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Sample records for male gametophyte development

  1. Proline is required for male gametophyte development in Arabidopsis

    PubMed Central

    2012-01-01

    Background In crosses between the proline-deficient mutant homozygous for p5cs1 and heterozygous for p5cs2 (p5cs1 p5cs2/P5CS2), used as male, and different Arabidopsis mutants, used as females, the p5cs2 mutant allele was rarely transmitted to the outcrossed progeny, suggesting that the fertility of the male gametophyte carrying mutations in both P5CS1 and P5CS2 is severely compromised. Results To confirm the fertility defects of pollen from p5cs1 p5cs2/P5CS2 mutants, transmission of mutant alleles through pollen was tested in two ways. First, the number of progeny inheriting a dominant sulfadiazine resistance marker linked to p5cs2 was determined. Second, the number of p5cs2/p5cs2 embryos was determined. A ratio of resistant to susceptible plantlets close to 50%, and the absence of aborted embryos were consistent with the hypothesis that the male gametophyte carrying both p5cs1 and p5cs2 alleles is rarely transmitted to the offspring. In addition, in reciprocal crosses with wild type, about 50% of the p5cs2 mutant alleles were transmitted to the sporophytic generation when p5cs1 p5cs2/P5CS2 was used as a female, while less than 1% of the p5cs2 alleles could be transmitted to the outcrossed progeny when p5cs1 p5cs2/P5CS2 was used as a male. Morphological and functional analysis of mutant pollen revealed a population of small, degenerated, and unviable pollen grains, indicating that the mutant homozygous for p5cs1 and heterozygous for p5cs2 is impaired in pollen development, and suggesting a role for proline in male gametophyte development. Consistent with these findings, we found that pollen from p5cs1 homozygous mutants, display defects similar to, but less pronounced than pollen from p5cs1 p5cs2/P5CS2 mutants. Finally, we show that pollen from p5cs1 p5cs2/P5CS2 plants contains less proline than wild type and that exogenous proline supplied from the beginning of another development can partially complement both morphological and functional pollen defects

  2. Integrating membrane transport with male gametophyte development and function through transcriptomics(1)[W

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Male fertility depends on the proper development of the male gametophyte, successful pollen germination, tube growth, and delivery of the sperm cells to the ovule. Previous studies have shown that nutrients like boron, and ion gradients or currents of Ca(2+), H(+), and K(+) are critical for pollen ...

  3. Development of a SCAR marker for male gametophyte of Gracilariopsis lemaneiformis based on AFLP technique

    NASA Astrophysics Data System (ADS)

    Zhou, Wei; Ding, Hongye; Sui, Zhenghong; Wang, Zhongxia; Wang, Jinguo

    2014-05-01

    The red alga Gracilariopsis lemaneiformis (Bory) is an economically valuable macroalgae. As a means to identify the sex of immature Gracilariopsis lemaneiformis, the amplified fragment length polymorphism (AFLP) technique was used to search for possible sex- or phase-related markers in male gametophytes, female gametophytes, and tetrasporophytes, respectively. Seven AFLP selective amplification primers were used in this study. The primer combination E-TG/M-CCA detected a specific band linked to male gametophytes. The DNA fragment was recovered and a 402-bp fragment was sequenced. However, no DNA sequence match was found in public databases. Sequence characterized amplified region (SCAR) primers were designed from the sequence to test the repeatability of the relationship to the sex, using 69 male gametophytes, 139 female gametophytes, and 47 tetrasporophytes. The test results demonstrate a good linkage and repeatability of the SCAR marker to sex. The SCAR primers developed in this study could reduce the time required for sex identification of Gracilariopsis lemaneiformis by four to six months. This can reduce both the time investment and number of specimens required in breeding experiments.

  4. Integrating Membrane Transport with Male Gametophyte Development and Function through Transcriptomics1[W

    PubMed Central

    Bock, Kevin W.; Honys, David; Ward, John M.; Padmanaban, Senthilkumar; Nawrocki, Eric P.; Hirschi, Kendal D.; Twell, David; Sze, Heven

    2006-01-01

    Male fertility depends on the proper development of the male gametophyte, successful pollen germination, tube growth, and delivery of the sperm cells to the ovule. Previous studies have shown that nutrients like boron, and ion gradients or currents of Ca2+, H+, and K+ are critical for pollen tube growth. However, the molecular identities of transporters mediating these fluxes are mostly unknown. As a first step to integrate transport with pollen development and function, a genome-wide analysis of transporter genes expressed in the male gametophyte at four developmental stages was conducted. Approximately 1,269 genes encoding classified transporters were collected from the Arabidopsis (Arabidopsis thaliana) genome. Of 757 transporter genes expressed in pollen, 16% or 124 genes, including AHA6, CNGC18, TIP1.3, and CHX08, are specifically or preferentially expressed relative to sporophytic tissues. Some genes are highly expressed in microspores and bicellular pollen (COPT3, STP2, OPT9), while others are activated only in tricellular or mature pollen (STP11, LHT7). Analyses of entire gene families showed that a subset of genes, including those expressed in sporophytic tissues, was developmentally regulated during pollen maturation. Early and late expression patterns revealed by transcriptome analysis are supported by promoter∷β-glucuronidase analyses of CHX genes and by other methods. Recent genetic studies based on a few transporters, including plasma membrane H+ pump AHA3, Ca2+ pump ACA9, and K+ channel SPIK, further support the expression patterns and the inferred functions revealed by our analyses. Thus, revealing the distinct expression patterns of specific transporters and unknown polytopic proteins during microgametogenesis provides new insights for strategic mutant analyses necessary to integrate the roles of transporters and potential receptors with male gametophyte development. PMID:16607029

  5. Integrating Membrane Transport with Male Gametophyte Development and Function through Transcriptomics.

    SciTech Connect

    Bock KW; D Honys; JM. Ward; S Padmanaban; EP Nawrocki; KD Hirschi; D Twell; H Sze

    2006-01-01

    Male fertility depends on the proper development of the male gametophyte, successful pollen germination, tube growth and delivery of the sperm cells to the ovule. Previous studies have shown that nutrients like boron, and ion gradients or currents of Ca2+, H+, and K+ are critical for pollen tube growth. However, the molecular identities of transporters mediating these fluxes are mostly unknown. As a first step to integrate transport with pollen development and function, a genome-wide analysis of transporter genes expressed in the male gametophyte at four developmental stages was conducted. About 1269 genes encoding classified transporters were collected from the Arabidopsis thaliana genome. Of 757 transporter genes expressed in pollen, 16% or 124 genes, including AHA6, CNGC18, TIP1.3 and CHX08, are specifically or preferentially expressed relative to sporophytic tissues. Some genes are highly expressed in microspores and bicellular pollen (COPT3, STP2, OPT9); while others are activated only in tricellular or mature pollen (STP11, LHT7). Analyses of entire gene families showed that a subset of genes, including those expressed in sporophytic tissues, were developmentally-regulated during pollen maturation. Early and late expression patterns revealed by transcriptome analysis are supported by promoter::GUS analyses of CHX genes and by other methods. Recent genetic studies based on a few transporters, including plasma membrane H+ pump AHA3, Ca2+ pump ACA9, and K+ channel SPIK, further support the expression patterns and the inferred functions revealed by our analyses. Thus, revealing the distinct expression patterns of specific transporters and unknown polytopic proteins during microgametogenesis provides new insights for strategic mutant analyses necessary to integrate the roles of transporters and potential receptors with male gametophyte development.

