scholarly journals Programming of the reproductive axis by hormonal and genetic manipulation in mice

Reproduction ◽  
2018 ◽  
Author(s):  
Susana B Rulli ◽  
María Julia Cambiasso ◽  
Laura D Ratner
Keyword(s):  
Sex Chromosome ◽  
Genetic Manipulation ◽  
Sex Differentiation ◽  
Reproductive Function ◽  
Gonadal Steroids ◽  
Critical Periods ◽  
Female Reproduction ◽  
Control Male ◽  
Male And Female ◽  
The Brain

In mammals, the reproductive function is controlled by the hypothalamic-pituitary-gonadal axis. During development, mechanisms mediated by gonadal steroids exert an imprinting at the hypothalamic-pituitary level, by establishing sexual differences in the circuits that control male and female reproduction. In rodents, the testicular production of androgens increases drastically during the fetal/neonatal stage. This process is essential for the masculinization of the reproductive tract, genitals and brain. The conversion of androgens to estrogens in the brain is crucial for the male sexual differentiation and behavior. Conversely, feminization of the brain occurs in the absence of high levels of gonadal steroids during the perinatal period in females. Potential genetic contribution to the differentiation of brain cells through direct effects of genes located on sex chromosomes is also relevant. In this review, we will focus on the phenotypic alterations that occur on the hypothalamic-pituitary-gonadal axis of transgenic mice with persistently elevated expression of the human chorionic gonadotropin hormone (hCG). Excess of endogenously synthesized gonadal steroids due to a constant hCG stimulation is able to disrupt the developmental programming of the hypothalamic-pituitary axis in both transgenic males and females. Locally produced estrogens by the hypothalamic aromatase might play a key role in the phenotype of these mice. The “four core genotypes” mouse model demonstrated a potential influence of sex chromosome genes in brain masculinization before critical periods of sex differentiation. Thus, hormonal and genetic factors interact to regulate the local production of the neurosteroids necessary for the programming of the male and female reproductive function.

scholarly journals Neurobehavioral effects of choninergic drugs in prenatal period

2017 ◽  
Vol 15 (3) ◽  
pp. 5-21 ◽  
Author(s):  
Elena V. Stashina ◽  
Nikolay A. Gavrilov ◽  
Petr D. Shabanov
Keyword(s):  
Reproductive Function ◽  
Prenatal Development ◽  
Environmental Toxicants ◽  
Critical Periods ◽  
Brain Neurotransmitter ◽  
Neurobehavioral Deficits ◽  
Neurobehavioral Effects ◽  
The Brain ◽  
Prenatal Effects

Environmental toxicants, chemicals exhibiting with cholinotropics properties, and drugs – agonists and antagonists of M- and N-cholinergic receptors by acting on the developing brain of the fetus in the embryonic period of ontogenesis, cause a change the activity of the cholinergic mechanisms of the brain during critical periods of prenatal development with the subsequent disruption of the formation of different brain systems, primarily the ontogeny of nerve cells and brain neurotransmitter systems. These changes in the long term is correlated with neurobehavioral deficits from adult individuals, dysfunction of the reproductive system of adult offspring. The relevance of the study of prenatal effects of cholinergic factors on the central mechanisms of reproductive function, memory processes and learning during ontogenetic development of the organism due to the need of prevention and treatment of subsequent mental, behavioral, and sexual dysfunctions, and abnormal sexual behavior, infertility.

scholarly journals Sex biased expression of hormone related genes at early stage of sex differentiation in papaya flowers

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Juan Liu ◽  
Li-Yu Chen ◽  
Ping Zhou ◽  
Zhenyang Liao ◽  
Hai Lin ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Early Stage ◽  
Sex Differentiation ◽  
Molecular Genetic ◽  
Morphological Difference ◽  
Gene Interaction ◽  
Development Stage ◽  
Male And Female

