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Sample records for early gonadal development

  1. Fibroblast growth factor signaling is required for early somatic gonad development in zebrafish.

    PubMed

    Leerberg, Dena M; Sano, Kaori; Draper, Bruce W

    2017-09-01

    The vertebrate ovary and testis develop from a sexually indifferent gonad. During early development of the organism, primordial germ cells (the gamete lineage) and somatic gonad cells coalesce and begin to undergo growth and morphogenesis to form this bipotential gonad. Although this aspect of development is requisite for a fertile adult, little is known about the genetic regulation of early gonadogenesis in any vertebrate. Here, we provide evidence that fibroblast growth factor (Fgf) signaling is required for the early growth phase of a vertebrate bipotential gonad. Based on mutational analysis in zebrafish, we show that the Fgf ligand 24 (Fgf24) is required for proliferation, differentiation, and morphogenesis of the early somatic gonad, and as a result, most fgf24 mutants are sterile as adults. Additionally, we describe the ultrastructural elements of the early zebrafish gonad and show that distinct somatic cell populations can be identified soon after the gonad forms. Specifically, we show that fgf24 is expressed in an epithelial population of early somatic gonad cells that surrounds an inner population of mesenchymal somatic gonad cells that are in direct contact with the germ cells, and that fgf24 is required for stratification of the somatic tissue. Furthermore, based on gene expression analysis, we find that differentiation of the inner mesenchymal somatic gonad cells into functional cell types in the larval and early juvenile-stage gonad is dependent on Fgf24 signaling. Finally, we argue that the role of Fgf24 in zebrafish is functionally analogous to the role of tetrapod FGF9 in early gonad development.

  2. Characterization of early gonadal development in smallmouth bass (Micropterus dolomieu) and effects of ethinyl estradiol on gonadal differentiation

    EPA Science Inventory

    Teleosts vary widely in patterns of gonadal sex differentiation, which might lead to differences in how gonadal development is affected by the presence of estrogenic compounds. This makes it difficult to apply our knowledge of model species such as medaka and fathead minnow to o...

  3. Recovery of gonadal development in tiger puffer Takifugu rubripes after exposure to 17β-estradiol during early life stages

    NASA Astrophysics Data System (ADS)

    Hu, Peng; Liu, Bin; Meng, Zhen; Liu, Xinfu; Jia, Yudong; Yang, Zhi; Lei, Jilin

    2017-05-01

    The aim of the present study was to investigate the long-term effects of 17β-estradiol (E2) exposure on gonadal development in the tiger puff er ( Takifugu rubripes), which has a genetic sex determination system of male homogametic XY-XX. Tiger puff er larvae were exposed to 1, 10 and 100 μg/L E2 from 15 to 100 days post-hatch (dph) and then maintained in clean seawater until 400 dph. Changes in sex ratio, gonadal structure and gonadosomatic index (GSI) were monitored at 100, 160, 270 and 400 dph. Sex-associated single nucleotide polymorphism (SNP) markers were used to analyze the genetic sex of samples, except those at 100 dph. Exposure had a positive effect on the conversion of genetically male gonads into phenotypically female gonads at 100 dph. However, gonads from 60% of genetic XY males in the 1-μg/L E2 group and 100% in the 10-μg/L E2 group developed intersexual gonads at 160 dph; gonads of all genetic XY males in the two treatment groups reverted to testis by 270 dph. While 38%, 57% and 44% of gonads of XY fish in the 100-μg/L E2 group reverted to intersexual gonads at 160, 270 and 400 dph, respectively, none reverted to testis after E2 treatment. In addition, E2 exposure inhibited gonadal growth of both genetic sexes, as indicated by the clear dose-dependent decrease in GSI at 270 and 400 dph. The results showed that exposure to E2 during the early life stages of tiger puff er disrupted gonadal development, but that fish recovered after migration to clean seawater. The study suggests the potential use of tiger puff er as a valuable indicator species to evaluate the effects of environmental estrogens on marine fish, thereby protecting valuable fishery resources.

  4. Gonad development during the early life of Octopus maya (Mollusca: Cephalopoda).

    PubMed

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

    2009-02-01

    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.

  5. Mutation of Gonadal soma-derived factor induces medaka XY gonads to undergo ovarian development.

    PubMed

    Imai, Takuto; Saino, Kentaro; Matsuda, Masaru

    2015-11-06

    Gonochoristic species have a bipotential gonad that develops into a testis or an ovary. In species whose sex is determined by a genetic factor, the expression of a sex-determining gene is the first cue that directs the development of a bipotential gonad. Subsequent expression of downstream genes induces the gonad to develop into a testis or an ovary. The TGF-ß family member Gonadal soma-derived factor (Gsdf) is thought to be an important gene for gonadal development in teleost fish, and it is expressed at higher levels in the testis than in the ovary from early to mature stages. However, there is little functional information about the gene. In this study, we targeted the Gsdf coding region in the medaka fish Oryzias latipes using transcription activator-like effector nucleases (TALENs) and studied the phenotypes of the Gsdf mutant medaka. Although normal and heterozygous XY gonads developed into a testis, all XY gonads with a homozygous mutation in Gsdf developed into an ovary at early developmental stages. However, two-thirds of Gsdf mutant XY gonads developed into testes in the adult stages. These results demonstrate that although a gonad can develop into a complete testis in the absence of Gsdf, Gsdf function is critical for directing the bipotential gonad at early developmental stages. Therefore, Gsdf is an endogenous inducer of testicular development similar to a master sex-determining gene. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Emergence, Development, and Maturity of the Gonad of Two Species of Chitons “Sea Cockroach” (Mollusca: Polyplacophora) through the Early Life Stages

    PubMed Central

    Avila-Poveda, Omar Hernando; Abadia-Chanona, Quetzalli Yasú

    2013-01-01

    This study describes and recognises, using histological and microscopical examinations on a morphometrical basis, several gonad traits through the early life stages of Chiton articulatus and C. albolineatus. Gonadal ontogenesis, gonad development stages, sexual differentiation, onset of the first sexual maturity, and growth sequences or “early life stages” were determined. In addition, allometry between lengths and body weight pooled for both sexes per each chiton were calculated using equation Y = aXb. A total of 125 chitons (4≤TL≤40 mm, in total length “TL”) were used. All allometric relations showed a strong positive correlation (r), close to 1, with b-values above three, indicating an isometric growth. Gonadal ontogenesis and gonad development stages were categorised into three periods (“Pw” without gonad, “Pe” gonad emergence, and “Pf” gonadal sac formed) and four stages (“S0” gametocytogenesis, “S1” gametogenesis, “S2” mature, and “S3” spawning), respectively. Compound digital images were attained for each process. Periods and stages are overlapped among them and between species, with the following overall confidence intervals in TL: Pw 6.13–14.32 mm, Pe 10.32–16.93 mm, Pf 12.99–25.01 mm, S0 16.08–24.34 mm (females) and 19.51–26.60 mm (males), S1 27.15–35.63 mm (females) and 23.45–32.27 mm (males), S2 24.48–40.24 mm (females) and 25.45–32.87 mm (males). Sexual differentiation (in S0) of both chitons occurs first as a female then as a male; although, males reach the onset of the first sexual maturity earlier than females, thus for C. articulatus males at 17 mm and females at 32 mm, and for C. albolineatus males at 23.5 mm and females at 28 mm, all in TL. Four early life stages (i.e., subjuvenile, juvenile, subadult, and adult) are described and proposed to distinguish growth sequences. Our results may be useful to diverse disciplines, from developmental biology to fisheries management. PMID:23936353

  7. Emergence, development, and maturity of the gonad of two species of chitons "sea cockroach" (Mollusca: Polyplacophora) through the early life stages.

    PubMed

    Avila-Poveda, Omar Hernando; Abadia-Chanona, Quetzalli Yasú

    2013-01-01

    This study describes and recognises, using histological and microscopical examinations on a morphometrical basis, several gonad traits through the early life stages of Chiton articulatus and C. albolineatus. Gonadal ontogenesis, gonad development stages, sexual differentiation, onset of the first sexual maturity, and growth sequences or "early life stages" were determined. In addition, allometry between lengths and body weight pooled for both sexes per each chiton were calculated using equation Y = aX(b) . A total of 125 chitons (4≤TL≤40 mm, in total length "TL") were used. All allometric relations showed a strong positive correlation (r), close to 1, with b-values above three, indicating an isometric growth. Gonadal ontogenesis and gonad development stages were categorised into three periods ("Pw" without gonad, "Pe" gonad emergence, and "Pf" gonadal sac formed) and four stages ("S0" gametocytogenesis, "S1" gametogenesis, "S2" mature, and "S3" spawning), respectively. Compound digital images were attained for each process. Periods and stages are overlapped among them and between species, with the following overall confidence intervals in TL: Pw 6.13-14.32 mm, Pe 10.32-16.93 mm, Pf 12.99-25.01 mm, S0 16.08-24.34 mm (females) and 19.51-26.60 mm (males), S1 27.15-35.63 mm (females) and 23.45-32.27 mm (males), S2 24.48-40.24 mm (females) and 25.45-32.87 mm (males). Sexual differentiation (in S0) of both chitons occurs first as a female then as a male; although, males reach the onset of the first sexual maturity earlier than females, thus for C. articulatus males at 17 mm and females at 32 mm, and for C. albolineatus males at 23.5 mm and females at 28 mm, all in TL. Four early life stages (i.e., subjuvenile, juvenile, subadult, and adult) are described and proposed to distinguish growth sequences. Our results may be useful to diverse disciplines, from developmental biology to fisheries management.

  8. Methods for the Study of Gonadal Development.

    PubMed

    Piprek, Rafal P

    2016-01-01

    Current knowledge on gonadal development and sex determination is the product of many decades of research involving a variety of scientific methods from different biological disciplines such as histology, genetics, biochemistry, and molecular biology. The earliest embryological investigations, followed by the invention of microscopy and staining methods, were based on histological examinations. The most robust development of histological staining techniques occurred in the second half of the nineteenth century and resulted in structural descriptions of gonadogenesis. These first studies on gonadal development were conducted on domesticated animals; however, currently the mouse is the most extensively studied species. The next key point in the study of gonadogenesis was the advancement of methods allowing for the in vitro culture of fetal gonads. For instance, this led to the description of the origin of cell lines forming the gonads. Protein detection using antibodies and immunolabeling methods and the use of reporter genes were also invaluable for developmental studies, enabling the visualization of the formation of gonadal structure. Recently, genetic and molecular biology techniques, especially gene expression analysis, have revolutionized studies on gonadogenesis and have provided insight into the molecular mechanisms that govern this process. The successive invention of new methods is reflected in the progress of research on gonadal development.

  9. A Critical Point of Male Gonad Development: Neuroendocrine Correlates of Accelerated Testicular Growth in Rats during Early Life

    PubMed Central

    Dygalo, Nikolay N.; Shemenkova, Tatjana V.; Kalinina, Tatjana S.; Shishkina, Galina T.

    2014-01-01

    Testis growth during early life is important for future male fertility and shows acceleration during the first months of life in humans. This acceleration coincides with the peak in gonadotropic hormones in the blood, while the role of hypothalamic factors remains vague. Using neonatal rats to assess this issue, we found that day 9 of life is likely critical for testis development in rats. Before this day, testicular growth was proportional to body weight gain, but after that the testes showed accelerated growth. Hypothalamic kisspeptin and its receptor mRNA levels begin to elevate 2 days later, at day 11. A significant increase in the mRNA levels for gonadotropin-releasing hormone (GnRH) receptors in the hypothalamus between days 5 and 7 was followed by a 3-fold decrease in GnRH mRNA levels in this brain region during the next 2 days. Starting from day 9, hypothalamic GnRH mRNA levels increased significantly and positively correlated with accelerated testicular growth. Triptorelin, an agonist of GnRH, at a dose that had no effect on testicular growth during “proportional” period, increased testis weights during the period of accelerated growth. The insensitivity of testicular growth to GnRH during “proportional” period was supported by inability of a 2.5-fold siRNA knockdown of GnRH expression in the hypothalamus of the 7-day-old animals to produce any effect on their testis weights. GnRH receptor blockade with cetrorelix was also without effect on testis weights during “proportional” period but the same doses of this GnRH antagonist significantly inhibited “accelerated” testicular growth. GnRH receptor mRNA levels in the pituitary as well as plasma LH concentrations were higher during “accelerated” period of testicular growth than during “proportional” period. In general, our data defined two distinct periods in rat testicular development that are primarily characterized by different responses to GnRH signaling. PMID:24695464

  10. Genetic regulation of mammalian gonad development.

    PubMed

    Eggers, Stefanie; Ohnesorg, Thomas; Sinclair, Andrew

    2014-11-01

    Sex-specific gonadal development starts with formation of the bipotential gonad, which then differentiates into either a mature testis or an ovary. This process is dependent on activation of either the testis-specific or the ovary-specific pathway while the opposite pathway is continuously repressed. A network of transcription factors tightly regulates initiation and maintenance of these distinct pathways; disruption of these networks can lead to disorders of sex development in humans and male-to-female or female-to-male sex reversal in mice. Sry is the Y-linked master switch that is both required and sufficient to drive the testis-determining pathway. Another key component of the testis pathway is Sox9, which acts immediately downstream of Sry. In contrast to the testis pathway, no single sex-determining factor has been identified in the ovary pathway; however, multiple genes, such as Foxl2, Rspo1, Ctnnb1, and Wnt4, seem to work synergistically and in parallel to ensure proper ovary development. Our understanding of the regulatory networks that underpin testis and ovary development has grown substantially over the past two decades.

  11. Dissecting the Role of Hedgehog Pathway in Murine Gonadal Development

    ERIC Educational Resources Information Center

    Barsoum, Ivraym Boshra

    2009-01-01

    Hedgehog (Hh) signaling pathway is one of the universal pathways involved in animal development. This dissertation focuses on Hh role in the mammalian gonad development, which is a central part of mammalian sexual development and identity. The central dogma of mammalian sex development is that genetic sex determines the gonadal sex, which in turn…

  12. WNT4 signaling in female gonadal development.

    PubMed

    Pellegrino, Miriam; Maiorino, Raffaella; Schonauer, Sergio

    2010-06-01

    WNT4 signaling pathways represent an important step in the multi-faceted process of mammalian gonadal differentiation and the development of internal genitalia. WNT4 protein controls the cytoplasmatic stability of specific transcriptional coactivator beta catenin during both embriogenesis and adult homeostasis. The biological significance of WNT4 consists in determining the final female reproductive system, inhibiting Wolff ducts' differentiation, male steroidogenesis and vascular cell migration. An overview of WNT4 cellular mechanisms is given in order to understand its critical role in the genesis of various human diseases such as congenital malformations and gynecological disorders like polycystic ovary syndrome (PCOS). The final discussion focusses on several possible therapeutic uses of Wnt4 both during pregnancy in order to correct the genetic loss of function of the protein and during adulthood in order to normalize fertility in PCOS-affected females planning pregnancy.

  13. Histological and transcriptomic effects of 17α-methyltestosterone on zebrafish gonad development.

    PubMed

    Lee, Stephanie Ling Jie; Horsfield, Julia A; Black, Michael A; Rutherford, Kim; Fisher, Amanda; Gemmell, Neil J

    2017-07-24

    Sex hormones play important roles in teleost ovarian and testicular development. In zebrafish, ovarian differentiation appears to be dictated by an oocyte-derived signal via Cyp19a1a aromatase-mediated estrogen production. Androgens and aromatase inhibitors can induce female-to-male sex reversal, however, the mechanisms underlying gonadal masculinisation are poorly understood. We used histological analyses together with RNA sequencing to characterise zebrafish gonadal transcriptomes and investigate the effects of 17α-methyltestosterone on gonadal differentiation. At a morphological level, 17α-methyltestosterone (MT) masculinised gonads and accelerated spermatogenesis, and these changes were paralleled in masculinisation and de-feminisation of gonadal transcriptomes. MT treatment upregulated expression of genes involved in male sex determination and differentiation (amh, dmrt1, gsdf and wt1a) and those involved in 11-oxygenated androgen production (cyp11c1 and hsd11b2). It also repressed expression of ovarian development and folliculogenesis genes (bmp15, gdf9, figla, zp2.1 and zp3b). Furthermore, MT treatment altered epigenetic modification of histones in zebrafish gonads. Contrary to expectations, higher levels of cyp19a1a or foxl2 expression in control ovaries compared to MT-treated testes and control testes were not statistically significant during early gonad development (40 dpf). Our study suggests that both androgen production and aromatase inhibition are important for androgen-induced gonadal masculinisation and natural testicular differentiation in zebrafish.

  14. Cloning, localization and differential expression of Neuropeptide-Y during early brain development and gonadal recrudescence in the catfish, Clarias gariepinus.

    PubMed

    Sudhakumari, Cheni-Chery; Anitha, Arumugam; Murugananthkumar, Raju; Tiwari, Dinesh Kumar; Bhasker, Dharavath; Senthilkumaran, Balasubramanian; Dutta-Gupta, Aparna

    2017-09-15

    Neuropeptide-Y (NPY) has diverse physiological functions which are extensively studied in vertebrates. However, regulatory role of NPY in relation to brain ontogeny and recrudescence with reference to reproduction is less understood in fish. Present report for the first time evaluated the significance of NPY by transient esiRNA silencing and also analyzed its expression during brain development and gonadal recrudescence in the catfish, Clarias gariepinus. As a first step, full-length cDNA of NPY was cloned from adult catfish brain, which shared high homology with its counterparts from other teleosts upon phylogenetic analysis. Tissue distribution revealed dominant expression of NPY in brain and testis. NPY expression increased during brain development wherein the levels were higher in 100 and 150days post hatch females than the respective age-matched males. Seasonal cycle analysis showed high expression of NPY in brain during pre-spawning phase in comparison with other reproductive phases. Localization studies exhibited the presence of NPY, abundantly, in the regions of preoptic area, hypothalamus and pituitary. Transient silencing of NPY-esiRNA directly into the brain significantly decreased NPY expression in both the male and female brain of catfish which further resulted in significant decrease of transcripts of tryptophan hydroxylase 2, catfish gonadotropin-releasing hormone (cfGnRH), tyrosine hydroxylase and 3β-hydroxysteroid dehydrogenase in brain and luteinizing hormone-β/gonadotropin-II (lh-β/GTH-II) in pituitary exhibiting its influence on gonadal axis. In addition, significant decrease of several ovary-related transcripts was observed in NPY-esiRNA silenced female catfish, indicating the plausible role of NPY in ovary through cfGnRH-GTH axis. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Comparing postnatal development of gonadal hormones and associated social behaviors in rats, mice, and humans.

    PubMed

    Bell, Margaret R

    2018-05-14

    Postnatal development includes dramatic changes in gonadal hormones and the many social behaviors they help regulate, both in rodents and humans. Parental care-seeking is the most salient social interaction in neonates and infants, play and pro-social behaviors are commonly studied in juveniles, and the development of aggression and sexual behavior begins in peripubertal stages but continues through late adolescence into adulthood. While parental behaviors are shown after reproductive success in adulthood, alloparenting behaviors are actually high in juveniles as well. These behaviors are sensitive to both early life organizational effects of gonadal hormones and later life activational regulation. However, changes in circulating gonadal hormones and the display of the above behaviors over development differs between rats, mice and humans. These endpoints are of interest to endocrinologist, toxicologists, neuroscientists because of their relevance to mental health disorders and their vulnerability to effects of endocrine disrupting chemical exposure. As such, the goal of this minireview is to succinctly describe and relate the postnatal development of gonadal hormones and social behaviors to each other, over time and across animal models. Ideally, this will help identify appropriate animal models and age ranges for continued study of both normative development and in contexts of environmental disruption.

  16. GPCRs Direct Germline Development and Somatic Gonad Function in Planarians

    PubMed Central

    Saberi, Amir; Beets, Isabel; Schoofs, Liliane; Newmark, Phillip A.

    2016-01-01

    Planarians display remarkable plasticity in maintenance of their germline, with the ability to develop or dismantle reproductive tissues in response to systemic and environmental cues. Here, we investigated the role of G protein-coupled receptors (GPCRs) in this dynamic germline regulation. By genome-enabled receptor mining, we identified 566 putative planarian GPCRs and classified them into conserved and phylum-specific subfamilies. We performed a functional screen to identify NPYR-1 as the cognate receptor for NPY-8, a neuropeptide required for sexual maturation and germ cell differentiation. Similar to NPY-8, knockdown of this receptor results in loss of differentiated germ cells and sexual maturity. NPYR-1 is expressed in neuroendocrine cells of the central nervous system and can be activated specifically by NPY-8 in cell-based assays. Additionally, we screened the complement of GPCRs with expression enriched in sexually reproducing planarians, and identified an orphan chemoreceptor family member, ophis, that controls differentiation of germline stem cells (GSCs). ophis is expressed in somatic cells of male and female gonads, as well as in accessory reproductive tissues. We have previously shown that somatic gonadal cells are required for male GSC specification and maintenance in planarians. However, ophis is not essential for GSC specification or maintenance and, therefore, defines a secondary role for planarian gonadal niche cells in promoting GSC differentiation. Our studies uncover the complement of planarian GPCRs and reveal previously unappreciated roles for these receptors in systemic and local (i.e., niche) regulation of germ cell development. PMID:27163480

  17. GPCRs Direct Germline Development and Somatic Gonad Function in Planarians.

    PubMed

    Saberi, Amir; Jamal, Ayana; Beets, Isabel; Schoofs, Liliane; Newmark, Phillip A

    2016-05-01

    Planarians display remarkable plasticity in maintenance of their germline, with the ability to develop or dismantle reproductive tissues in response to systemic and environmental cues. Here, we investigated the role of G protein-coupled receptors (GPCRs) in this dynamic germline regulation. By genome-enabled receptor mining, we identified 566 putative planarian GPCRs and classified them into conserved and phylum-specific subfamilies. We performed a functional screen to identify NPYR-1 as the cognate receptor for NPY-8, a neuropeptide required for sexual maturation and germ cell differentiation. Similar to NPY-8, knockdown of this receptor results in loss of differentiated germ cells and sexual maturity. NPYR-1 is expressed in neuroendocrine cells of the central nervous system and can be activated specifically by NPY-8 in cell-based assays. Additionally, we screened the complement of GPCRs with expression enriched in sexually reproducing planarians, and identified an orphan chemoreceptor family member, ophis, that controls differentiation of germline stem cells (GSCs). ophis is expressed in somatic cells of male and female gonads, as well as in accessory reproductive tissues. We have previously shown that somatic gonadal cells are required for male GSC specification and maintenance in planarians. However, ophis is not essential for GSC specification or maintenance and, therefore, defines a secondary role for planarian gonadal niche cells in promoting GSC differentiation. Our studies uncover the complement of planarian GPCRs and reveal previously unappreciated roles for these receptors in systemic and local (i.e., niche) regulation of germ cell development.

  18. Effects of tributyltin on early life-stage, reproduction, and gonadal sex differentiation in Japanese medaka (Oryzias latipes).

    PubMed

    Horie, Yoshifumi; Yamagishi, Takahiro; Shintaku, Yoko; Iguchi, Taisen; Tatarazako, Norihisa

    2018-07-01

    Tributyltin, an organotin compound, was used worldwide as an antifouling agent in aquatic environments and there has been much concern about the toxicological and ecotoxicological properties of organotin compounds. Even though it has been prohibited worldwide, tributyltin is still detected at low concentrations in aquatic environments. Here we investigated the effects of tributyltin on the early life-stage, reproduction, and gonadal sex differentiation in Japanese medaka (Oryzias latipes). In adults, exposure to tributyltin at 3.82 μg/L suppressed fecundity and fertility and increased mortality. At 10.48 μg/L all medaka died by the sixth day of exposure. Exposure to tributyltin during early life-stages induced no significant differences in mortality or embryonic development, but growth was suppressed in groups exposed to 0.13 and 0.68 μg/L. Furthermore, there was no abnormal gonadal development in Japanese medaka exposed to tributyltin. These results provide evidence of the negative effects of tributyltin on reproduction in a teleost fish. Tributyltin did not affect gonadal sex differentiation in Japanese medaka, but fecundity and fertility were suppressed, although it is not clear whether this suppression resulted from the endocrine-disrupting action of tributyltin or its toxicity. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Expression profiling of c-kit and its impact after esiRNA silencing during gonadal development in catfish.

    PubMed

    Laldinsangi, C; Senthilkumaran, B

    2018-04-03

    C-kit receptor is a member of a family of growth factor receptors that have tyrosine kinase activity, and are involved in the transduction of growth regulatory signals across plasma membrane by activation of its ligand, kitl/scf. The present study analysed mRNA and protein expression profiles of c-kit in the gonads of catfish, Clarias gariepinus, using real time PCR, in situ hybridization and immunohistochemistry. Tissue distribution analysis revealed higher expression mainly in the catfish gonads. Ontogeny studies showed minimal expression during early developmental stages and highest during 50-75 days post hatch, and the dimorphic expression in gonads decreased gradually till adulthood, which might suggest an important role for this gene around later stages of sex differentiation and gonadal development. Expression of C-kit was analysed at various phases of gonadal cycle in both male and female, which showed minimal expression during the resting phase, and higher expression in male compared to females during the pre-spawning phase. In vitro and in vivo induction using human chorionic gonadotropin elevated the expression of c-kit indicating the regulatory influence of hypothalamo-hypophyseal axis. In vivo transient gene silencing using c-kit-esiRNA in adult catfish during gonadal recrudescence showed a decrease in c-kit expression, which affected the expression level of germ cell meiotic marker sycp3, as well as several factors and steroidogenic enzyme genes involved in germ cell development. Decrease in the levels of serum 11-KT and T were also observed after esiRNA silencing. The findings of this study suggest that c-kit has an important role in the process of germ cell proliferation, development and maturation during gonadal development and recrudescence in catfish. Copyright © 2018. Published by Elsevier Inc.

  20. The C. elegans VAPB homolog VPR-1 is a permissive signal for gonad development.

    PubMed

    Cottee, Pauline A; Cole, Tim; Schultz, Jessica; Hoang, Hieu D; Vibbert, Jack; Han, Sung Min; Miller, Michael A

    2017-06-15

    VAMP/synaptobrevin-associated proteins (VAPs) contain an N-terminal major sperm protein domain (MSPd) that is associated with amyotrophic lateral sclerosis. VAPs have an intracellular housekeeping function, as well as an extracellular signaling function mediated by the secreted MSPd. Here we show that the C. elegans VAP homolog VPR-1 is essential for gonad development. vpr-1 null mutants are maternal effect sterile due to arrested gonadogenesis following embryo hatching. Somatic gonadal precursor cells and germ cells fail to proliferate fully and complete their respective differentiation programs. Maternal or zygotic vpr-1 expression is sufficient to induce gonadogenesis and fertility. Genetic mosaic and cell type-specific expression studies indicate that vpr-1 activity is important in the nervous system, germ line and intestine. VPR-1 acts in parallel to Notch signaling, a key regulator of germline stem cell proliferation and differentiation. Neuronal vpr-1 expression is sufficient for gonadogenesis induction during a limited time period shortly after hatching. These results support the model that the secreted VPR-1 MSPd acts at least in part on gonadal sheath cell precursors in L1 to early L2 stage hermaphrodites to permit gonadogenesis. © 2017. Published by The Company of Biologists Ltd.

  1. The C. elegans VAPB homolog VPR-1 is a permissive signal for gonad development

    PubMed Central

    Cole, Tim; Hoang, Hieu D.; Han, Sung Min

    2017-01-01

    VAMP/synaptobrevin-associated proteins (VAPs) contain an N-terminal major sperm protein domain (MSPd) that is associated with amyotrophic lateral sclerosis. VAPs have an intracellular housekeeping function, as well as an extracellular signaling function mediated by the secreted MSPd. Here we show that the C. elegans VAP homolog VPR-1 is essential for gonad development. vpr-1 null mutants are maternal effect sterile due to arrested gonadogenesis following embryo hatching. Somatic gonadal precursor cells and germ cells fail to proliferate fully and complete their respective differentiation programs. Maternal or zygotic vpr-1 expression is sufficient to induce gonadogenesis and fertility. Genetic mosaic and cell type-specific expression studies indicate that vpr-1 activity is important in the nervous system, germ line and intestine. VPR-1 acts in parallel to Notch signaling, a key regulator of germline stem cell proliferation and differentiation. Neuronal vpr-1 expression is sufficient for gonadogenesis induction during a limited time period shortly after hatching. These results support the model that the secreted VPR-1 MSPd acts at least in part on gonadal sheath cell precursors in L1 to early L2 stage hermaphrodites to permit gonadogenesis. PMID:28634273

  2. A novel morphological approach to gonads in disorders of sex development.

    PubMed

    Lepais, Laureline; Morel, Yves; Mouriquand, Pierre; Gorduza, Daniela; Plotton, Ingrid; Collardeau-Frachon, Sophie; Dijoud, Frédérique

    2016-11-01

    Disorders of sex development are defined as congenital conditions with discordance between the phenotype, the genotype, the karyotype, and the hormonal profile. The disorders of sex development consensus classification established in 2005 are mainly based on chromosomal and biological data. However, histological anomalies are not considered. The aims of this study were to define the specific pathological features of gonads in various groups of disorders of sex development in order to clarify the nosology of histological findings and to evaluate the tumor risk in case of a conservative approach. One hundred and seventy-five samples from 86 patients with disorders of sex development were analyzed following a strict histological reading protocol. The term 'gonadal dysgenesis' for the histological analysis was found confusing and therefore excluded. The concept of 'dysplasia' was subsequently introduced in order to describe the architectural disorganization of the gonad (various degrees of irregular seminiferous tubules, thin albuginea, fibrous interstitium). Five histological types were identified: normal gonad, hypoplastic testis, dysplastic testis, streak gonad, and ovotestis. The analysis showed an association between undifferentiated gonadal tissue, a potential precursor of gonadoblastoma, and dysplasia. Dysplasia and undifferentiated gonadal tissue were only encountered in cases of genetic or chromosomal abnormality ('dysgenesis' groups in the disorders of sex development consensus classification). 'Dysgenetic testes', related to an embryonic malformation of the gonad, have variable histological presentations, from normal to streak. Conversely, gonads associated with hormonal deficiencies always display a normal architecture. A loss of expression of AMH and α-inhibin was identified in dysplastic areas. Foci of abnormal expression of the CD117 and OCT4 immature germ cells markers in dysplasia and undifferentiated gonadal tissue were associated with an increased

  3. Transcriptome analysis identifies genes involved in sex determination and development of Xenopus laevis gonads.

    PubMed

    Piprek, Rafal P; Damulewicz, Milena; Kloc, Malgorzata; Kubiak, Jacek Z

    Development of the gonads is a complex process, which starts with a period of undifferentiated, bipotential gonads. During this period the expression of sex-determining genes is initiated. Sex determination is a process triggering differentiation of the gonads into the testis or ovary. Sex determination period is followed by sexual differentiation, i.e. appearance of the first testis- and ovary-specific features. In Xenopus laevis W-linked DM-domain gene (DM-W) had been described as a master determinant of the gonadal female sex. However, the data on the expression and function of other genes participating in gonad development in X. laevis, and in anurans, in general, are very limited. We applied microarray technique to analyze the expression pattern of a subset of X. laevis genes previously identified to be involved in gonad development in several vertebrate species. We also analyzed the localization and the expression level of proteins encoded by these genes in developing X. laevis gonads. These analyses pointed to the set of genes differentially expressed in developing testes and ovaries. Gata4, Sox9, Dmrt1, Amh, Fgf9, Ptgds, Pdgf, Fshr, and Cyp17a1 expression was upregulated in developing testes, while DM-W, Fst, Foxl2, and Cyp19a1 were upregulated in developing ovaries. We discuss the possible roles of these genes in development of X. laevis gonads. Copyright © 2018 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

  4. Body size and symbiotic status influence gonad development in Aiptasia pallida anemones.

    PubMed

    Carlisle, Judith F; Murphy, Grant K; Roark, Alison M

    2017-01-01

    Pale anemones ( Aiptasia pallida ) coexist with dinoflagellates (primarily Symbiodinium minutum ) in a mutualistic relationship. The purpose of this study was to investigate the role of these symbionts in gonad development of anemone hosts. Symbiotic and aposymbiotic anemones were subjected to light cycles that induced gametogenesis. These anemones were then sampled weekly for nine weeks, and gonad development was analyzed histologically. Anemone size was measured as mean body column diameter, and oocytes or sperm follicles were counted for each anemone. Generalized linear models were used to evaluate the influence of body size and symbiotic status on whether gonads were present and on the number of oocytes or sperm follicles produced. Body size predicted whether gonads were present, with larger anemones being more likely than smaller anemones to develop gonads. Both body size and symbiotic status predicted gonad size, such that larger and symbiotic anemones produced more oocytes and sperm follicles than smaller and aposymbiotic anemones. Overall, only 22 % of aposymbiotic females produced oocytes, whereas 63 % of symbiotic females produced oocytes. Similarly, 6 % of aposymbiotic males produced sperm follicles, whereas 60 % of symbiotic males produced sperm follicles. Thus, while gonads were present in 62 % of symbiotic anemones, they were present in only 11 % of aposymbiotic anemones. These results indicate that dinoflagellate symbionts influence gonad development and thus sexual maturation in both female and male Aiptasia pallida anemones. This finding substantiates and expands our current understanding of the importance of symbionts in the development and physiology of cnidarian hosts.

  5. Decision Processes During Development of Molecular Biomarkers for Gonadal Phenotypic Sex

    EPA Science Inventory

    Molecular biomarkers for determination of gonadal phenotypic sex in the Japanese medaka (Oryzias latipes), will serve as a case study. The medaka has unique features that aid in the development of appropriate molecular biomarkers of gonad phenotype, a) genetic sex can be determin...

  6. Dimorphic expression of sex-related genes in different gonadal development stages of sterlet, Acipenser ruthenus, a primitive fish species.

    PubMed

    Wang, Wei; Zhu, Hua; Dong, Ying; Tian, ZhaoHui; Dong, Tian; Hu, HongXia; Niu, CuiJuan

    2017-12-01

    Molecular mechanism of sex determination and differentiation of sturgeon, a primitive fish species, is extraordinarily important due to the valuable caviar; however, it is still poorly known. The present work aimed to identify the major genes involved in regulating gonadal development of sterlet, a small species of sturgeon, from 13 candidate genes which have been shown to relate to gonadal differentiation and development in other teleost fish. The sex and gonadal development of sterlets were determined by histological observation and levels of sex steroids testosterone (T), 11-ketotestosterone (11-KT), and 17β-estradiol (E2) in serum. Sexually dimorphic gene expressions were investigated. The results revealed that gonadal development were asynchronous in 2-year-old male and female sterlets with the testes in early or mid-spermatogenesis and the ovaries in chromatin nucleolus stage or perinucleolus stage, respectively. The levels of T and E2 were not significantly different between sexes or different gonadal development stages while 11-KT had the higher level in mid-spermatogenesis testis stage. In all the investigated gonadal development stages, gene dmrt1 and hsd11b2 were expressed higher in male whereas foxl2 and cyp19a1 were expressed higher in female. Thus, these genes provided the promising markers for sex identification of sterlet. It was unexpected that dkk1 and dax1 had significantly higher expression in ovarian perinucleolus stage than in ovarian chromatin nucleolus stage and in the testis, suggesting that these two genes had more correlation with ovarian development than with the testis, contrary to the previous reports in other vertebrates. Testicular development-related genes (gsdf and amh) and estrogen receptor genes (era and erb) differentially expressed at different testis or ovary development stages, but their expressions were not absolutely significantly different in male and female, depending on the gonadal development stage. Expression of

  7. Effect of early thermal experience on pituitary-gonadal axis in female rats.

    PubMed

    Kurowicka, Beata; Gajewska, Alina; Franczak, Anita

    2006-03-01

    The reproductive system fully develops during postnatal stages of life, and as such it may be susceptible to environmental cues such as high temperature. Thus, the purpose of the study was to compare how exposure to 34 degrees Celsius ambient temperature affects pituitary-gonadal axis of immature and adult female rats. Three groups of females at proestrous or metaestrous (n=38) were used in the study. The females were housed in ambient temperature of 34 degrees Celsius (WR group, n=10) or room temperature (CR group, n=16) from birth to adulthood. The females from the third group were acclimated to 34 degrees Celsius as adults (WA group, n=12). In the WR group the onset of puberty was delayed in comparison to the CR group. The plasma PRL level was lower during proestrous and higher during metaestrous in the WR group compared to the CR group. During metaestrous, lower FSH and higher progesterone (P(4)) plasma concentrations were found in the WR females. No changes in LH and oestradiol (E(2)) plasma concentrations were demonstrated. Higher in vitro E(2) and lower P(4) secretions under FSH stimulation were observed in the WR follicles compared to those of the CR group. The WR group also demonstrated higher basal and LH-stimulated luteal in vitro secretion of P(4) than controls. Plasma LH and FSH concentrations during metaestrous were higher in WA females than in the WR group, but PRL level was lower. Follicles of the WA group were unresponsive to FSH with respect to steroid secretion. In addition, LH stimulated luteal E(2) secretion in this group. P(4) release by luteal cells was lower in the WA than in the WR group. We concluded that WR females differ from WA in reproductive system adjustments to rearing temperature and that early thermal experience is more effective in antagonizing the effect of high temperature than acclimation of adult females.

  8. The organizing actions of adolescent gonadal steroid hormones on brain and behavioral development.

    PubMed

    Schulz, Kalynn M; Sisk, Cheryl L

    2016-11-01

    Adolescence is a developmental period characterized by dramatic changes in cognition, risk-taking and social behavior. Although gonadal steroid hormones are well-known mediators of these behaviors in adulthood, the role gonadal steroid hormones play in shaping the adolescent brain and behavioral development has only come to light in recent years. Here we discuss the sex-specific impact of gonadal steroid hormones on the developing adolescent brain. Indeed, the effects of gonadal steroid hormones during adolescence on brain structure and behavioral outcomes differs markedly between the sexes. Research findings suggest that adolescence, like the perinatal period, is a sensitive period for the sex-specific effects of gonadal steroid hormones on brain and behavioral development. Furthermore, evidence from studies on male sexual behavior suggests that adolescence is part of a protracted postnatal sensitive period that begins perinatally and ends following adolescence. As such, the perinatal and peripubertal periods of brain and behavioral organization likely do not represent two discrete sensitive periods, but instead are the consequence of normative developmental timing of gonadal hormone secretions in males and females. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. The organizing actions of adolescent gonadal steroid hormones on brain and behavioral development

    PubMed Central

    Schulz, Kalynn M.; Sisk, Cheryl L.

    2016-01-01

    Adolescence is a developmental period characterized by dramatic changes in cognition, risk-taking and social behavior. Although gonadal steroid hormones are well-known mediators of these behaviors in adulthood, the role gonadal steroid hormones play in shaping the adolescent brain and behavioral development has only come to light in recent years. Here we discuss the sex-specific impact of gonadal steroid hormones on the developing adolescent brain. Indeed, the effects of gonadal steroid hormones during adolescence on brain structure and behavioral outcomes differs markedly between the sexes. Research findings suggest that adolescence, like the perinatal period, is a sensitive period for the sex-specific effects of gonadal steroid hormones on brain and behavioral development. Furthermore, evidence from studies on male sexual behavior suggests that adolescence is part of a protracted postnatal sensitive period that begins perinatally and ends following adolescence. As such, the perinatal and peripubertal periods of brain and behavioral organization likely do not represent two discrete sensitive periods, but instead are the consequence of normative developmental timing of gonadal hormone secretions in males and females. PMID:27497718

  10. An XRCC4 Splice Mutation Associated With Severe Short Stature, Gonadal Failure, and Early-Onset Metabolic Syndrome

    PubMed Central

    de Bruin, Christiaan; Mericq, Verónica; Andrew, Shayne F.; van Duyvenvoorde, Hermine A.; Verkaik, Nicole S.; Losekoot, Monique; Porollo, Aleksey; Garcia, Hernán; Kuang, Yi; Hanson, Dan; Clayton, Peter; van Gent, Dik C.; Wit, Jan M.; Hwa, Vivian

    2015-01-01

    Context: Severe short stature can be caused by defects in numerous biological processes including defects in IGF-1 signaling, centromere function, cell cycle control, and DNA damage repair. Many syndromic causes of short stature are associated with medical comorbidities including hypogonadism and microcephaly. Objective: To identify an underlying genetic etiology in two siblings with severe short stature and gonadal failure. Design: Clinical phenotyping, genetic analysis, complemented by in vitro functional studies of the candidate gene. Setting: An academic pediatric endocrinology clinic. Patients or Other Participants: Two adult siblings (male patient [P1] and female patient 2 [P2]) presented with a history of severe postnatal growth failure (adult heights: P1, −6.8 SD score; P2, −4 SD score), microcephaly, primary gonadal failure, and early-onset metabolic syndrome in late adolescence. In addition, P2 developed a malignant gastrointestinal stromal tumor at age 28. Intervention(s): Single nucleotide polymorphism microarray and exome sequencing. Results: Combined microarray analysis and whole exome sequencing of the two affected siblings and one unaffected sister identified a homozygous variant in XRCC4 as the probable candidate variant. Sanger sequencing and mRNA studies revealed a splice variant resulting in an in-frame deletion of 23 amino acids. Primary fibroblasts (P1) showed a DNA damage repair defect. Conclusions: In this study we have identified a novel pathogenic variant in XRCC4, a gene that plays a critical role in non-homologous end-joining DNA repair. This finding expands the spectrum of DNA damage repair syndromes to include XRCC4 deficiency causing severe postnatal growth failure, microcephaly, gonadal failure, metabolic syndrome, and possibly tumor predisposition. PMID:25742519

  11. Copy Number Variation in Patients with Disorders of Sex Development Due to 46,XY Gonadal Dysgenesis

    PubMed Central

    White, Stefan; Ohnesorg, Thomas; Notini, Amanda; Roeszler, Kelly; Hewitt, Jacqueline; Daggag, Hinda; Smith, Craig; Turbitt, Erin; Gustin, Sonja; van den Bergen, Jocelyn; Miles, Denise; Western, Patrick; Arboleda, Valerie; Schumacher, Valerie; Gordon, Lavinia; Bell, Katrina; Bengtsson, Henrik; Speed, Terry; Hutson, John; Warne, Garry; Harley, Vincent; Koopman, Peter; Vilain, Eric; Sinclair, Andrew

    2011-01-01

    Disorders of sex development (DSD), ranging in severity from mild genital abnormalities to complete sex reversal, represent a major concern for patients and their families. DSD are often due to disruption of the genetic programs that regulate gonad development. Although some genes have been identified in these developmental pathways, the causative mutations have not been identified in more than 50% 46,XY DSD cases. We used the Affymetrix Genome-Wide Human SNP Array 6.0 to analyse copy number variation in 23 individuals with unexplained 46,XY DSD due to gonadal dysgenesis (GD). Here we describe three discrete changes in copy number that are the likely cause of the GD. Firstly, we identified a large duplication on the X chromosome that included DAX1 (NR0B1). Secondly, we identified a rearrangement that appears to affect a novel gonad-specific regulatory region in a known testis gene, SOX9. Surprisingly this patient lacked any signs of campomelic dysplasia, suggesting that the deletion affected expression of SOX9 only in the gonad. Functional analysis of potential SRY binding sites within this deleted region identified five putative enhancers, suggesting that sequences additional to the known SRY-binding TES enhancer influence human testis-specific SOX9 expression. Thirdly, we identified a small deletion immediately downstream of GATA4, supporting a role for GATA4 in gonad development in humans. These CNV analyses give new insights into the pathways involved in human gonad development and dysfunction, and suggest that rearrangements of non-coding sequences disturbing gene regulation may account for significant proportion of DSD cases. PMID:21408189

  12. Rapid Change of Microbiota Diversity in the Gut but Not the Hepatopancreas During Gonadal Development of the New Shrimp Model Neocaridina denticulata.

    PubMed

    Cheung, Man Kit; Yip, Ho Yin; Nong, Wenyan; Law, Patrick Tik Wan; Chu, Ka Hou; Kwan, Hoi Shan; Hui, Jerome Ho Lam

    2015-12-01

    During evolution of animals, their co-evolution with bacteria has generally been ignored. Recent studies have provided evidences that the symbiotic bacteria in the animal gut can either be essential or contributing to the plasticity of the host. The Crustacea includes crab, crayfish, lobster, and shrimp and represents the second largest subphylum on the planet. Although there are already studies investigating the intestinal bacterial communities in crustaceans, none of them has examined the microbiota in different parts of the digestive system during the gonad development of the host. Here, we utilized a new shrimp model Neocaridina denticulata and sequenced the 16S rRNA using the Ion Torrent platform to survey the bacterial populations colonizing the hepatopancreas, foregut, and intestine, including midgut and hindgut, of the early, mid, and late ovarian maturation stages of the shrimp. The predominant bacteria phylum was found to be Proteobacteria, with more than 80 % reads from the gut flora at the early gonad development belonged to a Coxiella-type bacterium. Distinct bacterial communities can be detected between the hepatopancreas and gut, although no significant difference could be revealed between the different regions of the gut investigated. Surprisingly, during the gonad development, bacterial diversity changed rapidly in the gut but not the hepatopancreas. This study provides the first evidence that microbiota modified differentially in specific regions of the digestive tract during gonadal development of crustaceans.

  13. Adrenal-kidney-gonad complex measurements may not predict gonad-specific changes in gene expression patterns during temperature-dependent sex determination in the red-eared slider turtle (Trachemys scripta elegans).

    PubMed

    Ramsey, Mary; Crews, David

    2007-08-01

    Many turtles, including the red-eared slider turtle (Trachemys scripta elegans) have temperature-dependent sex determination in which gonadal sex is determined by temperature during the middle third of incubation. The gonad develops as part of a heterogenous tissue complex that comprises the developing adrenal, kidney, and gonad (AKG complex). Owing to the difficulty in excising the gonad from the adjacent tissues, the AKG complex is often used as tissue source in assays examining gene expression in the developing gonad. However, the gonad is a relatively small component of the AKG, and gene expression in the adrenal-kidney (AK) compartment may interfere with the detection of gonad-specific changes in gene expression, particularly during early key phases of gonadal development and sex determination. In this study, we examine transcript levels as measured by quantitative real-time polymerase chain reaction for five genes important in slider turtle sex determination and differentiation (AR, ERalpha, ERbeta, aromatase, and Sf1) in AKG, AK, and isolated gonad tissues. In all cases, gonad-specific gene expression patterns were attenuated in AKG versus gonad tissue. All five genes were expressed in the AK in addition to the gonad at all stages/temperatures. Inclusion of the AK compartment masked important changes in gonadal gene expression. In addition, AK and gonad expression patterns are not additive, and gonadal gene expression cannot be predicted from intact AKG measurements. (c) 2007 Wiley-Liss, Inc.

  14. Intersex gonads in frogs: understanding the time course of natural development and role of endocrine disruptors.

    PubMed

    Storrs-Méndez, Sara I; Semlitsch, Raymond D

    2010-01-15

    The paucity of data on sexual development of anuran amphibians has played an important role in the recent controversy over atrazine exposure. Although some studies have demonstrated the presence of abnormal gonads in control treatments, others have not, leading to varying interpretations of the effects of atrazine exposure on sexual development. However, the timing of development varies among anuran amphibians such that, at any snapshot in time, different species may exhibit different stages of sexual differentiation. We examined three species representing each of the differentiation rates (Bufo americanus=retarded rate; Hyla versicolor=basic rate; Rana sphenocephala=accelerated rate), to examine the natural time course of sexual development along with the influence of atrazine exposure. For each species, exposure to atrazine (1, 3, 10, 30 parts per billion), 17-beta-estradiol or control water occurred throughout larval life. Gonad histology was performed at 3-week intervals during the larval period or at a juvenile stage to examine the proportion of males, females, underdeveloped testes, testicular oocytes (TO; testes with 0-30% oocytes), and ovotestes (OVTs; testes with>30% oocytes). Our results illustrate that a phase of intersex gonads (TO or OVT) is normal during R. sphenocephala sexual development, a species representing the accelerated differentiation rate. Further, intersex gonads were found in juvenile stages of B. americanus and H. versicolor, representing retarded and basic rates, respectively, suggesting that a phase of intersex may be common regardless of differentiation rate. Moreover, these data highlight the importance of longitudinal studies rather than snapshots in time. (c) 2009 Wiley-Liss, Inc.

  15. Disorders of sexual development and associated changes in the pituitary-gonadal axis in dogs.

    PubMed

    Buijtels, J J C W M; de Gier, J; Kooistra, H S; Grinwis, G C M; Naan, E C; Zijlstra, C; Okkens, A C

    2012-10-15

    Normal sexual differentiation depends on completion of chromosomal sex determination, gonadal differentiation, and development of the phenotypic sex. An irregularity in any of these three steps can lead to a disorder in sexual development (DSD). We examined nine dogs with DSD by abdominal ultrasonography, laparotomy, histologic examination of the gonads, and reproductive tract, cytogenetic analysis, and mRNA expression of the SRY gene. We also determined the plasma concentrations of luteinizing hormone (LH), estradiol-17β, and testosterone before and after administration of gonadotropin-releasing hormone (GnRH) and compared these results with those obtained in anestrous bitches and male control dogs. The gonads of three dogs with DSD contained both testicular and ovarian tissue, while in the other six only testicular tissue was found. Each of the dogs had a uterus. Based on gynecologic examination, cytogenetic analysis, and the histology of the gonads, seven of the nine dogs appeared to be XX sex reversals. Three of these were XX true hermaphrodites and four were XX males; the other two dogs had incomplete XY gonadal dysgenesis. All seven XX sex-reversed dogs were found to be negative for the SRY gene by polymerase chain reaction. The basal plasma luteinizing hormone (LH) concentration was significantly higher in dogs with DSD than in anestrous bitches but not significantly different from that in male dogs. The basal plasma LH concentration increased significantly after GnRH administration in all dogs with DSD. The basal plasma estradiol concentration was significantly higher in dogs with DSD than in anestrous bitches but not significantly different from that in male dogs. The basal plasma testosterone concentration was lower in dogs with DSD than in male dogs. In all dogs with DSD both the basal and GnRH-induced plasma testosterone concentrations were above the upper limit of their respective ranges in the anestrous bitches. In conclusion, the secretion of LH and

  16. An Unusual Presentation of 46,XY Pure Gonadal Dysgenesis: Spontaneous Breast Development and Menstruation

    PubMed Central

    Çatlı, Gönül; Alparslan, Caner; Can, P. Şule; Akbay, Sinem; Kelekçi, Sefa; Atik, Tahir; Özyılmaz, Berk; Dündar, Bumin N.

    2015-01-01

    46,XY pure gonadal dysgenesis (Swyer syndrome) is characterized by normal female genitalia at birth. It usually first becomes apparent in adolescence with delayed puberty and amenorrhea. Rarely, patients can present with spontaneous breast development and/or menstruation. A fifteen-year-old girl presented to our clinic with the complaint of primary amenorrhea. On physical examination, her external genitals were completely female. Breast development and pubic hair were compatible with Tanner stage V. Hormonal evaluation revealed a hypergonadotropic state despite a normal estrogen level. Chromosome analysis revealed a 46,XY karyotype. Pelvic ultrasonography showed small gonads and a normal sized uterus for age. SRY gene expression was confirmed by multiplex polymerase chain reaction. Direct sequencing on genomic DNA did not reveal a mutation in the SRY, SF1 and WT1 genes. After the diagnosis of Swyer syndrome was made, the patient started to have spontaneous menstrual cycles and therefore failed to attend her follow-up visits. After nine months, the patient underwent diagnostic laparoscopy. Frozen examination of multiple biopsies from gonad tissues revealed gonadoblastoma. With this report, we emphasize the importance of performing karyotype analysis, which is diagnostic for Swyer syndrome, in all cases with primary or secondary amenorrhea even in the presence of normal breast development. We also suggest that normal pubertal development in patients with Swyer syndrome may be associated with the presence of a hormonally active tumor. PMID:26316442

  17. An Unusual Presentation of 46,XY Pure Gonadal Dysgenesis: Spontaneous Breast Development and Menstruation.

    PubMed

    Çatlı, Gönül; Alparslan, Caner; Can, P Şule; Akbay, Sinem; Kelekçi, Sefa; Atik, Tahir; Özyılmaz, Berk; Dündar, Bumin N

    2015-06-01

    46,XY pure gonadal dysgenesis (Swyer syndrome) is characterized by normal female genitalia at birth. It usually first becomes apparent in adolescence with delayed puberty and amenorrhea. Rarely, patients can present with spontaneous breast development and/or menstruation. A fifteen-year-old girl presented to our clinic with the complaint of primary amenorrhea. On physical examination, her external genitals were completely female. Breast development and pubic hair were compatible with Tanner stage V. Hormonal evaluation revealed a hypergonadotropic state despite a normal estrogen level. Chromosome analysis revealed a 46,XY karyotype. Pelvic ultrasonography showed small gonads and a normal sized uterus for age. SRY gene expression was confirmed by multiplex polymerase chain reaction. Direct sequencing on genomic DNA did not reveal a mutation in the SRY, SF1 and WT1 genes. After the diagnosis of Swyer syndrome was made, the patient started to have spontaneous menstrual cycles and therefore failed to attend her follow-up visits. After nine months, the patient underwent diagnostic laparoscopy. Frozen examination of multiple biopsies from gonad tissues revealed gonadoblastoma. With this report, we emphasize the importance of performing karyotype analysis, which is diagnostic for Swyer syndrome, in all cases with primary or secondary amenorrhea even in the presence of normal breast development. We also suggest that normal pubertal development in patients with Swyer syndrome may be associated with the presence of a hormonally active tumor.

  18. Histological development of the gonad in juvenile Xenopus laevis

    EPA Science Inventory

    As directed by the Food Quality Protection Act, the US Environmental Protection Agency is developing a screening program for endocrine disrupting compounds. The Larval Amphibian Growth and Development Assay (LAGDA) is a tier II test intended to identify and characterize the adver...

  19. A timecourse analysis of systemic and gonadal effects of temperature on sexual development of the red-eared slider turtle Trachemys scripta elegans.

    PubMed

    Czerwinski, Michael; Natarajan, Anirudh; Barske, Lindsey; Looger, Loren L; Capel, Blanche

    2016-12-01

    Temperature dependent sex determination (TSD) is the process by which the environmental temperature experienced during embryogenesis influences the sex of an organism, as in the red-eared slider turtle Trachemys scripta elegans. In accord with current paradigms of vertebrate sex determination, temperature is believed to exert its effects on sexual development in T. scripta entirely within the middle third of development, when the gonad is forming. However, whether temperature regulates the transcriptome in T. scripta early embryos in a manner that could influence secondary sex characteristics or establish a pro-male or pro-female environment has not been investigated. In addition, apart from a handful of candidate genes, very little is known about potential similarities between the expression cascade during TSD and the genetic cascade that drives mammalian sex determination. Here, we conducted an unbiased transcriptome-wide analysis of the effects of male- and female-promoting temperatures on the turtle embryo prior to gonad formation, and on the gonad during the temperature sensitive period. We found sexually dimorphic expression reflecting differences in steroidogenic enzymes and brain development prior to gonad formation. Within the gonad, we mapped a cascade of differential expression similar to the genetic cascade established in mammals. Using a Hidden Markov Model based clustering approach, we identified groups of genes that show heterochronic shifts between M. musculus and T. scripta. We propose a model in which multiple factors influenced by temperature accumulate during early gonadogenesis, and converge on the antagonistic regulation of aromatase to canalize sex determination near the end of the temperature sensitive window of development. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Involvement of Antizyme Characterized from the Small Abalone Haliotis diversicolor in Gonadal Development.

    PubMed

    Li, Wei-Dong; Huang, Min; Lü, Wen-Gang; Chen, Xiao; Shen, Ming-Hui; Li, Xiang-Min; Wang, Rong-Xia; Ke, Cai-Huan

    2015-01-01

    The small abalone Haliotis diversicolor is an economically important mollusk that is widely cultivated in Southern China. Gonad precocity may affect the aquaculture of small abalone. Polyamines, which are small cationic molecules essential for cellular proliferation, may affect gonadal development. Ornithine decarboxylase (ODC) and antizyme (AZ) are essential elements of a feedback circuit that regulates cellular polyamines. This paper presents the molecular cloning and characterization of AZ from small abalone. Sequence analysis showed that the cDNA sequence of H. diversicolor AZ (HdiODCAZ) consisted of two overlapping open reading frames (ORFs) and conformed to the +1 frameshift property of the frame. Thin Layer chromatography (TLC) analysis suggested that the expressed protein encoded by +1 ORF2 was the functional AZ that targets ODC to 26S proteasome degradation. The result demonstrated that the expression level of AZ was higher than that of ODC in the ovary of small abalone. In addition, the expression profiles of ODC and AZ at the different development stages of the ovary indicated that these two genes might be involved in the gonadal development of small abalone.

  1. Involvement of Antizyme Characterized from the Small Abalone Haliotis diversicolor in Gonadal Development

    PubMed Central

    Lü, Wen-Gang; Chen, Xiao; Shen, Ming-Hui; Li, Xiang-Min; Wang, Rong-Xia; Ke, Cai-Huan

    2015-01-01

    The small abalone Haliotis diversicolor is an economically important mollusk that is widely cultivated in Southern China. Gonad precocity may affect the aquaculture of small abalone. Polyamines, which are small cationic molecules essential for cellular proliferation, may affect gonadal development. Ornithine decarboxylase (ODC) and antizyme (AZ) are essential elements of a feedback circuit that regulates cellular polyamines. This paper presents the molecular cloning and characterization of AZ from small abalone. Sequence analysis showed that the cDNA sequence of H. diversicolor AZ (HdiODCAZ) consisted of two overlapping open reading frames (ORFs) and conformed to the +1 frameshift property of the frame. Thin Layer chromatography (TLC) analysis suggested that the expressed protein encoded by +1 ORF2 was the functional AZ that targets ODC to 26S proteasome degradation. The result demonstrated that the expression level of AZ was higher than that of ODC in the ovary of small abalone. In addition, the expression profiles of ODC and AZ at the different development stages of the ovary indicated that these two genes might be involved in the gonadal development of small abalone. PMID:26313647

  2. A practical guide for evaluating gonadal germ cell tumor predisposition in differences of sex development.

    PubMed

    Pyle, Louise C; Nathanson, Katherine L

    2017-06-01

    Differences of Sex Development (DSD) includes a wide spectrum of etiologies and phenotypes. A subset of individuals with DSDs are predisposed to gonadal germ cell tumor (GCT). In this setting, GCT risk varies widely, depending on the DSD molecular etiology and penetrance. Prognostication based on molecular diagnosis remains challenging, as natural history data specific to recently identified molecular causes of DSD is lacking. In this review, we provide a framework for the clinical geneticist to consider GCT tumor risk in the patient with DSD. We discuss germ cell development and etiology of GCT growth, along with parameters to consider when recommending prophylactic gonadectomy including fertility, hormonal output, and malignant GTC treatment outcomes. Shortly after the 2006 reorganization of DSD nomenclature, literature reviews of natural history publications stratified GCT risk by a chromosomal, pathological, and hormonal taxonomy. Our 2017 literature review reveals a larger body of publications. However, the broad DSD GCT risk stratification within the 2006 taxonomy remains stable. We discuss precise GCT risk assessment for specific diagnoses, including androgen insensitivity, Smith-Lemli-Opitz, and 46,XY with MAP3K1 mutations and gonadal dysgenesis, as examples. We also examine the GCT risk in non-DSD syndromes, in addition to the cancer risks in DSD patients with dimorphic gonads and genitalia. This review is intended to provide a nuanced assessment of relative germ cell tumor risk in the DSD patient, including modern precise molecular diagnosis, for use by the clinical geneticist. © 2017 Wiley Periodicals, Inc.

  3. Gonad morphology, oocyte development and spawning cycle of the calanoid copepod Acartia clausi

    NASA Astrophysics Data System (ADS)

    Eisfeld, Sonja M.; Niehoff, Barbara

    2007-09-01

    Information on gonad morphology and its relation to basic reproductive parameters such as clutch size and spawning frequency is lacking for Acartia clausi, a dominant calanoid copepod of the North Sea. To fill this gap, females of this species were sampled at Helgoland Roads from mid March to late May 2001. Gonad structure and oogenesis were studied using a combination of histology and whole-body-analysis. In addition, clutch size and spawning frequency were determined in incubation experiments, during which individual females were monitored at short intervals for 8 and 12 h, respectively. The histological analysis revealed that the ovary of A. clausi is w-shaped with two distinct tips pointing posteriorly. It is slightly different from that of other Acartia species and of other copepod taxa. From the ovary, two anterior diverticula extend into the head region, and two posterior diverticula extend to the genital opening in the abdomen. Developing oocytes change in shape and size, and in the appearance of the nucleus and the ooplasm. Based on these morphological characteristics, different oocyte development stages (OS) were identified. Mitotically dividing oogonia and young oocytes (OS 0) were restricted to the ovary, whereas vitellogenic oocytes (OS 1 4) were present in the diverticula. The development stage of the oocytes increased with distance to the ovary in both, anterior and posterior diverticula. Most advanced oocytes were situated ventrally, and their number varied between 1 and 18, at a median of 4. All oocyte development stages co-occur indicating that oogenesis in A. clausi is a continuous process. These morphological features reflect the reproductive traits of this species. In accordance with the low numbers of mature oocytes in the gonads, females usually produced small clutches of one to five eggs. Clutches were released throughout the entire observation period at intervals of 90 min (median) resulting in mean egg production rates of 18 28 eggs female

  4. Sry and SoxE genes: How they participate in mammalian sex determination and gonadal development?

    PubMed

    She, Zhen-Yu; Yang, Wan-Xi

    2017-03-01

    In mammals, sex determination defines the differentiation of the bipotential genital ridge into either testes or ovaries. Sry, the mammalian Y-chromosomal testis-determining gene, is a master regulator of male sex determination. It acts to switch the undifferentiated genital ridge towards testis development, triggering the adoption of a male fate. Sry initiates a cascade of gene networks through the direct regulation of Sox9 expression and promotes supporting cell differentiation, Leydig cell specification, vasculature formation and testis cord development. In the absence of Sry, alternative genetic cascades, including female sex-determining genes RSPO1, Wnt4/β-catenin and Foxl2, are involved in the formation of female genitalia and the maintenance of female ovarian development. The mutual antagonisms between male and female sex-determining pathways are crucial in not just the initiation but also the maintenance of the somatic sex of the gonad throughout the organism's lifetime. Any imbalances in above sex-determining genes can cause disorders of sex development in humans and mice. In this review, we provide a detailed summary of the expression profiles, biochemical properties and developmental functions of Sry and SoxE genes in embryonic testis development and adult gonadal development. We also briefly summarize the dedicate balances between male and female sex-determining genes in mammalian sex development, with particular highlights on the molecular actions of Sry and Sox9 transcription factors. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Roles of GATA6 during Gonadal Development in Japanese Flounder: Gonadogenesis, Regulation of Gender-Related Genes, Estrogen Formation and Gonadal Function Maintenance.

    PubMed

    Li, Zan; Liu, Xiumei; Sun, Yan; Liu, Jinxiang; Liu, Yuezhong; Wang, Mengxun; Zhang, Quanqi; Wang, Xubo

    2017-01-16

    GATA-binding protein 6 (GATA6), a highly-conserved transcription factor of the GATA family plays an important role in gonadal cell proliferation, differentiation and endoderm development. In this study, the full-length cDNA of GATA6 of Paralichthys olivaceus (Japanese flounder) was obtained. Phylogenetic, gene structure and synteny analyses demonstrated that GATA6 of P. olivaceus is homologous to that of teleosts and tetrapods. The P. olivaceus GATA6 transcript showed higher expression in testis than in ovary, demonstrating a sexually dimorphic gene expression. During embryonic development, the expression of P. olivaceus GATA6 increased at the blastula stage, demonstrating that GATA6 is involved in morphogenesis. Results of in situ hybridization showed that GATA6 signals were detected in Sertoli cells, oogonia and oocytes. Moreover, 17α methyl testosterone, a male hormone, could moderately upregulate P. olivaceus GATA6 and downregulate P. olivaceus aromatase CYP19A1 in testis cells. These results suggest that GATA6 may play an important role in gonadal development in P. olivaceus . This study provides valuable information on the function of P. olivaceus GATA6, laying the foundation for further development of breeding techniques in this species.

  6. Roles of GATA6 during Gonadal Development in Japanese Flounder: Gonadogenesis, Regulation of Gender-Related Genes, Estrogen Formation and Gonadal Function Maintenance

    PubMed Central

    Li, Zan; Liu, Xiumei; Sun, Yan; Liu, Jinxiang; Liu, Yuezhong; Wang, Mengxun; Zhang, Quanqi; Wang, Xubo

    2017-01-01

    GATA-binding protein 6 (GATA6), a highly-conserved transcription factor of the GATA family plays an important role in gonadal cell proliferation, differentiation and endoderm development. In this study, the full-length cDNA of GATA6 of Paralichthys olivaceus (Japanese flounder) was obtained. Phylogenetic, gene structure and synteny analyses demonstrated that GATA6 of P. olivaceus is homologous to that of teleosts and tetrapods. The P. olivaceus GATA6 transcript showed higher expression in testis than in ovary, demonstrating a sexually dimorphic gene expression. During embryonic development, the expression of P. olivaceus GATA6 increased at the blastula stage, demonstrating that GATA6 is involved in morphogenesis. Results of in situ hybridization showed that GATA6 signals were detected in Sertoli cells, oogonia and oocytes. Moreover, 17α methyl testosterone, a male hormone, could moderately upregulate P. olivaceus GATA6 and downregulate P. olivaceus aromatase CYP19A1 in testis cells. These results suggest that GATA6 may play an important role in gonadal development in P. olivaceus. This study provides valuable information on the function of P. olivaceus GATA6, laying the foundation for further development of breeding techniques in this species. PMID:28275215

  7. Molecular cloning and expression analysis of Sox3 during gonad and embryonic development in Misgurnus anguillicaudatus.

    PubMed

    Xia, Xiaohua; Huo, Weiran; Wan, Ruyan; Zhang, Linxia; Xia, Xiaopei; Chang, Zhongjie

    2017-01-01

    Sox3 is a single-exon gene located on the X chromosome in most vertebrates. It belongs to the SoxB1 subfamily, which is part of the larger Sox family. Previous studies have revealed that Sox3 is expressed in many fish species. However, how Sox3 influences the development of Misgurnus anguillicaudatus remains unknown. In this study, a Sox3 homologue, termed MaSox3, was cloned from the brain of M. anguillicaudatus using homology-based cloning and the rapid amplification of cDNA ends method. Sequence analysis reveals that MaSox3 encodes a hydrophilic protein, which contains a characteristic HMG-box DNA-binding domain of 79 amino acids, and shares high homology with Sox3 in other species. Additionally, quantitative real-time reverse transcription PCR and in situ hybridization showed that MaSox3 is consistently expressed during embryogenesis, with peak expression during the neurula stage and broad expression in the central nervous system. Moreover, tissue distribution analyses have revealed that MaSox3 is abundant in the adult brain, the particle cell layer, and the gonad. Additionally, its expression is observed in primary spermatocyte cells, primary oocytes and previtellogenic oocyte cells. Taken together, all of these results suggest that the expression of the MaSox3 gene is highly conserved during vertebrate evolution and involved in a wide range of developmental processes including embryogenesis, neurogenesis and gonad development.

  8. Lasting effects of early exposure to temperature on the gonadal transcriptome at the time of sex differentiation in the European sea bass, a fish with mixed genetic and environmental sex determination.

    PubMed

    Díaz, Noelia; Piferrer, Francesc

    2015-09-04

    Sex in fish is plastic and in several species can be influenced by environmental factors. In sensitive species, elevated temperatures have a masculinizing effect. Previous studies on the effects of temperature on gene expression have been restricted to a few cognate genes, mostly related to testis or ovarian development, and analyzed in gonads once they had completed the process of sex differentiation. However, studies on the effect of temperature at the whole gonadal transcriptomic level are scarce in fish and, in addition, temperature effects at the time of sex differentiation at the transcriptomic level are also unknown. Here, we used the European sea bass, a gonochoristic teleost with a polygenic sex determination system influenced by temperature, and exposed larvae to elevated temperature during the period of early gonad formation. Transcriptomic analysis of the gonads was carried out about three months after the end of temperature exposure, shortly after the beginning of the process of sex differentiation. Elevated temperature doubled the number of males with respect to untreated controls. Transcriptomic analysis of early differentiating female gonads showed how heat caused: 1) an up-regulation of genes related to cholesterol transport (star), the stress response (nr3c1) and testis differentiation (amh, dmrt, etc.), 2) a decrease in the expression of genes related to ovarian differentiation such as cyp19a1a, and 3) an increase in the expression of several genes related to epigenetic regulatory mechanisms (hdac11, dicer1, ehmt2, jarid2a, pcgf2, suz12, mettl22). Taken together, the results of this study contribute to the understanding of how the early environment sets permanent changes that result in long-lasting consequences, in this case in the sexual phenotype. Results also show the usefulness of comparing the effects of heat on the behavior of cognate genes related to sex differentiation as well as that of genes involved in establishing and maintaining cell

  9. [Pure gonad dysgenesia or Swyer sindrome. A case report having tumoral development: melanoma].

    PubMed

    Russo, D; Blanco, M; Falke, G; Rocca Rivarola, M; Séller, R; Puigdevall, J C; Bergada, C

    2006-10-01

    A 14 year old girl having 10-days lumbar pain, polaquiuria and moderate pain to palpation is reported. Blood and urine analysis were normal. Abdominal ultrasound scan showed cavity free and solid, rounded, heterogeneous, intrapelvic mass compressing bladder and uterus. Magnetic resonance image was performed showing right gonad compromise with extensive liver and sacro-lumbar spine invasion. Tumoral markers were ruled out. During surgery, primary tumor mass localizad in the right gonad was completely excised. Melanotic peritoneal and hepatic disemination were observed. The patient had left streak gonad and infantile uterus (2 x 3 cm). As gonad dysgenesia was suspected, high resolution cromosomic study was performed and resulted in cariotype 46 XY. Microscopy of the resected gonad showed primary gonad melanoma. Chemotherapy was instituted with no tumor response and the patient died two month later.

