Sample records for oogonia

  1. No evidence for the presence of oogonia in the human ovary after their final clearance during the first two years of life

    DEFF Research Database (Denmark)

    Byskov, A G; Høyer, P E; Andersen, Claus Yding;


    BACKGROUND Conflicting results of studies on mouse and human have either verified or refuted the presence of oogonia/primordial germ cells in the post-natal ovary. The aim of this study was to trace whether oogonia recognized by immunohistochemical methods in the first trimester human ovary were...

  2. Oogenesis: From Oogonia to Ovulation in the Flagfish, Jordanella floridae Goode and Bean, 1879 (Teleostei: Cyprinodontidae). (United States)

    Uribe, Mari Carmen; Grier, Harry J; García-Alarcón, Adriana; Parenti, Lynne R


    We provide histological details of the development of oocytes in the cyprinodontid flagfish, Jordanella floridae. There are six stages of oogenesis: Oogonial proliferation, chromatin nucleolus, primary growth (previtellogenesis [PG]), secondary growth (vitellogenesis), oocyte maturation and ovulation. The ovarian lamellae are lined by a germinal epithelium composed of epithelial cells and scattered oogonia. During primary growth, the development of cortical alveoli and oil droplets, are initiated simultaneously. During secondary growth, yolk globules coalesce into a fluid mass. The full-grown oocyte contains a large globule of fluid yolk. The germinal vesicle is at the animal pole, and the cortical alveoli and oil droplets are located at the periphery. The disposition of oil droplets at the vegetal pole of the germinal vesicle during late secondary growth stage is a unique characteristic. The follicular cell layer is composed initially of a single layer of squamous cells during early PG which become columnar during early vitellogenesis. During primary and secondary growth stages, filaments develop among the follicular cells and also around the micropyle. The filaments are seen extending from the zona pellucida after ovulation. During ovulation, a space is evident between the oocyte and the zona pellucida. Asynchronous spawning activity is confirmed by the observation that, after ovulation, the ovarian lamellae contain follicles in both primary and secondary growth stages; in contrast, when the seasonal activity of oogenesis and spawning ends, after ovulation, the ovarian lamellae contain only follicles in the primary growth stage. J. Morphol. 277:1339-1354, 2016. © 2016 Wiley Periodicals, Inc.

  3. The number of oogonia and somatic cells in the human female embryo and fetus in relation to whether or not exposed to maternal cigarette smoking

    DEFF Research Database (Denmark)

    Lutterodt, M C; Sørensen, K P; Larsen, K B


    BACKGROUND: Prenatal exposure to maternal cigarette smoking or compounds of cigarette smoke is associated with serious reproductive hazards such as apoptotic death of oogonia in murine offspring and decreased fecundability in human offspring. The present study addresses potential effects...... of in utero exposure to cigarette smoking. METHODS: Twenty-nine human first-trimester ovaries from legal abortions [aged 38-64 days post-conception (p.c.)] were collected. Mothers filled out a questionnaire about their smoking habits and delivered a urine sample for cotinine analysis. The ovarian cell numbers...

  4. Variability in per capita oogonia and sporophyte production from giant kelp gametophytes (Macrocystis pyrifera, Phaeophyceae Variabilidad de la producción per cápita de oogonios y esporofitos de huiro (Macrocystis pyrifera, Phaeophyceae

    Directory of Open Access Journals (Sweden)



    Full Text Available Vegetative growth and fertility of kelp gametophytes are thought to be antagonistic, such that most successful kelp recruitment is assumed to result from fertilization of single oogonia released from unicellular female gametophytes. We used laboratory culture experiments to study the effect of temperature and nutrient addition on the per capita production of oogonia and sporophytes from Macrocystis pyrifera female gametophytes. Our results indicate that individual multicellular female gametophytes can give rise to more than one oogonium and that per capita oogonia production significantly increases with the enhancement of culture conditions (i.e., decreased temperature and increased nutrient concentration. Furthermore, the production of multiple oogonia per female often led to the production of multiple sporophytes per female. We discuss the importance of these results relative to variability in M. pyrifera life histories (e.g., annual vs. perennial and their likely ecological and evolutionary consequencesEl crecimiento vegetativo y la fertilidad de gametofitos de huiros son antagónicos, de modo tal, que un reclutamiento exitoso se obtiene tras la fertilización de un único oogonio liberado por un gametofito femenino unicelular. Se utilizaron técnicas de cultivo de laboratorio para estudiar el efecto que ejerce la temperatura y la adición de nutrientes sobre la producción per cápita de oogonios y esporofitos de Macrocystis pyrifera. Nuestros resultados indican que gametofitos femeninos multicelulares pueden producir más de un oogonio y la producción per cápita incrementa significativamente al modificarse las condiciones de cultivo (por ejemplo disminución de la temperatura e incremento de las concentraciones de nutrientes. La producción de oogonios múltiples por gametofito femenino llevó la mayoría de los casos a una producción múltiple de esporofitos por hembra. Discutimos la importancia de estos resultados en relación a la

  5. RSPO1/beta-Catenin Signaling Pathway Regulates Oogonia Differentiation and Entry into Meiosis in the Mouse Fetal Ovary

    NARCIS (Netherlands)

    Chassot, A.A.; Gregoire, E.P.; Lavery, R.; Taketo, M.M.; de Rooij, D.G.; Adams, I.R.; Chaboissier, M.C.


    Differentiation of germ cells into male gonocytes or female oocytes is a central event in sexual reproduction. Proliferation and differentiation of fetal germ cells depend on the sex of the embryo. In male mouse embryos, germ cell proliferation is regulated by the RNA helicase Mouse Vasa homolog

  6. Toxic effects of HgCl2 on the growth and oogonium formation in Oedogonium hatei. (United States)

    Singh, H V


    The effect of mercuric chloride on the germination and growth of swarmers and subsequent induction of oogonia was studied in Oedogonium hatei Kam. (Oedogoniales, Chorophyceae). HgCl2 within the concentration range of 0.01 to 1.0 mg/l produced a progressive increase in the initiation of germination and reduction in the growth of the alga. The percentage of oogonia formed, and mature oogonia developed, decreased linearly with a rise in the concentrations of HgCl2 employed. The results showed that 1 mg/l HgCl2 was highly toxic to the growth and/or multiplication of zoospores and further development of sexual structures in O. hatei. The germination of zoospores and growth of germlings were so severely affected that induction of oogonia remained completely inhibited at 1 mg/l HgCl2. Moreover, 2 mg/l of HgCl2 was lethal to the asexual zoospores.

  7. Saprolegnia oliviae sp. nov. isolated from an Argentine river (Tierra del Fuego Province, Argentina). (United States)

    Steciow, Mónica Mirta


    Saprolegnia oliviae sp. nov. is described from litter (floating dead twigs, leaves and roots) in the Olivia River, Ushuaia Department, Tierra del Fuego Province (Argentina). The new species is illustrated and compared with other species of the genus. Distinguishing characteristics of S. oliviae are the production of smooth oogonia (with some lateral or terminal projections) and the absence of antheridial branches on the majority of the oogonia, but when present, they are mostly diclinous, at times oogonia are supplied with androgynous and monoclinous antheridial branches. The oogonial stalks are predominantly short and straight or long and bent, curved or many times coiled; oospores are distinctive subcentric, (1-) 15-50 (-70) per oogonium. Morphological details of the new species and its comparison with other described species are discussed here.

  8. Regulation of oocyte growth in the mouse ovary

    DEFF Research Database (Denmark)

    Krarup, T.; Pedersen, T.; Faber, M.


    MICE are born with a finite number of oocytes which develop in foetal life from primordial oogonia and their direct mitotic progeny. After birth no new oocytes are formed, and the total number of oocytes decreases with advancing age. During the first 2 weeks of life this decrease is due to degene......MICE are born with a finite number of oocytes which develop in foetal life from primordial oogonia and their direct mitotic progeny. After birth no new oocytes are formed, and the total number of oocytes decreases with advancing age. During the first 2 weeks of life this decrease is due...

  9. Saprolegnia brachydanis, a new oomycete isolated from zebra fish. (United States)

    Ke, Xiaoli; Wang, Jianguo; Gu, Zemao; Li, Ming; Gong, Xiaoning


    Saprolegnia brachydanis is described from zebra fish (Brachydanio rerio) in Wuhan, Hubei Province, China. The species is illustrated and compared with other species of the genus. The distinctive characteristics of S. brachydanis are the production of glomerulate oogonia wrapped around by predominantly monoclinous antheridia which can be up to eight in one oogonium. The oogonial stalks are short, straight, or curved and the antheridia, twisted, can enwind one or more oogonia. The oospores cannot mature or easily abort. Morphological features of the oomycete and the ITS sequence of its rDNA as well as the comparison with related species are discussed in this article.

  10. Protandric hermaphroditism in the bivalve Arca noae (Mollusca: Arcidae

    Directory of Open Access Journals (Sweden)

    G. BELLO


    Full Text Available Following the histological analysis of Arca noae samples from the south-western Adriatic Sea, five hermaphroditic specimens were found out of 168 sexed individuals (3.0%. The hermaphrodite gonads showed the co-occurrence of male and female germ cells within the same acini, i.e. both spermatozoa in the lumen and oogonia lining its wall. Oogonia increased in size through winter, thus suggesting that the direction of sex change is from male to female. Both the biometrical analyses and theoretical considerations strongly suggest that A. noae is an obligate protandric species.

  11. Protandric hermaphroditism in the bivalve Arca noae (Mollusca: Arcidae

    Directory of Open Access Journals (Sweden)

    G. BELLO


    Full Text Available Following the histological analysis of Arca noae samples from the south-western Adriatic Sea, five hermaphroditic specimens were found out of 168 sexed individuals (3.0%. The hermaphrodite gonads showed the co-occurrence of male and female germ cells within the same acini, i.e. both spermatozoa in the lumen and oogonia lining its wall. Oogonia increased in size through winter, thus suggesting that the direction of sex change is from male to female. Both the biometrical analyses and theoretical considerations strongly suggest that A. noae is an obligate protandric species.

  12. Peronosporomycetes (Oomycota from a Middle Permian permineralised peat within the Bainmedart Coal Measures, Prince Charles Mountains, Antarctica.

    Directory of Open Access Journals (Sweden)

    Ben J Slater

    Full Text Available The fossil record of Peronosporomycetes (water moulds is rather sparse, though their distinctive ornamentation means they are probably better reported than some true fungal groups. Here we describe a rare Palaeozoic occurrence of this group from a Guadalupian (Middle Permian silicified peat deposit in the Bainmedart Coal Measures, Prince Charles Mountains, Antarctica. Specimens are numerous and comprise two morphologically distinct kinds of ornamented oogonia, of which some are attached to hyphae by a septum. Combresomyces caespitosus sp. nov. consists of spherical oogonia bearing densely spaced, long, hollow, slender, conical papillae with multiple sharply pointed, strongly divergent, apical branches that commonly form a pseudoreticulate pattern under optical microscopy. The oogonia are attached to a parental hypha by a short truncated stalk with a single septum. Combresomyces rarus sp. nov. consists of spherical oogonia bearing widely spaced, hollow, broad, conical papillae that terminate in a single bifurcation producing a pair of acutely divergent sharply pointed branches. The oogonium bears a short truncate extension where it attaches to the parental hypha. We propose that similarities in oogonium shape, size, spine morphology and hyphal attachment between the Permian forms from the Prince Charles Mountains and other reported Peronosporomycetes from Devonian to Triassic strata at widely separated localities elsewhere in the world delimit an extinct but once cosmopolitan Palaeozoic to early Mesozoic branch of the peronosporomycete clade. We name this order Combresomycetales and note that it played an important role in late Palaeozoic and early Mesozoic peatland ecosystems worldwide.

  13. Defined Media for Growth and Gamete Production by the Green Alga, Oedogonium cardiacum. (United States)

    Hill, G J; Machlis, L


    Defined media consisting of inorganic salts and vitamin B(12) are described for the male and female filaments of the green alga, Oedogonium cardiacum. These media provide for a maximal growth rate and for the induction of oogonia and antheridia under the prescribed conditions. The maximal amounts of growth, based on dry weight measurements, compare favorably with other green algae.

  14. Ultrastructural aspects of oogenesis and oocyte primary growth in Serrasalmus spilopleura (Teleostei, Characiformes, Characidae). (United States)

    Guimarães, A C; Quagio-Grassiotto, I


    The ultrastructural characteristics of the organelles present in Serrasalmus spilopleura oogonia and oocytes undergoing primary growth were described in detail, considering its role in the nuclear and cytoplasmic metabolic processes that occur in these cell types. Even though these cells do not significantly differ from those similar to them that are found in other teleost groups, the analysis of their ultrastructure makes available new data on the reproductive biology of Characiformes.

  15. On the presence of fertile gametophytes of Padina pavonica (Dictyotales, Phaeophyceae) from the Iberian coasts


    Gómez Garreta, Amelia; Rull Lluch, Jordi; Barceló Martí, M. Carme; Ribera Siguan, M. Antonia


    The gametophytes of Padina pavonica (L.) Thivy have received little attention in literature. Both female and predominantly male monoecious gametophytes of P. pavonica are recorded for the first time in the Iberian Peninsula. A detailed description of the morphology and the disposition of oogonia and antheridia is presented. In addition, a comparison with literature data on this and other Padina species is carried out.Los gametófitos de Padina pavonica (L.) Thivy han sido escasamente reseñados...

  16. Long-Term Oocyte-Like Cell Development in Cultures Derived from Neonatal Marmoset Monkey Ovary

    Directory of Open Access Journals (Sweden)

    Bentolhoda Fereydouni


    Full Text Available We use the common marmoset monkey (Callithrix jacchus as a preclinical nonhuman primate model to study reproductive and stem cell biology. The neonatal marmoset monkey ovary contains numerous primitive premeiotic germ cells (oogonia expressing pluripotent stem cell markers including OCT4A (POU5F1. This is a peculiarity compared to neonatal human and rodent ovaries. Here, we aimed at culturing marmoset oogonia from neonatal ovaries. We established a culture system being stable for more than 20 passages and 5 months. Importantly, comparative transcriptome analysis of the cultured cells with neonatal ovary, embryonic stem cells, and fibroblasts revealed a lack of germ cell and pluripotency genes indicating the complete loss of oogonia upon initiation of the culture. From passage 4 onwards, however, the cultured cells produced large spherical, free-floating cells resembling oocyte-like cells (OLCs. OLCs strongly expressed several germ cell genes and may derive from the ovarian surface epithelium. In summary, our novel primate ovarian cell culture initially lacked detectable germ cells but then produced OLCs over a long period of time. This culture system may allow a deeper analysis of early phases of female primate germ cell development and—after significant refinement—possibly also the production of monkey oocytes.

  17. Study on features of female fetal reproductive system development in Chinese northeast fine-wool sheep

    Institute of Scientific and Technical Information of China (English)

    LIU Yunbo; ZHANG Guixue; HU Pengfei; HUANG He; ZHENG Peng; LI Wanhua


    Some charaterasics of female fetal reproductive system were studied in different gestation phases of Chinese northeast fine-wool sheep. The results showed that reproductive system consisted of ovary, oviduct, uterus and genitalia. The fetal ovaries were granular in early phase and became elliptic in later phase. The functional formula of ovarian weight, length and volume was obtained.Primary oocyte was encapsulated by monolayer cells in 7-week fetal ovary cortex. Primordial follicles were formed in 8-week fetal ovary, the follicular cells were sporadically arranged and not always regular. Complete organization of primordial follicles appeared until 10-week gestation, most of them scattered in nests in the following weeks of gestation. Two types of follicular complexes were found in fetal. There were continuous and quick mitosis of oogonia in fetal ovaries, large complexes were formed by oogoniaes encapsulated by multilayer of follicular cells, then they differentiated into small complexes, one or more primary oocytes were formed by mitosis of oogonia, primordial follicles which were caused by follicular cell approaching into them developed.

  18. Phytophthora ×stagnum nothosp. nov., a new hybrid from irrigation reservoirs at ornamental plant nurseries in Virginia. (United States)

    Yang, Xiao; Richardson, Patricia A; Hong, Chuanxue


    A novel Phytophthora species was frequently recovered from irrigation reservoirs at several ornamental plant production facilities in eastern Virginia. Initial sequencing of the internal transcribed spacer (ITS) region of this species generated unreadable sequences due to continual polymorphic positions. Cloning and sequencing the ITS region as well as sequencing the mitochondrially encoded cytochrome c oxidase 1 and beta-tubulin genes revealed that it is a hybrid between P. taxon PgChlamydo as its paternal parent and an unknown species genetically close to P. mississippiae as its maternal parent. This hybrid has some diagnostic morphological features of P. taxon PgChlamydo and P. mississippiae. It produces catenulate hyphal swellings, characteristic of P. mississippiae, and chlamydospores, typical of P. taxon PgChlamydo. It also produces both ornamented and relatively smooth-walled oogonia. Ornamented oogonia are another important diagnostic character of P. mississippiae. The relatively smooth-walled oogonia may be indicative of oogonial character of P. taxon PgChlamydo. The new hybrid is described here as Phytophthora ×stagnum.

  19. Ovarian responses to undernutrition in pregnant ewes, USA

    Directory of Open Access Journals (Sweden)

    Vonnahme Kimberly A


    Full Text Available Abstract In most mammals oogonia proliferate by mitosis and begin meiotic development during fetal life. Previous studies indicated that there is a delay in the progression to the first stage of meiotic arrest in germ cells of female fetuses of undernourished ewes. We report that underfeeding (50% NRC requirement beginning on Day 28 of pregnancy provokes an increase in oxidative base lesions within DNA of mid-gestational (Day 78 fetal oogonia; this condition was associated with up-regulation of the tumor suppressor/cell-cycle arrest modulator p53, antiapoptotic factor Bcl-2, and base-excision repair polymerase β. Fetal ovarian weights and germ cell concentrations were not altered by nutrient deprivation. Ovaries of ewes on control diets (100% NRC contained more tertiary follicles than their restricted counterparts; however, peripheral venous estradiol-17β was not different between groups. There was no effect of treatment on p53 accumulation in maternal oocytes. Luteal structure-function was not perturbed by undernutrition. No fetal losses were attributed to the dietary restriction. It is proposed that DNA of interphase fetal oogonia is vulnerable to oxidative insults perpetrated by a nutritional stress to the dam, and that multiple/integrated adaptive molecular response mechanisms of cell-cycle inhibition (providing the time required for base repairs and survival hence sustain the genomic integrity and population stability of the germline.

  20. Occurrence and ultrastructural characterization of "nuage" during oogenesis and early spermatogenesis of Piaractus mesopotamicus Holmberg, 1887 (Teleostei

    Directory of Open Access Journals (Sweden)

    F. C. Abdalla

    Full Text Available We investigated the occurrence and ultrastructurally characterized electrondense nuclear material (nuage released from the nucleus during oogenesis and early spermatogenesis of Piaractus mesopotamicus, a fish from Pantanal Matogrossense (Brazil having a seasonal reproductive cycle. The female germ cells presented two instances of nuclear material extrusion: in the oogonia and in the oocyte in the perinucleolar phase. In males, material with similar morphology and behavior occurred in the spematogonia. In all cases, this material was associated to mitochondria. The possible function of this material is discussed.

