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At least 19 recordsLinked to original sources
PubMed1989

Primordial germ cells and gonadal development in the golden hamster.

We present results of a light and electron microscopical study of the developing hamster gonad. Two main problems have been examined: the source of somatic cells contributed to the developing gonad and the possible presence of nuage in germ cells. Nuage has been previously reported in hamster oocytes at meiosis; its possible presence at earlier stages and in male germ cells, especially meiotic spermatocytes, was investigated. The mesonephros was found to be the major source of somatic cells to the developing gonad, though a contribution from the coelomic epithelium could not be excluded, and interstitial tissue appeared to arise from mesenchymal cells. The presence of nuage associated with nuclear pores and mitochondria in hamster oocytes from Day 15 p.c. onwards has been confirmed. New findings are the association of nuage with intercellular bridges and its presence at earlier stages, including Day 8 p.c., and in male germ cells especially at the time of the entry to meiosis.

Animals↗
PubMed1992

Phenotypic changes in germ cells during gonadal development of the common carp (Cyprinus carpio). An immunohistochemical study with anti-carp spermatogonia monoclonal antibodies.

A procedure is described in which large early spermatogonia were isolated from carp testes and purified from an initial 4-5% recovery up to 60-70% using equilibrium density centrifugation on a continuous Percoll gradient. Mice were immunized with the spermatogonia via the intrasplenic route. Six hybridoma cultures, producing monoclonal antibodies (MAbs) reacting selectively with germ cells, were selected and further analysed. Reactivity with five of these MAbs was observed on primordial germ cells (PGCs) in the developing indifferent gonads at the onset of proliferation, i.e. the age of 7 weeks. One MAb, encoded WCG6, appeared to define a new surface marker on PGCs being gradually expressed on the surface membrane between the age of 2 and 4 weeks, concomitantly with an increase in size of these mitotically silent cells. The reactivity of germ cells with five of the MAbs disappeared completely (WCG 7, 12, 15, 21) or nearly completely (WCG 6) during spermatogenesis, providing a striking difference from patterns obtained with MAbs raised previously against carp spermatozoa. Differences between male and female germ cells were not observed with the WCG-MAbs during gonad development, indicating that a common set of surface antigens is shared between germ cells of both sexes up to and including spermatogonia and oogonia.

Aging↗
PubMed1991

Stimulation of gonadal development by sexual interaction of pubertal African catfish, Clarias gariepinus.

Stimulation and inhibition of gonadal development by intersexual contact was studied in pubertal African catfish, Clarias gariepinus. The effect of a possible interaction was studied by evaluation after a 98-day experimental period of gonadal development in combinations of intact and anosmic males and females. In addition, separate groups of males and females, respectively, were exposed to holding water from these combinations. A tentative model of stimulation of gonadal development by intersexual contact in pubertal fish was developed. Males stimulate ovarian development of females by both olfactory and tactile cues. In addition, males seem to enhance gonadal development of other males through olfactory stimulation via holding water. In contrast, females tended to inhibit male gonadal development, especially through tactile cues. It seems that although males are hampered by female tactile stimuli in their gonadal development and ability to stimulate male gonadal development, their ability to stimulate female gonadal development is not affected.

Animals↗
PubMed2026

Genome-wide characterization of the FOX gene family reveals sex-biased expression and FoxO-associated regulation during gonadal development in Bellamya aeruginosa.

Forkhead box (FOX) transcription factors are important regulators of development and reproduction, but their roles in molluscan gonadal development remain unclear. In this study, the FOX gene family was systematically identified in the freshwater gastropod Bellamya aeruginosa, and comparative gonadal transcriptomic analyses were performed across sexes and developmental stages.A total of 35 FOX genes were identified and classified into 19 subfamilies. Phylogenetic and synteny analyses indicated that the FOX gene family is generally conserved among mollusks, whereas FoxG and FoxL2 showed lineage-specific expansion. Structural analyses demonstrated that most BaeFOX proteins retained the conserved Forkhead domain architecture. Transcriptomic analyses revealed that gene expression divergence between testes and ovaries was markedly greater than that between developmental stages within the same gonad, indicating that sexual dimorphism is the major source of gonadal transcriptional variation. Functional enrichment consistently identified the FoxO signaling pathway in sex-biased comparisons. Several FOX genes also displayed clear gonad-biased expression patterns, and network analyses suggested that BaeFoxO, BaeFoxL2, and BaeFoxG may play central regulatory roles in gonadal development. These findings provide the first comprehensive characterization of the FOX gene family in B. aeruginosa and suggest that FOX-related regulatory networks potentially participate in gonadal development in gastropod mollusks.

