scholarly journals TEX14 Interacts with CEP55 To Block Cell Abscission

2010 ◽  
Vol 30 (9) ◽  
pp. 2280-2292 ◽  
Author(s):  
Tokuko Iwamori ◽  
Naoki Iwamori ◽  
Lang Ma ◽  
Mark A. Edson ◽  
Michael P. Greenbaum ◽  
...  
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Intercellular Bridge ◽  
Male Germ Cells ◽  
Physical Separation ◽  
Targeted Deletion ◽  
Intercellular Bridges ◽  
Daughter Cells ◽  
Stable Component ◽  
Evolutionarily Conserved

ABSTRACT In somatic cells, abscission, the physical separation of daughter cells at the completion of cytokinesis, requires CEP55, ALIX, and TSG101. In contrast, cytokinesis is arrested prior to abscission in differentiating male germ cells that are interconnected by TEX14-positive intercellular bridges. We have previously shown that targeted deletion of TEX14 disrupts intercellular bridges in all germ cells and causes male sterility. Although these findings demonstrate that intercellular bridges are essential for spermatogenesis, it remains to be shown how TEX14 and other proteins come together to prevent abscission and form stable intercellular bridges. Using a biochemical enrichment of male germ cell intercellular bridges, we identified additional bridge proteins, including CEP55. Although CEP55 is highly expressed in testes at the RNA level, there is no report of the presence of CEP55 in germ cells. We show here that CEP55 becomes a stable component of the intercellular bridge and that an evolutionarily conserved GPPX3Y motif of TEX14 binds strongly to CEP55 to block similar GPPX3Y motifs of ALIX and TSG101 from interacting and localizing to the midbody. Thus, TEX14 prevents the completion of cytokinesis by altering the destiny of CEP55 from a nidus for abscission to an integral component of the intercellular bridge.

scholarly journals C. elegans Anillin proteins regulate intercellular bridge stability and germline syncytial organization

2014 ◽  
Vol 206 (1) ◽  
pp. 129-143 ◽  
Author(s):  
Rana Amini ◽  
Eugénie Goupil ◽  
Sara Labella ◽  
Monique Zetka ◽  
Amy S. Maddox ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Germ Cell ◽  
Germ Cells ◽  
Cytoplasmic Streaming ◽  
Intercellular Bridge ◽  
Cell Specification ◽  
Intercellular Bridges ◽  
C Elegans ◽  
Daughter Cells ◽  
Germ Cell Specification

Cytokinesis generally produces two separate daughter cells, but in some tissues daughter nuclei remain connected to a shared cytoplasm, or syncytium, through incomplete cytokinesis. How syncytia form remains poorly understood. We studied syncytial formation in the Caenorhabditis elegans germline, in which germ cells connect to a shared cytoplasm core (the rachis) via intercellular bridges. We found that syncytial architecture initiates early in larval development, and germ cells become progressively interconnected until adulthood. The short Anillin family scaffold protein ANI-2 is enriched at intercellular bridges from the onset of germ cell specification, and ANI-2 loss resulted in destabilization of intercellular bridges and germ cell multinucleation defects. These defects were partially rescued by depleting the canonical Anillin ANI-1 or blocking cytoplasmic streaming. ANI-2 is also required for elastic deformation of the gonad during ovulation. We propose that ANI-2 promotes germ cell syncytial organization and allows for compensation of the mechanical stress associated with oogenesis by conferring stability and elasticity to germ cell intercellular bridges.

scholarly journals Overexpression of peroxisomal testis-specific 1 protein induces germ cell apoptosis and leads to infertility in male mice

2011 ◽  
Vol 22 (10) ◽  
pp. 1766-1779 ◽  
Author(s):  
Karina Kaczmarek ◽  
Maja Studencka ◽  
Andreas Meinhardt ◽  
Krzysztof Wieczerzak ◽  
Sven Thoms ◽  
...  
Keyword(s):  
Cell Death ◽  
Germ Cell ◽  
Germ Cells ◽  
Specific Gene ◽  
Male Mice ◽  
Terminal Part ◽  
Male Germ Cells ◽  
Germ Cell Apoptosis ◽  
Induced Apoptosis

