Onset Of Puberty In Females Research Articles

Developmental trajectory of social reward motivation from early adolescence into adulthood in female and male Long-Evans rats.

Most studies of adolescent and adult behavior involved one age group of each, whereas the dynamic changes in brain development suggest that there may be behavioral flux in adolescence. In two studies, we investigated developmental changes in social reward motivation in female and male Long-Evans rats from prepuberty to early adulthood in a social operant conditioning task. Given the earlier onset of puberty in females than in males, we predicted the course of social reward development would differ between the sexes. Overall, the pattern of results from both studies suggests that the trajectory of social motivation across adolescence is characterized by upward and downward shifts that do not depend on the sex of the rats. During training, in both studies, the mean number of social gate openings and percentage of social gate openings was higher at P30 (prepubertal, early adolescence) and P50 (late adolescence) than at P40 (mid adolescence) and P70 (adulthood) irrespective of sex. Nevertheless, the specific age comparisons that were significant depended on the study. In both studies, P30 rats had greater levels of social motivation than did adults in accessing a social reward when increased effort was required (progressive ratio tests). In an extinction test, only P30 and P50 rats continued to show more nose-pokes at the previously social gate than at the nonsocial gate, suggesting resistance to extinction. The results highlight the importance of characterizing behavior at several timepoints in adolescence to understand the neural mechanisms, many of which show similar discontinuities as they develop across adolescence.

Maternal cafeteria diet influences kisspeptin (Kiss1), kisspeptin receptor(Gpr54), and sirtuin (Sirt1) genes, hormonal and metabolic profiles, and reproductive functions in rat offspring in a sex-specific manner†.

Kisspeptin (KP, encoded by Kiss1, binding to the Gpr54 receptor) is a neuropeptide conveying information on the metabolic status to the hypothalamic-pituitary-gonadal axis. KP acts together with dynorphin A (encoded by Pdyn) and neurokinin B (encoded by Tac2) to regulate reproduction. KP is crucial for the onset of puberty and is under the control of sirtuin (encoded by Sirt1). We hypothesize that the maternal cafeteria (CAF) diet has adverse effects on the offspring's hormonal, metabolic, and reproductive functions due to sex-specific alterations in the expression of Kiss1, Gpr54, Pdyn, Tac2, and Sirt1 in the hypothalamus, and Kiss1, Gpr54, and Sirt1 in the liver. Rats were fed a CAF diet before pregnancy, during pregnancy, and during lactation. The vaginal opening was monitored. Offspring were sacrificed in three age points: PND 30, PND 35, and PND 60 (females) and PND 40, PND 45, and PND 60 (males). Their metabolic and hormonal status was assessed. mRNA for Kiss1, Gpr54, Pdyn, Tac2, and Sirt1 were measured by real-time PCR in the hypothalamus and/or livers. We found that CAF offspring had lower weight and altered body composition; increased cholesterol and triglyceride levels, sex-specific changes in glucose and insulin levels; sex-dependent changes in Sirt1/Kiss1 mRNA ratio in the hypothalamus; sex-specific alterations in Kiss1 and Sirt1 mRNA in the liver with more diversity in males; and a delayed puberty onset in females. We concluded that the mother's CAF diet leads to sex-specific alterations in metabolic and reproductive outcomes via Kiss1/Gpr54 and Sirt1 systems in offspring.

Leptin, but not Estradiol, Signaling in PACAP Neurons Modulates Puberty Onset

Abstract The adipose-derived hormone leptin critically modulates reproductive function, such that its absence results in hypothalamic hypogonadism. Pituitary adenylate cyclase-activating polypeptide (PACAP)-expressing neurons are potential mediators of leptin's action on the neuroendocrine reproductive axis because they are leptin-sensitive and involved in both feeding behavior and reproductive function. In the complete absence of PACAP, male and female mice exhibit metabolic and reproductive abnormalities, yet there is some sexual dimorphism in the reproductive impairments. We tested whether PACAP neurons play a critical and/or sufficient role in mediating leptin's effects on reproductive function by generating PACAP-specific leptin receptor (LepR) knockout and rescue mice, respectively. We also generated PACAP-specific estrogen receptor alpha knockout mice to determine whether estradiol-dependent regulation of PACAP was critically involved in the control of reproductive function and whether it contributed to the sexually dimorphic effects of PACAP. We showed that LepR signaling in PACAP neurons is critically involved in the timing of female, but not male, puberty onset, but not fertility. Rescuing LepR-PACAP signaling in otherwise LepR-deficient mice was unable to rescue the reproductive deficits observed in LepR null mice but led to a marginal improvement in body weight and adiposity in females. Finally, PACAP-specific estrogen receptor alpha knockout did not lead to any changes in body weight or puberty onset compared with control mice. These data highlight that PACAP is a critical mediator of some of leptin's, but not estradiol's, influence on puberty onset in females, but is not critically involved in relaying leptin's effects in males or in adult females.

