Browsing by Subject "Germ cells"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Publication
    Open Access
    An overview on the diversity of cellular organelles during the germ cell cycle
    (Murcia : F. Hernández, 2010) Chuva de Sousa Lopes, Susana M.; Roelen, Bernard A.J.
    In mammals, germ cells undergo a longjourney from specification until sexual maturation.During this journey, which takes place during the entirelife cycle of mammals, the germ cells dynamicallychange their morphology, their expression profile andalso the number and character of their cellular bodies.The focus of this review will be the diversity of cellularorganelles present in the nucleus and cytoplasm at thedifferent phases of germ cell development. We discusshow these organelles associate and behave to form amultitude of bodies that have long been observed byscientists, and how their presence or absence is used tocharacterize different stages of germ cell development.These organelles include the female Barr body, polarbodies and Balbiani body; and the male sex body and chromatoid body. It is concluded thatcompartmentalization of organelles and molecules in thecytoplasm (in particular of mitochondria and RNAs) andof the sex chromosomes in the nucleus seems to beimportant for regulating germ cell developmentthroughout the life cycle
  • Thumbnail Image
    Publication
    Open Access
    DNA repair mechanisms in mammalian germ cells
    (Murcia: F. Hernández, 2011) Ozturk, Saffet; Demir, Necdet
    Mammalian germ cells encounter several types of DNA damage. This damage is almost completely repaired in a short period of time to provide the maintenance of genomic integrity. The main repair mechanisms operating in mammalian germline cells are: nucleotide excision repair (NER), base excision repair (BER), mismatch repair (MMR), DNA double strand break repair (DSBR), and post replication repair (PRR). Currently, there are relatively few publications that summarize basic information and new findings on DNA repair mechanisms used in mammalian germ cells. In the present article, we review the studies that discuss repair mechanisms operating in the female and male germ cells. We then survey some of the recent discoveries made in this field.
  • Thumbnail Image
    Publication
    Open Access
    Germ cell sex and cell cycle
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2012) Miles, Denise C.; Western, Patrick S.
    Germ cells are the only cells in the body capable of transferring an individual’s genetic and epigenetic information to the next generation. However, the developmental processes that provide the foundation for male and female germ line development and later gamete production are complex and poorly understood. In mice the primordial germ cells enter the bipotential gonad at E10.5 and, in response to the testicular or ovarian micro-environment, commit to spermatogenesis or oogenesis. This paper reviews progress in understanding the molecular processes underlying the early stages of male and female germ line development.
  • Thumbnail Image
    Publication
    Open Access
    In situ demonstration of both TUNEL-labeled germ cell and Sertoli cell in the cimetidine-treated rats
    (Murcia : F. Hernández, 2002) Sasso-Cerri, E.; Miraglia, S.M.
    Cimetidine has caused dysfunction in the male reproductive system. In the rat testis, intratubu l a r alterations and loss of peritubular tissue due to p e r i t u bular myoid cell death by apoptosis have been recently shown. Thus, the aim of this study is to evaluate which cells of the seminiferous epithelium have been affected and/or died by apoptosis after the treatment with cimetidine. For this purpose, an experimental group containing five male albino Wistar rats received intraperitoneal injections of cimetidine (50 mg/kg body weight) during 52 days. The testes were f i xed with 4% bu ff e r e d f o r m a l d e hyde and were embedded in paraffin. Fo r detection of DNA breaks (apoptosis) in the cells of the seminiferous epithelium, the testicular sections were treated by the TUNEL method (Apop-Tag Plus Peroxidase Kit). In the tubules affected by cimetidine, altered p e r i t u bular tissue, including the presence of TUNEL labeling in the myoid peritubular cells, were usually found. In these tubules, the seminiferous epithelium exhibited low density of germ cells and TUNEL-positive labeling in the germ cells of the basal compartment. The concomitant staining in both germ cells of the basal compartment and late spermatids suggest a sensitivity of these cells in the damaged tubules. Besides germ cells, T U N E L - p o s i t ive Sertoli cells were also found in the injured seminiferous tubules. Thus, a relationship between dying germ cells and Sertoli cell damage and/or death must be considered in tubules where peritubu l a r tissue has been affected by toxicants.