  6. A Collection of Ds Insertional Mutants Associated With Defects in Male Gametophyte Development and Function in Arabidopsis thaliana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Functional analyses of the Arabidopsis genome require analysis of the gametophytic generation, since 10% of the genes are expressed in the male gametophyte and 9% in the female gametophyte. Here we describe the genetic and molecular characterization of 67 Ds insertion lines that show reduced transmi...

  7. Ribosomal protein L18aB is required for both male gametophyte function and embryo development in Arabidopsis.

    PubMed

    Yan, Hailong; Chen, Dan; Wang, Yifan; Sun, Yang; Zhao, Jing; Sun, Mengxiang; Peng, Xiongbo

    2016-01-01

    Ribosomal proteins are involved in numerous essential cell activities in plants. However, the regulatory role in specific plant developmental processes has not yet been fully elucidated. Here we identified the new ribosomal protein L18aB, which is specifically involved in sexual reproduction and plays a critical role in male gametophyte development and embryo pattern formation. In rpl18aB mutant plants, the mature pollen grains can germinate normally, but their competitiveness for growing in the style is significantly reduced. More interestingly, RPL18aB is required in early embryogenesis. rpl18aB embryos displayed irregular cell division orientations in the early pro-embryo and arrested at the globular stage with possible, secondary pattern formation defects. Further investigations revealed that the polar transportation of auxin is disturbed in the rpl18aB mutant embryos, which may explain the observed failure in embryo pattern formation. The cell type-specific complementation of RPL18aB in rpl18aB was not able to recover the phenotype, indicating that RPL18aB may play an essential role in early cell fate determination. This work unravels a novel role in embryo development for a ribosomal protein, and provides insight into regulatory mechanism of early embryogenesis. PMID:27502163

  8. Ribosomal protein L18aB is required for both male gametophyte function and embryo development in Arabidopsis

    PubMed Central

    Yan, Hailong; Chen, Dan; Wang, Yifan; Sun, Yang; Zhao, Jing; Sun, Mengxiang; Peng, Xiongbo

    2016-01-01

    Ribosomal proteins are involved in numerous essential cell activities in plants. However, the regulatory role in specific plant developmental processes has not yet been fully elucidated. Here we identified the new ribosomal protein L18aB, which is specifically involved in sexual reproduction and plays a critical role in male gametophyte development and embryo pattern formation. In rpl18aB mutant plants, the mature pollen grains can germinate normally, but their competitiveness for growing in the style is significantly reduced. More interestingly, RPL18aB is required in early embryogenesis. rpl18aB embryos displayed irregular cell division orientations in the early pro-embryo and arrested at the globular stage with possible, secondary pattern formation defects. Further investigations revealed that the polar transportation of auxin is disturbed in the rpl18aB mutant embryos, which may explain the observed failure in embryo pattern formation. The cell type-specific complementation of RPL18aB in rpl18aB was not able to recover the phenotype, indicating that RPL18aB may play an essential role in early cell fate determination. This work unravels a novel role in embryo development for a ribosomal protein, and provides insight into regulatory mechanism of early embryogenesis. PMID:27502163

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

    NASA Astrophysics Data System (ADS)

    Shi, Cuijuan; Kataoka, Hironao; Duan, Delin

    2005-09-01

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

  10. EXPORTIN1 Genes are Essential for Development and Function of the Gametophytes in Arabidopsis thaliana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gametes are produced in plants through mitotic divisions in the haploid gametophytes. We investigated the role of EXPORTIN1 (XPO1) genes during the development of both female and male gametophytes of Arabidopsis. Exportins exclude target proteins from the nucleus and are also part of a complex recru...

  11. Expression patterns of conserved microRNAs in the male gametophyte of loblolly pine (Pinus taeda).

    PubMed

    Quinn, Christina R; Iriyama, Rie; Fernando, Danilo D

    2014-06-01

    MicroRNAs (miRNAs) are small RNAs that regulate genes involved in various aspects of plant development, but their presence and expression patterns in the male gametophytes of gymnosperms have not yet been established. Therefore, this study identified and compared the expression patterns of conserved miRNAs from two stages of the male gametophyte of loblolly pine (Pinus taeda), which are the mature (ungerminated) and germinated pollen. Microarray was used to identify conserved miRNAs that varied in expression between these two stages of the loblolly pine male gametophyte. Forty-seven conserved miRNAs showed significantly different expression levels between mature and germinated loblolly pine pollen. In particular, miRNAs representing 14 and 8 families were up- and down-regulated in germinated loblolly pine pollen, respectively. qRT-PCR was used to validate their expression patterns using representative miRNAs. Target genes and proteins were identified using psRNATarget program. Predicted targets of the 22 miRNA families belong mostly to classes of genes involved in defense/stress response, metabolism, regulation, and signaling. qRT-PCR was also used to validate the expression patterns of representative target genes. This study shows that conserved miRNAs are expressed in mature and germinated loblolly pine pollen. Many of these miRNAs are differentially expressed, which indicates that the two stages of the male gametophyte examined are regulated at the miRNA level. This study also expands our knowledge of the male gametophytes of seed plants by providing insights on some similarities and differences in the types and expression patterns of conserved miRNAs between loblolly pine with those of rice and Arabidopsis. PMID:24664256

  12. Ubiquitous and Endoplasmic Reticulum–Located Lysophosphatidyl Acyltransferase, LPAT2, Is Essential for Female but Not Male Gametophyte Development in Arabidopsis

    PubMed Central

    Kim, Hyun Uk; Li, Yubing; Huang, Anthony H.C.