Animals↗
PubMed1975

[Gonad development and differentiation in the golden hamster].

Development and gonadal differentiation in the Golden Hamster embryo are studied from day 9 of development to adult stages by means of histological, histochemical and cytogenetical techniques. The gonad appears on the day 9 of development and remains in an indifferentiated stage until day 11, testicular differentiation is carried out from day 12 with testicular cords and Leydig cells. Ovarian differentiation occurs later from day 14 of development and is practically recognizable after birth.

Animals↗
PubMed1992

Plasticity of gonadal development and protandry in fishes.

Sexual differentiation in eutherian mammals follows a simple governing paradigm: development proceeds in a female direction unless a masculinizing mechanism intervenes. Sexual development in fishes is much more plastic than in mammals. It permits the intervention of environmental factors and follows several different types of sequences that produce successive hermaphrodites and alternative pathways for the development of the same final sex. In spite of this plasticity, the primacy of female development is suggested by the initial ovarian phase in the development of gonads of both sexes in some gonochoristic fishes and by protogynous sex change. One barrier to the application of this principle to fishes generally is the existence of protandric hermaphrodites. Recent evidence suggests a reinterpretation of gonadal differentiation in a protandric anemonefish and a protandric sparid. In both cases, testicular development is both preceded and followed by ovarian development. These patterns are interpreted to mean that female development is primary and that male development is a temporary phase initiated by a masculinizing mechanism and terminated by its cessation.

Animals↗
PubMed1976

Intrauterine gonadal development.

This review article summarizes the intrauterine gonadal development and differentiation of both male and female human embryos and fetuses. It describes in detail (1) the organization of the indifferent gonad and its seeding by the extra-gonadal germ cells, (2) the development of the duct systems before sex differentiation, and (3) the controlling mechanism of differentiation of the ovaries and testes. Timetable for the development of the human male and female reproductive systems have been compiled from the literature.

Animals↗
PubMed2026

Unveiling the molecular basis of gonadal development: Multi-omics uncovers sex-related genes and steroid pathways in Sinonovacula constricta.

The razor clam Sinonovacula constricta is an economically important cultured mollusk in China, but the molecular mechanism of its gonadal development and sexual differentiation remains unclear. This study integrated gonadal transcriptomic, proteomic, and metabolomic analysis to identify key sex-related molecules. Transcriptome analysis identified 2795 DELs and 6497 DEGs between sexes, including the sex-related genes Fem-1b, Fem-1c, GUCY1B2 and FAT4, as well as a regulatory network of 39 lncRNA-mRNA pairs involving Tektin-4, Ropporin-1, Histone H1, and FoxN4. Proteomic analysis revealed 3217 DEPs: Tektin family members, Ropporin-1 and Tssk proteins were upregulated in the testis, while histone H1 and FAT4 were upregulated in the ovary. Metabolomic analysis detected 409 DEMs, with uridine identified as a potential sex differential marker (upregulated in the ovary), and 23 gonadal development-related DEMs showed sex-specific upregulation. Integrative transcriptome-proteome analysis identified 1543 co-expressed DEGs/DEPs enriched in nucleosome assembly, oxidative phosphorylation, and carbon metabolism, including key sex-related genes AKAP14, Tektin/Tssk families, Histone H1, and FAT4. Transcriptome-metabolome integration identified 32 shared KEGG pathways (e.g., biosynthesis of unsaturated fatty acids, pyrimidine metabolism), while proteome-metabolome integration revealed 5 (positive ion) and 6 (negative ion) co-enriched pathways, with alanine, aspartate and glutamate metabolism and oxidative phosphorylation being functionally relevant to gonadal development. Collectively, these results reveal the molecular basis of gonadal development, highlight critical sex-related genes and steroid metabolic pathways, and provide valuable resources for future reproduction and breeding in S. constricta.