  1. Somatic pairing, endomitosis and chromosome aberrations in snakes (Viperidae and Colubridae

    Directory of Open Access Journals (Sweden)

    Beçak Maria Luiza


    Full Text Available The positioning of macrochromosomes of Bothrops jararaca and Bothrops insularis (Viperidae was studied in undistorted radial metaphases of uncultured cells (spermatogonia and oogonia not subjected to spindle inhibitors. Colchicinized metaphases from uncultured (spleen and intestine and cultured tissues (blood were also analyzed. We report two antagonic non-random chromosome arrangements in untreated premeiotic cells: the parallel configuration with homologue chromosomes associated side by side in the metaphase plate and the antiparallel configuration having homologue chromosomes with antipolar distribution in the metaphase ring. The antiparallel aspect also appeared in colchicinized cells. The spatial chromosome arrangement in both configurations is groupal size-dependent and maintained through meiosis. We also describe, in untreated gonia cells, endomitosis followed by reductional mitosis which restores the diploid number. In B. jararaca males we observed that some gonad regions present changes in the meiotic mechanism. In this case, endoreduplicated cells segregate the diplochromosomes to opposite poles forming directly endoreduplicated second metaphases of meiosis with the suppression of first meiosis. By a successive division, these cells form nuclei with one set of chromosomes. Chromosome doubling in oogonia is known in hybrid species and in parthenogenetic salamanders and lizards. This species also presented chromosome rearrangements leading to aneuploidies in mitosis and meiosis. It is suggested that somatic pairing, endomitosis, meiotic alterations, and chromosomal aberrations can be correlated processes. Similar aspects of nuclei configurations, endomitosis and reductional mitosis were found in other Viperidae and Colubridae species.

  2. Dynamics and cytochemistry of oogenesis in Astyanax fasciatus (Cuvier (Teleostei, Characiformes, Characidae from Rio Sapucaí, Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    José Antônio Dias Garcia


    Full Text Available Oogenesis involves a set of transformations which are undergone by female germ cells These cells change into oogonias and then into mature oocytes. Sexually mature female fish were collected monthly, during one year, from the Sapucaí River, a tributary of the Rio Grande, which is part of the Furnas Reservoir in the state of Minas Gerais. During the several stages of maturation, we observed small round oogonias with a large nucleus, a single nucleolus, and weakly stained cytoplasm with eosinophilic granules. The primary oocytes showed a large basophilic nucleus, with a developed peripheral nucleolus and a reduced cytoplasm. The previtellogenic oocytes presented voluminous cytoplasm and nucleus with several small peripheral nucleoli. The oocytes underwent vitellogenesis with the development of the zona radiata and the follicle cells. Their cytochemical reactions indicated that the two layers of the zona radiata of A. fasciatus contained proteins and polysaccharides. The initially squamous follicle cells, became cuboidal. In mature oocytes, the nucleus moved toward the periphery, next to the micropyle, and the yolk granules formed by proteins, fulfilled the cytoplasm. The clear unstained vesicles are likely to be the cortical alveoli in the perivitelline region.

  3. Phytophthora terminalis sp. nov. and Phytophthora occultans sp. nov., two invasive pathogens of ornamental plants in Europe. (United States)

    Man In 't Veld, Willem A; Rosendahl, Karin C H M; van Rijswick, Patricia C J; Meffert, Johan P; Westenberg, Marcel; van de Vossenberg, Bart T L H; Denton, Geoff; van Kuik, Fons A J


    In the past decade several Phytophthora strains were isolated from diseased Pachysandra terminalis plants suffering stem base and root rot, originating from the Netherlands and Belgium. All isolates were homothallic and had a felt-like colony pattern, produced semi-papillate sporangia, globose oogonia and had a maximum growth at ~ 27 C. Several additional Phytophthora strains were isolated from diseased Buxus sempervirens plants, originating from the Netherlands and Belgium, which had sustained stem base and root rot; similar strains also were isolated from Acer palmatum, Choisya ternata and Taxus in the United Kingdom. All isolates were homothallic and had a stellate colony pattern, produced larger semi-papillate sporangia and smaller globose oogonia than the isolates from Pa. terminalis and had a maximum growth temperature of ~ 30 C. Phylogenetic analyses of both species using the internal transcribed spacer region of the nuc rDNA (ITS), mt cytochrome oxidases subunit I gene (CoxI) and nuc translation elongation factor 1-α gene (TEF1α) revealed that all sequences of each species were identical at each locus and unique to that species, forming two distinct clusters in subclade 2a. Sequence analysis of partial β-tubulin genes showed that both taxa share an identical sequence that is identical to that of Ph. himalsilva, a species originating from Asia, suggesting a common Asian origin. Pathogenicity trials demonstrated disease symptoms on their respective hosts, and re-isolation and re-identification of the inoculated pathogens confirmed Koch's postulates.

  4. Phytophthora aquimorbida sp. nov. and Phytophthora taxon 'aquatilis' recovered from irrigation reservoirs and a stream in Virginia, USA. (United States)

    Hong, Chuanxue; Richardson, Patricia A; Hao, Wei; Ghimire, Sita R; Kong, Ping; Moorman, Gary W; Lea-Cox, John D; Ross, David S


    Two distinct subgroups (L2 and A(-2)) were recovered from irrigation reservoirs and a stream in Virginia, USA. After molecular, morphological and physiological examinations, the L2 subgroup was named Phytophthora aquimorbida and the A(-2) designated as Phytophthora taxon 'aquatilis'. Both taxa are homothallic. P. aquimorbida is characterized by its noncaducous and nonpapillate sporangia, catenulate and radiating hyphal swellings and thick-walled plerotic oospores formed in globose oogonia mostly in the absence of an antheridium. P. taxon 'aquatilis' produces plerotic oospores in globose oogonia mostly with a paragynous antheridium. It has semi-papillate, caducous sporangia with variable pedicels, but it does not have hyphal swelling. Analyses of ITS, CO1, β-tubulin and NADH1 sequences revealed that P. aquimorbida is closely related to P. hydropathica, P. irrigata and P. parsiana, and P. taxon 'aquatilis' is related to P. multivesiculata. The optimum temperature for culture growth is 30 and 20 C for P. aquimorbida and P. taxon 'aquatilis' respectively. Both taxa were pathogenic to rhododendron plants and caused root discoloration, pale leaves, wilting, tip necrosis and dieback. Their plant biosecurity risk also is discussed.

  5. Sex-specific differences in fetal germ cell apoptosis induced by ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Guerquin, M.J.; Duquenne, C.; Coffigny, H.; Rouiller-Fabre, V.; Lambrot, R.; Habert, R.; Livera, G. [CEA, DSV/DRR/SEGG/LDRG, Laboratory of Differentiation and Radiobiology of the Gonads, Unit of Gametogenesis and Genotoxicity, F-92265 Fontenay aux Roses (France); Guerquin, M.J.; Duquenne, C.; Coffigny, H.; Rouiller-Fabre, V.; Lambrot, R.; Habert, R.; Livera, G. [Univ. Paris 7-Denis Diderot, UFR of Biology, UMR-S 566, F-92265 Fontenay aux Roses (France); Guerquin, M.J.; Duquenne, C.; Coffigny, H.; Rouiller-Fabre, V.; Lambrot, R.; Habert, R.; Livera, G. [INSERM, U566, F-92265 Fontenay aux Roses (France); Bakalska, M. [Institute of Experimental Morphology and Anthropology, Bulgarian Academy of Sciences, Sofia (Bulgaria); Frydman, R. [Univ Paris-Sud, Clamart F-92140 (France); Frydman, R. [AP-HP, Service de Gynecologie-Obstetrique et Medecine de la Reproduction, Hopital Antoine Beclere, Clamart F-92141 (France); Frydman, R. [INSERM, U782, Clamart F-92140 (France)


    Background: We have previously shown that male human fetal germ cells are highly radiosensitive and that their death depends on p53 activation. Male germ cell apoptosis was initiated with doses as low as 0.1 Gy and was prevented by pifithrin {alpha}, a p53 inhibitor. In this study, we investigated the radiosensitivity of early female and male fetal proliferating germ cells. Methods and results: Both male and female fetal germ cells displayed a similar number of {gamma}H2AX foci in response to ionizing radiation (IR). In organ culture of human fetal ovaries, the germ cells underwent apoptosis only when exposed to high doses of IR (1.5 Gy and above). Accumulation of p53 was detected in irradiated male human fetal germ cells but not in female ones. Inhibition of p53 with pifithrin {alpha} did not affect oogonia apoptosis following irradiation. IR induced apoptosis similarly in mouse fetal ovaries in organ culture and in vivo during oogonial proliferation. Germ cell survival in testes from p53 knockout or p63 knockout mice exposed to IR was better than wild-type, whereas female germ cell survival was unaffected by p53 or p63 knockout. Conclusions: These findings show that pre-meiotic male and female fetal germ cells behave differently in response to a genotoxic stress-irradiation with oogonia being less sensitive and undergoing p53-independent apoptosis. (authors)

  6. Arrest at the diplotene stage of meiotic prophase I is delayed by progesterone but is not required for primordial follicle formation in mice. (United States)

    Dutta, Sudipta; Burks, Deion M; Pepling, Melissa E


    In mammalian females, reproductive capacity is determined by the size of the primordial follicle pool. During embryogenesis, oogonia divide mitotically but cytokinesis is incomplete so oogonia remain connected in germ cell cysts. Oogonia begin to enter meiosis at 13.5 days postcoitum in the mouse and over several days, oocytes progress through the stages of meiotic prophase I arresting in the diplotene stage. Concurrently, germ cell cysts break apart and individual oocytes become surrounded by granulosa cells forming primordial follicles. In rats, inhibition of a synaptonemal complex protein caused premature arrival at the diplotene stage and premature primordial follicle assembly suggesting diplotene arrest might trigger primordial follicle formation. Cyst breakdown and primordial follicle formation are blocked by exposure to steroid hormones but hormone effects on the timing of diplotene arrest are unclear. Here, we asked: (1) if oocytes were required to arrest in diplotene before follicles formed, (2) if all oocytes within a germ cell cyst arrested at diplotene synchronously, and (3) if steroid hormones affected progression through prophase I. Meiotic stage and follicle formation were assessed in histological sections. Statistical differences over time were determined using one-way ANOVA followed by Newman-Keuls multiple comparisons test. To determine if steroid hormones affect the rate of progression to the diplotene stage, 17.5 dpc ovaries were placed in organ culture with media containing estradiol, progesterone or both hormones. In this case, differences were determined using one-way ANOVA followed by Dunnett's multiple comparisons test. We found primordial follicles containing oocytes at the diplotene stage as well as follicles containing oocytes at pre-diplotene stages. We also found individual germ cell cysts containing oocytes at both diplotene and pre-diplotene stages. Progesterone but not estradiol reduced the number of diplotene oocytes in ovary

  7. [Present and future strategies for women at risk, or suffering from premature ovarian failure (POF)]. (United States)

    Gougeon, A


    The purpose of this review is to present the strategies for fertility preservation that are currently proposed to patients at risk from premature ovarian failure (POF) due to chemotherapy as well as some future solutions that could allow patients already affected by an IOP to recover their fertility. Today, cryo-preservation of pieces of ovarian cortex followed by orthotopic transplantation as well as in vitro maturation of oocytes (IVM) allow preservation of fertility in patients being to undergo an antitumor treatment. However, although promising results have been obtained, the pregnancy rate remains very low. Improvement of these techniques, but also stimulation of resting follicle activation, in vitro folliculogenesis, and culture of putative oogonia that may be present in the adult ovary, are all future opportunities for patients suffering from an IOP, and are currently the subject of intensive researches.

  8. Analysis of Gene Expression Profiles of Microdissected Cell Populations Indicates that Testicular Carcinoma In situ Is an Arrested Gonocyte

    DEFF Research Database (Denmark)

    Sonne, S. B.; Almstrup, K.; Dalgaard, M.


    performed laser microdissection of CIS cells. Highly enriched cell populations were obtained and subjected to gene expression analysis. The expression profile of CIS cells was compared with microdissected gonocytes, oogonia, and cultured embryonic stem cells with and without genomic aberrations. Three...... a meiotic cell, and the similarity to embryonic stem cells was modest compared with gonocytes. Thus, we provide new evidence that the molecular phenotype of CIS cells is similar to that of gonocytes. Our data are in line with the idea that CIS cells may be gonocytes that survived in the postnatal testis....... speculate that disturbed development of somatic cells in the fetal testis may play a role in allowing undifferentiated cells to survive in the postnatal testes. The further development of CIS into invasive germ cell tumors may depend on signals from their postpubertal niche of somatic cells, including...

  9. The ovary of the bignose fanskate Sympterygia acuta Garman, 1877 (Chondrichthyes, Rajidae) in the Bahía Blanca estuary, Argentina: morphology and reproductive features. (United States)

    Díaz-Andrade, M C; Galíndez, E; Estecondo, S


    Chondrichthyes have become an important economic resource in recent years. In spite of this importance, there is little knowledge about their reproductive biology, especially of species from the south-western Atlantic. In this work, we study the morphology and histology of the ovary of Sympterygia acuta. The results show that oogonia were present only in the immature females (stage I of maturity scale), whereas specimens in stages II and III of maturity displayed oocytes in all developmental steps. The most important histological features that vary throughout oocyte development are the presence or absence of yolk, the number of types and layers of follicular cells and the degree of development of the thecae. Follicular cells are, at least, of two different types. Finally, a new point of view for the determination of maturity stages in the field based on the size of follicles is discussed.

  10. New data on distribution, morphology and ecology of Oedogonium capillare Kützing ex Hirn (Oedogoniales, Chlorophyta in Poland

    Directory of Open Access Journals (Sweden)

    Marta Pikosz


    Full Text Available Algological investigations were focused on taxonomy, chorology and ecology of threatened filamentous green alga species in Poland. Studies on Oedogonium capillare Kützing ex Hirn growing in large quantities in association with Cladophora rivularis (Linnaeus Hoek in pond were conducted. The aim of these studies was to describe the distribution, ecology and morphology of O. capillare as part of a more comprehensive study of this filamentous green alga. It is the eighth record in Poland for O. capillare. Filaments of O. capillare were grown over a wide pH range (7.3-9.6 and in high variability of nutrients. Vegetative cells, oogonia and antheridia were observed, which allowed taxonomic identification. O. capillare occurs in eutrophic waters which requires protection of its habitat.

  11. Pharmacognostical study and phytochemical evaluation of brown seaweed Sargassum wightii

    Institute of Scientific and Technical Information of China (English)

    Jeyaraman Amutha Iswarya Devi; Gopalswamy Sathiya Balan; Kasiviswanathan Periyanayagam


    Objective: To explore the pharmacognostical and phytochemical properties of Sargassum wightii.Methods:and fluorescence analysis of the plant were carried out according to the standard procedure recommended in the WHO guidelines. The qualitative microscopy, phytochemical screening, physicochemical evaluation Results: Macroscopic study showed that plants were dark brown, 20-30 cm in height, leaves were 5-8 cm length, shape: linear to ovate, apex: midrib in conspicuous and having the entire, serrate margin. Microscopic evaluation of the transverse section of the leaf, stem, air bladder, receptacles showed the presence of epidermis layer followed by thick cuticle, conducting strand, mesophyll and possessed antheridia or oogonia at the swollen terminal portions. The different extracts of Sargassum wightii showed the presence of steroids, alkaloids, phenolic compounds, saponins and flavonoids with varied degree.Conclusions:Various pharmacognostical parameters evaluated in this study help in the identification and standardization of the of the seaweed Sargassum wightii.

  12. Prevalence of intersex in eelpout (Zoarces viviparus) as an ecosystem status indicator

    DEFF Research Database (Denmark)

    Tomkiewicz, Jonna; Strand, Jakob

    A histological analysis of 200 male eelpout gonads was performed as part of biological field studies carried out in coastal waters of Denmark during prespawning and spawning time in May-June. In the marine environment, the eelpout is often selected as sentinel species. Histology of the testis....... The severity of histological alterations ranged from a single oocyte to several hundreds in a pair of testes cross sections. In severe cases, the primary oocytes and oogonia could be either clustered or evenly distributed in the tissue. Presence of secondary oocytes was not detected in any sample. The eelpout...... exhibited the highest intersex prevalence at contaminated marine stations, but also occurred at sites with apparently little pollution. Severity of abnormality was not proportional to prevalence. The findings suggest that feminized male fish were exposed to endocrine disrupting substances...

  13. Pythium campanulatum sp. nov., isolated from the rhizosphere of maize, its taxonomy, ITS region of rDNA, and comparison with related species. (United States)

    Mathew, Ritta; Singh, Kusum Kumari; Paul, Bernard


    Pythium campanulatum sp. nov. was isolated from some soil samples taken in the rhizosphere of maize (Zea mays) in north-eastern India. This species is characterized by the absence of zoospores and sporangia, antheridial branches wrapping around the oogonia leaving one to two campanulate antheridial cells after fertilization, and aplerotic oospores. The ITS region of its rDNA is comprised of 922 bases. This oomycete is closely related to Pythium orthogonon, Pythium nunn and Pythium toruloides. However, it has its own characteristic features and is completely devoid of zoospores. Taxonomic description of this new species and its comparison with related oomycetes, together with the sequence of the PCR-amplified internal transcribed region (spacers ITS1, ITS2, and the gene 5.8S) of its rDNA are given here.

  14. Ovarian dysgerminomas are characterised by frequent KIT mutations and abundant expression of pluripotency markers

    DEFF Research Database (Denmark)

    Hoei-Hansen, Christina E; Kraggerud, Sigrid M; Abeler, Vera M


    examined in situ expression of stem cell-related (NANOG, OCT-3/4, KIT, AP-2gamma) and germ cell-specific proteins (MAGE-A4, NY-ESO-1, TSPY) using a tissue microarray consisting of 60 OGCT tissue samples and eight ovarian small cell carcinoma samples. Developmental pattern of expression of NANOG, TSPY, NY...... cell progenitor. Bilateral OGCTs expressed more stem cell markers than unilateral cases. However, KIT was mutated in 5/13 unilateral dysgerminomas, whereas all bilateral dysgerminomas (n = 4) and all other histological types (n = 22) showed a wild type sequence. Furthermore, tissue from five phenotypic...... to increased survival and proliferation of undifferentiated oogonia, the other related to presence of Y chromosome material and ensuing gonadal dysgenesis in phenotypic females....

  15. Dynamics and cytochemistry of oogenesis in Leporinus striatus Kner (Teleostei, Characiformes, Anostomidae from the Rio Sapucaí, Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    Helena A.S. Chini


    Full Text Available Oogenesis involves a sequense of transformations which are undergone by female germ cells. These cells change into oogonias and then into mature oocytes. Sexually mature females were collected monthly, during one year, from the Rio Sapucaí, tributary of the Rio Grande, which is part of the Furnas Reservoir system in the state of Minas Gerais. The observed material showed that oogonias were small spherical cells, had a big spherical nucleus, with a single nucleolus, and weakly stained cytoplasm with eosinophilic granules (FG stained, which indicate their protein content. The primary oocytes showed a big basophilic nucleus, with a large peripheral nucleolus, and several smaller nucleoli. They show a reduced cytoplasmic content. The previtellogenic oocytes presented voluminous cytoplasm and nucleus with several small peripheral nucleoli. The oocytes underwent vitellogenesis with the development of the zona radiata and the follicle cells. The zona radiata had two layers, the outer and the inner, which showed its protein content when stained with CM and FG techniques. TB pH 2.5 and pH 4.0 staining showed that oocytes undergoing vitellogenesis presented weakly stained cytoplasm and peripheral cytoplasmic vesicles. The follicle cells that were squamous became cuboidal. In mature oocytes, the yolk granules that filled the cytoplasm became green and blue when stained with FG and CM techniques, indicating their protein content. The perivitclline region showed rosy stained vesicles (TB pH 2.5 and pH 4.0 spread among the weakly stained peripheral vesicles, which seemed to be the cortical alveoli. The zona radiata cells, CM and FG stained, still showed two layers like the oocytes from the previous stage, but thicker.

