testosterone acts in the central nervous system, and especially the hypothalamus, to promote metabolic homeostasis or dysfunction in a sexually dimorphic manner. We compare the organizational actions of testosterone, which program the hypothalamic control of metabolic homeostasis during development, and the activational actions of testosterone, which affect metabolic function after puberty. We also discuss how the metabolic effect of testosterone is centrally mediated via the androgen receptor. PMID:28179813

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.

Social Behavior: Developmental Timing Defies Puberty.

PubMed

Prendergast, Brian J; Zucker, Irving

2018-05-07

A closer look at behavioral development in seasonally breeding rodents reveals more complex relations between puberty and social behavior than previously recognized. Pubertal hormones determine gross amounts of behavior, but play recedes and aggression emerges independently of puberty at predetermined chronological ages. Copyright © 2018 Elsevier Ltd. All rights reserved.

Age, sex, and gonadal hormones differently influence anxiety- and depression-related behavior during puberty in mice.

PubMed

Boivin, Josiah R; Piekarski, David J; Wahlberg, Jessica K; Wilbrecht, Linda

2017-11-01

Anxiety and depression symptoms increase dramatically during adolescence, with girls showing a steeper increase than boys after puberty onset. The timing of the onset of this sex bias led us to hypothesize that ovarian hormones contribute to depression and anxiety during puberty. In humans, it is difficult to disentangle direct effects of gonadal hormones from social and environmental factors that interact with pubertal development to influence mental health. To test the role of gonadal hormones in anxiety- and depression-related behavior during puberty, we manipulated gonadal hormones in mice while controlling social and environmental factors. Similar to humans, we find that mice show an increase in depression-related behavior from pre-pubertal to late-pubertal ages, but this increase is not dependent on gonadal hormones and does not differ between sexes. Anxiety-related behavior, however, is more complex during puberty, with differences that depend on sex, age, behavioral test, and hormonal status. Briefly, males castrated before puberty show greater anxiety-related behavior during late puberty compared to intact males, while pubertal females are unaffected by ovariectomy or hormone injections in all assays except the marble burying test. Despite this sex-specific effect of pubertal hormones on anxiety-related behavior, we find no sex differences in intact young adults, suggesting that males and females use separate mechanisms to converge on a similar behavioral phenotype. Our results are consistent with anxiolytic effects of testicular hormones during puberty in males but are not consistent with a causal role for ovarian hormones in increasing anxiety- and depression-related behavior during puberty in females. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bone Geometry as a Predictor of Tissue Fragility and Stress Fracture Risk

DTIC Science & Technology

2005-10-01

sectional growth. Bone 14:635–642. 23. Duan Y, Beck TJ, Wang XF, Seeman E 2003 Structural and biomechanical basis of sexual dimorphism in femoral neck...orientation in primary bone? An evaluation in the turkey ulna diaphysis. J Anat 205:121–134. 48. Jepsen KJ, Davy DT, Akkus O 2001 Observations of damage in bone...significantly alter their growth patterns after puberty and predispose them to dras- tically increased bone growth in association with sexual

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

Sexual size dimorphism, canine dimorphism, and male-male competition in primates: where do humans fit in?

PubMed

Plavcan, J Michael

2012-03-01

Sexual size dimorphism is generally associated with sexual selection via agonistic male competition in nonhuman primates. These primate models play an important role in understanding the origins and evolution of human behavior. Human size dimorphism is often hypothesized to be associated with high rates of male violence and polygyny. This raises the question of whether human dimorphism and patterns of male violence are inherited from a common ancestor with chimpanzees or are uniquely derived. Here I review patterns of, and causal models for, dimorphism in humans and other primates. While dimorphism in primates is associated with agonistic male mate competition, a variety of factors can affect male and female size, and thereby dimorphism. The causes of human sexual size dimorphism are uncertain, and could involve several non-mutually-exclusive mechanisms, such as mate competition, resource competition, intergroup violence, and female choice. A phylogenetic reconstruction of the evolution of dimorphism, including fossil hominins, indicates that the modern human condition is derived. This suggests that at least some behavioral similarities with Pan associated with dimorphism may have arisen independently, and not directly from a common ancestor.

Social and emotional predictors of the tempo of puberty in female rhesus monkeys

PubMed Central

Wilson, Mark E; Bounar, Shannon; Godfrey, Jodi; Michopoulos, Vasiliki; Higgins, Melinda; Sanchez, Mar

2012-01-01

A cascade of neuroendocrine events regulates the initiation and progression of female puberty. However, the factors that determine the timing of these events across individuals are still uncertain. While the consequences of puberty on subsequent emotional development and adult behavior have received significant attention, what is less understood are the social and environmental factors that actually alter the initiation and progression of puberty. In order to more fully understand what factors influence pubertal timing in females, the present study quantified social and emotional behavior; stress physiology; and growth and activity measures in juvenile female rhesus monkeys to determine what best predicts eventual puberty. Based on previous reports, we hypothesized that increased agonistic behavior resulting from subordinate status in their natal group, in combination with slowed growth, reduced prosocial behavior, and increased emotional reactivity would predict delayed puberty. The analyses were restricted to behavioral and physiological measures obtained prior to the onset of puberty, defined as menarche. Together, our findings indicate that higher rates of aggression but lower rates of submission received from group mates; slower weight gain; and greater emotional reactivity, evidenced by higher anxiety, distress and appeasing behaviors, and lower cortisol responsivity in response to a potentially threatening situation, predicts delayed puberty. Together the combination of these variables accounted for 58% of the variance in the age of menarche, 71% in age at first ovulation, and 45% in the duration of adolescent sterility. While early puberty may be more advantageous for the individual from a fertility standpoint, it presents significant health risks, including increased risk for a number of estrogen dependent cancers and as well as the emergence of mood disorders during adulthood. On the other hand, it is possible that increased emotional reactivity associated with delayed puberty could persist, increasing the risk for emotional dysregulation to socially challenging situations. The data argue for prospective studies that will determine how emotional reactivity shown to be important for pubertal timing is affected by early social experience and temperament, and how these stress-related variables contribute to body weight accumulation, affecting the neuroendocrine regulation of puberty. PMID:22658962

Child Development & Behavior Topics

MedlinePlus

... Willi Syndrome (PWS) Precocious Puberty Pregnancy and Smoking Pregnancy Prevention Resources for Teens and Families Preventing Tobacco Use Prom! Keeping it Safe and Fun— Resources for Teens and Their Parents Pseudohermaphroditism Puberty, Early Puberty, Early, Podcast Puberty, Late, Podcast Back to ...

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

[Psychopathology related to women pubertal precocity].

PubMed

Purper-Ouakil, D; Didillon, A

2016-10-01

Puberty is a developmental process characterized by hormonal and physical changes leading to the ability of reproduction. Precocious puberty, especially in girls, has been associated with an increased incidence of emotional and behavioral problems. Adolescence is a life stage influenced both by the biological changes of puberty and the emergence of new social challenges. In individuals facing these developmental issues at a younger age than expected, the exposure to internal and external stress factors may be greater than in other young people. This narrative review provides an overview of psychopathology associated with precocious puberty in order to raise awareness of clinicians dealing with adolescents at risk for adverse behavioral and emotional outcomes. Developmental challenges of standard puberty and adolescence will be outlined before a more detailed description of recent findings from clinical and epidemiological studies. Putative mechanisms underlying the association between precocious puberty and psychopathology will also be discussed. Epidemiological studies have shown that an early onset of puberty in girls is associated with an earlier onset of sexuality, an earlier age of first birth and a lesser professional qualification regardless of cognitive abilities and socio-economic status. In both population studies and clinical cohorts, girls with an early age of puberty or in treatment for precocious puberty have more disruptive behavior disorders such as conduct disorders, more substance abuse disorders and delinquent behavior compared to their standard developing peers. Precocious puberty and behavioral problems may have common genetic and environmental risk factors. In young people with conduct disorders and early puberty, findings have emphasized the role of non-shared environmental factors. Low birth weight, obesity, exposure to endocrine-disrupting chemicals and adoption are potentially shared between both conditions. Early puberty in girls is also associated with psychosocial stressors and at-risk environments. The early development of secondary sexual characteristics in girls attracts older and more deviant peers, raising probability of sexual contacts but also of drug use and of a disengagement in school activities. Adolescence is the life stage during which prevalence of depressive disorders rises significantly, especially in girls. Hormonal changes and increase of the Body Mass Index leading to dissatisfaction with body image, have been put forward to explain this trend. Psychosocial challenges (emerging sexuality, instability of identity and social role) are other sources of stress at this particular period of life characterized by emotional hyper-reactivity. These stressors may have greater impact in young people showing a discrepancy between physical and affective maturation. Follow-up studies have shown that emotional and behavioral problems tend to lessen with time. Nevertheless, a heightened risk of depressive disorder remains in girls having had an early onset of puberty when other risk factors co-exist. Early puberty, especially in girls, has been associated with a number of emotional and behavioral symptoms and difficulties in adaptive functioning. Even though these adverse outcomes seem to lessen with time, heightened risk for depression and negative impact on socio-professional outcomes persist in subjects with other risk factors. The impact of treatment of precocious puberty on psycho-behavioral outcomes is currently unknown. However, clinicians should be aware that the social and emotional challenges these adolescents with atypical pubertal development have to face put them at risk for psychopathology and are potentially accessible to preventive actions. Copyright © 2016 L'Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

Sex-specific processing of social cues in the medial amygdala

PubMed Central

Bergan, Joseph F; Ben-Shaul, Yoram; Dulac, Catherine

2014-01-01

Animal–animal recognition within, and across species, is essential for predator avoidance and social interactions. Despite its essential role in orchestrating responses to animal cues, basic principles of information processing by the vomeronasal system are still unknown. The medial amygdala (MeA) occupies a central position in the vomeronasal pathway, upstream of hypothalamic centers dedicated to defensive and social responses. We have characterized sensory responses in the mouse MeA and uncovered emergent properties that shed new light onto the transformation of vomeronasal information into sex- and species-specific responses. In particular, we show that the MeA displays a degree of stimulus selectivity and a striking sexually dimorphic sensory representation that are not observed in the upstream relay of the accessory olfactory bulb (AOB). Furthermore, our results demonstrate that the development of sexually dimorphic circuits in the MeA requires steroid signaling near the time of puberty to organize the functional representation of sensory stimuli. DOI: http://dx.doi.org/10.7554/eLife.02743.001 PMID:24894465

Pubertal Timing as a Potential Mediator of Adoption Effects on Problem Behaviors

ERIC Educational Resources Information Center

Brooker, Rebecca J.; Berenbaum, Sheri A.; Bricker, Josh; Corley, Robin P.; Wadsworth, Sally A.

2012-01-01

Adopted children show more problem behaviors than nonadopted children. Given that internationally adopted individuals show earlier puberty than nonadopted individuals, and early puberty is associated with problem behaviors in nonadopted youth, we analyzed data from adopted domestic adoptees to determine whether problem behaviors could be explained…

Cystic Fibrosis through a Female Perspective: Psychosocial Issues and Information Concerning Puberty and Motherhood.

ERIC Educational Resources Information Center

Johannesson, Marie; Carlson, Margareta; Brucefors, Agneta Bergsten; Hjelte, Lena

1998-01-01

Investigates psychosocial issues concerning puberty and motherhood among adult women with cystic fibrosis (CF) to see how they had obtained information on these matters and how they would like information to be given. Results reveal problems with destructive behavior during puberty. Information about puberty and fertility should be given…

Early puberty, negative peer influence, and problem behaviors in adolescent girls.

PubMed

Mrug, Sylvie; Elliott, Marc N; Davies, Susan; Tortolero, Susan R; Cuccaro, Paula; Schuster, Mark A

2014-01-01

To determine how early puberty and peer deviance relate to trajectories of aggressive and delinquent behavior in early adolescence and whether these relationships differ by race/ethnicity. In this longitudinal study, 2607 girls from 3 metropolitan areas and their parents were interviewed at ages 11, 13, and 16 years. Girls reported on their age of onset of menarche, best friend's deviant behavior, delinquency, and physical, relational, and nonphysical aggression. Parents provided information on family sociodemographic characteristics and girls' race/ethnicity. Sixteen percent of girls were classified as early maturers (defined by onset of menarche before age 11 years). Overall, relational and nonphysical aggression increased from age 11 to age 16, whereas delinquency and physical aggression remained stable. Early puberty was associated with elevated delinquency and physical aggression at age 11. The relationship with early puberty diminished over time for physical aggression but not for delinquency. Best friend's deviant behavior was linked with higher levels of all problem behaviors, but the effect lessened over time for most outcomes. Early puberty was associated with a stronger link between best friend's deviance and delinquency, suggesting increased vulnerability to negative peer influences among early-maturing girls. A similar vulnerability was observed for relational and nonphysical aggression among girls in the "other" racial/ethnic minority group only. Early puberty and friends' deviance may increase the risk of problem behavior in young adolescent girls. Although many of these associations dissipate over time, early-maturing girls are at risk of persistently higher delinquency and stronger negative peer influences.

Puberty and Adolescence as a Time of Vulnerability to Stressors that Alter Neurobehavioral Processes

PubMed Central

Holder, Mary K.; Blaustein, Jeffrey D.

2013-01-01

Puberty and adolescence are major life transitions during which an individual’s physiology and behavior changes from that of a juvenile to that of an adult. Here we review studies documenting the effects of stressors during pubertal and adolescent development on the adult brain and behavior. The experience of complex or compound stressors during puberty/adolescence generally increases stress reactivity, increases anxiety and depression, and decreases cognitive performance in adulthood. These behavioral changes correlate with decreased hippocampal volumes and alterations in neural plasticity. Moreover, stressful experiences during puberty disrupt behavioral responses to gonadal hormones both in sexual performance and on cognition and emotionality. These behavioral changes correlate with altered estrogen receptor densities in some estrogen-concentrating brain areas, suggesting a remodeling of the brain’s response to hormones. A hypothesis is presented that activation of the immune system results in chronic neuroinflammation that may mediate the alterations of hormone-modulated behaviors in adulthood. PMID:24184692

Comparison of Behavioral and Sexual Problems between Intellectually Disabled and Normal Adolescent Boys during Puberty in Yazd, Iran

PubMed Central

Akrami, Leila; Davudi, Maryam

2014-01-01

Objective: To compare sexual and behavioral puberty problems between intellectually disabled (ID) and normal boys in Yazd, Iran. Methods: In the present study, 65 intellectually disabled and 65 normal boys were included. The Child Behavior Check List (CBCL) was used to investigate behavioral problems. In order to study sexual problems, a questionnaire that was designed by the researchers was applie. Results: Anxiety, depression, social problems, attention problems, aggressiveness, and sexual problems were more frequent in intellectually disabled boys than in normal boys. On the other hand, regarding somatic complaints, withdrawal, thought problems, internalizing, delinquent behavior, and externalizing there was no difference between the two groups. Conclusion: Behavioral and sexual problems are more common in adolescent boys with intellectual disability (ID) than in normal boys during the puberty period. Therefore, puberty is an important period for intellectually disabled boys and their families; this should be taken into consideration by psychologists and clinicians. PMID:25053959

Puberty and adolescent sexuality.

PubMed

Fortenberry, J Dennis

2013-07-01

This article is part of a Special Issue "Puberty and Adolescence". Sexuality emerges as a major developmental element of puberty and the adolescent years that follow. However, connecting the sexuality that emerges with puberty and elements of adult sexuality is difficult because much adolescent sexuality research addresses the transition to partnered sexual behaviors (primarily coitus) and consequences such as unplanned pregnancy and sexually transmitted infections. This review proposes a framework of an expanded understanding of puberty and adolescent sexuality from the perspective of four hallmarks of adult sexuality: sexual desire; sexual arousal; sexual behaviors; and, sexual function. This approach thus addresses important gaps in understanding of the ontogeny of sex and the continuum of sexuality development from adolescence through the adult lifespan. Copyright © 2013 Elsevier Inc. All rights reserved.

Bending for love: losses and gains of sexual dimorphisms are strictly correlated with changes in the mounting position of sepsid flies (Sepsidae: Diptera).

PubMed

Puniamoorthy, Nalini; Su, Kathy Feng-Yi; Meier, Rudolf

2008-05-21

Sexually dimorphic structures contribute the largest number of morphological differences between closely related insect species thus implying that these structures evolve fast and are involved in speciation. The current literature focuses on the selective forces that drive these changes, be it 'sexual conflict' or 'female choice'. However, there are only few studies examining the function of sexual dimorphisms and even fewer that investigate how functional changes influence dimorphisms. This is largely due to the paucity of taxa for which the morphology, behavior, and phylogenetic relationships for multiple species are known. Here we present such data for sepsid flies. Sepsids have starkly dimorphic forelegs whose function can be documented under laboratory conditions. We use data from 10 genes to reconstruct the phylogenetic relationships for 33 species and test whether mounting positions are correlated with the presence and absence of sexual dimorphisms in the forelegs. The phylogenetic tree fully resolves the relationship with 29 of the 31 nodes of the tree having a posterior probability of 1.0. Twenty-eight of the 31 sepsid species have sexually dimorphic forelegs. All 28 species with such forelegs have the same mounting technique whereby the male uses his modified forelegs to grasp the female wingbase. Mapping mounting behavior and foreleg morphology onto the tree reveals that the wing grasp evolved once and was reduced twice. All changes in the mounting behavior are strictly and statistically significantly correlated with the origin and losses of sexually dimorphic legs (concentrated changes test: P < 0.001); i.e., the two species that have independently lost the wing grasp have both also re-evolved monomorphic legs. The wing grasp in these species is replaced with a novel but very similar mounting technique not involving the forelegs: the males bend their abdomens forward and directly establish genital contact to the female. In addition, one of the secondarily monomorphic species, Sepsis secunda, has evolved a new sexual dimorphism, a 'bump' on the dorsal side of the 4th tergite, which is now touching the ventral side of the female abdomen. Our study reveals that the evolution of sexually dimorphic legs in Sepsidae can only be understood once the function of the legs during mating is considered and the relationships of species with and without sexual dimorphisms are known. We demonstrate that homoplasy in sexually dimorphic structures can be due to homoplasy in mating behavior. We furthermore document that the two species with secondarily monomorphic legs have independently replaced the typical sepsid wing grasp with very similar, new mounting techniques. This suggests that convergent evolution may be common in mating behaviors.

Bending for love: losses and gains of sexual dimorphisms are strictly correlated with changes in the mounting position of sepsid flies (Sepsidae: Diptera)

PubMed Central

2008-01-01

Background Sexually dimorphic structures contribute the largest number of morphological differences between closely related insect species thus implying that these structures evolve fast and are involved in speciation. The current literature focuses on the selective forces that drive these changes, be it 'sexual conflict' or 'female choice'. However, there are only few studies examining the function of sexual dimorphisms and even fewer that investigate how functional changes influence dimorphisms. This is largely due to the paucity of taxa for which the morphology, behavior, and phylogenetic relationships for multiple species are known. Here we present such data for sepsid flies. Sepsids have starkly dimorphic forelegs whose function can be documented under laboratory conditions. We use data from 10 genes to reconstruct the phylogenetic relationships for 33 species and test whether mounting positions are correlated with the presence and absence of sexual dimorphisms in the forelegs. Results The phylogenetic tree fully resolves the relationship with 29 of the 31 nodes of the tree having a posterior probability of 1.0. Twenty-eight of the 31 sepsid species have sexually dimorphic forelegs. All 28 species with such forelegs have the same mounting technique whereby the male uses his modified forelegs to grasp the female wingbase. Mapping mounting behavior and foreleg morphology onto the tree reveals that the wing grasp evolved once and was reduced twice. All changes in the mounting behavior are strictly and statistically significantly correlated with the origin and losses of sexually dimorphic legs (concentrated changes test: P < 0.001); i.e., the two species that have independently lost the wing grasp have both also re-evolved monomorphic legs. The wing grasp in these species is replaced with a novel but very similar mounting technique not involving the forelegs: the males bend their abdomens forward and directly establish genital contact to the female. In addition, one of the secondarily monomorphic species, Sepsis secunda, has evolved a new sexual dimorphism, a 'bump' on the dorsal side of the 4th tergite, which is now touching the ventral side of the female abdomen. Conclusion Our study reveals that the evolution of sexually dimorphic legs in Sepsidae can only be understood once the function of the legs during mating is considered and the relationships of species with and without sexual dimorphisms are known. We demonstrate that homoplasy in sexually dimorphic structures can be due to homoplasy in mating behavior. We furthermore document that the two species with secondarily monomorphic legs have independently replaced the typical sepsid wing grasp with very similar, new mounting techniques. This suggests that convergent evolution may be common in mating behaviors. PMID:18492287

Puberty suppression in adolescents with gender identity disorder: a prospective follow-up study.

PubMed

de Vries, Annelou L C; Steensma, Thomas D; Doreleijers, Theo A H; Cohen-Kettenis, Peggy T

2011-08-01

Puberty suppression by means of gonadotropin-releasing hormone analogues (GnRHa) is used for young transsexuals between 12 and 16 years of age. The purpose of this intervention is to relieve the suffering caused by the development of secondary sex characteristics and to provide time to make a balanced decision regarding actual gender reassignment. To compare psychological functioning and gender dysphoria before and after puberty suppression in gender dysphoric adolescents. Of the first 70 eligible candidates who received puberty suppression between 2000 and 2008, psychological functioning and gender dysphoria were assessed twice: at T0, when attending the gender identity clinic, before the start of GnRHa; and at T1, shortly before the start of cross-sex hormone treatment. Behavioral and emotional problems (Child Behavior Checklist and the Youth-Self Report), depressive symptoms (Beck Depression Inventory), anxiety and anger (the Spielberger Trait Anxiety and Anger Scales), general functioning (the clinician's rated Children's Global Assessment Scale), gender dysphoria (the Utrecht Gender Dysphoria Scale), and body satisfaction (the Body Image Scale) were assessed. Behavioral and emotional problems and depressive symptoms decreased, while general functioning improved significantly during puberty suppression. Feelings of anxiety and anger did not change between T0 and T1. While changes over time were equal for both sexes, compared with natal males, natal females were older when they started puberty suppression and showed more problem behavior at both T0 and T1. Gender dysphoria and body satisfaction did not change between T0 and T1. No adolescent withdrew from puberty suppression, and all started cross-sex hormone treatment, the first step of actual gender reassignment. Puberty suppression may be considered a valuable contribution in the clinical management of gender dysphoria in adolescents. © 2010 International Society for Sexual Medicine.

HORMONAL AND PHYSICAL MARKERS OF PUBERTY AND THEIR RELATIONSHIP TO ADOLESCENT-TYPICAL NOVELTY-DIRECTED BEHAVIOR

PubMed Central

Vetter-O’Hagen, Courtney S.; Spear, Linda P.

2011-01-01

The extent to which characteristic adolescent behaviors are associated with pubertal changes or driven by more general, puberty-independent developmental alterations is largely unknown. Using physiological and hormonal markers of puberty, this experiment characterized pubertal timing across adolescence and examined the relationships among these variables and novelty-directed behaviors. Males and females were tested for response to novelty at P28, P32, P36, P40, P44, P48 and P75, and examined for balano-preputial skinfold separation and sperm presence (males) or vaginal opening (females), followed by blood collection for hormonal assessments. Despite earlier pubertal maturation in females, with maturation generally completed by P36 in females and P44 in males, novelty-directed behavior peaked at P32 and P36 in both sexes, and was unrelated to pubertal measures. These data support the suggestion that the ontogenetic peak in this behavior during adolescence is not notably puberty-dependent. PMID:21953609

Does puberty mark a transition in sensitive periods for plasticity in the associative neocortex?

PubMed Central

Piekarski, David J.; Johnson, Carolyn; Boivin, Josiah R.; Thomas, A. Wren; Lin, Wan Chen; Delevich, Kristen; Galarce, Ezequiel; Wilbrecht, Linda

2016-01-01

Postnatal brain development is studded with sensitive periods during which experience dependent plasticity is enhanced. This enables rapid learning from environmental inputs and reorganization of cortical circuits that matches behavior with environmental contingencies. Significant headway has been achieved in characterizing and understanding sensitive period biology in primary sensory cortices, but relatively little is known about sensitive period biology in associative neocortex. One possible mediator is the onset of puberty, which marks the transition to adolescence, when animals shift their behavior toward gaining independence and exploring their social world. Puberty onset correlates with reduced behavioral plasticity in some domains and enhanced plasticity in others, and therefore may drive the transition from juvenile to adolescent brain function. Pubertal onset is also occurring earlier in developed nations, particularly in unserved populations, and earlier puberty is associated with vulnerability for substance use, depression and anxiety. In the present article we review the evidence that supports a causal role for puberty in developmental changes in the function and neurobiology of the associative neocortex. We also propose a model for how pubertal hormones may regulate sensitive period plasticity in associative neocortex. We conclude that the evidence suggests puberty onset may play a causal role in some aspects of associative neocortical development, but that further research that manipulates puberty and measures gonadal hormones is required. We argue that further work of this kind is urgently needed to determine how earlier puberty may negatively impact human health and learning potential. PMID:27590721

Early Puberty, Negative Peer Influence, and Problem Behaviors in Adolescent Girls

PubMed Central

Elliott, Marc N.; Davies, Susan; Tortolero, Susan R.; Cuccaro, Paula; Schuster, Mark A.

2014-01-01

OBJECTIVE: To determine how early puberty and peer deviance relate to trajectories of aggressive and delinquent behavior in early adolescence and whether these relationships differ by race/ethnicity. METHODS: In this longitudinal study, 2607 girls from 3 metropolitan areas and their parents were interviewed at ages 11, 13, and 16 years. Girls reported on their age of onset of menarche, best friend’s deviant behavior, delinquency, and physical, relational, and nonphysical aggression. Parents provided information on family sociodemographic characteristics and girls’ race/ethnicity. RESULTS: Sixteen percent of girls were classified as early maturers (defined by onset of menarche before age 11 years). Overall, relational and nonphysical aggression increased from age 11 to age 16, whereas delinquency and physical aggression remained stable. Early puberty was associated with elevated delinquency and physical aggression at age 11. The relationship with early puberty diminished over time for physical aggression but not for delinquency. Best friend’s deviant behavior was linked with higher levels of all problem behaviors, but the effect lessened over time for most outcomes. Early puberty was associated with a stronger link between best friend’s deviance and delinquency, suggesting increased vulnerability to negative peer influences among early-maturing girls. A similar vulnerability was observed for relational and nonphysical aggression among girls in the “other” racial/ethnic minority group only. CONCLUSIONS: Early puberty and friends’ deviance may increase the risk of problem behavior in young adolescent girls. Although many of these associations dissipate over time, early-maturing girls are at risk of persistently higher delinquency and stronger negative peer influences. PMID:24324002

Sexually Monomorphic Maps and Dimorphic Responses in Rat Genital Cortex.

PubMed

Lenschow, Constanze; Copley, Sean; Gardiner, Jayne M; Talbot, Zoe N; Vitenzon, Ariel; Brecht, Michael

2016-01-11

Mammalian external genitals show sexual dimorphism [1, 2] and can change size and shape upon sexual arousal. Genitals feature prominently in the oldest pieces of figural art [3] and phallic depictions of penises informed psychoanalytic thought about sexuality [4, 5]. Despite this longstanding interest, the neural representations of genitals are still poorly understood [6]. In somatosensory cortex specifically, many studies did not detect any cortical representation of genitals [7-9]. Studies in humans debate whether genitals are represented displaced below the foot of the cortical body map [10-12] or whether they are represented somatotopically [13-15]. We wondered what a high-resolution mapping of genital representations might tell us about the sexual differentiation of the mammalian brain. We identified genital responses in rat somatosensory cortex in a region previously assigned as arm/leg cortex. Genital responses were more common in males than in females. Despite such response dimorphism, we observed a stunning anatomical monomorphism of cortical penis and clitoris input maps revealed by cytochrome-oxidase-staining of cortical layer 4. Genital representations were somatotopic and bilaterally symmetric, and their relative size increased markedly during puberty. Size, shape, and erect posture give the cortical penis representation a phallic appearance pointing to a role in sexually aroused states. Cortical genital neurons showed unusual multi-body-part responses and sexually dimorphic receptive fields. Specifically, genital neurons were co-activated by distant body regions, which are touched during mounting in the respective sex. Genital maps indicate a deep homology of penis and clitoris representations in line with a fundamentally bi-sexual layout [16] of the vertebrate brain. Copyright © 2016 Elsevier Ltd. All rights reserved.

Does puberty mark a transition in sensitive periods for plasticity in the associative neocortex?

PubMed

Piekarski, David J; Johnson, Carolyn M; Boivin, Josiah R; Thomas, A Wren; Lin, Wan Chen; Delevich, Kristen; M Galarce, Ezequiel; Wilbrecht, Linda

2017-01-01

Postnatal brain development is studded with sensitive periods during which experience dependent plasticity is enhanced. This enables rapid learning from environmental inputs and reorganization of cortical circuits that matches behavior with environmental contingencies. Significant headway has been achieved in characterizing and understanding sensitive period biology in primary sensory cortices, but relatively little is known about sensitive period biology in associative neocortex. One possible mediator is the onset of puberty, which marks the transition to adolescence, when animals shift their behavior toward gaining independence and exploring their social world. Puberty onset correlates with reduced behavioral plasticity in some domains and enhanced plasticity in others, and therefore may drive the transition from juvenile to adolescent brain function. Pubertal onset is also occurring earlier in developed nations, particularly in unserved populations, and earlier puberty is associated with vulnerability for substance use, depression and anxiety. In the present article we review the evidence that supports a causal role for puberty in developmental changes in the function and neurobiology of the associative neocortex. We also propose a model for how pubertal hormones may regulate sensitive period plasticity in associative neocortex. We conclude that the evidence suggests puberty onset may play a causal role in some aspects of associative neocortical development, but that further research that manipulates puberty and measures gonadal hormones is required. We argue that further work of this kind is urgently needed to determine how earlier puberty may negatively impact human health and learning potential. This article is part of a Special Issue entitled SI: Adolescent plasticity. Copyright © 2016 Elsevier B.V. All rights reserved.

Anxiogenic Effects of Developmental Bisphenol A Exposure Are Associated with Gene Expression Changes in the Juvenile Rat Amygdala and Mitigated by Soy

PubMed Central

Patisaul, Heather B.; Sullivan, Alana W.; Radford, Meghan E.; Walker, Deena M.; Adewale, Heather B.; Winnik, Bozena; Coughlin, Janis L.; Buckley, Brian; Gore, Andrea C.

2012-01-01

Early life exposure to Bisphenol A (BPA), a component of polycarbonate plastics and epoxy resins, alters sociosexual behavior in numerous species including humans. The present study focused on the ontogeny of these behavioral effects beginning in adolescence and assessed the underlying molecular changes in the amygdala. We also explored the mitigating potential of a soy-rich diet on these endpoints. Wistar rats were exposed to BPA via drinking water (1 mg/L) from gestation through puberty, and reared on a soy-based or soy-free diet. A group exposed to ethinyl estradiol (50 µg/L) and a soy-free diet was used as a positive estrogenic control. Animals were tested as juveniles or adults for anxiety-like and exploratory behavior. Assessment of serum BPA and genistein (GEN), a soy phytoestrogen, confirmed that internal dose was within a human-relevant range. BPA induced anxiogenic behavior in juveniles and loss of sexual dimorphisms in adult exploratory behavior, but only in the animals reared on the soy-free diet. Expression analysis revealed a suite of genes, including a subset known to mediate sociosexual behavior, associated with BPA-induced juvenile anxiety. Notably, expression of estrogen receptor beta (Esr2) and two melanocortin receptors (Mc3r, Mc4r) were downregulated. Collectively, these results show that behavioral impacts of BPA can manifest during adolescence, but wane in adulthood, and may be mitigated by diet. These data also reveal that, because ERβ and melanocortin receptors are crucial to their function, oxytocin/vasopressin signaling pathways, which have previously been linked to human affective disorders, may underlie these behavioral outcomes. PMID:22957036

Change in cortical bone density and its distribution differs between boys and girls during puberty.

PubMed

Kontulainen, Saija A; Macdonald, Heather M; McKay, Heather A

2006-07-01

Postmenarchal girls and premenopausal women have 3-4% higher cortical bone density (CoD, milligrams per cubic centimeter), compared with postpubertal boys and men, respectively. Females' denser cortical bone is thought to serve as a calcium reservoir for reproductive needs. However, prospective data are lacking that describe CoD development and bone mineral density distribution during puberty in both sexes. Thus, our objectives were to assess maturity and sex differences in the 20-month change of CoD and radial distribution of bone mineral density (RDBMD, milligrams per cubic centimeter) in early-, peri-, and postpubertal girls and boys. Maturity groups were based on change in menarcheal status (girls, n = 68) and pubic hair stage (Tanner) (boys, n = 59). Peripheral quantitative computed tomography was used to measure CoD and RDBMD at the tibial middiaphysis. The increase in average CoD was 1.9% [22.8 mg/cm(3); 95% confidence interval (CI), 10-36], 2.8% (33.8 mg/cm(3); 95% CI, 21-47), and 1.5% (55.0 mg/cm(3); 95% CI, 17-93) greater in early, peri-, and postpubertal girls, compared with boys, respectively. Analysis of RDBMD revealed that the change in density distribution varied across pubertal groups in girls. Across puberty, all girls showed an increase in the high density midcortical region, whereas only peripubertal girls showed an increase in the lower density subcortical region. A sex-difference in RDBMD change was noted within early and peripubertal groups. Our findings of sexual dimorphism in CoD development give support to the hypothesis that female bone deposits calcium for reproductive needs by consolidation of cortical bone during puberty.

Effects of Selective Deletion of Tyrosine Hydroxylase from Kisspeptin Cells on Puberty and Reproduction in Male and Female Mice.

PubMed

Stephens, Shannon B Z; Rouse, Melvin L; Tolson, Kristen P; Liaw, Reanna B; Parra, Ruby A; Chahal, Navi; Kauffman, Alexander S

2017-01-01

The neuropeptide kisspeptin, encoded by Kiss1 , regulates reproduction by stimulating GnRH secretion. Kiss1- syntheizing neurons reside primarily in the hypothalamic anteroventral periventricular (AVPV/PeN) and arcuate (ARC) nuclei. AVPV/PeN Kiss1 neurons are sexually dimorphic, with females expressing more Kiss1 than males, and participate in estradiol (E 2 )-induced positive feedback control of GnRH secretion. In mice, most AVPV/PeN Kiss1 cells coexpress tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine synthesis (in this case, dopamine). Dopamine treatment can inhibit GnRH neurons, but the function of dopamine signaling arising specifically from AVPV/PeN Kiss1 cells is unknown. We generated a novel TH flox mouse and used Cre-Lox technology to selectively ablate TH specifically from Kiss1 cells. We then examined the effects of selective TH knock-out on puberty and reproduction in both sexes. In control mice, 90% of AVPV/PeN Kiss1 neurons coexpressed TH , whereas in mice lacking TH exclusively in Kiss1 cells (termed Kiss THKOs), TH was successfully absent from virtually all Kiss1 cells. Despite this absence of TH , both female and male Kiss THKOs displayed normal body weights, puberty onset, and basal gonadotropin levels in adulthood, although testosterone (T) was significantly elevated in adult male Kiss THKOs. The E 2 -induced LH surge was unaffected in Kiss THKO females, and neuronal activation status of kisspeptin and GnRH cells was also normal. Supporting this, fertility and fecundity were normal in Kiss THKOs of both sexes. Thus, despite high colocalization of TH and Kiss1 in the AVPV/PeN, dopamine produced in these cells is not required for puberty or reproduction, and its function remains unknown.

Hunger-dependent and Sex-specific Antipredator Behaviour of Larvae of a Size-dimorphic Mosquito

PubMed Central

Wormington, Jillian; Juliano, Steven

2014-01-01

1. Modification of behaviors in the presence of predators or predation cues is widespread among animals. Costs of a behavioral change in the presence of predators or predation cues depend on fitness effects of lost feeding opportunities and, especially when organisms are sexually dimorphic in size or timing of maturation, these costs are expected to differ between the sexes. 2. Larval Aedes triseriatus (Say) (Diptera: Culicidae) were used to test the hypothesis that behavioral responses of the sexes to predation cues have been selected differently due to different energy demands. 3. Even in the absence of water-borne predation cues, hungry females (the larger sex) spent more time browsing than did males, indicating a difference in energy needs. 4. In the presence of predation cues, well-fed larvae of both sexes reduced their activity more than did hungry larvae, and males shifted away from high-risk behaviors to a greater degree than did females, providing the first evidence of sex-specific antipredator behavior in foraging mosquito larvae. 5. Because sexual size dimorphism is common across taxa, and energetic demands are likely correlated with size dimorphism, this research demonstrates the importance of investigating sex specific behavior and behavioral responses to enemies and cautions against generalizing results between sexes. PMID:25309025

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

Dietary DHA during development affects depression-like behaviors and biomarkers that emerge after puberty in adolescent rats

PubMed Central

Weiser, Michael J.; Wynalda, Kelly; Salem, Norman; Butt, Christopher M.

2015-01-01

DHA is an important omega-3 PUFA that confers neurodevelopmental benefits. Sufficient omega-3 PUFA intake has been associated with improved mood-associated measures in adult humans and rodents, but it is unknown whether DHA specifically influences these benefits. Furthermore, the extent to which development and puberty interact with the maternal diet and the offspring diet to affect mood-related behaviors in adolescence is poorly understood. We sought to address these questions by 1) feeding pregnant rats with diets sufficient or deficient in DHA during gestation and lactation; 2) weaning their male offspring to diets that were sufficient or deficient in DHA; and 3) assessing depression-related behaviors (forced swim test), plasma biomarkers [brain-derived neurotrophic factor (BDNF), serotonin, and melatonin], and brain biomarkers (BDNF) in the offspring before and after puberty. No dietary effects were detected when the offspring were evaluated before puberty. In contrast, after puberty depressive-like behavior and its associated biomarkers were worse in DHA-deficient offspring compared with animals with sufficient levels of DHA. The findings reported here suggest that maintaining sufficient DHA levels throughout development (both pre- and postweaning) may increase resiliency to emotional stressors and decrease susceptibility to mood disorders that commonly arise during adolescence. PMID:25411442

Lack of sexual dimorphism in femora of the eusocial and hypogonadic naked mole-rat; a novel animal model for the study of delayed puberty on the skeletal system

PubMed Central

Pinto, M; Jepsen, K J; Terranova, C J; Buffenstein

2015-01-01

Sex steroid hormones are major determinants of bone morphology and quality and are responsible for sexually dimorphic skeletal traits. Hypogonadism results in suboptimal skeletal development and may lead to an increased risk of bone fracture later in life. The etiology of delayed puberty and/or hypothalamic amenorrhea is poorly understood, and experimental animal models addressing this issue are predominantly based upon short-term experimental induction of hormonal suppression via gonadotropin releasing hormone antagonists (GnRH-a). This acute change in hormone profile does not necessarily emulate the natural progression of hypogonadic bone disorders. We propose a novel animal model with which to explore the effects of chronic hypogonadism on bone quality, the naked mole-rat (NMR; Heterocephalus glaber). This mouse-size rodent may remain reproductively suppressed throughout its life, if it remains as a subordinate within the eusocial mole-rat colony. NMRs live in large colonies with a single dominant breeding female. She, primarily by using aggressive social contact, naturally suppresses the hypothalamic gonadotropic axis of subordinate NMRs and thereby their reproductive expression. However should an NMR be separated from the dominant breeder, within less than a week reproductive hormones may become elevated and the animal attains breeding status. We questioned if sexual suppression of subordinates impact upon the development and maintenance of the femora, and lead to a sexually indistinct monomorphic skeleton. Femora were obtained from male and female NMRs that were either non-breeders (subordinate) or breeders at the time of sacrifice. Diaphyseal cross-sectional morphology, metaphyseal trabecular micro-architecture and tissue mineral density of the femur was measured using MicroComputed tomography and diaphyseal mechanical properties were assessed by four-point bending tests to failure. Subordinates were sexually monomorphic and showed no significant differences in body weight or femoral bone structure and quality between male and females. Femora of subordinate females differed significantly from that of breeding animals, whereas in males, the divergent trend among breeders and non-breeders did not reach statistical significance. Subordinate NMRs, naturally suppressed from entering puberty, may prove to be a useful model to tease apart the relationship between bone morphology and hypogonadism and evaluate skeletal development during pubertal maturation. PMID:19761882

Determinants of Physical Activity in Low-income, Overweight African American Girls

ERIC Educational Resources Information Center

Lown, Debbie A.; Braunschweig, Carol L.

2008-01-01

Objectives: To examine the relationship between puberty, sedentary behaviors, and psychosocial influences with intention for physical activity (PA) and PA. Methods: Low-income, overweight African American girls (n=72) completed 5 questionnaires that assessed PA, sedentary behaviors, and psychosocial influences. Puberty was assessed using Tanner…

Pubertal stage and the prevalence of violence and social relational aggression

PubMed Central

Hemphill, Sheryl A.; Kotevski, Aneta; Herrenkohl, Todd I.; Toumbourou, John W.; Carlin, John B.; Catalano, Richard F.; Patton, George C.

2010-01-01

Objective Violence and social relational aggression are global problems that become prominent in early adolescence. This study examines associations between pubertal stage and adolescent violent behavior and social relational aggression. Methods This paper draws on cross-sectional data from the International Youth Development Study (IYDS), which comprised two state-wide representative samples of students in grades 5, 7 and 9 (N = 5,769) in Washington State in the United States and Victoria, Australia, drawn as a 2-stage cluster sample in each state. The study used carefully matched methods to conduct a school-administered, self-report student survey measuring behavioral outcomes including past year violent behavior (measured as attacking or beating up another person) and social relational aggression (excluding peers from the group, threatening to spread lies or rumors), as well as a comprehensive range of risk and protective factors and pubertal development. Results Compared with early puberty, the odds of violent behavior were approximately three-fold higher in mid-puberty (odds ratio [OR]: 2.87; 95% confidence interval [CI]: 1.81,4.55) and late puberty (OR: 3.79; 95% CI: 2.25,6.39), after adjustment for age, gender, state, and state by gender interaction. For social relational aggression, there were weaker overall associations after adjustment but these included an interaction between pubertal stage and age, showing stronger associations with pubertal stage at younger age (p = .003; mid-puberty OR 1.78; 95% CI 1.20,2.63; late puberty OR 3.00; 95% CI 1.95,4.63. Associations between pubertal stage and violent behavior and social relational aggression remained (although the magnitude of effects was reduced), after the inclusion of social contextual mediators in the analyses. Conclusions Pubertal stage was associated with higher rates of violent behavior and social relational aggression, with the latter association seen only at younger ages. Puberty may be an important phase for interventions aimed at preventing the adolescent rise in violent and antisocial behaviors. PMID:20624807

Long term dietary methoxychlor exposure in rats increases sodium solution consumption but has few effects on other sexually dimorphic behaviors.

PubMed

Flynn, K M; Delclos, K B; Newbold, R R; Ferguson, S A

2005-09-01

Methoxychlor is an insecticide with estrogen-like activity, thus exposure during development might cause sexually dimorphic behavioral alterations. To evaluate this, pregnant rats consumed diets containing 0, 10, 100 or 1000 ppm methoxychlor from gestational day 7, and offspring continued on these diets until postnatal day (PND) 77. Assessments of sexually dimorphic behaviors in offspring indicated that intake of a 3.0% sodium chloride solution was significantly increased (41%) in males and females of the 1000 ppm group. No treatment group differed from controls in open field nor running wheel activity, play behavior, nor 0.3% saccharin solution intake. Offspring of the 1000 ppm group showed significantly decreased body weight, reaching 17% less than controls at PND 77, but not clearly related to their salt solution intake. During pregnancy, 1000 ppm dams consumed 23% less food and weighed 10% less than controls, but this did not affect litter outcomes. These results indicate that in rodents, developmental and chronic exposure to dietary methoxychlor alters the sexually dimorphic behavior of salt-solution intake in young adults of both sexes. Similar behavioral alterations with other xenoestrogens, and the potential for interactions among xenoestrogens, suggest that this report may minimize the true effects of dietary methoxychlor exposure.

[Age of puberty and western young women sexuality].

PubMed

Tresch, C; Ohl, J

2015-02-01

The onset of menarche and age of first sexual experience have both lowered over the past century. Does the age of puberty influence the sexuality of the girl/young occidental woman? If so, to what degree? Besides, is the acquisition of reproductive function, regardless of age, a sign of sufficient maturity to engage in sexual activity? Studies show that early puberty, early sex, unprotected sexual intercourse in adolescence and number of sexual partners in early adulthood are closely related. These early sexual experiences could be stimulated by early drug use as well as by depressive disorders. The age of puberty has a real influence on sexuality but this link will be modulated by a number of social behavioral factors and it is not sustainable. The age of puberty is not a good indicator of maturity for teenage sexuality; early maturation and early sexual activity are usually associated with risky behaviors. However, other studies on the subject are required, including a consideration of the issues associated with delayed puberty, a subject virtually absent from the literature. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Postnatal penile growth concurrent with mini-puberty predicts later sex-typed play behavior: Evidence for neurobehavioral effects of the postnatal androgen surge in typically developing boys.

PubMed

Pasterski, Vickie; Acerini, Carlo L; Dunger, David B; Ong, Ken K; Hughes, Ieuan A; Thankamony, Ajay; Hines, Melissa

2015-03-01

The masculinizing effects of prenatal androgens on human neurobehavioral development are well established. Also, the early postnatal surge of androgens in male infants, or mini-puberty, has been well documented and is known to influence physiological development, including penile growth. However, neurobehavioral effects of androgen exposure during mini-puberty are largely unknown. The main aim of the current study was to evaluate possible neurobehavioral consequences of mini-puberty by relating penile growth in the early postnatal period to subsequent behavior. Using multiple linear regression, we demonstrated that penile growth between birth and three months postnatal, concurrent with mini-puberty, significantly predicted increased masculine/decreased feminine behavior assessed using the Pre-school Activities Inventory (PSAI) in 81 healthy boys at 3 to 4years of age. When we controlled for other potential influences on masculine/feminine behavior and/or penile growth, including variance in androgen exposure prenatally and body growth postnally, the predictive value of penile growth in the early postnatal period persisted. More specifically, prenatal androgen exposure, reflected in the measurement of anogenital distance (AGD), and early postnatal androgen exposure, reflected in penile growth from birth to 3months, were significant predictors of increased masculine/decreased feminine behavior, with each accounting for unique variance. Our findings suggest that independent associations of PSAI with AGD at birth and with penile growth during mini-puberty reflect prenatal and early postnatal androgen exposures respectively. Thus, we provide a novel and readily available approach for assessing effects of early androgen exposures, as well as novel evidence that early postnatal aes human neurobehavioral development. Copyright © 2015. Published by Elsevier Inc.

Sex differences in neuromuscular androgen receptor expression and sociosexual behavior in a sex changing fish

PubMed Central

Pradhan, Devaleena S.; Thonkulpitak, Kevin; Drilling, Cathleen; Black, Michael; Grober, Matthew S.

2017-01-01

Androgen signaling, via receptor binding, is critical for regulating the physiological and morphological foundations of male-typical reproductive behavior in vertebrates. Muscles essential for male courtship behavior and copulation are highly sensitive to androgens. Differences in the distribution and density of the androgen receptor (AR) are important for maintaining dimorphic musculature and thus may provide for anatomical identification of sexually selected traits. In Lythrypnus dalli, a bi-directional hermaphroditic teleost fish, both sexes produce agonistic approach displays, but reproductive behavior is sexually dimorphic. The male-specific courtship behavior is characterized by rapid jerky movements (involving dorsal fin erection) towards a female or around their nest. Activation of the supracarinalis muscle is involved in dorsal fin contributions to both agonistic and sociosexual behavior in other fishes, suggesting that differences in goby sexual behavior may be reflected in sexual dimorphism in AR signaling in this muscle. We examined sex differences in the local distribution of AR in supracarinalis muscle and spinal cord. Our results demonstrate that males do express more AR in the supracarinalis muscle relative to females, but there was no sex difference in the number of spinal motoneurons expressing AR. Interestingly, AR expression in the supracarinalis muscle was also related to rates of sociosexual behavior in males, providing evidence that sexual selection may influence muscle androgenic sensitivity to enhance display vigor. Sex differences in the distribution and number of cells expressing AR in the supracarinalis muscle may underlie the expression of dimorphic behaviors in L. dalli. PMID:28520775

Using Digital Images of the Zebra Finch Song System as a Tool to Teach Organizational Effects of Steroid Hormones: A Free Downloadable Module

ERIC Educational Resources Information Center

Grisham, William; Schottler, Natalie A.; Beck McCauley, Lisa M.; Pham, Anh P.; Ruiz, Maureen L.; Fong, Michelle C.; Cui, Xinran

2011-01-01

Zebra finch song behavior is sexually dimorphic: males sing and females do not. The neural system underlying this behavior is sexually dimorphic, and this sex difference is easy to quantify. During development, the zebra finch song system can be altered by steroid hormones, specifically estradiol, which actually masculinizes it. Because of the…

Etiological heterogeneity in the development of antisocial behavior: the Virginia Twin Study of Adolescent Behavioral Development and the Young Adult Follow-Up.

PubMed

Silberg, Judy L; Rutter, Michael; Tracy, Kelly; Maes, Hermine H; Eaves, Lindon

2007-08-01

Longitudinal, genetically informed, prospective data collected on a large population of male twins (n=1037) were used to examine developmental differences in the etiology of antisocial behavior. Analyses were carried out on both mother- and child-reported symptoms of conduct disorder (CD) in 10- to 17-year-old twins from the Virginia Twin Study of Adolescent Behavioral Development (VTSABD) and self-reported antisocial behavior by the twins as young adults from the Young Adult Follow-Up (YAFU) study. The following trends were identified: (1) a single genetic factor influencing antisocial behavior beginning at age 10 through young adulthood ('life-course persistent'); (2) a shared-environmental effect beginning in adolescence ('adolescent-onset'); (3) a transient genetic effect at puberty; and (4) a genetic influence specific to adult antisocial behavior. Overall, these etiological findings are consistent with predictions from Moffitt's developmental theory of antisocial behavior. The genetic effect at puberty at ages 12-15 is also consistent with a genetically mediated influence on the timing of puberty affecting the expression of genetic differences in antisocial outcomes.

The aryl hydrocarbon receptor is indispensable for dioxin-induced defects in sexually-dimorphic behaviors due to the reduction in fetal steroidogenesis of the pituitary-gonadal axis in rats.

PubMed

Hattori, Yukiko; Takeda, Tomoki; Nakamura, Arisa; Nishida, Kyoko; Shioji, Yuko; Fukumitsu, Haruki; Yamada, Hideyuki; Ishii, Yuji

2018-05-16

Many forms of the toxic effects produced by dioxins and related chemicals take place following activation of the aryl hydrocarbon receptor (AHR). Our previous studies have demonstrated that treating pregnant rats with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a highly toxic dioxin, attenuates the pituitary expression of gonadotropins to reduce testicular steroidogenesis during the fetal stage, resulting in the impairment of sexually-dimorphic behaviors after the offspring reach maturity. To investigate the contribution of AHR to these disorders, we examined the effects of TCDD on AHR-knockout (AHR-KO) Wistar rats. When pregnant AHR-heterozygous rats were given an oral dose of 1 µg/kg TCDD at gestational day (GD) 15, TCDD reduced the expression of pituitary gonadotropins and testicular steroidogenic proteins in male wild-type fetuses at GD20 without affecting body weight, sex ratio and litter size. However, the same defect did not occur in AHR-KO fetuses. Further, fetal exposure to TCDD impaired the activity of masculine sexual behavior after reaching adulthood only in the wild-type offspring. Also, in female offspring, not only the fetal gonadotropins production but also sexual dimorphism, such as saccharin preference, after growing up were suppressed by TCDD only in the wild-type. Interestingly, in the absence of TCDD, deleting AHR reduced masculine sexual behavior, as well as fetal steroidogenesis of the pituitary-gonadal axis. These results provide novel evidence that 1) AHR is required for TCDD-produced defects in sexually-dimorphic behaviors of the offspring, and 2) AHR signaling plays a role in gonadotropin synthesis during the developmental stage to acquire sexual dimorphism after reaching adulthood. Copyright © 2018 Elsevier Inc. All rights reserved.

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.

Characterizing mandibular growth using three-dimensional imaging techniques and anatomic landmarks

PubMed Central

Kelly, Michael P.; Vorperian, Houri K.; Wang, Yuan; Tillman, Katelyn K.; Werner, Helen M.; Chung, Moo K.; Gentry, Lindell R.

2017-01-01

Objective To provide quantitative data on the multi-planar growth of the mandible, this study derived accurate linear and angular mandible measurements using landmarks on three dimensional (3D) mandible models. This novel method was used to quantify 3D mandibular growth and characterize the emergence of sexual dimorphism. Design Cross-sectional and longitudinal imaging data were obtained from a retrospective computed tomography (CT) database for 51 typically developing individuals between the ages of one and nineteen years. The software Analyze was used to generate 104 3DCT mandible models. Eleven landmarks placed on the models defined six linear measurements (lateral condyle, gonion, and endomolare width, ramus and mental depth, and mandible length) and three angular measurements (gonion, gnathion, and lingual). A fourth degree polynomial fit quantified growth trends, its derivative quantified growth rates, and a composite growth model determined growth types (neural/cranial and somatic/skeletal). Sex differences were assessed in four age cohorts, each spanning five years, to determine the ontogenetic pattern producing sexual dimorphism of the adult mandible. Results Mandibular growth trends and growth rates were non-uniform. In general, structures in the horizontal plane displayed predominantly neural/cranial growth types, whereas structures in the vertical plane had somatic/skeletal growth types. Significant prepubertal sex differences in the inferior aspect of the mandible dissipated when growth in males began to outpace that of females at eight to ten years of age, but sexual dimorphism re-emerged during and after puberty. Conclusions This 3D analysis of mandibular growth provides preliminary normative developmental data for clinical assessment and craniofacial growth studies. PMID:28161602

Delayed puberty, eroticism, and sense of smell: A psychological study of hypogonadotropinism, osmatic and anosmatic (Kallmann's syndrome).

PubMed

Bobrow, N A; Money, J; Lewis, V G

1971-12-01

In 13 male patients with a diagnosis of hypogonadotropic hypogonadism, associated in five cases with verified hyposmia (Kallmann's syndrome), social development and participation were delayed. The patients associated the lack of visible signs of male puberty with their delayed sociosexual maturation. However, the evidence of physical maturation after treatment did not have the ameliorative effect on their social behavior one would have liked to predict. Dating behavior was limited before and after treatment for all the patients, and sexual interest was low even for the three married ones. The experience of falling in love was notably absent in the relationships described. Two characteristic social reaction patterns were social introversion and hostile rejection of agemates. Intellectual functioning and the incidence of personality pathology were not diagnostically noteworthy. None of the patients had any problems with gender identity except for erotic apathy which extended to masturbation. There was an absence of homosexuality. Possibly hypogonadotropic patients have a primary defect of the hypothalamus, manifesting itself as a dysfunction of the behavioral concomitants of puberty as well as a failure of hormonal puberty.

Sexual Dimorphism and the Origins of Human Spinal Health.

PubMed

Gilsanz, Vicente; Wren, Tishya A L; Ponrartana, Skorn; Mora, Stefano; Rosen, Clifford J

2018-04-01

Recent observations indicate that the cross-sectional area (CSA) of vertebral bodies is on average 10% smaller in healthy newborn girls than in newborn boys, a striking difference that increases during infancy and puberty and is greatest by the time of sexual and skeletal maturity. The smaller CSA of female vertebrae is associated with greater spinal flexibility and could represent the human adaptation to fetal load in bipedal posture. Unfortunately, it also imparts a mechanical disadvantage that increases stress within the vertebrae for all physical activities. This review summarizes the potential endocrine, genetic, and environmental determinants of vertebral cross-sectional growth and current knowledge of the association between the small female vertebrae and greater risk for a broad array of spinal conditions across the lifespan.

Fruitless, doublesex and the genetics of social behavior in Drosophila melanogaster.

PubMed

Siwicki, Kathleen K; Kravitz, Edward A

2009-04-01

Two genes coding for transcription factors, fruitless and doublesex, have been suggested to play important roles in the regulation of sexually dimorphic patterns of social behavior in Drosophila melanogaster. The generalization that fruitless specified the development of the nervous system and doublesex specified non-neural tissues culminated with claims that fruitless was both necessary and sufficient to establish sex-specific patterns of behavior. Several recent articles refute this notion, however, demonstrating that at a minimum, both fruitless and doublesex are involved in establishing sexually dimorphic features of neural circuitry and behavior in fruit flies.

Influences on the onset and tempo of puberty in human beings and implications for adolescent psychological development.

PubMed

Lee, Yvonne; Styne, Dennis

2013-07-01

This article is part of a Special Issue "Puberty and Adolescence". Historical records reveal a secular trend toward earlier onset of puberty in both males and females, often attributed to improvements in nutrition and health status. The trend stabilized during the mid 20th century in many countries, but recent studies describe a recurrence of a decrease in age of pubertal onset. There appears to be an associated change in pubertal tempo in girls, such that girls who enter puberty earlier have a longer duration of puberty. Puberty is influenced by genetic factors but since these effects cannot change dramatically over the past century, environmental effects, including endocrine disrupting chemicals (EDCs), and perinatal conditions offer alternative etiologies. Observations that the secular trends in puberty in girls parallel the obesity epidemic provide another plausible explanation. Early puberty has implications for poor behavioral and psychosocial outcomes as well as health later in life. Irrespective of the underlying cause of the ongoing trend toward early puberty, experts in the field have debated whether these trends should lead clinicians to reconsider a lower age of normal puberty, or whether such a new definition will mask a pathologic etiology. Copyright © 2013 Elsevier Inc. All rights reserved.

The erosion of sexual dimorphism: challenges to religion and religious ethics.

PubMed

Gudorf, C E

2001-01-01

Late modernity has been witnessing the erosion of the dimorphic sexual paradigm that, in both strong and weak forms, has characterized human history as we know it. Recent discoveries in biology and the social sciences have combined with altered patterns in human sexual behavior to raise critical new questions about the inherited paradigm. Religions of the West whose sacred texts, mythologies, and codes of behavior assume that maleness and femaleness are exclusive and complementary types of sexuality-each of which determines sexual identity, reproductive role, social role, and the sex of one's partner-increasingly must grapple with both theoretical evidence for and experiential evidence of polymorphous human sexuality. Inherited categories of dimorphic sexuality not only are challenged but become less and less intelligible.

[Consequences of disturbed sex-hormone action in the central nervous system: behavioral, anatomical and functional changes].

PubMed

Kula, Krzysztof; Słowikowska-Hilczer, Jolanta

2003-01-01

Experimental studies revealed that transient action of sex steroids during perinatal period is crucial for the development of male sexual behavior and sexually dimorphic brain anatomy. Meanwhile, the lack of gonadal steroids in female foetus and estrogen effects at puberty determine female behavior together with female type of anatomical brain structures and of endocrine functions. In men psychic sex consists of gender identity (self-estimation), gender role (objective estimation of sex behavior). In addition, a sexual psycho-orientation (hetero-, bi- or homosexual) has been distinguished. Although it is believed that gender depends on the socio-environmental influences such as rearing, learning and individual choice, the biological factors are considered to be most important. This concept arises from recent study on patients with gender dysphoria syndrome (transsexualism). In intersexualism, in genetic men with disturbances of sexual differentiation of external genitalia because of the lack of testoterone production or action in peripheral tissues (male pseudohermaphroditism) or in genetic women with ambiguous genitalia because of the presence and action of androgens (female pseudohermaphroditism), a discordance between the formal sex (assigned after the birth) and the psychic gender may appear. In these individuals the legal sex established according to somatic and/or genetic sex at birth may be incompatible with their actual gender identity and role. The knowledge about gender identity is necessary at the decision of eventual (!) surgical correction of sex organs in patients with ambiguous genitalia. This decision should depend not on the expected, but on the actual gender identity of the individual patient. Meantime, early bilateral gonadectomy in patients with gonadal dysgenesis and male pseudohermaphroditism is an indication for life because of the highest risk of germ cell carcinoma.

Etiological heterogeneity in the development of antisocial behavior: the Virginia Twin Study of Adolescent Behavioral Development and the Young Adult Follow-Up

PubMed Central

SILBERG, JUDY L.; RUTTER, MICHAEL; TRACY, KELLY; MAES, HERMINE H.; EAVES, LINDON

2014-01-01

Background Longitudinal, genetically informed, prospective data collected on a large population of male twins (n = 1037) were used to examine developmental differences in the etiology of antisocial behavior. Method Analyses were carried out on both mother- and child-reported symptoms of conduct disorder (CD) in 10- to 17-year-old twins from the Virginia Twin Study of Adolescent Behavioral Development (VTSABD) and self-reported antisocial behavior by the twins as young adults from the Young Adult Follow-Up (YAFU) study. Results The following trends were identified: (1) a single genetic factor influencing antisocial behavior beginning at age 10 through young adulthood (‘life-course persistent’); (2) a shared-environmental effect beginning in adolescence (‘adolescent-onset’); (3) a transient genetic effect at puberty; and (4) a genetic influence specific to adult antisocial behavior. Conclusions Overall, these etiological findings are consistent with predictions from Moffitt’s developmental theory of antisocial behavior. The genetic effect at puberty at ages 12–15 is also consistent with a genetically mediated influence on the timing of puberty affecting the expression of genetic differences in antisocial outcomes. PMID:17376258

Puberty in the Girl Who is Retarded.

ERIC Educational Resources Information Center

Pattullo, Ann

Designed to help mothers of mentally retarded girls deal with the problems and concerns of puberty, the booklet provides information on physical and emotional changes, menstruation, masturbation, heterosexual behavior, contraception, protection against sexual aggression, the possibilities of marriage, and additional sources of information.…

Chronic social stress in puberty alters appetitive male sexual behavior and neural metabolic activity.

PubMed

Bastida, Christel C; Puga, Frank; Gonzalez-Lima, Francisco; Jennings, Kimberly J; Wommack, Joel C; Delville, Yvon

2014-07-01

Repeated social subjugation in early puberty lowers testosterone levels. We used hamsters to investigate the effects of social subjugation on male sexual behavior and metabolic activity within neural systems controlling social and motivational behaviors. Subjugated animals were exposed daily to aggressive adult males in early puberty for postnatal days 28 to 42, while control animals were placed in empty clean cages. On postnatal day 45, they were tested for male sexual behavior in the presence of receptive female. Alternatively, they were tested for mate choice after placement at the base of a Y-maze containing a sexually receptive female in one tip of the maze and an ovariectomized one on the other. Social subjugation did not affect the capacity to mate with receptive females. Although control animals were fast to approach females and preferred ovariectomized individuals, subjugated animals stayed away from them and showed no preference. Cytochrome oxidase activity was reduced within the preoptic area and ventral tegmental area in subjugated hamsters. In addition, the correlation of metabolic activity of these areas with the bed nucleus of the stria terminalis and anterior parietal cortex changed significantly from positive in controls to negative in subjugated animals. These data show that at mid-puberty, while male hamsters are capable of mating, their appetitive sexual behavior is not fully mature and this aspect of male sexual behavior is responsive to social subjugation. Furthermore, metabolic activity and coordination of activity in brain areas related to sexual behavior and motivation were altered by social subjugation. Copyright © 2014 Elsevier Inc. All rights reserved.

Chronic Social Stress in Puberty Alters Appetitive Male Sexual Behavior and Neural Metabolic Activity

PubMed Central

Bastida, Christel C.; Puga, Frank; Gonzalez-Lima, Francisco; Jennings, Kimberly J.; Wommack, Joel C.; Delville, Yvon

2014-01-01

Repeated social subjugation in early puberty lowers testosterone levels. We used hamsters to investigate the effects of social subjugation on male sexual behavior and metabolic activity within neural systems controlling social and motivational behaviors. Subjugated animals were exposed daily to aggressive adult males in early puberty for postnatal days 28 to 42, while control animals were placed in empty clean cages. On postnatal day 45, they were tested for male sexual behavior in the presence of receptive female. Alternatively, they were tested for mate choice after placement at the base of a Y-maze containing a sexually receptive female in one tip of the maze and an ovariectomized one on the other. Social subjugation did not affect the capacity to mate with receptive females. Although control animals were fast to approach females and preferred ovariectomized individuals, subjugated animals stayed away from them and showed no preference. Cytochrome oxidase activity was reduced within the preoptic area and ventral tegmental area in subjugated hamsters. In addition, the correlation of metabolic activity of these areas with the bed nucleus of the stria terminalis and anterior parietal cortex changed significantly from positive in controls to negative in subjugated animals. These data show that at mid-puberty, while male hamsters are capable of mating, their appetitive sexual behavior is not fully mature and this aspect of male sexual behavior is responsive to social subjugation. Furthermore, metabolic activity and coordination of activity in brain areas related to sexual behavior and motivation was altered by social subjugation. PMID:24852486

Is there sexual dimorphism of hyperserotonemia in autism spectrum disorder?

PubMed

Shuffrey, Lauren C; Guter, Stephen J; Delaney, Shannon; Jacob, Suma; Anderson, George M; Sutcliffe, James S; Cook, Edwin H; Veenstra-VanderWeele, Jeremy

2017-08-01

Approximately 30% of individuals with autism spectrum disorder (ASD) have elevated whole blood serotonin (5-HT) levels. Genetic linkage and association studies of ASD and of whole blood 5-HT levels as a quantitative trait have revealed sexual dimorphism. Few studies have examined the presence of a sex difference on hyperserotonemia within ASD. To assess whether the rate of hyperserotonemia is different in males than in females with ASD, we measured whole blood 5-HT levels in 292 children and adolescents with ASD, the largest sample in which this biomarker has been assessed. Based upon previous work suggesting that hyperserotonemia is more common prior to puberty, we focused our analysis on the 182 pre-pubertal children with ASD. 42% of pre-pubertal participants were within the hyperserotonemia range. In this population, we found that males were significantly more likely to manifest hyperserotonemia than females (P = 0.03). As expected, no significant difference was found in the post-pubertal population. Additional work will be needed to replicate this intriguing finding and to understand whether it could potentially explain differences in patterns of ASD risk between males and females. Autism Res 2017, 10: 1417-1423. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

The Onset of Puberty: Effects on the Psychophysiology of Defensive and Appetitive Motivation

PubMed Central

Quevedo, Karina; Benning, Stephen D; Gunnar, Megan R; Dahl, Ronald E

2010-01-01

We examined puberty-specific effects on affect-related behavior and on the psychophysiology of defensive and appetitive motivation while controlling for age. Adolescents (N=94, ages=12 and 13 years), viewed 75 pictures (IAPS: pleasant, neutral and aversive) while listening to auditory probes. Startle response and postauricular (PA) reflex were collected as measures of defensive and appetitive motivation respectively. Pubertal status and measures of anxiety/stress reaction and sensation/thrill seeking were obtained. Mid/late pubertal adolescents showed enhanced startle amplitude across all picture valences. A puberty by valence interaction revealed that mid/late pubertal adolescents showed appetitive potentiation of the PA, while pre/early pubertal adolescents showed no modulation of the PA reflex. Mid/late pubertal adolescents also scored significantly higher on measures of sensation/thrill seeking than did their pre/early pubertal peers and puberty moderated the association between psychophysiology and behavioral measures, suggesting that it plays a role in reorganizing defensive and appetitive motivational systems. PMID:19144221

The importance of puberty for adolescent development: conceptualization and measurement.

PubMed

Berenbaum, Sheri A; Beltz, Adriene M; Corley, Robin

2015-01-01

How and why are teenagers different from children and adults? A key question concerns the ways in which pubertal development shapes psychological changes in adolescence directly through changes to the brain and indirectly through the social environment. Empirical work linking pubertal development to adolescent psychological function draws from several different perspectives, often with varying approaches and a focus on different outcomes and mechanisms. The main themes concern effects of atypical pubertal timing on behavior problems during adolescence, effects of pubertal status (and associated hormones) on normative changes in behaviors that can facilitate or hinder development (especially risk-taking, social reorientation, and stress responsivity), and the role of puberty in triggering psychopathology in vulnerable individuals. There is also interest in understanding the ways in which changes in the brain reflect pubertal processes and underlie psychological development in adolescence. In this chapter, we consider the ways that puberty might affect adolescent psychological development, and why this is of importance to developmentalists. We describe the processes of pubertal development; summarize what is known about pubertal influences on adolescent development; consider the assumptions that underlie most work and the methodological issues that affect the interpretation of results; and propose research directions to help understand paths from puberty to behavior. Throughout, we emphasize the importance of pubertal change in all aspects of psychological development, and the ways in which puberty represents an opportunity to study the interplay of biological and social influences. © 2015 Elsevier Inc. All rights reserved.

Sex and sex steroids: impact on the kinetics of fatty acids underlying body shape.

PubMed

Santosa, Sylvia; Jensen, Michael D

2014-10-01

Adult humans have a remarkable sexual dimorphism in body shape. Men tend to store relatively more fat in the upper body whereas women store more fat in the lower body. We do not have a complete understanding of the mechanisms underlying these differences, but we know that people who preferentially store abdominal fat are at greater risk of metabolic disease. It is also known that the changes in sex steroid concentrations during puberty and again with advancing age are accompanied by changes in body fat distribution. The objective of this review is to describe what has been learned regarding the mechanisms underlying changes in regional body fat distribution that occur as a result of changes in sex hormones and to delineate effects of sex steroids in modulating body composition.

Sexual dimorphisms in avian and reptilian courtship: two systems that do not play by mammalian rules.

PubMed

Wade, J

1999-01-01

Sexual dimorphisms in the central nervous system exist in numerous vertebrate species, and in many cases these structural differences between males and females parallel differences in the display of reproductive behaviors. Often both the behavioral and anatomical differences are controlled by exposure to gonadal steroid hormones, either during ontogeny or in adulthood. This article reviews some of the evidence supporting the hypothesis that in mammals, testosterone or its metabolites regulate the structure and function of neural and muscle systems involved in the control of masculine sexual behaviors. It then describes data suggesting that the mechanisms regulating sexually dimorphic courtship systems in zebra finches and green anole lizards are not completely parallel to the mammalian systems. Finally, some directions for future study are suggested, with the hope that they will stimulate thought about the nature of comparisons made across vertebrate models when investigators are attempting to determine both which morphological sex differences are important to the control of the reproductive behaviors, and which mechanisms regulating both structure and function are widely employed or are unique.

Exposure to methylphenidate during peri-adolescence affects endocrine functioning and sexual behavior in female Long-Evans rats.

PubMed

Guarraci, Fay A; Holifield, Caroline; Morales-Valenzuela, Jessica; Greene, Kasera; Brown, Jeanette; Lopez, Rebecca; Crandall, Christina; Gibbs, Nicole; Vela, Rebekah; Delgado, Melissa Y; Frohardt, Russell J

2016-03-01

The present study was designed to test the effects of methylphenidate (MPH) exposure on the maturation of endocrine functioning and sexual behavior. Female rat pups received either MPH (2.0mg/kg, i.p.) or saline twice daily between postnatal days 20-35. This period of exposure represents the time just prior to puberty as well as puberty onset. Approximately five weeks after the last injection of MPH or saline, female subjects were hormone-primed and tested during their first sexual experience. Subjects were given the choice to interact with a sexually active male or a sexually receptive female rat (i.e., the partner-preference test). The partner-preference paradigm allows us to assess multiple aspects of female sexual behavior. MPH exposure during peri-adolescence delayed puberty and, when mated for the first time, affected sexual behavior (e.g., increased time spent with the male stimulus and decreased the likelihood of leaving after mounts) during the test of partner preference. When monitoring estrous cyclicity, female subjects treated with MPH during peri-adolescence frequently experienced irregular estrous cycles. The results of the present study suggest that chronic exposure to a therapeutic dose of MPH around the onset of puberty alters long-term endocrine functioning, but with hormone priming, increases sensitivity to sexual stimuli. Copyright © 2015 Elsevier Inc. All rights reserved.

