{"title":"Germ Cell Development and Sex Differentiation.","authors":"Minoru Tanaka, Katsuhiko Hayashi","doi":"10.1159/000530361","DOIUrl":"https://doi.org/10.1159/000530361","url":null,"abstract":"It is our great pleasure to have been able to publish cutting-edge monographs written by leaders of germ cell studies. Currently, a tremendous number of studies on germ cells can be read in the scientific journals of many fields. At this timing, it would be good to recall that the germ cell studies on early days conceived an issue of sexual fate [McClung, 1902; Stevens, 1905]. Behavior of a curious chromosome during meiosis led to the recognition of sex chromosome and of development of sexually two different gametes. The modern studies of germ cells began with addressing the timing of sexual fate decision of germ cells to develop into eggs or sperm [Burgoyne et al., 1988; McLaren, 1988]. These were done by a group of Dr. McLaren in 1988, more than 30 years ago before the first identification of the sex determination gene, Sry [Sinclair et al., 1990]. In the studies, XY germ cells isolated from mouse embryos were transplanted in XX body and vice versa. Since then, the germ cell studies have been prosperous at the levels of molecular and cellular mechanism. Recently in relation with stem cell biology, it is getting relevant to understand how germline stem cells leave the state of stemness and commit to either oogenesis and spermatogenesis. This stems a modern understanding of the sexual fate decision of germ cells [Spiller et al., 2017]. This issue will provide a current view of mechanisms of germ cell sexual fate decision. Germ cells in mammals have a sexually asymmetric feature, development of germline stem cells in male gonad but no germline stem cells defined in female gonad [Zhang et al., 2015]. This is different from other vertebrate species and shows that germ cells in mammals are not everything. In this context, germ cell studies in Drosophila and Nematoda (and other vertebrates) have been complementary to mammals and giving a deep insight on an essential nature of germ cells. In addition to the two chapters of Drosophila and Nematoda, the other chapters constitute different aspects of mechanisms underlying sexual fate of germ cells and describe the recent progress in mammals. These include signal transduction, cellular interaction, epigenetic regulation, recombination, and metabolism. In these chapters, the audience would recognize the detailed mechanisms analyzed by development of sophisticated techniques with big data. The editors believe that this special issue represents current trends of germ cell studies and will chart a scientific path in this field. Minoru Tanaka Nagoya University, Nagoya, Japan Katsuhiko Hayashi Osaka University, Suita, Japan","PeriodicalId":49536,"journal":{"name":"Sexual Development","volume":"16 5-6","pages":"303-304"},"PeriodicalIF":2.3,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9795049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Instructing Mouse Germ Cells to Adopt a Female Fate.","authors":"Cassy Spiller, Josephine Bowles","doi":"10.1159/000523763","DOIUrl":"https://doi.org/10.1159/000523763","url":null,"abstract":"<p><strong>Background: </strong>Germ cells are critical for the survival of our species. They are the only cells that undergo meiosis - the reductive form of cell division that is necessary for genetic reassortment of chromosomes and production of the haploid gametes, the sperm and eggs. Remarkably, the initial female/male fate decision in fetal germ cells does not depend on whether they are chromosomally XX or XY; rather, initial sexual fate is imposed by influences from the surrounding tissue. In mammals, the female germline is particularly precious: despite recent suggestions that germline stem cells exist in the ovary, it is still generally accepted that the ovarian reserve is finite, and its size is dependant on germ cells of the fetal ovary initiating meiosis in a timely manner.</p><p><strong>Summary: </strong>Prior to 2006, evidence suggested that gonadal germ cells initiate meiotic prophase I by default, but more recent data support a key role for the signalling molecule retinoic acid (RA) in instructing female germ cell fate. Newer findings also support a key meiosis-inducing role for another signalling molecule, bone morphogenic protein (BMP). Nonetheless, many questions remain.</p><p><strong>Key messages: </strong>Here, we review knowledge thus far regarding extrinsic and intrinsic determinants of a female germ cell fate, focusing on the mouse model.