Social communication advances the onset of puberty and increase body weight in female goats reared as a group

In small ruminant females, goats, and sheep, sensorial stimuli that emit (seeing, smelling, touching, hearing) have a marked influence on reproduction. The aim of this study was to determine if the females reared as a social group advance the onset of puberty and gained more body weight than females reared under social isolation. Females were isolated from males from weaning at 40 days of age and were split into two groups. In the first, females (n = 10) were placed together in a pen, while in the second (n = 10), each female was placed individually in a pen. The first ovulation, indicative of puberty’s onset, was denoted by the plasma progesterone (≥ 1 ng/mL) acquired from at least two consecutive blood samples collected weekly. The onset of puberty in females reared as a social group was at 342.2 ± 4.5 days of age, and in females reared in social isolation was at 360.8 ± 3.6 days. Body weight at the beginning of puberty in the social group was higher (28.7 ± 0.4 kg) than in those females reared under social isolation (24.5 ± 0.5 kg) (P < 0.5). In addition, at the end of the study, on day 379, the social group recorded a higher body weight (29.5 ± 1.8 kg) than those in social isolation (25.0 ± 0.5 kg) (P < 0.05). We conclude that female goats reared as a social group advanced the onset of puberty and gained more body weight compared to females reared under social isolation.

Asynchronous embryonic germ cell development leads to a heterogeneity of postnatal ovarian follicle activation and may influence the timing of puberty onset in mice

BackgroundOvarian follicles, which are the basic units of female reproduction, are composed of oocytes and surrounding somatic (pre) granulosa cells (GCs). A recent study revealed that signaling in somatic preGCs controlled the activation (initial recruitment) of follicles in the adult ovaries, but it is also known that there are two waves of follicle with age-related heterogeneity in their developmental dynamics in mammals. Although this heterogeneity was proposed to be crucial for female reproduction, our understanding of how it arises and its significance is still elusive.ResultsIn the current study, by deleting the key secreted factor KIT ligand from preGCs and analyzing the follicle cell developmental dynamics, we revealed distinct patterns of activation and growth associated with the two waves of follicles in mouse ovary. Our results confirmed that activation of adult wave follicles is initiated by somatic preGCs and dependent on the KIT ligand. By contrast, activation of first wave follicles, which are awakened from germ cells before follicle formation, can occur in the absence of preGC-secreted KIT ligand in postnatal ovaries and appears to be oocyte-initiated. We also found that the asynchronous activity of phosphatidylinositol 3 kinases (PI3K) signaling and meiotic process in embryonic germ cells lead to the follicle heterogeneity in postnatal ovaries. In addition, we supplied evidence that the time sequence of embryonic germ cell development and its related first wave follicle growth are correlated to the time of puberty onset in females.ConclusionTaken together, our study provides evidence that asynchronous development of embryonic oocytes leads to the heterogeneity of postnatal ovarian follicle activation and development, and affects the timing of onset of puberty in females.

Identifying Environmental Endocrine Disruptors Associated With the Age at Menarche by Integrating a Transcriptome-Wide Association Study With Chemical-Gene-Interaction Analysis.

Menarche is the first occurrence of menstrual bleeding and one of the most important events of female puberty. Alarmingly, over the last several decades, the mean age at menarche (AAM) has decreased. Environmental endocrine disruptors (EEDs) are chemicals that may interfere with the endocrine system, resulting in adverse developmental, immunological, neurological, and reproductive effects in humans. Thus, the effects of EEDs on fertility and reproduction are growing concerns in modern societies. In this study, we aimed to determine the influence of genetic and environmental factors on AAM. We used data from an AAM genome-wide association study of 329,345 women to conduct a transcriptome-wide association study (TWAS) with FUSION software. As references, we determined the gene-expression levels in the hypothalamus, pituitary gland, ovaries, uterus, and whole blood. We performed Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses using the significantly dysregulated genes identified by the TWAS. Using the STRING database, we also generated a protein–protein-interaction network to analyze common AAM-specific genes identified by the TWAS with different tissues. We performed chemical-related gene set enrichment analysis (CGSEA) and identified significant TWAS genes to uncover relationships between different chemicals and AAM. The TWAS identified 9,848 genes; among these, 1580 genes were significant (P < 0.05), and 11 genes were significant among the hypothalamus, pituitary, ovary, uterus, and whole blood. CGSEA identified 1,634 chemicals, including 120 chemicals significantly correlated with AAM. In summary, we performed a TWAS (for genetic factors) and CGSEA (for environmental factors) focusing on AAM and identified several AAM-associated genes and EEDs. The results of this study expand our understanding of genetic and environmental factors related to the onset of female puberty.

