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Primordial germ cell

Sheena L P Regan, Phil G Knight, John L Yovich, Yee Leung, Frank Arfuso, Arun Dharmarajan
Primordial germ cells migrate to the fetal gonads and proliferate during gestation to generate a fixed complement of primordial follicles, the so-called ovarian reserve. Primordial follicles comprise an oocyte arrested at the diplotene stage of meiosis, surrounded by a layer of pregranulosa cells. Activation of primordial follicles to grow beyond this arrested stage is of particular interest because, once activated, they are subjected to regulatory mechanisms involved in growth, selection, maturation, and ultimately, ovulation or atresia...
2018: Vitamins and Hormones
Maria Gomes Fernandes, Monika Bialecka, Daniela C F Salvatori, Susana M Chuva de Sousa Lopes
STUDY QUESTION: Which set of antibodies can be used to identify migratory and early post-migratory human primordial germ cells (hPGCs)? STUDY FINDING: We validated the specificity of 33 antibodies for 31 markers, including POU5F1, NANOG, PRDM1 and TFAP2C as specific markers of hPGCs at 4.5 weeks of development of Carnegie stage (CS12-13), whereas KIT and SOX17 also marked the intra-aortic hematopoietic stem cell cluster in the aorta-gonad-mesonephros (AGM). WHAT IS KNOWN ALREADY: The dynamics of gene expression during germ cell development in mice is well characterized and this knowledge has proved crucial to allow the development of protocols for the in-vitro derivation of functional gametes...
March 8, 2018: Molecular Human Reproduction
Peter W S Hill, Harry G Leitch, Cristina E Requena, Zhiyi Sun, Rachel Amouroux, Monica Roman-Trufero, Malgorzata Borkowska, Jolyon Terragni, Romualdas Vaisvila, Sarah Linnett, Hakan Bagci, Gopuraja Dharmalingham, Vanja Haberle, Boris Lenhard, Yu Zheng, Sriharsa Pradhan, Petra Hajkova
Gametes are highly specialized cells that can give rise to the next generation through their ability to generate a totipotent zygote. In mice, germ cells are first specified in the developing embryo around embryonic day (E) 6.25 as primordial germ cells (PGCs). Following subsequent migration into the developing gonad, PGCs undergo a wave of extensive epigenetic reprogramming around E10.5-E11.5, including genome-wide loss of 5-methylcytosine. The underlying molecular mechanisms of this process have remained unclear, leading to our inability to recapitulate this step of germline development in vitro...
March 7, 2018: Nature
Paul W Dyce, Neil Tenn, Gerald M Kidder
BACKGROUND: Retinoic acid (RA) signaling has been identified as a key driver in male and female gamete development. The presence of RA is a critical step in the initiation of meiosis and is required for the production of competent oocytes from primordial germ cells. Meiosis has been identified as a difficult biological process to recapitulate in vitro, when differentiating stem cells to germ cells. We have previously shown that primordial germ cell-like cells, and more advanced oocyte-like cells (OLCs), can be formed by differentiating mouse skin-derived stem cells...
March 1, 2018: Journal of Ovarian Research
Nahid Lorzadeh, Nastaran Kazemirad
Embryonic stem cells (ESCs) have the ability to differentiate into several cell lineages and self-renew. Through a spontaneous process, ESCs can differentiate into germ cells of various stages, partly due to their self-renewal ability and their microenvironment culture. Human and mouse ESC differentiation into putative primordial germ cells (PGCs) has been demonstrated by several studies; in fact, derivation of functional mouse male gametes has also been reported. However, the exact underlying mechanisms are yet to be understood properly, and as such clinical applications of ESC-derived PGC remains controversial...
February 28, 2018: American Journal of Perinatology
Aline F de Souza, Naira C Godoy Pieri, Kelly C S Roballo, Fabiana F Bressan, Juliana B Casals, Carlos E Ambrósio, Felipe Perecin, Daniele S Martins
Primordial germ cells (PGCs) are precursors of gametes that can generate new individuals throughout life in both males and females. Additionally, PGCs have been shown to differentiate into embryonic germ cells (EGCs) after in vitro culture. Most studies investigating germinative cells have been performed in rodents and humans but not dogs (Canis lupus familiaris). Here, we elucidated the dynamics of the expression of pluripotent (POU5F1 and NANOG), germline (DDX4, DAZL and DPPA3), and epigenetic (5mC, 5hmC, H3K27me3 and H3K9me2) markers that are important for the development of male canine germ cells during the early (22-30 days post-fertilization (dpf)), middle (35-40 dpf) and late (45-50 dpf) gestational periods...