    2005-01-01

    Lysophosphatidyl acyltransferase (LPAT) is a pivotal enzyme controlling the metabolic flow of lysophosphatidic acid into different phosphatidic acids in diverse tissues. We examined putative LPAT genes in Arabidopsis thaliana and characterized two related genes that encode the cytoplasmic LPAT. LPAT2 is the lone gene that encodes the ubiquitous and endoplasmic reticulum (ER)–located LPAT. It could functionally complement a bacterial mutant with defective LPAT. LPAT2 and 3 synthesized in recombinant bacteria and yeast possessed in vitro enzyme activity higher on 18:1-CoA than on 16:0-CoA. LPAT2 was expressed ubiquitously in diverse tissues as revealed by RT-PCR, profiling with massively parallel signature sequencing, and promoter-driven β-glucuronidase gene expression. LPAT2 was colocalized with calreticulin in the ER by immunofluorescence microscopy and subcellular fractionation. LPAT3 was expressed predominately but more actively than LPAT2 in pollen. A null allele (lpat2) having a T-DNA inserted into LPAT2 was identified. The heterozygous mutant (LPAT2/lpat2) had minimal altered vegetative phenotype but produced shorter siliques that contained normal seeds and remnants of aborted ovules in a 1:1 ratio. Results from selfing and crossing it with the wild type revealed that lpat2 caused lethality in the female gametophyte but not the male gametophyte, which had the redundant LPAT3. LPAT2-cDNA driven by an LPAT2 promoter functionally complemented lpat2 in transformed heterozygous mutants to produce the lpat2/lpat2 genotype. LPAT3-cDNA driven by the LPAT2 promoter could rescue the lpat2 female gametophytes to allow fertilization to occur but not to full embryo maturation. Two other related genes, putative LPAT4 and 5, were expressed ubiquitously albeit at low levels in diverse organs. When they were expressed in bacteria or yeast, the microbial extract did not contain LPAT activity higher than the endogenous LPAT activity. Whether LPAT4 and 5 encode LPATs remains

  13. Development of the gametophyte of the fern Schizaea pusilla

    NASA Technical Reports Server (NTRS)

    Kiss, J. Z.; Swatzell, L. J.

    1996-01-01

    Schizaea pusilla is a pteridophyte with several unique developmental characteristics. In contrast to most other fern species, S. pusilla gametophytes remain filamentous throughout their development, and the gametophytes are associated with an endophytic fungus which appears to be mycorrhizal. In terms of tropistic responses, apical filament cells of young gametophytes are negatively phototropic compared with germ filaments of other ferns which exhibit positive phototropism. Cryofixation (propane jet freezing and high-pressure freezing) in conjunction with freeze substitution electron microscopy was used to study young gametophytes. The results demonstrate that apical filament cells have a distinctive structural polarity and that rhizoids also can be successfully frozen by these methods. The cytoskeleton and endomembrane system were particularly well preserved in cryofixed cells. In addition, Schizaea gametophytes were used as a test system to evaluate potential artifacts of propane jet freezing and high pressure freezing. There was little apparent difference in ultrastructure between cells cryofixed by either freezing method. These gametophytes will be useful in determining the effectiveness of cryofixation techniques and as a model system in tip growth studies.

  14. Programmed Cell Death During Female Gametophyte Development

    SciTech Connect

    Drews, Gary, N.

    2004-09-15

    Endosperm is a storage tissue in the angiosperm seed that is important both biologically and agriculturally. Endosperm is biologically important because it provides nutrients to the embryo during seed development and agriculturally important because it is a significant source of food, feed, and industrial raw materials. Approximately two-thirds of human calories are derived from endosperm, either directly or indirectly through animal feed. Furthermore, endosperm is used as a raw material for numerous industrial products including ethanol. A major event in endosperm development is the transition between the syncytial phase, during which the endosperm nuclei undergo many rounds of mitosis without cytokinesis, and the cellularized phase, during which cell walls form around the endosperm nuclei. Understanding how the syncytial-cellular transition is regulated is agriculturally important because it influences seed size, seed sink strength, and grain weight. However, the molecular processes controlling this transition are not understood. This project led to the identification of the AGL62 gene that regulates the syncytial-cellular transition during endosperm development. AGL62 is expressed during the syncytial phase and suppresses endosperm cellularization during this period. AGL62 most likely does so by suppressing the expression of genes required for cellularization. At the end of the syncytial phase, the FIS PcG complex suppresses AGL62 expression, which allows expression of the cellularization genes and triggers the initiation of the cellularized phase. Endosperm arises following fertilization of the central cell within the female gametophyte. This project also led to the identification of the AGL80 gene that is required for development of the central cell into the endosperm. Within the ovule and seed, AGL80 is expressed exclusively in the central cell and uncellularized endosperm. AGL80 is required for expression of several central cell-expressed genes, including

  15. Genetic analysis of female gametophyte development and function.

    PubMed Central

    Drews, G N; Lee, D; Christensen, C A

    1998-01-01

    The female gametophyte is an absolutely essential structure for angiosperm reproduction. It produces the egg cell and central cell (which give rise to the embryo and endosperm, respectively) and mediates several reproductive processes including pollen tube guidance, fertilization, the induction of seed development, and perhaps also maternal control of embryo development. Although much has been learned about these processes at the cytological level, specific molecules mediating and controlling megagametogenesis and female gametophyte function have not been identified. A genetic approach to the identification of such molecules has been initiated in Arabidopsis and maize. Although genetic analyses are still in their infancy, mutations affecting female gametophyte function and specific steps of megagametogenesis have already been identified. Large-scale genetic screens aimed at identifying mutants affecting every step of megagametogenesis and female gametophyte function are in progress; the characterization of genes identified in these screens should go a long way toward defining the molecules that are required for female gametophyte development and function. PMID:9477569

  16. Pollination triggers female gametophyte development in immature Nicotiana tabacum flowers.

    PubMed

    Brito, Michael S; Bertolino, Lígia T; Cossalter, Viviane; Quiapim, Andréa C; DePaoli, Henrique C; Goldman, Gustavo H; Teixeira, Simone P; Goldman, Maria H S

    2015-01-01

    In Nicotiana tabacum, female gametophytes are not fully developed at anthesis, but flower buds pollinated 12 h before anthesis produce mature embryo sacs. We investigated several pollination-associated parameters in N. tabacum flower buds to determine the developmental timing of important events in preparation for successful fertilization. First, we performed hand pollinations in flowers from stages 4 to 11 to study at which developmental stage pollination would produce fruits. A Peroxtesmo test was performed to correlate peroxidase activity on the stigma surface, indicative of stigma receptivity, with fruit set. Pollen tube growth and female gametophyte development were microscopically analyzed in pistils of different developmental stages. Fruits were obtained only after pollinations of flower buds at late stage 7 and older; fruit weight and seed germination capacity increased as the developmental stage of the pollinated flower approached anthesis. Despite positive peroxidase activity and pollen tube growth, pistils at stages 5 and 6 were unable to produce fruits. At late stage 7, female gametophytes were undergoing first mitotic division. After 24 h, female gametophytes of unpollinated pistils were still in the end of the first division, whereas those of pollinated pistils showed egg cells. RT-qPCR assay showed that the expression of the NtEC1 gene, a marker of egg cell development, is considerably higher in pollinated late stage 7 ovaries compared with unpollinated ovaries. To test whether ethylene is the signal eliciting female gametophyte maturation, the expression of ACC synthase was examined in unpollinated and pollinated stage 6 and late stage 7 stigmas/styles. Pollination induced NtACS expression in stage 6 pistils, which are unable to produce fruits. Our results show that pollination is a stimulus capable of triggering female gametophyte development in immature tobacco flowers and suggests the existence of a yet undefined signal sensed by the pistil. PMID

  17. Pollination triggers female gametophyte development in immature Nicotiana tabacum flowers

    PubMed Central

    Brito, Michael S.; Bertolino, Lígia T.; Cossalter, Viviane; Quiapim, Andréa C.; DePaoli, Henrique C.; Goldman, Gustavo H.; Teixeira, Simone P.; Goldman, Maria H. S.