Sexual dimorphism in relation to big-game hunting and economy in modern human populations.

PubMed

Collier, S

1993-08-01

Postcranial skeletal data from two recent Eskimo populations are used to test David Frayer's model of sexual dimorphism reduction in Europe between the Upper Paleolithic and Mesolithic. Frayer argued that a change from big-game hunting and adoption of new technology in the Mesolithic reduced selection for large body size in males and led to a reduction in skeletal sexual dimorphism. Though aspects of Frayer's work have been criticized in the literature, the association of big-game hunting and high sexual dimorphism is untested. This study employs univariate and multivariate analysis to test that association by examining sexual dimorphism of cranial and postcranial bones of two recent Alaskan Eskimo populations, one being big-game (whale and other large marine mammal) hunting people, and the second being salmon fishing, riverine people. While big-game hunting influences skeletal robusticity, it cannot be said to lead to greater sexual dimorphism generally. The two populations had different relative sexual dimorphism levels for different parts of the body. Notably, the big-game hunting (whaling) Eskimos had the lower multivariate dimorphism in the humerus, which could be expected to be the structure under greatest exertion by such hunting in males. While the exertions of the whale hunting economic activities led to high skeletal robusticity, as predicted by Frayer's model, this was true of the females as well as the males, resulting in low sexual dimorphism in some features. Females are half the sexual dimorphism equation, and they cannot be seen as constants in any model of economic behavior.

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.

From Lucy to Kadanuumuu: balanced analyses of Australopithecus afarensis assemblages confirm only moderate skeletal dimorphism.

PubMed

Reno, Philip L; Lovejoy, C Owen

2015-01-01

Sexual dimorphism in body size is often used as a correlate of social and reproductive behavior in Australopithecus afarensis. In addition to a number of isolated specimens, the sample for this species includes two small associated skeletons (A.L. 288-1 or "Lucy" and A.L. 128/129) and a geologically contemporaneous death assemblage of several larger individuals (A.L. 333). These have driven both perceptions and quantitative analyses concluding that Au. afarensis was markedly dimorphic. The Template Method enables simultaneous evaluation of multiple skeletal sites, thereby greatly expanding sample size, and reveals that A. afarensis dimorphism was similar to that of modern humans. A new very large partial skeleton (KSD-VP-1/1 or "Kadanuumuu") can now also be used, like Lucy, as a template specimen. In addition, the recently developed Geometric Mean Method has been used to argue that Au. afarensis was equally or even more dimorphic than gorillas. However, in its previous application Lucy and A.L. 128/129 accounted for 10 of 11 estimates of female size. Here we directly compare the two methods and demonstrate that including multiple measurements from the same partial skeleton that falls at the margin of the species size range dramatically inflates dimorphism estimates. Prevention of the dominance of a single specimen's contribution to calculations of multiple dimorphism estimates confirms that Au. afarensis was only moderately dimorphic.

From Lucy to Kadanuumuu: balanced analyses of Australopithecus afarensis assemblages confirm only moderate skeletal dimorphism

PubMed Central

Lovejoy, C. Owen

2015-01-01

Sexual dimorphism in body size is often used as a correlate of social and reproductive behavior in Australopithecus afarensis. In addition to a number of isolated specimens, the sample for this species includes two small associated skeletons (A.L. 288-1 or “Lucy” and A.L. 128/129) and a geologically contemporaneous death assemblage of several larger individuals (A.L. 333). These have driven both perceptions and quantitative analyses concluding that Au. afarensis was markedly dimorphic. The Template Method enables simultaneous evaluation of multiple skeletal sites, thereby greatly expanding sample size, and reveals that A. afarensis dimorphism was similar to that of modern humans. A new very large partial skeleton (KSD-VP-1/1 or “Kadanuumuu”) can now also be used, like Lucy, as a template specimen. In addition, the recently developed Geometric Mean Method has been used to argue that Au. afarensis was equally or even more dimorphic than gorillas. However, in its previous application Lucy and A.L. 128/129 accounted for 10 of 11 estimates of female size. Here we directly compare the two methods and demonstrate that including multiple measurements from the same partial skeleton that falls at the margin of the species size range dramatically inflates dimorphism estimates. Prevention of the dominance of a single specimen’s contribution to calculations of multiple dimorphism estimates confirms that Au. afarensis was only moderately dimorphic. PMID:25945314

Sexual Conspecific Aggressive Response (SCAR): A Model of Sexual Trauma that Disrupts Maternal Learning and Plasticity in the Female Brain.

PubMed

Shors, Tracey J; Tobόn, Krishna; DiFeo, Gina; Durham, Demetrius M; Chang, Han Yan M

2016-01-25

Sexual aggression can disrupt processes related to learning as females emerge from puberty into young adulthood. To model these experiences in laboratory studies, we developed SCAR, which stands for Sexual Conspecific Aggressive Response. During puberty, a rodent female is paired daily for 30-min with a sexually-experienced adult male. During the SCAR experience, the male tracks the anogenital region of the female as she escapes from pins. Concentrations of the stress hormone corticosterone were significantly elevated during and after the experience. Moreover, females that were exposed to the adult male throughout puberty did not perform well during training with an associative learning task nor did they learn well to express maternal behaviors during maternal sensitization. Most females that were exposed to the adult male did not learn to care for offspring over the course of 17 days. Finally, females that did not express maternal behaviors retained fewer newly-generated cells in their hippocampus whereas those that did express maternal behaviors retained more cells, most of which would differentiate into neurons within weeks. Together these data support SCAR as a useful laboratory model for studying the potential consequences of sexual aggression and trauma for the female brain during puberty and young adulthood.

Fluoxetine disrupts motivation and GABAergic signaling in adolescent female hamsters.

PubMed

Shannonhouse, John L; DuBois, Dustin W; Fincher, Annette S; Vela, Alejandra M; Henry, Morgan M; Wellman, Paul J; Frye, Gerald D; Morgan, Caurnel

2016-08-01

Initial antidepressant treatment can paradoxically worsen symptoms in depressed adolescents by undetermined mechanisms. Interestingly, antidepressants modulate GABAA receptors, which mediate paradoxical effects of other therapeutic drugs, particularly in females. Although the neuroanatomic site of action for this paradox is unknown, elevated GABAA receptor signaling in the nucleus accumbens can disrupt motivation. We assessed fluoxetine's effects on motivated behaviors in pubescent female hamsters - anhedonia in the reward investigational preference (RIP) test as well as anxiety in the anxiety-related feeding/exploration conflict (AFEC) test. We also assessed accumbal signaling by RT-PCR and electrophysiology. Fluoxetine initially worsened motivated behaviors at puberty, relative to adulthood. It also failed to improve these behaviors as pubescent hamsters transitioned into adulthood. Low accumbal mRNA levels of multiple GABAA receptor subunits and GABA-synthesizing enzyme, GAD67, assessed by RT-PCR, suggested low GABAergic tone at puberty. Nonetheless, rapid fluoxetine-induced reductions of α5GABAA receptor and BDNF mRNA levels at puberty were consistent with age-related differences in GABAergic responses to fluoxetine and disruption of the motivational state. Whole-cell patch clamping of accumbal slices also suggested low GABAergic tone by the low amplitude of miniature inhibitory postsynaptic currents (mIPSCs) at puberty. It also confirmed age-related differences in GABAergic responses to fluoxetine. Specifically, fluoxetine potentiated mIPSC amplitude and frequency at puberty, but attenuated the amplitude during adulthood. These results implicate GABAergic tone and GABAA receptor plasticity in adverse motivational responses and resistance to fluoxetine during adolescence. Copyright © 2016 Elsevier Inc. All rights reserved.

"I Saw All That": A Lakota Girl's Puberty Ceremony.

ERIC Educational Resources Information Center

Bol, Marsha C.; Menard, Nellie Z. Star Boy

2000-01-01

Draws on the memoirs of Nellie Menard, Lakota archives, and other published materials to describe the traditional puberty ceremonies held for Lakota girls. Discusses the practice of seclusion, during which an elderly woman instructed the girl in appropriate behavior and women's crafts; the initiate's new social status; the ball-throwing ceremony;…

Sexual trajectories of abused and neglected youths.

PubMed

Brown, Jocelyn; Cohen, Patricia; Chen, Henian; Smailes, Elizabeth; Johnson, Jeffrey G

2004-04-01

The study objective was to examine whether childhood abuse or neglect is associated with the age of onset of puberty and sexual and romantic behavior. A cohort of children (the Children in the Community study) was randomly selected and studied prospectively from childhood to adulthood. A sample of 816 youths were interviewed in their homes at a mean age of 14, 16, and 22 years in 1983, from 1985 to 1986, and from 1991 to 1994. The outcome measures included age of menarche, signs of male puberty, first being in love, dating, sexual intercourse, and pregnancy reported by youths. Child abuse and neglect were measured by official records and youth reports. A history of two or more incidents of sexual abuse was significantly associated with early puberty and early pregnancy after gender, class, race, paternal absence, and mother's age at the birth of the study child were controlled statistically. Public education regarding risk for premature sexual behavior among youths who have experienced sexual abuse is warranted. Efforts to prevent teenage pregnancy should include monitoring and educating sexually abused children as they enter puberty.

Size-assortative mating and sexual size dimorphism are predictable from simple mechanics of mate-grasping behavior

PubMed Central

2010-01-01

Background A major challenge in evolutionary biology is to understand the typically complex interactions between diverse counter-balancing factors of Darwinian selection for size assortative mating and sexual size dimorphism. It appears that rarely a simple mechanism could provide a major explanation of these phenomena. Mechanics of behaviors can predict animal morphology, such like adaptations to locomotion in animals from various of taxa, but its potential to predict size-assortative mating and its evolutionary consequences has been less explored. Mate-grasping by males, using specialized adaptive morphologies of their forelegs, midlegs or even antennae wrapped around female body at specific locations, is a general mating strategy of many animals, but the contribution of the mechanics of this wide-spread behavior to the evolution of mating behavior and sexual size dimorphism has been largely ignored. Results Here, we explore the consequences of a simple, and previously ignored, fact that in a grasping posture the position of the male's grasping appendages relative to the female's body is often a function of body size difference between the sexes. Using an approach taken from robot mechanics we model coercive grasping of females by water strider Gerris gracilicornis males during mating initiation struggles. We determine that the male optimal size (relative to the female size), which gives the males the highest grasping force, properly predicts the experimentally measured highest mating success. Through field sampling and simulation modeling of a natural population we determine that the simple mechanical model, which ignores most of the other hypothetical counter-balancing selection pressures on body size, is sufficient to account for size-assortative mating pattern as well as species-specific sexual dimorphism in body size of G. gracilicornis. Conclusion The results indicate how a simple and previously overlooked physical mechanism common in many taxa is sufficient to account for, or importantly contribute to, size-assortative mating and its consequences for the evolution of sexual size dimorphism. PMID:21092131

Examination of the genetic basis for sexual dimorphism in the Aedes aegypti (dengue vector mosquito) pupal brain

PubMed Central

2014-01-01

Background Most animal species exhibit sexually dimorphic behaviors, many of which are linked to reproduction. A number of these behaviors, including blood feeding in female mosquitoes, contribute to the global spread of vector-borne illnesses. However, knowledge concerning the genetic basis of sexually dimorphic traits is limited in any organism, including mosquitoes, especially with respect to differences in the developing nervous system. Methods Custom microarrays were used to examine global differences in female vs. male gene expression in the developing pupal head of the dengue vector mosquito, Aedes aegypti. The spatial expression patterns of a subset of differentially expressed transcripts were examined in the developing female vs. male pupal brain through in situ hybridization experiments. Small interfering RNA (siRNA)-mediated knockdown studies were used to assess the putative role of Doublesex, a terminal component of the sex determination pathway, in the regulation of sex-specific gene expression observed in the developing pupal brain. Results Transcripts (2,527), many of which were linked to proteolysis, the proteasome, metabolism, catabolic, and biosynthetic processes, ion transport, cell growth, and proliferation, were found to be differentially expressed in A. aegypti female vs. male pupal heads. Analysis of the spatial expression patterns for a subset of dimorphically expressed genes in the pupal brain validated the data set and also facilitated the identification of brain regions with dimorphic gene expression. In many cases, dimorphic gene expression localized to the optic lobe. Sex-specific differences in gene expression were also detected in the antennal lobe and mushroom body. siRNA-mediated gene targeting experiments demonstrated that Doublesex, a transcription factor with consensus binding sites located adjacent to many dimorphically expressed transcripts that function in neural development, is required for regulation of sex-specific gene expression in the developing A. aegypti brain. Conclusions These studies revealed sex-specific gene expression profiles in the developing A. aegypti pupal head and identified Doublesex as a key regulator of sexually dimorphic gene expression during mosquito neural development. PMID:25729562

Puberty and the Manifestations of Loss of Control Eating in Children and Adolescents

PubMed Central

Vannucci, Anna; Tanofsky-Kraff, Marian; Ranzenhofer, Lisa M.; Kelly, Nichole R.; Hannallah, Louise M.; Pickworth, C. Katherine; Grygorenko, Mariya V.; Brady, Sheila M.; Condarco, Tania A.; Kozlosky, Merel; Demidowich, Andrew P.; Yanovski, Susan Z.; Shomaker, Lauren B.; Yanovski, Jack A.

2014-01-01

Objective We investigated the manifestations of pediatric loss of control (LOC) eating at different stages of pubertal development. Methods Participants were a non-clinical sample of 468 youth (8–17y). Physical examination determined pubertal stage. LOC eating and disordered eating attitudes were assessed with the Eating Disorder Examination. In a randomized crossover design, a subset (n=244) ate ad libitum from two test meals designed to capture normal and LOC eating. Results There were no differences in the prevalence rates or frequency of reported LOC eating episodes across pubertal stages (ps≥.50). There were, however, puberty by LOC eating interactions in disordered eating attitudes and palatable food consumption (ps≤.05), even after adjusting for age and body composition. LOC eating was associated with elevated global disordered eating attitudes, weight concern, and shape concern in post-pubertal youth (ps≤.001), but not pre-pubertal youth (ps≥.49). In late-puberty, youth with LOC eating consumed less energy from protein (p<.001) and more from carbohydrate (p=.003) and snack-type foods (p=.02) than those without LOC eating, whereas endorsement of LOC eating in pre- or early-to-mid-puberty was not associated with differences in eating behavior (ps≥.20). Conclusions Findings suggest that puberty may be a critical risk period, when LOC eating behaviors in boys and girls may become accompanied by greater weight and shape concerns and more obesogenic food consumption patterns. Interventions for LOC eating during pre-puberty should be evaluated to determine if they are particularly beneficial for the prevention of exacerbated eating disorder psychopathology and adverse weight outcomes. PMID:24888295

Sex differences in play behavior in juvenile tufted capuchin monkeys (Cebus apella).

PubMed

Paukner, Annika; Suomi, Stephen J

2008-10-01

According to the motor training hypothesis, play behavior in juvenile primates improves motor skills that are required in later adult life. Sex differences in juvenile play behavior can therefore be expected when adult animals assume distinct sexually dimorphic roles. Tufted capuchin monkeys show sexually dimorphic levels of physical antagonism in both inter- and intra-group encounters. Accordingly, it can be predicted that juvenile capuchins also show sex differences in social play behavior. To test this hypothesis, the play behavior of nine juvenile and two infant capuchins was examined. As predicted, juvenile males showed significantly higher levels of social play (wrestle, chase) than juvenile females, but no differences were found in nonsocial play (arboreal, object). Levels of infant play behavior were comparable to that of juveniles. These results lend support to the motor training hypothesis and highlight the need for more detailed investigations of individual differences in play behavior.

Early Puberty in African-American Girls: Nutrition Past and Present.

ERIC Educational Resources Information Center

Talpade, Medha; Talpade, Salil

2001-01-01

Early sexual maturation is associated with many high-risk behaviors and a prediction was made that food consumption may contribute to early onset of puberty. A comparison was made between the eating habits of several generations of African-American women. Girls today were found to consume more calcium, grains, and meat then older women did in…

Developmental Toxic Effects of Exposure to Chemical Warfare Nerve Agents in Rats: Effects on Brain and Behavior

DTIC Science & Technology

2015-03-01

Analysis of seizure activity and dendritic spine density following exposure to sarin during puberty Methods Female rats were surgically implanted...effects were observed in rats exposed to GB on PND 7 or 21. This study shows that nerve agent exposure during puberty results in severe and life

The Impact of Puberty and Sexual Activity upon the Health and Education of Adolescent Girls and Boys.

ERIC Educational Resources Information Center

Brooks-Gunn, J.

1987-01-01

Sex equity issues which are emphasized in this article include: (a) how boys and girls negotiate reproductive transitions; (b) how male and female sexual maturity is treated differently by parents, educators, and society; and (c) how the consequences of puberty and sexual behavior may differ for boys and girls. (IAH)

Timing of amphetamine exposure in relation to puberty onset determines its effects on anhedonia, exploratory behavior, and dopamine D1 receptor expression in young adulthood.

PubMed

Kang, Shuo; Wu, Mariah M; Galvez, Roberto; Gulley, Joshua M

2016-12-17

Non-medical use of amphetamine (AMPH) among adolescents is prevalent, which is problematic given the potential consequences of developmental drug exposure on brain function and behavior. Previously we found in adult male rats that AMPH exposure starting before puberty induces a persistent decrease in dopamine D 1 receptor (D 1 R) function in the medial prefrontal cortex (mPFC). Here we investigated if this dysfunction was associated with changes in D 1 R expression in the mPFC and nucleus accumbens (NAc). We also determined if starting drug exposure well before or near the onset of puberty would influence AMPH-induced changes in D 1 R expression and behavior. Male and female Sprague-Dawley rats were treated once every other day (10 injections total) with saline or 3mg/kg AMPH (i.p.) from either postnatal day (P) 27 to 45 (pre-puberty groups; Pre-P) or P37 to 55 (peri-puberty groups; Peri-P). After 1, 7 and 21days of withdrawal, sucrose preference tests were performed to assess anhedonia. Exploratory behavior was studied in an open-field arena and on an elevated plus maze (EPM). Rats were then sacrificed for Western blot analysis of D 1 R expression. We found that AMPH withdrawal induced decreases in sucrose preference that persisted in rats with Peri-P onset treatment. Pre-P onset AMPH exposure led to increased open-arm exploration in the EPM test, as well as a decreased D 1 R level in the mPFC but not NAc. Our results demonstrated that AMPH exposure starting at different developmental stages resulted in distinct neurobehavioral abnormalities, suggesting an important role of exposure timing in drug-induced plasticity. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Mental health problems of Iranian female adolescents and its association with pubertal development: a nationwide study.

PubMed

Rabbani, Ali; Mahmoudi-Gharaei, Javad; Mohammadi, Mohammad Reza; Motlagh, Mohammad Esmaeil; Mohammad, Kazem; Ardalan, Gelayol; Maftoon, Farzaneh; Shahryari, Safiyeh; Khodaei, Shahnaz; Sotoudeh, Aria; Ziaaldini, Hassan; Kamali, Kobra; Motaghian, Molouk

2012-01-01

Mental health problems including emotional and behavioral problems during puberty may be under influence of different risk factors including cultures, living in urban or rural areas and ethnic factors which may vary between different countries. The main aim of this study is to investigate the profile of emotional and behavioral problems and the role of factors such as age, stage of puberty, ethnicity, rurality and living in urban area, as risk factors in Iranian girls. As a part of a large national study we evaluated the emotional and behavioral problems in different stages of puberty in a community sample of Iranian adolescent girls from public schools that were selected by clustered random sampling method. In all subjects, demographic characteristics, and pubertal stages were measured. Emotional and behavioral problems were evaluated using Strength and Difficulties Questionnaire (SDQ). The associations of age, pubertal development indices, socioeconomic and demographic factors with the behavioral problems were assessed. A total number of 4576 students enrolled the study and responded to the questions. The mean age of participants was 13.83 ± 2.19 years. The mean total score of difficulties in participants was 14.34 ± 5.81. According to these results 813 (17.8%) adolescents had total problem scores higher than Goodman's cutoff points and the most frequent problem domain was conduct problems (20.5%). According to the results the most related variable with the total difficulty score of SDQ were ethnicity, residency in urban areas and development of menstrual cycle respectively. The results of this study showed that the most correlated factors with mental health problems in Iranian girls during puberty are ethnicity, urbanity and development of menstrual cycle.

Perinatal testosterone contributes to mid-to-post pubertal sex differences in risk for binge eating in male and female rats.

PubMed

Culbert, Kristen M; Sinclair, Elaine B; Hildebrandt, Britny A; Klump, Kelly L; Sisk, Cheryl L

2018-02-01

Exposure to testosterone early in life may contribute to sex differences and pubertal changes in risk for eating pathology (i.e., females > males, after pubertal onset). Specifically, perinatal testosterone permanently alters brain structure/function and drives the masculinization of several sex-differentiated behaviors. However, the effects of perinatal testosterone are often not evident until puberty when increases in gonadal hormones activate the expression of sex typical behavior, including eating behaviors (e.g., chow intake; saccharin preference) in rodents. Despite perinatal testosterone's masculinizing effects on general feeding behavior, it remains unknown if perinatal testosterone exposure contributes to sex differences in pathological eating. The current study addressed this gap by examining whether perinatal testosterone exposure decreases risk for binge eating proneness after pubertal onset in male and female rats. Sprague-Dawley rats (n = 40 oil-treated control females; n = 39 testosterone-treated females; n = 40 oil-treated control males) were followed longitudinally across pre-to-early puberty, mid-to-late puberty, and adulthood. The binge eating prone (BEP)/binge eating resistant (BER) rodent model was used to identify individual differences in binge eating proneness across the dimensional spectrum. As expected, testosterone-treated females and control males showed masculinized (i.e., lower) risk for binge eating as compared to control females, but only after midpuberty. These animal data are significant in suggesting that perinatal testosterone exposure may protect against binge eating and underlie sex differences in binge eating prevalence during and after puberty. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Puberty and the manifestations of loss of control eating in children and adolescents.

PubMed

Vannucci, Anna; Tanofsky-Kraff, Marian; Ranzenhofer, Lisa M; Kelly, Nichole R; Hannallah, Louise M; Pickworth, C Katie; Grygorenko, Mariya V; Brady, Sheila M; Condarco, Tania A; Kozlosky, Merel; Demidowich, Andrew P; Yanovski, Susan Z; Shomaker, Lauren B; Yanovski, Jack A

2014-11-01

We investigated the manifestations of pediatric loss of control (LOC) eating at different stages of pubertal development. Participants were a nonclinical sample of 468 youth (8-17 years). Physical examination determined pubertal stage. LOC eating and disordered eating attitudes were assessed with the Eating Disorder Examination. In a randomized crossover design, a subset (n = 244) ate ad libitum from two test meals designed to capture normal and LOC eating. There were no differences in the prevalence rates or frequency of reported LOC eating episodes across pubertal stages (ps ≥ 0.50). There were, however, puberty by LOC eating interactions in disordered eating attitudes and palatable food consumption (ps ≤ .05), even after adjusting for age and body composition. LOC eating was associated with elevated global disordered eating attitudes, weight concern, and shape concern in post-pubertal youth (ps ≤ .001), but not pre-pubertal youth (ps ≥ .49). In late-puberty, youth with LOC eating consumed less energy from protein (p < .001) and more from carbohydrate (p = .003) and snack-type foods (p = .02) than those without LOC eating, whereas endorsement of LOC eating in pre- or early-to-mid-puberty was not associated with differences in eating behavior (ps ≥ 0.20). Findings suggest that puberty may be a critical risk period, when LOC eating behaviors in boys and girls may become accompanied by greater weight and shape concerns and more obesogenic food consumption patterns. Interventions for LOC eating during pre-puberty should be evaluated to determine if they are particularly beneficial for the prevention of exacerbated eating disorder psychopathology and adverse weight outcomes. © 2014 Wiley Periodicals, Inc.

Sexual dimorphism of sleep regulated by juvenile hormone signaling in Drosophila

PubMed Central

Zhang, Enyan; Du, Juan; Liu, Suning; Price, Jeffrey

2018-01-01

Sexually dimorphic phenotypes are a universal phenomenon in animals. In the model animal fruit fly Drosophila, males and females exhibit long- and short-sleep phenotypes, respectively. However, the mechanism is still a mystery. In this study, we showed that juvenile hormone (JH) is involved in regulation of sexually dimorphic sleep in Drosophila, in which gain of JH function enlarges differences of the dimorphic sleep phenotype with higher sleep in males and lower sleep in females, while loss of JH function blurs these differences and results in feminization of male sleep and masculinization of female sleep. Further studies indicate that germ cell-expressed (GCE), one of the JH receptors, mediates the response in the JH pathway because the sexually dimorphic sleep phenotypes cannot be rescued by JH hormone in a gce deletion mutant. The JH-GCE regulated sleep dimorphism is generated through the sex differentiation-related genes -fruitless (fru) and doublesex (dsx) in males and sex-lethal (sxl), transformer (tra) and doublesex (dsx) in females. These are the “switch” genes that separately control the sleep pattern in males and females. Moreover, analysis of sleep deprivation and circadian behaviors showed that the sexually dimorphic sleep induced by JH signals is a change of sleep drive and independent of the circadian clock. Furthermore, we found that JH seems to also play an unanticipated role in antagonism of an aging-induced sleep decrease in male flies. Taken together, these results indicate that the JH signal pathway is critical for maintenance of sexually dimorphic sleep by regulating sex-relevant genes. PMID:29617359

Hormonally active agents in the environment and children's behavior: assessing effects on children's gender-dimorphic outcomes.

PubMed

Sandberg, David E; Vena, John E; Weiner, John; Beehler, Gregory P; Swanson, Mya; Meyer-Bahlburg, Heino F L

2003-03-01

Early sex hormone exposure contributes to gender-dimorphic behavioral development in mammals, including humans. Environmental toxicants concentrated in contaminated sport fish can interfere with the actions of sex steroids. This study developed an outcome variable by combining gender-dimorphic behaviors that differentiates boys and girls. Offspring of participants in the New York State Angler Cohort Study (NYSACS) were targeted in a parent-report postal survey. Instruments were selected based on findings of gender differences in the general population. A linear discriminant function model incorporating three gender behavior scales correctly classified the sex of 97.7% of children (252 boys and 234 girls) from a random NYSACS sample. The discriminant function was cross-validated by correctly classifying the sex of 98.4% of children (457 boys and 425 girls) from the remaining NYSACS cases and 97.6% of children (154 boys and 142 girls) from an independent school sample. Within-sex stepwise multiple regression analyses revealed that masculine behavior increased among boys with age and with the number of years of maternal sport fish consumption. In girls, older age and previous live-born siblings were associated with more masculine behavior, whereas feminine behavior increased with the duration of breast feeding. These associations were replicated in an independent sample. A linear discriminant function effectively transformed the binary classification of sex (male-female) to a bipolar continuum of gender (masculinity-femininity). Findings from this study are consistent with the hypothesis that environmental contaminants contribute to shifts in gender-role behavior. Future investigations will need to account for competing explanations of this effect.

Reward Sensitivity for a Palatable Food Reward Peaks During Pubertal Developmental in Rats

PubMed Central

Friemel, Chris M.; Spanagel, Rainer; Schneider, Miriam

2010-01-01

Puberty is a critical period for the initiation of drug use and abuse. Because early drug use onset often accounts for a more severe progression of addiction, it is of importance to understand the underlying mechanisms and neurodevelopmental changes during puberty that are contributing to enhanced reward processing in teenagers. The present study investigated the progression of reward sensitivity toward a natural food reward over the whole course of adolescence in male rats (postnatal days 30–90) by monitoring consummatory, motivational behavior and neurobiological correlates of reward. Using a limited-free intake paradigm, consumption of sweetened condensed milk (SCM) was measured repeatedly in adolescent and adult rats. Additionally, early- and mid-pubertal animals were tested in Progressive Ratio responding for SCM and c-fos protein expression in reward-associated brain structures was examined after odor conditioning for SCM. We found a transient increase in SCM consumption and motivational incentive for SCM during puberty. This increased reward sensitivity was most pronounced around mid-puberty. The behavioral findings are paralleled by enhanced c-fos staining in reward-related structures revealing an intensified neuronal response after reward-cue presentation, distinctive for pubertal animals. Taken together, these data indicate an increase in reward sensitivity during adolescence accompanied by enhanced responsiveness of reward-associated brain structures to incentive stimuli, and it seems that both is strongly pronounced around mid-puberty. Therefore, higher reward sensitivity during pubertal maturation might contribute to the enhanced vulnerability of teenagers for the initiation of experimental drug use. PMID:20700386

Prenatal lipopolysaccharide exposure affects sexual dimorphism in different germlines of mice with a depressive phenotype.

PubMed

Reis-Silva, Thiago M; Cohn, Daniel W H; Sandini, Thaísa M; Udo, Mariana S B; Teodorov, Elizabeth; Bernardi, Maria Martha

2016-03-15

The objective of the present study was to investigate whether prenatal lipopolysaccharide (LPS) administration modifies the expression of depressive and non-depressive-like behavior in male and female mice across two generations. The sexual dimorphism of these mice was also examined in the open-field test. Male and female mice of the parental (F0) generation were selected for depressive- or non-depressive-like behavioral profiles using the tail suspension test (TST). Animals with similar profiles were matched for further mating. On gestation day (GD) 15, pregnant F0 mice received LPS (100μg/kg, i.p.) and were allowed to nurture their offspring freely. Adult male and female of the F1 generation were then selected according to behavioral profiles and observed in the open field. Male and female mice of the two behavioral profiles were then mated to obtain the F2 generation. Adults from the F2 generation were also behaviorally phenotyped, and open field behavior was assessed. Male mice that were selected for depressive- and non-depressive-like behaviors and treated or not with LPS in the parental generation exhibited similar proportions of behavioral profiles in both filial lines, but LPS exposure increased the number of depressive-like behavior. An effect of gender was observed in the F1 and F2 generations, in which male mice were more sensitive to the intergenerational effects of LPS in the TST. These data indicate that prenatal LPS exposure on GD15 in the F0 generation influenced the transmission of depressive- and non-depressive-like behavior across filial lines, with sexual dimorphism between phenotypes. Copyright © 2016 Elsevier Inc. All rights reserved.

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…

Endocrine disrupters: a review of some sources, effects, and mechanisms of actions on behaviour and neuroendocrine systems.

PubMed

Frye, C A; Bo, E; Calamandrei, G; Calzà, L; Dessì-Fulgheri, F; Fernández, M; Fusani, L; Kah, O; Kajta, M; Le Page, Y; Patisaul, H B; Venerosi, A; Wojtowicz, A K; Panzica, G C

2012-01-01

Some environmental contaminants interact with hormones and may exert adverse consequences as a result of their actions as endocrine disrupting chemicals (EDCs). Exposure in people is typically a result of contamination of the food chain, inhalation of contaminated house dust or occupational exposure. EDCs include pesticides and herbicides (such as dichlorodiphenyl trichloroethane or its metabolites), methoxychlor, biocides, heat stabilisers and chemical catalysts (such as tributyltin), plastic contaminants (e.g. bisphenol A), pharmaceuticals (i.e. diethylstilbestrol; 17α-ethinylestradiol) or dietary components (such as phytoestrogens). The goal of this review is to address the sources, effects and actions of EDCs, with an emphasis on topics discussed at the International Congress on Steroids and the Nervous System. EDCs may alter reproductively-relevant or nonreproductive, sexually-dimorphic behaviours. In addition, EDCs may have significant effects on neurodevelopmental processes, influencing the morphology of sexually-dimorphic cerebral circuits. Exposure to EDCs is more dangerous if it occurs during specific 'critical periods' of life, such as intrauterine, perinatal, juvenile or puberty periods, when organisms are more sensitive to hormonal disruption, compared to other periods. However, exposure to EDCs in adulthood can also alter physiology. Several EDCs are xenoestrogens, which can alter serum lipid concentrations or metabolism enzymes that are necessary for converting cholesterol to steroid hormones. This can ultimately alter the production of oestradiol and/or other steroids. Finally, many EDCs may have actions via (or independent of) classic actions at cognate steroid receptors. EDCs may have effects through numerous other substrates, such as the aryl hydrocarbon receptor, the peroxisome proliferator-activated receptor and the retinoid X receptor, signal transduction pathways, calcium influx and/or neurotransmitter receptors. Thus, EDCs, from varied sources, may have organisational effects during development and/or activational effects in adulthood that influence sexually-dimorphic, reproductively-relevant processes or other functions, by mimicking, antagonising or altering steroidal actions. © 2011 The Authors. Journal of Neuroendocrinology © 2011 Blackwell Publishing Ltd.

Relative growth, ontogeny, and sexual dimorphism in gorilla (Gorilla gorilla gorilla and G. g. beringei): evolutionary and ecological considerations.

PubMed

Taylor, A B

1997-01-01

Gorillas are the largest and among the most sexually dimorphic of all extant primates. While gorillas have been incorporated in broad-level comparisons among large-bodied hominoids or in studies of the African apes, comparisons between gorilla subspecies have been rare. During the past decade, however, behavioral, morphological, and molecular data from a number of studies have indicated that the western lowland (Gorilla gorilla gorilla) and eastern mountain (Gorilla gorilla beringei) subspecies differ to a greater extent than has been previously believed. In this study I compare patterns of relative growth of the postcranial skeleton to evaluate whether differences between subspecies result from the differential extension of common patterns of relative growth. In addition, patterns of ontogeny and sexual dimorphism are also examined. Linear skeletal dimensions and skeletal weight were obtained for ontogenetic series of male and female G.g. gorilla (n = 315) and G.g. beringei (n = 38). Bivariate and multivariate methods of analysis were used to test for differences in patterns of relative growth, ontogeny, and sexual dimorphism between sexes of each subspecies and in same-sex comparisons between subspecies. Results indicate males and females of both subspecies are ontogenetically scaled for postcranial proportions and that females undergo an earlier skeletal growth spurt compared to males. However, results also indicate that the onset of the female growth spurt occurs at different dental stages in lowland and mountain gorillas and that mountain gorillas may be characterized by higher rates of growth. Finally, data demonstrate lowland and mountain gorilla females do not differ significantly in adult body size, but mountain gorilla males are significantly larger than lowland gorilla males, suggesting mountain gorillas are characterized by a higher degree of sexual dimorphism in body size. Thus, although lowland and mountain gorillas do not appear to have evolved novel adaptations of the postcranium which correlate with differences in locomotor behavior, the present investigation establishes subspecies differences in ontogeny and sexual dimorphism which may be linked with ecological variation. Specifically, these findings are evaluated in the context of risk aversion models which predict higher growth rates and increased levels of sexual dimorphism in extreme folivores.

Pediatric sexology and hermaphroditism.

PubMed

Money, J

1985-01-01

Lacking an empirically based theory of erotosexual development and health in childhood, pediatrics too easily falls back on reductionistic hypotheses of the nature versus nurture type. A new, three-term paradigm, namely, nature/critical-period/nurture, is needed to explain, for example, the phenomenology of hermaphroditism, and the differentiation of gender-identity/role (G-I/R) in individual cases. In 30 young women with a history of the early-treated, 46,XX congenital virilizing adrenal hyperplasia (CVAH) syndrome, 37% (N = 11) had a history of bisexual imagery or practice, as compared with 7% in the control patients (chi 2 = 17.7; p less than .001); and 5 of these 11 rated themselves as exclusively or predominantly lesbian. In Kinsey's sample, 15% of females reported homoerotic imagery by age 20, and 2 out of 3 of them also had homoerotic partner contact. The CVAH finding may be a function of prenatal and/or neonatal brain androgenization, but other variables, such as the history of juvenile erotosexual rehearsal play, cannot be ruled out. Among adolescents with a history of hermaphroditism, sex-reassignment applications are honored predominantly if they are made by 46,XY hermaphrodites assigned neonatally as girls and with nonfeminizing hormonal puberty, as medical and folk traditions both favor approval of such applicants more than others. Parthenogenic whiptail lizards that alternately simulate the male and female mating behavior of related diecious species provide an animal model that demonstrates the existence of both male and female sexual schemas in the same brain. In human beings, the irreducible sex differences are that males impregnate, and females menstruate, gestate, and lactate. Otherwise, sexual dimorphism that is programmed into the brain under the influence of prenatal hormones appears to be not sex-irreducible, but sex-shared and threshold-dimorphic. A complete theory of the differentiation of all the constituents of masculinity or femininity of G-I/R needs to be both multivariate and sequential in type. It must be applicable to all of the syndromes of hermaphroditism, and to the genesis of all the G-I/R phenomena, including transvestism and transsexualism, as well as to the genesis of a heterosexual G-I/R.

Metric variation and sexual dimorphism in the dentition of Ouranopithecus macedoniensis.

PubMed

Schrein, Caitlin M

2006-04-01

The fossil sample attributed to the late Miocene hominoid taxon Ouranopithecus macedoniensis is characterized by a high degree of dental metric variation. As a result, some researchers support a multiple-species taxonomy for this sample. Other researchers do not think that the sample variation is too great to be accommodated within one species. This study examines variation and sexual dimorphism in mandibular canine and postcanine dental metrics of an Ouranopithecus sample. Bootstrapping (resampling with replacement) of extant hominoid dental metric data is performed to test the hypothesis that the coefficients of variation (CV) and the indices of sexual dimorphism (ISD) of the fossil sample are not significantly different from those of modern great apes. Variation and sexual dimorphism in Ouranopithecus M(1) dimensions were statistically different from those of all extant ape samples; however, most of the dental metrics of Ouranopithecus were neither more variable nor more sexually dimorphic than those of Gorilla and Pongo. Similarly high levels of mandibular molar variation are known to characterize other fossil hominoid species. The Ouranopithecus specimens are morphologically homogeneous and it is probable that all but one specimen included in this study are from a single population. It is unlikely that the sample includes specimens of two sympatric large-bodied hominoid species. For these reasons, a single-species hypothesis is not rejected for the Ouranopithecus macedoniensis material. Correlations between mandibular first molar tooth size dimorphism and body size dimorphism indicate that O. macedoniensis and other extinct hominoids were more sexually size dimorphic than any living great apes, which suggests that social behaviors and life history profiles of these species may have been different from those of living species.

Puberty and structural brain development in humans.

PubMed

Herting, Megan M; Sowell, Elizabeth R

2017-01-01

Adolescence is a transitional period of physical and behavioral development between childhood and adulthood. Puberty is a distinct period of sexual maturation that occurs during adolescence. Since the advent of magnetic resonance imaging (MRI), human studies have largely examined neurodevelopment in the context of age. A breadth of animal findings suggest that sex hormones continue to influence the brain beyond the prenatal period, with both organizational and activational effects occurring during puberty. Given the animal evidence, human MRI research has also set out to determine how puberty may influence otherwise known patterns of age-related neurodevelopment. Here we review structural-based MRI studies and show that pubertal maturation is a key variable to consider in elucidating sex- and individual- based differences in patterns of human brain development. We also highlight the continuing challenges faced, as well as future considerations, for this vital avenue of research. Copyright © 2016. Published by Elsevier Inc.

Puberty and structural brain development in humans

PubMed Central

Herting, Megan M.; Sowell, Elizabeth R.

2017-01-01

Adolescence is a transitional period of physical and behavioral development between childhood and adulthood. Puberty is a distinct period of sexual maturation that occurs during adolescence. Since the advent of magnetic resonance imaging (MRI), human studies have largely examined neurodevelopment in the context of age. A breadth of animal findings suggest that sex hormones continue to influence the brain beyond the prenatal period, with both organizational and activational effects occurring during puberty. Given the animal evidence, human MRI research has also set out to determine how puberty may influence otherwise known patterns of age-related neurodevelopment. Here we review structural-based MRI studies and show that pubertal maturation is a key variable to consider in elucidating sex- and individual-based differences in patterns of human brain development. We also highlight the continuing challenges faced, as well as future considerations, for this vital avenue of research. PMID:28007528

Sex Differences in the Effect of Puberty on Hippocampal Morphology

PubMed Central

Satterthwaite, Theodore D.; Vandekar, Simon; Wolf, Daniel H.; Ruparel, Kosha; Roalf, David R.; Jackson, Chad; Elliott, Mark A.; Bilker, Warren B.; Calkins, Monica E.; Prabhakaran, Karthik; Davatzikos, Christos; Hakonarson, Hakon; Gur, Raquel E.; Gur, Ruben C.

2014-01-01

Objective Puberty is the defining process of adolescence, and is accompanied by divergent trajectories of behavior and cognition for males and females. Here we examine whether sex differences exist in the effect of puberty on the morphology of the hippocampus and amygdala. Method T1-weighted structural neuroimaging was performed in a sample of 524 pre- or postpubertal adolescents ages 10–22. Hippocampal and amygdala volume and shape were quantified using FSL’s FIRST procedure and scaled by intracranial volume. The effects on regional volume of age, sex, puberty, and their interactions were examined using linear regression. Postpubertal sex differences were examined using a vertex analysis. Results Prepubertal males and females had similar hippocampal volumes, whereas postpubertal females had significantly larger bilateral hippocampi, resulting in a significant puberty-by-sex interaction even when controlling for age and age-by-sex. This effect was regionally specific and was not apparent in the amygdala. Vertex analysis revealed that postpubertal differences were most prominent in the lateral aspect of the hippocampus bilaterally, corresponding to the CA1 subfield. Conclusions These results establish that there are regionally specific sex differences in the effect of puberty on the hippocampus. These findings are relevant for the understanding of psychiatric disorders that have both hippocampal dysfunction and prominent gender disparities during adolescence. PMID:24565361

Effects of peripubertal gonadotropin-releasing hormone agonist on brain development in sheep--a magnetic resonance imaging study.

PubMed

Nuruddin, Syed; Bruchhage, Muriel; Ropstad, Erik; Krogenæs, Anette; Evans, Neil P; Robinson, Jane E; Endestad, Tor; Westlye, Lars T; Madison, Cindee; Haraldsen, Ira Ronit Hebold

2013-10-01

In many species sexual dimorphisms in brain structures and functions have been documented. In ovine model, we have previously demonstrated that peri-pubertal pharmacological blockade of gonadotropin releasing hormone (GnRH) action increased sex-differences of executive emotional behavior. The structural substrate of this behavioral alteration however is unknown. In this magnetic resonance image (MRI) study on the same animals, we investigated the effects of GnRH agonist (GnRHa) treatment on the volume of total brain, hippocampus and amygdala. In total 41 brains (17 treated; 10 females and 7 males, and 24 controls; 11 females and 13 males) were included in the MRI study. Image acquisition was performed with 3-T MRI scanner. Segmentation of the amygdala and the hippocampus was done by manual tracing and total gray and white matter volumes were estimated by means of automated brain volume segmentation of the individual T2-weighted MRI volumes. Statistical comparisons were performed with general linear models. Highly significant GnRHa treatment effects were found on the volume of left and right amygdala, indicating larger amygdalae in treated animals. Significant sex differences were found for total gray matter and right amygdala, indicating larger volumes in male compared to female animals. Additionally, we observed a significant interaction between sex and treatment on left amygdala volume, indicating stronger effects of treatment in female compared to male animals. The effects of GnRHa treatment on amygdala volumes indicate that increasing GnRH concentration during puberty may have an important impact on normal brain development in mammals. These novel findings substantiate the need for further studies investigating potential neurobiological side effects of GnRHa treatment on the brains of young animals and humans. Copyright © 2013 Elsevier Ltd. All rights reserved.

Learning problems, delayed development, and puberty

PubMed Central

Wright, Beverly A.; Zecker, Steven G.

2004-01-01

Language-based learning disorders such as dyslexia affect millions of people, but there is little agreement as to their cause. New evidence from behavioral measures of the ability to hear tones in the presence of background noise indicates that the brains of affected individuals develop more slowly than those of their unaffected counterparts. In addition, it seems that brain changes occurring at ≈10 years of age, presumably associated with puberty, may prematurely halt this slower-than-normal development when improvements would normally continue into adolescence. The combination of these ideas can account for a wide range of previous results, suggesting that delayed brain development, and its interaction with puberty, may be key factors contributing to learning problems. PMID:15210987

Sexually dimorphic venom proteins in long-jawed orb-weaving spiders (Tetragnatha) comprise novel gene families

PubMed Central

Zobel-Thropp, Pamela A.; Bulger, Emily A.; Cordes, Matthew H.J.; Binford, Greta J.; Gillespie, Rosemary G.

2018-01-01

Venom has been associated with the ecological success of many groups of organisms, most notably reptiles, gastropods, and arachnids. In some cases, diversification has been directly linked to tailoring of venoms for dietary specialization. Spiders in particular are known for their diverse venoms and wide range of predatory behaviors, although there is much to learn about scales of variation in venom composition and function. The current study focuses on venom characteristics in different sexes within a species of spider. We chose the genus Tetragnatha (Tetragnathidae) because of its unusual courtship behavior involving interlocking of the venom delivering chelicerae (i.e., the jaws), and several species in the genus are already known to have sexually dimorphic venoms. Here, we use transcriptome and proteome analyses to identify venom components that are dimorphic in Tetragnatha versicolor. We present cDNA sequences including unique, male-specific high molecular weight proteins that have remote, if any, detectable similarity to known venom components in spiders or other venomous lineages and have no detectable homologs in existing databases. While the function of these proteins is not known, their presence in association with the cheliceral locking mechanism during mating together with the presence of prolonged male-male mating attempts in a related, cheliceral-locking species (Doryonychus raptor) lacking the dimorphism suggests potential for a role in sexual communication. PMID:29876146

The Relationship between the Second-to-Fourth Digit Ratio and Behavioral Sexual Dimorphism in School-Aged Children.

PubMed

Mitsui, Takahiko; Araki, Atsuko; Miyashita, Chihiro; Ito, Sachiko; Ikeno, Tamiko; Sasaki, Seiko; Kitta, Takeya; Moriya, Kimihiko; Cho, Kazutoshi; Morioka, Keita; Kishi, Reiko; Shinohara, Nobuo; Takeda, Masayuki; Nonomura, Katsuya

2016-01-01

Sexually dimorphic brain development and behavior are known to be influenced by sex hormones exposure in prenatal periods. On the other hand, second-to forth digit ratio (2D/4D) has been used as an indirect method to investigate the putative effects of prenatal exposure to androgen. In the present study, we herein investigated the relationship between gender-role play behavior and the second-to-fourth digit ratio (2D/4D), which has been used as an indirect method to investigate the putative effects of prenatal exposure to androgens, in school-aged children. Among 4981 children who became 8 years old by November 2014 and were contactable for this survey by The Hokkaido Study of Environment and Children's Health, 1631 (32.7%), who had data for 2D/4D and Pre-school Activities Inventory (PSAI) as well as data for the survey at baseline, were available for analysis. Parents sent reports of PSAI on the sex-typical characteristics, preferred toys, and play activities of children, and black and white photocopies of the left and right hand palms via mail. PSAI consisted of 12 masculine items and 12 feminine items, and a composite score was created by subtracting the feminine score from the masculine score, with higher scores representing masculine-typical behavior. While composite scores in PSAI were significantly higher in boys than in girls, 2D/4D was significantly lower in boys than in girls. Although the presence or absence of brothers or sisters affected the composite, masculine, and feminine scored of PSAI, a multivariate regression model revealed that 2D/4D negatively correlated with the composite scores of PSAI in boys, whereas no correlation was found in girls. Although 2D/4D negatively correlated with the masculine score in boys and girls, no correlation was observed between 2D/4D and the feminine score. In conclusion, although social factors, such as the existence of brother or sisters, affect dimorphic brain development and behavior in childhood, the present study revealed that the prenatal hormonal environment was an important factor influencing masculine-typical dimorphic brain development and behavior in school-aged children.

To fight or mate? Hormonal control of sex recognition, male sexual behavior and aggression in the gecko lizard.

PubMed

Schořálková, Tereza; Kratochvíl, Lukáš; Kubička, Lukáš

2018-01-01

Squamate reptiles are a highly diversified vertebrate group with extensive variability in social behavior and sexual dimorphism. However, hormonal control of these traits has not previously been investigated in sufficient depth in many squamate lineages. Here, we studied the hormonal control of male sexual behavior, aggressiveness, copulatory organ (hemipenis) size and sex recognition in the gecko Paroedura picta, comparing ovariectomized females, ovariectomized females treated with exogenous dihydrotestosterone (DHT), ovariectomized females treated with exogenous testosterone (T), control females and males. The administration of both T and DHT led to the expression of male-typical sexual behavior in females. However, in contrast to T, increased circulating levels of DHT alone were not enough to initiate the full expression of male-typical offensive aggressive behavior and development of hemipenes in females. Ovariectomized females were as sexually attractive as control females, which does not support the need for the demasculinization of the cues used for sex recognition by ovarian hormones as suggested in other sauropsids. On the other hand, our results point to the masculinization of the sex recognition cues by male gonadal androgens. Previously, we also demonstrated that sexually dimorphic growth is controlled by ovarian hormones in P. picta. Overall, it appears that individual behavioral and morphological sexually-dimorphic traits are controlled by multiple endogenous pathways in this species. Variability in the endogenous control of particular traits could have permitted their disentangling during evolution and the occurrence of (semi)independent changes across squamate phylogeny. Copyright © 2017 Elsevier Inc. All rights reserved.

AN ENVIRONMENTAL ANTIANDROGEN, VINCLOZOLIN, ALTERS THE ORGANIZATION OF PLAY BEHAVIOR

EPA Science Inventory

ABSTRACT

During mammalian sexual differentiation, the androgens, testosterone and dihydrotestosterone are critical for the organization of the male phenotype. In rats, play behavior is sexually dimorphic. Administration of exogenous androgens during the perinatal period r...

Sex differences in juvenile mouse social behavior are influenced by sex chromosomes and social context.

PubMed

Cox, K H; Rissman, E F

2011-06-01

Play behavior in juvenile primates, rats and other species is sexually dimorphic, with males showing more play than females. In mice, sex differences in juvenile play have only been examined in out-bred CD-1 mice. In this strain, contrary to other animals, male mice display less play soliciting than females. Using an established same-sex dyadic interaction test, we examined play in in-bred C57BL/6J (B6) 21-day-old mice. When paired with non-siblings, males tended to be more social than females, spending more time exploring the test cage. Females displayed significantly more anogenital sniffing and solicited play more frequently than did males. To determine if the origin of the sex difference was sex chromosome genes or gonadal sex, next we used the four core genotype mouse. We found significant interactions between gonadal sex and genotype for several behaviors. Finally, we asked if sibling pairs (as compared to non-siblings) would display qualitatively or quantitatively different behavior. In fact, XX females paired with a sibling were more social and less exploratory or investigative, whereas XY males exhibited less investigative and play soliciting behaviors in tests with siblings. Many neurobehavioral disorders, like autism spectrum disorder (ASD), are sexually dimorphic in incidence and patients interact less than normal with other children. Our results suggest that sex chromosome genes interact with gonadal hormones to shape the development of juvenile social behavior, and that social context can drastically alter sex differences. These data may have relevance for understanding the etiology of sexually dimorphic disorders such as ASD. © 2011 The Authors. Genes, Brain and Behavior © 2011 Blackwell Publishing Ltd and International Behavioural and Neural Genetics Society.

Young adult psychological outcome after puberty suppression and gender reassignment.

PubMed

de Vries, Annelou L C; McGuire, Jenifer K; Steensma, Thomas D; Wagenaar, Eva C F; Doreleijers, Theo A H; Cohen-Kettenis, Peggy T

2014-10-01

In recent years, puberty suppression by means of gonadotropin-releasing hormone analogs has become accepted in clinical management of adolescents who have gender dysphoria (GD). The current study is the first longer-term longitudinal evaluation of the effectiveness of this approach. A total of 55 young transgender adults (22 transwomen and 33 transmen) who had received puberty suppression during adolescence were assessed 3 times: before the start of puberty suppression (mean age, 13.6 years), when cross-sex hormones were introduced (mean age, 16.7 years), and at least 1 year after gender reassignment surgery (mean age, 20.7 years). Psychological functioning (GD, body image, global functioning, depression, anxiety, emotional and behavioral problems) and objective (social and educational/professional functioning) and subjective (quality of life, satisfaction with life and happiness) well-being were investigated. After gender reassignment, in young adulthood, the GD was alleviated and psychological functioning had steadily improved. Well-being was similar to or better than same-age young adults from the general population. Improvements in psychological functioning were positively correlated with postsurgical subjective well-being. A clinical protocol of a multidisciplinary team with mental health professionals, physicians, and surgeons, including puberty suppression, followed by cross-sex hormones and gender reassignment surgery, provides gender dysphoric youth who seek gender reassignment from early puberty on, the opportunity to develop into well-functioning young adults. Copyright © 2014 by the American Academy of Pediatrics.

Fungal Infection Induces Sex-Specific Transcriptional Changes and Alters Sexual Dimorphism in the Dioecious Plant Silene latifolia

PubMed Central

Zemp, Niklaus; Tavares, Raquel; Widmer, Alex

2015-01-01

Sexual dimorphism, including differences in morphology, behavior and physiology between females and males, is widespread in animals and plants and is shaped by gene expression differences between the sexes. Such expression differences may also underlie sex-specific responses of hosts to pathogen infections, most notably when pathogens induce partial sex reversal in infected hosts. The genetic changes associated with sex-specific responses to pathogen infections on the one hand, and sexual dimorphism on the other hand, remain poorly understood. The dioecious White Campion (Silene latifolia) displays sexual dimorphism in floral traits and infection with the smut fungus Micobrotryum lychnidis-dioicae induces a partial sex reversal in females. We find strong sex-specific responses to pathogen infection and reduced sexual dimorphism in infected S. latifolia. This provides a direct link between pathogen-mediated changes in sex-biased gene expression and altered sexual dimorphism in the host. Expression changes following infection affected mainly genes with male-biased expression in healthy plants. In females, these genes were up-regulated, leading to a masculinization of the transcriptome. In contrast, infection in males was associated with down-regulation of these genes, leading to a demasculinization of the transcriptome. To a lesser extent, genes with female-biased expression in healthy plants were also affected in opposite directions in the two sexes. These genes were overall down-regulated in females and up-regulated in males, causing, respectively, a defeminization in infected females and a feminization of the transcriptome in infected males. Our results reveal strong sex-specific responses to pathogen infection in a dioecious plant and provide a link between pathogen-induced changes in sex-biased gene expression and sexual dimorphism. PMID:26448481

Fungal Infection Induces Sex-Specific Transcriptional Changes and Alters Sexual Dimorphism in the Dioecious Plant Silene latifolia.

PubMed

Zemp, Niklaus; Tavares, Raquel; Widmer, Alex

2015-10-01

Sexual dimorphism, including differences in morphology, behavior and physiology between females and males, is widespread in animals and plants and is shaped by gene expression differences between the sexes. Such expression differences may also underlie sex-specific responses of hosts to pathogen infections, most notably when pathogens induce partial sex reversal in infected hosts. The genetic changes associated with sex-specific responses to pathogen infections on the one hand, and sexual dimorphism on the other hand, remain poorly understood. The dioecious White Campion (Silene latifolia) displays sexual dimorphism in floral traits and infection with the smut fungus Micobrotryum lychnidis-dioicae induces a partial sex reversal in females. We find strong sex-specific responses to pathogen infection and reduced sexual dimorphism in infected S. latifolia. This provides a direct link between pathogen-mediated changes in sex-biased gene expression and altered sexual dimorphism in the host. Expression changes following infection affected mainly genes with male-biased expression in healthy plants. In females, these genes were up-regulated, leading to a masculinization of the transcriptome. In contrast, infection in males was associated with down-regulation of these genes, leading to a demasculinization of the transcriptome. To a lesser extent, genes with female-biased expression in healthy plants were also affected in opposite directions in the two sexes. These genes were overall down-regulated in females and up-regulated in males, causing, respectively, a defeminization in infected females and a feminization of the transcriptome in infected males. Our results reveal strong sex-specific responses to pathogen infection in a dioecious plant and provide a link between pathogen-induced changes in sex-biased gene expression and sexual dimorphism.

Male dimorphism and alternative reproductive tactics in harvestmen (Arachnida: Opiliones).

PubMed

Buzatto, Bruno A; Machado, Glauco

2014-11-01

Strong sexual selection may lead small males or males in poor condition to adopt alternative reproductive tactics (ARTs) as a way to avoid the risk of being completely excluded from the mating pool. ARTs, sometimes accompanying morphological dimorphism among males, are taxonomically widespread, especially common in arthropods. Here we review the current knowledge on ARTs and male dimorphism in a diverse but relatively overlooked group of arachnids, the order Opiliones, popularly known as harvestmen or daddy long-legs. We begin with a summary of harvestman mating systems, followed by a review of the two lines of evidence for the presence of ARTs in the group: (1) morphological data from natural populations and museum collections; and (2) behavioral information from field studies. Despite receiving less attention than spiders, scorpions and insects, our review shows that harvestmen are an exciting group of organisms that are potentially great models for sexual selection studies focused on ARTs. We also suggest that investigating the proximate mechanisms underlying male dimorphism in the order would be especially important. New research on ARTs and male dimorphism will have implications for our understanding of the evolution of mating systems, sperm competition, and polyandry. This article is part of a Special Issue entitled: Neotropical Behaviour. Copyright © 2014 Elsevier B.V. All rights reserved.

Sexual Dimorphisms of Appendicular Musculoskeletal Morphology Related to Social Display in Cuban Anolis Lizards.

PubMed

Anzai, Wataru; Cádiz, Antonio; Endo, Hideki

2015-10-01

In Anolis lizards, sexual dimorphism has been reported in morphological and ecological traits. Males show larger body size and longer limbs related to territorial combat and courtship display with the dewlap. Although functional-anatomical traits are closely related to locomotor behaviors, differences between sexes in musculoskeletal traits on limbs remain unclear. We explored the relationships among sexual dimorphisms in musculoskeletal morphology, habitat, and locomotor traits in Anolis lizards. Specifically, we examined appendicular musculoskeletal morphology in three species of Cuban Anolis by measuring muscle mass and lengths of moment arms. Through comparisons of crossing locomotion, we found that the runner species possessed larger extensors in hindlimbs, which are advantageous for running, whereas the masses of the humeral and femoral retractors were larger in climber species, allowing these lizards to hold up their bodies and occupy tree substrates. Comparisons between the sexes showed different trends among the three species. Males of A. porcatus, which inhabit narrow branches or leaves, had stronger elbow extensors that maintain the display posture. In contrast, males of A. sagrei, which occupy broad surfaces, did not show sexual differences that affected social display. Moreover, A. bartschi indicated sexual differences despite the absence of dewlapping behavior. Our findings suggest that both sexes show fundamentally similar relationships between muscular morphology and locomotor habits to adapt arboreal or terrestrial substrates, and yet sexual dimorphism in forelimb muscles may additionally affected by male specific display with the dewlap.

Sexual dimorphism in stature (SDS), jealousy and mate retention.

PubMed

Brewer, Gayle; Riley, Charlene

2010-10-02

Previous research has investigated the manner in which absolute height impacts on jealousy and mate retention. Although relative height is also important, little information exists about the potential influence of sexual dimorphism in stature (SDS) within established relationships. The current study investigated the relationship between SDS and the satisfaction, jealousy and mate retention behaviors reported by men and women. Heterosexual men (n = 98) and women (n = 102) completed a questionnaire. Men in high SDS relationships reported the lowest levels of cognitive and behavioral jealousy, although the impact of SDS on relationship satisfaction was less clear. SDS was not associated with the overall use of mate retention strategies; SDS did however affect the use of three specific strategies (vigilance, monopolization of time, love and care). SDS did not affect women's relationship satisfaction, jealousy (cognitive, behavioral, or emotional) or the use of mate retention strategies (with the exception of resource display).

[Adolescent crises in puberty. Diagnosis and therapy (author's transl)].

PubMed

Müller-Küppers, M

1979-08-24

Psychological disorders which become manifest as adolescent crises must be seen as complex phenomena and treated thoroughly: besides the genetic, biographic and psychosocial background of the youthful individual the cultural and economic aspects play an important role. Nevertheless we must admit that associated causal explanations, e.g. for accelerated or late development are lacking. Focal points for the subsequent symptom complexes of sexual behavior in puberty are: psychosexual prematurity or retardation, masturbation, homosexual relations, pubertal asceticism and premature and frequently changing sexual relations.

Women's hormone levels modulate the motivational salience of facial attractiveness and sexual dimorphism.

PubMed

Wang, Hongyi; Hahn, Amanda C; Fisher, Claire I; DeBruine, Lisa M; Jones, Benedict C

2014-12-01

The physical attractiveness of faces is positively correlated with both behavioral and neural measures of their motivational salience. Although previous work suggests that hormone levels modulate women's perceptions of others' facial attractiveness, studies have not yet investigated whether hormone levels also modulate the motivational salience of facial characteristics. To address this issue, we investigated the relationships between within-subject changes in women's salivary hormone levels (estradiol, progesterone, testosterone, and estradiol-to-progesterone ratio) and within-subject changes in the motivational salience of attractiveness and sexual dimorphism in male and female faces. The motivational salience of physically attractive faces in general and feminine female faces, but not masculine male faces, was greater in test sessions where women had high testosterone levels. Additionally, the reward value of sexually dimorphic faces in general and attractive female faces, but not attractive male faces, was greater in test sessions where women had high estradiol-to-progesterone ratios. These results provide the first evidence that the motivational salience of facial attractiveness and sexual dimorphism is modulated by within-woman changes in hormone levels. Copyright © 2014 Elsevier Ltd. All rights reserved.

Within-person changes in salivary testosterone and physical characteristics of puberty predict boys' daily affect.

PubMed

Klipker, Kathrin; Wrzus, Cornelia; Rauers, Antje; Boker, Steven M; Riediger, Michaela

2017-09-01

Recent investigations highlighted the role of within-person pubertal changes for adolescents' behavior. Yet, little is known about effects on adolescents' daily affect, particularly regarding the hormonal changes underlying physical changes during puberty. In a study with 148 boys aged 10 to 20years, we tested whether within-person physical and hormonal changes over eight months predicted everyday affect fluctuations, measured with experience sampling. As expected, greater within-person changes in testosterone (but not in dehydroepiandrosterone) were associated with higher affect fluctuations in daily life. Additionally, greater physical changes predicted higher affect fluctuations for individuals in the beginning of puberty. The findings demonstrate the relevance of physical and hormonal changes in boys' affective (in)stability. Copyright © 2017 Elsevier Inc. All rights reserved.

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

Sex differences in the effect of puberty on hippocampal morphology.

PubMed

Satterthwaite, Theodore D; Vandekar, Simon; Wolf, Daniel H; Ruparel, Kosha; Roalf, David R; Jackson, Chad; Elliott, Mark A; Bilker, Warren B; Calkins, Monica E; Prabhakaran, Karthik; Davatzikos, Christos; Hakonarson, Hakon; Gur, Raquel E; Gur, Ruben C

2014-03-01

Puberty is the defining process of adolescence, and is accompanied by divergent trajectories of behavior and cognition for males and females. Here we examine whether sex differences exist in the effect of puberty on the morphology of the hippocampus and amygdala. T1-weighted structural neuroimaging was performed in a sample of 524 pre- or postpubertal individuals ages 10 to 22 years. Hippocampal and amygdala volume and shape were quantified using the Functional Magnetic Resonance Imaging of the Brain (FMRIB) Software Library (FSL) FIRST procedure and scaled by intracranial volume. The effects on regional volume of age, sex, puberty, and their interactions were examined using linear regression. Postpubertal sex differences were examined using a vertex analysis. Prepubertal males and females had similar hippocampal volumes, whereas postpubertal females had significantly larger bilateral hippocampi, resulting in a significant puberty-by-sex interaction even when controlling for age and age-by-sex. This effect was regionally specific and was not apparent in the amygdala. Vertex analysis revealed that postpubertal differences were most prominent in the lateral aspect of the hippocampus bilaterally, corresponding to the CA1 subfield. These results establish that there are regionally specific sex differences in the effect of puberty on the hippocampus. These findings are relevant for the understanding of psychiatric disorders that have both hippocampal dysfunction and prominent gender disparities during adolescence. Copyright © 2014 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Puberty in the Corpus Callosum

PubMed Central

Chavarria, Mary C.; Sánchez, Francisco J.; Chou, Yi-Yu; Thompson, Paul M.; Luders, Eileen

2014-01-01

Adolescence is an important period for brain development. White matter growth is influenced by sex hormones such as testosterone, and the corpus callosum—the largest white matter structure in the human brain—may change structurally during the hormone-laden period of adolescence. Little is known about puberty’s relationship to structural brain development, even though pubertal stage may better predict cognitive and behavioral maturity than chronological age. We therefore aimed to establish the presence and direction of pubertal effects on callosal anatomy. For this purpose, we applied advanced surface-based mesh-modeling to map correlations between callosal thickness and pubertal stage in a large and well-matched sample of 124 children and adolescents (62 female and 62 male) aged 5–18 years from a normative database. When linking callosal anatomy to pubertal status, only positive correlations reached statistical significance, indicating that callosal growth advances with puberty. In tests of differences in callosal anatomy at different stages of puberty, callosal growth was concentrated in different locations depending on the pubertal stage. Changing levels of circulating sex hormones during different phases of puberty likely contributed to the observed effects, and further research is clearly needed. Direct quantification of sex hormone levels and regional fiber connectivity—ideally using fiber tractography—will reveal whether hormones are the main drivers of callosal change during puberty. These callosal findings may lead to hypotheses regarding cortical changes during puberty, which may promote or result from changes in interhemispheric connectivity. PMID:24468104

Sex and gender issues in competitive sports: investigation of a historical case leads to a new viewpoint

PubMed Central

Ballantyne, Kaye N; Kayser, Manfred; Grootegoed, J Anton

2012-01-01

Based on DNA analysis of a historical case, the authors describe how a female athlete can be unknowingly confronted with the consequences of a disorder of sex development resulting in hyperandrogenism emerging early in her sports career. In such a situation, it is harmful and confusing to question sex and gender. Exposure to either a low or high level of endogenous testosterone from puberty is a decisive factor with respect to sexual dimorphism of physical performance. Yet, measurement of testosterone is not the means by which questions of an athlete's eligibility to compete with either women or men are resolved. The authors discuss that it might be justifiable to use the circulating testosterone level as an endocrinological parameter, to try to arrive at an objective criterion in evaluating what separates women and men in sports competitions, which could prevent the initiation of complicated, lengthy and damaging sex and gender verification procedures. PMID:21540190

Sex and gender issues in competitive sports: investigation of a historical case leads to a new viewpoint.

PubMed

Ballantyne, Kaye N; Kayser, Manfred; Grootegoed, J Anton

2012-06-01

Based on DNA analysis of a historical case, the authors describe how a female athlete can be unknowingly confronted with the consequences of a disorder of sex development resulting in hyperandrogenism emerging early in her sports career. In such a situation, it is harmful and confusing to question sex and gender. Exposure to either a low or high level of endogenous testosterone from puberty is a decisive factor with respect to sexual dimorphism of physical performance. Yet, measurement of testosterone is not the means by which questions of an athlete's eligibility to compete with either women or men are resolved. The authors discuss that it might be justifiable to use the circulating testosterone level as an endocrinological parameter, to try to arrive at an objective criterion in evaluating what separates women and men in sports competitions, which could prevent the initiation of complicated, lengthy and damaging sex and gender verification procedures.

SOCIAL PLAY BEHAVIOR IS ALTERED IN THE RAT BY PERINATAL EXPOSURE TO ANDROGENS AND THE ENVIRONMENTAL ANTIANDROGEN, VINCLOZOLIN

EPA Science Inventory

During mammalian sexual differentiation, the androgens, testosterone and dihydrotestosterone are critical for the organization of the male phenotype. In rats, play behavior is sexually dimorphic. Administration of exogenous androgens during the perinatal period results in masculi...

Tanzanian Adolescent Boys’ Transitions Through Puberty: The Importance of Context

PubMed Central

Likindikoki, Samuel; Kaaya, S.

2014-01-01

We explored the masculinity norms shaping transitions through puberty in rural and urban Tanzania and how these norms and their social-ecological context contribute to high-risk health behaviors. We conducted a qualitative case study of adolescent boys in and out of school in 2011 and 2012. Tanzania’s social and economic development is reshaping the transition into young manhood. Adolescent boys are losing traditional mechanisms of pubertal guidance, and new meanings of manhood are arising from globalization. Traditional masculinity norms, including pressures to demonstrate virility and fertility, remain strong. Adolescent boys in modernizing Tanzania receive inadequate guidance on their burgeoning sexuality. Contradictory masculinity norms from family and society are shaping their sexual expectations, with implications for their engagement in unsafe sexual behaviors. PMID:25320893

Sexually dimorphic effects of ancestral exposure to vinclozolin on stress reactivity in rats.

PubMed

Gillette, Ross; Miller-Crews, Isaac; Nilsson, Eric E; Skinner, Michael K; Gore, Andrea C; Crews, David

2014-10-01

How an individual responds to the environment depends upon both personal life history as well as inherited genetic and epigenetic factors from ancestors. Using a 2-hit, 3 generations apart model, we tested how F3 descendants of rats given in utero exposure to the environmental endocrine-disrupting chemical (EDC) vinclozolin reacted to stress during adolescence in their own lives, focusing on sexually dimorphic phenotypic outcomes. In adulthood, male and female F3 vinclozolin- or vehicle-lineage rats, stressed or nonstressed, were behaviorally characterized on a battery of tests and then euthanized. Serum was used for hormone assays, and brains were used for quantitative PCR and transcriptome analyses. Results showed that the effects of ancestral exposure to vinclozolin converged with stress experienced during adolescence in a sexually dimorphic manner. Debilitating effects were seen at all levels of the phenotype, including physiology, behavior, brain metabolism, gene expression, and genome-wide transcriptome modifications in specific brain nuclei. Additionally, females were significantly more vulnerable than males to transgenerational effects of vinclozolin on anxiety but not sociality tests. This fundamental transformation occurs in a manner not predicted by the ancestral exposure or the proximate effects of stress during adolescence, an interaction we refer to as synchronicity.

Measurements of neuron soma size and density in rat dorsal striatum, nucleus accumbens core and nucleus accumbens shell: differences between striatal region and brain hemisphere, but not sex.

PubMed

Meitzen, John; Pflepsen, Kelsey R; Stern, Christopher M; Meisel, Robert L; Mermelstein, Paul G

2011-01-07

Both hemispheric bias and sex differences exist in striatal-mediated behaviors and pathologies. The extent to which these dimorphisms can be attributed to an underlying neuroanatomical difference is unclear. We therefore quantified neuron soma size and density in the dorsal striatum (CPu) as well as the core (AcbC) and shell (AcbS) subregions of the nucleus accumbens to determine whether these anatomical measurements differ by region, hemisphere, or sex in adult Sprague-Dawley rats. Neuron soma size was larger in the CPu than the AcbC or AcbS. Neuron density was greatest in the AcbS, intermediate in the AcbC, and least dense in the CPu. CPu neuron density was greater in the left in comparison to the right hemisphere. No attribute was sexually dimorphic. These results provide the first evidence that hemispheric bias in the striatum and striatal-mediated behaviors can be attributed to a lateralization in neuronal density within the CPu. In contrast, sexual dimorphisms appear mediated by factors other than gross anatomical differences. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Sexual Dimorphism and Allometric Effects Associated With the Wing Shape of Seven Moth Species of Sphingidae (Lepidoptera: Bombycoidea)

PubMed Central

de Camargo, Nícholas Ferreira; Corrêa, Danilo do Carmo Vieira; de Camargo, Amabílio J. Aires; Diniz, Ivone Rezende

2015-01-01

Sexual dimorphism is a pronounced pattern of intraspecific variation in Lepidoptera. However, moths of the family Sphingidae (Lepidoptera: Bombycoidea) are considered exceptions to this rule. We used geometric morphometric techniques to detect shape and size sexual dimorphism in the fore and hindwings of seven hawkmoth species. The shape variables produced were then subjected to a discriminant analysis. The allometric effects were measured with a simple regression between the canonical variables and the centroid size. We also used the normalized residuals to assess the nonallometric component of shape variation with a t-test. The deformations in wing shape between sexes per species were assessed with a regression between the nonreduced shape variables and the residuals. We found sexual dimorphism in both wings in all analyzed species, and that the allometric effects were responsible for much of the wing shape variation between the sexes. However, when we removed the size effects, we observed shape sexual dimorphism. It is very common for females to be larger than males in Lepidoptera, so it is expected that the shape of structures such as wings suffers deformations in order to preserve their function. However, sources of variation other than allometry could be a reflection of different reproductive flight behavior (long flights in search for sexual mates in males, and flight in search for host plants in females). PMID:26206895

A TgCRND8 Mouse Model of Alzheimer's Disease Exhibits Sexual Dimorphisms in Behavioral Indices of Cognitive Reserve.