Leptin and Its Signaling Are Not Involved in Zebrafish Puberty Onset.

Leptin is a peptide hormone secreted from the adipose tissues and its signaling plays a central role in metabolic regulation of growth, especially on fat mass. In addition, leptin is also involved in regulating reproduction in mammals. In teleosts, there are two leptin ligands (lepa and lepb) and one cognate leptin receptor (lepr); however, their functions are still elusive. In this study, we created null-function mutants for lepa, lepb and lepr in zebrafish using CRISPR/Cas9 method and analyzed their phenotypes with emphasis on puberty onset, one major function widely reported for leptin in mammals. We demonstrated that the loss of leptin ligands or their receptor resulted in no obesity from prepubertal stage to adulthood. We then focused on leptin involvement in controlling puberty onset. We first confirmed the somatic threshold for puberty onset in females and proposed a criterion and somatic threshold for male puberty onset. We examined gonadal development and sex maturation in different genotypic combinations including single mutants (lepa-/-, lepb-/- and lepr-/-), double mutants (lepa-/-;lepb-/-) and triple mutants (lepa-/-;lepb-/-;lepr-/-). Our results showed that once the fish reached the thresholds, the siblings of all genotypes displayed comparable gonadal development in both sexes without obvious signs of changed puberty onset. In conclusion, this comprehensive genetic study on the lep-lepr system demonstrated that in contrast to its counterpart in mammals, leptin system plays little role in controlling growth and reproduction especially puberty onset in zebrafish.

Associations among maternal perfluoroalkyl substance levels, fetal sex-hormone enzymatic gene polymorphisms, and fetal sex hormone levels in the Hokkaido study

Prenatal sex hormones affect fetal growth; for example, prenatal exposure to low levels of androgen accelerates female puberty onset. We assessed the association of perfluoroalkyl substances (PFASs) in maternal sera and infant genotypes of genes encoding enzymes involved in sex steroid hormone biosynthesis on cord sera sex hormone levels in a prospective birth cohort study of healthy pregnant Japanese women (n = 224) recruited in Sapporo between July 2002 and October 2005. We analyzed PFAS and five sex hormone levels using liquid chromatography-tandem mass spectrometry. Cytochrome P450 (CYP) 17A1 (CYP17A1 rs743572), 19A1 (CYP19A1 rs10046, rs700519, and rs727479), 3β-hydroxysteroid dehydrogenase type 1 (HSD3B1 rs6203), type 2 (HSD3B2 rs1819698, rs2854964, and rs4659175), 17β-hydroxysteroid dehydrogenase type 1 (HSD17B1 rs605059, rs676387, and rs2676531), and type 3 (HSD17B3 rs4743709) were analyzed using real-time PCR. Multiple linear regression models were used to establish the influence of log10-transformed PFAS levels and infant genotypes on log10-transformed sex steroid hormone levels. When the interaction between perfluorooctanesulfonate (PFOS) levels and female infant genotype CYP17A1 (rs743572) on the androstenedione (A-dione) levels was considered, the estimated changes (95 % confidence intervals) in A-dione levels against PFOS levels, female infant genotype CYP17A1 (rs743572)-AG/GG, and interaction between them showed a mean increase of 0.445 (0.102, 0.787), mean increase of 0.392 (0.084, 0.707), and mean reduction of 0.579 (0.161, 0.997) (Pint = 0.007), respectively. Moreover, a female-specific interaction with testosterone levels was observed. A-dione and T levels showed positive main effects and negative interaction with PFOS levels and the female infant CYP17A1 genotype.