  16. Immunolocalization of cell wall carbohydrate epitopes in seaweeds: presence of land plant epitopes in Fucus vesiculosus L. (Phaeophyceae). (United States)

    Raimundo, Sandra Cristina; Avci, Utku; Hopper, Christina; Pattathil, Sivakumar; Hahn, Michael G; Popper, Zoë A


    Land plant cell wall glycan epitopes are present in Fucus vesiculosus. RG-I/AG mAbs recognize distinct glycan epitopes in structurally different galactans, and 3-linked glucans are also present in the cell walls. Cell wall-directed monoclonal antibodies (mAbs) have given increased knowledge of fundamental land plant processes but are not extensively used to study seaweeds. We profiled the brown seaweed Fucus vesiculosus glycome employing 155 mAbs that recognize predominantly vascular plant cell wall glycan components. The resulting profile was used to inform in situ labeling studies. Several of the mAbs recognized and bound to epitopes present in different thallus parts of Fucus vesiculosus. Antibodies recognizing arabinogalactan epitopes were divided into four groups based on their immunolocalization patterns. Group 1 bound to the stipe, blade, and receptacles. Group 2 bound to the antheridia, oogonia and paraphyses. Group 3 recognized antheridia cell walls and Group 4 localized on the antheridia inner wall and oogonia mesochite. This study reveals that epitopes present in vascular plant cell walls are also present in brown seaweeds. Furthermore, the diverse in situ localization patterns of the RG-I/AG clade mAbs suggest that these mAbs likely detect distinct epitopes present in structurally different galactans. In addition, 3-linked glucans were also detected throughout the cell walls of the algal tissues, using the β-glucan-directed LAMP mAb. Our results give insights into cell wall evolution, and diversify the available tools for the study of brown seaweed cell walls.

  17. A new model of development of the mammalian ovary and follicles.

    Directory of Open Access Journals (Sweden)

    Katja Hummitzsch

    Full Text Available Ovarian follicular granulosa cells surround and nurture oocytes, and produce sex steroid hormones. It is believed that during development the ovarian surface epithelial cells penetrate into the ovary and develop into granulosa cells when associating with oogonia to form follicles. Using bovine fetal ovaries (n = 80 we identified a novel cell type, termed GREL for Gonadal Ridge Epithelial-Like. Using 26 markers for GREL and other cells and extracellular matrix we conducted immunohistochemistry and electron microscopy and chronologically tracked all somatic cell types during development. Before 70 days of gestation the gonadal ridge/ovarian primordium is formed by proliferation of GREL cells at the surface epithelium of the mesonephros. Primordial germ cells (PGCs migrate into the ovarian primordium. After 70 days, stroma from the underlying mesonephros begins to penetrate the primordium, partitioning the developing ovary into irregularly-shaped ovigerous cords composed of GREL cells and PGCs/oogonia. Importantly we identified that the cords are always separated from the stroma by a basal lamina. Around 130 days of gestation the stroma expands laterally below the outermost layers of GREL cells forming a sub-epithelial basal lamina and establishing an epithelial-stromal interface. It is at this stage that a mature surface epithelium develops from the GREL cells on the surface of the ovary primordium. Expansion of the stroma continues to partition the ovigerous cords into smaller groups of cells eventually forming follicles containing an oogonium/oocyte surrounded by GREL cells, which become granulosa cells, all enclosed by a basal lamina. Thus in contrast to the prevailing theory, the ovarian surface epithelial cells do not penetrate into the ovary to form the granulosa cells of follicles, instead ovarian surface epithelial cells and granulosa cells have a common precursor, the GREL cell.

  18. Desenvolvimento morfológico dos ovários em embriões e fetos bovinos da raça Nelore Morphological development of the ovaries in embryos and fetuses of Nelore breed

    Directory of Open Access Journals (Sweden)

    E.G. Diniz


    Full Text Available Investigaram-se os eventos morfológicos relacionados ao desenvolvimento pré-natal de ovários de 81 embriões e fetos da raça Nelore, coletados em frigoríficos, com idades variando de 26 a 240 dias pós-fecundação. Observou-se formação da crista gonádica e presença de células germinativas em seu interior aos 29 e 34 dias, respectivamente. As oogônias e folículos primordiais, ao contrário dos folículos em crescimento, apresentaram diferenças significativas de diâmetro nos vários períodos estudados. Verificou-se correlação positiva (PThe morphologic events related to the prenatal development of the ovaries in 81 Nelore breed embryos and fetuses gathered in a local slaughterhouse, with age range from 26 to 240 days following fecundation were studied. The age of fetuses was estimated from measures taken in the cranium-caudal direction. The sex was identified from macroscopic observations and using Polymerase Chain Reaction (PCR technique. For histology the gonads were fixed in Bouin’s fluid for 24 hours and 5 µm thick section’s were stained with hematoxylin-eosin. Formation of gonadal ridge and presence of germinal cells were found within it at 29 and 34 days, respectively. Oogonia and primordial follicles, unlike the growing follicles, exhibited significant differences in diameter in the various periods studied. Positive correlation (P<0.05 was found between the diameter of oogonia and their nucleus as well as between primordial and growing follicles with their oocytes and respective nuclei. The gonad was fully formed at 40 days. Primordial follicles, in the growing stage, and antral follicles first appeared, approximately at 95, 140, and 180 days, respectively. Despite the onset and duration of oogenesis being similar to that of taurine breeds, folliculogenesis initiates at an early stages in the Nelore breed.

  19. Altered state of primordial follicles in neonatal and early infantile rats due to maternal hypothyroidism: Light and electron microscopy approach. (United States)

    Danilović Luković, Jelena; Korać, Aleksandra; Milošević, Ivan; Lužajić, Tijana; Puškaš, Nela; Kovačević Filipović, Milica; Radovanović, Anita


    Thyroid hormones (TH) are one of the key factors for normal prenatal development in mammals. Previously, we showed that subclinical maternal hypothyroidism leads to premature atresia of ovarian follicles in female rat offspring in the pre-pubertal and pubertal periods. The influence of decreased concentration of TH on primordial follicles pool formation during neonatal and early infantile period of rat pups was not investigated previously. Maternal hypothyroidism during pregnancy has irreversible negative influence on primordial follicles pool formation and population of resting oocytes in female rat offspring. The study was done on neonatal and early infantile control (n-10) and hypothyroid (n-10) female rat pups derived from control (n-6) and propylthiouracil (PTU) treated pregnant dams (n-6), respectively. Ovaries of all pups were removed and processed for light and transmission electron microscopy (TEM). Number of nests, oogonia and oocytes per nest, primordial, primary, secondary and preantral follicles were determined. Screening for overall calcium presence in ovarian tissue was done using Alizarin red staining. Morphology and volume density of nucleus, mitochondria and smooth endoplasmic reticulum (sER) in the oocytes in primordial follicles was also assessed. Caspase-3 and terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL), both markers for apoptosis, and proliferating cell nuclear antigen (PCNA) for proliferation were determined in oocytes and granulosa cells in different type of follicles. In neonatal period, ovaries of hypothyroid pups had a decreased number of oogonia, oocytes and nests, an increased number of primordial follicles and a decreased number of primary and secondary follicles, while in early infantile period, increased number of primary, secondary and preantral follicles were found. Alizarin red staining was intense in hypothyroid neonatal rats that also had the highest content of dilated sER. Number of mitochondria with

  20. The Loricrin-Like Protein (LLP) of Phytophthora infestans Is Required for Oospore Formation and Plant Infection (United States)

    Guo, Ting; Wang, Xiao-Wen; Shan, Kun; Sun, Wenxian; Guo, Li-Yun


    Loricrin-like protein (LLP) is characterized by a high content of glycine residues and is a major component of plant cell wall. Here, we identified a Phytophthora infestans ortholog of plant LLP, named PiLLP. In P. infestans, PiLLP is strongly expressed in asexual and sexual developmental stages, including in sporangia, zoospores and germinating cysts, and during oospore formation, as well as in the early stages of infection and during hydrogen peroxide stress. Compared with the wild type, the PiLLP-silenced transformants were defective in oospore formation, had slower colony expansion rates, produced less sporangia with lower germination and zoospore-release rates, and were more sensitive to hydrogen peroxide. Moreover, Nile red staining, and PiLLP-red fluorescent protein fusions indicated that PiLLP is involved in oogonia formation. The silenced transformants also had severely diminished virulence levels that could be partially restored with diphenyleneiodium treatments. The analysis of catalase activity showed a decrease of catalase activity in silenced transformants. Thus, PiLLP is important for sexual and asexual reproduction, and is required for oxidative stress tolerance and plant infection. PMID:28232841

  1. Spermatozoid life-span of two brown seaweeds, Saccharina japonica and Undaria pinnatifida, as measured by fertilization efficiency

    Institute of Scientific and Technical Information of China (English)

    LI Jing; PANG Shaojun; LIU Feng; SHAN Tifeng; GAO Suqin


    During sexual reproduction of seaweeds,spermatozoid (sperm) discharge is triggered by chemical messengers (pheromones) released by the female gametes.The chemotactic ability of the sperm ensures fertilization success.Using unialgal male and female gametophyte material under designated standard gametogenesis testing (SGT) conditions,the potential life-span of the sperm of two seaweeds,Saccharinajaponica and Undaria pinnatifida,was assessed by their ability to fertilize eggs.Results show that within 20-30 min after being discharged,sperm of both species could complete fertilization without an apparent decline in fertilization rate.Although fertilization rate 60-120 min after sperm discharge dropped significantly in both species,some sperm were viable enough to fertilize the eggs.In S.japonica,at 12℃,some sperm were able to fertilize eggs up to 12 h after discharge.In both species,egg discharge rates (EDR) in the male and female mixed positive controls were significantly higher than those of all the sperm-testing groups.Doubling the seeded male gametophytes of S.japonica in the SGT tests significantly increased the EDR,further confirming the effect of the presence of the male on the female in terms of facilitating egg discharge from oogonia.

  2. Effects of blue light on gametophyte development of Laminaria japonica (Laminariales, Phaeophyta)

    Institute of Scientific and Technical Information of China (English)


    Laminaria gametophyte was greatly influenced by light in its growth and development. Using light-emitting diodes (LED) as blue and red light sources, we analyzed the light effect on gametophytes development of Laminaria japonica Aresch. The gametophytes were obtained from zoospores collected in April, May,July, 2003 and September, 2004. We found that the growth of gametophytes was stimulated by increasing intensity of blue light (BL) and red light (RL) illumination, of which BL was obviously stronger than that of RL. The fertilization of gametophytes depended largely on BL, and only sufficient BL illumination could take the reproductive effect. In addition, we noticed that there was a significant difference in light responses for gametophytes developed from zoospore collected in different times. For zoospores released in April, under BL1 (73.90 μmol sperms respectively, and further developed towards sporophytes. However, for gametophytes developed in May,July or September, they became multi-cellular and never formed oogonia or antheridia. It is believed that the Laminaria sporangium maturation stage could affect the gametophytes reaction to BL under laboratory culture conditions. Therefore, cryptochrome- or phototropin-like BL photoreceptors is probably involved in BL-induced development of Laminaria gametophytes.

  3. Differentiation and function of the ovarian somatic cells in the pseudoscorpion, Chelifer cancroides (Linnaeus, 1761) (Chelicerata: Arachnida: Pseudoscorpionida). (United States)

    Jędrzejowska, Izabela; Mazurkiewicz-Kania, Marta; Garbiec, Arnold; Kubrakiewicz, Janusz


    Pseudoscorpion females carry fertilized eggs and embryos in specialized brood sacs, where embryos are fed with a nutritive fluid produced and secreted by somatic ovarian cells. We used various microscopic techniques to analyze the organization of the somatic cells in the ovary of a pseudoscorpion, Chelifer cancroides. In young specimens, the ovary is a cylindrical mass of internally located germline cells (oogonia and early previtellogenic oocytes) and two types of somatic cells: the epithelial cells of the ovarian wall and the internal interstitial cells. In subsequent stages of the ovary development, the oocytes grow and protrude from the ovary into the hemocoel (opisthosomal cavity). At the same time the interstitial cells differentiate into the follicular cells that directly cover the oocyte surface, whereas some epithelial cells of the ovarian wall form the oocyte stalks - tubular structures that connect the oocytes with the ovarian tube. The follicular cells do not seem to participate in oogenesis. In contrast, the cells of the stalk presumably have a dual function. During ovulation the stalk cells appear to contribute to the formation of the external egg envelope (chorion), while in the post-ovulatory phase of ovary function they cooperate with the other cells of the ovarian wall in the production of the nutritive fluid for the developing embryos.

  4. Initiation of two ovarian cell lines fromFugu rubripes (Temminck et. Schlegel)

    Institute of Scientific and Technical Information of China (English)

    ZHENG Debin; ZHANG Bo; SONG Wenping; PAN Luqing; MA Chao; XIAO Guangxia


    The ovary is an excellent system for studying stem cell renewal and differentiation, which is under the control of ovarian somatic cells. In order to understand oogenesis inFugu rubripes (Temminck et. Schlegel) as a marine fish model of aquaculture importance, we established cell lines called TSOC1 and TSOC2 from a juvenile ovary of this organism. TSOC1 is composed of spindle epithelial-like cells, while the other is cobblestone-like cells. Therefore, TSOC1 and TSOC2 appear to consist of ovarian somatic cells. Growth requirement condition was investigated including temperature, concentration of FBS and pH. Significant fluorescent signals were observed after TSOC1 and TSOC2 cells were transfected with pEGFP-N3 vector, indicating its potential utility for genetic manipulation such as gene function studies. It is shown that these cell lines are effective for infection by the turbot reddish body iridovirus and flounder lymphosystis disease virus as evidenced by the appearance of cytopathic effect and virus propagation in the virus-infected cells, and most convincingly, the observation of viral particles by electron microscopy, demonstrating that TSOC1 and TSOC2 are suitable to study interactions between virus and host cells. It is believed that TSOC1 and TSOC2 will be useful tools to study sex-related events and interactions between primordial germ cells and oogonia cells during oogenesis. Therefore, establishment of ovary cell lines fromFugu rubripes seems to be significant for those research areas.

  5. A stockpile of ova in the grass frog Rana temporaria is established once for the life span. Do ovaries in amphibians and in mammals follow the same evolutionary strategy? (United States)

    Ogielska, Maria; Kotusz, Agnieszka; Augustyńska, Renata; Ihnatowicz, Jerzy; Paśko, Łukasz


    Most anuran amphibians produce high numbers of eggs during several consecutive breeding seasons. The question is still open whether oocytes are formed anew as a result of oogonial proliferation after each spawning or the definitive pool of oocytes is established during the juvenile period and is sufficient for the whole reproductive life span of a female. Our quantitative studies show that primary oogonia in adult female frogs can proliferate, but they fail to differentiate further and do not enter meiosis, and thereby there is no supplementation of new generations of oocytes after each spawning. Ovaries of one-year-old grass frogs contain (median) 53,447 diplotene oocytes, in two-years-old frogs this number decreased to 33,583 and eventually reached 25,679 in virgin mature females. More than 50% decrease in the total oocyte number was accompanied by massive degeneration (atresia) of oocytes. The final number of oocytes in a female forms a stock for 11-12 breeding seasons and exceeds the number of eggs produced during the potential reproductive life span of this species. The phylogenetic context of oocyte recruitment modes in the major clades of vertebrates is discussed in respect to their ability to replenish the stock (a renewable stock in ovaries named "open" vs. a non-renewable stock in ovaries named "closed"). Copyright © 2013 Wiley Periodicals, Inc.

  6. Fasciola hepatica: a light and electron microscope study of the ovary and of the development of oocytes within eggs in the uterus provides an insight into reproductive strategy. (United States)

    Hanna, R E B; Moffett, D; Forster, F I; Trudgett, A G; Brennan, G P; Fairweather, I


    The ultrastructure of the ovary of Fasciola hepatica collected from field-infected sheep, was compared with that of flukes from laboratory-infected rats harbouring the Oberon or the Cullompton fluke isolate. At the periphery of the ovarian tubules, in all flukes, interstitial tissue was identified that appears to provide physical support and facilitate the metabolism of the germinal-line cells. Oogonia undergo mitotic division to maintain the cell population and to produce oocytes. Early oocytes feature conspicuous synaptonemal complexes in the nucleoplasm, and these become less evident as the oocytes grow in size, move towards the core of the ovarian tubule, and synthesise osmiophilic bodies. The latter may represent cortical granules, and serve to block polyspermy. The identity of the synaptonemal complexes was confirmed by immunocytochemical labelling of synaptonemal proteins. The occurrence of synaptonemal complexes in the oocytes of all fluke types examined indicates that pairing of bivalent chromosomes, with the potential for genetic recombination and chiasmata formation, is a feature of the triploid aspermic parthenogenetic Cullompton flukes, as well as of the wild-type out-breeding field-derived and Oberon isolate flukes. In oocytes within shelled eggs in the proximal uterus of all flukes, condensed chromosomes align at meiotic metaphase plates. Following the reduction division, two equal pronuclei appear in each oocyte in the distal uterus. On the basis of these observations, a mechanism of facultative parthenogenesis for F. hepatica is proposed that accommodates the survival and clonal expansion of triploid aspermic isolates.

  7. Possible participation of mitochondria in lipid yolk formation in oocytes of paddlefish and sturgeon. (United States)

    Zelazowska, Monika; Kilarski, Wincenty


    The ovary of paddlefish and sturgeons (Acipenseriformes) is composed of discrete units: the ovarian nests and ovarian follicles. The ovarian nests comprise oogonia and numerous early dictyotene oocytes surrounded by somatic prefollicular cells. Each ovarian follicle consists of a spherical oocyte and a layer of follicular cells situated on a thick basal lamina, encompassed by thecal cells. The cytoplasm of previtellogenic oocytes is differentiated into two distinct zones: the homogeneous and granular zones. The homogeneous cytoplasm is organelle-free, whereas the granular cytoplasm contains numerous organelles, including mitochondria and lipid droplets. We have analyzed the cytoplasm of early dictyotene and previtellogenic oocytes ultrastructurally and histologically. In the cytoplasm of early dictyotene oocytes, two morphologically different types of mitochondria can be distinguished: (1) with well-developed cristae and (2) with distorted and fused cristae. In previtellogenic oocytes, the mitochondria of the second type show various stages of cristae distortion; they contain and release material morphologically similar to that of lipid droplets and eventually degenerate. This process of mitochondrial transformation is accompanied by an accumulation of lipid droplets that form a single large accumulation (lipid body) located in the vicinity of the oocyte nucleus (germinal vesicle). The lipid body eventually disperses in the oocyte center. The possible participation of these mitochondria in the formation of oocyte lipid droplets is discussed.