  10. On the role of germ cells in mammalian gonad development: quiet passengers or back-seat drivers?

    PubMed

    Rios-Rojas, Clarissa; Bowles, Josephine; Koopman, Peter

    2015-04-01

    In addition to their role as endocrine organs, the gonads nurture and protect germ cells, and regulate the formation of gametes competent to convey the genome to the following generation. After sex determination, gonadal somatic cells use several known signalling pathways to direct germ cell development. However, the extent to which germ cells communicate back to the soma, the molecular signals they use to do so and the significance of any such signalling remain as open questions. Herein, we review findings arising from the study of gonadal development and function in the absence of germ cells in a range of organisms. Most published studies support the view that germ cells are unimportant for foetal gonadal development in mammals, but later become critical for stabilisation of gonadal function and somatic cell phenotype. However, the lack of consistency in the data, and clear differences between mammals and other vertebrates and invertebrates, suggests that the story may not be so simple and would benefit from more careful analysis using contemporary molecular, cell biology and imaging tools. © 2015 Society for Reproduction and Fertility.

  11. Gonad development and vitellogenin production in zebrafish (Danio rerio) exposed to ethinylestradiol and methyltestosterone.

    PubMed

    Orn, Stefan; Holbech, Henrik; Madsen, Trine H; Norrgren, Leif; Petersen, Gitte I

    2003-12-10

    In a partial life-cycle test, the impact of 17alpha-ethinylestradiol (EE2) and 17alpha-methyltestosterone (MT) on juvenile zebrafish was evaluated by use of vitellogenin measurements and gonadal development. Exposure to EE2 (1-25 ng/l) resulted in a dose-dependent increase in vitellogenin production starting at 2 ng/l. Significant changes in sex ratios in female direction were detected at 1 ng/l, with complete sex reversal taking place after exposure to 2 ng/l. No intersex fish were observed after exposure to EE2. Exposure to MT resulted in decreased vitellogenin concentrations. Complete sex reversal was detected in all MT concentrations used (26-1000 ng/l). A large proportion of intersex fish was observed after exposure to 1000 ng MT/l. The period of gonadal sex reversal in non-exposed zebrafish was also studied. The main morphological features of the transformation of ovaries into testis were observed 4-5 weeks after hatching.

  12. DAX1/NR0B1 was expressed during mammalian gonadal development and gametogenesis before it was recruited to the eutherian X chromosome.

    PubMed

    Stickels, Robert; Clark, Kevin; Heider, Thomas N; Mattiske, Deidre M; Renfree, Marilyn B; Pask, Andrew J

    2015-01-01

    The nuclear receptor subfamily 0, group B, member 1 (NR0B1) gene is an orphan nuclear receptor that is X-linked in eutherian mammals and plays a critical role in the establishment and function of the hypothalamic-pituitary-adrenal-gonadal axis. Duplication or overexpression of NR0B1 in eutherian males causes male to female sex reversal, and mutation and deletions of NR0B1 cause testicular defects. Thus, gene dosage is critical for the function of NR0B1 in normal gonadogenesis. However, NR0B1 is autosomal in all noneutherian vertebrates, including marsupials and monotreme mammals, and two active copies of the gene are compatible with both male and female gonadal development. In the current study, we examined the evolution and expression of autosomal NR0B1 during gonadal development in a marsupial (the tammar wallaby) as compared to the role of its X-linked orthologues in a eutherian (the mouse). We show that NR0B1 underwent rapid evolutionary change when it relocated from its autosomal position in the nonmammalian vertebrates, monotremes, and marsupials to an X-linked location in eutherian mammals. Despite the acquisition of a novel genomic location and a unique N-terminal domain, NR0B1 protein distribution was remarkably similar between mice and marsupials both throughout gonadal development and during gamete formation. A conserved accumulation of NR0B1 protein was observed in developing oocytes, where its function appears to be critical in the early embryo, prior to zygotic genome activation. Together these findings suggest that NR0B1 had a conserved role in gonadogenesis that existed long before it moved to the X chromosome and despite undergoing significant evolutionary change. © 2015 by the Society for the Study of Reproduction, Inc.

  13. Discovery and functional characterization of microRNAs and their potential roles for gonadal development in spotted knifejaw, Oplegnathus punctatus.

    PubMed

    Du, Xinxin; Liu, Xiaobing; Zhang, Kai; Liu, Yuxiang; Cheng, Jie; Zhang, Quanqi

    2018-05-16

    The spotted knifejaw (Oplegnathus punctatus) is a newly emerging economical fishery species in China. Studies focused on the regulation of gonadal development and gametogenesis of spotted knifejaw are still insufficient. As a key post-transcriptional regulator, miRNAs have been shown to play important roles in development and reproduction systems. In this study, small RNA deep sequencing in ovary and testis of spotted knifejaw were performed to screen miRNA expression patterns. After sequencing and bioinformatics analysis, a total of 247 conserved known miRNAs and 41 novel miRNAs were identified in spotted knifejaw gonads for the first time. In addition, 36 miRNAs were differentially expressed between testis and ovary. The putative target genes of differentially expressed (DE) miRNAs were significantly enriched in several pathways related to sexual differentiation and gonadal development, such as steroid hormone biosynthesis. Sequencing data was validated through qRT-PCR analysis of selected DE miRNAs. Dual-luciferase reporter analyses of filtered miRNA-target gene pairs confirmed that opu-miR-27b-3p targeted in piwi2 and mov10l1 3' UTRs and down-regulated their expressions in spotted knifejaw. The notion that mov10l1 and piwi2 enhance germ cells proliferation and regulate gonadal development and gametogenesis suggests that opu-miR-27b-3p may attenuated this process in the gonads of spotted knifejaw. These findings provided insights into regulatory roles of gonadal miRNAs and supplied fundamental resources for further studies on miRNA-mediated post-transcriptional regulation in reproductive system of spotted knifejaw. Copyright © 2018. Published by Elsevier Inc.

  14. Regulation of gonadal sex ratios and pubertal development by the thyroid endocrine system in zebrafish (Danio rerio)

    USGS Publications Warehouse

    Sharma, Prakash; Patino, Reynaldo

    2013-01-01

    We examined associations between thyroid condition, gonadal sex and pubertal development in zebrafish. Seventy-two-hour postfertilization larvae were reared in untreated medium or in the presence of goitrogens (sodium perchlorate, 0.82 mM; methimazole, 0.15 and 0.3 mM) or thyroxine (1 and 10 nM) for 30 days. Thyrocyte height, gonadal sex and gonadal development were histologically determined at 45 and 60 days postfertilization (dpf). Thyrocyte hypertrophy, an index of hypothyroidism, was observed at 45 and 60 dpf in perchlorate-treated but only at 45 dpf in methimazole-treated fish. Similarly, gonadal sex ratios were biased toward ovaries relative to control animals at 45 and 60 dpf in perchlorate-treated fish but only at 45 dpf in methimazole-treated fish. Gonadal sex ratios were biased toward testes at 45 and 60 dpf in thyroxine-treated fish. Spermatogenesis was delayed in testes from goitrogen-treated fish at 60 dpf relative to control values, but was unaffected in testes from thyroxine-treated individuals. Oogenesis seemed to be nonspecifically delayed in all treatments relative to control at 60 dpf. This study confirmed the previously reported association between hypothyroid condition and ovarian-skewed ratios, and hyperthyroid condition and testicular-skewed ratios, and also showed that male pubertal development is specifically delayed by experimental hypothyroidism. The simultaneous recovery from the hypothyroid and ovary-inducing effects of methimazole by 60 dpf (27 days post-treatment) suggests that the ovary-skewing effect of goitrogens is reversible when thyroid conditions return to basal levels before developmental commitment of gonadal sex. Conversely, the masculinizing effect of hyperthyroidism seems to be stable and perhaps permanent.

  15. Regulation of gonadal sex ratios and pubertal development by the thyroid endocrine system in zebrafish (Danio rerio).

    PubMed

    Sharma, Prakash; Patiño, Reynaldo

    2013-04-01

    We examined associations between thyroid condition, gonadal sex and pubertal development in zebrafish. Seventy-two-hour postfertilization larvae were reared in untreated medium or in the presence of goitrogens (sodium perchlorate, 0.82 mM; methimazole, 0.15 and 0.3 mM) or thyroxine (1 and 10 nM) for 30 days. Thyrocyte height, gonadal sex and gonadal development were histologically determined at 45 and 60 days postfertilization (dpf). Thyrocyte hypertrophy, an index of hypothyroidism, was observed at 45 and 60 dpf in perchlorate-treated but only at 45 dpf in methimazole-treated fish. Similarly, gonadal sex ratios were biased toward ovaries relative to control animals at 45 and 60 dpf in perchlorate-treated fish but only at 45 dpf in methimazole-treated fish. Gonadal sex ratios were biased toward testes at 45 and 60 dpf in thyroxine-treated fish. Spermatogenesis was delayed in testes from goitrogen-treated fish at 60 dpf relative to control values, but was unaffected in testes from thyroxine-treated individuals. Oogenesis seemed to be nonspecifically delayed in all treatments relative to control at 60 dpf. This study confirmed the previously reported association between hypothyroid condition and ovarian-skewed ratios, and hyperthyroid condition and testicular-skewed ratios, and also showed that male pubertal development is specifically delayed by experimental hypothyroidism. The simultaneous recovery from the hypothyroid and ovary-inducing effects of methimazole by 60 dpf (27 days post-treatment) suggests that the ovary-skewing effect of goitrogens is reversible when thyroid conditions return to basal levels before developmental commitment of gonadal sex. Conversely, the masculinizing effect of hyperthyroidism seems to be stable and perhaps permanent. Published by Elsevier Inc.

  16. The Distribution and Cellular Lineages of XX and XY Cells in Gonads Associated with Ovotesticular Disorder of Sexual Development.

    PubMed

    Nishina-Uchida, Noriko; Fukuzawa, Ryuji; Ishii, Tomohiro; Anaka, Matthew R; Hasegawa, Tomonobu; Hasegawa, Yukihiro

    2016-01-01

    Individuals with a 46,XX/46,XY karyotype are categorized as ovotesticular disorder of sexual development (ODSD) and have gonads with either an ovary on one side and a testis on the other side or a mixed ovotestis. To examine the distribution of 46,XX and 46,XY cells in gonads of 3 patients with ODSD, FISH for X and Y chromosomes and immunohistochemistry for SOX9 and FOXL2 were carried out. FISH analysis showed that XX signals were present in Sertoli cells in the seminiferous tubules, while cells containing Y signals were seen in epithelia of ovarian follicles. The immunolabeling of SOX9 and FOXL2 in the seminiferous tubules and ovarian follicles was mutually exclusive, irrespective of the presence of reversed sex chromosomes. We therefore suggest that the fate of individual gonadal epithelial cells is determined not only by the sex chromosomes but also by local environmental factors. © 2016 S. Karger AG, Basel.

  17. Disrupting effects of polychlorinated biphenyls on gonadal development and reproductive functions in chickens.

    PubMed

    Zhang, Caiqiao; Fang, Changge; Liu, Li; Xia, Guoliang; Qiao, Huili

    2002-01-01

    Polychlorinated biphenyls (PCBs) are worldwide persistent pollutants that have produced detrimental effects on endocrine function and reproduction in a variety of species. The present study revealed effects of PCBs on gonadal development and functions in chickens of different ages. Aroclor 1254 (0-100 microg/egg) was injected into Hyline chicken eggs before incubation. The adult chickens received Aroclor 1254 by gavage (50 mg/kg BW). It was observed that in day 5 embryos, PCBs resulted in a dose-dependent decrease of primordial germ cell (PGC) numbers, and caused PGCs pyknosis and vacuolation. Clomiphen failed to block the effects of PCBs. In the newly hatched chicken, PCBs induced a marked decrease in area of the transverse sections, diameter and relative area of the testicular tubules. The differentiation of germ cells was retarded after PCB treatment. In contrast, the area of the left ovarian transverse sections, the thickness of ovarian cortex and the number of oocytes increased dramatically in the female chickens after PCB exposure. In the adult chickens, PCBs caused no significant changes in body weight, respiration, heart rate, body temperature, red and white blood cell number, but induced a marked decrease in the testicular weight, and severe damage of the seminiferous tubules. The number of the spermatogenic cells and serum testosterone level were decreased significantly by PCBs. On the contrary, in the laying hens there was no significant effect of PCB on egg quality except a slight decrease in egg weight. These results indicated that PCBs exerted its disrupting effects on chicken reproduction with a sex and stage-related pattern, and in vivo disruption of gonadal development represents a possible model for risk assessment of environmental endocrine disrupters by in ovo treatment.

  18. Molecular cloning of cytochrome P450 side-chain cleavage and changes in its mRNA expression during gonadal development of brown hagfish, Paramyxine atami.

    PubMed

    Nishiyama, Maki; Uchida, Katsuhisa; Abe, Nozomi; Nozaki, Masumi

    2015-02-01

    Since hagfishes are considered the most primitive vertebrate known, extant or extinct, studies on their reproduction are indispensable for understanding phylogenetic aspects of vertebrate reproduction. However, little information is available on the endocrine regulation of the gonadal function in the hagfish. Based on EST analysis of the testis of the brown hagfish (Paramyxine atami), P450 side chain cleavage (CYP11A), which is the first and essential enzyme for steroidogenesis in jawed vertebrates, was cloned. The deduced amino acid sequence of hagfish CYP11A shows high identity to other animal forms especially in two functional domains, adrenodoxin binding domain and heme-binding domain. In the phylogenetic analysis, hagfish CYP11A forms a clade with the vertebrate CYP11A. Following the real-time PCR analysis, CYP11A mRNA expression levels were clearly correlated to the developmental stages of gonads in both sexes of the brown hagfish. By in situ hybridization, CYP11A mRNA signals were found in the theca cells of the ovarian follicles and Leydig cells and the tubule-boundary cells of the testis. These molecular and histological evidences are suggesting that CYP11A plays functional roles as a steroidogenic enzyme in gonadal development. Moreover, native GTH purified from hagfish pituitary stimulated the transcriptional levels of CYP11A in the organ-cultured testis in vitro, clearly suggesting that the steroidogenic activity of the hagfish is under the control of the pituitary GTH. It is suggested that vertebrates, during their early evolution, have established the pituitary-gonadal reproductive system. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Influence of Xenorhabdus (Gamma-Proteobacteria: Enterobacteriaceae) symbionts on gonad postembryonic development in Steinernema (Nematoda: Steinernematidae) nematodes.

    PubMed

    Roder, Alexandra C; Stock, S Patricia

    2018-03-01

    Steinernema nematodes and their Xenorhabdus partners form an obligate mutualistic association. This partnership is insecticidal to a wide range of insects. Steinernema rely on their Xenorhabdus partner to produce toxins inside the insect cadaver to liberate nutrients from the insect, as well as antimicrobials to sterilize the cadaver, thus creating a suitable environment for reproduction. In return, Steinernema vector their Xenorhabdus between insect hosts. Disruption of this partnership may affect the success of both partners. For instance, when Steinernema associates with non-cognate symbionts, their virulence and reproductive fitness are affected. In this study, we examined the effect of symbiotic (cognate and non-cognate) and non-symbiotic bacteria on maturation time, gonad postembryonic development, and sex ratio of first-generation Steinernema adults. Two Steinernema spp. were considered: S. feltiae SN and S. carpocapsae All. In vitro assays were carried out by pairing each nematode sp. with symbiotic (cognate and non-cognate) Xenorhabdus, and with non-symbiotic bacteria (Serratia proteamaculans). Additionally, for comparative purposes, we also considered adult nematodes reared in vivo in Galleria mellonella larvae to assess nematode development under natural conditions. Results from this study showed non-symbiotic Serratia proteamaculans did not support adult development of S. feltiae but it allowed development of S. carpocapsae adults. Sex ratio decreased from 2:1 to 1:1 (female: male) when S. carpocapsae adults were reared with the non-symbiotic S. proteamaculans. Cognate or non-cognate Xenorhabdus spp. and/or strains did not change the sex ratio of any of either Steinernema spp. tested. Morphometric analysis also revealed that bacterial conditions influenced adult size and gonad postembryonic development in both Steinernema species. Body size (length and width), and gonad length in both S. feltiae males and females, were significantly reduced when reared

  20. Effects of salinity on gonadal development, osmoregulation and metabolism of adult male Chinese mitten crab, Eriocheir sinensis

    PubMed Central

    Zhao, Lei; Ye, Haihui; Cheng, Yongxu; Zeng, Chaoshu

    2017-01-01

    As a catadromous species, salinity is a key parameter that affects gonadal development of Chinese mitten crab Eriocheir sinensis during reproductive migration. It is however unclear the effects of salinity on the gonadal development of male E. sinensis as well as their physiological responses to salinity during reproductive migration. This study investigated the effects of four salinities (0 ‰, 6 ‰, 12 ‰ and 18 ‰) on gonadal development, osmoregulation and metabolism of adult male E. sinensis over a 40-day period. The results showed that elevating salinity promote gonadal development, increase hemolymph osmolality and K+ and Mg2+ concentrations (P < 0.05). The 12 ‰ salinity resulted in the highest contents of taurine and arginine in the hemolymph while the highest contents of threonine, phenylalanine, lysine, ß-alanine, tryptophan, ornithine and total free amino acids were found for 0 ‰ treatment (P < 0.05). A decreasing trend was detected for the Na+/K+-ATPase activity and its mRNA expression level in the posterior gills with salinity (P < 0.05). Total saturated fatty acids in the anterior gills decreased with increasing salinity (P < 0.05); the 0 ‰ treatment had the highest total polyunsaturated fatty acids in the posterior gills while total n-6 polyunsaturated fatty acids increased with salinity (P < 0.05). The hemolymph glucose and uric acid showed a decreasing trend as salinity while an increasing trend was found for the hemolymph triglyceride and high-density lipoprotein cholesterol (P < 0.05). The 12 ‰ treatment had the highest levels of hemolymph malonaldehyde and hepatopancreatic γ-glutamyltranspeptidase (P < 0.05). In conclusion, these results suggested that the brackish water promote gonadal development of male E. sinensis, and increase osmolality and ionic concentrations in hemolymph while reduced the activity of Na+ /K+- ATPase and its mRNA expression in the posterior gills as well as metabolism. PMID:28628611

  1. A Novel igf3 Gene in Common Carp (Cyprinus carpio): Evidence for Its Role in Regulating Gonadal Development.

    PubMed

    Song, Feibiao; Wang, Lanmei; Zhu, Wenbin; Fu, Jianjun; Dong, Juanjuan; Dong, Zaijie

    2016-01-01

    Since the insulin-like growth factor 3 (igf3) gene was recently discovered in fish ovary, its function in the gonads has received much attention. In this study, we isolated two igf3 subtypes from common carp (Cyprinus carpio), which comprised full-length cDNA of 707 and 1153 nucleotides encoding 205 and 198 amino acids (aa), respectively. The Igf3 aa sequence had the highest gene homology of 72% with the corresponding sequence in zebrafish (Danio rerio). Phylogenetic tree construction revealed that the C. carpio igf3 gene was first clustered with D. rerio and then with other teleost species. Igf3 mRNA was widely expressed, with expression being highest in the gonads and blood. In the gonad development stage, igf3a mRNA expression was highest in the maturity and recession stage of the ovary, and decline phase of the testis, while igf3b was highest in the recession and fully mature periods of the ovaries and testes, respectively. Western blotting of testis protein samples showed two bands of approximately 21 kDa and 34 kDa corresponding to the calculated molecular mass of the two Igf3 subtypes; no signal was detected in the ovary. The Igf3 protein was localized in the ovary granulosa cells and testis spermatogonium and spermatids. 17β-Ethinylestradiol treatment increased both ovary and testis igf3 mRNA expression. These findings suggest that Igf3 may play an important role in C. carpio gonadal development.

  2. The expression of amh and amhr2 is associated with the development of gonadal tissue and sex change in the protandrous black porgy, Acanthopagrus schlegeli.

    PubMed

    Wu, Guan-Chung; Chiu, Po-Chia; Lyu, Ying-Syuan; Chang, Ching-Fong

    2010-09-01

    The protandrous black porgy, Acanthopagrus schlegeli, has a striking life cycle, with sex differentiation at the juvenile stage, mono-male development, a bisexual gonad during the first 2 yr of life, and a male-to-female sex change (with vitellogenic oocytes) at 3 yr of age. In the present study, we investigated the possible roles of amh and amhr2 in gonadal development in a nonmammalian model organism (protandrous black porgy), especially in relation to sex differentiation, testicular and ovarian growth, and sex change. Fish of various ages were treated with estradiol or an aromatase inhibitor to induce the fish to become female. Furthermore, a natural sex change (2(+)-yr-old [>2 yr and <3 yr] fish) and a nonchemical method to surgically remove one of the pair of gonads to examine the possible roles of amh in the natural sex change were conducted. We present integrative in situ hybridization, immunohistochemical, cellular, and molecular data describing these phenomena. During gonadal sex differentiation, an increase in amh and amhr2 expression was detected. Higher levels of amh and amhr2 transcripts were observed in the testicular tissue when compared to the ovarian tissue in the bisexual gonad of 1(+)-yr-old (>1 yr and <2 yr) fish. Transcripts of amh reached peak levels in November (prespermatogenesis period) and then declined to the lowest levels in January (spawning period). Chemical-induced ovarian tissue had very low amh transcript levels but high levels of amhr2. Active testes had significantly higher amh and amhr2 expression levels as compared to inactive testes. In contrast, no difference in the expression of amh and amhr2 between active and inactive ovarian tissues was found. Transcripts of amh were expressed in the somatic cells of the spermatogonia and vitellogenic oocytes, and amhr2 was expressed in the somatic cells of the spermatogonia. Transcripts of amh decreased in the testicular tissue 5 mo before occurrence of the sex change into a female. In

  3. Transcriptome analysis reveals differentially expressed genes associated with germ cell and gonad development in the Southern bluefin tuna (Thunnus maccoyii).

    PubMed

    Bar, Ido; Cummins, Scott; Elizur, Abigail

    2016-03-10

    Controlling and managing the breeding of bluefin tuna (Thunnus spp.) in captivity is an imperative step towards obtaining a sustainable supply of these fish in aquaculture production systems. Germ cell transplantation (GCT) is an innovative technology for the production of inter-species surrogates, by transplanting undifferentiated germ cells derived from a donor species into larvae of a host species. The transplanted surrogates will then grow and mature to produce donor-derived seed, thus providing a simpler alternative to maintaining large-bodied broodstock such as the bluefin tuna. Implementation of GCT for new species requires the development of molecular tools to follow the fate of the transplanted germ cells. These tools are based on key reproductive and germ cell-specific genes. RNA-Sequencing (RNA-Seq) provides a rapid, cost-effective method for high throughput gene identification in non-model species. This study utilized RNA-Seq to identify key genes expressed in the gonads of Southern bluefin tuna (Thunnus maccoyii, SBT) and their specific expression patterns in male and female gonad cells. Key genes involved in the reproductive molecular pathway and specifically, germ cell development in gonads, were identified using analysis of RNA-Seq transcriptomes of male and female SBT gonad cells. Expression profiles of transcripts from ovary and testis cells were compared, as well as testis germ cell-enriched fraction prepared with Percoll gradient, as used in GCT studies. Ovary cells demonstrated over-expression of genes related to stem cell maintenance, while in testis cells, transcripts encoding for reproduction-associated receptors, sex steroids and hormone synthesis and signaling genes were over-expressed. Within the testis cells, the Percoll-enriched fraction showed over-expression of genes that are related to post-meiosis germ cell populations. Gonad development and germ cell related genes were identified from SBT gonads and their expression patterns in

  4. Insulin and IGF1 Receptors Are Essential for XX and XY Gonadal Differentiation and Adrenal Development in Mice

    PubMed Central

    Romero, Yannick; Conne, Béatrice; Truong, Vy; Papaioannou, Marilena D.; Schaad, Olivier; Docquier, Mylène; Herrera, Pedro Luis; Wilhelm, Dagmar; Nef, Serge

    2013-01-01

    Mouse sex determination provides an attractive model to study how regulatory genetic networks and signaling pathways control cell specification and cell fate decisions. This study characterizes in detail the essential role played by the insulin receptor (INSR) and the IGF type I receptor (IGF1R) in adrenogenital development and primary sex determination. Constitutive ablation of insulin/IGF signaling pathway led to reduced proliferation rate of somatic progenitor cells in both XX and XY gonads prior to sex determination together with the downregulation of hundreds of genes associated with the adrenal, testicular, and ovarian genetic programs. These findings indicate that prior to sex determination somatic progenitors in Insr;Igf1r mutant gonads are not lineage primed and thus incapable of upregulating/repressing the male and female genetic programs required for cell fate restriction. In consequence, embryos lacking functional insulin/IGF signaling exhibit (i) complete agenesis of the adrenal cortex, (ii) embryonic XY gonadal sex reversal, with a delay of Sry upregulation and the subsequent failure of the testicular genetic program, and (iii) a delay in ovarian differentiation so that Insr;Igf1r mutant gonads, irrespective of genetic sex, remained in an extended undifferentiated state, before the ovarian differentiation program ultimately is initiated at around E16.5. PMID:23300479

  5. Effects of environmentally relevant concentrations of atrazine on gonadal development of snapping turtles (Chelydra serpentina).

    PubMed

    de Solla, Shane R; Martin, Pamela A; Fernie, Kimberly J; Park, Brad J; Mayne, Gregory

    2006-02-01

    The herbicide atrazine has been suspected of affecting sexual development by inducing aromatase, resulting in the increased conversion of androgens to estrogens. We used snapping turtles (Chelydra serpentina), a species in which sex is dependent on the production of estrogen through aromatase activity in a temperature-dependent manner, to investigate if environmentally relevant exposures to atrazine affected gonadal development. Eggs were incubated in soil to which atrazine was applied at a typical field application rate (3.1 L/ha), 10-fold this rate (31 L/ha), and a control rate (no atrazine) for the duration of embryonic development. The incubation temperature (25 degrees C) was selected to produce only males. Although some males with testicular oocytes and females were produced in the atrazine-treated groups (3.3-3.7%) but not in the control group, no statistical differences were found among treatments. Furthermore, snapping turtle eggs collected from natural nests in a corn field were incubated at the pivotal temperature (27.5 degrees C) at which both males and females normally would be produced, and some males had oocytes in the testes (15.4%). The presence of low numbers of males with oocytes may be a natural phenomenon, and we have limited evidence to suggest that the presence of normal males with oocytes may represent a feminizing effect of atrazine. Histological examination of the thyroid gland revealed no effect on thyroid morphology.

  6. Morphometric and histopathological parameters of gonadal development in adult common carp from contaminated and reference sites in Lake Mead, Nevada

    USGS Publications Warehouse

    Patino, R.; Goodbred, S.L.; Draugelis-Dale, R.; Barry, C.E.; Scott, Foott J.; Wainscott, M.R.; Gross, T.S.; Covay, K.J.

    2003-01-01

    This study examined the hypothesis that exposure to sublethal concentrations of contaminants alters the gonadal condition of feral common carp Cyprinus carpio. Adult common carp in Lake Mead, Nevada, were collected from a contaminated site (Las Vegas Bay) that receives municipal and industrial effluent and from a reference site (Overton Arm) with a relatively low level of contamination. Fish were sampled seven times over a 1-year period extending over two separate spawning seasons. Morphometric and histopathological parameters of gonadal and germ cell development were determined. In males, the pattern of seasonal changes in the gonadosomatic index (GSI) was similar between the sites and showed no clear association with site-specific seasonal temperature profiles. However, Las Vegas Bay males had consistently lower GSI values and, on one of the sampling dates, a lower proportion of sperm relative to other germ cell stages (determined histologically). Further, Las Vegas Bay males had a higher incidence of gonadal macrophage aggregates, which are putative tissue biomarkers of contaminant exposure in fishes. In females, seasonal GSI profiles, the frequency of fish with postovulatory follicles (an index of spawning activity), and the timing of new follicle recruitment all showed differences between sites, but these differences generally matched differences in water temperature profile. Also, the peak size-frequency of full-grown follicles did not differ between sites, and estimates of fecundity for the second spawning season indicated that females from the reference site unexpectedly produced a lower number of gametes, Overall, site differences in gonadal condition were observed in carp of both sexes but they seemed to be associated with site differences in contaminant levels only in males. The apparent lack of association between contaminant level and gonadal condition in female carp from mildly mesotrophic Lake Mead may indicate a lack of contaminant effects in

  7. Expression analysis of cyp11a1 during gonadal development, recrudescence and after hCG induction and sex steroid analog treatment in the catfish, Clarias batrachus.

    PubMed

    Rajakumar, Anbazhagan; Senthilkumaran, Balasubramanian

    2014-10-01

    In teleosts, the levels of steroids are critical for sexual development and hence, expression of steroidogenic enzyme genes and specific substrate availability are indispensable for gonadal steroidogenesis. Early stages of steroidogenesis specifically cholesterol to pregnenolone conversion by Cyp11a1 is crucial for estradiol and testosterone biosynthesis. Based on this, in this study, full length cDNA of cyp11a1 (2581bp) was cloned from catfish testis to investigate the importance of Cyp11a1 by analyzing the expression of cyp11a1 during gonadal development, seasonal reproductive cycle, after human chorionic gonadotropin (hCG) induction and sex steroid analog treatment. Phylogenetic analysis revealed that the Cyp11a1 is more conserved across teleosts. Tissue distribution analysis showed that the cyp11a1 expression was higher in the testis followed by the brain, head kidney, muscle and ovary compared to other tissues analyzed. High expression of cyp11a1 in the head kidney and muscle revealed that Cyp11a1 could potentially regulate the extra-gonadal and/or circulating steroid levels in teleosts. Developing and mature testes showed higher expression of cyp11a1 than the ovary of corresponding age group. Further, cyp11a1 expression was found to be higher during pre-spawning and spawning phases of testicular cycle and was upregulated by hCG, in vivo and in vitro, which indicates the possible regulation by gonadotropin. Exposure of methyltestosterone (1μg/L) and ethinylestradiol (1μg/L) for 21days during catfish testicular development showed lower cyp11a1 expression levels in the testis and brain indicating a certain feedback intervention. These results suggest possible role for Cyp11a1 in the testis development and recrudescence. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Gonadal development of larval male Xenopus laevis exposed to atrazine in outdoor microcosms

    USGS Publications Warehouse

    Jooste, A.M.; Du Preez, L.H.; Carr, J.A.; Giesy, J.P.; Gross, T.S.; Kendall, R.J.; Smith, E.E.; Van Der Kraak, G. L.; Solomon, K.R.

    2005-01-01

    The potential effects of atrazine on gonadal development in metamorphs and subadults of the African clawed frog (Xenopus laevis) were studied under conditions of natural photoperiod and temperatures in outdoor microcosms from August 2002 to June 2003 in South Africa. Triplicate 1100 L microcosms for each nominal concentration of 0.0, 1, 10, and 25 ??g of atrazine/L were used. Measured atrazine concentrations varied <25% throughout the study, and no atrazine was detected in the control microcosms. Tadpoles developed well at all concentrations. On the basis of histological examination of testes of recently metamorphosed stage 66 frogs, 57% of the individuals in the reference group exhibited testicular oocytes as compared with 57, 59, and 39% of the 1, 10, and 25 ??g/L atrazine groups, respectively. The average prevalence of testicular oocytes for all of the treatments including the controls was 54% in a single testis, while, in 35% of individuals, testicular oocytes were observed in both testes. The number of testicular oocytes per individual ranged from 0 to 58 with means of 9.5, 9.8, 8.5, and 11.1 for the 0.0, 1, 10, and 25 ??g of atrazine/L groups, respectively. Ten months after metamorphosis, another subset of juveniles was examined, and the maximum number of testicular oocytes observed was five in one animal. The presence of testicular oocytes was not related to exposure to atrazine and may be a natural phenomenon during ontogeny. ?? 2005 American Chemical Society.

  9. Sexual dichotomy of gonadal function in Prader-Willi syndrome from early infancy through the fourth decade.

    PubMed

    Hirsch, H J; Eldar-Geva, T; Bennaroch, F; Pollak, Y; Gross-Tsur, V

    2015-11-01

    At what age does the type of hypogonadism, namely hypothalamic or primary gonadal defect, become established in men and women with Prader-Willi syndrome (PWS)? The type of hypogonadism becomes established only in late adolescence and early adulthood. The etiology of hypogonadism in PWS is heterogeneous and the clinical expression is variable. Primary testicular failure is common in PWS men, while combinations of ovarian dysfunction and gonadotrophin deficiency are seen in women. This is a prospective study of a cohort of 106 PWS patients followed for a mean duration of 4.5 years. Serial blood samples were obtained and assayed for gonadotrophins, inhibin B, anti-Mullerian hormone (AMH), dehydroepiandrosterone sulfate (DHEAS), testosterone (males), and estradiol (females). Results were compared with normal reference values obtained from the literature. For the purpose of this study, we defined the following age groups: infants <1 year; children 1-10 years; adolescents 11-20 years and adults >20 years. Study participants were 49 males (aged 2 months to 36 years) and 57 females (aged 1 month to 37 years) with genetically confirmed diagnoses of PWS (deletions 60, uniparental disomy 54, imprinting center defect 2) followed in the Israel national multidisciplinary PWS clinic. Serum LH levels were in the normal range (1.0-6.0 mIU/ml) for 7/10 adult men, and high in 3, while FSH (normal range 1.0-6.1 mIU/ml) was elevated (34.4 ± 11.5 mIU/ml) in 6 and normal (3.5 ± 1.6 mIU/ml) in 4 men. Testosterone was low (5.7 ± 3.4 nmol/l) compared with the normal range of 12.0-34.5 nmol/l in the reference population in all men >20 years. AMH showed a normal decrease with age, despite low testosterone levels. Inhibin B was normal (241 ± 105 pg/ml) in infant boys, but low or undetectable in most adult men. Hormonal profiles were more heterogeneous in women than in men. Estradiol was consistently detectable in only 7/13 adult women. Inhibin B was low or undetectable in all PWS females

  10. Feeding prepubescent gilts a high-fat diet induces molecular changes in the hypothalamus-pituitary-gonadal axis and predicts early timing of puberty.

    PubMed

    Zhuo, Yong; Zhou, Dongsheng; Che, Lianqiang; Fang, Zhengfeng; Lin, Yan; Wu, De

    2014-01-01

    The onset of puberty in females has been occurring earlier over the past decades, presumably as a result of improved nutrition in developed countries. However, the underlying molecular mechanisms responsible for the early attainment of puberty as a result of nutrition fortification remain largely unknown. The aim of this study was to evaluate the hormone and gene expression changes in prepubescent gilts fed a high-fat diet to investigate whether these changes could predict the early timing of puberty. Forty gilts were fed a daily basal diet (LE) or a basal diet with an additional 270 g/d or 340 g/d of fat (HE) during the prepubescent phase. Blood samples were collected during the prepubescent phase to detect hormone secretion changes in insulin-like growth factor-1, kisspeptin, estradiol, progesterone, and leptin. The gene expressions at the hypothalamus-pituitary-gonadal axis were examined on day 73 of the experiment (average age on day 177) during the prepubescent phase. An HE diet resulted in accelerated body weight gain and back-fat thickness at the P2 point compared with LE gilts during the prepubescent phase. Gilts that were fed HE diets attained puberty 12 d earlier than LE gilts, and a larger proportion of HE gilts reached puberty at day 180 or 190 of age. A postmortem analysis revealed a promoted development of the uterus and ovary tissue that was characterized by a 53.7% and 29.5% increase in the uterine and ovary weight, respectively, and an increased length of the uterine horn and oviduct tissue in HE gilts. Real-time quantitative polymerase chain reaction revealed that HE gilts had higher Kiss-1, G protein-coupled receptor 54, gonadotropin-releasing hormone and estrogen receptor α mRNA expression levels in the hypothalamic anteroventral periventricular nucleus; the leptin receptor mRNA expression level was higher in the hypothalamic arcuate nucleus and ovary tissue; the insulin-like growth factor-1 receptor expression was higher in the pituitary and

  11. Sex Reversal and Analyses of Possible Involvement of Sex Steroids in Scallop Gonadal Development in Newly Established Organ-Culture Systems.

    PubMed

    Otani, Ayano; Nakajima, Tadaaki; Okumura, Tomomi; Fujii, Shiro; Tomooka, Yasuhiro

    2017-04-01

    Many molluscs perform sex reversal, and sex hormones may be involved in the process. In adult scallops, Patinopecten yessoensis, gonadotropin releasing hormone and 17β-estradiol (E 2 ) are involved in male sexual maturation, however, little is known about the effects of E 2 and testosterone (T) on the gonadal differentiation in young scallops. In the present study, scallop gonadal development was analyzed to determine the sex reversal stage in Funka bay, and effects of E 2 and T were examined. In Funka bay, almost all scallops were male at month 12. Scallops equipped with ambiguous gonads were 61.1% at month 16 and disappeared at month 18. Therefore, sex reversal in Funka bay occurs at around month 16. For establishment of organ culture systems for bivalves, Manila clam gonads were cultured in 15% L-15 medium diluted with HBSS containing 10% KSR on agarose gel at 10°C, and the gonads survived for 14 days. Scallop gonads were also able to be cultured in 30% L15 medium diluted with ASW containing 10% KSR on agarose gel for seven days. At mature stage, Foxl2 and Tesk were predominantly expressed in ovary and testis, respectively. When scallop gonads at sex reversal stage were organ-cultured, sex steroid treatment decreased Tesk expression in the majority of scallop gonads at sex reversal stage. However, no obvious change in Foxl2 and Tesk expression was detected in mature gonads in response to either E 2 or T in culture, suggesting sex steroid treatment might affect gonadal development at sex reversal stage.

  12. Sex-biased miRNAs in gonad and their potential roles for testis development in yellow catfish.

    PubMed

    Jing, Jing; Wu, Junjie; Liu, Wei; Xiong, Shuting; Ma, Wenge; Zhang, Jin; Wang, Weimin; Gui, Jian-Fang; Mei, Jie

    2014-01-01

    Recently, YY super-male yellow catfish had been created by hormonal-induced sex reversal and sex-linked markers, which provides a promising research model for fish sex differentiation and gonad development, especially for testis development. MicroRNAs (miRNAs) have been revealed to play crucial roles in the gene regulation and gonad development in vertebrates. In this study, three small RNA libraries constructed from gonad tissues of XX female, XY male and YY super-male yellow catfish were sequenced. The sequencing data generated a total of 384 conserved miRNAs and 113 potential novel miRNAs, among which 23, 30 and 14 miRNAs were specifically detected in XX ovary, XY testis, and YY testis, respectively. We observed relative lower expression of several miR-200 family members, including miR-141 and miR-429 in YY testis compared with XY testis. Histological analysis indicated a higher degree of testis maturity in YY super-males compared with XY males, as shown by larger spermatogenic cyst, more spermatids and fewer spermatocytes in the spermatogenic cyst. Moreover, five miR-200 family members were significantly up-regulated in testis when treated by 17α-ethinylestradiol (EE2), high dose of which will impair testis development and cell proliferation. The down-regulation of miR-141 and 429 coincides with the progression of testis development in both yellow catfish and human. At last, the expression pattern of nine arbitrarily selected miRNAs detected by quantitative RT-PCR was consistent with the Solexa sequencing results. Our study provides a comprehensive miRNA transcriptome analysis for gonad of yellow catfish with different sex genotypes, and identifies a number of sex-biased miRNAs, some of that are potentially involved in testis development and spermatogenesis.

  13. Transforming Growth Factor Beta (TGFβ1, TGFβ2 and TGFβ3) Null-Mutant Phenotypes in Embryonic Gonadal Development

    PubMed Central

    Memon, Mushtaq A.; Anway, Matthew D.; Covert, Trevor R.; Uzumcu, Mehmet; Skinner, Michael K.

    2008-01-01

    The role transforming growth factor beta (TGFb) isoforms TGFb1, TGFb2 and TGFb3 have in the regulation of embryonic gonadal development was investigated with the use of null-mutant (i.e. knockout) mice for each of the TGFb isoforms. Late embryonic gonadal development was investigated because homozygote TGFb null-mutant mice generally die around birth, with some embryonic loss as well. In the testis, the TGFb1 null-mutant mice had a decrease in the number of germ cells at birth, postnatal day 0 (P0). In the testis, the TGFb2 null-mutant mice had a decrease in the number of seminiferous cords at embryonic day 15 (E15). In the ovary, the TGFb2 null-mutant mice had an increase in the number of germ cells at P0. TGFb isoforms appear to have a role in gonadal development, but interactions between the isoforms is speculated to compensate in the different TGFb isoform null-mutant mice. PMID:18790002

  14. Gonadal transcriptome analysis of wild contaminated female European eels during artificial gonad maturation.

    PubMed

    Baillon, Lucie; Oses, Jennifer; Pierron, Fabien; Bureau du Colombier, Sarah; Caron, Antoine; Normandeau, Eric; Lambert, Patrick; Couture, Patrice; Labadie, Pierre; Budzinski, Hélène; Dufour, Sylvie; Bernatchez, Louis; Baudrimont, Magalie

    2015-11-01

    Since the early 1980s, the population of European eels (Anguilla anguilla) has dramatically declined. Nowadays, the European eel is listed on the red list of threatened species (IUCN Red List) and is considered as critically endangered of extinction. Pollution is one of the putative causes for the collapse of this species. Among their possible effects, contaminants gradually accumulated in eels during their somatic growth phase (yellow eel stage) would be remobilized during their reproductive migration leading to potential toxic events in gonads. The aim of this study was to investigate the effects of organic and inorganic contaminants on the gonad development of wild female silver eels. Female silver eels from two sites with differing contamination levels were artificially matured. Transcriptomic analyses by means of a 1000 candidate gene cDNA microarray were performed on gonads after 11weeks of maturation to get insight into the mechanisms of toxicity of contaminants. The transcription levels of several genes, that were associated to the gonadosomatic index (GSI), were involved in mitotic cell division but also in gametogenesis. Genes associated to contaminants were mainly involved in the mechanisms of protection against oxidative stress, in DNA repair, in the purinergic signaling pathway and in steroidogenesis, suggesting an impairment of gonad development in eels from the polluted site. This was in agreement with the fact that eels from the reference site showed a higher gonad growth in comparison to contaminated fish. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. A Novel igf3 Gene in Common Carp (Cyprinus carpio): Evidence for Its Role in Regulating Gonadal Development

    PubMed Central

    Zhu, Wenbin; Fu, Jianjun; Dong, Juanjuan; Dong, Zaijie

    2016-01-01

    Since the insulin-like growth factor 3 (igf3) gene was recently discovered in fish ovary, its function in the gonads has received much attention. In this study, we isolated two igf3 subtypes from common carp (Cyprinus carpio), which comprised full-length cDNA of 707 and 1153 nucleotides encoding 205 and 198 amino acids (aa), respectively. The Igf3 aa sequence had the highest gene homology of 72% with the corresponding sequence in zebrafish (Danio rerio). Phylogenetic tree construction revealed that the C. carpio igf3 gene was first clustered with D. rerio and then with other teleost species. Igf3 mRNA was widely expressed, with expression being highest in the gonads and blood. In the gonad development stage, igf3a mRNA expression was highest in the maturity and recession stage of the ovary, and decline phase of the testis, while igf3b was highest in the recession and fully mature periods of the ovaries and testes, respectively. Western blotting of testis protein samples showed two bands of approximately 21 kDa and 34 kDa corresponding to the calculated molecular mass of the two Igf3 subtypes; no signal was detected in the ovary. The Igf3 protein was localized in the ovary granulosa cells and testis spermatogonium and spermatids. 17β-Ethinylestradiol treatment increased both ovary and testis igf3 mRNA expression. These findings suggest that Igf3 may play an important role in C. carpio gonadal development. PMID:28002497

  16. Developmental staging of male murine embryonic gonad by SAGE analysis

    PubMed Central

    Lee, Tin-Lap; Li, Yunmin; Alba, Diana; Vong, Queenie P.; Wu, Shao-Ming; Baxendale, Vanessa; Rennert, Owen M.; Lau, Yun-Fai Chris; Chan, Wai-Yee

    2012-01-01

    Despite the identification of key genes such as Sry integral to embryonic gonadal development, the genomic classification and identification of chromosomal activation of this process is still poorly understood. To better understand the genetic regulation of gonadal development, we performed Serial Analysis of Gene Expression (SAGE) to profile the genes and novel transcripts, and an average of 152,000 tags from male embryonic gonads at E10.5 (embryonic day 10.5), E11.5, E12.5, E13.5, E15.5 and E17.5 were analyzed. A total of 275,583 non-singleton tags that do not map to any annotated sequence were identified in the six gonad libraries, and 47,255 tags were mapped to 24,975 annotated sequences, among which 987 sequences were uncharacterized. Utilizing an unsupervised pattern identification technique, we established molecular staging of male gonadal development. Rather than providing a static descriptive analysis, we developed algorithms to cluster the SAGE data and assign SAGE tags to a corresponding chromosomal position; these data are displayed in chromosome graphic format. A prominent increase in global genomic activity from E10.5 to E17.5 was observed. Important chromosomal regions related to the developmental processes were identified and validated based on established mouse models with developmental disorders. These regions may represent markers for early diagnosis for disorders of male gonad development as well as potential treatment targets. PMID:19376482

  17. Development and biological function of the female gonads and genitalia in IGF-I deficiency -- Laron syndrome as a model.

    PubMed

    Laron, Zvi

    2006-01-01

    Laron syndrome (LS) or primary GH insensitivity is a unique human model to study the effects of congenital IGF-I deficiency. Within our cohort of 63 patients with LS, 15 female patients were regularly followed since birth or infancy, throughout puberty. We observed that they were short at birth, with small genitalia and gonads -- during puberty, developed delayed puberty but eventually reached between 16 and 19 1/2 years full sexual development. Reproduction is unaffected at a young adult age. It is concluded that IGF-I in concert with the sex hormones has a modulatory but not essential function on female sexual development and maturation.

  18. Pisrt1, a gene implicated in XX sex reversal, is expressed in gonads of both sexes during mouse development.

    PubMed

    Loffler, Kelly A; Combes, Alexander N; Wilhelm, Dagmar; Beverdam, Annemiek; Bowles, Jo; Koopman, Peter

    2005-01-01

    XX sex reversal syndromes not involving Sry provide an opportunity to identify and study genes important for sexual development. The polled intersex syndrome (PIS) in goats, which shares some features with blepharophimosis, ptosis, epicanthus inversus syndrome (BPES) in humans, exemplifies such syndromes. BPES is caused by defects in the forkhead transcription factor gene FOXL2, while PIS is caused by a large deletion of goat chromosome 1q43 that affects transcription of the genes Pisrt1 and Foxl2. Pisrt1 is a non-translated gene that has a sexually dimorphic expression pattern in goats. Here, we describe the structure and expression of the mouse Pisrt1 locus, to investigate its likely role in ovarian development more broadly in mammals. This gene showed some sequence similarity, and was found in a similar genomic context, to its goat and human orthologues. Expression analyses indicated that Pisrt1 is transcribed, and its mRNA polyadenylated and exported to the cytoplasm, but no significant open reading frames were found in a 1.5kb mouse genomic region corresponding to goat Pisrt1. Pisrt1 transcripts were expressed very broadly among tissues of the developing mouse embryo, and at similar levels in male and female gonads at each stage examined, as determined by in situ hybridisation and RT-PCR. This profile of expression suggests that Pisrt1 is unlikely to contribute to sex-specific events during gonadal development in mice and that divergent pathways of ovarian development operate among different mammalian species.

  19. The interactive effect of dietary protein and vitamin levels on the depression of gonadal development in growing male rats kept under disturbed daily rhythm.

    PubMed

    Hanai, Miho; Esashi, Takatoshi

    2007-04-01

    The purpose of this study was to clarify the effects of nutrients on the gonadal development of male rats kept under constant darkness as a model of disturbed daily rhythm. The present study examined protein and vitamins, and their interactions. This study was based on three-way ANOVA; the three factors were lighting conditions, dietary protein and dietary vitamins, respectively. The levels of dietary protein were low or normal: 9% casein or 20% casein. The levels of dietary vitamins were low, normal or high: 1/3.3 of normal (AIN-93G diet) content, normal content, or three times the normal content, respectively. Other compositions were the same as those of the AIN-93G diet, and six kinds of experimental diet were prepared. Four-week-old rats (Fischer 344 strain) were kept under constant darkness or normal lighting (12-h light/dark cycle) for 4 wk. After 4 wk, the gonadal weights and serum testosterone content were evaluated. In the constant darkness groups (D-groups), the low-protein diet induced reduction of gonadal organ weights and serum testosterone concentrations. This reduction of gonadal organ weights was exacerbated by progressively higher levels of dietary vitamins. In the case of a normal-protein diet, the depression of gonadal development was not accelerated by high-vitamin intake. In the normal lighting groups (N-groups), the low-protein and high-vitamin diet slightly depressed gonadal development. These results suggest that the metabolism of protein and vitamins is different in rats being kept under constant darkness, and that excess dietary vitamins have an adverse effect on gonadal development in rats fed a low-protein diet.

  20. Integrated analysis of miRNA and mRNA expression profiles in tilapia gonads at an early stage of sex differentiation.

    PubMed

    Tao, Wenjing; Sun, Lina; Shi, Hongjuan; Cheng, Yunying; Jiang, Dongneng; Fu, Beide; Conte, Matthew A; Gammerdinger, William J; Kocher, Thomas D; Wang, Deshou

    2016-05-04

    MicroRNAs (miRNAs) represent a second regulatory network that has important effects on gene expression and protein translation during biological process. However, the possible role of miRNAs in the early stages of fish sex differentiation is not well understood. In this study, we carried an integrated analysis of miRNA and mRNA expression profiles to explore their possibly regulatory patterns at the critical stage of sex differentiation in tilapia. We identified 279 pre-miRNA genes in tilapia genome, which were highly conserved in other fish species. Based on small RNA library sequencing, we identified 635 mature miRNAs in tilapia gonads, in which 62 and 49 miRNAs showed higher expression in XX and XY gonads, respectively. The predicted targets of these sex-biased miRNAs (e.g., miR-9, miR-21, miR-30a, miR-96, miR-200b, miR-212 and miR-7977) included genes encoding key enzymes in steroidogenic pathways (Cyp11a1, Hsd3b, Cyp19a1a, Hsd11b) and key molecules involved in vertebrate sex differentiation (Foxl2, Amh, Star1, Sf1, Dmrt1, and Gsdf). These genes also showed sex-biased expression in tilapia gonads at 5 dah. Some miRNAs (e.g., miR-96 and miR-737) targeted multiple genes involved in steroid synthesis, suggesting a complex miRNA regulatory network during early sex differentiation in this fish. The sequence and expression patterns of most miRNAs in tilapia are conserved in fishes, indicating the basic functions of vertebrate miRNAs might share a common evolutionary origin. This comprehensive analysis of miRNA and mRNA at the early stage of molecular sex differentiation in tilapia XX and XY gonads lead to the discovery of differentially expressed miRNAs and their putative targets, which will facilitate studies of the regulatory network of molecular sex determination and differentiation in fishes.

  1. Ex vivo culture of human fetal gonads: manipulation of meiosis signalling by retinoic acid treatment disrupts testis development.

    PubMed

    Jørgensen, A; Nielsen, J E; Perlman, S; Lundvall, L; Mitchell, R T; Juul, A; Rajpert-De Meyts, E

    2015-10-01

    '-deoxyuridine (BrdU) incorporation assay. A novel ex vivo 'hanging-drop' culture model for human fetal gonads was successfully established. Continued proliferation of cells without signs of increased apoptosis was observed after 2 weeks of culture. In cultured fetal ovaries treated with RA, an increased number of meiotic germ cells (P < 0.05) and DMRT1-positive oogonia initiating meiosis (P < 0.05) was observed, which is in agreement with a previous study. In fetal testes, RA-treatment resulted in a decreased number of gonocytes (P < 0.05), a reduced percentage of proliferating gonocytes (P < 0.05), altered expression pattern of the somatic cell markers AMH and COUP-TFII, as well as disrupted seminiferous cord structure and testis morphology. The number of samples included in this study was relatively small due to the limited availability of human fetal tissue. The hanging-drop culture, similarly to other organ culture approaches, allows studies of germ cell-somatic niche interactions and determination of effects after manipulating specific signalling pathways. Our novel finding of disrupted fetal testis development after treatment with RA indicates that abnormal meiosis regulation can potentially cause gonadal dysgenesis. Further studies will elucidate the exact mechanisms and timing of observed effects. This work was supported in part by an ESPE Research Fellowship, sponsored by Novo Nordisk A/S to A.Jø. Additional funding for this project was obtained from The Research Council of the Capital Region of Denmark (E.R.-D.M.), The Research Fund at Rigshospitalet (A.Ju. and J.E.N.), Familien Erichssens Fund (A.Jø.), Dagmar Marshalls Fund (A.Jø.) and Aase & Ejnar Danielsens Fund (A.Jø.). The authors have no conflicts of interest. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Discovery and identification of candidate sex-related genes based on transcriptome sequencing of Russian sturgeon (Acipenser gueldenstaedtii) gonads.

    PubMed

    Chen, Yadong; Xia, Yongtao; Shao, Changwei; Han, Lei; Chen, Xuejie; Yu, Mengjun; Sha, Zhenxia

    2016-07-01

    As the Russian sturgeon (Acipenser gueldenstaedtii) is an important food and is the main source of caviar, it is necessary to discover the genes associated with its sex differentiation. However, the complicated life and maturity cycles of the Russian sturgeon restrict the accurate identification of sex in early development. To generate a first look at specific sex-related genes, we sequenced the transcriptome of gonads in different development stages (1, 2, and 5 yr old stages) with next-generation RNA sequencing. We generated >60 million raw reads, and the filtered reads were assembled into 263,341 contigs, which produced 38,505 unigenes. Genes involved in signal transduction mechanisms were the most abundant, suggesting that development of sturgeon gonads is under control of signal transduction mechanisms. Differentially expressed gene analysis suggests that more genes for protein synthesis, cytochrome c oxidase subunits, and ribosomal proteins were expressed in female gonads than in male. Meanwhile, male gonads expressed more transposable element transposase, reverse transcriptase, and transposase-related genes than female. In total, 342, 782, and 7,845 genes were detected in intersex, male, and female transcriptomes, respectively. The female gonad expressed more genes than the male gonad, and more genes were involved in female gonadal development. Genes (sox9, foxl2) are differentially expressed in different sexes and may be important sex-related genes in Russian sturgeon. Sox9 genes are responsible for the development of male gonads and foxl2 for female gonads. Copyright © 2016 the American Physiological Society.

  3. Effects of the antiandrogens, vinclozolin and cyproterone acetate on gonadal development in the Japanese medaka (Oryzias latipes).

    PubMed

    Kiparissis, Yiannis; Metcalfe, Tracy L; Balch, Gordon C; Metcalfe, Chris D

    2003-05-29

    This study was focused on determining the effects of exposure to antiandrogens on the gonadal development of Japanese medaka (Oryzias latipes). Test compounds included the fungicide, vinclozolin and the clinical antiandrogen, cyproterone acetate. Newly hatched medaka were exposed to aqueous solutions of vinclozolin (2500 microg/l) and the vinclozolin fungicide formulation, Ronilan (1000 and 5000 microg/l) and cyproterone acetate (1 and 10 microg/l), for 3 months. Histological evaluation of the gonadal tissues of exposed fish indicated that the 5000 microg/l concentration of the vinclozolin formulation (Ronilan) induced a low incidence of intersex (i.e. testis-ova) and the 2500 microg/l concentration of vinclozolin-affected spermatogenesis in males. Also, the vinclozolin treatments induced moderate ovarian atresia. Cyproterone acetate also induced a low incidence of testis-ova, but in contrast to the vinclozolin treatment the amount of ovarian tissue in the testis-ova was equal to or greater than the amount of testicular tissue. In the cyproterone acetate treatments, both oogenesis and spermatogenesis were moderately inhibited at all test concentrations. The results of this study indicate that antiandrogens have the potential to alter testicular development and gametogenesis in fish. However, research is needed to determine the mechanisms by which antiandrogens affect fish.

  4. Single-Cell RNA-Seq Analysis Maps Development of Human Germline Cells and Gonadal Niche Interactions.

    PubMed

    Li, Li; Dong, Ji; Yan, Liying; Yong, Jun; Liu, Xixi; Hu, Yuqiong; Fan, Xiaoying; Wu, Xinglong; Guo, Hongshan; Wang, Xiaoye; Zhu, Xiaohui; Li, Rong; Yan, Jie; Wei, Yuan; Zhao, Yangyu; Wang, Wei; Ren, Yixin; Yuan, Peng; Yan, Zhiqiang; Hu, Boqiang; Guo, Fan; Wen, Lu; Tang, Fuchou; Qiao, Jie

    2017-06-01

    Human fetal germ cells (FGCs) are precursors to sperm and eggs and are crucial for maintenance of the species. However, the developmental trajectories and heterogeneity of human FGCs remain largely unknown. Here we performed single-cell RNA-seq analysis of over 2,000 FGCs and their gonadal niche cells in female and male human embryos spanning several developmental stages. We found that female FGCs undergo four distinct sequential phases characterized by mitosis, retinoic acid signaling, meiotic prophase, and oogenesis. Male FGCs develop through stages of migration, mitosis, and cell-cycle arrest. Individual embryos of both sexes simultaneously contain several subpopulations, highlighting the asynchronous and heterogeneous nature of FGC development. Moreover, we observed reciprocal signaling interactions between FGCs and their gonadal niche cells, including activation of the bone morphogenic protein (BMP) and Notch signaling pathways. Our work provides key insights into the crucial features of human FGCs during their highly ordered mitotic, meiotic, and gametogenetic processes in vivo. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. De novo Transcriptome Analysis of Portunus trituberculatus Ovary and Testis by RNA-Seq: Identification of Genes Involved in Gonadal Development

    PubMed Central

    Meng, Xian-liang; Liu, Ping; Jia, Fu-long; Li, Jian; Gao, Bao-Quan

    2015-01-01

    The swimming crab Portunus trituberculatus is a commercially important crab species in East Asia countries. Gonadal development is a physiological process of great significance to the reproduction as well as commercial seed production for P. trituberculatus. However, little is currently known about the molecular mechanisms governing the developmental processes of gonads in this species. To open avenues of molecular research on P. trituberculatus gonadal development, Illumina paired-end sequencing technology was employed to develop deep-coverage transcriptome sequencing data for its gonads. Illumina sequencing generated 58,429,148 and 70,474,978 high-quality reads from the ovary and testis cDNA library, respectively. All these reads were assembled into 54,960 unigenes with an average sequence length of 879 bp, of which 12,340 unigenes (22.45% of the total) matched sequences in GenBank non-redundant database. Based on our transcriptome analysis as well as published literature, a number of candidate genes potentially involved in the regulation of gonadal development of P. trituberculatus were identified, such as FAOMeT, mPRγ, PGMRC1, PGDS, PGER4, 3β-HSD and 17β-HSDs. Differential expression analysis generated 5,919 differentially expressed genes between ovary and testis, among which many genes related to gametogenesis and several genes previously reported to be critical in differentiation and development of gonads were found, including Foxl2, Wnt4, Fst, Fem-1 and Sox9. Furthermore, 28,534 SSRs and 111,646 high-quality SNPs were identified in this transcriptome dataset. This work represents the first transcriptome analysis of P. trituberculatus gonads using the next generation sequencing technology and provides a valuable dataset for understanding molecular mechanisms controlling development of gonads and facilitating future investigation of reproductive biology in this species. The molecular markers obtained in this study will provide a fundamental basis for

  6. Expression of putative sex-determining genes during the thermosensitive period of gonad development in the snapping turtle, Chelydra serpentina.

    PubMed

    Rhen, T; Metzger, K; Schroeder, A; Woodward, R

    2007-01-01

    Modes of sex determination are quite variable in vertebrates. The developmental decision to form a testis or an ovary can be influenced by one gene, several genes, environmental variables, or a combination of these factors. Nevertheless, certain morphogenetic aspects of sex determination appear to be conserved in amniotes. Here we clone fragments of nine candidate sex-determining genes from the snapping turtle Chelydra serpentina, a species with temperature-dependent sex determination (TSD). We then analyze expression of these genes during the thermosensitive period of gonad development. In particular, we compare gene expression profiles in gonads from embryos incubated at a male-producing temperature to those from embryos at a female-producing temperature. Expression of Dmrt1 and Sox9 mRNA increased gradually at the male-producing temperature, but was suppressed at the female-producing temperature. This finding suggests that Dmrt1 and Sox9 play a role in testis development. In contrast, expression of aromatase, androgen receptor (Ar), and Foxl2 mRNA was constant at the male-producing temperature, but increased several-fold in embryos at the female-producing temperature. Aromatase, Ar, and Foxl2 may therefore play a role in ovary development. In addition, there was a small temperature effect on ER alpha expression with lower mRNA levels found in embryos at the female-producing temperature. Finally, Dax1, Fgf9, and SF-1 were not differentially expressed during the sex-determining period, suggesting these genes are not involved in sex determination in the snapping turtle. Comparison of gene expression profiles among amniotes indicates that Dmrt1 and Sox9 are part of a core testis-determining pathway and that Ar, aromatase, ER alpha, and Foxl2 are part of a core ovary-determining pathway. 2007 S. Karger AG, Basel

  7. Sexually dimorphic effects of NMDA receptor antagonism on brain-pituitary-gonad axis development in the platyfish

    NASA Technical Reports Server (NTRS)

    Flynn, Katherine M.; Miller, Shelly A.; Sower, Stacia A.; Schreibman, Martin P.

    2002-01-01

    The N-methyl-D-aspartate glutamate receptor (NMDAR) is found in hypothalamic nuclei involved in the regulation of reproduction in several species of mammals and fishes. NMDAR is believed to affect reproductive development and function by regulating gonadotropin releasing hormone (GnRH)-producing cells. These pathways are likely to be sexually dimorphic, as are several other neurotransmitter systems involved in reproductive function. In this report, male and female platyfish received intraperitoneal injections of 0, 5, 10, 20, 40 or 60 microg/g body wt. of the non-competitive NMDAR antagonist MK-801. Injections began at 6 weeks of age and continued thrice weekly until control animals reached puberty, as evidenced by anal fin maturation. The percent of pubescent animals was significantly affected by sex and treatment, with fewer MK-801-injected females in puberty than control females at each dose (P<0.001), and fewer pubescent females than males at 10, 20 and 40 microg/g (P<0.05). There were no MK-801-related effects in males. Histological analyses revealed typical immature gonads and pituitary glands in treated females, and typical mature morphology in control females and all males. Immunocytochemical distribution of the R1 subunit of the NMDAR within the brain-pituitary-gonad (BPG) axis was limited to GnRH-containing brain cells in all animals; however, NMDAR1 distribution was in an immature pattern in treated females and a mature pattern in all others. Neural concentrations of GnRH were unaffected by MK-801 treatment in both sexes. These data suggest that in the platyfish, NMDAR influence on reproductive development is sexually dimorphic and occurs at, or above, the level of GnRH-containing cells of the BPG axis.

  8. Early Developments, 1998.

    ERIC Educational Resources Information Center

    Little, Loyd, Ed.

    1998-01-01

    This document consists of the two 1998 issues of a journal reporting new research in early child development conducted by the Frank Porter Graham Child Development Center at the University of North Carolina at Chapel Hill. In the Spring 1998 issue, articles highlight the Center's diverse cross-cultural projects and global research, training and…

  9. Gonadal hormones do not alter the development of antinociceptive tolerance to delta-9-tetrahydrocannabinol in adult rats

    PubMed Central

    Wakley, Alexa A; Wiley, Jenny L; Craft, Rebecca M

    2015-01-01

    The purpose of this study was to determine whether sex differences in the development of antinociceptive tolerance to delta-9-tetrahydrocannabinol (THC) are due to activational effects of gonadal hormones. Rats were sham-gonadectomized (sham-GDX) or gonadectomized (GDX). GDX females received no hormone replacement (GDX+0), estradiol (GDX+E2), progesterone (GDX+P4), or both (GDX+E2/P4). GDX male rats received no hormone (GDX+0) or testosterone (GDX+T). Two weeks later, antinociceptive potency of THC was determined (pre-chronic test) on the warm water tail withdrawal and paw pressure assays. Vehicle or a sex-specific THC dose (females, 5.7 mg/kg, males, 9.9 mg/kg) was administered twice-daily for 9 days, then the THC dose-effect curves were re-determined (post-chronic test). On the pre-chronic test (both assays), THC was more potent in sham-GDX females than males, and gonadectomy did not alter this sex difference. In GDX females, P4 significantly decreased THC’s antinociceptive potency, whereas E2 had no effect. In GDX males, T did not alter THC’s antinociceptive potency. After chronic THC treatment, THC’s antinociceptive potency was decreased more in sham-GDX females than males, on the tail withdrawal test; this sex difference in tolerance was not altered in GDX or hormone-treated groups. These results suggest that greater antinociceptive tolerance in females, which occurred despite females receiving 40% less THC than males, is not due to activational effects of gonadal hormones. PMID:25863271

  10. Gonad development in Midas cichlids and the evolution of sex change in fishes.

    PubMed

    Oldfield, Ronald G

    2011-01-01

    Some fishes mature and function as one sex and later transform to the other sex in response to social interactions. Previous evidence suggested that a change in developmental timing may be involved in the evolution of adult sex change in fishes. The most recent support for this idea came from reports that sex in the Midas cichlid, Amphilophus citrinellus, was determined by social conditions experienced at the juvenile stage. Differentiation as a male was reported to be dependent on large body size relative to group-mates, and thought to be mediated through aggressive interactions. Here I demonstrate that socially controlled sex determination does not occur as was originally reported. Previously, I found that sex was not associated with body size in juveniles either in nature or in captivity. Similarly, I found no association between aggressive behavior and sex in juveniles. I later demonstrated that socially controlled sex determination does not typically occur in the Midas cichlid and closely related species and supported an alternative mechanism to explain large body size in adult males. Finally, in the current study I analyze gonad histology of fish from the same population used by the original authors and lay to rest the idea of socially controlled sex determination in this species. Recent observations of socially controlled sex determination in juveniles of species that typically change sex at the adult stage are examples of phenotypic plasticity, not genetic variation. Therefore, juvenile socially controlled sex determination does not support a theory that a change in developmental timing is involved in the evolution of adult sex change in fishes. © 2011 Wiley Periodicals, Inc.

  11. GONADAL DEVELOPMENT AND ENDOCRINE RESPONSES IN JAPANESE MEDAKA (ORYZIAS LATIPES) EXPOSED TO O,P'-DDT IN WATER OR THROUGH MATERNAL TRANSFER

    EPA Science Inventory

    Various isomers and metabolites of DDT disrupt endocrine systems and gonadal development in fish andxwildlife and o,p'-DDT has been shown to be a relatively potent estrogen agonist. In this study, we exposed Japanese medaka (Oryzias latipes) to o,p'-DDT using two exposure protoco...

  12. Specific Roles for 17ß-Estradiol versus Gonad Development in Nutrient Partitioning and Regulation of Nutrient- and Growth-Related Mechanisms During Sexual Maturation in Rainbow Trout

    USDA-ARS?s Scientific Manuscript database

    The contribution of sex steroids to nutrient partitioning and energy balance during gonad development was studied in rainbow trout (Oncorhynchus mykiss). Nineteen month old triploid (3N) female rainbow trout were fed a diet supplemented with 17ß-estradiol (E2) at 30 mg steroid/kg diet for a 1 month...

  13. Early Childhood Development.

    ERIC Educational Resources Information Center

    Koh, Edgar, Ed.

    1989-01-01

    Focused on early childhood development, this "UNICEF Intercom" asserts that developmental programs should aim to give children a fair chance at growth beyond survival. First presented are moral, scientific, social equity, economic, population, and programatic arguments for looking beyond the fundamental objective of saving young lives.…

  14. Early Program Development

    NASA Image and Video Library

    1971-01-01

    This 1971 artist's concept shows a Nuclear Shuttle and an early Space Shuttle docked with an Orbital Propellant Depot. As envisioned by Marshall Space Flight Center Program Development persornel, an orbital modular propellant storage depot, supplied periodically by the Space Shuttle or Earth-to-orbit fuel tankers, would be critical in making available large amounts of fuel to various orbital vehicles and spacecraft.

  15. Early Program Development

    NASA Image and Video Library

    1970-01-01

    This artist's concept from 1970 shows a Nuclear Shuttle docked to an Orbital Propellant Depot and an early Space Shuttle. As envisioned by Marshall Space Flight Center Program Development plarners, the Nuclear Shuttle, in either manned or unmanned mode, would deliver payloads to lunar orbit or other destinations then return to Earth orbit for refueling and additonal missions.

  16. Effect of dietary administration of letrozole and tamoxifen on gonadal development, sex differentiation and biochemical changes in common carp (Cyprinus carpio L.).

    PubMed

    Singh, Atul K; Srivastava, P P; Verma, Rita; Srivastava, Sharad C; Kumar, Dinesh; Ansari, Abubakar

    2015-03-01

    The effect of letrozole and tamoxifen on the specific growth rate (SGR; % day(-1)), gonado-somatic index (GSI), total haemoglobin (g%), gonadal and serum protein as well as lipid, sex differentiation and 17β-oestradiol levels were studied in sexually undifferentiated Cyprinus carpio fingerlings 30 days post fertilisation (30 dpf) for 60 days. Results showed decreased GSI with tamoxifen treatment whereas letrozole increased it. There were reduced protein, lipid, triglyceride and cholesterol levels after treatment with tamoxifen and letrozole during gonadal development. Tamoxifen (200mgkg(-1) feed) induced 82.5% masculinisation, whereas letrozole in the same dose produced 98.5% males. Gonadal 17β-oestradiol significantly declined from 86.0±1.41pg per 100mg (control) to 45.5±1.94pg per 100mg with tamoxifen and 36.0±0.72pg per 100mg with letrozole treatment. Similarly, serum 17β-oestradiol levels also decreased after tamoxifen and letrozole treatments. Testicular development in 37.8% of fish treated with tamoxifen and letrozole was found to be more advanced (spermatocytes) than in the control (spermatogonium); however, there was reduced ovarian growth and increased atresia. It was concluded that letrozole and tamoxifen both significantly affect sex differentiation and gonadal maturity in C. carpio leading to the production of sex-reversed males, yet the effect of letrozole was more potent.