PubMed

Granger, Matthew W; Franko, Bettina; Taylor, Matthew W; Messier, Claude; George-Hyslop, Peter St; Bennett, Steffany A L

2016-01-01

Cognitive decline is sexually dimorphic in Alzheimer's disease (AD). Men show higher incidences of amnestic mild cognitive impairment yet women disproportionally phenoconvert to AD. It is hypothesized that men maintain greater cognitive reserve than women under comparable amyloid-β (Aβ) challenge. One behavioral aspect of cognitive reserve in mice is the capacity to cope with Aβ-associated stereotypies by switching to increasingly effective navigational search strategies in the Morris water maze. To explore inherent sex differences in this paradigm, however, we require an AβPP mouse model wherein behavioral flexibility is impaired earlier in females than males despite equivalent Aβ load. Here, we show that when F1 C57Bl/6×C3H/HeJ TgCRND8 mice are placed on C57Bl/6 background, N5 Tg males and females exhibit equivalent Aβ pathologies at 2, 4, 6, and 8 months of age yet females display learning and memory deficits earlier than males. We further show that this N5 line does not carry the autosomal recessive pde6brd1 mutation that impairs visual acuity and that the estrous cycle is not disrupted on this genetic background. At 5.5 months of age, Tg males, but not females, compensate for Aβ-associated stereotypic behaviors (i.e., hyperactive tight circling) by alternating navigational search strategies and adopting increasingly productive spatial search strategies. Females fail to overcome Aβ-associated stereotypies and do not efficiently switch from systematic to spatial learning strategies. Together, these data identify a novel AβPP mouse model that can be used for preclinical testing of interventions targeting sexual dimorphisms in behavioral indices of cognitive reserve.

A Prospective Study of Extreme Weight Change Behaviors among Adolescent Boys and Girls

ERIC Educational Resources Information Center

McCabe, Marita P.; Ricciardelli, Lina A.

2006-01-01

This study examined changes in extreme weight change attitudes and behaviors (exercise dependence, food supplements, drive for thinness, bulimia) among adolescent boys and girls over a 16 month period. It also investigated the impact of body mass index, puberty, body image, depression and positive affect on these attitudes and behaviors 16 months…

Ecology of the bromeligenous frog Phyllodytes luteolus (Anura, Hylidae) from three restinga remnants across Brazil's coast.

PubMed

Motta-Tavares, Tatiana; Maia-Carneiro, Thiago; Dantas, Leonardo F; Sluys, Monique Van; Hatano, Fábio H; Vrcibradic, Davor; Rocha, Carlos F D

2016-03-01

In this study, we analyzed diet, sexual dimorphism and bromeliad use in three populations of the hylid frog Phyllodytes luteolus from restinga habitats along the Brazilian coast. We found 13 arthropods categories in 161 stomachs. Ants and termites were the dominant prey items. The similar trophic niche across populations suggests this species has a conservative diet. We found sexual dimorphism regarding body size and jaw width. We recordedP. luteolus in five bromeliad species, but predominantly inAechmeablanchetiana (35.6% of individuals recorded). We recorded solitary individuals in 44% of occupied bromeliads, and never found two males sharing the same bromeliad. The data is suggestive that populations ofP. luteolus has a conservative diet independent of area, with ants and termites the being most relevant prey items. The sexual dimorphism in jaw and the solitary males may suggest that this species have territorial behavior.

Ecological Sexual Dimorphism and Environmental Variability within a Community of Antarctic Penguins (Genus Pygoscelis)

PubMed Central

Gorman, Kristen B.; Williams, Tony D.; Fraser, William R.

2014-01-01

Background Sexual segregation in vertebrate foraging niche is often associated with sexual size dimorphism (SSD), i.e., ecological sexual dimorphism. Although foraging behavior of male and female seabirds can vary markedly, differences in isotopic (carbon, δ13C and nitrogen, δ15N) foraging niche are generally more pronounced within sexually dimorphic species and during phases when competition for food is greater. We examined ecological sexual dimorphism among sympatric nesting Pygoscelis penguins asking whether environmental variability is associated with differences in male and female pre-breeding foraging niche. We predicted that all Pygoscelis species would forage sex-specifically, and that higher quality winter habitat, i.e., higher or lower sea ice coverage for a given species, would be associated with a more similar foraging niche among the sexes. Results P2/P8 primers reliably amplified DNA of all species. On average, male Pygoscelis penguins are structurally larger than female conspecifics. However, chinstrap penguins were more sexually dimorphic in culmen and flipper features than Adélie and gentoo penguins. Adélies and gentoos were more sexually dimorphic in body mass than chinstraps. Only male and female chinstraps and gentoos occupied separate δ15N foraging niches. Strong year effects in δ15N signatures were documented for all three species, however, only for Adélies, did yearly variation in δ15N signatures tightly correlate with winter sea ice conditions. There was no evidence that variation in sex-specific foraging niche interacted with yearly winter habitat quality. Conclusion Chinstraps were most sexually size dimorphic followed by gentoos and Adélies. Pre-breeding sex-specific foraging niche was associated with overall SSD indices across species; male chinstrap and gentoo penguins were enriched in δ15N relative to females. Our results highlight previously unknown trophic pathways that link Pygoscelis penguins with variation in Southern Ocean sea ice suggesting that each sex within a species should respond similarly in pre-breeding trophic foraging to changes in future winter habitat. PMID:24599330

Reproductive physiology of the male camelid.

PubMed

Bravo, P W; Johnson, L W

1994-07-01

The physiology of reproduction with emphasis on endocrinology of llamas and alpacas is addressed. Information regarding male anatomy, puberty, testicular function, semen description, and sexual behavior is also included.

The influence of stress at puberty on mood and learning: Role of the α4βδ GABAA receptor

PubMed Central

Smith, Sheryl S.

2012-01-01

It is well-known that the onset of puberty is associated with changes in mood as well as cognition. Stress can have an impact on these outcomes, which in many cases, can be more influential in females, suggesting that gender differences exist. The adolescent period is a vulnerable time for the onset of certain psychopathologies, including anxiety disorders, depression and eating disorders, which are also more prevalent in females. One factor which may contribute to stress-triggered anxiety at puberty is the GABAA receptor (GABAR), which is known to play a pivotal role in anxiety. Expression of α4βδ GABARs increases on the dendrites of CA1 pyramidal cells at the onset of puberty in the hippocampus, part of the limbic circuitry which governs emotion. This receptor is a sensitive target for the stress steroid THP (3α-OH-5[α]β-pregnan-20-one), which paradoxically reduces inhibition and increases anxiety during the pubertal period (~PND 35–44) of female mice in contrast to its usual effect to enhance inhibition and reduce anxiety. Spatial learning and synaptic plasticity are also adversely impacted at puberty, likely a result of increased expression of α4βδ GABARs on the dendritic spines of CA1 hippocampal pyramidal cells, which are essential for consolidation of memory. This review will focus on the role of these receptors in mediating behavioral changes at puberty. Stress-mediated changes in mood and cognition in early adolescence may have relevance for the expression of psychopathologies in adulthood. PMID:23079628

Moxd1 Is a Marker for Sexual Dimorphism in the Medial Preoptic Area, Bed Nucleus of the Stria Terminalis and Medial Amygdala

PubMed Central

Tsuneoka, Yousuke; Tsukahara, Shinji; Yoshida, Sachine; Takase, Kenkichi; Oda, Satoko; Kuroda, Masaru; Funato, Hiromasa

2017-01-01

The brain shows various sex differences in its structures. Various mammalian species exhibit sex differences in the sexually dimorphic nucleus of the preoptic area (SDN-POA) and parts of the extended amygdala such as the principal nucleus of the bed nucleus of the stria terminalis (BNSTpr) and posterodorsal part of the medial amygdala (MePD). The SDN-POA and BNSTpr are male-biased sexually dimorphic nuclei, and characterized by the expression of calbindin D-28K (calbindin 1). However, calbindin-immunoreactive cells are not restricted to the SDN-POA, but widely distributed outside of the SDN-POA. To find genes that are more specific to sexually dimorphic nuclei, we selected candidate genes by searching the Allen brain atlas and examined the detailed expressions of the candidate genes using in situ hybridization. We found that the strong expression of monooxygenase DBH-like 1 (Moxd1) was restricted to the SDN-POA, BNSTpr and MePD. The numbers of Moxd1-positive cells in the SDN-POA, BNSTpr and MePD in male mice were larger than those in female mice. Most of the Moxd1-positive cells in the SDN-POA and BNSTpr expressed calbindin. Neonatal castration of male mice reduced the number of Moxd1-positive cells in the SDN-POA, whereas gonadectomy in adulthood did not change the expression of the Moxd1 gene in the SDN-POA in both sexes. These results suggest that the Moxd1 gene is a suitable marker for sexual dimorphic nuclei in the POA, BNST and amygdala, which enables us to manipulate sexually dimorphic neurons to examine their roles in sex-biased physiology and behaviors. PMID:28396628

Moxd1 Is a Marker for Sexual Dimorphism in the Medial Preoptic Area, Bed Nucleus of the Stria Terminalis and Medial Amygdala.

PubMed

Tsuneoka, Yousuke; Tsukahara, Shinji; Yoshida, Sachine; Takase, Kenkichi; Oda, Satoko; Kuroda, Masaru; Funato, Hiromasa

2017-01-01

The brain shows various sex differences in its structures. Various mammalian species exhibit sex differences in the sexually dimorphic nucleus of the preoptic area (SDN-POA) and parts of the extended amygdala such as the principal nucleus of the bed nucleus of the stria terminalis (BNSTpr) and posterodorsal part of the medial amygdala (MePD). The SDN-POA and BNSTpr are male-biased sexually dimorphic nuclei, and characterized by the expression of calbindin D-28K (calbindin 1). However, calbindin-immunoreactive cells are not restricted to the SDN-POA, but widely distributed outside of the SDN-POA. To find genes that are more specific to sexually dimorphic nuclei, we selected candidate genes by searching the Allen brain atlas and examined the detailed expressions of the candidate genes using in situ hybridization. We found that the strong expression of monooxygenase DBH-like 1 ( Moxd1 ) was restricted to the SDN-POA, BNSTpr and MePD. The numbers of Moxd1 -positive cells in the SDN-POA, BNSTpr and MePD in male mice were larger than those in female mice. Most of the Moxd1 -positive cells in the SDN-POA and BNSTpr expressed calbindin. Neonatal castration of male mice reduced the number of Moxd1 -positive cells in the SDN-POA, whereas gonadectomy in adulthood did not change the expression of the Moxd1 gene in the SDN-POA in both sexes. These results suggest that the Moxd1 gene is a suitable marker for sexual dimorphic nuclei in the POA, BNST and amygdala, which enables us to manipulate sexually dimorphic neurons to examine their roles in sex-biased physiology and behaviors.

Building a scientific framework for studying hormonal effects on behavior and on the development of the sexually dimorphic nervous system

EPA Science Inventory

There has been increasing concern that low-dose exposure to hormonally active chemicals disrupts sexual differentiation of the brain and peripheral nervous system. There also has been active drug development research on the therapeutic potential of hormone therapy on behaviors. T...

Children Are Not Little Adults!

EPA Pesticide Factsheets

They are often more likely to be at risk from environmental hazards because of unique activity patterns/behavior, physiological differences, and windows of susceptibility during early lifestages including fetal development and puberty.

Effects of male sex hormones on gender identity, sexual behavior, and cognitive function.

PubMed

Zhu, Yuan-shan; Cai, Li-qun

2006-04-01

Androgens, the male sex hormones, play an essential role in male sexual differentiation and development. However, the influence of these sex hormones extends beyond their roles in sexual differentiation and development. In many animal species, sex hormones have been shown to be essential for sexual differentiation of the brain during development and for maintaining sexually dimorphic behavior throughout life. The principals of sex determination in humans have been demonstrated to be similar to other mammals. However, the hormonal influence on sexual dimorphic differences in the nervous system in humans, sex differences in behaviors, and its correlations with those of other mammals is still an emerging field. In this review, the roles of androgens in gender and cognitive function are discussed with the emphasis on subjects with androgen action defects including complete androgen insensitivity due to androgen receptor mutations and 5alpha-reductase-2 deficiency syndromes due to 5alpha-reductase-2 gene mutations. The issue of the complex interaction of nature versus nurture is addressed.

Healthy adolescents' neural response to reward: associations with puberty, positive affect, and depressive symptoms.

PubMed

Forbes, Erika E; Ryan, Neal D; Phillips, Mary L; Manuck, Stephen B; Worthman, Carol M; Moyles, Donna L; Tarr, Jill A; Sciarrillo, Samantha R; Dahl, Ronald E

2010-02-01

Changes in reward-related behavior are an important component of normal adolescent affective development. Understanding the neural underpinnings of these normative changes creates a foundation for investigating adolescence as a period of vulnerability to affective disorders, substance use disorders, and health problems. Studies of reward-related brain function have revealed conflicting findings regarding developmental change in the reactivity of the striatum and medial prefrontal cortex (mPFC) and have not considered puberty. The current study focused on puberty-specific changes in brain function and their association with mood. A sample of 77 healthy adolescents (26 pre-/early pubertal, 51 mid-/late pubertal) recruited in a narrow age range (mean = 11.94 years, SD = 0.75) were assessed for sexual maturation and circulating testosterone, completed a functional magnetic resonance imaging (fMRI) guessing task with monetary reward, and underwent experience sampling of mood in natural environments. For comparison, 19 healthy adults completed the fMRI assessment. Adolescents with more advanced pubertal maturation exhibited less striatal and more mPFC reactivity during reward outcome than similarly aged adolescents with less advanced maturation. Testosterone was positively correlated with striatal reactivity in boys during reward anticipation and negatively correlated with striatal reactivity in girls and boys during reward outcome. Striatal reactivity was positively correlated with real-world subjective positive affect and negatively correlated with depressive symptoms. mPFC reactivity was positively correlated with depressive symptoms. Reward-related brain function changes with puberty and is associated with adolescents' positive affect and depressive symptoms. Increased reward-seeking behavior at this developmental point could serve to compensate for these changes.

Sexual Dimorphism and Allometric Effects Associated With the Wing Shape of Seven Moth Species of Sphingidae (Lepidoptera: Bombycoidea).

PubMed

de Camargo, Willian Rogers Ferreira; de Camargo, Nícholas Ferreira; Corrêa, Danilo do Carmo Vieira; de Camargo, Amabílio J Aires; Diniz, Ivone Rezende

2015-01-01

Sexual dimorphism is a pronounced pattern of intraspecific variation in Lepidoptera. However, moths of the family Sphingidae (Lepidoptera: Bombycoidea) are considered exceptions to this rule. We used geometric morphometric techniques to detect shape and size sexual dimorphism in the fore and hindwings of seven hawkmoth species. The shape variables produced were then subjected to a discriminant analysis. The allometric effects were measured with a simple regression between the canonical variables and the centroid size. We also used the normalized residuals to assess the nonallometric component of shape variation with a t-test. The deformations in wing shape between sexes per species were assessed with a regression between the nonreduced shape variables and the residuals. We found sexual dimorphism in both wings in all analyzed species, and that the allometric effects were responsible for much of the wing shape variation between the sexes. However, when we removed the size effects, we observed shape sexual dimorphism. It is very common for females to be larger than males in Lepidoptera, so it is expected that the shape of structures such as wings suffers deformations in order to preserve their function. However, sources of variation other than allometry could be a reflection of different reproductive flight behavior (long flights in search for sexual mates in males, and flight in search for host plants in females). © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

Sexually Dimorphic Effects of Ancestral Exposure to Vinclozolin on Stress Reactivity in Rats

PubMed Central

Gillette, Ross; Miller-Crews, Isaac; Nilsson, Eric E.; Skinner, Michael K.; Gore, Andrea C.

2014-01-01

How an individual responds to the environment depends upon both personal life history as well as inherited genetic and epigenetic factors from ancestors. Using a 2-hit, 3 generations apart model, we tested how F3 descendants of rats given in utero exposure to the environmental endocrine-disrupting chemical (EDC) vinclozolin reacted to stress during adolescence in their own lives, focusing on sexually dimorphic phenotypic outcomes. In adulthood, male and female F3 vinclozolin- or vehicle-lineage rats, stressed or nonstressed, were behaviorally characterized on a battery of tests and then euthanized. Serum was used for hormone assays, and brains were used for quantitative PCR and transcriptome analyses. Results showed that the effects of ancestral exposure to vinclozolin converged with stress experienced during adolescence in a sexually dimorphic manner. Debilitating effects were seen at all levels of the phenotype, including physiology, behavior, brain metabolism, gene expression, and genome-wide transcriptome modifications in specific brain nuclei. Additionally, females were significantly more vulnerable than males to transgenerational effects of vinclozolin on anxiety but not sociality tests. This fundamental transformation occurs in a manner not predicted by the ancestral exposure or the proximate effects of stress during adolescence, an interaction we refer to as synchronicity. PMID:25051444

Sexual dimorphism of gonadotropin-releasing hormone type-III (GnRH3) neurons and hormonal sex reversal of male reproductive behavior in Mozambique tilapia.

PubMed

Kuramochi, Asami; Tsutiya, Atsuhiro; Kaneko, Toyoji; Ohtani-Kaneko, Ritsuko

2011-10-01

In tilapia, hormone treatment during the period of sexual differentiation can alter the phenotype of the gonads, indicating that endocrine factors can cause gonadal sex reversal. However, the endocrine mechanism underlying sex reversal of reproductive behaviors remains unsolved. In the present study, we detected sexual dimorphism of gonadotropin-releasing hormone type III (GnRH3) neurons in Mozambique tilapia Oreochromis mossambicus. Our immunohistochemical observations showed sex differences in the number of GnRH3 immunoreactive neurons in mature tilapia; males had a greater number of GnRH3 neurons in the terminal ganglion than females. Treatment with androgen (11-ketotestosterone (11-KT) or methyltestosterone), but not that with 17β-estradiol, increased the number of GnRH3 neurons in females to a level similar to that in males. Furthermore, male-specific nest-building behavior was induced in 70% of females treated with 11-KT within two weeks after the onset of the treatment. These results indicate androgen-dependent regulation of GnRH3 neurons and nest-building behavior, suggesting that GnRH3 is importantly involved in sex reversal of male-specific reproductive behavior.

Facial Width-To-Height Ratio Relates to Alpha Status and Assertive Personality in Capuchin Monkeys

PubMed Central

Lefevre, Carmen Emilia; Wilson, Vanessa A. D.; Morton, F. Blake; Brosnan, Sarah F.; Paukner, Annika; Bates, Timothy C.

2014-01-01

Social dominance hierarchies play a pivotal role in shaping the behaviour of many species, and sex differences within these hierarchies often exist. To date, however, few physical markers of dominance have been identified. Such markers would be valuable in terms of understanding the etiology of dominant behaviour and changes in social hierarchies over time. Animals may also use such traits to evaluate the potential dominance of others relative to themselves (i.e. a physical “cue”). Facial width-to-height ratio (fWHR), for example, has been suggested as a cue to dominance in humans, with links to both dominant behaviour and the perception of dominance in other individuals. Whether this association is present in non-human animals is currently not known. Therefore, here we examine within-species links between fWHR and dominant behaviour in 64 brown capuchin monkeys (Sapajus spp.) aged between 2 and 40 years. fWHR was positively associated with alpha status and with a dimensional rating of assertive personality in both males and females. Moreover, fWHR showed significant sexual dimorphism in adults but not juveniles, suggesting a developmental change may occur during puberty. In a sub-sample, sex differences were mediated by weight, suggesting fWHR dimorphism does not exceed what would be expected by differences in body weight. This is the first report of an association between face shape and behaviour in a non-human species. Results are discussed in terms of the role that face-behaviour associations might play within capuchin societies, and the possible selective forces that might have led to the evolution of fWHR-dominance associations in humans. PMID:24705247

The Role of Mother in Informing Girls About Puberty: A Meta-Analysis Study

PubMed Central

Sooki, Zahra; Shariati, Mohammad; Chaman, Reza; Khosravi, Ahmad; Effatpanah, Mohammad; Keramat, Afsaneh

2016-01-01

Context Family, especially the mother, has the most important role in the education, transformation of information, and health behaviors of girls in order for them to have a healthy transition from the critical stage of puberty, but there are different views in this regard. Objectives Considering the various findings about the source of information about puberty, a meta-analysis study was conducted to investigate the extent of the mother’s role in informing girls about puberty. Data Sources This meta-analysis study was based on English articles published from 2000 to February 2015 in the Scopus, PubMed, and Science direct databases and on Persian articles in the SID, Magiran, and Iran Medex databases with determined key words and their MeSH equivalent. Study Selection Quantitative cross-sectional articles were extracted by two independent researchers and finally 46 articles were selected based on inclusion criteria. STROBE list were used for evaluation of studies. Data Extraction The percent of mothers as the current and preferred source of gaining information about the process of puberty, menarche, and menstruation from the perspective of adolescent girls was extracted from the articles. The results of studies were analyzed using meta-analysis (random effects model) and the studies’ heterogeneity was analyzed using the I2 calculation index. Variance between studies was analyzed using tau squared (Tau2) and review manager 5 software. Results The results showed that, from the perspective of teenage girls in Iran and other countries, in 56% of cases, the mother was the current source of information about the process of puberty, menarche, and menstruation. The preferred source of information about the process of puberty, menarche, and menstruation was the mother in all studies at 60% (Iran 57%, and other countries 66%). Conclusions According to the findings of this study, it is essential that health professionals and officials of the ministry of health train mothers about the time, trends, and factors affecting the start of puberty using a multi-dimensional approach that involves religious organizations, community groups, and peer groups. PMID:27331056

The Nuclear Receptor Corepressor Has Organizational Effects within the Developing Amygdala on Juvenile Social Play and Anxiety-Like Behavior

PubMed Central

Jessen, Heather M.; Kolodkin, Mira H.; Bychowski, Meaghan E.; Auger, Catherine J.; Auger, Anthony P.

2010-01-01

Nuclear receptor function on DNA is regulated by the balanced recruitment of coregulatory complexes. Recruited proteins that increase gene expression are called coactivators, and those that decrease gene expression are called corepressors. Little is known about the role of corepressors, such as nuclear receptor corepressor (NCoR), on the organization of behavior. We used real-time PCR to show that NCoR mRNA levels are sexually dimorphic, that females express higher levels of NCoR mRNA within the developing amygdala and hypothalamus, and that NCoR mRNA levels are reduced by estradiol treatment. To investigate the functional role of NCoR on juvenile social behavior, we infused small interfering RNA targeted against NCoR within the developing rat amygdala and assessed the enduring impact on juvenile social play behavior, sociability, and anxiety-like behavior. As expected, control males exhibited higher levels of juvenile social play than control females. Reducing NCoR expression during development further increased juvenile play in males only. Interestingly, decreased NCoR expression within the developing amygdala had lasting effects on increasing juvenile anxiety-like behavior in males and females. These data suggest that the corepressor NCoR functions to blunt sex differences in juvenile play behavior, a sexually dimorphic and hormone-dependent behavior, and appears critical for appropriate anxiety-like behavior in juvenile males and females. PMID:20051490

The nuclear receptor corepressor has organizational effects within the developing amygdala on juvenile social play and anxiety-like behavior.

PubMed

Jessen, Heather M; Kolodkin, Mira H; Bychowski, Meaghan E; Auger, Catherine J; Auger, Anthony P

2010-03-01

Nuclear receptor function on DNA is regulated by the balanced recruitment of coregulatory complexes. Recruited proteins that increase gene expression are called coactivators, and those that decrease gene expression are called corepressors. Little is known about the role of corepressors, such as nuclear receptor corepressor (NCoR), on the organization of behavior. We used real-time PCR to show that NCoR mRNA levels are sexually dimorphic, that females express higher levels of NCoR mRNA within the developing amygdala and hypothalamus, and that NCoR mRNA levels are reduced by estradiol treatment. To investigate the functional role of NCoR on juvenile social behavior, we infused small interfering RNA targeted against NCoR within the developing rat amygdala and assessed the enduring impact on juvenile social play behavior, sociability, and anxiety-like behavior. As expected, control males exhibited higher levels of juvenile social play than control females. Reducing NCoR expression during development further increased juvenile play in males only. Interestingly, decreased NCoR expression within the developing amygdala had lasting effects on increasing juvenile anxiety-like behavior in males and females. These data suggest that the corepressor NCoR functions to blunt sex differences in juvenile play behavior, a sexually dimorphic and hormone-dependent behavior, and appears critical for appropriate anxiety-like behavior in juvenile males and females.

Shingles

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PCP

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Extending the socio-sexual brain: arginine-vasopressin immunoreactive circuits in the telencephalon of mice.

PubMed

Otero-Garcia, Marcos; Martin-Sanchez, Ana; Fortes-Marco, Lluis; Martínez-Ricós, Joana; Agustin-Pavón, Carmen; Lanuza, Enrique; Martínez-García, Fernando

2014-05-01

Quantitative analysis of the immunoreactivity for arginine-vasopressin (AVP-ir) in the telencephalon of male (intact and castrated) and female CD1 mice allows us to precisely locate two sexually dimorphic (more abundant in intact than castrated males and females) AVP-ir cell groups in the posterior bed nucleus of the stria terminalis (BST) and the amygdala. Chemoarchitecture (NADPH diaphorase) reveals that the intraamygdaloid AVP-ir cells are located in the intra-amygdaloid BST (BSTIA) rather than the medial amygdala (Me), as previously thought. Then, we have used for the first time tract tracing (combined with AVP immunofluorescence) and fiber-sparing lesions of the BST to analyze the projections of the telencephalic AVP-ir cell groups. The results demonstrate that the posterior BST originates the sexually dimorphic innervation of the lateral septum, the posterodorsal Me and a substance P-negative area in the medioventral striato-pallidum (mvStP).The BSTIA may also contribute to some of these terminal fields. Our material also reveals non-dimorphic AVP-ir processes in two locations of the amygdala. First, the ventral Me shows dendrite-like AVP-ir processes apparently belonging supraoptic neurons, whose possible functions are discussed. Second, the Ce shows sparse, thick AVP-ir axons with high individual variability in density and distribution, whose possible influence on stress coping in relation to the affiliative or agonistic behaviors mediated by the Me are discussed. Finally, we propose that the region of the mvStP showing sexually dimorphic AVP-ir innervation is part of the brain network for socio-sexual behavior, in which it would mediate motivational aspects of chemosensory-guided social interactions.

“The Cooties Effect”: Amygdala Reactivity to Opposite-versus Same-sex Faces Declines from Childhood to Adolescence

PubMed Central

Telzer, Eva H.; Flannery, Jessica; Humphreys, Kathryn L.; Goff, Bonnie; Gabard-Durman, Laurel; Gee, Dylan G.; Tottenham, Nim

2017-01-01

One of the most important social identities that children learn to define themselves and others by is sex, becoming a salient social category by early childhood. Although older children begin to show greater flexibility in their gendered behaviors and attitudes, gender rigidity intensifies again around the time of puberty. In the current study, we assessed behavioral and neural biases to sex across a wide age group. Ninety-three youth (ages 7–17 years) provided behavioral rating of same- and opposite-sex attitudes, and 52 youth (ages 4–18 years) underwent an fMRI scan as they matched the emotion of same- and opposite-sex faces. We demonstrate significant age-related behavioral biases of sex that are mediated by differential amygdala response to opposite-sex relative to same-sex faces in children, an effect that completely attenuates by the teenage years. Moreover, we find a second peak in amygdala sensitivity to opposite-sex faces around the time of puberty. Thus, the amygdala codes for developmentally dependent and motivationally relevant social identification across development. PMID:25848681

School and Concussions

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Syphilis (For Parents)

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Shingles (For Parents)

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Predictors of online and offline sexual activities and behaviors among adolescents.

PubMed

Sevčíková, Anna; Vazsonyi, Alexander T; Sirůček, Jan; Konečný, Stěpán

2013-08-01

Despite the fact that many adolescents spend much time on the Internet, it is unknown who engages in sexually related online activities (SROA) and how these affect adolescent sexual development. The present longitudinal study on 323 adolescents (51.1% girls) aimed to explore how peer attachment processes predicted both SROA and offline sexual behaviors at the age of 17, while also considering puberty and prior offline sexual experiences in order to elucidate potential similarities or differences. Findings based on hierarchical, binary logistic regression analyses revealed that SROA were predicted by alienation attachment to peers (OR=3.36, p<0.05), puberty (OR=1.03, p<0.05), and prior SROA (OR=0.56, p<0.001), while only previous offline sexual experiences at the age of 15 increased the likelihood of offline sexual behaviors at the age of 17 (OR=6.04, p<0.001). Study findings indicate that the Internet provides an additional context for acquiring sexual experiences during adolescence.

Testosterone levels correspond with increased ventral striatum activation in response to monetary rewards in adolescents.

PubMed

Op de Macks, Zdeňa A; Gunther Moor, Bregtje; Overgaauw, Sandy; Güroğlu, Berna; Dahl, Ronald E; Crone, Eveline A

2011-10-01

Risk taking is an integral part of learning and development, particularly during adolescence the prevalence of risky behaviors peak. It is hypothesized that the tendency to take risks is related to pubertal maturation, where there is interplay between gonadal hormones, the neural mechanisms that underlie affective (e.g., reward) processing, and risky behavior. To test this hypothesis, fifty healthy adolescents (aged 10-16 years; 33 girls, 17 boys) at different stages of puberty performed a gambling task while lying in the MRI scanner, and provided saliva samples for hormone assessment. Gonadal hormone levels were correlated with the neural response to receiving a monetary reward. Results showed that testosterone level correlated positively with activation in the striatum for both boys and girls, suggesting that individual differences in hormones at puberty are related to the way adolescents respond to reward, which can ultimately affect risk-taking behavior. Copyright © 2011 Elsevier Ltd. All rights reserved.

Neural circuitry coordinating male copulation

PubMed Central

Pavlou, Hania J; Lin, Andrew C; Neville, Megan C; Nojima, Tetsuya; Diao, Fengqiu; Chen, Brian E; White, Benjamin H; Goodwin, Stephen F

2016-01-01

Copulation is the goal of the courtship process, crucial to reproductive success and evolutionary fitness. Identifying the circuitry underlying copulation is a necessary step towards understanding universal principles of circuit operation, and how circuit elements are recruited into the production of ordered action sequences. Here, we identify key sex-specific neurons that mediate copulation in Drosophila, and define a sexually dimorphic motor circuit in the male abdominal ganglion that mediates the action sequence of initiating and terminating copulation. This sexually dimorphic circuit composed of three neuronal classes – motor neurons, interneurons and mechanosensory neurons – controls the mechanics of copulation. By correlating the connectivity, function and activity of these neurons we have determined the logic for how this circuitry is coordinated to generate this male-specific behavior, and sets the stage for a circuit-level dissection of active sensing and modulation of copulatory behavior. DOI: http://dx.doi.org/10.7554/eLife.20713.001 PMID:27855059

Acute ethanol responses in Drosophila are sexually dimorphic

PubMed Central

Devineni, Anita V.; Heberlein, Ulrike

2012-01-01

In mammalian and insect models of ethanol intoxication, low doses of ethanol stimulate locomotor activity whereas high doses induce sedation. Sex differences in acute ethanol responses, which occur in humans, have not been characterized in Drosophila. In this study, we find that male flies show increased ethanol hyperactivity and greater resistance to ethanol sedation compared with females. We show that the sex determination gene transformer (tra) acts in the developing nervous system, likely through regulation of fruitless (fru), to at least partially mediate the sexual dimorphism in ethanol sedation. Although pharmacokinetic differences may contribute to the increased sedation sensitivity of females, neuronal tra expression regulates ethanol sedation independently of ethanol pharmacokinetics. We also show that acute activation of fru-expressing neurons affects ethanol sedation, further supporting a role for fru in regulating this behavior. Thus, we have characterized previously undescribed sex differences in behavioral responses to ethanol, and implicated fru in mediating a subset of these differences. PMID:23213244

White Matter Development in Adolescence: The Influence of Puberty and Implications for Affective Disorders

PubMed Central

Ladouceur, Cecile D.; Peper, Jiska S.; Crone, Eveline A.; Dahl, Ronald E.

2011-01-01

There have been rapid advances in understanding a broad range of changes in brain structure and function during adolescence, and a growing interest in identifying which of these neurodevelopmental changes are directly linked with pubertal maturation—at least in part because of their potential to provide insights into the numerous emotional and behavioral health problems that emerge during this developmental period. This review focuses on what is known about the influence of puberty on white matter development in adolescence. We focus on white matter because of its role in providing the structural architectural organization of the brain and as a structural correlate of communication within complex neural systems. We begin with a review of studies that report sex differences or sex by age interactions in white matter development as these findings can provide, although indirectly, information relevant to puberty-related changes. Studies are also critically reviewed based on methodological procedures used to assess pubertal maturation and relations with white matter changes. Findings are discussed in light of their implications for the development of neural systems underlying the regulation of emotion and behavior and how alterations in the development of these systems may mediate risk for affective disorders in vulnerable adolescents. PMID:22247751

Preferences for masculinity in male bodies change across the menstrual cycle.

PubMed

Little, Anthony C; Jones, Benedict C; Burriss, Robert P

2007-05-01

In human females cyclic shifts in preference have been documented for odour and physical and behavioral male traits. Women prefer the smell of dominant males, more masculine male faces and men behaving more dominantly when at peak fertility than at other times in their menstrual cycle. Here we examine variation in preferences for body sexual dimorphism. Across two studies, both between- and within-participant, we show that women prefer greater masculinity in male bodies at times when their fertility is likely highest, in the follicular phase of their cycle. Shifts were seen when rating for a short-term but not when rating for a long-term relationship. In line with studies showing similar effects for facial sexual dimorphism, we also show that women prefer greater masculinity when they think themselves attractive than when they think themselves less attractive. These results indicate that women's preferences for sexual dimorphism in male bodies follow a similar pattern as found for sexual dimorphism and dominance in other domains and such differences in preference may serve a similar function. Cyclic preferences could influence women to select partners when most likely to become pregnant that possess traits that may be most likely to maximize their offspring's quality via attraction to masculinity or serve to help acquire investment via attraction to femininity.

A possible instance of sexual dimorphism in the tails of two oviraptorosaur dinosaurs

PubMed Central

IV, W. Scott Persons; Funston, Gregory F.; Currie, Philip J.; Norell, Mark A.

2015-01-01

The hypothesis that oviraptorosaurs used tail-feather displays in courtship behavior previously predicted that oviraptorosaurs would be found to display sexually dimorphic caudal osteology. MPC-D 100/1002 and MPC-D 100/1127 are two specimens of the oviraptorosaur Khaan mckennai. Although similar in absolute size and in virtually all other anatomical details, the anterior haemal spines of MPC-D 100/1002 exceed those of MPC-D 100/1127 in ventral depth and develop a hitherto unreported “spearhead” shape. This dissimilarity cannot be readily explained as pathologic and is too extreme to be reasonably attributed to the amount of individual variation expected among con-specifics. Instead, this discrepancy in haemal spine morphology may be attributable to sexual dimorphism. The haemal spine form of MPC-D 100/1002 offers greater surface area for caudal muscle insertions. On this basis, MPC-D 100/1002 is regarded as most probably male, and MPC-D 100/1127 is regarded as most probably female. PMID:25824625

The nature of allometry in an exaggerated trait: The postocular flange in Platyneuromus Weele (Insecta: Megaloptera).

PubMed

Ramírez-Ponce, Andrés; Garfias-Lozano, Gabriela; Contreras-Ramos, Atilano

2017-01-01

The origin and function of exaggerated traits exhibited by a great number of species with sexual dimorphism remain largely unexplored. The usual model considered as the evolutionary mechanism for the development of these structures is sexual selection. The nature of growth of the postocular flange (POF) in three species of the dobsonfly genus Platyneuromus (Megaloptera, Corydalidae, Corydalinae) is analyzed to explore sexual size dimorphism and allometric scaling. Results involve positive allometry of POF in males of two species, and negative allometry in males of one species, in general with a female-biased sexual dimorphism. We suggest an ancestral condition of dual incipient ornamentation in Platyneuromus, with a subsequent departure of size and shape of POF in males, triggered by sexual selection. Different sexual selection intensities may explain the parallel or divergent growth of POF within the scheme of dual ornamentation. Empirical behavioral data as well as a phylogenetic framework are necessary to clarify possible causes of phenotypic development, time of origin, and evolution of the POF.

Human preferences for sexually dimorphic faces may be evolutionarily novel

PubMed Central

Scott, Isabel M.; Clark, Andrew P.; Josephson, Steven C.; Boyette, Adam H.; Cuthill, Innes C.; Fried, Ruby L.; Gibson, Mhairi A.; Hewlett, Barry S.; Jamieson, Mark; Jankowiak, William; Honey, P. Lynne; Huang, Zejun; Liebert, Melissa A.; Purzycki, Benjamin G.; Shaver, John H.; Snodgrass, J. Josh; Sosis, Richard; Sugiyama, Lawrence S.; Swami, Viren; Yu, Douglas W.; Zhao, Yangke; Penton-Voak, Ian S.

2014-01-01

A large literature proposes that preferences for exaggerated sex typicality in human faces (masculinity/femininity) reflect a long evolutionary history of sexual and social selection. This proposal implies that dimorphism was important to judgments of attractiveness and personality in ancestral environments. It is difficult to evaluate, however, because most available data come from large-scale, industrialized, urban populations. Here, we report the results for 12 populations with very diverse levels of economic development. Surprisingly, preferences for exaggerated sex-specific traits are only found in the novel, highly developed environments. Similarly, perceptions that masculine males look aggressive increase strongly with development and, specifically, urbanization. These data challenge the hypothesis that facial dimorphism was an important ancestral signal of heritable mate value. One possibility is that highly developed environments provide novel opportunities to discern relationships between facial traits and behavior by exposing individuals to large numbers of unfamiliar faces, revealing patterns too subtle to detect with smaller samples. PMID:25246593

Pubertal Timing and Substance Use in Middle Adolescence: A 2-Year Follow-Up Study

ERIC Educational Resources Information Center

Kaltiala-Heino, Riittakerttu; Koivisto, Anna-Maija; Marttunen, Mauri; Frojd, Sari

2011-01-01

Earlier research has associated early puberty with emotional and behavioral symptoms particularly among girls, while among boys, findings have been contradictory as to whether risks are associated with early or late pubertal timing. We studied the association between pubertal timing and substance use behaviors in middle adolescence in a 2-year…

The Role of Emotional Reactivity, Self-Regulation, and Puberty in Adolescents' Prosocial Behaviors

ERIC Educational Resources Information Center

Carlo, Gustavo; Crockett, Lisa J.; Wolff, Jennifer M.; Beal, Sarah J.

2012-01-01

This study was designed to examine the roles of emotional reactivity, self-regulation, and pubertal timing in prosocial behaviors during adolescence. Participants were 850 sixth graders (50 percent female, mean age = 11.03, standard deviation = 0.17) who were followed up at the age of 15. In hierarchical regression models, measures of emotional…

Pelvic dimorphism in relation to body size and body size dimorphism in humans.

PubMed

Kurki, Helen K

2011-12-01

Many mammalian species display sexual dimorphism in the pelvis, where females possess larger dimensions of the obstetric (pelvic) canal than males. This is contrary to the general pattern of body size dimorphism, where males are larger than females. Pelvic dimorphism is often attributed to selection relating to parturition, or as a developmental consequence of secondary sexual differentiation (different allometric growth trajectories of each sex). Among anthropoid primates, species with higher body size dimorphism have higher pelvic dimorphism (in converse directions), which is consistent with an explanation of differential growth trajectories for pelvic dimorphism. This study investigates whether the pattern holds intraspecifically in humans by asking: Do human populations with high body size dimorphism also display high pelvic dimorphism? Previous research demonstrated that in some small-bodied populations, relative pelvic canal size can be larger than in large-bodied populations, while others have suggested that larger-bodied human populations display greater body size dimorphism. Eleven human skeletal samples (total N: male = 229, female = 208) were utilized, representing a range of body sizes and geographical regions. Skeletal measurements of the pelvis and femur were collected and indices of sexual dimorphism for the pelvis and femur were calculated for each sample [ln(M/F)]. Linear regression was used to examine the relationships between indices of pelvic and femoral size dimorphism, and between pelvic dimorphism and female femoral size. Contrary to expectations, the results suggest that pelvic dimorphism in humans is generally not correlated with body size dimorphism or female body size. These results indicate that divergent patterns of dimorphism exist for the pelvis and body size in humans. Implications for the evaluation of the evolution of pelvic dimorphism and rotational childbirth in Homo are considered. Copyright © 2011 Elsevier Ltd. All rights reserved.

Developmental antecedents of abnormal eating attitudes and behaviors in adolescence.

PubMed

Le Grange, Daniel; O'Connor, Meredith; Hughes, Elizabeth K; Macdonald, Jacqui; Little, Keriann; Olsson, Craig A

2014-11-01

This study capitalizes on developmental data from an Australian population-based birth cohort to identify developmental markers of abnormal eating attitudes and behaviors in adolescence. The aims were twofold: (1) to develop a comprehensive path model identifying infant and childhood developmental correlates of Abnormal Eating Attitudes and Behaviors in adolescence, and (2) to explore potential gender differences. Data were drawn from a 30-year longitudinal study that has followed the health and development of a population based cohort across 15 waves of data collection from infancy since 1983: The Australian Temperament Project. Participants in this analysis were the 1,300 youth who completed the 11th survey at 15-16 years (1998) and who completed the eating disorder inventory at this time point. Developmental correlates of Abnormal Eating Attitudes and Behaviors in mid-adolescence were temperamental persistence, early gestational age, persistent high weight, teen depression, stronger peer relationships, maternal dieting behavior, and pubertal timing. Overall, these factors accounted for 28% of the variance in Abnormal Eating Attitudes and Behaviors at 15-16 years of age. Depressive symptoms, maternal dieting behavior, and early puberty were more important factors for girls. Late puberty was a more important factor for boys. Findings address an important gap in our understanding of the etiology of Abnormal Eating Attitudes and Behaviors in adolescence and suggest multiple targets for preventive intervention. © 2014 Wiley Periodicals, Inc.

Feeding Your 1- to 3-Month-Old

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5 Ways to Spot a Fad Diet

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Sexual Dimorphism in the Brain of the Monogamous California Mouse (Peromyscus californicus).

PubMed

Campi, Katharine L; Jameson, Chelsea E; Trainor, Brian C

2013-01-01

Sex differences in behavior and morphology are usually assumed to be stronger in polygynous species compared to monogamous species. A few brain structures have been identified as sexually dimorphic in polygynous rodent species, but it is less clear whether these differences persist in monogamous species. California mice are among the 5% or less of mammals that are considered to be monogamous and as such provide an ideal model to examine sexual dimorphism in neuroanatomy. In the present study we compared the volume of hypothalamic- and limbic-associated regions in female and male California mice for sexual dimorphism. We also used tyrosine hydroxylase (TH) immunohistochemistry to compare the number of dopamine neurons in the ventral tegmental area (VTA) in female and male California mice. Additionally, tract tracing was used to accurately delineate the boundaries of the VTA. The total volume of the sexually dimorphic nucleus of the preoptic area (SDN-POA), the principal nucleus of the bed nucleus of the stria terminalis (BNST), and the posterodorsal medial amygdala (MEA) was larger in males compared to females. In the SDN-POA we found that the magnitude of sex differences in the California mouse were intermediate between the large differences observed in promiscuous meadow voles and rats and the absence of significant differences in monogamous prairie voles. However, the magnitude of sex differences in MEA and the BNST were comparable to polygynous species. No sex differences were observed in the volume of the whole brain, the VTA, the nucleus accumbens or the number of TH-ir neurons in the VTA. These data show that despite a monogamous social organization, sexual dimorphisms that have been reported in polygynous rodents extend to California mice. Our data suggest that sex differences in brain structures such as the SDN-POA persist across species with different social organizations and may be an evolutionarily conserved characteristic of mammalian brains.

Loss of T cells influences sex differences in behavior and brain structure.

PubMed

Rilett, Kelly C; Friedel, Miriam; Ellegood, Jacob; MacKenzie, Robyn N; Lerch, Jason P; Foster, Jane A

2015-05-01

Clinical and animal studies demonstrate that immune-brain communication influences behavior and brain function. Mice lacking T cell receptor β and δ chains were tested in the elevated plus maze, open field, and light-dark test and showed reduced anxiety-like behavior compared to wild type. Interestingly sex differences were observed in the behavioural phenotype of TCRβ-/-δ- mice. Specifically, female TCRβ-/-δ- mice spent more time in the light chamber compared to wild type females, whereas male TCRβ-/-δ- spent more time in the center of the open field compared to wild type males. In addition, TCRβ-/-δ- mice did not show sex differences in activity-related behaviors observed in WT mice. Ex vivo brain imaging (7 Tesla MRI) revealed volume changes in hippocampus, hypothalamus, amygdala, periaqueductal gray, and dorsal raphe and other brain regions between wild type and T cell receptor knockout mice. There was also a loss of sexual dimorphism in brain volume in the bed nucleus of the stria terminalis, normally the most sexually dimorphic region in the brain, in immune compromised mice. These data demonstrate the presence of T cells is important in the development of sex differences in CNS circuitry and behavior. Copyright © 2015 Elsevier Inc. All rights reserved.

Relationships between day one piglet serum immunoglobulin immunocrit and subsequent growth, puberty attainment, litter size, and lactation performance.

PubMed

Vallet, J L; Miles, J R; Rempel, L A; Nonneman, D J; Lents, C A

2015-06-01

Colostrum affects gut and uterine gland development in the neonatal piglet, suggesting that subsequent growth and reproductive performance may be affected. Measuring immunoglobulin in piglet serum using the immunoglobulin immunocrit on Day 1 of age provides a simple, inexpensive indication of the amount of colostrum acquired by the piglet in the first day of life. Relationships between serum immunoglobulin immunocrit measures and subsequent growth rates, age at puberty, incidence of puberty failure, litter size, and lactation performance were examined in pigs born and subsequently farrowing between 2009 and 2013. Immunoglobulin immunocrit measures were collected on 16,762 piglets on Day 1 of age. Of these piglets, BW measurements were available from 15,324 (7,684 males and 7,640 females) piglets at a range of ages from weaning to 200 d of age, allowing an assessment of growth rates. Age at puberty was recorded from a subset of 2,857 of the females after observing them for estrous behavior from approximately 170 to 250 d of age. To examine relationships between d 1 immunocrit and puberty failure, gilts with immunocrit measures that failed to reach puberty (n = 119) were matched with littermate gilts with immunocrit measures that achieved puberty (n = 167). Similarly, number born alive was collected on a subset (n = 799) of females from first to fourth parities for which d 1 immunocrits were measured on them as neonates. Finally, d 1 immunocrit effect on adult lactational competence was assessed by measuring litter average (offspring of 440 females) and litter average piglet preweaning growth rate (offspring of 774 females) in females where d 1 immunocrits were available from them as neonates. Results indicated that low d 1 immunocrits were subsequently associated with reduced growth (P < 0.01), increased age at puberty (P < 0.01), reduced number born alive (P < 0.05), reduced litter average immunocrit (P < 0.05), and reduced litter average preweaning growth rate during lactation (P < 0.05). This suggests that management efforts to improve the amount of colostrum ingested by neonatal piglets would result in beneficial changes in production efficiency, particularly for gilts destined for the breeding herd. It also suggests that the immunoglobulin immunocrit can be useful in monitoring colostrum ingestion to maximize the beneficial effects of colostrum on subsequent performance.

Effects of early menarche on physical and psychosocial health problems in adolescent girls and adult women

PubMed Central

2016-01-01

The menarcheal age of Korean women has been rapidly decreasing for the last 50 years, and the average menarcheal age of women born in the 1990s is approaching 12.6 years. In addition, interest in early puberty has been increasing recently owing to the rapid increase in precocious puberty. Generally, out of concern for short stature and early menarche, idiopathic central precocious puberty in female adolescents is treated with gonadotropin-releasing hormone analogs. Studies to date have described the association between early menarche and psychosocial problems such as delinquency and risky sexual behavior, as well as physical health problems such as obesity, diabetes, cardiovascular diseases, and breast cancer throughout the lifespan of women. However, the pathophysiological mechanism underlying this association has not been clarified thus far. In this article, we review and discuss the existing literature to describe the current understanding of the effects of early menarche on the physical and psychosocial health of adolescent girls and adult women. PMID:27721839

Restoring Serotonergic Homeostasis in the Lateral Hypothalamus Rescues Sleep Disturbances Induced by Early-Life Obesity.

PubMed

Gazea, Mary; Patchev, Alexandre V; Anderzhanova, Elmira; Leidmaa, Este; Pissioti, Anna; Flachskamm, Cornelia; Almeida, Osborne F X; Kimura, Mayumi

2018-01-10

Early-life obesity predisposes to obesity in adulthood, a condition with broad medical implications including sleep disorders, which can exacerbate metabolic disturbances and disrupt cognitive and affective behaviors. In this study, we examined the long-term impact of transient peripubertal diet-induced obesity (ppDIO, induced between 4 and 10 weeks of age) on sleep-wake behavior in male mice. EEG and EMG recordings revealed that ppDIO increases sleep during the active phase but reduces resting-phase sleep quality. This impaired sleep phenotype persisted for up to 1 year, although animals were returned to a non-obesiogenic diet from postnatal week 11 onwards. To better understand the mechanisms responsible for the ppDIO-induced alterations in sleep, we focused on the lateral hypothalamus (LH). Mice exposed to ppDIO did not show altered mRNA expression levels of orexin and melanin-concentrating hormone, two peptides that are important for sleep-wake behavior and food intake. Conversely, the LH of ppDIO-exposed mice had reduced contents of serotonin (5-hydroxytryptamine, 5-HT), a neurotransmitter involved in both sleep-wake and satiety regulation. Interestingly, an acute peripheral injection of the satiety-signaling peptide YY 3-36 increased 5-HT turnover in the LH and ameliorated the ppDIO-induced sleep disturbances, suggesting the therapeutic potential of this peptide. These findings provide new insights into how sleep-wake behavior is programmed during early life and how peripheral and central signals are integrated to coordinate sleep. SIGNIFICANCE STATEMENT Adult physiology and behavior are strongly influenced by dynamic reorganization of the brain during puberty. The present work shows that obesity during puberty leads to persistently dysregulated patterns of sleep and wakefulness by blunting serotonergic signaling in the lateral hypothalamus. It also shows that pharmacological mimicry of satiety with peptide YY 3-36 can reverse this neurochemical imbalance and acutely restore sleep composition. These findings add insight into how innate behaviors such as feeding and sleep are integrated and suggest a novel mechanism through which diet-induced obesity during puberty imposes its long-lasting effects on sleep-wake behavior. Copyright © 2018 the authors 0270-6474/18/380441-11$15.00/0.

Rapid weight gain after birth predicts life history and reproductive strategy in Filipino males

PubMed Central

Kuzawa, Christopher W.; McDade, Thomas W.; Adair, Linda S.; Lee, Nanette

2010-01-01

Ecological cues during prenatal and postnatal development may allow organisms to adjust reproductive strategy. The hypothalamic-pituitary-gonadal (HPG) axis is a prime candidate for adaptive plasticity as a result of its critical period of birth to 6 mo (B6M) in humans and the role of testosterone in the development and maintenance of costly sexually dimorphic somatic and behavioral traits. We hypothesized that weight velocity specific to B6M would predict male life history characteristics, including maturational timing, reproductive hormones, adult size, strength, and sexual activity. Data come from 770 Filipino men (age 20.5–22.5 y) followed since birth, with predictor variables including birth weight and weight velocities calculated at 6-mo intervals during the first 2 y of life. As expected, infants who were breastfed experienced less diarrhea, lived in wealthier households with better hygiene, and grew faster from B6M. Males with rapid B6M growth reached puberty earlier and, as young adults, had higher testosterone levels, were taller, more muscular, and had higher grip strength. They also had sex earlier and were more likely to report having had sex in the past month, resulting in more lifetime sex partners. Relationships between B6M weight gain and physical outcomes were generally not present or weaker in female subjects. We conclude that rapid weight gain specific to the brief postnatal hypothalamic-pituitary-gonadal critical period predicts early maturation and sexual activity, elevated hormone production, and more costly adult somatic characteristics among the male subjects in this sample. These findings provide evidence for early life developmental plasticity in male life history and reproductive strategy in humans. PMID:20837542

Developmental Treatment with Ethinyl Estradiol, but Not Bisphenol A, Causes Alterations in Sexually Dimorphic Behaviors in Male and Female Sprague Dawley Rats

PubMed Central

Ferguson, Sherry A.; Law, Charles Delbert; Kissling, Grace E.

2014-01-01

The developing central nervous system may be particularly sensitive to bisphenol A (BPA)-induced alterations. Here, pregnant Sprague Dawley rats (n = 11–12/group) were gavaged daily with vehicle, 2.5 or 25.0 μg/kg BPA, or 5.0 or 10.0 μg/kg ethinyl estradiol (EE2) on gestational days 6–21. The BPA doses were selected to be below the no-observed-adverse-effect level (NOAEL) of 5 mg/kg/day. On postnatal days 1–21, all offspring/litter were orally treated with the same dose. A naïve control group was not gavaged. Body weight, pubertal age, estrous cyclicity, and adult serum hormone levels were measured. Adolescent play, running wheel activity, flavored solution intake, female sex behavior, and manually elicited lordosis were assessed. No significant differences existed between the vehicle and naïve control groups. Vehicle controls exhibited significant sexual dimorphism for most behaviors, indicating these evaluations were sensitive to sex differences. However, only EE2 treatment caused significant effects. Relative to female controls, EE2-treated females were heavier, exhibited delayed vaginal opening, aberrant estrous cyclicity, increased play behavior, decreased running wheel activity, and increased aggression toward the stimulus male during sexual behavior assessments. Relative to male controls, EE2-treated males were older at testes descent and preputial separation and had lower testosterone levels. These results suggest EE2-induced masculinization/defeminization of females and are consistent with increased volume of the sexually dimorphic nucleus of the preoptic area (SDN-POA) at weaning in female siblings of these subjects (He, Z., Paule, M. G. and Ferguson, S. A. (2012) Low oral doses of bisphenol A increase volume of the sexually dimorphic nucleus of the preoptic area in male, but not female, rats at postnatal day 21. Neurotoxicol. Teratol. 34, 331–337). Although EE2 treatment caused pubertal delays and decreased testosterone levels in males, their behaviors were within the range of control males. Conversely, BPA treatment did not alter any measured endpoint. Similar to our previous reports (Ferguson, S. A., Law, C. D. Jr and Abshire, J. S. (2011) Developmental treatment with bisphenol A or ethinyl estradiol causes few alterations on early preweaning measures. Toxicol. Sci. 124, 149–160; Ferguson, S. A., Law, C. D. and Abshire, J. S. (2012) Developmental treatment with bisphenol A causes few alterations on measures of postweaning activity and learning. Neurotoxicol. Teratol. 34, 598–606), the BPA doses and design used here produced few alterations. PMID:24798382

Sex-dimorphic face shape preference in heterosexual and homosexual men and women.

PubMed

Glassenberg, Aaron N; Feinberg, David R; Jones, Benedict C; Little, Anthony C; Debruine, Lisa M

2010-12-01

Studies have used manipulated faces to test the preferences of heterosexual individuals for sexually dimorphic facial cues. In contrast to previous studies, which have generally excluded homosexual participants, we directly compared homosexual and heterosexual male and female preferences for manipulated sexual dimorphism in faces (homosexual males: n = 311; heterosexual males: n = 215; homosexual females: n = 159; heterosexual females: n = 218). Prior studies on sexual orientation and preferences for faces that were paired with masculine and feminine behavioral descriptors suggest that homosexual men prefer more masculine men and that homosexual women demonstrate no preference for either masculinity or femininity in women. In our study, we tested for similarities and differences among heterosexual and homosexual males and females with regard to their preferences for a more specific aspect of faces: sexual dimorphism of face shape. Homosexual men demonstrated stronger preferences for masculinity in male faces than did all of the other groups. Homosexual women demonstrated stronger preferences for masculinity in female faces than did heterosexual women. These results suggest attractiveness judgments of same-sex faces made by homosexual individuals are not a mirror image of those made by heterosexual individuals of the opposite sex. Our data suggest that face preferences of homosexual individuals reflect a system of biologically and socially guided preferences at least as complex as those found among heterosexual individuals.

Mating Changes Sexually Dimorphic Gene Expression in the Seed Beetle Callosobruchus maculatus.

PubMed

Immonen, Elina; Sayadi, Ahmed; Bayram, Helen; Arnqvist, Göran

2017-03-01

Sexually dimorphic phenotypes arise largely from sex-specific gene expression, which has mainly been characterized in sexually naïve adults. However, we expect sexual dimorphism in transcription to be dynamic and dependent on factors such as reproductive status. Mating induces many behavioral and physiological changes distinct to each sex and is therefore expected to activate regulatory changes in many sex-biased genes. Here, we first characterized sexual dimorphism in gene expression in Callosobruchus maculatus seed beetles. We then examined how females and males respond to mating and how it affects sex-biased expression, both in sex-limited (abdomen) and sex-shared (head and thorax) tissues. Mating responses were largely sex-specific and, as expected, females showed more genes responding compared with males (∼2,000 vs. ∼300 genes in the abdomen, ∼500 vs. ∼400 in the head and thorax, respectively). Of the sex-biased genes present in virgins, 16% (1,041 genes) in the abdomen and 17% (243 genes) in the head and thorax altered their relative expression between the sexes as a result of mating. Sex-bias status changed in 2% of the genes in the abdomen and 4% in the head and thorax following mating. Mating responses involved de-feminization of females and, to a lesser extent, de-masculinization of males relative to their virgin state: mating decreased rather than increased dimorphic expression of sex-biased genes. The fact that regulatory changes of both types of sex-biased genes occurred in both sexes suggests that male- and female-specific selection is not restricted to male- and female-biased genes, respectively, as is sometimes assumed. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Mating Changes Sexually Dimorphic Gene Expression in the Seed Beetle Callosobruchus maculatus

PubMed Central

Sayadi, Ahmed; Bayram, Helen; Arnqvist, Göran

2017-01-01

Sexually dimorphic phenotypes arise largely from sex-specific gene expression, which has mainly been characterized in sexually naïve adults. However, we expect sexual dimorphism in transcription to be dynamic and dependent on factors such as reproductive status. Mating induces many behavioral and physiological changes distinct to each sex and is therefore expected to activate regulatory changes in many sex-biased genes. Here, we first characterized sexual dimorphism in gene expression in Callosobruchus maculatus seed beetles. We then examined how females and males respond to mating and how it affects sex-biased expression, both in sex-limited (abdomen) and sex-shared (head and thorax) tissues. Mating responses were largely sex-specific and, as expected, females showed more genes responding compared with males (∼2,000 vs. ∼300 genes in the abdomen, ∼500 vs. ∼400 in the head and thorax, respectively). Of the sex-biased genes present in virgins, 16% (1,041 genes) in the abdomen and 17% (243 genes) in the head and thorax altered their relative expression between the sexes as a result of mating. Sex-bias status changed in 2% of the genes in the abdomen and 4% in the head and thorax following mating. Mating responses involved de-feminization of females and, to a lesser extent, de-masculinization of males relative to their virgin state: mating decreased rather than increased dimorphic expression of sex-biased genes. The fact that regulatory changes of both types of sex-biased genes occurred in both sexes suggests that male- and female-specific selection is not restricted to male- and female-biased genes, respectively, as is sometimes assumed. PMID:28391318

Adolescent TBI-induced hypopituitarism causes sexual dysfunction in adult male rats.

PubMed

Greco, Tiffany; Hovda, David A; Prins, Mayumi L

2015-02-01

Adolescents are at greatest risk for traumatic brain injury (TBI) and repeat TBI (RTBI). TBI-induced hypopituitarism has been documented in both adults and juveniles and despite the necessity of pituitary function for normal physical and brain development, it is still unrecognized and untreated in adolescents following TBI. TBI induced hormonal dysfunction during a critical developmental window has the potential to cause long-term cognitive and behavioral deficits and the topic currently remains unaddressed. The purpose of this study was to determine if four mild TBIs delivered to adolescent male rats disrupts testosterone production and adult behavioral outcomes. Plasma testosterone was quantified from 72 hrs preinjury to 3 months postinjury and pubertal onset, reproductive organ growth, erectile function and reproductive behaviors were assessed at 1 and 2 months postinjury. RTBI resulted in both acute and chronic decreases in testosterone production and delayed onset of puberty. Significant deficits were observed in reproductive organ growth, erectile function and reproductive behaviors in adult rats at both 1 and 2 months postinjury. These data suggest adolescent RTBI-induced hypopituitarism underlies abnormal behavioral changes observed during adulthood. The impact of undiagnosed hypopituitarism following RTBI in adolescence has significance not only for growth and puberty, but also for brain development and neurobehavioral function as adults. © 2014 Wiley Periodicals, Inc.

The nature of allometry in an exaggerated trait: The postocular flange in Platyneuromus Weele (Insecta: Megaloptera)

PubMed Central

Ramírez-Ponce, Andrés; Garfias-Lozano, Gabriela; Contreras-Ramos, Atilano

2017-01-01

The origin and function of exaggerated traits exhibited by a great number of species with sexual dimorphism remain largely unexplored. The usual model considered as the evolutionary mechanism for the development of these structures is sexual selection. The nature of growth of the postocular flange (POF) in three species of the dobsonfly genus Platyneuromus (Megaloptera, Corydalidae, Corydalinae) is analyzed to explore sexual size dimorphism and allometric scaling. Results involve positive allometry of POF in males of two species, and negative allometry in males of one species, in general with a female-biased sexual dimorphism. We suggest an ancestral condition of dual incipient ornamentation in Platyneuromus, with a subsequent departure of size and shape of POF in males, triggered by sexual selection. Different sexual selection intensities may explain the parallel or divergent growth of POF within the scheme of dual ornamentation. Empirical behavioral data as well as a phylogenetic framework are necessary to clarify possible causes of phenotypic development, time of origin, and evolution of the POF. PMID:28212437

Cognitive Ecology in Hummingbirds: The Role of Sexual Dimorphism and Its Anatomical Correlates on Memory

PubMed Central

González-Gómez, Paulina L.; Madrid-Lopez, Natalia; Salazar, Juan E.; Suárez, Rodrigo; Razeto-Barry, Pablo; Mpodozis, Jorge; Bozinovic, Francisco; Vásquez, Rodrigo A.

2014-01-01

In scatter-hoarding species, several behavioral and neuroanatomical adaptations allow them to store and retrieve thousands of food items per year. Nectarivorous animals face a similar scenario having to remember quality, location and replenishment schedules of several nectar sources. In the green-backed firecrown hummingbird (Sephanoides sephanoides), males are territorial and have the ability to accurately keep track of nectar characteristics of their defended food sources. In contrast, females display an opportunistic strategy, performing rapid intrusions into males territories. In response, males behave aggressively during the non-reproductive season. In addition, females have higher energetic demands due to higher thermoregulatory costs and travel times. The natural scenario of this species led us to compared cognitive abilities and hippocampal size between males and females. Males were able to remember nectar location and renewal rates significantly better than females. However, the hippocampal formation was significantly larger in females than males. We discuss these findings in terms of sexually dimorphic use of spatial resources and variable patterns of brain dimorphisms in birds. PMID:24599049

Seasonal Effects on the Population, Morphology and Reproductive Behavior of Narnia femorata (Hemiptera: Coreidae).

PubMed

Cirino, Lauren A; Miller, Christine W

2017-01-17

Many insects are influenced by the phenology of their host plants. In North Central Florida, Narnia femorata (Hemiptera: Coreidae) spends its entire life cycle living and feeding on Opuntia mesacantha ssp. lata . This cactus begins producing flower buds in April that lead to unripe green fruit in June that ripen into red fruit through December. Many morphological and behavioral characteristics of N. femorata are known to be affected by cactus phenology in a controlled laboratory setting, including the degree of sexual dimorphism and mating behavior. Our goal with this study was to determine if similar phenotypic changes of N. femorata occurred over time in the wild, and the extent to which these changes were concordant with phenological changes in its host plant. Further, we investigate the length of the insect mouthparts (beak) over time. Ongoing work has suggested that beak length may change across cohorts of developing insects in response to feeding deep within cactus fruit where seed and pulp depth decrease as the fruit ripens. Our results revealed a drop in cactus fruit abundance between the months of July through October 2015 as cactus fruits turned red and ripened. Simultaneously, the average body size of both males and females of N. femorata declined at two sampled sites. Male hind femora (a sexually-selected weapon) decreased disproportionately in size over time so that males later in the year had relatively smaller hind femora for their body size. The sex-specific patterns of morphological change led to increased sexual-size dimorphism and decreased sexual dimorphism for hind femora later in the year. Further, we found that beak length decreased across cohorts of insects as cactus fruit ripened, suggesting phenotypic plasticity in mouthpart length. Behavioral studies revealed that female readiness to mate increased as the season progressed. In sum, we found pronounced changes in the phenotypes of these insects in the field. Although this study is far from comprehensive, it provides tantalizing patterns that suggest many directions for future research.

Female contact modulates male aggression via a sexually dimorphic GABAergic circuit in Drosophila

PubMed Central

Yuan, Quan; Song, Yuanquan; Yang, Chung-Hui; Jan, Lily Yeh; Jan, Yuh Nung

2014-01-01

Intraspecific male-male aggression, important for sexual selection, is regulated by environment, experience and internal states through largely undefined molecular and cellular mechanisms. To understand the basic neural pathway underlying the modulation of this innate behavior, we established a behavioral paradigm in Drosophila melanogaster and investigated the relationship between sexual experience and aggression. In the presence of mating partners, adult male flies exhibited elevated levels of aggression, which was largely suppressed by prior exposure to females via a sexually dimorphic neural mechanism. The suppression involved the ability of male flies to detect females by contact chemosensation through the pheromone-sensing ion channel, ppk29, and was mediated by male specific GABAergic neurons acting upon GABA-a receptor RDL in target cells. Silencing or activation of this circuit led to dis-inhibition or elimination of sex-related aggression, respectively. We propose that the GABAergic inhibition represents a critical cellular mechanism that enables prior experience to modulate aggression. PMID:24241395

Beyond Gorilla and Pongo: alternative models for evaluating variation and sexual dimorphism in fossil hominoid samples.

PubMed

Scott, Jeremiah E; Schrein, Caitlin M; Kelley, Jay

2009-10-01

Sexual size dimorphism in the postcanine dentition of the late Miocene hominoid Lufengpithecus lufengensis exceeds that in Pongo pygmaeus, demonstrating that the maximum degree of molar size dimorphism in apes is not represented among the extant Hominoidea. It has not been established, however, that the molars of Pongo are more dimorphic than those of any other living primate. In this study, we used resampling-based methods to compare molar dimorphism in Gorilla, Pongo, and Lufengpithecus to that in the papionin Mandrillus leucophaeus to test two hypotheses: (1) Pongo possesses the most size-dimorphic molars among living primates and (2) molar size dimorphism in Lufengpithecus is greater than that in the most dimorphic living primates. Our results show that M. leucophaeus exceeds great apes in its overall level of dimorphism and that L. lufengensis is more dimorphic than the extant species. Using these samples, we also evaluated molar dimorphism and taxonomic composition in two other Miocene ape samples--Ouranopithecus macedoniensis from Greece, specimens of which can be sexed based on associated canines and P(3)s, and the Sivapithecus sample from Haritalyangar, India. Ouranopithecus is more dimorphic than the extant taxa but is similar to Lufengpithecus, demonstrating that the level of molar dimorphism required for the Greek fossil sample under the single-species taxonomy is not unprecedented when the comparative framework is expanded to include extinct primates. In contrast, the Haritalyangar Sivapithecus sample, if itrepresents a single species, exhibits substantially greater molar dimorphism than does Lufengpithecus. Given these results, the taxonomic status of this sample remains equivocal.

Influence of sex steroid hormones on the adolescent brain and behavior: An update

PubMed Central

Vigil, Pilar; del Río, Juan Pablo; Carrera, BÁrbara; ArÁnguiz, Florencia C.

2016-01-01

This review explains the main effects exerted by sex steroids and other hormones on the adolescent brain. During the transition from puberty to adolescence, these hormones participate in the organizational phenomena that structurally shape some brain circuits. In adulthood, this will propitiate some specific behavior as responses to the hormones now activating those neural circuits. Adolescence is, then, a critical “organizational window” for the brain to develop adequately, since steroid hormones perform important functions at this stage. For this reason, the adolescent years are very important for future behaviors in human beings. Changes that occur or fail to occur during adolescence will determine behaviors for the rest of one's lifetime. Consequently, understanding the link between adolescent behavior and brain development as influenced by sex steroids and other hormones and compounds is very important in order to interpret various psycho-affective pathologies. Lay Summary: The effect of steroid hormones on the development of the adolescent brain, and therefore, on adolescent behavior, is noticeable. This review presents their main activational and organizational effects. During the transition from puberty to adolescence, organizational phenomena triggered by steroids structurally affect the remodeling of brain circuits. Later in adulthood, these changes will be reflected in behavioral responses to such hormones. Adolescence can then be seen as a fundamental “organizational window” during which sex steroids and other hormones and compounds play relevant roles. The understanding of the relationship between adolescent behavior and the way hormones influence brain development help understand some psychological disorders. PMID:27833209

School-Based HIV/AIDS Education Is Associated with Reduced Risky Sexual Behaviors and Better Grades with Gender and Race/Ethnicity Differences

ERIC Educational Resources Information Center

Ma, Zhen-qiang; Fisher, Monica A.; Kuller, Lewis H.

2014-01-01

Although studies indicate school-based HIV/AIDS education programs effectively reduce risky behaviors, only 33 states and the District of Columbia in US mandate HIV/AIDS education. Ideally, school-based HIV/AIDS education should begin before puberty, or at the latest before first sexual intercourse. In 2011, 20% US states had fewer schools…

The evolution of sexual size dimorphism in the house finch. II. Population divergence in relation to local selection.

PubMed

Badyaev, A V; Hill, G E; Stoehr, A M; Nolan, P M; McGraw, K J

2000-12-01

Recent colonization of ecologically distinct areas in North America by the house finch (Carpodacus mexicanus) was accompanied by strong population divergence in sexual size dimorphism. Here we examined whether this divergence was produced by population differences in local selection pressures acting on each sex. In a long-term study of recently established populations in Alabama, Michigan, and Montana, we examined three selection episodes for each sex: selection for pairing success, overwinter survival, and within-season fecundity. Populations varied in intensity of these selection episodes, the contribution of each episode to the net selection, and in the targets of selection. Direction and intensity of selection strongly differed between sexes, and different selection episodes often favored opposite changes in morphological traits. In each population, current net selection for sexual dimorphism was highly concordant with observed sexual dimorphism--in each population, selection for dimorphism was the strongest on the most dimorphic traits. Strong directional selection on sexually dimorphic traits, and similar intensities of selection in both sexes, suggest that in each of the recently established populations, both males and females are far from their local fitness optimum, and that sexual dimorphism has arisen from adaptive responses in both sexes. Population differences in patterns of selection on dimorphism, combined with both low levels of ontogenetic integration in heritable sexually dimorphic traits and sexual dimorphism in growth patterns, may account for the close correspondence between dimorphism in selection and observed dimorphism in morphology across house finch populations.