  8. On the presence of fertile gametophytes of Padina pavonica (Dictyotales, Phaeophyceae from the Iberian coasts

    Directory of Open Access Journals (Sweden)

    Gómez Garreta, Amelia


    Full Text Available The gametophytes of Padina pavonica (L. Thivy have received little attention in literature. Both female and predominantly male monoecious gametophytes of P. pavonica are recorded for the first time in the Iberian Peninsula. A detailed description of the morphology and the disposition of oogonia and antheridia is presented. In addition, a comparison with literature data on this and other Padina species is carried out.Los gametófitos de Padina pavonica (L. Thivy han sido escasamente reseñados en la bibliografía. En este trabajo se señala por primera vez en las costas de la Península Ibérica la presencia de gametófitos fértiles de P. pavonica, tanto femeninos como monoicos predominantemente masculinos. Se presenta una detallada descripción de la disposición y la morfología de los oogonios y anteridios. Asimismo, se realiza una comparación con los datos bibliográficos de esta especie y con los de otras especies de Padina

  9. Ovary organization and oogenesis in the tardigrade Macrobiotus polonicus Pilato, Kaczmarek, Michalczyk & Lisi, 2003 (Eutardigrada, Macrobiotidae): ultrastructural and histochemical analysis. (United States)

    Poprawa, Izabela; Schlechte-Wełnicz, Weronika; Hyra, Marta


    The female reproductive system, the process of oogenesis, and the morphology of the egg capsule of Macrobiotus polonicus were analyzed using transmission and scanning electron microscopy and histochemical methods. The female reproductive system of Macrobiotus polonicus consists of a single ovary and a single oviduct that opens into the cloaca. The seminal receptacle filled with sperm cells is present. The ovary is divided into two parts: a germarium that is filled with oogonia and a vitellarium that is filled with branched clusters of the germ cells. Meroistic oogenesis occurs in the species that was examined. The yolk material is synthesized by the oocyte (autosynthesis) and by the trophocytes and is transported to the oocyte through cytoplasmic bridges. The process of the formation of the egg envelopes starts in the late vitellogenesis. The egg capsule is composed of two envelopes-the vitelline envelope and the three-layered chorion. The vitelline envelope is of the primary type while the chorion is of a secondary type. The surface of the chorion is covered with conical processes that terminate with a strongly indented terminal disc.

  10. Development of the germinal ridge and ovary in the African elephant (Loxodonta africana). (United States)

    Stansfield, F J; Nöthling, J O; Soley, J T; Allen, W R


    The follicular reserve and its ontogeny in the elephant are of interest because elephants have the longest reproductive life of all land-based mammals. They also have the longest recorded pregnancy, which allows a protracted view of the series of significant events involved in the development of the embryonic and fetal gonads. The large elephant population of Zimbabwe provided the opportunity to collect conceptuses from elephants culled for management reasons and hunted professionally. Five embryos aged 76-96 days and the ovaries of four fetuses aged 4.8-11.2 months were fixed in 4% buffered formalin and studied by conventional histological sectioning and a stereological protocol to calculate the follicle reserve of each fetus. These observations enabled the conclusion that the migration of primordial germ cells into the indifferent gonad terminates at around 76 days of gestation while entry of oogonia into meiosis along with first follicle formation starts at around 5 months. Peak numbers of follicles are present by mid-gestation towards the end of the 6-month mitotic-meiotic transition period. It appears that the cortex of the elephant fetal ovary at mid-gestation (11 months) has already reached a developmental stage exhibited by the ovaries of many other mammals at full term.

  11. Germ cell cluster organization and oogenesis in the tardigrade Dactylobiotus parthenogeneticus Bertolani, 1982 (Eutardigrada, Murrayidae). (United States)

    Poprawa, Izabela; Hyra, Marta; Rost-Roszkowska, Magdalena Maria


    Germ cell cluster organization and the process of oogenesis in Dactylobiotus parthenogeneticus have been described using transmission electron microscopy and light microscopy. The reproductive system of D. parthenogeneticus is composed of a single, sac-like, meroistic ovary and a single oviduct that opens into the cloaca. Two zones can be distinguished in the ovary: a small germarium that is filled with oogonia and a vitellarium that is filled with germ cell clusters. The germ cell cluster, which has the form of a modified rosette, consists of eight cells that are interconnected by stable cytoplasmic bridges. The cell that has the highest number of stable cytoplasmic bridges (four bridges) finally develops into the oocyte, while the remaining cells become trophocytes. Vitellogenesis of a mixed type occurs in D. parthenogeneticus. One part of the yolk material is produced inside the oocyte (autosynthesis), while the second part is synthesized in the trophocytes and transported to the oocyte through the cytoplasmic bridges. The eggs are covered with two envelopes: a thin vitelline envelope and a three-layered chorion. The surface of the chorion forms small conical processes, the shape of which is characteristic for the species that was examined. In our paper, we present the first report on the rosette type of germ cell clusters in Parachela.

  12. Immunolocalization of Schistosoma mansoni and Schistosoma haematobium antigens reacting with their Egyptian snail vectors. (United States)

    El-Dafrawy, Shadia M; Mohamed, Amira H; Hammam, Olfat A; Rabia, Ibrahim


    The reaction of the haemolymph and the tissue of infected intermediate hosts, Biomphalaria alexandrina and Bulinus truncatus to Schistosoma mansoni and S. haematobium antigens were investigated using the indirect immunoperoxidase technique. A new technique, Agarose cell block was used in collection of haemolymph which helped in collecting plenty of well formed cells in comparison to the ordinary one using the cytospin. Collected haemolymph and prepared tissues of uninfected and infected B. alexandria and B. truncatus were fixed and then reacted with anti-S. mansoni and anti-S. haematobium IgG polyclonal antibodies. The haemolymph and tissue of infected B. alexandrina and B. truncatus gave a positive peroxidase reaction represented by a brown colour. In haemolymph, the positive peroxidase reaction was detected mainly in the cytoplasm of the amoebocytes. In the tissue, it was detected in epithelial cells lining the tubules, male cells in the lumen of the tubules and in female oogonia cells along the periphery of the tubules. The similarity in the strength and distribution of positive reaction in B. alexandrina and B. truncates was observed as compared to control. Thus, the immunoperoxidase technique proved to be an effective indicator for the schistosome-antigen in the snails.

  13. Characterization, expression and function analysis of DAX1 gene of scallop ( Chlamys farreri jones and preston 1904) during its gametogenesis (United States)

    Li, Hailong; Liu, Jianguo; Huang, Xiaoting; Wang, Dan; Zhang, Zhifeng


    DAX1, a member of nuclear receptor superfamily, has a function in the sex determination and gonadal differentiation of several vertebrate species. However, little information about DAX1 of invertebrates is available. Here we cloned a homolog of scallop ( Chlamys farreri Jones and Preston 1904) dax1, Cf-dax1, and determined its expression characteristics at mRNA and protein levels. The cDNA sequence of Cf-dax1 was 2093 bp in length, including 1404 bp open reading frame (ORF) encoding 467 amino acids. Unlike those of vertebrates, no conserved LXXLL-related motif was found in the putative DNA binding region of Cf-DAX1. Fluorescence in situ hybridization showed that Cf-dax1 located on the short arm of a pair of subtelocentric chromosomes. Tissue distribution analysis using semi-quantitative RT-PCR revealed that Cf-dax1 expressed widely in adult scallop tissues, with the highest expression level found in adductor muscle, moderate level in mantle, gill and testis, and low level in kidney, ovary and hepatopancreas. The result of quantitative real-time PCR indicated that the expression of Cf-dax1 was significantly higher ( Psex-dimorphic expression pattern. Furthermore, immunohistochemical detection found that Cf-DAX1 mainly located in spermatogonia and spermatocytes of testis and in oogonia and oocytes of ovary, implying that DAX1 may involve in gametogenesis of bivalves.

  14. Influence of corticosterone on FSH-induced ovarian recrudescence in the lizard Mabuya carinata. (United States)

    Nijagal, B S; Yajurvedi, H N


    Administration of bovine FSH (10 IU/lizard/alternate day for 30 days) in the postbreeding quiescent phase of the ovarian cycle caused a significant increase in the mean number of oogonia and oocytes, the relative weight of the oviduct, and the liver and serum estradiol levels compared to those of controls. In addition, the FSH-treated lizards showed a vitellogenic growth of follicles and development through to preovulatory follicles. However, the administration of corticosterone simultaneously with FSH (10 IU FSH + 40 microgram corticosterone/lizard/alternate day for 30 days) did not result in these changes and the ovaries resembled those of controls. The results indicate the absence of ovarian refractoriness to gonadotropic stimulation during the quiescent phase of the reproductive cycle and inhibition of FSH-induced ovarian recrudescence by corticosterone. It is suggested that corticosterone treatment reduces FSH-induced steroidogenic activity of the ovary, leads to impairment in vitellogenin secretion by the liver, and results as well in the failure of vitellogenic follicular growth in Mabuya carinata.

  15. Stress inhibits seasonal and FSH-induced ovarian recrudescence in the lizard,Mabuya carinata. (United States)

    Ganesh, C B; Yajurvedi, H N


    Stressors (handling, chasing, and noise) applied randomly five times per day for one month to lizards during the recrudescence phase of the ovarian cycle caused a significant reduction in mean number of oocytes and primordial follicles when compared to those of controls. Further, vitellogenic follicles were absent in the ovary of lizards subjected to stressors. Administration of bovine FSH during post-breeding regression phase of the ovarian cycle induced ovarian recrudescence as shown by significant increases in the mean number of oogonia, oocytes, and primordial follicles compared to controls, as well as vitellogenic growth of follicles. However, lizards treated with FSH and exposed to stressors did not exhibit ovarian recrudescence. Furthermore, FSH administration during the post-breeding regression phase caused a significant increase in serum levels of estradiol compared to controls, which was accompanied by significant increases in the relative weight of the liver and oviduct, as well as vitellogenic growth of follicles. Despite administration of FSH to lizards subjected to stressors, there was neither any increase in serum levels of estradiol and weight of the liver nor vitellogenic growth of follicles. The results indicate that repeated application of stressors inhibits vitellogenic growth of follicles by suppression of steroidogenic activity in M. carinata. This is the first report revealing that the ovary does not respond to gonadotrophin treatment under stressful conditions in reptiles.

  16. Ultrastructural studies on the nematode Xiphinema diversicaudatum: Oogenesis and fertilization. (United States)

    Bleve-Zacheo, T; Melillo, M T; Zacheo, G


    Oogenesis and fertilization in longidorid nematodes has been examined for the first time at electron microscope level in Xiphinema diversicaudatum. Oogonia in the germinative zone of the ovary are irregularly shaped and lie adjacent to each other or separated by processes of the epithelial cells of the ovary. Developing oocytes pass in single file up to the growth zone and fibrogranular formation occurs around their nucleus. The perinuclear deposits remain until the oocyte is fully grown. Oocytes increase rapidly in volume because of the production of secretory granules. Three types of granules are recognizable. Type 1 granules are spherical, amorphous in structure and delimited by a lighter area, probably consisting of lipoprotein. Type 2 granules, electron lucent, arranged in groups, are lipid inclusions. Type 3 are dense spheres and may represent yolk bodies. The two last are then utilized by the developing embryo. Mature oocytes assume a smooth, cylindrical configuration as they traverse the oviduct. A cone of fertilization seems to be formed at the distal pole of the oocyte, where the sperm penetrates. The sperm totally penetrates the oocyte, through an invagination formed at the oocyte surface. The oocyte continues to undergo two unequal cytoplasmic divisions, resulting in the formation of a female pronucleus and two polar bodies. Under the stimulus of fertilization, a new egg cell membrane is produced, the first one becoming the vitelline envelope.

  17. Molecular Cloning, Promoter Analysis and Expression Profiles of the sox3 Gene in Japanese Flounder, Paralichthys olivaceus

    Directory of Open Access Journals (Sweden)

    Jinning Gao


    Full Text Available Sox3, which belongs to the SoxB1 subgroup, plays major roles in neural and gonadal development. In the present study, Japanese flounder Paralichthys olivaceus sox3 gene (Posox3 and its promoter sequence were isolated and characterized. The deduced PoSox3 protein contained 298 amino acids with a characteristic HMG-box domain. Alignment and phylogenetic analyses indicated that PoSox3 shares highly identical sequence with Sox3 homologues from different species. The promoter region of Posox3 has many potential transcription factor (TF binding sites. The expression profiles of Posox3 in different developmental stages and diverse adult tissues were analyzed by quantitative real-time RT-PCR (qRT-PCR. Posox3 mRNA was maternally inherited, and maintained at a considerably high expression level between the blastula stage and the hatching stage during embryonic development. Posox3 was abundantly expressed in the adult brain and showed sexually dimorphic expression pattern. In situ hybridization (ISH was carried out to investigate the cellular distribution of Posox3 in the ovary, and results showed the uniform distribution of Posox3 throughout the cytoplasm of oogonia and stage I–III oocytes. These results indicate that Posox3 has potentially vital roles in embryonic and neural development and may be involved in the oogenesis process. Our work provides a fundamental understanding of the structure and potential functions of Sox3 in Paralichthys olivaceus.


    Estevez, José M; Leonardi, Patricia I; Alberghina, Josefina S


    Cell wall changes in vegetative and suffultory cells (SCs) and in oogonial structures from Oedogonium bharuchae N. D. Kamat f. minor Vélez were characterized using monoclonal antibodies against several carbohydrate epitopes. Vegetative cells and SCs develop only a primary cell wall (PCW), whereas mature oogonial cells secrete a second wall, the oogonium cell wall (OCW). Based on histochemical and immunolabeling results, (1→4)-β-glucans in the form of crystalline cellulose together with a variable degree of Me-esterified homogalacturonans (HGs) and hydroxyproline-rich glycoprotein (HRGP) epitopes were detected in the PCW. The OCW showed arabinosides of the extensin type and low levels of arabinogalactan-protein (AGP) glycans but lacked cellulose, at least in its crystalline form. Surprisingly, strong colabeling in the cytoplasm of mature oogonia cells with three different antibodies (LM-5, LM-6, and CCRC-M2) was found, suggesting the presence of rhamnogalacturonan I (RG-I)-like structures. Our results are discussed relating the possible functions of these cell wall epitopes with polysaccharides and O-glycoproteins during oogonium differentiation. This study represents the first attempt to characterize these two types of cell walls in O. bharuchae, comparing their similarities and differences with those from other green algae and land plants. This work represents a contribution to the understanding of how cell walls have evolved from simple few-celled to complex multicelled organisms.

  19. Survival and reproduction of some blue-green and green algae as affected by sewage water, fertilizer factory effluent, brassica oil, phenol, toluene and benzene. (United States)

    Agrawal, S C; Gupta, S


    Fourteen blue-green and green algae survived for widely different time periods ranging between 22-102 d in control culture medium. Irrespective of their long or short survival period in control cultures, their pro- or eukaryotic nature, their different morphological types or natural habitats, they all survived for a short time period ranging between 3-8 d in sewage water, 5-10 d in fertilizer factory effluent, (1/4)-2 d in brassica oil, (1/2)-2 d in phenol, 1-3 d in toluene, and 1-4 d in benzene (showing the relative toxicity of different chemicals to different algae, and the antialgal nature of brassica oil). Dilution decreased the toxicity of these agents very little, indicating that they all were very toxic to algae. None of the agent induced the formation of any reproductive or dormant cells. Sewage water, fertilizer factory effluent, brassica oil and/or benzene favored the formation of necridia cells in Phormidium bohneri, P. foveolarum, Microcoleus chthonoplastes, Lyngbya birgei, and L. major filaments. Scenedesmus quadricauda shed off all spines earlier, Hormidium flaccidum fragmented less or not at all, Scytonema millei formed no false branch and heterocyst, Aphanothece pallida and Gloeocapsa atrata cells did not divide, Cosmarium granatum cells did not form any zygospore and Oedogonium sp. not any oogonia-like cells under all or most of treatments with 25-100 % sewage water, 1-100 % fertilizer factory effluent, 1-100 % brassica oil, 25-100 % phenol, toluene and benzene.

  20. A novel gene, Pog, is necessary for primordial germ cell proliferation in the mouse and underlies the germ cell deficient mutation, gcd. (United States)

    Agoulnik, Alexander I; Lu, Baisong; Zhu, Qichao; Truong, Cavatina; Ty, Maria T; Arango, Nelson; Chada, Kiran K; Bishop, Colin E


    Primordial germ cells (PGCs) are the precursor of the germ cells in adult gonads. They arise extra-gonadally and migrate through somatic tissues to the presumptive genital ridges, where they proliferate and differentiate into oogonia or spermatogonia cells. Abnormalities in this developmental process can cause embryonic depletion of germ cells leading to infertility in the adult. We report here that the mouse gcd (germ cell deficient) mutant phenotype, characterized by reduced numbers of PGCs and adult sterility, is due to reduced PGC proliferation rather than aberrant migration and is caused by the partial deletion of a single novel gene, Pog (proliferation of germ cells). Pog is critical for normal PGC proliferation, starting between 9.5 and 10.25 dpc when germ cells begin to migrate to the developing genital ridge. Deletion of Pog is also accompanied by reduced embryonic body weight and, on some genetic backgrounds, embryonic lethality. Thus, in addition to being necessary for PGC proliferation, Pog may have a wider significance in early embryonic development.

  1. Phytophthora inundata sp. nov., a part heterothallic pathogen of trees and shrubs in wet or flooded soils. (United States)

    Brasier, Clive M; Sanchez-Hernandez, Esperanza; Kirk, Susan A


    A Phytophthora pathogen of trees and shrubs previously designated Phytophthora sp. O-group is formally named as P. inundata sp. nov. P. inundata falls within the P. gonapodyides-P. megasperma major ITS Clade 6, its present nearest known relative being P. humicola. It has non-papillate sporangia, fairly large oogonia (average ca 40 microns) with thick walled oospores, amphigynous antheridia, a distinctive colony type, a high optimum temperature for growth of 28-30 degrees C, fast growth at the optimum, and a high upper temperature limit for growth of ca 35-37 degrees. A study of the breeding system of eight P. inundata isolates showed them to be classically heterothallic with A1 and A2 compatibility types. However some P. inundata A1 x A2 combinations failed to mate even though the same isolates mated successfully with P. drechsleri testers. Others were 'silent' A1s or A2s, unable to produce their own gametangia but able to induce gametangial formation in the opposite sexual compatibility type of another species. This indicates a partial breakdown of the sexual mechanism in the species. Two isolates (one A1 and one A2) were unpredictably and chimaerically self-fertile, suggesting A1 + A2 chromosomal heteroploidy. The association of P. inundata with ponds and rivers and with root and collar roots of trees and shrubs after flooding is discussed.

  2. Endocrine modulation, inhibition of ovarian development and hepatic alterations in rainbow trout exposed to polluted river water

    Energy Technology Data Exchange (ETDEWEB)

    Vigano, Luigi, E-mail: vigano@irsa.cnr.i [Water Research Institute, National Council of Research, Brugherio, Milan (Italy); Benfenati, Emilio [Mario Negri Institute, Laboratory of Environmental Chemistry and Toxicology, Milan (Italy); Bottero, Sergio; Cevasco, Alessandra; Monteverde, Martino; Mandich, Alberta [Department of Environmental, Experimental and Applied Biology, University of Genoa, Genoa (Italy)


    Under laboratory conditions, female rainbow trout were exposed to graded concentrations of water from the River Lambro, a polluted tributary of the River Po, and to the effluent of a large wastewater treatment plant which flows into the River Lambro. In field exposures, trout were held in cages in the River Po upstream and downstream from the confluence of the River Lambro. After 10-day (laboratory) and 30-day (laboratory and field) exposures, trout were examined for several chemical, biochemical and histological endpoints. The results indicated that exposure to complex mixtures of chemicals, including estrogen receptor agonists, aryl-hydrocarbon receptor agonists, and probably antiandrogens, had occurred. Exposure altered the plasma levels of 17{beta}-estradiol and testosterone, and some treatments also enhanced the activity of hepatic ethoxyresorufin O-deethylase. Gonadal histology showed varying levels of degenerative processes characterised by oocyte atresia, haemorrhages, melano-macrophage centres (MMCs), and oogonia proliferation. Liver histology showed less severe effects. - This study examined the progression of hormonal and gonadal alterations in female trout exposed to river water from an area known to affect resident fish species.

