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Marine Biotechnology (New York, N.Y.) Oct 2012The embryonic gonad is the only organ that takes two mutually exclusive differentiating pathways and hence gives rise to two different adult organs: testes or ovaries.... (Comparative Study)
Comparative Study Review
The embryonic gonad is the only organ that takes two mutually exclusive differentiating pathways and hence gives rise to two different adult organs: testes or ovaries. The recent application of genomic tools including microarrays, next-generation sequencing approaches, and epigenetics can significantly contribute to decipher the molecular mechanisms involved in the processes of sex determination and sex differentiation. However, in fish, these studies are complicated by the fact that these processes depend, perhaps to a larger extent when compared to other vertebrates, on the interplay of genetic and environmental influences. Here, we review the advances made so far, taking into account different experimental approaches, and illustrate some technical complications deriving from the fact that as development progresses it becomes more and more difficult to distinguish whether changes in gene expression or DNA methylation patterns are the cause or the consequence of such developmental events. Finally, we suggest some avenues for further research in both model fish species and fish species facing specific problems within an aquaculture context.
Topics: Animals; Aquaculture; Environment; Fishes; Gene Expression Regulation; Genomics; Microarray Analysis; Reproduction; Sex Determination Processes; Sex Differentiation; Species Specificity
PubMed: 22544374
DOI: 10.1007/s10126-012-9445-4 -
Frontiers in Endocrinology 2022Over seventy years ago it was proposed that the fetal testis produces a hormone distinct from testosterone that is required for complete male sexual development. At the... (Review)
Review
Over seventy years ago it was proposed that the fetal testis produces a hormone distinct from testosterone that is required for complete male sexual development. At the time the hormone had not yet been identified but was invoked by Alfred Jost to explain why the Müllerian duct, which develops into the female reproductive tract, regresses in the male fetus. That hormone, anti-Müllerian hormone (AMH), and its specific receptor, AMHR2, have now been extensively characterized and belong to the transforming growth factor-β families of protein ligands and receptors involved in growth and differentiation. Much is now known about the downstream events set in motion after AMH engages AMHR2 at the surface of specific Müllerian duct cells and initiates a cascade of molecular interactions that ultimately terminate in the nucleus as activated transcription factors. The signals generated by the AMH signaling pathway are then integrated with signals coming from other pathways and culminate in a complex gene regulatory program that redirects cellular functions and fates and leads to Müllerian duct regression.
Topics: Anti-Mullerian Hormone; Female; Humans; Male; Mullerian Ducts; Peptide Hormones; Protein Serine-Threonine Kinases; Sex Differentiation; Signal Transduction
PubMed: 35721723
DOI: 10.3389/fendo.2022.905324 -
Hormone Research in Paediatrics 2010Sex steroids are crucial regulators of sexual differentiation and the proper development of secondary sex characteristics and patterns of sexual behavior. Since Leydig... (Review)
Review
Sex steroids are crucial regulators of sexual differentiation and the proper development of secondary sex characteristics and patterns of sexual behavior. Since Leydig cells are the primary major producers of these steroid hormones, maintenance of the normal functions of these cells determines the reproductive capacity and fertility of males. The present minireview discusses recent findings concerning endocrine and paracrine regulation of the proliferation, differentiation and involution of human Leydig cells. The physiology and function of the two distinct fetal and adult populations of human Leydig cells are described, with particular focus on the paracrine environment that triggers their differentiation and functional maturation. The roles of established and more recently discovered paracrine regulators of this maturation, including insulin-like factor 3, platelet-derived growth factor-alpha, desert hedgehog, ghrelin and leptin are considered. A brief description of the origin, ontogenesis and functional markers of human fetal and adult Leydig cells is presented.
Topics: Adult; Biomarkers; Cell Differentiation; Cell Proliferation; Fetus; Ghrelin; Gonadal Steroid Hormones; Hedgehog Proteins; Humans; Insulin; Leptin; Leydig Cells; Male; Paracrine Communication; Platelet-Derived Growth Factor; Proteins; Sex Differentiation
PubMed: 20190545
DOI: 10.1159/000277141 -
International Journal of Molecular... Aug 2022The Russian sturgeon (, AG) is an endangered fish species increasingly raised on fish farms for black caviar. Understanding the process of sex determination in AG is,...