A Study to assess the Effectiveness of Video-Assisted Teaching Programme on Knowledge regarding Menstrual Hygiene among Adolescent Girls at selected school in Rudrapur, Udham Singh Nagar

Introduction: Adolescent phase in girls is a transition from girlhood to womanhood and marks the onset of female puberty. Puberty is the age at which the internal reproductive organs reach maturity, usually between the age of 11 to 15 years and Menarche is a biological, psychological, social, as well as behavioral transition for an adolescent girl from girlhood to womanhood. Menstruation is the most important physiological and biological sign of female puberty. It is the results of changes in hormones in the body and it’s a natural phenomenon; most of the adolescent girls have some wrong beliefs and behavior regarding menstruation. The main of this study is to provide adequate knowledge about menstrual hygiene among adolescent girls. It will help to develop and improve the hygienic pattern of menstruation and reduce the risk of reproductive tract infections. Methodology: To achieve the objectives of the study quantitative research approach was used in the study; pre experimental one group pre-test post-test design was selected. The data were collected from 45 Adolescent girls from 6th to 9th standard students of Guru Ram Das International School Rudrapur, Udham Singh Nagar Uttarakhand. And the non probability purposive sampling technique was used. The tools used for the study was (1) structured questionnaire to assess the socio-demographic data and (2) Structured questionnaire to assess knowledge regarding menstrual hygiene. Result: The finding of study revealed that the mean post-test knowledge score (18.80) was significant greater than the pre-test knowledge score (13.57) of experimental group of student, [t (44) = 9.47, P&lt;0.05]. The result showed that there was significant association between knowledge of student regarding menstrual hygiene with per month family income and previous knowledge regarding menstrual hygiene as the Chi square value for per month family income and (25.76, P&lt;0.05) and previous knowledge about menstrual hygiene (6.78, P&lt;0.05). The knowledge of student regarding menstrual hygiene was improved.

The relationship between body weight and dietary habits with respect to the timing of puberty among saudi children and adolescents.

Objective:The objective is to investigate the timing of pubertal onset as determined by the development of secondary sexual characteristics in relation to body weight and dietary patterns among Saudi females.Methods:Children/adolescents visiting general and endocrinology pediatric clinics in King AbdulAziz University Hospital were invited to participate in this study. Female subjects between the ages of 5 and 20 years were included in this study, and those with syndromic disease, chronic comorbidities, endocrinopathies, organic causes of precocious puberty, positive family history of early pubertal onset, and under chronic medication were excluded from the study. Data were collected through clinical interviews with the consent of the legal guardians, and physical examinations were conducted.Results:A total of 164 females were investigated. The mean age of thelarche, adrenarche, and menarche was 10, 11.3, and 12.2 years, respectively. We found a significant correlation between higher weight standard deviation and an earlier age of both thelarche and adrenarche. In addition, daily consumption of fast foods was significantly associated with an earlier menarchal age. Consumption of nonorganic poultry was linked to early thelarche.Conclusion:Efforts should be directed to increase public and community awareness that fast food consumption, inorganic poultry, and higher body weight are important modifiable factors that lead to an earlier onset of female puberty across different parameters: breast development, adrenarche, and menstruation.

Sexually dimorphic effects of prolactin treatment on the onset of puberty and olfactory function in mice

The onset of puberty is associated with the psychophysiological maturation of the adolescent to an adult capable of reproduction when olfactory signals play an important role. This period begins with the secretion of the gonadotropin-releasing hormone (GnRH) from GnRH neurons within the hypothalamus. This is regulated by kisspeptin neurons that express high levels of transmembrane prolactin receptors (PRLR) that bind to and are activated by prolactin (PRL). The elevated levels of serum PRL found during lactation, or caused by chronic PRL infusion, decreases the secretion of gonadotropins and kisspeptin and compromised the estrous cyclicity and the ovulation. In the present work, we aimed to evaluate the effects of either increased or decreased PRL circulating levels within the peripubertal murine brain by administration of PRL or treatment with cabergoline (Cab) respectively. We showed that either treatment delayed the onset of puberty in females, but not in males. This was associated with the augmentation of the PRL receptor (Prlr) mRNA expression in the arcuate nucleus and decreased Kiss1 expression in the anteroventral periventricular zone. Then, during adulthood, we assessed the activation of the mitral and granular cells of the main (MOB) and accessory olfactory bulb (AOB) by cFos immunoreactivity (ir) after the exposure to soiled bedding of the opposite sex. In the MOB, the PRL treatment promoted an increased cFos-ir of the mitral cells of males and females. In the granular cells of male of either treatment an augmented activation was observed. In the AOB, an impaired cFos-ir was observed in PRL and Cab treated females after exposure to male soiled bedding. However, in males, only Cab impaired its activation. No effects were observed in the AOB-mitral cells. In conclusion, our results demonstrate that PRL contributes to pubertal development and maturation of the MOB-AOB during the murine juvenile period in a sex-dependent way.