    2015-01-01

    In Nicotiana tabacum, female gametophytes are not fully developed at anthesis, but flower buds pollinated 12 h before anthesis produce mature embryo sacs. We investigated several pollination-associated parameters in N. tabacum flower buds to determine the developmental timing of important events in preparation for successful fertilization. First, we performed hand pollinations in flowers from stages 4 to 11 to study at which developmental stage pollination would produce fruits. A Peroxtesmo test was performed to correlate peroxidase activity on the stigma surface, indicative of stigma receptivity, with fruit set. Pollen tube growth and female gametophyte development were microscopically analyzed in pistils of different developmental stages. Fruits were obtained only after pollinations of flower buds at late stage 7 and older; fruit weight and seed germination capacity increased as the developmental stage of the pollinated flower approached anthesis. Despite positive peroxidase activity and pollen tube growth, pistils at stages 5 and 6 were unable to produce fruits. At late stage 7, female gametophytes were undergoing first mitotic division. After 24 h, female gametophytes of unpollinated pistils were still in the end of the first division, whereas those of pollinated pistils showed egg cells. RT-qPCR assay showed that the expression of the NtEC1 gene, a marker of egg cell development, is considerably higher in pollinated late stage 7 ovaries compared with unpollinated ovaries. To test whether ethylene is the signal eliciting female gametophyte maturation, the expression of ACC synthase was examined in unpollinated and pollinated stage 6 and late stage 7 stigmas/styles. Pollination induced NtACS expression in stage 6 pistils, which are unable to produce fruits. Our results show that pollination is a stimulus capable of triggering female gametophyte development in immature tobacco flowers and suggests the existence of a yet undefined signal sensed by the pistil. PMID

  18. Maternal Gametophyte Effects on Seed Development in Maize

    PubMed Central

    Chettoor, Antony M.; Phillips, Allison R.; Coker, Clayton T.; Dilkes, Brian; Evans, Matthew M. S.

    2016-01-01

    Flowering plants, like placental mammals, have an extensive maternal contribution toward progeny development. Plants are distinguished from animals by a genetically active haploid phase of growth and development between meiosis and fertilization, called the gametophyte. Flowering plants are further distinguished by the process of double fertilization that produces sister progeny, the endosperm and the embryo, of the seed. Because of this, there is substantial gene expression in the female gametophyte that contributes to the regulation of growth and development of the seed. A primary function of the endosperm is to provide growth support to its sister embryo. Several mutations in Zea mays subsp. mays have been identified that affect the contribution of the mother gametophyte to the seed. The majority affect both the endosperm and the embryo, although some embryo-specific effects have been observed. Many alter the pattern of expression of a marker for the basal endosperm transfer layer, a tissue that transports nutrients from the mother plant to the developing seed. Many of them cause abnormal development of the female gametophyte prior to fertilization, revealing potential cellular mechanisms of maternal control of seed development. These effects include reduced central cell size, abnormal architecture of the central cell, abnormal numbers and morphology of the antipodal cells, and abnormal egg cell morphology. These mutants provide insight into the logic of seed development, including necessary features of the gametes and supporting cells prior to fertilization, and set up future studies on the mechanisms regulating maternal contributions to the seed. PMID:27466227

  19. Fern Gametophytes in Culture--A Simple System for Studying Plant Development and Reproduction.

    ERIC Educational Resources Information Center

    Dyer, A. F.

    1983-01-01

    Discusses fern life cycle and basic techniques for culturing fern gametophytes in the classroom. Also discusses investigations into the reproductive biology of ferns and into the early development of gametophytes. (JN)

  20. Rapid separation of Arabidopsis male gametophyte developmental stages using a Percoll gradient.

    PubMed

    Dupl'áková, Nikoleta; Dobrev, Petre I; Reňák, David; Honys, David

    2016-10-01

    Research investigating the dynamics of male gametophyte (MG) development has proven to be challenging for the plant science community. Here we describe our protocol for separating Arabidopsis MG developmental stages, which is based on the centrifugation of pollen through a discontinuous Percoll concentration gradient. This Percoll gradient can be formed using a pipette, and it does not require a gradient maker. The purity of the isolated developing spores is as high as 70%, and in most separations it is well above 80%. Using this protocol, we can separate four different stages of pollen development-uninucleate microspore (UNM), bicellular pollen (BCP), tricellular immature pollen (TCP) and mature pollen grain (MPG). The duration of the separation procedure, excluding the cutting of flower inflorescences, is 6 h. This is reduced to 4 h when using a vacuum cleaning method to remove the MPGs before the Percoll density separation. PMID:27583643

  1. The population ecology of male gametophytes: the link between pollination and seed production.

    PubMed

    Harder, Lawrence D; Aizen, Marcelo A; Richards, Shane A

    2016-05-01

    The fate of male gametophytes after pollen reaches stigmas links pollination to ovule fertilisation, governing subsequent siring success and seed production. Although male gametophyte performance primarily involves cellular processes, an ecological analogy may expose insights into the nature and implications of male gametophyte success. We elaborate this analogy theoretically and present empirical examples that illustrate associated insights. Specifically, we consider pollen loads on stigmas as localised populations subject to density-independent mortality and density-dependent processes as they traverse complex stylar environments. Different combinations of the timing of pollen-tube access to limiting stylar resources (simultaneous or sequential), the tube distribution among resources (repulsed or random) and the timing of density-independent mortality relative to competition (before or after) create signature relations of mean pollen-tube success and its variation among pistils to pollen receipt. Using novel nonlinear regression analyses (two-moment regression), we illustrate contrasting relations for two species, demonstrating that variety in these relations is a feature of reproductive diversity among angiosperms, rather than merely a theoretical curiosity. Thus, the details of male gametophyte ecology should shape sporophyte reproductive success and hence the dynamics and structure of angiosperm populations. PMID:26970246

  2. The Phosphorylated Pathway of Serine Biosynthesis Is Essential Both for Male Gametophyte and Embryo Development and for Root Growth in Arabidopsis[W

    PubMed Central

    Cascales-Miñana, Borja; Muñoz-Bertomeu, Jesús; Flores-Tornero, María; Anoman, Armand Djoro; Pertusa, José; Alaiz, Manuel; Osorio, Sonia; Fernie, Alisdair R.; Segura, Juan; Ros, Roc

