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Tedesco Marianna - - 2009
Stra8 (stimulated by retinoic acid 8) encodes a protein crucial for mammalian germ cells entering into premeiotic stages. Here, to elucidate the still unknown STRA8 molecular functions, we studied the cellular localization of the protein in several cell types, including premeiotic mouse germ cells and stem cell lines. We reported ...
Duarte Fernando - - 2010
The mechanism by which varicocele interferes in spermatogenesis has not been clearly defined. Germ cell apoptosis and oxidative stress appear to be involved in this process and the use of antioxidants has been proposed to counteract upon these effects. The present study evaluated the effects of N-acetylcysteine (NAC) on spermatogenesis ...
Kerr Candace L - - 2010
Embryonic stem cells have demonstrated the capacity to differentiate into germ cells in vitro. Until recently, the molecular basis of early post-meiotic germ cell development was largely unknown. Now, two reports including one published here recently, have demonstrated the significant contribution of Dazl in the differentiation of embryonic stem cells ...
Salonen Jonna - - 2010
OBJECTIVE: Testicular germ cell cancer is the most common malignancy among young males. The pre-invasive precursor, carcinoma in situ testis (CIS), presumably originates from arrested and transformed fetal gonocytes. Given that GATA transcription factors have essential roles in embryonic and testicular development, we explored the expression of GATA-4, GATA-6, cofactor ...
van der Heijden Godfried W - - 2009
Repression of transposable elements is crucial for the survival of germ cells. In this issue of Developmental Cell, Shoji et al. provide evidence that a Tudor domain protein TDRD9 partners with MIWI2 to specifically silence LINE-1 transposons in the fetal germline of male mice.
Yamaguchi Shinpei - - 2009
The pluripotency factor Nanog is expressed in peri-implantation embryos and primordial germ cells (PGCs). Nanog-deficient mouse embryos die soon after implantation. To explore the function of Nanog in germ cells, Nanog RNA was conditionally knocked down in vivo by shRNA. Nanog shRNA transgenic (NRi-Tg) mice were generated through the formation ...
Lee K-S - - 2010
In Drosophila ovaries, germline stem cells (GSCs) divide asymmetrically in the germaria to produce daughter GSCs and cystoblasts. Single cystoblasts differentiate to form germline cysts with 16 germline cells, all of which are connected by the fusome, a vesiculated structure critical for oocyte specification. We here show that histone H3K9 ...
Prasetyo Rangga - - 2009
AIM: Mullerian-inhibiting substance (MIS) may have a role in postnatal germ cell development, although this remains unproven. Elucidating the regulatory factors is crucial in finding new treatments for preventing infertility in cryptorchidism. We studied germ cell development in neonatal mice with MIS gene or receptor mutation to determine if germ ...
Brownfield Lynette - - 2009
The production of two functional sperm cells within each male gametophyte is essential for double fertilization in flowering plants and involves a single mitotic division of the male germ cell and cell specification to produce functional gametes. Several proteins that are important regulators of male germ cell division have been ...
Tripathi Rakshamani - - 2009
From the viewpoint of improving germ cell production and treatment of testicular cancers, understanding the control of testicular cell death is of great relevance. One of the prominent features of spermatogenesis is apoptosis of germ cells at different stages of differentiation, by which excess and unfit cells are discarded to ...
Rooijakkers Eveline F - - 2009
We studied the reproductive behaviour of the solitary bee Colletes halophilus based on the variation in cell size, larval food amount and larval sex in relation to the sexual size dimorphism in this bee. Brood cells with female larvae are larger and contain more larval food than cells with males. ...
Matsui Yasuhisa - - 2010
Time-critical extracellular stimuli as well as the intrinsic functions of transcriptional regulatory molecules play essential roles in fate determination and differentiation of mouse primordial germ cells (PGCs). We found that the precursor cells of PGCs require E-cadherin-mediated cell-cell interaction and the functions of transcription factor Oct3/4 to be specified to ...
Goldberg Erwin - - 2010
Lactate dehydrogenase C (LDHC) was, to the best of our knowledge, the first testis-specific isozyme discovered in male germ cells. In fact, this was accomplished shortly before "isozymes or isoenzymes" became a field of study. LDHC was detected initially in human spermatozoa and spermatogenic cells of the testes by gel ...