</p>","PeriodicalId":49536,"journal":{"name":"Sexual Development","volume":"16 5-6","pages":"342-354"},"PeriodicalIF":2.3,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9784210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Epigenetic Mechanisms Governing Female and Male Germline Development in Mammals.","authors":"Kenjiro Shirane, Matthew Lorincz","doi":"10.1159/000529336","DOIUrl":"https://doi.org/10.1159/000529336","url":null,"abstract":"<p><strong>Background: </strong>DNA methylation (DNAme) and histone posttranslational modifications (PTMs) play an integral role in the transcriptional regulation of specific sets of genes and retrotransposons. In turn, these chromatin marks are essential for cellular reprogramming, including during germline development. While DNAme is stably propagated in most somatic tissues, this epigenetic mark undergoes cycles of widespread erasure and re-establishment in the early embryo as well as in the germline.</p><p><strong>Summary: </strong>De novo DNAme occurs at distinct developmental stages in male and female germ cells; before birth in prospermatogonia (PSG) and after birth in growing oocytes. Furthermore, while only ∼40% of the mouse genome is methylated in mature oocytes, ∼80% of the genome is methylated in mature sperm. Here, we review recent epigenome studies which reveal a complex interplay between histone PTMs and de novo DNAme in shaping the sexually dimorphic profiles of DNAme observed in mature gametes in the mouse, including in intergenic regions as well as at imprinted gametic differentially methylated regions (gDMRs). We discuss the dynamics and distribution of key histone PTMs in male and female germ cells, including H3K36me2/me3, H3K4me3, and H3K27me3, and the implications of positive and negative crosstalk between these PTMs and the DNAme machinery. Finally, we reflect on how the sex-specific epigenetic landscapes observed in the mouse germline impact transcriptional regulation in both the gametes and the early embryo.</p><p><strong>Key messages: </strong>Investigation of the roles of chromatin modifying enzymes and the interplay between the chromatin marks that they deposit in germ cells has been facilitated by analyses of conventional or germline-specific knockout mice, combined with low-input genome-wide profiling methods that have been developed in recent years. While clearly informative, these findings generally reflect \"snapshots\" of chromatin states derived from analyses of cells analyzed in bulk at a specific period in development. Technological advances and novel experimental models will be required to further refine our understanding of the underlying mechanism and order of establishment of chromatin marks and the impact of sexually dimorphic epigenetic patterning on transcription and other nuclear processes in germ cells, the early embryo and beyond.</p>","PeriodicalId":49536,"journal":{"name":"Sexual Development","volume":"16 5-6","pages":"365-387"},"PeriodicalIF":2.3,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9787741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sexual DevelopmentPub Date : 2022-01-01Epub Date: 2022-03-08DOI: 10.1159/000521235
Lydia Grmai, Caitlin Pozmanter, Mark Van Doren
{"title":"The Regulation of Germline Sex Determination in Drosophila by Sex lethal.","authors":"Lydia Grmai, Caitlin Pozmanter, Mark Van Doren","doi":"10.1159/000521235","DOIUrl":"10.1159/000521235","url":null,"abstract":"<p><strong>Background: </strong>The establishment of male or female identity (sex determination) is essential for creating the anatomical, physiological, and behavioral differences between 2 sexes of the same species (sexual dimorphism). In many organisms, including mammals and Drosophila, sex is determined by inheritance of sex chromosomes, while in other animals, sex is determined by environmental factors. Arguably the most important consequence of sex determination is the production of healthy gametes necessary for reproduction: female oocytes and male spermatids.</p><p><strong>Summary: </strong>The generation of sperm and oocytes requires cooperation between 2 different cell types within the gonad: germ cells and somatic cells. Defects in sex determination in either the somatic gonad or germline lead to disorders of sexual development and infertility. In Drosophila, the gene Sex lethal (Sxl) is the key determinant of sex in both the soma and the germline. However, how Sxl controls sex determination is much more well understood in the soma than the germline. Key Mesage: This review will focus on Sxl in the germline, how it is activated specifically in female germ cells, and how it regulates germline sex determination and sexual development.</p>","PeriodicalId":49536,"journal":{"name":"Sexual Development","volume":"16 5-6","pages":"323-328"},"PeriodicalIF":2.3,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10540089/pdf/nihms-1765923.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9829994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sexual DevelopmentPub Date : 2022-01-01Epub Date: 2021-09-10DOI: 10.1159/000517085