  3. Endocrine function and reproductive impairment in an irradiated population of the lizard Uta stansburiana. [Effects of chronic, low-level /sup 137/Cs. gamma. irradiation underfield conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, A.K. (Univ. of California, Berkeley); Licht, P.; Nagy, K.A.; Medica, P.A.


    Gonadal changes in lizards (Uta stansburiana) exposed to chronic low levels of ..gamma.. radiation (1.5 to 10 R/day) under field conditions are described, and attempts to evaluate endocrine involvement in these changes are made. Reproductive impairment in irradiated males was demonstrated during the breeding season by reduced testes weights and by seminiferous tubules devoid of germ cells. Ultrastructural morphology of Leydig cells, plasma testosterone levels, and developed accessory sex structures indicatedd normal steroidogenesis in such males; cytology of the pituitary gonadotropes and pituitary gonadotropin content indicated normal gonadotropin levels. These findings suggest that low levels of radiation affect the spermatogenic process directly, rather than through damage to the pituitary. Comparable irradiation caused complete resorption of ovarian tissue in some female Uta. The oviducts were atrophic and the pituitary gonadotropes hyperactive. Resemblance of gonadotropes to those of castrated animals and reduced pituitary hormone content suggests elevated levels of gonadotropin production, probably due to the absence of ovarian steroid feedback in affected animals. The continued mitotic activity of oogonia in adult reptiles and their limited number contributed to the vulnerability of germinal tissue in irradiated female lizards. Destruction of the germ cells was accompanied by resorption of all ovarian tissue including steroidogenic elements. Thus, in females as in males, radiation appears to damage gametogenesis rather than pituitary function.

  4. Description of non-type Seinura winchesi from mushroom compost (Nematoda: Seinuridae). (United States)

    Kaisa, T R


    Non-type material identified as Seinura winchesi, and deposited in the collection of the Nematology Department, Rothamsted Experimental Station, England, is described. The material was collected from mushroom compost in Leeds, England, in 1957. Females of this population are characterized by a set-off head, knobless stylet (20-21 microm), two rows of oogonia-oocytes, and absence of a postuterine sac. The median bulb is oblong and, at times, is constricted in the middle. The body is 565 to 675 microm long and tapers posteriorly to a pointed terminus. The cuticle is finely annulated, and there are three incisures in the lateral field. The ovary is outstretched and overlaps the esophageal gland lobes. A spermatheca is present, and spermatozoa are visible. The vulva is posteriorly located (V = 77-80), and a flap is absent. Males are 550 to 680 microm long with a spicate tail that bears three pairs of subventral papillae. The spike is short (14-18 microm), about one-half the tail length. The testis is 360 to 412 microm long, not reflexed, and at times overlaps the esophageal gland lobes. Spermatogonia-spermatocytes are in two rows. Spicules are 14 to 15 microm long with a prominent apex, and small rostrum. A bursa and gubernaculum are absent.

  5. The annual cycle of oogenesis in the shanny, Lipophrys pholis (Pisces: Blenniidae

    Directory of Open Access Journals (Sweden)

    Filipa Ferreira


    Full Text Available Lipophrys pholis has been shown to be responsive to a variety of environmental contaminants, some of them able to impair reproduction. Description of the normal cycle of oogenesis of this newly proposed sentinel species is important since this data may function as a baseline for comparison in ecotoxicological studies, among other applications. Based on histological observations, L. pholis ovarian development in adult is asynchronous, and 7 ovarian germ cells can be described (oogonia, early and late perinuclear oocytes, cortical-alveolar oocytes, early vitellogenic oocytes, vitellogenic oocytes and spawning oocytes. Using a stereological approach together with the morphologic characteristics of ovarian cells, the ovarian cycle of L. pholis was divided into 3 maturation stages: early oogenesis (May; mid-oogenesis (September, and spawning (November to January. Ovarian cell proportions and gonadosomatic index confirmed that the reproductive period of L. pholis near the southern limit of distribution of the species occurs during cold-water periods, between November and May. The collected data will help to fill some of the gaps in information that still exist on L. pholis oogenesis, thus allowing a better integration of this species as a sentinel for the detection of contaminants in European coastal waters.

  6. A 6000-year record of ecological and hydrological changes from Laguna de la Leche, north coastal Cuba (United States)

    Peros, Matthew C.; Reinhardt, Eduard G.; Davis, Anthony M.


    Laguna de la Leche, north coastal Cuba, is a shallow (≤ 3 m), oligohaline (˜ 2.0-4.5‰) coastal lake surrounded by mangroves and cattail stands. A 227-cm core was studied using loss-on-ignition, pollen, calcareous microfossils, and plant macrofossils. From ˜6200 to ˜ 4800 cal yr BP, the area was an oligohaline lake. The period from ˜ 4800 to ˜ 4200 cal yr BP saw higher water levels and a freshened system; these changes are indicated by an increase in the regional pollen rain, as well as by the presence of charophyte oogonia and an increase in freshwater gastropods (Hydrobiidae). By ˜ 4000 cal yr BP, an open mesohaline lagoon had formed; an increase in salt-tolerant foraminifers suggests that water level increase was driven by relative sea level rise. The initiation of Laguna de la Leche correlates with a shift to wetter conditions as indicated in pollen records from the southeastern United States (e.g., Lake Tulane). This synchronicity suggests that sea level rise caused middle Holocene environmental change region-wide. Two other cores sampled from mangrove swamps in the vicinity of Laguna de la Leche indicate that a major expansion of mangroves was underway by ˜ 1700 cal yr BP.

  7. Germ cell development in the scleractinian coral Euphyllia ancora (Cnidaria, Anthozoa.

    Directory of Open Access Journals (Sweden)

    Shinya Shikina

    Full Text Available Sexual reproduction of scleractinian coral is among the most important means of establishing coral populations. However, thus far, little is known about the mechanisms underlying coral gametogenesis. To better understand coral germ cell development, we performed a histological analysis of gametogenesis in Euphyllia ancora and characterized the coral homolog of the Drosophila germline marker gene vasa. The histological analysis revealed that E. ancora gametogenesis occurs in the mesenterial mesoglea between the mesenterial filaments and the retractor muscle bands. The development of germ cells takes approximately one year in females and half a year in males. Staining of tissue sections with an antibody against E. ancora Vasa (Eavas revealed anti-Eavas immunoreactivity in the oogonia, early oocyte, and developing oocyte, but only faint or undetectable reactivity in developing oocytes that were >150 µm in diameters. In males, Eavas could be detected in the spermatogonia and primary spermatocytes but was only faintly detectable in the secondary spermatocytes, spermatids, and sperms. Furthermore, a reverse transcription-polymerase chain reaction analysis and Western blotting analysis of unfertilized mature eggs proved the presence of Eavas transcripts and proteins, suggesting that Eavas may be a maternal factor. Vasa may represent a germ cell marker for corals, and would allow us to distinguish germ cells from somatic cells in coral bodies that have no distinct organs.


    Kessel, R. G.; Beams, H. W.


    Annulated membranes in the form of single and short lamellae are present adjacent to and parallel to the nuclear envelope in oogonia and early oocyte (synaptene) stages of the dragonfly, Libellula pulchella. These solitary and short annulate lamellae are usually continuous with long, part rough- and part smooth-surfaced cisternae which extend into more distal areas of the oogonial ooplasm. These particular annulate lamellae then either disappear or decrease in number to be replaced by a much more extensive system of annulate lamellae in the cortical ooplasm of previtellogenic oocytes. The differentiation of extensive stacks of annulate lamellae is consistently observed to be restricted to large cytoplasmic areas of considerable electron density. These cytoplasmic regions consist of material which stains basophilic and contains RNA but differs structurally from the large number of ribosomes which surround the dense masses. The cytoplasmic dense masses, in terms of their formation and staining reactions, are comparable to the "yolk nuclei" or "Balbiani bodies" described in insect oocytes in earlier studies. The results of the present study thus provide evidence that the appearance of cortical ooplasmic stacks of annulate lamellae in the dragonfly oocyte is specifically limited to cytoplasmic areas of high electron density which contain RNA but which do not have a ribosomal morphology. PMID:5786982

  9. Morphological indicators of initial reproductive commitment in Mustelus schmitti (Springer 1939 (Chondrichthyes, Triakidae: folliculogenesis and ovarian structure over the life cycle

    Directory of Open Access Journals (Sweden)

    EJ Galíndez

    Full Text Available This work provides information about the sexual commitment and the folliculogenesis of the gatuzo, Mustelus schmitti. A total of 112 females of all maturity stages were fished in the Bahía Blanca estuary, between 2009 and 2010. The oogonia were present throughout the life cycle of the animals. The folliculogenesis follows a pattern similar to other elasmobranchs. The granulosa layer keeps monolayered throughout the folliculogenesis, but with two cell types in the vitellogenic follicle. The zona pellucida forms in the primordial follicles. The thecal system shows a connective inner layer and a glandular outer sheath. The microscopic beginning of the sexual commitment, indicated by the vitello hoarding, takes place in follicles from 500 micrometres, while the macroscopic evidence appears in follicles of 2500-3000 micrometres. The results presented in this study suggest that the fishery pressure may affect a susceptible range of sizes of the species, not previously considered and provides a biological framework for the development of fisheries policy.

  10. Descripción histológica y caracterización de los estados de madurez gonadal de hembras de Cryphiops caementarius (Molina, 1782 (Decapoda: Palaemonidae Histological description and characterization of the ovarian cycle of Cryphiops caementarius (Molina, 1782 (Decapoda: Palaemonidae

    Directory of Open Access Journals (Sweden)

    Jorge E Moreno


    commercial freshwater Palemonid present in Chilean inland waters. Even though this situation has awakened interest in studies which allow its controlled reproduction in captivity, currently little is known regarding basic reproductive aspects of this species. Given its relevance, this work describes and characterizes the whole ovarian cycle of Cryphiops caementarius, based on changes in external and internal ovarian morphology. Adult C. caementarius females, obtained from Limarí River, were dissected and its ovaries removed and prepared for histological examinations. Fibromuscular tissue divides the ovarian tissue of each lobe into cone-shaped ovarian pouches (Maturation cones, each one containing various steps of oocytes according to the stages of ovarian development. Based on light microscopic observations of cells' sizes, morphology, and staining with H-E, the female germ cells could be classified into six different types, which include oogonia (Ov, early previtellogenic oocytes (O1, late previtellogenic oocytes (O2, early vitellogenic oocytes (O3, late vitellogenic oocytes (O4 and mature oocytes (OM. The ovarian cycle is divided into five stages based on the amount and types of oocytes present in each stage. Stage 0 and I are spawned and previtellogenesis stages. Stage II and III are early and intermediate vitellogenesis stages, while stage IV is maturity advanced stage. The presence of oogonia and previtellogenic oocytes among fully mature oocytes in stage IV reflect the capacity of the ovary of C. caementarius females to start a new full maturity cycle in a short time period.

  11. A novel marsupial pri-miRNA transcript has a putative role in gamete maintenance and defines a vertebrate miRNA cluster paralogous to the miR-15a/miR-16-1 cluster. (United States)

    Au, Phil Chi Khang; Frankenberg, Stephen; Selwood, Lynne; Familari, Mary


    Successful maintenance, survival and maturation of gametes rely on bidirectional communication between the gamete and its supporting cells. Before puberty, factors from the gamete and its supporting cells are necessary for spermatogonial stem cell and primordial follicle oocyte maintenance. Following gametogenesis, gametes rely on factors and nutrients secreted by cells of the reproductive tracts, the epididymis and/or oviduct, to complete maturation. Despite extensive studies on female and male reproduction, many of the molecular mechanisms of germ cell maintenance remain relatively unknown, particularly in marsupial species. We present the first study and characterisation of a novel primary miRNA transcript, pri-miR-16c, in the marsupial, the stripe-faced dunnart. Bioinformatic analysis showed that its predicted processed miRNA - miR-16c - is present in a wide range of vertebrates, but not eutherians. In situ hybridisation revealed dunnart pri-miR-16c expression in day 4 (primordial germ cells) and day 7 (oogonia) pouch young, in primary oocytes and follicle cells of primordial follicles but then only in follicle cells of primary, secondary and antral follicles in adult ovaries. In the adult testis, pri-miR-16c transcripts were present in the cytoplasm of spermatogonial cells. The oviduct and the epididymis both showed expression, but not any other somatic tissues examined or conceptuses during early embryonic development. This pattern of expression suggests that pri-miR-16c function may be associated with gamete maintenance, possibly through mechanisms involving RNA transfer, until the zygote enters the uterus at the pronuclear stage.

  12. Histological organization of the female queen Devario regina (Fowler, 1934 during its juvenile stage

    Directory of Open Access Journals (Sweden)

    Piyakorn Boonyoung


    Full Text Available Limited research has been reported in the basic information about the structural organizations of fish organs in their juvenile state that could be used as histopathological biomarkers. Thus, the histological structures of important organs of the female fish Devario regina (Fowler, 1934 during its juvenile stage were exclusively examined using histological and histochemical approaches. Specimens were collected during the fishing season (July and October 2010 from the Tapee river, Thailand. Using histological analysis, the digestive system was distinctly composed of two parts; the digestive tract and accessory organs (liver and pancreas. Based on their histological structure, the epithelial organization of the oral cavity and pharynx was lined by stratified epithelium whereas the intestine was covered by a simple columnar epithelium and contained several goblet cells. The goblet cells were negatively stained with hematoxylin and eosin (H&E and Masson’s Trichrome (MT. In contrast, they were positively stained with Periodic Acid Schiff reaction (PAS and aniline blue (AB. The liver tissue in this fish was composed of polyhedral hepatocytes, with their sinusoids being distinctly located between the hepatocytes. The sinusoids were lined by a simple squamous epithelium. The pancreatic parenchyma mainly consisted of pyramidal cells that rested on a basal lamina in the acinar. Moreover, the pancreatic cells had a basophilic cytoplasm, a distinct basal nucleus and contained large eosinophilic zymogen granules. The excretory system especially referred to the kidney, and was composed of renal tubules and hematopoietic tissue. The female reproductive system was the ovary that was surrounded by a tunica albuginea. The ovary contained oocytes at differential stages of development including oogonia and the previtellogenic stage. Finally, the integument of this species consisted mainly of three layers of epidermis, dermis and hypodermis, respectively.

  13. Observaciones sobre algunos caracteres de valor taxonómico en el grupo de los carófitos

    Directory of Open Access Journals (Sweden)

    Pedrola, J.


    Full Text Available The variability of the microstructurals characters and mineralogical composition of the oogonia of some charophytes extant and fossils is described. Two types of microstructures (W & V are find. These are conservative into populations and are not able to change by the environmental factors. Moreover, these structures are quite constant in some of the phylogenetics groups studied. Consequently it is proposed its utilization in taxonomy. The apparition of original compounds in the Charophyta (vaterite. whewelite, aragonite, etc. is important because it supports an old idea that considerates the Charophyta as an autonomous class between the Clorophyta and the Traqueophyta.

    Se describe la variabilidad de los caracteres microestructurales y la composición mineralógica de las células espirales del oogonio en diversas especies actuales y fósiles del grupo de los carófitos. Se encuentran así, dos tipos de microestructuras diferentes (W y V que se muestran conservativas en el seno de las poblaciones, no moldeables por el ambiente y relativamente constantes dentro de los distintos grupos filogenéticos. En consecuencia, se propone su utilización con fines taxonómicos. La aparición de ciertos elementos mineralógicos (vaterita, whewelita, aragonito etc. resulta remarcable por su originalidad y su apoyo al viejo criterio que consideraba los carófitos como una clase autónoma y quizás de "enlace" entre clorófitos y traqueófitos.

  14. Mouse TEX14 Is Required for Embryonic Germ Cell Intercellular Bridges but Not Female Fertility1 (United States)

    Greenbaum, Michael P.; Iwamori, Naoki; Agno, Julio E.; Matzuk, Martin M.


    A conserved feature of germ cell cytokinesis is the formation of stable intercellular bridges between daughter cells. These intercellular bridges are seen in diverse species from Drosophila melanogaster to Homo sapiens and have been shown to have roles in communication of large numbers of germ cells. In testis expressed gene 14 (Tex14) knockout mice, intercellular bridges do not form during spermatogenesis, and male mice are sterile, demonstrating an essential role for intercellular bridges in postnatal spermatogenesis in mammals. Intercellular bridges also form between dividing germ cells in both male and female embryos. However, little is known about the formation or role of the embryonic intercellular bridges in mammals. In females, embryonic intercellular bridges have been proposed to have a role in development of the presumptive oocyte. Herein, we show that TEX14 is an essential component of male and female embryonic intercellular bridges. In addition, we demonstrate that mitotic kinesin-like protein 1 (MKLP1, official symbol KIF23), which we have discovered is a component of intercellular bridges during spermatogenesis, is also a component of male and female embryonic intercellular bridges. Germ cell intercellular bridges are readily identified by KIF23 immunofluorescence between the gonocytes and oogonia of control mice but are absent between germ cells of Tex14-null mice. Furthermore, by electron microscopy, intercellular bridges are present in all control newborn ovaries but are absent in the Tex14 knockout ovaries. Despite the absence of embryonic intercellular bridges in the Tex14-null mice, male mice initiate spermatogenesis, and female mice are fertile. Although fewer oocytes were present in Tex14-null neonatal ovaries, folliculogenesis was still active at 1 yr of age. Thus, while TEX14 and intercellular bridges have an essential role in postnatal spermatogenesis, they are not required in the embryo. PMID:19020301

  15. Structures of ovary and ovarian follicle in flathead lobster,Thenus orientalis (Lund, 1793) (Crustacea: Decapoda: Scyllarida)

    Institute of Scientific and Technical Information of China (English)


    The ovary contains four morphological components : (1) the ovarian wall, (2) therepro ductive epithelium, (3) the cellular layer containing oocytes, oogonia (especially for early-developing ovary) and follicle cells, and (4) the extensions of the ovarian wall. The ovarian wall and its extensions consist of blood vessels, sinuses, muscle cells and others. The extensions of the ovarian wall project into among the follicles and insert on the thick basal membrane of each follicle.From inside to outside, the follicles are composed of four parts: (1) the oocyte, (2) the perivitelline space, (3) the follicle cells, and (4) the basal membrane. The surface of the oocyte during vitellogenesis is folded into numerous long microvilli that project into the perivitelline space between the oocyte surface and the bace of the follicle cell layer. In addition, the plasma membrane of the vitellogenic oocyte contains many pinocytotic pits. The perivitelline space is engorged with more electrondenser material as the development of the follicle. The inclusion of perivitelline space in the mature follicle is named specially as the chorion. The chorion is composed of two region, a thinner exochorion and a thicker endochorion containing electron-dense granular material. The follicle cell layer is composed of a single layer of polygonal follicle cells which exhibit higher synthetic activity. The synthetic product of the follicle cell layer is one source for the inclusion of the perivitelline space.The structures of the ovary and ovarian follicle in T. orientalis show that the exogenously biosynthetic yolk plays important roles in the vitellogenesis.