2018: PloS One
Yoshiyuki Seki
PR-domain containing protein 14 (PRDM14) is a site-specific DNA-binding protein and is required for establishment of pluripotency in embryonic stem cells (ESCs) and primordial germ cells (PGCs) in mice. DNA methylation status is regulated by the balance between de novo methylation and passive/active demethylation, and global DNA hypomethylation is closely associated with cellular pluripotency and totipotency. PRDM14 ensures hypomethylation in mouse ESCs and PGCs through two distinct layers, transcriptional repression of the DNA methyltransferases Dnmt3a/b/l and active demethylation by recruitment of TET proteins...
2018: Frontiers in Cell and Developmental Biology
Lisbeth Charlotte Olsen, Ioannis Kourtesis, Henriette Busengdal, Marit Flo Jensen, Harald Hausen, Daniel Chourrout
BACKGROUND: Germ cell formation has been investigated in sessile forms of tunicates. This process involves the release of a subset of maternal transcripts from the centrosome-attracting body (CAB) in the progenitor cells of the germ line. When germ-soma segregation is completed, CAB structures are missing from the newly formed primordial germ cells (PGCs). In free-swimming tunicates, knowledge about germ cell formation is lacking. In this investigation, comparative gene expression and electron microscopy studies were used to address germ cell formation in Oikopleura dioica (O...
February 27, 2018: BMC Developmental Biology
Xianfa Yang, Ran Wang, Xiongjun Wang, Guoqing Cai, Yun Qian, Su Feng, Fangzhi Tan, Kun Chen, Ke Tang, Xingxu Huang, Naihe Jing, Yunbo Qiao
Clinical therapies of pluripotent stem cells (PSCs)-based transplantation have been hindered by frequent development of teratomas or tumors in animal models and clinical patients. Therefore, clarifying the mechanism of carcinogenesis in stem cell therapy is of great importance for reducing the risk of tumorigenicity. Here we differentiate Oct4-GFP mouse embryonic stem cells (mESCs) into neural progenitor cells (NPCs) and find that a minority of Oct4+ cells are continuously sustained at Oct4+ state. These cells can be enriched and proliferated in a standard ESC medium...
February 22, 2018: Journal of Molecular Cell Biology
R Bologna-Molina, T Mikami, V Pereira-Prado, G Tapia-Repetto, F R Pires, R Carlos, A Mosqueda-Taylor
Primordial odontogenic tumor (POT) is composed of variably cellular myxoid connective tissue, surrounded by cuboidal to columnar odontogenic epithelium resembling the inner epithelium of the enamel organ, which often invaginates into the underlying connective tissue. The tumor is delimited at least partially by a thin fibrous capsule. It derives from the early stages of tooth development. Syndecan-1 is a heparan sulfate proteoglycan that has a physiological role in several cellular functions, including maintenance of the epithelial architecture, cell-to-cell adhesion and interaction of cells with extracellular matrix, and with diverse growth factors, stimulating cell proliferation...
March 2018: Oral Diseases
Jana Pfeiffer, Katsiaryna Tarbashevich, Jan Bandemer, Thomas Palm, Erez Raz
Zebrafish primordial germ cells (PGCs) constitute a useful in vivo model to study cell migration and to elucidate the role of specific proteins in this process. Here we report on the role of the heat shock protein Hsp90aa1.2, a protein whose RNA level is elevated in the PGCs during their migration. Reducing Hsp90aa1.2 activity slows down the progression through the cell cycle, and leads to defects in the control over the MTOC number in the migrating cells. These defects result in a slower migration rate and compromise the arrival of PGCs at their target, the region where the gonad develops...
February 22, 2018: Developmental Biology
Jennifer M SanMiguel, Marisa S Bartolomei
DNA methylation is an essential epigenetic mark crucial for normal mammalian development. This modification controls the expression of a unique class of genes, designated as imprinted, which are expressed monoallelically and in a parent-of-origin-specific manner. Proper parental allele-specific DNA methylation at imprinting control regions (ICRs) is necessary for appropriate imprinting. Processes that deregulate DNA methylation of imprinted loci cause disease in humans. DNA methylation patterns dramatically change during mammalian development: first, the majority of the genome, with the exception of ICRs, is demethylated after fertilization, and subsequently undergoes genome-wide de novo DNA methylation...
February 15, 2018: Biology of Reproduction
Asma Almazyad, Chia-Cheng Li, Roberto Onner Cruz Tapia, Javier Portilla Robertson, David Collette, Sook-Bin Woo
Primordial odontogenic tumour (POT) is a rare mixed odontogenic neoplasm that is composed of primitive ecto-mesenchyme resembling dental papilla, surfaced by odontogenic epithelium resembling inner enamel epithelium, without hard tissue formation. Most reported cases have presented in the posterior mandible as a well-demarcated radiolucency associated with an unerupted tooth in the first two decades of life. AIM: To describe the clinico-pathological features of two more cases of POT. METHODS AND RESULTS: Each presented as an asymptomatic well-delineated radiolucency in the mandible in a 15-year-old female and an 18-year-old male respectively...
