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Quintar Amado A - - 2011
The initial segment of the caput epididymidis, the most proximal part of the rat epididymis, has specific functional characteristics. In the present study, the behavior of the epididymal epithelium from this region was evaluated after the exposure to a massive number of immature germ cells in the luminal fluid. The ...
Fujimoto Takafumi - - 2010
Germ cell-deficient fish usually develop as phenotypic males. Thus, the presence of germ cells is generally considered to be essential for female gonadal differentiation or the maintenance of ovarian structure. However, little is known of the role of germ cells in the determination of the sexual fate of gonadal somatic ...
Elliott Michael R - - 2010
Apoptosis and the subsequent clearance of dying cells occurs throughout development and adult life in many tissues. Failure to promptly clear apoptotic cells has been linked to many diseases. ELMO1 is an evolutionarily conserved cytoplasmic engulfment protein that functions downstream of the phosphatidylserine receptor BAI1, and, along with DOCK1 and ...
Wang Yuying - - 2010
Germ cells serve as intriguing examples of differentiated cells that retain the capacity to generate all cell types of an organism. Here we used functional genomic approaches in planarians to identify genes required for proper germ cell development. We conducted microarray analyses and in situ hybridization to discover and validate ...
Bowles Josephine - - 2010
Sex determination of mammalian germ cells occurs during fetal development and depends on signals from gonadal somatic cells. Previous studies have established that retinoic acid (RA) triggers ovarian germ cells to enter meiosis and thereby commit to oogenesis, whereas in the developing testis, the enzyme CYP26B1 degrades RA and germ ...
Ahn Kwang Sung - - 2010
This study was performed to produce transgenic pigs expressing the human complement regulatory protein CD59 (hCD59) using the nuclear transfer (NT) of embryonic germ (EG) cells, which are undifferentiated stem cells derived from primordial germ cells. Because EG cells can be cultured indefinitely in an undifferentiated state, they may provide ...
Ohta Kohei - - 2010
In both male and female germ cells of mice, retinoic acid (RA) is a meiosis-inducing factor. In the present study, we used a germ cell culture system to examine the direct effects of RA on meiotic initiation in male germ cells at the stage when they normally enter mitotic arrest ...
Almstrup K - - 2010
The majority of testicular germ cell cancers develop through a pre-invasive carcinoma in situ (CIS) stage. The CIS cell is a neoplastic counterpart of foetal germ cells. During their development, foetal germ cells undergo extensive and essential epigenetic modifications, but little is known about epigenetic patterns in CIS cells. Immunohistochemistry ...
Imamura Masanori - - 2010
Pluripotent stem cells can be established by various methods, but they share several cytological properties, including germ cell differentiation in vitro, independently of their origin. Although mouse induced pluripotent stem (iPS) cells can produce functional gametes in vivo, it is still unclear whether or not they have the ability to ...
Obata Mayu - - 2010
In bivalve, the distribution of primordial germ cells can be traced from early embryogenesis to the veliger larva by the expression of the vasa ortholog. However, the distribution of germ cells from metamorphosis to maturation in bivalves has not been examined extensively. In this study, we used in situ hybridization ...
Albert S - - 2010
The seminiferous epithelium in the nonhuman primate Callithrix jacchus is similarly organized to man. This monkey has therefore been used as a preclinical model for spermatogenesis and testicular stem cell physiology. However, little is known about the developmental dynamics of germ cells in the postnatal primate testis. In this study, ...
Rainey Paul B - - 2010
The emergence of individuality during the evolutionary transition from single cells to multicellularity poses a range of problems. A key issue is how variation in lower-level individuals generates a corporate (collective) entity with Darwinian characteristics. Of central importance to this process is the evolution of a means of collective reproduction, ...
Trivedi P P - - 2010
The present study was aimed to investigate the germ cell toxicity of doxorubicin and find out the possible correlation between sperm head morphological evaluation and sperm comet assay, which are used to assess male germ cell toxicity. The correlation between these two assays was validated using a potent germ cell ...