AbstractSex types of papaya are controlled by a pair of nascent sex chromosomes, but molecular genetic mechanisms of sex determination and sex differentiation in papaya are still unclear. We performed comparative analysis of transcriptomic profiles of male and female floral buds at the early development stage before the initiation of reproductive organ primordia at which there is no morphological difference between male and female flowers. A total of 1734 differentially expressed genes (DEGs) were identified, of which 923 showed female-biased expression and 811 showed male-biased expression. Functional annotation revealed that genes related to plant hormone biosynthesis and signaling pathways, especially in abscisic acid and auxin pathways, were overrepresented in the DEGs. Transcription factor binding motifs, such as MYB2, GAMYB, and AP2/EREBP, were enriched in the promoters of the hormone-related DEGs, and transcription factors with those motifs also exhibited differential expression between sex types. Among these DEGs, we also identified 11 genes in the non-recombining region of the papaya sex chromosomes and 9 genes involved in stamen and carpel development. Our results suggested that sex differentiation in papaya may be regulated by multiple layers of regulation and coordination and involved transcriptional, epigenetic, and phytohormone regulation. Hormones, especially ABA and auxin, transcription factors, and genes in the non-recombination region of the sex chromosome could be involved in this process. Our findings may facilitate the elucidation of signal transduction and gene interaction in sex differentiation of unisexual flowers in papaya.

scholarly journals Prenatal programming of the female reproductive neuroendocrine system by androgens

Reproduction ◽  
2006 ◽  
Vol 132 (4) ◽  
pp. 539-547 ◽  
Author(s):  
Jane Robinson
Keyword(s):  
Reproductive Function ◽  
Sexually Dimorphic ◽  
Critical Periods ◽  
The Neural Network ◽  
Gnrh Release ◽  
Steroid Sensitive ◽  
Neuroendocrine Axis ◽  
Species Specific ◽  
Male Hormones ◽  
The Brain

It has been clear for several decades that the areas of the brain that control reproductive function are sexually dimorphic and that the ‘programming actions’ of the male gonadal steroids are responsible for sex-specific release of the gonadotrophins from the pituitary gland. The administration of exogenous steroids to fetal/neonatal animals has pinpointed windows of time in an animals’ development when the reproductive neuroendocrine axis is responsive to the organisational influences of androgens. These ‘critical’ periods for sexual differentiation of the brain are trait- and species-specific. The neural network regulating the activity of the gonadotrophin releasing hormone (GnRH) neurones is vital to the control of reproductive function. It appears that early exposure to androgens does not influence the migratory pathway of the GnRH neurone from the olfactory placode or the size of the population of neurones that colonise the postnatal hypothalamus. However, androgens do influence the number and the nature of connections that these neurones make with other neural phenotypes. Gonadal steroid hormones play key roles in the regulation of GnRH release acting largely via steroid-sensitive intermediary neurones that impinge on the GnRH cells. Certain populations of hormonally responsive neurones have been identified that are sexually dimorphic and project from hypothalamic areas known to be involved in the regulation of GnRH release. These neurones are excellent candidates for the programming actions of male hormones in the reproductive neuroendocrine axis of the developing female.

Effects of aroclor 1254 on the expression of the KAP3 gene and reproductive function in rats

2007 ◽  
Vol 19 (4) ◽  
pp. 539 ◽  
Author(s):  
Chae Kwan Lee ◽  
Han Seung Kang ◽  
Ju Ran Kim ◽  
Byung Ju Lee ◽  
Jong Tae Lee ◽  
...  
Keyword(s):  
Sexual Differentiation ◽  
Reproductive Function ◽  
Female Rats ◽  
Mrna Levels ◽  
Critical Periods ◽  
Control Groups ◽  
Control Male ◽  
Control Female ◽  
Male Control ◽  
Brain Sexual Differentiation

