scholarly journals Cracd Marks the First Wave of Meiosis during Spermatogenesis and Is Mis-Expressed in Azoospermia Mice

2020 ◽  
Vol 8 (3) ◽  
pp. 21
Author(s):  
Paige L. Snider ◽  
Olga Simmons ◽  
Simon J. Conway
Keyword(s):  
Germ Cell ◽  
Gene Activation ◽  
Cell Lineage ◽  
Cell Loss ◽  
Cell Types ◽  
Round Spermatid ◽  
Testicular Development ◽  
Obstructive Azoospermia ◽  
Capping Protein ◽  
Polypyrimidine Tract Binding Protein

Testicular development starts in utero and maturation continues postnatally, requiring a cascade of gene activation and differentiation into different cell types, with each cell type having its own specific function. As we had previously reported that the Capping protein inhibiting regulator of actin (Cracd) gene was expressed in the adult mouse testis, herein we examine when and where the β-catenin associated Cracd is initially expressed during postnatal testis development. Significantly, Cracd mRNA is present in both the immature postnatal and adult testis in round spermatid cells, with highest level of expression occurring during the first wave of meiosis and spermatogenesis. In the juvenile testes, Cracd is initially expressed within the innermost region but as maturation occurs, Cracd mRNA switches to a more peripheral location. Thereafter, Cracd is downregulated to maintenance levels in the haploid male germ cell lineage. As Cracd mRNA was expressed within developing round spermatids, we tested its effectiveness as a biomarker of non-obstructive azoospermia using transgenic knockout mice models. Meaningfully, Cracd expression was absent in Deleted in azoospermia like (Dazl) null testis, which exhibit a dramatic germ cell loss. Moreover, Cracd was abnormally regulated and ectopically mis-expressed in Polypyrimidine tract binding protein-2 (Ptbp2) conditional germ cell restricted knockout testis, which exhibit a block during spermatid differentiation and a reduction in the number of late stage spermatocytes coincident with reduced β-catenin expression. Combined, these data suggest that Cracd is a useful first wave of spermatogenesis biomarker of azoospermia phenotypes, even prior to an overt phenotype being evident.

scholarly journals Estrogen Receptor β-Mediated Inhibition of Male Germ Cell Line Development in Mice by Endogenous Estrogens during Perinatal Life

Endocrinology ◽  
2004 ◽  
Vol 145 (7) ◽  
pp. 3395-3403 ◽  
Author(s):  
Géraldine Delbès ◽  
Christine Levacher ◽  
Catherine Pairault ◽  
Chrystèle Racine ◽  
Clotilde Duquenne ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Germ Cell ◽  
Experimental Studies ◽  
Cell Lineage ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Testicular Development ◽  
Fetal Life ◽  
Germ Cell Line ◽  
Highly Sensitive ◽  
Labeling Method

Abstract Epidemiological, clinical, and experimental studies have suggested that excessive exposure to estrogens during fetal/neonatal life can lead to reproductive disorders and sperm abnormalities in adulthood. However, it is unknown whether endogenous concentrations of estrogens affect the establishment of the male fetal germ cell lineage. We addressed this question by studying the testicular development of mice in which the estrogen receptor (ER) β or the ERα gene was inactivated. The homozygous inactivation of ERβ (ERβ−/−) increased the number of gonocytes by 50% in 2- and 6-d-old neonates. The numbers of Sertoli and Leydig cells and the level of testicular testosterone production were unaffected, suggesting that estrogens act directly on the gonocytes. The increase in the number of gonocytes did not occur during fetal life but instead occurred just after birth, when gonocytes resumed mitosis and apoptosis. It seems to result from a decrease in the apoptosis rate evaluated by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method and cleaved caspase-3 immunohistochemical detection. Last, mice heterozygous for the ERβ gene inactivation behaved similarly to their ERβ−/− littermates in terms of the number of gonocytes, apoptosis, and mitosis, suggesting that these cells are highly sensitive to the binding of estrogens to ERβ. ERα inactivation had no effect on the number of neonatal gonocytes and Sertoli cells. In conclusion, this study provides the first demonstration that endogenous estrogens can physiologically inhibit germ cell growth in the male. This finding may have important implications concerning the potential action of environmental estrogens.