The Russian sturgeon (, AG) is an endangered fish species increasingly raised on fish farms for black caviar. Understanding the process of sex determination in AG is, therefore, of scientific and commercial importance. AG lacks sexual dimorphism until sexual maturation and has a predominantly octoploid genome without a definite sex chromosome. A conserved short female-specific genomic sequence was recently described, leading to the development of a genetic sex marker. However, no biological function has been reported for this sequence. Thus, the mechanism of sex determination and the overall inter-sex genomic variation in AG are still unknown. To comprehensively analyze the inter-sex genomic variation and assess the overall inter-species variation between AG and (AR, sterlet), a related tetraploid sturgeon species, we performed whole-genome sequencing on DNA from 10 fish-farm-raised adult AG (5 males and 5 females). We produced a partially assembled, ~2390 MBp draft genome for AG. We validated in AG the female-specific region previously described in AR. We identified ~2.8 million loci (SNP/indels) varying between the species, but only ~7400 sex-associated loci in AG. We mapped the sex-associated AG loci to the AR genome and identified 15 peaks of sex-associated variation (10 kb segments with 30 or more sex-associated variants), 1 of which matched the previously reported sex-variable region. Finally, we identified 14 known and predicted genes in proximity to these peaks. Our analysis suggests that one or more of these genes may have functional roles in sex determination and/or sexual differentiation in sturgeons. Further functional studies are required to elucidate these roles.
Topics: Animals; Endangered Species; Female; Fishes; Genetic Markers; Genomics; Male; Sex Differentiation
PubMed: 36012734
DOI: 10.3390/ijms23169469 -
Current Opinion in Neurobiology Aug 2010Males and females exhibit numerous anatomical and physiological differences in the brain that often underlie important sex differences in physiology or behavior,... (Review)
Review
Males and females exhibit numerous anatomical and physiological differences in the brain that often underlie important sex differences in physiology or behavior, including aspects relating to reproduction. Neural sex differences are both region-specific and trait-specific and may consist of divergences in synapse morphology, neuron size and number, and specific gene expression levels. In most cases, sex differences are induced by the sex steroid hormonal milieu during early perinatal development. In rodents, the hypothalamic anteroventral periventricular nucleus (AVPV) is sexually differentiated as a result of postnatal sex steroids, and also specific neuronal populations in this nucleus are sexually dimorphic, with females possessing more kisspeptin, dopaminergic, and GABA/glutamate neurons than males. The ability of female rodents, but not males, to display an estrogen-induced luteinizing hormone (LH) surge is consistent with the higher levels of these neuropeptides in the AVPV of females. Of these AVPV populations, the recently identified kisspeptin system has been most strongly implicated as a crucial component of the sexually dimorphic LH surge mechanism, though GABA and glutamate have also received some attention. New findings have suggested that the sexual differentiation and development of kisspeptin neurons in the AVPV is mediated by developmental estradiol signaling. Although apoptosis is the most common process implicated in neuronal sexual differentiation, it is currently unknown how developmental estradiol acts to differentiate specific neuronal populations in the AVPV, such as kisspeptin or dopaminergic neurons.
Topics: Animals; Female; Male; Nerve Net; Neurons; Prosencephalon; Sex Differentiation; Steroids
PubMed: 20471241
DOI: 10.1016/j.conb.2010.04.004 -
Sexual Development : Genetics,... 2010
Topics: Animals; Climate Change; Models, Animal; Reptiles; Sex Determination Processes; Sex Differentiation; Temperature
PubMed: 20234153
DOI: 10.1159/000289512 -
International Journal of Molecular... Sep 2023This study investigated the potential to use double-stranded RNA insulin-like androgenic gland hormone () to induce sex reversal in and identified the molecular...
This study investigated the potential to use double-stranded RNA insulin-like androgenic gland hormone () to induce sex reversal in and identified the molecular mechanisms underlying crustacean reproduction and sex differentiation. The study aimed to determine whether could induce sex reversal in PL30-male during a critical period. The sex-related genes were selected by performing the gonadal transcriptome analysis of normal male (dsM), normal female (dsFM), neo-female sex-reversed individuals (dsRM), and unreversed males (dsNRM). After six injections, the experiment finally resulted in a 20% production of dsRM. Histologically, dsRM ovaries developed slower than dsFM, but dsNRM spermathecae developed normally. A total of 1718, 1069, and 255 differentially expressed genes were identified through transcriptome sequencing of the gonads in three comparison groups, revealing crucial genes related to reproduction and sex differentiation, such as , , , and . Principal Component Analysis (PCA) also distinguished dsM and dsRM very well. In addition, this study predicted that the eyestalks and the "phototransduction-fly" photoperiodic pathways of could play an important role in sex reversal. The enrichment of related pathways and growth traits in dsNRM were combined to establish that played a significant role in reproduction, growth regulation, and metabolism. Finally, complete sex reversal may depend on specific stimuli at critical periods. Overall, this study provides valuable findings for the regulation of sex differentiation, reproduction, and growth of in establishing a monoculture.