  17. Pod-1/Capsulin shows a sex- and stage-dependent expression pattern in the mouse gonad development and represses expression of Ad4BP/SF-1.

    PubMed

    Tamura, M; Kanno, Y; Chuma, S; Saito, T; Nakatsuji, N

    2001-04-01

    Mammalian sex-determination and differentiation are controlled by several genes, such as Sry, Sox-9, Dax-1 and Mullerian inhibiting substance (MIS), but their upstream and downstream genes are largely unknown. Ad4BP/SF-1, encoding a zinc finger transcription factor, plays important roles in gonadogenesis. Disruption of this gene caused disappearance of the urogenital system including the gonad. Ad4BP/SF-1, however, is also involved in the sex differentiation of the gonad at later stages, such as the regulation of steroid hormones and MIS. Pod-1/Capsulin, a member of basic helix-loop-helix transcription factors, is expressed in a pattern closely related but mostly complimentary to that of the Ad4BP/SF-1 expression in the developing gonad. In the co-transfection experiment using cultured cells, overexpression of Pod-1/Capsulin repressed expression of a reporter gene that carried the upstream regulatory region of the Ad4BP/SF-1 gene. Furthermore, forced expression of Pod-1/Capsulin repressed expression of Ad4BP/SF-1 in the Leydig cell-derived I-10 cells. These results suggest that Pod-1/Capsulin may play important roles in the development and sex differentiation of the mammalian gonad via transcriptional regulation of Ad4BP/SF-1.

  18. [Lipid variation in oocytes of the jellyfish Stomolophus meleagris (Scyphozoa: Rhizostomeae) from Las Guasimas Lagoon, Mexico, during gonadal development].

    PubMed

    Carvalho-Saucedo, Liliana; García-Domínguez, Federico; Rodríguez-Jaramillo, Carmen; López-Martínez, Juana

    2010-03-01

    The jellyfish Stomolophus meleagris has potential for commercial exploitation but there is little information on their reproductive biology. This paper seeks to evaluate some biochemical and demographic characteristics of the species. Samples were taken monthly during 2005 and 2006. Jellyfish collected in 2005 were used to describe the characteristics and quantity of oocyte triglycerides and phospholipids with the Sudan black technique, and to ascertain the degree of gonadal development and sex ratio by the hematoxylin-eosin technique. The 2006 jellyfish were used to determine the size at first maturity and protein and total lipids contents. Four stages of development in both sexes were determined, with a continuous gamete development. The highest percentage of mature organisms was recorded in April. The proportion of sexes was 0.7:1.3. We found higher concentrations of triglycerides than phospholipids in the cytoplasm. There was a positive correlation between triglycerides and the diameter of the oocyte. The size at first maturity for both sexes was 105 mm. The highest protein and lipids contents were obtained in April and March respectively.

  19. Characterization of the Epigenetic Changes During Human Gonadal Primordial Germ Cells Reprogramming.

    PubMed

    Eguizabal, C; Herrera, L; De Oñate, L; Montserrat, N; Hajkova, P; Izpisua Belmonte, J C

    2016-09-01

    Epigenetic reprogramming is a central process during mammalian germline development. Genome-wide DNA demethylation in primordial germ cells (PGCs) is a prerequisite for the erasure of epigenetic memory, preventing the transmission of epimutations to the next generation. Apart from DNA demethylation, germline reprogramming has been shown to entail reprogramming of histone marks and chromatin remodelling. Contrary to other animal models, there is limited information about the epigenetic dynamics during early germ cell development in humans. Here, we provide further characterization of the epigenetic configuration of the early human gonadal PGCs. We show that early gonadal human PGCs are DNA hypomethylated and their chromatin is characterized by low H3K9me2 and high H3K27me3 marks. Similarly to previous observations in mice, human gonadal PGCs undergo dynamic chromatin changes concomitant with the erasure of genomic imprints. Interestingly, and contrary to mouse early germ cells, expression of BLIMP1/PRDM1 persists in through all gestational stages in human gonadal PGCs and is associated with nuclear lysine-specific demethylase-1. Our work provides important additional information regarding the chromatin changes associated with human PGCs development between 6 and 13 weeks of gestation in male and female gonads. Stem Cells 2016;34:2418-2428. © 2016 AlphaMed Press.

  20. Impact of a gestational exposure to diesel exhaust on offspring gonadal development: experimental study in the rabbit.

    PubMed

    Bourdon, M; Torres-Rovira, L; Monniaux, D; Faure, C; Levy, R; Tarrade, A; Rousseau-Ralliard, D; Chavatte-Palmer, P; Jolivet, G

    2018-06-18

    The aim of the present work was to address experimentally the possible impact of exposure to air pollution during gestation on the differentiation and function of the gonads of the offspring using a rabbit model. Rabbits were exposed daily to diluted diesel exhaust gas or filtered air from the 3rd until the 27th day of gestation, during which time germ cells migrate in genital ridges and divide, and fetal sex is determined. Offspring gonads were collected shortly before birth (28th day of gestation) or after puberty (7.5 months after birth). The structure of the gonads was analyzed by histological and immunohistological methods. Serum concentrations of testosterone and anti-Müllerian hormone were determined using ELISA. The morphology and the endocrine function of the gonads collected just at the arrest of the exposure were similar in polluted and control animals in both sexes. No differences were observed as well in gonads collected after puberty. Sperm was collected at the head of the epididymis in adults. Sperm motility and DNA fragmentation were measured. Among all parameters analyzed, only the sperm DNA fragmentation rate was increased three-fold in exposed males. Mechanisms responsible for these modifications and their physiological consequences are to be further clarified.

  1. De novo disruption of promoter and exon 1 of STAR gene reveals essential role for gonadal development.

    PubMed

    Piya, Anil; Kaur, Jasmeet; Rice, Alan M; Bose, Himangshu S

    2017-01-01

    Cholesterol transport into the mitochondria is required for synthesis of the first steroid, pregnenolone. Cholesterol is transported by the steroidogenic acute regulatory protein (STAR), which acts at the outer mitochondrial membrane prior to its import. Mutations in the STAR protein result in lipoid congenital adrenal hyperplasia (CAH). Although the STAR protein consists of seven exons, biochemical analysis in nonsteroidogenic COS-1 cells showed that the first two were not essential for pregnenolone synthesis. Here, we present a patient with ambiguous genitalia, salt-lossing crisis within two weeks after birth and low cortisol levels. Sequence analysis of the STAR , including the exon-intron boundaries, showed the complete deletion of exon 1 as well as more than 50 nucleotides upstream of STAR promoter. Mitochondrial protein import with the translated protein through synthesis cassette of the mutant STAR lacking exon 1 showed protein translation, but it is less likely to have synthesized without a promoter in our patient. Thus, a full-length STAR gene is necessary for physiological mitochondrial cholesterol transport in vivo . STAR exon 1 deletion caused lipoid CAH.Exon 1 substitution does not affect biochemical activity.StAR promoter is responsible for gonadal development.

  2. [Effects of low doses of desmopressin (DDAPV) on gonadal and adrenal development, and on the testicular function and sperm motility].

    PubMed

    García-Pascual, I J; Sánchez-Yagüe, J; Rodríguez Hernández, M C; Paniagua Gómez-Alvárez, R

    1994-04-01

    The present study proved that desmopressin (DDAVP) (1 microgram DDAVP/12 h/5 días) does not affect ovary, testis and adrenal development in immature Wistar rats (17 days old), because the DDAVP does not modify the weight of the aforementioned organs as compared with the control group. Nevertheless, the male adults Wistar rats (80 days old) showed lower serum testosterone concentrations than the control group, after injection of 4 micrograms/day (2 micrograms/12 h) or 8 micrograms/day (4 micrograms/12 h) of DDAVP during a 5 days period time. Moreover, paradoxical significant lower concentrations of serum testosterone were found in 4 micrograms DDAVP/day-treated rats than in 8 micrograms DDAVP/day-treated ones. The former also showed a decreased number of spermatozoa as compared with the latter and with the control group. The percentage of mobile spermatozoa was lower in rats treated with both concentrations of DDAVP as compared with the control group. Therefore, desmopressin does not delay gonadal and adrenal growth in immature rats, but, at low doses, it affects the testicular function and the mobility of the spermatozoa in male adult rats.

  3. De novo disruption of promoter and exon 1 of STAR gene reveals essential role for gonadal development

    PubMed Central

    Piya, Anil; Kaur, Jasmeet; Rice, Alan M

    2017-01-01

    Summary Cholesterol transport into the mitochondria is required for synthesis of the first steroid, pregnenolone. Cholesterol is transported by the steroidogenic acute regulatory protein (STAR), which acts at the outer mitochondrial membrane prior to its import. Mutations in the STAR protein result in lipoid congenital adrenal hyperplasia (CAH). Although the STAR protein consists of seven exons, biochemical analysis in nonsteroidogenic COS-1 cells showed that the first two were not essential for pregnenolone synthesis. Here, we present a patient with ambiguous genitalia, salt-lossing crisis within two weeks after birth and low cortisol levels. Sequence analysis of the STAR, including the exon–intron boundaries, showed the complete deletion of exon 1 as well as more than 50 nucleotides upstream of STAR promoter. Mitochondrial protein import with the translated protein through synthesis cassette of the mutant STAR lacking exon 1 showed protein translation, but it is less likely to have synthesized without a promoter in our patient. Thus, a full-length STAR gene is necessary for physiological mitochondrial cholesterol transport in vivo. Learning points: STAR exon 1 deletion caused lipoid CAH. Exon 1 substitution does not affect biochemical activity. StAR promoter is responsible for gonadal development. PMID:28458886

  4. Molecular and morphological differentiation of testes and ovaries in relation to the thermosensitive period of gonad development in the snapping turtle, Chelydra serpentina.

    PubMed

    Rhen, Turk; Fagerlie, Ruby; Schroeder, Anthony; Crossley, Dane A; Lang, Jeffrey W

    2015-01-01

    Ambient temperatures during embryonic development determine gonadal sex in many reptiles. The temperature sensitive period for sex determination has been defined by shifting eggs between female- and male-producing temperatures in a few species. This phase spans 20-35% of embryogenesis in most species, which makes it difficult to define the mechanisms that transduce temperature into a signal for ovarian versus testicular development. We present an extensive set of studies that define a brief period when high temperature specifies, and then determines, ovarian fate in a northern population of snapping turtles, Chelydra serpentina. We shifted embryos from male to female temperatures, or vice versa, at various stages of development. Gonads in embryos incubated at female temperatures commit to ovarian fate earlier (by stage 18) than gonads in embryos incubated at male temperatures commit to testicular fate (by stages 19-21). In double shift studies, embryos were incubated at a female temperature, exposed to a male temperature for set times, and shifted back to the original temperature, or vice versa. The time required to induce ovarian development (≤6 days at female temperatures) was much shorter than the time required to induce testicular formation (>20 days at male temperatures). Differentiation of the gonads at the histological level occurred after the sex-determining period. Nevertheless, we found that a change in temperature rapidly (within 24h) influenced expression and splicing of WT1 mRNA: the absolute abundance of WT1 mRNA, the relative abundance of +KTS versus -KTS isoforms, as well as the ratio of +KTS:-KTS isoforms was higher in gonads at a male versus a female temperature. In conclusion, ovarian fate is more readily determined than testicular fate in snapping turtle embryos. The short sex-determining period in this species (6-8% of embryogenesis) will facilitate studies of molecular mechanisms for specification and determination of gonad fate by

  5. High-Throughput Sequencing Reveals Hypothalamic MicroRNAs as Novel Partners Involved in Timing the Rapid Development of Chicken (Gallus gallus) Gonads.

    PubMed

    Han, Wei; Zou, Jianmin; Wang, Kehua; Su, Yijun; Zhu, Yunfen; Song, Chi; Li, Guohui; Qu, Liang; Zhang, Huiyong; Liu, Honglin

    2015-01-01

    Onset of the rapid gonad growth is a milestone in sexual development that comprises many genes and regulatory factors. The observations in model organisms and mammals including humans have shown a potential link between miRNAs and development timing. To determine whether miRNAs play roles in this process in the chicken (Gallus gallus), the Solexa deep sequencing was performed to analyze the profiles of miRNA expression in the hypothalamus of hens from two different pubertal stages, before onset of the rapid gonad development (BO) and after onset of the rapid gonad development (AO). 374 conserved and 46 novel miRNAs were identified as hypothalamus-expressed miRNAs in the chicken. 144 conserved miRNAs were showed to be differentially expressed (reads > 10, P < 0.05) during the transition from BO to AO. Five differentially expressed miRNAs were validated by real-time quantitative RT-PCR (qRT-PCR) method. 2013 putative genes were predicted as the targets of the 15 most differentially expressed miRNAs (fold-change > 4.0, P < 0.01). Of these genes, 7 putative circadian clock genes, Per2, Bmal1/2, Clock, Cry1/2, and Star were found to be targeted multiple times by the miRNAs. qRT-PCR revealed the basic transcription levels of these clock genes were much higher (P < 0.01) in AO than in BO. Further functional analysis suggested that these 15 miRNAs play important roles in transcriptional regulation and signal transduction pathways. The results provide new insights into miRNAs functions in timing the rapid development of chicken gonads. Considering the characteristics of miRNA functional conservation, the results will contribute to the research on puberty onset in humans.

  6. Effects of spectral composition, photoperiod and light intensity on the gonadal development of Atlantic salmon Salmo salar in recirculating aquaculture systems (RAS)

    NASA Astrophysics Data System (ADS)

    Qiu, Denggao; Xu, Shihong; Song, Changbin; Chi, Liang; Li, Xian; Sun, Guoxiang; Liu, Baoliang; Liu, Ying

    2015-01-01

    Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement. However, when these operations are applied in commercial recirculating aquaculture systems (RAS) using standard lighting technology, sexual maturation is not suppressed. In this study, an L9 (33) orthogonal design was used to determine the effects of three factors (spectral composition, photoperiod, and light intensity) on the gonadal development of Atlantic salmon in RAS. We demonstrated that the photoperiod at the tested levels had a much greater effect on the gonadosomatic index and female Fulton condition factor than spectral composition and light intensity. The photoperiod had a significant effect on the secretion of sex steroids and melatonin ( P<0.05), and a short photoperiod delayed sex steroid and melatonin level increases. The three test factors had no significant effects on the survival rate, specific growth rate, relative weight gain, and male Fulton condition factor ( P>0.05). The optimum lighting levels in female and male Atlantic salmon were LD 8:16, 455 nm (or 625 nm), 8.60 W/m2; and LD 8:16, 8.60 W/m2, 455 nm respectively. These conditions not only delayed gonadal development, but also had no negative effects on Atlantic salmon growth in RAS. These results demonstrate that a combination of spectral composition, photoperiod and light intensity is effective at delaying the gonadal development of both male and female salmon in RAS.

  7. Effects of maternal separation, early handling, and gonadal sex on regional metabolic capacity of the preweanling rat brain

    PubMed Central

    Spivey, Jaclyn M.; Padilla, Eimeira; Shumake, Jason D.; Gonzalez-Lima, F.

    2010-01-01

    This is the first study to assess the effects of mother-infant separation on regional metabolic capacity in the preweanling rat brain. Mother-infant separation is generally known to be stressful for rat pups. Holtzman adolescent rats show a depressive-like behavioral phenotype after maternal separation during the preweanling period. However, information is lacking on the effects of maternal separation on the brains of rat pups. We addressed this issue by mapping the brains of preweanling Holtzman rat pups using cytochrome oxidase histochemistry, which reflects long-term changes in brain metabolic capacity, following two weeks of repeated, prolonged maternal separation, and compared this to both early handled and non-handled pups. Quantitative image analysis revealed that maternal separation reduced cytochrome oxidase activity in the medial prefrontal cortex and nucleus accumbens shell. Maternal separation reduced prefrontal cytochrome oxidase to a greater degree in female pups than in males. Early handling reduced cytochrome oxidase activity in the posterior parietal cortex, ventral tegmental area, and subiculum, but increased cytochrome oxidase activity in the lateral frontal cortex. The sex-dependent effects of early handling on cytochrome oxidase activity were limited to the medial prefrontal cortex. Regardless of separation group, females had greater cytochrome oxidase activity in the habenula and ventral tegmental area compared to males. These findings suggest that early life mother-infant separation results in dysfunction of prefrontal and mesolimbic regions in the preweanling rat brain that may contribute to behavioral changes later in life. PMID:20969837

  8. Effects of dietary exposure to brominated flame retardant BDE-47 on thyroid condition, gonadal development and growth of zebrafish

    USGS Publications Warehouse

    Torres, Leticia; Orazio, Carl E.; Peterman, Paul H.; Patino, Reynaldo

    2013-01-01

    Little is known about the effects of brominated flame retardants in teleosts and some of the information currently available is inconsistent. This study examined effects of dietary exposure to 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) on thyroid condition, body mass and size, and gonadal development of zebrafish. Pubertal, 49-day-old (posthatch) fish were fed diets without BDE-47 (control) or with 1, 5 or 25 μg/g BDE-47/diet. Treatments were conducted in triplicate 30-L tanks each containing 50 zebrafish, and 15 fish per treatment (5 per tank) were sampled at days 40, 80 and 120 of exposure. Measurements were taken of body mass, standard length, head depth and head length. Sex (at 40–120 days of exposure), germ cell stage (at 40 days) and thyroid condition (at 120 days; follicular cell height, colloid depletion, angiogenesis) were histologically determined. Whole-body BDE-47 levels at study completion were within the high end of levels reported in environmentally exposed (wild) fishes. Analysis of variance was used to determine differences among treatments at each sampling time. No effects were observed on thyroid condition or germ cell stage in either sex. Reduced head length was observed in females exposed to BDE-47 at 80 days but not at 40 or 120 days. In males, no apparent effects of BDE-47 were observed at 40 and 80 days, but fish exposed to 25 μg/g had lower body mass at 120 days compared to control fish. These observations suggest that BDE-47 at environmentally relevant whole-body concentrations does not affect thyroid condition or pubertal development of zebrafish but does affect growth during the juvenile-to-adult transition, especially in males.

  9. Effects of dietary exposure to brominated flame retardant BDE-47 on thyroid condition, gonadal development and growth of zebrafish.

    PubMed

    Torres, Leticia; Orazio, Carl E; Peterman, Paul H; Patiño, Reynaldo

    2013-10-01

    Little is known about the effects of brominated flame retardants in teleosts and some of the information currently available is inconsistent. This study examined effects of dietary exposure to 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) on thyroid condition, body mass and size, and gonadal development of zebrafish. Pubertal, 49-day-old (posthatch) fish were fed diets without BDE-47 (control) or with 1, 5 or 25 μg/g BDE-47/diet. Treatments were conducted in triplicate 30-L tanks each containing 50 zebrafish, and 15 fish per treatment (5 per tank) were sampled at days 40, 80 and 120 of exposure. Measurements were taken of body mass, standard length, head depth and head length. Sex (at 40-120 days of exposure), germ cell stage (at 40 days) and thyroid condition (at 120 days; follicular cell height, colloid depletion, angiogenesis) were histologically determined. Whole-body BDE-47 levels at study completion were within the high end of levels reported in environmentally exposed (wild) fishes. Analysis of variance was used to determine differences among treatments at each sampling time. No effects were observed on thyroid condition or germ cell stage in either sex. Reduced head length was observed in females exposed to BDE-47 at 80 days but not at 40 or 120 days. In males, no apparent effects of BDE-47 were observed at 40 and 80 days, but fish exposed to 25 μg/g had lower body mass at 120 days compared to control fish. These observations suggest that BDE-47 at environmentally relevant whole-body concentrations does not affect thyroid condition or pubertal development of zebrafish but does affect growth during the juvenile-to-adult transition, especially in males.

  10. Sex-specific gonadal and gene expression changes throughout development in fathead minnow

    EPA Science Inventory

    Although fathead minnows (Pimephales promelas) are commonly used as a model fish in endocrine disruption studies, none have characterized sex-specific baseline expression of genes involved in sex differentiation during development in this species. Using a sex-linked DNA marker t...

  11. Administration of kisspeptins accelerates gonadal development and alters gene expression in Moronids

    USDA-ARS?s Scientific Manuscript database

    The present study assesses the effects of chronic administration of peptides to fish, termed kisspeptins, which are the products of the KISS1 and KISS2 genes, and have been shown to control the development of puberty in animals. In aquaculture, one of the major obstacles to the commercial production...

  12. Steroid exposure during larval development of Xenopus laevis affects mRNA expression of the reproductive pituitary-gonadal axis in a sex- and stage-dependent manner.

    PubMed

    Urbatzka, Ralph; Lorenz, Claudia; Wiedemann, Caterina; Lutz, Ilka; Kloas, Werner

    2014-03-01

    Steroids are known to influence the reproductive pituitary-gonadal axis in adult amphibians. Here, we studied the effects of hormones on pituitary and gonadal mRNA expression during the development of Xenopus laevis. Tadpoles at NF 58 (prometamorphosis) and at NF 66 (freshly metamorphosed) were exposed for three days to 17β-estradiol (E2), tamoxifen (TAM), testosterone (T), dihydrotestosterone (DHT) at 10(-7)M, and flutamide (FLU) at 10(-6)M. In both genders at NF 58 and 66, T and DHT decreased luteinizing hormone beta (lhβ), but increased follicle stimulating hormone beta (fshβ), while FLU induced lhβ specifically in males. In the testis steroidogenic genes (p450 side chain cleavage enzyme, p450scc; steroid acute regulatory protein, star) at NF 58 showed a similar pattern as for lhβ, while the response at NF 66 was only partially present. In females, TAM induced lhβ at NF 58, while E2 decreased lhβ and increased fshβ at NF 66. In the ovaries, no alterations were observed for the steroidogenic genes. Summarizing, gonadotropic and steroidogenic mRNA expression may indicate control of androgen level during testis differentiation in male tadpoles at NF 58. In females the non-responsiveness of steroidogenic genes could be a sign of gonadal quiescence during pre-pubertal stages. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Reversing sex steroid deficiency and optimizing skeletal development in the adolescent with gonadal failure.

    PubMed

    Vanderschueren, Dirk; Vandenput, Liesbeth; Boonen, Steven

    2005-01-01

    During puberty, the acquisition of skeletal mass and areal bone mineral density (BMD) mainly reflects an increase in bone size (length and perimeters) and not true volumetric BMD. Sexual dimorphism in bone mass and areal BMD is also explained by differences in bone size (longer and wider bones in males) and not by differences in volumetric BMD. Androgens stimulate skeletal growth by activation of the androgen receptor, whereas estrogens (following aromatization of androgens and stimulation of estrogen receptors) have a biphasic effect on skeletal growth during puberty. Recent evidence from clinical cases has shown that many of the growth-promoting effects of the sex steroids are mediated through estrogens rather than androgens. In addition, skeletal maturation and epiphyseal fusion are also estrogen-dependent in both sexes. Nevertheless, independent actions of androgens in these processes also occur. Both sex steroids maintain volumetric BMD during puberty. Androgens interact with the growth hormone (GH)-insulin-like growth factor-I (IGF-I) axis neonatally, resulting in a sexual dimorphic GH pattern during puberty, whereas estrogens stimulate GH and hereby IGF-I in both sexes. Hypogonadism in adolescents impairs not only bone size but also maintenance of volumetric BMD, hereby severely reducing peak areal BMD. Delayed puberty in boys and Turner's syndrome in women impair both bone length and size, reducing areal BMD. Whether volumetric BMD is also reduced and whether fracture risk is increased in these conditions remains controversial. Replacing sex steroids according to a biphasic pattern (starting at low doses and ending at high-normal doses) seems the safest approach to reach targeted height and to optimize bone development.

  14. The interactive effect of dietary water-soluble vitamin levels on the depression of gonadal development in growing male rats kept under disturbed daily rhythm.

    PubMed

    Hanai, Miho; Esashi, Takatoshi

    2012-01-01

    The purpose of this study was to clarify the effects of nutrients on the gonadal development of male rats kept under constant darkness as a model of disturbed daily rhythm. In the present study we examined the effects of nine water-soluble vitamins. We selected 7 water-soluble vitamins (choline, nicotinic acid (NA), pantothenic acid (PA), vitamin B6 (VB6), vitamin B1 (VB1), vitamin B2 (VB2) and folic acid (FA)) as experimental factors for the first experiment (Ex. 1) and biotin and vitamin B12 (VB12) as experimental factors for the second experiment (Ex. 2). The dietary content of these vitamins was normal or six times the normal content. Lighting condition (L.C.) was also added as a factor. Four-week-old male rats (Fischer 344 strain) were kept under constant darkness or normal lighting (12-h light/dark cycle) for 4 wk. The depression of gonadal development in the constant darkness groups (D-groups) was shown. The L.C., PA, VB6 and VB1 influenced testes development, and these three vitamins had interactions with L.C. Among the normal lighting groups (N-groups), the highest value for testes weight was observed under the normal-PA, high-VB6 and high-B1 diet; on the other hand, among the D-groups, it was observed under the high-PA, normal-VB6 and normal-VB1 diet. The results showed that the depression of gonadal development in rats kept under disturbed daily rhythm was improved by getting a high amount of PA and normal amount of VB6 and VB1.

  15. Early Adolescent Ego Development.

    ERIC Educational Resources Information Center

    James, Michael A.

    1980-01-01

    Presented are the theoretical characteristics of social identity in early adolescence (ages 10 to 15). It is suggested that no longer is identity thought to begin with adolescence, but may have its beginnings in the preteen years. The article draws heavily on Eriksonian concepts. (Editor/KC)

  16. Early Program Development

    NASA Image and Video Library

    1969-01-01

    As part of the Space Task Group's recommendations for more commonality and integration in America's space program, Marshall Space Flight Center engineers proposed an orbiting propellant storage facility to augment Space Shuttle missions. In this artist's concept from 1969 an early version of the Space Shuttle is shown refueling at the facility.

  17. Early Program Development

    NASA Image and Video Library

    1969-01-01

    This 1969 artist's concept illustrates the use of three major elements of NASA's Integrated program, as proposed by President Nixon's Space Task Group. In Phases I and II, a Space Tug with a manipulator-equipped crew module removes a cargo module from an early Space Shuttle Orbiter and docks with it. In Phases III and IV, the Space Tug with attached cargo module flys toward a Nuclear Shuttle. As a result of the Space Task Group's recommendations for more commonality and integration in the American space program, Marshall Space Flight Center engineers studied many of the spacecraft depicted here.

  18. The large Maf factor Traffic Jam controls gonad morphogenesis in Drosophila.

    PubMed

    Li, Michelle A; Alls, Jeffrey D; Avancini, Rita M; Koo, Karen; Godt, Dorothea

    2003-11-01

    Interactions between somatic and germline cells are critical for the normal development of egg and sperm. Here we show that the gene traffic jam (tj) produces a soma-specific factor that controls gonad morphogenesis and is required for female and male fertility. tj encodes the only large Maf factor in Drosophila melanogaster, an orthologue of the atypical basic Leu zipper transcription factors c-Maf and MafB/Kreisler in vertebrates. Expression of tj occurs in somatic gonadal cells that are in direct contact with germline cells throughout development. In tj mutant gonads, somatic cells fail to inter-mingle and properly envelop germline cells, causing an early block in germ cell differentiation. In addition, tj mutant somatic cells show an increase in the level of expression for several adhesion molecules. We propose that tj is a critical modulator of the adhesive properties of somatic cells, facilitating germline-soma interactions that are essential for germ cell differentiation.

  19. Interactive effects of near-future temperature increase and ocean acidification on physiology and gonad development in adult Pacific sea urchin, Echinometra sp . A

    NASA Astrophysics Data System (ADS)

    Uthicke, S.; Liddy, M.; Nguyen, H. D.; Byrne, M.

    2014-09-01

    Increased atmospheric CO2 will have a twofold impact on future marine ecosystems, increasing global sea surface temperatures and uptake of CO2 (Ocean Acidification). Many experiments focus on the investigation of one of these stressors, but under realistic future climate predictions, these stressors may have interactive effects on individuals. Here, we investigate the effect of warming and acidification in combination. We test for interactive effects of potential near-future (2100) temperature (+2 to 3 °C) and pCO2 (~860-940 μAtm) levels on the physiology of the tropical echinoid Echinometra sp . A. The greatest reduction in growth was under simultaneous temperature and pH/ pCO2 stress (marginally significant temperature × pH/ pCO2 interaction). This was mirrored by the physiological data, with highest metabolic activity (measured as respiration and ammonium excretion) occurring at the increased temperature and pCO2 treatment, although this was not significant for excretion. The perivisceral coelomic fluid pH was ~7.5-7.6, as typical for echinoids, and showed no significant changes between treatments. Indicative of active calcification, internal magnesium and calcium concentrations were reduced compared to the external medium, but were not different between treatments. Gonad weight was lower at the higher temperature, and this difference was more distinct and statistically significant for males. The condition of the gonads assessed by histology declined in increased temperature and low pH treatments. The Echinometra grew in all treatments indicating active calcification of their magnesium calcite tests even as carbonate mineral saturation decreased. Our results indicate that the interactive temperature and pH effects are more important for adult echinoids than individual stressors. Although adult specimens grow and survive in near-future conditions, higher energy demands may influence gonad development and thus population maintenance.

  20. Transcriptional regulation of Drosophila gonad formation.

    PubMed

    Tripathy, Ratna; Kunwar, Prabhat S; Sano, Hiroko; Renault, Andrew D

    2014-08-15

    The formation of the Drosophila embryonic gonad, involving the fusion of clusters of somatic gonadal precursor cells (SGPs) and their ensheathment of germ cells, provides a simple and genetically tractable model for the interplay between cells during organ formation. In a screen for mutants affecting gonad formation we identified a SGP cell autonomous role for Midline (Mid) and Longitudinals lacking (Lola). These transcriptional factors are required for multiple aspects of SGP behaviour including SGP cluster fusion, germ cell ensheathment and gonad compaction. The lola locus encodes more than 25 differentially spliced isoforms and we have identified an isoform specific requirement for lola in the gonad which is distinct from that in nervous system development. Mid and Lola work in parallel in gonad formation and surprisingly Mid overexpression in a lola background leads to additional SGPs at the expense of fat body cells. Our findings support the idea that although the transcription factors required by SGPs can ostensibly be assigned to those being required for either SGP specification or behaviour, they can also interact to impinge on both processes. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Transcriptomic responses to environmental temperature by turtles with temperature-dependent and genotypic sex determination assessed by RNAseq inform the genetic architecture of embryonic gonadal development

    PubMed Central

    Radhakrishnan, Srihari; Literman, Robert; Neuwald, Jennifer; Severin, Andrew

    2017-01-01

    Vertebrate sexual fate is decided primarily by the individual’s genotype (GSD), by the environmental temperature during development (TSD), or both. Turtles exhibit TSD and GSD, making them ideal to study the evolution of sex determination. Here we analyze temperature-specific gonadal transcriptomes (RNA-sequencing validated by qPCR) of painted turtles (Chrysemys picta TSD) before and during the thermosensitive period, and at equivalent stages in soft-shell turtles (Apalone spinifera—GSD), to test whether TSD’s and GSD’s transcriptional circuitry is identical but deployed differently between mechanisms. Our data show that most elements of the mammalian urogenital network are active during turtle gonadogenesis, but their transcription is generally more thermoresponsive in TSD than GSD, and concordant with their sex-specific function in mammals [e.g., upregulation of Amh, Ar, Esr1, Fog2, Gata4, Igf1r, Insr, and Lhx9 at male-producing temperature, and of β-catenin, Foxl2, Aromatase (Cyp19a1), Fst, Nf-kb, Crabp2 at female-producing temperature in Chrysemys]. Notably, antagonistic elements in gonadogenesis (e.g., β-catenin and Insr) were thermosensitive only in TSD early-embryos. Cirbp showed warm-temperature upregulation in both turtles disputing its purported key TSD role. Genes that may convert thermal inputs into sex-specific development (e.g., signaling and hormonal pathways, RNA-binding and heat-shock) were differentially regulated. Jak-Stat, Nf-κB, retinoic-acid, Wnt, and Mapk-signaling (not Akt and Ras-signaling) potentially mediate TSD thermosensitivity. Numerous species-specific ncRNAs (including Xist) were differentially-expressed, mostly upregulated at colder temperatures, as were unannotated loci that constitute novel TSD candidates. Cirbp showed warm-temperature upregulation in both turtles. Consistent transcription between turtles and alligator revealed putatively-critical reptilian TSD elements for male (Sf1, Amh, Amhr2) and female (Crabp2 and

  2. Transcriptomic responses to environmental temperature by turtles with temperature-dependent and genotypic sex determination assessed by RNAseq inform the genetic architecture of embryonic gonadal development.

    PubMed

    Radhakrishnan, Srihari; Literman, Robert; Neuwald, Jennifer; Severin, Andrew; Valenzuela, Nicole

    2017-01-01

    Vertebrate sexual fate is decided primarily by the individual's genotype (GSD), by the environmental temperature during development (TSD), or both. Turtles exhibit TSD and GSD, making them ideal to study the evolution of sex determination. Here we analyze temperature-specific gonadal transcriptomes (RNA-sequencing validated by qPCR) of painted turtles (Chrysemys picta TSD) before and during the thermosensitive period, and at equivalent stages in soft-shell turtles (Apalone spinifera-GSD), to test whether TSD's and GSD's transcriptional circuitry is identical but deployed differently between mechanisms. Our data show that most elements of the mammalian urogenital network are active during turtle gonadogenesis, but their transcription is generally more thermoresponsive in TSD than GSD, and concordant with their sex-specific function in mammals [e.g., upregulation of Amh, Ar, Esr1, Fog2, Gata4, Igf1r, Insr, and Lhx9 at male-producing temperature, and of β-catenin, Foxl2, Aromatase (Cyp19a1), Fst, Nf-kb, Crabp2 at female-producing temperature in Chrysemys]. Notably, antagonistic elements in gonadogenesis (e.g., β-catenin and Insr) were thermosensitive only in TSD early-embryos. Cirbp showed warm-temperature upregulation in both turtles disputing its purported key TSD role. Genes that may convert thermal inputs into sex-specific development (e.g., signaling and hormonal pathways, RNA-binding and heat-shock) were differentially regulated. Jak-Stat, Nf-κB, retinoic-acid, Wnt, and Mapk-signaling (not Akt and Ras-signaling) potentially mediate TSD thermosensitivity. Numerous species-specific ncRNAs (including Xist) were differentially-expressed, mostly upregulated at colder temperatures, as were unannotated loci that constitute novel TSD candidates. Cirbp showed warm-temperature upregulation in both turtles. Consistent transcription between turtles and alligator revealed putatively-critical reptilian TSD elements for male (Sf1, Amh, Amhr2) and female (Crabp2 and Hspb1

  3. Early Program Development

    NASA Image and Video Library

    1970-01-01

    In 1970, NASA initiated Phase A contracts to study alternate Space Shuttle designs in addition to the two-stage fully-reusable Space Shuttle system already under development. A number of alternate systems were developed to ensure the development of the optimum earth-to-orbit system, including the Stage-and-a-half Chemical Interorbital Shuttle, shown here. The concept would utilize a reusable marned spacecraft with an onboard propulsion system attached to an expendable fuel tank to provide supplementary propellants.

  4. Development in Early Childhood.

    ERIC Educational Resources Information Center

    Elkind, David

    1991-01-01

    Reviews some of the major cognitive, social, and emotional achievements of young children and discusses some of their limitations. Divides description of development into intellectual, language, social, and emotional development. Notes that this division represents adult categories of thought and does not represent young children's actual modes of…

  5. Early Program Development

    NASA Image and Video Library

    1970-01-01

    This artist's concept from 1970 shows a Nuclear Shuttle taking on fuel from an orbiting Liquid Hydrogen Depot. As envisioned by Marshall Space Flight Center Program Development persornel, the Nuclear Shuttle would deliver payloads to lunar orbit or other destinations then return to Earth orbit for refueling and additional missions.

  6. Early Program Development

    NASA Image and Video Library

    1970-01-01

    This 1970 artist's concept shows a Nuclear Shuttle in flight. As envisioned by Marshall Space Flight Center Program Development engineers, the Nuclear Shuttle would deliver payloads to lunar orbit or other destinations then return to Earth orbit for refueling and additional missions.

  7. Early Program Development

    NASA Image and Video Library

    1971-01-01

    In this 1971 artist's concept, the Nuclear Shuttle is shown in various space-based applications. As envisioned by Marshall Space Flight Center Program Development persornel, the Nuclear Shuttle would deliver payloads to geosychronous Earth orbits or lunar orbits then return to low Earth orbit for refueling. A cluster of Nuclear Shuttle units could form the basis for planetary missions.

  8. Early Program Development

    NASA Image and Video Library

    1971-01-01

    This 1971 artist's concept shows the Nuclear Shuttle in both its lunar logistics configuraton and geosynchronous station configuration. As envisioned by Marshall Space Flight Center Program Development persornel, the Nuclear Shuttle would deliver payloads to lunar orbits or other destinations then return to Earth orbit for refueling and additional missions.

  9. Early Program Development

    NASA Image and Video Library

    1963-01-01

    This artist's concept from 1963 shows a proposed NERVA (Nuclear Engine for Rocket Vehicle Application) incorporating the NRX-A1, the first NERVA-type cold flow reactor. The NERVA engine, based on Kiwi nuclear reactor technology, was intended to power a RIFT (Reactor-In-Flight-Test) nuclear stage, for which Marshall Space Flight Center had development responsibility.

  10. Early Program Development

    NASA Image and Video Library

    2004-04-15

    This artist's concept illustrates the NERVA (Nuclear Engine for Rocket Vehicle Application) engine's hot bleed cycle in which a small amount of hydrogen gas is diverted from the thrust nozzle, thus eliminating the need for a separate system to drive the turbine. The NERVA engine, based on KIWI nuclear reactor technology, would power a RIFT (Reactor-In-Flight-Test) nuclear stage, for which the Marshall Space Flight Center had development responsibility.

  11. Early Program Development

    NASA Image and Video Library

    1970-01-01

    In this 1970 artist's concept, the Nuclear Shuttle is shown in its lunar and geosynchronous orbit configuration and in its planetary mission configuration. As envisioned by Marshall Space Flight Center Program Development plarners, the Nuclear Shuttle would deliver payloads to lunar orbit or other destinations then return to Earth orbit for refueling. A cluster of Nuclear Shuttle units could form the basis for planetary missions.

  12. Early Program Development

    NASA Image and Video Library

    1996-06-20

    Engineers at one of MSFC's vacuum chambers begin testing a microthruster model. The purpose of these tests are to collect sufficient data that will enabe NASA to develop microthrusters that will move the Space Shuttle, a future space station, or any other space related vehicle with the least amount of expended energy. When something is sent into outer space, the forces that try to pull it back to Earth (gravity) are very small so that it only requires a very small force to move very large objects. In space, a force equal to a paperclip can move an object as large as a car. Microthrusters are used to produce these small forces.

  13. Dynamics of biochemical components, lipid classes and energy values on gonadal development of R. philippinarum associated with the temperature and ingestion rate.

    PubMed

    Fernández-Reiriz, M J; Pérez-Camacho, A; Delgado, M; Labarta, U

    2007-08-01

    This study evaluates the effect of temperature, coupled with ingestion rate, on the dynamics of biochemical components and lipid classes in R. philippinarum. The data are discussed with regard to sexual development and energy balance. Experimental protocol developed in the present study used two groups of the clam R. philippinarum: L (temperatures of 14 degrees C and 18 degrees C) and H (temperatures of 18 degrees C and 22 degrees C). The intra-group ingestion level was similar, although the ingestion level of the clams in the group H was 2.4 times higher than group L. We observed that R. philippinarum conditioned at 18 degrees C (18L) shows higher protein content, furthermore an important loss of organic weight was observed after 48 days. In such a situation, the clams use their own reserves (carbohydrates and glycogen) for sexual development while in situations without food stress (positive energy balance) and low temperature (14 degrees C) an accumulation of reserves is produced. Strikingly dissimilar behaviour in biochemical composition was observed for the 18H and 22H treatments, both with a positive energy balance. Despite similar protein content, the highest levels of carbohydrates were observed at the lower temperature (18 degrees C). Glycogen was also higher for the 18 degrees C treatment, although the differences were significant only in the males. Although the total lipids in R. philippinarum showed no significant differences in any treatment, they became apparent and related to sex when considering the individual lipid classes. There was no variation in lipid classes in the males between the 14L and 22H treatments despite the large disparity in the degree of sexual development. However, in the females significant differences in lipid classes (phospholipids, triglycerides) were observed. The results of this study show that a positive energy balance permits R. philippinarum gonadal development and accumulation of reserves both in low and high temperature

  14. Biomechanics of Early Cardiac Development

    PubMed Central

    Goenezen, Sevan; Rennie, Monique Y.

    2012-01-01

    Biomechanics affect early cardiac development, from looping to the development of chambers and valves. Hemodynamic forces are essential for proper cardiac development, and their disruption leads to congenital heart defects. A wealth of information already exists on early cardiac adaptations to hemodynamic loading, and new technologies, including high resolution imaging modalities and computational modeling, are enabling a more thorough understanding of relationships between hemodynamics and cardiac development. Imaging and modeling approaches, used in combination with biological data on cell behavior and adaptation, are paving the road for new discoveries on links between biomechanics and biology and their effect on cardiac development and fetal programming. PMID:22760547

  15. An Equine Intersex with Unilateral Gonadal Agenesis

    PubMed Central

    Basrur, P. K.; Kanagawa, H.; Gilman, J. P. W.

    1969-01-01

    Cytogenetic and histological studies have been carried out on an intersex horse which was clinically diagnosed as a cryptorchid. The horse had the general conformation of a stallion but the external genitalia included a well developed vulva and a penis. The right testis which was descended was devoid of germ cells and the left “gonad” located in the cavum vaginale contained neither testicular nor ovarian tissue. The male duct system on both sides were relatively well developed despite the absence of a testis on the left side. Chromosome analysis on cultured cells from the descended testis revealed the presence of four chromosomally-distinct cell types with XX, XY, XXY and XO sex complements indicating a quadruple mosaicism. The presence of polymorphonuclear neutrophils exhibiting a drumstick, in the hemopoietic tissues and a sex chromatin body in the nucleated cells of buccal mucosa suggest that mosaicism prevails in other somatic tissues of the horse. On the basis of information derived from similar conditions in humans and some domestic animals it would appear that this horse resulted from an XXY zygote. The four cell types noted in the horse probably resulted through mitotic mechanisms favouring the loss of an X and a Y at different stages during embryonic development. The absence of gonad on the left side of this horse might be causally related to the preponderance of XO cell types in the somatic blastema during early gonadal differentiation. ImagesFig. 1.Fig. 2.Fig. 3.Fig. 4.Fig. 5.Fig. 6.Fig. 7.Fig. 8.Fig. 9.Fig. 10.Fig. 11.Fig. 12.Fig. 13.Fig. 14.Fig. 15.Fig. 16.Fig. 17.Fig. 18.Fig. 19. PMID:4391028

  16. Black carp vasa identifies embryonic and gonadal germ cells.

    PubMed

    Xue, Ting; Yu, Miao; Pan, Qihua; Wang, Yizhou; Fang, Jian; Li, Lingyu; Deng, Yu; Chen, Kai; Wang, Qian; Chen, Tiansheng

    2017-07-01

    Identification of molecular markers is an essential step in the study of germ cells. Vasa is an RNA helicase and a well-known germ cell marker that plays a crucial role in germ cell development. Here, we identified the Vasa homolog termed Mpvasa as the first germ cell marker in black carp (Mylopharyngodon piceus). First, a 2819-bp full-length Mpvasa complementary DNA (cDNA) was cloned by PCR using degenerated primers of conserved sequences and gene-specific primers. The Mpvasa cDNA sequence encodes a 637-amino acid protein that contains eight conserved characteristic motifs of the DEAD box protein family, and shares high identity to grass carp (81%) and zebrafish (74%) vasa homologs. Second, Mpvasa expression was restricted to the gonad in adulthood by RT-PCR and Western blot analysis. The dynamic patterns of temporal-spatial expression of Mpvasa during gametogenesis were examined by in situ hybridization, and Mpvasa transcripts were strictly detected in gonadal germ cells throughout oogenesis, predominantly in immature oocytes (stage I, II, and III oocytes). Third, Mpvasa transcripts were highly detected in unfertilized eggs and early embryos, and the signal indicated a dynamic migration of the primordial germ cells during embryogenesis, suggesting that Mpvasa transcripts were maternally inherited and specifically distributed in germ cells. Taken together, these results demonstrated that Mpvasa is an applicable molecular marker for identification of gonadal and embryonic germ cells, which facilitates the isolation and utilization of germ cells in black carp.

  17. miRNAome expression profiles in the gonads of adult Melopsittacus undulatus

    PubMed Central

    Jiang, Lan; Wang, Qingqing; Yu, Jue; Gowda, Vinita; Johnson, Gabriel; Yang, Jianke

    2018-01-01

    The budgerigar (Melopsittacus undulatus) is one of the most widely studied parrot species, serving as an excellent animal model for behavior and neuroscience research. Until recently, it was unknown how sexual differences in the behavior, physiology, and development of organisms are regulated by differential gene expression. MicroRNAs (miRNAs) are endogenous short non-coding RNA molecules that can post-transcriptionally regulate gene expression and play a critical role in gonadal differentiation as well as early development of animals. However, very little is known about the role gonadal miRNAs play in the early development of birds. Research on the sex-biased expression of miRNAs in avian gonads are limited, and little is known about M. undulatus. In the current study, we sequenced two small non-coding RNA libraries made from the gonads of adult male and female budgerigars using Illumina paired-end sequencing technology. We obtained 254 known and 141 novel miRNAs, and randomly validated five miRNAs. Of these, three miRNAs were differentially expressed miRNAs and 18 miRNAs involved in sexual differentiation as determined by functional analysis with GO annotation and KEGG pathway analysis. In conclusion, this work is the first report of sex-biased miRNAs expression in the budgerigar, and provides additional sequences to the avian miRNAome database which will foster further functional genomic research. PMID:29666766

  18. Characterization of migratory primordial germ cells in the aorta-gonad-mesonephros of a 4.5-week-old human embryo: a toolbox to evaluate in vitro early gametogenesis.

    PubMed

    Gomes Fernandes, Maria; Bialecka, Monika; Salvatori, Daniela C F; Chuva de Sousa Lopes, Susana M

    2018-05-01

    Which set of antibodies can be used to identify migratory and early post-migratory human primordial germ cells (hPGCs)? We validated the specificity of 33 antibodies for 31 markers, including POU5F1, NANOG, PRDM1 and TFAP2C as specific markers of hPGCs at 4.5 weeks of development of Carnegie stage (CS12-13), whereas KIT and SOX17 also marked the intra-aortic hematopoietic stem cell cluster in the aorta-gonad-mesonephros (AGM). The dynamics of gene expression during germ cell development in mice is well characterized and this knowledge has proved crucial to allow the development of protocols for the in vitro derivation of functional gametes. Although there is a great interest in generating human gametes in vitro, it is still unclear which markers are expressed during the early stages of hPGC development and many studies use markers described in mouse to benchmark differentiation of human PGC-like cells (hPGCLCs). Early post-implantation development differs significantly between mice and humans, and so some germ cells markers, including SOX2, SOX17, IFITM3 and ITGA6 may not identify mPGCs and hPGCs equally well. This immunofluorescence study investigated the expression of putative hPGC markers in the caudal part of a single human embryo at 4.5 weeks of development. We have investigated by immunofluorescence the expression of a set of 33 antibodies for 31 markers, including pluripotency, germ cell, adhesion, migration, surface, mesenchymal and epigenetic markers on paraffin sections of the caudal part, including the AGM region, of a single human embryo (CS12-13). The human material used was anonymously donated with informed consent from elective abortions without medical indication. We observed germ cell specific expression of NANOG, TFAP2C and PRDM1 in POU5F1+ hPGCs in the AGM. The epigenetic markers H3K27me3 and 5mC were sufficient to distinguish hPGCs from the surrounding somatic cells. Some mPGC-markers were not detected in hPGCs, but marked other tissues; whereas

  19. Effects of environmentally relevant sub-chronic atrazine concentrations on African clawed frog (Xenopus laevis) survival, growth and male gonad development.

    PubMed

    Rimayi, Cornelius; Odusanya, David; Weiss, Jana M; de Boer, Jacob; Chimuka, Luke; Mbajiorgu, Felix

    2018-06-01

    Sub-chronic toxicity of environmentally relevant atrazine concentrations on exposed tadpoles and adult male African clawed frogs (Xenopus laevis) was evaluated in a quality controlled laboratory for 90 days. The aim of this study was to determine the effects of atrazine on the survival, growth and gonad development of African clawed frogs. After exposure of tadpoles to atrazine concentrations of 0 (control), 0.01, 200 and 500 μg L -1 in water, mortality rates of 0, 0, 3.3 and 70% respectively were recorded for the 90 day exposure period. Morphometry showed significantly reduced tadpole mass in the 500 μg L -1 atrazine exposed tadpoles (p < 0.05). Light microscopy on testes of adult frogs exposed to the same atrazine concentrations using hematoxylin and eosin (H&E) and Van Gieson staining techniques revealed gonadal atrophy, disruption of germ cell lines, seminiferous tubule structure damage and formation of extensive connective tissue around seminiferous tubules of frogs exposed to 200 μg L -1 and 500 μg L -1 atrazine concentrations. Ultrastructural analysis of the cellular organelles using transmission electron microscopy (TEM) revealed significant amounts of damaged mitochondria in testosterone producing Leydig cells as well as Sertoli cells. Biochemical analysis revealed reduced serum testosterone levels in adult frogs at all exposure levels as well as presence of six atrazine metabolites in frog serum and liver. The results indicate that atrazine concentrations greater than the calculated LC50 of 343.7 μg L -1 cause significant mortality in tadpoles, while concentrations ≥200 μg L -1 adversely affect reproductive health of adult frogs and development of tadpoles sub-chronically exposed to atrazine. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Cell adhesion molecules expression pattern indicates that somatic cells arbitrate gonadal sex of differentiating bipotential fetal mouse gonad.

    PubMed

    Piprek, Rafal P; Kolasa, Michal; Podkowa, Dagmara; Kloc, Malgorzata; Kubiak, Jacek Z

    2017-10-01

    Unlike other organ anlagens, the primordial gonad is sexually bipotential in all animals. In mouse, the bipotential gonad differentiates into testis or ovary depending on the genetic sex (XY or XX) of the fetus. During gonad development cells segregate, depending on genetic sex, into distinct compartments: testis cords and interstitium form in XY gonad, and germ cell cysts and stroma in XX gonad. However, our knowledge of mechanisms governing gonadal sex differentiation remains very vague. Because it is known that adhesion molecules (CAMs) play a key role in organogenesis, we suspected that diversified expression of CAMs should also play a crucial role in gonad development. Using microarray analysis we identified 129 CAMs and factors regulating cell adhesion during sexual differentiation of mouse gonad. To identify genes expressed differentially in three cell lines in XY and XX gonads: i) supporting (Sertoli or follicular cells), ii) interstitial or stromal cells, and iii) germ cells, we used transgenic mice expressing EGFP reporter gene and FACS cell sorting. Although a large number of CAMs expressed ubiquitously, expression of certain genes was cell line- and genetic sex-specific. The sets of CAMs differentially expressed in supporting versus interstitial/stromal cells may be responsible for segregation of these two cell lines during gonadal development. There was also a significant difference in CAMs expression pattern between XY supporting (Sertoli) and XX supporting (follicular) cells but not between XY and XX germ cells. This indicates that differential CAMs expression pattern in the somatic cells but not in the germ line arbitrates structural organization of gonadal anlagen into testis or ovary. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. EFFECT OF 17B-ESTRADIOL, O,P'-DDT, OCTYLPHENOL AND P,P'-DDE ON GONADAL DEVELOPMENT AND LIVER AND KIDNEY PATHOLOGY IN JUVENILE MALE SUMMER FLOUNDER (PARALICHTYS DENTATUS)

    EPA Science Inventory

    The intent of this study was to compare histopathologically the effect of 17 -estradiol (E2), o,p' DDT, octylphenol and p,p' DDE on gonadal development and liver and kidney condition in sexually immature (juvenile) summer flounder (Paralichthys dentatus). The dorsal sinus of 2-...

  2. Cell-autonomous sex determination outside of the gonad

    PubMed Central

    Arnold, Arthur P.; Chen, Xuqi; Link, Jenny C.; Itoh, Yuichiro; Reue, Karen

    2013-01-01

    The classic model of sex determination in mammals states that the sex of the individual is determined by the type of gonad that develops, which in turn determines the gonadal hormonal milieu that creates sex differences outside of the gonads. However, XX and XY cells are intrinsically different because of the cell-autonomous sex-biasing action of X and Y genes. Recent studies of mice, in which sex chromosome complement is independent of gonadal sex, reveal that sex chromosome complement has strong effects contributing to sex differences in phenotypes such as metabolism. Adult mice with two X chromosomes (relative to mice with one X chromosome) show dramatically greater increases in body weight and adiposity after gonadectomy, irrespective of their gonadal sex. When fed a high fat diet, XX mice develop striking hyperinsulinemia and fatty liver, relative to XY mice. The sex chromosome effects are modulated by the presence of gonadal hormones, indicating an interaction of the sex-biasing effects of gonadal hormones and sex chromosome genes. Other cell-autonomous sex chromosome effects are detected in mice in many phenotypes. Birds (relative to eutherian mammals) are expected to show more widespread cell-autonomous sex determination in non-gonadal tissues, because of ineffective sex chromosome dosage compensation mechanisms. PMID:23361913

  3. Telomere lengthening early in development.

    PubMed

    Liu, Lin; Bailey, Susan M; Okuka, Maja; Muñoz, Purificación; Li, Chao; Zhou, Lingjun; Wu, Chao; Czerwiec, Eva; Sandler, Laurel; Seyfang, Andreas; Blasco, Maria A; Keefe, David L

    2007-12-01

    Stem cells and cancer cells maintain telomere length mostly through telomerase. Telomerase activity is high in male germ line and stem cells, but is low or absent in mature oocytes and cleavage stage embryos, and then high again in blastocysts. How early embryos reset telomere length remains poorly understood. Here, we show that oocytes actually have shorter telomeres than somatic cells, but their telomeres lengthen remarkably during early cleavage development. Moreover, parthenogenetically activated oocytes also lengthen their telomeres, thus the capacity to elongate telomeres must reside within oocytes themselves. Notably, telomeres also elongate in the early cleavage embryos of telomerase-null mice, demonstrating that telomerase is unlikely to be responsible for the abrupt lengthening of telomeres in these cells. Coincident with telomere lengthening, extensive telomere sister-chromatid exchange (T-SCE) and colocalization of the DNA recombination proteins Rad50 and TRF1 were observed in early cleavage embryos. Both T-SCE and DNA recombination proteins decrease in blastocyst stage embryos, whereas telomerase activity increases and telomeres elongate only slowly. We suggest that telomeres lengthen during the early cleavage cycles following fertilization through a recombination-based mechanism, and that from the blastocyst stage onwards, telomerase only maintains the telomere length established by this alternative mechanism.

  4. Effects of incubation temperature and estrogen exposure on aromatase activity in the brain and gonads of embryonic alligators.

    PubMed Central

    Milnes, Matthew R; Roberts, Robert N; Guillette, Louis J

    2002-01-01

    During embryogenesis, incubation temperature and the hormonal environment influence gonadal differentiation of some reptiles, including all crocodilians. Current evidence suggests that aromatase, the enzyme that converts androgens to estrogens, has a role in sexual differentiation of species that exhibit temperature-dependent sex determination (TSD). During the temperature-sensitive period (TSP) of sex determination, we compared aromatase activity in the brain and gonads of putative male and female alligator embryos to determine if aromatase activity in the embryonic brain could provide the hormonal environment necessary for ovarian development in a TSD species. In addition, we assessed the pattern of aromatase activity in the brain and gonads of embryos treated with estradiol-17beta (E(2)) and incubated at male-producing temperatures to compare enzyme activity in E(2) sex-reversed females to control males and females. This has particular significance regarding wildlife species living in areas contaminated with suspected environmental estrogens. Gonadal aromatase activity remained low during the early stages of the TSP in both sexes and increased late in the TSP only in females. Aromatase activity in the brain increased prior to gonadal differentiation in both sexes. These results suggest that aromatase activity in the brain is not directly responsible for mediating differentiation of the gonad. E(2) exposure at male-producing temperatures resulted in sex-reversed females that had intermediate gonad function and masculinized brain activity. This study indicates the need to examine multiple end points and to determine the persistence of developmental alterations in contaminant-exposed wildlife populations. PMID:12060834

  5. [The role of gonadal peptides in clinical investigation].

    PubMed

    Lahlou, N; Bouvattier, C; Linglart, A; Rodrigue, D; Teinturier, C

    2009-01-01

    Inhibins, activins, and anti-Mullerian hormone (AMH) are gonadal dimeric peptides produced in ovaries and testes by homologous cells, granulosa cells and Sertoli cells, respectively. The production of inhibins is driven by FSH, that of AMH may indirectly depends on FSH, while it is down regulated, at least in the male, by testosterone. In the past decade, measurements of serum inhibin and AMH have provided useful tools for clinical investigation in gonadal disorders: pseudohermaphroditism, androgen insensitivity, anorchidism, gonadal dysgenesis, disorders of pubertal developpement. Inhibins, activins, and AMH are also reliable markers of gonadal tumors. They are extensively used as indexes of fertility: in the male the production of inhibin B reflects the spermatogenetic activity, in women both inhibin B and AMH levels are correlated with the number of preantral and early antral follicles and reflect the ovarian reserve of follicles available for recruitment.

  6. Morphology, sex steroid level and gene expression analysis in gonadal sex reversal of triploid female (XXX) rainbow trout (Oncorhynchus mykiss).

    PubMed

    Xu, Gefeng; Huang, Tianqing; Jin, Xian; Cui, Cunhe; Li, Depeng; Sun, Cong; Han, Ying; Mu, Zhenbo

    2016-02-01

    In non-mammalian vertebrates, estrogens and expressions of cyp19a1 and foxl2 play critical roles in maintaining ovary differentiation and development, while dmrt1 and sox9 are male-specific genes in testicular differentiation and are highly conserved. In order to deeply understand the morphological change, sex steroids level and molecular mechanism of triploid female gonadal reversal in rainbow trout, we studied the ovary morphology, tendency of estradiol-17β (E2) and testosterone (T) levels and the relative expressions of dmrt1, cyp19a1, sox9 and foxl2 in juvenile and adult fish. Our results demonstrated that the development of triploid female gonads in rainbow trout went through arrested development, oocytes dedifferentiation, ovary reconstruction and sex reversal finally. During early gonadal development (154-334 days post-fertilization), the expressions of foxl2 and cyp19a1 increased linearly, while expressions of dmrt1 and sox9 were extremely suppressed, and E2 level was higher, while T level was lower. During the mid-to-late period of triploid female gonadal development (574-964 days post-fertilization), the expressions of dmrt1 and sox9 remained high and were very close to the quantity of diploid male genes, and T levels were even reaching diploid male plasma concentrations, while expressions of cyp19a1 and foxl2 were decreased, leading to decrease in E2 level. We realized that the development model of rainbow trout triploid female gonads was extremely rare, and the regulatory mechanism was very special. Genes involved in gonadal development and endogenous estrogens are pivotal factors in fish natural sex reversal.

  7. Dietary vitamin A, ascorbic acid and α-tocopherol affect the gonad development and reproductive performance of starry flounder Platichthys stellatus broodstock

    NASA Astrophysics Data System (ADS)

    Wang, Jiying; Li, Baoshan; Liu, Xudong; Ma, Jingjing; Wang, Shixin; Zhang, Limin

    2014-03-01

    The present trial was conducted with starry flounder Platichthys stellatus broodstock to evaluate the effects of dietary vitamin A, ascorbic acid, and α-tocopherol on the gonadal development and reproductive performance. 8 000 IU/kg diet vitamin A (VA group), 500 mg/kg diet ascorbic acid (Vcpp group), or 250 mg/kg diet α-tocopherol (α-TA group) was added into basal diet to create 3 vitamin experimental diets, respectively. Each diet was fed to 450 starry flounder broodstock for 104 days. Samples were collected weekly. The gonadosomatic index (GSI) of 3 vitamin experimental groups first decreased and then increased. Maximum GSI of Vcpp group was higher than that of α-TA group but lower than that of VA group. The spawning periods of 3 vitamin experimental groups lasted 49, 56, and 45 days, respectively. No mature eggs were observed in the control group during the trial. The absolute fecundity (AF) and relative fecundity (RF) of α-TA group was higher than that of Vcpp group but lower than that of VA group. The results suggest that different vitamins play different roles in the fish reproductive process. Vitamin A stimulated the maturation of the ovary, ascorbic acid prolonged the spawning period, and α-tocopherol affected the development of the eggs.

  8. Cognitive Development in Early Readers.

    ERIC Educational Resources Information Center

    Briggs, Chari; Elkind, David

    Some studies of early readers are discussed. It is pointed out that study of early readers has relevance for practical and theoretical issues in psychology and education. Of interest in this document are the following questions: (1) Are there any special talents or traits distinguishing early from non-early readers? (2) Do children who read early…

  9. [Early childhood growth and development].

    PubMed

    Arce, Melitón

    2015-01-01

    This article describes and discusses issues related to the process of childhood growth and development, with emphasis on the early years, a period in which this process reaches critical speed on major structures and functions of the human economy. We reaffirm that this can contribute to the social availability of a generation of increasingly better adults, which in turn will be able to contribute to building a better world and within it a society that enjoys greater prosperity. In the first chapter, we discuss the general considerations on the favorable evolution of human society based on quality of future adults, meaning the accomplishments that today’s children will gain. A second chapter mentions the basics of growth and development in the different fields and the various phenomena that occur in it. In the third we refer to lost opportunities and negative factors that can affect delaying the process and thereby result in not obtaining the expected accomplishments. In the fourth, conclusions and recommendations are presented confirming the initial conception that good early child care serves to build a better society and some recommendations are formulated to make it a good practice.

  10. Methylation Patterns of SOX3, SOX9, and WNT4 Genes in Gonads of Dogs with XX (SRY-Negative) Disorder of Sexual Development.

    PubMed

    Salamon, Sylwia; Flisikowski, Krzysztof; Switonski, Marek

    2017-01-01

    Ovotesticular or testicular disorder of sexual development in dogs with female karyotype and lack of SRY (XX DSD) is a common sexual anomaly diagnosed in numerous breeds. The molecular background, however, remains unclear, and epigenetic mechanisms, including DNA methylation, have not been studied. The aim of our study was comparative methylation analysis of CpG islands in promoters of candidate genes for XX DSD: SOX9, SOX3, and WNT4. Methylation studies were performed on DNA extracted from formalin-fixed/paraffin-embedded or frozen gonads from 2 dogs with ovotesticular and 2 dogs with testicular XX DSD as well as control females (n = 4) and males (n = 2). Bisulfite-converted DNA was used for CpG methylation analysis using quantitative pyrosequencing. Promoter regions of SOX9 and WNT4 showed similar CpG methylation in each group, ranging from 0 to 5.5% and from 39 to 74%, respectively. The SOX3 promoter showed significantly higher methylation in the ovotesticular XX DSD cases and the testicular XX DSD and control males, suggesting that SOX3 methylation may play a role in canine XX DSD pathogenesis. © 2017 S. Karger AG, Basel.

  11. MeDIP-seq and nCpG analyses illuminate sexually dimorphic methylation of gonadal development genes with high historic methylation in turtle hatchlings with temperature-dependent sex determination.

    PubMed

    Radhakrishnan, Srihari; Literman, Robert; Mizoguchi, Beatriz; Valenzuela, Nicole

    2017-01-01

    DNA methylation alters gene expression but not DNA sequence and mediates some cases of phenotypic plasticity. Temperature-dependent sex determination (TSD) epitomizes phenotypic plasticity where environmental temperature drives embryonic sexual fate, as occurs commonly in turtles. Importantly, the temperature-specific transcription of two genes underlying gonadal differentiation is known to be induced by differential methylation in TSD fish, turtle and alligator. Yet, how extensive is the link between DNA methylation and TSD remains unclear. Here we test for broad differences in genome-wide DNA methylation between male and female hatchling gonads of the TSD painted turtle Chrysemys picta using methyl DNA immunoprecipitation sequencing, to identify differentially methylated candidates for future study. We also examine the genome-wide nCpG distribution (which affects DNA methylation) in painted turtles and test for historic methylation in genes regulating vertebrate gonadogenesis. Turtle global methylation was consistent with other vertebrates (57% of the genome, 78% of all CpG dinucleotides). Numerous genes predicted to regulate turtle gonadogenesis exhibited sex-specific methylation and were proximal to methylated repeats. nCpG distribution predicted actual turtle DNA methylation and was bimodal in gene promoters (as other vertebrates) and introns (unlike other vertebrates). Differentially methylated genes, including regulators of sexual development, had lower nCpG content indicative of higher historic methylation. Ours is the first evidence suggesting that sexually dimorphic DNA methylation is pervasive in turtle gonads (perhaps mediated by repeat methylation) and that it targets numerous regulators of gonadal development, consistent with the hypothesis that it may regulate thermosensitive transcription in TSD vertebrates. However, further research during embryogenesis will help test this hypothesis and the alternative that instead, most differential methylation

  12. Taiwanese Early Childhood Educators' Professional Development

    ERIC Educational Resources Information Center

    Hsu, Ching-Yun

    2008-01-01

    This study was designed based on a qualitative paradigm to explore the professional development of Taiwanese early childhood educators. The method of phenomenology was employed. The main research question addressed was "How do early childhood educators construe their professional development experience?" Seven Taiwanese early childhood…

  13. Early Childhood Diplomacy: Policy Planning for Early Childhood Development

    ERIC Educational Resources Information Center

    Vargas-Barón, Emily; Diehl, Kristel

    2018-01-01

    Children who are well nurtured, appropriately cared for, and provided with positive learning opportunities in their early years have a better chance of becoming healthy and productive citizens of nations and of the world. This article reviews the art and science of policy planning for early childhood development (ECD) from a diplomacy perspective.…

  14. Gonadal development and transcript profiling of steroidogenic enzymes in response to 17α-methyltestosterone in the rare minnow Gobiocypris rarus.

    PubMed

    Liu, Shaozhen; Wang, Lihong; Qin, Fang; Zheng, Yao; Li, Meng; Zhang, Yingying; Yuan, Cong; Wang, Zaizhao

    2014-09-01

    It is well known that natural and anthropogenic chemicals interfere with the hormonal system of vertebrate and invertebrate organisms. How these chemicals regulate gonadal steroidogenesis remains to be determined. The main objective of this study was to evaluate the effects of 17α-methyltestosterone (MT), a synthetic model androgen, on gene expression profiles of six key steroidogenic genes in adult rare minnow. The full-length cDNA encoding 11β-hydroxysteroid dehydrogenase-2 (11β-HSD2) was firstly isolated and characterized by RT-PCR and RACE methods. The gonadal transcript changes of StAR, cyp11a1, 3β-HSD, cyp17a1, 11β-HSD2 and cyp19a1a in 6-month adult Gobiocypris rarus exposed to MT and 17α-ethinylestradiol (EE2) for 7, 14 and 21 days were detected by qRT-PCR. To make an effort to connect the transcriptional changes of steroidogenic enzymes with effects on higher levels of biological organization and on VTG, one remarkable sensitive target of steroids, body and gonad weights, histology of gonads, and hepatic vtg mRNA level were measured. MT caused varying degree of abnormalities in ovaries and testes. The hepatic vtg mRNA level was highly inhibited in females and slightly altered in males by MT. Transcripts of several steroidogenic genes including StAR, cyp17a1, and cyp11a1 showed high responsiveness to MT exposure in G. rarus. The gene expression profiles of these steroidogenic genes in MT-treated groups were much distinct with the EE2-treated group. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Gonadal Identity in the Absence of Pro-Testis Factor SOX9 and Pro-Ovary Factor Beta-Catenin in Mice1

    PubMed Central

    Nicol, Barbara; Yao, Humphrey H.-C.

    2015-01-01

    Sex-reversal cases in humans and genetic models in mice have revealed that the fate of the bipotential gonad hinges upon the balance between pro-testis SOX9 and pro-ovary beta-catenin pathways. Our central query was: if SOX9 and beta-catenin define the gonad's identity, then what do the gonads become when both factors are absent? To answer this question, we developed mouse models that lack either Sox9, beta-catenin, or both in the somatic cells of the fetal gonads and examined the morphological outcomes and transcriptome profiles. In the absence of Sox9 and beta-catenin, both XX and XY gonads progressively lean toward the testis fate, indicating that expression of certain pro-testis genes requires the repression of the beta-catenin pathway, rather than a direct activation by SOX9. We also observed that XY double knockout gonads were more masculinized than their XX counterpart. To identify the genes responsible for the initial events of masculinization and to determine how the genetic context (XX vs. XY) affects this process, we compared the transcriptomes of Sox9/beta-catenin mutant gonads and found that early molecular changes underlying the XY-specific masculinization involve the expression of Sry and 21 SRY direct target genes, such as Sox8 and Cyp26b1. These results imply that when both Sox9 and beta-catenin are absent, Sry is capable of activating other pro-testis genes and drive testis differentiation. Our findings not only provide insight into the mechanism of sex determination, but also identify candidate genes that are potentially involved in disorders of sex development. PMID:26108792

  16. Estrogen treatment up-regulates female genes but does not suppress all early testicular markers during rainbow trout male-to-female gonadal transdifferentiation.