Goel Sandeep - - 2010
Buffalo is an economically important livestock species in Asia. Little is known about male germ line technology owing to lack of sufficient understanding regarding expression of germ- and somatic-cell specific-proteins in the testis. In this study, we identified UCHL-1 (PGP 9.5) and lectin- Dolichos biflorus agglutinin (DBA) as specific markers ...
Kuijk Ewart W - - 2011
Pluripotent stem cells have been derived from a variety of sources such as from the inner cell mass of preimplantation embryos, from primordial germ cells, from teratocarcinomas and from male germ cells. The recent development of induced pluripotent stem cells demonstrates that somatic cells can be reprogrammed to a pluripotent ...
Guerquin Marie-Justine - - 2010
In mammals, early fetal germ cells are unique in their ability to initiate the spermatogenesis or oogenesis programs dependent of their somatic environment. In mice, female germ cells enter into meiosis at 13.5 dpc whereas in the male, germ cells undergo mitotic arrest. Recent findings indicate that Cyp26b1, a RA-degrading ...
Mitchell Rod T RT MRC Human Reproductive Sciences Unit, Centre for Reproductive Biology, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, - - 2010
Abnormal fetal testis development can result in disorders of sex development (DSDs) and predispose to later testicular dysgenesis syndrome (TDS) disorders such as testicular germ cell tumours. Studies of human fetal testis development are hampered by the lack of appropriate model, and intervention systems. We hypothesized that human fetal testis ...
Müller-Wille Staffan - - 2010
The cell is not only the structural, physiological, and developmental unit of life, but also the reproductive one. So far, however, this aspect of the cell has received little attention from historians and philosophers of biology. I will argue that cell theory had far-reaching consequences for how biologists conceptualized the ...
Orazizadeh M - - 2010
Exposure to glucocorticoids (GCs) leads to numerous changes in various biological systems including the reproductive system. This work evaluated effects of dexamethasone (Dex), a widely used GC, on mouse testicular germ cells. Experimental groups (E1-E3) received one of the following treatments daily for 7 days: 4, 7 and 10 mg ...
Fukunaga Naoto - - 2010
Recently, several research groups have shown that germ cells can be produced in vitro from pluripotent embryonic stem cells (ESCs). In the mouse, live births of offspring using germ cells induced from ESCs in vitro have been reported. Furthermore, some efficient methods for inducing the useful number of germ cells ...
Furuhashi Hirofumi - - 2010
Epigenetic mechanisms are thought to help regulate the unique transcription program that is established in germ cell development. During the germline cycle of many organisms, the epigenome undergoes waves of extensive resetting events, while a part of epigenetic modification remains faithful to specific loci. Little is known about the mechanisms ...
Wermann Hendrik - - 2010
Differences in the global methylation pattern, ie hyper- as well as hypo-methylation, are observed in cancers including germ cell tumours (GCTs). Related to their precursor cells, GCT methylation status differs according to histology. We investigated the methylation pattern of normal fetal, infantile, and adult germ cells (n = 103) and ...
Payne Christopher J - - 2010
Microenvironments support the maintenance of stem cells and the growth of tumors through largely unknown mechanisms. While cell-autonomous chromatin modifications have emerged as important determinants for self-renewal and differentiation of stem cells, a role for non-cell autonomous epigenetic contributions is not well established. Here, we genetically ablated the chromatin modifier ...
Ferrara Diana - - 2010
Prothymosin alpha (PTMA) is a highly acidic small polypeptide, that is, widely distributed and conserved among mammals. Its possible involvement in male gametogenesis has been mentioned but not clarified yet; in particular, it has been suggested that, in non-mammalian vertebrates, it could play a role during GC meiosis and differentiation. ...
Morgan Dyan E - - 2010
The hermaphrodite Caenorhabditis elegans germline has become a classic model for stem cell regulation, but the male C. elegans germline has been largely neglected. This work provides a cellular analysis of the adult C. elegans male germline, focusing on its predicted stem cell region in the distal gonad. The goals ...
Miething Andreas - - 2010
Mammalian male germ cells go through the process of spermatogenesis as cell clones. The members of a clone are joined by intercellular bridges which are responsible for synchronizing the spermatogenetic process. The present ultrastructural study on pubertal and adult golden hamster and mouse testes, however, demonstrates that a strict synchronization ...