The present study investigated the effects of aroclor 1254 (A1254) on the expression of the kinesin superfamily associated protein 3 (KAP3) gene in F1 rat brain during brain sexual differentiation and puberty. In addition, the effects of A1254 on reproductive function were examined. The KAP3 gene is involved in the neurogenesis and synaptogenesis of sexual differentiation in rats and also during puberty. In the present study, pregnant Sprague–Dawley rats each received a daily dose of A1254 (0, 10, 50 mg kg–1) dissolved in 1.0 mL corn oil by gavage, from gestational Day (GD) 8 to postnatal Day (PD) 21. The mRNA levels of the KAP3 gene in hypothalamic tissues were analysed by northern blot hybridisation during the critical periods of brain sexual differentiation (GD18 and PD5) and puberty (PD28). Variables affecting reproduction in F1 female rats, such as vaginal opening (VO), vaginal oestrus (VE) and oestrous cyclicity, were recorded. Depending on the sex and A1254 exposure (control or 50 mg kg–1 day–1), F1 rats were divided into three mating groups, namely control male–control female, control male–A1254-treated female and A1254-treated male–control female. During the critical periods of brain sexual differentiation (GD18, PD5) and puberty (PD28), KAP3 mRNA levels were significantly reduced in A1254-treated fetal and pubertal rat brains relative to those of control groups. In A1254-treated F1 female rats, VO and VE were delayed, the percentage of irregular oestrous cycles was increased and the duration of the oestrous cycle was extended in a dose-dependent manner compared with control groups. Treatment with a high dose of A1254 significantly impaired the reproductive function of both male and female F1 rats, including mating and pregnancy indices and the number of live fetuses. These data suggest that A1254 disrupts transcriptional regulation of the KAP3 gene in fetal and pubertal rat brains and that these effects may be related to A1254-induced abnormal brain sexual differentiation and lowered reproductive function in F1 rats.

scholarly journals Role of leptin in female reproduction

2015 ◽  
Vol 53 (1) ◽  
Author(s):  
Antonio Pérez-Pérez ◽  
Flora Sánchez-Jiménez ◽  
Julieta Maymó ◽  
José L. Dueñas ◽  
Cecilia Varone ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Reproductive Function ◽  
Fat Distribution ◽  
Female Reproduction ◽  
Cellular Mechanisms ◽  
Complex Interactions ◽  
Physiological Processes ◽  
Integral Role ◽  
The Brain

AbstractReproductive function is dependent on energy resources. The role of weight, body composition, fat distribution and the effect of diet have been largely investigated in experimental female animals as well as in women. Any alteration in diet and/or weight may induce abnormalities in timing of sexual maturation and fertility. However, the cellular mechanisms involved in the fine coordination of energy balance and reproduction are largely unknown. The brain and hypothalamic structures receive endocrine and/or metabolic signals providing information on the nutritional status and the degree of fat stores. Adipose tissue acts both as a store of energy and as an active endocrine organ, secreting a large number of biologically important molecules termed adipokines. Adipokines have been shown to be involved in regulation of the reproductive functions. The first adipokine described was leptin. Extensive research over the last 10 years has shown that leptin is not only an adipose tissue-derived messenger of the amount of energy stores to the brain, but also a crucial hormone/cytokine for a number of diverse physiological processes, such as inflammation, angiogenesis, hematopoiesis, immune function, and most importantly, reproduction. Leptin plays an integral role in the normal physiology of the reproductive system with complex interactions at all levels of the hypothalamic-pituitary gonadal (HPG) axis. In addition, leptin is also produced by placenta, where it plays an important autocrine function. Observational studies have demonstrated that states of leptin excess, deficiency, or resistance can be associated with abnormal reproductive function. This review focuses on the leptin action in female reproduction.

scholarly journals Protein expression reveals a molecular sexual identity of avian primordial germ cells at pre-gonadal stages

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Laura Soler ◽  
Sabine Alves ◽  
Aurélien Brionne ◽  
Aurore Jacques ◽  
Vanessa Guérin ◽  
...  
Keyword(s):  
Genetic Resources ◽  
Sexual Identity ◽  
Cell Fate ◽  
Germ Cells ◽  
Sex Chromosome ◽  
Sex Differentiation ◽  
Primordial Germ Cells ◽  
Specific Cell ◽  
Male And Female

