scholarly journals Nuclear androgen receptor regulates testes organization and oocyte maturation in zebrafish

2017 ◽  
Author(s):  
Camerron M. Crowder ◽  
Christopher S. Lassiter ◽  
Daniel A. Gorelick
Keyword(s):  
Androgen Receptor ◽  
Oocyte Maturation ◽  
Sexual Differentiation ◽  
Gonad Development ◽  
External Genitalia ◽  
Endocrine Function ◽  
Secondary Sexual Characteristics ◽  
Gonad Differentiation ◽  
Sexual Characteristics

ABSTRACTAndrogens act through the nuclear androgen receptor (AR) to regulate gonad differentiation and development. In mice, AR is required for spermatogenesis, testis development and formation of external genitalia in males and oocyte maturation in females. However, the extent to which these phenotypes are conserved in nonmammalian vertebrates is not well understood, because mutations in AR have not been generated in any other species. Here, we generate zebrafish with a mutation in the ar gene and examine the role of AR on sexual differentiation and gonad development. We find that zebrafish AR is not required for male sexual differentiation, since a portion of ar mutants develop a testis. However, we show that in zebrafish, as in mice, AR is required for the development of secondary sexual characteristics and for proper organization of the testis in males and for oocyte maturation in females. Additionally, we find that zebrafish ar mutant males have functional, mature sperm present in their testis, but are infertile due to an inability to release sperm. These findings suggest that AR is required for male sexual development and fertility, but not essential for sexual differentiation in zebrafish. The ar mutant we developed will be useful for modeling human endocrine function in zebrafish.

scholarly journals Gradual, temperature-induced change of secondary sexual characteristics in Trichogramma pretiosum infected with parthenogenesis-inducing Wolbachia

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7567
Author(s):  
Su-fang Ning ◽  
Jin-cheng Zhou ◽  
Quan-quan Liu ◽  
Qian Zhao ◽  
Hui Dong
Keyword(s):  
High Temperature ◽  
Sexual Differentiation ◽  
External Genitalia ◽  
Intermediate Stage ◽  
External Morphology ◽  
Trichogramma Pretiosum ◽  
Secondary Sexual Characteristics ◽  
Sexual Characteristics ◽  
Male External Genitalia ◽  
Secondary Sexual

Intersex is an intermediate stage of sexual differentiation in insects. Determining intersex morphology and the cause of its production will aid in the understanding of the mechanism of sexual differentiation in insects. In this paper, Wolbachia-infected Trichogramma pretiosum (T. preW+) that shows thelytokous parthenogenesis were used as subjects. In order to determine the causes of the T. preW+ intersex and the influence of parental generation temperature on gradual changes in secondary masculinization in intersex offspring, we examined the occurrence of intersex offspring (F1 and F2 generation) after the parental generations were treated with high temperature (27, 29, 31, and 33 °C) and described the external morphology of the intersexes. The results showed that the T. preW+ parental generation temperature is positively correlated with the probability of intersex offspring. The probability of F1 intersex is significantly higher than that of F2 intersex in different high temperature. The degree of secondary masculinization in T. preW+ intersexes increases as parental generation temperature increases. In addition, our study first identified 11 intersex types in T. preW+ and found that the primary and secondary sexual characteristics showed a regular distribution. We also found that the D type and H type of intersex have the highest frequency of appearance. The external genitalia of most intersexes were female, and only three intersex types have male external genitalia. Conclusions were ultimately obtained: Wolbachia is a direct factor that causes the occurrence of intersexes, while high temperature is an indirect factor that determines the external morphology of intersexes. The effects of high temperature on T. preW+ intersexes is passed through the parental generation to offspring, and this maternal effect weakens as the number of generations increases. In T. preW+ intersex individuals, most exhibit female primary sexual characteristics, and secondary sexual characteristics exhibit signs of masculinization.

scholarly journals The Role of Androgens in Mammals Folliculogenesis

2018 ◽  
Vol 44 (1) ◽  
pp. 15
Author(s):  
Livia Brunetti Apolloni ◽  
Jamily Bezerra Bruno ◽  
Benner Geraldo Alves ◽  
José Ricardo de Figueiredo
Keyword(s):  
Androgen Receptor ◽  
In Vitro Culture ◽  
Steroid Hormones ◽  
Oocyte Maturation ◽  
Follicular Development ◽  
Follicular Growth ◽  
Preantral Follicles ◽  
Ovarian Cells

