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Pediatrics in Review Jul 2016
Review
Topics: Adolescent; Child; Female; Humans; Male; Puberty; Sexual Maturation
PubMed: 27368360
DOI: 10.1542/pir.2015-0065 -
Seminars in Reproductive Medicine Jul 2019Puberty is a fundamental developmental event in the lifespan of any individual, when sexual and somatic maturation is completed, and reproductive capacity is achieved.... (Review)
Review
Puberty is a fundamental developmental event in the lifespan of any individual, when sexual and somatic maturation is completed, and reproductive capacity is achieved. While the tempo of puberty is under strong genetic determination, it is also modulated by a wide array of internal and environmental cues, including, prominently, nutritional and metabolic signals. In the last decade, our understanding of the neurohormonal basis of normal puberty and its perturbations has enlarged considerably. This is illustrated by the elucidation of the essential roles of kisspeptins, encoded by the Kiss1 gene, in the hypothalamic circuits controlling puberty. Moreover, other neuropeptide pathways, convergent with kisspeptin signaling, have been pointed out as important coregulators of pubertal timing. These include the cotransmitters of Kiss1 neurons in the arcuate nucleus (ARC), neurokinin B, and dynorphin, as well as melanocortins, produced by ARC neurons expressing proopiomelanocortin, which are endowed with key roles also in the control of metabolic homeostasis. This neuropeptide setup seemingly participates, in a coordinated manner, in transmitting the regulatory actions of metabolic cues on pubertal maturation. In this function, cellular metabolic sensors, such as the AMP-activated protein kinase, and the fuel-sensing deacetylase, SIRT1, have also been shown recently to contribute to the metabolic regulation of puberty. Altogether, elucidation of the physiological roles of these signals and regulatory circuits will help uncover the intimacies of the brain control of puberty, and its alterations in conditions of metabolic stress, ranging from subnutrition to obesity.
Topics: Animals; Humans; Hypothalamus; Kisspeptins; Neurokinin B; Neurons; Neuropeptides; Puberty; Reproduction; Sexual Maturation; Signal Transduction
PubMed: 31972860
DOI: 10.1055/s-0039-3400967 -
Human Reproduction (Oxford, England) Feb 2009The reproductive health of children born of infertile couples may be affected by infertility treatment or factors associated with infertility. We examined sexual...
BACKGROUND
The reproductive health of children born of infertile couples may be affected by infertility treatment or factors associated with infertility. We examined sexual maturation in children of parents with infertility.
METHODS
We used data from a follow-up of 3382 girls and 2810 boys born between 1984 and 1987 in the Aalborg-Odense Birth Cohort. We had mothers' report of time to pregnancy (TTP) and infertility treatment (at the time, mostly hormonal) from the pregnancy questionnaire administered in 1984-1987, and the children's report of their own sexual maturation from the follow-up questionnaire administered in 2005, when they were between 18 and 21 years old. Many reported age only in year when they had the events related to sexual maturation, and for each event, we imputed the month based on the median month at each year of age among those reporting both years and months.
RESULTS
In girls, the mean age at menarche was 13.3 years and, in boys, the mean age at appearance of acne, voice break, regular shaving and first nocturnal emission were 14.5, 14.5, 17.2 and 14.7 years, respectively. We saw no significant differences in age at these events among children born of either fertile (with TTP of 0-12 months and no treatment), untreated infertile (with TTP of more than 12 months and no treatment) or treated infertile couples (with a history of examination or treatment for infertility).
CONCLUSIONS
Our data suggest no significant association between parental infertility or hormonal treatment and timing of sexual maturation in the offspring.
Topics: Adolescent; Adult; Cohort Studies; Female; Fertility Agents; Follow-Up Studies; Humans; Infertility; Male; Maternal Exposure; Puberty; Sexual Maturation; Time Factors
PubMed: 18840889
DOI: 10.1093/humrep/den366 -
Bulletin of Entomological Research Aug 2012The physiological age of adult males of seven mealybug species was measured in relation to the elongation of the male pair of the waxy caudal filaments. These filaments...