    2013-01-01

    This study characterizes the phosphorylated pathway of Ser biosynthesis (PPSB) in Arabidopsis thaliana by targeting phosphoserine phosphatase (PSP1), the last enzyme of the pathway. Lack of PSP1 activity delayed embryo development, leading to aborted embryos that could be classified as early curled cotyledons. The embryo-lethal phenotype of psp1 mutants could be complemented with PSP1 cDNA under the control of Pro35S (Pro35S:PSP1). However, this construct, which was poorly expressed in the anther tapetum, did not complement mutant fertility. Microspore development in psp1.1/psp1.1 Pro35S:PSP1 arrested at the polarized stage. The tapetum from these lines displayed delayed and irregular development. The expression of PSP1 in the tapetum at critical stages of microspore development suggests that PSP1 activity in this cell layer is essential in pollen development. In addition to embryo death and male sterility, conditional psp1 mutants displayed a short-root phenotype, which was reverted in the presence of Ser. A metabolomic study demonstrated that the PPSB plays a crucial role in plant metabolism by affecting glycolysis, the tricarboxylic acid cycle, and the biosynthesis of amino acids. We provide evidence of the crucial role of the PPSB in embryo, pollen, and root development and suggest that this pathway is an important link connecting primary metabolism with development. PMID:23771893

  3. A New Mutation, hap1-2, Reveals a C Terminal Domain Function in AtMago Protein and Its Biological Effects in Male Gametophyte Development in Arabidopsis thaliana.

    PubMed

    Cilano, Kevin; Mazanek, Zachary; Khan, Mahmuda; Metcalfe, Sarah; Zhang, Xiao-Ning

    2016-01-01

    The exon-exon junction complex (EJC) is a conserved eukaryotic multiprotein complex that examines the quality of and determines the availability of messenger RNAs (mRNAs) posttranscriptionally. Four proteins, MAGO, Y14, eIF4AIII and BTZ, function as core components of the EJC. The mechanisms of their interactions and the biological indications of these interactions are still poorly understood in plants. A new mutation, hap1-2. leads to premature pollen death and a reduced seed production in Arabidopsis. This mutation introduces a viable truncated transcript AtMagoΔC. This truncation abolishes the interaction between AtMago and AtY14 in vitro, but not the interaction between AtMago and AteIF4AIII. In addition to a strong nuclear presence of AtMago, both AtMago and AtMagoΔC exhibit processing-body (P-body) localization. This indicates that AtMagoΔC may replace AtMago in the EJC when aberrant transcripts are to be degraded. When introducing an NMD mutation, upf3-1, into the existing HAP1/hap1-2 mutant, plants showed a severely reduced fertility. However, the change of splicing pattern of a subset of SR protein transcripts is mostly correlated with the sr45-1 and upf3-1 mutations, not the hap1-2 mutation. These results imply that the C terminal domain (CTD) of AtMago is required for the AtMago-AtY14 heterodimerization during EJC assembly, UPF3-mediated NMD pathway and the AtMago-AtY14 heterodimerization work synergistically to regulate male gametophyte development in plants. PMID:26867216

  4. A New Mutation, hap1-2, Reveals a C Terminal Domain Function in AtMago Protein and Its Biological Effects in Male Gametophyte Development in Arabidopsis thaliana

    PubMed Central

    Cilano, Kevin; Mazanek, Zachary; Khan, Mahmuda; Metcalfe, Sarah; Zhang, Xiao-Ning

    2016-01-01

    The exon-exon junction complex (EJC) is a conserved eukaryotic multiprotein complex that examines the quality of and determines the availability of messenger RNAs (mRNAs) posttranscriptionally. Four proteins, MAGO, Y14, eIF4AIII and BTZ, function as core components of the EJC. The mechanisms of their interactions and the biological indications of these interactions are still poorly understood in plants. A new mutation, hap1-2. leads to premature pollen death and a reduced seed production in Arabidopsis. This mutation introduces a viable truncated transcript AtMagoΔC. This truncation abolishes the interaction between AtMago and AtY14 in vitro, but not the interaction between AtMago and AteIF4AIII. In addition to a strong nuclear presence of AtMago, both AtMago and AtMagoΔC exhibit processing-body (P-body) localization. This indicates that AtMagoΔC may replace AtMago in the EJC when aberrant transcripts are to be degraded. When introducing an NMD mutation, upf3-1, into the existing HAP1/hap1-2 mutant, plants showed a severely reduced fertility. However, the change of splicing pattern of a subset of SR protein transcripts is mostly correlated with the sr45-1 and upf3-1 mutations, not the hap1-2 mutation. These results imply that the C terminal domain (CTD) of AtMago is required for the AtMago-AtY14 heterodimerization during EJC assembly, UPF3-mediated NMD pathway and the AtMago-AtY14 heterodimerization work synergistically to regulate male gametophyte development in plants. PMID:26867216

  5. Early development of fern gametophytes in microgravity

    NASA Astrophysics Data System (ADS)

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

    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.

  6. 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.

  7. Developmental morphology of strap-shaped gametophytes of Colysis decurrens: a new look at meristem development and function in fern gametophytes

    PubMed Central

    Takahashi, Naoko; Hashino, Mie; Kami, Chieko; Imaichi, Ryoko

    2009-01-01

    Background and Aims The gametophytes of most homosporous ferns are cordate–thalloid in shape. Some are strap- or ribbon-shaped and have been assumed to have evolved from terrestrial cordate shapes as an adaptation to epiphytic habitats. The aim of the present study was to clarify the morphological evolution of the strap-shaped gametophyte of microsoroids (Polypodiaceae) by precise analysis of their development. Methods Spores of Colysis decurrens collected in Kagoshima, Japan, were cultured and observed microscopically. Epi-illuminated micrographs of growing gametophytes were captured every 24 h, allowing analysis of the cell lineage of meristems. Light microscopy of resin-sections and scanning electron microscopy were also used. Key Results Contrary to previous assumptions that strap-shaped Colysis gametophytes have no organized meristem, three different types of meristems are formed during development: (1) apical-cell based – responsible for early growth; (2) marginal – further growth, including gametophyte branching; and (3) multicellular – formation of cushions with archegonia. The cushion is two or three layers thick and intermittent. The apical-cell and multicellular meristems are similar to those of cordate gametophytes of other ferns, but the marginal meristem is unique to the strap-shaped gametophyte of this fern. Conclusions The strap-shaped gametophytes of C. decurrens may have evolved from ancestors with a cordate shape by insertion of the marginal meristem phase between the first apical-cell-based meristem and subsequent multicellular meristem phases. Repeated retrieval of the marginal meristem at the multicellular meristem phase would result in indefinite prolongation of gametophyte growth, an ecological adaptation to epiphytic habitats. PMID:19812067