Topics: Humans; Female; Male; Animals; Insulin; Androgens; Palaemonidae; Sex Differentiation; Insulin, Regular, Human; Reproduction
PubMed: 37762609
DOI: 10.3390/ijms241814306 -
Medecine Sciences : M/S Oct 2011Our knowledge on sex differentiation in mammals has considerably progressed during the last decennials, beginning with the discovery of the testis-determining factor.... (Review)
Review
Our knowledge on sex differentiation in mammals has considerably progressed during the last decennials, beginning with the discovery of the testis-determining factor. Here, the morphogenetic processes involved in the early gonadic switch will be presented, together with the major genes involved in testis and ovary formation. Existing differences between the widely used mouse model and other mammals, such as human and goat, will be highlighted.
Topics: Animals; Female; Forkhead Box Protein L2; Forkhead Transcription Factors; Gene Dosage; Genes, sry; Goats; Hormones; Humans; Male; Mammals; Mice; Models, Biological; Morphogenesis; Ovary; Sex Characteristics; Sex Chromosomes; Sex Determination Processes; Sex Differentiation; Species Specificity; Testis
PubMed: 22027423
DOI: 10.1051/medsci/20112710014 -
International Journal of Molecular... Mar 2020The complex process of sexual differentiation is known to be influenced by biological and environmental determinants. The present review has the aim of summarizing the... (Review)
Review
The complex process of sexual differentiation is known to be influenced by biological and environmental determinants. The present review has the aim of summarizing the most relevant studies on the biological basis of sexual development, and in particular, it focuses on the impact of sex hormones and genetic background on the development of sexual differentiation and gender identity. The authors conducted a search of published studies on Medline (from January 1948 to December 2019). The evidence suggests that the sexual dimorphic brain could be the anatomical substrate of psychosexual development, on which gonadal hormones may have a shaping role during prenatal and pubertal periods. Additionally, according to several heritability studies, genetic components may have a role, but a promising candidate gene has not been identified. Even though growing evidence underlines the primary role of biological factors on psychosexual development, further studies are necessary to better explain their complex interactions.
Topics: Brain; Female; Gender Identity; Gene Expression Regulation; Hormones; Humans; Male; Sex Characteristics; Sex Differentiation; Sex Factors
PubMed: 32204531
DOI: 10.3390/ijms21062123 -
Journal of Neuroendocrinology Jan 2020There is perhaps no endocrine disrupting chemical more controversial than bisphenol A (BPA). Comprising a high-volume production chemical used in a variety of... (Review)
Review
There is perhaps no endocrine disrupting chemical more controversial than bisphenol A (BPA). Comprising a high-volume production chemical used in a variety of applications, BPA has been linked to a litany of adverse health-related outcomes, including effects on brain sexual differentiation and behaviour. Risk assessors preferentially rely on classical guideline-compliant toxicity studies over studies published by academic scientists, and have generally downplayed concerns about the potential risks that BPA poses to human health. It has been argued, however, that, because traditional toxicity studies rarely contain neural endpoints, and only a paucity of endocrine-sensitive endpoints, they are incapable of fully evaluating harm. To address current controversies on the safety of BPA, the United States National Institute of Environmental Health Sciences, the National Toxicology Program (NTP), and the US Food and Drug Administration established the Consortium Linking Academic and Regulatory Insights on BPA Toxicity (CLARITY-BPA). CLARITY-BPA performed a classical regulatory-style toxicology study (Core study) in conjunction with multiple behavioural, molecular and cellular studies conducted by academic laboratories (grantee studies) using a collaboratively devised experimental framework and the same animals and tissues. This review summarises the results from the grantee studies that focused on brain and behaviour. Evidence of altered neuroendocrine development, including age- and sex-specific expression of oestrogen receptor (ER)α and ERβ, and the abrogation of brain and behavioural sexual dimorphisms, supports the conclusion that developmental BPA exposure, even at doses below what regulatory agencies regard as "safe" for humans, contribute to brain and behavioural change. The consistency and the reproducibility of the effects across CLARITY-BPA and prior studies using the same animal strain and almost identical experimental conditions are compelling. Combined analysis of all of the data from the CLARITY-BPA project is underway at the NTP and a final report expected in late 2019.
Topics: Animals; Behavior, Animal; Benzhydryl Compounds; Brain; Endocrine Disruptors; Female; Humans; Male; Neurons; Phenols; Pregnancy; Sex Differentiation; United States; United States Food and Drug Administration
PubMed: 31063678
DOI: 10.1111/jne.12730