February 19, 2018: Histopathology
Juliana M B Ricci, Emanuel R M Martinez, Arno J Butzge, Lucas B Doretto, Marcos A Oliveira, Robie Allan Bombardelli, Jan Bogerd, Rafael H Nóbrega
We have characterized the full-length vasa cDNA from Jundiá, Rhamdia quelen (Heptapteridae, Siluriformes). vasa encodes a member of the DEAD-box protein family of ATP-dependent RNA helicases. This protein is highly conserved among different organisms and its role is associated with RNA metabolism. In the majority of the investigated species, vasa is restricted to the germ cell lineage and its expression has been used to study germline development in many organisms, including fish. The deduced R. quelen vasa amino acid sequence displayed high similarity with Vasa protein sequences from other organisms, and did not cluster with PL10 or P68 DEAD-box protein subfamilies...
February 14, 2018: Gene
Takahiro Tsuboyama, Yumiko Hori, Masatoshi Hori, Hiromitsu Onishi, Mitsuaki Tatsumi, Makoto Sakane, Takashi Ota, Noriyuki Tomiyama
We report the imaging findings of three ovarian dysgerminomas that coexisted with other germ cell tumors or gonadoblastomas, focusing on the distribution of tumor nests and vascular architecture, which might provide information about the pathogenesis of dysgerminomas. In a 14-year-old female with dysgerminoma and coexisting gonadoblastomas, contrast-enhanced magnetic resonance imaging (MRI) demonstrated a solid mass in the right ovary, which presented as hyperintense lobules on diffusion-weighted imaging separated by fibrovascular septa...
February 15, 2018: Abdominal Radiology
Caitlin A Cooper, Timothy J Doran, Arjun Challagulla, Mark L V Tizard, Kristie A Jenkins
The tools available for genome engineering have significantly improved over the last 5 years, allowing scientist to make precise edits to the genome. Along with the development of these new genome editing tools has come advancements in technologies used to deliver them. In mammals genome engineering tools are typically delivered into in vitro fertilized single cell embryos which are subsequently cultured and then implanted into a recipient animal. In avian species this is not possible, so other methods have been developed for genome engineering in birds...
2018: Journal of Animal Science and Biotechnology
Joel C Glover, Karen L Elliott, Albert Erives, Victor V Chizhikov, Bernd Fritzsch
Wilhelm His (1831-1904) provided lasting insights into the development of the central and peripheral nervous system using innovative technologies such as the microtome, which he invented. 150 years after his resurrection of the classical germ layer theory of Wolff, von Baer and Remak, his description of the developmental origin of cranial and spinal ganglia from a distinct cell population, now known as the neural crest, has stood the test of time and more recently sparked tremendous advances regarding the molecular development of these important cells...
February 12, 2018: Developmental Biology
Ira L Blitz
The creation of mutant lines by genome editing is accelerating genetic analysis in many organisms. CRISPR/Cas9 methods have been adapted for use in the African clawed frog, Xenopus, a longstanding model organism for biomedical research. Traditional breeding schemes for creating homozygous mutant lines with CRISPR/Cas9-targeted mutagenesis have several time-consuming and laborious steps. To facilitate the creation of mutant embryos, particularly to overcome the obstacles associated with knocking out genes that are essential for embryogenesis, a new method called leapfrogging was developed...
February 1, 2018: Journal of Visualized Experiments: JoVE
Jae Yong Han, Young Hyun Park
Transgenesis and genome editing in birds are based on a unique germline transmission system using primordial germ cells (PGCs), which is quite different from the mammalian transgenic and genome editing system. PGCs are progenitor cells of gametes that can deliver genetic information to the next generation. Since avian PGCs were first discovered in nineteenth century, there have been numerous efforts to reveal their origin, specification, and unique migration pattern, and to improve germline transmission efficiency...
2018: Journal of Animal Science and Biotechnology
Laura Heckmann, Tim Pock, Ina Tröndle, Nina Neuhaus
In zebrafish, action of the chemokine Cxcl12 is mediated through its G-protein coupled seven-transmembrane domain receptor Cxcr4 and the atypical receptor Cxcr7. Employing this animal model it was revealed that this Cxcl12 signalling system plays a crucial role for directed migration of primordial germ cells (PGC) during early testicular development. Importantly, subsequent studies indicated that this regulatory mechanism is evolutionarily conserved also in mice. What is more, the functional role of the CXCL12 system does not seem to be limited to early phases of testicular development...
February 2, 2018: Reproduction: the Official Journal of the Society for the Study of Fertility
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