scholarly journals TRIM71 deficiency causes germ cell loss during mouse embryogenesis and promotes human male infertility

2021 ◽  
Author(s):  
Lucia A. Torres-Fernández ◽  
Jana Emich ◽  
Yasmine Port ◽  
Sibylle Mitschka ◽  
Marius Wöste ◽  
...  
Keyword(s):  
Male Infertility ◽  
Germ Cell ◽  
Germ Cells ◽  
Cell Loss ◽  
Seminiferous Tubules ◽  
Obstructive Azoospermia ◽  
Sequencing Analysis ◽  
Mouse Embryogenesis ◽  
Human Male

AbstractMutations affecting the germline can result in infertility or the generation of germ cell tumors (GCT), highlighting the need to identify and characterize the genes controlling the complex molecular network orchestrating germ cell development. TRIM71 is a stem cell-specific factor essential for embryogenesis, and its expression has been reported in GCT and adult mouse testes. To investigate the role of TRIM71 in mammalian germ cell embryonic development, we generated a germline-specific conditional Trim71 knockout mouse (cKO) using the early primordial germ cell (PGC) marker Nanos3 as a Cre-recombinase driver. cKO mice are infertile, with male mice displaying a Sertoli cell-only (SCO) phenotype, which in humans is defined as a specific subtype of non-obstructive azoospermia characterized by the absence of developing germ cells in the testes’ seminiferous tubules. Infertility originates during embryogenesis, as the SCO phenotype was already apparent in neonatal mice. The in vitro differentiation of mouse embryonic stem cells (ESCs) into PGC-like cells (PGCLCs) revealed reduced numbers of PGCLCs in Trim71-deficient cells. Furthermore, in vitro growth competition assays with wild type and CRISPR/Cas9-generated TRIM71 mutant NCCIT cells, a human GCT-derived cell line which we used as a surrogate model for proliferating PGCs, showed that TRIM71 promotes NCCIT cell proliferation and survival. Our data collectively suggest that germ cell loss in cKO mice results from combined defects during the specification and maintenance of PGCs prior to their sex determination in the genital ridges. Last, via exome sequencing analysis, we identified several TRIM71 variants in a cohort of infertile men, including a loss-of-function variant in a patient with SCO phenotype. Our work reveals for the first time an association of TRIM71 variants with human male infertility, and uncovers further developmental roles for TRIM71 in the generation and maintenance of germ cells during mouse embryogenesis.

scholarly journals Male germ cell apoptosis: regulation and biology

2010 ◽  
Vol 365 (1546) ◽  
pp. 1501-1515 ◽  
Author(s):  
Chandrima Shaha ◽  
Rakshamani Tripathi ◽  
Durga Prasad Mishra
Keyword(s):  
Germ Cell ◽  
Cell Apoptosis ◽  
Cell Types ◽  
Male Germ Cell ◽  
Current Status ◽  
Testicular Development ◽  
Apoptotic Pathway ◽  
Germ Cell Apoptosis ◽  
Cellular Apoptosis ◽  
Intense Activity

Cellular apoptosis appears to be a constant feature in the adult testis and during early development. This is essential because mammalian spermatogenesis is a complex process that requires precise homeostasis of different cell types. This review discusses the latest information available on male germ cell apoptosis induced by hormones, toxins and temperature in the context of the type of apoptotic pathway either the intrinsic or the extrinsic that may be used under a variety of stimuli. The review also discusses the importance of mechanisms pertaining to cellular apoptosis during testicular development, which is independent of exogenous stimuli. Since instances of germ cell carcinoma have increased over the past few decades, the current status of research on apoptotic pathways in teratocarcinoma cells is included. One other important aspect that is covered in this review is microRNA-mediated control of germ cell apoptosis, a field of research that is going to see intense activity in near future. Since knockout models of various kinds have been used to study many aspects of germ cell development, a comprehensive summary of literature on knockout mice used in reproduction studies is also provided.