Kee Kehkooi - - 2009
The leading cause of infertility in men and women is quantitative and qualitative defects in human germ-cell (oocyte and sperm) development. Yet, it has not been possible to examine the unique developmental genetics of human germ-cell formation and differentiation owing to inaccessibility of germ cells during fetal development. Although several ...
Spiller Cassy M - - 2010
During mouse germ cell development, the first sign of sex differentiation occurs when XY germ cells enter G(1)/G(0) arrest from 12.5 days postcoitum (dpc). Retinoblastoma 1 (RB1), a potent cell cycle regulator, was investigated in XY germ cell arrest by studying germ cell proliferation in Rb1(-/-) mutant mouse embryos. Because ...
West F D - - 2010
BACKGROUND: Signaling mechanisms involved in early human germ cell development are largely unknown and believed to be similar to mouse germ cell development; however, there may be species specific differences. KIT ligand (KITL) and Bone morphogenetic protein 4 (BMP4) are necessary in mouse germ cell development and may play an ...
Yao Pei-Li - - 2010
Tight junctions between Sertoli cells of the testicular seminiferous epithelium establishes the blood-testis barrier (BTB) and creates a specialized adluminal microenvironment above the BTB that is required for the development of the germ cells that reside there. Actin filament-based anchoring junctions between Sertoli cells and germ cells are important for ...
Trifonova Anastassia - - 2009
Absence of spermiogenesis in mice with meiotic defects complicates the staging of meiotic arrest using light microscopy. Consequently, new methodologies are required to establish accurate relationships among germ cells. In this study, we utilized a novel approach to analyze germ cell degeneration in juvenile mice. We used terminal deoxynucleotidyl transferase ...
Nandan Mandayam O MO Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, - - 2009
The potential for clinical application of pluripotent embryonic stem cells is immense but hampered by moral and ethical complications. Recent advances in the reprogramming of somatic cells by defined factors to a state that resemble embryonic stem cells have created tremendous excitement in the field. Four factors, Sox2, Oct4, Klf4 ...
Stewart M David MD Department of Genetics, University of Texas M.D. Anderson Cancer Center, Houston, Texas, - - 2009
Fluorescent proteins (FPs) are useful tools for visualizing live cells and their behaviors. Protein domains that mediate subcellular localization have been fused to FPs to highlight cellular structures. FPs fused with histone H2B incorporate into chromatin allowing visualization of nuclear events. FPs fused to a glycosylphosphatidylinositol anchor signal sequence label ...
Yu Zhuo - - 2009
It has been demonstrated that through the formation of embryoid bodies (EBs) germ cells can be derived from embryonic stem (ES) cells. Here, we describe a transgene expression approach to derive germ cells directly from ES cells in vitro without EB formation. Through the ectopic expression of Deleted in Azoospermia-Like ...
Aflatoonian B B Centre for Stem Cell Biology, Department of Biomedical Sciences, The University of Sheffield, Western Bank, Alfred Denny Building, Sheffield S10 2TN, UK. - - 2009
Investigating the mechanisms of human primordial germ cell (PGC) and gamete development are important for understanding the causes of infertility and effects of environmental chemicals on reproductive development. However, there are practical and ethical difficulties associated with obtaining human tissue in early development. The aim of this study was to ...
Mart?nez-Fr?as Mar?a Luisa - - 2010
Having identified teratogenic factors, primary prevention of congenital defects is possible by the implementation of specific measures in pregnant women or those planning pregnancy. Our current understanding of the epigenetic processes acting during reproductive events raises new possibilities to prevent both heritable and sporadic congenital anomalies. Cell differentiation during embryonic-fetal ...
Dorsett Maia - - 2009
During normal development as well as in diseased states such as cancer, extracellular "niches" often provide cues to proximal cells and activate intracellular pathways. Activation of such signaling pathways in turn instructs cellular proliferation and differentiation. In the Caenorhabditis elegans gonad, GLP-1/Notch signaling instructs germ line stem cells to self-renew ...
Matsui Yasuhisa - - 2009
Primordial germ cells (PGCs) are undifferentiated germ cells in embryos. We previously found that some mouse PGCs develop into pluripotential cells (EG cells) when cultured on a feeder layer expressing the membrane bound form of Steel factor with culture medium containing leukemia inhibitory factor and basic fibroblast growth factor. To ...