    PubMed

    Vizziano-Cantonnet, Denise; Baron, Daniel; Mahè, Sophie; Cauty, Chantal; Fostier, Alexis; Guiguen, Yann

    2008-11-01

    In non-mammalian vertebrates, estrogens are key players in ovarian differentiation, but the mechanisms by which they act remain poorly understood. The present study on rainbow trout was designed to investigate whether estrogens trigger the female pathway by activating a group of early female genes (i.e. cyp19a1, foxl2a, foxl2b, fst, bmp4, and fshb) and by repressing early testicular markers (i.e. dmrt1, nr0b1, sox9a1 and sox9a2). Feminization was induced in genetically all-male populations using 17alpha-ethynylestradiol (EE2, 20 mg/kg of food during 2 months). The expression profiles of 100 candidate genes were obtained by real-time RT-PCR and 45 expression profiles displayed a significant differential expression between control populations (males and females) and EE2-treated populations. These expression profiles were grouped in five temporally correlated expression clusters. The estrogen treatment induced most of the early ovarian differentiation genes (foxl2a, foxl2b, fst, bmp4, and fshb) and in particular foxl2a, which was strongly and quickly up-regulated. Simultaneously, Leydig cell genes, involved in androgen synthesis, as well as some Sertoli cell markers (amh, sox9a2) were strongly repressed. However, in contrast to our initial hypothesis, some genes considered as essential for mammalian and fish testis differentiation were not suppressed during the early process of estrogen-induced feminization (dmrt1, nr0b1, sox9a1 and pax2a) and some were even strongly up-regulated (nr0b1, sox9a1and pax2a). In conclusion, estrogens trigger male-to-female transdifferentiation by up-regulating most ovarian specific genes and this up-regulation appears to be crucial for an effective feminization, but estrogens do not concomitantly down-regulate all the testicular differentiation markers.

  17. Kentucky's Statewide Early Childhood Professional Development System

    ERIC Educational Resources Information Center

    Rous, Beth; Grove, Jaime; Townley, Kim

    2007-01-01

    Public school systems have recently become major players in providing services for children in their early years. In addition, a number of other services are available to young children including child care, Head Start, and Early Head Start programs. The link between program quality and professional development of early care and education…

  18. Stem Cells in Mammalian Gonads.

    PubMed

    Wu, Ji; Ding, Xinbao; Wang, Jian

    Stem cells have great value in clinical application because of their ability to self-renew and their potential to differentiate into many different cell types. Mammalian gonads, including testes for males and ovaries for females, are composed of germline and somatic cells. In male mammals, spermatogonial stem cells maintain spermatogenesis which occurs continuously in adult testis. Likewise, a growing body of evidence demonstrated that female germline stem cells could be found in mammalian ovaries. Meanwhile, prior studies have shown that somatic stem cells exist in both testes and ovaries. In this chapter, we focus on mammalian gonad stem cells and discuss their characteristics as well as differentiation potentials.

  19. Extraction and analysis of carotenoids from the New Zealand sea urchin Evechinus chloroticus gonads.

    PubMed

    Garama, Daniel; Bremer, Phil; Carne, Alan

    2012-01-01

    Sea urchin gonad (roe) is a highly valued food in Japan and North America. Gonad price is strongly influenced by quality, with appearance, especially colour being a major determinant. Previous attempts to extract a carotenoid profile from the New Zealand sea urchin species Evechinus chloroticus have been challenging due to the large amount of lipid present in the gonad. A carotenoid extraction and high performance liquid chromatography (HPLC) analysis method was developed to reduce lipid contamination by incorporating a saponification and lipid cold precipitation in the extraction procedure. This method enabled greater carotenoid purity and enhanced analysis by HPLC. Echinenone was found to be the main carotenoid present in all E. chloroticus gonads. Dark coloured gonads contained higher levels of fucoxanthin/fucoxanthinol, β-carotene and xanthophylls such as astaxanthin and canthaxanthin. This information on the modification and deposition of carotenoids will help in the development of diets to enhance gonad colour.

  20. SRY protein is expressed in ovotestis and streak gonads from human sex-reversal.

    PubMed

    Salas-Cortés, L; Jaubert, F; Nihoul-Feketé, C; Brauner, R; Rosemblatt, M; Fellous, M

    2000-01-01

    In mammals, a master gene located on the Y chromosome, the testis-determining gene SRY, controls sex determination. SRY protein is expressed in the genital ridge before testis determination, and in the testis it is expressed in Sertoli and germ cells. Completely sex-reversed patients are classified as either 46,XX males or 46,XY females. SRY mutations have been described in only 15% of patients with 46,XY complete or partial gonadal dysgenesis. However, although incomplete or partial sex-reversal affects 46,XX true hermaphrodites, 46,XY gonadal dysgenesis, and 46,XX/46,XY mosaicism, only 15% of the 46,XX true hermaphrodites analyzed have the SRY gene. Here, we demonstrate that the SRY protein is expressed in the tubules of streak gonads and rete testis, indicating that the SRY protein is normally expressed early during testis determination. Based on these results, we propose that some factors downstream from SRY may be mutated in these 46,XY sex-reversal patients. We have also analyzed SRY protein expression in the ovotestis from 46,XX true hermaphrodites and 46,XX/46,XY mosaicism, demonstrating SRY protein expression in both testicular and ovarian portions in these patients. This suggests that the SRY protein does not inhibit ovary development. These results confirm that other factors are needed for complete testis development, in particular, those downstream of the SRY protein. Copyright 2001 S. Karger AG, Basel

  1. The Development of STAR Early Literacy. Report.

    ERIC Educational Resources Information Center

    School Renaissance Inst., Inc., Madison, WI.

    This report describes the development and testing of a computerized early literacy diagnostic assessment for students in prekindergarten to grade 3 that can measure skills across a variety of preliteracy and reading domains. The STAR Early Literacy assessment was developed by a team of more than 50 people, including literacy experts,…

  2. Critical Issues in Early Childhood Professional Development

    ERIC Educational Resources Information Center

    Zaslow, Martha, Ed.; Martinez-Beck, Ivelisse, Ed.

    2005-01-01

    Effective teaching leads to positive student outcomes, and professional development for early childhood teachers is key to improving both. But what exactly is meant by "professional development"? What effect does it have on school readiness? Which models and approaches really work? This is the book the early childhood field needs to take the…

  3. Control of early seed development.

    PubMed

    Chaudhury, A M; Koltunow, A; Payne, T; Luo, M; Tucker, M R; Dennis, E S; Peacock, W J

    2001-01-01

    Seed development requires coordinated expression of embryo and endosperm and has contributions from both sporophytic and male and female gametophytic genes. Genetic and molecular analyses in recent years have started to illuminate how products of these multiple genes interact to initiate seed development. Imprinting or differential expression of paternal and maternal genes seems to be involved in controlling seed development, presumably by controlling gene expression in developing endosperm. Epigenetic processes such as chromatin remodeling and DNA methylation affect imprinting of key seed-specific genes; however, the identity of many of these genes remains unknown. The discovery of FIS genes has illuminated control of autonomous endosperm development, a component of apomixis, which is an important developmental and agronomic trait. FIS genes are targets of imprinting, and the genes they control in developing endosperm are also regulated by DNA methylation and chromatin remodeling genes. These results define some exciting future areas of research in seed development.

  4. Sex, stress, and mood disorders: at the intersection of adrenal and gonadal hormones.

    PubMed

    Fernández-Guasti, A; Fiedler, J L; Herrera, L; Handa, R J

    2012-07-01

    The risk for neuropsychiatric illnesses has a strong sex bias, and for major depressive disorder (MDD), females show a more than 2-fold greater risk compared to males. Such mood disorders are commonly associated with a dysregulation of the hypothalamo-pituitary-adrenal (HPA) axis. Thus, sex differences in the incidence of MDD may be related with the levels of gonadal steroid hormone in adulthood or during early development as well as with the sex differences in HPA axis function. In rodents, organizational and activational effects of gonadal steroid hormones have been described for the regulation of HPA axis function and, if consistent with humans, this may underlie the increased risk of mood disorders in women. Other developmental factors, such as prenatal stress and prenatal overexposure to glucocorticoids can also impact behaviors and neuroendocrine responses to stress in adulthood and these effects are also reported to occur with sex differences. Similarly, in humans, the clinical benefits of antidepressants are associated with the normalization of the dysregulated HPA axis, and genetic polymorphisms have been found in some genes involved in controlling the stress response. This review examines some potential factors contributing to the sex difference in the risk of affective disorders with a focus on adrenal and gonadal hormones as potential modulators. Genetic and environmental factors that contribute to individual risk for affective disorders are also described. Ultimately, future treatment strategies for depression should consider all of these biological elements in their design. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Androgenic and estrogenic effects of the synthetic androgen 17alpha-methyltestosterone on sexual development and reproductive performance in the fathead minnow (Pimephales promelas) determined using the gonadal recrudescence assay.

    PubMed

    Pawlowski, S; Sauer, A; Shears, J A; Tyler, C R; Braunbeck, T

    2004-06-24

    The effects of the androgen, 17alpha-methyltestosterone were assessed on sexual development and reproductive performance in the fathead minnow (Pimephales promelas) using a gonadal recrudescence assay. In this assay, mature male and female fathead minnow, previously kept under simulated winter conditions (15 degrees C; 8:16 h light:dark regime) were transferred to simulated summer conditions (25 degrees C water temperature; 16:8 h light:dark regime) to induce gonadal recrudescence. To assess sexual development fish were exposed to nominal concentrations of 0, 0.1, 1, 5 and 50 microg/L 17alpha-methyltestosterone. After 3 weeks of chemical exposure, effects on condition (condition factor, CF), plasma vitellogenin (VTG), secondary sex characteristics, gonad growth (gonadosomatic index; GSI) and gonad histology were investigated. Reproductive performance, including reproductive output (egg production), spawning behaviour, and fertilisation rate were measured over a subsequent 3-week-period in breeding adults maintained in clean water. 17alpha-Methyltestosterone had no effects on the condition of fish at any of the doses tested. 17alpha-Methyltestosterone induced both androgenic and estrogenic effects with females generally more affected by 17alpha-methyltestosterone than males: atretic follicles and male-specific sex characteristics (androgenic effect) were induced in females at > or = 0.1 and > or = 1 microg/L 17alpha-methyltestosterone, respectively. An inhibitory effect on ovary growth occurred at an exposure concentration of 50 microg/L 17alpha-methyltestosterone. In males 1 microg/L 17alpha-methyltestosterone induced a concentration-response induction of plasma vitellogenin (estrogenic effect) likely due to its conversion into 17alpha-methylestradiol, rather to the competition with endogenous steroids and their cross reactivity with the estrogen receptor. In the fish breeding studies, concentration-dependent reductions in egg number, fertilisation rate and

  6. Early childhood development in deprived urban settlements.

    PubMed

    Nair, M K C; Radhakrishnan, S Rekha

    2004-03-01

    Poverty, the root cause of the existence of slums or settlement colonies in urban areas has a great impact on almost all aspects of life of the urban poor, especially the all-round development of children. Examples from countries, across the globe provide evidence of improved early child development, made possible through integrated slum improvement programs, are few in numbers. The observed 2.5% prevalence of developmental delay in the less than 2 year olds of deprived urban settlements, the presence of risk factors for developmental delay like low birth weight, birth asphyxia, coupled with poor environment of home and alternate child care services, highlights the need for simple cost effective community model for promoting early child development. This review on early child development focuses on the developmental status of children in the deprived urban settlements, who are yet to be on the priority list of Governments and international agencies working for the welfare of children, the contributory nature-nurture factors and replicable working models like infant stimulation, early detection of developmental delay in infancy itself, developmental screening of toddlers, skill assessment for preschool children, school readiness programs, identification of mental sub-normality and primary education enhancement program for primary school children. Further, the review probes feasible intervention strategies through community owned early child care and development facilities, utilizing existing programs like ICDS, Urban Basic Services and by initiating services like Development Friendly Well Baby Clinics, Community Extension services, Child Development Referral Units at district hospitals and involving trained manpower like anganwadi/creche workers, public health nurses and developmental therapists. With the decentralization process the local self-government at municipalities and city corporations are financially equipped to be the prime movers to initiate, monitor and

  7. Gonadal steroids and bone metabolism in men.

    PubMed

    Leder, Benjamin

    2007-06-01

    Over the past decade, our increasing awareness of the clinical importance of osteoporosis in men has stimulated intense interest in trying to better understand male skeletal physiology and pathophysiology. The present review focuses on a major focus of research in this area, namely the attempt to define the influence and therapeutic potential of gonadal steroids in male bone metabolism. Building on previous work defining the relative roles of androgens and estrogens in the developing male skeleton and in maintaining normal bone turnover, recent studies have begun to define these issues from epidemiologic, physiologic and therapeutic perspectives. With access to data from large prospectively defined populations of men, investigators are confirming and challenging existing hypotheses and forwarding new concepts. Clinical trials have expanded beyond standard androgen replacement studies to explore more complex hormonal interventions. Physiologic investigation has continued to probe the mechanisms underlying the differential and independent roles of androgens and estrogens in male bone metabolism. Recent work has added significantly to our understanding of the role of gonadal steroids in male skeletal physiology. Nonetheless, further research is necessary to build on these initial human studies and to capitalize on rapidly emerging advances in our understanding of the basic biology of bone metabolism.

  8. Proteomic analysis of three gonad types of swamp eel reveals genes differentially expressed during sex reversal.

    PubMed

    Sheng, Yue; Zhao, Wei; Song, Ying; Li, Zhigang; Luo, Majing; Lei, Quan; Cheng, Hanhua; Zhou, Rongjia

    2015-05-18

    A variety of mechanisms are engaged in sex determination in vertebrates. The teleost fish swamp eel undergoes sex reversal naturally and is an ideal model for vertebrate sexual development. However, the importance of proteome-wide scanning for gonad reversal was not previously determined. We report a 2-D electrophoresis analysis of three gonad types of proteomes during sex reversal. MS/MS analysis revealed a group of differentially expressed proteins during ovary to ovotestis to testis transformation. Cbx3 is up-regulated during gonad reversal and is likely to have a role in spermatogenesis. Rab37 is down-regulated during the reversal and is mainly associated with oogenesis. Both Cbx3 and Rab37 are linked up in a protein network. These datasets in gonadal proteomes provide a new resource for further studies in gonadal development.

  9. Early Brain Development Research Review and Update

    ERIC Educational Resources Information Center

    Schiller, Pam

    2010-01-01

    Thanks to imaging technology used in neurobiology, people have access to useful and critical information regarding the development of the human brain. This information allows them to become much more effective in helping children in their early development. In fact, when people base their practices on the findings from medical science research,…

  10. Dynamic and differential expression of the gonadal aromatase during the process of sexual differentiation in a novel transgenic cyp19a1a-eGFP zebrafish line.

    PubMed

    Hinfray, Nathalie; Sohm, Frédéric; Caulier, Morgane; Chadili, Edith; Piccini, Benjamin; Torchy, Camille; Porcher, Jean-Marc; Guiguen, Yann; Brion, François

    2018-05-15

    In zebrafish, there exists a clear need for new tools to study sex differentiation dynamic and its perturbation by endocrine disrupting chemicals. In this context, we developed and characterized a novel transgenic zebrafish line expressing green fluorescent protein (GFP) under the control of the zebrafish cyp19a1a (gonadal aromatase) promoter. In most gonochoristic fish species including zebrafish, cyp19a1a, the enzyme responsible for the synthesis of estrogens, has been shown to play a critical role in the processes of reproduction and sexual differentiation. This novel cyp19a1a-eGFP transgenic line allowed a deeper characterization of expression and localization of cyp19a1a gene in zebrafish gonads both at the adult stage and during development. At the adult stage, GFP expression was higher in ovaries than in testis. We showed a perfect co-expression of GFP and endogenous Cyp19a1a protein in gonads that was mainly localized in the cytoplasm of peri-follicular cells in the ovary and of Leydig and germ cells in the testis. During development, GFP was expressed in all immature gonads of 20 dpf-old zebrafish. Then, GFP expression increased in early differentiated female at 30 and 35dpf to reach a high GFP intensity in well-differentiated ovaries at 40dpf. On the contrary, males consistently displayed low GFP expression as compared to female whatever their stage of development, resulting in a clear dimorphic expression between both sexes. Interestingly, fish that undergoes ovary-to-testis transition (35 and 40dpf) presented GFP levels similar to males or intermediate between females and males. In this transgenic line our results confirm that cyp19a1a is expressed early during development, before the histological differentiation of the gonads, and that the down-regulation of cyp19a1a expression is likely responsible for the testicular differentiation. Moreover, we show that although cyp19a1a expression exhibits a clear dimorphic expression pattern in gonads during

  11. Natural reversal of left-right gut/gonad asymmetry in C. elegans males is independent of embryonic chirality.

    PubMed

    Callander, Davon C; Alcorn, Melissa R; Birsoy, Bilge; Rothman, Joel H

    2014-06-01

    Anatomical left-right (L/R) asymmetry in C. elegans is established in the four-cell embryo as a result of anteroposterior skewing of transverse mitotic spindles with a defined handedness. This event creates a chiral embryo and ultimately an adult body plan with fixed L/R positioning of internal organs and components of the nervous system. While this "dextral" configuration is invariant in hermaphrodites, it can be reversed by physical manipulation of the early embryo or by mutations that interfere with mitotic spindle orientation, which leads to viable, mirror-reversed (sinistral) animals. During normal development of the C. elegans male, the gonad develops on the right of the midline, with the gut bilaterally apposed on the left. However, we found that in males of the laboratory N2 strain and Hawaiian ("Hw") wild isolate, the gut/gonad asymmetry is frequently reversed in a temperature-dependent manner, independent of normal embryonic chirality. We also observed sporadic errors in gonad migration occurring naturally during early larval stages of these and other wild strains; however, the incidence of such errors does not correlate with the frequency of L/R gut/gonad reversals in these strains. Analysis of N2/Hw hybrids and recombinant inbred advanced intercross lines (RIAILs) indicate that the L/R organ reversals are likely to result from recessively acting variations in multiple genes. Thus, unlike the highly reproducible L/R asymmetries of most structures in hermaphrodites, the L/R asymmetry of the male C. elegans body plan is less rigidly determined and subject to natural variation that is influenced by a multiplicity of genes. © 2014 Wiley Periodicals, Inc.

  12. Early executive function predicts reasoning development.

    PubMed

    Richland, Lindsey E; Burchinal, Margaret R

    2013-01-01

    Analogical reasoning is a core cognitive skill that distinguishes humans from all other species and contributes to general fluid intelligence, creativity, and adaptive learning capacities. Yet its origins are not well understood. In the study reported here, we analyzed large-scale longitudinal data from the Study of Early Child Care and Youth Development to test predictors of growth in analogical-reasoning skill from third grade to adolescence. Our results suggest an integrative resolution to the theoretical debate regarding contributory factors arising from smaller-scale, cross-sectional experiments on analogy development. Children with greater executive-function skills (both composite and inhibitory control) and vocabulary knowledge in early elementary school displayed higher scores on a verbal analogies task at age 15 years, even after adjusting for key covariates. We posit that knowledge is a prerequisite to analogy performance, but strong executive-functioning resources during early childhood are related to long-term gains in fundamental reasoning skills.

  13. Bioecological Theory, Early Child Development and the Validation of the Population-Level Early Development Instrument

    ERIC Educational Resources Information Center

    Guhn, Martin; Goelman, Hillel

    2011-01-01

    The Early Development Instrument (EDI; Janus and Offord in "Canadian Journal of Behavioural Science" 39:1-22, 2007) project is a Canadian population-level, longitudinal research project, in which teacher ratings of Kindergarten children's early development and wellbeing are linked to health and academic achievement variables at the…

  14. Aromatase, steroid-5-alpha-reductase type 1 and type 2 mRNA expression in gonads and in brain of Xenopus laevis during ontogeny.

    PubMed

    Urbatzka, R; Lutz, I; Kloas, W

    2007-01-01

    The key enzymes involved in the production of endogenous sex steroids are steroid-5-alpha-reductase and aromatase converting testosterone (T) into dihydrotestosterone (DHT) and into estradiol (E2), respectively. To gain more insights into the molecular mechanisms of sexual differentiation of amphibians, we determined the mRNA expression of steroid-5-alpha-reductase type1 (Srd5a1), type2 (Srd5a2) and aromatase (Aro) during ontogeny starting from the egg and ending after completion of metamorphosis in Xenopus laevis. Expression of all three enzymes was measured by means of semi-quantitative RT-PCR, determining for the first time Srd5a1 and Srd5a2 mRNA expression in amphibians. mRNA was analyzed in whole body homogenates from stage 12 to 48, while brain and gonads with kidney were studied separately from stage 48 to 66. Different ontogenetic mRNA expression patterns were observed for all genes analyzed, revealing early mRNA expression of Srd5a1 already in the egg at stage 12 whereas Srd5a2 and Aro was detected at stage 39. Sex-specific mRNA expressions of Srd5a2 and of Aro were determined in the gonads with kidney but not in brain. Srd5a2 was two-fold higher expressed in testes than in ovaries while Aro mRNA was ten-fold higher in ovaries. No gender-specific mRNA expression was observed for Srd5a1 in gonads and in brain. The ontogenetic patterns of Aro, Srd5a1 and Srd5a2 suggest that these genes are involved in sexual differentiation of gonads and brain already in early developmental stages. Especially in gonads Srd5a2 seems to be important for physiological regulation of testis development while Aro is associated with the development of ovaries.

  15. Early Phonological Development: Creating an Assessment Test

    ERIC Educational Resources Information Center

    Stoel-Gammon, Carol; Williams, A. Lynn

    2013-01-01

    This paper describes a new protocol for assessing the phonological systems of two-year-olds with typical development and older children with delays in vocabulary acquisition. The test (Profiles of Early Expressive Phonological Skills ("PEEPS"), Williams & Stoel-Gammon, in preparation) differs from currently available assessments in…

  16. Early Intervention, Maternal Development and Children's Play.

    ERIC Educational Resources Information Center

    Slaughter, Diana T.

    The purposes of this longitudinal study of early intervention with 83 black mother-child dyads were (a) to test the thesis that sociocultural transmission influences childhood development in educationally significant ways, and (b) to describe the process through which such transmission can occur. Two social intervention programs were contrasted;…

  17. The Early Years: Development, Learning and Teaching.

    ERIC Educational Resources Information Center

    Boulton-Lewis, Gillian, Ed.; Catherwood, Di, Ed.

    Designed for teachers, students, caregivers, and health professionals who work with children from birth to age 8, this book provides a review of recent research and theories of development and learning in the early childhood years, with an emphasis on implications for effective teaching. Where appropriate, the book takes an Australian perspective,…

  18. EARLY CRANIOFACIAL DEVELOPMENT: LIFE AMONG THE SIGNALS

    EPA Science Inventory

    Early Craniofacial Development: Life Among the Signals. Sid Hunter and Keith Ward. Reproductive Toxicology Division, NHEERL, US EPA, RTP, NC, 27711

    Haloacetic acids (HAA) are chemicals formed during drinking water disinfection and present in finished tap water. Exposure o...

  19. The para-aortic ridge plays a key role in the formation of the renal, adrenal and gonadal vascular systems

    PubMed Central

    Isogai, Sumio; Horiguchi, Mayuko; Hitomi, Jiro

    2010-01-01

    Renal, adrenal, gonadal, ureteral and inferior phrenic arteries vary in their level of origin and in their calibre, number and precise anatomical relationship to other structures. Studies of the origin and early development of these arteries have evoked sharp disputes. The ladder theory of Felix, which states that ‘All the mesonephric arteries may persist; from them are formed the phrenic, suprarenal, renal and internal spermatic arteries’ has been generally quoted in the anatomical textbooks without rigorous verification for 100 years. In this study, we re-examined this theory by performing micro-injection of dye and resin into rat (Rattus norvegicus) embryos. Our results revealed that most of the mesonephric arteries had degenerated before the metanephros started its ascent. The definitive renal, adrenal, gonadal, ureteral and inferior phrenic arteries appeared as new branches from the gonadal artery and/or directly from the abdominal aorta to the para-aortic ridge. Coincidental to this, the anatomical architecture of the inter-renal vascular cage, which consists of the interlobar and arcuate arteries and their collateral veins, was completed within the developing metanephros. We demonstrated that the delicate renal vascular cage switched from the primary renal artery to the definitive renal artery and that the route of venous drainage changed from the posterior cardinal vein to the inferior (caudal) vena cava. PMID:20579173

  20. Morphological and transcriptomic effects of endocrine modulators on the gonadal differentiation of chicken embryos: The case of tributyltin (TBT).

    PubMed

    Scheider, Jessica; Afonso-Grunz, Fabian; Jessl, Luzie; Hoffmeier, Klaus; Winter, Peter; Oehlmann, Jörg

    2018-03-01

    Morphological malformations induced by tributyltin (TBT) exposure during embryonic development have already been characterized in various taxonomic groups, but, nonetheless, the molecular processes underlying these changes remain obscure. The present study provides the first genome-wide screening for differentially expressed genes that are linked to morphological alterations of gonadal tissue from chicken embryos after exposure to TBT. We applied a single injection of TBT (between 0.5 and 30 pg as Sn/g egg) into incubated fertile eggs to simulate maternal transfer of the endocrine disruptive compound. Methyltestosterone (MT) served as a positive control (30 pg/g egg). After 19 days of incubation, structural features of the gonads as well as genome-wide gene expression profiles were assessed simultaneously. TBT induced significant morphological and histological malformations of gonadal tissue from female embryos that show a virilization of the ovaries. This phenotypical virilization was mirrored by altered expression profiles of sex-dependent genes. Among these are several transcription and growth factors (e.g. FGF12, CTCF, NFIB), whose altered expression might serve as a set of markers for early identification of endocrine active chemicals that affect embryonic development by transcriptome profiling without the need of elaborate histological analyses. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  1. Equine fetal adrenal, gonadal and placental steroidogenesis.

    PubMed

    Legacki, Erin L; Ball, Barry A; Corbin, C Jo; Loux, Shavahn C; Scoggin, Kirsten E; Stanley, Scott D; Conley, Alan J

    2017-10-01

    Equine fetuses have substantial circulating pregnenolone concentrations and thus have been postulated to provide significant substrate for placental 5α-reduced pregnane production, but the fetal site of pregnenolone synthesis remains unclear. The current studies investigated steroid concentrations in blood, adrenal glands, gonads and placenta from fetuses (4, 6, 9 and 10 months of gestational age (GA)), as well as tissue steroidogenic enzyme transcript levels. Pregnenolone and dehydroepiandrosterone (DHEA) were the most abundant steroids in fetal blood, pregnenolone was consistently higher but decreased progressively with GA. Tissue steroid concentrations generally paralleled those in serum with time. Adrenal and gonadal tissue pregnenolone concentrations were similar and 100-fold higher than those in allantochorion. DHEA was far higher in gonads than adrenals and progesterone was higher in adrenals than gonads. Androstenedione decreased with GA in adrenals but not in gonads. Transcript analysis generally supported these data. CYP17A1 was higher in fetal gonads than adrenals or allantochorion, and HSD3B1 was higher in fetal adrenals and allantochorion than gonads. CYP11A1 transcript was also significantly higher in adrenals and gonads than allantochorion and CYP19 and SRD5A1 transcripts were higher in allantochorion than either fetal adrenals or gonads. Given these data, and their much greater size, the fetal gonads are the source of DHEA and likely contribute more than fetal adrenal glands to circulating fetal pregnenolone concentrations. Low CYP11A1 but high HSD3B1 and SRD5A1 transcript abundance in allantochorion, and low tissue pregnenolone, suggests that endogenous placental pregnenolone synthesis is low and likely contributes little to equine placental 5α-reduced pregnane secretion. © 2017 Society for Reproduction and Fertility.

  2. Breastfeeding, parenting, and early cognitive development.

    PubMed

    Gibbs, Benjamin G; Forste, Renata

    2014-03-01

    To explain why breastfeeding is associated with children's cognitive development. By using a nationally representative longitudinal survey of early childhood (N = 7500), we examined how breastfeeding practices, the early introduction of solid foods, and putting an infant to bed with a bottle were associated with cognitive development across early childhood. We also explored whether this link can be explained by parenting behaviors and maternal education. There is a positive relationship between predominant breastfeeding for 3 months or more and child reading skills, but this link is the result of cognitively supportive parenting behaviors and greater levels of education among women who predominantly breastfed. We found little-to-no relationship between infant feeding practices and the cognitive development of children with less-educated mothers. Instead, reading to a child every day and being sensitive to a child's development were significant predictors of math and reading readiness outcomes. Although breastfeeding has important benefits in other settings, the encouragement of breastfeeding to promote school readiness does not appear to be a key intervention point. Promoting parenting behaviors that improve child cognitive development may be a more effective and direct strategy for practitioners to adopt, especially for disadvantaged children. Copyright © 2014 Mosby, Inc. All rights reserved.

  3. [The mixed gonadal dysgenesis. Diagnostic criteria and surgical treatment].

    PubMed

    Blanco, J A; Martínez-Mora, J; Granada, M; Toran, N; Isnard, R M; Castellví, A; Casasa, J M

    1997-01-01

    The Mixed Gonadal Dysgenesis represents the 7.6% of all our patients with intersexual states. We report 14 patients who present Mixed Gonadal Dysgenesis. We have studied: diagnosis age; external genitalia description; sex assigned in birth and if has changed; the karyotype; sex chromatine; hormonal study; genitography; internal genitalia and internal Mullerians ducts structures; gonadal histologycal study; surgical treatment and hormonal treatment. The results show that 50% of the cases presents a 46XY karyotype and the other 50% mosaicisme 45XO/46XY. The histological study is very distinctive. A vulvovagynoplasty and clitoroplasty was made in all the cases. Four patients must follow an hormonal treatment after reaching puberal age. Summing up, with patients having ambiguous genitalia we can suspect it consists of a Mixed Gonadal Dysgenesis. The diagnosis must be precocious. And this diagnosis will be based in an ambiguous genitalia, with a karyotype 46XY or 45XO/46XY, the persistence of the internal Müllerian duct structures, and the histological study with a dysgenetic testis. These patients should be raised as females because they can obtain a good morphological and functional development like a normal female.

  4. [Gonadal ontogenesis and sex differentiation in the sea bass, Dicentrarchus labrax, under fish-farming conditions].

    PubMed

    Roblin, C; Bruslé, J

    1983-01-01

    The histology of the different stages of gonadal development (appearance of PGC, edification of gonad primordium, organization of an undifferentiated gonad, testicular or ovarian development) has been studied in fingerlings and juveniles of sea-bass in fish-culture conditions. Sex differentiation with a caudo-cranial gradient was direct and more in accordance with length than with age. Ovarian and testicular differentiation occurred in fish 11 to 23 months old and from 90 to 187 mm SL. Testis ova were frequently observed.

  5. Nurturing care: promoting early childhood development.

    PubMed

    Britto, Pia R; Lye, Stephen J; Proulx, Kerrie; Yousafzai, Aisha K; Matthews, Stephen G; Vaivada, Tyler; Perez-Escamilla, Rafael; Rao, Nirmala; Ip, Patrick; Fernald, Lia C H; MacMillan, Harriet; Hanson, Mark; Wachs, Theodore D; Yao, Haogen; Yoshikawa, Hirokazu; Cerezo, Adrian; Leckman, James F; Bhutta, Zulfiqar A

    2017-01-07

    The UN Sustainable Development Goals provide a historic opportunity to implement interventions, at scale, to promote early childhood development. Although the evidence base for the importance of early childhood development has grown, the research is distributed across sectors, populations, and settings, with diversity noted in both scope and focus. We provide a comprehensive updated analysis of early childhood development interventions across the five sectors of health, nutrition, education, child protection, and social protection. Our review concludes that to make interventions successful, smart, and sustainable, they need to be implemented as multi-sectoral intervention packages anchored in nurturing care. The recommendations emphasise that intervention packages should be applied at developmentally appropriate times during the life course, target multiple risks, and build on existing delivery platforms for feasibility of scale-up. While interventions will continue to improve with the growth of developmental science, the evidence now strongly suggests that parents, caregivers, and families need to be supported in providing nurturing care and protection in order for young children to achieve their developmental potential. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    PubMed

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

    2015-03-01

    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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Early childhood development: putting knowledge into action.

    PubMed

    2000-11-01

    As part of its continuing mission to serve trustees and staff of health foundations and corporate giving programs, Grantmakers In Health (GIH) convened a select group of grantmakers and national experts who have made a major commitment to improve the health and well being of young children. The roundtable explored the latest research examining early childhood development, as well as public and private programs serving families with young children. The discussion ultimately centered upon the importance of grantmaker involvement to improve early childhood development, including the services delivered to young children and their families, training for professionals, and continued research and evaluation. This report brings together key points from the day's discussion with factual information on demographic, health and human services, and public policy trends drawn from a background paper prepared for the meeting. When available, recent findings, facts, and figures have been incorporated.

  8. QCD development in the early universe

    SciTech Connect

    Gromov, N. A., E-mail: gromov@dm.komisc.ru

    The high-energy limit of Quantum Chromodynamics is generated by the contraction of its gauge groups. Contraction parameters are taken identical with those of the Electroweak Model and tend to zero when energy increases. At the infinite energy limit all quarks lose masses and have only one color degree of freedom. The limit model represents the development of Quantum Chromodynamics in the early Universe from the Big Bang up to the end of several milliseconds.

  9. Gonad establishment during asexual reproduction in the annelid Pristina leidyi.

    PubMed

    Özpolat, B Duygu; Bely, Alexandra E

    2015-09-01

    Animals that can reproduce by both asexual agametic reproduction and sexual reproduction must transmit or re-establish their germ line post-embryonically. Although such a dual reproductive mode has evolved repeatedly among animals, how asexually produced individuals establish their germ line remains poorly understood in most groups. We investigated germ line development in the annelid Pristina leidyi, a species that typically reproduces asexually by paratomic fission, intercalating a new tail and head in the middle of the body followed by splitting. We found that in fissioning individuals, gonads occur in anterior segments in the anterior-most individual as well as in new heads forming within fission zones. Homologs of the germ line/multipotency genes piwi, vasa, and nanos are expressed in the gonads, as well as in proliferative tissues including the posterior growth zone, fission zone, and regeneration blastema. In fissioning animals, certain cells on the ventral nerve cord express a homolog of piwi, are abundant near fission zones, and sometimes make contact with gonads. Such cells are typically undetectable near the blastema and posterior growth zone. Time-lapse imaging provides direct evidence that cells on the ventral nerve cord migrate preferentially towards fission zones. Our findings indicate that gonads form routinely in fissioning individuals, that a population of piwi-positive cells on the ventral nerve cord is associated with fission and gonads, and that cells resembling these piwi-positive cells migrate along the ventral nerve cord. We suggest that the piwi-positive ventral cells are germ cells that transmit the germ line across asexually produced individuals via migration along the ventral nerve cord. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Early colonial health developments in Mauritius.

    PubMed

    Parahoo, K A

    1986-01-01

    The historical development of Mauritius and in particular the early developments in health care are crucial to an understanding of the contemporary health system. The introduction of major epidemic diseases through the movements of French soldiers to and from India and the immigration of indentured laborers from India account for the high mortality and morbidity rates in the 18th and 19th centuries and later. The colonial economy created and fortified the dependence on a single cash crop and on imported food. It also contributed toward the impoverization of large sections of the Mauritian population. The colonial era is also responsible for initiating a three tier system of health care.

  11. Age, growth, and gonadal characteristics of adult bighead carp, Hypophthalmichthys nobilis, in the lower Missouri River

    USGS Publications Warehouse

    Schrank, S.J.; Guy, C.S.

    2002-01-01

    Bighead carp were introduced into Arkansas in 1973 to improve water clarity in production ponds. Bighead carp subsequently escaped aquaculture facilities in the early 1980's and dispersed into the Mississippi and Missouri rivers. The first documentation of bighead carp reproduction in the Mississippi River system was in 1989. The population has increased in the Missouri River as is evident in their increased proportion in the commercial harvest since 1990. The effect of this exotic planktivore on native ecosystems of the U.S. has not been examined. Basic biological data on bighead carp Hypophthalmichthys nobilis in the Missouri River are needed to predict potential ecological problems and provide a foundation for manipulative studies. The objectives of this study were to assess age, growth, and gonadal characteristics of bighead carp in the Missouri River. Adult bighead carp in our sample varied from age 3 to age 7 and length varied from 475 to 1050 mm. There was a large variation in length at age, and overall bighead carp exhibited fast growth. For example, mean back-calculated length at age 3 was 556 mm. The sample was dominated by bighead carp from the 1994 year class. There was no difference in gonad development (i.e., gonadal somatic index, egg diameter) between winter and spring samples. Length of male bighead carp and GSI were not significantly correlated; however, females exhibited a positive linear relationship between length and GSI. In each ovary, egg diameter frequencies exhibited a bimodal distribution, indicating protracted spawning. Mean fecundity was 226 213, with a maximum fecundity of 769 964. Bighead carp in the Missouri River have similar life history characteristics to Asian and European populations. They have become well established in the Missouri River and it is likely that dispersal and population density will increase.

  12. Pharmacogenomics in early-phase clinical development

    PubMed Central

    Burt, Tal; Dhillon, Savita

    2015-01-01

    Pharmacogenomics (PGx) offers the promise of utilizing genetic fingerprints to predict individual responses to drugs in terms of safety, efficacy and pharmacokinetics. Early-phase clinical trial PGx applications can identify human genome variations that are meaningful to study design, selection of participants, allocation of resources and clinical research ethics. Results can inform later-phase study design and pipeline developmental decisions. Nevertheless, our review of the clinicaltrials.gov database demonstrates that PGx is rarely used by drug developers. Of the total 323 trials that included PGx as an outcome, 80% have been conducted by academic institutions after initial regulatory approval. Barriers for the application of PGx are discussed. We propose a framework for the role of PGx in early-phase drug development and recommend PGx be universally considered in study design, result interpretation and hypothesis generation for later-phase studies, but PGx results from underpowered studies should not be used by themselves to terminate drug-development programs. PMID:23837482

  13. The developing hypopharyngeal microbiota in early life.

    PubMed

    Mortensen, Martin Steen; Brejnrod, Asker Daniel; Roggenbuck, Michael; Abu Al-Soud, Waleed; Balle, Christina; Krogfelt, Karen Angeliki; Stokholm, Jakob; Thorsen, Jonathan; Waage, Johannes; Rasmussen, Morten Arendt; Bisgaard, Hans; Sørensen, Søren Johannes

    2016-12-30

    The airways of healthy humans harbor a distinct microbial community. Perturbations in the microbial community have been associated with disease, yet little is known about the formation and development of a healthy airway microbiota in early life. Our goal was to understand the establishment of the airway microbiota within the first 3 months of life. We investigated the hypopharyngeal microbiota in the unselected COPSAC 2010 cohort of 700 infants, using 16S rRNA gene sequencing of hypopharyngeal aspirates from 1 week, 1 month, and 3 months of age. Our analysis shows that majority of the hypopharyngeal microbiota of healthy infants belong to each individual's core microbiota and we demonstrate five distinct community pneumotypes. Four of these pneumotypes are dominated by the genera Staphylococcus, Streptococcus, Moraxella, and Corynebacterium, respectively. Furthermore, we show temporal pneumotype changes suggesting a rapid development towards maturation of the hypopharyngeal microbiota and a significant effect from older siblings. Despite an overall common trajectory towards maturation, individual infants' microbiota are more similar to their own, than to others, over time. Our findings demonstrate a consolidation of the population of indigenous bacteria in healthy airways and indicate distinct trajectories in the early development of the hypopharyngeal microbiota.

  14. Early androgen exposure and human gender development.

    PubMed

    Hines, Melissa; Constantinescu, Mihaela; Spencer, Debra

    2015-01-01

    During early development, testosterone plays an important role in sexual differentiation of the mammalian brain and has enduring influences on behavior. Testosterone exerts these influences at times when the testes are active, as evidenced by higher concentrations of testosterone in developing male than in developing female animals. This article critically reviews the available evidence regarding influences of testosterone on human gender-related development. In humans, testosterone is elevated in males from about weeks 8 to 24 of gestation and then again during early postnatal development. Individuals exposed to atypical concentrations of testosterone or other androgenic hormones prenatally, for example, because of genetic conditions or because their mothers were prescribed hormones during pregnancy, have been consistently found to show increased male-typical juvenile play behavior, alterations in sexual orientation and gender identity (the sense of self as male or female), and increased tendencies to engage in physically aggressive behavior. Studies of other behavioral outcomes following dramatic androgen abnormality prenatally are either too small in their numbers or too inconsistent in their results, to provide similarly conclusive evidence. Studies relating normal variability in testosterone prenatally to subsequent gender-related behavior have produced largely inconsistent results or have yet to be independently replicated. For studies of prenatal exposures in typically developing individuals, testosterone has been measured in single samples of maternal blood or amniotic fluid. These techniques may not be sufficiently powerful to consistently detect influences of testosterone on behavior, particularly in the relatively small samples that have generally been studied. The postnatal surge in testosterone in male infants, sometimes called mini-puberty, may provide a more accessible opportunity for measuring early androgen exposure during typical development. This

  15. Early Literacy and Early Numeracy: The Value of Including Early Literacy Skills in the Prediction of Numeracy Development

    ERIC Educational Resources Information Center

    Purpura, David J.; Hume, Laura E.; Sims, Darcey M.; Lonigan, Cristopher J.

    2011-01-01

    The purpose of this study was to examine whether early literacy skills uniquely predict early numeracy skills development. During the first year of the study, 69 3- to 5-year-old preschoolers were assessed on the Preschool Early Numeracy Skills (PENS) test and the Test of Preschool Early Literacy Skills (TOPEL). Participants were assessed again a…

  16. Development of chronic tests for endocrine active chemicals. Part 1. An extended fish early-life stage test for oestrogenic active chemicals in the fathead minnow (Pimephales promelas).

    PubMed

    Panter, G H; Hutchinson, T H; Hurd, K S; Bamforth, J; Stanley, R D; Duffell, S; Hargreaves, A; Gimeno, S; Tyler, C R

    2006-05-10

    An extended early-life stage test (based on OECD test guideline 210) was developed to allow the evaluation of a weak environmental oestrogen, 4-tert-pentyphenol (4TPP), on sexual differentiation and gonadal development. Fathead minnow (Pimephales promelas) embryos were exposed to three concentrations of 4TPP (56, 180 and 560 microg l(-1)) in a flow-through system, at 25+/-1 degrees C, for <107 days post-hatch (dph). In addition, some embryos were exposed to 180 microg 4TPPl(-1) until 30 or 60 dph, after which they were exposed to dilution water only until 107 dph. At 30, 60 and 107 dph fish were evaluated for growth and gonadal development (via histology), and at 107 dph fish were also evaluated for secondary sexual characteristics (SSC), gonadosomatic index (GSI) and plasma vitellogenin (VTG). There were no effects of 4TPP on hatching success or survival, however, there was a delay in the time taken for embryos to hatch (560 microg 4TPPl(-1)). No treatment-related effects were observed on fish growth, with the exception of at 107 dph when the condition factor in female fish was reduced in all 4TPP continuous exposure treatments. Plasma VTG was only elevated in female fish exposed to 180 microg 4TPPl(-1) and inhibition of gonadal growth (GSI) occurred only in females exposed to 560 microg 4TPPl(-1). Histological examination of the gonads revealed delays and disruption in male sexual differentiation and development (180 microg 4TPPl(-1)) and no testicular tissue was observed in any fish exposed to 560 microg 4TPPl(-1). Mixed gonads (predominately testes with a scattering of primary oocytes) were present in fish exposed to all doses of 180 microg 4TPPl(-1) at 107 dph. Feminisation of the reproductive ducts (formation of an ovarian like cavity) occurred in the testis of all males exposed to 180 microg l(-1), regardless of length of 4TPP exposure. Results indicate that the period of 30-60 dph appears to be the sensitive window for disruption of formation of the

  17. Development of Life on Early Mars

    NASA Technical Reports Server (NTRS)

    Gibson, Everett K.; McKay, David S.; Thomas-Keprta, Kathie L.; Clemett, Simon J.; Wentworth, Susan J.

    2009-01-01

    Exploration of Mars has begun to unveil the history of the planet. Combinations of remote sensing, in situ compositional measurements and photographic observations have shown Mars had a dynamic and active geologic evolution. Mars geologic evolution encompassed conditions that were suitable for supporting life. A habitable planet must have water, carbon and energy sources along with a dynamic geologic past. Mars meets all of these requirements. The first 600 My of Martian history were ripe for life to develop because of the abundance of (i) Water- as shown by carved canyons and oceans or lakes with the early presence of near surface water shown by precipitated carbonates in ALH84001, well-dated at 3.9 Gy, (ii) Energy from the original accretional processes, a molten core which generated a strong magnetic field leaving a permanent record in the early crust, active volcanism continuing throughout Martian history, and continuing impact processes, (iii) Carbon, water and a likely thicker atmosphere from extensive volcanic outgassing (i.e. H20, CO2, CH4, CO, O2, N2, H2S, SO2, etc.) and (iv) crustal tectonics as revealed by faulting and possible plate movement reflected by the magnetic pattern in the crust [1]. The question arises: "Why would life not develop from these favorable conditions on Mars in its first 600 My?" During this period, environmental near-surface conditions on Mars were more favorable to life than at any later time. Standing bodies of water, precipitation and flowing surface water, and possibly abundant hydrothermal energy would favor the formation of early life. (Even if life developed elsewhere on Earth, Venus, or on other bodies-it was transported to Mars where surface conditions were suitable for life to evolve). The commonly stated requirement that life would need hundreds of millions of year to get started is only an assumption; we know of no evidence that requires such a long interval for the development of life, if the proper habitable

  18. Cell fate regulation in early mammalian development

    NASA Astrophysics Data System (ADS)

    Oron, Efrat; Ivanova, Natalia

    2012-08-01

    Preimplantation development in mammals encompasses a period from fertilization to implantation and results in formation of a blastocyst composed of three distinct cell lineages: epiblast, trophectoderm and primitive endoderm. The epiblast gives rise to the organism, while the trophectoderm and the primitive endoderm contribute to extraembryonic tissues that support embryo development after implantation. In many vertebrates, such as frog or fish, maternally supplied lineage determinants are partitioned within the egg. Cell cleavage that follows fertilization results in polarization of these factors between the individual blastomeres, which become restricted in their developmental fate. In contrast, the mouse oocyte and zygote lack clear polarity and, until the eight-cell stage, individual blastomeres retain the potential to form all lineages. How are cell lineages specified in the absence of a maternally supplied blueprint? This is a fundamental question in the field of developmental biology. The answer to this question lies in understanding the cell-cell interactions and gene networks involved in embryonic development prior to implantation and using this knowledge to create testable models of the developmental processes that govern cell fates. We provide an overview of classic and contemporary models of early lineage development in the mouse and discuss the emerging body of work that highlights similarities and differences between blastocyst development in the mouse and other mammalian species.

  19. How Early Hormones Shape Gender Development

    PubMed Central

    Berenbaum, Sheri A.; Beltz, Adriene M.

    2015-01-01

    Many important psychological characteristics show sex differences, and are influenced by sex hormones at different developmental periods. We focus on the role of sex hormones in early development, particularly the differential effects of prenatal androgens on aspects of gender development. Increasing evidence confirms that prenatal androgens have facilitative effects on male-typed activity interests and engagement (including child toy preferences and adult careers), and spatial abilities, but relatively minimal effects on gender identity. Recent emphasis has been directed to the psychological mechanisms underlying these effects (including sex differences in propulsive movement, and androgen effects on interest in people versus things), and neural substrates of androgen effects (including regional brain volumes, and neural responses to mental rotation, sexually arousing stimuli, emotion, and reward). Ongoing and planned work is focused on understanding the ways in which hormones act jointly with the social environment across time to produce varying trajectories of gender development, and clarifying mechanisms by which androgens affect behaviors. Such work will be facilitated by applying lessons from other species, and by expanding methodology. Understanding hormonal influences on gender development enhances knowledge of psychological development generally, and has important implications for basic and applied questions, including sex differences in psychopathology, women’s underrepresentation in science and math, and clinical care of individuals with variations in gender expression. PMID:26688827

  20. The union of somatic gonad precursors and primordial germ cells during C. elegans embryogenesis

    PubMed Central

    Rohrschneider, Monica R.; Nance, Jeremy

    2013-01-01

    Somatic gonadal niche cells control the survival, differentiation, and proliferation of germline stem cells. The establishment of this niche-stem cell relationship is critical, and yet the precursors to these two cell types are often born at a distance from one another. The simple C. elegans gonadal primordium, which contains two somatic gonad precursors (SGPs) and two primordial germ cells (PGCs), provides an accessible model for determining how stem cell and niche cell precursors first assemble during development. To visualize the morphogenetic events that lead to formation of the gonadal primordium, we generated transgenic strains to label the cell membranes of the SGPs and PGCs and captured time-lapse movies as the gonadal primordium formed. We identify three distinct phases of SGP behavior: posterior migration along the endoderm towards the PGCs, extension of a single long projection around the adjacent PGC, and a dramatic wrapping over the PGC surfaces. We show that the endoderm and PGCs are dispensable for SGP posterior migration and initiation of projections. However, both tissues are required for the final positioning of the SGPs and the morphology of their projections, and PGCs are absolutely required for SGP wrapping behaviors. Finally, we demonstrate that the basement membrane component laminin, which localizes adjacent to the developing gonadal primordium, is required to prevent the SGPs from over-extending past the PGCs. Our findings provide a foundation for understanding the cellular and molecular regulation of the establishment of a niche-stem cell relationship. PMID:23562590

  1. Early Vascular Ageing - A Concept in Development.

    PubMed

    M Nilsson, Peter

    2015-04-01

    Cardiovascular disease (CVD) is a prevalent condition in the elderly, often associated with metabolic disturbance and type 2 diabetes. For a number of years, research dedicated to understand atherosclerosis dominated, and for many good reasons, this pathophysiological process being proximal to the CVD events. In recent years, research has been devoted to an earlier stage of vascular pathology named arteriosclerosis (arterial stiffness) and the new concept of early vascular ageing (EVA), developed by a group of mostly European researchers. This overview describes recent developments in research dedicated to EVA and new emerging aspects found in studies of families at high cardiovascular risk. There are new aspects related to genetics, telomere biology and the role of gut microbiota. However, there is still no unifying definition available of EVA and no direct treatment, but rather only recommendations for conventional cardiovascular risk factor control. New interventions are being developed - not only new antihypertensive drugs, but also new drugs for vascular protection - the selective angiotensin-II (AT2) agonist Compound 21 (C21). Human studies are eagerly awaited. Even new functional food products could have the potential to positively influence cardiometabolic regulation, to be confirmed.

  2. Calcium at fertilization and in early development

    PubMed Central

    Whitaker, Michael

    2012-01-01

    Fertilization calcium waves are introduced and the evidence from which we can infer general mechanisms of these waves is presented. The two main classes of hypothesis put forward to explain the generation of the fertilization calcium wave are set out and it is concluded that initiation of the fertilization calcium wave can be most generally explained in inverterbrates by a mechanism in which an activating substance enters the egg from the sperm on sperm-egg fusion, activating the egg by stimulating phospholipase C activation through a src family kinase pathway and in mammals by the diffusion of a sperm-specific phospholipase C from sperm to egg on sperm-egg fusion. The fertilization calcium wave is then set into the context of cell cycle control and the mechanism of repetitive calcium spiking in mammalian eggs is investigated. Evidence that calcium signals control cell division in early embryos is reviewed, and it is concluded that calcium signals are essential at all three stages of cell division in early embryos. Evidence that phosphoinositide signalling pathways control the resumption of meiosis during oocyte maturation is considered. It is concluded on balance that the evidence points to a need for phosphoinositide/calcium signalling during resumption of meiosis. Changes to the calcium signalling machinery occur during meiosis to enable the production of a calcium wave in the mature oocyte when it is fertilized; evidence that the shape and structure of the endoplasmic reticulum alters dynamically during maturation and after fertilization is reviewed and the link between ER dynamics and the cytoskeleton is discussed. There is evidence that calcium signalling plays a key part in the development of patterning in early embryos. Morphogenesis in ascidian, frog and zebrafish embryos is briefly described to provide the developmental context in which calcium signals act. Intracellular calcium waves that may play a role in axis formation in ascidian are discussed

  3. Lactobacillus rhamnosus Accelerates Zebrafish Backbone Calcification and Gonadal Differentiation through Effects on the GnRH and IGF Systems

    PubMed Central

    Avella, Matteo A.; Place, Allen; Du, Shao-Jun; Williams, Ernest; Silvi, Stefania; Zohar, Yonathan; Carnevali, Oliana

    2012-01-01

    Endogenous microbiota play essential roles in the host’s immune system, physiology, reproduction and nutrient metabolism. We hypothesized that a continuous administration of an exogenous probiotic might also influence the host’s development. Thus, we treated zebrafish from birth to sexual maturation (2-months treatment) with Lactobacillus rhamnosus, a probiotic species intended for human use. We monitored for the presence of L. rhamnosus during the entire treatment. Zebrafish at 6 days post fertilization (dpf) exhibited elevated gene expression levels for Insulin-like growth factors -I and -II, Peroxisome proliferator activated receptors -α and -β, VDR-α and RAR-γ when compared to untreated-10 days old zebrafish. Using a gonadotropin-releasing hormone 3 GFP transgenic zebrafish (GnRH3-GFP), higher GnRH3 expression was found at 6, 8 and 10 dpf upon L. rhamnosus treatment. The same larvae exhibited earlier backbone calcification and gonad maturation. Noteworthy in the gonad development was the presence of first testes differentiation at 3 weeks post fertilization in the treated zebrafish population -which normally occurs at 8 weeks- and a dramatic sex ratio modulation (93% females, 7% males in control vs. 55% females, 45% males in the treated group). We infer that administration of L. rhamnosus stimulated the IGF system, leading to a faster backbone calcification. Moreover we hypothesize a role for administration of L. rhamnosus on GnRH3 modulation during early larval development, which in turn affects gonadal development and sex differentiation. These findings suggest a significant role of the microbiota composition on the host organism development profile and open new perspectives in the study of probiotics usage and application. PMID:23029107

  4. Early Years Practitioners' Views on Early Personal, Social and Emotional Development

    ERIC Educational Resources Information Center

    Aubrey, Carol; Ward, Karen

    2013-01-01

    Current policy guidance stresses the need for early identification of obstacles to learning and appropriate intervention. New standards for learning (Early Years Foundation Stage) place personal, social and emotional development (PSED) as central to learning and development. This paper reports a survey and follow-up interviews with early years…

  5. Gonadal Mosaicism Induced by Chemical Treatment of Sperm in Drosophila melanogaster

    PubMed Central

    Lindsley, Dan L.; Hardy, Robert W.; Ripoll, Pedro; Lindsley, Dart

    2016-01-01

    Accurate interpretation of forward genetic screens of chromosomes exposed in mature spermatozoa to a mutagenic chemical requires understanding—incomplete to date—of how exposed chromosomes and their replicas proceed through early development stages from the fertilized ovum to establishment of the germline of the treated male’s offspring. We describe a model for early embryonic development and establishment of the germline of Drosophila melanogaster and a model-validating experiment. Our model proposes that, barring repair, DNA strands modified by treatment with alkylating agents are stable and mutagenic. Each replication of an alkylated strand can result in misreplication and a mutant-bearing daughter nucleus. Daughter nuclei thenceforth replicate faithfully and their descendants comprise the embryonic syncytium. Of the 256 nuclei present after the eighth division, several migrate into the polar plasm at the posterior end of the embryo to found the germline. Based upon distribution of descendants of the alkylated strands, the misreplication rate, and the number of nuclei selected as germline progenitors, the frequency of gonadal mosaicism is predictable. Experimentally, we tracked chromosomes 2 and 3 from EMS-treated sperm through a number of generations, to characterize autosomal recessive lethal mutations and infer gonadal genetic content of the sons of treated males. Over 50% of 106 sons bore germlines that were singly, doubly, or triply mosaic for chromosome 2 or chromosome 3. These findings were consistent with our model, assuming a rate of misreplication between 0.65 and 0.80 at each replication of an alkylated strand. Crossing treated males to mismatch-repair-deficient females had no apparent effect on mutation rate. PMID:26163187

  6. Early Parental Depression and Child Language Development

    ERIC Educational Resources Information Center

    Paulson, James F.; Keefe, Heather A.; Leiferman, Jenn A.

    2009-01-01

    Objective: To examine the effects of early maternal and paternal depression on child expressive language at age 24 months and the role that parent-to-child reading may play in this pathway. Participants and methods: The 9-month and 24-month waves from a national prospective study of children and their families, the Early Childhood Longitudinal…

  7. Suppressive effects of long-term exposure to P-nitrophenol on gonadal development, hormonal profile with disruption of tissue integrity, and activation of caspase-3 in male Japanese quail (Coturnix japonica).

    PubMed

    Ahmed, Eman; Nagaoka, Kentaro; Fayez, Mostafa; Abdel-Daim, Mohamed M; Samir, Haney; Watanabe, Gen

    2015-07-01

    P-Nitrophenol (PNP) is considered to be one of nitrophenol derivatives of diesel exhaust particles. PNP is a major metabolite of some organophosphorus compounds. PNP is a persistent organic pollutant as well as one of endocrine-disrupting compounds. Consequently, bioaccumulation of PNP potentiates toxicity. The objectives of the current study were to assess in vivo adverse effects of long-term low doses of PNP exposure on reproductive system during development stage. Twenty-eight-day-old male Japanese quails were orally administered different doses of PNP (0, 0.01, 0.1, 1 mg/kg body weight) daily for 2.5 months. Testicular histopathology, hormones, caspase-3 (CASP3), and claudin-1 (CLDN1) tight junction protein, as well as plasma hormones were analyzed. The results revealed that long-term PNP exposure caused testicular histopathological changes such as vacuolation of spermatogenic cell and spermatocyte with significant testicular and cloacal gland atrophy. PNP activated CASP3 enzyme that is an apoptosis-related cysteine peptidase. Besides, it disrupted the expression of CLDN1. Furthermore, a substantial decrease in plasma concentrations of luteinizing hormone (LH) and testosterone was observed after 2 and 2.5 months in the PNP-treated groups. Meanwhile, the pituitary LH did not significantly change. Site of action of PNP may be peripheral on testicular development and/or centrally on the hypothalamic-pituitary-gonadal axis through reduction of pulsatile secretion of gonadotrophin-releasing hormone. Consequently, it may reduce the sensitivity of the anterior pituitary gland to secrete LH. In conclusion, PNP induced profound endocrine disruption in the form of hormonal imbalance, induction of CASP3, and disruption of CLDN1 expression in the testis. Hence, it may hinder the reproductive processes.

  8. The early research and development of ebselen.

    PubMed

    Parnham, Michael J; Sies, Helmut

    2013-11-01

    Ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one; PZ-51, DR-3305), is an organoselenium compound with glutathione peroxidase (GPx)-like, thiol-dependent, hydroperoxide reducing activity. As an enzyme mimic for activity of the selenoenzyme GPx, this compound has proved to be highly useful in research on mechanisms in redox biology. Furthermore, the reactivity of ebselen with protein thiols has helped to identify novel, selective targets for inhibitory actions on several enzymes of importance in pharmacology and toxicology. Importantly, the selenium in ebselen is not released and thus is not bioavailable, ebselen metabolites being excreted in bile and urine. As a consequence, initial concerns about selenium toxicity, fortunately, were unfounded. Potential applications in medical settings have been explored, notably in brain ischemia and stroke. More recently, there has been a surge in interest as new medical applications have been taken into consideration. The first publication on the biochemical effects of ebselen appeared 30 years ago (Müller et al.), which prompted the authors to retrace the early development from their perspective. It is a fascinating example of fruitful interaction between research-oriented industry and academia. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Parental Obesity and Early Childhood Development.

    PubMed

    Yeung, Edwina H; Sundaram, Rajeshwari; Ghassabian, Akhgar; Xie, Yunlong; Buck Louis, Germaine

    2017-02-01

    Previous studies identified associations between maternal obesity and childhood neurodevelopment, but few examined paternal obesity despite potentially distinct genetic/epigenetic effects related to developmental programming. Upstate KIDS (2008-2010) recruited mothers from New York State (excluding New York City) at ∼4 months postpartum. Parents completed the Ages and Stages Questionnaire (ASQ) when their children were 4, 8, 12, 18, 24, 30, and 36 months of age corrected for gestation. The ASQ is validated to screen for delays in 5 developmental domains (ie, fine motor, gross motor, communication, personal-social functioning, and problem-solving ability). Analyses included 3759 singletons and 1062 nonrelated twins with ≥1 ASQs returned. Adjusted odds ratios (aORs) and 95% confidence intervals were estimated by using generalized linear mixed models accounting for maternal covariates (ie, age, race, education, insurance, marital status, parity, and pregnancy smoking). Compared with normal/underweight mothers (BMI <25), children of obese mothers (26% with BMI ≥30) had increased odds of failing the fine motor domain (aOR 1.67; confidence interval 1.12-2.47). The association remained after additional adjustment for paternal BMI (1.67; 1.11-2.52). Paternal obesity (29%) was associated with increased risk of failing the personal-social domain (1.75; 1.13-2.71), albeit attenuated after adjustment for maternal obesity (aOR 1.71; 1.08-2.70). Children whose parents both had BMI ≥35 were likely to additionally fail the problem-solving domain (2.93; 1.09-7.85). Findings suggest that maternal and paternal obesity are each associated with specific delays in early childhood development, emphasizing the importance of family information when screening child development. Copyright © 2017 by the American Academy of Pediatrics.

  10. Parental Obesity and Early Childhood Development

    PubMed Central

    Sundaram, Rajeshwari; Ghassabian, Akhgar; Xie, Yunlong; Buck Louis, Germaine

    2017-01-01

    BACKGROUND: Previous studies identified associations between maternal obesity and childhood neurodevelopment, but few examined paternal obesity despite potentially distinct genetic/epigenetic effects related to developmental programming. METHODS: Upstate KIDS (2008–2010) recruited mothers from New York State (excluding New York City) at ∼4 months postpartum. Parents completed the Ages and Stages Questionnaire (ASQ) when their children were 4, 8, 12, 18, 24, 30, and 36 months of age corrected for gestation. The ASQ is validated to screen for delays in 5 developmental domains (ie, fine motor, gross motor, communication, personal-social functioning, and problem-solving ability). Analyses included 3759 singletons and 1062 nonrelated twins with ≥1 ASQs returned. Adjusted odds ratios (aORs) and 95% confidence intervals were estimated by using generalized linear mixed models accounting for maternal covariates (ie, age, race, education, insurance, marital status, parity, and pregnancy smoking). RESULTS: Compared with normal/underweight mothers (BMI <25), children of obese mothers (26% with BMI ≥30) had increased odds of failing the fine motor domain (aOR 1.67; confidence interval 1.12–2.47). The association remained after additional adjustment for paternal BMI (1.67; 1.11–2.52). Paternal obesity (29%) was associated with increased risk of failing the personal-social domain (1.75; 1.13–2.71), albeit attenuated after adjustment for maternal obesity (aOR 1.71; 1.08–2.70). Children whose parents both had BMI ≥35 were likely to additionally fail the problem-solving domain (2.93; 1.09–7.85). CONCLUSIONS: Findings suggest that maternal and paternal obesity are each associated with specific delays in early childhood development, emphasizing the importance of family information when screening child development. PMID:28044047

  11. Identification of Gender-specific Transcripts by Microarray in Gonad Tissue of Larval and Juvenile Xenopus tropicalis

    EPA Science Inventory

    Amphibian model species Xenopus tropicalis is currently being utilized by EPA in the development of a standardized in vivo reproductive toxicity assay. Perturbations to the hypothalamic-pituitary-gonadal axis from exposure to endocrine disrupting compounds during larval develop...

  12. Development of chronic tests for endocrine active chemicals. Part 2: an extended fish early-life stage test with an androgenic chemical in the fathead minnow (Pimephales promelas).

    PubMed

    Bogers, Rinus; De Vries-Buitenweg, Selinda; Van Gils, Mariëlle; Baltussen, Erik; Hargreaves, Adam; van de Waart, Beppy; De Roode, Daphne; Legler, Juliette; Murk, Albertinka

    2006-11-16

    The Endocrine Modulators Study Group (EMSG) of the European Chemical Industry has proposed an extended fish early-life stage (ELS) test based on OECD test guideline 210 in combination with a fish pair-breeding reproduction study as a possible alternative for fish full life cycle testing. In this paper the androgen methyldihydrotestosterone (MDHT) was tested in an extended ELS test with fathead minnow supplementary to such a test with the weak estrogen 4-tert-pentylphenol (4TPP). Main endpoints were secondary sexual characteristics (SSC), plasma vitellogenin (VTG) induction and gonadal development. Early blastula embryos were exposed to 0, 0.10, 0.32 and 1.0 microgMDHTl(-1) for up to 114 days post-hatch (dph). A batch of fish exposed to 1.0 microg l(-1) was transferred to clean water after 30 or 63 dph for the remainder of the study. Ethinylestradiol (EE2) was included as estrogenic reference substance at 0.01 microg l(-1). Exposure to MDHT had no significant effect on hatching success or survival, but significantly increased the condition factor of fish exposed for 63 and 114 dph (up to 150% of the control). At 63 dph MDHT exposure induced appearance of tubercles on the snout (a male SSC) of more than 80% of fish. Compared to the controls, plasma VTG was not detectable or significantly lower in fish exposed to MDHT at 0.10 microg/l, but not significantly affected at higher MDHT concentrations. Both lower levels of MDHT significantly inhibited the development of female gonads as of 30 dph. Fish exposed to MDHT at 0.32 and 1.0 microg l(-1) showed higher incidences of mixed sex gonads (10-25%) and smaller testes or dysplasia of gonadal tissue. Dysplasia was present in 80% of the fish continuously exposed to 1.0 microg l(-1) up to 114 dph, but reversible when fish were transferred to dilution water. Results indicate that suppression of ovarian development was the most sensitive endpoint for MDHT exposure after 30 dph. Other endpoints (e.g., growth and SSC) required

  13. Prostaglandin D2 Regulates SOX9 Nuclear Translocation during Gonadal Sex Determination in Tammar Wallaby, Macropus eugenii.

    PubMed

    Chen, Yu; Yu, Hongshi; Pask, Andrew J; Shaw, Geoff; Renfree, Marilyn B

    2017-01-01

    Sex determination and sexual differentiation pathways are highly conserved between marsupials and eutherians. There are 2 different pathways of prostaglandin D2 (PGD2) synthesis: prostaglandin D synthase (PTGDS) and haematopoietic prostaglandin D synthase (HPGDS). PGD2 regulates the subcellular localization of SOX9 during gonadal sexual differentiation. To investigate the function of PGD2 in the tammar gonad, we cultured undifferentiated male gonads in the presence of the HPGDS inhibitor HQL-79 and female gonads with exogenous PGD2 to mimic activation of the PTGDS-PGD2 pathway. Tammar PTGDS and HPGDS have only 50% similarity with mouse and human orthologues, but functional domains are conserved. The expression of SOX9 was unchanged by the treatments in cultured gonads, but its subcellular localization was markedly affected. SOX9 remained cytoplasmic in the Sertoli cells of testes treated with HQL-79. Treated testes developed a thickened ovary-like surface epithelium. In contrast, SOX9 became nuclear in the granulosa cells of developing ovaries treated with PGD2 and the surface epithelium was thin, as in testes. These results demonstrate that PGD2 regulates the subcellular localization of SOX9 and subsequent gonadal development in the developing marsupial gonads, as it does in mice, and that it must have been an ancestral mechanism. © 2017 S. Karger AG, Basel.

  14. Production of Antiserum to LH-Releasing Hormone (LH-RH) Associated with Gonadal Atrophy in Rabbits: Development of Radioimmunoassays for LH-RH

    SciTech Connect

    ARIMURA, A.; SATO, H.; KUMASAKA, T.

    1973-11-01

    Repeated injections of synthetic LH -- RH decapeptide, adsorbed on polyvinylpyrrolidone and emulsified with complete Freund's adjuvant, resulted in the production of a specific antiserum to LH-- RH in two of three rabbits. The animals that produced this antiserum showed a reduction of pituitary LH content and marked atrophy of the testes. The antiserum-antibody complex was detected by the complement flxation test. The antiserum was capable of binding /sup 125/I- labeled LH--RH. After iodination of LHRH (using /sup 125/I and either the chloramine T or lactoperoxidase method) separation of the iodination products on CMC yielded three main peaks of radioactivity:more » The first was free iodide, the second was labeled peptide with low immunoreactivity, and the third was immunoreactive peptide. This 3rd peak consisted of two or three subpeaks; the leading subpeak(s) were more readily bound by antiserum than the trailing one(s). Binding of these fractions to antiserum was increased in the presence of small amounts of unlabeled LH--RH (a phenomenon called paradoxical binding or hock effect) but inhibited by larger amounts. Both the augmentation and the inhibition effects were dose-related, allowing the development of two different radioimmunoassay (RIA) systems for LH--RH. An ordinary (coinpetitive) type of RIA was developed in which a small amount (0.31 ng/assay tube) of unlabeled LH-- RH was added to the labeled peptide. This saturated the antiserum's capacity for paradoxical binding, so that further addition of LH-- RH (from 0.04 to 2.5 ng/ tube) inhibited binding of labeled LH--RH. The assay developed using paradoxical binding omitted the premixing of labeled and unlabeled LH--RH; in this assay addition of very small amounts (0.5 to 310 pg) of unlabeled LH--RH to the assay tubes increased the amount of label bound to antiserum and allowed construction of a parabolic curve of positive slope when B/T was plotted against arithmetic dose. The assays seem to be highly

  15. Male-specific expression of Sox9 during gonad development of crocodile and mouse is mediated by alternative splicing of its proline-glutamine-alanine rich domain.