The physiological age of adult males of seven mealybug species was measured in relation to the elongation of the male pair of the waxy caudal filaments. These filaments begin to emerge after eclosion and reached their maximum length from 29.4-46.6 h. The studied males were divided into three age groups, expressed as percentages of the total waxy caudal filaments length. Attraction to a sex pheromone source was significantly higher in the oldest male group (maximum filaments growth) compared with youngest one. Only the oldest male group copulated successfully; few of the younger males tested displayed 'courtship' behavior towards conspecific virgin females. The calculated duration of the sexually active phase of the adult male life cycle varied among species ranging from 34.4 to 46.6 h. There were marked variations in the strength of attraction to a pheromone source according to time of day. There was a continuous decrease in sexual activity from morning to evening. Our findings reveal clear maturation periods for adult males of the seven studied species. The long immature phase of the adult male mealybug is probably also related to several physiological processes that are needed to complete male maturation. The most noticeable change is the elongation of the waxy caudal filaments. However, mating may be performed at any time ambient conditions are suitable. Whereas male mealybug flight towards a pheromone source is restricted to a few hours, the male may continue mating activity throughout its sexually active period.
Topics: Age Factors; Animals; Copulation; Female; Hemiptera; Humans; Male; Sex Attractants; Sexual Behavior, Animal; Sexual Maturation
PubMed: 22082650
DOI: 10.1017/S0007485311000605 -
Trends in Endocrinology and Metabolism:... Nov 2004At puberty, pulsatile secretion of hormones initiates sexual maturation of the gonads. The G-protein-coupled receptor GPR54 is crucially involved in the initiation of... (Review)
Review
At puberty, pulsatile secretion of hormones initiates sexual maturation of the gonads. The G-protein-coupled receptor GPR54 is crucially involved in the initiation of puberty, along with its ligand metastin. Mice lacking GPR54 fail to undergo puberty and have immature reproductive organs and low levels of sex steroids and gonadotrophic hormones, but have normal levels of gonadotrophin-releasing hormone in the hypothalamus. In humans, several cases of hypogonadism have been ascribed to mutations in GPR54. Production of metastin and, to a lesser extent, GPR54 are negatively regulated by testosterone and oestrogen, and injecting GPR54 ligands can increase hormone secretion in rodents. Thus, GPR54 is required for normal functioning of the hypothalamic-pituitary-gonadal axis, probably at the level of gonadotrophin-releasing-hormone secretion.
Topics: Animals; Humans; Puberty; Receptors, G-Protein-Coupled; Receptors, Kisspeptin-1; Receptors, Neuropeptide; Sexual Maturation
PubMed: 15519892
DOI: 10.1016/j.tem.2004.09.008 -
Journal of Endocrinological... 1989Adolescence represents the period of important somatic changes which lead to sexual maturation, pubertal growth and active functions of reproduction. Mean ages of onset... (Review)
Review
Adolescence represents the period of important somatic changes which lead to sexual maturation, pubertal growth and active functions of reproduction. Mean ages of onset of puberty are 10.9 and 11.2 in girls and boys respectively. Menarche occurs at a mean age of 13.4 yr and may be related to a critical weight. In boys, testicular growth above 4 cm2 or 4 ml is the first clinical sign of gonadal pubertal maturation. In girls, the first sign is the budding of the breast. At onset of puberty, the hypothalamus after a "quiescent" period resumes a marked pulsatile secretion of gonadotrophin-releasing hormone, leading to an increased secretion of pituitary gonadotropins which in turn stimulate the gonadal functions, i.e. the secretion of testosterone or estradiol and maturation of the spermatogenesis or the ovarian follicle. Neuroendocrine factors which probably control the onset of puberty are numerous: cerebral adrenergic and/or dopamine neurotransmitters, endogenous opioids, melatonin from the pineal gland. Gonadal maturation (gonadarche) is preceded in the infant by a post-natal surge of luteinizing hormone and at age 7 to 8 yr by an adrenal maturation (adrenarche).