 Peroxisomal testis-specific 1 gene (Pxt1) is the only male germ cell–specific gene that encodes a peroxisomal protein known to date. To elucidate the role of Pxt1 in spermatogenesis, we generated transgenic mice expressing a c-MYC-PXT1 fusion protein under the control of the PGK2 promoter. Overexpression of Pxt1 resulted in induction of male germ cells’ apoptosis mainly in primary spermatocytes, finally leading to male infertility. This prompted us to analyze the proapoptotic character of mouse PXT1, which harbors a BH3-like domain in the N-terminal part. In different cell lines, the overexpression of PXT1 also resulted in a dramatic increase of apoptosis, whereas the deletion of the BH3-like domain significantly reduced cell death events, thereby confirming that the domain is functional and essential for the proapoptotic activity of PXT1. Moreover, we demonstrated that PXT1 interacts with apoptosis regulator BAT3, which, if overexpressed, can protect cells from the PXT1-induced apoptosis. The PXT1-BAT3 association leads to PXT1 relocation from the cytoplasm to the nucleus. In summary, we demonstrated that PXT1 induces apoptosis via the BH3-like domain and that this process is inhibited by BAT3.

217 PROTEIN-INDUCED TRANSDIFFERENTIATION INTO MALE GERM CELL-LIKE LINEAGE FROM CHICKEN FETAL BONE MARROW STEM CELLS

2012 ◽  
Vol 24 (1) ◽  
pp. 220
Author(s):  
J. M. Yoo ◽  
J. J. Park ◽  
K. Gobianand ◽  
J. Y. Ji ◽  
J. S. Kim ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Retinoic Acid ◽  
Germ Cell ◽  
Germ Cells ◽  
Cultured Cells ◽  
Male Germ Cell ◽  
Male Germ Cells ◽  
Germ Cell Differentiation ◽  
Transgenic Chickens

Bone marrow (BM)-derived stem cells are capable of transdifferentiation into multilineage cells like muscle, bone, cartilage, fat and nerve cells. In this study, we investigated the capability of mesenchymal stem cells (MSC) derived from BM into germ cell differentiation in the chicken. Chicken MSCs were isolated from BM of day 20 fertilized fetal chicken with Ficoll-Paque Plus. Isolated cells were cultured in advance-DMEM (ADMEM) supplemented with 10% fetal bovine serum and antibiotics. Once confluent, cells were subcultured until five passages. The cultured cells showed fibroblast-like morphology. The cells had positive expressions of Oct4, Sox2 and Nanog. Two induction methods were conducted to examine the ability of transdifferentation into male germ cells. In group 1, MSC were cultured in ADMEM containing retinoic acid and chicken testicular extracts proteins for 10 to 15 days. In group 2, MSC were permeabilized by streptolysin O and treated with chicken testicular protein extracts. In both treatment groups, MSC were cultured in ADMEM containing retinoic acid for 10 to 15 days. We found that chicken MSC had a positive expression of pluripotent proteins such as Oct4, Sox2, Nanog and a small population of chicken MSC seem to transdifferentiate into male germ cell-like cells. These cells expressed early germ cell markers and male germ-cell-specific markers (Dazl, C-kit, Stra8 and DDX4) as analysed by reverse transcription-PCR and immunohistochemistry. These results demonstrated that chicken MSC may differentiate into male germ cells and the same might be used as a potential source of cells for production of transgenic chickens. This study was carried out with the support of Agenda Program (Project No. PJ0064692011), RDA and Republic of Korea.

scholarly journals Cannabinoid Receptors Signaling in the Development, Epigenetics, and Tumours of Male Germ Cells