    PubMed

    Agrawal, Raman; Wessely, Oliver; Anand, Amit; Singh, Lalji; Aggarwal, Ramesh K

    2009-08-01

    The initial trigger for sexual differentiation is regulated by multiple ways during embryonic development. In vertebrates, chromosome-based mechanisms generally known as genetic sex determination are prevalent; however, some species, such as many reptilians, display temperature-dependent sex determination. The Sry-related transcription factor, Sox9, which is expressed by an evolutionary conserved gene, has been shown to be a key player in the process of sex determination. In the present study, we report the identification and expression of crocodile homolog of Sox9 (cpSox9) from the Indian Mugger, Crocodylus palustris. We show that cpSox9 undergoes extensive alternative splicing around the proline-glutamine-alanine rich transactivation domain that results in cpSox9 variants with presumably impaired or reduced transactivation potential. The multiple isoforms were also detected in various embryonic tissues, with some of them displaying a differential expression profile. With respect to sex differentiation, a putative unspliced full-length cpSox9 could be detected only in the genital ridge-adrenal-mesonephros complex of male, but not female embryos during the temperature-sensitive period. Importantly, we further show that this phenomenon was not restricted to the temperature-dependent sex determination species C. palustris, but was also observed in the mouse, a species exhibiting genetic sex determination. Thus, the present study describes, for the first time, a complete coding locus of Sox9 homolog from a temperature-dependent sex determination species. More importantly, we demonstrate an evolutionarily conserved role of alternative splicing resulting in transcriptional diversity and male-sex specific expression of Sox9 during testis development in vertebrates (i.e. irrespective of their underlying sex-determination mechanisms).

  16. Gene Expression Profiling Reveals Potential Players of Left-Right Asymmetry in Female Chicken Gonads.

    PubMed

    Wan, Zhiyi; Lu, Yanan; Rui, Lei; Yu, Xiaoxue; Yang, Fang; Tu, Chengfang; Li, Zandong

    2017-06-20

    Most female birds develop only a left ovary, whereas males develop bilateral testes. The mechanism underlying this process is still not completely understood. Here, we provide a comprehensive transcriptional analysis of female chicken gonads and identify novel candidate side-biased genes. RNA-Seq analysis was carried out on total RNA harvested from the left and right gonads on embryonic day 6 (E6), E12, and post-hatching day 1 (D1). By comparing the gene expression profiles between the left and right gonads, 347 differentially expressed genes (DEGs) were obtained on E6, 3730 were obtained on E12, and 2787 were obtained on D1. Side-specific genes were primarily derived from the autosome rather than the sex chromosome. Gene ontology and pathway analysis showed that the DEGs were most enriched in the Piwi-interactiing RNA (piRNA) metabolic process, germ plasm, chromatoid body, P granule, neuroactive ligand-receptor interaction, microbial metabolism in diverse environments, and methane metabolism. A total of 111 DEGs, five gene ontology (GO) terms, and three pathways were significantly different between the left and right gonads among all the development stages. We also present the gene number and the percentage within eight development-dependent expression patterns of DEGs in the left and right gonads of female chicken.

  17. Early Intervention Paraprofessional Standards: Development and Field Validation

    ERIC Educational Resources Information Center

    Banerjee, Rashida; Chopra, Ritu V.; DiPalma, Geraldine

    2017-01-01

    Personnel standards are the foundations for how states and nations approve a program, engage in systemic assessment, and provide effective professional development to its early childhood professionals. However, despite the extensive use of paraprofessionals in early intervention/early childhood special education programs, there is a lack of…

  18. Early Developments in Argumentation in Physics.

    ERIC Educational Resources Information Center

    Bazerman, Charles

    An evaluation of four seventeenth and eighteenth century essays on optics revealed early trends in the evolution of scientific articles. The later articles showed a growing tendency to (1) separate practice from pure knowledge, (2) organize information around problems of knowledge and theory rather than around chronological events, (3) emphasize…

  19. The Development of Self-Regulation across Early Childhood

    ERIC Educational Resources Information Center

    Montroy, Janelle J.; Bowles, Ryan P.; Skibbe, Lori E.; McClelland, Megan M.; Morrison, Frederick J.

    2016-01-01

    The development of early childhood self-regulation is often considered an early life marker for later life successes. Yet little longitudinal research has evaluated whether there are different trajectories of self-regulation development across children. This study investigates the development of behavioral self-regulation between the ages of 3 and…

  20. Early Development and the Brain: Teaching Resources for Educators

    ERIC Educational Resources Information Center

    Gilkerson, Linda, Ed.; Klein, Rebecca, Ed.

    2008-01-01

    This nine-unit curriculum translates current scientific research on early brain development into practical suggestions to help early childhood professionals understand the reciprocal link between caregiving and brain development. The curriculum was created and extensively field-tested by the Erikson Institute Faculty Development Project on the…

  1. Parents' Role in the Early Head Start Children's Language Development

    ERIC Educational Resources Information Center

    Griswold, Cecelia Smalls

    2014-01-01

    The development of language during a child's early years has been linked to parental involvement. While Early Head Start (EHS) researchers have theorized that parental involvement is an important factor in language development, there has been little research on how parents view their roles in the language development process. The purpose of this…

  2. Classroom Effects of an Early Childhood Educator Professional Development Partnership

    ERIC Educational Resources Information Center

    Algozzine, Bob; Babb, Julie; Algozzine, Kate; Mraz, Maryann; Kissel, Brian; Spano, Sedra; Foxworth, Kimberly

    2011-01-01

    We evaluated an Early Childhood Educator Professional Development (ECEPD) project that provided high-quality, sustained, and intensive professional development designed to support developmentally appropriate instruction for preschool-age children based on the best available research on early childhood pedagogy, child development, and preschool…

  3. Early literacy and early numeracy: the value of including early literacy skills in the prediction of numeracy development.

    PubMed

    Purpura, David J; Hume, Laura E; Sims, Darcey M; Lonigan, Christopher J

    2011-12-01

    The purpose of this study was to examine whether early literacy skills uniquely predict early numeracy skills development. During the first year of the study, 69 3- to 5-year-old preschoolers were assessed on the Preschool Early Numeracy Skills (PENS) test and the Test of Preschool Early Literacy Skills (TOPEL). Participants were assessed again a year later on the PENS test and on the Applied Problems and Calculation subtests of the Woodcock-Johnson III Tests of Achievement. Three mixed effect regressions were conducted using Time 2 PENS, Applied Problems, and Calculation as the dependent variables. Print Knowledge and Vocabulary accounted for unique variance in the prediction of Time 2 numeracy scores. Phonological Awareness did not uniquely predict any of the mathematics domains. The findings of this study identify an important link between early literacy and early numeracy development. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. FGF9, activin and TGFβ promote testicular characteristics in an XX gonad organ culture model.

    PubMed

    Gustin, Sonja E; Stringer, Jessica M; Hogg, Kirsten; Sinclair, Andrew H; Western, Patrick S

    2016-11-01

    Testis development is dependent on the key sex-determining factors SRY and SOX9, which activate the essential ligand FGF9. Although FGF9 plays a central role in testis development, it is unable to induce testis formation on its own. However, other growth factors, including activins and TGFβs, also present testis during testis formation. In this study, we investigated the potential of FGF9 combined with activin and TGFβ to induce testis development in cultured XX gonads. Our data demonstrated differing individual and combined abilities of FGF9, activin and TGFβ to promote supporting cell proliferation, Sertoli cell development and male germ line differentiation in cultured XX gonads. FGF9 promoted proliferation of supporting cells in XX foetal gonads at rates similar to those observed in vivo during testis cord formation in XY gonads but was insufficient to initiate testis development. However, when FGF9, activin and TGFβ were combined, aspects of testicular development were induced, including the expression of Sox9, morphological reorganisation of the gonad and deposition of laminin around germ cells. Enhancing β-catenin activity diminished the testis-promoting activities of the combined growth factors. The male promoting activity of FGF9 and the combined growth factors directly or indirectly extended to the germ line, in which a mixed phenotype was observed. FGF9 and the combined growth factors promoted male germ line development, including mitotic arrest, but expression of pluripotency genes was maintained, rather than being repressed. Together, our data provide evidence that combined signalling by FGF9, activin and TGFβ can induce testicular characteristics in XX gonads. © 2016 Society for Reproduction and Fertility.

  5. MAP3K1-related gonadal dysgenesis: Six new cases and review of the literature.

    PubMed

    Granados, Andrea; Alaniz, Veronica I; Mohnach, Lauren; Barseghyan, Hayk; Vilain, Eric; Ostrer, Harry; Quint, Elisabeth H; Chen, Ming; Keegan, Catherine E

    2017-06-01

    Investigation of disorders of sex development (DSD) has resulted in the discovery of multiple sex-determining genes. MAP3K1 encodes a signal transduction regulator in the sex determination pathway and is emerging as one of the more common genes responsible for 46,XY DSD presenting as complete or partial gonadal dysgenesis. Clinical assessment, endocrine evaluation, and genetic analysis were performed in six individuals from four unrelated families with 46,XY DSD. All six individuals were found to have likely pathogenic MAP3K1 variants. Three of these individuals presented with complete gonadal dysgenesis, characterized by bilateral streak gonads with typical internal and external female genitalia, while the other three presented with partial gonadal dysgenesis, characterized by incomplete testicular development, resulting in clitoral hypertrophy with otherwise typical female external genitalia. Testing for MAP3K1 variants should be considered in patients with 46,XY complete or partial gonadal dysgenesis, particularly in families with multiple members affected with 46,XY DSD. Identification of a MAP3K1 variant should prompt an evaluation for DSD in female siblings of the proband. © 2017 Wiley Periodicals, Inc.

  6. Conceptions of and Early Childhood Educators' Experiences in Early Childhood Professional Development Programs: A Qualitative Metasynthesis

    ERIC Educational Resources Information Center

    Brown, Christopher P.; Englehardt, Joanna

    2016-01-01

    Policy makers and early childhood stakeholders across the United States continue to seek policy solutions that improve early educators' instruction of young children. A primary vehicle for attaining this goal is professional development. This has led to an influx of empirical studies that seek to develop a set of best practices for professional…

  7. Multiscale mathematical modeling of the hypothalamo-pituitary-gonadal axis.

    PubMed

    Clément, Frédérique

    2016-07-01

    Although the fields of systems and integrative biology are in full expansion, few teams are involved worldwide into the study of reproductive function from the mathematical modeling viewpoint. This may be due to the fact that the reproductive function is not compulsory for individual organism survival, even if it is for species survival. Alternatively, the complexity of reproductive physiology may be discouraging. Indeed, the hypothalamo-pituitary-gonadal (HPG) axis involves not only several organs and tissues but also intricate time (from the neuronal millisecond timescale to circannual rhythmicity) and space (from molecules to organs) scales. Yet, mathematical modeling, and especially multiscale modeling, can renew our approaches of the molecular, cellular, and physiological processes underlying the control of reproductive functions. In turn, the remarkable dynamic features exhibited by the HPG axis raise intriguing and challenging questions to modelers and applied mathematicians. In this article, we draw a panoramic review of some mathematical models designed in the framework of the female HPG, with a special focus on the gonadal and central control of follicular development. On the gonadal side, the modeling of follicular development calls to the generic formalism of structured cell populations, that allows one to make mechanistic links between the control of cell fate (proliferation, differentiation, or apoptosis) and that of the follicle fate (ovulation or degeneration) or to investigate how the functional interactions between the oocyte and its surrounding cells shape the follicle morphogenesis. On the central, mainly hypothalamic side, models based on dynamical systems with multiple timescales allow one to represent within a single framework both the pulsatile and surge patterns of the neurohormone GnRH. Beyond their interest in basic research investigations, mathematical models can also be at the source of useful tools to study the encoding and decoding of

  8. Constructivist Early Education for Moral Development.

    ERIC Educational Resources Information Center

    DeVries, Rheta; Hildebrandt, Carolyn; Zan, Betty

    2000-01-01

    Examines role that constructivist teachers play in fostering moral development in young children. Traces development of perspective taking, autonomy, and self- regulation, and examines effects of different teaching and parenting practices on children's character development. Provides suggestions for teachers to promote optimal moral development by…

  9. Redefining Leadership: Lessons from an Early Education Leadership Development Initiative

    ERIC Educational Resources Information Center

    Douglass, Anne

    2018-01-01

    This study examined how experienced early educators developed as change agents in the context of a leadership development program. Unlike in many other professions, experienced early educators lack opportunities to grow throughout their careers and access the supports they need to lead change in their classrooms, organizations, the profession, and…

  10. Promoting Professional Development for Physical Therapists in Early Intervention

    ERIC Educational Resources Information Center

    Catalino, Tricia; Chiarello, Lisa A.; Long, Toby; Weaver, Priscilla

    2015-01-01

    Early intervention service providers are expected to form cohesive teams to build the capacity of a family to promote their child's development. Given the differences in personnel preparation across disciplines of service providers, the Early Childhood Personnel Center is creating integrated and comprehensive professional development models for…

  11. Investments for Future: Early Childhood Development and Education

    ERIC Educational Resources Information Center

    Kartal, Hulya

    2007-01-01

    Investments relevant to the first years of life are directly connected to the future of societies. It can be argued that investments for early childhood development and education are one of the best ways of decreasing social inequality caused by adverse environments which hinder development in early ages and tackling poverty by reducing the rate…

  12. Assessing Home Environment for Early Child Development in Pakistan

    ERIC Educational Resources Information Center

    Nadeem, Sanober; Rafique, Ghazala; Khowaja, Liaquat; Yameen, Anjum

    2014-01-01

    Family environment plays a very important role in early child development and the availability of stimulating material in the early years of a child's life is crucial for optimising development. The Home Observation for Measurement of the Environment (HOME) inventory is one of the most widely used measures to assess the quality and quantity of…

  13. Early Communication Development and Intervention for Children with Autism

    ERIC Educational Resources Information Center

    Landa, Rebecca

    2007-01-01

    Autism is a neurodevelopmental disorder defined by impairments in social and communication development, accompanied by stereotyped patterns of behavior and interest. The focus of this paper is on the early development of communication in autism, and early intervention for impairments in communication associated with this disorder. An overview of…

  14. Comparative transcriptomics of early dipteran development

    PubMed Central

    2013-01-01

    Background Modern sequencing technologies have massively increased the amount of data available for comparative genomics. Whole-transcriptome shotgun sequencing (RNA-seq) provides a powerful basis for comparative studies. In particular, this approach holds great promise for emerging model species in fields such as evolutionary developmental biology (evo-devo). Results We have sequenced early embryonic transcriptomes of two non-drosophilid dipteran species: the moth midge Clogmia albipunctata, and the scuttle fly Megaselia abdita. Our analysis includes a third, published, transcriptome for the hoverfly Episyrphus balteatus. These emerging models for comparative developmental studies close an important phylogenetic gap between Drosophila melanogaster and other insect model systems. In this paper, we provide a comparative analysis of early embryonic transcriptomes across species, and use our data for a phylogenomic re-evaluation of dipteran phylogenetic relationships. Conclusions We show how comparative transcriptomics can be used to create useful resources for evo-devo, and to investigate phylogenetic relationships. Our results demonstrate that de novo assembly of short (Illumina) reads yields high-quality, high-coverage transcriptomic data sets. We use these data to investigate deep dipteran phylogenetic relationships. Our results, based on a concatenation of 160 orthologous genes, provide support for the traditional view of Clogmia being the sister group of Brachycera (Megaselia, Episyrphus, Drosophila), rather than that of Culicomorpha (which includes mosquitoes and blackflies). PMID:23432914

  15. History and early development of INCAP.

    PubMed

    Scrimshaw, Nevin S

    2010-02-01

    Nevin Scrimshaw was the founding Director of the Institute of Nutrition of Central America and Panama (INCAP), serving as Director from 1949 to 1961. In this article, he reviews the history of the founding of INCAP, including the role of the Rockefeller and Kellogg Foundations, the Central American governments, and the Pan American Health Organization. The objectives pursued by INCAP in its early years were to assess the nutrition and related health problems of Central America, to carry out research to find practical solutions to these problems, and to provide technical assistance to its member countries to implement solutions. INCAP pursued a strategy of selecting promising Central Americans for advanced education and training in the US who assumed positions of leadership on their return. After this early phase, talented non-Central Americans of diverse origins were brought to INCAP, as well as additional researchers from the region. Growth of INCAP, as reflected in its annual budget and in the physical plant, was rapid and this was accompanied by high scientific productivity. Several field studies were launched that contributed impetus and design elements for the Oriente Longitudinal Study, which is the focus of this supplement.

  16. Developments in early intervention for psychosis in Hong Kong.

    PubMed

    Wong, G H Y; Hui, C L M; Wong, D Y; Tang, J Y M; Chang, W C; Chan, S K W; Lee, E H M; Xu, J Q; Lin, J J X; Lai, D C; Tam, W; Kok, J; Chung, D W S; Hung, S F; Chen, E Y H

    2012-09-01

    The year 2011 marked the 10-year milestone of early intervention for psychosis in Hong Kong. Since 2001, the landscape of early psychosis services has changed markedly in Hong Kong. Substantial progress has been made in the areas of early intervention service implementation, knowledge generation, and public awareness promotion. Favourable outcomes attributable to the early intervention service are supported by solid evidence from local clinical research studies; early intervention service users showed improved functioning, ameliorated symptoms, and decreased hospitalisation and suicide rates. Continued development of early intervention in Hong Kong over the decade includes the introduction and maturation of several key platforms, such as the Hospital Authority Early Assessment Service for Young People with Psychosis programme, the Psychosis Studies and Intervention Unit by the University of Hong Kong, the Hong Kong Early Psychosis Intervention Society, the Jockey Club Early Psychosis Project, and the postgraduate Psychological Medicine (Psychosis Studies) programme. In this paper, we reviewed some of the major milestones in local service development with reference to features of the Hong Kong mental health system. We describe chronologically the implementation and consolidation of public early intervention services as well as recent progresses in public awareness work that are tied in with knowledge generation and transfer, and outline the prospects for early intervention in the next decade and those that follow.

  17. Sex Role Development in Early Adolescence.

    ERIC Educational Resources Information Center

    Wittig, Michele Andrisin

    1983-01-01

    Research involving adolescent identification with and development of sex roles is reviewed in the areas of cognitive skills and personality traits, theories of sex role development, and minority group adolescent sex role development. Emerging issues and educational implications in these areas are discussed. (CJ)

  18. Neuropeptides in the Gonads: From Evolution to Pharmacology

    PubMed Central

    McGuire, Nicolette L.; Bentley, George E.

    2010-01-01

    Vertebrate gonads are the sites of synthesis and binding of many peptides that were initially classified as neuropeptides. These gonadal neuropeptide systems are neither well understood in isolation, nor in their interactions with other neuropeptide systems. Further, our knowledge of the control of these gonadal neuropeptides by peripheral hormones that bind to the gonads, and which themselves are under regulation by true neuropeptide systems from the hypothalamus, is relatively meager. This review discusses the existence of a variety of neuropeptides and their receptors which have been discovered in vertebrate gonads, and the possible way in which such systems could have evolved. We then focus on two key neuropeptides for regulation of the hypothalamo-pituitary-gonadal axis: gonadotropin-releasing hormone (GnRH) and gonadotropin-inhibitory hormone (GnIH). Comparative studies have provided us with a degree of understanding as to how a gonadal GnRH system might have evolved, and they have been responsible for the discovery of GnIH and its gonadal counterpart. We attempt to highlight what is known about these two key gonadal neuropeptides, how their actions differ from their hypothalamic counterparts, and how we might learn from comparative studies of them and other gonadal neuropeptides in terms of pharmacology, reproductive physiology and evolutionary biology. PMID:21607065

  19. Early Numeracy Assessment: The Development of the Preschool Early Numeracy Scales

    ERIC Educational Resources Information Center

    Purpura, David J.; Lonigan, Christopher J.

    2015-01-01

    Research Findings: The focus of this study was to construct and validate 12 brief early numeracy assessment tasks that measure the skills and concepts identified as key to early mathematics development by the National Council of Teachers of Mathematics (2006) and the National Mathematics Advisory Panel (2008)-as well as critical developmental…

  20. Parents Resourcing Children's Early Development and Learning

    ERIC Educational Resources Information Center

    Nichols, Sue; Nixon, Helen; Pudney, Valerie; Jurvansuu, Sari

    2009-01-01

    Parents deal with a complex web of choices when seeking and using knowledge and resources related to their young children's literacy development. Information concerning children's learning and development comes in many forms and is produced by an increasingly diverse range of players including governments, non-government organizations and…

  1. Adaptive Responses to Prochloraz Exposure in the Hypothalamic-Pituitary Gonadal Axis of Fathead Minnows

    EPA Science Inventory

    Exposure to endocrine disrupting chemicals can affect reproduction and development in both humans and wildlife. We are developing a mechanistic mathematical model of the hypothalamic-pituitary-gonadal (HPG) axis in female fathead minnows to predict doseresponse and time-course ...

  2. Adaptive Response in Female Modeling of the Hypothalamic-pituitary-gonadal Axis

    EPA Science Inventory

    Exposure to endocrine disrupting chemicals can affect reproduction and development in both humans and wildlife. We are developing a mechanistic computational model of the hypothalamic-pituitary-gonadal (HPG) axis in female fathead minnows to predict dose-response and time-course ...

  3. UV laser radiation alters the embryonic protein profile of adrenal-kidney-gonadal complex and gonadal differentiation in the lizard, Calotes Versicolor.

    PubMed

    Khodnapur, Bharati S; Inamdar, Laxmi S; Nindi, Robertraj S; Math, Shivkumar A; Mulimani, B G; Inamdar, Sanjeev R

    2015-02-01

    To examine the impact of ultraviolet (UV) laser radiation on the embryos of Calotes versicolor in terms of its effects on the protein profile of the adrenal-kidney-gonadal complex (AKG), sex determination and differentiation, embryonic development and hatching synchrony. The eggs of C. versicolor, during thermo-sensitive period (TSP), were exposed to third harmonic laser pulses at 355 nm from a Q-switched Nd:YAG laser for 180 sec. Subsequent to the exposure they were incubated at the male-producing temperature (MPT) of 25.5 ± 0.5°C. The AKG of hatchlings was subjected to protein analysis by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and to histology. The UV laser radiation altered the expression of the protein banding pattern in the AKG complex of hatchlings and it also affected the gonadal sex differentiation. SDS-PAGE of AKG of one-day-old hatchlings revealed a total of nine protein bands in the control group whereas UV laser irradiated hatchlings expressed a total of seven protein bands only one of which had the same Rf as a control band. The UV laser treated hatchlings have an ovotestes kind of gonad exhibiting a tendency towards femaleness instead of the typical testes. It is inferred that 355 nm UV laser radiation during TSP induces changes in the expression of proteins as well as their secretions. UV laser radiation had an impact on the gonadal differentiation pathway but no morphological anomalies were noticed.

  4. Early psychosis workforce development: Core competencies for mental health professionals working in the early psychosis field.

    PubMed

    Osman, Helen; Jorm, Anthony F; Killackey, Eoin; Francey, Shona; Mulcahy, Dianne

    2017-08-09

    The aim of this study was to identify the core competencies required of mental health professionals working in the early psychosis field, which could function as an evidence-based tool to support the early psychosis workforce and in turn assist early psychosis service implementation and strengthen early psychosis model fidelity. The Delphi method was used to establish expert consensus on the core competencies. In the first stage, a systematic literature search was conducted to generate competency items. In the second stage, a panel consisting of expert early psychosis clinicians from around the world was formed. Panel members then rated each of the competency items on how essential they are to the clinical practice of all early psychosis clinicians. In total, 1023 pieces of literature including textbooks, journal articles and grey literature were reviewed. A final 542 competency items were identified for inclusion in the questionnaire. A total of 63 early psychosis experts participated in 3 rating rounds. Of the 542 competency items, 242 were endorsed as the required core competencies. There were 29 competency items that were endorsed by 62 or more experts, and these may be considered the foundational competencies for early psychosis practice. The study generated a set of core competencies that provide a common language for early psychosis clinicians across professional disciplines and country of practice, and potentially are a useful professional resource to support early psychosis workforce development and service reform. © 2017 John Wiley & Sons Australia, Ltd.

  5. Early development of fern gametophytes in microgravity

    NASA Technical Reports Server (NTRS)

    Roux, Stanley J.; Chatterjee, Ani; Hillier, Sheila; Cannon, Tom

    2003-01-01

    Dormant spores of the fern Ceratopteris richardii were flown on Shuttle mission STS-93 to evaluate the effects of micro-g on their development and on their pattern of gene expression. Prior to flight the spores were sterilized and sown into one of two environments: (1) Microscope slides in a video-microscopy module; and (2) Petri dishes. All spores were then stored in darkness until use. Spore germination was initiated on orbit after exposure to light. For the spores on microscope slides, cell level changes were recorded through the clear spore coat of the spores by video microscopy. After their exposure to light, spores in petri dishes were frozen in orbit at four different time points during which on earth gravity fixes the polarity of their development. Spores were then stored frozen in Biological Research in Canister units until recovery on earth. The RNAs from these cells and from 1-g control cells were extracted and analyzed on earth after flight to assay changes in gene expression. Video microscopy results revealed that the germinated spores developed normally in microgravity, although the polarity of their development, which is guided by gravity on earth, was random in space. Differential Display-PCR analyses of RNA extracted from space-flown cells showed that there was about a 5% change in the pattern of gene expression between cells developing in micro-g compared to those developing on earth. c2002 Published by Elsevier Science Ltd on behalf of COSPAR.

  6. Erratum: Erratum to: Recovery of gonadal development in tiger puffer Takifugu rubripes after exposure to 17β-estradiol during early life stages

    NASA Astrophysics Data System (ADS)

    Hu, Peng; Liu, Bin; Meng, Zhen; Liu, Xinfu; Jia, Yudong; Yang, Zhi; Lei, Jilin

    2017-09-01

    A mistake was found in Section 2.2. The current expression is "In each treatment group, juveniles were exposed to E2 at the set concentration for 2 h once a day from 15 to 100 dph." The correct version should be "In each treatment group, juveniles were exposed to E2 at the set concentration for 2 h once two days from 15 to 100 dph."

  7. Chaos, Poverty, and Parenting: Predictors of Early Language Development

    ERIC Educational Resources Information Center

    Vernon-Feagans, Lynne; Garrett-Peters, Patricia; Willoughby, Michael; Mills-Koonce, Roger

    2012-01-01

    Studies have shown that distal family risk factors like poverty and maternal education are strongly related to children's early language development. Yet, few studies have examined these risk factors in combination with more proximal day-to-day experiences of children that might be critical to understanding variation in early language. Young…

  8. Childhood Immunization: A Key Component of Early Childhood Development

    ERIC Educational Resources Information Center

    Messonnier, Nancy

    2017-01-01

    Physical health is a key component of early childhood development and school readiness. By keeping children healthy and decreasing the chances of disease outbreaks, immunizations help early childhood programs create a safe environment for children. While overall vaccination rates are high nationally for most vaccines routinely recommended for…

  9. Online Professional Development: Choices for Early Childhood Educators

    ERIC Educational Resources Information Center

    Olsen, Heather; Donaldson, Ana J.; Hudson, Susan D.

    2010-01-01

    Early childhood educators are responsible for providing young children with the best possible early care and education. Research on child care workers' education has shown that professional preparation makes a significant impact on children's cognitive and emotional development (National Association for the Education of Young Children [NAEYC],…

  10. Alberta Learning: Early Development Instrument Pilot Project Evaluation.

    ERIC Educational Resources Information Center

    Meaney, Wanda; Harris-Lorenze, Elayne

    The Early Development Instrument (EDI) was designed by McMaster University to measure the outcomes of childrens early years as they influence their readiness to learn at school. The EDI was piloted in several Canadian cities in recent years through two national initiatives. Building on these initiatives, Alberta Learning piloted the EDI as a…

  11. Activities for Career Development in Early Childhood Curriculum.

    ERIC Educational Resources Information Center

    Yawkey, Thomas Daniels; Aronin, Eugene L.

    The book presents career education activities and approaches for use by teachers, administrators, counselors, and students involved in early childhood education (ages three through eight). Part One stresses the importance of and rationale for career development in the early childhood curriculum. Research support for the approach to career…

  12. Family Strategies to Support and Develop Resilience in Early Childhood

    ERIC Educational Resources Information Center

    Taket, A. R.; Nolan, A.; Stagnitti, K.

    2014-01-01

    Early childhood is an important time for the development of resilience. A recently completed study has followed three cohorts of resilient children and young people living in disadvantaged areas in Victoria, Australia, through different transitions in their educational careers. This paper focuses on the early childhood cohort, where we have…

  13. Developing Prosocial Behaviors in Early Adolescence with Reactive Aggression

    ERIC Educational Resources Information Center

    Fung, Annis L. C.

    2008-01-01

    Despite the alarming rise of early adolescence aggression in Hong Kong, it is the pioneer evidence-based outcome study on Anger Coping Training (ACT) program for early adolescence with reactive aggression to develop their prosocial behaviors. This research program involved experimental and control groups with pre- and post-comparison using a …

  14. Early Speech Motor Development: Cognitive and Linguistic Considerations

    ERIC Educational Resources Information Center

    Nip, Ignatius S. B.; Green, Jordan R.; Marx, David B.

    2009-01-01

    This longitudinal investigation examines developmental changes in orofacial movements occurring during the early stages of communication development. The goals were to identify developmental trends in early speech motor performance and to determine how these trends differ across orofacial behaviors thought to vary in cognitive and linguistic…

  15. Loss of p300 and CBP disrupts histone acetylation at the mouse Sry promoter and causes XY gonadal sex reversal

    PubMed Central

    Carré, Gwenn-Aël; Siggers, Pam; Xipolita, Marilena; Brindle, Paul; Lutz, Beat; Wells, Sara; Greenfield, Andy

    2018-01-01

    Abstract CREB-binding protein (CBP, CREBBP, KAT3A) and its closely related paralogue p300 (EP300, KAT3B), together termed p300/CBP, are histone/lysine acetyl-transferases that control gene expression by modifying chromatin-associated proteins. Here, we report roles for both of these chromatin-modifying enzymes in mouse sex determination, the process by which the embryonic gonad develops into a testis or an ovary. By targeting gene ablation to embryonic gonadal somatic cells using an inducible Cre line, we show that gonads lacking either gene exhibit major abnormalities of XY gonad development at 14.5 dpc, including partial sex reversal. Embryos lacking three out of four functional copies of p300/Cbp exhibit complete XY gonadal sex reversal and have greatly reduced expression of the key testis-determining genes Sry and Sox9. An analysis of histone acetylation at the Sry promoter in mutant gonads at 11.5 dpc shows a reduction in levels of the positive histone mark H3K27Ac. Our data suggest a role for CBP/p300 in testis determination mediated by control of histone acetylation at the Sry locus and reveal a novel element in the epigenetic control of Sry and mammalian sex determination. They also suggest possible novel causes of human disorders of sex development (DSD). PMID:29145650

  16. ECR-MAPK regulation in liver early development.

    PubMed

    Zhao, Xiu-Ju; Zhuo, Hexian

    2014-01-01

    Early growth is connected to a key link between embryonic development and aging. In this paper, liver gene expression profiles were assayed at postnatal day 22 and week 16 of age. Meanwhile another independent animal experiment and cell culture were carried out for validation. Significance analysis of microarrays, qPCR verification, drug induction/inhibition assays, and metabonomics indicated that alpha-2u globulin (extracellular region)-socs2 (-SH2-containing signals/receptor tyrosine kinases)-ppp2r2a/pik3c3 (MAPK signaling)-hsd3b5/cav2 (metabolism/organization) plays a vital role in early development. Taken together, early development of male rats is ECR and MAPK-mediated coordination of cancer-like growth and negative regulations. Our data represent the first comprehensive description of early individual development, which could be a valuable basis for understanding the functioning of the gene interaction network of infant development.

  17. Reading Development Subtypes and Their Early Characteristics

    ERIC Educational Resources Information Center

    Torppa, Minna; Tolvanen, Asko; Poikkeus, Anna-Maija; Eklund, Kenneth; Lerkkanen, Marja-Kristiina; Leskinen, Esko; Lyytinen, Heikki

    2007-01-01

    The present findings are drawn from the Jyvaskyla Longitudinal Study of Dyslexia (JLD), in which approximately 100 children with familial risk of dyslexia and 100 control children have been followed from birth. In this paper we report data on the reading development of the JLD children and their classmates, a total of 1,750 children from four…

  18. Developing an Engineering Identity in Early Childhood

    ERIC Educational Resources Information Center

    Pantoya, Michelle L.; Aguirre-Munoz, Zenaida; Hunt, Emily M.

    2015-01-01

    This project describes a strategy to introduce young children to engineering in a way that develops their engineering identity. The targeted age group is 3-7 year old students because they rarely experience purposeful engineering instruction. The curriculum was designed around an engineering storybook and included interactive academic discussions…

  19. Early developments in solar cooling equipment

    NASA Technical Reports Server (NTRS)

    Price, J. M.

    1978-01-01

    A brief description of a development program to design, fabricate and field test a series of solar operated or driven cooling devices, undertaken by the Marshall Space Flight Center in the context of the Solar Heating and Cooling Demonstration Act of 1974, is presented. Attention is given to two basic design concepts: the Rankine cycle principle and the use of a dessicant for cooling.

  20. School Building in Early Development. Part 2.

    ERIC Educational Resources Information Center

    Dijkgraaf, C.; Giertz, L. M.

    1975-01-01

    Development is characterized by urbanization. New settlements grow either as enlargements of existing ones or as new population concentrations. Three periods may be distinguished in the growth of a settlement: (1) the wild period of first settling, (2) the consolidation period, and (3) the stabilized society. The number of school-aged children per…

  1. Economic Deprivation and Early Childhood Development.

    ERIC Educational Resources Information Center

    Duncan, Greg J.; And Others

    1994-01-01

    Examined the relationship between poverty and children's developmental outcomes, the effects of the timing and duration of poverty, and the effects of poverty at the family and neighborhood level, analyzing data from two longitudinal surveys. Found that poverty status was strongly related to low levels of cognitive development, even after…

  2. The Early Development of Programmable Machinery.

    ERIC Educational Resources Information Center

    Collins, Martin D.

    1985-01-01

    Programmable equipment innovations, precursors of today's technology, are examined, including the development of the binary code and feedback control systems, such as temperature sensing devices, interchangeable parts, punched cards carrying instructions, continuous flow oil refining process, assembly lines for mass production, and the…

  3. Plasticity during Early Brain Development Is Determined by Ontogenetic Potential.

    PubMed

    Krägeloh-Mann, Ingeborg; Lidzba, Karen; Pavlova, Marina A; Wilke, Marko; Staudt, Martin

    2017-04-01

    Two competing hypotheses address neuroplasticity during early brain development: the "Kennard principle" describes the compensatory capacities of the immature developing CNS as superior to those of the adult brain, whereas the "Hebb principle" argues that the young brain is especially sensitive to insults. We provide evidence that these principles are not mutually exclusive. Following early brain lesions that are unilateral, the brain can refer to homotopic areas of the healthy hemisphere. This potential for reorganization is unique to the young brain but available only when, during ontogenesis of brain development, these areas have been used for the functions addressed. With respect to motor function, ipsilateral motor tracts can be recruited, which are only available during early brain development. Language can be reorganized to the right after early left hemispheric lesions, as the representation of the language network is initially bilateral. However, even in these situations, compensatory capacities of the developing brain are found to have limitations, probably defined by early determinants. Thus, plasticity and adaptivity are seen only within ontogenetic potential; that is, axonal or cortical structures cannot be recruited beyond early developmental possibilities. The young brain is probably more sensitive and vulnerable to lesions when these are bilateral. This is shown here for bilateral periventricular white matter lesions that clearly have an impact on cortical architecture and function, thus probably interfering with early network building. Georg Thieme Verlag KG Stuttgart · New York.

  4. Scattered dose to gonads and associated risks from radiotherapy for common pediatric malignancies : a phantom study.

    PubMed

    Mazonakis, Michalis; Zacharopoulou, Fotini; Kachris, Stefanos; Varveris, Charalambos; Damilakis, John; Gourtsoyiannis, Nicholas

    2007-06-01

    To measure the scattered dose to ovaries and testes from radiotherapy for common pediatric malignancies and to assess the relevant risks for radiation-induced gonadal damage and hereditary disorders in future generations. Radiotherapy for central nervous system tumors, acute leukemia, neuroblastoma, Hodgkin's disease, Wilms' tumor, and sarcoma was simulated on three humanoid phantoms representing patients of 5, 10, and 15 years of age. Ovarian and testicular dose measurements were performed using thermoluminescent dosimeters on a linear accelerator with multileaf collimator (MLC) producing 6-MV X-rays. The effect of lead block introduction into the primary beam on the gonadal dose was evaluated. Gonadal dose from radiotherapy for abdominal tumors was measured using an 18-MV photon beam. For a tumor dose range of 12-55 Gy, the scattered dose to ovaries was 0.5-62.4 cGy depending upon the patient's age (corresponding phantom) and treatment site. The corresponding dose to testes was 0.4-145.0 cGy. The use of blocks for field shaping can increase the gonadal dose up to a factor of 2.0 compared to that measured using MLC. Abdominal irradiation with 18-MV instead of 6-MV X-rays reduced the gonadal dose by more than 1.3 times. For female and male patients, the risk for induction of hereditary disorders was less than 81 x 10(-4) and 188 x 10(-4), respectively. The present dosimetric data suggest that pediatric radiotherapy is not associated with a risk for permanent damage to gonads excluded from the treatment volume. The risk for development of hereditary disorders in offspring conceived after exposure is low.

  5. Female gonadal shielding with automatic exposure control increases radiation risks.

    PubMed

    Kaplan, Summer L; Magill, Dennise; Felice, Marc A; Xiao, Rui; Ali, Sayed; Zhu, Xiaowei

    2018-02-01

    Gonadal shielding remains common, but current estimates of gonadal radiation risk are lower than estimated risks to colon and stomach. A female gonadal shield may attenuate active automatic exposure control (AEC) sensors, resulting in increased dose to colon and stomach as well as to ovaries outside the shielded area. We assess changes in dose-area product (DAP) and absorbed organ dose when female gonadal shielding is used with AEC for pelvis radiography. We imaged adult and 5-year-old equivalent dosimetry phantoms using pelvis radiograph technique with AEC in the presence and absence of a female gonadal shield. We recorded DAP and mAs and measured organ absorbed dose at six internal sites using film dosimetry. Female gonadal shielding with AEC increased DAP 63% for the 5-year-old phantom and 147% for the adult phantom. Absorbed organ dose at unshielded locations of colon, stomach and ovaries increased 21-51% in the 5-year-old phantom and 17-100% in the adult phantom. Absorbed organ dose sampled under the shield decreased 67% in the 5-year-old phantom and 16% in the adult phantom. Female gonadal shielding combined with AEC during pelvic radiography increases absorbed dose to organs with greater radiation sensitivity and to unshielded ovaries. Difficulty in proper use of gonadal shields has been well described, and use of female gonadal shielding may be inadvisable given the risks of increasing radiation.

  6. Effects of centrifugation on gonadal and adrenocortical steroids in rats

    NASA Technical Reports Server (NTRS)

    Kakihana, R.; Butte, J. C.

    1980-01-01

    Many endocrine systems are sensitive to external changes in the environment. Both the pituitary adrenal and pituitary gonadal systems are affected by stress including centrifugation stress. The effect of centrifugation on the pituitary gonadal and pituitary adrenocortical systems was examined by measuring the gonadal and adrenal steroids in the plasma and brain following different duration and intensity of centrifugation stress in rats. Two studies were completed and the results are presented. The second study was carried out to describe the developmental changes of brain, plasma and testicular testosterone and dihydrotestosterone in Sprague Dawley rats so that the effect of centrifugation stress on the pituitary gonadal syatem could be better evaluated in future studies.

  7. Gonadal disorder in the thinlip grey mullet (Liza ramada, Risso 1827) as a biomarker of environmental stress in surface waters.

    PubMed

    Tancioni, Lorenzo; Caprioli, Riccardo; Al-Khafaji, Ayad Hantoosh Dawood; Mancini, Laura; Boglione, Clara; Ciccotti, Eleonora; Cataudella, Stefano

    2015-02-05

    The aim of this study was to evaluate the use of gonadal alterations in the thinlip grey mullet (Liza ramada) as a biological indicator in assessing aquatic ecosystems health, with particular emphasis to river ecosystems exposed to sewage discharges. For this purpose, the reproductive status and the presence of gonadal alterations were studied in 206 mullets collected from two sites on the low course of the Tiber River, downstream of a large urban sewage treatment plant and in the estuarine area, and from an uncontaminated pond considered as reference site. Intersex and irregularly shaped gonads were observed in 20.8% of the mullets from the most polluted site, and intersex gonads in 10.3% of those from the estuarine area. No alterations were detected in the fish from the reference site, which also showed distinct stages of gonadal development. Conversely, unclear stages of testicular and ovary development were observed in the fish from the two polluted river sites. The results of this study suggest that L. ramada may represent a sentinel species in environmental risk assessment and support the use of gonadal alterations of this species as a bioindicator for extensive monitoring of pollution in lower stretches of rivers and estuarine areas.

  8. Gonadal Disorder in the Thinlip Grey Mullet (Liza ramada, Risso 1827) as a Biomarker of Environmental Stress in Surface Waters

    PubMed Central

    Tancioni, Lorenzo; Caprioli, Riccardo; Dawood Al-Khafaji, Ayad Hantoosh; Mancini, Laura; Boglione, Clara; Ciccotti, Eleonora; Cataudella, Stefano

    2015-01-01

    The aim of this study was to evaluate the use of gonadal alterations in the thinlip grey mullet (Liza ramada) as a biological indicator in assessing aquatic ecosystems health, with particular emphasis to river ecosystems exposed to sewage discharges. For this purpose, the reproductive status and the presence of gonadal alterations were studied in 206 mullets collected from two sites on the low course of the Tiber River, downstream of a large urban sewage treatment plant and in the estuarine area, and from an uncontaminated pond considered as reference site. Intersex and irregularly shaped gonads were observed in 20.8% of the mullets from the most polluted site, and intersex gonads in 10.3% of those from the estuarine area. No alterations were detected in the fish from the reference site, which also showed distinct stages of gonadal development. Conversely, unclear stages of testicular and ovary development were observed in the fish from the two polluted river sites. The results of this study suggest that L. ramada may represent a sentinel species in environmental risk assessment and support the use of gonadal alterations of this species as a bioindicator for extensive monitoring of pollution in lower stretches of rivers and estuarine areas. PMID:25664693

  9. Resource Prospector (RP) - Early Prototyping and Development

    NASA Technical Reports Server (NTRS)

    Andrews, D.; Colaprete, A.; Quinn, J.; Bluethmann, B.; Trimble, J.

    2015-01-01

    The Resource Prospector (RP) is an In-Situ Resource Utilization (ISRU) technology demonstration mission under study by the NASA Human Exploration and Operations Mission Directorate's (HEOMD) Advanced Exploration Systems (AES) Division. The mission, currently planned to launch in 2020, will demonstrate extraction of oxygen from lunar regolith to validate ISRU capability. The mission will address key Strategic Knowledge Gaps (SKGs) for robotic and human exploration to the Moon, Near Earth Asteroids (NEAs), and ultimately Mars, as well as meet the strategic goals of the Global Exploration Roadmap (GER), offered by the International Space Exploration Coordination Group (ISECG). In this roadmap, the use of local resources is specifically addressed relating to human exploration. RP will provide knowledge to inform the selection of future mission destinations, support the development of exploration systems, and reduce the risk associated with human exploration. Expanding human presence beyond low-Earth orbit to asteroids and Mars will require the maximum possible use of local materials, so-called in-situ resources. The moon presents a unique destination to conduct robotic investigations that advance ISRU capabilities, as well as providing significant exploration and science value. Lunar regolith contains useful resources such as oxygen, water, silicon, and light metals, like aluminum and titanium. Oxygen can be separated from the regolith for life support (breathable air), or used to create rocket propellant (oxidizer). Regolith can be used to protect against radiation exposure, be processed into solar cells, or used to manufacture construction materials such as bricks and glass. RP will characterize the constituents and distribution of water and other volatiles at the poles of the Moon, enabling innovative uses of local resources, in addition to validating ISRU capabilities. This capability, as well as a deeper understanding of regolith, will be valuable in the

  10. Early intestinal growth and development in poultry.

    PubMed

    Lilburn, M S; Loeffler, S

    2015-07-01

    While there are many accepted "facts" within the field of poultry science that are in truth still open for discussion, there is little debate with respect to the tremendous genetic progress that has been made with commercial broilers and turkeys (Havenstein et al., 2003, 2007). When one considers the changes in carcass development in poultry meat strains, these genetic "improvements" have not always been accompanied by correlated changes in other physiological systems and this can predispose some birds to developmental anomalies (i.e. ascites; Pavlidis et al., 2007; Wideman et al., 2013). Over the last decade, there has been increased interest in intestinal growth/health as poultry nutritionists have attempted to adopt new approaches to deal with the broader changes in the overall nutrition landscape. This landscape includes not only the aforementioned genetic changes but also a raft of governmental policies that have focused attention on the environment (phosphorus and nitrogen excretion), consumer pressure on the use of antibiotics, and renewable biofuels with its consequent effects on ingredient costs. Intestinal morphology has become a common research tool for assessing nutritional effects on the intestine but it is only one metric among many that can be used and histological results can often be interpreted in a variety of ways. This study will address the broader body of research on intestinal growth and development in commercial poultry and will attempt to integrate the topics of the intestinal: microbial interface and the role of the intestine as an immune tissue under the broad umbrella of intestinal physiology. © 2015 Poultry Science Association Inc.

  11. Advancing Early Childhood Development: from Science to Scale 1

    PubMed Central

    Black, Maureen M; Walker, Susan P; Fernald, Lia C H; Andersen, Christopher T; DiGirolamo, Ann M; Lu, Chunling; McCoy, Dana C; Fink, Günther; Shawar, Yusra R; Shiffman, Prof Jeremy; Devercelli, Amanda E; Wodon, Quentin T; Vargas-Barón, Emily; Grantham-McGregor, Sally

    2018-01-01

    Early childhood development programmes vary in coordination and quality, with inadequate and inequitable access, especially for children younger than 3 years. New estimates, based on proxy measures of stunting and poverty, indicate that 250 million children (43%) younger than 5 years in low-income and middle-income countries are at risk of not reaching their developmental potential. There is therefore an urgent need to increase multisectoral coverage of quality programming that incorporates health, nutrition, security and safety, responsive caregiving, and early learning. Equitable early childhood policies and programmes are crucial for meeting Sustainable Development Goals, and for children to develop the intellectual skills, creativity, and wellbeing required to become healthy and productive adults. In this paper, the first in a three part Series on early childhood development, we examine recent scientific progress and global commitments to early childhood development. Research, programmes, and policies have advanced substantially since 2000, with new neuroscientific evidence linking early adversity and nurturing care with brain development and function throughout the life course. PMID:27717614

  12. Global Survey of Protein Expression during Gonadal Sex Determination in Mice*

    PubMed Central

    Ewen, Katherine; Baker, Mark; Wilhelm, Dagmar; Aitken, R. John; Koopman, Peter

    2009-01-01

    The development of an embryo as male or female depends on differentiation of the gonads as either testes or ovaries. A number of genes are known to be important for gonadal differentiation, but our understanding of the regulatory networks underpinning sex determination remains fragmentary. To advance our understanding of sexual development beyond the transcriptome level, we performed the first global survey of the mouse gonad proteome at the time of sex determination by using two-dimensional nanoflow LC-MS/MS. The resulting data set contains a total of 1037 gene products (154 non-redundant and 883 redundant proteins) identified from 620 peptides. Functional classification and biological network construction suggested that the identified proteins primarily serve in RNA post-transcriptional modification and trafficking, protein synthesis and folding, and post-translational modification. The data set contains potential novel regulators of gonad development and sex determination not revealed previously by transcriptomics and proteomics studies and more than 60 proteins with potential links to human disorders of sexual development. PMID:19617587

  13. 45 CFR 1304.21 - Education and early childhood development.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... as art, music, movement, and dialogue; (iii) Promoting interaction and language use among children... DEVELOPMENT SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION FOR CHILDREN, YOUTH AND... early childhood development. (a) Child development and education approach for all children. (1) In order...

  14. 45 CFR 1304.21 - Education and early childhood development.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... as art, music, movement, and dialogue; (iii) Promoting interaction and language use among children... DEVELOPMENT SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION FOR CHILDREN, YOUTH AND... early childhood development. (a) Child development and education approach for all children. (1) In order...

  15. 45 CFR 1304.21 - Education and early childhood development.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... as art, music, movement, and dialogue; (iii) Promoting interaction and language use among children... DEVELOPMENT SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION FOR CHILDREN, YOUTH AND... early childhood development. (a) Child development and education approach for all children. (1) In order...

  16. 45 CFR 1304.21 - Education and early childhood development.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... as art, music, movement, and dialogue; (iii) Promoting interaction and language use among children... DEVELOPMENT SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION FOR CHILDREN, YOUTH AND... early childhood development. (a) Child development and education approach for all children. (1) In order...

  17. Hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axes: sex differences in regulation of stress responsivity.

    PubMed

    Oyola, Mario G; Handa, Robert J

    2017-09-01

    Gonadal hormones play a key role in the establishment, activation, and regulation of the hypothalamic-pituitary-adrenal (HPA) axis. By influencing the response and sensitivity to releasing factors, neurotransmitters, and hormones, gonadal steroids help orchestrate the gain of the HPA axis to fine-tune the levels of stress hormones in the general circulation. From early life to adulthood, gonadal steroids can differentially affect the HPA axis, resulting in sex differences in the responsivity of this axis. The HPA axis influences many physiological functions making an organism's response to changes in the environment appropriate for its reproductive status. Although the acute HPA response to stressors is a beneficial response, constant activation of this circuitry by chronic or traumatic stressful episodes may lead to a dysregulation of the HPA axis and cause pathology. Compared to males, female mice and rats show a more robust HPA axis response, as a result of circulating estradiol levels which elevate stress hormone levels during non-threatening situations, and during and after stressors. Fluctuating levels of gonadal steroids in females across the estrous cycle are a major factor contributing to sex differences in the robustness of HPA activity in females compared to males. Moreover, gonadal steroids may also contribute to epigenetic and organizational influences on the HPA axis even before puberty. Correspondingly, crosstalk between the hypothalamic-pituitary-gonadal (HPG) and HPA axes could lead to abnormalities of stress responses. In humans, a dysregulated stress response is one of the most common symptoms seen across many neuropsychiatric disorders, and as a result, such interactions may exacerbate peripheral pathologies. In this review, we discuss the HPA and HPG axes and review how gonadal steroids interact with the HPA axis to regulate the stress circuitry during all stages in life.

  18. Hypothalamic–pituitary–adrenal and hypothalamic–pituitary–gonadal axes: sex differences in regulation of stress responsivity

    PubMed Central

    Oyola, Mario G.; Handa, Robert J.

    2018-01-01

    Gonadal hormones play a key role in the establishment, activation, and regulation of the hypothalamic–pituitary–adrenal (HPA) axis. By influencing the response and sensitivity to releasing factors, neurotransmitters, and hormones, gonadal steroids help orchestrate the gain of the HPA axis to fine-tune the levels of stress hormones in the general circulation. From early life to adulthood, gonadal steroids can differentially affect the HPA axis, resulting in sex differences in the responsivity of this axis. The HPA axis influences many physiological functions making an organism’s response to changes in the environment appropriate for its reproductive status. Although the acute HPA response to stressors is a beneficial response, constant activation of this circuitry by chronic or traumatic stressful episodes may lead to a dysregulation of the HPA axis and cause pathology. Compared to males, female mice and rats show a more robust HPA axis response, as a result of circulating estradiol levels which elevate stress hormone levels during non-threatening situations, and during and after stressors. Fluctuating levels of gonadal steroids in females across the estrous cycle are a major factor contributing to sex differences in the robustness of HPA activity in females compared to males. Moreover, gonadal steroids may also contribute to epigenetic and organizational influences on the HPA axis even before puberty. Correspondingly, crosstalk between the hypothalamic–pituitary–gonadal (HPG) and HPA axes could lead to abnormalities of stress responses. In humans, a dysregulated stress response is one of the most common symptoms seen across many neuropsychiatric disorders, and as a result, such interactions may exacerbate peripheral pathologies. In this review, we discuss the HPA and HPG axes and review how gonadal steroids interact with the HPA axis to regulate the stress circuitry during all stages in life. PMID:28859530

  19. Early development of an enterprise health data warehouse.

    PubMed

    Househ, Mowafa Said; Al-Tuwaijri, Majid

    2011-01-01

    The purpose of this study is to describe early development challenges of an enterprise data warehouse within a Saudi Arabian academic healthcare facility. An action case research method was selected for this paper. The study took place between December 2009 and February 2010. Data collection included interviews, meeting observations, and meeting minutes. Early development challenges centered on the development of clear contracts with vendors; development of a clear project plan; a need to fast-track bureaucracy; and educate clinicians and staff about the project; and lack of data standardization.

  20. Early Brain and Child Development: Connections to Early Education and Child Care

    ERIC Educational Resources Information Center

    Romano, Judith T.

    2013-01-01

    The vast majority of young children spend time in settings outside of the home, and the nature of those settings directly impacts the child's health and development. The ecobiodevelopmental framework of early brain and child development serve as the backdrop for establishing quality. This article describes the use of quality rating systems,…

  1. Integrated and Early Childhood Education: Preparation for Social Development. Theme A: Relevant Provision for Early Childhood.

    ERIC Educational Resources Information Center

    Axton, J. H. M.

    Factors which influence child development are listed and briefly discussed. These factors are (1) mother's childhood, (2) mother's age, (3) care during pregnancy and delivery, (4) early neonatal factors, (5) birth interval, (6) effect of repeated infection and malnutrition on brain growth and intellectual development, and (7) home environment. The…

  2. Getting an Early Start on Early Child Development. Education Notes. 30194

    ERIC Educational Resources Information Center

    Young, Mary Eming; Dunkelberg, Erika

    2004-01-01

    The children born this year--2004--will be eleven years old in 2015--the age of primary school completion in most countries. This is the MDG (Millennium Development Goal) generation--for whom the international community has pledged that by 2015, all children will be able to complete primary schooling. Ensuring good early child development is the…

  3. FOXL2 activates P450 aromatase gene transcription: towards a better characterization of the early steps of mammalian ovarian development.

    PubMed

    Pannetier, Maëlle; Fabre, Stéphane; Batista, Frank; Kocer, Ayhan; Renault, Lauriane; Jolivet, Geneviève; Mandon-Pépin, Béatrice; Cotinot, Corinne; Veitia, Reiner; Pailhoux, Eric

    2006-06-01

    Previous studies have equated FOXL2 as a crucial actor in the ovarian differentiation process in different vertebrate species. Its transcriptional extinction in the polled intersex syndrome (PIS) leads primarily to a drastic decrease of aromatase (CYP19) expression in the first steps of goat ovarian development. In this study, we provide a better characterization of early ovarian development in goat, and we provide experimental evidence demonstrating that FOXL2 represents a direct transcriptional activator of the CYP19 gene through its ovarian-specific promoter 2. Moreover, the ovarian location of FOXL2 and CYP19 proteins, together with their expression profiles in the female gonads, stress the involvement of FOXL2 co-factor(s) for regulating CYP19 transcription. Expressional analyses show that activin-betaA can be considered as a strong candidate for being one of these FOXL2 co-factors. Finally, we discuss evidence for a role of activin and estrogens in somatic and germinal cell proliferation occurring before germ cell meiosis. This period, of 20 days in goat, seems to have no equivalent in mouse. This species-specific difference could explain the phenotype discrepancy observed between XX goat PIS(-/-) and XX mouse Foxl2(-/-).

  4. The Drosophila actin regulator ENABLED regulates cell shape and orientation during gonad morphogenesis.

    PubMed

    Sano, Hiroko; Kunwar, Prabhat S; Renault, Andrew D; Barbosa, Vitor; Clark, Ivan B N; Ishihara, Shuji; Sugimura, Kaoru; Lehmann, Ruth

    2012-01-01

    Organs develop distinctive morphologies to fulfill their unique functions. We used Drosophila embryonic gonads as a model to study how two different cell lineages, primordial germ cells (PGCs) and somatic gonadal precursors (SGPs), combine to form one organ. We developed a membrane GFP marker to image SGP behaviors live. These studies show that a combination of SGP cell shape changes and inward movement of anterior and posterior SGPs leads to the compaction of the spherical gonad. This process is disrupted in mutants of the actin regulator, enabled (ena). We show that Ena coordinates these cell shape changes and the inward movement of the SGPs, and Ena affects the intracellular localization of DE-cadherin (DE-cad). Mathematical simulation based on these observations suggests that changes in DE-cad localization can generate the forces needed to compact an elongated structure into a sphere. We propose that Ena regulates force balance in the SGPs by sequestering DE-cad, leading to the morphogenetic movement required for gonad compaction.

  5. Maturity Gonad Sea Cucumber Holothuria scabra Under The Month Cycle

    NASA Astrophysics Data System (ADS)

    Penina Tua Rahantoknam, Santi

    2017-10-01

    Gonad maturity level of the sea cucumber Holothuria scabra is important to note for selection of parent ready spawn. Sea cucumbers are giving a reaction to the treatment of excitatory spawn mature individuals only. For the determination of the level of maturity of gonads of sea cucumbers, the necessary observation of the gonads are microscopic, macroscopic and gonad maturity gonado somatic indeks (GSI). GSI value is important to know the changes that occur in the gonads quantitatively, so that time can be presumed spawning (Effendie, 1997). Reproductive cycle can be determined by observing the evolution of GSI. The study of sea cucumbers Holothuria scabra gonad maturity conducted in Langgur, Southeast Maluku. Observations were made at every cycle of the moon is the full moon phase (BP) and new moon (BB) in the period January 29, 2017 until July 23, 2017. Observations H. scabra gonad maturity level is done with surgery, observation and calculation GSI gonad histology. GSI highest value obtained in May that full moon cycle at 90% of individuals that are in the spawning stage (phase 5), then 70% of the individuals that are in the spawning stage (phase 5) in March that the full moon cycle. The results obtained show that the peak spawning H. scabra period January 2017 to July 2017 occurred on the full moon cycle in May.

  6. Promoting equity through integrated early child development and nutrition interventions.

    PubMed

    Black, Maureen M; Dewey, Kathryn G

    2014-01-01

    Sustainable development, a foundation of the post-2015 global agenda, depends on healthy and productive citizens. The origins of adult health begin early in life, stemming from genetic-environmental interactions that include adequate nutrition and opportunities for responsive learning. Inequities associated with inadequate nutrition and early learning opportunities can undermine children's health and development, thereby compromising their productivity and societal contributions. Transactional theory serves as a useful framework for examining the associations that link early child development and nutrition because it emphasizes the interplay that occurs between children and the environment, mediated through caregiver interactions. Although single interventions targeting early child development or nutrition can be effective, there is limited evidence on the development, implementation, evaluation, and scaling up of integrated interventions. This manuscript introduces a special edition of papers on six topics central to integrated child development/nutrition interventions: (1) review of integrated interventions; (2) methods and topics in designing integrated interventions; (3) economic considerations related to integrated interventions; (4) capacity-building considerations; (5) examples of integrated interventions; and (6) policy implications of integrated interventions. Ensuring the health and development of infants and young children through integrated child development/nutrition interventions promotes equity, a critical component of sustainable development. © 2014 New York Academy of Sciences.

  7. Early childhood traumatic development and its impact on gender identity.

    PubMed

    Cohen, Y

    2001-03-01

    The author clarifies issues of gender identity typical to contemporary Western societies. Nowadays, we tend to emphasize self-autonomy as the main target of the individual's development. In adolescence this may cause many questions as to the adolescent's conception of his or her gender and sexual identity. These questions are the outcome of early development, and thus early traumas may impact the entire gender development. In this context, trauma includes not only major violations such as sexual abuse, terror attacks, and so forth, but also comprises events heretofore considered minor.

  8. Normal development of the female reproductive system

    EPA Science Inventory

    The embryonic development of the female reproductive system involves a progression of events that is conserved across vertebrate species. The early gonad progresses from a form that is undifferentiated in both genotypic males and females. Rudimentary male (Wolffian) and female (M...

  9. Early Learning and Development: Cultural-Historical Concepts in Play

    ERIC Educational Resources Information Center

    Fleer, Marilyn

    2010-01-01

    "Early Learning and Development" provides a unique synthesis of cultural-historical theory from Vygotsky, Elkonin and Leontiev in the 20th century to the ground-breaking research of scholars such as Siraj-Blatchford, Kratsova and Hedegaard today. It demonstrates how development and learning are culturally embedded and institutionally defined, and…

  10. Child Development, Early Childhood Education and Family Life: A Bibliography.

    ERIC Educational Resources Information Center

    Reardon, Beverly, Comp.

    This bibliographical listing of approximately 2500 books on child development, early childhood education and family life was compiled as a resource for parents and students. Books are listed alphabetically by author and are grouped according to the following categories: child development; observation of children; adolescence; language…

  11. Helping Families Connect Early Literacy with Social-Emotional Development

    ERIC Educational Resources Information Center

    Santos, Rosa Milagros; Fettig, Angel; Shaffer, LaShorage

    2012-01-01

    Early childhood educators know that home is a child's first learning environment. From birth, children are comforted by hearing and listening to their caregivers' voices. The language used by families supports young children's development of oral language skills. Exposure to print materials in the home also supports literacy development. Literacy…

  12. Aesthetic Experience and Early Language and Literacy Development

    ERIC Educational Resources Information Center

    Johnson, Helen L.

    2007-01-01

    The present paper explores the connections between theory and research in language development and aesthetic education and their implications for early childhood classroom practice. The present paper posits that arts experiences make a unique and vital contribution to the child's development of language and literacy, as well as to the sense of…

  13. Professional development session for early career scientists at SITC 2012

    PubMed Central

    2013-01-01

    The Society for Immunotherapy of Cancer (SITC) 2012 Professional Development Session was held as part of the SITC 27th Annual Meeting, Washington, DC, on October 24, 2012. The session was designed as a new opportunity for early career investigators to learn about relevant career development topics in a didactic setting. PMID:25742323

  14. Promising Directions for Research and Development in Early Childhood Education.

    ERIC Educational Resources Information Center

    Elliott, David L.

    A survey of research and development studies currently needed in early childhood education stresses child development and its relation to instruction. Topics which have been discussed are perception, oral language, concept formation, learning set, motivation, and the psychology of learning. Universities and public school systems working together…

  15. Instructional Development for Early Career Academics: An Overview of Impact

    ERIC Educational Resources Information Center

    Stes, Ann; Van Petegem, Peter

    2011-01-01

    Background: Over the past decades, the issue of improving teaching in higher education has been seriously addressed. Centres for instructional development, aimed at enhancing teaching, have been set up in many countries. Instructional development for early career academics is perceived to be of particular importance. Given the considerable…

  16. Early Markers of Vulnerable Language Skill Development in Galactosaemia

    ERIC Educational Resources Information Center

    Lewis, Fiona M.; Coman, David J.; Syrmis, Maryanne

    2014-01-01

    There are no known biomedical or genetic markers to identify which infants with galactosaemia (GAL) are most at risk of poor language skill development, yet pre-linguistic communicative "red flag" behaviours are recognised as early identifiers of heightened vulnerability to impaired language development. We report on pre-linguistic…

  17. Understanding Emotional Development: Helping Early Childhood Providers Better Support Families

    ERIC Educational Resources Information Center

    Edwards, Nicole Megan

    2012-01-01

    This article is intended to provide early childhood providers with a concise overview of emerging emotional development in young children (birth-5), the important role of primary caregivers, and the link between parenting, emotional development, and behavior. Specific suggestions that have been shared with urban Head Start mothers are offered,…

  18. Culture and Early Language Development: Implications for Assessment and Intervention

    ERIC Educational Resources Information Center

    Parada, Patricia M.

    2013-01-01

    The purpose of this qualitative study--"Culture and Early Language Development: Implications for Assessment and Intervention"--was to explore and describe the perceptions and beliefs of Salvadoran mothers of low socioeconomic status regarding the language development of their young children in order to identify cultural variations in…

  19. RNA-seq analysis of the gonadal transcriptome during Alligator mississippiensis temperature-dependent sex determination and differentiation.

    PubMed

    Yatsu, Ryohei; Miyagawa, Shinichi; Kohno, Satomi; Parrott, Benjamin B; Yamaguchi, Katsushi; Ogino, Yukiko; Miyakawa, Hitoshi; Lowers, Russell H; Shigenobu, Shuji; Guillette, Louis J; Iguchi, Taisen

    2016-01-25

    The American alligator (Alligator mississippiensis) displays temperature-dependent sex determination (TSD), in which incubation temperature during embryonic development determines the sexual fate of the individual. However, the molecular mechanisms governing this process remain a mystery, including the influence of initial environmental temperature on the comprehensive gonadal gene expression patterns occurring during TSD. Our characterization of transcriptomes during alligator TSD allowed us to identify novel candidate genes involved in TSD initiation. High-throughput RNA sequencing (RNA-seq) was performed on gonads collected from A. mississippiensis embryos incubated at both a male and a female producing temperature (33.5 °C and 30 °C, respectively) in a time series during sexual development. RNA-seq yielded 375.2 million paired-end reads, which were mapped and assembled, and used to characterize differential gene expression. Changes in the transcriptome occurring as a function of both development and sexual differentiation were extensively profiled. Forty-one differentially expressed genes were detected in response to incubation at male producing temperature, and included genes such as Wnt signaling factor WNT11, histone demethylase KDM6B, and transcription factor C/EBPA. Furthermore, comparative analysis of development- and sex-dependent differential gene expression revealed 230 candidate genes involved in alligator sex determination and differentiation, and early details of the suspected male-fate commitment were profiled. We also discovered sexually dimorphic expression of uncharacterized ncRNAs and other novel elements, such as unique expression patterns of HEMGN and ARX. Twenty-five of the differentially expressed genes identified in our analysis were putative transcriptional regulators, among which were MYBL2, MYCL, and HOXC10, in addition to conventional sex differentiation genes such as SOX9, and FOXL2. Inferred gene regulatory network was constructed

  20. Confocal Imaging of Early Heart Development in Xenopus laevis

    PubMed Central

    Kolker, Sandra J.; Tajchman, Urszula; Weeks, Daniel L.

    2013-01-01

    Xenopus laevis provides a number of advantages for studies on cardiovascular development. The embryos are fairly large, easy to obtain, and can develop at ambient temperature in simple buffer solutions. Although classic descriptions of heart development exist, the ability to use whole mount immunohistochemical methods and confocal microscopy may enhance the ability to understand both normal and experimentally perturbed cardiovascular development. We have started to examine the early stages of cardiac development in Xenopus, seeking to identify antibodies and fixatives that allow easy examination of the developing heart. We have used monoclonal antibodies (mAbs) raised against bovine cardiac troponin T and chicken tropomyosin to visualize cardiac muscle, a goat antibody recognizing bovine type VI collagen to stain the lining of vessels, and the JB3 mAb raised against chicken fibrillin which allows the visualization of a variety of cardiovascular tissues during early development. Results from embryonic stages 24–46 are presented. PMID:10644411

  1. Challenges in early clinical development of adjuvanted vaccines.

    PubMed

    Della Cioppa, Giovanni; Jonsdottir, Ingileif; Lewis, David

    2015-06-08

    A three-step approach to the early development of adjuvanted vaccine candidates is proposed, the goal of which is to allow ample space for exploratory and hypothesis-generating human experiments and to select dose(s) and dosing schedule(s) to bring into full development. Although the proposed approach is more extensive than the traditional early development program, the authors suggest that by addressing key questions upfront the overall time, size and cost of development will be reduced and the probability of public health advancement enhanced. The immunogenicity end-points chosen for early development should be critically selected: an established immunological parameter with a well characterized assay should be selected as primary end-point for dose and schedule finding; exploratory information-rich end-points should be limited in number and based on pre-defined hypothesis generating plans, including system biology and pathway analyses. Building a pharmacodynamic profile is an important aspect of early development: to this end, multiple early (within 24h) and late (up to one year) sampling is necessary, which can be accomplished by sampling subgroups of subjects at different time points. In most cases the final target population, even if vulnerable, should be considered for inclusion in early development. In order to obtain the multiple formulations necessary for the dose and schedule finding, "bed-side mixing" of various components of the vaccine is often necessary: this is a complex and underestimated area that deserves serious research and logistical support. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Development of Early Measures of Comprehension: Innovation in Individual Growth and Development Indicators

    ERIC Educational Resources Information Center

    Wackerle-Hollman, Alisha K.; Rodriguez, Megan I.; Bradfield, Tracy A.; Rodriguez, Michael C.; McConnell, Scott R.

    2015-01-01

    Early comprehension is an important, but not well-understood, contribution to early literacy and language development. Specifically, research regarding the nature of skills representative of early comprehension, including how they contribute to later reading success, is needed to support best practices to adequately prepare students. This article…

  3. The development of self-regulation across early childhood.

    PubMed

    Montroy, Janelle J; Bowles, Ryan P; Skibbe, Lori E; McClelland, Megan M; Morrison, Frederick J

    2016-11-01

    The development of early childhood self-regulation is often considered an early life marker for later life successes. Yet little longitudinal research has evaluated whether there are different trajectories of self-regulation development across children. This study investigates the development of behavioral self-regulation between the ages of 3 and 7 years, with a direct focus on possible heterogeneity in the developmental trajectories, and a set of potential indicators that distinguish unique behavioral self-regulation trajectories. Across 3 diverse samples, 1,386 children were assessed on behavioral self-regulation from preschool through first grade. Results indicated that majority of children develop self-regulation rapidly during early childhood, and that children follow 3 distinct developmental patterns of growth. These 3 trajectories were distinguishable based on timing of rapid gains, as well as child gender, early language skills, and maternal education levels. Findings highlight early developmental differences in how self-regulation unfolds, with implications for offering individualized support across children. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  4. The Development of Self-Regulation across Early Childhood

    PubMed Central

    Montroy, Janelle J.; Bowles, Ryan P.; Skibbe, Lori E.; McClelland, Megan M.; Morrison, Frederick J.