  8. Expression of the Arabidopsis transposable element Tag1 is targeted to developing gametophytes.

    PubMed

    Galli, Mary; Theriault, Angie; Liu, Dong; Crawford, Nigel M

    2003-12-01

    The Arabidopsis transposon Tag1 undergoes late excision during vegetative and germinal development in plants containing 35S-Tag1-GUS constructs. To determine if transcriptional regulation can account for the developmental control of Tag1 excision, the transcriptional activity of Tag1 promoter-GUS fusion constructs of various lengths was examined in transgenic plants. All constructs showed expression in the reproductive organs of developing flowers but no expression in leaves. Expression was restricted to developing gametophytes in both male and female lineages. Quantitative RT-PCR analysis confirmed that Tag1 expression predominates in the reproductive organs of flower buds. These results are consistent with late germinal excision of Tag1, but they cannot explain the vegetative excision activity of Tag1 observed with 35S-Tag1-GUS constructs. To resolve this issue, Tag1 excision was reexamined using elements with no adjacent 35S promoter sequences. Tag1 excision in this context is restricted to germinal events with no detectable vegetative excision. If a 35S enhancer sequence is placed next to Tag1, vegetative excision is restored. These results indicate that the intrinsic activity of Tag1 is restricted to germinal excision due to targeted expression of the Tag1 transposase to developing gametophytes and that this activity is altered by the presence of adjacent enhancers or promoters. PMID:14704189

  9. The Female Gametophyte

    PubMed Central

    Drews, Gary N.; Koltunow, Anna M.G

    2011-01-01

    The angiosperm female gametophyte is critical for plant reproduction. It contains the egg cell and central cell that become fertilized and give rise to the embryo and endosperm of the seed, respectively. Female gametophyte development begins early in ovule development with the formation of a diploid megaspore mother cell that undergoes meiosis. One resulting haploid megaspore then develops into the female gametophyte. Genetic and epigenetic processes mediate specification of megaspore mother cell identity and limit megaspore mother cell formation to a single cell per ovule. Auxin gradients influence female gametophyte polarity and a battery of transcription factors mediate female gametophyte cell specification and differentiation. The mature female gametophyte secretes peptides that guide the pollen tube to the embryo sac and contains protein complexes that prevent seed development before fertilization. Post-fertilization, the female gametophyte influences seed development through maternal-effect genes and by regulating parental contributions. Female gametophytes can form by an asexual process called gametophytic apomixis, which involves formation of a diploid female gametophyte and fertilization-independent development of the egg into the embryo. These functions collectively underscore the important role of the female gametophyte in seed and food production. PMID:22303279

  10. The female gametophyte.

    PubMed

    Drews, Gary N; Koltunow, Anna M G

    2011-01-01

    The angiosperm female gametophyte is critical for plant reproduction. It contains the egg cell and central cell that become fertilized and give rise to the embryo and endosperm of the seed, respectively. Female gametophyte development begins early in ovule development with the formation of a diploid megaspore mother cell that undergoes meiosis. One resulting haploid megaspore then develops into the female gametophyte. Genetic and epigenetic processes mediate specification of megaspore mother cell identity and limit megaspore mother cell formation to a single cell per ovule. Auxin gradients influence female gametophyte polarity and a battery of transcription factors mediate female gametophyte cell specification and differentiation. The mature female gametophyte secretes peptides that guide the pollen tube to the embryo sac and contains protein complexes that prevent seed development before fertilization. Post-fertilization, the female gametophyte influences seed development through maternal-effect genes and by regulating parental contributions. Female gametophytes can form by an asexual process called gametophytic apomixis, which involves formation of a diploid female gametophyte and fertilization-independent development of the egg into the embryo. These functions collectively underscore the important role of the female gametophyte in seed and food production. PMID:22303279

  11. Sporogenesis and development of gametophytes in an endangered plant, Tetracentron sinense Oliv.

    PubMed

    Gan, Xiaohong; Xie, Dan; Cao, Lingling

    2012-01-01

    The sporogenesis and development of gametophytes in Tetracentron sinense Oliv. were studied with light microscopy. The anther has four microsporangia; its primary anther wall consists of an epidermis, an endothecium, one or two middle layers and one glandular tapetum. Simultaneous cytokinesis follows meiosis, forming a tetrahedral tetrad. Mature pollen grains are two-celled at the time of anther dehiscence. Its ovule is anatropous, bitegmic and crassinucellate; the development of the female gametophyte is of the monosporic 8-nucleate Polygonum type. Significantly, some striking features were first found in T. sinense: (1) anther dehiscence occurs soon after the endothecium fibrously thickens and the intersporangial septum degenerates; (2) tapetum degeneration is retarded, persisting up to the stage of two-celled pollen grain; (3) a few cellular events such as the vacuolization and the contraction and deformation of the pollen mother cell (PMC) and microspore are not normal at the PMC, dyad and tetrad stages. The abnormalities during male reproduction might be one of important factors resulting in the poor natural regeneration of T. sinense. PMID:23558997

  12. Gametophytic development of Brassica napus pollen in vitroenables examination of cytoskeleton and nuclear movements.

    PubMed

    Dubas, Ewa; Wedzony, Maria; Custers, Jan; Kieft, Henk; van Lammeren, André A M

    2012-04-01

    Isolated microspores and pollen suspension of Brassica napus "Topas" cultured in NLN-13 medium at 18°C follow gametophytic pathway and develop into pollen grains closely resembling pollen formed in planta. This culture system complemented with whole-mount immunocytochemical technology and novel confocal laser scanning optical technique enables detailed studies of male gametophyte including asymmetric division, cytoskeleton, and nuclear movements. Microtubular cytoskeleton configurationally changed in successive stages of pollen development. The most prominent role of microtubules (MTs) was observed just before and during nuclear migration at the early and mid-bi-cellular stage. At the early bi-cellular stage, parallel arrangement of cortical and endoplasmic MTs to the long axis of the generative cell (GC) as well as MTs within GC under the plasmalemma bordering vegetative cell (VC) were responsible for GC lens shape. At the beginning of the GC migration, endoplasmic microtubules (EMTs) of the VC radiated from the nuclear envelope. Most cortical and EMTs of the VC were found near the sporoderm. At the same time, pattern of MTs observed in GC was considerably different. Multiple EMTs of the GC, previously parallel aligned, reorganized, and start to surround GC, forming a basket-like structure. These results suggest that EMTs of GC provoke changes in GC shape, its detachment from the sporoderm, and play an important role in GC migration to the vegetative nucleus (VN). During the process of migration of the GC to the VC, multiple and thick bundles of MTs, radiating from the cytoplasm near GC plasma membrane, arranged perpendicular to the narrow end of the GC and organized into a "comet-tail" form. These GC "tail" MTs became shortened and the generative nucleus (GN) took a ball shape. The dynamic changes of MTs accompanied polarized distribution pattern of mitochondria and endoplasmic reticulum. In order to confirm the role of MTs in pollen development, a "whole