  16. Ultrastructural changes and programmed cell death of trophocytes in the gonad of Isohypsibius granulifer granulifer Thulin, 1928 (Tardigrada, Eutardigrada, Isohypsibiidae). (United States)

    Poprawa, Izabela; Hyra, Marta; Kszuk-Jendrysik, Michalina; Rost-Roszkowska, Magdalena Maria


    The studies on the fates of the trophocytes, the apoptosis and autophagy in the gonad of Isohypsibius granulifer granulifer have been described using transmission electron microscope, light and fluorescent microscopes. The results presented here are the first that are connected with the cell death of nurse cells in the gonad of tardigrades. However, here we complete the results presented by Węglarska (1987). The reproductive system of I. g. granulifer contains a single sack-like hermaphroditic gonad and a single gonoduct. The gonad is composed of three parts: a germarium filled with proliferating germ cells (oogonia); a vitellarium that has clusters of female germ cells (the region of oocytes development); and a male part filled with male germ cells in which the sperm cells develop. The trophocytes (nurse cells) show distinct alterations during all of the stages of oogenesis: previtello-, vitello- and choriogenesis. During previtellogenesis the female germ cells situated in the vitellarium are connected by cytoplasmic bridges, and form clusters of cells. No ultrastructural differences appear among the germ cells in a cluster during this stage of oogenesis. In early vitellogenesis, the cells in each cluster start to grow and numerous organelles gradually accumulate in their cytoplasm. However, at the beginning of the middle of vitellogenesis, one cell in each cluster starts to grow in order to differentiate into oocyte, while the remaining cells are trophocytes. Eventually, the cytoplasmic bridges between the oocyte and trophocytes disappear. Autophagosomes also appear in the cytoplasm of nurse cells together with many degenerating organelles. The cytoplasm starts to shrink, which causes the degeneration of the cytoplasmic bridges between trophocytes. Apoptosis begins when the cytoplasm of these cells is full of autophagosomes/autolysosomes and causes their death.

  17. Expression characteristics of Odf3 in gonad are different between Chlamys farreri and vertebrates (United States)

    Ma, Xiaoshi; Liang, Shaoshuai; Yang, Dandan; Ji, Aichang; Ma, Xiaoru; Zhang, Zhifeng


    Outer dense fibers are specific subcellular components of mammal sperm flagella, apart from the axoneme and its associated proteins. As one of the outer dense fibers components, ODF3 is essential for the formation of mammal sperm flagella. In the present study, we isolated the Odf3 gene, 1033 bp in length, from Zhikong scallop Chlamys farreri, which was named as Cf-Odf3. It was predicted that Cf-Odf3 encodes a protein of 240 amino acids which contains 5 discontinuous Pro-Gly-Pro repeats. The Cf-Odf3 transcripts were detected in both testis and ovary of C. farreri at various stages through qRT-PCR. The Cf-ODF3 protein synthesized by prokaryotes was purified using Ni2+-NTA affinity chromatography and used to produce its polyclonal antibody. The antibody product was effective and specific as was examined by Western blotting. The Cf-Odf3 transcript and Cf-ODF3 protein were located in intragonadal somatic cells (ISCs), spermatogonia and spermatocytes of C. farreri testes, while no transcription of Cf-Odf3 and synthesis of Cf-ODF3 were detected in spermatids and spermatozoa. The location of Odf3 expression is different from that of vertebrates where ODF3 is synthesized specifically in spermatids and sperm flagella. Moreover, the Cf-Odf3 expression was also detected in ISCs, oogonia and oocytes of the scallop ovaries. Our finding revealed a different characteristic of Odf3 expression between scallop and vertebrates, which implied that Cf-Odf3 played a role in the gametogenesis of C. farreri.

  18. Assembly of ovarian follicles in the caecilians Ichthyophis tricolor and Gegeneophis ramaswamii: light and transmission electron microscopic study. (United States)

    Beyo, R S; Sreejith, P; Divya, L; Oommen, O V; Akbarsha, M A


    Though much is known about various aspects of reproductive biology of amphibia, there is little information on the cellular and mechanistic basis of assembly of ovarian follicles in this group. This is especially true of the caecilians. Therefore, taking advantage of the abundant distribution of caecilians in the Western Ghats of India, two species of caecilians, Ichthyophis tricolor and Gegeneophis ramaswamii, were subjected to light and transmission electron microscopic analysis to trace the sequential changes during the assembly of ovarian follicles. The paired ovaries of these caecilians are elongated sac-like structures each including numerous vitellogenic follicles. The follicles are connected by a connective tissue stroma. This stroma contains nests of oogonia, primary oocytes and pregranulosa cells as spatially separated nests. During assembly of follicles the oocytes increase in size and enter the meiotic prophase when the number of nucleoli in the nucleus increases. The mitochondrial cloud or Balbiani vitelline body, initially localized at one pole of the nucleus, disperses through out the cytoplasm subsequently. Synaptonemal complexes are prominent in the pachytene stage oocytes. The pregranulosa cells migrate through the connective tissue fibrils of the stroma and arrive at the vicinity of the meiotic prophase oocytes. On contacting the oocyte, the pregranulosa cells become cuboidal in shape, wrap the diplotene stage oocyte as a discontinuous layer and increase the content of cytoplasmic organelles and inclusions. The oocytes increase in size and are arrested in diplotene when the granulosa cells become flat and form a continuous layer. Soon a perivitelline space appears between the oolemma and granulosa cells, completing the process of assembly of follicles. Thus, the events in the establishment of follicles in the caecilian ovary are described.

  19. Notch pathway regulates female germ cell meiosis progression and early oogenesis events in fetal mouse. (United States)

    Feng, Yan-Min; Liang, Gui-Jin; Pan, Bo; Qin, Xun-Si; Zhang, Xi-Feng; Chen, Chun-Lei; Li, Lan; Cheng, Shun-Feng; De Felici, Massimo; Shen, Wei


    A critical process of early oogenesis is the entry of mitotic oogonia into meiosis, a cell cycle switch regulated by a complex gene regulatory network. Although Notch pathway is involved in numerous important aspects of oogenesis in invertebrate species, whether it plays roles in early oogenesis events in mammals is unknown. Therefore, the rationale of the present study was to investigate the roles of Notch signaling in crucial processes of early oogenesis, such as meiosis entry and early oocyte growth. Notch receptors and ligands were localized in mouse embryonic female gonads and 2 Notch inhibitors, namely DAPT and L-685,458, were used to attenuate its signaling in an in vitro culture system of ovarian tissues from 12.5 days post coitum (dpc) fetus. The results demonstrated that the expression of Stra8, a master gene for germ cell meiosis, and its stimulation by retinoic acid (RA) were reduced after suppression of Notch signaling, and the other meiotic genes, Dazl, Dmc1, and Rec8, were abolished or markedly decreased. Furthermore, RNAi of Notch1 also markedly inhibited the expression of Stra8 and SCP3 in cultured female germ cells. The increased methylation status of CpG islands within the Stra8 promoter of the oocytes was observed in the presence of DAPT, indicating that Notch signaling is probably necessary for maintaining the epigenetic state of this gene in a way suitable for RA stimulation. Furthermore, in the presence of Notch inhibitors, progression of oocytes through meiosis I was markedly delayed. At later culture periods, the rate of oocyte growth was decreased, which impaired subsequent primordial follicle assembly in cultured ovarian tissues. Taken together, these results suggested new roles of the Notch signaling pathway in female germ cell meiosis progression and early oogenesis events in mammals.

  20. Ovarian histology of the placentotrophic Mabuya mabouya (Squamata, Scincidae). (United States)

    Gómez, Duperly; Ramírez-Pinilla, Martha Patricia


    Ovarian structure and folliculogenesis of females at different reproductive stages are described for the viviparous placentotrophic lizard Mabuya mabouya. The small ovaries have a thin wall formed by the ovarian epithelium and a thin tunica albuginea. One to two germinal beds that contain numerous oogonia and developing primordial follicles are derived from the ovarian epithelium and are next to the ovarian hilum. The ovarian cortex contains follicles at different stages of development, corpora lutea, and atretic follicles. The yolk nucleus and Balbiani complex were not evident in the ooplasm of previtellogenic follicles. The follicular epithelium of these follicles is polymorphic, as in other species of Squamata, but the larger cells are spherical and monolayered rather than pyriform. The zona radiata of the preovulatory follicles is less developed than in lecithotrophic species. These features suggest a decrease in metabolic and absorptive processes during follicular growth. In preovulatory follicles (1.5-1.8 mm diameter), primordial yolk vacuoles and small cortical granules are deposited in the ooplasm instead of fatty yolk platelets, so that only one stage of vitellogenesis is observed. Polyovular atretic follicles occur in some females. Follicular atresia is minimal for preovulatory follicles, but is more frequent in follicles with polymorphic epithelia. In the corpus luteum, the luteal tissue is formed from granulosa cells and luteolysis occurs during the late gastrula -- late neurula embryonic stages. Thus, the maintenance of gestation from the pharyngula to preparturition stages seems to be related to secretion of extraluteal progesterone, possibly of placental origin. These observed ovarian features are related to the high degree of placental complexity of this species and show that the evolution of advanced placentotrophy in species of this lineage has been accompanied by concomitant changes in ovarian function.

  1. Oogenesis in the viviparous matrotrophic lizard Mabuya brachypoda. (United States)

    Hernández-Franyutti, Arlette; Uribe Aranzábal, Mari Carmen; Guillette, Louis J


    Oogenesis in the lizard Mabuya brachypoda is seasonal, with oogenesis initiated during May-June and ovulation occurring during July-August. This species ovulates an egg that is microlecithal, having very small yolk stores. The preovulatory oocyte attains a maximum diameter of 0.9-1.3 mm. Two elongated germinal beds, formed by germinal epithelia containing oogonia, early oocytes, and somatic cells, are found on the dorsal surface of each ovary. Although microlecithal eggs are ovulated in this species, oogenesis is characterized by both previtellogenic and vitellogenic stages. During early previtellogenesis, the nucleus of the oocyte contains lampbrush chromosomes, whereas the ooplasm stains lightly with a perinuclear yolk nucleus. During late previtellogenesis the ooplasm displays basophilic staining with fine granular material composed of irregularly distributed bundles of thin fibers. A well-defined zona pellucida is also observed. The granulosa, initially composed of a single layer of squamous cells during early previtellogenesis, becomes multilayered and polymorphic. As with other squamate reptiles, the granulosa at this stage is formed by three cell types: small, intermediate, and large or pyriform cells. As vitellogenesis progresses the oocyte displays abundant vacuoles and small, but scarce, yolk platelets at the periphery of the oocyte. The zona pellucida attains its maximum thickness during late oogenesis, a period when the granulosa is again reduced to a single layer of squamous cells. The vitellogenic process observed in M. brachypoda corresponds with the earliest vitellogenic stages seen in other viviparous lizard species with larger oocytes. The various species of the genus Mabuya provided us with important models to understand a major transition in the evolution of viviparity, the development of a microlecithal egg.

  2. The basement membrane and the sex establishment in the juvenile hermaphroditism during gonadal differentiation of the Gymnocorymbus ternetzi (Teleostei: Characiformes: Characidae). (United States)

    Mazzoni, Talita Sarah; Grier, Harry J; Quagio-Grassiotto, Irani


    Although there are several studies on morphogenesis in Teleostei, until now there is no research describing the role of the basement membrane in the establishment of the germinal epithelium during gonadal differentiation in Characiformes. In attempt to study these events that result in the formation of ovarian and testicular structures, gonads of Gymnocorymbus ternetzi were prepared for light microscopy. During gonadal development in G. ternetzi, all individuals first developed ovarian tissue. The undifferentiated gonad was formed by somatic cells (SC) and primordial germ cells (PGCs). After successive mitosis, the PGCs became oogonia, which entered into meiosis originating oocytes. An interstitial tissue developed. In half of the individuals, presumptive female, prefollicle cells synthesized a basement membrane around oocyte forming a follicle. Along the ventral region of the ovary, the tissue invaginated to form the ovigerous lamellae, bordered by the germinal epithelium. Stroma developed and the follicle complexes were formed. The gonadal aromatase was detected in interstitial cells in the early steps of the gonadal differentiation in both sexes. In another half of the individuals, presumptive male, there was no synthesis of basement membrane. The interstitium was invaded by numerous granulocytes. Pre-Leydig cells proliferated. Apoptotic oocytes were observed and afterward degenerated. Spermatogonia appeared near the degenerating oocytes and associated to SCs, forming testicular tubules. Germinal epithelium developed and the basement membrane was synthesized. Concomitantly, there was decrease of the gonadal aromatase and increase in the 3β-HSD enzyme expression. Thus, the testis was organized on an ovary previously developed, constituting an indirect gonochoristic differentiation. © 2015 Wiley Periodicals, Inc.

  3. Gametogenesis and reproductive cycle of Melanorivulus aff. punctatus (Boulenger, 1895 (Cyprinodontiformes, Rivulidae in Chapada dos Guimarães, Mato Grosso, Brazil

    Directory of Open Access Journals (Sweden)

    Monica Cassel

    Full Text Available The comprehension of the reproductive cycle allows to understand which are the morphological changes that develop in the gonad during this interval. Thus, many studies have been undertaken in order to describe and classify the stages of gonadal development and reproductive status of Neotropical fishes. For this purpose, specimens of Melanorivulus aff. punctatus were collected in a permanent dam in Chapada dos Guimarães, Mato Grosso, Brazil. The gonads were prepared for analysis by light microscopy. The oogenesis and spermatogenesis have been described, characterizing the stages of gonadal development, together with assessments of the gonadosomatic ratio, germ cell count and verification of variation of mature oocytes in females. Throughout the year the male gonads presented themselves as capable of reproducing, characterized by the presence of undifferentiated and differentiated spermatogonia, spermatocytes organized into cysts, spermatids in cysts whose wall was thicker and the spermatozoa was free in the lumen and the duct. This can indicate a continuous reproductive cycle with split spermiation. The females had gonads in the development stage from May to September with undifferentiated and differentiated oogonias and early oocytes always facing the lumen, abundant pre-vitellogenic and vitellogenic oocytes and some atresias. In the phase capable of spawning, observed from October to March, the mature oocytes are abundant, there are many post-ovulatory complexes and some atresia in advanced stage. The regression, observed in some individuals from February to April, is characterized by ovaries with many atresias and post-ovulatory complexes. The same results were found in the quantitative assessments. Therefore, it may be characterized as discontinuous cycle with split spawning. Thus, the reproductive cycle of this species can be characterized as continuous for males and discontinuous for females, which have a most intense phase of reproduction

  4. Distribution of ghrelin-ike immunoreactive cells in amphioxus, Branchiostoma belcheri- A study of immunohistochemistry

    Institute of Scientific and Technical Information of China (English)

    You-Zhu Weng; Hai-Xia Song; Yong-Qiang Fang


    The distribution of ghrelin-like immunoreactive cells in amphioxus (Branchiostoma belcheri) was investigated by using immunohisto-chemical staining with rabbit antiserum against synthetical mammalian ghrelin. The results showed that ghrelin-like immunoreactive cells were distributed widely in the nervous system, Hatschek's pit, wheel organ, digestive tract and gonads (ovary and testis). In nervous system, ghrelin-like immunoreactive neurons and their protrusions were distributed specifically on the dorsal side, ventral side and funnel part of brain vesicle, with a few dispersive immunoreactive nerve cells and their fibers in nerve tube. Ghrelin-like immunoreactivities were also detected in Hatschek's pit epithelial cells and wheel organ cells, with positive substance located along cell membrane. In digestive tract, ghrelin-like immunoreactive cells existed in hepatic diverticulum, anterior and posterior region of midgut, and could be classified into two types, closed- and opened-type endocrine cells. The number of positive cells was most in hepatic diverticulum, secondary in posterior region of midgut and least in anterior region of midgut. In gonads, ghrelin-like immunoreactive substance was detected in oogonia, oocytes and follicle cells in ovary at the small and large growth stages and in early spermatogenic cells and Sertoli cells in testis. The extensive distribution of ghrelin-like cells in amphioxus suggested that these kinds of cells are conservative in evolution and diversified in function. At the same time, we found for the first time that ghrelin-like immunoreactive cells existed in brain vesicle and Hatschek's pit, which provided new morphological evidence for the existence of an activation pathway between brain vesicle and Hatschek's pit for the regulation of growth hormone excretion.

  5. Gonadal morphogenesis and sex differentiation in intraovarian embryos of the viviparous fish Zoarces viviparus (Teleostei, Perciformes, Zoarcidae): a histological and ultrastructural study. (United States)

    Rasmussen, Tina H; Jespersen, Ase; Korsgaard, Bodil


    It is essential to know the timing and process of normal gonadal differentiation and development in the specific species being investigated in order to evaluate the effect of exposure to endocrine-disrupting chemicals on these processes. In the present study gonadal sex differentiation and development were investigated in embryos of a viviparous species of marine fish, the eelpout, Zoarces viviparus, during their intraovarian development (early September to January) using light and electron microscopy. In both sexes of the embryos at the time of hatching (September 20) the initially undifferentiated paired bilobed gonad contains primordial germ cells. In the female embryos, ovarian differentiation, initiated 14 days posthatch (dph), is characterized by the initial formation of the endoovarian cavity of the single ovary as well as by the presence of some early meiotic oocytes in a chromatin-nucleolus stage. By 30 dph, the endoovarian cavity has formed. By 44 dph and onward, the ovary and the oocytes grow in size and at 134 dph, just prior to birth, the majority of the oocytes are at the perinucleolar stage of primary growth and definitive follicles have formed. In the presumptive bilobed testis of the male embryos, the germ cells (spermatogonia), in contrast to the germ cells of the ovary, remain quiescent and do not enter meiosis during intraovarian development. However, other structural (somatic) changes, such as the initial formation of the sperm duct (30 dph), the presence of blood vessels in the stromal areas of the testis (30 dph), and the appearance of developing testicular lobules (102 dph), indicate testicular differentiation. Ultrastructually, the features of the primordial germ cells, oogonia, and spermatogonia are similar, including nuage, mitochondria, endoplasmic reticulum, and Golgi complexes.

  6. Hemipenes in females of the Mexican viviparous lizard Barisia imbricata (Squamata: Anguidae): an example of heterochrony in sexual development. (United States)

    Martínez-Torres, Martín; Rubio-Morales, Beatriz; Piña-Amado, José Juan; Luis, Juana


    The sexual development of saurians follows a similar pattern to that described for other amniotes. Changes in the timing or sequence of development events are known as heterochrony. We describe the pattern of sexual development in the viviparous Mexican lizard Barisia imbricata and report heterochrony in the regression of hemipenes in this lizard. We collected gestating females; some lizards were subjected to partial hysterectomy and the embryos were processed using routine histological technique to assess gonadal development; the remaining embryos were used to assess the development of hemipenes. Other pregnant females were kept in captivity in individual terraria until the time of delivery. All neonates were sexed by eversion of hemipenes and some of their body characteristics were recorded. Several neonates were sacrificed and processed to establish gonadal histology and the young of the remaining litters were maintained in captivity to observe the fate of the hemipenes in both sexes. Gonadal development began at embryonic stage 33 and the hemipenes were visible at the same stage. In the neonates, the ovary contained oogonias and ovarian follicles, whereas the testicles showed testicular cords. All neonates had hemipenes and sex could only be established through direct observation of the reproductive ducts and gonadal histology. The hemipenes regression in the females begins after approximately 7 months of postnatal development and concludes at about 15 months of age. We think that the delayed regression of the hemipenes reflects evolutionary differences among reptiles and may be an indication of a stage in the evolutionary process of this species.