    2016-01-01

    The development of early childhood self-regulation is often considered an early life marker for later life successes. Yet little longitudinal research has evaluated whether there are different trajectories of self-regulation development across children. This study investigates the development of behavioral self-regulation between the ages of three and seven, with a direct focus on possible heterogeneity in the developmental trajectories, and a set of potential indicators that distinguish unique behavioral self-regulation trajectories. Across three diverse samples, 1,386 children were assessed on behavioral self-regulation from preschool through first grade. Results indicated that majority of children develop self-regulation rapidly during early childhood, and that children follow three distinct developmental patterns of growth. These three trajectories were distinguishable based on timing of rapid gains, as well as child gender, early language skills, and maternal education levels. Findings highlight early developmental differences in how self-regulation unfolds with implications for offering individualized support across children. PMID:27709999

  5. Sleep, rhythms, and the endocrine brain: influence of sex and gonadal hormones.

    PubMed

    Mong, Jessica A; Baker, Fiona C; Mahoney, Megan M; Paul, Ketema N; Schwartz, Michael D; Semba, Kazue; Silver, Rae

    2011-11-09

    While much is known about the mechanisms that underlie sleep and circadian rhythms, the investigation into sex differences and gonadal steroid modulation of sleep and biological rhythms is in its infancy. There is a growing recognition of sex disparities in sleep and rhythm disorders. Understanding how neuroendocrine mediators and sex differences influence sleep and biological rhythms is central to advancing our understanding of sleep-related disorders. While it is known that ovarian steroids affect circadian rhythms in rodents, the role of androgen is less understood. Surprising findings that androgens, acting via androgen receptors in the master "circadian clock" within the suprachiasmatic nucleus, modulate photic effects on activity in males point to novel mechanisms of circadian control. Work in aromatase-deficient mice suggests that some sex differences in photic responsiveness are independent of gonadal hormone effects during development. In parallel, aspects of sex differences in sleep are also reported to be independent of gonadal steroids and may involve sex chromosome complement. This a summary of recent work illustrating how sex differences and gonadal hormones influence sleep and circadian rhythms that was presented at a Mini-Symposium at the 2011 annual meeting of the Society for Neuroscience.

  6. Sleep, Rhythms, and the Endocrine Brain: Influence of Sex and Gonadal Hormones

    PubMed Central

    Mong, Jessica A.; Baker, Fiona C.; Mahoney, Megan M.; Paul, Ketema N.; Schwartz, Michael D.; Semba, Kazue; Silver, Rae

    2011-01-01

    While much is known about the mechanisms that underlie sleep and circadian rhythms, the investigation into sex differences and gonadal steroid modulation of sleep and biological rhythms is in its infancy. There is a growing recognition of sex disparities in sleep and rhythm disorders. Understanding how neuroendocrine mediators and sex differences influence sleep and biological rhythms is central to advancing our understanding of sleep-related disorders. While it is known that ovarian steroids affect circadian rhythms in rodents, the role of androgen is less understood. Surprising findings that androgens, acting via androgen receptors in the master “circadian clock” within the suprachiasmatic nucleus (SCN), modulate photic effects on activity in males points to novel mechanisms of circadian control. Work in aromatase deficient (ArKO) mice suggests that some sex differences in photic responsiveness are independent of gonadal hormone effects during development. In parallel, aspects of sex differences in sleep are also reported to be independent of gonadal steroids and may involve sex chromosome complement. This a summary of recent work illustrating how sex differences and gonadal hormones influence sleep and circadian rhythms that was presented at a mini-symposium at the 2011 annual meeting of the Society for Neuroscience. PMID:22072663

  7. Epigenetic Control of Gonadal Aromatase (cyp19a1) in Temperature-Dependent Sex Determination of Red-Eared Slider Turtles

    PubMed Central

    Matsumoto, Yuiko; Buemio, Alvin; Chu, Randy; Vafaee, Mozhgon; Crews, David

    2013-01-01

    In the red-eared slider turtle (Trachemys scripta), a species with temperature-dependent sex determination (TSD), the expression of the aromatase gene during gonad development is strictly limited to the female-producing temperature. The underlying mechanism remains unknown. In this study, we identified the upstream 5′-flanking region of the aromatase gene, gonad-specific promoter, and the temperature-dependent DNA methylation signatures during gonad development in the red-eared slider turtle. The 5′-flanking region of the slider aromatase exhibited sequence similarities to the aromatase genes of the American alligator, chicken, quail, and zebra finch. A putative TATA box was located 31 bp upstream of the gonad-specific transcription start site. DNA methylation at the CpG sites between the putative binding sites of the fork head domain factor (FOX) and vertebrate steroidogenic factor 1 (SF1) and adjacent TATA box in the promoter region were significantly lower in embryonic gonads at the female-producing temperature compared the male-producing temperature. A shift from male- to female-, but not from female- to male-, producing temperature changed the level of DNA methylation in gonads. Taken together these results indicate that the temperature, particularly female-producing temperature, allows demethylation at the specific CpG sites of the promoter region which leads the temperature-specific expression of aromatase during gonad development. PMID:23762231

  8. Genetics of Gonadal Stem Cell Renewal

    PubMed Central

    Greenspan, Leah Joy; de Cuevas, Margaret

    2015-01-01

    Stem cells are necessary for the maintenance of many adult tissues. Signals within the stem cell microenvironment, or niche, regulate the self-renewal and differentiation capability of these cells. Misregulation of these signals through mutation or damage can lead to overgrowth or depletion of different stem cell pools. In this review, we focus on the Drosophila testis and ovary, both of which contain well-defined niches, as well as the mouse testis, which has become a more approachable stem cell system with recent technical advances. We discuss the signals that regulate gonadal stem cells in their niches, how these signals mediate self-renewal and differentiation under homeostatic conditions, and how stress, whether from mutations or damage, can cause changes in cell fate and drive stem cell competition. PMID:26355592

  9. On gonads and gadflies: the estrus angle.

    PubMed

    Hillier, Stephen G

    2017-06-01

    The first sex steroid to be crystallized was the vertebrate ovarian hormone, estrone - a less potent metabolite of 17β-estradiol, which in mammals stimulates the female urge to mate (estrus). The gadfly (Greek oistros ) lent its name to the process of estrus, as an insect that bites and torments in classical Greek mythology. With the purification and crystallization of a moult-inducing steroid (ecdysone) from insects, an interesting parallel emerged between mating and moulting in lower mammals and arthropods. Ecdysterone (potent ecdysone metabolite) has anabolic effects in mammalian muscle cells that can be blocked by selective estrogen receptor antagonists. Insects utilize ecdysteroids in similar ways that vertebrates use estrogens, including stimulation of oocyte growth and maturation. Ecdysteroids also modify precopulatory insect mating behaviour, further reinforcing the gonad-gadfly/mate-moult analogy. © 2017 Society for Endocrinology.

  10. Temperament, Executive Control, and ADHD across Early Development

    PubMed Central

    Rabinovitz, Beth B.; O’Neill, Sarah; Rajendran, Khushmand; Halperin, Jeffrey M.

    2015-01-01

    Research examining factors linking early temperament and later ADHD is limited by cross-sectional approaches and having the same informant rate both temperament and psychopathology. We used multi-informant/multi-method longitudinal data to test the hypothesis that negative emotionality during preschool is positively associated with ADHD symptom severity in middle childhood, but developing executive control mediates this relation. Children (N=161) with and without ADHD were evaluated three times: Parent and teacher temperament ratings and NEPSY Visual Attention at ages 3–4 years; WISC-IV Working Memory Index and NEPSY Response Set at age 6 years; and ADHD symptoms using the Kiddie-SADS at age 7 years. Parent and teacher ratings of preschoolers’ temperament were combined to form an Anger/Frustration composite. Similarly, an Executive Functioning composite was derived from age 6 measures. Bootstrapping was used to determine whether age 6 Executive Functioning mediated the relation between early Anger/Frustration and later ADHD symptom severity, while controlling for early executive functioning. Preschoolers’ Anger/Frustration was significantly associated with later ADHD symptoms, with this relation partially mediated by age 6 Executive Functioning. Developing executive control mediates the relation between early Anger/Frustration and later ADHD symptom severity, suggesting that Anger/Frustration influences ADHD symptom severity through its impact on developing executive control. Early interventions targeting the harmful influences of negative emotionality or enhancing executive functioning may diminish later ADHD severity. PMID:26854505

  11. Use of gene expression data to determine effects on gonad phenotype in Japanese medaka after exposure to trenbolone or estradiol.

    PubMed

    Flynn, Kevin; Swintek, Joe; Johnson, Rodney

    2013-06-01

    Various aquatic bioassays using one of several fish species have been developed or are in the process of being developed by organizations like the US Environmental Protection Agency and the Office of Economic Cooperation and Development for testing potential endocrine-disrupting chemicals (EDCs). Often, these involve assessment of the gonad phenotype of individuals as a key endpoint that is inputted into a risk or hazard assessment. Typically, gonad phenotype is determined histologically, which involves specialized and time-consuming techniques. The methods detailed here utilize an entirely different methodology, reverse-transcription quantitative polymerase chain reaction, to determine the relative expression levels of 4 genes after exposure to either 17β-estradiol or 17β-trenbolone and, by extension, the effects of EDCs on the phenotypic status of the gonad. The 4 genes quantified, Sox9b, protamine, Fig1α, and ZPC1, are all involved in gonad development and maintenance in Japanese medaka (Oryzias latipes); these data were then inputted into a permutational multivariate analysis of variance to determine whether significant differences exist between treatment groups. This information in conjunction with the sexual genotype, which can be determined in medaka, can be used to determine adverse effects of exposure to EDCs in a similar fashion to the histologically determined gonad phenotype. Copyright © 2013 SETAC.

  12. Embedded Professional Development and Classroom-Based Early Reading Intervention: Early Diagnostic Reading Intervention through Coaching

    ERIC Educational Resources Information Center

    Amendum, Steven J.

    2014-01-01

    The purpose of the current mixed-methods study was to investigate a model of professional development and classroom-based early reading intervention implemented by the 1st-grade teaching team in a large urban/suburban school district in the southeastern United States. The intervention provided teachers with ongoing embedded professional…

  13. New Hampshire Early Childhood Professional Development System: Guide to Early Childhood Careers.

    ERIC Educational Resources Information Center

    McDonnell, Tessa, Ed.

    The community of child care providers in New Hampshire has adopted the Early Childhood Professional Development System as an initial step toward assuring quality care and education for children. This guide describes the components of that system and is presented in eight sections. Section 1 of the guide introduces the system based on a set of two…

  14. The Australian Early Development Index: Reshaping Family-Child Relationships in Early Childhood Education

    ERIC Educational Resources Information Center

    Peers, Chris

    2011-01-01

    This article addresses the cultural significance of the Australian Early Development Index (AEDI) and discusses changes that the discourse of this instrument makes to the way in which the child is conceptualised. It analyses the technological function of the AEDI to examine how it makes the child a universal resource for human capital. The article…

  15. Early Learning Foundations. Indiana's Early Learning Development Framework Aligned to the Indiana Academic Standards, 2014

    ERIC Educational Resources Information Center

    Indiana Department of Education, 2015

    2015-01-01

    The "Foundations" (English/language arts, mathematics, social emotional skills, approaches to play and learning, science, social studies, creative arts, and physical health and growth) are Indiana's early learning development framework and are aligned to the 2014 Indiana Academic Standards. This framework provides core elements that…

  16. Early childhood obesity is associated with compromised cerebellar development.

    PubMed

    Miller, Jennifer L; Couch, Jessica; Schwenk, Krista; Long, Michelle; Towler, Stephen; Theriaque, Douglas W; He, Guojun; Liu, Yijun; Driscoll, Daniel J; Leonard, Christiana M

    2009-01-01

    As part of a study investigating commonalities between Prader-Willi syndrome (PWS-a genetic imprinting disorder) and early-onset obesity of unknown etiology (EMO) we measured total cerebral and cerebellar volume on volumetric magnetic resonance imaging (MRI) images. Individuals with PWS (N = 16) and EMO (N = 12) had smaller cerebellar volumes than a control group of 15 siblings (p = .02 control vs. EMO; p = .0005 control vs. PWS), although there was no difference among the groups in cerebral volume. Individuals with PWS and EMO also had impaired cognitive function: general intellectual ability (GIA): PWS 65 +/- 25; EMO 81 +/- 19; and Controls 112 +/- 13 (p < .0001 controls vs. PWS and controls vs. EMO). As both conditions are characterized by early-onset obesity and slowed cognitive development, these results raise the possibility that early childhood obesity retards both cerebellar and cognitive development.

  17. On gonadic maturation and reproductive strategy in deep-sea benthic octopus Graneledone macrotyla

    NASA Astrophysics Data System (ADS)

    Guerra, Ángel; Sieiro, María Pilar; Roura, Álvaro; Portela, Julio M.; del Río, José Luís

    2013-09-01

    The new information reported in this paper is based on five maturing and mature females of the large-tuberculate octopus Graneledone macrotyla. These specimens were caught in bottom trawl surveys ATLANTIS 2009 (February 24 to April 1, 2009) and ATLANTIS 2010 (March 9 to April 5, 2010) carried out off the Argentinean Economic Exclusive Zone. Capture depth ranged from 475 to 921 m and sea bottom temperature between 2.8 and 3.1 °C. Development of the complex ovary, oviducts, and oviducal glands during gonadic maturation is described. The absence of spermathecae in the oviducal glands and the presence of fertilized eggs inside the ovary suggested that fertilization took place within the ovary. Histological techniques showed the presence of four types of oocytes. Maturing oocyte size-frequency distribution was polymodal. Fluorescence reaction showed that atresia occurred in both early and later oocyte maturation stages. Atresia affected 48-55 % of the initial number of oocytes. The maximum observed potential fecundity was estimated at 250-300 eggs. G. macrotyla showed a group-synchronous ovulation pattern, regulative atresia, and a batching spawning pattern with a few egg batches spawned intermittently over an extended period of spawning.

  18. Activated ovarian endothelial cells promote early follicular development and survival.

    PubMed

    Kedem, Alon; Aelion-Brauer, Anate; Guo, Peipei; Wen, Duancheng; Ding, Bi-Sen; Lis, Raphael; Cheng, Du; Sandler, Vladislav M; Rafii, Shahin; Rosenwaks, Zev

    2017-09-19

    New data suggests that endothelial cells (ECs) elaborate essential "angiocrine factors". The aim of this study is to investigate the role of activated ovarian endothelial cells in early in-vitro follicular development. Mouse ovarian ECs were isolated using magnetic cell sorting or by FACS and cultured in serum free media. After a constitutive activation of the Akt pathway was initiated, early follicles (50-150 um) were mechanically isolated from 8-day-old mice and co-cultured with these activated ovarian endothelial cells (AOEC) (n = 32), gel (n = 24) or within matrigel (n = 27) in serum free media for 14 days. Follicular growth, survival and function were assessed. After 6 passages, flow cytometry showed 93% of cells grown in serum-free culture were VE-cadherin positive, CD-31 positive and CD 45 negative, matching the known EC profile. Beginning on day 4 of culture, we observed significantly higher follicular and oocyte growth rates in follicles co-cultured with AOECs compared with follicles on gel or matrigel. After 14 days of culture, 73% of primary follicles and 83% of secondary follicles co-cultured with AOEC survived, whereas the majority of follicles cultured on gel or matrigel underwent atresia. This is the first report of successful isolation and culture of ovarian ECs. We suggest that co-culture with activated ovarian ECs promotes early follicular development and survival. This model is a novel platform for the in vitro maturation of early follicles and for the future exploration of endothelial-follicular communication. In vitro development of early follicles necessitates a complex interplay of growth factors and signals required for development. Endothelial cells (ECs) may elaborate essential "angiocrine factors" involved in organ regeneration. We demonstrate that co-culture with ovarian ECs enables culture of primary and early secondary mouse ovarian follicles.

  19. Early development of synchrony in cortical activations in the human.

    PubMed

    Koolen, N; Dereymaeker, A; Räsänen, O; Jansen, K; Vervisch, J; Matic, V; Naulaers, G; De Vos, M; Van Huffel, S; Vanhatalo, S

    2016-05-13

    Early intermittent cortical activity is thought to play a crucial role in the growth of neuronal network development, and large scale brain networks are known to provide the basis for higher brain functions. Yet, the early development of the large scale synchrony in cortical activations is unknown. Here, we tested the hypothesis that the early intermittent cortical activations seen in the human scalp EEG show a clear developmental course during the last trimester of pregnancy, the period of intensive growth of cortico-cortical connections. We recorded scalp EEG from altogether 22 premature infants at post-menstrual age between 30 and 44 weeks, and the early cortical synchrony was quantified using recently introduced activation synchrony index (ASI). The developmental correlations of ASI were computed for individual EEG signals as well as anatomically and mathematically defined spatial subgroups. We report two main findings. First, we observed a robust and statistically significant increase in ASI in all cortical areas. Second, there were significant spatial gradients in the synchrony in fronto-occipital and left-to-right directions. These findings provide evidence that early cortical activity is increasingly synchronized across the neocortex. The ASI-based metrics introduced in our work allow direct translational comparison to in vivo animal models, as well as hold promise for implementation as a functional developmental biomarker in future research on human neonates. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Regulation of early Xenopus development by ErbB signaling

    PubMed Central

    Nie, Shuyi; Chang, Chenbei

    2008-01-01

    ErbB signaling has long been implicated in cancer formation and progression and is shown to regulate cell division, migration and death during tumorigenesis. The functions of the ErbB pathway during early vertebrate embryogenesis, however, are not well understood. Here we report characterization of ErbB activities during early frog development. Gain-of-function analyses show that EGFR, ErbB2 and ErbB4 induce ectopic tumor-like cell mass that contains increased numbers of mitotic cells. Both the muscle and the neural markers are expressed in these ectopic protrusions. ErbBs also induce mesodermal markers in ectodermal explants. Loss-of-function studies using carboxyl terminal-truncated dominant-negative ErbB receptors demonstrate that blocking ErbB signals leads to defective gastrulation movements and malformation of the embryonic axis with a reduction in the head structures in early frog embryos. These data, together with the observation that ErbBs are expressed early during frog embryogenesis, suggest that ErbBs regulate cell proliferation, movements and embryonic patterning during early Xenopus development. PMID:16258939

  1. Family Concepts in Early Learning and Development Standards

    ERIC Educational Resources Information Center

    Walsh, Bridget A.; Sanchez, Claudia; Lee, Angela M.; Casillas, Nicole; Hansen, Caitlynn

    2016-01-01

    This exploratory study investigated the use of concepts related to families, parents, and the home in 51 state-level early learning and development standards documents. Guidelines from six national family involvement, engagement, and school-partnership models were used to create the Family Involvement Models Analysis Chart (FIMAC), which served as…

  2. Regionalism and Development in Early Nineteenth Century Spanish America.

    ERIC Educational Resources Information Center

    Friedman, Douglas

    An understanding of regionalism in early 19th century Spanish America is crucial to any understanding of this region's economic development. Regionalism became the barrier to the kind of integrated national economy that some writers claim could have been implemented had it not been for the imposition of dependency by external forces. This…

  3. Starting Smart: How Early Experiences Affect Brain Development. Second Edition.

    ERIC Educational Resources Information Center

    Hawley, Theresa

    Based on recent research, it is now believed that brain growth is highly dependent upon children's early experiences. Neurons allow communication and coordinated functioning among various brain areas. Brain development after birth consists of an ongoing process of wiring and rewiring the connections among neurons. The forming and breaking of…

  4. Applying cognitive training to target executive functions during early development.

    PubMed

    Wass, Sam V

    2015-01-01

    Developmental psychopathology is increasingly recognizing the importance of distinguishing causal processes (i.e., the mechanisms that cause a disease) from developmental outcomes (i.e., the symptoms of the disorder as it is eventually diagnosed). Targeting causal processes early in disordered development may be more effective than waiting until outcomes are established and then trying to reverse the pathogenic process. In this review, I evaluate evidence suggesting that neural and behavioral plasticity may be greatest at very early stages of development. I also describe correlational evidence suggesting that, across a number of conditions, early emerging individual differences in attentional control and working memory may play a role in mediating later-developing differences in academic and other forms of learning. I review the currently small number of studies that applied direct and indirect cognitive training targeted at young individuals and discuss methodological challenges associated with targeting this age group. I also discuss a number of ways in which early, targeted cognitive training may be used to help us understand the developmental mechanisms subserving typical and atypical cognitive development.

  5. The Ecology of Early Reading Development for Children in Poverty

    ERIC Educational Resources Information Center

    Kainz, Kirsten; Vernon-Feagans, Lynne

    2007-01-01

    In this study we investigated reading development from kindergarten to third grade for 1,913 economically disadvantaged children from the Early Childhood Longitudinal Study-Kindergarten Cohort. Characteristics of the child, the family, classroom instruction, and school composition were used to model influences from multiple levels of children's…

  6. Rethinking Early Learning and Development Standards in the Ugandan Context

    ERIC Educational Resources Information Center

    Ejuu, Godfrey

    2013-01-01

    Concerns that the African child is being tailored to be a "global child," alongside other homogenizing and dominating projections, such as early learning and development standards (ELDS), have increased. African communities need to be assured that global standards and global indicators will not further homogenize nations and thereby risk…

  7. Changing the Perspective on Early Development of Rett Syndrome

    ERIC Educational Resources Information Center

    Marschik, Peter B.; Kaufmann, Walter E.; Sigafoos, Jeff; Wolin, Thomas; Zhang, Dajie; Bartl-Pokorny, Katrin D.; Pini, Giorgio; Zappella, Michele; Tager-Flusberg, Helen; Einspieler, Christa; Johnston, Michael V.

    2013-01-01

    We delineated the achievement of early speech-language milestones in 15 young children with Rett syndrome ("MECP2" positive) in the first two years of life using retrospective video analysis. By contrast to the commonly accepted concept that these children are normal in the pre-regression period, we found markedly atypical development of…

  8. Model of Early Support of Child Development in Poland

    ERIC Educational Resources Information Center

    Czyz, Anna Katarzyna

    2018-01-01

    The development of a child, especially a child with a disability, is conditional upon the initiation of rehabilitation measures immediately after the problem has been identified. The quality of the reaction is conditioned by the functioning of the therapeutic team. The main purpose of the research was the diagnosis of early support system for…

  9. Identification of the Social Development in Early Childhood in Pakistan

    ERIC Educational Resources Information Center

    Malik, Asif; Sarwar, Muhammad; Khan, Naeemullah

    2010-01-01

    This study was conducted to identify the social development in early childhood years. It was delimited to eight private schools of Lahore City from the area of Faisal Town and Shadman. Forty students (male and female) were randomly selected as the sample. Five students from Nursery, Prep and grade one were selected from each school. A checklist…

  10. The Use of Electrophysiology in the Study of Early Development

    ERIC Educational Resources Information Center

    Szucs, Denes

    2005-01-01

    Electrophysiology is a timely and important tool in the study of early cognitive development. This commentary polishes the definition of event-related potential (ERP) components; often interpreted as expressions of mental processes. Further, attention is drawn to time-frequency analysis of the electroencephalogram (EEG) which conveys much more…

  11. Development of the Life Story in Early Adolescence

    ERIC Educational Resources Information Center

    Steiner, Kristina L.; Pillemer, David B.

    2018-01-01

    Life span developmental psychology proposes that the ability to create a coherent life narrative does not develop until early adolescence. Using a novel methodology, 10-, 12-, and 14-year-old participants were asked to tell their life stories aloud to a researcher. Later, participants separated their transcribed narratives into self-identified…

  12. MAMMARY GLAND DEVELOPMENT: EARLY LIFE EFFECTS FROM THE ENVIRONMENT

    EPA Science Inventory

    Mammary Gland Development: Early Life Effects from the Environment

    S.E. Fenton. Reproductive Toxicology Division, National Health and Environmental Effects Laboratory, ORD, U.S. EPA, Research Triangle Park, NC 27711.

    As signs of precocious puberty in girls reach ...

  13. Predictors of Early versus Later Spelling Development in Danish

    ERIC Educational Resources Information Center

    Nielsen, Anne-Mette Veber; Juul, Holger

    2016-01-01

    The present study examined phoneme awareness, phonological short term memory, letter knowledge, rapid automatized naming (RAN), and visual-verbal paired associate learning (PAL) as longitudinal predictors of spelling skills in an early phase (Grade 2) and a later phase (Grade 5) of development in a sample of 140 children learning to spell in the…

  14. Career Planning and Development for Early-Career Scientists

    EPA Science Inventory

    Early career development can be looked at as being of two major phases. The first phase is the formal educational process leading to an awarded degree, postdoctoral training, and potentially formal certification in a scientific discipline. The second phase is the informal educa...

  15. Early Intervention and Its Effects on Maternal and Child Development.

    ERIC Educational Resources Information Center

    Slaughter, Diana T.

    1983-01-01

    The longitudinal study reported used an intervention strategy to test the thesis that sociocultural background, mediated by maternal attitudes and behaviors, influences Black children's early development in educationally significant ways. Two models of parent education were contrasted: the Levenstein toy demonstration program and the…

  16. Developing Early Undergraduate Research at a Two-Year College

    ERIC Educational Resources Information Center

    Sibbernsen, Kendra

    2013-01-01

    Two-year college (TYC) physics teachers are not often required to provide student research experiences as a part of their contracted duties. However, some TYC physics faculty members are interested in developing research opportunities for their freshman- and sophomore-level students, often called "early undergraduate research" (EUR).…

  17. Applying cognitive training to target executive functions during early development

    PubMed Central

    Wass, Sam V.

    2015-01-01

    Developmental psychopathology is increasingly recognizing the importance of distinguishing causal processes (i.e., the mechanisms that cause a disease) from developmental outcomes (i.e., the symptoms of the disorder as it is eventually diagnosed). Targeting causal processes early in disordered development may be more effective than waiting until outcomes are established and then trying to reverse the pathogenic process. In this review, I evaluate evidence suggesting that neural and behavioral plasticity may be greatest at very early stages of development. I also describe correlational evidence suggesting that, across a number of conditions, early emerging individual differences in attentional control and working memory may play a role in mediating later-developing differences in academic and other forms of learning. I review the currently small number of studies that applied direct and indirect cognitive training targeted at young individuals and discuss methodological challenges associated with targeting this age group. I also discuss a number of ways in which early, targeted cognitive training may be used to help us understand the developmental mechanisms subserving typical and atypical cognitive development. PMID:24511910

  18. Guidelines for Making a Video Presentation on Early Development.

    ERIC Educational Resources Information Center

    Cooper, Carolyn S.; And Others

    This paper discusses the production of videotape recordings illustrating developmental milestones of early childhood to serve as a reference point in working with parents or staff caring for young children who have disabilities. Procedures for making a video presentation include the following steps: select a topic (such as motor development,…

  19. Approaches to Developing Health in Early Years Settings

    ERIC Educational Resources Information Center

    Mooney, Ann; Boddy, Janet; Statham, June; Warwick, Ian

    2008-01-01

    Purpose: The purpose of the paper is to consider the opportunities and difficulties in developing health-promotion work in early years settings in the UK. Design/methodology/approach: As the first study of its kind conducted in the UK, a multi-method approach was adopted involving: an overview of health-related guidance and of effective…

  20. Formative Evaluation of the Early Development Instrument: Progress and Prospects

    ERIC Educational Resources Information Center

    Keating, Daniel P.

    2007-01-01

    This article is a commentary for the special issue on the Early Development Instrument (EDI), a community tool to assess children's school readiness and developmental outcomes at a group level. The EDI is administered by kindergarten teachers, who assess their kindergarten students on 5 developmental domains: physical health and well-being, social…

  1. State Guide to Developing Successful Early Childhood Data Systems

    ERIC Educational Resources Information Center

    ICF International (NJ1), 2012

    2012-01-01

    Early education leaders--inside and outside of government--are looking for new ways to improve quality, accountability, and efficiency across many different programs serving young children and their families, and they see investment in data systems as a pivotal part of that effort. However, it can be challenging to develop and implement effective…

  2. Towards Sustainable National Development through Well Managed Early Childhood Education

    ERIC Educational Resources Information Center

    Abraham, Nath M.

    2012-01-01

    This paper discusses issues relating to sustainable development and effective management of early childhood education. The child is the "owner" of the future. The problems that confront the current generation are complex and serious that cannot be addressed in the same way they were created. But they can be addressed. The concept of…

  3. More Alike than Different: Early Childhood Professional Development in Guatemala

    ERIC Educational Resources Information Center

    Hardin, Belinda J.; Vardell, Rosemarie; de Castaneda, Albertina

    2008-01-01

    This article describes an early childhood professional development project that took place in the summer of 2005 in Guatemala City. Located in Central America, Guatemala has a population of approximately 12.3 million people, including more than two million children under the age of 5 (UNESCO Institute for Statistics, 2007; UNICEF, 2004). Events…

  4. Black Female Faculty Success and Early Career Professional Development

    ERIC Educational Resources Information Center

    Jones, Tamara Bertrand; Osborne-Lampkin, La'Tara

    2013-01-01

    In recent years, a number of Black female junior scholars have participated in an early career professional development program designed to address socialization issues through individual and small group mentoring. This descriptive qualitative study investigated scholars' perceptions of the importance and effectiveness of a research…

  5. HIV Infection: Transmission, Effects on Early Development, and Interventions.

    ERIC Educational Resources Information Center

    Lowenthal, Barbara

    1997-01-01

    Describes the modes of transmission of HIV and the course of the disease in infants and toddlers. Information is provided on its effects on early development, medical screening and treatments, therapies, psychosocial assistance, and interventions, including nutritional therapy, occupational and physical therapies, and speech and language therapy.…

  6. Cholinergic Mechanisms, Early Brain Development, and Risk for Schizophrenia

    PubMed Central

    Ross, Randal G; Stevens, Karen E; Proctor, William R; Leonard, Sherry; Kisley, Michael A; Hunter, Sharon K; Freedman, Robert; Adams, Catherine E

    2009-01-01

    Neuropsychiatric diseases are complex illnesses where the onset of diagnostic symptomology is often the end result of a decades-long process of aberrant brain development. The identification of novel treatment strategies aimed at normalizing early brain development and preventing mental illness should be a major therapeutic goal; however, there are few models for how this goal might be achieved. This report uses the attentional deficits of schizophrenia as an example and reviews data from genetic, anatomical, physiological, and pharmacologic studies to hypothesize a developmental model with translational primary prevention implications. Specifically, the model suggests that an early interaction between α7 nicotinic receptor density and choline availability may contribute to the development of schizophrenia-associated attentional deficits. Translational implications, including perinatal dietary choline supplementation, are discussed. It is hoped that presentation of this model will stimulate other efforts to develop empirically-driven primary prevention strategies. PMID:19925602

  7. Developing International Collaborations for Early Career Researchers in Psychology

    PubMed Central

    Flanagan, Julianne C.; Barrett, Emma L.; Crome, Erica; Forbes, Miriam

    2015-01-01

    International collaboration is becoming increasingly vital as the emphasis on unmet need for mental health across cultures and nations grows. Opportunities exist for early career researchers to engage in international collaboration. However, little information is provided about such opportunities in most current psychology training models. The authors are early career researchers in psychology from U.S. and Australia who have developed a collaborative relationship over the past two years. Our goal is to increase awareness of funding opportunities to support international research and to highlight the benefits and challenges associated with international collaboration based on our experience. PMID:27453624

  8. Early development of Xenopus embryos is affected by simulated gravity

    NASA Technical Reports Server (NTRS)

    Yokota, Hiroki; Neff, Anton W.; Malacinski, George M.

    1994-01-01

    Early amphibian (Xenopus laevis) development under clinostat-simulated weightlessness and centrifuge-simulated hypergravity was studied. The results revealed significant effects on (i) 'morphological patterning' such as the cleavage furrow pattern in the vegetal hemisphere at the eight-cell stage and the shape of the dorsal lip in early gastrulae and (ii) 'the timing of embryonic events' such as the third cleavage furrow completion and the dorsal lip appearance. Substantial variations in sensitivity to simulated force fields were observed, which should be considered in interpreting spaceflight data.

  9. Effects of early life stress on amygdala and striatal development

    PubMed Central

    Fareri, Dominic S.; Tottenham, Nim

    2016-01-01

    Species-expected caregiving early in life is critical for the normative development and regulation of emotional behavior, the ability to effectively evaluate affective stimuli in the environment, and the ability to sustain social relationships. Severe psychosocial stressors early in life (early life stress; ELS) in the form of the absence of species expected caregiving (i.e., caregiver deprivation), can drastically impact one’s social and emotional success, leading to the onset of internalizing illness later in life. Development of the amygdala and striatum, two key regions supporting affective valuation and learning, is significantly affected by ELS, and their altered developmental trajectories have important implications for cognitive, behavioral and socioemotional development. However, an understanding of the impact of ELS on the development of functional interactions between these regions and subsequent behavioral effects is lacking. In this review, we highlight the roles of the amygdala and striatum in affective valuation and learning in maturity and across development. We discuss their function separately as well as their interaction. We highlight evidence across species characterizing how ELS induced changes in the development of the amygdala and striatum mediate subsequent behavioral changes associated with internalizing illness, positing a particular import of the effect of ELS on their interaction. PMID:27174149

  10. Effects of early life stress on amygdala and striatal development.

    PubMed

    Fareri, Dominic S; Tottenham, Nim

    2016-06-01

    Species-expected caregiving early in life is critical for the normative development and regulation of emotional behavior, the ability to effectively evaluate affective stimuli in the environment, and the ability to sustain social relationships. Severe psychosocial stressors early in life (early life stress; ELS) in the form of the absence of species expected caregiving (i.e., caregiver deprivation), can drastically impact one's social and emotional success, leading to the onset of internalizing illness later in life. Development of the amygdala and striatum, two key regions supporting affective valuation and learning, is significantly affected by ELS, and their altered developmental trajectories have important implications for cognitive, behavioral and socioemotional development. However, an understanding of the impact of ELS on the development of functional interactions between these regions and subsequent behavioral effects is lacking. In this review, we highlight the roles of the amygdala and striatum in affective valuation and learning in maturity and across development. We discuss their function separately as well as their interaction. We highlight evidence across species characterizing how ELS induced changes in the development of the amygdala and striatum mediate subsequent behavioral changes associated with internalizing illness, positing a particular import of the effect of ELS on their interaction. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Fathers' sensitive parenting and the development of early executive functioning.

    PubMed

    Towe-Goodman, Nissa R; Willoughby, Michael; Blair, Clancy; Gustafsson, Hanna C; Mills-Koonce, W Roger; Cox, Martha J

    2014-12-01

    Using data from a diverse sample of 620 families residing in rural, predominately low-income communities, this study examined longitudinal links between fathers' sensitive parenting in infancy and toddlerhood and children's early executive functioning, as well as the contribution of maternal sensitive parenting. After accounting for the quality of concurrent and prior parental care, children's early cognitive ability, and other child and family factors, fathers' and mothers' sensitive and supportive parenting during play at 24 months predicted children's executive functioning at 3 years of age. In contrast, paternal parenting quality during play at 7 months did not make an independent contribution above that of maternal care, but the links between maternal sensitive and supportive parenting and executive functioning seemed to operate in similar ways during infancy and toddlerhood. These findings add to prior work on early experience and children's executive functioning, suggesting that both fathers and mothers play a distinct and complementary role in the development of these self-regulatory skills.

  12. Early development of physical aggression and early risk factors for chronic physical aggression in humans.

    PubMed

    Tremblay, Richard E

    2014-01-01

    This chapter describes the state of knowledge on the development of physical aggression from early childhood to adulthood, the long term outcomes of chronic physical aggression during childhood and the risk factors for chronic physical aggression. Unraveling the development of physical aggression is important to understand when and why humans start using physical aggression, to understand why some humans suffer from chronic physical aggression and to understand how to prevent the development of this disorder which causes much distress to the aggressors and their victims. The study of the developmental origins of aggression also sheds light on the reasons why situational prevention of aggression is important at all ages and in all cultures.

  13. Alternatives to the fish early life-stage test: Developing a conceptual model for early fish development

    EPA Science Inventory

    Chronic fish toxicity is a key parameter for hazard classification and environmental risk assessment of chemicals, and the OECD 210 fish early life-stage (FELS) test is the primary guideline test used for various international regulatory programs. There exists a need to develop ...

  14. Gonadotrophic cells and gonadal sex differentiation in medaka: Characterization of several northern and southern strains.

    PubMed

    Horie, Yoshifumi; Kobayashi, Tohru

    2015-07-01

    Gonadotropins play an important role in gametogenesis and reproduction in vertebrates. Their localization in the pituitary during gonadal sex differentiation has been studied mainly in southern (Oryzias latipes) strains of medaka fish, with that in northern medaka (O. sakaizumii) remaining poorly understood. Hence, in this study, we characterized gonadal differentiation and gonadotrophic cells during sex differentiation in two northern strains (HNI and Kaga) and two southern strains (Hd-rR and d-rR/Tokyo). All strains exhibited similar sex differentiation at hatching, such as (1) sex difference in germ cell number (XX > XY), and (2) the transition of XX germ cells into meiosis, and (3) presence of glycoprotein-α (Gpa)-positive cells. However, follicle-stimulating hormone-β (Fshb)-positive cells were first detected in the pituitary 1 day post-hatching in HNI. Exposure to high-temperature conditions and to cortisol in a dose dependent manner resulted in the localization of Fshb cells in the pituitary at hatching. This study demonstrates differences in gonadotropin subunit expression between northern and southern strains of medaka, and suggests that Fsh is not involved in early gonadal sex differentiation, such as the sex difference in germ cell number, and that high-temperature induce Fshb expression via cortisol production in medaka. © 2015 Wiley Periodicals, Inc.

  15. Gross Motor Development, Movement Abnormalities, and Early Identification of Autism

    PubMed Central

    Young, Gregory S.; Goldring, Stacy; Greiss-Hess, Laura; Herrera, Adriana M.; Steele, Joel; Macari, Suzanne; Hepburn, Susan; Rogers, Sally J.

    2015-01-01

    Gross motor development (supine, prone, rolling, sitting, crawling, walking) and movement abnormalities were examined in the home videos of infants later diagnosed with autism (regression and no regression subgroups), developmental delays (DD), or typical development. Group differences in maturity were found for walking, prone, and supine, with the DD and Autism-No Regression groups both showing later developing motor maturity than typical children. The only statistically significant differences in movement abnormalities were in the DD group; the two autism groups did not differ from the typical group in rates of movement abnormalities or lack of protective responses. These findings do not replicate previous investigations suggesting that early motor abnormalities seen on home video can assist in early identification of autism. PMID:17805956

  16. Early stress and human behavioral development: emerging evolutionary perspectives.

    PubMed

    Del Giudice, M

    2014-08-01

    Stress experienced early in life exerts a powerful, lasting influence on development. Converging empirical findings show that stressful experiences become deeply embedded in the child's neurobiology, with an astonishing range of long-term effects on cognition, emotion, and behavior. In contrast with the prevailing view that such effects are the maladaptive outcomes of 'toxic' stress, adaptive models regard them as manifestations of evolved developmental plasticity. In this paper, I offer a brief introduction to adaptive models of early stress and human behavioral development, with emphasis on recent theoretical contributions and emerging concepts in the field. I begin by contrasting dysregulation models of early stress with their adaptive counterparts; I then introduce life history theory as a unifying framework, and review recent work on predictive adaptive responses (PARs) in human life history development. In particular, I discuss the distinction between forecasting the future state of the environment (external prediction) and forecasting the future state of the organism (internal prediction). Next, I present the adaptive calibration model, an integrative model of individual differences in stress responsivity based on life history concepts. I conclude by examining how maternal-fetal conflict may shape the physiology of prenatal stress and its adaptive and maladaptive effects on postnatal development. In total, I aim to show how theoretical work from evolutionary biology is reshaping the way we think about the role of stress in human development, and provide researchers with an up-to-date conceptual map of this fascinating and rapidly evolving field.

  17. Conditions on Early Mars Might Have Fostered Rapid and Early Development of Life

    NASA Technical Reports Server (NTRS)

    Gibson, Everett K.; McKay, David S.; Thomas-Keprta, Kathie L.; Clemett, Simon J.; Wentworth, Susan J.

    2007-01-01

    The exploration of Mars during the past decades has begun to unveil the history of the planet. The combinations of remote sensing, in situ geochemical compositional measurements and photographic observations from both above and on the surface have shown Mars to have a dynamic and active geologic evolution. Mars geologic evolution clearly had conditions that were suitable for supporting life. For a planet to be able to be habitable, it must have water, carbon sources, energy sources and a dynamic geologic past. Mars meets all of these requirements. The first 600 My of Martian history were ripe for life to develop because of the abundance of (i) Water-carved canyons and oceans or lakes with the early presence of near surface water shown by precipitated carbonates in ALH84001 well-dated at approx.3.9 Gy., (ii) Energy from the original accretional processes, a molten core which generated a strong magnetic field leaving a permanent record in the early crust, early active volcanism continuing throughout Martian history, and, and continuing impact processes, (iii) Carbon and water from possibly extensive volcanic outgassing (i.e. H2O, CO2, CH4, CO, O2, N2, H2S, SO2, etc.) and (iv) some crustal tectonics as revealed by faulting and possible plate movement reflected by the magnetic pattern in the crust. The question arises: "Why would life not evolve from these favorable conditions on early Mars in its first 600 My?" During this period, it seems likely that environmental near-surface conditions on Mars were more favorable to life than at any later time. Standing bodies of water, precipitation and flowing surface water, and possibly abundant hydrothermal energy would all favor the formation of early life. Even if life developed elsewhere (on Earth, Venus, or on other solar systems) and was transported to Mars, the surface conditions were likely very hospitable for that introduced life to multiply and evolve.

  18. Characteristics of effective professional development for early career science teachers

    NASA Astrophysics Data System (ADS)

    Simon, Shirley; Campbell, Sandra; Johnson, Sally; Stylianidou, Fani

    2011-04-01

    The research reported here set out to investigate the features in schools and science departments that were seen as effective in contributing to the continuing professional development (CPD) of early career science teachers. Ten schools took part in the study, selected on the basis of their reputation for having effective CPD practices. To gain different perspectives from within the organisations we conducted interviews with senior members of staff, heads of science departments and early career teachers. A thematic analysis of the interviews is presented, drawing on findings from across the 10 schools, and exemplified in more detail by a vignette to show specific features of effective CPD practice. The study has revealed a wealth of practice across the 10 schools, which included a focus on broadening experience beyond the classroom, having an open, sharing, non-threatening culture and systemic procedures for mentoring and support that involved ring-fenced budgets. The schools also deployed staff judiciously in critical roles that model practice and motivate early career science teachers. Early career teachers were concerned primarily with their overall development as teachers, though some science specific examples such as observing practical work and sessions to address subject knowledge were seen as important.

  19. Endosperm turgor pressure decreases during early Arabidopsis seed development.

    PubMed

    Beauzamy, Léna; Fourquin, Chloé; Dubrulle, Nelly; Boursiac, Yann; Boudaoud, Arezki; Ingram, Gwyneth

    2016-09-15

    In Arabidopsis, rapid expansion of the coenocytic endosperm after fertilisation has been proposed to drive early seed growth, which is in turn constrained by the seed coat. This hypothesis implies physical heterogeneity between the endosperm and seed coat compartments during early seed development, which to date has not been demonstrated. Here, we combine tissue indentation with modelling to show that the physical properties of the developing seed are consistent with the hypothesis that elevated endosperm-derived turgor pressure drives early seed expansion. We provide evidence that whole-seed turgor is generated by the endosperm at early developmental stages. Furthermore, we show that endosperm cellularisation and seed growth arrest are associated with a drop in endosperm turgor pressure. Finally, we demonstrate that this decrease is perturbed when the function of POLYCOMB REPRESSIVE COMPLEX 2 is lost, suggesting that turgor pressure changes could be a target of genomic imprinting. Our results indicate a developmental role for changes in endosperm turgor pressure in the Arabidopsis seed. © 2016. Published by The Company of Biologists Ltd.

  20. The end of gonad-centric sex determination in mammals

    PubMed Central

    Arnold, Arthur P.

    2011-01-01

    The 20th century theory of mammalian sex determination states that the embryo is sexually indifferent until the differentiation of gonads, after which sex differences in phenotype are caused by differential effects of gonadal hormones. That theory is inadequate because some sex differences precede differentiation of the gonads and/or are determined by non-gonadal effects of the sexual inequality in number and type of sex chromosomes. A general theory of sex determination is proposed, which recognizes multiple parallel primary sex-determining pathways initiated by genes or factors encoded by the sex chromosomes. The separate sex-specific pathways interact to synergize with or antagonize each other, enhancing or reducing sex differences in phenotype. PMID:22078126

  1. [Dental caries and early childhood development: a pilot study].

    PubMed

    Núñez, F Loreto; Sanz, B Javier; Mejía, L Gloria

    2015-01-01

    To investigate the association between dental caries and early childhood development in 3-year-olds from Talca, Chile. A pilot study with a convenience sample of 3-year-olds from Talca (n = 39) who attend public healthcare centers. Child development was measured by the Psychomotor Development Index (PDI), a screening tool used nationally among pre-school children to assess language development, fine motor skills and coordination areas. Dental caries prevalence was evaluated by decayed, missing, filled teeth (DFMT) and decayed, missing, filled tooth surfaces (DFMS) ceo-d and ceo-s indexes. The children were divided into two groups according to the PDIscore: those with a score of 40 or more were considered developmentally normal (n = 32), and those with a score below 40 were considered as having impaired development (n = 7). The severity of caries (DMFT) was negatively correlated with PDI (r = -0.82), and children with the lowest TEPSI score had the highest DFMT values. The average DMFT in children with normal development was 1.31, and 3.57 for those with impaired development. This pilot study indicates that the severity of dental caries is correlated with early childhood development. Copyright © 2015. Publicado por Elsevier España, S.L.U.

  2. The early Cambrian fossil embryo Pseudooides is a direct-developing cnidarian, not an early ecdysozoan

    PubMed Central

    2017-01-01

    Early Cambrian Pseudooides prima has been described from embryonic and post-embryonic stages of development, exhibiting long germ-band development. There has been some debate about the pattern of segmentation, but this interpretation, as among the earliest records of ecdysozoans, has been generally accepted. Here, we show that the ‘germ band’ of P. prima embryos separates along its mid axis during development, with the transverse furrows between the ‘somites’ unfolding into the polar aperture of the ten-sided theca of Hexaconularia sichuanensis, conventionally interpreted as a scyphozoan cnidarian; co-occurring post-embryonic remains of ecdysozoans are unrelated. We recognize H. sichuanensis as a junior synonym of P. prima as a consequence of identifying these two form-taxa as distinct developmental stages of the same organism. Direct development in P. prima parallels the co-occuring olivooids Olivooides, and Quadrapyrgites and Bayesian phylogenetic analysis of a novel phenotype dataset indicates that, despite differences in their tetra-, penta- and pseudo-hexa-radial symmetry, these hexangulaconulariids comprise a clade of scyphozoan medusozoans, with Arthrochites and conulariids, that all exhibit direct development from embryo to thecate polyp. The affinity of hexangulaconulariids and olivooids to extant scyphozoan medusozoans indicates that the prevalence of tetraradial symmetry and indirect development are a vestige of a broader spectrum of body-plan symmetries and developmental modes that was manifest in their early Phanerozoic counterparts. PMID:29237861

  3. The early Cambrian fossil embryo Pseudooides is a direct-developing cnidarian, not an early ecdysozoan.

    PubMed

    Duan, Baichuan; Dong, Xi-Ping; Porras, Luis; Vargas, Kelly; Cunningham, John A; Donoghue, Philip C J

    2017-12-20

    Early Cambrian Pseudooides prima has been described from embryonic and post-embryonic stages of development, exhibiting long germ-band development. There has been some debate about the pattern of segmentation, but this interpretation, as among the earliest records of ecdysozoans, has been generally accepted. Here, we show that the 'germ band' of P. prima embryos separates along its mid axis during development, with the transverse furrows between the 'somites' unfolding into the polar aperture of the ten-sided theca of Hexaconularia sichuanensis , conventionally interpreted as a scyphozoan cnidarian; co-occurring post-embryonic remains of ecdysozoans are unrelated. We recognize H. sichuanensis as a junior synonym of P. prima as a consequence of identifying these two form-taxa as distinct developmental stages of the same organism. Direct development in P. prima parallels the co-occuring olivooids Olivooides, and Quadrapyrgites and Bayesian phylogenetic analysis of a novel phenotype dataset indicates that, despite differences in their tetra-, penta- and pseudo-hexa-radial symmetry, these hexangulaconulariids comprise a clade of scyphozoan medusozoans, with Arthrochites and conulariids, that all exhibit direct development from embryo to thecate polyp. The affinity of hexangulaconulariids and olivooids to extant scyphozoan medusozoans indicates that the prevalence of tetraradial symmetry and indirect development are a vestige of a broader spectrum of body-plan symmetries and developmental modes that was manifest in their early Phanerozoic counterparts. © 2017 The Authors.

  4. The genetics of XX gonadal dysgenesis

    SciTech Connect

    Aittomaeki, K.

    1994-05-01

    In a nationwide population-based study of women born between 1950 and 1976, 75 patients with XX gonadal dysgenesis (XXGD) were identified in Finland. Patients were ascertained through hospital records and the registers of chromosome laboratories. In one family 4 daughters were affected; in six families 2 daughters were affected; and 57 cases were isolated. In one additional family the two affected females were in successive generations. Population records were utilized to trace ancestors of patients back to the beginning of the 19th century, in most cases. Consanguinity was detected in 8 (12%) of 66 families. When females only are considered,more » the segregation analyses yield a proportion of .23 affected. The relatively large number of affected individuals identified (incidence 1 in 8,300 live-born girls) implies a high gene frequency in the Finnish population. The geographic distribution was highly uneven, with most families originating in the sparsely populated north-central part of Finland. These findings support the existence of an autosomal recessive (XXGD) gene (locus designation [open quotes]ODG1[close quotes]) that is highly enriched in Finland. The multiplex families already identified will make it possible to map the ODG1 gene by a random search for linkage by using polymorphic markers. Linkage-disequilibrium analysis in the sporadic patients will then be used to test for genetic homogeneity versus heterogeneity. 27 refs., 3 figs.« less

  5. Social conversational skills development in early implanted children.

    PubMed

    Guerzoni, Letizia; Murri, Alessandra; Fabrizi, Enrico; Nicastri, Maria; Mancini, Patrizia; Cuda, Domenico

    2016-09-01

    Social conversational skills are a salient aspect of early pragmatic development in young children. These skills include two different abilities, assertiveness and responsiveness. This study investigated the development of these abilities in early implanted children and their relationships with lexical development and some language-sensitive variables. Prospective, observational, nonrandomized study. Participants included 28 children with congenital profound sensorineural hearing loss. The mean age at device activation was 13.3 months (standard deviation [SD] ±4.2). The Social-Conversational Skills Rating Scale was used to evaluate assertiveness and responsiveness. The MacArthur-Bates Communicative Development Inventory (Words and Sentences form) was used to analyze the lexical development. The device experience was 12 months for each child, and the mean age at testing was 25.9 months (SD ±4.6). Assertiveness and responsiveness scores were within the normal range of normal-hearing age-matched peers. Age at cochlear implant activation exerted a significant impact, with the highest scores associated to the youngest patients. The residual correlations between assertiveness and responsiveness with the lexical development were positive and strongly significant (r = 0.69 and 0.73, respectively). Preoperative hearing threshold demonstrated an associated significant coefficient on the assertiveness score. Age at diagnosis and maternal education level were not correlated with the social conversational skills. Early-implanted children developed social conversational skills that are similar to normal-hearing peers matched for age 1 year after device activation. Social conversational skills and lexical development were strongly correlated, but the present study design cannot specify the direction of this relationship. Children with better preoperative residual hearing exhibited better assertive ability. 4 Laryngoscope, 126:2098-2105, 2016. © 2015 The American Laryngological

  6. Laparoscopic Removal of Streak Gonads in Turner Syndrome.

    PubMed

    Mandelberger, Adrienne; Mathews, Shyama; Andikyan, Vaagn; Chuang, Linus

    To demonstrate the skills necessary for complete resection of bilateral streak gonads in Turner syndrome. Video case presentation with narration highlighting the key techniques used. The video was deemed exempt from formal review by our institutional review board. Turner syndrome is a form of gonadal dysgenesis that affects 1 in 2500 live births. Patients often have streak gonads and may present with primary amenorrhea or premature ovarian failure. Patients with a mosaic karyotype that includes a Y chromosome are at increased risk for gonadoblastoma and subsequent transformation into malignancy. Gonadectomy is recommended for these patients, typically at adolescence. Streak gonads can be difficult to identify, and tissue margins are often in close proximity to critical retroperitoneal structures. Resection can be technically challenging and requires a thorough understanding of retroperitoneal anatomy and precise dissection techniques to ensure complete removal. Laparoscopic approach to bilateral salpingo-oophorectomy of streak gonads. Retroperitoneal dissection and ureterolysis are performed, with the aid of the Ethicon Harmonic Ace, to ensure complete gonadectomy. Careful and complete resection of gonadal tissue in the hands of a skilled laparoscopic surgeon is key for effective cancer risk reduction surgery in Turner syndrome mosaics. Copyright © 2016 AAGL. Published by Elsevier Inc. All rights reserved.

  7. Studies Toward Birth and Early Mammalian Development in Space

    NASA Technical Reports Server (NTRS)

    Ronca, April E.; Dalton, Bonnie (Technical Monitor)

    2002-01-01

    Successful reproduction is the hallmark of a species' ability to adapt to its environment and must be realized to sustain life beyond Earth. Before taking this immense step, we need to understand the effects of altered gravity on critical phases of mammalian reproduction, viz., those events surrounding pregnancy, birth and the early development of offspring. No mammal has yet undergone birth in space. however studies spanning the gravity continuum from 0 to 2-g are revealing insights into how birth and early postnatal development will proceed in space. In this presentation, I will report the results of behavioral studies of rat mothers and offspring exposed from mid- to late pregnancy to either hypogravity (0-g) or hypergravity (1.5 or 2-g).

  8. Relationship between the neighbourhood built environment and early child development.

    PubMed

    Christian, Hayley; Ball, Stephen J; Zubrick, Stephen R; Brinkman, Sally; Turrell, Gavin; Boruff, Bryan; Foster, Sarah

    2017-11-01

    The relationship between features of the neighbourhood built environment and early child development was investigated using area-level data from the Australian Early Development Census. Overall 9.0% of children were developmentally vulnerable on the Physical Health and Well-being domain, 8.1% on the Social Competence domain and 8.1% on the Emotional Maturity domain. After adjustment for socio-demographic factors, Local Communities with the highest quintile of home yard space had significantly lower odds of developmental vulnerability on the Emotional Maturity domain. Residing in a Local Community with fewer main roads was associated with a decrease in the proportion of children developmentally vulnerable on the Social Competence domain. Overall, sociodemographic factors were more important than aspects of the neighbourhood physical environment for explaining variation between Local Communities in the developmental vulnerability of children. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Lexically-based learning and early grammatical development.

    PubMed

    Lieven, E V; Pine, J M; Baldwin, G

    1997-02-01

    Pine & Lieven (1993) suggest that a lexically-based positional analysis can account for the structure of a considerable proportion of children's early multiword corpora. The present study tests this claim on a second, larger sample of eleven children aged between 1;0 and 3;0 from a different social background, and extends the analysis to later in development. Results indicate that the positional analysis can account for a mean of 60% of all the children's multiword utterances and that the great majority of all other utterances are defined as frozen by the analysis. Alternative explanations of the data based on hypothesizing underlying syntactic or semantic relations are investigated through analyses of pronoun case marking and of verbs with prototypical agent-patient roles. Neither supports the view that the children's utterances are being produced on the basis of general underlying rules and categories. The implications of widespread distributional learning in early language development are discussed.

  10. Hazards to Early Development: The Biological Embedding of Early Life Adversity.

    PubMed

    Nelson, Charles A

    2017-10-11

    The number of children under 18 years of age has increased worldwide over the past decade. This growth spurt is due, in part, to remarkable progress in child survival. Alas, surviving early hazards, like prematurity or infectious disease, does not guarantee that children's development will not be compromised by other hazards as they grow older. Throughout the world, children continue to be confronted with a large number of biological and psychosocial challenges that greatly limit their developmental potential. The focus of this article is how such adverse experiences impact the developing brain. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Early zebrafish development: It’s in the maternal genes

    PubMed Central

    Abrams, Elliott W.; Mullins, Mary C.

    2009-01-01

    Summary The earliest stages of embryonic development in all animals examined rely on maternal gene products that are generated during oogenesis and supplied to the egg. The period of maternal control of embryonic development varies among animals according to the onset of zygotic transcription and the persistence of maternal gene products. This maternal regulation has been little studied in vertebrates, due to the difficulty in manipulating maternal gene function and lack of basic molecular information. However, recent maternal-effect screens in the zebrafish have generated more than 40 unique mutants that are providing new molecular entry points to the maternal control of early vertebrate development. Here we discuss recent studies of 12 zebrafish mutant genes that illuminate the maternal molecular controls on embryonic development, including advances in the regulation of animal-vegetal polarity, egg activation, cleavage development, body plan formation, tissue morphogenesis, microRNA function and germ cell development. PMID:19608405

  12. Gonadal Transcriptome Analysis of Male and Female Olive Flounder (Paralichthys olivaceus)

    PubMed Central

    Fan, Zhaofei; You, Feng; Wang, Lijuan; Weng, Shenda; Wu, Zhihao; Hu, Jinwei; Zou, Yuxia; Tan, Xungang; Zhang, Peijun

    2014-01-01

    Olive flounder (Paralichthys olivaceus) is an important commercially cultured marine flatfish in China, Korea, and Japan, of which female grows faster than male. In order to explore the molecular mechanism of flounder sex determination and development, we used RNA-seq technology to investigate transcriptomes of flounder gonads. This produced 22,253,217 and 19,777,841 qualified reads from ovary and testes, which were jointly assembled into 97,233 contigs. Among them, 23,223 contigs were mapped to known genes, of which 2,193 were predicted to be differentially expressed in ovary and 887 in testes. According to annotation information, several sex-related biological pathways including ovarian steroidogenesis and estrogen signaling pathways were firstly found in flounder. The dimorphic expression of overall sex-related genes provides further insights into sex determination and gonadal development. Our study also provides an archive for further studies of molecular mechanism of fish sex determination. PMID:25121093

  13. Reading Instruction Affects the Cognitive Skills Supporting Early Reading Development

    ERIC Educational Resources Information Center

    McGeown, Sarah P.; Johnston, Rhona S.; Medford, Emma

    2012-01-01

    This study examined the cognitive skills associated with early reading development when children were taught by different types of instruction. Seventy-nine children (mean age at pre-test 4;10 (0.22 S.D.) and post-test 5;03 (0.21 S.D.)) were taught to read either by an eclectic approach which included sight-word learning, guessing from context and…

  14. Dynamic Self-Organization and Early Lexical Development in Children

    ERIC Educational Resources Information Center

    Li, Ping; Zhao, Xiaowei; Whinney, Brian Mac

    2007-01-01

    In this study we present a self-organizing connectionist model of early lexical development. We call this model DevLex-II, based on the earlier DevLex model. DevLex-II can simulate a variety of empirical patterns in children's acquisition of words. These include a clear vocabulary spurt, effects of word frequency and length on age of acquisition,…

  15. Early Life Growth Predicts Pubertal Development in South African Adolescents.

    PubMed

    Lundeen, Elizabeth A; Norris, Shane A; Martorell, Reynaldo; Suchdev, Parminder S; Mehta, Neil K; Richter, Linda M; Stein, Aryeh D

    2016-03-01

    Given global trends toward earlier onset of puberty and the adverse psychosocial consequences of early puberty, it is important to understand the childhood predictors of pubertal timing and tempo. We examined the association between early growth and the timing and tempo of puberty in adolescents in South Africa. We analyzed prospectively collected data from 1060 boys and 1135 girls participating in the Birth-to-Twenty cohort in Soweto, South Africa. Height-for-age z scores (HAZs) and body mass index-for-age z scores (BMIZs) were calculated based on height (centimeters) and body mass index (kilograms per meter squared) at ages 5 y and 8 y. The development of genitals, breasts, and pubic hair was recorded annually from 9 to 16 y of age with the use of the Tanner sexual maturation scale (SMS). We used latent class growth analysis to identify pubertal trajectory classes and also characterized children as fast or slow developers based on the SMS score at 12 y of age. We used multinomial logistic regression to estimate associations of HAZ and BMIZ at ages 5 and 8 y with pubertal development. We identified 3 classes for pubic hair development (for both girls and boys) and 4 classes for breast (for girls) and genital (for boys) development. In girls, both HAZ and BMIZ at age 5 y were positively associated with pubic hair development [relative risk ratio (RRR): 1.57, P < 0.001 and RRR: 1.51, P < 0.01, respectively], as was BMI at age 8 y (RRR: 2.06, P = 0.03); similar findings were observed for breast development. In boys, HAZ and BMIZ at age 5 y were positively associated with pubic hair development (RRR: 1.78, P < 0.001 and RRR: 1.43, P < 0.01, respectively); HAZ at age 5 y was associated with development of genitals (RRR: 2.19, P < 0.01). In boys and girls, both height and body mass index in early childhood predicted the trajectory of pubertal development. This may provide a tool to identify children at risk of early pubertal onset.

  16. Biased gene expression in early honeybee larval development

    PubMed Central

    2013-01-01

    Background Female larvae of the honeybee (Apis mellifera) develop into either queens or workers depending on nutrition. This nutritional stimulus triggers different developmental trajectories, resulting in adults that differ from each other in physiology, behaviour and life span. Results To understand how these trajectories are established we have generated a comprehensive atlas of gene expression throughout larval development. We found substantial differences in gene expression between worker and queen-destined larvae at 6 hours after hatching. Some of these early changes in gene expression are maintained throughout larval development, indicating that caste-specific developmental trajectories are established much earlier than previously thought. Within our gene expression data we identified processes that potentially underlie caste differentiation. Queen-destined larvae have higher expression of genes involved in transcription, translation and protein folding early in development with a later switch to genes involved in energy generation. Using RNA interference, we were able to demonstrate that one of these genes, hexamerin 70b, has a role in caste differentiation. Both queen and worker developmental trajectories are associated with the expression of genes that have alternative splice variants, although only a single variant of a gene tends to be differentially expressed in a given caste. Conclusions Our data, based on the biases in gene expression early in development together with published data, supports the idea that caste development in the honeybee consists of two phases; an initial biased phase of development, where larvae can still switch to the other caste by differential feeding, followed by commitment to a particular developmental trajectory. PMID:24350621

  17. Early development and replacement of the stickleback dentition

    PubMed Central

    Ellis, Nicholas A.; Donde, Nikunj N.; Miller, Craig T.

    2017-01-01

    Teeth have long served as a model system to study basic questions about vertebrate organogenesis, morphogenesis, and evolution. In non-mammalian vertebrates, teeth typically regenerate throughout adult life. Fish have evolved a tremendous diversity in dental patterning in both their oral and pharyngeal dentitions, offering numerous opportunities to study how morphology develops, regenerates, and evolves in different lineages. Threespine stickleback fish (Gasterosteus aculeatus) have emerged as a new system to study how morphology evolves, and provide a particularly powerful system to study the development and evolution of dental morphology. Here we describe the oral and pharyngeal dentitions of stickleback fish, providing additional morphological, histological, and molecular evidence for homology of oral and pharyngeal teeth. Focusing on the ventral pharyngeal dentition in a dense developmental time course of lab-reared fish, we describe the temporal and spatial consensus sequence of early tooth formation. Early in development, this sequence is highly stereotypical and consists of seventeen primary teeth forming the early tooth field, followed by the first tooth replacement event. Comparing this detailed morphological and ontogenetic sequence to that described in other fish reveals that major changes to how dental morphology arises and regenerates have evolved across different fish lineages. PMID:27145214

  18. Developing an Early Childhood Teacher Workforce Development Strategy for Rural and Remote Communities

    ERIC Educational Resources Information Center

    Price, Anne; Jackson-Barrett, Elizabeth

    2009-01-01

    The North West Early Childhood and Primary Teacher Workforce Development Strategy offers students in the Pilbara and Kimberley the opportunity to enrol in a Western Australian University's fully accredited Bachelor of Education (Early Childhood and Primary) part time and externally--so they can continue to live and work in their communities. The…

  19. Early mathematics development and later achievement: Further evidence

    NASA Astrophysics Data System (ADS)

    Aubrey, Carol; Godfrey, Ray; Dahl, Sarah

    2006-05-01

    There is a growing international recognition of the importance of the early years of schooling as well as an interest being shown in the relationship of early education to later achievement. This article focuses on a cohort of English pupils who have been tracked through primary school during the first five years of the new National Numeracy Strategy. It reports a limited longitudinal study of young children's early mathematical development, initially within three testing cycles: at the mid-point and towards the end of their reception year (at five years-of-age) and again at the mid-point of Year 1 (at six years-ofage). These cycles were located within the broader context of progress through to the end of Key Stage 1 (at seven years) and Key Stage 2 (at eleven years) on the basis of national standardised assessment tests (SATs). Results showed that children who bring into school early mathematical knowledge do appear to be advantaged in terms of their mathematical progress through primary school. Numerical attainment increases in importance across the primary years and practical problem solving remains an important element of this. This finding is significant given the current emphasis on numerical calculation in the English curriculum. It is concluded that without active intervention, it is likely that children with little mathematical knowledge at the beginning of formal schooling will remain low achievers throughout their primary years and, probably, beyond.

  20. Germ Cells Are Not Required to Establish the Female Pathway in Mouse Fetal Gonads

    PubMed Central

    Maatouk, Danielle M.; Mork, Lindsey; Hinson, Ashley; Kobayashi, Akio; McMahon, Andrew P.; Capel, Blanche

    2012-01-01

    The fetal gonad is composed of a mixture of somatic cell lineages and germ cells. The fate of the gonad, male or female, is determined by a population of somatic cells that differentiate into Sertoli or granulosa cells and direct testis or ovary development. It is well established that germ cells are not required for the establishment or maintenance of Sertoli cells or testis cords in the male gonad. However, in the agametic ovary, follicles do not form suggesting that germ cells may influence granulosa cell development. Prior investigations of ovaries in which pre-meiotic germ cells were ablated during fetal life reported no histological changes during stages prior to birth. However, whether granulosa cells underwent normal molecular differentiation was not investigated. In cases where germ cell loss occurred secondary to other mutations, transdifferentiation of granulosa cells towards a Sertoli cell fate was observed, raising questions about whether germ cells play an active role in establishing or maintaining the fate of granulosa cells. We developed a group of molecular markers associated with ovarian development, and show here that the loss of pre-meiotic germ cells does not disrupt the somatic ovarian differentiation program during fetal life, or cause transdifferentiation as defined by expression of Sertoli markers. Since we do not find defects in the ovarian somatic program, the subsequent failure to form follicles at perinatal stages is likely attributable to the absence of germ cells rather than to defects in the somatic cells. PMID:23091613

  1. Sex hormones alter sex ratios in the Indian skipper frog, Euphlyctis cyanophlyctis: Determining sensitive stages for gonadal sex reversal.

    PubMed

    Phuge, S K; Gramapurohit, N P

    2015-09-01

    In amphibians, although genetic factors are involved in sex determination, gonadal sex differentiation can be modified by exogenous steroid hormones suggesting a possible role of sex steroids in regulating the process. We studied the effect of testosterone propionate (TP) and estradiol-17β (E2) on gonadal differentiation and sex ratio at metamorphosis in the Indian skipper frog, Euphlyctis cyanophlyctis with undifferentiated type of gonadal differentiation. A series of experiments were carried out to determine the optimum dose and sensitive stages for gonadal sex reversal. Our results clearly indicate the importance of sex hormones in controlling gonadal differentiation of E. cyanophlyctis. Treatment of tadpoles with 10, 20, 40, and 80μg/L TP throughout larval period resulted in the development of 100% males at metamorphosis at all concentrations. Similarly, treatment of tadpoles with 40μg/L TP during ovarian and testicular differentiation resulted in the development of 90% males, 10% intersexes and 100% males respectively. Treatment of tadpoles with 10, 20, 40, and 80μg/L E2 throughout larval period likewise produced 100% females at all concentrations. Furthermore, exposure to 40μg/L E2 during ovarian and testicular differentiation produced 95% females, 5% intersexes and 91% females, 9% intersexes respectively. Both TP and E2 were also effective in advancing the stages of gonadal development. Present study shows the effectiveness of both T and E2 in inducing complete sex reversal in E. cyanophlyctis. Generally, exposure to E2 increased the larval period resulting in significantly larger females than control group while the larval period of control and TP treated groups was comparable. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. The molecular and cellular basis of gonadal sex reversal in mice and humans

    PubMed Central

    Warr, Nick; Greenfield, Andy

    2012-01-01

    The mammalian gonad is adapted for the production of germ cells and is an endocrine gland that controls sexual maturation and fertility. Gonadal sex reversal, namely, the development of ovaries in an XY individual or testes in an XX, has fascinated biologists for decades. The phenomenon suggests the existence of genetic suppressors of the male and female developmental pathways and molecular genetic studies, particularly in the mouse, have revealed controlled antagonism at the core of mammalian sex determination. Both testis and ovary determination represent design solutions to a number of problems: how to generate cells with the right properties to populate the organ primordium; how to produce distinct organs from an initially bipotential primordium; how to pattern an organ when the expression of key cell fate determinants is initiated only in a discrete region of the primordium and extends to other regions asynchronously; how to coordinate the interaction between distinct cell types in time and space and stabilize the resulting morphology; and how to maintain the differentiated state of the organ throughout the adult period. Some of these, and related problems, are common to organogenesis in general; some are distinctive to gonad development. In this review, we discuss recent studies of the molecular and cellular events underlying testis and ovary development, with an emphasis on the phenomenon of gonadal sex reversal and its causes in mice and humans. Finally, we discuss sex-determining loci and disorders of sex development in humans and the future of research in this important area. WIREs Dev Biol 2012, 1:559–577. doi: 10.1002/wdev.42 PMID:23801533

  3. Predicting Adaptive Response to Fadrozole Exposure: Computational Model of the Fathead Minnow Hypothalamic-Pituitary-Gonadal Axis

    EPA Science Inventory

    Exposure to endocrine disrupting chemicals can affect reproduction and development in both humans and wildlife. We are developing a mechanistic mathematical model of the hypothalamic-pituitary-gonadal (HPG) axis in female fathead minnows to predict dose-response and time-course (...