AbstractIn poultry, in vitro propagated primordial germ cells (PGCs) represent an important tool for the cryopreservation of avian genetic resources. However, several studies have highlighted sexual differences exhibited by PGCs during in vitro propagation, which may compromise their reproductive capacities. To understand this phenomenon, we compared the proteome of pregonadal migratory male (ZZ) and female (ZW) chicken PGCs propagated in vitro by quantitative proteomic analysis using a GeLC-MS/MS strategy. Many proteins were found to be differentially abundant in chicken male and female PGCs indicating their early sexual identity. Many of the proteins more highly expressed in male PGCs were encoded by genes localised to the Z sex chromosome. This suggests that the known lack of dosage compensation of the transcription of Z-linked genes between sexes persists at the protein level in PGCs, and that this may be a key factor of their autonomous sex differentiation. We also found that globally, protein differences do not closely correlate with transcript differences indicating a selective translational mechanism in PGCs. Male and female PGC expressed protein sets were associated with differential biological processes and contained proteins known to be biologically relevant for male and female germ cell development, respectively. We also discovered that female PGCs have a higher capacity to uptake proteins from the cell culture medium than male PGCs. This study presents the first evidence of an early predetermined sex specific cell fate of chicken PGCs and their sexual molecular specificities which will enable the development of more precise sex-specific in vitro culture conditions for the preservation of avian genetic resources.

scholarly journals Possible Epigenetic Origin of a Recurrent Gynandromorph Pattern in Megachile Wild Bees

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 437
Author(s):  
Daniele Sommaggio ◽  
Giuseppe Fusco ◽  
Marco Uliana ◽  
Alessandro Minelli
Keyword(s):  
Current Knowledge ◽  
Sex Differentiation ◽  
General Pattern ◽  
Body Parts ◽  
Wild Bees ◽  
Male And Female ◽  
Female Phenotype ◽  
In The Wild ◽  
Gene Transcripts ◽  
Individual Body

Gynandromorphs, i.e., individuals with a mix of male and female traits, are common in the wild bees of the genus Megachile (Hymenoptera, Apoidea). We described new transverse gynandromorphs in Megachile pilidens Alfkeen, 1924 and analyze the spatial distribution of body parts with male vs. female phenotype hitherto recorded in the transverse gynandromorphs of the genus Megachile. We identified 10 different arrangements, nine of which are minor variants of a very general pattern, with a combination of male and female traits largely shared by the gynandromorphs recorded in 20 out of 21 Megachile species in our dataset. Based on the recurrence of the same gynandromorph pattern, the current knowledge on sex determination and sex differentiation in the honey bee, and the results of recent gene-knockdown experiments in these insects, we suggest that these composite phenotypes are possibly epigenetic, rather than genetic, mosaics, with individual body parts of either male or female phenotype according to the locally expressed product of the alternative splicing of sex-determining gene transcripts.

The Role of Tanycytes in the Hypothalamus-Pituitary-Thyroid Axis and the Possibilities for Their Genetic Manipulation

2019 ◽  
Vol 128 (06/07) ◽  
pp. 388-394
Author(s):  
Helge Müller-Fielitz ◽  
Markus Schwaninger
Keyword(s):  
Energy Homeostasis ◽  
Genetic Manipulation ◽  
Heart Function ◽  
Feedback Regulation ◽  
Target Organs ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis ◽  
Hpt Axis ◽  
The Brain

AbstractThyroid hormone (TH) regulation is important for development, energy homeostasis, heart function, and bone formation. To control the effects of TH in target organs, the hypothalamus-pituitary-thyroid (HPT) axis and the tissue-specific availability of TH are highly regulated by negative feedback. To exert a central feedback, TH must enter the brain via specific transport mechanisms and cross the blood-brain barrier. Here, tanycytes, which are located in the ventral walls of the 3rd ventricle in the mediobasal hypothalamus (MBH), function as gatekeepers. Tanycytes are able to transport, sense, and modify the release of hormones of the HPT axis and are involved in feedback regulation. In this review, we focus on the relevance of tanycytes in thyrotropin-releasing hormone (TRH) release and review available genetic tools to investigate the physiological functions of these cells.

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