Topics: Adolescent; Child; Female; Humans; Male; Puberty; Sexual Maturation
PubMed: 2681349
DOI: No ID Found -
Reproductive Biology Mar 2003It is known that growth hormone (GH) plays an important role in growth and development.Additionally, emerging evidence suggest that it also influences... (Review)
Review
It is known that growth hormone (GH) plays an important role in growth and development.Additionally, emerging evidence suggest that it also influences hypothalamic-pituitary-gonadal function. We have found that GH from different species has different effects in mice. In rodents, human GH (hGH) binds to both GH and prolactin (PRL) receptors; it has both somatotrophic and lactotrophic effects. Since PRL has a profound effect on neuroendocrine function, the results obtained from hGH treatment or from transgenic animals expressing the hGH gene reflect PRL-like effects of this hormone. However, bovine GH (bGH) is purely somatogenic and therefore the effects of bGH represent the function of the natural GH produced in rodents. Furthermore, our studies in mice and rats have shown that not all effects of GH are stimulatory and the duration of exposure of the hypothalamo-hypophyseal-gonadal system to GH might influence the secretions of gonadotropins and gonadal steroids. In humans, excess productions of GH in acromegaly and GH resistance in Laron syndrome adversely affect reproduction. Similarly, it has been demonstrated that in transgenic mice expressing various GH genes, in insulin-like growth factor-I (IGF-I) gene-knockout mice, in GH receptor gene-disrupted (GHR-KO) mice, and in Ames dwarf mice the onset of puberty and/or fertility is altered. Therefore, excess or subnormal secretion of GH can affect reproduction. We have shown that the hypothalamic-pituitary functions are affected in transgenic mice expressing the GH genes, Ames dwarf mice and in GH receptor gene knockout mice. The majority of the GH effects are mediated via IGF-I and the aforementioned effects may be due to the GH-induced IGF-I secretion or due to the absence of this peptide production. It is important to realize that the syntheses and actions of IGF binding proteins are controlled by IGF-I. Furthermore, some IGF binding proteins can inhibit IGF-I action. Therefore, the concentrations of IGF binding proteins and the ratio of these binding proteins and IGF-I within the body might play a pivotal role in modulating IGF-I effects on the neuroendocrine-gonadal system.
Topics: Animals; Insulin-Like Growth Factor I; Models, Animal; Neurosecretory Systems; Sexual Maturation
PubMed: 14666141
DOI: No ID Found -
Effect of age at photostimulation on sexual maturation and egg-laying performance of layer breeders.Poultry Science Feb 2020The objective of this study was to determine the effect of age at photostimulation on sexual maturity and performance of layer breeders. A total of 192 fourteen-wk-old...
The objective of this study was to determine the effect of age at photostimulation on sexual maturity and performance of layer breeders. A total of 192 fourteen-wk-old White Leghorn (WL) breeder hens were randomly allocated to 4 treatments of 48 birds each, with 2 replicates per treatment. The birds were photostimulated at 16 (PS16), 18 (PS18), 20 (PS20), and 22 (PS22) wk of age. Four birds per treatment were randomly selected to evaluate sexual organ development at 1 D before photostimulation and 2, 4, and 6 wk after photostimulation. The ovary weight, large yellow follicles number (LYF), oviduct weight, and oviduct length of PS18 increased sharply after photostimulation. Conversely, the increase in PS16 was not observed until 2 wk after photostimulation. There was no difference in age at sexual maturity between treatments (P > 0.05). The PS16 had the longest interval (28 D) from photostimulation to 5% egg production, while PS22 reached 5% egg production 7 D before photostimulation. The PS22 had lower peak production (P = 0.02) and less egg production (P = 0.02) than other treatments. The PS16 had more broken and abnormal eggs (P = 0.01) and lower hatchability (P = 0.04) than other treatments. In conclusion, photostimulation at 16 and 22 wk of age decreases hatchability and egg production, respectively, and photostimulation at 18 wk is appreciated for the WL breeder hens.