Mitsui Jun - - 2010
Common fragile sites (CFSs) are specific chromosome regions that exhibit an increased frequency of breaks when cells are exposed to a DNA-replication inhibitor such as aphidicolin. PARK2 and DMD, the causative genes for autosomal-recessive juvenile Parkinsonism and Duchenne and Becker muscular dystrophy, respectively, are two very large genes that are ...
Yamasaki Hideki - - 2010
In the testis, developing germ cells are dependent on supportive physical and paracrine interactions with Sertoli cells. The intimate nature of this relationship is demonstrated by the fact that a toxic insult compromising the stability of Sertoli cells will have deleterious effects on the associated germ cells. 2,5-Hexanedione (HD) and ...
Campion Sarah N SN Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island 02912, - - 2010
Sertoli cells are essential for testicular germ cell maintenance and survival. We made the unexpected observation that x-radiation (x-ray)-induced germ cell loss is attenuated by co-exposure with the Sertoli cell toxicant 2,5-hexanedione (HD). The mechanisms underlying this attenuation of germ cell apoptosis with reduced Sertoli cell support are unknown. The ...
Jung Yoon Hee - - 2010
The testis-derived male germ-line stem (GS) cell, the in vitro counterpart of spermatogonial stem cell (SSC), can initiate donor-derived spermatogenesis in recipient testes and therefore, has been viewed as a future therapeutic modality for treatment of male infertility in azoospermic patients and in cancer patients who are expecting chemotherapy. Upon ...
Sawada Takashi - - 2011
Amelogenesis imperfecta (AI) is associated with mutations in a number of genes, including AMELX and ENAM. However, the precise mechanism leading to enamel malformation in different AI types remains to be elucidated. In the present study, we investigated morphological change in tooth germ obtained from ENAM-mutant mice (Enam(Rgsc521) homozygotes) as ...
Zhou Guang-Bin - - 2010
Previous reports have shown that embryonic stem (ES) cells, derived from the inner cell mass of mouse or human blastocysts, could differentiate in vitro into female and male germ cells as well as into the cell types of all three germ layers. While in one case, the ES cell-derived germ ...
Ledda S - - 2010
Primordial germ cell (PGC) allocation, characterization, lineage restriction, and differentiation have been extensively studied in the mouse. Murine PGC can be easily identified using markers as alkaline phosphatase content or the expression of pluripotent markers such as Pou5f1, Nanog, Sox2, Kit, SSEA1, and SSEA4. These tools allowed us to clarify ...
Waters Katherine - - 2010
Proliferating germ cells in Caenorhabditiselegans provide a useful model system for deciphering fundamental mechanisms underlying the balance between proliferation and differentiation. Using gene expression profiling, we identified approximately 200 genes upregulated in the proliferating germ cells of C. elegans. Functional characterization using RNA-mediated interference demonstrated that over forty of these ...
Zovoilis Athanasios - - 2010
Cells originating from the germ cell lineage retain the remarkable property under special culture conditions to give rise to cells with embryonic stem cell (ESC) properties, such as the multipotent adult germline stem cells (maGSCs) derived from adult mouse testis. To get an insight into the mechanisms that control pluripotency ...
Kee Kehkooi - - 2010
Historically, effects of environmental toxicants on human development have been deduced via epidemiological studies because direct experimental analysis has not been possible. However, in recent years, the derivation of human pluripotent stem cells has provided a potential experimental system to directly probe human development. Here, we used human embryonic stem ...
Pleskacova J - - 2010
Certain patients with disorders of sex development (DSD), who bear Y chromosome material in their karyotype, are at increased risk for the development of type II germ cell tumors (GCT), which arise from early fetal germ cells. DSD gonads frequently harbor immature germ cells which express early fetal germ cell ...
Nagasawa Kazue - - 2010
In mammals, several cell surface molecular markers have been characterized in order to identify the mitotic germ cells. However, little is known in fish about their cell surface antigen. In this study, we identified lymphocyte antigen 75 (Ly75/CD205) as a germ cell-specific cell surface marker by combination expressed sequence tag ...