Sexually dimorphic tridimensionally preserved pterosaurs and their eggs from China.

PubMed

Wang, Xiaolin; Kellner, Alexander W A; Jiang, Shunxing; Wang, Qiang; Ma, Yingxia; Paidoula, Yahefujiang; Cheng, Xin; Rodrigues, Taissa; Meng, Xi; Zhang, Jialiang; Li, Ning; Zhou, Zhonghe

2014-06-16

The pterosaur record is generally poor, with little information about their populations, and pterosaur eggs are even rarer, with only four isolated and flattened eggs found to date. We report here a population of a new sexually dimorphic pterosaur species (Hamipterus tianshanensis gen. et sp. nov.), with five exceptionally well-preserved three-dimensional eggs, from the Early Cretaceous deposit in northwestern China. About 40 male and female individuals in total were recovered, but the actual number associated might be in the hundreds. All of the discovered skulls have crests, which exhibit two different morphologies in size, shape, and robustness. The eggs show pliable depressions with cracking and crazing on the outer surface. The eggshell, observed by scanning electron microscopy and energy-dispersive spectroscopy, comprises a thin calcareous external hard shell followed by a soft membrane. These fossils shed new light on the reproductive strategy, ontogeny, and behavior of pterosaurs. The cranial crests show sexually dimorphic morphologies, with presumed males and females differing in crest size, shape, and robustness. Ontogenetic variation is reflected mainly in the expansion of the rostrum. The eggs have some external rigidity of the general pliable eggshell, and the microstructure of the eggshell is similar to that of some modern "soft" snake eggs. We suggest that this new pterosaur nested in colonies and thus exhibited gregarious behavior, a possible general trend for at least derived pterodactyloid pterosaurs. Copyright © 2014 Elsevier Ltd. All rights reserved.

USMARC update on swine reproduction research

USDA-ARS?s Scientific Manuscript database

Swine research at USMARC has continued to focus on meat quality, improvement of genomic resources and reproduction, specifically estrus traits, sow longevity and lifetime productivity. This report will focus on research in behavioral anestrus in gilts. Gilts that reach puberty at an earlier age are ...

Timing and Stages of Puberty

MedlinePlus

... and stages of puberty Timing and stages of puberty Adolescence and puberty can be so confusing! Here’s some info on what to expect and when: Puberty in girls usually starts between the ages of ...

Evaluation of growth hormone treatment efficacy in short Japanese children born small for gestational age: Five-year treatment outcome and impact on puberty

PubMed Central

Horikawa, Reiko; Tanaka, Toshiaki; Nishinaga, Hiromi; Ogawa, Yoshihisa; Yokoya, Susumu

2017-01-01

Abstract. Some children born small for gestational age (SGA) have short stature and are at an increased risk of developing psychosocial or behavioral problems. Here we evaluated the efficacy of GH and its effects on the timing of pubertal onset in a 3-yr extension of our previous 2-yr (total 5 yr) multicenter, randomized, double-blind, parallel-group clinical trial of 65 short Japanese children born SGA. Patients received low or high doses of GH (0.033 or 0.067 mg/kg/day, respectively). Age at onset of puberty was not statistically different for male and female patients receiving high- or low-dose GH. After the onset of puberty, no difference in height gain was observed between the two GH dose groups. At the onset of puberty, height standard deviation scores for chronological age of boys and girls improved significantly in both dose groups with evidence of a dose-response effect. Mean bone age/chronological age ratios in the low- and high-dose groups were significantly increased compared with baseline, being significantly greater in the high-dose group at 5 yr after treatment initiation. Delayed bone age at baseline was close to chronological age following GH treatment. GH treatment, especially high-dose GH, induced advanced bone age in short children born SGA. PMID:28458458

Sexual development of dairy bulls in the Mexican tropics.

PubMed

Jiménez-Severiano, Hector

2002-09-01

Sexual development and pubertal traits were studied in Holstein Frisian (Ho) and Brown Swiss (BS) bulls born and maintained under tropical conditions. Characteristics evaluated every 2 weeks, from 27 to 63 weeks of age, included live weight, scrotal circumference, testicular diameter, semen quality and sexual behavior. Puberty was defined as the age at which a bull first produced an ejaculate containing at least 50 x 106 spermatozoa, with a minimum of 10% progressive motility. Testicular growth was linear in Ho bulls and quadratic in BS bulls. There was no breed difference in age at puberty (Ho, 333 +/- 15.8 days; BS, 311 +/- 10.5 days). However, at puberty, live weight and scrotal circumference tended to be greater in Ho (276 +/- 16.9 kg and 28.4 +/- 1 cm, respectively) than in BS bulls (233 +/- 11.3 kg and 25.9 +/- 0.7 cm, respectively), and testicular diameter was larger for Ho (5.5 +/- 0.24 cm) than for BS bulls (4.8 +/- 0.16 cm). Pooled data for all bulls for semen characteristics at puberty were: volume, 6.3 +/- 0.6 ml; progressive motility, 26.8 +/- 4.4%; sperm concentration, 58.5 +/- 13.9 x 10(6) spermatozoa/ml, and 351.5 +/- 91.2 x 10(6) spermatozoa/ejaculate. These values improved until at least 18 weeks after puberty. Eighty-five percent of bulls mounted heifers by 206 days of age, but only a few bulls had mounts with ejaculation during the study. It was concluded that reproductive development was similar between Ho and BS bulls, but slower than that reported for dairy bulls in temperate areas. Variation in some characteristics, such as scrotal circumference, was observed among bulls within each breed group, which might be of benefit for genetic selection.

Two organizational effects of pubertal testosterone in male rats: transient social memory and a shift away from long-term potentiation following a tetanus in hippocampal CA1.

PubMed

Hebbard, Pamela C; King, Rebecca R; Malsbury, Charles W; Harley, Carolyn W

2003-08-01

The organizational role of pubertal androgen receptor (AR) activation in synaptic plasticity in hippocampal CA1 and in social memory was assessed. Earlier data suggest pubertal testosterone reduces adult hippocampal synaptic plasticity. Four groups were created following gonadectomy at the onset of puberty: rats given testosterone; rats given testosterone but with the AR antagonist flutamide, present during puberty; rats given testosterone at the end of puberty; and rats given cholesterol at the end of puberty. A tetanus normally inducing long-term potentiation (LTP) was used to stimulate CA1 in the urethane-anesthetized adults during the dark phase of their cycle. Social memory was assessed prior to electrophysiology. Social memory for a juvenile rat at 120 min was seen only in rats not exposed to AR activation during puberty. Pubertal AR activation may induce the reduced social memory of male rats. Early CA1 LTP occurred following tetanus in rats with no pubertal testosterone. Short-term potentiation occurred in rats exposed to pubertal testosterone. Unexpectedly, rats with pubertal AR activation developed long-term depression (LTD). The same pattern was seen in normal male rats. Lack of LTP during the dark phase is consistent with other data on circadian modulation of CA1 LTP. No correlations were seen among social memory scores and CA1 plasticity measures. These data argue for two organizational effects of pubertal testosterone: (1) CA1 synaptic plasticity shifts away from potentiation toward depression; (2) social memory is reduced. Enduring effects of pubertal androgen on limbic circuits may contribute to reorganized behaviors in the postpubertal period.

Pubertal status associations with reward and threat sensitivities and subcortical brain volumes during adolescence.

PubMed

Urošević, Snežana; Collins, Paul; Muetzel, Ryan; Lim, Kelvin O; Luciana, Monica

2014-08-01

Adolescence is characterized by complex developmental processes that impact behavior, biology, and social functioning. Two such adolescence-specific processes are puberty and increases in reward sensitivity. Relations between these processes are poorly understood. The present study focused on examining unique effects of puberty, age, and sex on reward and threat sensitivities and volumes of subcortical brain structures relevant for reward/threat processing in a healthy sample of 9-18year-olds. Unlike age, pubertal status had a significant unique positive relationship with reward sensitivity. In addition, there was a trend for adolescent females to exhibit higher threat sensitivity with more advanced pubertal development and higher reward and threat sensitivity with older age. Similarly, there were significant puberty by sex interaction effects on striatal volumes, i.e., left nucleus accumbens and right pallidum. The present pattern of results suggests that pubertal development, independent of chronological age, is uniquely associated with reward hypersensitivity and with structural differences in striatal regions implicated in reward processing. Copyright © 2014 Elsevier Inc. All rights reserved.

What Are the Symptoms of Puberty, Precocious Puberty, and Delayed Puberty?

MedlinePlus

... puberty include: Growth of pubic and other body hair Growth spurt Breast development Onset of menstruation (after puberty ... of pubic hair, other body hair, and facial hair Enlargement of testicles and penis Muscle growth Growth spurt Acne Deepening of the voice Precocious ...

Does the GH/IGF-1 axis contribute to skeletal sexual dimorphism? Evidence from mouse studies.

PubMed

Liu, Zhongbo; Mohan, Subburaman; Yakar, Shoshana

2016-04-01

The contribution of the gonadotropic axis to skeletal sexual dimorphism (SSD) was clarified in recent years. Studies with animal models of estrogen receptor (ER) or androgen receptor (AR) null mice, as well as mice with bone cell-specific ablation of ER or AR, revealed that both hormones play major roles in skeletal acquisition, and that estrogen regulates skeletal accrual in both sexes. The growth hormone (GH) and its downstream effector, the insulin-like growth factor-1 (IGF-1) are also major determinants of peak bone mass during puberty and young adulthood, and play important roles in maintaining bone integrity during aging. A few studies in both humans and animal models suggest that in addition to the differences in sex steroid actions on bone, sex-specific effects of GH and IGF-1 play essential roles in SSD. However, the contributions of the somatotropic (GH/IGF-1) axis to SSD are controversial and data is difficult to interpret. GH/IGF-1 are pleotropic hormones that act in an endocrine and autocrine/paracrine fashion on multiple tissues, affecting body composition as well as metabolism. Thus, understanding the contribution of the somatotropic axis to SSD requires the use of mouse models that will differentiate between these two modes of action. Elucidation of the relative contribution of GH/IGF-1 axis to SSD is significant because GH is approved for the treatment of normal children with short stature and children with congenital growth disorders. Thus, if the GH/IGF-1 axis determines SSD, treatment with GH may be tailored according to sex. In the following review, we give an overview of the roles of sex steroids in determining SSD and how they may interact with the GH/IGF-1 axis in bone. We summarize several mouse models with impaired somatotropic axis and speculate on the possible contribution of that axis to SSD. Copyright © 2015 Elsevier Ltd. All rights reserved.

The role of kisspeptins and GPR54 in the neuroendocrine regulation of reproduction.

PubMed

Popa, Simina M; Clifton, Donald K; Steiner, Robert A

2008-01-01

Neurons that produce gonadotropin-releasing hormone (GnRH) reside in the basal forebrain and drive reproductive function in mammals. Understanding the circuitry that regulates GnRH neurons is fundamental to comprehending the neuroendocrine control of puberty and reproduction in the adult. This review focuses on a family of neuropeptides encoded by the Kiss1 gene, the kisspeptins, and their cognate receptor, GPR54, which have been implicated in the regulation of GnRH secretion. Kisspeptins are potent secretagogues for GnRH, and the Kiss1 gene is a target for regulation by gonadal steroids (e.g., estradiol and testosterone), metabolic factors (e.g., leptin), photoperiod, and season. Kiss1 neurons in the arcuate nucleus may regulate the negative feedback effect of gonadal steroids on GnRH and gonadotropin secretion in both sexes. The expression of Kiss1 in the anteroventral periventricular nucleus (AVPV) is sexually dimorphic, and Kiss1 neurons in the AVPV may participate in the generation of the preovulatory GnRH/luteinizing hormone (LH) surge in the female rodent. Kiss1 neurons have emerged as primary transducers of internal and environmental cues to regulate the neuroendocrine reproductive axis.

Sex differences and the impact of steroid hormones on the developing human brain.

PubMed

Neufang, Susanne; Specht, Karsten; Hausmann, Markus; Güntürkün, Onur; Herpertz-Dahlmann, Beate; Fink, Gereon R; Konrad, Kerstin

2009-02-01

Little is known about the hormonal effects of puberty on the anatomy of the developing human brain. In a voxel-based morphometry study, sex-related differences in gray matter (GM) volume were examined in 46 subjects aged 8-15 years. Males had larger GM volumes in the left amygdala, whereas females had larger right striatal and bilateral hippocampal GM volumes than males. Sexually dimorphic areas were related to Tanner stages (TS) of pubertal development and to circulating level of steroid hormones in a subsample of 30 subjects. Regardless of sex, amygdala and hippocampal volumes varied as a function of TS and were associated with circulating testosterone (TEST) levels. By contrast, striatal GM volumes were unrelated to pubertal development and circulating steroid hormones. Whole-brain regression analyses revealed positive associations between circulating estrogen levels and parahippocampal GM volumes as well as between TEST levels and diencephalic brain structures. In addition, a negative association was found between circulating TEST and left parietal GM volumes. These data suggest that GM development in certain brain regions is associated with sexual maturation and that pubertal hormones might have organizational effects on the developing human brain.

Insulin Resistance of Puberty.

PubMed

Kelsey, Megan M; Zeitler, Philip S

2016-07-01

Puberty is a time of considerable metabolic and hormonal change. Notably, puberty is associated with a marked decrease in insulin sensitivity, on par with that seen during pregnancy. In otherwise healthy youth, there is a nadir in insulin sensitivity in mid-puberty, and then it recovers at puberty completion. However, there is evidence that insulin resistance (IR) does not resolve in youth who are obese going into puberty and may result in increased cardiometabolic risk. Little is known about the underlying pathophysiology of IR in puberty, and how it might contribute to increased disease risk (e.g., type 2 diabetes). In this review, we have outlined what is known about the IR in puberty in terms of pattern, potential underlying mechanisms and other mediating factors. We also outline other potentially related metabolic changes that occur during puberty, and effects of underlying insulin resistant states (e.g., obesity) on pubertal changes in insulin sensitivity.

Puberty and Its Measurement: A Decade in Review

ERIC Educational Resources Information Center

Dorn, Lorah D.; Biro, Frank M.

2011-01-01

Since the early 1980s, the focus on the importance of puberty to adolescent development has continued with variability in the methodology selected to measure puberty. To capture the relevant and important issues regarding the measurement of puberty in the last decade, this paper will address (1) the neuroendocrine aspects of puberty and its…

Sex differences and the development of the rabbit brain: effects of vinclozolin.

PubMed

Bisenius, Erin S; Veeramachaneni, D N Rao; Sammonds, Ginger E; Tobet, Stuart

2006-09-01

The preoptic/anterior hypothalamic area (POA/AH) is one of the most sexually dimorphic areas of the vertebrate brain and plays a pivotal role in regulating male sexual behavior. Vinclozolin is a fungicide thought to be an environmental antiandrogen, which disrupts masculine sexual behavior when administered to rabbits during development. In this study, we examined several characteristics of the rabbit POA/AH for sexual dimorphism and endocrine disruption by vinclozolin. Pregnant rabbits were dosed orally with vinclozolin (10 mg/kg body weight) or carrot paste vehicle once daily for 6 wk beginning at midgestation and continuing through nursing until Postpartum Week 4. At 6 wk, offspring were perfused with 4% paraformaldehyde and brains processed for immunocytochemical localization of tyrosine hydroxylase, calbindin, gonadotropin-releasing hormone (GnRH), or Nissl stain. There were significant sex differences in the distribution of calbindin in the POA/AH and the size of cells in the dorsal POA/AH (values greater in females than in males), but not in the number or distribution of tyrosine hydroxylase or GnRH neurons. In both sexes, exposure to vinclozolin significantly increased calbindin expression in the ventral POA/AH and significantly decreased number of GnRH neurons selectively in the region of the organum vasculosum of the lamina terminalis (OVLT) but not more caudally in the POA/AH. This is the first documentation of a sexually dimorphic region in the rabbit brain, and further supports the use of this species as a model for studying the influence of vinclozolin on reproductive development with potential application to human systems.

Eye movements reveal sexually dimorphic deficits in children with fetal alcohol spectrum disorder

PubMed Central

Paolozza, Angelina; Munn, Rebecca; Munoz, Douglas P.; Reynolds, James N.

2015-01-01

Background: We examined the accuracy and characteristics of saccadic eye movements in children with fetal alcohol spectrum disorder (FASD) compared with typically developing control children. Previous studies have found that children with FASD produce saccades that are quantifiably different from controls. Additionally, animal studies have found sex-based differences for behavioral effects after prenatal alcohol exposure. Therefore, we hypothesized that eye movement measures will show sexually dimorphic results. Methods: Children (aged 5–18 years) with FASD (n = 71) and typically developing controls (n = 113) performed a visually-guided saccade task. Saccade metrics and behavior were analyzed for sex and group differences. Results: Female control participants had greater amplitude saccades than control males or females with FASD. Accuracy was significantly poorer in the FASD group, especially in males, which introduced significantly greater variability in the data. Therefore, we conducted additional analyses including only those trials in which the first saccade successfully reached the target within a ± 1° window. In this restricted amplitude dataset, the females with FASD made saccades with significantly lower velocity and longer duration, whereas the males with FASD did not differ from the control group. Additionally, the mean and peak deceleration were selectively decreased in the females with FASD. Conclusions: These data support the hypothesis that children with FASD exhibit specific deficits in eye movement control and sensory-motor integration associated with cerebellar and/or brain stem circuits. Moreover, prenatal alcohol exposure may have a sexually dimorphic impact on eye movement metrics, with males and females exhibiting differential patterns of deficit. PMID:25814922

Oocyte pick-up in juvenile lambs affects neither onset of puberty nor their future fertility.

PubMed

Valasi, Irene; Menegatos, I; Papanikolaou, Th; Goulas, P; Amiridis, G S

2006-12-01

A study was designed to evaluate whether the time of onset of puberty and fertility of young ewe lambs would be affected by oocyte pick-up conducted in single or repeated sessions during the first months of lambs' live. Five groups of lambs from the Karagouniko breed were used (A-E each n=12). In group A no treatments were applied (control group) while, laparoscopical follicular aspiration (OPU) was performed early in the third, fourth and fifth month of lambs age (groups C-E, respectively). From the second to fifth month of their age, group B lambs were aspirated four times in monthly intervals. All lambs were weighed at birth, weaning, at second month and monthly thereafter until the eighth month of age. Progesterone priming and ovarian stimulation by serial FSH administrations proceeded each OPU session. To determine onset of puberty blood progesterone concentration was assayed in samples collected initially every week and after the seventh month of age twice weekly. From the seventh month a fertile ram was introduced in each group and oestrous behavior/mating was daily monitored and recorded. Pregnancy diagnosis was carried out by transabdominal ultrasound scanning 55 days after rams' removal. At the fourth and fifth month of age group B lambs were lighter (p<0.05) than controls, but this difference was later equalized. The time of onset of puberty did not differ between groups (p=0.069) and ranged between 224 and 270 days. Some animals (n=15) entered puberty with a full-length luteal phase having progesterone concentration greater than 1ng/ml, while others (n=32) exhibited one or two short luteal phases before luteal length restoration. During the first breeding season 41 animals were fertilized and maintained pregnancy to term, without noticeable differences between groups (p=0.555). During the second breeding season, all ewes were naturally served and lambed at the expected time. It is concluded that OPU in young dairy lambs does not affect the time of onset of puberty, the endocrine profile of the lambs and it does not compromise their future fertility even if it is applied at four successive months.

Healthy Adolescents' Neural Response to Reward: Associations with Puberty, Positive Affect, and Depressive Symptoms

ERIC Educational Resources Information Center

Forbes, Erika E.; Ryan, Neal D.; Phillips, Mary L.; Manuck, Stephen B.; Worthman, Carol M.; Moyles, Donna L.; Tarr, Jill A.; Sciarrillo, Samantha R.; Dahl, Ronald E.

2010-01-01

Objective: Changes in reward-related behavior are an important component of normal adolescent affective development. Understanding the neural underpinnings of these normative changes creates a foundation for investigating adolescence as a period of vulnerability to affective disorders, substance use disorders, and health problems. Studies of…

Reproductive endocrinology of llamas and alpacas.

PubMed

Bravo, P W

1994-07-01

The physiology of reproduction with emphasis in endocrinology of llamas and alpacas is addressed. Basic concepts of ovarian follicular dynamics, endocrine events associated with induction of ovulation, corpus luteum formation, pregnancy, parturition, postpartum interval, puberty, and sexual behavior on the female are reviewed. Pathologic conditions of the reproductive process are also reviewed.

The relationship between obesity and body compositions with respect to the timing of puberty in Chongqing adolescents: a cross-sectional study.

PubMed

He, Fang; Guan, Peiyu; Liu, Qin; Crabtree, Donna; Peng, Linli; Wang, Hong

2017-08-18

It is well known that excess adiposity during childhood may influence pubertal development. However, the extent to which body compositions vary in throughout puberty in boys and girls is currently unknown. The aim of this study was to investigate whether obesity and body compositions correlate with the timing of puberty in boys and girls. By random cluster sampling, our study analyzed data from 1472 students (690 girls, 782 boys) aged 6-17 years from two schools in the Chongqing area. Data were collected by physical examination of weight, height, and skinfold thicknesses. Testicular volume was measured in boys and breast development in girls. By which we got the indicators of obesity, timing of puberty and body compositions. Probit regression analysis was used to group subjects into early puberty (>P 25 ), on-time puberty (P 25  ~ P 75 ), and delayed puberty (

 0.05). In girls, delayed puberty was negatively correlated with Obesity, percentage of body fat, fat mass and fat-free mass, and positively correlated with body density. But in boys, delayed puberty was only negatively correlated with Obesity, the relation between puberty and body compositions was not found.

Puberty.

PubMed

Biro, Frank M

2007-12-01

Puberty consists of interrelated biological changes and occurs at a time when the individual also encounters cognitive and social changes. In this article we examine our current knowledge regarding the onset of puberty, the sequence and timing of puberty, and medical issues and physiologic changes that may arise with pubertal maturation. Figures included demonstrate the sexual maturation stages and interrelationships between the various parameters of puberty.

Behavioral effects of chronic adolescent stress are sustained and sexually dimorphic

PubMed Central

Bourke, Chase H.; Neigh, Gretchen N.

2011-01-01

Evidence suggests that women are more susceptible to stress-related disorders than men. Animal studies demonstrate a similar female sensitivity to stress and have been used to examine the underlying neurobiology of sex-specific effects of stress. Although our understanding of the sex-specific effects of chronic adolescent stress has grown in recent years, few studies have reported the effects of adolescent stress on depressive-like behavior. The purpose of this study was to determine if a chronic mixed modality stressor (consisting of isolation, restraint, and social defeat) during adolescence (PND37-49) resulted in differential and sustained changes in depressive-like behavior in male and female Wistar rats. Female rats exposed to chronic adolescent stress displayed decreased sucrose consumption, hyperactivity in the elevated plus maze, decreased activity in the forced swim test, and a blunted corticosterone response to an acute forced swim stress compared to controls during both adolescence (PND48-57) and adulthood (PND96-104). Male rats exposed to chronic adolescent stress did not manifest significant behavioral changes at either the end of adolescence or in adulthood. These data support the proposition that adolescence may be a stress sensitive period for females and exposure to stress during adolescence results in behavioral effects that persist in females. Studies investigating the sex-specific effects of chronic adolescent stress may lead to a better understanding of the sexually dimorphic incidence of depressive and anxiety disorders in humans and ultimately improve prevention and treatment strategies. PMID:21466807

Reduction of sexual dimorphism in stream-resident forms of three-spined stickleback Gasterosteus aculeatus

PubMed Central

Kitano, J.; Mori, S.; Peichel, C. L.

2013-01-01

Sexual dimorphism in geometric body shape and external morphology was compared between marine and stream-resident forms of three-spined stickleback Gasterosteus aculeatus collected from North America and Japan. Some aspects of sexual dimorphism were shared between ecotypes: males had larger heads than females with no significant effect of ecotype on the magnitude of sexual dimorphism. By contrast, a significant sex-by-ecotype interaction was found for body depth. Males tended to have deeper bodies than females in both forms, but the magnitude of sexual dimorphism was reduced in stream-resident forms. Although females were generally larger in standard length and had larger pelvic girdles, significant sexual dimorphism in these traits was not consistently found across populations or ecotypes. These results suggest that some aspects of sexual dimorphism were shared between ecotypes, while others were unique to each population. The results further suggest that ecology may influence the evolution of sexual dimorphism in some external morphological traits, such as body depth. PMID:22220894

Sexual dimorphism of bed bug (Cimex lectularis) attraction and aggregation responses to cuticular extracts from nymph exuviae

USDA-ARS?s Scientific Manuscript database

A large variety of releaser pheromones are used by insects to attract or disperse conspecifics, while group cohesion is often influenced by primer pheromones that induce behavioral or physiological changes. Differentiating the roles of such pheromones in insect taxa displaying intermediate levels of...

SEXUALLY DIMORPHIC LORDOSIS BEHAVIOR IS MORE SENSITIVE TO DISRUPTION BY DEVELOPMENTAL EXPOSURE TO ETHINYL ESTRADIOL THAN IS REPRODUCTIVE MORPHOLOGY IN THE LONG EVANS FEMALE RAT.

EPA Science Inventory

Anthropogenic estrogens are pervasive in the environment. Although the effects of these xenoestrogens are controversial in humans, some fish species are adversely affected in contaminated ecosystems. While studies investigating endocrine disruptors typically focus on reproducti...

Genetics Home Reference: familial male-limited precocious puberty

MedlinePlus

... male-limited precocious puberty Familial male-limited precocious puberty Printable PDF Open All Close All Enable Javascript ... expand/collapse boxes. Description Familial male-limited precocious puberty is a condition that causes early sexual development ...

Maternal gestational androgens are associated with decreased juvenile play in white-faced marmosets (Callithrix geoffroyi)

PubMed Central

Birnie, Andrew K.; Hendricks, Shelton E.; Smith, Adam S.; Milam, Ross; French, Jeffrey A.

2013-01-01

Exposure to androgens during prenatal development shapes both physiological and behavioral developmental trajectories. Notably, in rhesus macaques, prenatal androgen exposure has been shown to increase rough-and-tumble play, a prominent behavioral feature in males during the juvenile period in primates. While macaques are an Old World, polygamous species with marked sexually dimorphic behavior, New World callitrichine primates (marmosets and tamarins) live in cooperative breeding groups and are considered to be socially monogamous and exhibit minimal sexual dimorphism in social play, which suggests that androgen may affect this species in different ways compared to macaques. In addition, we previously described considerable variation in maternal androgen production during gestation in marmosets. Here we tested the association between this variation and variation in offspring rough-and-tumble play patterns in both males and females. We measured testosterone and androstenedione levels in urine samples collected from pregnant marmoset mothers and then observed their offspring's play behavior as juveniles (5–10 months of age). In contrast to findings in rhesus macaques, hierarchical regression analyses showed that higher gestational testosterone levels, primarily in the second semester, were associated with decreased rough-and-tumble play in juveniles, and this relationship appears to be driven more so by males than females. We found no reliable associations between gestational androstenedione and juvenile play behavior. Our findings provide evidence to suggest that normative variation in levels of maternal androgen during gestation may influence developmental behavioral trajectories in marmosets in a way that contradicts previous findings in Old World primates. PMID:22705955

Maternal androgen excess and obesity induce sexually dimorphic anxiety-like behavior in the offspring.

PubMed

Manti, Maria; Fornes, Romina; Qi, Xiaojuan; Folmerz, Elin; Lindén Hirschberg, Angelica; de Castro Barbosa, Thais; Maliqueo, Manuel; Benrick, Anna; Stener-Victorin, Elisabet

2018-03-22

Maternal polycystic ovary syndrome (PCOS), a condition associated with hyperandrogenism, is suggested to increase anxiety-like behavior in the offspring. Because PCOS is closely linked to obesity, we investigated the impact of an adverse hormonal or metabolic maternal environment and offspring obesity on anxiety in the offspring. The obese PCOS phenotype was induced by chronic high-fat-high-sucrose (HFHS) consumption together with prenatal dihydrotestosterone exposure in mouse dams. Anxiety-like behavior was assessed in adult offspring with the elevated-plus maze and open-field tests. The influence of maternal androgens and maternal and offspring diet on genes implicated in anxiety were analyzed in the amygdala and hypothalamus with real-time PCR ( n = 47). Independent of diet, female offspring exposed to maternal androgens were more anxious and displayed up-regulation of adrenoceptor α 1B in the amygdala and up-regulation of hypothalamic corticotropin-releasing hormone ( Crh). By contrast, male offspring exposed to a HFHS maternal diet had increased anxiety-like behavior and showed up-regulation of epigenetic markers in the amygdala and up-regulation of hypothalamic Crh. Overall, there were substantial sex differences in gene expression in the brain. These findings provide novel insight into how maternal androgens and obesity exert sex-specific effects on behavior and gene expression in the offspring of a PCOS mouse model.-Manti, M., Fornes, R., Qi, X., Folmerz, E., Lindén Hirschberg, A., de Castro Barbosa, T., Maliqueo, M., Benrick, A., Stener-Victorin, E. Maternal androgen excess and obesity induce sexually dimorphic anxiety-like behavior in the offspring.

Self-reported sexual desire in homosexual men and women predicts preferences for sexually dimorphic facial cues.

PubMed

Welling, Lisa L M; Singh, Kevin; Puts, David A; Jones, Benedict C; Burriss, Robert P

2013-07-01

Recent studies investigating the relationship between self-reported sexual desire and attraction to same- and opposite-sex individuals have found that homosexual men's sexual desire is positively correlated with their self-reported attraction to own-sex individuals only, while homosexual women's sexual desire is positively correlated with their self-reported attraction to both men and women. These data have been interpreted as evidence that sexual desire strengthens men's pre-existing (i.e., dominant) sexual behaviors and strengthens women's sexual behaviors in general. Here we show that homosexual men's (n = 106) scores on the Sexual Desire Inventory-2 (SDI-2) were positively correlated with their preferences for exaggerated sex-typical shape cues in own-sex, but not opposite-sex, faces. Contrary to the hypothesis that sexual desire strengthens women's preferences for sexual dimorphism generally, homosexual women's (n = 83) SDI-2 scores were positively correlated with their preferences for exaggerated sex-typical shape cues in opposite-sex faces only. Together with previous research in heterosexual subjects, our findings support the proposal that sexual desire increases the incidence of existing sexual behaviors in homosexual and heterosexual men, and increases the incidence of sexual responses more generally in heterosexual women, although not necessarily in homosexual women.

Sexual Dimorphism and Mating Behavior in Anomala testaceipennis

PubMed Central

Rodrigues, Sérgio Roberto; Gomes, Elias Soares; Bento, José Maurício Simões

2014-01-01

Abstract The beetle, Anomala testaceipennis Blanchard (Coleoptera: Scarabaeidae), occurs in central-western Brazil where larvae feed on the roots of plants causing damage. This research aimed to study sexual dimorphism and mating behavior of A. testaceipennis . Adults of A. testaceipennis were collected with light traps in the experimental area of the State University of Mato Grosso do Sul, in Aquidauana. Laboratory experiments were performed to describe copulation behavior and adult morphology of males and females. In males the last abdominal segment has a pronounced constriction, which is absent in females, and the male’s last segment of the first pair of legs has a ventral projection, which is poorly developed in females. The mating activities of adults begin soon after sunset, when adults leave the soil and fly. When the male encounters a female, he touches her with antennae and tarsi. If accepted, the male climbs on the female and remains on her back, and soon after the copulation begins. When the female does not accept the male for mating, she moves rapidly and can roll on the ground, and by so removing the male. In the field, adults feed and mate on bloomed trees of Oiti, Licania tomentosa Benth (Malpighiales: Chrysobalanaceae) and Louro, Cordia glabrata Martius (Boraginaceae). In trees without inflorescences no adults of this species were found. PMID:25502043

Pubertal development in children diagnosed with diabetes mellitus type 1 before puberty.

PubMed

Pereira, K C X; Pugliese, B S; Guimarães, M M; Gama, M P

2015-02-01

To investigate an association between pubertal development and timing of menarche with glycemic control, disease duration, and body mass index (BMI) in patients diagnosed with diabetes mellitus type 1 (DM1) before puberty. Retrospective study. The study was performed at the diabetes outpatient clinic of Instituto de Puericultura e Pediatria Martagão Gesteira--IPPMG of the Federal University of Rio de Janeiro--UFRJ. A total of 131 children, 61 girls and 70 boys, diagnosed with DM1 before puberty participated in the study. The study investigated how age at puberty onset relates to mean glycated hemoglobin (HbA1c) before puberty, BMI percentile, and disease duration; how puberty duration relates to mean HbA1c before and during puberty and to disease duration; and how timing of menarche relates to mean HbA1c before puberty, BMI percentile, and disease duration. Age at puberty onset was positively correlated with mean HbA1c before puberty (r = 0.204, R(2) = 0.042; P = .019) and disease duration (r = 0.451, R(2) = 0.203; P < .0001), and negatively correlated with BMI percentile (r = -0.289, R(2) = 0.084; P = .001). Timing of menarche was negatively correlated with BMI percentile (r = -0.556, R(2) = 0.310; P < .001). Children with longer disease duration began puberty later than those diagnosed more recently. Girls in higher BMI percentiles reached menarche sooner.

Seasonal Effects on the Population, Morphology and Reproductive Behavior of Narnia femorata (Hemiptera: Coreidae)

PubMed Central

Cirino, Lauren A.; Miller, Christine W.

2017-01-01

Many insects are influenced by the phenology of their host plants. In North Central Florida, Narnia femorata (Hemiptera: Coreidae) spends its entire life cycle living and feeding on Opuntia mesacantha ssp. lata. This cactus begins producing flower buds in April that lead to unripe green fruit in June that ripen into red fruit through December. Many morphological and behavioral characteristics of N. femorata are known to be affected by cactus phenology in a controlled laboratory setting, including the degree of sexual dimorphism and mating behavior. Our goal with this study was to determine if similar phenotypic changes of N. femorata occurred over time in the wild, and the extent to which these changes were concordant with phenological changes in its host plant. Further, we investigate the length of the insect mouthparts (beak) over time. Ongoing work has suggested that beak length may change across cohorts of developing insects in response to feeding deep within cactus fruit where seed and pulp depth decrease as the fruit ripens. Our results revealed a drop in cactus fruit abundance between the months of July through October 2015 as cactus fruits turned red and ripened. Simultaneously, the average body size of both males and females of N. femorata declined at two sampled sites. Male hind femora (a sexually-selected weapon) decreased disproportionately in size over time so that males later in the year had relatively smaller hind femora for their body size. The sex-specific patterns of morphological change led to increased sexual-size dimorphism and decreased sexual dimorphism for hind femora later in the year. Further, we found that beak length decreased across cohorts of insects as cactus fruit ripened, suggesting phenotypic plasticity in mouthpart length. Behavioral studies revealed that female readiness to mate increased as the season progressed. In sum, we found pronounced changes in the phenotypes of these insects in the field. Although this study is far from comprehensive, it provides tantalizing patterns that suggest many directions for future research. PMID:28106715

Genome-scan analysis for genetic mapping of quantitative trait loci underlying birth weight and onset of puberty in doe kids (Capra hircus).

PubMed

Esmailizadeh, A K

2014-12-01

The objective of this study was to locate quantitative trait loci (QTL) causing variation in birth weight and age of puberty of doe kids in a population of Rayini cashmere goats. Four hundred and thirty kids from five half-sib families were genotyped for 116 microsatellite markers located on the caprine autosomes. The traits recorded were birth weight of the male and female kids, body weight at puberty, average daily gain from birth to age of puberty and age at puberty of the doe kids. QTL analysis was conducted using the least squares interval mapping approach. Linkage analysis indicated significant QTL for birth weight on Capra hircus chromosomes (CHI) 4, 5, 6, 18 and 21. Five QTL located on CHI 5, 14 and 29 were associated with age at puberty. Across-family analysis revealed evidence for overlapping QTL affecting birth weight (78 cM), body weight at puberty (72 cM), average daily gain from birth to age of puberty (72 cM) and age at puberty (76 cM) on CHI 5 and overlapping QTL controlling body weight at puberty and age at puberty on CHI 14 at 18-19 cM. The proportion of the phenotypic variance explained by the detected QTL ranged between 7.9% and 14.4%. Confirming some of the previously reported results for birth weight and growth QTL in goats, this study identified more QTL for these traits and is the first report of QTL for onset of puberty in doe kids. © 2014 Stichting International Foundation for Animal Genetics.

Fungal spore germination into yeast or mycelium: possible implications of dimorphism in evolution and human pathogenesis

NASA Astrophysics Data System (ADS)

Ghormade, Vandana; Deshpande, M. V.

The ability of dimorphism in fungi is conventionally regarded as a reversible change between the two vegetative forms, yeast and mycelium, in response to environmental change. A zygomycetous isolate, Benjaminiella poitrasii, exhibited yeast-mycelium transition in response to the change in temperature (37-28 °C) and decrease in glucose concentration. For the first time the presence of dimorphic response during asexual and sexual spore germination is reported under the dimorphism-triggering conditions in B. poitrasii. The zygospores germinated into budding yeast when subjected to yeast-form supporting conditions. The mycelium-form favoring conditions gave rise to true mycelium. Similarly, the asexual spores displayed a dimorphic response during germination. Our observations suggest that dimorphism is an intrinsic ability present in the vegetative, asexual, and sexual forms of the fungus. As dimorphic fungi are intermediate to the unicellular yeast and the filamentous forms, understanding of the dimorphic character could be useful to trace the evolutionary relationships among taxonomically different fungi. Moreover, the implications of spore germination during the onset of pathogenesis and in drug development for human health care are discussed.

Variation in Craniomandibular Morphology and Sexual Dimorphism in Pantherines and the Sabercat Smilodon fatalis

PubMed Central

Christiansen, Per; Harris, John M.

2012-01-01

Sexual dimorphism is widespread among carnivorans, and has been an important evolutionary factor in social ecology. However, its presence in sabertoothed felids remains contentious. Here we present a comprehensive analysis of extant Panthera and the sabertoothed felid Smilodon fatalis. S. fatalis has been reported to show little or no sexual dimorphism but to have been intraspecifically variable in skull morphology. We found that large and small specimens of S. fatalis could be assigned to male and female sexes with similar degrees of confidence as Panthera based on craniomandibular shape. P. uncia is much less craniomandibularly variable and has low levels of sexual size-dimorphism. Shape variation in S. fatalis probably reflects sexual differences. Craniomandibular size-dimorphism is lower in S. fatalis than in Panthera except P. uncia. Sexual dimorphism in felids is related to more than overall size, and S. fatalis and the four large Panthera species show marked and similar craniomandibular and dental morphometric sexual dimorphism, whereas morphometric dimorphism in P. uncia is less. Many morphometric-sexually dimorphic characters in Panthera and Smilodon are related to bite strength and presumably to killing ecology. This suggests that morphometric sexual dimorphism is an evolutionary adaptation to intraspecific resource partitioning, since large males with thicker upper canines and stronger bite forces would be able to hunt larger prey than females, which is corroborated by feeding ecology in P. leo. Sexual dimorphism indicates that S. fatalis could have been social, but it is unlikely that it lived in fusion-fission units dominated by one or a few males, as in sub-Saharan populations of P. leo. Instead, S. fatalis could have been solitary and polygynous, as most extant felids, or it may have lived in unisexual groups, as is common in P. leo persica. PMID:23110232

The Toll pathway underlies host sexual dimorphism in resistance to both Gram-negative and Gram-positive bacteria in mated Drosophila.

PubMed

Duneau, David F; Kondolf, Hannah C; Im, Joo Hyun; Ortiz, Gerardo A; Chow, Christopher; Fox, Michael A; Eugénio, Ana T; Revah, J; Buchon, Nicolas; Lazzaro, Brian P

2017-12-21

Host sexual dimorphism is being increasingly recognized to generate strong differences in the outcome of infectious disease, but the mechanisms underlying immunological differences between males and females remain poorly characterized. Here, we used Drosophila melanogaster to assess and dissect sexual dimorphism in the innate response to systemic bacterial infection. We demonstrated sexual dimorphism in susceptibility to infection by a broad spectrum of Gram-positive and Gram-negative bacteria. We found that both virgin and mated females are more susceptible than mated males to most, but not all, infections. We investigated in more detail the lower resistance of females to infection with Providencia rettgeri, a Gram-negative bacterium that naturally infects D. melanogaster. We found that females have a higher number of phagocytes than males and that ablation of hemocytes does not eliminate the dimorphism in resistance to P. rettgeri, so the observed dimorphism does not stem from differences in the cellular response. The Imd pathway is critical for the production of antimicrobial peptides in response to Gram-negative bacteria, but mutants for Imd signaling continued to exhibit dimorphism even though both sexes showed strongly reduced resistance. Instead, we found that the Toll pathway is responsible for the dimorphism in resistance. The Toll pathway is dimorphic in genome-wide constitutive gene expression and in induced response to infection. Toll signaling is dimorphic in both constitutive signaling and in induced activation in response to P. rettgeri infection. The dimorphism in pathway activation can be specifically attributed to Persephone-mediated immune stimulation, by which the Toll pathway is triggered in response to pathogen-derived virulence factors. We additionally found that, in absence of Toll signaling, males become more susceptible than females to the Gram-positive Enterococcus faecalis. This reversal in susceptibility between male and female Toll pathway mutants compared to wildtype hosts highlights the key role of the Toll pathway in D. melanogaster sexual dimorphism in resistance to infection. Altogether, our data demonstrate that Toll pathway activity differs between male and female D. melanogaster in response to bacterial infection, thus identifying innate immune signaling as a determinant of sexual immune dimorphism.

Modeling Pubertal Timing and Tempo and Examining Links to Behavior Problems

ERIC Educational Resources Information Center

Beltz, Adriene M.; Corley, Robin P.; Bricker, Josh B.; Wadsworth, Sally J.; Berenbaum, Sheri A.

2014-01-01

Research on the role of puberty in adolescent psychological development requires attention to the meaning and measurement of pubertal development. Particular questions concern the utility of self-report, the need for complex models to describe pubertal development, the psychological significance of pubertal timing vs. tempo, and sex differences in…

Precocious Puberty in Adolescent Girls: A Biomarker of Later Psychosocial Adjustment Problems

ERIC Educational Resources Information Center

Tremblay, Line; Frigon, Jean-Yves

2005-01-01

We have investigated the hypothesis that stress condition will accelerate pubertal maturation in adolescent girls and that faster maturing girls will display more behavioral problems than their on-time or late-maturing peers during pubertal development. Longitudinal data were collected yearly from 1986 to 1997. Parents of 1039 French-speaking…

A Validation Study of Early Adolescents' Pubertal Self-Assessments

ERIC Educational Resources Information Center

Schmitz, Katharine E.; Hovell, Melbourne F.; Nichols, Jeanne F.; Irvin, Veronica L.; Keating, Kristen; Simon, Gayle M.; Gehrman, Christine; Jones, Kenneth Lee

2004-01-01

This study aimed to determine whether self-assessed puberty is sufficiently reliable and valid to substitute for physician examination when feasibility of physician examination is low (e.g., behavioral research). Adolescents (convenience sample N = 178 endocrinology patients and N = 125 from educational trial; mean age 12.7 and 11.3 years,…

Maleficent Reborn: Disney's Fairytale View of Gender Reaches Puberty

ERIC Educational Resources Information Center

Justice, Benjamin

2014-01-01

Fairy tales--indeed all tales--are told for a purpose. They are a form of social education, a form that some scholars argue is older than civilization itself. They imagine dilemmas and offer a range of permissible solutions, labeling socially acceptable and unacceptable behavior, demarcating good and evil, exploring existential questions, binding…

Mating and Parental Care in Lake Tanganyika's Cichlids

PubMed Central

Sefc, Kristina M.

2011-01-01

Cichlid fishes of Lake Tanganyika display a variety of mating and parental care behaviors, including polygamous and monogamous mouthbrooding and substrate breeding, cooperative breeding, as well as various alternative reproductive tactics such as sneaking and piracy. Moreover, reproductive behaviors sometimes vary within species both in space and in time. Here, I survey reports on mating and parenting behaviors of Lake Tanganyika cichlid species and address the evolution of mating and parental care patterns and sexual dimorphism. Notes on measures of sexual selection intensity and the difficulties of defining mating systems and estimating selection intensities at species level conclude the essay. PMID:21822482

Sexual Dimorphism Analysis and Gender Classification in 3D Human Face

NASA Astrophysics Data System (ADS)

Hu, Yuan; Lu, Li; Yan, Jingqi; Liu, Zhi; Shi, Pengfei

In this paper, we present the sexual dimorphism analysis in 3D human face and perform gender classification based on the result of sexual dimorphism analysis. Four types of features are extracted from a 3D human-face image. By using statistical methods, the existence of sexual dimorphism is demonstrated in 3D human face based on these features. The contributions of each feature to sexual dimorphism are quantified according to a novel criterion. The best gender classification rate is 94% by using SVMs and Matcher Weighting fusion method.This research adds to the knowledge of 3D faces in sexual dimorphism and affords a foundation that could be used to distinguish between male and female in 3D faces.

Effect of Weight Loss on Puberty Onset in Overweight Children.

PubMed

Reinehr, Thomas; Bosse, Christina; Lass, Nina; Rothermel, Juliane; Knop, Caroline; Roth, Christian Ludwig

2017-05-01

To assess the impact of weight changes on the onset of puberty in overweight children. We evaluated the timing of puberty onset in 160 prepubertal overweight children (aged 11.2 ± 1.0 years) depending on the changes of their weight status in a 1-year lifestyle intervention. We determined body mass index (BMI), pubertal stage, luteinizing hormone (LH), follicle-stimulating hormone, insulin-like growth factor (IGF)-1, insulin-like growth factor binding protein-3, insulin resistance index homeostatic model assessment, and serum gonadotropins at baseline and 1 year later. Puberty onset during the 1-year follow-up was significantly (P = .014) more frequent in girls without BMI-SDS reduction (75.0%) compared with girls with BMI-SDS reduction (45.7%). The start of puberty was significantly (P = .024) more frequent in boys with BMI-SDS reduction (76.9%) compared with boys without BMI-SDS reduction (53.6%). In logistic regression analyses adjusted for baseline age and BMI-SDS, BMI-SDS reduction was associated with a decreased likelihood for puberty onset in girls (OR 0.24; 95% CI 0.07-0.85) and an increased likelihood in boys (OR 3.77; 95% CI 1.34-10.52). Central onset of puberty was confirmed by an increase of LH concentration and LH/follicle-stimulating hormone ratio in both boys and girls. Homeostatic model assessment, IGF-1, and IGF-1/insulin-like growth factor binding protein-3 ratio as marker for free IGF-1 at baseline or their changes were not associated with the onset of puberty. BMI-SDS reduction in overweight children was associated with earlier gonadotropin-dependent onset of puberty in boys and later onset of puberty in girls, suggesting earlier puberty in obese girls and later puberty in obese boys. We found no evidence that insulin resistance or IGF-1 have an impact on the start of puberty in obese children. ClinicalTrials.gov: NCT00435734. Copyright © 2017 Elsevier Inc. All rights reserved.

Influence of oxygen availability on the metabolism and morphology of Yarrowia lipolytica: insights into the impact of glucose levels on dimorphism.

PubMed

Timoumi, Asma; Bideaux, Carine; Guillouet, Stéphane E; Allouche, Yohan; Molina-Jouve, Carole; Fillaudeau, Luc; Gorret, Nathalie

2017-10-01

Dynamic behavior of Yarrowia lipolytica W29 strain under conditions of fluctuating, low, and limited oxygen supply was characterized in batch and glucose-limited chemostat cultures. In batch cultures, transient oscillations between oxygen-rich and -deprived environments induced a slight citric acid accumulation (lower than 29 mg L -1 ). By contrast, no citric acid was detected in continuous fermentations for all stress conditions: full anoxia (zero pO 2 value, 100% N 2 ), limited (zero pO 2 value, 75% of cell needs), and low (pO 2 close to 2%) dissolved oxygen (DO) levels. The macroscopic behavior (kinetic parameters, yields, viability) of Y. lipolytica was not significantly affected by the exposure to DO fluctuations under both modes of culture. Nevertheless, conditions of oxygen limitation resulted in the destabilization of the glucose-limited growth during the continuous cultivations. Morphological responses of Y. lipolytica to DO oscillations were different between batch and chemostat runs. Indeed, a yeast-to-mycelium transition was induced and progressively intensified during the batch fermentations (filamentous subpopulation reaching 74% (v/v)). While, in chemostat bioreactors, the culture consisted mainly of yeast-like cells (mean diameter not exceeding 5.7 μm) with a normal size distribution. During the continuous cultures, growth at low DO concentration did not induce any changes in Y. lipolytica morphology. Dimorphism (up to 80.5% (v/v) of filaments) was only detected under conditions of oxygen limitation in the presence of a residual glucose excess (more than 0.75 g L -1 ). These data suggest an impact of glucose levels on the signaling pathways regulating dimorphic responses in Y. lipolytica.

Female-biased dimorphism underlies a female-specific role for post-embryonic Ilp7 neurons in Drosophila fertility

PubMed Central

Castellanos, Monica C.; Tang, Jonathan C. Y.; Allan, Douglas W.

2013-01-01

In Drosophila melanogaster, much of our understanding of sexually dimorphic neuronal development and function comes from the study of male behavior, leaving female behavior less well understood. Here, we identify a post-embryonic population of Insulin-like peptide 7 (Ilp7)-expressing neurons in the posterior ventral nerve cord that innervate the reproductive tracts and exhibit a female bias in their function. They form two distinct dorsal and ventral subsets in females, but only a single dorsal subset in males, signifying a rare example of a female-specific neuronal subset. Female post-embryonic Ilp7 neurons are glutamatergic motoneurons innervating the oviduct and are required for female fertility. In males, they are serotonergic/glutamatergic neuromodulatory neurons innervating the seminal vesicle but are not required for male fertility. In both sexes, these neurons express the sex-differentially spliced fruitless-P1 transcript but not doublesex. The male fruitless-P1 isoform (fruM) was necessary and sufficient for serotonin expression in the shared dorsal Ilp7 subset, but although it was necessary for eliminating female-specific Ilp7 neurons in males, it was not sufficient for their elimination in females. By contrast, sex-specific RNA-splicing by female-specific transformer is necessary for female-type Ilp7 neurons in females and is sufficient for their induction in males. Thus, the emergence of female-biased post-embryonic Ilp7 neurons is mediated in a subset-specific manner by a tra- and fru-dependent mechanism in the shared dorsal subset, and a tra-dependent, fru-independent mechanism in the female-specific subset. These studies provide an important counterpoint to studies of the development and function of male-biased neuronal dimorphism in Drosophila. PMID:23981656

Effects of Prenatal Testosterone Exposure on Sexually Dimorphic Gene Expression in the Neonatal Mouse Cortex and Hippocampus

PubMed Central

Armoskus, Chris; Mota, Thomas; Moreira, Debbie; Tsai, Houng-Wei

2014-01-01

Objective Using gene expression microarrays and reverse transcription with quantitative polymerase chain reaction (RT-qPCR), we have recently identified several novel genes that are differentially expressed in the neonatal male versus female mouse cortex/hippocampus (Armoskus et al.). Since perinatal testosterone (T) secreted by the developing testes masculinizes cortical and hippocampal structures and the behaviors regulated by these brain regions, we hypothesized that sexually dimorphic expression of specific selected genes in these areas might be regulated by T during early development. Methods To test our hypothesis, we treated timed pregnant female mice daily with vehicle or testosterone propionate (TP) starting on embryonic day 16 until the day of birth. The cortex/hippocampus was collected from vehicle- and TP-treated, male and female neonatal pups. Total RNA was extracted from these brain tissues, followed by RT-qPCR to measure relative mRNA levels of seven sex chromosome genes and three autosomal genes that have previously showed sex differences. Results The effect of prenatal TP was confirmed as it stimulated Dhcr24 expression in the neonatal mouse cortex/hippocampus and increased the anogenital distance in females. We found a significant effect of sex, but not TP, on expression of three Y-linked (Ddx3y, Eif2s3y, and Kdm5d), four X-linked (Eif2s3x, Kdm6a, Mid1, and Xist), and one autosomal (Klk8) genes in the neonatal mouse cortex/hippocampus. Conclusion Although most of the selected genes are not directly regulated by prenatal T, their sexually dimorphic expression might play an important role in the control of sexually differentiated cognitive and social behaviors as well as in the etiology of sex-biased neurological disorders and mental illnesses. PMID:25411648

Genetic-gonadal-genitals sex (3G-sex) and the misconception of brain and gender, or, why 3G-males and 3G-females have intersex brain and intersex gender

PubMed Central

2012-01-01

The categorization of individuals as “male” or “female” is based on chromosome complement and gonadal and genital phenotype. This combined genetic-gonadal-genitals sex, here referred to as 3G-sex, is internally consistent in ~99% of humans (i.e., one has either the “female” form at all levels, or the “male” form at all levels). About 1% of the human population is identified as “intersex” because of either having an intermediate form at one or more levels, or having the “male” form at some levels and the “female” form at other levels. These two types of “intersex” reflect the facts, respectively, that the different levels of 3G-sex are not completely dimorphic nor perfectly consistent. Using 3G-sex as a model to understand sex differences in other domains (e.g., brain, behavior) leads to the erroneous assumption that sex differences in these other domains are also highly dimorphic and highly consistent. But parallel lines of research have led to the conclusion that sex differences in the brain and in behavior, cognition, personality, and other gender characteristics are for the most part not dimorphic and not internally consistent (i.e., having one brain/gender characteristic with the “male” form is not a reliable predictor for the form of other brain/gender characteristics). Therefore although only ~1% percent of humans are 3G-“intersex”, when it comes to brain and gender, we all have an intersex gender (i.e., an array of masculine and feminine traits) and an intersex brain (a mosaic of “male” and “female” brain characteristics). PMID:23244600

Genetic-gonadal-genitals sex (3G-sex) and the misconception of brain and gender, or, why 3G-males and 3G-females have intersex brain and intersex gender.

PubMed

Joel, Daphna

2012-12-17

The categorization of individuals as "male" or "female" is based on chromosome complement and gonadal and genital phenotype. This combined genetic-gonadal-genitals sex, here referred to as 3G-sex, is internally consistent in ~99% of humans (i.e., one has either the "female" form at all levels, or the "male" form at all levels). About 1% of the human population is identified as "intersex" because of either having an intermediate form at one or more levels, or having the "male" form at some levels and the "female" form at other levels. These two types of "intersex" reflect the facts, respectively, that the different levels of 3G-sex are not completely dimorphic nor perfectly consistent. Using 3G-sex as a model to understand sex differences in other domains (e.g., brain, behavior) leads to the erroneous assumption that sex differences in these other domains are also highly dimorphic and highly consistent. But parallel lines of research have led to the conclusion that sex differences in the brain and in behavior, cognition, personality, and other gender characteristics are for the most part not dimorphic and not internally consistent (i.e., having one brain/gender characteristic with the "male" form is not a reliable predictor for the form of other brain/gender characteristics). Therefore although only ~1% percent of humans are 3G-"intersex", when it comes to brain and gender, we all have an intersex gender (i.e., an array of masculine and feminine traits) and an intersex brain (a mosaic of "male" and "female" brain characteristics).

Masculinization of Gene Expression Is Associated with Exaggeration of Male Sexual Dimorphism

PubMed Central

Pointer, Marie A.; Harrison, Peter W.; Wright, Alison E.; Mank, Judith E.

2013-01-01

Gene expression differences between the sexes account for the majority of sexually dimorphic phenotypes, and the study of sex-biased gene expression is important for understanding the genetic basis of complex sexual dimorphisms. However, it has been difficult to test the nature of this relationship due to the fact that sexual dimorphism has traditionally been conceptualized as a dichotomy between males and females, rather than an axis with individuals distributed at intermediate points. The wild turkey (Meleagris gallopavo) exhibits just this sort of continuum, with dominant and subordinate males forming a gradient in male secondary sexual characteristics. This makes it possible for the first time to test the correlation between sex-biased gene expression and sexually dimorphic phenotypes, a relationship crucial to molecular studies of sexual selection and sexual conflict. Here, we show that subordinate male transcriptomes show striking multiple concordances with their relative phenotypic sexual dimorphism. Subordinate males were clearly male rather than intersex, and when compared to dominant males, their transcriptomes were simultaneously demasculinized for male-biased genes and feminized for female-biased genes across the majority of the transcriptome. These results provide the first evidence linking sexually dimorphic transcription and sexually dimorphic phenotypes. More importantly, they indicate that evolutionary changes in sexual dimorphism can be achieved by varying the magnitude of sex-bias in expression across a large proportion of the coding content of a genome. PMID:23966876

Masculinization of gene expression is associated with exaggeration of male sexual dimorphism.

PubMed

Pointer, Marie A; Harrison, Peter W; Wright, Alison E; Mank, Judith E

2013-01-01

Gene expression differences between the sexes account for the majority of sexually dimorphic phenotypes, and the study of sex-biased gene expression is important for understanding the genetic basis of complex sexual dimorphisms. However, it has been difficult to test the nature of this relationship due to the fact that sexual dimorphism has traditionally been conceptualized as a dichotomy between males and females, rather than an axis with individuals distributed at intermediate points. The wild turkey (Meleagris gallopavo) exhibits just this sort of continuum, with dominant and subordinate males forming a gradient in male secondary sexual characteristics. This makes it possible for the first time to test the correlation between sex-biased gene expression and sexually dimorphic phenotypes, a relationship crucial to molecular studies of sexual selection and sexual conflict. Here, we show that subordinate male transcriptomes show striking multiple concordances with their relative phenotypic sexual dimorphism. Subordinate males were clearly male rather than intersex, and when compared to dominant males, their transcriptomes were simultaneously demasculinized for male-biased genes and feminized for female-biased genes across the majority of the transcriptome. These results provide the first evidence linking sexually dimorphic transcription and sexually dimorphic phenotypes. More importantly, they indicate that evolutionary changes in sexual dimorphism can be achieved by varying the magnitude of sex-bias in expression across a large proportion of the coding content of a genome.

Pubertal development and regulation

PubMed Central

Abreu, Ana Paula; Kaiser, Ursula B

2016-01-01

Puberty marks the end of childhood and is a period when individuals undergo physiological and psychological changes to achieve sexual maturation and fertility. The hypothalamic-pituitary-gonadal axis controls puberty and reproduction and is tightly regulated by a complex network of excitatory and inhibitory factors. This axis is active in the embryonic and early postnatal stages of life and is subsequently restrained during childhood, and its reactivation culminates in puberty initiation. The mechanisms underlying this reactivation are not completely known. The age of puberty onset varies between individuals and the timing of puberty initiation is associated with several health outcomes in adult life. In this Series paper, we discuss pubertal markers, epidemiological trends of puberty initiation over time, and the mechanisms whereby genetic, metabolic, and other factors control secretion of gonadotropin-releasing hormone to determine initiation of puberty. PMID:26852256

Genome-wide methylation analysis identified sexually dimorphic methylated regions in hybrid tilapia

PubMed Central

Wan, Zi Yi; Xia, Jun Hong; Lin, Grace; Wang, Le; Lin, Valerie C. L.; Yue, Gen Hua

2016-01-01

Sexual dimorphism is an interesting biological phenomenon. Previous studies showed that DNA methylation might play a role in sexual dimorphism. However, the overall picture of the genome-wide methylation landscape in sexually dimorphic species remains unclear. We analyzed the DNA methylation landscape and transcriptome in hybrid tilapia (Oreochromis spp.) using whole genome bisulfite sequencing (WGBS) and RNA-sequencing (RNA-seq). We found 4,757 sexually dimorphic differentially methylated regions (DMRs), with significant clusters of DMRs located on chromosomal regions associated with sex determination. CpG methylation in promoter regions was negatively correlated with the gene expression level. MAPK/ERK pathway was upregulated in male tilapia. We also inferred active cis-regulatory regions (ACRs) in skeletal muscle tissues from WGBS datasets, revealing sexually dimorphic cis-regulatory regions. These results suggest that DNA methylation contribute to sex-specific phenotypes and serve as resources for further investigation to analyze the functions of these regions and their contributions towards sexual dimorphisms. PMID:27782217

Disorders of childhood growth and development: precocious puberty.

PubMed

Chauhan, Alia; Grissom, Maureen

2013-07-01

Precocious puberty is defined as pubertal development that begins at an earlier age than expected; most US pediatric endocrinology subspecialists use cutoff ages of 8 years for girls and 9 years for boys. Early activation and maturation of the hypothalamic-pituitary-gonadal axis leads to hormonal changes, physical signs of puberty, and acceleration of linear growth. Factors affecting puberty include race/ethnicity, obesity, and endocrine disruptors. The 2 forms of precocious puberty are central (gonadotropin-dependent precocious puberty) and peripheral (gonadotropin-independent precocious puberty). Most cases of the former have no identifiable etiology, whereas the latter is caused by increased secretion of sex hormones by the gonads or adrenal glands. It is important to differentiate progressive from nonprogressive precocious puberty to avoid unnecessary treatment for the latter; if diagnosis is uncertain, the child should be reassessed within several months. Evaluation begins with a detailed history and physical examination followed by an x-ray for bone age; in precocious puberty, bone age is greater than chronologic age. If indicated, additional serum testing (basal luteinizing hormone) and imaging studies should be obtained. Patients should be referred to a pediatric endocrinology subspecialist for treatment. It is essential to manage underlying etiologies. Gonadotropin-releasing hormone agonists should be considered only for children with progressive central precocious puberty to prevent short stature. For children with apparent nonprogressive precocious puberty, follow-up every 3 to 6 months between ages 6 and 7 years is recommended to assess for progression. Written permission from the American Academy of Family Physicians is required for reproduction of this material in whole or in part in any form or medium.

Childhood family disruption and adult height: is there a mediating role of puberty?

PubMed Central

Sheppard, Paula; Garcia, Justin R.; Sear, Rebecca

2015-01-01

Background and objectives: Childhood family background is known to be associated with child growth and development, including the onset of puberty, but less is known about the influence of childhood family disruption on outcomes in later life. Given the associations between early family disruption and childhood development, we predicted that there may be long-term health-relevant consequences of childhood disruption. Methodology: Using data from a large US interview sample (n = 16 207), we test if death or divorce of parents, at different childhood periods, was associated with adult stature, and whether age at puberty mediated this relationship, for men and women. Results: Men: parental death and divorce during early childhood was associated with shorter adult height, and later puberty. Later puberty was associated with shorter adult height. Path analyses demonstrated that the relationship between parental divorce and height was completely mediated by age at puberty; although parental death was only partially mediated by age at puberty. Women: the father’s death during early childhood was associated with earlier puberty, which was in turn associated with shorter adult stature. The relationship between paternal death and height is entirely mediated by age at puberty; no evidence of a direct relationship between childhood family disruption and adult height. Conclusions: Early childhood familial disruption is associated with shorter height for men, and is partially mediated by later puberty. For women, the relationship between father’s death, and height was completely mediated by earlier puberty. These findings indicate that disruption during childhood can have long-reaching health repercussions, particularly for boys. PMID:26609061

Ancestrality and evolution of trait syndromes in finches (Fringillidae).

PubMed

Ponge, Jean-François; Zuccon, Dario; Elias, Marianne; Pavoine, Sandrine; Henry, Pierre-Yves; Théry, Marc; Guilbert, Éric

2017-12-01

Species traits have been hypothesized by one of us (Ponge, 2013) to evolve in a correlated manner as species colonize stable, undisturbed habitats, shifting from "ancestral" to "derived" strategies. We predicted that generalism, r-selection, sexual monomorphism, and migration/gregariousness are the ancestral states (collectively called strategy A) and evolved correlatively toward specialism, K-selection, sexual dimorphism, and residence/territoriality as habitat stabilized (collectively called B strategy). We analyzed the correlated evolution of four syndromes, summarizing the covariation between 53 traits, respectively, involved in ecological specialization, r-K gradient, sexual selection, and dispersal/social behaviors in 81 species representative of Fringillidae, a bird family with available natural history information and that shows variability for all these traits. The ancestrality of strategy A was supported for three of the four syndromes, the ancestrality of generalism having a weaker support, except for the core group Carduelinae (69 species). It appeared that two different B-strategies evolved from the ancestral state A, both associated with highly predictable environments: one in poorly seasonal environments, called B1, with species living permanently in lowland tropics, with "slow pace of life" and weak sexual dimorphism, and one in highly seasonal environments, called B2, with species breeding out-of-the-tropics, migratory, with a "fast pace of life" and high sexual dimorphism.

Dimorphism throughout the European eel's life cycle: are ontogenetic changes in head shape related to dietary differences?

PubMed

De Meyer, J; Goethals, T; Van Wassenbergh, S; Augustijns, T; Habraken, J; Hellemans, J; Vandewiele, V; Dhaene, J; Bouillart, M; Adriaens, D

2018-05-31

A well-known link exists between an organism's ecology and morphology. In the European eel, a dimorphic head has been linked to differences in feeding ecology, with broad-headed eels consuming harder prey items than narrow-headed ones. Consequently, we hypothesized that broad-heads should exhibit a cranial musculoskeletal system that increases bite force and facilitates the consumption of harder prey. Using 3D-reconstructions and a bite model, we tested this hypothesis in two life stages: the sub-adult yellow eel stage and its predecessor, the elver eel stage. This allowed us to test whether broad- and narrow-headed phenotypes show similar trait differences in both life stages and whether the dimorphism becomes more pronounced during ontogeny. We show that broad-headed eels in both stages have larger jaw muscles and a taller coronoid, which are associated with higher bite forces. This increased bite force together with the elongated upper and lower jaws in broad-headed eels can also improve grip during spinning behavior, which is used to manipulate hard prey. Head shape variation in European eel is therefore associated with musculoskeletal variation that can be linked to feeding ecology. However, although differences in muscle volume become more pronounced during ontogeny, this was not the case for skeletal features. © 2018 Anatomical Society.

Sexually dimorphic responses to neonatal basal forebrain lesions in mice: I. Behavior and neurochemistry.

PubMed

Arters, J; Hohmann, C F; Mills, J; Olaghere, O; Berger-Sweeney, J

1998-12-01

The nucleus basalis magnocellularis (nBM) provides the primary source of cholinergic input to the cortex. Neonatal lesions of the nBM produce transient reductions in cholinergic markers, persistent abnormalities in cortical morphology, and spatial navigation impairments in adult mice. The present study examined sex differences in the effects of an electrolytic nBM lesion on postnatal day 1 (PND 1) in mice on behavior and neurochemistry in adulthood. Mice were lesioned on PND 1 and tested at 8 weeks of age on a battery of behavioral tests including passive avoidance, cued and spatial tasks in the Morris water maze, simple and delayed nonmatch to sample versions of an odor discrimination task, and locomotor activity measurements. Following behavioral testing, mice were sacrificed for either morphological assessment or neurochemical analysis of a cholinergic marker or catecholamines. There were no lesion or sex differences in acquisition or retention of passive avoidance, performance of the odor discrimination tasks, or activity levels. Control mice showed a robust sex difference in performance of the spatial water maze task. The lesion produced a slight cued but more dramatic spatial navigation deficit in the water maze which affected only the male mice. Neurochemical analyses revealed no lesion-induced changes in either choline acetyltransferase activity or levels of norepinephrine or serotonin at the time of testing. The subsequent report shows a sex difference in lesion-induced changes in cortical morphology which suggests that sexually dimorphic cholinergic influences on cortical development are responsible for the behavioral deficits seen in this study.

For Parents: What to Expect When Your Child Goes through Puberty

MedlinePlus

... What are the first signs of puberty in boys and girls? The first sign of puberty in most girls ... development. The first sign of puberty in most boys is an increase in the size of ... Yes. In girls, breasts develop first. Then, hair starts growing in ...

Interpreting digit ratio (2D:4D)-behavior correlations: 2D:4D sex difference, stability, and behavioral correlates and their replicability in young children.

PubMed

Wong, Wang I; Hines, Melissa

2016-02-01

The popularity of using the ratio of the second to the fourth digit (2D:4D) to study influences of early androgen exposure on human behavior relies, in part, on a report that the ratio is sex-dimorphic and stable from age 2 years (Manning etal., 1998). However, subsequent research has rarely replicated this finding. Moreover, although 2D:4D has been correlated with many behaviors, these correlations are often inconsistent. Young children's 2D:4D-behavior correlations may be more consistent than those of older individuals, because young children have experienced fewer postnatal influences. To evaluate the usefulness of 2D:4D as a biomarker of prenatal androgen exposure in studies of 2D:4D-behavior correlations, we assessed its sex difference, temporal stability, and behavioral correlates over a 6- to 8-month period in 126, 2- to 3-year-old children, providing a rare same-sample replicability test. We found a moderate sex difference on both hands and high temporal stability. However, between-sex overlap and within-sex variability were also large. Only 3 of 24 correlations with sex-typed behaviors-scores on the Preschool Activities Inventory (PSAI), preference for a boy-typical toy, preference for a girl-typical toy, were significant and in the predicted direction, all of which involved the PSAI, partially confirming findings from another study. Correlation coefficients were larger for behaviors that showed larger sex differences. But, as in older samples, the overall pattern showed inconsistency across time, sex, and hand. Therefore, although sex-dimorphic and stable, 2D:4D-behavior correlations are no more consistent for young children than for older samples. Theoretical and methodological implications are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

Sex differences in pain-related behavior and expression of calcium/calmodulin-dependent protein kinase II in dorsal root ganglia of rats with diabetes type 1 and type 2.

PubMed

Ferhatovic, Lejla; Banozic, Adriana; Kostic, Sandra; Sapunar, Damir; Puljak, Livia

2013-06-01

Sex differences in pain-related behavior and expression of calcium/calmodulin dependent protein kinase II (CaMKII) in dorsal root ganglia were studied in rat models of Diabetes mellitus type 1 (DM1) and type 2 (DM2). DM1 was induced with 55mg/kg streptozotocin, and DM2 with a combination of high-fat diet and 35mg/kg of streptozotocin. Pain-related behavior was analyzed using thermal and mechanical stimuli. The expression of CaMKII was analyzed with immunofluorescence. Sexual dimorphism in glycemia, and expression of CaMKII was observed in the rat model of DM1, but not in DM2 animals. Increased expression of total CaMKII (tCaMKII) in small-diameter dorsal root ganglia neurons, which are associated with nociception, was found only in male DM1 rats. None of the animals showed increased expression of the phosphorylated alpha CaMKII isoform in small-diameter neurons. The expression of gamma and delta isoforms of CaMKII remained unchanged in all analyzed animal groups. Different patterns of glycemia and tCaMKII expression in male and female model of DM1 were not associated with sexual dimorphism in pain-related behavior. The present findings do not suggest sex-related differences in diabetic painful peripheral neuropathy in male and female diabetic rats. Copyright © 2012 Elsevier GmbH. All rights reserved.

Function-related Drivers of Skull Morphometric Variation and Sexual Size Dimorphism in a Subterranean Rodent, Plateau Zokor (Eospalax baileyi).