scholarly journals Selective deletion of SHIP-1 in hematopoietic cells in mice leads to severe lung inflammation involving ILC2 cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xujun Ye ◽  
Fengrui Zhang ◽  
Li Zhou ◽  
Yadong Wei ◽  
Li Zhang ◽  
...  
Keyword(s):  
Lung Inflammation ◽  
Airway Remodeling ◽  
Pulmonary Inflammation ◽  
Hematopoietic Cells ◽  
Cell Lineage ◽  
Allergic Inflammation ◽  
Cell Types ◽  
Lymphoid Cells ◽  
Whole Body

AbstractSrc homology 2 domain–containing inositol 5-phosphatase 1 (SHIP-1) regulates the intracellular levels of phosphotidylinositol-3, 4, 5-trisphosphate, a phosphoinositide 3–kinase (PI3K) product. Emerging evidence suggests that the PI3K pathway is involved in allergic inflammation in the lung. Germline or induced whole-body deletion of SHIP-1 in mice led to spontaneous type 2-dominated pulmonary inflammation, demonstrating that SHIP-1 is essential for lung homeostasis. However, the mechanisms by which SHIP-1 regulates lung inflammation and the responsible cell types are still unclear. Deletion of SHIP-1 selectively in B cells, T cells, dendritic cells (DC) or macrophages did not lead to spontaneous allergic inflammation in mice, suggesting that innate immune cells, particularly group 2 innate lymphoid cells (ILC2 cells) may play an important role in this process. We tested this idea using mice with deletion of SHIP-1 in the hematopoietic cell lineage and examined the changes in ILC2 cells. Conditional deletion of SHIP-1 in hematopoietic cells in Tek-Cre/SHIP-1 mice resulted in spontaneous pulmonary inflammation with features of type 2 immune responses and airway remodeling like those seen in mice with global deletion of SHIP-1. Furthermore, when compared to wild-type control mice, Tek-Cre/SHIP-1 mice displayed a significant increase in the number of IL-5/IL-13 producing ILC2 cells in the lung at baseline and after stimulation by allergen Papain. These findings provide some hints that PI3K signaling may play a role in ILC2 cell development at baseline and in response to allergen stimulation. SHIP-1 is required for maintaining lung homeostasis potentially by restraining ILC2 cells and type 2 inflammation.

scholarly journals Stomatal Development in the Context of Epidermal Tissues

2021 ◽  
Author(s):  
Keiko U Torii
Keyword(s):  
Arabidopsis Thaliana ◽  
Molecular Genetic ◽  
Cell Lineage ◽  
Optimal Growth ◽  
Cell Types ◽  
State Transitions ◽  
Stomatal Development ◽  
Water Control ◽  
Pavement Cells ◽  
The Core