  4. Adaptive Response in Female Fathead Minnows Exposed to an Aromatase Inhibitor: Computational Modeling of the Hypothalamic-Pituitary-Gonadal Axis

    EPA Science Inventory

    Exposure to endocrine disrupting chemicals can affect reproduction and development in both humans and wildlife. We are developing a mechanistic computational model of the hypothalamic-pituitary-gonadal (HPG) axis in female fathead minnows to predict dose-response and time-course ...

  5. Predicting Adaptive Response to Fadrozole Exposure:Computational Model of the Fathead MinnowsHypothalamic-Pituitary-Gonadal Axis

    EPA Science Inventory

    Exposure to endocrine disrupting chemicals can affect reproduction and development in both humans and wildlife. We are developing a mechanistic mathematical model of the hypothalamic-pituitary-gonadal (HPG) axis in female fathead minnows to predict doseresponse and time-course (...

  6. Reflections on the early development of poxvirus vectors.

    PubMed

    Moss, Bernard

    2013-09-06

    Poxvirus expression vectors were described in 1982 and quickly became widely used for vaccine development as well as research in numerous fields. Advantages of the vectors include simple construction, ability to accommodate large amounts of foreign DNA and high expression levels. Numerous poxvirus-based veterinary vaccines are currently in use and many others are in human clinical trials. The early reports of poxvirus vectors paved the way for and stimulated the development of other viral vectors and recombinant DNA vaccines. Published by Elsevier Ltd.

  7. Early career professional development issues for military academic psychiatrists.

    PubMed

    Warner, Christopher H; Bobo, William V; Flynn, Julianne

    2005-01-01

    Academically motivated graduates of military psychiatric residency programs confront serious challenges. In this article, the authors present a junior faculty development model organized around four overlapping domains: mentorship, scholarship, research, and career planning/development. Using these four domains as a platform for discussion, the authors focus on challenges facing academically oriented early-career military psychiatrists and provide guidance. The authors believe that a proactive stance, skillful mentoring, self-awareness through conscious planning and effort, ability to capitalize on existing opportunities for growth, and attention to detail are all vital to the junior military psychiatrist.

  8. Development of an assisting detection system for early infarct diagnosis

    SciTech Connect

    Sim, K. S.; Nia, M. E.; Ee, C. S.

    2015-04-24

    In this paper, a detection assisting system for early infarct detection is developed. This new developed method is used to assist the medical practitioners to diagnose infarct from computed tomography images of brain. Using this assisting system, the infarct could be diagnosed at earlier stages. The non-contrast computed tomography (NCCT) brain images are the data set used for this system. Detection module extracts the pixel data from NCCT brain images, and produces the colourized version of images. The proposed method showed great potential in detecting infarct, and helps medical practitioners to make earlier and better diagnoses.

  9. Early childhood development: impact of national human development, family poverty, parenting practices and access to early childhood education.

    PubMed

    Tran, T D; Luchters, S; Fisher, J

    2017-05-01

    This study was to describe and quantify the relationships among family poverty, parents' caregiving practices, access to education and the development of children living in low- and middle-income countries (LAMIC). We conducted a secondary analysis of data collected in UNICEF's Multiple Indicator Cluster Surveys (MICS). Early childhood development was assessed in four domains: language-cognitive, physical, socio-emotional and approaches to learning. Countries were classified into three groups on the basis of the Human Development Index (HDI). Overall, data from 97 731 children aged 36 to 59 months from 35 LAMIC were included in the after analyses. The mean child development scale score was 4.93 out of a maximum score of 10 (95%CI 4.90 to 4.97) in low-HDI countries and 7.08 (95%CI 7.05 to 7.12) in high-HDI countries. Family poverty was associated with lower child development scores in all countries. The total indirect effect of family poverty on child development score via attending early childhood education, care for the child at home and use of harsh punishments at home was -0.13 SD (77.8% of the total effect) in low-HDI countries, -0.09 SD (23.8% of the total effect) in medium-HDI countries and -0.02 SD (6.9% of the total effect) in high-HDI countries. Children in the most disadvantaged position in their societies and children living in low-HDI countries are at the greatest risk of failing to reach their developmental potential. Optimizing care for child development at home is essential to reduce the adverse effects of poverty on children's early development and subsequent life. © 2016 John Wiley & Sons Ltd.

  10. vasa is expressed in somatic cells of the embryonic gonad in a sex-specific manner in Drosophila melanogaster.

    PubMed

    Renault, Andrew D

    2012-10-15

    Vasa is a DEAD box helicase expressed in the Drosophila germline at all stages of development. vasa homologs are found widely in animals and vasa has become the gene of choice in identifying germ cells. I now show that Drosophila vasa expression is not restricted to the germline but is also expressed in a somatic lineage, the embryonic somatic gonadal precursor cells. This expression is sexually dimorphic, being maintained specifically in males, and is regulated post-transcriptionally. Although somatic Vasa expression is not required for gonad coalescence, these data support the notion that Vasa is not solely a germline factor.

  11. vasa is expressed in somatic cells of the embryonic gonad in a sex-specific manner in Drosophila melanogaster

    PubMed Central

    Renault, Andrew D.

    2012-01-01

    Summary Vasa is a DEAD box helicase expressed in the Drosophila germline at all stages of development. vasa homologs are found widely in animals and vasa has become the gene of choice in identifying germ cells. I now show that Drosophila vasa expression is not restricted to the germline but is also expressed in a somatic lineage, the embryonic somatic gonadal precursor cells. This expression is sexually dimorphic, being maintained specifically in males, and is regulated post-transcriptionally. Although somatic Vasa expression is not required for gonad coalescence, these data support the notion that Vasa is not solely a germline factor. PMID:23213382

  12. Ca2+ signalling and early embryonic patterning during zebrafish development.

    PubMed

    Webb, Sarah E; Miller, Andrew L

    2007-09-01

    1. It has been proposed that Ca2+ signalling, in the form of pulses, waves and steady gradients, may play a crucial role in key pattern-forming events during early vertebrate development. 2. With reference to the embryo of the zebrafish (Danio rerio), herein we review the Ca2+ transients reported from the cleavage to segmentation periods. This time-window includes most of the major pattern-forming events of early development, which transform a single-cell zygote into a complex multicellular embryo with established primary germ layers and body axes. 3. Data are presented to support our proposal that intracellular Ca2+ waves are an essential feature of embryonic cytokinesis and that propagating intercellular Ca2+ waves (both long and short range) may play a crucial role in: (i) the establishment of the embryonic periderm and the coordination of cell movements during epiboly, convergence and extension; (ii) the establishment of the basic embryonic axes and germ layers; and (iii) definition of the morphological boundaries of specific tissue domains and embryonic structures, including future organ anlagen. 4. The potential downstream targets of these Ca2+ transients are also discussed, as well as how they may integrate with other pattern-forming signalling pathways known to modulate early developmental events.

  13. Early Intravascular Events are Associated with Development of ARDS.

    PubMed

    Abdulnour, Raja-Elie E; Gunderson, Tina; Barkas, Ioanna; Timmons, Jack Y; Barnig, Cindy; Gong, Michelle; Kor, Daryl J; Gajic, Ognjen; Talmor, Daniel; Carter, Rickey E; Levy, Bruce D

    2018-05-21

    The acute respiratory distress syndrome (ARDS) is a devastating illness with limited therapeutic options. A better understanding of early biochemical and immunological events in ARDS could inform the development of new preventive and treatment strategies. To determine select peripheral blood lipid mediator and leukocyte responses in patients at-risk for ARDS. Patients at risk for ARDS were randomized as part of a multicenter, double-blind clinical trial of aspirin versus placebo (LIPS-A; NCT01504867). Plasma thromboxane B2 (TxB2), 15-epi-LXA4 (aspirin-triggered lipoxin A4, ATL), and peripheral blood leukocyte number and activation were determined upon enrollment and after treatment with either aspirin or placebo. Thirty-three of 367 subjects (9.0%) developed ARDS after randomization. Baseline ATL levels, total monocyte counts, intermediate monocyte (IntMo) counts, and Mo-PA were associated with the development of ARDS. Peripheral blood neutrophil count and monocyte-platelet aggregates significantly decreased over time. Of note, 9 subjects developed ARDS after randomization yet prior to study drug initiation, including 7 subjects assigned to aspirin treatment. Subjects without ARDS at the time of first dose demonstrated a lower incidence of ARDS with aspirin treatment. Compared with placebo, aspirin significantly decreased TxB2 and increased the ATL/TxB2 ratio. Biomarkers of intravascular monocyte activation in at-risk patients were associated with development of ARDS. The potential clinical benefit of early aspirin for prevention of ARDS remains uncertain. Together, results of the biochemical and immunological analyses provide a window into the early pathogenesis of human ARDS, and represent potential vascular biomarkers of ARDS risk.

  14. Characterization of gonadal soma-derived factor expression during sex change in the protogynous wrasse, Halichoeres trimaculatus.

    PubMed

    Horiguchi, Ryo; Nozu, Ryo; Hirai, Toshiaki; Kobayashi, Yasuhisa; Nagahama, Yoshitaka; Nakamura, Masaru

    2013-04-01

    Sex change in fishes provides a good experimental model for understanding the mechanisms and plasticity of sex determination and differentiation. The three-spot wrasse, Halichoeres trimaculatus is a protogynous hermaphrodite. During sex change from female to male, the ovary is replaced by the testis through the degeneration of oocytes and subsequent spermatogenesis. In the present study, we cloned a cDNA-encoding gonadal soma-derived factor (GSDF) from protogynous wrasse and examined its expression pattern in the sexually mature gonads and the sex-changing gonad induced experimentally by aromatase inhibition. Expression of gsdf was predominantly observed in the testis, and it was mainly localized to the supporting cells surrounding the spermatogonia. In the ovary, only slight expression of gsdf was observed in morphologically undifferentiated supporting cells in contact with oogonia. During sex change, strong expression of gsdf appeared first in the supporting cells surrounding the gonial germ cells before the onset of spermatogenesis. Thereafter, the expression of gsdf continually increased in the supporting cells surrounding the proliferating spermatogonia throughout the sex change. These results suggest that gsdf is involved in the proliferation of spermatogonia and subsequent spermatogenesis in both the testis and the gonad in the early stages of sex change. Copyright © 2013 Wiley Periodicals, Inc.

  15. Gonadal dysfunction in morbidly obese adolescent girls.

    PubMed

    Chin, Vivian; Censani, Marisa; Lerner, Shulamit; Conroy, Rushika; Oberfield, Sharon; McMahon, Donald; Zitsman, Jeffrey; Fennoy, Ilene

    2014-04-01

    To describe gonadal dysfunction and evaluate polycystic ovary syndrome (PCOS) and its association with metabolic syndrome (MeS) among girls in a morbidly obese adolescent population. In a cross-sectional study of 174 girls, height, weight, waist circumference, Tanner stage, reproductive hormones, carbohydrate and lipid markers, drug use, and menstrual history were obtained at baseline. Exclusion criteria were menarcheal age <2 years, hormonal contraceptive or metformin use, Tanner stage <4, and incomplete data on PCOS or MeS classification. University medical center outpatient clinic. Ninety-eight girls ages 13-19.6 years, Tanner 5, average body mass index of 46.6 kg/m(2), menarche at 11.4 years, and average menarcheal age of 5 years. None. Polycystic ovary syndrome and MeS. Ninety-eight girls were divided into four groups: PCOS by National Institutes of Health criteria (PCOSN, n = 24), irregular menses only (n = 25), elevated T (≥55 ng/dL) only (n = 6), and obese controls (n = 43). Metabolic syndrome by modified Cook criteria affected 32 girls or 33% overall: 6 of 24 PCOSN, 7 of 25 irregular menses only, 4 of 6 elevated T only, and 15 of 43 obese controls. Polycystic ovary syndrome by National Institutes of Health criteria and its individual components were not associated with MeS after adjusting for body mass index. Unlike obese adults, PCOSN and its individual components were not associated with MeS in the untreated morbidly obese adolescent population. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  16. Illinois Early Learning Project Tip Sheets: Physical Development and Health.

    ERIC Educational Resources Information Center

    2003

    The Illinois Early Learning Project (IEL) is funded by the Illinois State Board of Education to provide information resources on early learning and training related to implementing the Illinois Early Learning Standards for parents and for early childhood personnel in all settings. The IEL tip sheets offer suggestions to parents and early childhood…

  17. Mortality, size of the gonads, and ultrastructure of primordial germ cell in chick embryos treated with gamma-irradiation or injected with donor cells.

    PubMed

    Maeda, T; Clark, M E; Etches, R J

    1998-06-01

    The effects of injection and/or gamma-irradiation prior to injection on mortality, size of the gonads, and ultrastructure of primordial germ cell (PGC) were examined after 5 d of incubation. The mortality of embryos injected with donor cells was significantly higher than that of control and irradiated embryos. All irradiated embryos were alive, although their development was delayed compared to those not exposed to irradiation. The size of the gonads of embryos injected with donor cells were similar to those of control embryos, however, the size of the gonads in irradiated embryos was significantly smaller than those of control embryos. The number of PGC in the gonads was significantly decreased by irradiation. There was no notable effect of irradiation or injection on the nuclei and cytoplasmic organelles in PGC.

  18. A rare case of 46,XX gonadal dysgenesis and Mayer-Rokitansky-Kuster-Hauser syndrome.

    PubMed

    Manne, Sriharibabu; Veeraabhinav, C H; Jetti, Mounica; Himabindu, Yalamanchali; Donthu, Kiranmai; Badireddy, Mutyalarayudu

    2016-01-01

    46,XX gonadal dysgenesis is a rare genetically heterogeneous disorder characterized by underdeveloped ovaries with consequent, impuberism, primary amenorrhea, and hypergonadotropic hypogonadism. Mullerian agenesis or Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome is characterized by congenital aplasia of the uterus and the upper part (2/3) of the vagina in a woman with normal development of secondary sexual characteristics and a normal 46,XX karyotype. The phenotypic manifestations of MRKH syndrome may sometimes overlap with various other syndromes and require accurate delineation. The coexistence of both these disorders is extremely rare. Here, we report a case of 46,XX gonadal dysgenesis and MRKH syndrome with anatomically dispersed congenital anomalies unique among reported cases.

  19. Effects of tributyltin on metamorphosis and gonadal differentiation of Xenopus laevis at environmentally relevant concentrations.

    PubMed

    Shi, Huahong; Zhu, Pan; Guo, Suzhen

    2014-05-01

    Tributyltin (TBT), a well known endocrine disruptor, has high teratogenicity to embryos of amphibian (Xenopus tropicalis). An amphibian metamorphosis assay (AMA) and a complete AMA (CAMA) were conducted for TBT. In AMA, the body weight, the snout-to-vent length and the hind limb length of X. laevis tadpoles were decreased in tributyltin chloride (TBTCl; 12.5-200 ng/L) treatment groups after 7 days exposure. TBT greatly retarded the development of tadpoles, decreased the number of follicle and induced thyroid follicle cell hyperplasia after 19 days exposure. In CAMA, 10 and 100 ng/L TBTCl led to various malformations of gonad, including intersex, segmental aplasia and multiple ovary cavities of X. laevis following exposure from stages 46 to stage 66. The sex ratio was male-biased in TBT treatment groups. These results suggest that TBT delayed the metamorphosis, inhibited the growth of tadpoles and disrupted the gonadal differentiation of X. laevis at environmentally relevant concentrations.

  20. Excess iron: considerations related to development and early growth.

    PubMed

    Wessling-Resnick, Marianne

    2017-12-01

    What effects might arise from early life exposures to high iron? This review considers the specific effects of high iron on the brain, stem cells, and the process of erythropoiesis and identifies gaps in our knowledge of what molecular damage may be incurred by oxidative stress that is imparted by high iron status in early life. Specific areas to enhance research on this topic include the following: longitudinal behavioral studies of children to test associations between iron exposures and mood, emotion, cognition, and memory; animal studies to determine epigenetic changes that reprogram brain development and metabolic changes in early life that could be followed through the life course; and the establishment of human epigenetic markers of iron exposures and oxidative stress that could be monitored for early origins of adult chronic diseases. In addition, efforts to understand how iron exposure influences stem cell biology could be enhanced by establishing platforms to collect biological specimens, including umbilical cord blood and amniotic fluid, to be made available to the research community. At the molecular level, there is a need to better understand stress erythropoiesis and changes in iron metabolism during pregnancy and development, especially with respect to regulatory control under high iron conditions that might promote ineffective erythropoiesis and iron-loading anemia. These investigations should focus not only on factors such as hepcidin and erythroferrone but should also include newly identified interactions between transferrin receptor-2 and the erythropoietin receptor. Finally, despite our understanding that several key micronutrients (e.g., vitamin A, copper, manganese, and zinc) support iron's function in erythropoiesis, how these nutrients interact remains, to our knowledge, unknown. It is necessary to consider many factors when formulating recommendations on iron supplementation. © 2017 American Society for Nutrition.

  1. Regulation of bone morphogenetic proteins in early embryonic development

    NASA Astrophysics Data System (ADS)

    Yamamoto, Yukiyo; Oelgeschläger, Michael

    2004-11-01

    Bone morphogenetic proteins (BMPs), a large subgroup of the TGF-β family of secreted growth factors, control fundamental events in early embryonic development, organogenesis and adult tissue homeostasis. The plethora of dose-dependent cellular processes regulated by BMP signalling demand a tight regulation of BMP activity. Over the last decade, a number of proteins have been identified that bind BMPs in the extracellular space and regulate the interaction of BMPs with their cognate receptors, including the secreted BMP antagonist Chordin. In the early vertebrate embryo, the localized secretion of BMP antagonists from the dorsal blastopore lip establishes a functional BMP signalling gradient that is required for the determination of the dorsoventral or back to belly body axis. In particular, inhibition of BMP activity is essential for the formation of neural tissue in the development of vertebrate and invertebrate embryos. Here we review recent studies that have provided new insight into the regulation of BMP signalling in the extracellular space. In particular, we discuss the recently identified Twisted gastrulation protein that modulates, in concert with metalloproteinases of the Tolloid family, the interaction of Chordin with BMP and a family of proteins that share structural similarities with Chordin in the respective BMP binding domains. In addition, genetic and functional studies in zebrafish and frog provide compelling evidence that the secreted protein Sizzled functionally interacts with the Chd BMP pathway, despite being expressed ventrally in the early gastrula-stage embryo. These intriguing discoveries may have important implications, not only for our current concept of early embryonic patterning, but also for the regulation of BMP activity at later developmental stages and tissue homeostasis in the adult.

  2. Early somatosensory processing in individuals at risk for developing psychoses.

    PubMed

    Hagenmuller, Florence; Heekeren, Karsten; Theodoridou, Anastasia; Walitza, Susanne; Haker, Helene; Rössler, Wulf; Kawohl, Wolfram

    2014-01-01

    Human cortical somatosensory evoked potentials (SEPs) allow an accurate investigation of thalamocortical and early cortical processing. SEPs reveal a burst of superimposed early (N20) high-frequency oscillations around 600 Hz. Previous studies reported alterations of SEPs in patients with schizophrenia. This study addresses the question whether those alterations are also observable in populations at risk for developing schizophrenia or bipolar disorders. To our knowledge to date, this is the first study investigating SEPs in a population at risk for developing psychoses. Median nerve SEPs were investigated using multichannel EEG in individuals at risk for developing bipolar disorders (n = 25), individuals with high-risk status (n = 59) and ultra-high-risk status for schizophrenia (n = 73) and a gender and age-matched control group (n = 45). Strengths and latencies of low- and high-frequency components as estimated by dipole source analysis were compared between groups. Low- and high-frequency source activity was reduced in both groups at risk for schizophrenia, in comparison to the group at risk for bipolar disorders. HFO amplitudes were also significant reduced in subjects with high-risk status for schizophrenia compared to healthy controls. These differences were accentuated among cannabis non-users. Reduced N20 source strengths were related to higher positive symptom load. These results suggest that the risk for schizophrenia, in contrast to bipolar disorders, may involve an impairment of early cerebral somatosensory processing. Neurophysiologic alterations in schizophrenia precede the onset of initial psychotic episode and may serve as indicator of vulnerability for developing schizophrenia.

  3. Early somatosensory processing in individuals at risk for developing psychoses

    PubMed Central

    Hagenmuller, Florence; Heekeren, Karsten; Theodoridou, Anastasia; Walitza, Susanne; Haker, Helene; Rössler, Wulf; Kawohl, Wolfram

    2014-01-01

    Human cortical somatosensory evoked potentials (SEPs) allow an accurate investigation of thalamocortical and early cortical processing. SEPs reveal a burst of superimposed early (N20) high-frequency oscillations around 600 Hz. Previous studies reported alterations of SEPs in patients with schizophrenia. This study addresses the question whether those alterations are also observable in populations at risk for developing schizophrenia or bipolar disorders. To our knowledge to date, this is the first study investigating SEPs in a population at risk for developing psychoses. Median nerve SEPs were investigated using multichannel EEG in individuals at risk for developing bipolar disorders (n = 25), individuals with high-risk status (n = 59) and ultra-high-risk status for schizophrenia (n = 73) and a gender and age-matched control group (n = 45). Strengths and latencies of low- and high-frequency components as estimated by dipole source analysis were compared between groups. Low- and high-frequency source activity was reduced in both groups at risk for schizophrenia, in comparison to the group at risk for bipolar disorders. HFO amplitudes were also significant reduced in subjects with high-risk status for schizophrenia compared to healthy controls. These differences were accentuated among cannabis non-users. Reduced N20 source strengths were related to higher positive symptom load. These results suggest that the risk for schizophrenia, in contrast to bipolar disorders, may involve an impairment of early cerebral somatosensory processing. Neurophysiologic alterations in schizophrenia precede the onset of initial psychotic episode and may serve as indicator of vulnerability for developing schizophrenia. PMID:25309363

  4. Dual effects of fluoxetine on mouse early embryonic development.

    PubMed

    Kim, Chang-Woon; Choe, Changyong; Kim, Eun-Jin; Lee, Jae-Ik; Yoon, Sook-Young; Cho, Young-Woo; Han, Sunkyu; Tak, Hyun-Min; Han, Jaehee; Kang, Dawon

    2012-11-15

    Fluoxetine, a selective serotonin reuptake inhibitor, regulates a variety of physiological processes, such as cell proliferation and apoptosis, in mammalian cells. Little is known about the role of fluoxetine in early embryonic development. This study was undertaken to investigate the effect of fluoxetine during mouse early embryonic development. Late two-cell stage embryos (2-cells) were cultured in the presence of various concentrations of fluoxetine (1 to 50μM) for different durations. When late 2-cells were incubated with 5μM fluoxetine for 6h, the percentage that developed into blastocysts increased compared to the control value. However, late 2-cells exposed to fluoxetine (5μM) over 24h showed a reduction in blastocyst formation. The addition of fluoxetine (5μM) together with KN93 or KN62 (calcium/calmodulin-dependent protein kinase II (CaMKII) inhibitors) failed to increase blastocyst formation. Fluoxetine treatment inhibited TREK-1 and TREK-2, members of the two-pore domain K(+) channel family expressed in mouse embryos, activities, indicating that fluoxetine-induced membrane depolarization in late 2-cells might have resulted from TREK inhibition. In addition, long-term exposure to fluoxetine altered the TREK mRNA expression levels. Furthermore, injection of siRNA targeting TREKs significantly decreased blastocyst formation by ~30% compared to injection of scrambled siRNA. Long-term exposure of fluoxetine had no effect on blastocyst formation of TREK deficient embryos. These results indicate that low-dose and short-term exposures of late 2-cells to fluoxetine probably increase blastocyst formation through activation of CaMKII-dependent signal transduction pathways, whereas long-term exposure decreases mouse early embryonic development through inhibition of TREK channel gating. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. The Proteomic Signature of Aspergillus fumigatus During Early Development*

    PubMed Central

    Cagas, Steven E.; Jain, Mohit Raja; Li, Hong; Perlin, David S.

    2011-01-01

    Aspergillus fumigatus is a saprophytic fungus that causes a range of diseases in humans including invasive aspergillosis. All forms of disease begin with the inhalation of conidia, which germinate and develop. Four stages of early development were evaluated using the gel free system of isobaric tagging for relative and absolute quantitation to determine the full proteomic profile of the pathogen. A total of 461 proteins were identified at 0, 4, 8, and 16 h and fold changes for each were established. Ten proteins including the hydrophobin rodlet protein RodA and a protein involved in melanin synthesis Abr2 were found to decrease relative to conidia. To generate a more comprehensive view of early development, a whole genome microarray analysis was performed comparing conidia to 8 and 16 h of growth. A total of 1871 genes were found to change significantly at 8 h with 1001 genes up-regulated and 870 down-regulated. At 16 h, 1235 genes changed significantly with 855 up-regulated and 380 down-regulated. When a comparison between the proteomics and microarray data was performed at 8 h, a total of 22 proteins with significant changes also had corresponding genes that changed significantly. When the same comparison was performed at 16 h, 12 protein and gene combinations were found. This study, the most comprehensive to date, provides insights into early pathways activated during growth and development of A. fumigatus. It reveals a pathogen that is gearing up for rapid growth by building translation machinery, generating ATP, and is very much committed to aerobic metabolism. PMID:21825280

  6. Clinical assessment of early language development: a simplified short form of the Mandarin communicative development inventory.

    PubMed

    Soli, Sigfrid D; Zheng, Yun; Meng, Zhaoli; Li, Gang

    2012-09-01

    The purpose of this study was to develop a practical mean for clinical evaluation of early pediatric language development by establishing developmental trajectories for receptive and expressive vocabulary growth in children between 6 and 32 months of age using a simple, time-efficient assessment tool. Simplified short form versions of the Words and Gestures and Words and Sentences vocabulary inventories in the Mandarin Communicative Development Inventory [1] were developed and used to assess early language development in developmentally normal children from 6 to 32 months of age during routine health checks. Developmental trajectories characterizing the rate of receptive and expressive vocabulary growth between 6 and 32 months of age are reported. These trajectories allow the equivalent age corresponding to a score to be determined after a brief structured interview with the child's parents that can be conducted in a busy clinical setting. The simplified short forms of the Mandarin Communicative Development Inventories can serve as a clinically useful tool to assess early child language development, providing a practical mean of objectively assessing early language development following early interventions to treat young children with hearing impairment as well as speech and language delays. Objective evidence of language development is essential for achievement of effective (re)habilitation outcomes. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  7. Studies toward birth and early mammalian development in space

    NASA Astrophysics Data System (ADS)

    Ronca, April E.

    2003-10-01

    Sustaining life beyond Earth on either space stations or other planets will require a clear understanding of how the space environment affects key phases of mammalian reproduction and development. Pregnancy, parturition (birth) and the early development of offspring are complex processes essential for successful reproduction and the proliferation of mammalian species. While no mammal has yet undergone birth within the space environment, studies spanning the gravity continuum from 0- to 2-g are revealing startling insights into how reproduction and development may proceed under gravitational conditions deviating from those typically experienced on Earth. In this report, I review studies of pregnant Norway rats and their offspring flown in microgravity (μg) onboard the NASA Space Shuttle throughout the period corresponding to mid- to late gestation, and analogous studies of pregnant rats exposed to hypergravity ( ht) onboard the NASA Ames Research Center 24-ft centrifuge. Studies of postnatal rats flown in space or exposed to centrifugation are reviewed. Although many important questions remain unanswered, the available data suggest that numerous aspects of pregnancy, birth and early mammalian development can proceed under altered gravity conditions. Published by Elsevier Ltd on behalf of COSPAR.

  8. Zebrafish monosex population reveals female dominance in sex determination and earliest events of gonad differentiation.

    PubMed

    Tong, Sok-Keng; Hsu, Hwei-Jan; Chung, Bon-chu

    2010-08-15

    The zebrafish is a popular model for genetic analysis and its sex differentiation has been the focus of attention for breeding purposes. Despite numerous efforts, very little is known about the mechanism of zebrafish sex determination. The lack of discernible sex chromosomes and the difficulty of distinguishing the sex of juvenile fish are two major obstacles that hamper the progress in such studies. To alleviate these problems, we have developed a scheme involving methyltestosterone treatment followed by natural mating to generate fish with predictable sex trait. Female F1 fish that gave rise to all-female offspring were generated. This predictable sex trait enables characterization of gonadal development in juvenile fish by histological examination and gene expression analysis. We found the first sign of zebrafish sex differentiation to be ovarian gonocyte proliferation and differentiation at 10 to 12 days post-fertilization (dpf). Somatic genes were expressed indifferently at 10 to 17 dpf, and then became sexually dimorphic at three weeks. This result indicates clear distinction of male and female gonads derived independently from primordial gonads. We classified the earliest stages of zebrafish sex determination into the initial preparation followed by female germ cell growth, oocyte differentiation, and somatic differentiation. Our genetic selection scheme matches the prediction that female-dominant genetic factors are required to determine zebrafish sex. Copyright 2010 Elsevier Inc. All rights reserved.

  9. Retinoic Acid Metabolic Genes, Meiosis, and Gonadal Sex Differentiation in Zebrafish

    PubMed Central

    Rodríguez-Marí, Adriana; Cañestro, Cristian; BreMiller, Ruth A.; Catchen, Julian M.; Yan, Yi-Lin; Postlethwait, John H.

    2013-01-01

    To help understand the elusive mechanisms of zebrafish sex determination, we studied the genetic machinery regulating production and breakdown of retinoic acid (RA) during the onset of meiosis in gonadogenesis. Results uncovered unexpected mechanistic differences between zebrafish and mammals. Conserved synteny and expression analyses revealed that cyp26a1 in zebrafish and its paralog Cyp26b1 in tetrapods independently became the primary genes encoding enzymes available for gonadal RA-degradation, showing lineage-specific subfunctionalization of vertebrate genome duplication (VGD) paralogs. Experiments showed that zebrafish express aldh1a2, which encodes an RA-synthesizing enzyme, in the gonad rather than in the mesonephros as in mouse. Germ cells in bipotential gonads of all zebrafish analyzed were labeled by the early meiotic marker sycp3, suggesting that in zebrafish, the onset of meiosis is not sexually dimorphic as it is in mouse and is independent of Stra8, which is required in mouse but was lost in teleosts. Analysis of dead-end knockdown zebrafish depleted of germ cells revealed the germ cell-independent onset and maintenance of gonadal aldh1a2 and cyp26a1 expression. After meiosis initiated, somatic cell expression of cyp26a1 became sexually dimorphic: up-regulated in testes but not ovaries. Meiotic germ cells expressing the synaptonemal complex gene sycp3 occupied islands of somatic cells that lacked cyp26a1 expression, as predicted by the hypothesis that Cyp26a1 acts as a meiosis-inhibiting factor. Consistent with this hypothesis, females up-regulated cyp26a1 in oocytes that entered prophase-I meiotic arrest, and down-regulated cyp26a1 in oocytes resuming meiosis. Co-expression of cyp26a1 and the pluripotent germ cell stem cell marker pou5f1(oct4) in meiotically arrested oocytes was consistent with roles in mouse to promote germ cell survival and to prevent apoptosis, mechanisms that are central for tipping the sexual fate of gonads towards the female

  10. Toward an Integrated View of Early Language and Communication Development and Socioemotional Development.

    ERIC Educational Resources Information Center

    Prizant, Barry M.; Wetherby, Amy M.

    1990-01-01

    The article reviews literature on the integrated nature of early communication and socioemotional development in children. It discusses two models, one addressing the role of the development of mutual (interactive) and self-regulatory capacities in young children's socioemotional development, and a transactional model conceptualizing the complex…

  11. Disruption of apoptosis pathways involved in zebrafish gonad differentiation by 17α-ethinylestradiol and fadrozole exposures.

    PubMed

    Luzio, Ana; Matos, Manuela; Santos, Dércia; Fontaínhas-Fernandes, António A; Monteiro, Sandra M; Coimbra, Ana M

    2016-08-01

    Zebrafish (Danio rerio) sex determination seems to involve genetic factors (GSD) but also environmental factors (ESD), such as endocrine disrupting chemicals (EDCs) that are known to mimic endogenous hormones and disrupt gonad differentiation. Apoptosis has also been proposed to play a crucial role in zebrafish gonad differentiation. Nevertheless, the interactions between EDCs and apoptosis have received little attention. Thus, this study aimed to assess if and which apoptotic pathways are involved in zebrafish gonad differentiation and how EDCs may interfere with this process. With these purposes, zebrafish were exposed to 17α-ethinylestradiol (EE2, 4ng/L) and fadrozole (Fad, 50μg/L) from 2h to 35days post-fertilization (dpf). Afterwards, a gene expression analysis by qRT-PCR and a stereological analysis, based on systematic sampling and protein immunohistochemistry, were performed. The death receptors (FAS; TRADD), anti-apoptotic (BCL-2; MDM2), pro-apoptotic (CASP-2 and -6) and cell proliferation (BIRC5/survivin; JUN) genes and proteins were evaluated. In general, apoptosis was inhibited in females through the involvement of anti-apoptotic pathways, while in males apoptosis seemed to be crucial to the failure of the "juvenile ovary" development and the induction of testes transformation. The JUN protein was shown to be necessary in juvenile ovaries, while the BIRC5 protein seemed to be involved in zebrafish spermatogenesis. Both EDCs, EE2 and Fad, increased the apoptosis stimulus in zebrafish gonad. It was noticed that the few females that were resistant to Fad-induced sex reversal had increased anti-apoptotic factor levels, while males exposed to EE2 showed increased pro-apoptotic genes/proteins and were more advanced in gonad differentiation. Overall, our findings show that apoptosis pathways are involved in zebrafish gonad differentiation and that EDCs can disrupt this process. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Chaos, Poverty, and Parenting: Predictors of Early Language Development

    PubMed Central

    Vernon-Feagans, Lynne; Garrett-Peters, Patricia; Willoughby, Mike; Mills-Koonce, Roger

    2011-01-01

    Studies have shown that distal family risk factors like poverty and maternal education are strongly related to children's early language development. Yet, few studies have examined these risk factors in combination with more proximal day-to-day experiences of children that might be critical to understanding variation in early language. Young children's exposure to a chronically chaotic household may be one critical experience that is related to poorer language, beyond the contribution of SES and other demographic variables. In addition, it is not clear whether parenting might mediate the relationship between chaos and language. The purpose of this study was to understand how multiple indicators of chaos over children's first three years of life, in a representative sample of children living in low wealth rural communities, were related to child expressive and receptive language at 36 months. Factor analysis of 10 chaos indicators over five time periods suggested two factors that were named household disorganization and instability. Results suggested that after accounting for thirteen covariates like maternal education and poverty, one of two chaos composites (household disorganization) accounted for significant variance in receptive and expressive language. Parenting partially mediated this relationship although household disorganization continued to account for unique variance in predicting early language. PMID:23049162

  13. Macrosomia has its roots in early placental development

    PubMed Central

    Schwartz, Nadav; Quant, Hayley S.; Sammel, Mary D.; PARRY, Samuel

    2014-01-01

    Introduction We sought to determine if early placental size, as measured by 3-dimensional ultrasonography, is associated with an increased risk of delivering a macrosomic or large-for-gestational age (LGA) infant. Methods We prospectively collected 3-dimensional ultrasound volume sets of singleton pregnancies at 11–14 weeks and 18–24 weeks. Birth weights were collected from the medical records. After delivery, the ultrasound volume set were used to measure the placental volume (PV) and placental quotient (PQ=PV/gestational age), as well as the mean placental and chorionic diameters (MPD and MCD, respectively). Placental measures were analyzed as predictors of macrosomia (birth weight ≥4000 grams) and LGA (birth weight ≥90th percentile). Results The 578 pregnancies with first trimester volumes included 44 (7.6%) macrosomic and 43 (7.4%) LGA infants. 373 subjects also had second trimester volumes available. A higher PV and PQ were both significantly associated with macrosomia and LGA in both the first and second trimesters. Second trimester MPD was significantly associated with both outcomes as well, while second trimester MCD was only associated with LGA. The above associations remained significant after adjusting for maternal demographic variables such as race, ethnicity, age and diabetes. Adjusted models yielded moderate prediction of macrosomia and LGA (AUC: 0.71–0.77). Conclusions Sonographic measurement of the early placenta can identify pregnancies at greater risk of macrosomia and LGA. Macrosomia and LGA are already determined in part by early placental growth and development. PMID:25064071

  14. Fathers’ Sensitive Parenting and the Development of Early Executive Functioning

    PubMed Central

    Towe-Goodman, Nissa R.; Willoughby, Michael; Blair, Clancy; Gustafsson, Hanna C.; Mills-Koonce, W. Roger; Cox, Martha J.

    2014-01-01

    Using data from a diverse sample of 620 families residing in rural, predominately low-income communities, this study examined longitudinal links between fathers’ sensitive parenting in infancy and toddlerhood and children’s early executive functioning, as well as the contribution of maternal sensitive parenting. After accounting for the quality of concurrent and prior parental care, children’s early cognitive ability, and other child and family factors, fathers’ and mothers’ sensitive and supportive parenting during play at 24-months predicted children’s executive functioning at 3-years of age. In contrast, paternal parenting quality during play at 7-months did not make an independent contribution above that of maternal care, but the links between maternal sensitive and supportive parenting and executive functioning seemed to operate in similar ways during infancy and toddlerhood. These findings add to prior work on early experience and children’s executive functioning, suggesting that both fathers and mothers play a distinct and complementary role in the development of these self-regulatory skills. PMID:25347539

  15. Gonad Transcriptome Analysis of the Pacific Oyster Crassostrea gigas Identifies Potential Genes Regulating the Sex Determination and Differentiation Process.

    PubMed

    Yue, Chenyang; Li, Qi; Yu, Hong

    2018-04-01

    The Pacific oyster Crassostrea gigas is a commercially important bivalve in aquaculture worldwide. C. gigas has a fascinating sexual reproduction system consisting of dioecism, sex change, and occasional hermaphroditism, while knowledge of the molecular mechanisms of sex determination and differentiation is still limited. In this study, the transcriptomes of male and female gonads at different gametogenesis stages were characterized by RNA-seq. Hierarchical clustering based on genes differentially expressed revealed that 1269 genes were expressed specifically in female gonads and 817 genes were expressed increasingly over the course of spermatogenesis. Besides, we identified two and one gene modules related to female and male gonad development, respectively, using weighted gene correlation network analysis (WGCNA). Interestingly, GO and KEGG enrichment analysis showed that neurotransmitter-related terms were significantly enriched in genes related to ovary development, suggesting that the neurotransmitters were likely to regulate female sex differentiation. In addition, two hub genes related to testis development, lncRNA LOC105321313 and Cg-Sh3kbp1, and one hub gene related to ovary development, Cg-Malrd1-like, were firstly investigated. This study points out the role of neurotransmitter and non-coding RNA regulation during gonad development and produces lists of novel relevant candidate genes for further studies. All of these provided valuable information to understand the molecular mechanisms of C. gigas sex determination and differentiation.

  16. Regional early development and eruption of permanent teeth: case report.

    PubMed

    Al Mullahi, A M; Bakathir, A; Al Jahdhami, S

    2017-02-01

    Early development and eruption of permanent teeth are rarely reported in scientific literature. Early eruption of permanent teeth has been reported to occur due to local factors such as trauma or dental abscesses in primary teeth, and in systemic conditions. Congenital diffuse infiltrating facial lipomatosis (CDIFL) is a rare condition that belongs to a group of lipomatosis tumours. In this disorder, the mature adipocytes invade adjacent soft and hard tissues in the facial region. Accelerated tooth eruption is one of the dental anomalies associated with CDIFL. A 3-year-old boy presented with a swelling of the lower lip localised early development and eruption of permanent teeth and dental caries involving many primary teeth. The planned treatment included biopsy of the swollen lower lip to confirm the diagnosis, surgical reduction and reconstruction of lip aesthetics. The management of the carious primary teeth included preventative and comprehensive dental care and extractions. These procedures were completed under general anaesthesia due to the child's young age and poor cooperation. The lip biopsy showed features of CDIFL such as the presence of infiltrating adipose tissue, prominent number of nerve bundles and thickened vessels. The high recurrence rate of CDIFL mandates long-term monitoring during the facial growth period of the child. Follow-up care by the paediatric dentist and maxillofacial surgeon has been required to manage all aspects of this congenital malformation. This rare disorder has many implications affecting child's facial aesthetics, psychological well being, developing occlusion and risk of dental caries. A multi-disciplinary approach is needed for management of this condition.

  17. Environmental estrogens alter early development in Xenopus laevis.

    PubMed

    Bevan, Cassandra L; Porter, Donna M; Prasad, Anita; Howard, Marthe J; Henderson, Leslie P

    2003-04-01

    A growing number of environmental toxicants found in pesticides, herbicides, and industrial solvents are believed to have deleterious effects on development by disrupting hormone-sensitive processes. We exposed Xenopus laevis embryos at early gastrula to the commonly encountered environmental estrogens nonylphenol, octylphenol, and methoxychlor, the antiandrogen, p,p-DDE, or the synthetic androgen, 17 alpha-methyltestosterone at concentrations ranging from 10 nM to 10 microM and examined them at tailbud stages (approximately 48 hr of treatment). Exposure to the three environmental estrogens, as well as to the natural estrogen 17 beta-estradiol, increased mortality, induced morphologic deformations, increased apoptosis, and altered the deposition and differentiation of neural crest-derived melanocytes in tailbud stage embryos. Although neural crest-derived melanocytes were markedly altered in embryos treated with estrogenic toxicants, expression of the early neural crest maker Xslug, a factor that regulates both the induction and subsequent migration of neural crest cells, was not affected, suggesting that the disruption induced by these compounds with respect to melanocyte development may occur at later stages of their differentiation. Co-incubation of embryos with the pure antiestrogen ICI 182,780 blocked the ability of nonylphenol to induce abnormalities in body shape and in melanocyte differentiation but did not block the effects of methoxychlor. Our data indicate not only that acute exposure to these environmental estrogens induces deleterious effects on early vertebrate development but also that different environmental estrogens may alter the fate of a specific cell type via different mechanisms. Finally, our data suggest that the differentiation of neural crest-derived melanocytes may be particularly sensitive to the disruptive actions of these ubiquitous chemical contaminants.

  18. Development of a GNSS-Enhanced Tsunami Early Warning System

    NASA Astrophysics Data System (ADS)

    Bawden, G. W.; Melbourne, T. I.; Bock, Y.; Song, Y. T.; Komjathy, A.

    2015-12-01

    The past decade has witnessed a terrible loss of life and economic disruption caused by large earthquakes and resultant tsunamis impacting coastal communities and infrastructure across the Indo-Pacific region. NASA has funded the early development of a prototype real-time Global Navigation Satellite System (RT-GNSS) based rapid earthquake and tsunami early warning (GNSS-TEW) system that may be used to enhance seismic tsunami early warning systems for large earthquakes. This prototype GNSS-TEW system geodetically estimates fault parameters (earthquake magnitude, location, strike, dip, and slip magnitude/direction on a gridded fault plane both along strike and at depth) and tsunami source parameters (seafloor displacement, tsunami energy scale, and 3D tsunami initials) within minutes after the mainshock based on dynamic numerical inversions/regressions of the real-time measured displacements within a spatially distributed real-time GNSS network(s) spanning the epicentral region. It is also possible to measure fluctuations in the ionosphere's total electron content (TEC) in the RT-GNSS data caused by the pressure wave from the tsunami. This TEC approach can detect if a tsunami has been triggered by an earthquake, track its waves as they propagate through the oceanic basins, and provide upwards of 45 minutes early warning. These combined real-time geodetic approaches will very quickly address a number of important questions in the immediate minutes following a major earthquake: How big was the earthquake and what are its fault parameters? Could the earthquake have produced a tsunami and was a tsunami generated?

  19. Gross motor development is delayed following early cardiac surgery.

    PubMed

    Long, Suzanne H; Harris, Susan R; Eldridge, Beverley J; Galea, Mary P

    2012-10-01

    To describe the gross motor development of infants who had undergone cardiac surgery in the neonatal or early infant period. Gross motor performance was assessed when infants were 4, 8, 12, and 16 months of age with the Alberta Infant Motor Scale. This scale is a discriminative gross motor outcome measure that may be used to assess infants from birth to independent walking. Infants were videotaped during the assessment and were later evaluated by a senior paediatric physiotherapist who was blinded to each infant's medical history, including previous clinical assessments. Demographic, diagnostic, surgical, critical care, and medical variables were considered with respect to gross motor outcomes. A total of 50 infants who underwent elective or emergency cardiac surgery at less than or up to 8 weeks of age, between July 2006 and January 2008, were recruited to this study and were assessed at 4 months of age. Approximately, 92%, 84%, and 94% of study participants returned for assessment at 8, 12, and 16 months of age, respectively. Study participants had delayed gross motor development across all study time points; 62% of study participants did not have typical gross motor development during the first year of life. Hospital length of stay was associated with gross motor outcome across infancy. Active gross motor surveillance of all infants undergoing early cardiac surgery is recommended. Further studies of larger congenital heart disease samples are required, as are longitudinal studies that determine the significance of these findings at school age and beyond.

  20. Early anther ablation triggers parthenocarpic fruit development in tomato.

    PubMed

    Medina, Mónica; Roque, Edelín; Pineda, Benito; Cañas, Luis; Rodriguez-Concepción, Manuel; Beltrán, José Pío; Gómez-Mena, Concepción

    2013-08-01

    Fruit set and fruit development in tomato is largely affected by changes in environmental conditions, therefore autonomous fruit set independent of fertilization is a highly desirable trait in tomato. Here, we report the production and characterization of male-sterile transgenic plants that produce parthenocarpic fruits in two tomato cultivars (Micro-Tom and Moneymaker). We generated male-sterility using the cytotoxic gene barnase targeted to the anthers with the PsEND1 anther-specific promoter. The ovaries of these plants grew in the absence of fertilization producing seedless, parthenocarpic fruits. Early anther ablation is essential to trigger the developing of the transgenic ovaries into fruits, in the absence of the signals usually generated during pollination and fertilization. Ovaries are fully functional and can be manually pollinated to obtain seeds. The transgenic plants obtained in the commercial cultivar Moneymaker show that the parthenocarpic development of the fruit does not have negative consequences in fruit quality. Throughout metabolomic analyses of the tomato fruits, we have identified two elite lines which showed increased levels of several health promoting metabolites and volatile compounds. Thus, early anther ablation can be considered a useful tool to promote fruit set and to obtain seedless and good quality fruits in tomato plants. These plants are also useful parental lines to be used in hybrid breeding approaches. © 2013 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  1. Early Numeracy Assessment: The Development of the Preschool Numeracy Scales

    PubMed Central

    Purpura, David J.; Lonigan, Christopher J.

    2015-01-01

    Research Findings The focus of this study was to construct and validate twelve brief early numeracy assessment tasks that measure the skills and concepts identified as key to early mathematics development by the National Council of Teachers of Mathematics (2006) and the National Mathematics Advisory Panel (2008)—as well as critical developmental precursors to later mathematics skill by the Common Core State Standards (CCSS; 2010). Participants were 393 preschool children ages 3 to 5 years old. Measure development and validation occurred through three analytic phases designed to ensure that the measures were brief, reliable, and valid. These measures included: one-to-one counting, cardinality, counting subsets, subitizing, number comparison, set comparison, number order, numeral identification, set-to-numerals, story problems, number combinations, and verbal counting. Practice or Policy Teachers have extensive demands on their time, yet, they are tasked with ensuring that all students’ academic needs are met. To identify individual instructional needs and measure progress, they need to be able to efficiently assess children’s numeracy skills. The measures developed in this study are not only reliable and valid, but also easy to use and can be utilized for measuring the effects of targeted instruction on individual numeracy skills. PMID:25709375

  2. APECS: A Network for Polar Early Career Scientist Professional Development

    NASA Astrophysics Data System (ADS)

    Enderlin, E. M.

    2014-12-01

    The Association of Polar Early Career Researchers (APECS) is an international and interdisciplinary organization for undergraduate and graduate students, postdoctoral researchers, early faculty members, educators and others with interests in the polar regions, alpine regions and the wider Cryosphere. APECS is a scientific, non-profit organization with free individual membership that aims to stimulate research collaborations and develop effective future leaders in polar research, education, and outreach. APECS grew out of the 4th International Polar Year (2007-08), which emphasized the need to stimulate and nurture the next generation of scientists in order to improve the understanding and communication of the polar regions and its global connections. The APECS organizational structure includes a Council and an elected Executive Committee that are supported by a Directorate. These positions are open to all individual members through a democratic process. The APECS Directorate is funded by the Norwegian Research Council, the University of Tromsø and the Norwegian Polar Institute and is hosted by the University of Tromsø. Early career scientists benefit from a range of activities hosted/organized by APECS. Every year, numerous activities are run with partner organizations and in conjunction with major polar conferences and meetings. In-person and online panels and workshops focus on a range of topics, from developing field skills to applying for a job after graduate school. Career development webinars are hosted each fall and topical research webinars are hosted throughout the year and archived online (http://www.apecs.is). The APECS website also contains abundant information on polar news, upcoming conferences and meetings, and job postings for early career scientists. To better respond to members' needs, APECS has national/regional committees that are linked to the international overarching organization. Many of these committees organize regional meetings or

  3. Expression profile analysis of aorta-gonad-mesonephros region-derived stromal cells reveals genes that regulate hematopoiesis

    SciTech Connect

    Nagao, Kenji; Ohta, Takayuki; Hinohara, Atsushi

    The aorta-gonad-mesonephros (AGM) region is involved in the generation and maintenance of the first definitive hematopoietic stem cells (HSCs). A mouse AGM-derived cell line, AGM-S3, was shown to support the development of HSCs. To elucidate the molecular mechanisms regulating early hematopoiesis, we obtained subclones from AGM-S3, one of which was hematopoiesis supportive (S3-A9) and the other one of which was non-supportive (S3-A7), and we analyzed their gene expression profiles by gene chip analysis. In the present study, we found that Glypican-1 (GPC1) was highly expressed in the supportive subclone AGM-S3-A9. Over-expression of GPC1 in non-supportive cells led to the proliferationmore » of progenitor cells in human cord blood when cocultured with the transfected-stromal cells. Thus, GPC1 may have an important role in the establishment of a microenvironment that supports early events in hematopoiesis.« less

  4. [Gonad protective effect of radiation protective apron in chest radiography].

    PubMed

    Hashimoto, Masatoshi; Kato, Hideyuki; Fujibuchi, Toshiou; Ochi, Shigehiro; Morita, Fuminori

    2004-12-01

    Depending on the facility, a radiation protective apron (protector) is used to protect the gonad from radiation exposure in chest radiography. To determine the necessity of using a protector during chest radiography, we measured the effect of the protector on the gonad in this study. First, using a human body phantom, we measured the absorbed dose of the female gonad with and without the protector, using a thermoluminescence dosimeter (TLD), and confirmed its protective effect. Using the protector, the absorbed dose was reduced to 28+/-2% and 39+/-4% for field sizes of 14 x 17 inch and 14 x 14 inch, respectively. Next, we used Monte Carlo simulation and confirmed, not only the validity of the actual measurement values, but also the fact that the influence of radiation on the absorbed dose of the gonad was mostly from scattered radiation from inside the body for the 14 x 17 inch field size, and also from the X-ray tube for the 14 x 14 inch field size. Although a certain protective effect is achieved by using the protector, the radiation dose to the gonad is only a few microGy even without a protector. Thus, the risk of a genetic effect would be as small as 10(-8). Given that acceptable risk is below 10(-6), we conclude the use of a radiation protective apron is not necessary for diagnostic chest radiography.

  5. Relationship between gonad maturation and heavy metal accumulation in the clam, Galatea paradoxa (Born 1778) from the Volta estuary, Ghana.

    PubMed

    Adjei-Boateng, D; Obirikorang, K A; Amisah, S; Madkour, H A; Otchere, F A

    2011-12-01

    The relationship between gonadal development and the concentrations of four heavy metals Mn, Zn, Fe and Hg in the tissues of the clam Galatea paradoxa was evaluated at the Volta estuary, Ghana, over an 18-month period. Metal concentrations in the clam tissues were highly variable over the sampling period and seemed to be influenced by the reproductive cycle of the clam. Mn concentrations varied over a wide range from 49 to 867 μg/g and exhibited a significant positive correlation with gonadal development (p = 0.0146, r(2) = 0.3190). Zn and Fe concentrations ranged from 13 to 59 μg/g and 79 to 484 μg/g, respectively and both revealed negative relationships between gonad development and metal accumulation (Zn (p = 0.0554, r(2) = 0.0554) and Fe (p = 0.1040, r(2) = 0.1567)). Hg concentrations ranged from 0.026 to 0.059 μg/g over the sampling period and exhibited a slight positive relationship between gonadal development and metal accumulation (p = 0.0861, r(2) = 0.1730).

  6. Gonadal sex differentiation and effects of dietary methyltestosterone treatment in sablefish (Anoplopoma fimbria).

    PubMed

    Luckenbach, J Adam; Fairgrieve, William T

    2016-02-01

    Methods for sex control are needed to establish monosex aquaculture of sablefish (Anoplopoma fimbria). Here we conducted the first characterization of sex differentiation by histology and hormonal sex reversal experiment in sablefish. Ovarian differentiation was first discernible at ~80 mm fork length (FL) and characterized by development of lamellar structures and onset of meiosis. Testes exhibited a dual-lobe appearance over much of their length and remained non-meiotic until males were ≥520 mm FL (2 years post-fertilization). Juveniles with undifferentiated gonads were provided diets containing 0 (control), 5 or 50 mg 17α-methyltestosterone (MT)/kg for 2 months. Following treatment, controls possessed either ovaries or non-meiotic testes, whereas MT-treated fish exhibited meiotic testes (60% of the fish), intersex gonads (~30%), or gonads that appeared sterile (~10%). A genetic sex marker revealed that all intersex fish were genetic females, although other females appeared to be completely sex reversed (i.e., neomales). One year after treatment, MT-treated fish possessed non-meiotic testes similar to control males or intersex gonads with reduced ovarian features, presumably due to atresia following MT withdrawal. Milt collected from neomales and genetic males 3 years post-treatment permitted sperm motility analyses; however, neomale sperm were virtually immotile. These results demonstrated that sablefish are differentiated gonochorists and that MT treatment from 76 to 196 mm FL induced permanent masculinization of a portion of the genetic females, but acquisition of sperm motility was impaired. Earlier administration of MT may be necessary to sex reverse a higher proportion of genetic females and reduce negative effects on fertility.

  7. Neural, not gonadal, origin of brain sex differences in a gynandromorphic finch.

    PubMed

    Agate, Robert J; Grisham, William; Wade, Juli; Mann, Suzanne; Wingfield, John; Schanen, Carolyn; Palotie, Aarno; Arnold, Arthur P

    2003-04-15

    In mammals and birds, sex differences in brain function and disease are thought to derive exclusively from sex differences in gonadal hormone secretions. For example, testosterone in male mammals acts during fetal and neonatal life to cause masculine neural development. However, male and female brain cells also differ in genetic sex; thus, sex chromosome genes acting within cells could contribute to sex differences in cell function. We analyzed the sexual phenotype of the brain of a rare gynandromorphic finch in which the right half of the brain was genetically male and the left half genetically female. The neural song circuit on the right had a more masculine phenotype than that on the left. Because both halves of the brain were exposed to a common gonadal hormone environment, the lateral differences indicate that the genetic sex of brain cells contributes to the process of sexual differentiation. Because both sides of the song circuit were more masculine than that of females, diffusible factors such as hormones of gonadal or neural origin also likely played a role in sexual differentiation.

  8. Medical students' professional identity development in an early nursing attachment.

    PubMed

    Helmich, Esther; Derksen, Els; Prevoo, Mathieu; Laan, Roland; Bolhuis, Sanneke; Koopmans, Raymond

    2010-07-01

    The importance of early clinical experience for medical training is well documented. However, to our knowledge there are no studies that assess the influence of very early nursing attachments on the professional development and identity construction of medical students. Working as an assistant nurse while training to be a doctor may offer valuable learning experiences, but may also present the student with difficulties with respect to identity and identification issues. The aim of the present study was to describe first-year medical students' perceptions of nurses, doctors and their own future roles as doctors before and after a nursing attachment. A questionnaire containing open questions concerning students' perceptions of nurses, doctors and their own future roles as doctors was administered to all Year 1 medical students (n=347) before and directly after a 4-week nursing attachment in hospitals and nursing homes. We carried out two confirmatory focus group interviews. We analysed the data using qualitative and quantitative content analyses. The questionnaire was completed by 316 students (response rate 91%). Before starting the attachment students regarded nurses as empathic, communicative and responsible. After the attachment students reported nurses had more competencies and responsibilities than they had expected. Students' views of doctors were ambivalent. Before and after the attachment, doctors were seen as interested and reliable, but also as arrogant, detached and insensible. However, students maintained positive views of their own future roles as doctors. Students' perceptions were influenced by age, gender and place of attachment. An early nursing attachment engenders more respect for the nursing profession. The ambivalent view of doctors needs to be explored further in relation to students' professional development. It would seem relevant to attune supervision to the age and gender differences revealed in this study.

  9. Early Childhood Development and Iranian Parents' Knowledge: A Qualitative Study.

    PubMed

    Habibi, Elham; Sajedi, Firouzeh; Afzali, Hosein Malek; Hatamizadeh, Nikta; Shahshahanipour, Soheila; Glascoe, Frances Page

    2017-01-01

    Early childhood is the most important step throughout the lifespan and it is a critical period continuing to the end of 8-year-old. Mothers' knowledge is one of the important aspects of child development. The goals of this study were to determine the situation of knowledge in Iranian parents about the concept and the importance of early childhood development (ECD) and determining the sources of parental knowledge about ECD from the perspective of parents and grandparents. This qualitative study was conducted based on the directional content analysis in 2016. The purposive sampling method is utilized to select 24 participants among parents and grandparents in Tehran. The inclusion criteria consisted of speaking in Persian and having a child or grandchild <3-year-old. Data were collected through four focus group discussions and four individual interviews. Iranian parental knowledge about integrative ECD is not enough, their knowledge about motor development and speech and language are relatively better, about cognitive development is little and socialemotional is very little. They said parents and other caregivers influence the process of children's development. Parents' knowledge resources about ECD included human resources, physical resources, virtual space, and the media. According to the majority of participants, "pediatricians are the most reliable source of parents' knowledge about ECD" even though the main focus of pediatricians is on treating diseases, physical health, and growth of children. According to the results, the knowledge of Iranian parent is not enough about ECD; therefore, actions must be taken to increase their knowledge in these domains. Parents look for reliable and valid sources to enhance their knowledge and they rely the most on pediatricians in this regard. Therefore, more studies on assessing parents' knowledge in community and the practical methods for knowledge promotion in this field is recommended.

  10. Early-stage aeolian protodune development and migration

    NASA Astrophysics Data System (ADS)

    Nield, J. M.; Baddock, M. C.; Wiggs, G.

    2017-12-01

    Early-stage bedforms, or protodunes, can be observed to form on sandy beaches, desert gravels or superimposed on the surfaces of larger dunes and can develop topography of 0.1 m or more over several hours. These protodunes are the precursors to embryo and eventually mature dunes, and so it is important to understand how feedbacks between flow, transport and form contribute to this development sequence. Whilst theory and conceptual models have offered some explanation for protodune existence and development, we know surprisingly little about how these bedforms initiate and migrate because it is difficult to measure small changes in form (millimetres; seconds) on highly active surfaces of limited topographic expression. Here, we employ terrestrial laser scanning (TLS) to measure morphological change at the high frequency and spatial resolution (sub-millimetre) required to gain new insights into protodune behaviour. Along with TLS derived saltation and surface moisture, additional sediment flux and windspeed measurements help to elucidate how the protodune topography interacts with airflow and sand transport. We focus on a number of coastal bedforms in various development stages including a 0.06 m high protodune which grew vertically by 0.005 m in two hours with the switch from erosion to deposition identified to occur at a point 0.07 m upwind of the crest. This growth was associated with a reduction in time-averaged sediment flux of 18% over the crestal region. We also observed a decline in lower stoss slope steepness (by 3°) and a steepening of the lee slope, indicating a reshaping of initial protodune form towards the morphology of a more mature dune. Our findings highlight the crucial role of form-flow feedbacks, even on very small bedforms, in driving early-stage bedform growth and development, and show how the use of high resolution TLS to measure both surface topography and grains moving above the surface, can offer new insights into a long standing deficiency

  11. Determinants of early child development in rural Tanzania.

    PubMed

    Ribe, Ingeborg G; Svensen, Erling; Lyngmo, Britt A; Mduma, Estomih; Hinderaker, Sven G

    2018-01-01

    It has been estimated that more than 200 million children under the age of five do not reach their full potential in cognitive development. Much of what we know about brain development is based on research from high-income countries. There is limited evidence on the determinants of early child development in low-income countries, especially rural sub-Saharan Africa. The present study aimed to identify the determinants of cognitive development in children living in villages surrounding Haydom, a rural area in north-central Tanzania. This cohort study is part of the MAL-ED (The Interactions of Malnutrition & Enteric Infections: Consequences for Child Health and Development) multi-country consortium studying risk factors for ill health and poor development in children. Descriptive analysis and linear regression analyses were performed. Associations between nutritional status, socio-economic status, and home environment at 6 months of age and cognitive outcomes at 15 months of age were studied. The third edition of the Bayley Scales for Infant and Toddler Development was used to assess cognitive, language and motor development. There were 262 children enrolled into the study, and this present analysis included the 137 children with data for 15-month Bayley scores. Univariate regression analysis, weight-for-age and weight-for-length z-scores at 6 months were significantly associated with 15-month Bayley gross motor score, but not with other 15-month Bayley scores. Length-for-age z-scores at 6 months were not significantly associated with 15-month Bayley scores. The socio-economic status, measured by a set of assets and monthly income was significantly associated with 15-month Bayley cognitive score, but not with language, motor, nor total 15-month Bayley scores. Other socio-economic variables were not significantly associated with 15-month Bayley scores. No significant associations were found between the home environment and 15-month Bayley scores. In multivariate

  12. Downregulation of ribosome biogenesis during early forebrain development

    PubMed Central

    Chau, Kevin F; Shannon, Morgan L; Fame, Ryann M; Fonseca, Erin; Mullan, Hillary; Johnson, Matthew B; Sendamarai, Anoop K; Springel, Mark W; Laurent, Benoit

    2018-01-01

    Forebrain precursor cells are dynamic during early brain development, yet the underlying molecular changes remain elusive. We observed major differences in transcriptional signatures of precursor cells from mouse forebrain at embryonic days E8.5 vs. E10.5 (before vs. after neural tube closure). Genes encoding protein biosynthetic machinery were strongly downregulated at E10.5. This was matched by decreases in ribosome biogenesis and protein synthesis, together with age-related changes in proteomic content of the adjacent fluids. Notably, c-MYC expression and mTOR pathway signaling were also decreased at E10.5, providing potential drivers for the effects on ribosome biogenesis and protein synthesis. Interference with c-MYC at E8.5 prematurely decreased ribosome biogenesis, while persistent c-MYC expression in cortical progenitors increased transcription of protein biosynthetic machinery and enhanced ribosome biogenesis, as well as enhanced progenitor proliferation leading to subsequent macrocephaly. These findings indicate large, coordinated changes in molecular machinery of forebrain precursors during early brain development. PMID:29745900

  13. Early Development of the Gut Microbiota and Immune Health

    PubMed Central

    Francino, M. Pilar

    2014-01-01

    In recent years, the increase in human microbiome research brought about by the rapidly evolving “omic” technologies has established that the balance among the microbial groups present in the human gut, and their multipronged interactions with the host, are crucial for health. On the other hand, epidemiological and experimental support has also grown for the ‘early programming hypothesis’, according to which factors that act in utero and early in life program the risks for adverse health outcomes later on. The microbiota of the gut develops during infancy, in close interaction with immune development, and with extensive variability across individuals. It follows that the specific process of gut colonization and the microbe-host interactions established in an individual during this period have the potential to represent main determinants of life-long propensity to immune disease. Although much remains to be learnt on the progression of events by which the gut microbiota becomes established and initiates its intimate relationships with the host, and on the long-term repercussions of this process, recent works have advanced significatively in this direction. PMID:25438024

  14. Elevated aminopeptidase N affects sperm motility and early embryo development

    PubMed Central

    Ryu, Do-Yeal; Kwon, Woo-Sung

    2017-01-01

    Aminopeptidase N (APN) is a naturally occurring ectopeptidase present in mammalian semen. Previous studies have demonstrated that APN adversely affects male fertility through the alteration of sperm motility. This enzyme constitutes 0.5 to 1% of the seminal plasma proteins, which can be transferred from the prostasomes to sperms by a fusion process. In the present study, we investigated the molecular mechanism of action of APN and its role in regulating sperm functions and male fertility. In this in vitro study, epididymal mouse spermatozoa were incubated in a capacitating media (pH 7) containing 20 ng/mL of recombinant mouse APN for 90 min. Our results demonstrated that the supplementation of recombinant APN in sperm culture medium significantly increased APN activity, and subsequently altered motility, hyperactivated motility, rapid and medium swimming speeds, viability, and the acrosome reaction of mouse spermatozoa. These effects were potentially caused by increased toxicity in the spermatozoa. Further, altered APN activity in sperm culture medium affected early embryonic development. Interestingly, the effect of elevated APN activity in sperm culture medium was independent of protein tyrosine phosphorylation and protein kinase A activity. On the basis of these results, we concluded that APN plays a significant role in the regulation of several sperm functions and early embryonic development. In addition, increased APN activity could potentially lead to several adverse consequences related to male fertility. PMID:28859152

  15. Dihydroartemisinin promotes angiogenesis during the early embryonic development of zebrafish

    PubMed Central

    Ba, Qian; Duan, Juan; Tian, Jia-qiang; Wang, Zi-liang; Chen, Tao; Li, Xiao-guang; Chen, Pei-zhan; Wu, Song-jie; Xiang, Li; Li, Jing-quan; Chu, Rui-ai; Wang, Hui

    2013-01-01

    Aim: To investigate the embryotoxicity of dihydroartemisinin (DHA), the main active metabolite of artemisinin, in zebrafish, and explore the corresponding mechanisms. Methods: The embryos of wild type and TG (flk1:GFP) transgenic zebrafish were exposed to DHA. Developmental phenotypes of the embryos were observed. Development of blood vessels was directly observed in living embryos of TG (flk1:GFP) transgenic zebrafish under fluorescence microscope. The expression of angiogenesis marker genes vegfa, flk1, and flt1 in the embryos was detected using real-time PCR and RNA in situ hybridization assays. Results: Exposure to DHA (1–10 mg/L) dose-dependently caused abnormal zebrafish embryonic phenotypes in the early developmental stage. Furthermore, exposure to DHA (10 mg/L) resulted in more pronounced embryonic angiogenesis in TG (flk1:GFP) zebrafish line. Exposure to DHA (10 mg/L) significantly increased the mRNA expression of vegfa, flk1, and flt1 in the embryos. Knockdown of the flk1 protein partially blocked the effects of DHA on embryogenesis. Conclusion: DHA causes abnormal embryonic phenotypes and promotes angiogenesis in zebrafish early embryonic development, demonstrating the potential embryotoxicity of DHA. PMID:23708556

  16. Early lexical development in Spanish-speaking infants and toddlers.

    PubMed

    Jackson-Maldonado, D; Thal, D; Marchman, V; Bates, E; Gutierrez-Clellen, V

    1993-10-01

    This paper describes the early lexical development of a group of 328 normal Spanish-speaking children aged 0;8 to 2;7. First the development and structure of a new parent report instrument, Inventario del Desarollo de Habilidades Communicativas is described. Then five studies carried out with the instrument are presented. In the first study vocabulary development of Spanish-speaking infants and toddlers is compared to that of English-speaking infants and toddlers. The English data were gathered using a comparable parental report, the MacArthur Communicative Development Inventories. In the second study the general characteristics of Spanish language acquisition, and the effects of various demographic factors on that process, are examined. Study 3 examines the differential effects of three methods of collecting the data (mail-in, personal interview, and clinic waiting room administration). Studies 4 and 5 document the reliability and validity of the instrument. Results show that the trajectories of development are very similar for Spanish- and English-speaking children in this age range, that children from varying social groups develop similarly, and that mail-in and personal interview administration techniques produce comparable results. Inventories administered in a medical clinic waiting room, on the other hand, produced lower estimates of toddler vocabulary than the other two models.

  17. Altered Gravity and Early Heart Development in Culture

    NASA Technical Reports Server (NTRS)

    Wiens, Darrell J.; Lwigale, P.; Denning, J.