Leitch Harry G HG Wellcome Trust Cancer Research UK Gurdon Institute, The Henry Wellcome Building of Cancer and Developmental Biology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, - - 2010
Mouse and rat embryonic stem cells can be sustained in defined medium by dual inhibition (2i) of the mitogen-activated protein kinase (Erk1/2) cascade and of glycogen synthase kinase 3. The inhibitors suppress differentiation and enable self-renewal of pluripotent cells that are ex vivo counterparts of naïve epiblast cells in the ...
Emerson Robert E - - 2010
Recent advances in the understanding of the molecular pathology of testicular tumours have led to the identification of several new immunohistochemical markers for invasive and in situ germ cell neoplasms. OCT3/4 and NANOG are nuclear stains that have high sensitivity and specificity for the identification of intratubular germ cell neoplasia ...
Calvel Pierre - - 2010
Sperm are, arguably, the most differentiated cells produced within the body of any given species. This is owing to the fact that spermatogenesis is an intricate and highly specialized process evolved to suit the individual particularities of each sexual species. Despite a vast diversity in method, the aim of spermatogenesis ...
Lie Pearl P Y - - 2010
Different cellular events occur during spermatogenesis, and these include (i) mitosis for self-renewal of spermatogonia, (ii) differentiation of type A spermatogonia into type B and commitment of type B spermatogonia to develop into preleptotene primary spermatocytes, (iii) transit of preleptotene/leptotene spermatocytes across the blood-testis barrier in coordination with germ cell ...
Kopera Ilona A - - 2010
Spermatogenesis is a process that involves an array of cellular and biochemical events, collectively culminating in the formation of haploid spermatids from diploid precursor cells known as spermatogonia. As germ cells differentiate from spermatogonia into elongated spermatids, they also progressively migrate across the entire length of the seminiferous epithelium until ...
Lizama Carlos - - 2010
The pathways leading to male germ cell apoptosis in vivo are poorly understood, but are highly relevant for the comprehension of sperm production regulation by the testis. In this work, we show the evidence of a mechanism where germ cell apoptosis is induced through the inactivation and shedding of the ...
Braydich-Stolle Laura K - - 2010
Silver nanoparticles (Ag-NPs) are being utilized in an increasing number of fields and are components of antibacterial coatings, antistatic materials, superconductors, and biosensors. A number of reports have now described the toxic effects of silver nanoparticles on somatic cells; however, no study has examined their effects on the germ line ...
Jin Zhe Wu - - 2010
Both M2A (D2-40) and c-KIT have frequently been used as markers of germ cell tumors. However, comparative studies of their immunoreactivities in human fetal gonads have been limited. Using horizontal semiserial whole-abdomen sections of 9 human abortuses at 12 weeks (2 males and 1 females; CRL 70-80 mm), 15 weeks ...
Kuramochi-Miyagawa Satomi - - 2010
VASA is an evolutionarily conserved RNA helicase essential for germ cell development. The mouse PIWI family proteins MILI and MIWI2 are involved in production of Piwi-interacting RNAs (piRNAs) in fetal male germ cells through a ping-pong amplification cycle. Expression of retrotransposons is elevated in MILI- and MIWI2-deficient male germ cells ...
Renault Andrew D - - 2010
In Drosophila, germ cell survival and directionality of migration are controlled by two lipid phosphate phosphatases (LPP), wunen (wun) and wunen-2 (wun2). wun wun2 double mutant analysis reveals that the two genes, hereafter collectively called wunens, act redundantly in primordial germ cells. We find that wunens mediate germ cell-germ cell ...
Kuroda Yasumasa - - 2010
We found adult human stem cells that can generate, from a single cell, cells with the characteristics of the three germ layers. The cells are stress-tolerant and can be isolated from cultured skin fibroblasts or bone marrow stromal cells, or directly from bone marrow aspirates. These cells can self-renew; form ...
Thomas Jaiyeola - - 2011
Sinonasal teratocarcinosarcoma is an uncommon, aggressive, morphologically heterogenous tumor composed of cells derived from the 3 somatic layers. A histogenetic origin from a multipotential adult somatic stem cell with divergent differentiation has been favored over a germ cell origin. This assumption has been based on the lack of germ cell ...
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