Introduction: Steroid hormones production is a physiological process termed steroidogenesis. An important stage of this process is the conversion of androgens into estrogens through aromatase enzyme. Furthermore, androgens are important in the process of folliculogenesis, promoting follicular growth in different species. Thus, the aim of this review was to present the process of synthesis, mechanism of action, and importance of androgens in folliculogenesis. Additionally, the main results of in vitro culture of ovarian cells in the presence of these hormones were emphasized.Review: Folliculogenesis begins in prenatal life in most of species and can be defined as the process of formation, follicular growth, and oocyte maturation. Preantral follicles represent 95% of the follicular population and assisted reproductive technologies have been developed (e.g., Manipulation of Oocytes Enclosed in Preantral Follicles - MOEPF) in order to avoid the great follicle loss that occurs naturally in vivo by atresia. The MOEPF aim to obtain a large number of competent oocytes from preantral follicles and then subject to in vitro maturation, fertilization, and culture for embryo production. However, the development of an efficient medium to ensure the follicular survival and oocyte maturation is the major challenge of this biotechnology. To achieve the success on in vitro culture, the effects of substances as androgens on follicular development have been evaluated. Androgens are steroid hormones produced in theca cells (TC) that are fundamental for follicular growth. These cells provide all the androgens required by the developing follicles for conversion into estrogens by the granulosa cells (GC). Androgens receptors (AR) are localized in cell cytoplasm of all follicular categories, being more expressed in preantral follicles. The androgen pathway initiates through its connection to its receptor, making a complex androgen-AR, that in the nucleus helps on the process of gene transcription related with follicular survival. This mechanism is androgen receptor genomic activity. In addition to genomic action, there is an androgen receptor non-genomic activity. This occurs through activation of AR and its interaction with different signaling molecules located on the cell membrane, triggering events that aid in the follicular development. Regardless of the androgens actions, ovarian cells of several species subjected to in vitro culture have shown the importance of these hormones on the follicle development. Recent studies demonstrated that androgens addition on the culture medium stimulated the activation of preantral follicles (bovine and caprine), antrum formation (swine), survival (non-primate), and oocyte maturation (antral follicles; bovine). Also, some studies suggest that the addition of these hormones on in vitro culture is dose-dependent and species-specific.Conclusion: This review shows the role of androgens in different stages of follicular development and its action as a substrate for steroidogenesis and transcription of genes related to follicular survival and oocyte maturation. However, when these hormones should be added during in vitro follicular culture and which concentration is required remains unclear, being necessary more studies to elucidate these aspects.

scholarly journals Endocrine-Disrupting Chemicals and Their Effects during Female Puberty: A Review of Current Evidence

2020 ◽  
Vol 21 (6) ◽  
pp. 2078 ◽  
Author(s):  
Laura Lucaccioni ◽  
Viola Trevisani ◽  
Lucia Marrozzini ◽  
Natascia Bertoncelli ◽  
Barbara Predieri ◽  
...  
Keyword(s):  
Endocrine Disrupting Chemicals ◽  
Current Evidence ◽  
Secondary Sexual Characteristics ◽  
Endocrine Disrupting ◽  
Sexual Characteristics ◽  
Single Chemical ◽  
Windows Of Susceptibility ◽  
Physical Changes ◽  
Temporal Windows

Puberty is the process of physical changes between childhood and adulthood during which adolescents reach sexual maturity and become capable of reproduction. It is considered one of the main temporal windows of susceptibility for the influence of the endocrine-disrupting chemicals (EDCs). EDCs may act as single chemical agents or as chemical mixtures; they can be pubertal influencers, accelerating and anticipating the processing of maturation of secondary sexual characteristics. Moreover, recent studies have started to point out how exposure to EDCs during puberty may predispose to breast cancer later in life. In fact, the estrogen-mimicking endocrine disruptors (EEDs) may influence breast tissue development during puberty in two main ways: the first is the action on the proliferation of the breast stromal cells, the second concerns epigenetic mechanisms. The aim of this mini-review was to better highlight what is new and what is not completely known regarding the role of EDCs during puberty.

The under-appreciated role of the androgen receptor (AR) in sexual differentiation of the brain

2009 ◽  
Vol 65 ◽  
pp. S11
Author(s):  
S. Marc Breedlove ◽  
Damian G. Zuloaga ◽  
Cynthia L. Jordan
Keyword(s):  
Androgen Receptor ◽  
Sexual Differentiation ◽  
The Brain

THE TESTIS IN PATIENTS WITH ABNORMALITIES OF SEX DIFFERENTIATION. HISTOLOGY AND ENDOCRINE FUNCTION

1973 ◽  
Vol 73 (1) ◽  
pp. 179-188 ◽  
Author(s):  
R. Sandrini Neto ◽  
M. A. Rivarola ◽  
R. Coco ◽  
C. Bergadá
Keyword(s):  
Sexual Differentiation ◽  
Normal Values ◽  
Sex Differentiation ◽  
External Genitalia ◽  
Poor Response ◽  
Testicular Tissue ◽  
Endocrine Function ◽  
Plasma Testosterone ◽  
Before And After ◽  
Female External Genitalia