  13. Embryo and endosperm development is disrupted in the female gametophytic capulet mutants of Arabidopsis.

    PubMed Central

    Grini, Paul E; Jürgens, Gerd; Hülskamp, Martin

    2002-01-01

    The female gametophyte of higher plants gives rise, by double fertilization, to the diploid embryo and triploid endosperm, which develop in concert to produce the mature seed. What roles gametophytic maternal factors play in this process is not clear. The female-gametophytic effects on embryo and endosperm development in the Arabidopsis mea, fis, and fie mutants appear to be due to gametic imprinting that can be suppressed by METHYL TRANSFERASE1 antisense (MET1 a/s) transgene expression or by mutation of the DECREASE IN DNA METHYLATION1 (DDM1) gene. Here we describe two novel gametophytic maternal-effect mutants, capulet1 (cap1) and capulet2 (cap2). In the cap1 mutant, both embryo and endosperm development are arrested at early stages. In the cap2 mutant, endosperm development is blocked at very early stages, whereas embryos can develop to the early heart stage. The cap mutant phenotypes were not rescued by wild-type pollen nor by pollen from tetraploid plants. Furthermore, removal of silencing barriers from the paternal genome by MET1 a/s transgene expression or by the ddm1 mutation also failed to restore seed development in the cap mutants. Neither cap1 nor cap2 displayed autonomous seed development, in contrast to mea, fis, and fie mutants. In addition, cap2 was epistatic to fis1 in both autonomous endosperm and sexual development. Finally, both cap1 and cap2 mutant endosperms, like wild-type endosperms, expressed the paternally inactive endosperm-specific FIS2 promoter GUS fusion transgene only when the transgene was introduced via the embryo sac, indicating that imprinting was not affected. Our results suggest that the CAP genes represent novel maternal functions supplied by the female gametophyte that are required for embryo and endosperm development. PMID:12524359

  14. Dihydroxyacid dehydratase is important for gametophyte development and disruption causes increased susceptibility to salinity stress in Arabidopsis.

    PubMed

    Zhang, Chun; Pang, Qiuying; Jiang, Luguang; Wang, Shoucai; Yan, Xiufeng; Chen, Sixue; He, Yan

    2015-02-01

    Dihydroxyacid dehydratase (DHAD) catalyses a key step in the branched-chain amino acid (BCAA) biosynthetic pathway that exists in numerous organisms, including bacteria, fungi, and plants, but not humans. In Arabidopsis thaliana, DHAD is encoded by a single gene (AT3G23940), but its biological function in controlling plant development remains uncharacterized. In this study, we showed that DHAD is highly expressed in most vegetative and reproductive tissues. It is an essential gene, and complete disruption caused partial sterility in both male and female gametophyte phases. In addition, reduced expression of DHAD in knockdown mutants resulted in a reduction in the accumulation of all three BCAAs in roots and, as a consequence, led to a shorter root phenotype, which could be restored by an exogenous supplement of free BCAAs. Interestingly, the knockdown mutants became hypersensitive to salt stress, not to heavy metal stress, implying that BCAAs may act as osmolytes in salt tolerance. This would be the second amino acid shown to confer such a function in addition to the well-documented proline. Our results provide evidence that BCAA biosynthesis plays important roles in gametophyte and root development, and BCAA homeostasis contributes to the adaptation of Arabidopsis to salinity stress. PMID:25399005

  15. Sporophyte and gametophyte development of Platycerium coronarium (Koenig) Desv. and P. grande (Fee) C. Presl. (Polypodiaceae) through in vitro propagation

    PubMed Central

    Aspiras, Reyno A.

    2009-01-01

    The sporophyte and gametophyte development of Platycerium coronarium and P. grande were compared through ex situ propagation using in vitro culture technique and under greenhouse and field conditions. The morphology of the sporophyte and gametophyte, type of spore germination and prothallial development of P. coronarium and P. grande were documented. Gametophytes of P. coronarium and P. grande were cultured in vitro using different media. The gametophytes were then transferred and potted in sterile chopped Cyathea spp. (anonotong) roots and garden soil for sporophyte formation. Sporophytes (plantlets) of the two Platycerium species were attached on the slabs of anonotong and on branches and trunks of Swietenia macrophylla (mahogany) under greenhouse and field conditions. Sporophyte morphology of P. coronarium and P. grande varies but not their gametophyte morphology. P. coronarium and P. grande exhibited rapid spore germination and gametophyte development in both spore culture medium and Knudson C culture medium containing 2% glucose. Gametophytes of P. coronarium and P. grande transferred to potting medium produced more number of sporophytes while the gametophytes inside the culture media did not produce sporophytes. Sporophytes of P. grande attached on mahogany branches produced more number of leaves with bigger leaf area than those attached on anonotong slabs. Likewise, sporophytes of P. coronarium attached on mahogany branches and anonotong slabs did not develop new leaves during two weeks monitoring and are still in a period of adjustment to its environment. Sporophytes of P. grande grown or attached on the trunk of mahogany trees in the field and under shaded environment favored their growth. PMID:23961053

  16. Sporophyte and gametophyte development of Platycerium coronarium (Koenig) Desv. and P. grande (Fee) C. Presl. (Polypodiaceae) through in vitro propagation.

    PubMed

    Aspiras, Reyno A

    2010-01-01

    The sporophyte and gametophyte development of Platycerium coronarium and P. grande were compared through ex situ propagation using in vitro culture technique and under greenhouse and field conditions. The morphology of the sporophyte and gametophyte, type of spore germination and prothallial development of P. coronarium and P. grande were documented. Gametophytes of P. coronarium and P. grande were cultured in vitro using different media. The gametophytes were then transferred and potted in sterile chopped Cyathea spp. (anonotong) roots and garden soil for sporophyte formation. Sporophytes (plantlets) of the two Platycerium species were attached on the slabs of anonotong and on branches and trunks of Swietenia macrophylla (mahogany) under greenhouse and field conditions. Sporophyte morphology of P. coronarium and P. grande varies but not their gametophyte morphology. P. coronarium and P. grande exhibited rapid spore germination and gametophyte development in both spore culture medium and Knudson C culture medium containing 2% glucose. Gametophytes of P. coronarium and P. grande transferred to potting medium produced more number of sporophytes while the gametophytes inside the culture media did not produce sporophytes. Sporophytes of P. grande attached on mahogany branches produced more number of leaves with bigger leaf area than those attached on anonotong slabs. Likewise, sporophytes of P. coronarium attached on mahogany branches and anonotong slabs did not develop new leaves during two weeks monitoring and are still in a period of adjustment to its environment. Sporophytes of P. grande grown or attached on the trunk of mahogany trees in the field and under shaded environment favored their growth. PMID:23961053

  17. Downregulation of the δ-Subunit Reduces Mitochondrial ATP Synthase Levels, Alters Respiration, and Restricts Growth and Gametophyte Development in Arabidopsis[W][OA

    PubMed Central

    Geisler, Daniela A.; Päpke, Carola; Obata, Toshihiro; Nunes-Nesi, Adriano; Matthes, Annemarie; Schneitz, Kay; Maximova, Eugenia; Araújo, Wagner L.; Fernie, Alisdair R.; Persson, Staffan