Mirian Yumie Nishi, José Antônia Diniz Faria Júnior, Ana Cristina Victorino Krepischi, Daniela Rodrigues de Moraes, Silvia Souza da Costa, Elinaelma Suelane do Nascimento Silva, Elaine Maria Frade Costa, Berenice Bilharinho Mendonca, Sorahia Domenice
{"title":"A Small Supernumerary Xp Marker Chromosome Including Genes NR0B1 and MAGEB Causing Partial Gonadal Dysgenesis and Gonadoblastoma.","authors":"Mirian Yumie Nishi, José Antônia Diniz Faria Júnior, Ana Cristina Victorino Krepischi, Daniela Rodrigues de Moraes, Silvia Souza da Costa, Elinaelma Suelane do Nascimento Silva, Elaine Maria Frade Costa, Berenice Bilharinho Mendonca, Sorahia Domenice","doi":"10.1159/000517085","DOIUrl":"https://doi.org/10.1159/000517085","url":null,"abstract":"<p><p>Copy number variations of several genes involved in the process of gonadal determination have been identified as a cause of 46,XY differences of sex development. We report a non-syndromic 14-year-old female patient who was referred with primary amenorrhea, absence of breast development, and atypical genitalia. Her karyotype was 47,XY,+mar/46,XY, and FISH analysis revealed the X chromosome origin of the marker chromosome. Array-CGH data identified a pathogenic 2.0-Mb gain of an Xp21.2 segment containing NR0B1/DAX1 and a 1.9-Mb variant of unknown significance from the Xp11.21p11.1 region. This is the first report of a chromosomal microarray analysis to reveal the genetic content of a small supernumerary marker chromosome detected in a 47,XY,+der(X)/46,XY karyotype in a non-syndromic girl with partial gonadal dysgenesis and gonadoblastoma. Our findings indicate that the mosaic presence of the small supernumerary Xp marker, encompassing the NR0B1/DAX1 gene, may have been the main cause of dysgenetic testes development, although the role of MAGEB and other genes mapped to the Xp21 segment could not be completely ruled out.</p>","PeriodicalId":49536,"journal":{"name":"Sexual Development","volume":"16 1","pages":"55-63"},"PeriodicalIF":2.3,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39406359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sexual DevelopmentPub Date : 2022-01-01Epub Date: 2021-09-09DOI: 10.1159/000518091
Barbara Leitao Braga, Nathalia Lisboa Gomes, Mirian Y Nishi, Bruna L Freire, Rafael L Batista, Jose A D Faria Junior, Mariana F A Funari, Anna F Figueredo Benedetti, Amanda de Moraes Narcizo, Lais Cavalca Cardoso, Antonio M Lerario, Gil Guerra-Junior, Elaine M Frade Costa, Sorahia Domenice, Alexander A L Jorge, Berenice B Mendonca
{"title":"Variants in 46,XY DSD-Related Genes in Syndromic and Non-Syndromic Small for Gestational Age Children with Hypospadias.","authors":"Barbara Leitao Braga, Nathalia Lisboa Gomes, Mirian Y Nishi, Bruna L Freire, Rafael L Batista, Jose A D Faria Junior, Mariana F A Funari, Anna F Figueredo Benedetti, Amanda de Moraes Narcizo, Lais Cavalca Cardoso, Antonio M Lerario, Gil Guerra-Junior, Elaine M Frade Costa, Sorahia Domenice, Alexander A L Jorge, Berenice B Mendonca","doi":"10.1159/000518091","DOIUrl":"https://doi.org/10.1159/000518091","url":null,"abstract":"<p><p>Hypospadias is a common congenital disorder of male genital formation. Children born small for gestational age (SGA) present a high frequency of hypospadias of undetermined etiology. No previous study investigated the molecular etiology of hypospadias in boys born SGA using massively parallel sequencing. Our objective is to report the genetic findings of a cohort of patients born SGA with medium or proximal hypospadias. We identified 46 individuals with this phenotype from a large cohort of 46,XY DSD patients, including 5 individuals with syndromic features. DNA samples from subjects were studied by either whole exome sequencing or target gene panel approach. Three of the syndromic patients have 5 main clinical features of Silver-Russell syndrome (SRS) and were first studied by MLPA. Among the syndromic patients, loss of DNA methylation at the imprinting control region H19/IGF2 was identified in 2 individuals with SRS clinical diagnosis. Two novel pathogenic variants in compound heterozygous state were identified in the CUL7 gene establishing the diagnosis of 3M syndrome in one patient, and a novel homozygous variant in TRIM37 was identified in another boy with Mulibrey nanism phenotype. Among the non-syndromic subjects, 7 rare heterozygous variants were identified in 6 DSD-related genes. However, none of the variants found can explain the phenotype by themselves. In conclusion, a genetic defect that clarifies the etiology of hypospadias was not found in most of the non-syndromic SGA children, supporting the hypothesis that multifactorial causes, new genes, and/or unidentified epigenetic defects may have an influence in this condition.</p>","PeriodicalId":49536,"journal":{"name":"Sexual Development","volume":"16 1","pages":"27-33"},"PeriodicalIF":2.3,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39413579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}