Animals↗
PubMed1991

Correlation of annual change of luteinizing hormone-releasing hormone (LH-RH) with gonadal development in amphioxus.

The present study demonstrates for the first time by RIA that LH-RH is present in the heads as well as the bodies of the amphioxuses of both sexes. Gonadoliberin increases gradually during the course of gonadal development. At the time of gonadal maturity, LH-RH content reaches a maximum. The annual change of LH-RH correlates well with gonadal development and the gonadosomatic index (GSI). The reproductive season of the amphioxus covers about three months from May to July, and LH-RH content starts to increase in May (66.89 +/- 5.26 ng) and reaches the peak in June (158.57 +/- 3.17 ng), indicating that LH-RH is likely also to be involved in the reproductive activity of the chordate. This finding is of significance in understanding the evolutionary process of the reproductive endocrine in the vertebrate.

Animals↗
PubMed2026

Genomic identification and functional characterization of the nuclear receptor gene family in relation to sex determination and gonad development in the Pacific oyster (Crassostrea gigas).

Nuclear receptors (NRs) are a large superfamily of transcription factors that control a wide range of physiological processes by modulating the expression of downstream target genes. Numerous studies have confirmed that NR family members play critical and conserved roles in sex determination and gonadal development across metazoans. However, in mollusks, systematic characterization of NRs and their potential functions in gonadal regulation remain largely unexplored. In this study, 46 NR gene family members in the Pacific oyster (Crassostrea gigas) were identified and assigned to eight subfamilies. All NR family members contain at least one of the two core domains (DNA-binding domain, DBD; ligand-binding domain, LBD), and conserved exon-intron structures were observed within the same subgroup, indicating their evolutionary conservation. Furthermore, expression profiling revealed high expression of CgNR2F, CgNR5A1-1, and CgNR0B1 in undifferentiated gonads, suggesting their potential involvement in sex determination. CgNR1A and CgNR2E5 were specifically expressed in female gonads and exhibited female-biased expression patterns, indicating a putative role in ovarian development. Moreover, CgNR3A and CgNR3B showed high expression levels during the undifferentiated stage and early male development stage, implying their possible participation in male gonadal development and gametogenesis. These results expand the understanding of the NR gene family in C. gigas and help elucidate the potential functions of NR genes in sex determination and gonadal development.

Animals↗
PubMed1989

Pineal and ocular influences on male and female turkeys: plasma luteinizing hormone and prolactin levels during gonadal development.

Plasma levels of prolactin (PRL) and luteinizing hormone (LH) were determined in pinealectomized (PX) and/or bilateral ocular enucleated (EX) turkey hens and toms during gonadal development. Measurements were obtained weekly for 6 weeks following photo-induced ovarian recrudescence in adult hens and biweekly from 12 to 34 weeks of age in sexually developing toms. Both hens and toms were maintained on a photoperiod of 16L:8D. Plasma PRL levels were significantly correlated with time (P less than 0.01) and were linear with significant slopes (P less than 0.01) in all treatment groups of hens and toms. However, the regression coefficients were positive for the hens and negative for the toms. Both PX and EX reduced PRL levels in the hens. PX did not significantly affect PRL levels of toms but EX depressed PRL levels. In hens LH was not correlated with weeks of photostimulation but in toms LH was positively correlated to age and linear with significant slopes in all treatment groups. There were no significant treatment effects on plasma LH levels of hens or toms. It was concluded that neither the pineal gland nor the eyes affect plasma LH levels of male turkeys during testicular development or female turkeys during photostimulated ovarian recrudescence. Although the eyes affected plasma PRL of both males and females during gonadal development, the pineal only influenced female PRL levels.