  7. Conserved form and function of the germinal epithelium through 500 million years of vertebrate evolution. (United States)

    Grier, Harry J; Uribe, Mari Carmen; Lo Nostro, Fabiana L; Mims, Steven D; Parenti, Lynne R


    The germinal epithelium, i.e., the site of germ cell production in males and females, has maintained a constant form and function throughout 500 million years of vertebrate evolution. The distinguishing characteristic of germinal epithelia among all vertebrates, males, and females, is the presence of germ cells among somatic epithelial cells. The somatic epithelial cells, Sertoli cells in males or follicle (granulosa) cells in females, encompass and isolate germ cells. Morphology of all vertebrate germinal epithelia conforms to the standard definition of an epithelium: epithelial cells are interconnected, border a body surface or lumen, are avascular and are supported by a basement membrane. Variation in morphology of gonads, which develop from the germinal epithelium, is correlated with the evolution of reproductive modes. In hagfishes, lampreys, and elasmobranchs, the germinal epithelia of males produce spermatocysts. A major rearrangement of testis morphology diagnoses osteichthyans: the spermatocysts are arranged in tubules or lobules. In protogynous (female to male) sex reversal in teleost fishes, female germinal epithelial cells (prefollicle cells) and oogonia transform into the first male somatic cells (Sertoli cells) and spermatogonia in the developing testis lobules. This common origin of cell types from the germinal epithelium in fishes with protogynous sex reversal supports the homology of Sertoli cells and follicle cells. Spermatogenesis in amphibians develops within spermatocysts in testis lobules. In amniotes vertebrates, the testis is composed of seminiferous tubules wherein spermatogenesis occurs radially. Emerging research indicates that some mammals do not have lifetime determinate fecundity. The fact emerged that germinal epithelia occur in the gonads of all vertebrates examined herein of both sexes and has the same form and function across all vertebrate taxa. Continued study of the form and function of the germinal epithelium in vertebrates

  8. Analysis of the Behavior of Mitochondria in the Ovaries of the Earthworm Dendrobaena veneta Rosa 1839 (United States)

    Faron, Justyna; Bernaś, Tytus; Sas–Nowosielska, Hanna; Klag, Jerzy


    We examined six types of cells that form the ovary of the earthworm Dendrobena veneta ogonia, prooocytes, vitellogenic oocytes, trophocytes, fully grown postvitellogenic oocytes and somatic cells of the gonad. The quantitative stereological method revealed a much higher “volume density” of mitochondria in all of the types of germ-line cells except for the somatic cells. Fluorescent vital stain JC-1, however, showed a much higher oxidative activity of mitochondria in the somatic cells than in the germ-line cells. The distribution of active and inactive mitochondria within the studied cells was assessed using the computer program ImageJ. The analysis showed a higher luminosity of inactive mitochondria in all of the types of germ-line cells and a higher luminosity of active mitochondria in somatic cells. The OXPHOS activity was found in somatic cells mitochondria and in the peripheral mitochondria of the vitellogenic oocytes. The detection of reactive oxygen species (ROS) revealed a differentiated distribution of ROS in the different cell types. The amount of ROS substances was lower in somatic cells than in younger germ-line cells. The ROS level was also low in the cytoplasm of fully grown postwitellogenic oocytes. The distribution of the MnSOD enzyme that protects mitochondria against destructive role of ROS substances was high in the oogonia and in prooocytes and it was very high in vitellogenic and postvitellogenic oocytes. However, a much lower level of this protective enzyme was observed in the trophocytes and the lowest level was found in the cytoplasm of somatic cells. The lower mitochondrial activity and higher level of MnSOD activity in germ-line cells when compared to somatic cells testifies to the necessity of the organisms to protect the mitochondria of oocytes against the destructive role of the ROS that are produced during oxidative phosphorylation. The protection of the mitochondria in oocytes is essential for the transfer of healthy organelles to


    Directory of Open Access Journals (Sweden)

    KOZÁK P.


    Full Text Available The aim of this study was to follow the gonadal development in freshwater crayfish Orconectes limosus (Rafinesque by histological examination of ovaries and testes as well as monthly investigation of the gonadosomatic index over a period of one year. Male gonadosomatic index (IG ranged between 0.11 to 0.79% with a minimum in July (0.11% and maximum in September (0.79% while in females it ranged between 0.25 to 6.15% with a minimum in July (0.25% and maximum in April (6.15%. Between April and May, the histological dissection indicated presence of mature oocytes and oocytes undergoing resorption. Egg extrusion took place in mid April. During the summer months, the volume of oocytes gradually decreased. In winter and spring, the volume of oocytes began to increase during preparation for egg extrusion. The size of oocytes in the ovary increased from 0.2 mm at the beginning of the reproductive cycle to 1.8 mm immediately before egg extrusion. Average number of eggs in the ovary was 140.8 ± 51.63 (76-290. The ovary was of brown colour for the majority of the cycle, but white in June and July and orange in August and September. Mating started in October and continued through the winter. A difference was found in the proportions of testis and vas deferens in the male reproductive organ during the year. The male gonadosomatic index increased in September during preparation for mating (IG = 0.79%. During the mating season, the male spermatophores were predominantly filled with spermatozoa and sperm was also noted in the vas deferens. Two out of 15 males sampled during the winter were found to be intersex, in which atretic oogonia and oocytes were present at the periphery of testicular tissue and occupied less than 15% of testicular tissue. The evidence of intersex strongly suggested transitional stages of a gradual change of sex, which may be qualified as partial hermaphroditism.

  10. Primordial germ cell migration in the yellowtail kingfish (Seriola lalandi) and identification of stromal cell-derived factor 1. (United States)

    Fernández, J A; Bubner, E J; Takeuchi, Y; Yoshizaki, G; Wang, T; Cummins, S F; Elizur, A


    Primordial germ cells (PGCs) are progenitors of the germ cell lineage, giving rise to either spermatogonia or oogonia after the completion of gonadal differentiation. Currently, there is little information on the mechanism of PGCs migration leading to the formation of the primordial gonad in perciform fish. Yellowtail kingfish (Seriola lalandi) (YTK) (order Perciforms) inhabit tropical and temperate waters in the southern hemisphere. Fundamental details into the molecular basis of larval development in this species can be easily studied in Australia, as they are commercially cultured and readily available. In this study, histological analysis of YTK larvae revealed critical time points for the migration of PGCs to the genital ridge, resulting in the subsequent development of the primordial gonad. In YTK larvae at 3, 5, 7 and 10 days post hatch (DPH), PGCs were not yet enclosed by somatic cells, indicating the primordial gonad had not yet started to form. While at 15, 18 and 20 DPH PGCs had already settled at the genital ridge and started to become enclosed by somatic cells indicating the primordial gonad had started to develop. A higher number of PGCs were observed in the larvae at 15 and 18 DPH indicating PGCs proliferation, which corresponds with them becoming enclosed by the somatic cells. Directional migration of PGCs toward the genital ridge is a critical event in the subsequent development of a gonad. In zebrafish, mouse and chicken, stromal-cell derived factor (SDF1) signalling is one of the key molecules for PGC migration. We subsequently isolated from YTK the SDF1 (Slal-SDF1) gene, which encodes for a 98-residue precursor protein with a signal peptide at the N-terminus. There is spatial conservation between fish species of four cysteine residues at positions C9, C11, C34 and C49, expected to form disulphide bonds and stabilize the SDF structure. In YTK, Slal-SDF1 gene expression analyses shows that this gene is expressed in larvae from 1 to 22 DPH and

  11. Reinterpretation of evidence advanced for neo-oogenesis in mammals, in terms of a finite oocyte reserve. (United States)

    Notarianni, Elena


    The central tenet of ovarian biology, that the oocyte reserve in adult female mammals is finite, has been challenged over recent years by proponents of neo-oogenesis, who claim that germline stem cells exist in the ovarian surface epithelium or the bone marrow. Currently opinion is divided over these claims, and further scrutiny of the evidence advanced in support of the neo-oogenesis hypothesis is warranted - especially in view of the enormous implications for female fertility and health. This article contributes arguments against the hypothesis, providing alternative explanations for key observations, based on published data. Specifically, DNA synthesis in germ cells in the postnatal mouse ovary is attributed to mitochondrial genome replication, and to DNA repair in oocytes lagging in meiotic progression. Lines purported to consist of germline stem cells are identified as ovarian epithelium or as oogonia, from which cultures have been derived previously. Effects of ovotoxic treatments are found to negate claims for the existence of germline stem cells. And arguments are presented for the misidentification of ovarian somatic cells as de novo oocytes. These clarifications, if correct, undermine the concept that germline stem cells supplement the oocyte quota in the postnatal ovary; and instead comply with the theory of a fixed, unregenerated reserve. It is proposed that acceptance of the neo-oogenesis hypothesis is erroneous, and may effectively impede research in areas of ovarian biology. To illustrate, a novel explanation that is consistent with orthodox theory is provided for the observed restoration of fertility in chemotherapy-treated female mice following bone marrow transplantation, otherwise interpreted by proponents of neo-oogenesis as involving stimulation of endogenous germline stem cells. Instead, it is proposed that the chemotherapeutic regimens induce autoimmunity to ovarian antigens, and that the haematopoietic chimaerism produced by bone marrow

  12. Effects of specific and prolonged expression of zebrafish growth factors, Fgf2 and Lif in primordial germ cells in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Ten-Tsao, E-mail: [Department of Animal Sciences, Purdue University, 901 W. State Street, West Lafayette, IN 47907 (United States); Collodi, Paul [Department of Animal Sciences, Purdue University, 901 W. State Street, West Lafayette, IN 47907 (United States)


    Highlights: Black-Right-Pointing-Pointer We discovered that nanos3 3 Prime UTR prolonged PGC-specific protein expression up to 26 days. Black-Right-Pointing-Pointer Expression of Fgf2 in PGCs significantly increased PGC number at later developmental stages. Black-Right-Pointing-Pointer Expression of Lif in PGCs resulted in a significant disruption of PGC migration. Black-Right-Pointing-Pointer Lif illicited its effect on PGC migration through Lif receptor a. Black-Right-Pointing-Pointer Our approach could be used to achieve prolonged PGC-specific expression of other proteins. -- Abstract: Primordial germ cells (PGCs), specified early in development, proliferate and migrate to the developing gonad before sexual differentiation occurs in the embryo and eventually give rise to spermatogonia or oogonia. In this study, we discovered that nanos3 3 Prime UTR, a common method used to label PGCs, not only directed PGC-specific expression of DsRed but also prolonged this expression up to 26 days post fertilization (dpf) when DsRed-nanos3 3 Prime UTR hybrid mRNAs were introduced into 1- to 2-cell-stage embryos. As such, we employed this knowledge to express zebrafish leukemia inhibitory factor (Lif), basic fibroblast growth factor (Fgf2) and bone morphogenetic protein 4 (Bmp4) in the PGCs and evaluate their effects on PGC development in vivo for over a period of 3 weeks. The results show that expression of Fgf2 significantly increased PGC number at 14- and 21-dpf while Bmp4 resulted in severe ventralization and death of the embryos by 3 days. Expression of Lif resulted in a significant disruption of PGC migration. Mopholino knockdown experiments indicated that Lif illicited its effect on PGC migration through Lif receptor a (Lifra) but not Lifrb. The general approach described in this study could be used to achieve prolonged PGC-specific expression of other proteins to investigate their roles in germ cell and gonad development. The results also indicate that zebrafish PGCs

  13. The palaeoecologic and biostratigraphic evaluation of Middle Miocene freshwater sediments and microfossils near Denkendorf (Bavaria) (United States)

    Pirkenseer, C.; Reichenbacher, B.


    Isolated freshwater sediments that partially cover the Jurassic limestones of the Swabian and Franconian Alb represent the northernmost expansion of the Molasse sediments. These sediments represent the analogue to the Brackish Molasse and part of the Upper Freshwater Molasse (Ottnangian to Badenian). Samples of six drillcores from the vicinity of Denkendorf (Franconian Alb, Bavaria) yielded ostracods of the superfamily Cypridoidea, frequent oogonia of charophytes, otoliths of the family Gobiidae, teeth of several taxa of micromammals as well as abundant material of amphibians, reptiles and gastropods. The sediments show a general trend from basal, more clastic influenced deposits to uniformly developed marly sediments with freshwater carbonate intercalations. The acme of microfossil occurrences is associated with the latter section. The palaeoecologic analysis characterises the environment as structured littoral zone (e.g. Pseudocandona steinheimensis, Gyraulus sp., Planorbarius sp., Rana ridibunda, Triturus sp.) of a larger oligo- to mesotrophic (Chara spp., Nitellopsis spp.) low-energy freshwater system under a warm subtropical to tropical climate (Diplocynodon cf. D. styriacus, Channa sp.). The cooccurrence of suboxia- and oligotrophy-tolerant species like Palaeocarassius sp. and Channa sp. may indicate short intervals of regional depletion of oxygene and raise of nutrient content. Mediocypris candonaeformis and Gobius latiformis represent relict species of the preceding Brackwassermolasse. Terrestrial elements include Proboscidea (phalanx), Cervidae (astragalus), land turtles (Testudo sp.) and gastropods (Clausiliidae, Pupillidae, Cepaea sp.). The occurrence of Jurassic xenoclasts and bean iron ore indicate the presence of a tributary system. The faunal and floral assemblages show close affinities to other localities of the Molasse Basin (e.g., Sandelzhausen). In accordance with the depositional history this indicates a palaeogeographic connection with the

  14. Effects Of Treatment With Radioactive Iodine On Gonadal Functions In Patients With Differentiated Thyroid Cancer

    Directory of Open Access Journals (Sweden)

    Fard Esfahani A


    Full Text Available Background: The purpose of this study was to evaluate the effect of treatment with radioactive iodine on the function of gonads in males and females with follicular and papillary thyroid carcinoma. Materials and Methods: Consenting patients in the reproductive age were grouped according to the cumulative dose of received radioiodine and followed for at least 12 months. For all men, serum levels of FSH, LH, and testosterone were measured; some (53 cases were also studied by semen analysis. For women, tests for serum levels of LH, FSH, estrogen, and progesterone were performed. Results: Overall, 246 patients (159 females, 87 males were studied. In 87.4% of men, there was an increase in serum FSH level after radioiodine therapy, in 20.7% of whom the level remained high during follow-up period. The average serum level of FSH after each course of treatment was significantly higher than the level before treatment (p<0.01, and there was a meaningful correlation with the cumulative dose of received iodine (p<0.001. Reduced number of sperms was shown in 35.8% of male patients, among whom 73.7% also showed reduced motility. In 36.8% of the patients with reduced sperm number (13.2% of the total, this finding was persistent during the follow-up period. Increased level of FSH was correlated with reduced sperm counts in all doses (poogonia cell line, the radiosensitivity is

  15. Cenozoic Carbonate Stratigraphy of the Yucatan Shelf, Southern Gulf of Mexico (United States)

    Ortega-Nieto, A.; Urrutia-Fucugauchi, J.


    The Yucatan shelf in the southern Gulf of Mexico has developed as a large shallow ramp shelf, tectonically stable that preserves a continuous sedimentary record for the Late Mesozoic and Cenozoic. We present the preliminary results of a study involving well stratigraphy, X-ray diffraction and petrography of the Cenozoic sequence sampled in the UNAM-5, UNAM-6 and UNAM-7 exploratory boreholes drilled in the southwestern and southern sectors of the Yucatan state. The boreholes were drilled as part of the Chicxulub Drilling Project aimed to investigate the formation and characteristics of the large crater, formed by an asteroid impact at the Cretaceous/Paleogene (K/Pg) boundary. Our study aims to investigate the stratigraphic relations, textural changes and characteristics of the sedimentary units, to identify events associated with the evolution of the platform during the Cenozoic. We constructed detailed stratigraphic columns for the three borehole cores and prepared samples collected across the stratigraphic section for petrography and clay analyses. The petrographic studies were made at different depths above the K/Pg boundary to recognize textural variations, the identification of dolomite was made by the method of staining thin sections, and the dolomite fabrics were analyzed to identify the nature and shape of their crystal boundaries. The method of X-ray diffraction was used to identify clay types. The three boreholes cross the K/Pg boundary at different depths. The stratigraphic column is formed, from bottom to top, of a limestone sequence with evaporites nodules, little contents of benthic foraminifera, scarce planktic foraminifera and oogonia fossils suggesting internal lagoonal environments that vary to outer lagoon. This sequence is underlain by limestones with different degrees of dolomitization that in many cases present poorly preserved microfossil contents. Above this sequence, there is a clay bed identified as palygorskita, which has a variable

  16. Phytophthora Root and Crown Rot on Apples in Bulgaria

    Directory of Open Access Journals (Sweden)

    Mariana Nakova


    Full Text Available Phytophthora is a genus of Oomycota responsible for some of the most serious diseases with great economic impact (Judelson and Blanco, 2005. While 54 species were found in the 20th century (Erwin and Ribeiro, 1996 another 51-54 new species have been identified(Brasier, 2008 since the year 2000. They are spread worldwide and have broad range of host plants – fruit trees, citrus, forest and park species. Phytophthora can cause serious damages in orchards and nurseries of apples, cherries, etc. In Bulgaria they have been found first on young apples and cherries (1998-1999 in Plovdiv region (Nakova, 2003. Surveys have been done for discovering disease symptoms in Plovdiv and Kjustendil regions. Isolates have been obtained from infected plant material (roots and stem bases applying baiting bioassay (green apples, variety Granny Smith and/or PARP 10 selective media. Phytophthora strains were identified based on standard morphology methods – types of colonies on PDA, CMA, V 8, type and size of sporangia, oogonia and antheridia, andoospores. Cardial temperatures for their growth were tested on CMA and PDA.For molecular studies, DNA was extracted from mycelium using the DNA extraction kit.DNA was amplified using universal primers ITS 6 and ITS 4. Amplification products concentrations were estimated by comparison with the standard DNA. Sequencing was done at the Scottish Crop Research Institute (SCRI, Dundee, Scotland. Phytophthora root and crown rot symptoms first appear in early spring. Infected trees show bud break delay, have small chlorotic leaves, and branches die all of a sudden. Later symptoms are found in August-September. Leaves of the infected trees show reddish discoloration and drop down. Both symptoms are connected with lesions (wet, necrotic in appearance at stem bases of the trees.Disease spread was 2-3% in most gardens, only in an apple orchard in Bjaga (Plovdiv region it was up to 8-10%. Morphologically, the isolates acquired from

  17. Piscine follicle-stimulating hormone triggers progestin production in gilthead seabream primary ovarian follicles. (United States)

    Zapater, Cinta; Chauvigné, François; Scott, Alexander P; Gómez, Ana; Katsiadaki, Ioanna; Cerdà, Joan


    Ovarian growth (vitellogenesis) in most lower vertebrates is mediated by estradiol-17beta (E2) secreted by the follicles in response to follicle-stimulating hormone (Fsh), whereas oocyte maturation and ovulation are mediated by progestins, such as 17alpha,20beta-dihydroxypregn-4-en-3-one (17,20beta-P), produced in response to luteinizing hormone (Lh). In teleosts, follicular synthesis of 17,20beta-P at the time of maturation is due primarily to up-regulation of the enzymes P450c17-II (Cyp17a2) and 20beta-hydroxysteroid dehydrogenase (Cbr1). Here, we show that follicular cells associated with primary growth (previtellogenic) oocytes of the gilthead seabream also express cyp17a2 and cbr1, in addition to P450c17-I (cyp17a1) and aromatase (cyp19a1), enzymes required for E2 synthesis. Ovaries containing only oogonia and early primary ovarian follicles had a 60-fold higher concentration of 17,20beta-P than ovaries in the succeeding stages and had a higher expression of cbr1 and Fsh receptor (fshra). Stimulation of explants of primary follicles in vitro with recombinant piscine Fsh (rFsh), which specifically activates the seabream Fshra, promoted a rapid accumulation of 17,20beta-P, and synthesis was sustained by an external supply of 17alpha-hydroxyprogesterone. In the presence of Cbr1 inhibitors, rFsh-mediated 17,20beta-P production was reduced, with a concomitant increase in testosterone and E2 synthesis. In primary explants, rFsh up-regulated cyp17a2 and cbr1 transcription and simultaneously down-regulated cyp17a1 and cyp19a1 steady-state mRNA levels within 24 h. In contrast, in explants containing vitellogenic follicles, rFsh had no effect on cyp17a2 and cbr1 expression, but increased that of cyp17a1 and cyp19a1. These data suggest a functional Fshra-activated Cyp17a2/Cbr1 steroidogenic pathway in gilthead seabream primary ovarian follicles triggering the production of 17,20beta-P.