PubMed

Su, Junhu; Hegab, Ibrahim M; Ji, Weihong; Nan, Zhibiao

2018-05-01

Sexual dimorphism is prevalent in most living organisms. The difference in size between sexes of a given species is generally known as sexual size dimorphism (SSD). The magnitude of the SSD is determined by Rensch's rule where size dimorphism increases with increasing body size when the male is the larger sex and decreases with increasing average body size when the female is the larger sex. The unique underground environment that zokors ( Eospalax baileyi ) live under in the severe habitat of the Qinghai-Tibetan Plateau (QTP) could create SSD selection pressures that may or may not be supported by Rensch's rule, making this scientific question worthy of investigation. In this study, we investigated the individual variation between sexes in body size and SSD of plateau zokors using measurements of 19 morphological traits. We also investigated the evolutionary mechanisms underlying SSD in plateau zokors. Moreover, we applied Rensch's rule to all extant zokor species. Our results showed male-biased SSD in plateau zokors: The body- and head-related measurements were greater in males than in females. Linear regression analysis between body length, body weight, and carcass weight showed significant relationships with some traits such as skull length, lower incisor length, and tympanic bulla width, which might support our prediction that males have faster growth rates than females. Further, the SSD pattern corroborated the assumption of Rensch's rule in plateau zokors but not in the other zokor species. Our findings suggest that the natural underground habitat and behavioral differences between sexes can generate selection pressures on male traits and contribute to the evolution of SSD in plateau zokors.

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

Puberty as an accelerator for diabetes complications.

PubMed

Cho, Yoon Hi; Craig, Maria E; Donaghue, Kim C

2014-02-01

Much is written about how difficult it is to deal with diabetes during adolescence, and rightly so. Less is understood as to how puberty may be an accelerator of vascular complications. With the increase in childhood diabetes, complication risks need to be revisited in relation to puberty and the secular increase in adiposity. Recent data suggest greater risk for severe vascular complications in those with diabetes during puberty, compared with young people who develop diabetes after puberty. It is also widely recognized that higher hemoglobin A1c (HbA1c) results are often seen during the pubertal period. This article will review complication outcomes in relation to puberty and examine mechanisms by which puberty may modify risk above glycemic exposure, and possible gender disparities in the risk of complications in the adolescent period. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Lowering Risk for Type 2 Diabetes in High-Risk Youth

ERIC Educational Resources Information Center

Bobo, Nichole; Schantz, Shirley; Kaufman, Francine R.; Kollipara, Sobha

2009-01-01

Among children and youth who develop type 2 diabetes (T2DM) there are a number of genetic and environmental factors that lead to a combination of insulin resistance and relative-cell secretory failure of the pancreas. These factors include ethnicity (highest in American Indian youth), obesity, sedentary behavior, family history of T2DM, puberty,…

Who Dates? The Effects of Temperament, Puberty, and Parenting on Early Adolescent Experience with Dating: The TRAILS Study

ERIC Educational Resources Information Center

Ivanova, Katya; Veenstra, Rene; Mills, Melinda

2012-01-01

This article focuses on how temperament, pubertal maturation, and perception of parenting behaviors affect the propensity to date in early adolescence (mean age = 13.55). Hypotheses are tested with a representative sample of 2,230 Dutch adolescents, the TRacking Adolescents' Individual Lives Survey (TRAILS). The results suggest that adolescents…

Family Life and Human Development (Sex Education): The Prince George's County Public Schools Experience.

ERIC Educational Resources Information Center

Schaffer, Michael J.

1981-01-01

The Prince George's County schools' sex education program for grades K-12 was developed and implemented in the late 1960s and has three focus areas: family life and interpersonal relationships; the physiological and personality changes during puberty; and advanced physiology and psychology of human sexual behavior. The program augments what the…

Development and validation of a method for precise dating of female puberty in laboratory rodents: The puberty ovarian maturation score (Pub-Score)

PubMed Central

Gaytan, Francisco; Morales, Concepción; Leon, Silvia; Heras, Violeta; Barroso, Alexia; Avendaño, Maria S.; Vazquez, Maria J.; Castellano, Juan M.; Roa, Juan; Tena-Sempere, Manuel

2017-01-01

Puberty is a key developmental event whose primary regulatory mechanisms remain poorly understood. Precise dating of puberty is crucial for experimental (preclinical) studies on its complex neuroendocrine controlling networks. In female laboratory rodents, external signs of puberty, such as vaginal opening (VO) and epithelial cell cornification (i.e., first vaginal estrus, FE), are indirectly related to the maturational state of the ovary and first ovulation, which is the unequivocal marker of puberty. Whereas in rats, VO and FE are almost simultaneous with the first ovulation, these events are not so closely associated in mice. Moreover, external signs of puberty can be uncoupled with first ovulation in both species under certain experimental conditions. We propose herein the Pubertal Ovarian Maturation Score (Pub-score), as novel, reliable method to assess peripubertal ovarian maturation in rats and mice. This method is founded on histological evaluation of pre-pubertal ovarian maturation, based on antral follicle development, and the precise timing of first ovulation, by retrospective dating of maturational and regressive changes in corpora lutea. This approach allows exact timing of puberty within a time-window of at least two weeks after VO in both species, thus facilitating the identification and precise dating of advanced or delayed puberty under various experimental conditions. PMID:28401948

Childhood family disruption and adult height: is there a mediating role of puberty?

PubMed

Sheppard, Paula; Garcia, Justin R; Sear, Rebecca

2015-11-24

Childhood family background is known to be associated with child growth and development, including the onset of puberty, but less is known about the influence of childhood family disruption on outcomes in later life. Given the associations between early family disruption and childhood development, we predicted that there may be long-term health-relevant consequences of childhood disruption. Using data from a large US interview sample (n = 16 207), we test if death or divorce of parents, at different childhood periods, was associated with adult stature, and whether age at puberty mediated this relationship, for men and women. RESULTS MEN: : parental death and divorce during early childhood was associated with shorter adult height, and later puberty. Later puberty was associated with shorter adult height. Path analyses demonstrated that the relationship between parental divorce and height was completely mediated by age at puberty; although parental death was only partially mediated by age at puberty. WOMEN: the father's death during early childhood was associated with earlier puberty, which was in turn associated with shorter adult stature. The relationship between paternal death and height is entirely mediated by age at puberty; no evidence of a direct relationship between childhood family disruption and adult height. Early childhood familial disruption is associated with shorter height for men, and is partially mediated by later puberty. For women, the relationship between father's death, and height was completely mediated by earlier puberty. These findings indicate that disruption during childhood can have long-reaching health repercussions, particularly for boys. © The Author(s) 2015. Published by Oxford University Press on behalf of the Foundation for Evolution, Medicine, and Public Health.

THE ROLE OF ANDROGENS AND ESTROGENS IN THE DEVELOPMENT OF BRAIN AND PERIPHERAL NERVOUS SYSTEM: APPROACHES TO DEVELOPING ANIMAL MODELS FOR SEXUALLY DIMORPHIC BEHAVIORS

EPA Science Inventory

This presentation provides an overview of research on the effects of hormonally active chemicals on sexual differentiation of the brain including (a) research on the role of androgens and estrogens in the development of the brain and peripheral nervous system, (b) approaches to d...

GENETIC VARIATION IN BABOON CRANIOFACIAL SEXUAL DIMORPHISM

PubMed Central

Willmore, Katherine E.; Roseman, Charles C.; Rogers, Jeffrey; Richtsmeier, Joan T.; Cheverud, James M.

2010-01-01

Sexual dimorphism is a widespread phenomenon and contributes greatly to intraspecies variation. Despite a long history of active research, the genetic basis of dimorphism for complex traits remains unknown. Understanding the sex-specific differences in genetic architecture for cranial traits in a highly dimorphic species could identify possible mechanisms through which selection acts to produce dimorphism. Using distances calculated from three-dimensional landmark data from CT scans of 402 baboon skulls from a known genealogy, we estimated genetic variance parameters in both sexes to determine the presence of gene-by-sex (G × S) interactions and X-linked heritability. We hypothesize that traits exhibiting the greatest degree of sexual dimorphism (facial traits in baboons) will demonstrate either stronger G × S interactions or X-linked effects. We found G × S interactions and X-linked effects for a few measures that span the areas connecting the face to the neurocranium but for no traits restricted to the face. This finding suggests that facial traits will have a limited response to selection for further evolution of dimorphism in this population. We discuss the implications of our results with respect to the origins of cranial sexual dimorphism in this baboon sample, and how the genetic architecture of these traits affects their potential for future evolution. PMID:19210535

Evolution of sexual dimorphism in bill size and shape of hermit hummingbirds (Phaethornithinae): a role for ecological causation

PubMed Central

Temeles, Ethan J.; Miller, Jill S.; Rifkin, Joanna L.

2010-01-01

Unambiguous examples of ecological causation of sexual dimorphism are rare, and the best evidence involves sexual differences in trophic morphology. We show that moderate female-biased sexual dimorphism in bill curvature is the ancestral condition in hermit hummingbirds (Phaethornithinae), and that it is greatly amplified in species such as Glaucis hirsutus and Phaethornis guy, where bills of females are 60 per cent more curved than bills of males. In contrast, bill curvature dimorphism is lost or reduced in a lineage of short-billed hermit species and in specialist Eutoxeres sicklebill hermits. In the hermits, males tend to be larger than females in the majority of species, although size dimorphism is typically small. Consistent with earlier studies of hummingbird feeding performance, both raw regressions of traits and phylogenetic independent contrasts supported the prediction that dimorphism in bill curvature of hermits is associated with longer bills. Some evidence indicates that differences between sexes of hermit hummingbirds are associated with differences in the use of food plants. We suggest that some hermit hummingbirds provide model organisms for studies of ecological causation of sexual dimorphism because their sexual dimorphism in bill curvature provides a diagnostic clue for the food plants that need to be monitored for studies of sexual differences in resource use. PMID:20194168

Sexual dimorphism in striatal dopaminergic responses promotes monogamy in social songbirds.

PubMed

Tokarev, Kirill; Hyland Bruno, Julia; Ljubičić, Iva; Kothari, Paresh J; Helekar, Santosh A; Tchernichovski, Ofer; Voss, Henning U

2017-08-11

In many songbird species, males sing to attract females and repel rivals. How can gregarious, non-territorial songbirds such as zebra finches, where females have access to numerous males, sustain monogamy? We found that the dopaminergic reward circuitry of zebra finches can simultaneously promote social cohesion and breeding boundaries. Surprisingly, in unmated males but not in females, striatal dopamine neurotransmission was elevated after hearing songs. Behaviorally too, unmated males but not females persistently exchanged mild punishments in return for songs. Song reinforcement diminished when dopamine receptors were blocked. In females, we observed song reinforcement exclusively to the mate's song, although their striatal dopamine neurotransmission was only slightly elevated. These findings suggest that song-triggered dopaminergic activation serves a dual function in social songbirds: as low-threshold social reinforcement in males and as ultra-selective sexual reinforcement in females. Co-evolution of sexually dimorphic reinforcement systems can explain the coexistence of gregariousness and monogamy.

Sexual dimorphism in striatal dopaminergic responses promotes monogamy in social songbirds

PubMed Central

Hyland Bruno, Julia; Ljubičić, Iva; Kothari, Paresh J; Helekar, Santosh A; Tchernichovski, Ofer; Voss, Henning U

2017-01-01

In many songbird species, males sing to attract females and repel rivals. How can gregarious, non-territorial songbirds such as zebra finches, where females have access to numerous males, sustain monogamy? We found that the dopaminergic reward circuitry of zebra finches can simultaneously promote social cohesion and breeding boundaries. Surprisingly, in unmated males but not in females, striatal dopamine neurotransmission was elevated after hearing songs. Behaviorally too, unmated males but not females persistently exchanged mild punishments in return for songs. Song reinforcement diminished when dopamine receptors were blocked. In females, we observed song reinforcement exclusively to the mate’s song, although their striatal dopamine neurotransmission was only slightly elevated. These findings suggest that song-triggered dopaminergic activation serves a dual function in social songbirds: as low-threshold social reinforcement in males and as ultra-selective sexual reinforcement in females. Co-evolution of sexually dimorphic reinforcement systems can explain the coexistence of gregariousness and monogamy. PMID:28826502

Everything you always wanted to know about sex ... in flies.

PubMed

Arbeitman, M N; Kopp, Artyom; Siegal, M L; Van Doren, M

2010-01-01

'Everything you always wanted to know about sex' is a workshop organized as part of the annual Drosophila Research Conference of the Genetics Society of America. This workshop provides an intellectual venue for interaction among research groups that study sexual dimorphism from the molecular, evolutionary, genomic, and behavioral perspectives. The speakers summarize the key ideas behind their research for people working in other fields, outline unsolved questions, and offer their opinions about future directions. The 2010 workshop highlighted the power of the Drosophila model for understanding sexual dimorphism at levels ranging from cell biology and gene regulation to population genetics and genome evolution, and demonstrated the importance of cross-disciplinary interactions in the study of sex. In this respect, Drosophila sets a good example for research in other organisms, including humans and their mammalian relatives. Copyright © 2010 S. Karger AG, Basel.

Displacement behaviors in chimpanzees (Pan troglodytes): A neurogenomics investigation of the RDoC Negative Valence Systems domain.

PubMed

Latzman, Robert D; Young, Larry J; Hopkins, William D

2016-03-01

The current study aimed to systematically investigate genetic and neuroanatomical correlates of individual variation in scratching behaviors, a well-validated animal-behavioral indicator of negative emotional states with clear links to the NIMH Research Domain Criteria (RDoC) response to potential harm ("anxiety") construct within the Negative Valence Systems domain. Utilizing data from a sample of 76 captive chimpanzees (Pan troglodytes), we (a) examined the association between scratching and presence or absence of the RS3-containing DupB element in the AVPR1A 5' flanking region, (b) utilized voxel-based morphometry (VBM) to identify gray matter (GM) voxel clusters that differentiated AVPR1A genotype, and (c) conducted a VBM-guided voxel-of-interest analysis to examine the association between GM intensity and scratching. AVPR1A evidenced sexually dimorphic associations with scratching. VBM analyses revealed significant differences in GM by genotype across twelve clusters largely in the frontal cortex. Regions differentiating AVPR1A genotype showed sex-specific associations with scratching. Results suggest that sexually dimorphic associations between AVPR1A and scratching may be explained by genotype-specific neuroanatomical variation. The current study provides an example of the way in which chimpanzee research is uniquely poised for multilevel, systematic investigations of psychopathology-relevant constructs within the context of the RDoC framework. © 2016 Society for Psychophysiological Research.

Early Female Puberty: A Review of Research on Etiology and Implications

ERIC Educational Resources Information Center

Daniel, Eileen; Balog, Linda F.

2009-01-01

The age of female puberty appears to have decreased in the United States and western countries as child health and nutrition have improved and obesity has become more prevalent. Also, environmental contaminants, particularly endocrine disruptors, may also play a role in lowering the age of puberty. Puberty at an early age increases the risk of…

Potential functional variants associated with age at puberty in a validation population of swine

USDA-ARS?s Scientific Manuscript database

Puberty in pigs is defined as age at first estrus and gilts that have an earlier age at puberty are more likely to have greater sow lifetime productivity. Because age at puberty is predictive for sow longevity and lifetime productivity, but not routinely measured in commercial herds, it would be ben...

A genome-wide survey of sexually dimorphic expression of Drosophila miRNAs identifies the steroid hormone-induced miRNA let-7 as a regulator of sexual identity.

PubMed

Fagegaltier, Delphine; König, Annekatrin; Gordon, Assaf; Lai, Eric C; Gingeras, Thomas R; Hannon, Gregory J; Shcherbata, Halyna R

2014-10-01

MiRNAs bear an increasing number of functions throughout development and in the aging adult. Here we address their role in establishing sexually dimorphic traits and sexual identity in male and female Drosophila. Our survey of miRNA populations in each sex identifies sets of miRNAs differentially expressed in male and female tissues across various stages of development. The pervasive sex-biased expression of miRNAs generally increases with the complexity and sexual dimorphism of tissues, gonads revealing the most striking biases. We find that the male-specific regulation of the X chromosome is relevant to miRNA expression on two levels. First, in the male gonad, testis-biased miRNAs tend to reside on the X chromosome. Second, in the soma, X-linked miRNAs do not systematically rely on dosage compensation. We set out to address the importance of a sex-biased expression of miRNAs in establishing sexually dimorphic traits. Our study of the conserved let-7-C miRNA cluster controlled by the sex-biased hormone ecdysone places let-7 as a primary modulator of the sex-determination hierarchy. Flies with modified let-7 levels present doublesex-related phenotypes and express sex-determination genes normally restricted to the opposite sex. In testes and ovaries, alterations of the ecdysone-induced let-7 result in aberrant gonadal somatic cell behavior and non-cell-autonomous defects in early germline differentiation. Gonadal defects as well as aberrant expression of sex-determination genes persist in aging adults under hormonal control. Together, our findings place ecdysone and let-7 as modulators of a somatic systemic signal that helps establish and sustain sexual identity in males and females and differentiation in gonads. This work establishes the foundation for a role of miRNAs in sexual dimorphism and demonstrates that similar to vertebrate hormonal control of cellular sexual identity exists in Drosophila. Copyright © 2014 by the Genetics Society of America.

Selection for predation, not female fecundity, explains sexual size dimorphism in the orchid mantises.

PubMed

Svenson, Gavin J; Brannoch, Sydney K; Rodrigues, Henrique M; O'Hanlon, James C; Wieland, Frank

2016-12-01

Here we reconstruct the evolutionary shift towards floral simulation in orchid mantises and suggest female predatory selection as the likely driving force behind the development of extreme sexual size dimorphism. Through analysis of body size data and phylogenetic modelling of trait evolution, we recovered an ancestral shift towards sexual dimorphisms in both size and appearance in a lineage of flower-associated praying mantises. Sedentary female flower mantises dramatically increased in size prior to a transition from camouflaged, ambush predation to a floral simulation strategy, gaining access to, and visually attracting, a novel resource: large pollinating insects. Male flower mantises, however, remained small and mobile to facilitate mate-finding and reproductive success, consistent with ancestral male life strategy. Although moderate sexual size dimorphisms are common in many arthropod lineages, the predominant explanation is female size increase for increased fecundity. However, sex-dependent selective pressures acting outside of female fecundity have been suggested as mechanisms behind niche dimorphisms. Our hypothesised role of predatory selection acting on females to generate both extreme sexual size dimorphism coupled with niche dimorphism is novel among arthropods.

Dimorphism in the Size and Shape of the Birth Canal Across Anthropoid Primates.

PubMed

Moffett, Elizabeth A

2017-05-01

It has long been noted that the human female birth canal is well adapted to giving birth to large-brained neonates. However, several species of nonhuman primates give birth to large-headed neonates compared to the maternal birth canal. The presence of such large cephalopelvic proportions in nonhuman primates presents the question of whether dimorphism in the birth canals of these other species is related to obstetric demand, as such dimorphism is presumed to be in humans. In this study, the hypothesis that either the presence or magnitude of dimorphism in the birth canal is related to large cephalopelvic proportions among anthropoid primates is directly tested. This study shows that birth canal dimorphism is common among anthropoids regardless of cephalopelvic proportions, but taxa with large cephalopelvic proportions have a higher magnitude of dimorphism than those that give birth to relatively small-headed neonates. Furthermore, humans have exceptionally high levels of dimorphism that cannot be explained based on our large cephalopelvic proportions alone. Anat Rec, 300:870-889, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Selection for predation, not female fecundity, explains sexual size dimorphism in the orchid mantises

PubMed Central

Svenson, Gavin J.; Brannoch, Sydney K.; Rodrigues, Henrique M.; O’Hanlon, James C.; Wieland, Frank

2016-01-01

Here we reconstruct the evolutionary shift towards floral simulation in orchid mantises and suggest female predatory selection as the likely driving force behind the development of extreme sexual size dimorphism. Through analysis of body size data and phylogenetic modelling of trait evolution, we recovered an ancestral shift towards sexual dimorphisms in both size and appearance in a lineage of flower-associated praying mantises. Sedentary female flower mantises dramatically increased in size prior to a transition from camouflaged, ambush predation to a floral simulation strategy, gaining access to, and visually attracting, a novel resource: large pollinating insects. Male flower mantises, however, remained small and mobile to facilitate mate-finding and reproductive success, consistent with ancestral male life strategy. Although moderate sexual size dimorphisms are common in many arthropod lineages, the predominant explanation is female size increase for increased fecundity. However, sex-dependent selective pressures acting outside of female fecundity have been suggested as mechanisms behind niche dimorphisms. Our hypothesised role of predatory selection acting on females to generate both extreme sexual size dimorphism coupled with niche dimorphism is novel among arthropods. PMID:27905469

Individual Differences in Boys’ and Girls’ Timing and Tempo of Puberty: Modeling Development With Nonlinear Growth Models

PubMed Central

Marceau, Kristine; Ram, Nilam; Houts, Renate M.; Grimm, Kevin J.; Susman, Elizabeth J.

2014-01-01

Pubertal development is a nonlinear process progressing from prepubescent beginnings through biological, physical, and psychological changes to full sexual maturity. To tether theoretical concepts of puberty with sophisticated longitudinal, analytical models capable of articulating pubertal development more accurately, we used nonlinear mixed-effects models to describe both the timing and tempo of pubertal development in the sample of 364 White boys and 373 White girls measured across 6 years as part of the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development. Individual differences in timing and tempo were extracted with models of logistic growth. Differential relations emerged for how boys’ and girls’ timing and tempo of development were related to physical characteristics (body mass index, height, and weight) and psychological outcomes (internalizing problems, externalizing problems, and risky sexual behavior). Timing and tempo are associated in boys but not girls. Pubertal timing and tempo are particularly important for predicting psychological outcomes in girls but only sparsely related to boys’ psychological outcomes. Results highlight the importance of considering the nonlinear nature of puberty and expand the repertoire of possibilities for examining important aspects of how and when pubertal processes contribute to development. PMID:21639623

A longitudinal study: changes in cortical thickness and surface area during pubertal maturation.

PubMed

Herting, Megan M; Gautam, Prapti; Spielberg, Jeffrey M; Dahl, Ronald E; Sowell, Elizabeth R

2015-01-01

Sex hormones have been shown to contribute to the organization and function of the brain during puberty and adolescence. Moreover, it has been suggested that distinct hormone changes in girls versus boys may contribute to the emergence of sex differences in internalizing and externalizing behavior during adolescence. In the current longitudinal study, the influence of within-subject changes in puberty (physical and hormonal) on cortical thickness and surface area was examined across a 2-year span, while controlling for age. Greater increases in Tanner Stage predicted less superior frontal thinning and decreases in precuneus surface area in both sexes. Significant Tanner Stage and sex interactions were also seen, with less right superior temporal thinning in girls but not boys, as well as greater decreases in the right bank of the superior temporal sulcus surface area in boys compared to girls. In addition, within-subject changes in testosterone over the 2-year follow-up period were found to relate to decreases in middle superior frontal surface area in boys, but increases in surface area in girls. Lastly, larger increases in estradiol in girls predicted greater middle temporal lobe thinning. These results show that within-subject physical and hormonal markers of puberty relate to region and sex-specific changes in cortical development across adolescence.

Androgen therapy for delayed male puberty.

PubMed

Ambler, Geoffrey R

2009-06-01

Delayed puberty in men is a commonly presenting problem to paediatricians and an understanding of the available evidence on cause, treatments and outcomes is important to guide practice. Understanding of the regulation of the onset of puberty is gradually unfolding, although the genetic factors that dictate the timing of puberty in individuals and families remain poorly elucidated. Mutations and polymorphisms in candidate genes are being actively studied and it is likely that there is significant overlap between traditional diagnostic categories. Also, environmental endocrine disruptors may interact with the genetic regulation of puberty. Delayed puberty may not always be a benign condition, with increased risks of failing to achieve target height, adverse psychological and educational consequences, delayed sexual and psychosocial integration into society and effects on skeletal proportions and bone mass reported. Appropriate evaluation and follow-up is needed to guide clinical practice, particularly to distinguish constitutional delay in growth and puberty from that associated with other medical disease or permanent disorders. In milder cases of delayed puberty, treatment is often not required; however, considerable evidence exists for the efficacy and safety of short courses of low-dose testosterone therapy for appropriately selected individuals. This treatment is associated with high levels of patient satisfaction. There is not yet sufficient evidence for the routine use of other therapies (e.g. growth hormone, aromatase inhibitors) for constitutional delay in growth and puberty and better characterization of cause may lead to more targeted individual therapy.

Familial central precocious puberty suggests autosomal dominant inheritance.

PubMed

de Vries, Liat; Kauschansky, Arieh; Shohat, Mordechai; Phillip, Moshe

2004-04-01

The prevalence of precocious puberty is higher in certain ethnic groups, and some cases may be familial. The aim of this study was to investigate the mode of inheritance of familial precocious puberty and to identify characteristics that distinguish familial from isolated precocious puberty. Of the 453 children referred to our center for suspected precocious puberty between January 1, 1997, and December 31, 2000, 156 (147 girls and 9 boys) were found to have idiopathic central precocious puberty, which was familial in 43 (42 girls and 1 boy) (27.5%). Data of the familial and sporadic cases were compared. The familial group was characterized by a significantly lower maternal age at menarche than the sporadic group (mean, 11.47 +/- 1.96 vs. 12.66 +/- 1.18 yr; P = 0.0001) and more advanced puberty at admission (Tanner stage 2, 56.5% vs. 78.1%; P = 0.006). Segregation analysis was used to study the mode of inheritance. The segregation ratio for precocious puberty was 0.38 (0.45 after exclusion of young siblings) assuming incomplete penetrance and 0.58 (0.65 after exclusion of young siblings) assuming complete ascertainment. These results suggest autosomal dominant transmission with incomplete, sex-dependent penetrance.

Circulating MKRN3 Levels Decline During Puberty in Healthy Boys.

PubMed

Busch, Alexander S; Hagen, Casper P; Almstrup, Kristian; Juul, Anders

2016-06-01

Initiation and progression of puberty requires concerted action of hypothalamic activating and inhibiting factors. Recently, cases of familial central precocious puberty have been linked to loss-of-function mutations of makorin RING-finger protein 3 (MKRN3) indicating a pivotal inhibitory role of the protein on GnRH secretion. To investigate peripubertal circulating MKRN3 levels in healthy boys. Population-based longitudinal study in healthy Danish boys. General community. Healthy boys (n = 60) aged (median [range]) 9.3 (5.8-11.8) years at baseline followed for 6.0 (0.5-7.6) years (2006-2014) with blood sampling every 6 months. None. Serum levels of MKRN3: 623 samples, median (range) 12 (2-14) per boy. MKRN3 levels declined before onset of puberty; the geometric mean (95% confidence interval) 5 years before onset of puberty vs last visit before onset of puberty was 216 (169-272) pg/mL vs 128 (118-139) pg/mL (P < .001), respectively. MKRN3 levels continued to decrease as puberty progressed. MKRN3 levels were not associated with age at onset of puberty. Declining MKRN3 before pubertal onset support MKRN3 as an inhibitor of GnRH secretion during midchildhood.

Cortisol Response to Psychosocial Stress in Chinese Early Puberty Girls: Possible Role of Depressive Symptoms.

PubMed

Sun, Ying; Deng, Fang; Liu, Yang; Tao, Fang-Biao

2015-01-01

Objective. The present study aimed at investigating unique patterns of salivary cortisol reactivity and recovery in response to a social stressor among girls with early puberty and exploring possible role of depressive symptom in this association. Design. Case-control study. Patients. Fifty-six girls with early puberty and age- and body mass index- (BMI-) matched normal puberty controls (n = 56) were selected. Measurements. Salivary cortisol was measured in response to the Groningen Social Stress Test for Children. Results. Girls with early puberty had higher cortisol concentration at the end of the GSST (C3), cortisol concentration 20 min after the end of the GSST (C4), and AUC increment (AUCi) compared to non-early puberty girls. Depressive symptoms correlated with blunted HPA reactivity among girls with early puberty. Conclusion. This study demonstrated the disturbance effect of objectively examined early pubertal timing on HPA axis responses. It also suggested that stress reactivity might be blunted for individuals with depressive symptoms.

True Precocious Puberty Following Treatment of a Leydig Cell Tumor: Two Case Reports and Literature Review.

PubMed

Verrotti, Alberto; Penta, Laura; Zenzeri, Letizia; Lucchetti, Laura; Giovenali, Paolo; De Feo, Pierpaolo

2015-01-01

Leydig cell testicular tumors are a rare cause of precocious pseudopuberty in boys. Surgery is the main therapy and shows good overall prognosis. The physical signs of precocious puberty are expected to disappear shortly after surgical removal of the mass. We report two children, 7.5 and 7.7 year-old boys, who underwent testis-sparing surgery for a Leydig cell testicular tumor causing precocious pseudopuberty. During follow-up, after an immediate clinical and laboratory regression, both boys presented signs of precocious puberty and ultimately developed central precocious puberty. They were successfully treated with gonadotropin-releasing hormone (GnRH) analogs. Only six other cases have been described regarding the development of central precocious puberty after successful treatment of a Leydig cell tumor causing precocious pseudopuberty. Gonadotropin-dependent precocious puberty should be considered in children treated for a Leydig cell tumor presenting persistent or recurrent physical signs of puberty activation. In such cases, therapy with GnRH analogs appears to be the most effective medical treatment.

Age-related changes in urinary testosterone levels suggest differences in puberty onset and divergent life history strategies in bonobos and chimpanzees.

PubMed

Behringer, V; Deschner, T; Deimel, C; Stevens, J M G; Hohmann, G

2014-08-01

Research on age-related changes in morphology, social behavior, and cognition suggests that the development of bonobos (Pan paniscus) is delayed in comparison to chimpanzees (Pan troglodytes). However, there is also evidence for earlier reproductive maturation in bonobos. Since developmental changes such as reproductive maturation are induced by a number of endocrine processes, changes in hormone levels are indicators of different developmental stages. Age-related changes in testosterone excretion are an indirect marker for the onset of puberty in human and non-human primates. In this study we investigated patterns of urinary testosterone levels in male and female bonobos and chimpanzees to determine the onset of puberty. In contrast to other studies, we found that both species experience age-related changes in urinary testosterone levels. Older individuals of both sexes had significantly higher urinary testosterone levels than younger individuals, indicating that bonobos and chimpanzees experience juvenile pause. The males of both species showed a similar pattern of age-related changes in urinary testosterone levels, with a sharp increase in levels around the age of eight years. This suggests that species-differences in aggression and male mate competition evolved independently of developmental changes in testosterone levels. Females showed a similar pattern of age-related urinary testosterone increase. However, in female bonobos the onset was about three years earlier than in female chimpanzees. The earlier rise of urinary testosterone levels in female bonobos is in line with reports of their younger age of dispersal, and suggests that female bonobos experience puberty at a younger age than female chimpanzees. Copyright © 2014 Elsevier Inc. All rights reserved.

Sexually Dimorphic Patterns of Cell Proliferation in the Brain Are Linked to Seasonal Life-History Transitions in Red-Sided Garter Snakes.

PubMed

Lutterschmidt, Deborah I; Lucas, Ashley R; Karam, Ritta A; Nguyen, Vicky T; Rasmussen, Meghann R

2018-01-01

Seasonal rhythms in physiology and behavior are widespread across diverse taxonomic groups and may be mediated by seasonal changes in neurogenesis, including cell proliferation, migration, and differentiation. We examined if cell proliferation in the brain is associated with the seasonal life-history transition from spring breeding to migration and summer foraging in a free-ranging population of red-sided garter snakes ( Thamnophis sirtalis ) in Manitoba, Canada. We used the thymidine analog 5-bromo-2'-deoxyuridine (BrdU) to label newly proliferated cells within the brain of adult snakes collected from the den during the mating season or from a road located along their migratory route. To assess rates of cell migration, we further categorized BrdU-labeled cells according to their location within the ventricular zone or parenchymal region of the nucleus sphericus (homolog of the amygdala), preoptic area/hypothalamus, septal nucleus, and cortex (homolog of the hippocampus). We found that cell proliferation and cell migration varied significantly with sex, the migratory status of snakes, and reproductive behavior in males. In most regions of interest, patterns of cell proliferation were sexually dimorphic, with males having significantly more BrdU-labeled cells than females prior to migration. However, during the initial stages of migration, females exhibited a significant increase in cell proliferation within the nucleus sphericus, hypothalamus, and septal nucleus, but not in any subregion of the cortex. In contrast, migrating males exhibited a significant increase in cell proliferation within the medial cortex but no other brain region. Because it is unlikely that the medial cortex plays a sexually dimorphic role in spatial memory during spring migration, we speculate that cell proliferation within the male medial cortex is associated with regulation of the hypothalamus-pituitary-adrenal axis. Finally, the only brain region where cell migration into the parenchymal region varied significantly with sex or migratory status was the hypothalamus. These results suggest that the migration of newly proliferated cells and/or the continued division of undifferentiated cells are activated earlier or to a greater extent in the hypothalamus. Our data suggest that sexually dimorphic changes in cell proliferation and cell migration in the adult brain may mediate sex differences in the timing of seasonal life-history transitions.

Sexually Dimorphic Patterns of Cell Proliferation in the Brain Are Linked to Seasonal Life-History Transitions in Red-Sided Garter Snakes

PubMed Central

Lutterschmidt, Deborah I.; Lucas, Ashley R.; Karam, Ritta A.; Nguyen, Vicky T.; Rasmussen, Meghann R.

2018-01-01

Seasonal rhythms in physiology and behavior are widespread across diverse taxonomic groups and may be mediated by seasonal changes in neurogenesis, including cell proliferation, migration, and differentiation. We examined if cell proliferation in the brain is associated with the seasonal life-history transition from spring breeding to migration and summer foraging in a free-ranging population of red-sided garter snakes (Thamnophis sirtalis) in Manitoba, Canada. We used the thymidine analog 5-bromo-2′-deoxyuridine (BrdU) to label newly proliferated cells within the brain of adult snakes collected from the den during the mating season or from a road located along their migratory route. To assess rates of cell migration, we further categorized BrdU-labeled cells according to their location within the ventricular zone or parenchymal region of the nucleus sphericus (homolog of the amygdala), preoptic area/hypothalamus, septal nucleus, and cortex (homolog of the hippocampus). We found that cell proliferation and cell migration varied significantly with sex, the migratory status of snakes, and reproductive behavior in males. In most regions of interest, patterns of cell proliferation were sexually dimorphic, with males having significantly more BrdU-labeled cells than females prior to migration. However, during the initial stages of migration, females exhibited a significant increase in cell proliferation within the nucleus sphericus, hypothalamus, and septal nucleus, but not in any subregion of the cortex. In contrast, migrating males exhibited a significant increase in cell proliferation within the medial cortex but no other brain region. Because it is unlikely that the medial cortex plays a sexually dimorphic role in spatial memory during spring migration, we speculate that cell proliferation within the male medial cortex is associated with regulation of the hypothalamus-pituitary-adrenal axis. Finally, the only brain region where cell migration into the parenchymal region varied significantly with sex or migratory status was the hypothalamus. These results suggest that the migration of newly proliferated cells and/or the continued division of undifferentiated cells are activated earlier or to a greater extent in the hypothalamus. Our data suggest that sexually dimorphic changes in cell proliferation and cell migration in the adult brain may mediate sex differences in the timing of seasonal life-history transitions.

Cross-sex genetic correlation does not extend to sexual size dimorphism in spiders

NASA Astrophysics Data System (ADS)

Turk, Eva; Kuntner, Matjaž; Kralj-Fišer, Simona

2018-02-01

Males and females are often subjected to different selection pressures for homologous traits, resulting in sex-specific optima. Because organismal attributes usually share their genetic architectures, sex-specific selection may lead to intralocus sexual conflict. Evolution of sexual dimorphism may resolve this conflict, depending on the degree of cross-sex genetic correlation ( r MF) and the strength of sex-specific selection. In theory, high r MF implies that sexes largely share the genetic base for a given trait and are consequently sexually monomorphic, while low r MF indicates a sex-specific genetic base and sexual dimorphism. Here, we broadly test this hypothesis on three spider species with varying degrees of female-biased sexual size dimorphism, Larinioides sclopetarius (sexual dimorphism index, SDI = 0.85), Nuctenea umbratica (SDI = 0.60), and Zygiella x-notata (SDI = 0.46). We assess r MF via same-sex and opposite-sex heritability estimates. We find moderate body mass heritability but no obvious patterns in sex-specific heritability. Against the prediction, the degree of sexual size dimorphism is unrelated to the relative strength of same-sex versus opposite-sex heritability. Our results do not support the hypothesis that sexual size dimorphism is negatively associated with r MF. We conclude that sex-specific genetic architecture may not be necessary for the evolution of a sexually dimorphic trait.

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.

Usefulness and Reliability of Tanner Pubertal Self-Rating to Urban Black Adolescents in South Africa

ERIC Educational Resources Information Center

Norris, Shane A.; Richter, Linda M.

2005-01-01

Self-rating of pubertal development is the recommended method to assess puberty in large community-based surveys of adolescent development and behavior. The aim of this study was to validate for the first time pubertal self-assessment using the sexual maturation scale developed by Tanner among Black South African adolescents (n=182) aged between…

Sexual behavior of gender-dysphoric individuals before gender-confirming interventions: a European multicenter study.

PubMed

Cerwenka, Susanne; Nieder, Timo O; Cohen-Kettenis, Peggy; De Cuypere, Griet; Haraldsen, Ira R Hebold; Kreukels, Baudewijntje P C; Richter-Appelt, Hertha

2014-01-01

A transsexual course of development that starts before puberty (early onset) or during or after puberty, respectively (late onset), may lead to diverse challenges in coping with sexual activity. The authors explored the sexual behavior of 380 adult male-to-female and female-to-male individuals diagnosed according to DSM-IV-TR criteria who had not yet undergone gender-confirming interventions. Data originated from the European Network for the Investigation of Gender Incongruence Initiative, conducted in Belgium, Germany, The Netherlands, and Norway. Information on outcome variables was collected using self-administered questionnaires at first clinical presentation. Compared with late-onset male-to-females, early-onset individuals tended to show sexual attraction toward males more frequently (50.5%), involve genitals less frequently in partner-related sexual activity, and consider penile sensations and orgasm as more negative. Early-onset female-to-males predominantly reported sexual attraction toward females (84.0%), whereas those with a late-onset more frequently showed other sexual attractions (41.7%). The study (a) shows that early- and late-onset male-to-females differ considerably with regard to coping strategies involving their body during sexual relations and (b) reveals initial insights into developmental pathways of late-onset female-to-males.

Dysmenorrhea

MedlinePlus

... Learn about the various causes and treatments for primary…Girls and PubertyRead Article >>Kids and TeensGirls and PubertyPuberty in girls can start as early as age 9 and will include many physical and emotional ...

Weight gain in Turner Syndrome: association to puberty induction? - longitudinal analysis of KIGS data.

PubMed

Reinehr, Thomas; Lindberg, Anders; Toschke, Christina; Cara, Jose; Chrysis, Dionisis; Camacho-Hübner, Cecilia

2016-07-01

Girls with Turner Syndrome (TS) treated or not treated with growth hormone (GH) are prone to overweight. Therefore, we hypothesize that puberty induction in TS is associated with weight gain. We analyzed weight changes (BMI-SDS) between onset of GH treatment and near adult height (NAH) in 887 girls with TS enrolled in KIGS (Pfizer International Growth Database). Puberty was induced with estrogens in 646 (72·8%) girls with TS. Weight status did not change significantly between GH treatment start and 1 year later (mean difference -0·02 BMI-SDS), but increased significantly (P < 0·001) until NAH (+0·40 BMI-SDS). The BMI-SDS increased +0·21 until start of puberty (P < 0·001). Girls with spontaneous and induced puberty showed similar BMI-SDS changes. Puberty induction at ≥12 years was associated with a significant (P < 0·001) less increase of BMI-SDS (+0·7 BMI-SDS) between baseline and NAH compared to puberty induction at <12 year (+1·0 BMI-SDS). In multiple linear regression analyses changes of BMI-SDS between baseline and NAH were negatively associated with baseline BMI-SDS (P < 0·001), GH doses (P = 0·015), and age at puberty induction (P < 0·001), positively with years on GH treatment (P = 0·004), while duration and dose of estrogens, its route of administration (transdermal/oral), changes of height-SDS, thyroxin and oxandrolone treatment, and karyotype did not correlate significantly to changes of BMI-SDS in this time period. Puberty does not seem to play a major role in weight gain in girls with TS since the majority of the increases in BMI-SDS occurred before puberty. However, late puberty induction seems to decrease the risk of weight gain. © 2016 John Wiley & Sons Ltd.

Dietary ethinyl estradiol exposure during development causes increased voluntary sodium intake and mild maternal and offspring toxicity in rats.

PubMed

Ferguson, Sherry A; Delclos, K Barry; Newbold, Retha R; Flynn, Katherine M

2003-01-01

Exogenous estrogen exposure during development often results in behavioral masculinization and/or defeminization of genetic females. Genetic males may be defeminized, hypermasculinized or even demasculinized after similar treatment. Here, pregnant Sprague-Dawley rats consumed phytoestrogen-free diets containing 0, 1, 5 or 200 ppb EE(2) beginning on gestational day (GD) 7. Offspring were weaned to the same maternal diet and maintained gonadally intact. There were mild effects on body weight and food consumption in dams of the 200 ppb group and their offspring weighed less at birth than those of the control group; however, gross assessments of nursing behavior were normal in all dietary groups. Postweaning, offspring of the 200 ppb group weighed less and consumed less food than controls. There were no EE(2)-related effects on open-field activity (tested at postnatal days (PND) 22-24, 43-45 and 64-66), play behavior (tested at PND 35), running wheel activity (PND 63-77) or intake of a 0.3% saccharin-flavored solution (PND 69-71). Intake of a 3.0% sodium chloride-flavored solution on PND 73-75 was increased in both male and female offspring of the 200 ppb group relative to same-sex controls, an effect that is reportedly estrogen mediated. Sodium chloride-flavored solution intake is a sexually dimorphic behavior for which female rats consume more than males. Here, while EE(2) exposure had few effects on the conventional tests of sexually dimorphic behaviors, exposure to 200 ppb in the diet appeared to feminize genetic males and hyperfeminize genetic females with regard to sodium intake.

Sexual conflict predicts morphology and behavior in two species of penduline tits

PubMed Central

2010-01-01

Background The evolutionary interests of males and females rarely coincide (sexual conflict), and these conflicting interests influence morphology, behavior and speciation in various organisms. We examined consequences of variation in sexual conflict in two closely-related passerine birds with contrasting breeding systems: the Eurasian penduline tit Remiz pendulinus (EPT) exhibiting a highly polygamous breeding system with sexually antagonistic interests over parental care, and the socially monogamous Cape penduline tit Anthoscopus minutus (CPT). We derived four a priori predictions from sexual conflict theory and tested these using data collected in Central Europe (EPT) and South Africa (CPT). Firstly, we predicted that EPTs exhibit more sexually dimorphic plumage than CPTs due to more intense sexual selection. Secondly, we expected brighter EPT males to provide less care than duller males. Thirdly, since song is a sexually selected trait in many birds, male EPTs were expected to exhibit more complex songs than CPT males. Finally, intense sexual conflict in EPT was expected to lead to low nest attendance as an indication of sexually antagonistic interests, whereas we expected more cooperation between parents in CPT consistent with their socially monogamous breeding system. Results Consistent with our predictions EPTs exhibited greater sexual dimorphism in plumage and more complex song than CPTs, and brighter EPT males provided less care than duller ones. EPT parents attended the nest less frequently and less simultaneously than CPT parents. Conclusions These results are consistent with sexual conflict theory: species in which sexual conflict is more manifested (EPT) exhibited a stronger sexual dimorphism and more elaborated sexually selected traits than species with less intense sexual conflict (CPT). Our results are also consistent with the notion that EPTs attempt to force their partner to work harder as expected under sexual conflict: each member of the breeding pair attempts to shift the costs of care to the other parent. More brightly colored males benefit more from desertion than dull ones, because they are more likely to remate with a new female. Taken together, the comparison between two closely related species with contrasting breeding systems suggest that sexual conflict over care has influenced the evolution of behavior and morphology in penduline tits. PMID:20416066

Sexual conflict predicts morphology and behavior in two species of penduline tits.

PubMed

van Dijk, René E; Pogány, Akos; Komdeur, Jan; Lloyd, Penn; Székely, Tamás

2010-04-23

The evolutionary interests of males and females rarely coincide (sexual conflict), and these conflicting interests influence morphology, behavior and speciation in various organisms. We examined consequences of variation in sexual conflict in two closely-related passerine birds with contrasting breeding systems: the Eurasian penduline tit Remiz pendulinus (EPT) exhibiting a highly polygamous breeding system with sexually antagonistic interests over parental care, and the socially monogamous Cape penduline tit Anthoscopus minutus (CPT). We derived four a priori predictions from sexual conflict theory and tested these using data collected in Central Europe (EPT) and South Africa (CPT). Firstly, we predicted that EPTs exhibit more sexually dimorphic plumage than CPTs due to more intense sexual selection. Secondly, we expected brighter EPT males to provide less care than duller males. Thirdly, since song is a sexually selected trait in many birds, male EPTs were expected to exhibit more complex songs than CPT males. Finally, intense sexual conflict in EPT was expected to lead to low nest attendance as an indication of sexually antagonistic interests, whereas we expected more cooperation between parents in CPT consistent with their socially monogamous breeding system. Consistent with our predictions EPTs exhibited greater sexual dimorphism in plumage and more complex song than CPTs, and brighter EPT males provided less care than duller ones. EPT parents attended the nest less frequently and less simultaneously than CPT parents. These results are consistent with sexual conflict theory: species in which sexual conflict is more manifested (EPT) exhibited a stronger sexual dimorphism and more elaborated sexually selected traits than species with less intense sexual conflict (CPT). Our results are also consistent with the notion that EPTs attempt to force their partner to work harder as expected under sexual conflict: each member of the breeding pair attempts to shift the costs of care to the other parent. More brightly colored males benefit more from desertion than dull ones, because they are more likely to remate with a new female. Taken together, the comparison between two closely related species with contrasting breeding systems suggest that sexual conflict over care has influenced the evolution of behavior and morphology in penduline tits.

Puberty

MedlinePlus

Puberty is the time in life when a boy or girl becomes sexually mature. It is a process that ... for boys. It causes physical changes, and affects boys and girls differently. In girls: The first sign of puberty ...

Effects of puberty on cystic fibrosis related pulmonary exacerbations in women versus men.

PubMed

Sutton, Shelby; Rosenbluth, Daniel; Raghavan, Deepa; Zheng, Jie; Jain, Raksha

2014-01-01

Epidemiologic data from studies of airway diseases, such as asthma, chronic obstructive pulmonary disease, and cystic fibrosis indicate a gender disparity where women have worse outcomes. The explanation for this is largely unknown. We hypothesize that female sex hormones play a role in this gender disparity, predisposing women to more exacerbations and decreased lung function post-puberty. In Cystic Fibrosis, to determine if puberty marks a point of increasing exacerbations and decreasing lung function in women relative to men. Using the United States Cystic Fibrosis Foundation Patient Registry, we used linear regression to compare lung function and rate of pulmonary exacerbations in men versus women before and after puberty. Of 5,137 subjects who met inclusion criteria, 2,689 were male and 2,448 were female. Average age of puberty was found to be 13.2 ± 2.2 years in men and 11.2 ± 2.0 years of age in women. Percent predicted FEV1 pre- and post-puberty were no different between males versus females (P = 0.44 pre-puberty and P = 0.16 post-puberty). In contrast, women had a significantly higher rate of pulmonary exacerbations post-puberty than men (1.17 ± 1.35 exacerbations per year in women versus 0.95 ± 1.27 in men; P < 0.001) despite controlling for morphometrics, co-morbidities, and microbiologic variables. After puberty, the rate of pulmonary exacerbations increased in adolescent women relative to men with cystic fibrosis, supporting a role for sex hormones in the disease process. Further understanding of the mechanisms that modulate sex hormone receptors in airway disease may serve as future targets for therapy. © 2013 Wiley Periodicals, Inc.

Effects of Puberty on Cystic Fibrosis Related Pulmonary Exacerbations in Women Versus Men

PubMed Central

Sutton, Shelby; Rosenbluth, Daniel; Raghavan, Deepa; Zheng, Jie; Jain, Raksha

2014-01-01

Summary Background Epidemiologic data from studies of airway diseases, such as asthma, chronic obstructive pulmonary disease, and cystic fibrosis indicate a gender disparity where women have worse outcomes. The explanation for this is largely unknown. We hypothesize that female sex hormones play a role in this gender disparity, predisposing women to more exacerbations and decreased lung function post-puberty. Objective In Cystic Fibrosis, to determine if puberty marks a point of increasing exacerbations and decreasing lung function in women relative to men. Methods Using the United States Cystic Fibrosis Foundation Patient Registry, we used linear regression to compare lung function and rate of pulmonary exacerbations in men versus women before and after puberty. Results Of 5,137 subjects who met inclusion criteria, 2,689 were male and 2,448 were female. Average age of puberty was found to be 13.2 ± 2.2 years in men and 11.2 ± 2.0 years of age in women. Percent predicted FEV1 pre-and post-puberty were no different between males versus females (P = 0.44 pre-puberty and P = 0.16 post-puberty). In contrast, women had a significantly higher rate of pulmonary exacerbations post-puberty than men (1.17 ± 1.35 exacerbations per year in women versus 0.95 ± 1.27 in men; P < 0.001) despite controlling for morphometrics, co-morbidities, and microbiologic variables. Conclusion After puberty, the rate of pulmonary exacerbations increased in adolescent women relative to men with cystic fibrosis, supporting a role for sex hormones in the disease process. Further understanding of the mechanisms that modulate sex hormone receptors in airway disease may serve as future targets for therapy. PMID:23460461

Sex differences in strategy and performance on computerized neuropsychological tests as related to gender identity and age at puberty.

PubMed

Meurling, A W; Tonning-Olsson, I; Levander, S

2000-06-01

Neuropsychological sex differences have since long been under debate. Support for the relation between behavioral differences and biological variables like hormone influence is, however, emerging. Sixteen men and sixteen women, all university students, were tested with computerized neuropsychological tests (APT), the Bem Sexual Role Inventory, and asked about pubertal age. The results were in line with earlier findings of sex differences in neuropsychological tests, men being faster and women more cautious. The assumption that women tend to use left-hemispheric, verbal/serial strategies also in spatial tasks was also partly supported. In women, late onset of puberty was related to better spatial performance, and there were also more intercorrelations between verbal and spatial tests in the female than in the male group, indicating that women use less specific strategies (more g-factor intelligence) in problem solving, or that aptitudes are less compartmentalized in women than in men.

The Value of Comparative Approaches to our Understanding of Puberty as Illustrated by Investigations in Birds and Reptiles

PubMed Central

Ball, Gregory F.; Wade, Juli

2013-01-01

Studies of birds and reptiles have provided many basic insights into the neuroendocrine control of reproductive processes. This research has elucidated mechanisms regulating both early development, including sexual differentiation, and adult neuroendocrine function and behavior. However, phenomena associated with the transition into sexual maturation (puberty) have not been a focus of investigators working on species in these taxonomic classes. Research is complicated in birds and reptiles by a variety of factors, including what can be extended times to maturation, the need to reach particular body size regardless of age, and environmental conditions that can support or inhibit endocrine responses. However, careful selection of model systems, particularly those with available genetic tools, will lead to important comparative studies that can elucidate both generalizability and diversity of mechanisms regulating the onset of reproductive maturity. PMID:23998665

Puberty as a critical risk period for eating disorders: a review of human and animal studies.

PubMed

Klump, Kelly L

2013-07-01

This article is part of a Special Issue "Puberty and Adolescence". Puberty is one of the most frequently discussed risk periods for the development of eating disorders. Prevailing theories propose environmentally mediated sources of risk arising from the psychosocial effects (e.g., increased body dissatisfaction, decreased self-esteem) of pubertal development in girls. However, recent research highlights the potential role of ovarian hormones in phenotypic and genetic risk for eating disorders during puberty. The goal of this paper is to review data from human and animal studies in support of puberty as a critical risk period for eating disorders and evaluate the evidence for hormonal contributions. Data are consistent in suggesting that both pubertal status and pubertal timing significantly impact risk for most eating disorders in girls, such that advanced pubertal development and early pubertal timing are associated with increased rates of eating disorders and their symptoms in both cross-sectional and longitudinal research. Findings in boys have been much less consistent and suggest a smaller role for puberty in risk for eating disorders in boys. Twin and animal studies indicate that at least part of the female-specific risk is due to genetic factors associated with estrogen activation at puberty. In conclusion, data thus far support a role for puberty in risk for eating disorders and highlight the need for additional human and animal studies of hormonal and genetic risk for eating disorders during puberty. Copyright © 2013 Elsevier Inc. All rights reserved.

Multivariate dynamical modelling of structural change during development.

PubMed

Ziegler, Gabriel; Ridgway, Gerard R; Blakemore, Sarah-Jayne; Ashburner, John; Penny, Will

2017-02-15

Here we introduce a multivariate framework for characterising longitudinal changes in structural MRI using dynamical systems. The general approach enables modelling changes of states in multiple imaging biomarkers typically observed during brain development, plasticity, ageing and degeneration, e.g. regional gray matter volume of multiple regions of interest (ROIs). Structural brain states follow intrinsic dynamics according to a linear system with additional inputs accounting for potential driving forces of brain development. In particular, the inputs to the system are specified to account for known or latent developmental growth/decline factors, e.g. due to effects of growth hormones, puberty, or sudden behavioural changes etc. Because effects of developmental factors might be region-specific, the sensitivity of each ROI to contributions of each factor is explicitly modelled. In addition to the external effects of developmental factors on regional change, the framework enables modelling and inference about directed (potentially reciprocal) interactions between brain regions, due to competition for space, or structural connectivity, and suchlike. This approach accounts for repeated measures in typical MRI studies of development and aging. Model inversion and posterior distributions are obtained using earlier established variational methods enabling Bayesian evidence-based comparisons between various models of structural change. Using this approach we demonstrate dynamic cortical changes during brain maturation between 6 and 22 years of age using a large openly available longitudinal paediatric dataset with 637 scans from 289 individuals. In particular, we model volumetric changes in 26 bilateral ROIs, which cover large portions of cortical and subcortical gray matter. We account for (1) puberty-related effects on gray matter regions; (2) effects of an early transient growth process with additional time-lag parameter; (3) sexual dimorphism by modelling parameter differences between boys and girls. There is evidence that the regional pattern of sensitivity to dynamic hidden growth factors in late childhood is similar across genders and shows a consistent anterior-posterior gradient with strongest impact to prefrontal cortex (PFC) brain changes. Finally, we demonstrate the potential of the framework to explore the coupling of structural changes across a priori defined subnetworks using an example of previously established resting state functional connectivity. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Biological sex influences learning strategy preference and muscarinic receptor binding in specific brain regions of prepubertal rats.

PubMed

Grissom, Elin M; Hawley, Wayne R; Hodges, Kelly S; Fawcett-Patel, Jessica M; Dohanich, Gary P

2013-04-01

According to the theory of multiple memory systems, specific brain regions interact to determine how the locations of goals are learned when rodents navigate a spatial environment. A number of factors influence the type of strategy used by rodents to remember the location of a given goal in space, including the biological sex of the learner. We recently found that prior to puberty male rats preferred a striatum-dependent stimulus-response strategy over a hippocampus-dependent place strategy when solving a dual-solution task, while age-matched females showed no strategy preference. Because the cholinergic system has been implicated in learning strategy and is known to be sexually dimorphic prior to puberty, we explored the relationship between learning strategy and muscarinic receptor binding in specific brain regions of prepubertal males and female rats. We confirmed our previous finding that at 28 days of age a significantly higher proportion of prepubertal males preferred a stimulus-response learning strategy than a place strategy to solve a dual-solution visible platform water maze task. Equal proportions of prepubertal females preferred stimulus-response or place strategies. Profiles of muscarinic receptor binding as assessed by autoradiography varied according to strategy preference. Regardless of biological sex, prepubertal rats that preferred stimulus-response strategy exhibited lower ratios of muscarinic receptor binding in the hippocampus relative to the dorsolateral striatum compared to rats that preferred place strategy. Importantly, much of the variance in this ratio was related to differences in the ventral hippocampus to a greater extent than the dorsal hippocampus. The ratios of muscarinic receptors in the hippocampus relative to the basolateral amygdala also were lower in rats that preferred stimulus-response strategy over place strategy. Results confirm that learning strategy preference varies with biological sex in prepubertal rats with males biased toward a stimulus-response strategy, and that stimulus-response strategy is associated with lower ratios of muscarinic binding in the hippocampus relative to either the striatum or amygdala. Copyright © 2012 Wiley Periodicals, Inc.

Sexual dimorphism in cuticular hydrocarbons of the Australian field cricket Teleogryllus oceanicus (Orthoptera: Gryllidae).

PubMed

Thomas, Melissa L; Simmons, Leigh W

2008-06-01

Sexual dimorphism is presumed to reflect adaptive divergence in response to selection favouring different optimal character states in the two sexes. Here, we analyse patterns of sexual dimorphism in the cuticular hydrocarbons of the Australian field cricket Teleogryllus oceanicus using gas chromatography. Ten of the 25 peaks found in our chromatographs, differed in their relative abundance between the sexes. The presence of sexual dimorphism in T. oceanicus is discussed in reference to a review of sexual dimorphism in cuticular hydrocarbons of other insects. We found that this trait has been examined in 103 species across seven different orders. Seventy-six of these species (73%) displayed sex specificity of cuticular hydrocarbons, the presence/absence of which does not appear to be directly linked to phylogeny. The occurrence of sexual dimorphism in cuticular hydrocarbons of some but not other species, and the extent of variation within genera, suggest that this divergence has been driven primarily by sexual selection.

Descriptive review: hormonal influences on risk for eating disorder symptoms during puberty and adolescence.

PubMed

Harden, K Paige; Kretsch, Natalie; Moore, Sarah R; Mendle, Jane

2014-11-01

Puberty is an important period of risk for the onset of eating pathology in adolescent females. This review focuses on changes in reproductive hormones during puberty as one specific psychopathogenic mechanism. Studies of puberty and eating disorder-related phenotypes were identified using search databases and the reference sections of previous literature. Correlational studies of adult women and experimental studies of animals provide evidence for the effects of reproductive hormones on eating disorder symptoms. Very few studies of puberty, however, have directly measured or tested the effects of hormonal change in samples of human adolescents. Commonly used measures of pubertal development, such as menarche or self-reported pubertal status, are relatively poor indicators of individual differences in hormones. The extent to which puberty-related hormonal change accounts for elevated risk for disordered eating remains unclear. Future research is necessary to elucidate the specific relations between hormonal change during puberty and risk for disordered eating. In particular, there is a need for longitudinal studies with multivariate measurement of pubertal development, including direct measures of change in reproductive hormones. © 2014 Wiley Periodicals, Inc.

Shared genetic aetiology of puberty timing between sexes and with health-related outcomes

PubMed Central

Day, Felix R.; Bulik-Sullivan, Brendan; Hinds, David A.; Finucane, Hilary K.; Murabito, Joanne M.; Tung, Joyce Y.; Ong, Ken K.; Perry, John R.B.

2015-01-01

Understanding of the genetic regulation of puberty timing has come largely from studies of rare disorders and population-based studies in women. Here, we report the largest genomic analysis for puberty timing in 55,871 men, based on recalled age at voice breaking. Analysis across all genomic variants reveals strong genetic correlation (0.74, P=2.7 × 10−70) between male and female puberty timing. However, some loci show sex-divergent effects, including directionally opposite effects between sexes at the SIM1/MCHR2 locus (Pheterogeneity=1.6 × 10−12). We find five novel loci for puberty timing (P<5 × 10−8), in addition to nine signals in men that were previously reported in women. Newly implicated genes include two retinoic acid-related receptors, RORB and RXRA, and two genes reportedly disrupted in rare disorders of puberty, LEPR and KAL1. Finally, we identify genetic correlations that indicate shared aetiologies in both sexes between puberty timing and body mass index, fasting insulin levels, lipid levels, type 2 diabetes and cardiovascular disease. PMID:26548314

Shared genetic aetiology of puberty timing between sexes and with health-related outcomes.

PubMed

Day, Felix R; Bulik-Sullivan, Brendan; Hinds, David A; Finucane, Hilary K; Murabito, Joanne M; Tung, Joyce Y; Ong, Ken K; Perry, John R B

2015-11-09

Understanding of the genetic regulation of puberty timing has come largely from studies of rare disorders and population-based studies in women. Here, we report the largest genomic analysis for puberty timing in 55,871 men, based on recalled age at voice breaking. Analysis across all genomic variants reveals strong genetic correlation (0.74, P=2.7 × 10(-70)) between male and female puberty timing. However, some loci show sex-divergent effects, including directionally opposite effects between sexes at the SIM1/MCHR2 locus (Pheterogeneity=1.6 × 10(-12)). We find five novel loci for puberty timing (P<5 × 10(-8)), in addition to nine signals in men that were previously reported in women. Newly implicated genes include two retinoic acid-related receptors, RORB and RXRA, and two genes reportedly disrupted in rare disorders of puberty, LEPR and KAL1. Finally, we identify genetic correlations that indicate shared aetiologies in both sexes between puberty timing and body mass index, fasting insulin levels, lipid levels, type 2 diabetes and cardiovascular disease.

ALTERATIONS IN SEXUALLY DIMORPHIC BIOTRANSFORMATION OF TESTOSTERONE IN JUVENILE AMERICAN ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS) FROM CONTAMINATED LAKES

EPA Science Inventory

The goal of this study was to determine whether hepatic biotransformation of testosterone is normally sexually dimorphic in juvenile alligators and whether living in a contaminated environment affects hepatic dimorphism. Lake Woodruff served as our reference site. Moonshine Bay, ...

What Are Normal Puberty, Precocious Puberty, and Delayed Puberty?

MedlinePlus

... Snapshot of Pregnancy & Infant Development Advances Snapshot of Child Development Advances Snapshot of Adult & Family Health Advances NICHD ... the New NICHD Director Exploring Factors That Influence Child Development Picture This: NICHD Support for Neuroscience Research All ...

Genetics Home Reference: central precocious puberty

MedlinePlus

... girls and between ages 9 and 14 in boys, girls with central precocious puberty begin exhibiting signs before ... of puberty is even earlier than normal in girls than in boys. Boys with an MKRN3 gene mutation inherited from ...

Twisted Gastrulation as a BMP Modulator during Mammary Gland Development and Tumorigenesis

DTIC Science & Technology

2014-05-01

present at the onset of puberty , roughly 6 weeks of age, but not at later time points we began our Q-PCR analysis at this time point. Analyzing...rudimentary ductal tree that during puberty , pregnancy and lactation undergoes complex morphological changes (Hens and Wysolmerski, 2005; Hovey and Trott...proliferates and elongates into the developing fat pad forming a rudimentary tree. Development is arrested at this point until puberty . At puberty , terminal

Contemporary Trends in Onset and Completion of Puberty, Gain in Height and Adiposity.

PubMed

Biro, Frank M; Kiess, Wieland

2016-01-01

Recent studies have documented earlier pubertal maturation in both girls and boys. Several factors have been proposed to account for earlier maturation. Epidemiologic studies have indicated that genetic factors are the most important influence contributing to the variability in the onset of puberty. Studies have also noted the association of elevated BMI with earlier puberty in girls, although the relationship between BMI and onset of puberty in boys is less consistent. The relationship of BMI and onset of puberty may be mediated by several factors, including leptin and kisspeptin, changes in bioavailable sex hormones, and environmental exposures. Recently, there have been genome-wide meta-analyses examining onset of puberty and anthropometric traits that may provide insight into the relationships of BMI, height velocity, and pubertal timing. Newer fields of investigation include examination of epigenetic modification. © 2016 S. Karger AG, Basel.

From Caregivers to Peers: Puberty Shapes Human Face Perception.

PubMed

Picci, Giorgia; Scherf, K Suzanne

2016-11-01

Puberty prepares mammals to sexually reproduce during adolescence. It is also hypothesized to invoke a social metamorphosis that prepares adolescents to take on adult social roles. We provide the first evidence to support this hypothesis in humans and show that pubertal development retunes the face-processing system from a caregiver bias to a peer bias. Prior to puberty, children exhibit enhanced recognition for adult female faces. With puberty, superior recognition emerges for peer faces that match one's pubertal status. As puberty progresses, so does the peer recognition bias. Adolescents become better at recognizing faces with a pubertal status similar to their own. These findings reconceptualize the adolescent "dip" in face recognition by showing that it is a recalibration of the face-processing system away from caregivers toward peers. Thus, in addition to preparing the physical body for sexual reproduction, puberty shapes the perceptual system for processing the social world in new ways. © The Author(s) 2016.

Environmental pollutants and dysregulation of male puberty--a comparison among species.

PubMed

Magnusson, Ulf; Ljungvall, Karl

2014-04-01

The scientific literature on altered onset of puberty predominantly involves studies on females. This paper reviews current knowledge on the role of environmental pollutants in dysregulation of male puberty in humans, laboratory rodents and farm animals. The methods used to determine the onset of puberty are well developed in humans and farm animals, and standardized across studies in humans. In laboratory rodents standardized external morphological endpoints are used. There is an increasing weight of evidence from epidemiological studies in humans, as well as from experiments in animals, indicating that environmental pollutants dysregulate puberty in males. Most data are from studies on "classical" persistent environmental pollutants. Assessing the effect of multichemical environmental pollution on dysregulation of puberty in humans is more challenging; further solid epidemiological data would likely contribute most to our understanding, especially if combined with systematically collected field-data from selected wildlife. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

The role of luteinizing hormone-releasing hormone in the diagnosis of constitutional delayed puberty

PubMed Central

Sagel, Julius; Distiller, Larry A.; Joffe, Barry I.

1975-01-01

The presumptive diagnosis of constitutional delayed adolescence is difficult to substantiate. Clinical examination and routine biochemical testing are not sufficient to exclude isolated gonadotrophin deficiency. Seven males are reported who presented with delayed puberty. These patients were given 100 μg luteinizing hormone-releasing hormone (LH-RH) intravenously, and the luteinizing hormone (LH) and follicle stimulating hormone (FSH) responses were measured. Three of four males who were completely prepubertal (Stage 1) had a normal adult male response. These three patients have progressed further into puberty several months after this diagnostic test. The fourth patient in stage 1 puberty had a prepubertal LH response. A year later the response became adult in type, and 3 months thereafter stage 2 puberty was evident. The LH response to LH-RH thus appears to have some prognostic value in the assessment of males presenting with delayed puberty. PMID:1105498

Diagnosis and constitutional and laboratory features of Korean girls referred for precocious puberty

PubMed Central

Kim, Doosoo; Cho, Sung-Yoon; Maeng, Se-Hyun; Yi, Eun Sang; Jung, Yu Jin; Park, Sung Won; Sohn, Young Bae

2012-01-01

Purpose Precocious puberty is defined as breast development before the age of 8 years in girls. The present study aimed to reveal the diagnosis of Korean girls referred for precocious puberty and to compare the constitutional and endocrinological features among diagnosis groups. Methods The present study used a retrospective chart review of 988 Korean girls who had visited a pediatric endocrinology clinic from 2006 to 2010 for the evaluation of precocious puberty. Study groups comprised fast puberty, true precocious puberty (PP), pseudo PP, premature thelarche, and control. We determined the height standard deviation score (HSDS), weight standard deviation score (WSDS), and body mass index standard deviation score (BMISDS) of each group using the published 2007 Korean growth charts. Hormone tests were performed at our outpatient clinic. Results The PP groups comprised fast puberty (67%), premature thelarche (17%), true PP (15%), and pseudo PP (1%). Advanced bone age and levels of estradiol, basal luteinizing hormone (LH), and peak LH after gonadotropin-releasing hormone stimulation testing were significantly high in the fast puberty and true PP groups compared with the control group. HSDS, WSDS, and BMISDS were significantly higher in the true PP group than in the control group (P<0.05). Conclusion The frequent causes of PP were found to be fast puberty, true PP, and premature thelarche. Furthermore, BMISDS were significantly elevated in the true PP group. Therefore, we emphasize the need for regular follow-up of girls who are heavier or taller than others in the same age group. PMID:23300504

Facial Anthropometric Norms among Kosovo - Albanian Adults.

PubMed

Staka, Gloria; Asllani-Hoxha, Flurije; Bimbashi, Venera

2017-09-01

The development of an anthropometric craniofacial database is a necessary multidisciplinary proposal. The aim of this study was to establish facial anthropometric norms and to investigate into sexual dimorphism in facial variables among Kosovo Albanian adults. The sample included 204 students of Dental School, Faculty of Medicine, University of Pristina. Using direct anthropometry, a series of 8 standard facial measurements was taken on each subject with digital caliper with an accuracy of 0.01 mm (Boss, Hamburg-Germany). The normative data and percentile rankings were calculated. Gender differences in facial variables were analyzed using t- test for independent samples (p<0.05). The index of sexual dimorphism (ISD) and percentage of sexual dimorphism were calculated for each facial measurement. ormative data for all facial anthropometric measurements in males were higher than in females. Male average norms compared with the female average norms differed significantly from each other (p>0.05).The highest index of sexual dimorphism (ISD) was found for the lower facial height 1.120, for which the highest percentage of sexual dimorphism, 12.01%., was also found. The lowest ISD was found for intercanthal width, 1.022, accompanied with the lowest percentage of sexual dimorphism, 2.23%. The obtained results have established the facial anthropometric norms among Kosovo Albanian adults. Sexual dimorphism has been confirmed for each facial measurement.

Puberty and Girls' Sexuality: Why Hormones Are Not the Complete Answer

ERIC Educational Resources Information Center

Graber, Julia A.; Sontag, Lisa M.

2006-01-01

The psychosocial impact of puberty on changes in girls' feelings about their bodies and their sexuality is discussed. We present a model of girls' sexuality development that incorporates puberty, self, and peer systems. (Contains 2 figures.)

Cardiometabolic risk factors and insulin resistance in obese children and adolescents: relation to puberty.

PubMed

Tobisch, B; Blatniczky, L; Barkai, L

2015-02-01

The prevalence of obesity with concomitant increasing risk for having cardiometabolic diseases is rising in the childhood population. Insulin resistance has a key role in metabolic changes in these children. Insulin levels elevate as puberty commences in every individual. Children with increased risk for cardiometabolic diseases show significant differences in insulin levels even before the onset of puberty compared with those without risks. The pattern of appearance of dyslipidaemia also varies in children with risk factors even in the pre-pubertal group from those without risk. Children with metabolic syndrome display considerably pronounced changes in their metabolic parameters before the onset of puberty, which become more pronounced as puberty passes. Insulin resistance (IR) has a key role in the metabolic changes in obese children. In commencing puberty, the insulin levels elevate. It is not clear, however, how insulin levels develop if the metabolic syndrome appears. Metabolic changes were assessed in obese children before, during and after puberty to analyse the relationship between IR and puberty in subjects with and without metabolic syndrome. Three hundred thirty-four obese children (5-19 years) attended the study. The criteria of the International Diabetes Federation were used to assess the presence of cardiometabolic risks (CMRs). Subjects with increased CMR were compared with those without risk (nCMR). Pubertal staging, lipid levels, plasma glucose and insulin levels during oral glucose tolerance test were determined in each participant. IR was expressed by homeostasis model assessment (HOMA-IR) and the ratio of glucose and insulin areas under the curve (AUC-IR). Significantly higher AUC-IR were found in pre-pubertal CMR children compared with nCMR subjects (11.84 ± 1.03 vs. 8.00 ± 0.69; P < 0.01), but no difference was discovered during and after puberty. HOMA-IR differs between CMR and nCMR only in post-puberty (6.03 ± 1.26 vs. 2.54 ± 0.23; P < 0.01). CMR children have dyslipidaemia before the onset of puberty. CMR is associated with increased postprandial IR in pre-pubertal and increased fasting IR in post-pubertal obese children. Dyslipidaemia appeared already in pre-puberty in CMR children. © 2013 The Authors. Pediatric Obesity © 2013 International Association for the Study of Obesity.

Sex-dimorphic psychomotor activation after perinatal exposure to (-)-delta 9-tetrahydrocannabinol. An ontogenic study in Wistar rats.