Loss of Inhibin Advances Follicle Activation and Female Puberty Onset but Blocks Oocyte Maturation in Zebrafish.

Inhibin was first characterized in mammals as a gonadal dimeric protein that inhibited pituitary follicle-stimulating hormone (FSH) secretion. As in mammals, the inhibin-specific α subunit (INHA/Inha/inha) has also been characterized in teleosts; however, its functions and physiological importance in fish reproduction remain unknown. Using CRISPR/Cas9 method, we generated an inha-deficient zebrafish line and analyzed its reproductive performance. As expected, pituitary expression of fshb increased significantly in both the young and the adult inha mutant. The expression of lhb also increased in the mutant, but only in sexually mature adults. Interestingly, the expression of activin βA (inhbaa) increased significantly in both the ovary and the testis of inha mutant, and the expression of ovarian aromatase (cyp19a1a) also increased dramatically in the mutant ovary. The juvenile female mutant showed clear signs of early follicle activation or precocious puberty onset. However, the adult female mutant was infertile with follicles arrested at the full-grown stage without final oocyte maturation and ovulation. Although follicle growth was normal overall in the mutant, the size and distribution of yolk granules in oocytes were distinct and some follicles showed granulosa cell hypertrophy. In contrast to females, inha-null males showed normal spermatogenesis and fertility. As reported in mammals, we also found sporadic tumor formation in inha mutants. Taken together, our study not only confirmed some conserved roles of inhibin across vertebrates, such as inhibition of FSH biosynthesis and tumor formation, but also revealed novel aspects of inhibin functions such as disruption of folliculogenesis and female infertility but no obvious involvement in spermatogenesis in fish.

Prenatal anxiety, breastfeeding and child growth and puberty: linking evolutionary models with human cohort studies

Background: Stress experienced by mothers during pregnancy can have both immediate and long-term effects on child development, potentially mediated by breastfeeding.Aim: Using a UK birth cohort study, we asked how maternal stress relates to breastfeeding and consequences for growth and puberty onset.Subjects and methods: We analysed data from the Avon Longitudinal Study of Parents and Children, collected via questionnaires and clinic visits (N: 698–8,506). We used reports of prenatal anxiety, breastfeeding, early growth and age at menarche or first voice change. Confounding by maternal age, parity, smoking, education and body mass index (BMI) was considered.Results: Mothers with higher levels of reported anxiety were less likely to breastfeed (Odds ratio (OR): 0.83, 95% confidence interval (CI): 0.71, 0.97). Breastfed infants had slower growth before weaning, although growth differences were unclear thereafter. Being breastfed for more than six months was associated with later puberty onset in females (2.76 months later than non-breastfed; CI: 0.9, 4.63), although the association was attenuated by confounders and BMI (1.51 months, CI: −0.38, 3.40). No association between breastfeeding and puberty onset in males was found.Conclusion: Our studies fit results shown previously, and we consider these in light of evolutionary life history theory while discussing key challenges in such an approach.

Impacts of nutrition on reproduction in female red deer: phenotypic flexibility within a photoperiod-mediated seasonal cycle

Red deer (Cervus elaphus) are widely distributed throughout cold northern temperate latitudes, where they have evolved to cope within highly seasonal continental environments. Naturalisation of red deer to the more moderate seasonal (but variable climatic) environment of New Zealand has been spectacularly successful, and they are widely farmed in the country’s pastoral environment for venison and antlers. The species is genetically programmed to exhibit photoperiodic control of voluntary feed intake, growth and reproduction, ensuring that energy demands are aligned with seasonally available resources and offspring are born in summer when climate is favourable for survival. However, despite genetic control of their endogenous seasonal cycles, there appears to be a strong ability for environmental factors such as nutrition to generate large phenotypic variation of seasonal traits. This may have contributed to their successful naturalisation to a wider range of seasonal environments than would be expected within their ancestral range. While precise timing of conception and duration of gestation length are the two fundamental mechanisms by which the strict seasonality of birth is maintained in seasonally breeding mammals, red deer exhibit considerable variation in both these traits. The present paper examines the outcomes of recent studies on farmed red deer on the impacts of lactation on conception date, the influence of nutrition during pregnancy on gestation length, and early life growth effects on the onset of female puberty. These studies have collectively demonstrated that while red deer are assumed to be under fairly rigorous genetic control of seasonality traits, they have a repertoire of phenotypic variation at various points of the reproductive cycle that may potentially allow a degree of adaptation to climatic variation that influences annual feed supply. This may explain the success of red deer in colonising a range of new environments that differ seasonally from their ancestral environment.