2019 ◽  
Vol 21 (1) ◽  
pp. 25 ◽  
Author(s):  
Marco Barchi ◽  
Elisa Innocenzi ◽  
Teresa Giannattasio ◽  
Susanna Dolci ◽  
Pellegrino Rossi ◽  
...  
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Cannabinoid Receptors ◽  
Endocannabinoid System ◽  
Male Reproduction ◽  
Metabolizing Enzymes ◽  
Male Germ Cells ◽  
Testicular Tumours ◽  
Germ Cell Differentiation ◽  
Degradative Enzymes

Endocannabinoids are natural lipid molecules whose levels are regulated by specific biosynthetic and degradative enzymes. They bind to and activate two main cannabinoid receptors type 1 (CB1) and type 2 (CB2), and together with their metabolizing enzymes form the “endocannabinoid system” (ECS). In the last years, the relevance of endocannabinoids (eCBs) as critical modulators in various aspects of male reproduction has been pointed out. Mammalian male germ cells, from mitotic to haploid stage, have a complete ECS which is modulated during spermatogenesis. Compelling evidence indicate that in the testis an appropriate “eCBs tone”, associated to a balanced CB receptors signaling, is critical for spermatogenesis and for the formation of mature and fertilizing spermatozoa. Any alteration of this system negatively affects male reproduction, from germ cell differentiation to sperm functions, and might have also an impact on testicular tumours. Indeed, most of testicular tumours develop during early germ-cell development in which a maturation arrest is thought to be the first key event leading to malignant transformation. Considering the ever-growing number and complexity of the data on ECS, this review focuses on the role of cannabinoid receptors CB1 and CB2 signaling in male germ cells development from gonocyte up to mature spermatozoa and in the induction of epigenetic alterations in these cells which might be transmitted to the progeny. Furthermore, we present new evidence on their relevance in testicular cancer.

scholarly journals Proteomic and metabolomic analyses uncover sex-specific regulatory pathways in mouse fetal germline differentiation†

2020 ◽  
Vol 103 (4) ◽  
pp. 717-735
Author(s):  
Yohei Hayashi ◽  
Masaru Mori ◽  
Kaori Igarashi ◽  
Keiko Tanaka ◽  
Asuka Takehara ◽  
...  
Keyword(s):  
Oxidative Phosphorylation ◽  
Germ Cell ◽  
Germ Cells ◽  
Cell Development ◽  
Nucleotide Synthesis ◽  
Male Germ Cells ◽  
Regulatory Pathways ◽  
Germ Cell Development ◽  
Germ Cell Differentiation ◽  
Germline Differentiation

Abstract Regulatory mechanisms of germline differentiation have generally been explained via the function of signaling pathways, transcription factors, and epigenetic regulation; however, little is known regarding proteomic and metabolomic regulation and their contribution to germ cell development. Here, we conducted integrated proteomic and metabolomic analyses of fetal germ cells in mice on embryonic day (E)13.5 and E18.5 and demonstrate sex- and developmental stage-dependent changes in these processes. In male germ cells, RNA processing, translation, oxidative phosphorylation, and nucleotide synthesis are dominant in E13.5 and then decline until E18.5, which corresponds to the prolonged cell division and more enhanced hyper-transcription/translation in male primordial germ cells and their subsequent repression. Tricarboxylic acid cycle and one-carbon pathway are consistently upregulated in fetal male germ cells, suggesting their involvement in epigenetic changes preceding in males. Increased protein stability and oxidative phosphorylation during female germ cell differentiation suggests an upregulation of aerobic energy metabolism, which likely contributes to the proteostasis required for oocyte maturation in subsequent stages. The features elucidated in this study shed light on the unrevealed mechanisms of germ cell development.

scholarly journals Identification of a candidate c-mos repressor that restricts transcription of germ cell-specific genes.