PubMed

Navarro, M; Rubio, P; Rodríguez de Fonseca, F

1994-12-01

The ontogeny and the adult expression of motor behaviors were studied in male and female rats born from mothers exposed to delta 9-tetrahydrocannabinol (THC, 5 mg/kg) during gestation and lactation. Perinatal exposure to THC increased both rearing and locomotor activities in males and females at immature preweanling ages (P-15 and P-20). These effects disappeared after ceasing THC exposure (postweaning ages), but they were observed again in adult (P-70) females. The effects appeared as persistently high motor activity in familiar environments, disappearing the characteristic habituation profile in locomotor and exploratory behaviors. In novel environment condition tests, adult (P-70) THC-exposed females, but not males, exhibited lower locomotor activity in the socio-sexual approach test, and an increase in the emergence latency in the dark-light emergence test. Additionally, animals of both sexes exposed to THC showed a increase in the time spent grooming measured in novelty conditions. These findings suggest that perinatal exposure to THC affects both the development and the adult expression of motor behaviors and it resulted in a sex-dimorphic psychomotor activation very similar to that observed after perinatal exposure to other drugs of abuse. A possible role of THC-induced pituitary-adrenal (PA) axis activation was also evaluated by measuring plasma corticosterone levels in adult animals perinatally exposed: THC-exposed females exhibit a clear increase of this adrenal hormone, whereas THC-exposed males displayed lower levels of this hormone.(ABSTRACT TRUNCATED AT 250 WORDS)

Fat and muscle mass in different groups of pre-pubertal and pubertal rural children. Cross-cultural comparisons between Sahelian (rural Senegal) and Amazonian (Beni River, Bolivia) children.

PubMed

Benefice, Eric; Luna Monrroy, Selma J; Lopez Rodriguez, Ronald W; Ndiaye, Gnagna

2011-07-01

An increase in fat accretion is essential for triggering the puberty spurt. Hence, nutritional constraints may influence puberty timing. To measure changes in fat and muscle mass in children living in natural environments but with different nutritional exposures. Cross-comparisons of children from rural Senegal and lowland (Amazonian) Bolivia were carried out. Anthropometric measurements of stature, weight, four subcutaneous skin-folds (triceps, biceps, subscapular, supra-iliac) and arm circumference were made. Children were divided into two age groups (5-9.9-year-olds or 'pre pubescents' (n = 381) and 10-15-year-olds or 'pubescents' (n = 692)). Senegalese girls menstruated later than Bolivian girls and Senegalese boys also matured later than Bolivian boys. Bolivian children displayed more fat and muscle before puberty and during puberty than the Senegalese. They also had more fat deposited on the trunk. There were substantial differences in living conditions and nutritional patterns between both locations. In Senegal, nutritional stress is likely to appear early during in utero life and to persist throughout the growth period, including puberty. This leads to a deficit in fat accretion before and during puberty that is associated with a considerable delay in puberty occurrence. In Bolivia, such stress is far less severe. Variability in puberty should be analysed taking into account these differences.

Congenital hypogonadotropic hypogonadism: implications of absent mini-puberty.

PubMed

Dwyer, Andrew A; Jayasena, Channa N; Quinton, Richard

2016-06-01

The phenomenon known as "mini-puberty" refers to activation of the neonatal hypothalamo-pituitary axis causing serum concentrations of gonadotrophins and testosterone (T) to approach adult male levels. This early neonatal period is a key proliferative window for testicular germ cells and immature Sertoli cells. Although failure to spontaneously initiate (adolescent) puberty is the most evident consequence of a defective gonadotropin-releasing hormone (GnRH) neurosecretory network, absent mini-puberty is also likely to have a major impact on the reproductive phenotype of men with congenital hypogonadotrophic hypogonadism (CHH). Furthermore, the phase of male mini-puberty represents a key window-of-opportunity to identify congenital GnRH deficiency (either isolated CHH, or as part of combined pituitary hormone deficiency) in childhood. Among male neonates exhibiting "red flag" indicators for CHH (i.e. maldescended testes with or without cryptorchidism) a single serum sample (between 4-8 weeks of life) can pinpoint congenital GnRH deficiency far more rapidly and with much greater accuracy than dynamic tests performed in later childhood or adolescence. Potential consequences for missing absent mini-puberty in a male neonate include the lack of monitoring of pubertal progression/lack of progression, and the missed opportunity for early therapeutic intervention. This article will review our current understanding of the mechanisms and clinical consequences of mini-puberty. Furthermore, evidence for the optimal clinical management of patients with absent mini-puberty will be discussed.

Puberty as a Critical Risk Period for Eating Disorders: A Review of Human and Animal Studies

PubMed Central

Klump, Kelly L.

2013-01-01

Puberty is one of the most frequently discussed risk periods for the development of eating disorders. Prevailing theories propose environmentally mediated sources of risk arising from the psychosocial effects (e.g., increased body dissatisfaction, decreased self-esteem) of pubertal development in girls. However, recent research highlights the potential role of ovarian hormones in phenotypic and genetic risk for eating disorders during puberty. The goal of this paper is to review data from human and animal studies in support of puberty as a critical risk period for eating disorders and evaluate the evidence for hormonal contributions. Data are consistent in suggesting that both pubertal status and pubertal timing significantly impact risk for most eating disorders in girls, such that advanced pubertal development and early pubertal timing are associated with increased rates of eating disorders and their symptoms in both cross-sectional and longitudinal research. Findings in boys have been much less consistent and suggest a smaller role for puberty in risk for eating disorders in boys. Twin and animal studies indicate that at least part of the female-specific risk is due to genetic factors associated with estrogen activation at puberty. In conclusion, data thus far support a role for puberty in risk for eating disorders and highlight the need for additional human and animal studies of hormonal and genetic risk for eating disorders during puberty. PMID:23998681

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.

Reward-related brain function and sleep in pre/early pubertal and mid/late pubertal adolescents.

PubMed

Holm, Stephanie M; Forbes, Erika E; Ryan, Neal D; Phillips, Mary L; Tarr, Jill A; Dahl, Ronald E

2009-10-01

The onset of adolescence is a time of dramatic changes, including changes in sleep, and a time of new health concerns related to increases in risk-taking, sensation seeking, depression, substance use, and accidents. As part of a larger study examining puberty-specific changes in adolescents' reward-related brain function, the current article focuses on the relationship between functional neuroimaging measures of reward and measures of sleep. A total of 58 healthy participants 11-13 years of age completed a functional magnetic resonance imaging scan using a guessing task with monetary rewards and 4 days of at-home actigraphy and self-reported sleep ratings. Sleep variables included actigraph measures of mean weekend minutes asleep, sleep onset time, and sleep offset time, as well as self-reported sleep quality. During reward anticipation, less activation in the caudate (part of the ventral striatum) was associated with fewer minutes asleep, later sleep onset time, and lower sleep quality. During reward outcome, less caudate activation was associated with later sleep onset time, earlier sleep offset time, and lower sleep quality. It has been hypothesized that adolescents' low reactivity in reward-related brain areas could lead to compensatory increases in reward-driven behavior. This study's findings suggest that sleep could contribute to such behavior. Because decreased sleep has been associated with risky behavior and negative mood, these findings raise concerns about a negative spiral whereby the effects of puberty and sleep deprivation may have synergistic effects on reward processing, contributing to adolescent behavioral and emotional health problems.

Hypothesis: Irisin is a metabolic trigger for the activation of the neurohormonal axis governing puberty onset.

PubMed

Wahab, Fazal; Shahab, Muhammad; Behr, Rüdiger

2016-10-01

A large body of data suggests that body weight influences puberty onset and adult reproduction. However, the underlying mechanism of how body weight influences puberty onset and fertility is not completely understood. The hypothalamic neuronal circuit regulating reproduction is restrained by inhibitory signals during childhood. At the time of puberty, these inhibitory signals are weakened and supplanted by stimulatory signals that, in turn, stimulate the release of gonadotropin-releasing hormone (GnRH) - a hypothalamic neuropeptide governing reproduction. A number of studies, however, suggest that puberty commencement occurs when body (fat) weight reaches a certain threshold, which is critical for the initiation of puberty and for support of the adult reproductive function. Previously, various signals have been studied which might link body (fat) weight-related information to the hypothalamic neuronal network regulating reproduction. However, the nature of the signal(s) that may link body fat and/or muscle mass with the hypothalamic neuronal network governing reproduction is still unclear. It has been intuitively speculated that augmentation of such signal(s) will cause a restriction of inhibitory input and activation of stimulatory input to GnRH secreting neurons at the time of puberty onset. Therefore, the unveiling of such signal(s) will greatly help in understanding the mechanism of puberty onset. Recently, it has been shown that expression of fibronectin type III domain containing-5 (FNDC5) mRNA in central and peripheral tissues upsurges during postnatal development, especially around the time of puberty onset. Moreover, the systemic level of irisin - one of the protein products of the FNDC5 gene that is secreted as myokine and adipokine - also rises during postnatal development and correlates with the timing of puberty onset. Therefore, we propose here that irisin might serve as a possible signal for linking body fat/muscle mass with the hypothalamic center governing reproductive function. We hypothesize that irisin acts as a trigger for the activation of the hypothalamic neuronal network monitoring the onset of puberty. Copyright © 2016 Elsevier Ltd. All rights reserved.

Caenorhabditis elegans Male Copulation Circuitry Incorporates Sex-Shared Defecation Components To Promote Intromission and Sperm Transfer

PubMed Central

LeBoeuf, Brigitte; Garcia, L. Rene

2016-01-01

Sexual dimorphism can be achieved using a variety of mechanisms, including sex-specific circuits and sex-specific function of shared circuits, though how these work together to produce sexually dimorphic behaviors requires further investigation. Here, we explore how components of the sex-shared defecation circuitry are incorporated into the sex-specific male mating circuitry in Caenorhabditis elegans to produce successful copulation. Using behavioral studies, calcium imaging, and genetic manipulation, we show that aspects of the defecation system are coopted by the male copulatory circuitry to facilitate intromission and ejaculation. Similar to hermaphrodites, male defecation is initiated by an intestinal calcium wave, but circuit activity is coordinated differently during mating. In hermaphrodites, the tail neuron DVB promotes expulsion of gut contents through the release of the neurotransmitter GABA onto the anal depressor muscle. However, in the male, both neuron and muscle take on modified functions to promote successful copulation. Males require calcium-dependent activator protein for secretion (CAPS)/unc-31, a dense core vesicle exocytosis activator protein, in the DVB to regulate copulatory spicule insertion, while the anal depressor is remodeled to promote release of sperm into the hermaphrodite. This work shows how sex-shared circuitry is modified in multiple ways to contribute to sex-specific mating. PMID:28031243

Using Digital Images of the Zebra Finch Song System as a Tool to Teach Organizational Effects of Steroid Hormones: A Free Downloadable Module

PubMed Central

Grisham, William; Schottler, Natalie A.; McCauley, Lisa M. Beck; Pham, Anh P.; Ruiz, Maureen L.; Fong, Michelle C.; Cui, Xinran

2011-01-01

Zebra finch song behavior is sexually dimorphic: males sing and females do not. The neural system underlying this behavior is sexually dimorphic, and this sex difference is easy to quantify. During development, the zebra finch song system can be altered by steroid hormones, specifically estradiol, which actually masculinizes it. Because of the ease of quantification and experimental manipulation, the zebra finch song system has great potential for use in undergraduate labs. Unfortunately, the underlying costs prohibit use of this system in undergraduate labs. Further, the time required to perform a developmental study renders such undertakings unrealistic within a single academic term. We have overcome these barriers by creating digital tools, including an image library of song nuclei from zebra finch brains. Students using this library replicate and extend a published experiment examining the dose of estradiol required to masculinize the female zebra finch brain. We have used this library for several terms, and students not only obtain significant experimental results but also make gains in understanding content, experimental controls, and inferential statistics (analysis of variance and post hoc tests). We have provided free access to these digital tools at the following website: http://mdcune.psych.ucla.edu/modules/birdsong. PMID:21633071

Honey Bee Location- and Time-Linked Memory Use in Novel Foraging Situations: Floral Color Dependency

PubMed Central

Amaya-Márquez, Marisol; Hill, Peggy S. M.; Abramson, Charles I.; Wells, Harrington

2014-01-01

Learning facilitates behavioral plasticity, leading to higher success rates when foraging. However, memory is of decreasing value with changes brought about by moving to novel resource locations or activity at different times of the day. These premises suggest a foraging model with location- and time-linked memory. Thus, each problem is novel, and selection should favor a maximum likelihood approach to achieve energy maximization results. Alternatively, information is potentially always applicable. This premise suggests a different foraging model, one where initial decisions should be based on previous learning regardless of the foraging site or time. Under this second model, no problem is considered novel, and selection should favor a Bayesian or pseudo-Bayesian approach to achieve energy maximization results. We tested these two models by offering honey bees a learning situation at one location in the morning, where nectar rewards differed between flower colors, and examined their behavior at a second location in the afternoon where rewards did not differ between flower colors. Both blue-yellow and blue-white dimorphic flower patches were used. Information learned in the morning was clearly used in the afternoon at a new foraging site. Memory was not location-time restricted in terms of use when visiting either flower color dimorphism. PMID:26462587

Improving the assessment of endocrine disrupting chemical (EDC) effects on puberty

EPA Science Inventory

During puberty, key developmental events occur that are critical for normal adult male and female reproductive maturation. Recent studies raised concern that exposure to environmental chemicals alter the normal progression through puberty and lead to impaired reproductive functio...

Risk-taking and decision-making in youth: relationships to addiction vulnerability.

PubMed

Balogh, Kornelia N; Mayes, Linda C; Potenza, Marc N

2013-03-01

Decision-making and risk-taking behavior undergo developmental changes during adolescence. Disadvantageous decision-making and increased risk-taking may lead to problematic behaviors such as substance use and abuse, pathological gambling and excessive internet use. Based on MEDLINE searches, this article reviews the literature on decision-making and risk-taking and their relationship to addiction vulnerability in youth. Decision-making and risk-taking behaviors involve brain areas that undergoing developmental changes during puberty and young adulthood. Individual differences and peer pressure also relate importantly to decision-making and risk-taking. Brain-based changes in emotional, motivational and cognitive processing may underlie risk-taking and decision-making propensities in adolescence, making this period a time of heightened vulnerability for engagement in additive behaviors.

Sexual Differentiation of Motivation: a novel mechanism?

PubMed Central

Becker, Jill B.

2009-01-01

Sex differences in motivation are apparent for the motivation to engage in sexual behavior, the motivation to take drugs of abuse, and the motivation to engage in parental behavior. In both males and females there is an increase in NAcc DA associated with motivated behaviors. Here it proposed that sex differences in the regulation of DA activity in the ascending mesolimbic projections may underlie sex differences in motivation. In particular, sex differences in the neuroendocrine regulation of this brain system plays a role in the expression of sex differences in motivated behaviors. Here it is proposed that sexual differentiation of motivation is mediated, at least in part, by a novel mechanism in which ovarian hormones secreted at puberty in the female actively feminize the DA system. PMID:19446081

Leuprolide acetate-stimulated androgen response during female puberty.

PubMed

Hernandez, María Isabel; Martinez-Aguayo, Alejandro; Cavada, Gabriel; Avila, Alejandra; Iñiguez, German; Mericq, Veronica

2015-08-01

A physiological increase in androgen levels occurs during adolescence. Measuring androgen concentrations is the best method to distinguish normal evolution processes from hyperandrogenic disorders. The increase in circulating androgens during puberty is inversely associated with insulin sensitivity in normal weight girls. To assess circulating levels of ovarian androgens and anti-Müllerian hormone (AMH) at baseline and after GnRH analogue (GnRH-a) stimulation in normal pubertal girls across different Tanner stages. We also studied the association between this response and insulin sensitivity. Prospective study of healthy girls (6-12 years) from the local community (n = 63). Tanner I (n = 23) subjects were assessed cross-sectionally, and Tanner II girls (n = 40) were evaluated every 6 months until they reached Tanner V. Early morning dehydroepiandrosterone sulphate (DHEA-S), AMH, sex hormone-binding globulin (SHBG), androstenedione, glucose and insulin levels were measured. A GnRH-a test (500 μg/m(2) ; sc) and oral glucose intolerance test (OGTT) were performed. Differences throughout puberty were evaluated. Basal and/or stimulated Testosterone DHEA-S and 17-hydroxyprogesterone (17OHP) were inversely associated with insulin sensitivity (WIBSI) from the beginning of puberty, whereas androstenedione was directly associated with gonadotrophins. AMH was inversely associated with basal and stimulated gonadotrophins and directly with insulin area under the curve (AUC) only in the early stages of puberty. 17OHP and testosterone responsiveness increased significantly during puberty in all subjects, whereas testosterone levels changed less consistently. This pattern of ovarian-steroidogenic response was most evident during mid- and late puberty. Moreover, during late puberty only, basal 17OHP, testosterone and DHEA-S were positively associated with gonadotrophins. In normal nonobese girls born appropriate for gestational age, androgen synthesis was associated with insulin sensitivity in early puberty and with LH only in late puberty. © 2014 John Wiley & Sons Ltd.

A randomised trial on pubertal development and health in China.

PubMed

Zang, Yuli; Zhao, Yong; Yang, Qing; Pan, Yaoyun; Li, Na; Liu, Ting

2011-11-01

Puberty signifies noticeable physical, psychosocial and sexual development. It is crucial to help adolescents reach an understanding about puberty and related health issues. Considering the sexually conservative culture in some areas, to explore appropriate ways to address sexuality and health-related concerns during puberty is of interest to all stakeholders. This study aimed to examine the effectiveness of the ecological approach to improve adolescents' understanding about puberty and related health risks. Modified Solomon four group design. Two Grade7 classes were randomly selected to form experiment and control group, respectively. A two-hour seminar and a brochure about health and development during puberty were provided, and some students, parents and instructors in the experimental group commented on the intervention. Pre- and post-tests were conducted to measure students' pubertal development status and their knowledge, attitudes and behaviours related to puberty. Students (n = 228) were aged 13·0 years (SD 0·45). The majority was categorised at the stage of mid-puberty or later, and approximately 11·2% of 116 girls and 22·3% of 112 boys were classified as overweight or obese according to body mass index. No significant changes were identified within or between groups about knowledge, attitudes and behaviours related to puberty and health before and after the intervention. The invention was considered helpful, and an enriched delivery was required. Although the overall feedback was positive, this ecological approach to adolescent health and development targeting at Grade7 students failed to generate significant effects on students' knowledge, attitudes and behaviours surrounding puberty and health. This study reveals that sexuality, particularly romantic relationships during puberty, may be perceived negatively in the local society. There is a need for school nurses to help all relevant people to understand and respond to sexuality-related concerns in a cultural appropriate way. © 2011 Blackwell Publishing Ltd.

Ontogeny of sensorimotor gating and short-term memory processing throughout the adolescent period in rats.

PubMed

Goepfrich, Anja A; Friemel, Chris M; Pauen, Sabina; Schneider, Miriam

2017-06-01

Adolescence and puberty are highly susceptible developmental periods during which the neuronal organization and maturation of the brain is completed. The endocannabinoid (eCB) system, which is well known to modulate cognitive processing, undergoes profound and transient developmental changes during adolescence. With the present study we were aiming to examine the ontogeny of cognitive skills throughout adolescence in male rats and clarify the potential modulatory role of CB1 receptor signalling. Cognitive skills were assessed repeatedly every 10th day in rats throughout adolescence. All animals were tested for object recognition memory and prepulse inhibition of the acoustic startle reflex. Although cognitive performance in short-term memory as well as sensorimotor gating abilities were decreased during puberty compared to adulthood, both tasks were found to show different developmental trajectories throughout adolescence. A low dose of the CB1 receptor antagonist/inverse agonist SR141716 was found to improve recognition memory specifically in pubertal animals while not affecting behavioral performance at other ages tested. The present findings demonstrate that the developmental trajectory of cognitive abilities does not occur linearly for all cognitive processes and is strongly influenced by pubertal maturation. Developmental alterations within the eCB system at puberty onset may be involved in these changes in cognitive processing. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Metabolic control of female puberty: potential therapeutic targets.

PubMed

Castellano, Juan M; Tena-Sempere, Manuel

2016-10-01

The onset of puberty in females is highly sensitive to the nutritional status and the amount of energy reserves of the organism. This metabolic information is sensed and transmitted to hypothalamic GnRH neurons, considered to be ultimately responsible for triggering puberty through the coordinated action of different peripheral hormones, central neurotransmitters, and molecular mediators. This article will review and discuss (i) the relevant actions of the adipose hormone leptin, as a stimulatory/permissive signal, and the gut hormone ghrelin, as an inhibitory factor, in the metabolic control of female puberty; (ii) the crucial role of the hypothalamic kisspeptin neurons, recently emerged as essential gatekeepers of puberty, in transmitting this metabolic information to GnRH neurons; and (iii) the potential involvement of key cellular energy sensors, such as mTOR, as molecular mediators in this setting. The thorough characterization of the physiological roles of the above elements in the metabolic control of female puberty, along with the discovery of novel factors, pathways, and mechanisms involved, will promote our understanding of the complex networks connecting metabolism and puberty and, ultimately, will aid in the design of target-specific treatments for female pubertal disorders linked to conditions of metabolic stress.

Substance p regulates puberty onset and fertility in the female mouse.

PubMed

Simavli, Serap; Thompson, Iain R; Maguire, Caroline A; Gill, John C; Carroll, Rona S; Wolfe, Andrew; Kaiser, Ursula B; Navarro, Víctor M

2015-06-01

Puberty is a tightly regulated process that leads to reproductive capacity. Kiss1 neurons are crucial in this process by stimulating GnRH, yet how Kiss1 neurons are regulated remains unknown. Substance P (SP), an important neuropeptide in pain perception, induces gonadotropin release in adult mice in a kisspeptin-dependent manner. Here, we assessed whether SP, through binding to its receptor NK1R (neurokinin 1 receptor), participates in the timing of puberty onset and fertility in the mouse. We observed that 1) selective NK1R agonists induce gonadotropin release in prepubertal females; 2) the expression of Tac1 (encoding SP) and Tacr1 (NK1R) in the arcuate nucleus is maximal before puberty, suggesting increased SP tone; 3) repeated exposure to NK1R agonists prepubertally advances puberty onset; and 4) female Tac1(-/-) mice display delayed puberty; moreover, 5) SP deficiency leads to subfertility in females, showing fewer corpora lutea and antral follicles and leading to decreased litter size. Thus, our findings support a role for SP in the stimulation of gonadotropins before puberty, acting via Kiss1 neurons to stimulate GnRH release, and its involvement in the attainment of full reproductive capabilities in female mice.

Biological Risk for the Development of Problem Behavior in Adolescence: Integrating Insights from Behavioral Genetics and Neuroscience.

PubMed

Harden, K Paige; Mann, Frank D

2015-12-01

Adolescence is a time of increasing engagement in a variety of problem behaviors, including substance use and delinquency. Genetic risk for problem behavior increases over adolescence, is mediated partially by individual differences in sensation seeking, and is exacerbated by involvement with deviant peers. In this article, we describe how findings from behavioral genetic research on problem behavior intersect with research from developmental neuroscience. In particular, the incentive-processing system, including the ventral striatum, responds increasingly to rewards in adolescence, particularly in peer contexts. This developmental shift may be influenced by hormonal changes at puberty. Individual differences in the structure and function of reward-responsive brain regions may be intermediary phenotypes that mediate adolescents' genetic risk for problem behavior. The study of problem behavior can be enriched by interdisciplinary research that integrates measures of brain structure and function into genetically informed studies.

Size, dimorphism, and related characteristics of Ciccaba owls from Guatemala

Treesearch

Richard P. Gerhardt; Dawn McAnnis Gerhardt

1997-01-01

Tropical owls, being poorly studied, have been excluded from discussions of reversed size dimorphism. As part of a breeding and food habits study, we weighed and measured 20 Mottled Owls (Ciccaba virgata) and a mated pair of Black-and-white Owls (C. nigrolineata) in northern Guatemala. Mottled Owls exhibited pronounced dimorphism...

Isolation of UmRrm75, a gene involved in dimorphism and virulence of Ustilago maydis

USDA-ARS?s Scientific Manuscript database

Ustilago maydis displays dimorphic growth, alternating between a saprophytic haploid yeast form and a filamentous dikaryon, generated by mating of haploid cells and which is an obligate parasite. Induction of the dimorphic transition of haploid strains in vitro by change in ambient pH has been used...

Sex ratio variation shapes the ecological effects of a globally introduced freshwater fish

PubMed Central

Fryxell, David C.; Arnett, Heather A.; Apgar, Travis M.; Kinnison, Michael T.; Palkovacs, Eric P.

2015-01-01

Sex ratio and sexual dimorphism have long been of interest in population and evolutionary ecology, but consequences for communities and ecosystems remain untested. Sex ratio could influence ecological conditions whenever sexual dimorphism is associated with ecological dimorphism in species with strong ecological interactions. We tested for ecological implications of sex ratio variation in the sexually dimorphic western mosquitofish, Gambusia affinis. This species causes strong pelagic trophic cascades and exhibits substantial variation in adult sex ratios. We found that female-biased populations induced stronger pelagic trophic cascades compared with male-biased populations, causing larger changes to key community and ecosystem responses, including zooplankton abundance, phytoplankton abundance, productivity, pH and temperature. The magnitude of such effects indicates that sex ratio is important for mediating the ecological role of mosquitofish. Because both sex ratio variation and sexual dimorphism are common features of natural populations, our findings should encourage broader consideration of the ecological significance of sex ratio variation in nature, including the relative contributions of various sexually dimorphic traits to these effects. PMID:26490793

Role of Microbiota in Sexually Dimorphic Immunity.

PubMed

Elderman, Marlies; de Vos, Paul; Faas, Marijke

2018-01-01

Sex differences in peripheral immune responses are well recognized. This is associated with sex differences in many immunological diseases. As the intestinal microbiota is known to influence the immune system, such sex differences in immune responses may be a consequence of sex-specific microbiota. Therefore, this mini-review discusses sex differences in intestinal microbiota and the possible role of microbiota in shaping sexually dimorphic immunity. Sex differences in microbiota composition are clearly found in mice studies and also in human studies. However, the lack of standardization in human studies may mask the sexual dimorphism in microbiota composition in human studies, since many factors such as age, genetic background, BMI, diet, and sex hormones appear to interfere with the sexual dimorphism in microbiota composition. Only a few mice studies found that differences in gut microbiota composition are causative for some aspects of sexually dimorphic immunity. Therefore, future studies should focus on a causal relationship between sexually dimorphic immunity and microbiota, considering the abovementioned interfering confounding factors. This would benefit the development of more sex-specific effective treatment options for immunological diseases.

An interesting sexually dimorphic species, Neoribates isabelaensis sp. nov. (Acari, Oribatida, Parakalummidae) with remarks on sexual dimorphism in Oripodoidea.

PubMed

Bayartogtokh, Badamdorj; Ermilov, Sergey G; Corpuz-Raros, Leonila

2017-11-10

A new species Neoribates isabelaensis sp. nov. showing an interesting sexual dimorphism is described from bamboo litter on Luzon Island in the Philippines. This species is unique among other species of Neoribates in the structure of the posterior part of notogaster in males, which has a large round concavity bearing a pair of large sacculi S3. The specific function of this structure is not yet known, but the found sexual dimorphism is presumably involved in pheromonal communication allowing rapid sperm transfer. This is the fourth Neoribates species displaying sexually dimorphic characters. Additionally, Neoribates isabelaensis sp. nov. differs from the morphologically most similar species, Neoribates barbatus Hammer, 1968, by its smaller body size, pointed rostrum, long and setiform bothridial setae and the localization of notogastral setae h1 and h2, which insert close to each other. Further, we discussed all cases of sexual dimorphism in the family Parakalummidae as well as other related groups of Oripodoidea, and the possible function of these modifications.

Safety Extension Study Of Leuprolide Acetate (Lupron Depot) In The Treatment Of Central Precocious Puberty

ClinicalTrials.gov

2014-01-08

Precocious; Leuprolide Acetate; Luteinizing Hormone (LH); Gonadotrophin-releasing Hormone Agonist (GnRHa); Tanner Staging; Depot Formulation; Suppression of LH; Central Precocious Puberty (CPP); Gonadotrophin-releasing Hormone (GnRH); Lupron; GnRH Analog; Pediatrics Central Precocious Puberty

Evolution of Fseg/Cseg dimorphism in region III of the Plasmodium falciparum eba-175 gene.

PubMed

Yasukochi, Yoshiki; Naka, Izumi; Patarapotikul, Jintana; Hananantachai, Hathairad; Ohashi, Jun

2017-04-01

The 175-kDa erythrocyte binding antigen (EBA-175) of the malaria parasite Plasmodium falciparum is important for its invasion into human erythrocytes. The primary structure of eba-175 is divided into seven regions, namely I to VII. Region III contains highly divergent dimorphic segments, termed Fseg and Cseg. The allele frequencies of segmental dimorphism within a P. falciparum population have been extensively examined; however, the molecular evolution of segmental dimorphism is not well understood. A comprehensive comparison of nucleotide sequences among 32 P. falciparum eba-175 alleles identified in our previous study, two Plasmodium reichenowi, and one P. gaboni orthologous alleles obtained from the GenBank database was conducted to uncover the origin and evolutionary processes of segmental dimorphism in P. falciparum eba-175. In the eba-175 nucleotide sequence derived from a P. reichenowi CDC strain, both Fseg and Cseg were found in region III, which implies that the original eba-175 gene had both segments, and deletions of F- and C-segments generated Cseg and Fseg alleles, respectively. We also confirmed the presence of allele with Fseg and Cseg in another P. reichenowi strain (SY57), by re-mapping short reads obtained from the GenBank database. On the other hand, the segmental sequence of eba-175 ortholog in P. gaboni was quite diverged from those of the other species, suggesting that the original eba-175 dimorphism of P. falciparum can be traced back to the stem linage of P. falciparum and P. reichenowi. Our findings suggest that Fseg and Cseg alleles are derived from a single eba-175 allele containing both segments in the ancestral population of P. falciparum and P. reichenowi, and that the allelic dimorphism of eba-175 was shaped by the independent emergence of similar dimorphic lineage in different species that has never been observed in any evolutionary mode of allelic dimorphism at other loci in malaria genomes. Copyright © 2017 Elsevier B.V. All rights reserved.

Continuation of Gradual Weight Gain Necessary for the Onset of Puberty May Be Responsible for Obesity Later in Life

PubMed Central

Lehrer, Steven

2016-01-01

A continuation of the gradual weight gain necessary for the onset of puberty may be responsible for obesity later in life. Hypothetically, a group of brain nuclei form components of a single pubertal clock mechanism that drives pre-pubertal weight gain and governs the onset of puberty and fertility. No mechanism evolved to shut off pre-pubertal and pubertal weight and body fat gain after puberty. The weight gain continues unabated throughout life. A better understanding of the mechanism of puberty and pre-pubertal weight gain could provide new insights into obesity and diseases associated with obesity such as type 2 diabetes, dyslipidemia, hypertension, heart disease, depression, etc. PMID:26562472

Neuroendocrine control of the onset of puberty.

PubMed

Plant, Tony M

2015-07-01

This chapter is based on the Geoffrey Harris Memorial Lecture presented at the 8th International Congress of Neuroendocrinology, which was held in Sydney, August 2014. It provides the development of our understanding of the neuroendocrine control of puberty since Harris proposed in his 1955 monograph (Harris, 1955) that "a major factor responsible for puberty is an increased rate of release of pituitary gonadotrophin" and posited "that a neural (hypothalamic) stimulus, via the hypophysial portal vessels, may be involved." Emphasis is placed on the neurobiological mechanisms governing puberty in highly evolved primates, although an attempt is made to reverse translate a model for the timing of puberty in man and monkey to non-primate species. Copyright © 2015 Elsevier Inc. All rights reserved.

Sex differences in the representation of call stimuli in a songbird secondary auditory area

PubMed Central

Giret, Nicolas; Menardy, Fabien; Del Negro, Catherine

2015-01-01

Understanding how communication sounds are encoded in the central auditory system is critical to deciphering the neural bases of acoustic communication. Songbirds use learned or unlearned vocalizations in a variety of social interactions. They have telencephalic auditory areas specialized for processing natural sounds and considered as playing a critical role in the discrimination of behaviorally relevant vocal sounds. The zebra finch, a highly social songbird species, forms lifelong pair bonds. Only male zebra finches sing. However, both sexes produce the distance call when placed in visual isolation. This call is sexually dimorphic, is learned only in males and provides support for individual recognition in both sexes. Here, we assessed whether auditory processing of distance calls differs between paired males and females by recording spiking activity in a secondary auditory area, the caudolateral mesopallium (CLM), while presenting the distance calls of a variety of individuals, including the bird itself, the mate, familiar and unfamiliar males and females. In males, the CLM is potentially involved in auditory feedback processing important for vocal learning. Based on both the analyses of spike rates and temporal aspects of discharges, our results clearly indicate that call-evoked responses of CLM neurons are sexually dimorphic, being stronger, lasting longer, and conveying more information about calls in males than in females. In addition, how auditory responses vary among call types differ between sexes. In females, response strength differs between familiar male and female calls. In males, temporal features of responses reveal a sensitivity to the bird's own call. These findings provide evidence that sexual dimorphism occurs in higher-order processing areas within the auditory system. They suggest a sexual dimorphism in the function of the CLM, contributing to transmit information about the self-generated calls in males and to storage of information about the bird's auditory experience in females. PMID:26578918

Sexual dimorphism of staminate- and pistillate-phase flowers of Saponaria officinalis (bouncing bet) affects pollinator behavior and seed set.

PubMed

Davis, Sandra L; Dudle, Dana A; Nawrocki, Jenna R; Freestone, Leah M; Konieczny, Peter; Tobin, Michael B; Britton, Michael M

2014-01-01

The sequential separation of male and female function in flowers of dichogamous species allows for the evolution of differing morphologies that maximize fitness through seed siring and seed set. We examined staminate- and pistillate-phase flowers of protandrous Saponaria officinalis for dimorphism in floral traits and their effects on pollinator attraction and seed set. Pistillate-phase flowers have larger petals, greater mass, and are pinker in color, but due to a shape change, pistillate-phase flowers have smaller corolla diameters than staminate-phase flowers. There was no difference in nectar volume or sugar content one day after anthesis, and minimal evidence for UV nectar guide patterns in staminate- and pistillate-phase flowers. When presented with choice arrays, pollinators discriminated against pistillate-phase flowers based on their pink color. Finally, in an experimental garden, in 2012 there was a negative correlation between seed set of an open-pollinated, emasculated flower and pinkness (as measured by reflectance spectrometry) of a pistillate-phase flower on the same plant in plots covered with shade cloth. In 2013, clones of genotypes chosen from the 2012 plants that produced pinker flowers had lower seed set than those from genotypes with paler flowers. Lower seed set of pink genotypes was found in open-pollinated and hand-pollinated flowers, indicating the lower seed set might be due to other differences between pink and pale genotypes in addition to pollinator discrimination against pink flowers. In conclusion, staminate- and pistillate-phase flowers of S. officinalis are dimorphic in shape and color. Pollinators discriminate among flowers based on these differences, and individuals whose pistillate-phase flowers are most different in color from their staminate-phase flowers make fewer seeds. We suggest morphological studies of the two sex phases in dichogamous, hermaphroditic species can contribute to understanding the evolution of sexual dimorphism in plants without the confounding effects of genetic differences between separate male and female individuals.

Sexual Dimorphism of Staminate- and Pistillate-Phase Flowers of Saponaria officinalis (Bouncing Bet) Affects Pollinator Behavior and Seed Set

PubMed Central

Davis, Sandra L.; Dudle, Dana A.; Nawrocki, Jenna R.; Freestone, Leah M.; Konieczny, Peter; Tobin, Michael B.; Britton, Michael M.

2014-01-01

The sequential separation of male and female function in flowers of dichogamous species allows for the evolution of differing morphologies that maximize fitness through seed siring and seed set. We examined staminate- and pistillate-phase flowers of protandrous Saponaria officinalis for dimorphism in floral traits and their effects on pollinator attraction and seed set. Pistillate-phase flowers have larger petals, greater mass, and are pinker in color, but due to a shape change, pistillate-phase flowers have smaller corolla diameters than staminate-phase flowers. There was no difference in nectar volume or sugar content one day after anthesis, and minimal evidence for UV nectar guide patterns in staminate- and pistillate-phase flowers. When presented with choice arrays, pollinators discriminated against pistillate-phase flowers based on their pink color. Finally, in an experimental garden, in 2012 there was a negative correlation between seed set of an open-pollinated, emasculated flower and pinkness (as measured by reflectance spectrometry) of a pistillate-phase flower on the same plant in plots covered with shade cloth. In 2013, clones of genotypes chosen from the 2012 plants that produced pinker flowers had lower seed set than those from genotypes with paler flowers. Lower seed set of pink genotypes was found in open-pollinated and hand-pollinated flowers, indicating the lower seed set might be due to other differences between pink and pale genotypes in addition to pollinator discrimination against pink flowers. In conclusion, staminate- and pistillate-phase flowers of S. officinalis are dimorphic in shape and color. Pollinators discriminate among flowers based on these differences, and individuals whose pistillate-phase flowers are most different in color from their staminate-phase flowers make fewer seeds. We suggest morphological studies of the two sex phases in dichogamous, hermaphroditic species can contribute to understanding the evolution of sexual dimorphism in plants without the confounding effects of genetic differences between separate male and female individuals. PMID:24690875

Sex differences in the representation of call stimuli in a songbird secondary auditory area.

PubMed

Giret, Nicolas; Menardy, Fabien; Del Negro, Catherine

2015-01-01

Understanding how communication sounds are encoded in the central auditory system is critical to deciphering the neural bases of acoustic communication. Songbirds use learned or unlearned vocalizations in a variety of social interactions. They have telencephalic auditory areas specialized for processing natural sounds and considered as playing a critical role in the discrimination of behaviorally relevant vocal sounds. The zebra finch, a highly social songbird species, forms lifelong pair bonds. Only male zebra finches sing. However, both sexes produce the distance call when placed in visual isolation. This call is sexually dimorphic, is learned only in males and provides support for individual recognition in both sexes. Here, we assessed whether auditory processing of distance calls differs between paired males and females by recording spiking activity in a secondary auditory area, the caudolateral mesopallium (CLM), while presenting the distance calls of a variety of individuals, including the bird itself, the mate, familiar and unfamiliar males and females. In males, the CLM is potentially involved in auditory feedback processing important for vocal learning. Based on both the analyses of spike rates and temporal aspects of discharges, our results clearly indicate that call-evoked responses of CLM neurons are sexually dimorphic, being stronger, lasting longer, and conveying more information about calls in males than in females. In addition, how auditory responses vary among call types differ between sexes. In females, response strength differs between familiar male and female calls. In males, temporal features of responses reveal a sensitivity to the bird's own call. These findings provide evidence that sexual dimorphism occurs in higher-order processing areas within the auditory system. They suggest a sexual dimorphism in the function of the CLM, contributing to transmit information about the self-generated calls in males and to storage of information about the bird's auditory experience in females.

Sexual dimorphism in the volume of song control nuclei in European starlings: assessment by a Nissl stain and autoradiography for muscarinic cholinergic receptors.

PubMed

Bernard, D J; Casto, J M; Ball, G F

1993-08-22

Previous studies have found that the volume of several song control nuclei is larger in male songbirds than in female songbirds. The degree of this volumetric sex difference within a given species appears to be systematically related to the degree of the behavioral sex difference. The largest volumetric differences have been reported in species in which the male sings and the female sings little, if at all, and the smallest sex differences in volume have been reported in species in which males and females both sing in nearly equal amounts. We compared the volume of three song control nuclei in male and female European starlings (Sturnus vulgaris), a species in which females are known to sing, though at a much lower rate than males. We investigated the volume of hyperstriatum ventrale, pars caudale, nucleus robustus archistriatalis, and area X of the lobus parolfactorius as defined with the use of a Nissl stain. In addition, we measured the volume of area X as defined by the density of muscarinic cholinergic receptors visualized by in vitro receptor autoradiographic methods. The volumes of all three of the song nuclei, as defined by Nissl staining, are significantly larger in males than in females. For area X, Nissl staining and receptor autoradiography indicate the same significant volumetric sex difference. The three nuclei are approximately one and one half to two times larger in males than in females, a degree of dimorphism that is intermediate to those reported for other species. Previous investigations of sex differences in the avian vocal control system have used only Nissl stains to define nuclear volumes. We demonstrate in this paper that receptor autoradiography can be used to assess dimorphisms in nuclear volume. Broad application of this approach to a number of neurotransmitter receptor systems will better characterize the dimorphisms in the song system, and therefore will provide greater insight into the neuroanatomical and neurochemical control of birdsong.

Darwinian sex roles confirmed across the animal kingdom

PubMed Central

Janicke, Tim; Häderer, Ines K.; Lajeunesse, Marc J.; Anthes, Nils

2016-01-01

Since Darwin’s conception of sexual selection theory, scientists have struggled to identify the evolutionary forces underlying the pervasive differences between male and female behavior, morphology, and physiology. The Darwin-Bateman paradigm predicts that anisogamy imposes stronger sexual selection on males, which, in turn, drives the evolution of conventional sex roles in terms of female-biased parental care and male-biased sexual dimorphism. Although this paradigm forms the cornerstone of modern sexual selection theory, it still remains untested across the animal tree of life. This lack of evidence has promoted the rise of alternative hypotheses arguing that sex differences are entirely driven by environmental factors or chance. We demonstrate that, across the animal kingdom, sexual selection, as captured by standard Bateman metrics, is indeed stronger in males than in females and that it is evolutionarily tied to sex biases in parental care and sexual dimorphism. Our findings provide the first comprehensive evidence that Darwin’s concept of conventional sex roles is accurate and refute recent criticism of sexual selection theory. PMID:26933680

Darwinian sex roles confirmed across the animal kingdom.

PubMed

Janicke, Tim; Häderer, Ines K; Lajeunesse, Marc J; Anthes, Nils

2016-02-01

Since Darwin's conception of sexual selection theory, scientists have struggled to identify the evolutionary forces underlying the pervasive differences between male and female behavior, morphology, and physiology. The Darwin-Bateman paradigm predicts that anisogamy imposes stronger sexual selection on males, which, in turn, drives the evolution of conventional sex roles in terms of female-biased parental care and male-biased sexual dimorphism. Although this paradigm forms the cornerstone of modern sexual selection theory, it still remains untested across the animal tree of life. This lack of evidence has promoted the rise of alternative hypotheses arguing that sex differences are entirely driven by environmental factors or chance. We demonstrate that, across the animal kingdom, sexual selection, as captured by standard Bateman metrics, is indeed stronger in males than in females and that it is evolutionarily tied to sex biases in parental care and sexual dimorphism. Our findings provide the first comprehensive evidence that Darwin's concept of conventional sex roles is accurate and refute recent criticism of sexual selection theory.

Brain-wide Maps Reveal Stereotyped Cell-Type-Based Cortical Architecture and Subcortical Sexual Dimorphism.

PubMed

Kim, Yongsoo; Yang, Guangyu Robert; Pradhan, Kith; Venkataraju, Kannan Umadevi; Bota, Mihail; García Del Molino, Luis Carlos; Fitzgerald, Greg; Ram, Keerthi; He, Miao; Levine, Jesse Maurica; Mitra, Partha; Huang, Z Josh; Wang, Xiao-Jing; Osten, Pavel

2017-10-05

The stereotyped features of neuronal circuits are those most likely to explain the remarkable capacity of the brain to process information and govern behaviors, yet it has not been possible to comprehensively quantify neuronal distributions across animals or genders due to the size and complexity of the mammalian brain. Here we apply our quantitative brain-wide (qBrain) mapping platform to document the stereotyped distributions of mainly inhibitory cell types. We discover an unexpected cortical organizing principle: sensory-motor areas are dominated by output-modulating parvalbumin-positive interneurons, whereas association, including frontal, areas are dominated by input-modulating somatostatin-positive interneurons. Furthermore, we identify local cell type distributions with more cells in the female brain in 10 out of 11 sexually dimorphic subcortical areas, in contrast to the overall larger brains in males. The qBrain resource can be further mined to link stereotyped aspects of neuronal distributions to known and unknown functions of diverse brain regions. Copyright © 2017 Elsevier Inc. All rights reserved.

What Educational Contexts Should Teachers Consider for Their Puberty Education Programmes?

ERIC Educational Resources Information Center

Collier-Harris, Christine A.; Goldman, Juliette D. G.

2017-01-01

This paper analyses some contemporary educational contexts that teachers should consider for their puberty education programmes and/or curricula, for primary and secondary school students. The educational contexts addressed here include significant international puberty education framework documents, socio-biological factors including earlier…

The influence of puberty on subcortical brain development.

PubMed

Goddings, Anne-Lise; Mills, Kathryn L; Clasen, Liv S; Giedd, Jay N; Viner, Russell M; Blakemore, Sarah-Jayne

2014-03-01

Puberty is characterized by hormonal, physical and psychological transformation. The human brain undergoes significant changes between childhood and adulthood, but little is known about how puberty influences its structural development. Using a longitudinal sample of 711 magnetic resonance imaging scans from 275 individuals aged 7-20years, we examined how subcortical brain regions change in relation to puberty. Our regions of interest included the amygdala, hippocampus and corpus striatum including the nucleus accumbens (NA), caudate, putamen and globus pallidus (GP). Pubertal development was significantly related to structural volume in all six regions in both sexes. Pubertal development and age had both independent and interactive influences on volume for the amygdala, hippocampus and putamen in both sexes, and the caudate in females. There was an interactive puberty-by-age effect on volume for the NA and GP in both sexes, and the caudate in males. These findings suggest a significant role for puberty in structural brain development. © 2013. Published by Elsevier Inc. All rights reserved.

Kisspeptin and Puberty in Mammals

PubMed Central

Terasawa, Ei; Guerriero, Kathryn A.; Plant, Tony M.

2014-01-01

Since the discovery of the G-protein coupled receptor (kisspeptin receptor) and its ligand, kisspeptin, our understanding of the neurobiological mechanisms that govern the pituitary-gonadal axis has evolved dramatically. In this chapter, we have reviewed progress regarding the relationship between kisspeptin and puberty, and have proposed a novel hypothesis for the role of kisspeptin signaling in the onset of this crucial developmental event. According to this hypothesis, although kisspeptin neurons in the arcuate nucleus (ARC) are critical for puberty, this is simply because these cells are an integral component of the hypothalamic GnRH pulse generating mechanism that drives intermittent release of the decapeptide, as an increase in GnRH is obligatory for the onset of puberty. In our model, ARC kisspeptin neurons play no “regulatory” role in controlling the timing of puberty. Rather, as a component of the neural network responsible for GnRH pulse generation, they subserve upstream regulatory mechanisms that are responsible for the timing of puberty. PMID:23550010

The influence of puberty on subcortical brain development

PubMed Central

Goddings, Anne-Lise; Mills, Kathryn L.; Clasen, Liv S.; Giedd, Jay N.; Viner, Russell M.; Blakemore, Sarah-Jayne

2014-01-01

Puberty is characterized by hormonal, physical and psychological transformation. The human brain undergoes significant changes between childhood and adulthood, but little is known about how puberty influences its structural development. Using a longitudinal sample of 711 magnetic resonance imaging scans from 275 individuals aged 7–20 years, we examined how subcortical brain regions change in relation to puberty. Our regions of interest included the amygdala, hippocampus and corpus striatum including the nucleus accumbens (NA), caudate, putamen and globus pallidus (GP). Pubertal development was significantly related to structural volume in all six regions in both sexes. Pubertal development and age had both independent and interactive influences on volume for the amygdala, hippocampus and putamen in both sexes, and the caudate in females. There was an interactive puberty-by-age effect on volume for the NA and GP in both sexes, and the caudate in males. These findings suggest a significant role for puberty in structural brain development. PMID:24121203

Epigenetic regulation of puberty via Zinc finger protein-mediated transcriptional repression.

PubMed

Lomniczi, Alejandro; Wright, Hollis; Castellano, Juan Manuel; Matagne, Valerie; Toro, Carlos A; Ramaswamy, Suresh; Plant, Tony M; Ojeda, Sergio R

2015-12-16

In primates, puberty is unleashed by increased GnRH release from the hypothalamus following an interval of juvenile quiescence. GWAS implicates Zinc finger (ZNF) genes in timing human puberty. Here we show that hypothalamic expression of several ZNFs decreased in agonadal male monkeys in association with the pubertal reactivation of gonadotropin secretion. Expression of two of these ZNFs, GATAD1 and ZNF573, also decreases in peripubertal female monkeys. However, only GATAD1 abundance increases when gonadotropin secretion is suppressed during late infancy. Targeted delivery of GATAD1 or ZNF573 to the rat hypothalamus delays puberty by impairing the transition of a transcriptional network from an immature repressive epigenetic configuration to one of activation. GATAD1 represses transcription of two key puberty-related genes, KISS1 and TAC3, directly, and reduces the activating histone mark H3K4me2 at each promoter via recruitment of histone demethylase KDM1A. We conclude that GATAD1 epitomizes a subset of ZNFs involved in epigenetic repression of primate puberty.

Sexual variation in assimilation efficiency: its link to phenotype and potential role in sexual dimorphism.

PubMed

Stahlschmidt, Zachary R; Davis, Jon R; Denardo, Dale F

2011-04-01

Sex-specific variation in morphology (sexual dimorphism) is a prevalent phenomenon among animals, and both dietary intake and resource allocation strategies influence sexually dimorphic traits (e.g., body size or composition). However, we investigated whether assimilation efficiency (AE), an intermediate step between dietary intake and allocation, can also vary between the sexes. Specifically, we tested whether sex-based differences in AE can explain variation in phenotypic traits. We measured morphometric characteristics (i.e., body length, mass, condition, and musculature) and AE of total energy, crude protein, and crude fat in post-reproductive adult Children's pythons (which exhibit a limited female-biased sexual size dimorphism) fed both low and high dietary intakes. Meal size was negatively related to AE of energy. Notably, male snakes absorbed crude protein more efficiently and increased epaxial (dorsal) musculature faster than females, which demonstrates a link between AE and phenotype. However, females grew in body length faster but did not absorb any nutrient more efficiently than males. Although our results do not provide a direct link between AE and sexual size dimorphism, they demonstrate that sexual variation in nutrient absorption exists and can contribute to other types of sex-based differences in phenotype (i.e., sexual dimorphism in growth of musculature). Hence, testing the broader applicability of AE's role in sexually dimorphic traits among other species is warranted.

A test of the size-constraint hypothesis for a limit to sexual dimorphism in plants.

PubMed

Labouche, Anne-Marie; Pannell, John R

2016-07-01

In flowering plants, many dioecious species display a certain degree of sexual dimorphism in non-reproductive traits, but this dimorphism tends to be much less striking than that found in animals. Sexual size dimorphism in plants may be limited because competition for light in crowded environments so strongly penalises small plants. The idea that competition for light constrains the evolution of strong sexual size dimorphism in plants (the size-constraint hypothesis) implies a strong dependency of the expression of sexual size dimorphism on the neighbouring density as a result of the capacity of plants to adjust their reproductive effort and investment in growth in response to their local environment. Here, we tested this hypothesis by experimentally altering the context of competition for light among male-female pairs of the light-demanding dioecious annual plant Mercurialis annua. We found that males were smaller than females across all treatments, but sexual size dimorphism was diminished for pairs grown at higher densities. This result is consistent with the size-constraint hypothesis. We discuss our results in terms of the tension between selection on size acting in opposite directions on males and females, which have different optima under sexual selection, and stabilizing selection for similar sizes in males and females, which have similar optima under viability selection for plasticity in size expression under different density conditions.

[Relevant factors of early puberty timing in urban primary schools in Chongqing].

PubMed

Luo, Yan; Liu, Qin; Wen, Yi; Liu, Shudan; Lei, Xun; Wang, Hong

2016-05-01

To investigate the status of puberty timing and relevant factors of early puberty timing in children from grade one to four in urban primary schools of Chongqing. According to the purposive sample method, four urban primary schools in Chongqing were selected and of which 1471 children from grade one to four who have obtained informed consent were recruited. Questionnaire survey on social-demographic characteristics and family environment (e.g., age, parents' relationship, diet and lifestyle, etc), and Pubertal Development Scale (PDS) survey and physical examination (measurements of height, weight, pubertal development status, etc) were conducted. P25, P50, P75 ages of each important pubertal event were calculated by probit regression. Univariate and multivariate analysis were used to analyze relevant factors. The detection rate of early puberty timing was 17.7%, and the median ages of the onset of breast and testicular development were 10.77 and 11.48 years old, respectively. Multivariate logistic regression showed that early puberty timing occurred more likely in girls than in boys (OR = 0.561, 95% CI 0.406-0.774), and bad relationship between parents (OR = 1.320, 95% CI 1.007-1.729) and hair-products-use (OR = 1.685, 95%, CI 1.028-2.762) were risk factors of early puberty timing. Early onset of puberty in urban Chongqing is still exist. Gender, parents' relationship, and hair-products-use have an essential impact on early puberty timing.

The Effect of Bisphenol A on Puberty: A Critical Review of the Medical Literature.

PubMed

Leonardi, Alberto; Cofini, Marta; Rigante, Donato; Lucchetti, Laura; Cipolla, Clelia; Penta, Laura; Esposito, Susanna

2017-09-10

Many scientific studies have revealed a trend towards an earlier onset of puberty and have disclosed an increasing number of children that display precocious puberty. As an explanation, some authors have considered the global socio-economic improvement across different populations, and other authors have considered the action of endocrine disrupting chemicals (EDCs). Among these, bisphenol A (BPA), an aromatic compound largely used worldwide as a precursor of some plastics and chemical additives, is well known for its molecular oestrogen-like and obesogenic actions. We reviewed the medical literature of the previous 20 years that examined associations between BPA exposure and the age of puberty in humans, considering only those referring to clinical or epidemiological data. Of 19 studies, only 7 showed a correlation between BPA and puberty. In particular, the possible disruptive role of BPA on puberty may be seen in those with central precocious puberty or isolated premature breast development aged 2 months to 4 years old, even if the mechanism is undefined. Some studies also found a close relationship between urinary BPA, body weight, and early puberty, which can be explained by the obesogenic effect of BPA itself. The currently available data do not allow establishment of a clear role for BPA in pubertal development because of the conflicting results among all clinical and epidemiological studies examined. Further research is needed to fully understand the potential role of exposure to EDCs and their adverse endocrine health outcomes.

Pubertal development of the understanding of social emotions: Implications for education

PubMed Central

Burnett, Stephanie; Thompson, Stephanie; Bird, Geoffrey; Blakemore, Sarah-Jayne

2011-01-01

Recent developmental cognitive neuroscience research has supported the notion that puberty and adolescence are periods of profound socio-emotional development. The current study was designed to investigate whether the onset of puberty marks an increase in the awareness of complex, or “mixed,” emotions. Eighty-three female participants (aged 9–16 years) were divided into three groups according to a self-report measure of puberty stage (early-, mid- and post-puberty). Participants were presented with emotional scenarios, and used four linear scales to rate their emotional response to each scenario. Scenarios were designed to evoke social emotions (embarrassment or guilt) or basic emotions (anger or fear), where social emotions are defined as those which require the representation of others' mental states. We measured the relative complexity or “mixedness” of emotional responses, that is, the degree to which participants reported feeling more than one emotion for a given scenario. We found that mixed emotion reporting increased between early- and post-puberty for social emotion scenarios, and showed no relationship with age, whereas there was no change in mixed emotion reporting for basic emotion scenarios across age or puberty groups. This suggests that the awareness of mixed emotions develops during the course of puberty, and that this development is specific to social emotions. Results are discussed in the context of brain development across puberty and adolescence, with speculation regarding the potential implications for education. PMID:22211052

The Effect of Bisphenol A on Puberty: A Critical Review of the Medical Literature

PubMed Central

Leonardi, Alberto; Cofini, Marta; Lucchetti, Laura; Cipolla, Clelia; Penta, Laura

2017-01-01

Many scientific studies have revealed a trend towards an earlier onset of puberty and have disclosed an increasing number of children that display precocious puberty. As an explanation, some authors have considered the global socio-economic improvement across different populations, and other authors have considered the action of endocrine disrupting chemicals (EDCs). Among these, bisphenol A (BPA), an aromatic compound largely used worldwide as a precursor of some plastics and chemical additives, is well known for its molecular oestrogen-like and obesogenic actions. We reviewed the medical literature of the previous 20 years that examined associations between BPA exposure and the age of puberty in humans, considering only those referring to clinical or epidemiological data. Of 19 studies, only 7 showed a correlation between BPA and puberty. In particular, the possible disruptive role of BPA on puberty may be seen in those with central precocious puberty or isolated premature breast development aged 2 months to 4 years old, even if the mechanism is undefined. Some studies also found a close relationship between urinary BPA, body weight, and early puberty, which can be explained by the obesogenic effect of BPA itself. The currently available data do not allow establishment of a clear role for BPA in pubertal development because of the conflicting results among all clinical and epidemiological studies examined. Further research is needed to fully understand the potential role of exposure to EDCs and their adverse endocrine health outcomes. PMID:28891963

Allometry, sexual size dimorphism, and niche partitioning in the Mediterranean gecko (Hemidactylus turcicus)

Treesearch

James B. Johnson; Lance D. McBrayer; Daniel Saenz

2005-01-01

Hemidactylus tucrius is a small gekkonid lizard native to the Middle East and Asia that is known to exhibit sexual dimorphism in head size. Several potential explanations exist for the evolution and maintenance of sexual dimorphism in lizards. We tested 2 of these competing hypotheses concerning diet partitioning and differential growth. We found no...

Effects of environmental enrichment during abstinence in morphine dependent parents on anxiety, depressive-like behaviors and voluntary morphine consumption in rat offspring.

PubMed

Pooriamehr, Alireza; Sabahi, Parviz; Miladi-Gorji, Hossein

2017-08-24

Chronic morphine exposure during puberty increased morphine-induced rewarding effects and sensitization in the next generation. Given the well-known beneficial effects of environmental enrichment on the severity of physical and psychological dependence on morphine, we examined effects of enriched environment during morphine abstinence in morphine dependent parental rats before mating on the anxiety and depressive-like behaviors, and voluntary morphine consumption in their offspring. Paternal and/or maternal rats were injected with bi-daily doses (10mg/kg, 12h intervals) of morphine for 14days followed by rearing in a standard environment (SE) or enriched environment (EE) during 30days of morphine abstinence before mating. The pubertal male and female rat offspring were tested for anxiety (the elevated plus maze- EPM) and depression (sucrose preference test-SPT), and voluntary morphine consumption using a two-bottle choice (TBC) paradigm. The results showed that EE experience in morphine-dependent both parents result in an increase in the percentage of time spent into open arms/time spent on both arms using EPM in male offspring, higher levels of sucrose preference in female offspring and lower levels of voluntary morphine consumption in male and female offspring. Thus, EE experience in morphine-dependent both parents reduced anxiety, depressive-like behavior and also the voluntary morphine consumption in their offspring during puberty which may prevent the vulnerability of the next generation to drug abuse. Copyright © 2017 Elsevier B.V. All rights reserved.

Large Sex Differences in Chicken Behavior and Brain Gene Expression Coincide with Few Differences in Promoter DNA-Methylation

PubMed Central

Nätt, Daniel; Agnvall, Beatrix; Jensen, Per

2014-01-01

While behavioral sex differences have repeatedly been reported across taxa, the underlying epigenetic mechanisms in the brain are mostly lacking. Birds have previously shown to have only limited dosage compensation, leading to high sex bias of Z-chromosome gene expression. In chickens, a male hyper-methylated region (MHM) on the Z-chromosome has been associated with a local type of dosage compensation, but a more detailed characterization of the avian methylome is limiting our interpretations. Here we report an analysis of genome wide sex differences in promoter DNA-methylation and gene expression in the brain of three weeks old chickens, and associated sex differences in behavior of Red Junglefowl (ancestor of domestic chickens). Combining DNA-methylation tiling arrays with gene expression microarrays we show that a specific locus of the MHM region, together with the promoter for the zinc finger RNA binding protein (ZFR) gene on chromosome 1, is strongly associated with sex dimorphism in gene expression. Except for this, we found few differences in promoter DNA-methylation, even though hundreds of genes were robustly differentially expressed across distantly related breeds. Several of the differentially expressed genes are known to affect behavior, and as suggested from their functional annotation, we found that female Red Junglefowl are more explorative and fearful in a range of tests performed throughout their lives. This paper identifies new sites and, with increased resolution, confirms known sites where DNA-methylation seems to affect sexually dimorphic gene expression, but the general lack of this association is noticeable and strengthens the view that birds do not have dosage compensation. PMID:24782041

The roles of sex and serotonin transporter levels in age- and stress-related emotionality in mice.

PubMed

Joeyen-Waldorf, Jennifer; Edgar, Nicole; Sibille, Etienne

2009-08-25

Mood disorders are influenced by genetic make-up and differentially affect men and women. The s/l promoter polymorphism in the serotonin transporter (SERT) gene moderates both trait emotion and the vulnerability to develop depressive states in humans. Similarly, male mice lacking SERT (Knockout/KO) display an elevated emotionality phenotype. We now report that the SERT-KO phenotype is maintained throughout late-adulthood, and that female KO mice develop a larger emotionality phenotype with increasing age. Thus, to test the hypothesis that these findings reflected a putative sexual dimorphism in SERT-mediated modulation of emotionality, we submitted adult male and female wild-type, heterozygous (HZ) and KO mice to unpredictable chronic mild stress (UCMS) and assessed behavioral changes. In males, the elevated SERT-KO emotion-related behavior converged with other groups after UCMS. Conversely, female SERT-KO displayed a normal non-stressed baseline, but highest UCMS-induced emotionality. SERT-HZ displayed variable and intermediate phenotypes in both experiments. Thus, consistent results across different biological modalities (age, stress) revealed a high contribution of SERT genotype for baseline "trait" emotionality in males, and low contribution for females. In contrast, age-correlated and stress-induced behavioral changes resulted in a high SERT genotype-mediated behavioral variance in females, but low in males. This suggests that high emotionality states associated with low SERT were differentially achieved in males (high baseline/trait) compared to females (increased vulnerability to develop high emotionality). This sex-by-SERT double dissociation provides a framework to investigate molecular substrates of emotionality regulation in concert with serotonin function and may contribute to the sexually dimorphic features of mood disorders.

Independent evolution of sexual dimorphism and female-limited mimicry in swallowtail butterflies (Papilio dardanus and Papilio phorcas).

PubMed

Timmermans, M J T N; Thompson, M J; Collins, S; Vogler, A P

2017-03-01

Several species of swallowtail butterflies (genus Papilio) are Batesian mimics that express multiple mimetic female forms, while the males are monomorphic and nonmimetic. The evolution of such sex-limited mimicry may involve sexual dimorphism arising first and mimicry subsequently. Such a stepwise scenario through a nonmimetic, sexually dimorphic stage has been proposed for two closely related sexually dimorphic species: Papilio phorcas, a nonmimetic species with two female forms, and Papilio dardanus, a female-limited polymorphic mimetic species. Their close relationship indicates that female-limited polymorphism could be a shared derived character of the two species. Here, we present a phylogenomic analysis of the dardanus group using 3964 nuclear loci and whole mitochondrial genomes, showing that they are not sister species and thus that the sexually dimorphic state has arisen independently in the two species. Nonhomology of the female polymorphism in both species is supported by population genetic analysis of engrailed, the presumed mimicry switch locus in P. dardanus. McDonald-Kreitman tests performed on SNPs in engrailed showed the signature of balancing selection in a polymorphic population of P. dardanus, but not in monomorphic populations, nor in the nonmimetic P. phorcas. Hence, the wing polymorphism does not balance polymorphisms in engrailed in P. phorcas. Equally, unlike in P. dardanus, none of the SNPs in P. phorcas engrailed were associated with either female morph. We conclude that sexual dimorphism due to female polymorphism evolved independently in both species from monomorphic, nonmimetic states. While sexual selection may drive male-female dimorphism in nonmimetic species, in mimetic Papilios, natural selection for protection from predators in females is an alternative route to sexual dimorphism. © 2017 John Wiley & Sons Ltd.

Social Network Analysis Reveals Potential Fission-Fusion Behavior in a Shark

NASA Astrophysics Data System (ADS)

Haulsee, Danielle E.; Fox, Dewayne A.; Breece, Matthew W.; Brown, Lori M.; Kneebone, Jeff; Skomal, Gregory B.; Oliver, Matthew J.

2016-09-01

Complex social networks and behaviors are difficult to observe for free-living marine species, especially those that move great distances. Using implanted acoustic transceivers to study the inter- and intraspecific interactions of sand tiger sharks Carcharias taurus, we observed group behavior that has historically been associated with higher order mammals. We found evidence strongly suggestive of fission-fusion behavior, or changes in group size and composition of sand tigers, related to five behavioral modes (summering, south migration, community bottleneck, dispersal, north migration). Our study shows sexually dimorphic behavior during migration, in addition to presenting evidence of a potential solitary phase for these typically gregarious sharks. Sand tigers spent up to 95 consecutive and 335 cumulative hours together, with the strongest relationships occurring between males. Species that exhibit fission-fusion group dynamics pose a particularly challenging issue for conservation and management because changes in group size and composition affect population estimates and amplify anthropogenic impacts.

[Deviation in psychosexual development in the pre-puberty children].

PubMed

Liavshina, G Kh

2002-01-01

Psychosexual health of 308 children, aged 2-11 years, as well as that of their families, was studied. Deviations in psychosexual development were found in 34.6% of the children examined. The following types were detected: difficulties in formation of gender-determined behavior features--64.4%, precocious psychosexual development--13.7%, delayed psychosexual development--12.3%, obsessive masturbation--9.6%. Risk factors for deviant psychosexual development were found.

Family scents: developmental changes in the perception of kin body odor?

PubMed

Ferdenzi, Camille; Schaal, Benoist; Roberts, S Craig

2010-08-01

There is increasing evidence that human body odors are involved in adaptive behaviors, such as parental attachment in infants or partner choice in adults. The aim of the present study was to investigate changes in body-odor perception around puberty, a period largely ignored for odor-mediated behavioral changes, despite major changes in social needs and in odor emission and perception. Nine families with two children (8 pre-pubertal, aged 7-10, and 10 pubertal, aged 11-18) evaluated body odors of family members and unfamiliar individuals for pleasantness, intensity, and masculinity, and performed a recognition task. The hypothesized emergence of a parent-child mutual aversion for the odor of opposite-sex family members at puberty was not found, contradicting one of the few studies on the topic (Weisfeld et al., J. Exp. Child Psychol. 85:279-295, 2003). However, some developmental changes were observed, including reduced aversion for odor of the same-sex parent, and increased ability of adults, compared to children, to recognize odor of family members. Sex and personality (depressive and aggressive traits) also significantly influenced odor judgments. Further research with larger samples is needed to investigate the poorly explored issue of how olfactory perception of self and family members develops, and how it could correlate with normal reorganizations in social interactions at adolescence.

The influence of perceived parenting styles on socio-emotional development from pre-puberty into puberty.

PubMed

Ong, Min Yee; Eilander, Janna; Saw, Seang Mei; Xie, Yuhuan; Meaney, Michael J; Broekman, Birit F P

2018-01-01

The relative impact of parenting on socio-emotional development of children has rarely been examined in a longitudinal context. This study examined the association between perceived parenting styles and socio-emotional functioning from childhood to adolescence. We hypothesized that optimal parenting associated with improvement in socio-emotional functioning from childhood into early adulthood, especially for those with more behavioral problems in childhood. Children between ages 7 and 9 years were recruited for the Singapore Cohort Study of Risk Factors for Myopia (SCORM). Nine years later, 700 out of 1052 subjects were followed up (67%). During childhood, parents completed the Child Behavior Checklist (CBCL), while young adults completed the Youth Self-Report (YSR) and Parental Bonding Instrument (PBI). Perceived optimal parental care resulted in less internalizing and externalizing problems in early adulthood in comparison to non-optimal parental care styles. Perceived optimal paternal parenting, but not maternal parenting, in interaction with childhood externalizing problems predicted externalizing symptoms in early adulthood. No significant interactions were found between perceived parenting styles and internalizing problems. In conclusion, perceived parental care associates with the quality of socio-emotional development, while optimal parenting by the father is especially important for children with more externalizing problems in childhood.

[Population aspects of sexual dimorphism in guild of the Mustelidae: Mustela lutreola, Neovison vison, Mustela putorius, Martes martes as an example].

PubMed

Korablev, M P; Korablev, N P; Korablev, P N

2013-01-01

Size sexual dimorphism was investigated on 695 skulls of four Mustelidae species. By extent of increasing of differences between sexes the species are placed in following order: European pine marten (Martes martes), European mink (Mustela lutreola), American mink (Neovison vison), and European polecat (Mustela putorius). Extent of the dimorphism characterizes ecological plasticity of the species and is population characteristic. It is shown that M. martes takes specific and relatively narrow ecological niche of forest ecosystems, entering into weak competitive relationships with smaller Mustelidae species. The level of sexual dimorphism of M. lutreola, N. vison and M. putorius reflects intensity of its interspecific relationships within study area. High level of sexual dimorphism of M. putorius is determined by further divergence of ecological niches of males and females, and also appears to be compensatory mechanism reducing consequences of hardened environmental requirements.

SPECT Imaging to Evaluate Post Traumatic Stress Disorder

DTIC Science & Technology

2011-02-01

Verbeem, and D.M. Kuhn, Gene expression profile of activated microglia under conditions associated with dopamine neuronal damage. FASEB J., 2005: p. 05...specific. Pharmacology Biochemistry and Behavior, 1995. 50(4): p. 551. 39. Drugan, R.C., P.V. Holmes, and A.P. Stringer, Sexual dimorphism of stress...childhood sexual abuse and posttraumatic stress disorder. Am J Psychiatry, 2003. 160(5): p. 924-32. 22 48. Sapolsky, R.M., Atrophy of the hippocampus

Parents and Puberty: Encouraging Family Communication.

ERIC Educational Resources Information Center

Bower, Don; And Others

A community-based sexuality education program for parents and their puberty-aged children is described, and findings of a follow-up survey of the program are reported. The program was developed to provide factual information about puberty and sexuality which would serve as a basis for increased communication about sexuality between parents and…

Multi-tissue omics analyses reveal molecular regulatory networks for puberty in composite beef cattle

USDA-ARS?s Scientific Manuscript database

Puberty is a complex physiological event by which animals mature into an adult capable of sexual reproduction. In order to enhance our understanding of the genes and regulatory pathways and networks involved in puberty, we characterized the transcriptome of five reproductive tissues (i.e., hypothal...

Is Puberty Education Evident in Australia's First National Curriculum?

ERIC Educational Resources Information Center

Collier-Harris, Christine A.; Goldman, Juliette D. G.

2017-01-01

The processes of puberty, including reproductive fertility and social-role transitions, now begin earlier, last longer, and are experienced in very different contexts. Because of this, all children and adolescents need good-quality puberty education in school curricula, and this need is supported by positive cost-benefit analysis and international…

Gonadotropin-Dependent Precocious Puberty: Neoplastic Causes and Endocrine Considerations

PubMed Central

2011-01-01

Premature activation of the hypothalamic-pituitary-gonadal (HPG) axis manifests as gonadotropin-dependent precocious puberty. The mechanisms behind HPG activation are complex and a clear etiology for early activation is often not elucidated. Though collectively uncommon, the neoplastic and developmental causes of gonadotropin-dependent precocious puberty are very important to consider, as a delay in diagnosis may lead to adverse patient outcomes. The intent of the current paper is to review the neoplastic and developmental causes of gonadotropin-dependent precocious puberty. We discuss the common CNS lesions and human chorionic gonadotropin-secreting tumors that cause sexual precocity, review the relationship between therapeutic radiation and gonadotropin-dependent precocious puberty, and finally, provide an overview of the therapies available for height preservation in this unique patient population. PMID:21603196

Female puberty acceleration by male odour in mice: neural pathway and behavioural consequences.