SAT-422 Galanin-Like Peptide Neurons Are Required for Correctly-Timed Puberty Onset in Mice

The timing of puberty requires exquisite coordination of hormones and brain circuitry. Numerous neuronal pathways have been identified as being involved, but exactly how they affect puberty onset is poorly understood. Galanin-like peptide (GALP)-expressing neurons are located in the arcuate nucleus of the hypothalamus, and their fibers make apparent contacts with GnRH neurons. Many GALP neurons express receptors for estrogens (ERα) and leptin, so they are good candidates for estrogenic and metabolic regulation of puberty onset and adult fertility. Prior experiments involving central GALP antiserum infusion suggest a stimulatory role for GALP, but the animal models for elucidating this role have been lacking to date. We therefore generated a GALP-Cre recombinase mouse to enable GALP neuronal ablation and activity modulation. To test if GALP neurons are required for male and female puberty onset, in experiment 1 we used GALP-Cre mice crossed with Cre-dependant diphtheria toxin (DT) receptor mice to produce mice with DT-inducible GALP neuronal ablation. In males treated with DT on day 18 of age, preputial separation was delayed in DT receptor-expressing mice vs controls (27.9 ± 0.6 vs 26.2 ± 0.5 days old (P<0.05, n=6-11). There was no significant difference in age of vaginal opening in DT receptor-expressing females compared to controls. To test if activation of GALP neurons advances male and female puberty onset, in experiment 2 we used GALP-Cre mice crossed with Cre-dependant hM3Dq excitatory designer receptor mice to produce mice with clozapine-n-oxide (CNO; hM3Dq receptor ligand)-inducible GALP neuron activation. In females receiving chronic CNO in drinking water from day 26 to day 30 of age, there was a non-significant trend towards advanced vaginal opening age in hM3Dq receptor-expressing mice vs controls (31.9 ± 0.7 vs 33.3 ± 0.6 days old (P=0.2, n=4-8). There was no significant difference in preputial separation age in DT receptor-expressing males compared to controls. These results support a stimulatory role for GALP neurons in puberty onset. One possible explanation for the sex differences in this study is that males may have higher GALP neuronal activity at the time of treatment compared to females, making them more responsive to neuronal ablation. Follow-up studies will use earlier ablation and activation protocols.

MON-222 Blocking GABAB Receptors (GABABR) from Birth to Weaning in Mice Induces Profound Changes in the Gonadotropic Axis