ABSTRACT Testicular function was studied in 18 patients with abnormalities of sexual differentiation. Fourteen patients were prepubertal and four postpubertal. Plasma testosterone was determined before and after 5000 IU HCG administered daily during 5' days. Of the fourteen prepubertal patients, the two true hermaphrodites and the patient with asymmetrical gonadal differentiation showed a poor response to gonadotrophin stimulation. This could be explained by the small amount of active testicular tissue or its coexistence with ovarian and rudimentary gonadal tissue which might exert some influence on the endocrine function of the testis. In the group of eight patients with male pseudo-hermaphroditism and ambiguous external genitalia, the response to HCG showed a large variation. The three patients with small testes had lowest values i. e. 210, 198 and 192 ng/100 ml. The remaining five patients showed normal values ranging between 360 and 720 ng/100 ml. The ambiguous external genitalia of these patients could be explained as being due to a diminished androgen target organ sensitivity limited to the external genitalia. The three prepubertal patients with male pseudo-hermaphroditism and female external genitalia showed a marked increase in plasma testosterone with HCG ranging between 598 and 1100 ng/100 ml. The four pubertal cases also had high values in basal conditions, between 920 and 1870, which increased even more after gonadotrophin stimulation, in one case from 1382 to 2264 ng/100 ml. This hypersensitivity to exogenous HCG, even in infancy, correlates with the elevated basal values observed in adult patients with otherwise female external genitalia and androgen insensitivity. Finally, the HCG stimulation test could be useful for the demonstration of testicular tissue in prepubertal patient with abnormalities of sexual differentiation, although it cannot be used as a prognosis of masculinization or feminization at puberty.

Hypogonadism and Testosterone Replacement Therapy

2005 ◽  
Vol 00 (01) ◽  
pp. 75
Author(s):  
Adrian S Dobs
Keyword(s):  
Bone Mass ◽  
Sexual Function ◽  
Replacement Therapy ◽  
External Genitalia ◽  
Testosterone Replacement Therapy ◽  
Male Hypogonadism ◽  
Secondary Sexual Characteristics ◽  
The Us ◽  
Sexual Characteristics ◽  
Normal Spermatogenesis

Male hypogonadism affects an estimated four to five million men in the US. It is defined as failure of the testes to produce an adequate amount of testosterone and/or conduct normal spermatogenesis. The production of adequate amounts of testosterone is necessary for development of external genitalia and development of secondary sexual characteristics in children and adolescents. In adults, androgen production is necessary for maintenance of lean body mass (LBM), bone mass, libido, sexual function, and spermatogenesis.

scholarly journals Genomic actions of the androgen receptor are required for normal male sexual differentiation in a mouse model

2005 ◽  
Vol 35 (3) ◽  
pp. 547-555 ◽  
Author(s):  
A J Notini ◽  
R A Davey ◽  
J F McManus ◽  
K L Bate ◽  
J D Zajac
Keyword(s):  
Androgen Receptor ◽  
Dna Binding ◽  
Zinc Finger ◽  
Sexual Differentiation ◽  
Target Genes ◽  
External Genitalia ◽  
Normal Male ◽  
Target Cells ◽  
Reading Frame ◽  
Rapid Activation

Androgens mediate their effects in target cells via the androgen receptor (AR), which acts predominantly as a ligand-dependent transcription factor. In addition, androgens induce rapid activation of second messenger signal transduction cascades, and this is thought to occur via non-genomic mechanisms. We have used the Cre/loxP system to generate an AR knockout (ARKO) mouse targeting exon 3, which encodes the second zinc finger of the DNA-binding domain. To generate universal ARKO mice, floxed AR mice were mated with CMV-Cre mice, which express Cre recombinase ubiquitously. Deletion of the floxed allele in our mice does not disrupt the reading frame, and has been designed so that the mutant AR can bind ligand but not target genes. ARKO males displayed a complete androgen insensitivity phenotype, with female external genitalia and a reduction in body weight compared with wild-type males (P < 0.001). Testes of ARKO males were smaller than control males (P < 0.0001) and were located intra-abdominally. We have demonstrated that genotypically XY mice lacking the second zinc finger of the AR have a female phenotype, and we conclude that the genomic actions of the AR (mediated by DNA binding) are indispensable for normal male sexual differentiation.

Role of testosterone binding to the androgen receptor in male sexual differentiation of patients with 5α-reductase deficiency

1979 ◽  
Vol 11 (4) ◽  
pp. 1385-1390 ◽  
Author(s):  
Marc Maes ◽  
Charles Sultan ◽  
Nadia Zerhouni ◽  
Stephen W. Rothwell ◽  
Claude J. Migeon
Keyword(s):  
Androgen Receptor ◽  
Sexual Differentiation ◽  
Reductase Deficiency ◽  
5Α Reductase Deficiency
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