PubMed

Jouhanneau, Mélanie; Szymanski, Laura A; Keller, Matthieu

2014-08-01

In female mice, exposure to male chemosignals results in early puberty onset characterized by advanced vaginal opening and higher uterine weight. Evidence suggests that the male chemosignals responsible for acceleration of female puberty are androgen-dependent, but not all of the compounds that contribute to puberty acceleration have been identified. The male chemosignals are primarily detected and processed by the vomeronasal system including the vomeronasal organ, the accessory olfactory bulb and the medial amygdala. By contrast, the mechanism by which this olfactory information is integrated in the hypothalamus is poorly understood. In this context, the recent identification of the neuropeptide kisspeptin as a gatekeeper of puberty onset may provide a good candidate neuropeptide system for the transmission of chemosensory information to the gonadotrope axis.

Central precocious puberty: from physiopathological mechanisms to treatment.

PubMed

Chirico, V; Lacquaniti, A; Salpietro, V; Buemi, M; Salpietro, C; Arrigo, T

2014-01-01

Puberty is a complex, coordinated biological process with multiple levels of regulations. The timing of puberty varies greatly in children and it is influenced by environmental, endocrine and genetic factors. Precocious puberty (PP) is an important issue, affecting between 1 in 5.000-10.000 children. The physiopathological mechanism is still unknown. From an etiological point of view, PP may be subdivided into gonadotropin-releasing hormone (GnRH) -dependent and independent causes. GnRH-dependent PP, often called central precocious puberty (CPP), is based on hypothalamic-pituitary-gonadal axis activation associated with progressive pubertal development, accelerated growth rate and advancement of skeletal age. Conversely, peripheral precocious puberty (PPP) is related to sex steroid exposure, independently of hypothalamic-–pituitary-–gonadal (HPG) axis activation. Kisspeptins play a central role in the modulation of GnRH secretion with peripheral factors that influence the timing of puberty, such as adipokines and endocrine disrupting chemicals. Moreover, PP could be related to genetic disorders, involving pivotal genes of the HPG axis. The standard test used to verify HPG activity is the gonadotropin response to administered GnRH analogs. We describe the physiopathological mechanisms of PP and its clinical implications, analysing diagnostic flow-chart and new potential biomarkers that could reveal PP. An update of the current literature was also carried out regarding the recent novelty for treatment.

Substance P Regulates Puberty Onset and Fertility in the Female Mouse

PubMed Central

Simavli, Serap; Thompson, Iain R.; Maguire, Caroline A.; Gill, John C.; Carroll, Rona S.; Wolfe, Andrew; Kaiser, Ursula B.

2015-01-01

Puberty is a tightly regulated process that leads to reproductive capacity. Kiss1 neurons are crucial in this process by stimulating GnRH, yet how Kiss1 neurons are regulated remains unknown. Substance P (SP), an important neuropeptide in pain perception, induces gonadotropin release in adult mice in a kisspeptin-dependent manner. Here, we assessed whether SP, through binding to its receptor NK1R (neurokinin 1 receptor), participates in the timing of puberty onset and fertility in the mouse. We observed that 1) selective NK1R agonists induce gonadotropin release in prepubertal females; 2) the expression of Tac1 (encoding SP) and Tacr1 (NK1R) in the arcuate nucleus is maximal before puberty, suggesting increased SP tone; 3) repeated exposure to NK1R agonists prepubertally advances puberty onset; and 4) female Tac1−/− mice display delayed puberty; moreover, 5) SP deficiency leads to subfertility in females, showing fewer corpora lutea and antral follicles and leading to decreased litter size. Thus, our findings support a role for SP in the stimulation of gonadotropins before puberty, acting via Kiss1 neurons to stimulate GnRH release, and its involvement in the attainment of full reproductive capabilities in female mice. PMID:25856429

No sexual dimorphism in human prenatal metacarpal ratios.

PubMed

Van Dongen, Stefan; Galis, Frietson; Ten Broek, Clara; Heikinheimo, Kristiina; Wijnaendts, Liliane C D; Delen, Sofie; Bots, Jessica

2014-03-01

Ratios of digit lengths are studied intensively as markers of prenatal sex hormone levels. Study sexual dimorphism in ratios of metacarpals, which received less attention. We studied six metacarpal ratios in deceased human fetuses of ages 10 to 42weeks. We found no indication of a sexual dimorphism at this early stage of development. Copyright © 2014 Elsevier Ltd. All rights reserved.

Transcriptomic analysis of the dimorphic transition of Ustilago maydis induced in vitro by a change in pH.

PubMed

Martínez-Soto, Domingo; Ruiz-Herrera, José

2013-01-01

Dimorphism is the property of fungi to grow as budding yeasts or mycelium, depending on the environmental conditions. This phenomenon is important as a model of differentiation in eukaryotic organisms, and since a large number of fungal diseases are caused by dimorphic fungi, its study is important for practical reasons. In this work, we examined the transcriptome during the dimorphic transition of the basidiomycota phytopathogenic fungus Ustilago maydis using microarrays, utilizing yeast and mycelium monomorphic mutants as controls. This way, we thereby identified 154 genes of the fungus that are specifically involved in the dimorphic transition induced by a pH change. Of these, 82 genes were up-regulated, and 72 were down-regulated. Differential categorization of these genes revealed that they mostly belonged to the classes of metabolism, cell cycle and DNA processing, transcription and protein fate, transport and cellular communication, stress, cell differentiation and biogenesis of cellular components, while a significant number of them corresponded to unclassified proteins. The data reported in this work are important for our understanding of the molecular bases of dimorphism in U. maydis, and possibly of other fungi. Copyright © 2013. Published by Elsevier Inc.

Deep sexual dimorphism in adult medaka fish liver highlighted by multi-omic approach

PubMed Central

Qiao, Qin; Le Manach, Séverine; Sotton, Benoit; Huet, Hélène; Duvernois-Berthet, Evelyne; Paris, Alain; Duval, Charlotte; Ponger, Loïc; Marie, Arul; Blond, Alain; Mathéron, Lucrèce; Vinh, Joelle; Bolbach, Gérard; Djediat, Chakib; Bernard, Cécile; Edery, Marc; Marie, Benjamin

2016-01-01

Sexual dimorphism describes the features that discriminate between the two sexes at various biological levels. Especially, during the reproductive phase, the liver is one of the most sexually dimorphic organs, because of different metabolic demands between the two sexes. The liver is a key organ that plays fundamental roles in various physiological processes, including digestion, energetic metabolism, xenobiotic detoxification, biosynthesis of serum proteins, and also in endocrine or immune response. The sex-dimorphism of the liver is particularly obvious in oviparous animals, as the female liver is the main organ for the synthesis of oocyte constituents. In this work, we are interested in identifying molecular sexual dimorphism in the liver of adult medaka fish and their sex-variation in response to hepatotoxic exposures. By developing an integrative approach combining histology and different high-throughput omic investigations (metabolomics, proteomics and transcriptomics), we were able to globally depict the strong sexual dimorphism that concerns various cellular and molecular processes of hepatocytes comprising protein synthesis, amino acid, lipid and polysaccharide metabolism, along with steroidogenesis and detoxification. The results of this work imply noticeable repercussions on the biology of oviparous organisms environmentally exposed to chemical or toxin issues. PMID:27561897

A Lack of Sexual Dimorphism in Width-to-Height Ratio in White European Faces Using 2D Photographs, 3D Scans, and Anthropometry

PubMed Central

Kramer, Robin S. S.; Jones, Alex L.; Ward, Robert

2012-01-01

Facial width-to-height ratio has received a great deal of attention in recent research. Evidence from human skulls suggests that males have a larger relative facial width than females, and that this sexual dimorphism is an honest signal of masculinity, aggression, and related traits. However, evidence that this measure is sexually dimorphic in faces, rather than skulls, is surprisingly weak. We therefore investigated facial width-to-height ratio in three White European samples using three different methods of measurement: 2D photographs, 3D scans, and anthropometry. By measuring the same individuals with multiple methods, we demonstrated high agreement across all measures. However, we found no evidence of sexual dimorphism in the face. In our third study, we also found a link between facial width-to-height ratio and body mass index for both males and females, although this relationship did not account for the lack of dimorphism in our sample. While we showed sufficient power to detect differences between male and female width-to-height ratio, our results failed to support the general hypothesis of sexual dimorphism in the face. PMID:22880088

Of mice and rats: key species variations in the sexual differentiation of brain and behavior.

PubMed

Bonthuis, P J; Cox, K H; Searcy, B T; Kumar, P; Tobet, S; Rissman, E F

2010-07-01

Mice and rats are important mammalian models in biomedical research. In contrast to other biomedical fields, work on sexual differentiation of brain and behavior has traditionally utilized comparative animal models. As mice are gaining in popularity, it is essential to acknowledge the differences between these two rodents. Here we review neural and behavioral sexual dimorphisms in rats and mice, which highlight species differences and experimental gaps in the literature, that are needed for direct species comparisons. Moving forward, investigators must answer fundamental questions about their chosen organism, and attend to both species and strain differences as they select the optimal animal models for their research questions. Copyright 2010 Elsevier Inc. All rights reserved.

Volumetric analysis of medial temporal lobe structures in brain development from childhood to adolescence.

PubMed

Hu, Shiyan; Pruessner, Jens C; Coupé, Pierrick; Collins, D Louis

2013-07-01

Puberty is an important stage of development as a child's sexual and physical characteristics mature because of hormonal changes. To better understand puberty-related effects on brain development, we investigated the magnetic resonance imaging (MRI) data of 306 subjects from 4 to 18 years of age. Subjects were grouped into before and during puberty groups according to their sexual maturity levels measured by the puberty scores. An appearance model-based automatic segmentation method with patch-based local refinement was employed to segment the MRI data and extract the volumes of medial temporal lobe (MTL) structures including the amygdala (AG), the hippocampus (HC), the entorhinal/perirhinal cortex (EPC), and the parahippocampal cortex (PHC). Our analysis showed age-related volumetric changes for the AG, HC, right EPC, and left PHC but only before puberty. After onset of puberty, these volumetric changes then correlate more with sexual maturity level, as measured by the puberty score. When normalized for brain volume, the volumes of the right HC decrease for boys; the volumes of the left HC increase for girls; and the volumes of the left and right PHC decrease for boys. These findings suggest that the rising levels of testosterone in boys and estrogen in girls might have opposite effects, especially for the HC and the PHC. Our findings on sex-specific and sexual maturity-related volumes may be useful in better understanding the MTL developmental differences and related learning, memory, and emotion differences between boys and girls during puberty. Copyright © 2013 Elsevier Inc. All rights reserved.

Timing of Puberty in Overweight Versus Obese Boys.

PubMed

Lee, Joyce M; Wasserman, Richard; Kaciroti, Niko; Gebremariam, Achamyeleh; Steffes, Jennifer; Dowshen, Steven; Harris, Donna; Serwint, Janet; Abney, Dianna; Smitherman, Lynn; Reiter, Edward; Herman-Giddens, Marcia E

2016-02-01

Studies of the relationship of weight status with timing of puberty in boys have been mixed. This study examined whether overweight and obesity are associated with differences in the timing of puberty in US boys. We reanalyzed recent community-based pubertal data from the American Academy of Pediatrics' Pediatric Research in Office Settings study in which trained clinicians assessed boys 6 to 16 years for height, weight, Tanner stages, testicular volume (TV), and other pubertal variables. We classified children based on BMI as normal weight, overweight, or obese and compared median age at a given Tanner stage or greater by weight class using probit and ordinal probit models and a Bayesian approach. Half of boys (49.9%, n = 1931) were white, 25.8% (n = 1000) were African American, and 24.3% (n = 941) were Hispanic. For genital development in white and African American boys across a variety of Tanner stages, we found earlier puberty in overweight compared with normal weight boys, and later puberty in obese compared with overweight, but no significant differences for Hispanics. For TV (≥3 mL or ≥4 mL), our findings support earlier puberty for overweight compared with normal weight white boys. In a large, racially diverse, community-based sample of US boys, we found evidence of earlier puberty for overweight compared with normal or obese, and later puberty for obese boys compared with normal and overweight boys. Additional studies are needed to understand the possible relationships among race/ethnicity, gender, BMI, and the timing of pubertal development. Copyright © 2016 by the American Academy of Pediatrics.

Surface facial modelling and allometry in relation to sexual dimorphism.

PubMed

Velemínská, J; Bigoni, L; Krajíček, V; Borský, J; Šmahelová, D; Cagáňová, V; Peterka, M

2012-04-01

Sexual dimorphism is responsible for a substantial part of human facial variability, the study of which is essential for many scientific fields ranging from evolution to special biomedical topics. Our aim was to analyse the relationship between size variability and shape facial variability of sexual traits in the young adult Central European population and to construct average surface models of adult males and females. The method of geometric morphometrics allowed not only the identification of dimorphic traits, but also the evaluation of static allometry and the visualisation of sexual facial differences. Facial variability in the studied sample was characterised by a strong relationship between facial size and shape of sexual dimorphic traits. Large size of face was associated with facial elongation and vice versa. Regarding shape sexual dimorphic traits, a wide, vaulted and high forehead in combination with a narrow and gracile lower face were typical for females. Variability in shape dimorphic traits was smaller in females compared to males. For female classification, shape sexual dimorphic traits are more important, while for males the stronger association is with face size. Males generally had a closer inter-orbital distance and a deeper position of the eyes in relation to the facial plane, a larger and wider straight nose and nostrils, and more massive lower face. Using pseudo-colour maps to provide a detailed schematic representation of the geometrical differences between the sexes, we attempted to clarify the reasons underlying the development of such differences. Copyright © 2012 Elsevier GmbH. All rights reserved.

Sexual dimorphism of head morphology in three-spined stickleback Gasterosteus aculeatus.

PubMed

Aguirre, W E; Akinpelu, O

2010-09-01

This study examined sexual dimorphism of head morphology in the ecologically diverse three-spined stickleback Gasterosteus aculeatus. Male G. aculeatus had longer heads than female G. aculeatus in all 10 anadromous, stream and lake populations examined, and head length growth rates were significantly higher in males in half of the populations sampled, indicating that differences in head size increased with body size in many populations. Despite consistently larger heads in males, there was significant variation in size-adjusted head length among populations, suggesting that the relationship between head length and body length was flexible. Inter-population differences in head length were correlated between sexes, thus population-level factors influenced head length in both sexes despite the sexual dimorphism present. Head shape variation between lake and anadromous populations was greater than that between sexes. The common divergence in head shape between sexes across populations was about twice as important as the sexual dimorphism unique to each population. Finally, much of the sexual dimorphism in head length was due to divergence in the anterior region of the head, where the primary trophic structures were found. It is unclear whether the sexual dimorphism was due to natural selection for niche divergence between sexes or sexual selection. This study improves knowledge of the magnitude, growth rate divergence, inter-population variation and location of sexual dimorphism in G. aculeatus head morphology. © 2010 The Authors. Journal compilation © 2010 The Fisheries Society of the British Isles.

Colony size as a species character in massive reef corals

NASA Astrophysics Data System (ADS)

Soong, Keryea

1993-07-01

In a study of seven massive, Caribbean corals, I have found major differences in reproductive behavior between species with large maximum colony sizes and species with smaller maximum colony sizes. Four species ( Diploria clivosa, D. strigosa, Montastrea cavernosa, Siderastrea siderea) which are large (<1000 cm2 in surface area) broadcast gametes during a short spawning season. Their puberty size is relatively large (>100 cm2, except M. cavernosa). In contrast, two small massive species (<100 cm2, Favia fragum and S. radians), and one medium-sized (100 1000 cm2, Porites astreoides) massive species, brood larvae during an extended season (year-round in Panama). The puberty size of the small species is only 2 4 cm2. Given these close associations between maximum colony sizes and a number of fundamental reproductive attributes, greater attention should be given to the colony size distributions of different species of reef corals in nature, since many important life history and population characters may be inferred.

Risk-taking and decision-making in youth: relationships to addiction vulnerability

PubMed Central

Balogh, Kornelia N.; Mayes, Linda C.; Potenza, Marc N.

2013-01-01

Background Decision-making and risk-taking behavior undergo developmental changes during adolescence. Disadvantageous decision-making and increased risk-taking may lead to problematic behaviors such as substance use and abuse, pathological gambling and excessive internet use. Methods Based on MEDLINE searches, this article reviews the literature on decision-making and risk-taking and their relationship to addiction vulnerability in youth. Results Decision-making and risk-taking behaviors involve brain areas that undergoing developmental changes during puberty and young adulthood. Individual differences and peer pressure also relate importantly to decision-making and risk-taking. Conclusions Brain-based changes in emotional, motivational and cognitive processing may underlie risk-taking and decision-making propensities in adolescence, making this period a time of heightened vulnerability for engagement in additive behaviors. PMID:24294500

[Early death of the stronger sex. Could behavior change influence men's fate].

PubMed

Klotz, T

2003-11-06

Life expectancy in men is approximately 6.5 years shorter than in women. As an explanation for this difference, isolated consideration of the higher prevalence of coronary heart disease and cancer in men is inadequate. But it would also appear erroneous to postulate that differences in male and female thinking and behavior patterns in regard to health-risk behavior are subject to controllable socialization processes and "rational" realizations. The interaction of genetic and environmental risk factors and socialization is largely unknown. A sex-specific consideration of risk behavior and quality of life suggest that a healthy lifestyle, relevant information and preventive measures - in particular in males - must be initiated before puberty if they are to have a positive effect on mortality and morbidity during the course of a person's life.

Pubertal Development: Correspondence between Hormonal and Physical Development

ERIC Educational Resources Information Center

Shirtcliff, Elizabeth A.; Dahl, Ronald E.; Pollak, Seth D.

2009-01-01

Puberty is advanced by sex hormones, yet it is not clear how it is best measured. The interrelation of multiple indices of puberty was examined, including the Pubertal Development Scale (PDS), a picture-based interview about puberty (PBIP), and a physical exam. These physical pubertal measures were then associated with basal hormones responsible…

Middle School Teachers' Theories of Puberty.

ERIC Educational Resources Information Center

LeTendre, Gerald

This study explored middle school teachers' perspectives on and expectations of adolescence and puberty, using observations and interviews of 15 teachers in two Japanese middle schools and two United States (U.S.) middle schools, as well as a survey of teachers in selected schools in both nations. Teachers in the U.S. described puberty as being…

Body Talk for Boys Growing Up.

ERIC Educational Resources Information Center

Stubbs, Margaret L.

This pamphlet, targeted to boys, discusses issues surrounding puberty. The introduction describes the reaction of parents' to their children's process of growing up, as well as the reaction of other boys and girls to the physical changes of puberty. Physical changes that happen during puberty for girls and boys are listed. Books for boys on…

Body Talk for Girls Growing Up.

ERIC Educational Resources Information Center

Stubbs, Margaret L.

This pamphlet, targeted to girls, discusses issues surrounding puberty. The introduction describes the reaction of parents' to their children's process of growing up, as well as the reaction of other boys and girls to the physical changes of puberty. Physical changes that happen during puberty for girls and boys are listed. Books for girls on…

Multigenerational exposure to dietary zearalenone (ZEA), an estrogenic mycotoxin, affects puberty and reproduction in female mice

PubMed Central

Zhao, Fei; Li, Rong; Xiao, Shuo; Honglu, Diao; El Zowalaty, Ahmed E.; Ye, Xiaoqin

2014-01-01

This study investigated potential cumulative effects of multiple pregnancy and multigenerational exposure to dietary ZEA (0, 0.8, 4, or 20 ppm) on female puberty and reproduction in C57BL/6J mice. Multiple pregnancies did not significantly affect litter size or offspring puberty. Significant effects were observed in 20 ppm ZEA-treated females: advanced puberty onset in F0, F1, and F2 generations; decreased implantation rate, pregnancy rate, and litter size, and increased pregnancy gap and gestation period in F1 and F2 generations; and reduced fertility index in F2 generation. F3 females from 0 and 20 ppm groups were split into 0 or 20 ppm ZEA diets at weaning, with advanced puberty onset seen in 0-20 and 20-20 groups and decreased implantation rate observed in 20-20 group. In summary, 20 ppm dietary ZEA advanced puberty onset without obvious cumulative effect and impaired fertility with multigenerational cumulative effect, which could be partially alleviated upon exposure cessation. PMID:24972337

Genetic Determinants of Pubertal Timing in the General Population

PubMed Central

Gajdos, Zofia K.Z.; Henderson, Katherine D.; Hirschhorn, Joel N.

2010-01-01

Puberty is an important developmental stage during which reproductive capacity is attained. The timing of puberty varies greatly among healthy individuals in the general population and is influenced by both genetic and environmental factors. Although genetic variation is known to influence the normal spectrum of pubertal timing, the specific genes involved remain largely unknown. Genetic analyses have identified a number of genes responsible for rare disorders of pubertal timing such as hypogonadotropic hypogonadism and Kallmann syndrome. Recently, the first loci with common variation reproducibly associated with population variation in the timing of puberty were identified at 6q21 in or near LIN28B and at 9q31.2. However, these two loci explain only a small fraction of the genetic contribution to population variation in pubertal timing, suggesting the need to continue to consider other loci and other types of variants. Here we provide an update of the genes implicated in disorders of puberty, discuss genes and pathways that may be involved in the timing of normal puberty, and suggest additional avenues of investigation to identify genetic regulators of puberty in the general population. PMID:20144687

Epigenetic regulation of puberty via Zinc finger protein-mediated transcriptional repression

PubMed Central

Lomniczi, Alejandro; Wright, Hollis; Castellano, Juan Manuel; Matagne, Valerie; Toro, Carlos A.; Ramaswamy, Suresh; Plant, Tony M.; Ojeda, Sergio R.

2015-01-01

In primates, puberty is unleashed by increased GnRH release from the hypothalamus following an interval of juvenile quiescence. GWAS implicates Zinc finger (ZNF) genes in timing human puberty. Here we show that hypothalamic expression of several ZNFs decreased in agonadal male monkeys in association with the pubertal reactivation of gonadotropin secretion. Expression of two of these ZNFs, GATAD1 and ZNF573, also decreases in peripubertal female monkeys. However, only GATAD1 abundance increases when gonadotropin secretion is suppressed during late infancy. Targeted delivery of GATAD1 or ZNF573 to the rat hypothalamus delays puberty by impairing the transition of a transcriptional network from an immature repressive epigenetic configuration to one of activation. GATAD1 represses transcription of two key puberty-related genes, KISS1 and TAC3, directly, and reduces the activating histone mark H3K4me2 at each promoter via recruitment of histone demethylase KDM1A. We conclude that GATAD1 epitomizes a subset of ZNFs involved in epigenetic repression of primate puberty. PMID:26671628

Trithorax dependent changes in chromatin landscape at enhancer and promoter regions drive female puberty.

PubMed

Toro, Carlos A; Wright, Hollis; Aylwin, Carlos F; Ojeda, Sergio R; Lomniczi, Alejandro

2018-01-04

Polycomb group (PcG) proteins control the timing of puberty by repressing the Kiss1 gene in hypothalamic arcuate nucleus (ARC) neurons. Here we identify two members of the Trithorax group (TrxG) of modifiers, mixed-lineage leukemia 1 (MLL1), and 3 (MLL3), as central components of an activating epigenetic machinery that dynamically counteracts PcG repression. Preceding puberty, MLL1 changes the chromatin configuration at the promoters of Kiss1 and Tac3, two genes required for puberty to occur, from repressive to permissive. Concomitantly, MLL3 institutes a chromatin structure that changes the functional status of a Kiss1 enhancer from poised to active. RNAi-mediated, ARC-specific Mll1 knockdown reduced Kiss1 and Tac3 expression, whereas CRISPR-Cas9-directed epigenome silencing of the Kiss1 enhancer selectively reduced Kiss1 activity. Both interventions delay puberty and disrupt reproductive cyclicity. Our results demonstrate that an epigenetic switch from transcriptional repression to activation is crucial to the regulatory mechanism controlling the timing of mammalian puberty.

Management of pre-pubertal small ruminants: physiological basis and clinical approach.

PubMed

Valasi, I; Chadio, S; Fthenakis, G C; Amiridis, G S

2012-02-01

Puberty is a gradual process, during which animal reproductive competence is attained with respect to physiology, morphology and behaviour. Onset of puberty in small ruminants differs between sexes, due to early sexual differentiation in the control of steroid feedback systems and, thus, GnRH secretion. A number of puberty determinants have been identified, which include genetic factors, as well as endogenous signals, such as energy balance and environmental cues, whose dynamic interplay is responsible for the timing of puberty onset. Puberty timing affects reproduction through age at first lambing, which impacts on subsequent reproductive life and productivity of small ruminants. Thus, a greater knowledge of the mechanisms underlying puberty process would lead to optimisation of commonly applied strategies for selection of replacement animals. In addition, understanding reproductive responses of animals to exteroceptive factors, such as photoperiod, nutrition and socio-sexual signals, will enable development and improvement of those management tools that that will fulfil the requirements of a 'clean, green and ethical' production. Copyright © 2012 Elsevier B.V. All rights reserved.

The timing of normal puberty and the age limits of sexual precocity: variations around the world, secular trends, and changes after migration.

PubMed

Parent, Anne-Simone; Teilmann, Grete; Juul, Anders; Skakkebaek, Niels E; Toppari, Jorma; Bourguignon, Jean-Pierre

2003-10-01

During the past decade, possible advancement in timing of puberty has been reported in the United States. In addition, early pubertal development and an increased incidence of sexual precocity have been noticed in children, primarily girls, migrating for foreign adoption in several Western European countries. These observations are raising the issues of current differences and secular trends in timing of puberty in relation to ethnic, geographical, and socioeconomic background. None of these factors provide an unequivocal explanation for the earlier onset of puberty seen in the United States. In the formerly deprived migrating children, refeeding and catch-up growth may prime maturation. However, precocious puberty is seen also in some nondeprived migrating children. Attention has been paid to the changing milieu after migration, and recently, the possible role of endocrine- disrupting chemicals from the environment has been considered. These observations urge further study of the onset of puberty as a possible sensitive and early marker of the interactions between environmental conditions and genetic susceptibility that can influence physiological and pathological processes.

Cortisol and alpha amylase reactivity and timing of puberty: Vulnerabilities for antisocial behaviour in young adolescents

PubMed Central

Susman, Elizabeth J.; Granger, Douglas A; Blades, Keeva T.; Randazzo, William; Heaton, Jodi A.; Dorn, Lorah D.

2009-01-01

The theoretical framework proposed that cortisol and saliva alpha amylase (sAA) reactivitiy are vulnerabilities for antisocial behaviour. These indices of hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenal-medulary (SAM) components of the stress system, respectively, were considered vulnerabilities that also interact with the putative stressful transition of timing of puberty to predispose adolescents toward antisocial behaviour. The sample consisted of 8- to-13-year-old boys and girls (N=135) and a parent. For boys, timing of puberty moderated the association between cortisol and sAA reactivity and antisocial behaviour. Higher cortisol reactivity in later timing boys was related to a composite index of antisocial behaviour and rule-breaking behaviour problems. In contrast, lower sAA reactivity and earlier timing of puberty in boys was related to rule breaking and conduct disorder symptoms. The interaction between timing of puberty and HPA or SAM regulation and timing of puberty in boys suggests that reproductive, neuroendocrine mechanisms may be involved in the extensively documented adverse consequences of off-time pubertal development. PMID:19819639

Cortisol and alpha amylase reactivity and timing of puberty: vulnerabilities for antisocial behaviour in young adolescents.

PubMed

Susman, Elizabeth J; Dockray, Samantha; Granger, Douglas A; Blades, Keeva T; Randazzo, William; Heaton, Jodi A; Dorn, Lorah D

2010-05-01

The theoretical framework proposed that cortisol and saliva alpha amylase (sAA) reactivitiy are vulnerabilities for antisocial behaviour. These indices of hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenal-medulary (SAM) components of the stress system, respectively, were considered vulnerabilities that also interact with the putative stressful transition of timing of puberty to predispose adolescents toward antisocial behaviour. The sample consisted of 8- to-13-year-old boys and girls (N=135) and a parent. For boys, timing of puberty moderated the association between cortisol and sAA reactivity and antisocial behaviour. Higher cortisol reactivity in later timing boys was related to a composite index of antisocial behaviour and rule-breaking behaviour problems. In contrast, lower sAA reactivity and earlier timing of puberty in boys was related to rule breaking and conduct disorder symptoms. The interaction between timing of puberty and HPA or SAM regulation and timing of puberty in boys suggests that reproductive, neuroendocrine mechanisms may be involved in the extensively documented adverse consequences of off-time pubertal development. Copyright 2009 Elsevier Ltd. All rights reserved.

Do internationally adopted children in the Netherlands use more medication than their non-adopted peers?

PubMed

van Ginkel, Joost R; Juffer, Femmie; Bakermans-Kranenburg, Marian J; van IJzendoorn, Marinus H

2016-05-01

Empirical evidence has shown that international adoptees present physical growth delays, precocious puberty, behavioral problems, and mental health referrals more often than non-adoptees. We hypothesized that the higher prevalence of (mental) health problems in adoptees is accompanied by elevated consumption of prescription drugs, including antidepressants, attention deficit hyperactivity disorder (ADHD) medication, and medication for growth inhibition/stimulation. In an archival, population-based Dutch cohort study, data on medication use were available from the Health Care Insurance Board by Statistics Netherlands from 2006 to 2011. The Dutch population born between 1994 and 2005 and alive during the period of measurement was included (2,360,450 including 10,602 international adoptees, of which 4447 from China). Their mean age was 6.5 years at start (range 1-12 years) and 11.5 years at the end of the measurement period (range 6-17 years). Chinese female adoptees used less medication for precocious puberty (as treatment for precocious puberty; odds ratio (OR) = 0.57, effect size Cohen's d = -0.31) and contraception (OR = 0.65, d = -0.24) than non-adoptees. For both males and females, non-Chinese adoptees used more medication for ADHD than non-adoptees (males: OR = 1.22, females: OR = 1.32), but the effect was small (males: d = 0.11, females: d = 0.15). Adoptees in the Netherlands generally do not use more medication than their non-adopted peers. • Meta-analytical evidence shows that international adoptees present physical growth delays and mental health referrals more often than non-adopted controls. • With the exception of one Swedish study on ADHD medication, there is no other systematic research on medication use of international adoptees. What is New: • All differences in medication use between international adoptees in the Netherlands and non-adopted controls were below the threshold of a small effect with the exception of medication for precocious puberty, but this effect was in the opposite direction with female adoptees using less medication for precocious puberty than non-adoptees. • International adoptees in the Netherlands do not use more medication despite experiences of preadoption adversity and higher rates of mental health referrals during childhood and adolescence.

The potential link between sugar-sweetened beverage consumption and post-exercise airway narrowing across puberty: a longitudinal cohort study.

PubMed

Emerson, Sam R; Rosenkranz, Sara K; Rosenkranz, Richard R; Kurti, Stephanie P; Harms, Craig A

2016-09-01

The prevalence of asthma is rising, presenting serious public health challenges. Recent data suggest that sugar-sweetened beverage (SSB) consumption plays a role in asthma aetiology. The purpose of the present study was to determine whether SSB consumption is linked to post-exercise airway narrowing (predictor of asthma development) across puberty. Participants completed pulmonary function tests, physical activity and dietary habit questionnaires, and an exercise test to exhaustion. Community in Manhattan, Kansas, USA. We recruited ten boys and ten girls from an original cohort of forty participants tested in our laboratory approximately 5 years prior. Participants were aged 9·7 (sd 0·9) years at baseline and 14·7 (sd 0·9) years at follow-up. Pre-puberty, boys consumed 6·8 (sd 4·8) servings/week and girls consumed 6·9 (sd 3·7) servings/week, while post-puberty boys consumed 11·5 (sd 5·3) servings/week and girls consumed 7·7 (sd 4·3) servings/week. Using Pearson correlation, SSB consumption was not significantly related to post-exercise airway narrowing at pre-puberty (r=-0·35, P=0·130). In linear regression analyses, SSB consumption was significantly related to post-exercise airway narrowing post-puberty before (standardized β=-0·60, P=0·005) but not after (standardized β=-0·33, P=0·211) adjustment for confounders. Change in SSB consumption from pre- to post-puberty was significantly associated with post-exercise airway narrowing post-puberty (r=-0·61, P=0·010) and change in post-exercise airway narrowing from pre- to post-puberty (r=-0·45, P=0·048) when assessed via Pearson correlations. These findings suggest a possible link between SSB consumption and asthma development during maturation. Reduced SSB intake may be a possible public health avenue for blunting rising asthma prevalence.

The study design and methodology for the ARCHER study - adolescent rural cohort study of hormones, health, education, environments and relationships

PubMed Central

2012-01-01

Background Adolescence is characterized by marked psychosocial, behavioural and biological changes and represents a critical life transition through which adult health and well-being are established. Substantial research confirms the role of psycho-social and environmental influences on this transition, but objective research examining the role of puberty hormones, testosterone in males and oestradiol in females (as biomarkers of puberty) on adolescent events is lacking. Neither has the tempo of puberty, the time from onset to completion of puberty within an individual been studied, nor the interaction between age of onset and tempo. This study has been designed to provide evidence on the relationship between reproductive hormones and the tempo of their rise to adult levels, and adolescent behaviour, health and wellbeing. Methods/Design The ARCHER study is a multidisciplinary, prospective, longitudinal cohort study in 400 adolescents to be conducted in two centres in regional Australia in the State of New South Wales. The overall aim is to determine how changes over time in puberty hormones independently affect the study endpoints which describe universal and risk behaviours, mental health and physical status in adolescents. Recruitment will commence in school grades 5, 6 and 7 (10–12 years of age). Data collection includes participant and parent questionnaires, anthropometry, blood and urine collection and geocoding. Data analysis will include testing the reliability and validity of the chosen measures of puberty for subsequent statistical modeling to assess the impact over time of tempo and onset of puberty (and their interaction) and mean-level repeated measures analyses to explore for significant upward and downward shifts on target outcomes as a function of main effects. Discussion The strengths of this study include enrollment starting in the earliest stages of puberty, the use of frequent urine samples in addition to annual blood samples to measure puberty hormones, and the simultaneous use of parental questionnaires. PMID:22950846

NELL2 participates in formation of the sexually dimorphic nucleus of the pre-optic area in rats.

PubMed

Jeong, Jin Kwon; Ryu, Byung Jun; Choi, Jungil; Kim, Dong Hee; Choi, Eun Jung; Park, Jeong Woo; Park, Joong Jean; Lee, Byung Ju

2008-08-01

Formation of the sexually dimorphic nucleus of the pre-optic area (SDN-POA) in the rat hypothalamus shows a sexually differential development of neurons. Volume of the SDN-POA in males is much bigger than that in females which is because of a neuroprotective effect of estradiol converted from circulating testosterone during a critical period of brain development. We found that neural epidermal growth factor-like like-2 (NELL2), a neural tissue-enriched protein, is a potential downstream target of estrogen. In this study, we examined a possible role of NELL2 in the development of the SDN-POA and in the normalcy of sexual behavior in the male rats. NELL2 was expressed and co-localized with estrogen receptor alpha in the SDN-POA. A blockade of NELL2 synthesis in the brain during postnatal day 0 (d0) to d4 by an intracerebroventricular injection of an antisense NELL2 oligodeoxynucleotide, resulted in a decrease in volume of the SDN-POA in males. Interestingly, it reduced some components of the male sexual behavior such as mounting and intromission, but not the sexual partner preference in adulthood. In vitro study using the hippocampal neuroprecursor HiB5 cells showed that NELL2 has a protective effect from a cell death condition. These data suggest that a relevant expression of NELL2 in the neonatal brain is important for the estrogen-induced normal development of the SDN-POA and the normalcy of sexual behavior in male rats.

Detection of pup odors by non-canonical adult vomeronasal neurons expressing an odorant receptor gene is influenced by sex and parenting status.

PubMed

Nakahara, Thiago S; Cardozo, Leonardo M; Ibarra-Soria, Ximena; Bard, Andrew D; Carvalho, Vinicius M A; Trintinalia, Guilherme Z; Logan, Darren W; Papes, Fabio

2016-02-15

Olfaction is a fundamental sense through which most animals perceive the external world. The olfactory system detects odors via specialized sensory organs such as the main olfactory epithelium and the vomeronasal organ. Sensory neurons in these organs use G-protein coupled receptors to detect chemosensory stimuli. The odorant receptor (OR) family is expressed in sensory neurons of the main olfactory epithelium, while the adult vomeronasal organ is thought to express other types of receptors. Here, we describe Olfr692, a member of the OR gene family identified by next-generation RNA sequencing, which is highly upregulated and non-canonically expressed in the vomeronasal organ. We show that neurons expressing this gene are activated by odors emanating from pups. Surprisingly, activity in Olfr692-positive cells is sexually dimorphic, being very low in females. Our results also show that juvenile odors activate a large number of Olfr692 vomeronasal neurons in virgin males, which is correlated with the display of infanticide behavior. . In contrast, activity substantially decreases in parenting males (fathers), where infanticidal aggressive behavior is not frequently observed. Our results describe, for the first time, a sensory neural population with a specific molecular identity involved in the detection of pup odors. Moreover, it is one of the first reports of a group of sensory neurons the activity of which is sexually dimorphic and depends on social status. Our data suggest that the Olfr692 population is involved in mediating pup-oriented behaviors in mice.

Dimorphic ejaculates and sperm release strategies associated with alternative mating behaviors in the squid.

PubMed

Apostólico, Lígia H; Marian, José E A R

2017-11-01

Sperm competition is a powerful postcopulatory selective force influencing male adaptations associated with increasing fertilization success, and it is usually related to the evolution of different strategies of ejaculate expenditure between individuals. Ejaculates may also be influenced by additional selective pressures associated with sperm competition, such as timing between insemination and fertilization, female reproductive tract morphology, and fertilization environment. Also, males that adopt alternative mating tactics may face distinct sperm competition pressures, which may lead to the evolution of intraspecific diversity in ejaculates. In loliginid squids, males with alternative reproductive tactics (sneakers and consorts) differ not only in mating behavior, but also transfer spermatophores into two distinct sites within the female. Here, we compared structure and functioning of spermatophores between sneakers and consorts in the squid Doryteuthis plei applying microscopy techniques and in vitro experiments. Sneakers and consorts exhibit differences in spermatophore structure that lead to distinct spermatophoric reactions and spermatangium morphologies. Moreover, in sneakers, sperm release lasts longer and their sperm show an aggregative behavior not detected in consorts. Slow sperm release may be a strategy to guarantee longer sperm provision, given the wide interval between sneaker mating and egg release. For consorts, in turn, intense and quick sperm discharge may be advantageous, as timing between mating and egg-laying is relatively short. Within the complex squid mating system, factors such as (i) different fertilization sites and (ii) interval between mating and egg release may also influence sperm competition, and ultimately shape the evolution of divergent ejaculates between dimorphic males. © 2017 Wiley Periodicals, Inc.

Promiscuity is related to masculine and feminine body traits in both men and women: evidence from Brazilian and Czech samples.

PubMed

Varella, Marco Antonio Correa; Valentova, Jaroslava Varella; Pereira, Kamila Janaina; Bussab, Vera Silvia Raad

2014-11-01

One of the possible explanations for human within-sex variation in promiscuity stems from conditional strategies dependent on the level of body sex-dimorphism. There is some evidence that masculine men and feminine women are more promiscuous than their sex-atypical counterparts, although mixed results persist. Moreover, another line of evidence shows that more promiscuous women are rather sex-atypical. We tested whether diverse sex-dimorphic body measures (2D:4D, WHR/WSR, handgrip strength, and height and weight) influence sociosexual desires, attitudes, promiscuous behavior, and age of first intercourse in a sex-typical or sex-atypical direction. Participants were 185 young adults, 51 men and 54 women from Brazil, and 40 men and 40 women from the Czech Republic. In men stronger handgrip and more feminine 2D:4D predicted higher sociosexual behaviors, desires, and lower age of the first sexual intercourse. While in women, sociosexual desires were predicted by lower handgrip strength and more feminine 2D:4D. It thus seems that it is rather a mixture of masculine and feminine traits in men, and feminine traits in women that increase their sociosexuality. Masculine traits (height) predicting female promiscuous behavior were specific for only one population. In conclusion, a mosaic combination of sex-typical but also sex-atypical independent body traits can lead to higher promiscuity, particularly in men. Limitations, implications, and future directions for research are considered. This article is part of a Special Issue entitled: Neotropical Behaviour. Copyright © 2014 Elsevier B.V. All rights reserved.

Does salt have a permissive role in the induction of puberty?

PubMed

Pitynski, Dori; Flynn, Francis W; Skinner, Donal C

2015-10-01

Puberty is starting earlier than ever before and there are serious physiological and sociological implications as a result of this development. Current research has focused on the potential role of high caloric, and commensurate high adiposity, contributions to early puberty. However, girls with normal BMI also appear to be initiating puberty earlier. Westernized diets, in addition to being high in fat and sugar, are also high in salt. To date, no research has investigated a link between elevated salt and the reproductive axis. We hypothesize that a high salt diet can result in an earlier onset of puberty through three mechanisms that are not mutually exclusive. (1) High salt activates neurokinin B, a hormone that is involved in both the reproductive axis and salt regulation, and this induces kisspeptin release and ultimate activation of the reproductive axis. (2) Vasopressin released in response to high salt acts on vasopressin receptors expressed on kisspeptin neurons in the anteroventral periventricular nucleus, thereby stimulating gonadotropin releasing hormone and subsequently luteinizing hormone secretion. (3) Salt induces metabolic changes that affect the reproductive axis. Specifically, salt acts indirectly to modulate adiposity, ties in with the obesity epidemic, and further compounds the pathologic effects of obesity. Our overall hypothesis offers an additional cause behind the induction of puberty and provides testable postulates to determine the mechanism of potential salt-mediated affects on puberty. Copyright © 2015. Published by Elsevier Ltd.

Puberty timing associated with diabetes, cardiovascular disease and also diverse health outcomes in men and women: the UK Biobank study.

PubMed

Day, Felix R; Elks, Cathy E; Murray, Anna; Ong, Ken K; Perry, John R B

2015-06-18

Early puberty timing is associated with higher risks for type 2 diabetes (T2D) and cardiovascular disease in women and therefore represents a potential target for early preventive interventions. We characterised the range of diseases and other adverse health outcomes associated with early or late puberty timing in men and women in the very large UK Biobank study. Recalled puberty timing and past/current diseases were self-reported by questionnaire. We limited analyses to individuals of White ethnicity (250,037 women; 197,714 men) and to disease outcomes with at least 500 cases (~ 0.2% prevalence) and we applied stringent correction for multiple testing (corrected threshold P < 7.48 × 10(-5)). In models adjusted for socioeconomic position and adiposity/body composition variables, both in women and men separately, earlier puberty timing was associated with higher risks for angina, hypertension and T2D. Furthermore, compared to the median/average group, earlier or later puberty timing in women or men was associated with higher risks for 48 adverse outcomes, across a range of cancers, cardio-metabolic, gynaecological/obstetric, gastrointestinal, musculoskeletal, and neuro-cognitive categories. Notably, both early and late menarche were associated with higher risks for early natural menopause in women. Puberty timing in both men and women appears to have a profound impact on later health.

Does salt have a permissive role in the induction of puberty?

PubMed Central

Pitynski, Dori; Flynn, Francis W.; Skinner, Donal C.

2017-01-01

Puberty is starting earlier than ever before and there are serious physiological and sociological implications as a result of this development. Current research has focused on the potential role of high caloric, and commensurate high adiposity, contributions to early puberty. However, girls with normal BMI also appear to be initiating puberty earlier. Westernized diets, in addition to being high in fat and sugar, are also high in salt. To date, no research has investigated a link between elevated salt and the reproductive axis. We hypothesize that a high salt diet can result in an earlier onset of puberty through three mechanisms that are not mutually exclusive. (1) High salt activates neurokinin B, a hormone that is involved in both the reproductive axis and salt regulation, and this induces kisspeptin release and ultimate activation of the reproductive axis. (2) Vasopressin released in response to high salt acts on vasopressin receptors expressed on kisspeptin neurons in the anteroventral periventricular nucleus, thereby stimulating gonadotropin releasing hormone and subsequently luteinizing hormone secretion. (3) Salt induces metabolic changes that affect the reproductive axis. Specifically, salt acts indirectly to modulate adiposity, ties in with the obesity epidemic, and further compounds the pathologic effects of obesity. Our overall hypothesis offers an additional cause behind the induction of puberty and provides testable postulates to determine the mechanism of potential salt-mediated affects on puberty. PMID:26190310

Puberty without gonadotropins. A unique mechanism of sexual development.

PubMed

Wierman, M E; Beardsworth, D E; Mansfield, M J; Badger, T M; Crawford, J D; Crigler, J F; Bode, H H; Loughlin, J S; Kushner, D C; Scully, R E

1985-01-10

Recent evidence suggests that a group of children exists in whom premature sexual maturation occurs in the absence of pubertal levels of gonadotropins; that is, they have gonadotropin-independent precocious puberty. We compared six boys and one girl with this disorder with four boys and five girls with central precocious puberty, in which there is a pubertal pattern of gonadotropin release. The two groups were similar in age of onset, degree of sexual development, growth velocity, and rate of skeletal maturation. A family history of precocity was noted in four of the boys with gonadotropin-independent precocity, and the girl had McCune-Albright syndrome. Children with central precocious puberty demonstrated a pulsatile release of gonadotropins, pubertal responses to luteinizing hormone-releasing hormone, and complete suppression of gonadarche after exposure to an analogue of luteinizing hormone-releasing hormone (LHRHa). In contrast, children with gonadotropin-independent precocity demonstrated an absence of gonadotropin pulsations, variable responses to luteinizing hormone-releasing hormone, lack of suppression of puberty in response to LHRHa, and cyclic steroidogenesis. Tissue from testicular biopsies performed in five of six boys with gonadotropin-independent precocity showed a range from incipient pubertal development of the tubules with proliferation of Leydig cells to the appearance of normal adult testes. We conclude that gonadotropin-independent precocious puberty is a distinct syndrome, of unknown cause, that may be familial and may have been responsible for many previously reported cases of precocious puberty.

The experience of puberty in Iranian adolescent girls: a qualitative content analysis

PubMed Central

2012-01-01

Background Adolescence is an important stage in human life span. Physiologic changes associated with puberty manifest themselves in often complex and bizarre ways to which girls show different reactions. This study aims to explore to puberty experiences in adolescent girls who live in the city of Sari in Iran. Methods The present study is a qualitative study of content analysis. Sampling took place in the city of Sari, Iran and was objective focused in accordance with qualitative studies. Participants were 38 girls of 12–20 years old who had at least experienced 3 menstrual cycles. Data was collected by means of focus group and in-depth interviews. Results As follows, Seven main themes were extracted from the interviews are follows: Menarche as the most unpleasant event in puberty, getting nervous about and ashamed of bodily changes, psychological changes, discordance with parents, sexual orientation and the need for education on this issue, scholastic dysfunction and religious considerations. Conclusion The results showed that for the majority of the participants puberty was an unpleasant experience. Most of them were in need of education on how to go about the issues surrounding puberty. The society, families and of course the adolescents themselves are responsible to work together in order to create an atmosphere in which correct information on puberty and the associated issues are readily accessible. PMID:22925369

The roles of age at puberty and energy restriction in sow reproductive longevity: a genomic perspective

USDA-ARS?s Scientific Manuscript database

Approximately 50% of sows are culled annually with more than one third due to poor fertility. Our research demonstrated that age at puberty is an early pre-breeding indicator of reproductive longevity. Age at puberty can be measured early in life, has a moderate heritability and is negatively correl...

UNESCO's Guidance on Puberty and Sexual Health Education for Students Aged 9-12 Years Compared to an Upper Primary School Curriculum

ERIC Educational Resources Information Center

Goldman, Juliette D. G.

2015-01-01

Background: Children and young adolescents are reaching puberty earlier. Providing information about such changes before puberty can help them develop in a more competent and informed manner. Context and Objective: UNESCO's "International Technical Guidance on Sexuality Education" forms a comprehensive, evidence-based, authoritative…

Primary School Puberty/Sexuality Education: Student-Teachers' Past Learning, Present Professional Education, and Intention to Teach These Subjects

ERIC Educational Resources Information Center

Goldman, Juliette D. G.; Coleman, Stephanie J.

2013-01-01

Primary school teachers are often tasked with puberty/sexuality education for students who are undergoing sexual maturation at ever-earlier ages. This study explores the changing trajectories of the pre-service learning and teaching of primary school puberty/sexuality education at an urban university, including student-teachers' childhood…

Distress and Violent Victimization among Young Adolescents: Early Puberty and the Social Interactionist Explanation

ERIC Educational Resources Information Center

Schreck, Christopher J.; Burek, Melissa W.; Stewart, Eric A.; Miller, J. Mitchell

2007-01-01

This article explores the empirical validity of the Social Interactionist (SI) perspective as an explanation of violent victimization. An additional goal is to explain why early puberty among adolescents is connected to violent victimization. Using SI, we theorize that early puberty creates unusually high levels of distress for adolescents (more…

What Do Preservice Teachers Want to Learn about Puberty and Sexuality Education? An Australian Perspective

ERIC Educational Resources Information Center

Goldman, Juliette D. G.; Grimbeek, Peter

2016-01-01

The processes of puberty are now commonly observed in primary school-aged students. Schools, therefore, need to address puberty and sexuality education for students' health, well-being, safety and pastoral care. Similarly, preservice teacher education needs to address future primary school teachers' unfamiliarity and lack of confidence with these…

The role of puberty, media and popularity with peers on strategies to increase weight, decrease weight and increase muscle tone among adolescent boys and girls.

PubMed

McCabe, Marita P; Ricciardelli, Lina A; Finemore, Jennifer

2002-03-01

The present study was concerned with the impact of pubertal development, relationships with peers and perceived pressure from the media on body dissatisfaction and body change behaviors among adolescent boys and girls. In particular, the study investigated the underresearched area of strategies to increase weight and muscle. The exploration of body change strategies among adolescent boys has been a neglected area of research. Respondents were 1185 adolescents (527 males, 598 females) who were enrolled in Grades 7 and 9. Participants completed measures of pubertal development, media and peer influence, body dissatisfaction and strategies to lose weight, increase weight and to increase muscle. The findings demonstrated that girls were more likely than boys to adopt strategies to lose weight, whereas boys were more likely to adopt strategies to increase muscle tone (but not weight). For boys in both Years 7 and 9, the main predictors of body change strategies were puberty and, to a lesser extent, perceived popularity with peers. The major influences for Years 7 and 9 girls were puberty and the media, but these mainly focused on weight loss. For Year 9 girls, perceived popularity with opposite-sex peers also predicted body dissatisfaction and strategies to increase muscle tone. The implications of these findings for understanding factors related to a range of body change strategies for adolescent boys and girls are discussed.

Influence of male morphology on male mating status and behavior during interunit encounters in western lowland gorillas.

PubMed

Caillaud, Damien; Levréro, Florence; Gatti, Sylvain; Ménard, Nelly; Raymond, Michel

2008-04-01

The western lowland gorilla (Gorilla gorilla gorilla) is one of the most sexually dimorphic primate species. Mature males are twice the size of females and have grey fur on their backs and a fibrous, adipose crest on their heads. Such traits are likely to have evolved by sexual selection, either because they confer advantages during male-male fights or because females prefer males with more dimorphic traits. We developed photogrammetric methods for distance collection of morphological data from silverback males frequenting the Lokoué forest clearing in Odzala-Kokoua National Park, Republic of the Congo. Body length, head-crest size, musculature development, and extent of the grey color on the back were assessed in 87 nonbreeding and breeding mature males. Behavioral data were also collected during 312 male-male encounters involving 67 mature males in order to estimate their level of aggressiveness. The number of females belonging to a mature male positively correlated with the male crest size, body length, and musculature. Whereas morphological variables did not significantly affect the intensity of male-male encounters, the number of females attending male-male encounters strongly affected the number of agonistic displays by the two males. We discuss the mechanisms through which males with more exaggerated traits could obtain a mating advantage, namely male-male fights or female mate choice. (c) 2007 Wiley-Liss, Inc.

Stability of upper face sexual dimorphism in central European populations (Czech Republic) during the modern age.

PubMed

Bejdová, Šárka; Dupej, Ján; Krajíček, Václav; Velemínská, Jana; Velemínský, Petr

2018-01-01

One of the most fundamental issues in forensic anthropology is the determination of sex and population affinity based on various skeletal elements. Therefore, we compared the sexual dimorphism of the upper facial skeleton from a recent Czech population (twenty-first century) with that of a population from Early Modern Age Bohemia (sixteenth to eighteenth centuries). Methods of geometric morphometrics were applied. According to the results, sexual dimorphism in terms of size, shape, and form was statistically significant in both populations. The best results of sex estimation originated from analyses of form. Thus, both size and shape differences should be taken into account for determination of the sex. The accuracy of prediction achieved 91.1% for individuals in the recent population and 87.5% for individuals from the early modern population. Only minor differences were found between sexual dimorphism in the studied populations. We conclude that sexual dimorphism of the upper facial skeleton is stable during the relatively short time period.

Timing of puberty and physical growth in obese children: a longitudinal study in boys and girls.

PubMed

De Leonibus, C; Marcovecchio, M L; Chiavaroli, V; de Giorgis, T; Chiarelli, F; Mohn, A

2014-08-01

To assess whether puberty and physical growth vary in obese when compared to normal-weight children. One hundred obese pre-pubertal children (44 boys; mean age (±SD): 9.01 ± 0.62 years; 56 girls; 8.70 ± 0.57 years) were compared to 55 normal-weight controls (27 boys; 9.17 ± 0.26 years; 28 girls; 8.71 ± 0.62 years). All study participants were followed prospectively with 6-monthly follow-up visits. At each study visit, height, weight, body mass index (BMI) and pubertal stage were assessed. Obese children entered puberty and achieved later stages of puberty earlier than controls (onset of puberty: boys: 11.66 ± 1.00 vs. 12.12 ± 0.91 years, P = 0.049; girls: 9.90 ± 0.78 vs. 10.32 ± 1.70, P = 0.016; late puberty: boys: 13.33 ± 0.71 vs. 14.47 ± 1.00 years, P < 0.001; girls: 11.54 ± 0.99 vs. 12.40 ± 1.02, P = 0.001). Pre-pubertal BMI standard deviation score (SDS) was inversely associated with both age at the onset of puberty (β = -0.506, P < 0.001) and age at late puberty (β = -0.514, P < 0.001). Obese children also showed an earlier age at peak height velocity (PHV) (boys: 12.62 ± 0.82 vs. 13.19 ± 0.96 years, P = 0.01; girls: 11.37 ± 0.89 vs. 12.77 ± 0.76, P < 0.001) and a lower PHV (boys: 7.74 ± 1.49 vs. 9.28 ± 1.64 cm year(-1) , P < 0.001; girls: 7.60 ± 1.64 vs. 8.29 ± 1.03, P = 0.03). Height SDS progressively declined over the study period in the obese group (P for trend <0.001), whereas there were no significant changes in the control group (P for trend = 0.5). Obese boys and girls presented an earlier onset of puberty and completion of puberty and an impaired height gain during puberty. © 2013 The Authors. Pediatric Obesity © 2013 International Association for the Study of Obesity.

BMI change during puberty and the risk of heart failure.

PubMed

Kindblom, J M; Bygdell, M; Sondén, A; Célind, J; Rosengren, A; Ohlsson, C

2018-03-12

Hospitalization for heart failure amongst younger men has increased. The reason for this is unknown but it coincides with the obesity epidemic. The aim of this study was to evaluate the association between childhood BMI (Body Mass Index) and BMI change during puberty for risk of adult heart failure in men. Using the BMI Epidemiology Study (BEST), a population-based study in Gothenburg, Sweden, we collected information on childhood BMI at age 8 years and BMI change during puberty (BMI at age 20 - BMI at 8) for men born 1945-1961, followed until December 2013 (n = 37 670). BMI was collected from paediatric growth charts and mandatory military conscription tests. Information on heart failure was retrieved from high-quality national registers (342 first hospitalizations for heart failure). BMI change during puberty was independently of childhood BMI associated with risk of heart failure in a nonlinear J-shaped manner. Subjects in the upper quartile of BMI change during puberty (Q4) had more than twofold increased risk of heart failure compared with subjects in Q1 [HR (Hazard Ratio) = 2.29, 95% CI (Confidence Interval) 1.68-3.12]. Childhood BMI was not independently associated with risk of heart failure. Boys developing overweight during puberty (HR 3.14; 95% CI 2.25-4.38) but not boys with childhood overweight that normalized during puberty (HR 1.12, 95% CI 0.63-2.00) had increased risk of heart failure compared with boys without childhood or young adult overweight. BMI change during puberty is a novel risk factor for adult heart failure in men. © 2018 The Association for the Publication of the Journal of Internal Medicine.

[Genetic study on somatotype of child and adolescent twins in Han nationality].

PubMed

Li, Yu-Ling; Ji, Cheng-Ye; Lu, Shun-Hua; Suo, Li-Ya; Chen, Tian-Jiao

2006-11-01

To assess the genetic and environmental influences on the somatotype of children and adolescents, and the effects of sex and age. The components of somatotype were calculated by using Heather-Cater method in a total of 376 twin pairs of Han nationality, including 245 monozygotic (MZ) and 131 like-sex dizygotic (DZ) twin pairs aged 6 to 18 years. Model-fitting method by Mx package was performed to evaluate the proportion of variance components and to analyze the effects of sex and age on each component of somatotype using the adjusted data for other two somatotype components. The heritability of each component in different development periods divided by growth spurt was also evaluated. The estimated heritabilities of endomorphic, mesomorphic and ectomorphic components were 0.45, 0.80, 0.44 in boys, 0.82, 0.79 and 0.81 in girls respectively after adjusting age. In boys, the heritability of endomorphic component during late puberty was significantly higher than that during pre-puberty (t = 4.99, P < 0.01) and puberty (t = 6.16, P < 0.01), while the heritability of ectomorphic component during late puberty was significantly lower than that during pre-puberty (t = 3.35, P < 0.01) and puberty (t = 4.12, P < 0.01). In girls, the heritability of endomorphic (t = 2.77, P < 0.01) or mesomorphic (t = 2.08, P < 0.05) component during pre-puberty was significantly higher than that in early puberty. The genetic influence on somatotype of girls should be much more than that of boys, especially on the endomorphic and ectomorphic components. For boys, the mesomorphic component is mainly determined by genetic factors, but the other components are mainly affected by environmental ones. The effects of the development periods on the heritability of somatotype should be paid much attention to.

Nocturnal Urinary Excretion of FSH and LH in Children and Adolescents With Normal and Early Puberty.

PubMed

Kolby, Nanna; Busch, Alexander S; Aksglaede, Lise; Sørensen, Kaspar; Petersen, Jorgen Holm; Andersson, Anna-Maria; Juul, Anders

2017-10-01

Clinical use of single serum gonadotropin measurements in children is limited by the pulsatile secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). However, first morning voided (FMV) urine may integrate the fluctuating gonadotropin serum levels. We aimed to evaluate urinary and serum gonadotropin levels according to age, sex, and pubertal stage in healthy children and to assess the clinical use of FMV urinary gonadotropins in children with disordered puberty. Cross-sectional part of the COPENHAGEN Puberty Study and longitudinal study of patients. Population-based and outpatient clinic. Eight hundred forty-three healthy children from the COPENHAGEN Puberty Study and 25 girls evaluated for central precocious puberty (CPP). Clinical pubertal staging, including serum and urinary gonadotropin levels. Urinary gonadotropins increased with advancing age and pubertal development and were detectable in FMV urine before physical signs of puberty. FMV urinary LH correlated strongly with basal (r = 0.871, P < 0.001) and gonadotropin-releasing hormone (GnRH)-stimulated serum LH (r = 0.82, P < 0.001). Urinary LH was superior to urinary FSH in differentiating the pubertal stage. Receiver operating curve analysis revealed that a cut-off standard deviation (SD) score of 2 for urinary LH (IU/L) gave a sensitivity of 75% and a specificity of 92% in predicting a positive GnRH stimulation test (LHmax > 5 IU/L). Urinary concentrations of LH decreased after 3 months of GnRH treatment to levels below +2 SDs. Urinary gonadotropin levels increased before the onset of puberty and were elevated in girls with CPP. We suggest urinary LH as an alternative noninvasive method to improve diagnosing and therapeutic management of children with disordered puberty. Copyright © 2017 Endocrine Society

High-Throughput Sequencing Reveals Circulating miRNAs as Potential Biomarkers for Measuring Puberty Onset in Chicken (Gallus gallus).

PubMed

Han, Wei; Zhu, Yunfen; Su, Yijun; Li, Guohui; Qu, Liang; Zhang, Huiyong; Wang, Kehua; Zou, Jianmin; Liu, Honglin

2016-01-01

There are still no highly sensitive and unique biomarkers for measurement of puberty onset. Circulating miRNAs have been shown to be promising biomarkers for diagnosis of various diseases. To identify circulating miRNAs that could be served as biomarkers for measuring chicken (Gallus gallus) puberty onset, the Solexa deep sequencing was performed to analyze the miRNA expression profiles in serum and plasma of hens from two different pubertal stages, before puberty onset (BO) and after puberty onset (AO). 197 conserved and 19 novel miRNAs (reads > 10) were identified as serum/plasma-expressed miRNAs in the chicken. The common miRNA amounts and their expression changes from BO to AO between serum and plasma were very similar, indicating the different treatments to generate serum and plasma had quite small influence on the miRNAs. 130 conserved serum-miRNAs were showed to be differentially expressed (reads > 10, P < 0.05) from BO to AO, with 68 up-regulated and 62 down-regulated. 4829 putative genes were predicted as the targets of the 40 most differentially expressed miRNAs (|log2(fold-change)|>1.0, P < 0.01). Functional analysis revealed several pathways that were associated with puberty onset. Further quantitative real-time PCR (RT-qPCR) test found that a seven-miRNA panel, including miR-29c, miR-375, miR-215, miR-217, miR-19b, miR-133a and let-7a, had great potentials to serve as novel biomarkers for measuring puberty onset in chicken. Due to highly conserved nature of miRNAs, the findings could provide cues for measurement of puberty onset in other animals as well as humans.

High-Throughput Sequencing Reveals Circulating miRNAs as Potential Biomarkers for Measuring Puberty Onset in Chicken (Gallus gallus)

PubMed Central

Su, Yijun; Li, Guohui; Qu, Liang; Zhang, Huiyong; Wang, Kehua; Zou, Jianmin; Liu, Honglin

2016-01-01

There are still no highly sensitive and unique biomarkers for measurement of puberty onset. Circulating miRNAs have been shown to be promising biomarkers for diagnosis of various diseases. To identify circulating miRNAs that could be served as biomarkers for measuring chicken (Gallus gallus) puberty onset, the Solexa deep sequencing was performed to analyze the miRNA expression profiles in serum and plasma of hens from two different pubertal stages, before puberty onset (BO) and after puberty onset (AO). 197 conserved and 19 novel miRNAs (reads > 10) were identified as serum/plasma-expressed miRNAs in the chicken. The common miRNA amounts and their expression changes from BO to AO between serum and plasma were very similar, indicating the different treatments to generate serum and plasma had quite small influence on the miRNAs. 130 conserved serum-miRNAs were showed to be differentially expressed (reads > 10, P < 0.05) from BO to AO, with 68 up-regulated and 62 down-regulated. 4829 putative genes were predicted as the targets of the 40 most differentially expressed miRNAs (|log2(fold-change)|>1.0, P < 0.01). Functional analysis revealed several pathways that were associated with puberty onset. Further quantitative real-time PCR (RT-qPCR) test found that a seven-miRNA panel, including miR-29c, miR-375, miR-215, miR-217, miR-19b, miR-133a and let-7a, had great potentials to serve as novel biomarkers for measuring puberty onset in chicken. Due to highly conserved nature of miRNAs, the findings could provide cues for measurement of puberty onset in other animals as well as humans. PMID:27149515

Developmental Timing of Trauma Exposure Relative to Puberty and the Nature of Psychopathology Among Adolescent Girls.

PubMed

Marshall, Amy D

2016-01-01

Increased neuroplasticity and neural development during puberty provide a context for which stress and trauma can have dramatic and long-lasting effects on psychological systems; therefore, this study was designed to determine whether exposure to potentially traumatic events during puberty uniquely predicts adolescent girls' psychopathology. Because neural substrates associated with different forms of psychopathology seemingly develop at different rates, the possibility that the developmental timing of trauma relative to puberty predicts the nature of psychopathology (posttraumatic stress disorder [PTSD], depressive, and anxiety disorders) was examined. A subset of 2,899 adolescent girls from the National Comorbidity Survey Replication-Adolescent Supplement who completed the study 2+ years postmenarche was selected. Past-year psychiatric disorders and reports of age of trauma exposure were assessed using the Composite International Diagnostic Interview. Developmental stages were defined as the 2 years after the year of menarche ("postpuberty"), 3 years before and year of menarche ("puberty"), 2 to 6 years before the puberty period ("grade school"), and 4 to 5 years after birth ("infancy-preschool"). Compared to other developmental periods, trauma during puberty conferred significantly more risk (50.47% of model R(2)) for girls' past-year anxiety disorder diagnoses (primarily social phobia), whereas trauma during the grade school period conferred significantly more risk (47.24% of model R(2)) for past-year depressive disorder diagnoses. Recency of trauma best predicted past-year PTSD diagnoses. Supporting rodent models, puberty may be a sensitive period for the impact of trauma on girls' development of an anxiety disorder. Trauma prepuberty or postpuberty distinctly predicts depression or PTSD, suggesting differential etiological processes. Copyright © 2016 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Postnatal risk factors for testicular cancer: The EPSAM case-control study.

PubMed

Moirano, Giovenale; Zugna, Daniela; Grasso, Chiara; Mirabelli, Dario; Lista, Patrizia; Ciuffreda, Libero; Segnan, Nereo; Merletti, Franco; Richiardi, Lorenzo

2017-11-01

Testicular cancer is considered to originate from an impaired differentiation of fetal germ cells, but puberty could represent another time window of susceptibility. Our study aimed at investigating the association between environmental exposures acting during puberty/adolescence (13-19 years of age) and the risk of testicular cancer. We used data of the EPSAM study, a case-control study on germ-cell testicular cancer conducted in the province of Turin, Italy, involving cases diagnosed between 1997 and 2008. Histologically confirmed cases (n = 255) and controls (n = 459) completed a postal questionnaire focusing in particular on the pubertal period (namely age 13 years) with questions on physical activity (competitive sports, gardening), lifestyle (alcohol consumption, smoking), occupational history and medical conditions. All analyses were adjusted for the matching variables, cryptorchidism and educational level. Having done at least one competitive sport during puberty (odds ratio [OR]: 0.72, 95% confidence interval: 0.52-1.00), gardening activities during puberty (OR: 0.62, 0.42-0.94) and having a lower weight than peers during puberty (OR: 0.64, 0.42-0.97) were all inversely associated with the risk of testicular cancer. No evidence of association between smoking or alcohol consumption during puberty and the risk of testicular cancer was observed. Regarding agriculture-related occupations, we found an association with the risk of testicular cancer both for occasional jobs during puberty (OR: 2.40, 95% CI: 1.08-5.29) and ever employment in adolescence (OR: 2.59, 95% CI: 0.83-8.10). Our results suggest that postnatal exposures could play a role in testicular cancer aetiology, at least when acting in puberty or adolescence. © 2017 UICC.

Biosystematics of Aedes (Neomelaniconion)

DTIC Science & Technology

1991-11-01

reasons. One of these is the extreme sexual dimorphism of many of the species, particularly those in the Forest Section. For example, four of the known...males. There are many other instances of sexual dimorphism involving the number of pleural bristles, dentition of the hindclaws, and banding of the...abdominal terga. Because of the extreme sexual dimorphism , oftentimes it is not possible to associate males and females collected in the field in those

Sex chromosome linked genetic variance and the evolution of sexual dimorphism of quantitative traits.

PubMed

Husby, Arild; Schielzeth, Holger; Forstmeier, Wolfgang; Gustafsson, Lars; Qvarnström, Anna

2013-03-01

Theory predicts that sex chromsome linkage should reduce intersexual genetic correlations thereby allowing the evolution of sexual dimorphism. Empirical evidence for sex linkage has come largely from crosses and few studies have examined how sexual dimorphism and sex linkage are related within outbred populations. Here, we use data on an array of different traits measured on over 10,000 individuals from two pedigreed populations of birds (collared flycatcher and zebra finch) to estimate the amount of sex-linked genetic variance (h(2)z ). Of 17 traits examined, eight showed a nonzero h(2)Z estimate but only four were significantly different from zero (wing patch size and tarsus length in collared flycatchers, wing length and beak color in zebra finches). We further tested how sexual dimorphism and the mode of selection operating on the trait relate to the proportion of sex-linked genetic variance. Sexually selected traits did not show higher h(2)Z than morphological traits and there was only a weak positive relationship between h(2)Z and sexual dimorphism. However, given the relative scarcity of empirical studies, it is premature to make conclusions about the role of sex chromosome linkage in the evolution of sexual dimorphism. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

Extreme Telomere Length Dimorphism in the Tasmanian Devil and Related Marsupials Suggests Parental Control of Telomere Length

PubMed Central

Bender, Hannah S.; Murchison, Elizabeth P.; Pickett, Hilda A.; Deakin, Janine E.; Strong, Margaret A.; Conlan, Carly; McMillan, Daniel A.; Neumann, Axel A.; Greider, Carol W.; Hannon, Gregory J.; Reddel, Roger R.; Graves, Jennifer A. Marshall.

2012-01-01

Telomeres, specialised structures that protect chromosome ends, play a critical role in preserving chromosome integrity. Telomere dynamics in the Tasmanian devil (Sarcophilus harrisii) are of particular interest in light of the emergence of devil facial tumour disease (DFTD), a transmissible malignancy that causes rapid mortality and threatens the species with extinction. We used fluorescent in situ hybridisation to investigate telomere length in DFTD cells, in healthy Tasmanian devils and in four closely related marsupial species. Here we report that animals in the Order Dasyuromorphia have chromosomes characterised by striking telomere length dimorphism between homologues. Findings in sex chromosomes suggest that telomere length dimorphism may be regulated by events in the parental germlines. Long telomeres on the Y chromosome imply that telomere lengthening occurs during spermatogenesis, whereas telomere diminution occurs during oogenesis. Although found in several somatic cell tissue types, telomere length dimorphism was not found in DFTD cancer cells, which are characterised by uniformly short telomeres. This is, to our knowledge, the first report of naturally occurring telomere length dimorphism in any species and suggests a novel strategy of telomere length control. Comparative studies in five distantly related marsupials and a monotreme indicate that telomere dimorphism evolved at least 50 million years ago. PMID:23049977

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.

The geography of sex-specific selection, local adaptation, and sexual dimorphism.

PubMed

Connallon, Tim

2015-09-01

Local adaptation and sexual dimorphism are iconic evolutionary scenarios of intraspecific adaptive differentiation in the face of gene flow. Although theory has traditionally considered local adaptation and sexual dimorphism as conceptually distinct processes, emerging data suggest that they often act concurrently during evolutionary diversification. Here, I merge theories of local adaptation in space and sex-specific adaptation over time, and show that their confluence yields several new predictions about the roles of context-specific selection, migration, and genetic correlations, in adaptive diversification. I specifically revisit two influential predictions from classical studies of clinal adaptation and sexual dimorphism: (1) that local adaptation should decrease with distance from the species' range center and (2) that opposing directional selection between the sexes (sexual antagonism) should inevitably accompany the evolution of sexual dimorphism. I show that both predictions can break down under clinally varying selection. First, the geography of local adaptation can be sexually dimorphic, with locations of relatively high local adaptation differing profoundly between the sexes. Second, the intensity of sexual antagonism varies across the species' range, with subpopulations near the range center representing hotspots for antagonistic selection. The results highlight the context-dependent roles of migration versus sexual conflict as primary constraints to adaptive diversification. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

Reproductive skew drives patterns of sexual dimorphism in sponge-dwelling snapping shrimps

PubMed Central

Chak, Solomon Tin Chi; Duffy, J. Emmett; Rubenstein, Dustin R.