We have previously shown that the administration of a GABAB antagonist (CGP55845) to neonatal BALB/C mice from postnatal day (PND) 2-6 significantly decreased arcuate nucleus (ARC) kisspeptin (Kiss1) expression in both sexes. Furthermore, this neonatal CGP55845 treatment delayed puberty onset in females and altered gonadotropin secretion in both sexes in adulthood. Here our aim was to induce a more sustained inhibition of GABABR signaling and evaluate its effects on the gonadotropic axis. Neonatal Balb/c male (M) and female (F) mice were injected with CGP55845 (1 mg/kg, sc, CGP) or saline (CTRL) from PND2-21, three times/day (8AM, 1PM, 6PM) and sacrificed at 3PM (after two injections on the last day). Serum samples and gonads were collected for hormonal measurements by RIA. Brains were frozen and 500 µm slices were obtained on a cryostat. ARC and antero ventral periventricular nucleus (AVPV) micropunches were obtained. Kiss1, kisspeptin receptor (Kiss1r), prodynorfin (Pdyn), neurokinin B (Tac2), tyrosine hydrolxylase (TH), progesterone receptor (Pgr), GABAB1 and GABAB2 subunits of the GABABR (GABAB1, GABAB2) mRNA expression was assessed in the micropunches by qPCR (control gene: Cyclophilin B). Body weight (BW) and AGI (anogenital distance/BW) were evaluated on PND 7, 14 and 21. In the ARC CGP induced a significant decrease in Kiss1 expression (FCTRL: 1,16±0.24 vs FCGP: 0,67±0.16 vs MCTRL: 1,22±0.24 vs MCGP: 0,70±0.13, CGP vs CTRL p<0,04) and an increase in Pdyn (FCTRL: 0,97±0.26 vs FCGP: 1,77±0,49 vs MCTRL: 1,37±0.32 vs MCGP: 3,01±0.85, CGP vs CTRL: p<0,02) and GABAB1 (FCTRL: 0,42±0.08 vs FCGP: 1,37±0.43 vs MCTRL: 0,74±0.13 vs MCGP: 1,38±0.46, CGP vs CTRL: p<0,04) in both sexes, while a decrease in Tac2 was only observed in males (MCTRL: 1,01±0.14 vs MCGP: 0,45±0.045: p<0,02); no changes were observed in Kiss1r or Pgr expression. In AVPV no CGP-induced changes in Kiss1,Kiss1r, TH, Pgr, GABABR expression were detected. FSH was significantly decreased in CGP-treated males (FSH (ng/ml): MCTRL: 9,3±1,28 vs MCGP: 5,78±0.9: p<0,003). BW was significantly decreased by CGP on PND21 in females while this parameter was decreased at all ages studied in males. CGP significantly decreased AGI in both sexes. These results demonstrate that sustained inhibition of GABABR signaling during the critical postnatal period of development and maturation of the gonadotropic axis profoundly alters key ARC gene expression such as Kiss1, Pdyn, Tac2, altering sexual differentiation (AGI) and BW. In addition, in males FSH levels are decreased to female levels in agreement with feminization of AGI. (Supported by CONICET, ANPCYT, UBA, Fundación René Barón, Fundación Williams).

Exposure to Gestational Diabetes Is a Stronger Predictor of Dysmetabolic Traits in Children Than Size at Birth.

Being born small or large for gestational age and intrauterine exposure to gestational diabetes (GDM) increase the risk of type 2 diabetes in the offspring. However, the potential combined deleterious effects of size at birth and GDM exposure remains unknown. We examined the independent effect of size at birth and the influence of GDM exposure in utero on cardiometabolic traits, body composition, and puberty status in children. The present study was a longitudinal birth cohort study. We used clinical data from 490 offspring of mothers with GDM and 527 control offspring aged 9 to 16 years, born singleton at term from the Danish National Birth Cohort with available birthweight data. We found no evidence of a U-shaped association between size at birth (expressed as birthweight, sex, and gestational age adjusted z-score) and cardiometabolic traits. Body size in childhood and adolescence reflected the size at birth but was not reflected in any metabolic outcome. No synergistic adverse effect of being born small or large for gestational age and exposure to GDM was shown. However, GDM was associated with an adverse metabolic profile and earlier onset of female puberty in childhood and adolescence independently of size at birth. In childhood and adolescence, we found GDM was a stronger predictor of dysmetabolic traits than size at birth. The combination of being born small or large and exposed to GDM does not exacerbate the metabolic profile in the offspring.

Methylome profiling of healthy and central precocious puberty girls

BackgroundRecent studies demonstrated that changes in DNA methylation (DNAm) and inactivation of two imprinted genes (MKRN3 and DLK1) alter the onset of female puberty. We aimed to investigate the association of DNAm profiling with the timing of human puberty analyzing the genome-wide DNAm patterns of peripheral blood leukocytes from ten female patients with central precocious puberty (CPP) and 33 healthy girls (15 pre- and 18 post-pubertal). For this purpose, we performed comparisons between the groups: pre- versus post-pubertal, CPP versus pre-pubertal, and CPP versus post-pubertal.ResultsAnalyzing the methylome changes associated with normal puberty, we identified 120 differentially methylated regions (DMRs) when comparing pre- and post-pubertal healthy girls. Most of these DMRs were hypermethylated in the pubertal group (99%) and located on the X chromosome (74%). Only one genomic region, containing the promoter of ZFP57, was hypomethylated in the pubertal group. ZFP57 is a transcriptional repressor required for both methylation and imprinting of multiple genomic loci. ZFP57 expression in the hypothalamus of female rhesus monkeys increased during peripubertal development, suggesting enhanced repression of downstream ZFP57 target genes. Fourteen other zinc finger (ZNF) genes were related to the hypermethylated DMRs at normal puberty. Analyzing the methylome changes associated with CPP, we demonstrated that the patients with CPP exhibited more hypermethylated CpG sites compared to both pre-pubertal (81%) and pubertal (89%) controls. Forty-eight ZNF genes were identified as having hypermethylated CpG sites in CPP.ConclusionMethylome profiling of girls at normal and precocious puberty revealed a widespread pattern of DNA hypermethylation, indicating that the pubertal process in humans is associated with specific changes in epigenetically driven regulatory control. Moreover, changes in methylation of several ZNF genes appear to be a distinct epigenetic modification underlying the initiation of human puberty.