Animals↗
PubMed2026

Genome-wide identification and expression profiling of HSD3B and SDR42E1 genes in the Pacific oyster (Crassostrea gigas): potential associations with gonadal development.

Sex steroids are lipid-soluble signaling molecules that regulate sex differentiation, reproductive development and physiological homeostasis in animals. 3β-Hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase (3β-HSD) is a key steroidogenic enzyme, whereas SDR42E1, an extended short-chain dehydrogenase/reductase, has been implicated in sterol- and steroid-related metabolism. However, the composition, evolutionary relationships and expression patterns of the HSD3B- and SDR42E1-related genes in bivalve gonadal development remain poorly characterized. In this study, five PF01073-containing genes, comprising three CgHsd3b and two CgSdr42e1 genes, were identified in the Pacific oyster Crassostrea gigas. Phylogenetic analysis separated the proteins into HSD3B-related and SDR42E1-related groups, and gene-structure and motif analyses indicated subfamily-level divergence. All five proteins retained the SDR domain but differed in exon-intron structure and motif composition. Each contained the extended-SDR TGxxGxxG motif, whereas exact classical [ST]GxxxGxG and NNAG motifs were absent. Tyr- and Lys-equivalent residues were conserved, while the HSD3B1 Ser-equivalent position contained Thr in two C. gigas proteins and Ser in one. These features support their classification as extended-SDR proteins but do not establish enzymatic activity or substrate specificity. The three CgHsd3b genes were dispersed on one chromosome, whereas CgSdr42e1-1 and CgSdr42e1-2 were adjacent on another chromosome, suggesting a possible local duplication event for the CgSdr42e1 pair. Public RNA-seq data showed distinct tissue- and gonadal-stage expression patterns, with several genes displaying gonad-biased or female-stage-associated expression. Independent RT-qPCR profiling of the representative genes CgHsd3b-3 and CgSdr42e1-1 detected stage-dependent expression, although tissue rankings differed from those in the public RNA-seq datasets. These differences may reflect the use of independent biological samples, tissue composition, normalization procedures, and platform-specific measurements. Because enzymatic assays, metabolite measurements, cellular localization, and functional perturbation were not performed, the results identify candidate genes whose expression is associated with gonadal development rather than demonstrating regulatory roles. This study provides a comparative framework for future functional investigation of sterol- and steroid-related metabolism in bivalves.

Animals↗
PubMed1976

Effects of early treatment with antiserum to ovine follicle-stimulating hormone and luteinizing hormone on gonadal development in the rat.

Neonatal rats secrete considerable amounts of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) between 5 and 15 days of age. Antisera to LH and FSH were injected during this 11-day period in an attempt to study the importance of gonadotropins for functional development of the gonads. Autopsies at 15 days of age revealed normal ovarian follicular histology after either antiserum treatment, but antiserum to LH significantly retarded differentiation of interstitial tissue. Uterine weights were increased, and some of the serum samples showed elevated FSH levels following the antiserum treatments. The testes of antiserum-treated rats were heavier at 15 days of age, while accessory sex organ weights were unchanged. Vaginal opening after antiserum treatment was more variable than in controls, but tended to be earlier. The first appearance of penile serum was not significantly changed. Both males and females were fertile as adults. Important limitations to the use of chronic antiserum injections were found in immature rats. The antisera were present for at least 34 days after injection. The ways in which this pool of antiserum might have influenced the results are discussed.

Animals↗
PubMed1991

Gonadal development and growth in 46,XX and 46,XY individuals with P450scc deficiency (congenital lipoid adrenal hyperplasia).