2015-01-01

Sexual dimorphism is typically a result of strong sexual selection on male traits used in male–male competition and subsequent female choice. However, in social species where reproduction is monopolized by one or a few individuals in a group, selection on secondary sexual characteristics may be strong in both sexes. Indeed, sexual dimorphism is reduced in many cooperatively breeding vertebrates and eusocial insects with totipotent workers, presumably because of increased selection on female traits. Here, we examined the relationship between sexual dimorphism and sociality in eight species of Synalpheus snapping shrimps that vary in social structure and degree of reproductive skew. In species where reproduction was shared more equitably, most members of both sexes were physiologically capable of breeding. However, in species where reproduction was monopolized by a single individual, a large proportion of females—but not males—were reproductively inactive, suggesting stronger reproductive suppression and conflict among females. Moreover, as skew increased across species, proportional size of the major chela—the primary antagonistic weapon in snapping shrimps—increased among females and sexual dimorphism in major chela size declined. Thus, as reproductive skew increases among Synalpheus, female–female competition over reproduction appears to increase, resulting in decreased sexual dimorphism in weapon size. PMID:26041357

Epigenetic regulation of female puberty.

PubMed

Lomniczi, Alejandro; Wright, Hollis; Ojeda, Sergio R

2015-01-01

Substantial progress has been made in recent years toward deciphering the molecular and genetic underpinnings of the pubertal process. The availability of powerful new methods to interrogate the human genome has led to the identification of genes that are essential for puberty to occur. Evidence has also emerged suggesting that the initiation of puberty requires the coordinated activity of gene sets organized into functional networks. At a cellular level, it is currently thought that loss of transsynaptic inhibition, accompanied by an increase in excitatory inputs, results in the pubertal activation of GnRH release. This concept notwithstanding, a mechanism of epigenetic repression targeting genes required for the pubertal activation of GnRH neurons was recently identified as a core component of the molecular machinery underlying the central restraint of puberty. In this chapter we will discuss the potential contribution of various mechanisms of epigenetic regulation to the hypothalamic control of female puberty. Copyright © 2014 Elsevier Inc. All rights reserved.

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.

Specialization for aggression in sexually dimorphic skeletal morphology in grey wolves (Canis lupus)

PubMed Central

Morris, Jeremy S; Brandt, Ellissa K

2014-01-01

Aggressive behaviour is important in the life history of many animals. In grey wolves (Canis lupus), territory defence through direct competition with conspecifics is severe and often lethal. Thus, performance in aggressive encounters may be under strong selection. Additionally, grey wolves frequently kill large dangerous prey species. Because both sexes actively participate in aggressive activities and prey capture, wolves are expected to exhibit a low level of musculoskeletal sexual dimorphism. However, male wolves more often lead in agonistic encounters with conspecifics and must provision the nursing female during the pup-rearing period of the breeding season. These behaviours may select for males that exhibit a higher degree of morphological adaptation associated with aggression and prey capture performance. To test this prediction, we assessed skeletal sexual dimorphism in three subspecies of grey wolves using functional indices reflecting morphological specialization for aggression. As expected, sexual dimorphism in skeletal shape was limited. However, in two of three subspecies, we found sexually dimorphic traits in the skull, forelimbs and hindlimbs that are consistent with the hypothesis that males are more specialized for aggression. These characters may also be associated with selection for improved prey capture performance by males. Thus, the sexually dimorphic functional traits identified by our analysis may be adaptive in the contexts of both natural and sexual selection. Several of these traits may conflict with locomotor economy, indicating the importance of aggression in the life history of male grey wolves. The presence of functional specialization for aggression in a generally monogamous species indicates that sexual dimorphism in specific musculoskeletal traits may be widespread among mammals. PMID:24810384

Selective pressures in the human bony pelvis: Decoupling sexual dimorphism in the anterior and posterior spaces.

PubMed

Brown, Kirsten M

2015-07-01

Sexual dimorphism in the human bony pelvis is commonly assumed to be related to the intensity of obstetrical selective pressures. With intense obstetrical selective pressures, there should be greater shape dimorphism; with minimal obstetrical selective pressures, there should be reduced shape dimorphism. This pattern is seen in the nondimorphic anterior spaces and highly dimorphic posterior spaces. Decoupling sexual dimorphism in these spaces may in turn be related to the differential influence of other selective pressures, such as biomechanical ones. The relationship between sexual dimorphism and selective pressures in the human pelvis was examined using five skeletal samples (total female n = 101; male n = 103). Pelvic shape was quantified by collecting landmark coordinate data on articulated pelves. Euclidean distance matrix analysis was used to extract the distances that defined the anterior and posterior pelvic spaces. Sex and body mass were used as proxies for obstetrical and biomechanical selective pressures, respectively. MANCOVA analyses demonstrate significant effects of sex and body mass on distances in both the anterior and the posterior spaces. A comparison of the relative contribution of shape variance attributed to each of these factors suggests that the posterior space is more influenced by sex, and obstetrics by proxy, whereas the anterior space is more influenced by body mass, and biomechanics by proxy. Although the overall shape of the pelvis has been influenced by obstetrical and biomechanical selective pressures, there is a differential response within the pelvis to these factors. These results provide new insight into the ongoing debate on the obstetrical dilemma hypothesis. © 2015 Wiley Periodicals, Inc.

Sexual dimorphism in sister species of Leucoraja skate and its relationship to reproductive strategy and life history.

PubMed

Martinez, Christopher M; Rohlf, F James; Frisk, Michael G

2016-01-01

Instances of sexual dimorphism occur in a great variety of forms and manifestations. Most skates (Batoidea: Rajoidei) display some level of body shape dimorphism in which the pectoral fins of mature males develop to create a distinct bell-shaped body not found in females. This particular form of dimorphism is present in each of the sister species Leucoraja erinacea and Leucoraja ocellata, but differences between sexes are much greater in the former. In order to understand the nature and potential causes of pectoral dimorphism, we used geometric morphometrics to investigate allometry of fin shape in L. erinacea and L. ocellata and its relationship to the development of reproductive organs, based on previous work on the bonnethead shark, Sphyrna tiburo. We found that allometric trajectories of overall pectoral shape were different in both species of skate, but only L. erinacea varied significantly with respect to endoskeleton development. Male maturation was characterized by a number of sex-specific morphological changes, which appeared concurrently in developmental timing with elongation of cartilage-supported claspers. We suggest that external sexual dimorphism of pectoral fins in skates is a byproduct of skeletal growth needed for clasper development. Further, the magnitude of male shape change appears to be linked to the differential life histories of species. This work reports for the first time that pectoral dimorphism is a persistent feature in rajoid fishes, occurring in varying degrees across several genera. Lastly, our results suggest that pectoral morphology may be useful as a relative indicator of reproductive strategy in some species. © 2016 Wiley Periodicals, Inc.

Age-Related Sexual Dimorphism in Temporal Discrimination and in Adult-Onset Dystonia Suggests GABAergic Mechanisms.

PubMed

Butler, John S; Beiser, Ines M; Williams, Laura; McGovern, Eavan; Molloy, Fiona; Lynch, Tim; Healy, Dan G; Moore, Helena; Walsh, Richard; Reilly, Richard B; O'Riordan, Seán; Walsh, Cathal; Hutchinson, Michael

2015-01-01

Adult-onset isolated focal dystonia (AOIFD) presenting in early adult life is more frequent in men, whereas in middle age it is female predominant. Temporal discrimination, an endophenotype of adult-onset idiopathic isolated focal dystonia, shows evidence of sexual dimorphism in healthy participants. We assessed the distinctive features of age-related sexual dimorphism of (i) sex ratios in dystonia phenotypes and (ii) sexual dimorphism in temporal discrimination in unaffected relatives of cervical dystonia patients. We performed (i) a meta-regression analysis of the proportion of men in published cohorts of phenotypes of adult-onset dystonia in relation to their mean age of onset and (ii) an analysis of temporal discrimination thresholds in 220 unaffected first-degree relatives (125 women) of cervical dystonia patients. In 53 studies of dystonia phenotypes, the proportion of men showed a highly significant negative association with mean age of onset (p < 0.0001, pseudo-R (2) = 59.6%), with increasing female predominance from 40 years of age. Age of onset and phenotype together explained 92.8% of the variance in proportion of men. Temporal discrimination in relatives under the age of 35 years is faster in women than men but the age-related rate of deterioration in women is twice that of men; after 45 years of age, men have faster temporal discrimination than women. Temporal discrimination in unaffected relatives of cervical dystonia patients and sex ratios in adult-onset dystonia phenotypes show similar patterns of age-related sexual dimorphism. Such age-related sexual dimorphism in temporal discrimination and adult-onset focal dystonia may reflect common underlying mechanisms. Cerebral GABA levels have been reported to show similar age-related sexual dimorphism in healthy participants and may be the mechanism underlying the observed age-related sexual dimorphism in temporal discrimination and the sex ratios in AOIFD.

The Effect of Target Sex, Sexual Dimorphism, and Facial Attractiveness on Perceptions of Target Attractiveness and Trustworthiness

PubMed Central

Hu, Yuanyan; Abbasi, Najam ul Hasan; Zhang, Yang; Chen, Hong

2018-01-01

Facial sexual dimorphism has widely demonstrated as having an influence on the facial attractiveness and social interactions. However, earlier studies show inconsistent results on the effect of sexual dimorphism on facial attractiveness judgments. Previous studies suggest that the level of attractiveness might work as a moderating variable among the relationship between sexual dimorphism and facial preference and have often focused on the effect of sexual dimorphism on general attractiveness ratings, rather than concentrating on trustworthiness perception. Male and female participants viewed target male and female faces that varied on attractiveness (more attractive or less attractive) and sexual dimorphism (masculine or feminine). Participants rated the attractiveness of the faces and reported how much money they would give to the target person as a measure of trust. For the facial attractiveness ratings, (a) both men and women participants preferred masculine male faces to feminine male ones under the more attractive condition, whereas preferred feminine male faces to masculine male ones under the less attractive condition; (b) all participants preferred feminine female faces to masculine female ones under the less attractive condition, while there were no differences between feminine female faces and masculine female faces under the more attractive condition. For the target trustworthiness perception, (a) participants showed no preference between masculine male faces and feminine male faces, neither under the more attractive condition nor the less attractiveness condition; (b) however, all the participants preferred masculine female faces over feminine female faces under the more attractive condition, exhibiting no preference between feminine female faces and masculine female faces under the less attractive condition. These findings suggest that the attractiveness of facial stimulus may be a reason to interpret the inconsistent results from the previous studies, which focused on the effect of facial sexual dimorphism on the facial attractiveness. Furthermore, implications about the effect of target facial sexual dimorphism on participants’ trustworthiness perception were discussed.

The androgen receptor governs the execution, but not programming, of male sexual and territorial behaviors

PubMed Central

Juntti, Scott A; Tollkuhn, Jessica; Wu, Melody V; Fraser, Eleanor J; Soderborg, Taylor; Tan, Stella; Honda, Shin-Ichiro; Harada, Nobuhiro; Shah, Nirao M

2010-01-01

SUMMARY Testosterone and estrogen are essential for male behaviors in vertebrates. How these two signaling pathways interact to control masculinization of the brain and behavior remains to be established. Circulating testosterone activates the androgen receptor (AR) and also serves as the source of estrogen in the brain. We have used a genetic strategy to delete AR specifically in the mouse nervous system. This approach permits us to determine the function of AR in sexually dimorphic behaviors in males while maintaining circulating testosterone levels within the normal range. We find that AR mutant males exhibit masculine sexual and territorial displays, but they have striking deficits in specific components of these behaviors. Taken together with the surprisingly limited expression of AR in the developing brain, our findings indicate that testosterone acts as a precursor to estrogen to masculinize the brain and behavior, and signals via AR to control the levels of male behavioral displays. PMID:20435002

An Early Window of Opportunity for Promoting Girls' Health: Policy Implications of the Girl's Puberty Book Project in Tanzania

ERIC Educational Resources Information Center

Sommer, Marni

2011-01-01

The onset of puberty, and specifically menstruation, is an opportune moment for reaching girls as they transition into adolescence and young womanhood. Despite the importance of this transitional period, the reproductive health community has tended to overlook the onset of menstruation and early puberty in global, national and local policy and…

Pubertal administration of DEHP delays puberty, suppresses testosterone production and inhibits reproductive tract development in male Sprague-Dawley and Long-Evans Rats

EPA Science Inventory

While is clear that exposure to high dosage levels of some phthalates delays the onset of puberty in the male rat it has been hypothesized that low levels of DEHP accelerate puberty by enhancing testicular androgen synthesis. The current study was designed to determine if the do...

Adolescent Development and the Biology of Puberty: Summary of a Workshop on New Research.

ERIC Educational Resources Information Center

Kipke, Michele D., Ed.

On March 23 and 24, 1998, the Forum on Adolescence gathered an interdisciplinary group of researchers and practitioners to review the state of knowledge about adolescent development at a workshop entitled "New Research on the Biology of Puberty and Adolescent Development." This workshop focused both on puberty, a set of physical changes rooted in…

Nutritional and Genetic Determinants of Early Puberty

DTIC Science & Technology

2007-06-01

AD_________________ Award Number: W81XWH-04-1-0575 TITLE: Nutritional and Genetic Determinants...CONTRACT NUMBER Nutritional and Genetic Determinants of Early Puberty 5b. GRANT NUMBER W81XWH-04-1-0575 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR...later in life. Nutritional factors during childhood and puberty, and inherited genetic factors are suspected to interact in modulating these early

Complete androgen insensitivity syndrome associated with male gender identity or female precocious puberty in the same family.

PubMed

Bermúdez de la Vega, José A; Fernández-Cancio, Mónica; Bernal, Susana; Audí, Laura

2015-01-01

In 4 complete androgen insensitivity syndrome (CAIS) members of one family, 2 presented extreme and unusual clinical features: male gender identity disorder (case 1) and female precocious central puberty (case 2). The AR gene carried the mutation c.1752C>G, p.Phe584Leu. Gender dysphoria in CAIS may be considered as a true transgender and has been described in 3 other cases. Central precocious puberty has only been described in 1 case; Müllerian ducts in case 2 permitted menarche. Despite the common CAIS phenotype, there was a familial disparity for gender identity adequacy and timing and type of puberty.

[Associations between overweight-obesity and puberty timing in children with different genders in China].

PubMed

Xu, Y Y; Sun, L; Guo, X; Zhang, J; Lou, X M; Wang, H; Tao, F B

2017-09-06

Objective: To understand the associations between overweight-obesity and puberty timing in children with different genders. Methods: The girls in grade 2, 3, 7, 8 and boys in grade 3, 4, 7, 8 were recruited from primary and middle schools in North new area of Shenyang, Yanqing district of Beijing, Erqi district of Zhengzhou and Jiulongpo district of Chongqing by purposive sampling method between October and December 2014, respectively. The information of demographic characteristics of the respondents were collected and the pubertal development status was evaluated by Pubertal Development Scale (PDS). A total of 6 701 students were recruited; 6 137 out of which were valid with complete questionnaires. The associations between overweight-obesity and puberty timing were estimated by multivariate logistic regression analysis. Results: The prevalence of overweight-obesity in primary schools were 34.8% (522/1 499) among boys and 24.2% (341/1 409) among girls, respectively. The prevalence of overweight-obesity in middle schools were 31.3% (591/1 658) among boys and 21.8% (342/1 571) among girls, respectively. The prevalence of premature puberty in primary schools were 15.0% (225/1 499) among boys and 14.2% (200/1 409) among girls, respectively. The prevalence of delayed puberty in middle schools were 14.3% (237/1 658) among boys and 14.9% (234/1 571) among girls, respectively. After adjusting the effects of region, age, one-child, family income and the parents' educational levels, multivariate logistic regression analysis showed that overweight-obesity had significantly positive association with premature puberty ( OR= 2.16, 95 %CI: 1.56-2.99) among girls in primary schools, and significantly negative association with delayed puberty ( OR= 0.54, 95 %CI: 0.36-0.80) among girls in middle schools when compared with students with normal weights, both P values were <0.05. There was no significant associations among boys in primary and middle schools between overweight-obesity and puberty timing, and the corresponding OR (95 %CI ) were 1.08(0.80-1.45) and 0.93(0.69-1.27) respectively, both P values >0.05. Conclusion: There was significantly positive association between overweight-obesity and premature puberty among girls, and significantly negative association with delayed puberty among girls in middle schools; but the association was not found among boys.

Provocative questions in parochial sex education classes: higher incidence in younger students.

PubMed

Moreno, Megan; Breuner, Cora C; Lozano, Paula

2008-10-01

Recent data show US adolescents are engaging in sexual activity at earlier ages; however, little is known about young teens' sexual attitudes and behaviors. Examining teens' questions in sex education classes may provide insight into these attitudes and behaviors. Quasi cohort study Parochial middle school sex education classes 5(th) through 8(th) graders Students' anonymous written questions submitted at the outset of sex education classes between 2003 and 2005. Questions were classified into topic categories. Three additional variables were then coded for each question. Ethics/guidance questions included requests for advice or value judgments. Prohibited questions included the topics homosexuality, abortion, masturbation, and contraception. "Red flag" questions were those that suggested consideration of or engagement in sexual behavior. Among 473 questions submitted by 410 students, the most popular topics for 5(th)/6(th) graders were pregnancy and puberty, and for 7(th)/8(th) graders puberty and menstruation. 41 questions (8.6%) were prohibited. 29 questions (6.2%) asked about ethics/guidance. 18 questions (3.81%) were coded as red flag questions. A chi-square analysis showed that 5(th)/6(th) graders asked more questions in the ethics/guidance (8.3% versus 3.64%) and red flag question categories (5.53% versus 1.82%) (P < 0.05) than 7(th)/8(th) graders. Although provocative questions represent a minority of these middle students' queries, these requests suggest the urgency of providing appropriate guidance to young teens, given the risks of early sexual activity. The role of school education programs, physicians and parents in addressing questions of this sort should be considered.

Pubertally born neurons and glia are functionally integrated into limbic and hypothalamic circuits of the male Syrian hamster.

PubMed

Mohr, Margaret A; Sisk, Cheryl L

2013-03-19

During puberty, the brain goes through extensive remodeling, involving the addition of new neurons and glia to brain regions beyond the canonical neurogenic regions (i.e., dentate gyrus and olfactory bulb), including limbic and hypothalamic cell groups associated with sex-typical behavior. Whether these pubertally born cells become functionally integrated into neural circuits remains unknown. To address this question, we gave male Syrian hamsters daily injections of the cell birthdate marker bromodeoxyuridine throughout puberty (postnatal day 28-49). Half of the animals were housed in enriched environments with access to a running wheel to determine whether enrichment increased the survival of pubertally born cells compared with the control environment. At 4 wk after the last BrdU injection, animals were allowed to interact with a receptive female and were then killed 1 h later. Triple-label immunofluorescence for BrdU, the mature neuron marker neuronal nuclear antigen, and the astrocytic marker glial fibrillary acidic protein revealed that a proportion of pubertally born cells in the medial preoptic area, arcuate nucleus, and medial amygdala differentiate into either mature neurons or astrocytes. Double-label immunofluorescence for BrdU and the protein Fos revealed that a subset of pubertally born cells in these regions is activated during sociosexual behavior, indicative of their functional incorporation into neural circuits. Enrichment affected the survival and activation of pubertally born cells in a brain region-specific manner. These results demonstrate that pubertally born cells located outside of the traditional neurogenic regions differentiate into neurons and glia and become functionally incorporated into neural circuits that subserve sex-typical behaviors.

[Dimorphism of cerumen, facts and theory].

PubMed

Meyer zum Gottesberge, A; Meyer zum Gottesberge, A

1995-10-01

¿Dimorphism¿ means the existence of two phenotypic different types of the human cerumen and morphology of the cerumen glands. In this paper, the morphological, biochemical, and functional differences are reviewed. The wet cerumen is better adapted to a hot and humid climate where infections of the outer ear are very frequent and sometimes severe. In a cold and dry climate, the dry cerumen is advantageous. In the moderate climates, both types are equivalent (balanced dimorphism).

[Age of onset of puberty in Chilean boys according to testicular volume and Tanner stage].

PubMed

Gaete, Ximena; García, Roberto; Riquelme, Joel; Codner, Ethel

2015-03-01

A secular trend towards a younger age of puberty onset has been reported in Chilean girls. To evaluate the age of onset of puberty and prevalence of early puberty in Chilean boys. A pediatric endocrinologist examined 319 children attending schools in central Santiago. Pubertal development was assessed by testicular volume (TV) and genital inspection (GI) using Tanner graduation. Precocious and early puberty development was diagnosed if TV ≥ 4 ml or GI > stage 2 occurred in boys younger than 9 years and at 9-10 years of age, respectively. Pubertal onset occurred at 10.2 ± 1.5 years according to TV and at 11.1 ± 1.6 years according to GI (p < 0.01). Before the age of nine, 15.2% of children had a VT ≥ 4 ml, 3% had genital changes in GI and only 3% had both changes simultaneously. Early puberty was observed in 23.8% of children according to TV and 9.5% according to GI. However, no child of less than 11 years old had a TV ≥ 4 ml, genital changes and pubic hair simultaneously. Late pubertal stages occurred at the same age according to both criteria used. Body mass index z score was not associated with the age of pubertal onset. Testicular enlargement occurs one year earlier than changes in genitalia according to inspection. Testicular growth, but not late stages of puberty, are occurring one year earlier than previously reported in Chile 10 years ago.

Nutrigenomics and its role in male puberty of cattle: a mini review.

PubMed

Deb, Rajib; Chakraborty, Sandip; Mahima; Verma, Amit Kumar; Tiwari, Rruchi; Dhama, Kuldeep

2014-02-01

Nutrigenomics a novel era in genomics research is based on puzzling issue on how nutrition and genes re-interacts. Perusal of literature reveals that very few information are available in this field and especially when it is associated with puberty in cattle which is a multigenic trait of great economic importance. Thus it opens a new area of research interest. Various markers like-gonadotropin releasing hormone/GNRH (responsible for sexual differentiation and reproduction), interstitial growth regulating factor/IGF1 (having signal controlling reproduction function linked to somatic growth); circulating metabolic hormones viz., leptin apart from GnRH and IGF1 (having impact on testicular development in peripubertal bull) are proved to be associated with male puberty in cattle. Various minerals (copper, selenium, manganese, zinc, chromium, iron and molybdenum) and vitamins (Vit. A, D, E and C) are directly or indirectly linked to male puberty. But no research till today initiated how the nutrients effect on the transcriptome/proteome/metabolome level of marker genes associated with male puberty in cattle. Application of nanotechnology to make food safer for promotion of good health has created much excitement and nanoparticles has been developed against infectious diseases (e.g., Campylobacteriosis) affecting puberty along with certain nanocarriers that can facilitate the uptake of essential nutrients associated with puberty. Much of nutrigenomics research is however in infancy and hence the present mini-review will allow building the concept among researchers and scientists to initiate research in this interesting area.

Association of estrogen receptor gene polymorphisms with human precocious puberty: a systematic review and meta-analysis.

PubMed

Luo, Yan; Liu, Qin; Lei, Xun; Wen, Yi; Yang, Ya-Lan; Zhang, Rui; Hu, Meng-Yao

2015-07-01

This study aims to estimate the association between ESR1 polymorphisms (PvuII and XbaI) and ESR2 polymorphisms (RsaI and AluI) with precocious puberty. Relevant studies published before March 2014 were retrieved by a electronic search among nine databases. Meta-analysis of the pooled odds ratios (ORs) with 95% confidence intervals (CIs) was calculated. Four eligible case-control studies including 491 precocious puberty patients and 370 healthy controls were identified. Three studies reported ESR1 PvuII and XbaI polymorphism and one study reported ESR2 RsaI and AluI polymorphism. Increment of precocious puberty risk was associated with PvuII polymorphism in the heterosis model ((CT) versus TT: OR 1.42, 95% CI: 1.05-1.91, p = 0.02). Risk of precocious puberty was associated with XbaI polymorphism in the dominant model (GG + GA versus AA: OR 1.48, 95% CI: 1.11-1.97, p = 0.007) and the heterosis model (GA versus AA: OR 1.68, 95% CI: 1.23-2.29, p = 0.001). This meta-analysis suggests that ESR1 XbaI and PvuII polymorphisms are associated with precocious puberty susceptibility, and the relationship between ESR2 RsaI and AluI polymorphism with precocious puberty remains to be further investigated. Well-designed studies with large sample size among different polymorphisms and ethnicities are in urgent need to provide and update reliable data for comprehensive and definite conclusion.

"When You're a Baby You Don't Have Puberty": Understanding of Puberty and Human Reproduction in Late Childhood and Early Adolescence

ERIC Educational Resources Information Center

Hurwitz, Lisa B.; Lauricella, Alexis R.; Hightower, Brianna; Sroka, Iris; Woodruff, Teresa K.; Wartella, Ellen

2017-01-01

Basic knowledge of human reproduction can help youth prepare for puberty and make later classes focused on advanced reproductive health topics manageable. With the intention of potentially informing the creation of learning materials, we conducted a needs assessment among children ages 7 to 12 in our suburban Chicago community to ascertain their…

Comparison of relative and actual chest compression depths during cardiac arrest in children, adolescents, and young adults☆

PubMed Central

Niles, Dana E.; Nishisaki, Akira; Sutton, Robert M.; Nysæther, Jon; Eilevstjønn, Joar; Leffelman, Jessica; Maltese, Matthew R.; Arbogast, Kristy B.; Abella, Benjamin S.; Helfaer, Mark A.; Berg, Robert A.; Nadkarni, Vinay M.

2013-01-01

Aim Cardiopulmonary resuscitation (CPR) guidelines recommend specific chest compression (CC) target depths for children. We quantitatively describe relative anterior–posterior diameter (APD) depth, actual depth, and force of CCs during real CPR events in children. Methods CC depth and force were recorded during real CPR events in children ≥8 years using FDA-approved CC sensor. Patient chest APD was measured at conclusion of each CPR event. CC data was stratified and analyzed according to age (pre-puberty, 8–14 years; post-puberty, 15+ years). Relative (% APD) and actual CC depth, corrected for mattress deflection, were assessed and compared with American Heart Association (AHA) 2005 and 2010 pediatric CPR guidelines. Results 35 events in 32 subjects included 16,158 CCs for data analysis: 16 pre-puberty (CCs = 7484, age 11.9 ± 2 years, APD 164.6 ± 25.1 mm); 19 post-puberty (CCs = 8674, age 18.0 ± 2.7 years, APD 196.5 ± 30.4 mm). After correction for mattress deflection, 92% of CC delivered to pre-puberty were <1/3 relative APD and 60% of CC were <38 mm actual depth. Mean actual CC depth (36.2 ± 9.6 mm vs. 36.8 ± 9.9 mm, p = 0.64), mean relative APD (22.5% ± 7.0% vs. 19.5 ± 6.7%, p = 0.13), and mean CC force (30.7 ± 7.6 kg vs. 33.6 ± 9.4 kg, p = 0.07) were not significantly less in pre-puberty vs. post-puberty. Conclusions During in-hospital cardiac arrest of children ≥8 years, CCs delivered by resuscitation teams were frequently <1/3 relative APD and <38 mm actual depth after mattress deflection correction, below pediatric and adult target guidelines. Mean CC actual depth and force were not significantly different in pre-puberty and post-puberty. Additional investigation to determine depth of CCs to optimize hemodynamics and outcomes is needed to inform future CPR guidelines. PMID:22079410

Puberty and Pubertal Growth in GH-treated SGA Children: Effects of 2 Years of GnRHa Versus No GnRHa.

PubMed

van der Steen, Manouk; Lem, Annemieke J; van der Kaay, Danielle C M; Hokken-Koèelega, Anita C S

2016-05-01

Most studies on puberty in children born small for gestational age (SGA) report height and age at onset of puberty. GH-treated SGA children with an adult height (AH) expectation below -2.5 SDS at onset of puberty can benefit from an additional 2 years of GnRH analog (GnRHa) treatment. There are no data on puberty and growth after discontinuation of GnRHa treatment in GH-treated SGA children. This study aimed to investigate the effects on puberty and pubertal growth of 2 years GnRHa vs no GnRHa in GH-treated SGA children. This was a GH trial involving 76 prepubertal short SGA children (36 girls) treated with GH. Thirty-two children received additional GnRHa for 2 years. Pubertal stages were 3-monthly assessed according to Tanner. Age, bone age, and median height at pubertal onset were lower in girls and boys in the GH/GnRHa group compared with the GH group. In girls and boys treated with GH/GnRHa, pubertal duration after stop of GnRHa treatment was shorter than pubertal duration in those with GH only (40.9 vs 46.7 mo; P = .044; 50.8 vs 57.5 months; P = .006; respectively). Height gain from onset of puberty until AH, including height gain during 2 years of GnRHa treatment, was 25.4 cm in girls and 33.0 cm in boys, which was 6.6 cm more than girls and boys treated with GH only. AH was similar in children treated with GH/GnRHa compared with those with GH only. GH-treated SGA children who start puberty with an AH expectation below -2.5 SDS and are treated with 2 years of GnRHa have a shorter pubertal duration after discontinuation of GnRHa compared with pubertal duration in children treated with GH only. Height gain from onset of puberty until AH is, however, more due to adequate growth during 2 years of GnRHa treatment resulting in a similar AH as children treated with GH only.

Gender identification of Caspian Terns using external morphology and discriminant function analysis

USGS Publications Warehouse

Ackerman, Joshua T.; Takekawa, John Y.; Bluso, J.D.; Yee, J.L.; Eagles-Smith, Collin A.

2008-01-01

Caspian Tern (Sterna caspia) plumage characteristics are sexually monochromatic and gender cannot easily be distinguished in the field without extensive behavioral observations. We assessed sexual size dimorphism and developed a discriminant function to assign gender in Caspian Terns based on external morphology. We collected and measured Caspian Terns in San Francisco Bay, California, and confirmed their gender based on necropsy and genetic analysis. Of the eight morphological measurements we examined, only bill depth at the gonys and head plus bill length differed between males and females with males being larger than females. A discriminant function using both bill depth at the gonys and head plus bill length accurately assigned gender of 83% of terns for which gender was known. We improved the accuracy of our discriminant function to 90% by excluding individuals that had less than a 75% posterior probability of correctly being assigned to gender. Caspian Terns showed little sexual size dimorphism in many morphometries, but our results indicate they can be reliably assigned to gender in the field using two morphological measurements.

Structural and molecular brain sexual differences: A tool to understand sex differences in health and disease.

PubMed

Panzica, GianCarlo; Melcangi, Roberto C

2016-08-01

Sex differences are present both in the genotype and in the phenotype of all vertebrates, and they have been evidenced also within the central and peripheral nervous system. Earlier studies on brain sex differences suggested a relatively simple view based on (1) the presence of sexually dimorphic circuits in the hypothalamus (or in regions related to reproductive behaviors), (2) the action of gonadal hormones to masculinize the brain, and (3) the gonadal steroids' action to modulate gene transcription through nuclear receptors. These assumptions are today contradicted by the findings accumulated in the last 20 years. We know now that mechanisms determining sexual dimorphisms may vary according to location and species, and may involve several factors, as genes, epigenetic factors, gonadal hormones and neurosteroids. Sex differences were also revealed by epidemiological studies in several neural pathologies. This suggests that the approach to understand the genesis of these pathologies, should involve specific attention to interactions among genes, gonadal and brain-born steroid hormones, epigenetic and environmental factors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Specialization for aggression in sexually dimorphic skeletal morphology in grey wolves (Canis lupus).

PubMed

Morris, Jeremy S; Brandt, Ellissa K

2014-07-01

Aggressive behaviour is important in the life history of many animals. In grey wolves (Canis lupus), territory defence through direct competition with conspecifics is severe and often lethal. Thus, performance in aggressive encounters may be under strong selection. Additionally, grey wolves frequently kill large dangerous prey species. Because both sexes actively participate in aggressive activities and prey capture, wolves are expected to exhibit a low level of musculoskeletal sexual dimorphism. However, male wolves more often lead in agonistic encounters with conspecifics and must provision the nursing female during the pup-rearing period of the breeding season. These behaviours may select for males that exhibit a higher degree of morphological adaptation associated with aggression and prey capture performance. To test this prediction, we assessed skeletal sexual dimorphism in three subspecies of grey wolves using functional indices reflecting morphological specialization for aggression. As expected, sexual dimorphism in skeletal shape was limited. However, in two of three subspecies, we found sexually dimorphic traits in the skull, forelimbs and hindlimbs that are consistent with the hypothesis that males are more specialized for aggression. These characters may also be associated with selection for improved prey capture performance by males. Thus, the sexually dimorphic functional traits identified by our analysis may be adaptive in the contexts of both natural and sexual selection. Several of these traits may conflict with locomotor economy, indicating the importance of aggression in the life history of male grey wolves. The presence of functional specialization for aggression in a generally monogamous species indicates that sexual dimorphism in specific musculoskeletal traits may be widespread among mammals. © 2014 Anatomical Society.

Convergent evolution of sexual shape dimorphism in Diptera.

PubMed

Bonduriansky, Russell

2006-05-01

Several patterns of sexual shape dimorphism, such as male body elongation, eye stalks, or extensions of the exoskeleton, have evolved repeatedly in the true flies (Diptera). Although these dimorphisms may have evolved in response to sexual selection on male body shape, conserved genetic factors may have contributed to this convergent evolution, resulting in stronger phenotypic convergence than might be expected from functional requirements alone. I compared phenotypic variation in body shape in two distantly related species exhibiting sexually dimorphic body elongation: Prochyliza xanthostoma (Piophilidae) and Telostylinus angusticollis (Neriidae). Although sexual selection appears to act differently on male body shape in these species, they exhibited strikingly similar patterns of sexual dimorphism. Likewise, patterns of within-sex shape variation were similar in the two species, particularly in males: relative elongation of the male head capsule, antenna, and legs was associated with reduced head capsule width and wing length, but was nearly independent of variation in thorax length. However, the two species presented contrasting patterns of static allometry: male sexual traits exhibited elevated allometric slopes in T. angusticollis, but not in P. xanthostoma. These results suggest that a shared pattern of covariation among traits may have channeled the evolution of sexually dimorphic body elongation in these species. Nonetheless, static allometries may have been shaped by species-specific selection pressures or genetic architectures. Copyright 2006 Wiley-Liss, Inc.

Cognitive sex differences are not magnified as a function of age, sex hormones, or puberty development during early adolescence.

PubMed

Herlitz, Agneta; Reuterskiöld, Lena; Lovén, Johanna; Thilers, Petra P; Rehnman, Jenny

2013-01-01

Are cognitive sex differences magnified by individual differences in age, sex hormones, or puberty development? Cross-sectional samples of 12- to 14-year-old boys (n = 85) and girls (n = 102) completed tasks assessing episodic memory, face recognition, verbal fluency, and mental rotations. Blood estradiol, free testosterone, and self-rated puberty scores were obtained. Sex differences were found on all cognitive measures. However, the magnitude was not larger for older children, hormones and cognitive performance were not associated, and early maturers did not perform better than late maturers. Thus, cognitive sex differences were not associated with age, levels of sex hormones, or puberty development.

Fungal dimorphism: the switch from hyphae to yeast is a specialized morphogenetic adaptation allowing colonization of a host.

PubMed

Boyce, Kylie J; Andrianopoulos, Alex

2015-11-01

The ability of pathogenic fungi to switch between a multicellular hyphal and unicellular yeast growth form is a tightly regulated process known as dimorphic switching. Dimorphic switching requires the fungus to sense and respond to the host environment and is essential for pathogenicity. This review will focus on the role of dimorphism in fungi commonly called thermally dimorphic fungi, which switch to a yeast growth form during infection. This group of phylogenetically diverse ascomycetes includes Talaromyces marneffei (recently renamed from Penicillium marneffei), Blastomyces dermatitidis (teleomorph Ajellomyces dermatitidis), Coccidioides species (C. immitis and C. posadasii), Histoplasma capsulatum (teleomorph Ajellomyces capsulatum), Paracoccidioides species (P. brasiliensis and P. lutzii) and Sporothrix schenckii (teleomorph Ophiostoma schenckii). This review will explore both the signalling pathways regulating the morphological transition and the transcriptional responses necessary for intracellular growth. The physiological requirements of yeast cells during infection will also be discussed, highlighting recent advances in the understanding of the role of iron and calcium acquisition during infection. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Menstrual cycle influence on cognitive function and emotion processing-from a reproductive perspective.

PubMed

Sundström Poromaa, Inger; Gingnell, Malin

2014-01-01

The menstrual cycle has attracted research interest ever since the 1930s. For many researchers the menstrual cycle is an excellent model of ovarian steroid influence on emotion, behavior, and cognition. Over the past years methodological improvements in menstrual cycle studies have been noted, and this review summarizes the findings of methodologically sound menstrual cycle studies in healthy women. Whereas the predominant hypotheses of the cognitive field state that sexually dimorphic cognitive skills that favor men are improved during menstrual cycle phases with low estrogen and that cognitive skills that favor women are improved during cycle phases with increased estrogen and/or progesterone, this review has not found sufficient evidence to support any of these hypotheses. Mental rotation has gained specific interest in this aspect, but a meta-analysis yielded a standardized mean difference in error rate of 1.61 (95% CI -0.35 to 3.57), suggesting, at present, no favor of an early follicular phase improvement in mental rotation performance. Besides the sexually dimorphic cognitive skills, studies exploring menstrual cycle effects on tasks that probe prefrontal cortex function, for instance verbal or spatial working memory, have also been reviewed. While studies thus far are few, results at hand suggest improved performance at times of high estradiol levels. Menstrual cycle studies on emotional processing, on the other hand, tap into the emotional disorders of the luteal phase, and may be of relevance for women with premenstrual disorders. Although evidence at present is limited, it is suggested that emotion recognition, consolidation of emotional memories, and fear extinction is modulated by the menstrual cycle in women. With the use of functional magnetic resonance imaging, several studies report changes in brain reactivity across the menstrual cycle, most notably increased amygdala reactivity in the luteal phase. Thus, to the extent that behavioral changes have been demonstrated over the course of the menstrual cycle, the best evidence suggests that differences in sexually dimorphic tasks are small and difficult to replicate. However, emotion-related changes are more consistently found, and are better associated with progesterone than with estradiol such that high progesterone levels are associated with increased amygdala reactivity and increased emotional memory.

Menstrual cycle influence on cognitive function and emotion processing—from a reproductive perspective

PubMed Central

Sundström Poromaa, Inger; Gingnell, Malin

2014-01-01

The menstrual cycle has attracted research interest ever since the 1930s. For many researchers the menstrual cycle is an excellent model of ovarian steroid influence on emotion, behavior, and cognition. Over the past years methodological improvements in menstrual cycle studies have been noted, and this review summarizes the findings of methodologically sound menstrual cycle studies in healthy women. Whereas the predominant hypotheses of the cognitive field state that sexually dimorphic cognitive skills that favor men are improved during menstrual cycle phases with low estrogen and that cognitive skills that favor women are improved during cycle phases with increased estrogen and/or progesterone, this review has not found sufficient evidence to support any of these hypotheses. Mental rotation has gained specific interest in this aspect, but a meta-analysis yielded a standardized mean difference in error rate of 1.61 (95% CI −0.35 to 3.57), suggesting, at present, no favor of an early follicular phase improvement in mental rotation performance. Besides the sexually dimorphic cognitive skills, studies exploring menstrual cycle effects on tasks that probe prefrontal cortex function, for instance verbal or spatial working memory, have also been reviewed. While studies thus far are few, results at hand suggest improved performance at times of high estradiol levels. Menstrual cycle studies on emotional processing, on the other hand, tap into the emotional disorders of the luteal phase, and may be of relevance for women with premenstrual disorders. Although evidence at present is limited, it is suggested that emotion recognition, consolidation of emotional memories, and fear extinction is modulated by the menstrual cycle in women. With the use of functional magnetic resonance imaging, several studies report changes in brain reactivity across the menstrual cycle, most notably increased amygdala reactivity in the luteal phase. Thus, to the extent that behavioral changes have been demonstrated over the course of the menstrual cycle, the best evidence suggests that differences in sexually dimorphic tasks are small and difficult to replicate. However, emotion-related changes are more consistently found, and are better associated with progesterone than with estradiol such that high progesterone levels are associated with increased amygdala reactivity and increased emotional memory. PMID:25505380

Willow Flycatcher nonbreeding territory defense behavior in Costa Rica

USGS Publications Warehouse

Sogge, M.K.; Koronkiewicz, T.J.; van Riper, Charles; Durst, S.L.

2007-01-01

We studied the intraspecific territorial defense behavior of wintering Willow Flycatchers (Empidonax traillii) in Costa Rica using a randomized playback experiment that exposed male and female birds to recordings of Willow Flycatcher songs and calls, Lesser Ground Cuckoo (Morococcyx erythropygius) vocalizations, and random noise. Flycatchers of both sexes responded most strongly to simulated conspecific territory intrusion, and the agonistic behaviors that we observed were similar to those seen during natural intraspecific encounters in winter. Both males and females engaged in song and aggressive behaviors in defense of territories, and there was no significant difference between the sexes in scored agonistic responses. The similarity between the sexes in intraspecific territorial defense behaviors and aggressiveness may account for both sexes of flycatchers using the same habitats at our study sites in Costa Rica, and wintering females defending territories against males. The Willow Flycatcher, a sexually monomorphic species, differs in this way from a number of sexually dimorphic passerines, in which behaviorally dominant males occur in more optimal winter habitats. ?? The Cooper Ornithological Society 2007.

Apparent Transition in the Human Height Distribution Caused by Age-Dependent Variation during Puberty Period

NASA Astrophysics Data System (ADS)

Iwata, Takaki; Yamazaki, Yoshihiro; Kuninaka, Hiroto

2013-08-01

In this study, we examine the validity of the transition of the human height distribution from the log-normal distribution to the normal distribution during puberty, as suggested in an earlier study [Kuninaka et al.: J. Phys. Soc. Jpn. 78 (2009) 125001]. Our data analysis reveals that, in late puberty, the variation in height decreases as children grow. Thus, the classification of a height dataset by age at this stage leads us to analyze a mixture of distributions with larger means and smaller variations. This mixture distribution has a negative skewness and is consequently closer to the normal distribution than to the log-normal distribution. The opposite case occurs in early puberty and the mixture distribution is positively skewed, which resembles the log-normal distribution rather than the normal distribution. Thus, this scenario mimics the transition during puberty. Additionally, our scenario is realized through a numerical simulation based on a statistical model. The present study does not support the transition suggested by the earlier study.

Recollections of puberty and disordered eating in young women.

PubMed

Moore, Sarah R; McKone, Kirsten M P; Mendle, Jane

2016-12-01

Puberty begins a period of vulnerability for disordered eating that is maintained and amplified through adolescence and early adulthood. In the present study, we test the association between young women's recollections of physical maturation and disordered eating outcomes in early adulthood. Participants comprised N = 421 female undergraduate students at a large, northeastern university in the United States (M age  = 19.7 years). Three models assessed the relative contributions of recollected puberty (perceptions of changes and preparedness, and timing of puberty), current contextual (social support, romantic bond, sorority or sport participation), and demographic (race, socioeconomic status, family structure) variables to three eating-disorder outcomes. Recollections of feeling unprepared and disliking the physical changes of puberty predicted eating disorder symptoms more than any other demographic or current contextual factor. Results indicate that how young women experience the pubertal transition is related to eating disorder symptoms many years later. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Factors affecting onset of puberty in Denizli province in Turkey.

PubMed

Semiz, Serap; Kurt, Funda; Kurt, Devrim Tanil; Zencir, Mehmet; Sevinç, Ozgür

2009-01-01

The relationship between the possible factors affecting pubertal onset and pubertal timing was investigated in the Denizli province in Turkey. A total number of 3311 subjects (1562 girls, 1749 boys) aged 6-16.5 years participated in this study. Body mass index (BMI) was calculated. Pubertal stages were assessed according to methods of Marshall and Tanner. Testicular volume was determined using Prader orchidometer. Menarcheal age was recorded. All parents and students completed different questionnaires on demographic variables affecting pubertal timing such as socioeconomic conditions, psychosocial factors, exercise, nutritional status, chronic diseases, migration and birth weight. Using distribution percentiles of pubertal stages according to age, the relation between pubertal timing and factors affecting puberty was investigated. There was no significant association between exercise, birth weight, migration, chronic disease, and socioeconomic status and age of puberty onset. Menarcheal age of overweight and obese girls was significantly lower than that of girls with normal weight. In-family stress was the cause of early puberty in girls and of delayed puberty in boys.

Dimorphous expressions of positive emotion: displays of both care and aggression in response to cute stimuli.

PubMed

Aragón, Oriana R; Clark, Margaret S; Dyer, Rebecca L; Bargh, John A

2015-03-01

Extremely positive experiences, and positive appraisals thereof, produce intense positive emotions that often generate both positive expressions (e.g., smiles) and expressions normatively reserved for negative emotions (e.g., tears). We developed a definition of these dimorphous expressions and tested the proposal that their function is to regulate emotions. We showed that individuals who express emotions in this dimorphous manner do so as a general response across a variety of emotionally provoking situations, which suggests that these expressions are responses to intense positive emotion rather than unique to one particular situation. We used cute stimuli (an elicitor of positive emotion) to demonstrate both the existence of these dimorphous expressions and to provide preliminary evidence of their function as regulators of emotion. © The Author(s) 2015.

Pubertal development of the first cohort of young adults conceived by in-vitro fertilization in the United States

PubMed Central

Beydoun, Hind A.; Sicignano, Nicholas; Beydoun, May; Bocca, Silvina; Stadtmauer, Laurel; Oehninger, Sergio

2010-01-01

Objective To characterize pubertal development of the first generation of young adults born as a result of in-vitro fertilization (IVF). Demographic, clinical and body size characteristics were examined in relation to developmental milestones. Design Cross-sectional. Setting Academic center. Patients Young adults (18–26 years) conceived by IVF (no gamete/embryo manipulation), 1981–1990. Intervention Self-administered questionnaire. Main outcome measures Age at puberty onset, body size. Results Of 560 eligible young adults, 173 completed the survey (response rate=30.9%). We analyzed data on 166 respondents, 71 males and 95 females. No cases of delayed or precocious puberty were observed in the study sample. As expected, age at puberty onset was significantly higher (P < 0.0001) among males (12.3 years) compared to females (11.5 years). A few developmental milestones were predicted by maternal age and infertility diagnoses. For both genders, a direct association was noted between age at puberty onset and height achieved in young adulthood. Structural equations models suggested an inverse relationship of female gender with age at puberty onset and body mass index. Conclusions IVF-conceived young adults did not exhibit pubertal abnormalities. Female gender and age at puberty onset independently predicted body mass index of IVF offspring in young adulthood. PMID:20547390

The effects of puberty on white matter development in boys.

PubMed

Menzies, Lara; Goddings, Anne-Lise; Whitaker, Kirstie J; Blakemore, Sarah-Jayne; Viner, Russell M

2015-02-01

Neuroimaging studies demonstrate considerable changes in white matter volume and microstructure during adolescence. Most studies have focused on age-related effects, whilst puberty-related changes are not well understood. Using diffusion tensor imaging and tract-based spatial statistics, we investigated the effects of pubertal status on white matter mean diffusivity (MD) and fractional anisotropy (FA) in 61 males aged 12.7-16.0 years. Participants were grouped into early-mid puberty (≤Tanner Stage 3 in pubic hair and gonadal development; n=22) and late-post puberty (≥Tanner Stage 4 in pubic hair or gonadal development; n=39). Salivary levels of pubertal hormones (testosterone, DHEA and oestradiol) were also measured. Pubertal stage was significantly related to MD in diverse white matter regions. No relationship was observed between pubertal status and FA. Regression modelling of MD in the significant regions demonstrated that an interaction model incorporating puberty, age and puberty×age best explained our findings. In addition, testosterone was correlated with MD in these pubertally significant regions. No relationship was observed between oestradiol or DHEA and MD. In conclusion, pubertal status was significantly related to MD, but not FA, and this relationship cannot be explained by changes in chronological age alone. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

The effects of puberty on white matter development in boys

PubMed Central

Menzies, Lara; Goddings, Anne-Lise; Whitaker, Kirstie J.; Blakemore, Sarah-Jayne; Viner, Russell M.

2015-01-01

Neuroimaging studies demonstrate considerable changes in white matter volume and microstructure during adolescence. Most studies have focused on age-related effects, whilst puberty-related changes are not well understood. Using diffusion tensor imaging and tract-based spatial statistics, we investigated the effects of pubertal status on white matter mean diffusivity (MD) and fractional anisotropy (FA) in 61 males aged 12.7–16.0 years. Participants were grouped into early-mid puberty (≤Tanner Stage 3 in pubic hair and gonadal development; n = 22) and late-post puberty (≥Tanner Stage 4 in pubic hair or gonadal development; n = 39). Salivary levels of pubertal hormones (testosterone, DHEA and oestradiol) were also measured. Pubertal stage was significantly related to MD in diverse white matter regions. No relationship was observed between pubertal status and FA. Regression modelling of MD in the significant regions demonstrated that an interaction model incorporating puberty, age and puberty × age best explained our findings. In addition, testosterone was correlated with MD in these pubertally significant regions. No relationship was observed between oestradiol or DHEA and MD. In conclusion, pubertal status was significantly related to MD, but not FA, and this relationship cannot be explained by changes in chronological age alone. PMID:25454416

The Emerging Role of Epigenetics in the Regulation of Female Puberty.

PubMed

Lomniczi, Alejandro; Ojeda, Sergio R

2016-01-01

In recent years the pace of discovering the molecular and genetic underpinnings of the pubertal process has accelerated considerably. Genes required for human puberty to occur have been identified and evidence has been provided suggesting that the initiation of puberty requires coordinated changes in the output of a multiplicity of genes organized into functional networks. Recent evidence suggests that a dual mechanism of epigenetic regulation affecting the transcriptional activity of neurons involved in stimulating gonadotropin-releasing hormone release plays a fundamental role in the timing of puberty. The Polycomb group (PcG) of transcriptional silencers appears to be a major component of the repressive arm of this mechanism. PcG proteins prevent the premature initiation of female puberty by silencing the Kiss1 gene in kisspeptin neurons of the arcuate nucleus (ARC) of the hypothalamus. Because the abundance of histone marks either catalyzed by--or associated with--the Trithorax group (TrxG) of transcriptional activators increases at the time when PcG control subsides, it appears that the TrxG complex is the counteracting partner of PcG-mediated gene silencing. In this chapter, we discuss the concept that a switch from epigenetic repression to activation within ARC kisspeptin neurons is a core mechanism underlying the initiation of female puberty. © 2016 S. Karger AG, Basel.

The Emerging Role of Epigenetics in the Regulation of Female Puberty

PubMed Central

Lomniczi, Alejandro; Ojeda, Sergio R.

2016-01-01

In recent years the pace of discovering the molecular and genetic underpinnings of the pubertal process has accelerated considerably. Genes required for human puberty to occur have been identified and evidence has been provided suggesting that the initiation of puberty requires coordinated changes in the output of a multiplicity of genes organized into functional networks. Recent evidence suggests that a dual mechanism of epigenetic regulation affecting the transcriptional activity of neurons involved in stimulating gonadotropin-releasing hormone release plays a fundamental role in the timing of puberty. The Polycomb group (PcG) of transcriptional silencers appears to be a major component of the repressive arm of this mechanism. PcG proteins prevent the premature initiation of female puberty by silencing the Kiss1 gene in kisspeptin neurons of the arcuate nucleus (ARC) of the hypothalamus. Because the abundance of histone marks either catalyzed by – or associated with – the Trithorax group (TrxG) of transcriptional activators increases at the time when PcG control subsides, it appears that the TrxG complex is the counteracting partner of PcG-mediated gene silencing. In this chapter, we discuss the concept that a switch from epigenetic repression to activation within ARC kisspeptin neurons is a core mechanism underlying the initiation of female puberty. PMID:26680569

The influence of puberty on vitamin D status in obese children and the possible relation between vitamin D deficiency and insulin resistance.

PubMed

Gutiérrez Medina, Sonsoles; Gavela-Pérez, Teresa; Domínguez-Garrido, María Nieves; Gutiérrez-Moreno, Elisa; Rovira, Adela; Garcés, Carmen; Soriano-Guillén, Leandro

2015-01-01

Puberty can affect vitamin D levels. The goal of this study was to analyze the relation between vitamin D deficiency and puberty in obese Spanish children, along with the possible interrelation between vitamin D status and degree of insulin resistance. A cross-sectional study was carried out, in which clinical and biochemical data were gathered from 120 obese and 50 normal weight children between January 2011 and January 2013. Mean vitamin D levels were 19.5 and 31.6 ng/mL in obese pubertal and obese prepubertal children, respectively. About 75% of the obese pubertal subjects and 46% of the obese prepubertal subjects had vitamin D deficiency. Vitamin D levels were significantly lower in pubescent subjects compared with pre-pubescent subjects in summer, fall, and winter. There was no apparent relation between vitamin D levels and homeostasis model assessment index for insulin resistence (expressed in standard deviation score for sex and Tanner stage) in either puberty or pre-puberty. Puberty may be a risk factor for the vitamin D deficiency commonly found in the obese child population. This deficiency is not associated with higher insulin resistance in obese pubertal children compared with obese prepubertal children.

The effect of puberty on fat oxidation rates during exercise in overweight and normal-weight girls.

PubMed

Chu, L; Riddell, M C; Schneiderman, J E; McCrindle, B W; Hamilton, J K

2014-01-01

Excess weight is often associated with insulin resistance (IR) and may disrupt fat oxidation during exercise. This effect is further modified by puberty. While studies have shown that maximal fat oxidation rates (FOR) during exercise decrease with puberty in normal-weight (NW) and overweight (OW) boys, the effect of puberty in NW and OW girls is unclear. Thirty-three NW and OW girls ages 8-18 yr old completed a peak aerobic capacity test on a cycle ergometer. FOR were calculated during progressive submaximal exercise. Body composition and Tanner stage were determined. For each participant, a best-fit polynomial curve was constructed using fat oxidation vs. exercise intensity to estimate max FOR. In a subset of the girls, IR derived from an oral glucose tolerance test (n = 20), and leptin and adiponectin levels (n = 11) were assessed in relation to FOR. NW pre-early pubertal girls had higher max FOR [6.9 ± 1.4 mg·kg fat free mass (FFM)(-1)·min(-1)] than NW mid-late pubertal girls (2.2 ± 0.9 mg·kg FFM(-1)·min(-1)) (P = 0.002), OW pre-early pubertal girls (3.8 ± 2.1 mg·kg FFM(-1)·min(-1)), and OW mid-late pubertal girls (3.3 ± 0.9 mg·kg FFM(-1)·min(-1)) (P < 0.05). Bivariable analyses showed positive associations between FOR with homeostatic model assessment of IR (P = 0.001), leptin (P < 0.001), and leptin-to-adiponectin ratio (P = 0.001), independent of percent body fat. Max FOR decreased in NW girls during mid-late puberty; however, this decrease associated with puberty was blunted in OW girls due to lower FOR in pre-early puberty. The presence of IR due to obesity potentially masks the effect of puberty on FOR during exercise in girls.

Metabolic control of puberty: roles of leptin and kisspeptins.

PubMed

Sanchez-Garrido, Miguel A; Tena-Sempere, Manuel

2013-07-01

This article is part of a Special Issue "Puberty and Adolescence". Reproduction is an energy-demanding function. Accordingly, puberty is metabolically gated, as a means to prevent fertility in conditions of energy insufficiency. In addition, obesity has been shown to impact the timing of puberty and may be among the causes for the earlier trends of pubertal age reported in various countries. The metabolic control of puberty in such a spectrum of situations, ranging from energy deficit to extreme overweight, is the result of the concerted action of different peripheral hormones and central transmitters that sense the metabolic state of the organism and transmit this information to the various elements of the reproductive axis, mainly the GnRH neurons. Among the peripheral signals involved, the adipose hormone, leptin, is known to play an essential role in the regulation of puberty, especially in females. Yet, although it is clear that the effects of leptin on puberty onset are predominantly permissive and mainly conducted at central (hypothalamic) levels, the primary sites and mechanisms of action of leptin within the reproductive brain remain unsolved. In this context, neurons expressing kisspeptins, the products of the Kiss1 gene that have emerged recently as essential upstream regulators of GnRH neurons, operate as key sensors of the metabolic state and funnel of the reproductive effects of leptin. Yet, much debate has arisen recently on whether the putative actions of leptin on the Kiss1 system are actually indirect and/or may primarily target Kiss1-independent pathways, such as those originating from the ventral premmamilary nucleus. Moreover, evidence has been presented for extra-hypothalamic or peripheral actions of leptin, including direct gonadal effects, which may contribute to the metabolic control of reproduction in extreme body weight conditions. In this work, we will critically review the experimental evidence supporting a role of leptin, kisspeptin and putatively related pathways in the concerted control of puberty by energy balance and metabolism. Copyright © 2013 Elsevier Inc. All rights reserved.

Combined Treatment with Gonadotropin-releasing Hormone Analog and Anabolic Steroid Hormone Increased Pubertal Height Gain and Adult Height in Boys with Early Puberty for Height.

PubMed

Tanaka, Toshiaki; Naiki, Yasuhiro; Horikawa, Reiko

2012-04-01

Twenty-one boys with a height of 135 cm or less at onset of puberty were treated with a combination of GnRH analog and anabolic steroid hormone, and their pubertal height gain and adult height were compared with those of untreated 29 boys who enter puberty below 135 cm. The mean age at the start of treatment with a GnRH analog, leuprorelin acetate depot (Leuplin(®)) was 12.3 yr, a mean of 1.3 yr after the onset of puberty, and GnRH analog was administered every 3 to 5 wk thereafter for a mean duration of 4.1 yr. The anabolic steroid hormone was started approximately 1 yr after initiation of treatment with the GnRH analog. The mean pubertal height gain from onset of puberty till adult height was significantly greater in the combination treatment group (33.9 cm) than in the untreated group (26.4 cm) (p<0.0001). The mean adult height was significantly greater in the combination treatment group (164.3 cm) than in the untreated group (156.9 cm) (p<0.0001). The percentage of subjects with an adult height of 160 cm or taller was 90.5% (19/21) in the combination treatment group, and it was 13.8% (4/29) in the untreated group (p<0.0001). Since growth of the penis and pubic hair is promoted by the anabolic steroid hormone, no psychosocial problems arose because of delayed puberty. No clinically significant adverse events appeared. Combined treatment with GnRH analog and anabolic steroid hormone significantly increased height gain during puberty and adult height in boys who entered puberty with a short stature, since the period until epiphyseal closure was extended due to deceleration of the bone age maturation by administration of the GnRH analog and the growth rate at this time was maintained by the anabolic steroid hormone.

Combined Treatment with Gonadotropin-releasing Hormone Analog and Anabolic Steroid Hormone Increased Pubertal Height Gain and Adult Height in Boys with Early Puberty for Height

PubMed Central

Tanaka, Toshiaki; Naiki, Yasuhiro; Horikawa, Reiko

2012-01-01

Twenty-one boys with a height of 135 cm or less at onset of puberty were treated with a combination of GnRH analog and anabolic steroid hormone, and their pubertal height gain and adult height were compared with those of untreated 29 boys who enter puberty below 135 cm. The mean age at the start of treatment with a GnRH analog, leuprorelin acetate depot (Leuplin®) was 12.3 yr, a mean of 1.3 yr after the onset of puberty, and GnRH analog was administered every 3 to 5 wk thereafter for a mean duration of 4.1 yr. The anabolic steroid hormone was started approximately 1 yr after initiation of treatment with the GnRH analog. The mean pubertal height gain from onset of puberty till adult height was significantly greater in the combination treatment group (33.9 cm) than in the untreated group (26.4 cm) (p<0.0001). The mean adult height was significantly greater in the combination treatment group (164.3 cm) than in the untreated group (156.9 cm) (p<0.0001). The percentage of subjects with an adult height of 160 cm or taller was 90.5% (19/21) in the combination treatment group, and it was 13.8% (4/29) in the untreated group (p<0.0001). Since growth of the penis and pubic hair is promoted by the anabolic steroid hormone, no psychosocial problems arose because of delayed puberty. No clinically significant adverse events appeared. Combined treatment with GnRH analog and anabolic steroid hormone significantly increased height gain during puberty and adult height in boys who entered puberty with a short stature, since the period until epiphyseal closure was extended due to deceleration of the bone age maturation by administration of the GnRH analog and the growth rate at this time was maintained by the anabolic steroid hormone. PMID:23926409

[Effect of anticancer treatment on leptin level, fat body mass (FM) and lean body mass (LBM)].

PubMed

Krawczyk-Rybak, Maryna; Muszyńska-Rosłan, Katarzyna; Konstantynowicz, Jerzy; Solarz, Elzbieta; Wołczynski, Sławomir; Protas, Piotr

2004-01-01

Leptin plays an important role in the metabolism of adipose tissue. Considering that malignancy and its treatment cans affect normal development in childhood. We analysed the correlations between serum leptin levels and body composition after anticancer treatment. We studied 33 survivors (24 boys and 9 girls) who before our study, have been treated for acute lymphoblastic leukaemia (ALL) (n=23) and Hodgkin disease (n=10) after 7.15+/-3.5 years. Sixteen patients with ALL received cranial irradiation (12Gy). We measured body mass index (BM1) fat mass (FM) and lean body mass (LBM) using dual energy x-ray absorptiometry (DXA). We compared these results to the results obtained from reference values (SD score). Leptin levels were measured with the RIA method. 1. Mean leptin levels were higher in girls after puberty (10.93 ng/mL+/-8.9) than in boys (3.73 ng/mL+/-3. 7). In boys no differences were found in leptin levels between T2-4 and T5 stages. In girls the leptin values increased after puberty. Leptin SD score levels were higher in boys during (1.55 +/-1.0) and after puberty (1.46+/-0.75) and in girls - after puberty (1.19 +/-1.51). We did not find any influence of cranial irradiation (12Gy) or various methotrexate doses (5 g/m(2) vs. 19/m(2)) leptin values. 2. No difference in BMI SD score was found within the whole study group. 3. FM did not change ill boys during and after puberty, although FM SD score were higher during puberty (2.98 +/-4.8). In girls FM and FM SD score were higher after puberty. In boys and girls LBM augmented with pubertal development but LBM SD score in boys were lower after puberty (-1.67 +/-1.7) in comparison to puberty (0.2 +/-1.7). No differences were found between LBM SD score in girls during and after puberty. 4. We found a correlation between leptin levels and BMI (r=0.59 p=0.001) and FM (r=0.77 p=0.0001). 5. Relation of FM to LBM in boys remained unchanged, however in girls it increased within pubertal development. l. Anticancer treatment during childhood shows no influence on body mass index although the tendency to higher fat mass in pubertal boys and in post pubertal girls is observed. 2. Leptin values depend on fat mass and do not relate directly to the pubertal stage.

[Rapidly progressive puberty in a patient with mosaic Turner syndrome: a case report and literature review].

PubMed

Liang, Y; Wei, H; Yu, X; Huang, W; Luo, X P

2017-02-02

Objective: To explore the clinical characteristics of diagnosis and treatment in patients with Turner syndrome and rapidly progressive puberty. Method: A rare case of rapidly progressive puberty in Turner syndrome with a mosaic karyotype of 45, X/46, X, del(X)(p21)(80%/20%)was diagnosed at Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology in January. 2015. Clinical characteristics and the related literature were reviewed. Original papers on precocious puberty or rapidly progressive puberty in Turner syndrome, published until Apr. 2016 were retrieved at PubMed and CNKI databases by the use of the key words "Turner syndrome" , "precocious puberty" and "rapidly progressive puberty" . Result: The patient was born at term with birth weight of 2 450 g and was diagnosed with SGA at 3 years of age for the first evaluating of growth and development. Then recombined human growth hormone (rhGH )was given at 4 years of age due to short stature (height<3 percentile) and low growth velocity(<5.0 cm/year) as well. However, rhGH treatment was discontinued after 9 months because of economic burdens. Breast development was noted at 9 years and 3 months. The patient was followed up at 3 months intervals. Physical examination revealed a Tanner stage Ⅲ breast development at 10.33 years , the bone age was 11.6 years. Then, gonadotropin-releasing hormone analogs treatment was added to slow pubertal progression and to preserve maximum adult height. The growth rate decreased with therapy from 7.5 cm/year to 4.4 cm/year. The patient was reevaluated, and the chromosome analysis of peripheral blood revealed a mosaic karyotype 45, X/46, X, del(X)(p21)(80%/ 20%). To date, only 10 cases have been reported in the literature. Six of them showing mosaic TS, three karyotypes with structural abnormality of short arm of X chromosome, one with the karyotype 45, X. Conclusion: It is the first time that rapidly progressive puberty in a 45, X/46, X, del(X)(p21) mosaic Turner syndrome is reported. Although short stature and ovarian dysgenesis are common in TS, precocious puberty may occur in TS, which is liable to cause delayed diagnosis and misdiagnosis. Careful examination is recommended for patients with unusual growth pattern, even though girls have normal height in accord with standard growth curve or spontaneous puberty. Evaluation for TS and subsequent investigation should be prompted.

Association between excessive BMI increase during puberty and risk of cardiovascular mortality in adult men: a population-based cohort study.

PubMed

Ohlsson, Claes; Bygdell, Maria; Sondén, Arvid; Rosengren, Annika; Kindblom, Jenny M

2016-12-01

Being overweight during childhood and adolescence is associated with increased risk of cardiovascular disease in adulthood, but the relative contribution of prepubertal childhood BMI and BMI change during puberty to adult mortality due to cardiovascular disease is unknown. We assessed the contribution of these two distinct developmental BMI parameters for cardiovascular mortality in adult men. As a part of the ongoing population-based BMI Epidemiology Study (BEST) in Gothenburg, Sweden, men born between 1945 and 1961 with information on both their childhood BMI at age 8 years and BMI change during puberty were included in the study and followed up until December, 2013. Participants who died or emigrated before age 20 years were excluded from the analysis. BMI was collected from paediatric growth charts and mandatory military conscription tests. Childhood overweight (BMI of ≥17·9 kg/m 2 ) was defined according to the Centers for Disease Control and Prevention's cutoff at 8 years of age, and BMI change during puberty was defined as the difference between young adult BMI and childhood BMI (BMI at age 20 years minus BMI at age 8 years). Information on mortality was retrieved from high quality national registers with the participants' ten-digit personal identity number. We used Cox proportional hazard regression to analyse the association between exposures and mortality. The ethics committee of the University of Gothenburg, Sweden, approved the study and waived the requirement for written informed consent. We followed 37 672 Swedish men from age 20 years for a mean of 37·8 years (1 422 185 person-years follow-up). 3188 all-cause deaths and 710 cardiovascular deaths occurred during follow-up. The correlation between childhood BMI and BMI change during puberty was marginal (r=0·06). BMI change during puberty, but not childhood BMI, was independently associated with adult all-cause and cardiovascular mortality in men. Boys that became overweight during puberty (HR 2·39; 95% CI 1·86-3·09) and boys who were overweight consistently throughout childhood and puberty (1·85; 1·28-2·67), but not boys overweight in childhood that normalised during puberty (0·99, 0·65-1·50), had increased risk of cardiovascular mortality compared with participants who were not overweight in childhood or as young adults. The association between BMI change during puberty and cardiovascular mortality was non-linear with a substantial association above a threshold of 6·7 units increase in BMI. Excessive BMI increase during puberty is a risk marker of adult cardiovascular mortality. These results indicate that BMI should be monitored during puberty to identify boys with increased risk of adult cardiovascular mortality. Swedish Research Council, the Swedish Government (under the Avtal om Läkarutbildning och Medicinsk Forskning [Agreement for Medical Education and Research]), the Lundberg Foundation, the Torsten Söderberg Foundation, the Novo Nordisk Foundation, the Knut and Alice Wallenberg Foundation, and the Anna Ahrenberg Foundation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Familial idiopathic gonadotropin deficiency not linked to gene for gonadotropin-releasing hormone (GnRH) in Brazilian kindred

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faraco, J.; Francke, U.; Toledo, S.

Familial idiopathic gonadotropin deficiency (FIGD) is an autosomal recessive disorder which results in failure to develop secondary sexual characteristics. The origin is a hypothalamic defect resulting in insufficient secretion of gonadotropin-releasing hormone GnRH (also called LHRH, luteinizing hormone releasing hormone) and follicle-stimuating hormone (FSH). FIGD has been determined to be a separate entity from Kallmann syndrome which presents with hypogonadism as well as anosmia. The FIGD phenotype appears to be analogous to the phenotype of the hpg (hypogonadal) mouse. Because the hpg phenotype is the result of a structurally abnormal GnRH gene, we have studied the GnRH gene in individualsmore » from a previously reported Brazilian FIGD family. An informative dimorphic marker in the signal peptide sequence of the GnRH gene allowed assessment of linkage between the disease gene and the GnRH locus in this pedigree. We have concluded that the GnRH locus is not linked to the disease-causing mutation in these hypogonadal individuals. Recent evidence suggests that neuropeptide Y (NPY) may play a role in the initiation of puberty. We hypothesize that mutations in NPY may result in failure to secrete GnRH. We have characterized three diallelic frequent-cutter restriction fragment length polymorphisms within the human NPY locus, and are currently using these markers to determine if the NPY gene is linked to, and possibly the site of the disease mutation in this kindred.« less

An augmented dopamine system function is present prior to puberty in the methylazoxymethanol acetate rodent model of schizophrenia.

PubMed

Chen, Li; Perez, Stephanie M; Lodge, Daniel J

2014-09-01

Schizophrenia is a disease typically associated with an adolescent onset. Although there have been a considerable number of imaging studies investigating the transition to psychosis in prodromal patients, there are relatively few preclinical studies examining potential mechanisms that may contribute to adolescent onset. We have previously demonstrated, in the methylazoxymethanol acetate (MAM) rodent model of schizophrenia, that an enhanced activity within the ventral hippocampus may underlie the dopamine system hyperfunction, suggested to contribute to positive symptoms in patients. Here we demonstrate that the aberrant regulation of dopamine system function, in MAM-treated rats, is present prior to puberty. Furthermore, we now report that while the afferent regulation of ventral tegmental area dopamine neurons (from the hippocampus and pedunculopontine tegmental area) appears intact in preadolescent rats, the behavioral response to alterations in dopamine system function appears to be attenuated in preadolescent rats. Thus, we posit that the pathological alterations underlying psychosis may be present prior to symptom onset and that the "normal" development of the postsynaptic side of the dopamine system may underlie the transition to psychosis. © 2014 Wiley Periodicals, Inc.

Therapeutic and Ethical Dilemma of Puberty and Menstruation Problems in an Intellectually Disabled (Autistic) Female: a Case Report.

PubMed

Memarian, Azadeh; Mehrpisheh, Shahrokh

2015-10-01

Intellectual disability is a term used when a person has certain limitations in mental functioning and skills. Autism is a group of developmental brain disorders, collectively called autism spectrum disorder (ASD). Teenagers with learning and physical disabilities are more likely to have menstrual problems compared to the general populations. The parents of a 12-year-old girl with autism spectrum disorder and intellectual disability referred to the coroner due to her numerous problems of puberty (menstruation) including: poor hygiene and polluting herself and the environment, not allowing to put or change the pads and changes in mood and physical health prior period, requested for the surgery (hysterectomy). In legal medicine organization after reviewing the medical records, physical exams and medical consultations with a gynecologist and psychiatric, surgery was not accepted. Hysterectomy (surgery) due to the age of the child, either physically or morally is not recommended. The use of hormone replacement therapy has side effects such as osteoporosis. In these cases, it seems noninvasive methods (behavioral therapy and learning care skills) under the welfare experts is also more effective and morally.