Transcriptomic Analysis for Differentially Expressed Genes in Ovarian Follicle Activation in the Zebrafish.

In teleosts, the onset of puberty in females is marked by the appearance of the first wave of pre-vitellogenic (PV) follicles from the pool of primary growth (PG) follicles (follicle activation) in the ovary during sexual maturation. To understand the mechanisms underlying follicle activation and therefore puberty onset, we undertook this transcriptomic study to investigate gene expression profiles in the event. Our analysis revealed a total of 2,027 up-regulated and 859 down-regulated genes during the PG-PV transition. Gene Ontology (GO) analysis showed that in addition to basic cellular functions such as gene transcription, cell differentiation, and cell migration, other biological processes such as steroidogenesis, cell signaling and angiogenesis were also enriched in up-regulated genes; by comparison, some processes were down-regulated including piRNA metabolism, gene silencing and proteolysis. Further Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis identified a variety of signaling pathways that might play pivotal roles in PG-PV transition, including MAPK, TGF-β, Hedgehog, FoxO, VEGF, Jak-STAT, and phosphatidylinositol signaling pathways. Other pathways of particular interest included endocytosis and glycosaminoglycan biosynthesis. We also analyzed expression changes of genes expressed in different compartments viz. oocytes and follicle cells. Interestingly, most oocyte-specific genes remained unchanged in expression during follicle activation whereas a great number of genes specifically expressed in the follicle cells showed significant changes in expression. Overall, this study reported a comprehensive analysis for genes, biological processes and pathways involved in follicle activation, which also marks female puberty onset in the zebrafish when occurring for the first time in sexual maturation.

Temporal Expression Patterns of Genes Related to Sex Steroid Action in Sexually Dimorphic Nuclei During Puberty.

Sex steroids play a major role in sexually dimorphic brain development during not only the perinatal period but also the pubertal period. We previously showed that, in male mice, the estrogen receptor-α (Esr1) and aromatase (Cyp19a1) genes are essential to the sexually dimorphic formation of the anteroventral periventricular nucleus (AVPV) and the principal nucleus of the bed nucleus of the stria terminalis (BNSTp), but the estrogen receptor-β (Esr2) gene is not necessary. We also showed that the androgen receptor (Ar) gene is essential to the sexually dimorphic formation of the BNSTp. These genes are expressed in the AVPV and BNSTp of perinatal mice. However, it remains unknown whether these genes are expressed in the AVPV and BNSTp during puberty, and whether the expression, if any, differs by sex, age, and brain region. Here, we dissected the AVPV and BNSTp from Nissl-stained brain sections of male and female mice on postnatal day (PD) 20 (prepuberty), PD30 (puberty onset in females), PD40 (puberty onset in males), and PD60 (young adult) using a laser microdissection system. We then examined the mRNA levels of Esr1, Esr2, Cyp19a1, and Ar in these brain regions. In the AVPV, Esr1 mRNA levels were greater in females than males during PD20–60. Esr2 and Ar mRNA expressions did not differ between sexes. Ar mRNA levels were higher at PD30 than PD20. Cyp19a1 mRNA was not detected in the AVPV at PD20–60. In the BNSTp, Esr1 and Esr2 mRNA levels were higher in females than in males during PD20–60, although the mRNA levels of Cyp19a1 and Ar did not differ between sexes. Additionally, we revealed that orchiectomy at PD20 induced a failure of normal formation of the male BNSTp and testosterone replacement in the prepubertal period rescued the effect of orchiectomy at PD20. Taken together, it is suggested that pubertal testosterone transported to the AVPV is not converted to estradiol there and does not act via ESR1 and ESR2. By contrast, the formation of the male BNSTp may be affected by testicular testosterone during puberty via AR and/or via ESR1 after conversion to estradiol by CYP19A1.