  18. Beta-endorphin disrupts seasonal and FSH-induced ovarian recrudescence in the lizard Mabuya carinata. (United States)

    Ganesh, C B; Yajurvedi, H N


    Administration (ip) of an opioid peptide, beta-endorphin (beta-EP) (0.1, 0.5, or 1 microg beta-EP/day/lizard for 30 days) during seasonal recrudescence phase of the ovarian cycle inhibited ovarian recrudescence as shown by the absence of vitellogenic follicles in the ovary in contrast to their presence in treatment controls in the lizard Mabuya carinata. In the germinal bed, treatment of 0.1 microg beta-EP did not affect primordial follicles, whereas their mean number was significantly lower in lizards treated with 0.5 or 1 microg beta-EP compared to those of treatment controls. There was also suppression of oviductal development as shown by a significantly lower relative weight of the oviduct and regressed oviductal glands in lizards treated with all the dosages of beta-EP compared to treatment controls. In another experiment, administration of FSH (10 IU FSH/alternate day/lizard for 30 days) during the regression phase of the ovarian cycle induced development of vitellogenic follicles, whereas the treatment controls showed only previtellogenic follicles. In addition, there was a significant increase in the ovarian and oviductal weights compared to initial and treatment controls. However, simultaneous administration of similar dosage of FSH and beta-EP (0.5 microg/day/lizard) did not induce ovarian recrudescence as shown by the absence of vitellogenic follicles in the ovary and significantly lower weight of the ovary and the oviduct and the mean number of oogonia, oocytes, and primordial follicles compared to those of FSH-treated lizards. The results indicate that beta-EP inhibits seasonal as well as FSH-induced ovarian recrudescence. Inhibitory effect of beta-EP on follicular development despite FSH administration implies its effect at the ovarian level in M. carinata. While adversely affecting the ovarian follicular development, beta-EP did not affect the adrenal gland as there was no significant variation in the mean nuclear diameter of the adrenocortical cells

  19. Rate of temperature reduction at cryopreservation primordial germ cells (PGC of three Indonesian native chicken.

    Directory of Open Access Journals (Sweden)

    Tatan Kostaman


    Full Text Available Primordial germ cells (PGCs are original cells of spermatogonia in the testes or oogonia in the ovary. PGCs in poultry can be harvested and stored in the liquid nitrogen and can be used for conservation as genetic materials of poultry. The objective of this study was to obtain the optimal rate of temperature reduction on PGCs quality from three different Indonesian native chicken after thawing. Fertile eggs obtained from native chicken were incubated for 56 hours to obtain embryo at stage of 14-16. PGCs were isolated from the blood using modified Nycodenz Gradient Centrifugation technique. There after they were kept in a straw and equilibrated for 15 minutes at 5oC and frozen at the rate of temperature reduction of 0.3, 0.5, and 1oC per minute using embryo freezing machine (FHK Fujihara: ET-1. After the temperature reached -30oC, then they were plunged directly into the liquid nitrogen. Recovery rate and viability of PGCs after freezing and thawing were measured. The results of this study showed that the average recovery rate of PGCs that have been frozen at rate of temperature reduction of 1, 0.5, and 0.3oC per minute were 35.6, 43.9, and 44.9% respectively. However the rate of temperature reduction of 0.5 and 0.3oC per minute did not significantly affect the recovery rate. The average percentage of viability of PGCs that were frozen at the rate of 1, 0.5 and 0.3oC per minute were respectively 62.6, 77.5, and 77.4%. It seems that the viability followed the trend of recovery rates where the 1oC per minute reduction was the lowest quality compared to the other two treatments. It is concluded that the reduction of 0.5 or 0.3oC per minute are considered as the ideal temperature reduction when native chicken PGCs are frozen.

  20. Sexual difference in gonadal development of embryonic chickens after treatment of polychlorinated biphenyls

    Institute of Scientific and Technical Information of China (English)


    with gonadal development with a sex-specific pattern and retarded differentiation of spermatogonia into spermatocytes but accelerated differentiation of oogonia into oocytes in the embryonic chickens.

  1. Analysis of meiosis regulators in human gonads: a sexually dimorphic spatio-temporal expression pattern suggests involvement of DMRT1 in meiotic entry. (United States)

    Jørgensen, Anne; Nielsen, John E; Blomberg Jensen, Martin; Græm, Niels; Rajpert-De Meyts, Ewa


    The mitosis-meiosis switch is a key event in the differentiation of germ cells. In humans, meiosis is initiated in fetal ovaries, whereas in testes meiotic entry is inhibited until puberty. The purpose of this study was to examine the expression pattern of meiosis regulators in human gonads and to investigate a possible role of DMRT1 in the regulation of meiotic entry. The expression pattern of DMRT1, STRA8, SCP3, DMC1, NANOS3, CYP26B1 and NANOS2 was investigated by RT-PCR and immunohistochemistry in a series of human testis samples from fetal life to adulthood, and in fetal ovaries. DMRT1 was expressed in testes throughout development but with marked spatio-temporal changes. At the early fetal period of 8-20 gestational weeks (GW) and at infantile mini-puberty, DMRT1 was predominantly expressed in Sertoli cells, whereas at later stages of gestation (22-40 GW), during childhood and in post-pubertal testes, DMRT1 was most abundant in spermatogonia, except in the A-dark type. In fetal ovaries, DMRT1 was detected in oogonia and oocytes until 20 GW, but was completely down-regulated following meiotic entry. STRA8, SCP3 and DMC1 were expressed mainly in oocytes and spermatogonia in accordance with their role in initiation and progression of meiosis. The putative meiosis inhibitors, CYP26B1 and NANOS2, were primarily expressed in Leydig cells and spermatocytes, respectively. In conclusion, the expression pattern of the investigated meiotic regulators is largely conserved in the human gonads compared with rodents, but with some minor differences, such as a stable expression of CYP26B1 in human fetal ovaries. The sexually dimorphic expression pattern of DMRT1 indicates a similar role in the mitosis-meiosis switch in human gonads as previously demonstrated in mice. The biological importance of the changes in expression of DMRT1 in Sertoli cells remains to be established, but it is consistent with DMRT1 reinforcing the inhibition of meiosis in the testis.

  2. Submerged terrestrial landscapes in the Baltic Sea: Evidence from multiproxy analyses of sediment cores from Fehmarnbelt (United States)

    Enters, Dirk; Wolters, Steffen; Blume, Katharina; Segschneider, Martin; Lücke, Andreas; Theuerkauf, Martin; Hübener, Thomas


    deposited during floods in old river channels of the hypothesized Dana River. Instead diatom assemblages indicate rather calm conditions. Between 9.850 and 8.900 cal. BP carbonate rich sediments were deposited under now shallow water conditions consisting of autochthonous carbonates, mollusk shells (especially Bithynia tentaculata) and oogonia of charophytes. The diatom record shows first indications of slightly brackish conditions starting ca. 10.300 cal. BP with the appearance of Mastogloia smithii which is about 2000 years older than the Littorina transgression dated in our record to around 8.300 cal. BP. This marine transgression finally inundated the inland lake and caused a rise of the water level of more than 20 m.

  3. Gonad development during the early life of Octopus maya (Mollusca: Cephalopoda). (United States)

    Avila-Poveda, Omar Hernando; Colin-Flores, Rafael Francisco; Rosas, Carlos


    Gonad development during the early life of Octopus maya is described in terms of histological, morphometric, oocytes growth, and somatic-oocyte relationship data obtained from octopus cultured at the UMDI-UNAM, in Sisal, Yucatan, Mexico. This study is the first publication on gonad development during the early life of Octopus maya. A total of 83 O. maya specimens were used; their sizes ranged from 6.5 to 76 mm of total length (TL), 4 to 28 mm of dorsal mantle length (DML), 2.5 to 20 mm of ventral mantle length (VML), and 0.0180 to 7.2940 g of fixed body weight (fBW). Animals were weighed and measured only after preservation. A loss of 10% of living weight was estimated for juvenile octopuses after formalin preservation. The relation of length to weight (VML, DML, TL/fBW) pooled for both sexes had a strong positive correlation (r), as shown by a potential power function that was quite close to 1. Compound images were produced from numerous microscopic fields. The histological examination revealed that, 4 months after hatching, male octopus (24.5 mm DML and 7.2940 g fBW) were in gonad stages 2 (maturing) to 3 (mature), with spermatogonia and spermatocytes in the tubule wall and abundant spermatids and spermatozoa in the central lumen of the seminiferous tubules, suggesting the occurrence of different phases of gonad development at different maturity stages. In contrast, females (22.5 mm DML and 4.8210 g fBW) at the same time since hatching were immature (stage 1), with many oogonia, few oocytes, and germinal epithelium. This suggests that males reach maturity earlier than females, indicating a probable onset of maturity for males at around 4 months of culture or 8 g of wet body weight. Our results indicate the possibility that the size-at-weight can be recognized early with a degree of certainty that allows the sexes to be separated for culture purposes; but more detailed studies on reproduction in relation to endocrinology and nutrition are needed.

  4. Identification and biological characteristics of a pathogenic Saprolegnia sp.from the egg of Pengze crucian carp(Carassius auratus pengzesis)%彭泽鲫卵源致病性水霉的鉴定及其生物学特性

    Institute of Scientific and Technical Information of China (English)

    夏文伟; 曹海鹏; 王浩; 张世奇; 杨先乐


    Three filamentous fungal strains were isolated form Carassius auratus eggs with Saprolegniasis, and strain JL1 was proved to be pathogenic to Carassius auratus eggs by artificial infection.Therefore, morphology and growth characteristics of strain JL1 were studied, and the phylogenetic analysis based on its ITS rDNA sequence was further conducted. The experimental results showed that the hyphae of strain JL1 was aseptate, transparent and seldom branched. Its zoosporangia were often clavate and renewed internally. Primary zoospore was multi-row arrangement in zoosporangia and discharged in Saprolegnia fashion. Spherical oogonia was attached by monoclinous or diclinous antheridium hyphae. The ITS rDNA sequences of strain JL1 was naturally clustered with ITS rDNA sequences of Saprolegnia sp. submitted to GenBank with 99% of homology, and had closest relationship with Saprolegnia sp. H (accession number: EF460351). Combined morphological characterization with phylogenetic analysis based on ITS rDNA sequence, strain JL1 was identified as Saprolegnia sp.. In addition, strain JL1 could grow at 5℃-30℃ and pH 4-11, its optimum growing temperature and pH were 25 ℃-30℃ and 6-9, respectively. Strain JL1 was sensitive to sodium chloride, its growth could be completely inhibited by 2% NaCI, which could serve as a foundation for the Saprolegniasis control.%从患病的彭泽鲫卵上分离3 株丝状真菌,经人工感染试验证实其中1 株丝状真菌JL1 对彭泽鲫卵具有致病性,并进一步研究了其形态与生长特性,开展了ITS rDNA 序列分析.实验结果表明,菌株JL1 菌丝为透明管状结构,中间无横隔,分枝较少; 游动孢子囊多数呈棒状,游动孢子呈多排排列,发育成熟后从孢子囊中释放出来,并迅速游离; 藏卵器呈球形,与雄器同枝或异枝.菌株JL1 的ITS rDNA 序列与GenBank 基因库中水霉属菌株自然聚类,同源性高达99%,与Saprolegnia sp.H (登录号:EF460351)的亲缘关系

  5. 银鲫种系细胞标记分子Vasa: cDNA克隆及其抗体制备%Gibel carp germ cell marker Vasa: cDNA cloning and its antibody preparation

    Institute of Scientific and Technical Information of China (English)

    徐红艳; 彭金霞; 桂建芳; 洪云汉


    (CagVasa) that possesses 14 RGG-repeats and all the eight conserved motifs of Vasa proteins. CagVasa shows sequence identities of 95%, 89%, 61%-66% and 50% to Vasa proteins from the common carp, zebrafish, tetrapods and Drosophila, respectively. RNA in situ hybridization on ovarian sections showed that Cagvasa was absent in any gonadal somatic cells but dynamically expressed throughout oogenesis: the signal is weak in oogonia, peaks in vitellogenic oocytes and deceases in maturing oocytes. To develop a tool for analyzing fish germ cells, we generated αVasa, a rabbit antibody against a recombinant protein of 310-aa N-terminal CagVasa. Western blot analyses showed that αVasa detected a 75 kD protein exclusively in the gibel carp gonads and isolated oocytes. To confirm the germ cell-specifity of αVasa, fluorescent immunostaining was performed on gonadal sections. This antibody stains exclusively germ cells throughout oogenesis and early stages of spermatogenesis. We conclude that vasa encodes a Vasa ortholog that services a first germ cell marker in the gibel carp, and that αVasa provides a highly sensitive and powerful tool for the analysis of germ cell specification and differentiation in the gibel carp

  6. 雌核发育二倍体鲫鲤及其他倍性鱼cdc2基因cDNA全序列克隆及表达%The cloning of cdc2 cDNAs and a comparative study of its expression in different ploidy fishes including the diploid gynogenetic hybrid of red crucian carp × common carp

    Institute of Scientific and Technical Information of China (English)

    陶敏; 刘少军; 钟欢; 周毅; 宋灿; 张纯; 刘筠


    Cdc2(Cyclin Dependent Kinase,namely CDK1)encoded by cdc2 gene and CyclinB combination regulates G2/M transition. To find out molecular mechanism that diploid hybrid fish could produce diploid gamete,the full length cDNAs of cdcl in the third gynogenetic generation(G3) ,red crucian carp( Carassius auratus red var. ) ,triploid crucian carp and allotetraploid were obtained by PCR and rapid amplification of cDNA ends. Our data showed that all the cDNAs of cdcl gene in the four different ploidy fishes encode a protein of 302 amino acids containing a domain (PSTAVRE) which combine Cyclins. A high homology of 97. 6% of the Cdc2 protein can be drawn by comparing the amino acid sequences in these four fishes, which indicates the higher conservative function and evolution of Cdc2 protein in these four fishes. A comparative expression pattern of cdcl in early-stage gonads of G3 and different ploidy fishes was carried out by Realtime PCR using specific primers against the same sequences of coding regions in the four fishes. The results showed that the expression of cdcl in the ovary of G3 was higher than those of red crucian carp and triploid crucian carp, while lower than that of allotetraploid, which, at the molecular level, indicates existence of polyploid oogonia in early-stage gonads of G3. The higher expression of cdcl in G3 suggests that consecutive S-phase replication may occur without intervening mitosis, which might be related to the formation mechanisms for the diploid eggs generated by diploid hybrids.%为研究雌核发育二倍体鲫鲤产生二倍体卵子的分子机制,实验采用PCR和cDNA末端快速分离法,克隆获得了雌核发育二倍体鲫鲤第三代(G3)、二倍体红鲫、三倍体湘云鲫和四倍体鲫鲤的细胞周期相关基因——cdc2基因cDNA全序列.结果显示,4种不同倍性鱼cdc2基因均编码含有302个氨基酸蛋白,而且编码的蛋白都含有与其他CDK激酶相当保守的序列PSTAVRE;同源性分析发现,4

  7. Identification and asexual reproduction characterization of a Saprolegniaferax pathogen from the egg of Yellow catfish (Pelteobagrus fulvidraco)%黄颡鱼卵水霉病病原的分离鉴定及其无性繁殖特性

    Institute of Scientific and Technical Information of China (English)

    许佳露; 曹海鹏; 欧仁建; 杨先乐


    [Objective] The aim of the present study was to isolate and identify the pathogen of Pelteobagrus fulvidraco eggs suffering from saprolegniasis, and study its asexual reproduction characteristics. [Methods] Filamentous fungal strains were first isolated from the Pelteobagrus fulvidraco eggs suffering from saprolegniasis using the traditional method. The pathogenic strain was further confirmed through artificial infection experiment, and identified by using morphological observation and phylogenetic analysis based on its ITS rDNA sequence. Additionally, its asexual reproduction characteristics was studied using single factor method. (Results) Four filamentous fungal strains were isolated form Pelteobagrus fulvidraco eggs with saprolegniasis, and strain HP was proved to be pathogenic to Pelteobagrus fulvidraco eggs by artificial infection. Therefore, morphology and asexual reproduction characteristics of strain HP were studied, and the phylogenetic analysis based on its ITS rDNA sequence was further conducted. The experimental results showed that the hyphae of strain HP were aseptate, transparent and seldom branched. Its zoosporangia were often clavate and renewed internally. Primary zoospore was discharged in Saprolegnia fashion. New sporangium generated from the base of old sporangium by the way of internal proliferation. Spherical oogonia were attached by monoclinous or diclinous antheridium hyphae. The ITS rDNA sequences of strain HP were naturally clustered with ITS rDNA sequences of Saprolegnia sp. in GenBank with 99% of homology, and had closest relationship with Saprolegnia ferax strain Arg4S (GenBank accession number: GQ119935). Combined morphological characterization with phylogenetic analysis based on ITS rDNA sequence, strain HP was identified as Saprolegnia ferax. In addition, strain HP could produce zoospores at 5 ℃-35 ℃ and pH 4-10, its optimum temperature and pH for the zoospore production were 20 ℃ and 7, respectively. It was greatly inhibited

  8. 植物微体遗存分析在第四纪环境研究中的应用:综述与展望%Application of plant microfossils in Quaternary environmental research:a review and perspective

    Institute of Scientific and Technical Information of China (English)

    张继效; 徐海


    identiifcation of plant species. So starch grains are expected to be used in Quaternary research, especially in archaeology. In the oceans, lakes, wetlands and other sediments, a large number of micro-algaes, such as diatoms, Charophytes oogonia, dinolfagellates,Pediastrum may appear, which are complex and diverse, and they can be categorized in the plant microfossils too. Generally, during the analytic process of sporopollen, charcoals and fungal spores can be found. Charcoals are commonly used in the study on the history of ifre. Fungal spores can implicate some certain environmental information. Furthermore, some plants contain calcium oxalate crystals, which are similar to phytoliths and can be referred to as “plant calcium body”, and now studies on them are relatively less, but with the deepening of the research, they could be expected to be used in Quaternary research. Plant microfossils is dispersed in sediments and mixed with organic and inorganic impurities, so they should be separated and puriifed for the implementation of further research. Depending on the chemical composition of plant microfossils in different types, extraction method also has a corresponding difference. To sum up, the method to extract sporopollen mainly includes hydrofluoric acid screening method, heavy liquid flotation method and screening method, and in actual extraction process, all these methods are integratedly used. Phytoliths and diatoms are mainly composed of the silicon, and they often coexist in the sediments. To extract them, oxidants are used to remove organic components, while hydrochloric acid is used to remove the soluble carbonate minerals. Besides, sedimentation method, microwave ablation method or sieving method is used to remove clay during the extraction process of phytoliths. In physics, different sizes of particles have different sedimentation velocities in a liquid, which can be calculated by Stokes sedimentation equation. Based on this principle, the author of this