    1996-01-01

    The macromolecules comprising the cytoskeleton and extracellular matrix of cells may be sensitive to gravitation. Since early development of organs depends on dynamic interactions across cell surfaces, altered gravity may disturb development. We investigated this possibility for heart development. Previous studies showed that the extracellular matrix glycoprotein fibronectin (Fn) is necessary for normal heart development. We cultured precardiac tissue explants in a high aspect ratio bioreactor vessel (HARV) to simulate microgravity. We observed tissue morphology, contraction, and Fn distribution by immunolocalization in HARV rotated and control (lxg) explants, cultured 18 hr. We also measured Fn amount by immunoassay. Explants in HARV were rotated at 6 rpm to achieve continuous freefall. Thirty-five of 37 control, but only 1 of 37 matched rotated explants exhibited contractions. Tissue architecture was identical. Immunolocalization of Fn showed remarkable differences which may be related to the development of contractions. The Fn staining in the HARV explants was less intense in all areas. Areas of linear staining along epithelia were present but shorter, and there was less intercellular staining in both mesenchymal tissue and myocardium. Initial immunoassay results of 5 matched pairs of explants showed a 22% reduction in total tissue Fn in the HARV rotated samples. Our results indicate that altered gravity in the HARV reduced the amount and distribution of Fn, as assessed by two independent criteria. This was correlated with a reduction in the development of contractile activity.

  18. Behavioral development in embryonic and early juvenile cuttlefish (Sepia officinalis).

    PubMed

    O'Brien, Caitlin E; Mezrai, Nawel; Darmaillacq, Anne-Sophie; Dickel, Ludovic

    2017-03-01

    Though a mollusc, the cuttlefish Sepia officinalis possesses a sophisticated brain, advanced sensory systems, and a large behavioral repertoire. Cuttlefish provide a unique perspective on animal behavior due to their phylogenic distance from more traditional (vertebrate) models. S. officinalis is well-suited to addressing questions of behavioral ontogeny. As embryos, they can perceive and learn from their environment and experience no direct parental care. A marked progression in learning and behavior is observed during late embryonic and early juvenile development. This improvement is concomitant with expansion and maturation of the vertical lobe, the cephalopod analog of the mammalian hippocampus. This review synthesizes existing knowledge regarding embryonic and juvenile development in this species in an effort to better understand cuttlefish behavior and animal behavior in general. It will serve as a guide to future researchers and encourage greater awareness of the utility of this species to behavioral science. © 2016 Wiley Periodicals, Inc.

  19. Transposable elements as genetic regulatory substrates in early development.

    PubMed

    Gifford, Wesley D; Pfaff, Samuel L; Macfarlan, Todd S

    2013-05-01

    The abundance and ancient origins of transposable elements (TEs) in eukaryotic genomes has spawned research into the potential symbiotic relationship between these elements and their hosts. In this review, we introduce the diversity of TEs, discuss how distinct classes are uniquely regulated in development, and describe how they appear to have been coopted for the purposes of gene regulation and the orchestration of a number of processes during early embryonic development. Although young, active TEs play an important role in somatic tissues and evolution, we focus mostly on the contributions of the older, fixed elements in mammalian genomes. We also discuss major challenges inherent in the study of TEs and contemplate future experimental approaches to further investigate how they coordinate developmental processes. Published by Elsevier Ltd.

  20. Transposable elements as genetic regulatory substrates in early development

    PubMed Central

    Gifford, Wesley D.; Pfaff, Samuel L.; Macfarlan, Todd S.

    2014-01-01

    The abundance and ancient origins of transposable elements (TEs) in eukaryotic genomes has spawned research into the potential symbiotic relationship between these elements and their hosts. In this review, we introduce the diversity of TEs, discuss how distinct classes are uniquely regulated in development, and describe how they appear to have been coopted for the purposes of gene regulation and the orchestration of a number of processes during early embryonic development. Although young, active TEs play an important role in somatic tissues and evolution, we focus mostly on the contributions of the older, fixed elements in mammalian genomes. We also discuss major challenges inherent in the study of TEs and contemplate future experimental approaches to further investigate how they coordinate developmental processes. PMID:23411159

  1. Modeling and managing risk early in software development

    NASA Technical Reports Server (NTRS)

    Briand, Lionel C.; Thomas, William M.; Hetmanski, Christopher J.

    1993-01-01

    In order to improve the quality of the software development process, we need to be able to build empirical multivariate models based on data collectable early in the software process. These models need to be both useful for prediction and easy to interpret, so that remedial actions may be taken in order to control and optimize the development process. We present an automated modeling technique which can be used as an alternative to regression techniques. We show how it can be used to facilitate the identification and aid the interpretation of the significant trends which characterize 'high risk' components in several Ada systems. Finally, we evaluate the effectiveness of our technique based on a comparison with logistic regression based models.

  2. GONADAL AND BONE MARROW DOSE IN MEDICAL DIAGNOSTIC RADIOLOGY

    SciTech Connect

    Mahmoud, K.A.; Mahfouz, M.M.; Mahmoud, M.E.

    1961-08-01

    Measurements were made of the active mean bone marrow, integral bone marrow, gonadal, and maximum skin doses from diagnostic x-ray procedures used in Cairo University Hospitals. The active mean marrow dose in cervical, dorsal, and lumbar spine diagnostic exposures were: found to be somewhat smaller than those reported by some western couatries. One of the most striking results of the survey was the relatively high values of the urinary tract cases investigated diagnostically; owing to the high incidence of urinary tract Schistosomiasis. The gonadal dose delivered to males and females was found to be almosi negligible for all diagnostic investigationsmore » of the spine, except for the lumbo-dorsal region which was within the range 50 to 500 mrads. It was also found that the gonadal dose was significant in investigations of the lower gastrointestinal tract, gall bladder, and urinary tract. (P.C.H.)« less

  3. Brain Development and Early Learning: Research on Brain Development. Quality Matters. Volume 1, Winter 2007

    ERIC Educational Resources Information Center

    Edie, David; Schmid, Deborah

    2007-01-01

    For decades researchers have been aware of the extraordinary development of a child's brain during the first five years of life. Recent advances in neuroscience have helped crystallize earlier findings, bringing new clarity and understanding to the field of early childhood brain development. Children are born ready to learn. They cultivate 85…

  4. Development of a Human Neurovascular Unit Organotypic Systems Model of Early Brain Development

    EPA Science Inventory

    The inability to model human brain and blood-brain barrier development in vitro poses a major challenge in studies of how chemicals impact early neurogenic periods. During human development, disruption of thyroid hormone (TH) signaling is related to adverse morphological effects ...

  5. Deuterostome evolution: early development in the enteropneust hemichordate, Ptychodera flava

    NASA Technical Reports Server (NTRS)

    Henry, J. Q.; Tagawa, K.; Martindale, M. Q.

    2001-01-01

    Molecular and morphological comparisons indicate that the Echinodermata and Hemichordata represent closely related sister-phyla within the Deuterostomia. Much less is known about the development of the hemichordates compared to other deuterostomes. For the first time, cell lineage analyses have been carried out for an indirect-developing representative of the enteropneust hemichordates, Ptychodera flava. Single blastomeres were iontophoretically labeled with Dil at the 2- through 16-cell stages, and their fates followed through development to the tornaria larval stage. The early cleavage pattern of P. flava is similar to that of the direct-developing hemichordate, Saccoglossus kowalevskii, as well as that displayed by indirect-developing echinoids. The 16-celled embryo contains eight animal "mesomeres," four slightly larger "macromeres," and four somewhat smaller vegetal "micromeres." The first cleavage plane was not found to bear one specific relationship relative to the larval dorsoventral axis. Although individual blastomeres generate discrete clones of cells, the appearance and exact locations of these clones are variable with respect to the embryonic dorsoventral and bilateral axes. The eight animal mesomeres generate anterior (animal) ectoderm of the larva, which includes the apical organ; however, contributions to the apical organ were found to be variable as only a subset of the animal blastomeres end up contributing to its formation and this varies from embryo to embryo. The macromeres generate posterior larval ectoderm, and the vegetal micromeres form all the internal, endomesodermal tissues. These blastomere contributions are similar to those found during development of the only other hemichordate studied, the direct-developing enteropneust, S. kowalevskii. Finally, isolated blastomeres prepared at either the two- or the four-cell stage are capable of forming normal-appearing, miniature tornaria larvae. These findings indicate that the fates of these

  6. Dual effects of fluoxetine on mouse early embryonic development

    SciTech Connect

    Kim, Chang-Woon; Department of Obstetrics and Gynecology, Samsung Changwon Hospital, Sungkyunkwan University, Changwon 630-723; Choe, Changyong

    2012-11-15

    Fluoxetine, a selective serotonin reuptake inhibitor, regulates a variety of physiological processes, such as cell proliferation and apoptosis, in mammalian cells. Little is known about the role of fluoxetine in early embryonic development. This study was undertaken to investigate the effect of fluoxetine during mouse early embryonic development. Late two-cell stage embryos (2-cells) were cultured in the presence of various concentrations of fluoxetine (1 to 50 μM) for different durations. When late 2-cells were incubated with 5 μM fluoxetine for 6 h, the percentage that developed into blastocysts increased compared to the control value. However, late 2-cells exposed to fluoxetinemore » (5 μM) over 24 h showed a reduction in blastocyst formation. The addition of fluoxetine (5 μM) together with KN93 or KN62 (calcium/calmodulin-dependent protein kinase II (CaMKII) inhibitors) failed to increase blastocyst formation. Fluoxetine treatment inhibited TREK-1 and TREK-2, members of the two-pore domain K{sup +} channel family expressed in mouse embryos, activities, indicating that fluoxetine-induced membrane depolarization in late 2-cells might have resulted from TREK inhibition. In addition, long-term exposure to fluoxetine altered the TREK mRNA expression levels. Furthermore, injection of siRNA targeting TREKs significantly decreased blastocyst formation by ∼ 30% compared to injection of scrambled siRNA. Long-term exposure of fluoxetine had no effect on blastocyst formation of TREK deficient embryos. These results indicate that low-dose and short-term exposures of late 2-cells to fluoxetine probably increase blastocyst formation through activation of CaMKII-dependent signal transduction pathways, whereas long-term exposure decreases mouse early embryonic development through inhibition of TREK channel gating. Highlights: ► Short-term exposure of 2-cells to fluoxetine enhances mouse blastocyst formation. ► The enhancive effect of fluoxetine is resulted from Ca

  7. Genetic effects of radiotherapy for childhood cancer: gonadal dose reconstruction.

    PubMed

    Stovall, Marilyn; Donaldson, Sarah S; Weathers, Rita E; Robison, Leslie L; Mertens, Ann C; Winther, Jeanette Falck; Olsen, Jorgen H; Boice, John D

    2004-10-01

    To estimate the doses of radiation to organs of interest during treatment of childhood cancer for use in an epidemiologic study of possible heritable diseases, including birth defects, chromosomal abnormalities, cancer, stillbirth, and neonatal and premature death. The study population was composed of more than 25,000 patients with cancer in Denmark and the United States who were survivors of childhood cancer and subsequently had nearly 6,500 children of their own. Radiation therapy records were sought for the survivors who parented offspring who had adverse pregnancy outcomes (>300 offspring), and for a sample of all survivors in a case-cohort design. The records were imaged and centrally abstracted. Water phantom measurements were made to estimate doses for a wide range of treatments. Mathematical phantoms were used to apply measured results to estimate doses to ovaries, uterus, testes, and pituitary for patients ranging in age from newborn to 25 years. Gonadal shielding, ovarian pinning (oophoropexy), and field blocking were taken into account. Testicular radiation doses ranged from <1 to 700 cGy (median, 7 cGy) and ovarian doses from <1 to >2,500 cGy (median, 13 cGy). Ten percent of the records were incomplete, but sufficient data were available for broad characterizations of gonadal dose. More than 49% of the gonadal doses were >10 cGy and 16% were >100 cGy. Sufficient radiation therapy data exist as far back as 1943 to enable computation of gonadal doses administered for curative therapy for childhood cancer. The range of gonadal doses is broad, and for many cancer survivors, is high and just below the threshold for infertility. Accordingly, the epidemiologic study has >90% power to detect a 1.3-fold risk of an adverse pregnancy outcome associated with radiation exposure to the gonads. This study should provide important information on the genetic consequences of radiation exposure to humans.

  8. GATA-3 is required for early T lineage progenitor development

    PubMed Central

    Hosoya, Tomonori; Kuroha, Takashi; Moriguchi, Takashi; Cummings, Dustin; Maillard, Ivan; Lim, Kim-Chew

    2009-01-01

    Most T lymphocytes appear to arise from very rare early T lineage progenitors (ETPs) in the thymus, but the transcriptional programs that specify ETP generation are not completely known. The transcription factor GATA-3 is required for the development of T lymphocytes at multiple late differentiation steps as well as for the development of thymic natural killer cells. However, a role for GATA-3 before the double-negative (DN) 3 stage of T cell development has to date been obscured both by the developmental heterogeneity of DN1 thymocytes and the paucity of ETPs. We provide multiple lines of in vivo evidence through the analysis of T cell development in Gata3 hypomorphic mutant embryos, in irradiated mice reconstituted with Gata3 mutant hematopoietic cells, and in mice conditionally ablated for the Gata3 gene to show that GATA-3 is required for ETP generation. We further show that Gata3 loss does not affect hematopoietic stem cells or multipotent hematopoietic progenitors. Finally, we demonstrate that Gata3 mutant lymphoid progenitors exhibit neither increased apoptosis nor diminished cell-cycle progression. Thus, GATA-3 is required for the cell-autonomous development of the earliest characterized thymic T cell progenitors. PMID:19934022

  9. Evaluation of basal sex hormone levels for activation of the hypothalamic-pituitary-gonadal axis.

    PubMed

    Ding, Yu; Li, Juan; Yu, Yongguo; Yang, Peirong; Li, Huaiyuan; Shen, Yongnian; Huang, Xiaodong; Liu, Shijian

    2018-03-28

    This study aimed to identify the predictive value of basal sex hormone levels for activation of the hypothalamic-pituitary-gonadal (HPG) axis in girls. Gonadotropin-releasing hormone (GnRH) stimulation tests were performed and evaluated in a total of 1750 girls with development of secondary sex characteristics. Correlation analyses were conducted between basal sex hormones and peak luteinizing hormone (LH) levels ≥5 IU/L during the GnRH stimulation test. Receiver operating characteristic (ROC) curves for basal levels of LH, follicle-stimulating hormone (FSH), LH/FSH, and estradiol (E2) before the GnRH stimulation test were plotted. The area under the curve (AUC) and 95% confidence intervals (CIs) were measured for each curve. The maximum AUC value was observed for basal LH levels (0.77, 95% CI: 0.74-0.79), followed by basal FSH levels (0.73, 95% CI: 0.70-0.75), the basal LH/FSH ratio (0.68, 95% CI: 0.65-0.71), and basal E2 levels (0.61, 95% CI: 0.59-0.64). The appropriate cutoff value of basal LH levels associated with a positive response of the GnRH stimulation test was 0.35 IU/L, with a sensitivity of 63.96% and specificity of 76.3% from the ROC curves when Youden's index showed the maximum value. When 100% of patients had peak LH levels ≥5 IU/L, basal LH values were >2.72 IU/L, but the specificity was only 5.45%. Increased basal LH levels are a significant predictor of a positive response during the GnRH stimulation test for assessing activation of the HPG axis in most girls with early pubertal signs.

  10. Pyrethroid Insecticide Cypermethrin Accelerates Pubertal Onset in Male Mice via Disrupting Hypothalamic-Pituitary-Gonadal Axis.

    PubMed

    Ye, Xiaoqing; Li, Feixue; Zhang, Jianyun; Ma, Huihui; Ji, Dapeng; Huang, Xin; Curry, Thomas E; Liu, Weiping; Liu, Jing

    2017-09-05

    Pyrethroids, a class of insecticides that are widely used worldwide, have been identified as endocrine-disrupting chemicals (EDCs). Our recent epidemiological study reported on an association of increased pyrethroids exposure with elevated gonadotropins levels and earlier pubertal development in Chinese boys. In this study, we further investigated the effects of cypermethrin (CP), one of the most ubiquitous pyrethroid insecticides, on hypothalamic-pituitary-gonadal (HPG) axis and pubertal onset in male animal models. Early postnatal exposure to CP at environmentally relevant doses (0.5, 5, and 50 μg/kg CP) significantly accelerated the age of puberty onset in male mice. Administration of CP induced a dose-dependent increase in serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone in male mice. CP did not affect gonadotropin-releasing hormone (GnRH) gene expression in the hypothalamus, but CP at higher concentrations stimulated GnRH pulse frequency. CP could induce the secretion of LH and FSH, as well as the expression of gonadotropin subunit genes [chorionic gonadotropin α (CGα), LHβ, and FSHβ] in pituitary gonadotropes. CP stimulated testosterone production and the expression of steroidogenesis-related genes [steroidogenic acute regulatory (StAR) and Cytochrome p 450, family 11, subfamily A, polypeptide 1 (CYP11A1)] in testicular Leydig cells. The interference with hypothalamic sodium channels as well as calcium channels in pituitary gonadotropes and testicular Leydig cells was responsible for CP-induced HPG axis maturation. Our findings established in animal models provide further evidence for the biological plausibility of pyrethroid exposure as a potentially environmental contributor to earlier puberty in males.

  11. Ranitidine does not affect gonadal function in man.

    PubMed Central

    Wang, C; Wong, K L; Lam, K C; Lai, C L

    1983-01-01

    We studied the effect of ranitidine on gonadal function in 20 male subjects with chronic duodenal ulcer. Eleven were treated with ranitidine 150 mg twice daily for 3 months and 150 mg at night for 9 months, nine with placebo for 3 months. Similar to placebo, treatment with ranitidine did not influence basal serum concentrations of testosterone (T), luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin (PRL). No significant changes were found in sperm concentration, motility or morphology. Ranitidine does not affect gonadal function in man. PMID:6313029

  12. Short National Early Warning Score - Developing a Modified Early Warning Score.

    PubMed

    Luís, Leandro; Nunes, Carla

    2017-12-11

    Early Warning Score (EWS) systems have been developed for detecting hospital patients clinical deterioration. Many studies show that a National Early Warning Score (NEWS) performs well in discriminating survival from death in acute medical and surgical hospital wards. NEWS is validated for Portugal and is available for use. A simpler EWS system may help to reduce the risk of error, as well as increase clinician compliance with the tool. The aim of the study was to evaluate whether a simplified NEWS model will improve use and data collection. We evaluated the ability of single and aggregated parameters from the NEWS model to detect patients' clinical deterioration in the 24h prior to an outcome. There were 2 possible outcomes: Survival vs Unanticipated intensive care unit admission or death. We used binary logistic regression models and Receiver Operating Characteristic Curves (ROC) to evaluate the parameters' performance in discriminating among the outcomes for a sample of patients from 6 Portuguese hospital wards. NEWS presented an excellent discriminating capability (Area under the Curve of ROC (AUCROC)=0.944). Temperature and systolic blood pressure (SBP) parameters did not contribute significantly to the model. We developed two different models, one without temperature, and the other by removing temperature and SBP (M2). Both models had an excellent discriminating capability (AUCROC: 0.965; 0.903, respectively) and a good predictive power in the optimum threshold of the ROC curve. The 3 models revealed similar discriminant capabilities. Although the use of SBP is not clearly evident in the identification of clinical deterioration, it is recognized as an important vital sign. We recommend the use of the first new model, as its simplicity may help to improve adherence and use by health care workers. Copyright © 2017 Australian College of Critical Care Nurses Ltd. Published by Elsevier Ltd. All rights reserved.

  13. Early motor development and cognitive abilities among Mexican preschoolers.

    PubMed

    Osorio-Valencia, Erika; Torres-Sánchez, Luisa; López-Carrillo, Lizbeth; Rothenberg, Stephen J; Schnaas, Lourdes

    2017-07-18

    Psychomotricity plays a very important role in children's development, especially for learning involving reading-writing and mathematical calculations. Evaluate motor development in children 3 years old and its relationship with their cognitive abilities at the age of 5 years. Based on a cohort study, we analyzed the information about motor performance evaluated at 3 years old by Peabody Motor Scale and cognitive abilities at 5 years old. The association was estimated using linear regression models adjusted by mother's intelligence quotient, sex, Bayley mental development index at 18 months, and quality of the environment at home (HOME scale). 148 children whose motor performance was determined at age 3 and was evaluated later at age 5 to determine their cognitive abilities. Cognitive abilities (verbal, quantitative, and memory) measured by McCarthy Scales. Significant positive associations were observed between stationary balance at age 3 with verbal abilities (β = 0.67, p = .04) and memory (β = 0.81, p = .02) at 5 years. Grasping and visual-motor integration were significant and positively associated with quantitative abilities (β = 0.74, p = .005; β = 0.61, p = .01) and memory (β = 2.11, p = .001; β = 1.74, p = .004). The results suggest that early motor performance contributes to the establishment of cognitive abilities at 5 years. Evaluation and early motor stimulation before the child is faced with formal learning likely helps to create neuronal networks that facilitate the acquisition of academic knowledge.

  14. Development of Mechanochemically Active Polymers for Early Damage Detection

    NASA Astrophysics Data System (ADS)

    Zou, Jin

    Identification of early damage in polymer composite materials is of significant importance so that preventative measures can be taken before the materials reach catastrophic failure. Scientists have been developing damage detection technologies over many years and recently, mechanophore-based polymers, in which mechanical energy is translated to activate a chemical transformation, have received increasing attention. More specifically, the damage can be made detectable by mechanochromic polymers, which provide a visible color change upon the scission of covalent bonds under stress. This dissertation focuses on the study of a novel self-sensing framework for identifying early and in-situ damage by employing unique stress-sensing mechanophores. Two types of mechanophores, cyclobutane and cyclooctane, were utilized, and the former formed from cinnamoyl moeities and the latter formed from anthracene upon photodimerization. The effects on the thermal and mechanical properties with the addition of the cyclobutane-based polymers into epoxy matrices were investigated. The emergence of cracks was detected by fluorescent signals at a strain level right after the yield point of the polymer blends, and the fluorescence intensified with the accumulation of strain. Similar to the mechanism of fluorescence emission from the cleavage of cyclobutane, the cyclooctane moiety generated fluorescent emission with a higher quantum yield upon cleavage. The experimental results also demonstrated the success of employing the cyclooctane type mechanophore as a potential force sensor, as the fluorescence intensification was correlated with the strain increase.

  15. Investigational drugs in early development for treating dengue infection.

    PubMed

    Beesetti, Hemalatha; Khanna, Navin; Swaminathan, Sathyamangalam

    2016-09-01

    Dengue has emerged as the most significant arboviral disease of the current century. A drug for dengue is an urgent unmet need. As conventional drug discovery efforts have not produced any promising clinical candidates, there is a shift toward re-positioning pre-existing drugs for dengue to fast-track dengue drug development. This article provides an update on the current status of recently completed and ongoing dengue drug trials. All dengue drug trials described in this article were identified from a list of >230 trials that were returned upon searching the World Health Organization's International Clinical Trials Registry Platform web portal using the search term 'dengue' on December 31(st), 2015. None of the handful of drugs tested so far has yielded encouraging results. Early trial experience has served to emphasize the challenge of drug testing in the short therapeutic time window available, the need for tools to predict 'high-risk' patients early on and the limitations of the existing pre-clinical model systems. Significant investment of efforts and resources is a must before the availability of a safe, effective and inexpensive dengue drug becomes a reality. Currently, supportive fluid therapy remains the only option available for dengue treatment.

  16. Measuring the implementation of early childhood development programs.

    PubMed

    Aboud, Frances E; Prado, Elizabeth L

    2018-05-01

    In this paper we describe ways to measure variables of interest when evaluating the implementation of a program to improve early childhood development (ECD). The variables apply to programs delivered to parents in group sessions and home or clinic visits, as well as in early group care for children. Measurements for four categories of variables are included: training and assessment of delivery agents and supervisors; program features such as quality of delivery, reach, and dosage; recipients' acceptance and enactment; and stakeholders' engagement. Quantitative and qualitative methods are described, along with when measures might be taken throughout the processes of planning, preparing, and implementing. A few standard measures are available, along with others that researchers can select and modify according to their goals. Descriptions of measures include who might collect the information, from whom, and when, along with how information might be analyzed and findings used. By converging on a set of common methods to measure implementation variables, investigators can work toward improving programs, identifying gaps that impede the scalability and sustainability of programs, and, over time, ascertain program features that lead to successful outcomes. © 2018 The Authors. Annals of the New York Academy of Sciences published by Wiley Periodicals, Inc. on behalf of New York Academy of Sciences.

  17. Early Miocene sequence development across the New Jersey margin

    USGS Publications Warehouse

    Monteverde, D.H.; Mountain, Gregory S.; Miller, K.G.

    2008-01-01

    Sequence stratigraphy provides an understanding of the interplay between eustasy, sediment supply and accommodation in the sedimentary construction of passive margins. We used this approach to follow the early to middle Miocene growth of the New Jersey margin and analyse the connection between relative changes of sea level and variable sediment supply. Eleven candidate sequence boundaries were traced in high-resolution multi-channel seismic profiles across the inner margin and matched to geophysical log signatures and lithologic changes in ODP Leg 150X onshore coreholes. Chronologies at these drill sites were then used to assign ages to the intervening seismic sequences. We conclude that the regional and global correlation of early Miocene sequences suggests a dominant role of global sea-level change but margin progradation was controlled by localized sediment contribution and that local conditions played a large role in sequence formation and preservation. Lowstand deposits were regionally restricted and their locations point to both single and multiple sediment sources. The distribution of highstand deposits, by contrast, documents redistribution by along shelf currents. We find no evidence that sea level fell below the elevation of the clinoform rollover, and the existence of extensive lowstand deposits seaward of this inflection point indicates efficient cross-shelf sediment transport mechanisms despite the apparent lack of well-developed fluvial drainage. ?? 2008 The Authors. Journal compilation ?? 2008 Blackwell Publishing.

  18. Longitudinal development of prefrontal function during early childhood.

    PubMed

    Moriguchi, Yusuke; Hiraki, Kazuo

    2011-04-01

    This is a longitudinal study on development of prefrontal function in young children. Prefrontal areas have been observed to develop dramatically during early childhood. To elucidate this development, we gave children cognitive shifting tasks related to prefrontal function at 3 years of age (Time 1) and 4 years of age (Time 2). We then monitored developmental changes in behavioral performance and examined prefrontal activation using near infrared spectroscopy. We found that children showed better behavioral performance and significantly stronger inferior prefrontal activation at Time 2 than they did at Time 1. Moreover, we demonstrated individual differences in prefrontal activation for the same behavioral tasks. Children who performed better in tasks at Time 1 showed significant activation of the right inferior prefrontal regions at Time 1 and significant activation of the bilateral inferior prefrontal regions at Time 2. Children who showed poorer performance at Time 1 exhibited no significant inferior prefrontal activation at Time 1 but significant left inferior prefrontal activation at Time 2. These results indicate the importance of the longitudinal method to address the link between cognitive and neural development. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. The development of phonological skills in late and early talkers

    PubMed Central

    KEHOE, Margaret; CHAPLIN, Elisa; MUDRY, Pauline; FRIEND, Margaret

    2016-01-01

    This study examined the relationship between phonological and lexical development in a group of French-speaking children (n=30), aged 29 months. The participants were divided into three sub-groups based on the number of words in their expressive vocabulary : low vocabulary (below the 15th percentile) (<< late-talkers >>) ; average-sized vocabulary (40-60th percentile) (<< middle group >>) and advanced vocabulary (above the 90th percentile) (<< precocious >> or “early talkers”). The phonological abilities (e.g., phonemic inventory, percentage of correct consonants, and phonological processes) of the three groups were compared. The comparison was based on analyses of spontaneous language samples. Most findings were consistent with previous results found in English-speaking children, indicating that the phonological abilities of late talkers are less well developed than those of children with average-sized vocabularies which in turn are less well-developed than those of children with advanced vocabularies. Nevertheless, several phonological measures were not related to vocabulary size, in particular those concerning syllable-final position. These findings differ from those obtained in English. The article finally discusses the clinical implications of the findings for children with delayed language development. PMID:26924855

  20. Oligodendrocytes as Regulators of Neuronal Networks during Early Postnatal Development

    PubMed Central

    Ramos, Maria; Ikrar, Taruna; Kinoshita, Chisato; De Mei, Claudia; Tirotta, Emanuele; Xu, Xiangmin; Borrelli, Emiliana

    2011-01-01

    Oligodendrocytes are the glial cells responsible for myelin formation. Myelination occurs during the first postnatal weeks and, in rodents, is completed during the third week after birth. Myelin ensures the fast conduction of the nerve impulse; in the adult, myelin proteins have an inhibitory role on axon growth and regeneration after injury. During brain development, oligodendrocytes precursors originating in multiple locations along the antero-posterior axis actively proliferate and migrate to colonize the whole brain. Whether the initial interactions between oligodendrocytes and neurons might play a functional role before the onset of myelination is still not completely elucidated. In this article, we addressed this question by transgenically targeted ablation of proliferating oligodendrocytes during cerebellum development. Interestingly, we show that depletion of oligodendrocytes at postnatal day 1 (P1) profoundly affects the establishment of cerebellar circuitries. We observed an impressive deregulation in the expression of molecules involved in axon growth, guidance and synaptic plasticity. These effects were accompanied by an outstanding increase of neurofilament staining observed 4 hours after the beginning of the ablation protocol, likely dependent from sprouting of cerebellar fibers. Oligodendrocyte ablation modifies localization and function of ionotropic glutamate receptors in Purkinje neurons. These results show a novel oligodendrocyte function expressed during early postnatal brain development, where these cells participate in the formation of cerebellar circuitries, and influence its development. PMID:21589880

  1. Brain anatomical networks in early human brain development.

    PubMed

    Fan, Yong; Shi, Feng; Smith, Jeffrey Keith; Lin, Weili; Gilmore, John H; Shen, Dinggang

    2011-02-01

    Recent neuroimaging studies have demonstrated that human brain networks have economic small-world topology and modular organization, enabling efficient information transfer among brain regions. However, it remains largely unknown how the small-world topology and modular organization of human brain networks emerge and develop. Using longitudinal MRI data of 28 healthy pediatric subjects, collected at their ages of 1 month, 1 year, and 2 years, we analyzed development patterns of brain anatomical networks derived from morphological correlations of brain regional volumes. The results show that the brain network of 1-month-olds has the characteristically economic small-world topology and nonrandom modular organization. The network's cost efficiency increases with the brain development to 1 year and 2 years, so does the modularity, providing supportive evidence for the hypothesis that the small-world topology and the modular organization of brain networks are established during early brain development to support rapid synchronization and information transfer with minimal rewiring cost, as well as to balance between local processing and global integration of information. Copyright © 2010. Published by Elsevier Inc.

  2. Mechanical origins of rightward torsion in early chick brain development

    NASA Astrophysics Data System (ADS)

    Chen, Zi; Guo, Qiaohang; Dai, Eric; Taber, Larry

    2015-03-01

    During early development, the neural tube of the chick embryo undergoes a combination of progressive ventral bending and rightward torsion. This torsional deformation is one of the major organ-level left-right asymmetry events in development. Previous studies suggested that bending is mainly due to differential growth, however, the mechanism for torsion remains poorly understood. Since the heart almost always loops rightwards that the brain twists, researchers have speculated that heart looping affects the direction of brain torsion. However, direct evidence is lacking, nor is the mechanical origin of such torsion understood. In our study, experimental perturbations show that the bending and torsional deformations in the brain are coupled and that the vitelline membrane applies an external load necessary for torsion to occur. Moreover, the asymmetry of the looping heart gives rise to the chirality of the twisted brain. A computational model and a 3D printed physical model are employed to help interpret these findings. Our work clarifies the mechanical origins of brain torsion and the associated left-right asymmetry, and further reveals that the asymmetric development in one organ can induce the asymmetry of another developing organ through mechanics, reminiscent of D'Arcy Thompson's view of biological form as ``diagram of forces''. Z.C. is supported by the Society in Science - Branco Weiss fellowship, administered by ETH Zurich. L.A.T acknowledges the support from NIH Grants R01 GM075200 and R01 NS070918.

  3. Probable influence of early Carboniferous (Tournaisian-early Visean) geography on the development of Waulsortian and Waulsortian-like mounds

    NASA Astrophysics Data System (ADS)

    King, David T., Jr.

    1990-07-01

    All of the known Tournaisian-early Visean (ca. 360-348 Ma) age carbonate mud mounds (Waulsortian and Waulsortian-like mounds) developed in low paleolatitudes on the southern shelf margin of Laurussia and in the Laurussian interior seaway. The Tournaisian-early Visean geography probably prevented hurricanes, tropical storms, and winter storms from crossing the shelf margin or interior seaway where these mounds developed. Implications of the lack of storm energy on mound development are discussed.

  4. Investing in the foundation of sustainable development: pathways to scale up for early childhood development.

    PubMed

    Richter, Linda M; Daelmans, Bernadette; Lombardi, Joan; Heymann, Jody; Boo, Florencia Lopez; Behrman, Jere R; Lu, Chunling; Lucas, Jane E; Perez-Escamilla, Rafael; Dua, Tarun; Bhutta, Zulfiqar A; Stenberg, Karin; Gertler, Paul; Darmstadt, Gary L

    2017-01-07

    Building on long-term benefits of early intervention (Paper 2 of this Series) and increasing commitment to early childhood development (Paper 1 of this Series), scaled up support for the youngest children is essential to improving health, human capital, and wellbeing across the life course. In this third paper, new analyses show that the burden of poor development is higher than estimated, taking into account additional risk factors. National programmes are needed. Greater political prioritisation is core to scale-up, as are policies that afford families time and financial resources to provide nurturing care for young children. Effective and feasible programmes to support early child development are now available. All sectors, particularly education, and social and child protection, must play a role to meet the holistic needs of young children. However, health provides a critical starting point for scaling up, given its reach to pregnant women, families, and young children. Starting at conception, interventions to promote nurturing care can feasibly build on existing health and nutrition services at limited additional cost. Failure to scale up has severe personal and social consequences. Children at elevated risk for compromised development due to stunting and poverty are likely to forgo about a quarter of average adult income per year, and the cost of inaction to gross domestic product can be double what some countries currently spend on health. Services and interventions to support early childhood development are essential to realising the vision of the Sustainable Development Goals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Investing in the foundation of sustainable development: pathways to scale up for early childhood development

    PubMed Central

    Richter, Linda M; Daelmans, Bernadette; Lombardi, Joan; Heymann, Jody; Boo, Florencia Lopez; Behrman, Jere R; Lu, Chunling; Lucas, Jane E; Perez-Escamilla, Rafael; Dua, Tarun; Bhutta, Zulfiqar A; Stenberg, Karin; Gertler, Paul; Darmstadt, Gary L

    2018-01-01

    Building on long-term benefits of early intervention (Paper 2 of this Series) and increasing commitment to early childhood development (Paper 1 of this Series), scaled up support for the youngest children is essential to improving health, human capital, and wellbeing across the life course. In this third paper, new analyses show that the burden of poor development is higher than estimated, taking into account additional risk factors. National programmes are needed. Greater political prioritisation is core to scale-up, as are policies that afford families time and financial resources to provide nurturing care for young children. Effective and feasible programmes to support early child development are now available. All sectors, particularly education, and social and child protection, must play a role to meet the holistic needs of young children. However, health provides a critical starting point for scaling up, given its reach to pregnant women, families, and young children. Starting at conception, interventions to promote nurturing care can feasibly build on existing health and nutrition services at limited additional cost. Failure to scale up has severe personal and social consequences. Children at elevated risk for compromised development due to stunting and poverty are likely to forgo about a quarter of average adult income per year, and the cost of inaction to gross domestic product can be double what some countries currently spend on health. Services and interventions to support early childhood development are essential to realising the vision of the Sustainable Development Goals. PMID:27717610

  6. Late Cretaceous-Early Palaeogene tectonic development of SE Asia

    NASA Astrophysics Data System (ADS)

    Morley, C. K.

    2012-10-01

    The Late Cretaceous-Early Palaeogene history of the continental core of SE Asia (Sundaland) marks the time prior to collision of India with Asia when SE Asia, from the Tethys in the west to the Palaeo-Pacific in the east, lay in the upper plate of subduction zones. In Myanmar and Sumatra, subduction was interrupted in the Aptian-Albian by a phase of arc accretion (Woyla and Mawgyi arcs) and in Java, eastern Borneo and Western Sulawesi by collision of continental fragments rifted from northern Australia. Subsequent resumption of subduction in the Myanmar-Thailand sector explains: 1) early creation of oceanic crust in the Andaman Sea in a supra-subduction zone setting ~ 95 Ma, 2) the belt of granite plutons of Late Cretaceous-Early Palaeogene age (starting ~ 88 Ma) in western Thailand and central Myanmar, and 3) amphibolite grade metamorphism between 70 and 80 Ma seen in gneissic outcrops in western and central Thailand, and 4) accretionary prism development in the Western Belt of Myanmar, until glancing collision with the NE corner of Greater India promoted ophiolite obduction, deformation and exhumation of marine sediments in the early Palaeogene. The Ranong strike-slip fault and other less well documented faults, were episodically active during the Late Cretaceous-Palaeogene time. N to NW directed subduction of the Palaeo-Pacific ocean below Southern China, Vietnam and Borneo created a major magmatic arc, associated with rift basins, metamorphic core complexes and strike-slip deformation which continued into the Late Cretaceous. The origin and timing of termination of subduction has recently been explained by collision of a large Luconia continental fragment either during the Late Cretaceous or Palaeogene. Evidence for such a collision is absent from the South China Sea well and seismic reflection record and here collision is discounted. Instead relocation of the subducting margin further west, possibly in response of back-arc extension (which created the Proto

  7. The quantum defect: Early history and recent developments

    SciTech Connect

    Rau, A.R.; Inokuti, M.

    1997-03-01

    The notion of the quantum defect is important in atomic and molecular spectroscopy and also in unifying spectroscopy with collision theory. In the latter context, the quantum defect may be viewed as an ancestor of the phase shift. However, the origin of the term {open_quotes}quantum defect{close_quotes} does not seem to be explained in standard textbooks. It occurred in a 1921 paper by Schr{umlt o}dinger, preceding quantum mechanics, yet giving the correct meaning as an index of the short-range interactions with the core of an atom. We present the early history of the quantum-defect idea, and sketch its recent developments. {copyright}more » {ital 1997 American Association of Physics Teachers.}« less

  8. Nuclear lamins during gametogenesis, fertilization and early development

    NASA Technical Reports Server (NTRS)

    Maul, G. G.; Schatten, G.

    1986-01-01

    The distribution of lamins (described by Gerace, 1978, as major proteins of nuclear envelope) during gametogenesis, fertilization, and early development was investigated in germ cells of a mouse (Mus musculus), an echinoderm (Lytechinus variegatus), and the surf clam (Spisula solidissima) was investigated in order to determine whether the differences detected could be correlated with differences in the function of cells in these stages of the germ cells. In order to monitor the behavior of lamins, the gametes and embryos were labeled with antibodies to lamins A, C, and B extracted from autoimmune sera of patients with scleroderma and Lupus erythematosus. Results indicated that lamin B could be identified in nuclear envelopes on only those nuclei where chromatin is attached and where RNA synthesis takes place.

  9. Exploring Parental Involvement in Early Years Education in China: Development and Validation of the Chinese Early Parental Involvement Scale (CEPIS)

    ERIC Educational Resources Information Center

    Lau, Eva Yi Hung; Li, Hui; Rao, Nirmala

    2012-01-01

    This study developed and validated an instrument, the Chinese Early Parental Involvement Scale (CEPIS), that can be widely used in both local and international contexts to assess Chinese parental involvement in early childhood education. The study was carried out in two stages: (1) focus group interviews were conducted with 41 teachers and 35…

  10. Ethnic Group Differences in Early Head Start Parents Parenting Beliefs and Practices and Links to Children's Early Cognitive Development

    ERIC Educational Resources Information Center

    Keels, Micere

    2009-01-01

    Data from the Early Head Start Research and Evaluation study were used to examine the extent to which several factors mediate between- and within-ethnic-group differences in parenting beliefs and behaviors, and children's early cognitive development (analysis sample of 1198 families). The findings indicate that Hispanic-, European-, and…

  11. The Legacy of Early Experiences in Development: Formalizing Alternative Models of How Early Experiences Are Carried Forward over Time

    ERIC Educational Resources Information Center

    Fraley, R. Chris; Roisman, Glenn I.; Haltigan, John D.

    2013-01-01

    Psychologists have long debated the role of early experience in social and cognitive development. However, traditional approaches to studying this issue are not well positioned to address this debate. The authors present simulations that indicate that the associations between early experiences and later outcomes should approach different…

  12. Documenting with Early Childhood Education Teachers: Pedagogical Documentation as a Tool for Developing Early Childhood Pedagogy and Practises

    ERIC Educational Resources Information Center

    Rintakorpi, Kati

    2016-01-01

    The Finnish social pedagogical curriculum for early childhood education directs early childhood teachers to use documentation to assess and develop pedagogy and practise. This empirical study examines the challenges and benefits a group of Finnish preschool teachers experienced when they learned to document their work. Although the idea of…

  13. Improving Latino Children's Early Language and Literacy Development: Key Features of Early Childhood Education within Family Literacy Programmes

    ERIC Educational Resources Information Center

    Jung, Youngok; Zuniga, Stephen; Howes, Carollee; Jeon, Hyun-Joo; Parrish, Deborah; Quick, Heather; Manship, Karen; Hauser, Alison

    2016-01-01

    Noting the lack of research on how early childhood education (ECE) programmes within family literacy programmes influence Latino children's early language and literacy development, this study examined key features of ECE programmes, specifically teacher-child interactions and child engagement in language and literacy activities and how these…

  14. RNA sequencing reveals sexually dimorphic gene expression before gonadal differentiation in chicken and allows comprehensive annotation of the W-chromosome

    PubMed Central

    2013-01-01

    Background Birds have a ZZ male: ZW female sex chromosome system and while the Z-linked DMRT1 gene is necessary for testis development, the exact mechanism of sex determination in birds remains unsolved. This is partly due to the poor annotation of the W chromosome, which is speculated to carry a female determinant. Few genes have been mapped to the W and little is known of their expression. Results We used RNA-seq to produce a comprehensive profile of gene expression in chicken blastoderms and embryonic gonads prior to sexual differentiation. We found robust sexually dimorphic gene expression in both tissues pre-dating gonadogenesis, including sex-linked and autosomal genes. This supports the hypothesis that sexual differentiation at the molecular level is at least partly cell autonomous in birds. Different sets of genes were sexually dimorphic in the two tissues, indicating that molecular sexual differentiation is tissue specific. Further analyses allowed the assembly of full-length transcripts for 26 W chromosome genes, providing a view of the W transcriptome in embryonic tissues. This is the first extensive analysis of W-linked genes and their expression profiles in early avian embryos. Conclusion Sexual differentiation at the molecular level is established in chicken early in embryogenesis, before gonadal sex differentiation. We find that the W chromosome is more transcriptionally active than previously thought, expand the number of known genes to 26 and present complete coding sequences for these W genes. This includes two novel W-linked sequences and three small RNAs reassigned to the W from the Un_Random chromosome. PMID:23531366

  15. Development of global cortical networks in early infancy.

    PubMed

    Homae, Fumitaka; Watanabe, Hama; Otobe, Takayuki; Nakano, Tamami; Go, Tohshin; Konishi, Yukuo; Taga, Gentaro

    2010-04-07

    Human cognition and behaviors are subserved by global networks of neural mechanisms. Although the organization of the brain is a subject of interest, the process of development of global cortical networks in early infancy has not yet been clarified. In the present study, we explored developmental changes in these networks from several days to 6 months after birth by examining spontaneous fluctuations in brain activity, using multichannel near-infrared spectroscopy. We set up 94 measurement channels over the frontal, temporal, parietal, and occipital regions of the infant brain. The obtained signals showed complex time-series properties, which were characterized as 1/f fluctuations. To reveal the functional connectivity of the cortical networks, we calculated the temporal correlations of continuous signals between all the pairs of measurement channels. We found that the cortical network organization showed regional dependency and dynamic changes in the course of development. In the temporal, parietal, and occipital regions, connectivity increased between homologous regions in the two hemispheres and within hemispheres; in the frontal regions, it decreased progressively. Frontoposterior connectivity changed to a "U-shaped" pattern within 6 months: it decreases from the neonatal period to the age of 3 months and increases from the age of 3 months to the age of 6 months. We applied cluster analyses to the correlation coefficients and showed that the bilateral organization of the networks begins to emerge during the first 3 months of life. Our findings suggest that these developing networks, which form multiple clusters, are precursors of the functional cerebral architecture.

  16. Napping facilitates word learning in early lexical development.

    PubMed

    Horváth, Klára; Myers, Kyle; Foster, Russell; Plunkett, Kim

    2015-10-01

    Little is known about the role that night-time sleep and daytime naps play in early cognitive development. Our aim was to investigate how napping affects word learning in 16-month-olds. Thirty-four typically developing infants were assigned randomly to nap and wake groups. After teaching two novel object-word pairs to infants, we tested their initial performance with an intermodal preferential looking task in which infants are expected to increase their target looking time compared to a distracter after hearing its auditory label. A second test session followed after approximately a 2-h delay. The delay contained sleep for the nap group or no sleep for the wake group. Looking behaviour was measured with an automatic eye-tracker. Vocabulary size was assessed using the Oxford Communicative Development Inventory. A significant interaction between group and session was found in preferential looking towards the target picture. The performance of the nap group increased after the nap, whereas that of the wake group did not change. The gain in performance correlated positively with the expressive vocabulary size in the nap group. These results indicate that daytime napping helps consolidate word learning in infancy. © 2015 European Sleep Research Society.

  17. Recent early clinical drug development for acute kidney injury.

    PubMed

    Gallagher, Kevin M; O'neill, Stephen; Harrison, Ewen M; Ross, James A; Wigmore, Stephen J; Hughes, Jeremy

    2017-02-01

    Despite significant need and historical trials, there are no effective drugs in use for the prevention or treatment of acute kidney injury (AKI). There are several promising agents in early clinical development for AKI and two trials have recently been terminated. There are also exciting new findings in pre-clinical AKI research. There is a need to take stock of current progress in the field to guide future drug development for AKI. Areas covered: The main clinical trial registries, PubMed and pharmaceutical company website searches were used to extract the most recent clinical trials for sterile, transplant and sepsis-associated AKI. We summarise the development of the agents recently in clinical trial, update on their trial progress, consider reasons for failed efficacy of two agents, and discuss new paradigms in pre-clinical targets for AKI. Agents covered include- QPI-1002, THR-184, BB-3, heme arginate, human recombinant alkaline phosphatase (recAP), ciclosporin A, AB103, levosimendan, AC607 and ABT-719. Expert opinion: Due to the heterogenous nature of AKI, agents with the widest pleiotropic effects on multiple pathophysiological pathways are likely to be most effective. Linking preclinical models to clinical indication and improving AKI definition and diagnosis are key areas for improvement in future clinical trials.

  18. The obesogenic effect of high fructose exposure during early development

    PubMed Central

    Goran, Michael I.; Dumke, Kelly; Bouret, Sebastien G.; Kayser, Brandon; Walker, Ryan W.; Blumberg, Bruce

    2016-01-01

    Obesogens are compounds that disrupt the function and development of adipose tissue or the normal metabolism of lipids, leading to an increased risk of obesity and associated diseases. Evidence for the adverse effects of industrial and agricultural obesogens, such as tributyltin, bisphenol A and other organic pollutants is well-established. Current evidence suggests that high maternal consumption of fat promotes obesity and increased metabolic risk in offspring, but less is known about the effects of other potential nutrient obesogens. Widespread increase in dietary fructose consumption over the past 30 years is associated with chronic metabolic and endocrine disorders and alterations in feeding behaviour that promote obesity. In this Perspectives, we examine the evidence linking high intakes of fructose with altered metabolism and early obesity. We review the evidence suggesting that high fructose exposure during critical periods of development of the fetus, neonate and infant can act as an obesogen by affecting lifelong neuroendocrine function, appetite control, feeding behaviour, adipogenesis, fat distribution and metabolic systems. These changes ultimately favour the long-term development of obesity and associated metabolic risk. PMID:23732284

  19. Structural and Maturational Covariance in Early Childhood Brain Development.

    PubMed

    Geng, Xiujuan; Li, Gang; Lu, Zhaohua; Gao, Wei; Wang, Li; Shen, Dinggang; Zhu, Hongtu; Gilmore, John H

    2017-03-01

    Brain structural covariance networks (SCNs) composed of regions with correlated variation are altered in neuropsychiatric disease and change with age. Little is known about the development of SCNs in early childhood, a period of rapid cortical growth. We investigated the development of structural and maturational covariance networks, including default, dorsal attention, primary visual and sensorimotor networks in a longitudinal population of 118 children after birth to 2 years old and compared them with intrinsic functional connectivity networks. We found that structural covariance of all networks exhibit strong correlations mostly limited to their seed regions. By Age 2, default and dorsal attention structural networks are much less distributed compared with their functional maps. The maturational covariance maps, however, revealed significant couplings in rates of change between distributed regions, which partially recapitulate their functional networks. The structural and maturational covariance of the primary visual and sensorimotor networks shows similar patterns to the corresponding functional networks. Results indicate that functional networks are in place prior to structural networks, that correlated structural patterns in adult may arise in part from coordinated cortical maturation, and that regional co-activation in functional networks may guide and refine the maturation of SCNs over childhood development. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. The SCL gene specifies haemangioblast development from early mesoderm.

    PubMed

    Gering, M; Rodaway, A R; Göttgens, B; Patient, R K; Green, A R

    1998-07-15

    The SCL gene encodes a basic helix-loop-helix (bHLH) transcription factor that is essential for the development of all haematopoietic lineages. SCL is also expressed in endothelial cells, but its function is not essential for specification of endothelial progenitors and the role of SCL in endothelial development is obscure. We isolated the zebrafish SCL homologue and show that it was co-expressed in early mesoderm with markers of haematopoietic, endothelial and pronephric progenitors. Ectopic expression of SCL mRNA in zebrafish embryos resulted in overproduction of common haematopoietic and endothelial precursors, perturbation of vasculogenesis and concomitant loss of pronephric duct and somitic tissue. Notochord and neural tube formation were unaffected. These results provide the first evidence that SCL specifies formation of haemangioblasts, the proposed common precursor of blood and endothelial lineages. Our data also underline the striking similarities between the role of SCL in haematopoiesis/vasculogenesis and the function of other bHLH proteins in muscle and neural development.

  1. RNAi-Mediated Gene Silencing in a Gonad Organ Culture to Study Sex Determination Mechanisms in Sea Turtle.

    PubMed

    Sifuentes-Romero, Itzel; Merchant-Larios, Horacio; Milton, Sarah L; Moreno-Mendoza, Norma; Díaz-Hernández, Verónica; García-Gasca, Alejandra

    2013-06-07

    The autosomal Sry-related gene, Sox9, encodes a transcription factor, which performs an important role in testis differentiation in mammals. In several reptiles, Sox9 is differentially expressed in gonads, showing a significant upregulation during the thermo-sensitive period (TSP) at the male-promoting temperature, consistent with the idea that SOX9 plays a central role in the male pathway. However, in spite of numerous studies, it remains unclear how SOX9 functions during this event. In the present work, we developed an RNAi-based method for silencing Sox9 in an in vitro gonad culture system for the sea turtle, Lepidochelys olivacea. Gonads were dissected as soon as the embryos entered the TSP and were maintained in organ culture. Transfection of siRNA resulted in the decrease of both Sox9 mRNA and protein. Furthermore, we found coordinated expression patterns for Sox9 and the anti-Müllerian hormone gene, Amh, suggesting that SOX9 could directly or indirectly regulate Amh expression, as it occurs in mammals. These results demonstrate an in vitro method to knockdown endogenous genes in gonads from a sea turtle, which represents a novel approach to investigate the roles of important genes involved in sex determination or differentiation pathways in species with temperature-dependent sex determination.

  2. Factors influencing frontal cortex development and recovery from early frontal injury.

    PubMed

    Halliwell, Celeste; Comeau, Wendy; Gibb, Robbin; Frost, Douglas O; Kolb, Bryan

    2009-01-01

    Neocortical development represents more than a simple unfolding of a genetic blueprint but rather represents a complex dance of genetic and environmental events that interact to adapt the brain to fit a particular environmental context. Although most cortical regions are sensitive to a wide range of experiential factors during development and later in life, the prefrontal cortex appears to be unusually sensitive to perinatal experiences and relatively immune to many adulthood experiences relative to other neocortical regions. One way to examine experience-dependent prefrontal development is to conduct studies in which experiential perturbations are related neuronal morphology. This review of the research reveals both pre- and post-natal factors have important effects on prefrontal development and behaviour. Such factors include psychoactive drugs, including both illicit drugs and prescription drugs, stress, gonadal hormones and sensory and motor stimulation. A second method of study is to examine both the effects of perinatal prefrontal injury on the development of the remaining cerebral mantle and correlated behaviours as well as the effects of post-injury rehabilitation programmes on the anatomical and behavioural measures. Prefrontal injury alters cerebral development in a developmental-stage dependent manner with perinatal injuries having far more deleterious effects than similar injuries later in infancy. The outcome of perinatal injuries can be modified, however, by rehabilitation with many of the factors shown to influence prefrontal development in the otherwise normal brain.

  3. In silico predicted reproductive endocrine transcriptional regulatory networks during zebrafish (Danio rerio) development.

    PubMed

    Hala, D

    2017-03-21

    The interconnected topology of transcriptional regulatory networks (TRNs) readily lends to mathematical (or in silico) representation and analysis as a stoichiometric matrix. Such a matrix can be 'solved' using the mathematical method of extreme pathway (ExPa) analysis, which identifies uniquely activated genes subject to transcription factor (TF) availability. In this manuscript, in silico multi-tissue TRN models of brain, liver and gonad were used to study reproductive endocrine developmental programming in zebrafish (Danio rerio) from 0.25h post fertilization (hpf; zygote) to 90 days post fertilization (dpf; adult life stage). First, properties of TRN models were studied by sequentially activating all genes in multi-tissue models. This analysis showed the brain to exhibit lowest proportion of co-regulated genes (19%) relative to liver (23%) and gonad (32%). This was surprising given that the brain comprised 75% and 25% more TFs than liver and gonad respectively. Such 'hierarchy' of co-regulatory capability (braingonad) indicated presence of highly gene-specific TRNs in the brain, alluding to its role as 'master controller' of endocrine function. Second, TRN models were constrained with varying TF availabilities during zebrafish development. Normalized numbers of genes active during development showed concomitant activations between brain and gonad from 10 to 12 hpf (embryonic life stage) up to 30-90 dpf (adult life stage). This indicated a putative 'syncing' between the brain and gonad, and initiation of an early reproductive endocrine developmental program. Finally, comparison of in vivo active genes with those predicted in silico showed relatively good agreement for brain (49%), liver (27%) and gonad (32%). The multi-tissue TRN models presented can lend diagnostic insights into the effects of changing environmental and/or genetic constraints on reproductive endocrine function. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Development of Water Resources Drought Early Warning System

    NASA Astrophysics Data System (ADS)

    Chen, B. P. T.; Chen, C. H.

    2017-12-01

    Signs of impending drought are often vague and result from hydrologic uncertainty. Because of this, determining the appropriate time to enforce water supply restrictions is difficult. This study proposes a drought early warning index (DEWI) that can help water resource managers to anticipate droughts so that preparations can be made to mitigate the impact of water shortages. This study employs the expected-deficit-rate of normal water supply conditions as the drought early warning index. An annual-use-reservoir-based water supply system in southern Taiwan was selected as the case study. The water supply simulation was based on reservoir storage at the evaluation time and the reservoir inflow series to cope with the actual water supply process until the end of the hydrologic year. A variety of deficits could be realized during different hydrologic years of records and assumptions of initial reservoir storage. These deficits are illustrated using the Average Shortage Rate (ASR) and the value of the ASR, namely the DEWI. The ASR is divided into 5 levels according to 5 deficit-tolerance combinations of each kind of annual demand. A linear regression model and a Neuro-Fuzzy Computing Technique model were employed to estimate the DEWI using selected factors deduced from supply-demand traits and available information, including: rainfall, reservoir inflow and storage data. The chosen methods mentioned above are used to explain a significant index is useful for both model development and decision making. Tests in the Tsengwen-Wushantou reservoir system showed this DEWI to perform very well in adopting the proper mitigation policy at the end of the wet season.

  5. Early aspirin use and the development of cardiac allograft vasculopathy.

    PubMed

    Kim, Miae; Bergmark, Brian A; Zelniker, Thomas A; Mehra, Mandeep R; Stewart, Garrick C; Page, Deborah S; Woodcome, Erica L; Smallwood, Jennifer A; Gabardi, Steven; Givertz, Michael M

    2017-12-01

    Cardiac allograft vasculopathy (CAV) remains a leading cause of morbidity and mortality after orthotopic heart transplantation (OHT). Little is known about the influence of aspirin on clinical expression of CAV. We followed 120 patients with OHT at a single center for a median of 7 years and categorized them by the presence or absence of early aspirin therapy post-transplant (aspirin treatment ≥6 months in the first year). The association between aspirin use and time to the primary end-point of angiographic moderate or severe CAV (International Society for Heart and Lung Transplantation grade ≥2) was investigated. Propensity scores for aspirin treatment were estimated using boosting models and applied by inverse probability of treatment weighting (IPTW). Despite a preponderance of risk factors for CAV among patients receiving aspirin (male sex, ischemic heart disease as the etiology of heart failure, and smoking), aspirin therapy was associated with a lower rate of moderate or severe CAV at 5 years. Event-free survival was 95.9% for patients exposed to aspirin compared with 79.6% for patients without aspirin exposure (log-rank p = 0.005). IPTW-weighted Cox regression revealed a powerful inverse association between aspirin use and moderate to severe CAV (adjusted hazard ratio 0.13; 95% confidence interval 0.03-0.59), which was directionally consistent for CAV of any severity (adjusted hazard ratio 0.50; 95% confidence interval 0.23-1.08). This propensity score-based comparative observational analysis suggests that early aspirin exposure may be associated with a reduced risk of development of moderate to severe CAV. These findings warrant prospective validation in controlled investigations. Copyright © 2017 International Society for the Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  6. Impact of Early Postnatal Androgen Exposure on Voice Development

    PubMed Central

    Grisa, Leila; Leonel, Maria L.; Gonçalves, Maria I. R.; Pletsch, Francisco; Sade, Elis R.; Custódio, Gislaine; Zagonel, Ivete P. S.; Longui, Carlos A.; Figueiredo, Bonald C.

    2012-01-01

    Background The impact of early postnatal androgen exposure on female laryngeal tissue may depend on certain characteristics of this exposure. We assessed the impact of the dose, duration, and timing of early androgen exposure on the vocal development of female subjects who had been treated for adrenocortical tumor (ACT) in childhood. Methods The long-term effects of androgen exposure on the fundamental vocal frequency (F0), vocal pitch, and final height and the presence of virilizing signs were examined in 9 adult (age, 18.4 to 33.5 years) and 10 adolescent (13.6 to 17.8 years) female ACT patients. We also compared the current values with values obtained 0.9 years to 7.4 years after these subjects had undergone ACT surgery, a period during which they had shown normal androgen levels. Results Of the 19 subjects, 17 (89%) had been diagnosed with ACT before 4 years of age, 1 (5%) at 8.16 years, and 1 (5%) at 10.75 years. Androgen exposure (2 to 30 months) was sufficiently strong to cause pubic hair growth in all subjects and clitoromegaly in 74% (14/19) of the subjects, but did not reduce their height from the target value. Although androgen exposure induced a remarkable reduction in F0 (132 Hz) and moderate pitch virilization in 1 subject and partial F0 virilization, resulting in F0 of 165 and 169 Hz, in 2 subjects, the majority had normal F0 ranging from 189 to 245 Hz. Conclusions Female laryngeal tissue is less sensitive to androgen exposure between birth and adrenarche than during other periods. Differential larynx sensitivity to androgen exposure in childhood and F0 irreversibility in adulthood are age-, concentration-, duration-, and timing-dependent events that may also be affected by exposure to inhibitory or stimulatory hormones. Further studies are required to better characterize each of these factors. PMID:23284635

  7. Developing an Early Warning System for Machu Picchu Pueblo, Peru.

    NASA Astrophysics Data System (ADS)

    Bulmer, Mark; Farquhar, Tony

    2010-05-01

    The town of Machu Picchu, Peru, is linked to Ollantaytambo and Cusco by rail and serves as the main station for the 400,000+ tourists visiting Machu Picchu. Due to the tourist industry the town grown threefold in population in the past two decades. Today, due to the limited availability of low-lying ground, construction is occurring higher up on the unstable valley slopes. The town is located at 2000 m asl while the surrounding peaks rise to over 4000 m asl. Slopes range from < 10° on the valley floor to > 70° in the surrounding granite mountains. The town has grown on the downstream right bank of the Vilcanota River, at the confluence of the Alcamayo and the Aguas Calientes Rivers. Broadly, a dry winter season runs from May to August with a rainy summer season running from October to March. The rainy months provide around 80% of the annual rainfall average, which ranges from 1,600 to 2,300 mm. Seasonal temperature variations are considered modest. An assessment of the geohazards in and around the town has been undertaken. Those of particular concern to the town are 1) large rocks falling onto the town and/or the rail line, 2) flash flooding by any one of its three rivers, and 3) mudflows and landslides. To improve the existing municipal warning system a prototype early warning system incorporating suitable technologies that could monitor weather, river flow and slope satability was installed along the Aguas Calientes River in 2009. This has a distributed modular construction allowing most components to be installed, maintained, swapped, salvaged, repaired and/or replaced by local technicians. A diverse set of candidate power, communication and sensor technologies was deployed and evaluated. Most of the candidate technologies had never been deployed in similar terrain, altitude or weather. The successful deployment of the prototype proved that it is technically feasible to develop early warning capacity in the town.

  8. Socioeconomic disadvantage and neural development from infancy through early childhood

    PubMed Central

    Chin-Lun Hung, Galen; Hahn, Jill; Alamiri, Bibi; Buka, Stephen L; Goldstein, Jill M; Laird, Nan; Nelson, Charles A; Smoller, Jordan W; Gilman, Stephen E

    2015-01-01

    Background: Early social experiences are believed to shape neurodevelopment, with potentially lifelong consequences. Yet minimal evidence exists regarding the role of the social environment on children’s neural functioning, a core domain of neurodevelopment. Methods: We analysed data from 36 443 participants in the United States Collaborative Perinatal Project, a socioeconomically diverse pregnancy cohort conducted between 1959 and 1974. Study outcomes included: physician (neurologist or paediatrician)-rated neurological abnormality neonatally and thereafter at 4 months and 1 and 7 years; indicators of neurological hard signs and soft signs; and indicators of autonomic nervous system function. Results: Children born to socioeconomically disadvantaged parents were more likely to exhibit neurological abnormalities at 4 months [odds ratio (OR) = 1.20; 95% confidence interval (CI) = 1.06, 1.37], 1 year (OR = 1.35; CI = 1.17, 1.56), and 7 years (OR = 1.67; CI = 1.48, 1.89), and more likely to exhibit neurological hard signs (OR = 1.39; CI = 1.10, 1.76), soft signs (OR = 1.26; CI = 1.09, 1.45) and autonomic nervous system dysfunctions at 7 years. Pregnancy and delivery complications, themselves associated with socioeconomic disadvantage, did not account for the higher risks of neurological abnormalities among disadvantaged children. Conclusions: Parental socioeconomic disadvantage was, independently from pregnancy and delivery complications, associated with abnormal child neural development during the first 7 years of life. These findings reinforce the importance of the early environment for neurodevelopment generally, and expand knowledge regarding the domains of neurodevelopment affected by environmental conditions. Further work is needed to determine the mechanisms linking socioeconomic disadvantage with children’s neural functioning, the timing of such mechanisms and their potential reversibility. PMID:26675752

  9. Developing Adaptive Systems at Early Stages of Children's Foreign Language Development

    ERIC Educational Resources Information Center

    Espada, Ana Belen Cumbreno; Garcia, Mercedes Rico; Fuentes, Alejandro Curado; Gomez, Eva Ma Dominguez

    2006-01-01

    This paper describes the integration of hypermedia adaptive systems for foreign language learners at an early age. Our research project is concerned with exploring the relationship between language learning and information technology according to six different phases: a preliminary study of the plausible adaptive system; the development of lessons…

  10. Preschoolers Know, but How Do They Know? Developing a Framework for Early Epistemology Development

    ERIC Educational Resources Information Center

    Winsor, Denise L.; Blake, Sally

    2009-01-01

    Two areas that are lacking for the purpose of training high-quality preschool teachers; and constructing developmentally appropriate learning standards and curriculum for preschool children are awareness of early epistemic development (beliefs about knowledge and knowing) and understanding preschoolers' cognitive processes during epistemic…

  11. Origins and early development of human body knowledge.

    PubMed

    Slaughter, Virginia; Heron, Michelle

    2004-01-01

    As a knowable object, the human body is highly complex. Evidence from several converging lines of research, including psychological studies, neuroimaging and clinical neuropsychology, indicates that human body knowledge is widely distributed in the adult brain, and is instantiated in at least three partially independent levels of representation. Sensorimotor body knowledge is responsible for on-line control and movement of one's own body and may also contribute to the perception of others' moving bodies; visuo-spatial body knowledge specifies detailed structural descriptions of the spatial attributes of the human body; and lexical-semantic body knowledge contains language-based knowledge about the human body. In the first chapter of this Monograph, we outline the evidence for these three hypothesized levels of human body knowledge, then review relevant literature on infants' and young children's human body knowledge in terms of the three-level framework. In Chapters II and III, we report two complimentary series of studies that specifically investigate the emergence of visuo-spatial body knowledge in infancy. Our technique is to compare infants'responses to typical and scrambled human bodies, in order to evaluate when and how infants acquire knowledge about the canonical spatial layout of the human body. Data from a series of visual habituation studies indicate that infants first discriminate scrambled from typical human body picture sat 15 to 18 months of age. Data from object examination studies similarly indicate that infants are sensitive to violations of three-dimensional human body stimuli starting at 15-18 months of age. The overall pattern of data supports several conclusions about the early development of human body knowledge: (a) detailed visuo-spatial knowledge about the human body is first evident in the second year of life, (b) visuo-spatial knowledge of human faces and human bodies are at least partially independent in infancy and (c) infants' initial

  12. Infant feeding effects on early neurocognitive development in Asian children.

    PubMed

    Cai, Shirong; Pang, Wei Wei; Low, Yen Ling; Sim, Lit Wee; Sam, Suet Chian; Bruntraeger, Michaela Bianka; Wong, Eric Qinlong; Fok, Doris; Broekman, Birit F P; Singh, Leher; Richmond, Jenny; Agarwal, Pratibha; Qiu, Anqi; Saw, Seang Mei; Yap, Fabian; Godfrey, Keith M; Gluckman, Peter D; Chong, Yap-Seng; Meaney, Michael J; Kramer, Michael S; Rifkin-Graboi, Anne

    2015-02-01

    Breastfeeding has been shown to enhance global measures of intelligence in children. However, few studies have examined associations between breastfeeding and specific cognitive task performance in the first 2 y of life, particularly in an Asian population. We assessed associations between early infant feeding and detailed measures of cognitive development in the first 2 y of life in healthy Asian children born at term. In a prospective cohort study, neurocognitive testing was performed in 408 healthy children (aged 6, 18, and 24 mo) from uncomplicated pregnancies (i.e., birth weight >2500 and <4000 g, gestational age ≥37 wk, and 5-min Apgar score ≥9). Tests included memory (deferred imitation, relational binding, habituation) and attention tasks (visual expectation, auditory oddball) as well as the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III). Children were stratified into 3 groups (low, intermediate, and high) on the basis of breastfeeding duration and exclusivity. After potential confounding variables were controlled for, significant associations and dose-response relations were observed for 4 of the 15 tests. Higher breastfeeding exposure was associated with better memory at 6 mo, demonstrated by greater preferential looking toward correctly matched items during early portions of a relational memory task (i.e., relational binding task: P-trend = 0.015 and 0.050 for the first two 1000-ms time bins, respectively). No effects of breastfeeding were observed at 18 mo. At 24 mo, breastfed children were more likely to display sequential memory during a deferred imitation memory task (P-trend = 0.048), and toddlers with more exposure to breastfeeding scored higher in receptive language [+0.93 (0.23, 1.63) and +1.08 (0.10, 2.07) for intermediate- and high-breastfeeding groups, respectively, compared with the low-breastfeeding group], as well as expressive language [+0.58 (-0.06, 1.23) and +1.22 (0.32, 2.12) for intermediate- and high

  13. Controls on development and diversity of Early Archean stromatolites

    PubMed Central

    Allwood, Abigail C.; Grotzinger, John P.; Knoll, Andrew H.; Burch, Ian W.; Anderson, Mark S.; Coleman, Max L.; Kanik, Isik

    2009-01-01

    The ≈3,450-million-year-old Strelley Pool Formation in Western Australia contains a reef-like assembly of laminated sedimentary accretion structures (stromatolites) that have macroscale characteristics suggestive of biological influence. However, direct microscale evidence of biology—namely, organic microbial remains or biosedimentary fabrics—has to date eluded discovery in the extensively-recrystallized rocks. Recently-identified outcrops with relatively good textural preservation record microscale evidence of primary sedimentary processes, including some that indicate probable microbial mat formation. Furthermore, we find relict fabrics and organic layers that covary with stromatolite morphology, linking morphologic diversity to changes in sedimentation, seafloor mineral precipitation, and inferred microbial mat development. Thus, the most direct and compelling signatures of life in the Strelley Pool Formation are those observed at the microscopic scale. By examining spatiotemporal changes in microscale characteristics it is possible not only to recognize the presence of probable microbial mats during stromatolite development, but also to infer aspects of the biological inputs to stromatolite morphogenesis. The persistence of an inferred biological signal through changing environmental circumstances and stromatolite types indicates that benthic microbial populations adapted to shifting environmental conditions in early oceans. PMID:19515817

  14. Isolated 46,XY gonadal dysgenesis in two sisters caused by a Xp21.2 in