Hammond Shirley S - - 2009
Germ cells are essential for the propagation of individual species. Studies on germ cell development in mice highlight important biological paradigms. Beginning with their first appearance around embryonic day 7 (E7), germ cells undergo specific cellular changes at different stages of their embryonic and adult development. Germ cells migrate through ...
Oestrup O - - 2009
The increasing focus on the pig as a biomedical model calls for studies which investigate morphological and molecular mechanisms during initial embryonic development in this species. In the pig, the paternal genome is actively demethylated in the zygote, whereas the maternal genome remains methylated. The major genome activation occurs at ...
Lee Kyung-Hoon - - 2009
Estrogens are responsible for most characteristics of the female sex of a species, such as metabolic, behavioral, and morphological changes during reproduction. Artificial estradiol-17beta (E2) treatment Induces sex reversal in some fish. The Japanese pufferfish (Takifugu rubripes) has the most compact genome among vertebrates and great pottial for comparative genome ...
Kim Jin Nam - - 2010
This study evaluated gonadal migration and postmigratory proliferation of intact and genetically modified chicken primordial germ cells (PGCs). A randomized, controlled trial was conducted with the gonadal population of PGCs and transgenic chicken production as major parameters. PGCs (0, 90, 900, 1800, or 3000 cells) were transferred into 53-h-old embryos. ...
Tingen Candace C The Department of Obstetrics and Gynecology, The Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, - - 2009
The creation of the pool of follicles available for selection and ovulation is a multi-faceted, tightly regulated process that spans the period from embryonic development through to the first reproductive cycle of the organism. In mice, this development can occur in mere weeks, but in humans, it is sustained for ...
Dupont Cathérine C Departments of Obstetrics & Gynecology, Wayne State University, Detroit, Michigan 48201, - - 2009
A vast array of successive epigenetic modifications ensures the creation of a healthy individual. Crucial epigenetic reprogramming events occur during germ cell development and early embryogenesis in mammals. As highlighted by the large offspring syndrome with in vitro conceived ovine and bovine animals, any disturbance during germ cell development or ...
Abban Gulcin - - 2009
The possibility that women produce new oocytes post-natally as part of the normal physiological function of the ovary is currently under investigation. Post-natal production of oocyte-like cells has been detected under experimental conditions in the mouse. Although these cells have many characteristics of oocytes, their potential to mature to fertilization-competence ...
Segatelli T M - - 2009
The bullfrog (Lithobates catesbeianus) has substantial economic importance and has also been used as an experimental model for biological studies in the fields of pharmacology, medicine, and reproductive biology, especially studies addressing gametogenesis. However, there is a lack of comprehensive information in the literature regarding testis structure and function in ...
Hua Jinlian - - 2009
Pluripotent mesenchymal stem-like cell lines were established from lungs of 3-4 months old aborted fetus. The cells present the high ex vivo expansion potential of MSC, a typical fibroblast-like morphology and proliferate up to 15 passages without displaying clear changes in morphology. Immunological localization and flow cytometry analyses showed that ...
Shalet Stephen M - - 2009
The testis performs two basic functions, sperm production and testosterone secretion. Formation of the testis is genetically controlled; expression of the SRY gene directs the embryonic gonads into the pathway leading to the development of testes. By the fourth week of gestation in humans, the primordial germ cells derived from ...
Matzuk Martin M - - 2009
The transcription factor BLIMP1 is a master regulator of primordial germ cell (PGC) specification and is suppressed by the microRNA let-7. In a recent issue of Nature, West and colleagues use a unique in vitro ES cell differentiation strategy to show that LIN28 is an essential regulator of PGC formation ...
Doyle Timothy J TJ School of Molecular Biosciences, Center for Reproductive Biology, Washington State University, Pullman, Washington 99164-4234, - - 2009
At least in mammals, retinoic acid is a pivotal factor in maintaining the functionality of the testis, in particular, for the progression of germ cells from mitosis to meiosis. Removal of dietary vitamin A or a targeted deletion of retinoic acid receptor alpha gene (Rara), the receptor for retinoic acid, ...