We have investigated gonadal development and growth in 4 individuals (3 with 46,XY and 1 with 46,XX karyotype) with P450scc deficiency. One patient died at 2 months of age from adrenal insufficiency, while the remaining 3 individuals were healthy and developed normally (age at follow-up: 18, 10 and 8 years). In the surviving individuals, the diagnosis was established during the first 2-4 months of life by extensive endocrine studies of blood and urine. In the remaining patient, the diagnosis was made on the basis of karyotype (46,XY), anatomy of internal and external genitalia and adrenal pathology. Gonadectomy was performed in the 2 surviving 46,XY individuals at the age of 7 years, and histological examination showed normal testicular morphology but very few germ cells. Postmortem examination of the testes of the 2-month-old subject showed normal testicular histology, and quantitative analysis revealed a normal number of germ cells. Ultrasound of the 46,XX individual showed normal internal female genitalia including ovaries with follicles. The 3 surviving patients grew along the 75th (46,XY), the 90th (46,XY) and the 50th percentile (46,XX), respectively. The oldest girl experienced normal breast and pubic hair development after oral estrogen replacement and topical testosterone administration. The glucocorticoid and mineralocorticoid replacement was adjusted in accordance with repeated measurements of serum sodium and serum potassium, plasma renin concentration and blood pressure. No attempts were made to normalize serum ACTH. We conclude that prenatal testicular maturation and development of female internal genitalia may take place in the absence of normal steroid hormone production. Normal growth and development may be obtained in P450scc-deficient individuals with adequate hormone replacement.

Adolescent↗
PubMed1989

Fibroblast growth factor and the control of pituitary and gonad development and function.

Evidence from in vitro studies support the concept that growth factors could be involved in the development, maturation and function of endocrine organs. Included among the growth factors which are known to influence endocrine cell proliferation and differentiation is the fibroblast growth factor (FGF), which controls the proliferation, differentiation, and other functions of mesodermal- and neuroectodermal-derived cells. Its modulator, transforming growth factor beta (TGF beta), which determines the positive or negative direction of the effects of FGF, may play a role as well. In this review, we present a speculative view of how FGF in the pituitary gland, and both FGF and TGF beta in the gonads could influence the development and function of these organs through regulating mechanisms involving paracrine and autocrine control of cell proliferation and differentiation.

Aging↗
PubMedDate not supplied

[Genetic support for gonadal development].

The problem of the sexes appearance has concerned the mankind since the oldest times. The paper surveys the theories that appeared during the ages, from Plato to the beginning of the 20th century when the spermatozoon was differentiated from the ovule, the chromosomes were identified and their importance for determining the sex was recognized. The paper reports on the role of the HY antigen--discovered in 1955 by Eichwald and Simser--and its mode of action, corroborating the control structural gene. The differentiating disturbances of the gonads are reviewed: the disturbances in the development of the male sex, its hormonal and enzymatic bases The authors also discuss the theories trying to explain the genetic mutations that have a diminishing effect on the estrogenic synthesis or on the appearance of the resistance to estrogens, emphasizing that the estrogenic effect is essential for the embryo life. The sexual development is too complex to be due only to the sex chromosomes. Its most important stages are determined by the genes located both on the autosomal chromosomes and on the sexual ones.

Disorders of Sex Development↗
PubMed1991

High-resolution scanning electron micrographs of freeze-cracked cells in testes from normal and irradiated rats at different stages of gonadal development.

Newly developed techniques in high-resolution scanning electron microscopy (SEM) and for tissue-processing procedures have been applied to an investigation of structures of various cells in rat testes at different stages of gonadal maturation. A series of high-resolution SEM micrographs are presented which survey the surfaces of different types of testis cells during normal development, and which also illustrate ultrastructural features of some of their intracellular organelles. In addition, a series of high-resolution SEM micrographs are presented which compare the structural features of Sertoli cells in normal testes with those in germ-cell-depleted testes obtained from rats killed at varying times after having been irradiated in utero. We describe our observations on the structural properties of surfaces and intracellular organelles in Sertoli cells, Leydig cells, peritubular myoid cells, and some classes of germinal cells. We also consider the possible role of Sertoli cell apical cytoplasmic processes in lumen formation. Similarities are pointed out between the structure of germ-cell-depleted testes, resulting from irradiation in utero, and the structure of germ-cell-depleted testes in seasonal breeders during periods of involution. Finally, we discuss advantages and disadvantages of methods employed to reveal the fine structure of intracellular organelles in cells of the testis.

Animals↗