Topics: Age Factors; Animals; Chickens; Egg Shell; Female; Fertility; Photic Stimulation; Random Allocation; Reproduction; Sexual Maturation
PubMed: 32029163
DOI: 10.1016/j.psj.2019.12.027 -
Journal of Proteome Research Jun 2020Allotetraploid hybrids of Red Crucian Carp ( red var, abbreviated as RCC) (♀) and common Carp ( L, abbreviated as CC) (♂) is a species produced by distant...
Allotetraploid hybrids of Red Crucian Carp ( red var, abbreviated as RCC) (♀) and common Carp ( L, abbreviated as CC) (♂) is a species produced by distant hybridization. In this study, SWATH mass spectrometry (SWATH-MS) was applied for quantitative proteomics profiling of gonad tissues of allotetraploids and their parents RCC (♀) and CC (♂). A total of 2338 unique proteins were identified in our proteomic profiling by SWATH-MS. Gene enrichment and network analysis based on differentially expressed proteins revealed some metabolic enzymes involved in gonad growth and development of allotetraploids. Especially, the upregulated gene ( = 2.59, = 0.02) in allotetraploids plays a significant role in spermatogenesis, which could speed up the sexual maturation during the process of gonad growth and development. Protein-protein interaction and pathway analysis further suggested that served as a hub protein in metabolic-related pathways and networks. It could regulate gonad development via regulating metabolic pathways in a synergistic way with surrounding regulatory factors including , , , and . In addition, could directly regulate spermatogenesis in conjunction with , , and . Quantitative proteomics integrated with network analysis explored the molecular mechanism in that regulated sexual maturation, development, and growth of allotetraploids in a synergetic way with metabolic genes and pathways.
Topics: Animals; Carps; Goldfish; Male; Proteomics; Sexual Maturation; Up-Regulation
PubMed: 32286072
DOI: 10.1021/acs.jproteome.0c00008 -
Frontiers in Cellular and Infection... 2023Schistosomes are the only mammalian flatworms that have evolved separate sexes. A key question of schistosome research is the male-dependent sexual maturation of the...
INTRODUCTION
Schistosomes are the only mammalian flatworms that have evolved separate sexes. A key question of schistosome research is the male-dependent sexual maturation of the female since a constant pairing contact with a male is required for the onset of gonad development in the female. Although this phenomenon is long known, only recently a first peptide-based pheromone of males was identified that contributes to the control of female sexual development. Beyond this, our understanding of the molecular principles inducing the substantial developmental changes in a paired female is still rudimentary.
OBJECTIVES
Previous transcriptomic studies have consistently pointed to neuronal genes being differentially expressed and upregulated in paired males. These genes included Smp_135230 and Smp_171580, both annotated as aromatic-L-amino-acid decarboxylases (DOPA decarboxylases). Here, we characterized both genes and investigated their roles in male-female interaction of .
METHODOLOGIES/FINDINGS
Sequence analyses indicated that Smp_135230 represents an L-tyrosine decarboxylase (Sm), whereas Smp_171580 represents a DOPA decarboxylase (Sm). By qRT-PCR, we confirmed the male-specific and pairing-dependent expression of both genes with a significant bias toward paired males. RNA-interference experiments showed a strong influence of each gene on gonad differentiation in paired females, which was enhanced by double knockdown. Accordingly, egg production was significantly reduced. By confocal laser scanning microscopy, a failure of oocyte maturation was found in paired knockdown females. Whole-mount hybridization patterns exhibited the tissue-specific occurrence of both genes in particular cells at the ventral surface of the male, the gynecophoral canal, which represents the physical interface of both genders. These cells probably belong to the predicted neuronal cluster 2 of
CONCLUSION
Our results suggest that Sm and Sm are male-competence factors that are expressed in neuronal cells at the contact zone between the genders as a response of pairing to subsequently control processes of female sexual maturation.
Topics: Female; Male; Animals; Schistosoma mansoni; Sexual Maturation; Schistosomatidae; Cell Differentiation; Gene Expression Profiling; Mammals
PubMed: 37305409
DOI: 10.3389/fcimb.2023.1173557