1995 ◽  
Vol 15 (10) ◽  
pp. 5369-5375 ◽  
Author(s):  
W Xu ◽  
G M Cooper
Keyword(s):  
Germ Cell ◽  
Somatic Cell ◽  
Binding Site ◽  
Germ Cells ◽  
Phosphoglycerate Kinase ◽  
3T3 Cells ◽  
Male Germ Cells ◽  
Nuclear Extracts ◽  
Genes Encoding ◽  
Nih 3T3

The c-mos proto-oncogene is specifically expressed in female and male germ cells. Previous studies identified a negative regulatory element (NRE) upstream of the c-mos promoter that suppresses c-mos transcription in transfected NIH 3T3 cells. In this study, we used gel shift assays to detect proteins in nuclear extracts of NIH 3T3 cells that bind to the c-mos NRE in a sequence-specific manner. One protein was found to bind to a region of the NRE which was shown by site-directed mutagenesis to be required for suppression of c-mos transcription. This factor was present in nuclear extracts of several somatic cell lines and tissues but not in male germ cells in which c-mos is transcribed, suggesting that it is a somatic cell repressor of c-mos transcription. The binding site of the candidate repressor within the c-mos NRE consists of sequences related to putative NREs identified in two other male germ cell-specific genes (encoding protamine 2 and phosphoglycerate kinase 2). The c-mos repressor bound and could be UV cross-linked to these protamine 2 and phosphoglycerate kinase 2 gene sequences as a protein with an apparent molecular mass of approximately 30 kDa. The repressor binding site is also conserved in two other germ cell-specific genes (encoding testis-specific cytochrome c and heat shock-like protein 70), suggesting that the c-mos repressor may be generally involved in suppressing transcription of germ cell-specific genes in somatic cells.

Effect of Zinc Ions on Differentiation of Bone Marrow-Derived Mesenchymal Stem Cells to Male Germ Cells and Some Germ Cell-Specific Gene Expression in Rams

2012 ◽  
Vol 150 (1-3) ◽  
pp. 137-146 ◽  
Author(s):  
Mohammad Ghasemzadeh-Hasankolai ◽  
Roozali Batavani ◽  
Mohamadreza Baghaban Eslaminejad ◽  
Mohammadali Sedighi-Gilani
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Bone Marrow ◽  
Mesenchymal Stem Cells ◽  
Germ Cell ◽  
Germ Cells ◽  
Specific Gene ◽  
Zinc Ions ◽  
Male Germ Cells ◽  
Specific Gene Expression

scholarly journals Different expression and activity of the α1 and α4 isoforms of the Na,K-ATPase during rat male germ cell ontogeny

Reproduction ◽  
2005 ◽  
Vol 130 (5) ◽  
pp. 627-641 ◽  
Author(s):  
K Wagoner ◽  
G Sanchez ◽  
A-N Nguyen ◽  
G C Enders ◽  
G Blanco
Keyword(s):  
Plasma Membrane ◽  
Germ Cell ◽  
Germ Cells ◽  
Cell Biology ◽  
Mrna Level ◽  
Male Gamete ◽  
Male Germ Cell ◽  
Male Germ Cells ◽  
And Function ◽  
Expression And Activity

Two catalytic isoforms of the Na,K-ATPase, α1 and α4, are present in testis. While α1 is ubiquitously expressed in tissues, α4 predominates in male germ cells. Each isoform has distinct enzymatic properties and appears to play specific roles. To gain insight into the relevance of the Na,K-ATPase α isoforms in male germ cell biology, we have studied the expression and activity of α1 and α4 during spermatogenesis and epididymal maturation. This was explored in rat testes at different ages, in isolated spermatogenic cells and in spermatozoa from the caput and caudal regions of the epididymis. Our results show that α1 and α4 undergo differential regulation during development. Whereas α1 exhibits only modest changes, α4 increases with gamete differentiation. The most drastic changes for α4 take place in spermatocytes at the mRNA level, and with the transition of round spermatids into spermatozoa for expression and activity of the protein. No further changes are detected during transit of spermatozoa through the epididymis. In addition, the cellular distribution of α4 is modified with development, being diffusely expressed at the plasma membrane and intracellular compartments of immature cells, finally to localize to the midregion of the spermatozoon flagellum. In contrast, the α1 isoform is evenly present along the plasma membrane of the developing and mature gametes. In conclusion, the Na,K-ATPase α1 and α4 isoforms are functional in diploid, meiotic and haploid male germ cells, α4 being significantly upregulated during spermatogenesis. These results support the importance of α4 in male gamete differentiation and function.