Spiller Cassy - - 2009
BACKGROUND INFORMATION: Primordial germ cells in developing male and female gonads are responsive to somatic cell cues that direct their sex-specific differentiation into functional gametes. The first divergence of the male and female pathways is a change in cell cycle state observed from 12.5 dpc (days post coitum) in mice. ...
de Las Heras José Manuel - - 2009
Segregation of the germline is a fundamental event during early development. In Drosophila, germ cells are specified at the posterior pole of the embryo by the germplasm. As zygotic expression is activated, germ cells remain transcriptionally silent owing to the polar granule component (Pgc), a small peptide present in germ ...
Saitou Mitinori - - 2009
Specification of germ cell fate is vital to development and heredity. In mice, germ cell fate is induced in a subset of pluripotent epiblast cells during early gastrulation. Reflecting the function of the germ line as the transducer of genetic information, germ cell specification integrates at least three key events: ...
Takeuchi Yutaka - - 2009
In a recently established system for intraperitoneal spermatogonial cell transplantation in salmonids, donor type A spermatogonia (type A SG) were microinjected into the peritoneal cavity of newly hatched larvae. Compared with salmonids, the larvae of marine teleosts are small and vulnerable to physiological and physical stresses, making it difficult to ...
Johnson K J - - 2009
Maternally reported congenital abnormalities (CAs) were examined in a case-control study of 278 cases of paediatric germ cell tumours (GCTs) and 423 controls. Germ cell tumours were significantly associated with cryptorchidism in males (OR=10.8, 95% CI: 2.1-55.1), but not with any other specific CA in either sex.
Dorsett Maia - - 2009
Germ-line stem cells are unique because they either self-renew through mitosis or, at a certain frequency, switch to meiosis and produce gametes. The switch from proliferation to meiosis is tightly regulated, and aberrations in switching result in either too little or too much proliferation. To understand the genetic basis of ...
Lehraiki Abdelali - - 2009
Data from experiments conducted almost exclusively in the rat have established that some phthalates have deleterious effects on the fetal testis probably due to their antiandrogenic and/or estrogenic effects, but their mechanisms of action remain unknown. A recent study reported that phthalates also have deleterious effects on human fetal testis ...
Li Hui - - 2009
Vitamin A (retinol) is required for male and female reproduction as well as to support many developmental processes. In the male, meiotic entry of germ cells occurs after birth and throughout adulthood, whereas in the female, the entry into meiosis I occurs during embryonic development. Evidence from cultured embryonic ovaries ...
Morita-Fujimura Yuiko - - 2009
Primordial germ cells (PGCs) in mouse embryos likely include heterogeneous cells having distinct cellular properties. In the present study, we found that heterogeneity of PGCs can be defined by the expression of integrin alpha6 and c-Kit. The changes in integrin alpha6 and c-Kit expression in PGCs were obvious as embryonic ...
West Jason A JA Division of Pediatric Hematology/Oncology, Children's Hospital Boston and the Dana-Farber Cancer Institute, MA 02115, - - 2009
The rarity and inaccessibility of the earliest primordial germ cells (PGCs) in the mouse embryo thwart efforts to investigate molecular mechanisms of germ-cell specification. stella (also called Dppa3) marks the rare founder population of the germ lineage. Here we differentiate mouse embryonic stem cells carrying a stella transgenic reporter into ...
Dong Wu-Zi - - 2010
The purpose of this study was to isolate the foetal cattle male germ cells (mGCs) and then induce them into sperm cells. The mGCs were purified and enriched by a two-step plating method based on the different adherence velocities of mGCs and somatic cells. The percentage of the vasa and ...
Brownfield Lynette - - 2009
Male germline development in angiosperms produces the pair of sperm cells required for double fertilization. A key regulator of this process in Arabidopsis thaliana is the male germline-specific transcription factor DUO POLLEN1 (DUO1) that coordinates germ cell division and gamete specification. Here, we uncover the role of DUO3, a nuclear ...
Mithraprabhu Sridurga - - 2009
The KIT ligand (KITL)/KIT-signalling system is among several pathways known to be essential for fertility. In the postnatal testis, the KIT/KITL interaction is crucial for spermatogonial proliferation, differentiation, survival and subsequent entry into meiosis. Hence, identification of endogenous factors that regulate KIT synthesis is important for understanding the triggers driving ...
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