Abstract Background Stomata are adjustable pores on the surface of plant shoots for efficient gas exchange and water control. The presence of stomata is essential for plant growth and survival, and the evolution of stomata is considered as a key developmental innovation of the land plants, allowing colonization on land from aquatic environments some 450 million years ago. In the past two decades, molecular genetic studies using the model plant Arabidopsis thaliana identified key genes and signalling modules that regulate stomatal development: master-regulatory transcription factors that orchestrate cell-state transitions and peptide-receptor signal transduction pathways, which, together, enforce proper patterning of stomata within the epidermis. Studies in diverse plant species, ranging from bryophytes to angiosperm grasses, have begun to unravel the conservation and uniqueness of the core modules in stomatal development. Scope Here, I review the mechanisms of stomatal development in the context of epidermal tissue patterning. First, I introduce the core regulatory mechanisms of stomatal patterning and differentiation in the model species Arabidopsis thaliana. Subsequently, experimental evidence is presented supporting the idea that different cell types within the leaf epidermis, namely stomata, hydathodes pores, pavement cells, and trichomes, either share developmental origins or mutually influence each other’s gene regulatory circuits during development. Emphasis is taken on extrinsic and intrinsic signals regulating the balance between stomata and pavement cells, specifically by controlling the fate of Stomatal-Lineage Ground Cells (SLGCs) to remain within the stomatal-cell lineage or differentiate into pavement cells. Finally, I discuss the influence of inter-tissue-layer communication between the epidermis and underlying mesophyll/vascular tissues on stomatal differentiation. Understanding the dynamic behaviors of stomatal precursor cells and their differentiation in the broader context of tissue and organ development may help design plants tailored for optimal growth and productivity in specific agricultural applications and a changing environment.

Decreased expression of DNA methyltransferases in the testes of patients with non-obstructive azoospermia leads to changes in global DNA methylation levels

2019 ◽  
Vol 31 (8) ◽  
pp. 1386 ◽  
Author(s):  
Fatma Uysal ◽  
Gokhan Akkoyunlu ◽  
Saffet Ozturk
Keyword(s):  
Dna Methylation ◽  
Male Infertility ◽  
De Novo ◽  
Biological Effects ◽  
Testicular Biopsy ◽  
Round Spermatid ◽  
Dna Methyltransferases ◽  
Global Dna Methylation ◽  
Obstructive Azoospermia ◽  
Spermatogenic Cells

DNA methylation plays key roles in epigenetic regulation during mammalian spermatogenesis. DNA methyltransferases (DNMTs) function in de novo and maintenance methylation processes by adding a methyl group to the fifth carbon atom of the cytosine residues within cytosine–phosphate–guanine (CpG) and non-CpG dinucleotide sites. Azoospermia is one of the main causes of male infertility, and is classified as obstructive (OA) or non-obstructive (NOA) azoospermia based on histopathological characteristics. The molecular background of NOA is still largely unknown. DNA methylation performed by DNMTs is implicated in the transcriptional regulation of spermatogenesis-related genes. The aim of the present study was to evaluate the cellular localisation and expression levels of the DNMT1, DNMT3A and DNMT3B proteins, as well as global DNA methylation profiles in testicular biopsy samples obtained from men with various types of NOA, including hypospermatogenesis (hyposperm), round spermatid (RS) arrest, spermatocyte (SC) arrest and Sertoli cell-only (SCO) syndrome. In the testicular biopsy samples, DNMT1 expression and global DNA methylation levels decreased gradually from the hyposperm to SCO groups (P<0.05). DNMT3A expression was significantly decreased in the RS arrest, SC arrest and SCO groups compared with the hyposperm group (P<0.05). DNMT3B expression was significantly lower in the RS arrest and SCO groups than in the hyposperm group (P<0.05). Although both DNMT1 and DNMT3A were localised in the cytoplasm and nucleus of the spermatogenic cells, staining for DNMT3B was more intensive in the nucleus of spermatogenic cells. In conclusion, the findings suggest that significant changes in DNMT expression and global DNA methylation levels in spermatogenic cells may contribute to development of male infertility in the NOA groups. Further studies are needed to determine the molecular biological effects of the altered DNMT expression and DNA methylation levels on development of male infertility.

scholarly journals Drosophila CG2469 Encodes a Homolog of Human CTR9 and Is Essential for Development