scholarly journals NANOS2 suppresses the cell cycle by repressing mTORC1 activators in embryonic male germ cells

2020 ◽  
Author(s):  
Ryuki Shimada ◽  
Hiroko Koike ◽  
Takamasa Hirano ◽  
Yumiko Saga
Keyword(s):  
Cell Cycle ◽  
Germ Cell ◽  
Germ Cells ◽  
Rna Binding ◽  
Initial Step ◽  
Sexually Dimorphic ◽  
Wild Type ◽  
Male Germ Cells ◽  
Cycle Arrest ◽  
Male Specific

AbstractDuring murine germ cell development, male germ cells enter the mitotically arrested G0 stage, which is an initial step of sexually dimorphic differentiation. The male specific RNA-binding protein NANOS2 has a key role in suppressing the cell cycle in germ cells. However, the detailed mechanism of how NANOS2 regulates the cell cycle remains unclear. Using single-cell RNA sequencing (scRNA-seq), we extracted the cell cycle state of each germ cell in wild-type and Nanos2-KO testes, and revealed that Nanos2 expression starts in mitotic cells and induces mitotic arrest. We also found that NANOS2 and p38 MAPK work in parallel to regulate the cell cycle, suggesting that several different cascades are involved in the induction of cell cycle arrest. Furthermore, we identified Rheb, a regulator of mTORC1, and Ptma as possible targets of NANOS2. We propose that the repression of the cell cycle is a primary function of NANOS2 and that it is mediated via the suppression of mTORC1 activity by repressing Rheb in a post-transcriptional manner.

scholarly journals Germ cell mutagenesis in Drosophila: multiple endpoint analysis.

1998 ◽  
Vol 45 (2) ◽  
pp. 545-559 ◽  
Author(s):  
M J Nivard ◽  
J Wijen ◽  
E W Vogel
Keyword(s):  
Germ Cell ◽  
Germ Cells ◽  
Excision Repair ◽  
Alkylating Agents ◽  
Molecular Data ◽  
Molecular Spectra ◽  
Male Germ Cells ◽  
Genetic Changes ◽  
Wide Range ◽  
Genotoxic Carcinogens

Genotoxic carcinogens, able to damage DNA by alkylation reactions, represent a very diverse class of agents which are capable of producing a wide range of DNA modifications. The mechanisms leading to genetic changes as a result of exposure to alkylating agents (AAs) have been studied in male germ cells of Drosophila using a structure-activity relationship approach (SAR). The analytical tools available concern both genetic and molecular assays. The genetic tests enable to quantify excision repair and clastogenic potency of the AA after treatment of post-meiotic male germ cells and to determine the degree of germ-cell specificity, i.e., the mutagenic effectiveness in post- versus premeiotic cell stages. For a selected group of alkylating agents the molecular spectra have been studied in post-meiotic cell stages. On the basis of these descriptors clear SAR's between genotoxic activity in germ cells and physico-chemical parameters (s-values and O6/N7-alkylguanine adducts) and carcinogenic potency in rodents became apparent, resulting in five distinct classes of alkylating agents so far. These classes are: 1) SN2-type monofunctional AAs, 2) SN1-type monofunctional AAs, 3) polyfunctional AAs, 4) agents able to form etheno-DNA adducts, and 5) aflatoxin B1 (AFB1) a bulky-adduct forming agent. The recent finding that the molecular data obtained with Drosophila and data of the specific locus tests in male mice show remarkable similarities for most genotoxic agents supports the view that Drosophila is a useful model system for the study of transgenerational damage.

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