2016 ◽  
Vol 6 (12) ◽  
pp. 3849-3857 ◽  
Author(s):  
Dhananjay Chaturvedi ◽  
Mayu Inaba ◽  
Shane Scoggin ◽  
Michael Buszczak
Keyword(s):  
Germ Cell ◽  
Sequence Similarity ◽  
Cell Loss ◽  
Germline Stem Cell ◽  
Cell Nuclei ◽  
Transcriptional Initiation ◽  
Histone Locus Bodies ◽  
Paf1 Complex ◽  
Histone Locus ◽  
Drosophila Cells

Abstract Conserved from yeast to humans, the Paf1 complex participates in a number of diverse processes including transcriptional initiation and polyadenylation. This complex typically includes five proteins: Paf1, Rtf1, Cdc73, Leo1, and Ctr9. Previous efforts identified clear Drosophila homologs of Paf1, Rtf1, and Cdc73 based on sequence similarity. Further work showed that these proteins help to regulate gene expression and are required for viability. To date, a Drosophila homolog of Ctr9 has remained uncharacterized. Here, we show that the gene CG2469 encodes a functional Drosophila Ctr9 homolog. Both human and Drosophila Ctr9 localize to the nuclei of Drosophila cells and appear enriched in histone locus bodies. RNAi knockdown of Drosophila Ctr9 results in a germline stem cell loss phenotype marked by defects in the morphology of germ cell nuclei. A molecular null mutation of Drosophila Ctr9 results in lethality and a human cDNA CTR9 transgene rescues this phenotype. Clonal analysis in the ovary using this null allele reveals that loss of Drosophila Ctr9 results in a reduction of global levels of histone H3 trimethylation of lysine 4 (H3K4me3), but does not compromise the maintenance of stem cells in ovaries. Given the differences between the null mutant and RNAi knockdown phenotypes, the germ cell defects caused by RNAi likely result from the combined loss of Drosophila Ctr9 and other unidentified genes. These data provide further evidence that the function of this Paf1 complex component is conserved across species.

scholarly journals Molecular dissection of the male germ cell lineage identifies putative spermatogonial stem cells in rhesus macaques

2009 ◽  
Vol 24 (7) ◽  
pp. 1704-1716 ◽  
Author(s):  
Brian P. Hermann ◽  
Meena Sukhwani ◽  
David R. Simorangkir ◽  
Tianjiao Chu ◽  
Tony M. Plant ◽  
...  
Keyword(s):  
Stem Cells ◽  
Germ Cell ◽  
Rhesus Macaques ◽  
Cell Lineage ◽  
Spermatogonial Stem Cells ◽  
Male Germ Cell ◽  
Molecular Dissection

scholarly journals Non-apoptotic enteroblast-specific role of the initiator caspase Dronc for development and homeostasis of the Drosophila intestine

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jillian L. Lindblad ◽  
Meghana Tare ◽  
Alla Amcheslavsky ◽  
Alicia Shields ◽  
Andreas Bergmann
Keyword(s):  
Normal Development ◽  
Cell Lineage ◽  
Cell Types ◽  
Specific Role ◽  
Mutant Phenotype ◽  
Apoptotic Pathway ◽  
Specific Expression ◽  
Card Domain

AbstractThe initiator caspase Dronc is the only CARD-domain containing caspase in Drosophila and is essential for apoptosis. Here, we report that homozygous dronc mutant adult animals are short-lived due to the presence of a poorly developed, defective and leaky intestine. Interestingly, this mutant phenotype can be significantly rescued by enteroblast-specific expression of dronc+ in dronc mutant animals, suggesting that proper Dronc function specifically in enteroblasts, one of four cell types in the intestine, is critical for normal development of the intestine. Furthermore, enteroblast-specific knockdown of dronc in adult intestines triggers hyperplasia and differentiation defects. These enteroblast-specific functions of Dronc do not require the apoptotic pathway and thus occur in a non-apoptotic manner. In summary, we demonstrate that an apoptotic initiator caspase has a very critical non-apoptotic function for normal development and for the control of the cell lineage in the adult midgut and therefore for proper physiology and homeostasis.

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