    2012-01-01

    The mitochondrial ATP synthase (F1Fo complex) is an evolutionary conserved multimeric protein complex that synthesizes the main bulk of cytosolic ATP, but the regulatory mechanisms of the subunits are only poorly understood in plants. In yeast, the δ-subunit links the membrane-embedded Fo part to the matrix-facing central stalk of F1. We used genetic interference and an inhibitor to investigate the molecular function and physiological impact of the δ-subunit in Arabidopsis thaliana. Delta mutants displayed both male and female gametophyte defects. RNA interference of delta resulted in growth retardation, reduced ATP synthase amounts, and increased alternative oxidase capacity and led to specific long-term increases in Ala and Gly levels. By contrast, inhibition of the complex using oligomycin triggered broad metabolic changes, affecting glycolysis and the tricarboxylic acid cycle, and led to a successive induction of transcripts for alternative respiratory pathways and for redox and biotic stress-related transcription factors. We conclude that (1) the δ-subunit is essential for male gametophyte development in Arabidopsis, (2) a disturbance of the ATP synthase appears to lead to an early transition phase and a long-term metabolic steady state, and (3) the observed long-term adjustments in mitochondrial metabolism are linked to reduced growth and deficiencies in gametophyte development. PMID:22805435

  18. Downregulation of the δ-subunit reduces mitochondrial ATP synthase levels, alters respiration, and restricts growth and gametophyte development in Arabidopsis.

    PubMed

    Geisler, Daniela A; Päpke, Carola; Obata, Toshihiro; Nunes-Nesi, Adriano; Matthes, Annemarie; Schneitz, Kay; Maximova, Eugenia; Araújo, Wagner L; Fernie, Alisdair R; Persson, Staffan

    2012-07-01

    The mitochondrial ATP synthase (F(1)F(o) complex) is an evolutionary conserved multimeric protein complex that synthesizes the main bulk of cytosolic ATP, but the regulatory mechanisms of the subunits are only poorly understood in plants. In yeast, the δ-subunit links the membrane-embedded F(o) part to the matrix-facing central stalk of F(1). We used genetic interference and an inhibitor to investigate the molecular function and physiological impact of the δ-subunit in Arabidopsis thaliana. Delta mutants displayed both male and female gametophyte defects. RNA interference of delta resulted in growth retardation, reduced ATP synthase amounts, and increased alternative oxidase capacity and led to specific long-term increases in Ala and Gly levels. By contrast, inhibition of the complex using oligomycin triggered broad metabolic changes, affecting glycolysis and the tricarboxylic acid cycle, and led to a successive induction of transcripts for alternative respiratory pathways and for redox and biotic stress-related transcription factors. We conclude that (1) the δ-subunit is essential for male gametophyte development in Arabidopsis, (2) a disturbance of the ATP synthase appears to lead to an early transition phase and a long-term metabolic steady state, and (3) the observed long-term adjustments in mitochondrial metabolism are linked to reduced growth and deficiencies in gametophyte development. PMID:22805435

  19. Characterization of the Two Maize Embryo-Lethal Defective Kernel Mutants Rgh*-1210 and Fl*-1253b: Effects on Embryo and Gametophyte Development

    PubMed Central

    Clark, J. K.; Sheridan, W. F.

    1988-01-01

    We have examined the effects on embryonic and gametophytic development of two nonallelic defective-kernel mutants of maize. Earlier studies indicated that both mutants are abnormal in embryonic morphogenesis as well as in the formation of their endosperm. Mutant rgh*-1210 embryos depart from the normal embryogenic pathway at the proembryo and transition stage, by developing meristematic lobes and losing bilateral symmetry. They continue growth as irregular cell masses that enlarge and become necrotic. Somatic embryos arising in rgh*-1210 callus cultures display the rgh*-1210 mutant phenotype. Mutant fl*-1253B embryos are variably blocked from the coleoptilar stage through stage 2. Following formation of the shoot apex in the mutant embryos the leaf primordia and tissues surrounding the embryonic axis continue growth and cell division, while the scutellum ceases development and becomes hypertrophied. Mutant fl*-1253B embryos are unable to germinate, either in mutant kernels or as immature embryos in culture, and the mutant scutellar tissue does not produce regenerable callus. Expression of the fl*-1253B locus during male gametophytic development is revealed by a marked reduction in pollen transmission as a result of mutant expression during the interval between meiosis and the initiation of pollen tube growth. In both mutants, there is considerable proliferation of the aleurone cells of the endosperm. Mutant expression of rgh*-1210 in the female gametophyte is revealed by the abnormal antipodal cells of the embryo sac. These results show that these two gene loci play unique and crucial roles in normal morphogenesis of the embryo. In addition, it is evident that both mutants are pleiotropic in affecting the development of the endosperm and gametophyte as well as the embryo. These pleiotropisms suggest some commonality in the gene regulation of development in these three tissues. PMID:17246478

  20. Zoospore-derived monoecious gametophytes in Undaria pinnatifida (Phaeophyceae)

    NASA Astrophysics Data System (ADS)

    Li, Jing; Pang, Shaojun; Shan, Tifeng; Liu, Feng; Gao, Suqin

    2014-03-01

    The annual life cycle of the brown seaweed Undaria pinnatifida (Harvey) Suringer comprises a macroscopic diploid sporophyte stage and a microscopic haploid gametophyte stage. In 2011, an unusual zoospore-derived monoecious gametophyte isolate (designated as line 10-5-3) of U. pinnatifida was observed. To understand this phenomenon, a comprehensive screening of eighty-two previously identified male gametophyte cultures, isolated from three randomly selected cultivars (lines 10, 7, and 5) was performed. Thirty-six of the isolates developed both antheridia and oogonia on the same filamentous fragment in a standard gametogenesis test (SGT: 18°C, 60 μmol photons/(m2·s)). Selfing of the monoecious gametophyte or crossing it with a normal male gametophyte both gave rise to morphologically normal sporophytic offspring. However, crossing resulted in a much higher fertilization rate (89.7%). The hybrid and selfed sporophytic offspring were grown to maturity in flow tanks at an ambient temperature of 10-18°C over a period of 69 days. Active zoospores were released from both types of mature sporophylls. The majority of these developed into male gametophytes, while 15%-20% developed into the observed monoecious structures on the same filament. Using PCR amplification it was found that all the monoecious gametophyte isolates and the sporophytic offspring resulting from the selfing and crossing lacked the femalelinked microsatellite sequence (a part of the locus Up-AC-2A8, GenBank accession No. AY738602.1), indicating their male nature. U. pinnatifida is an invasive species in some regions and the implications of the above findings for this species in nature are briefly discussed.

  1. The female gametophyte: an emerging model for cell type-specific systems biology in plant development.

    PubMed

    Schmid, Marc W; Schmidt, Anja; Grossniklaus, Ueli

    2015-01-01

    Systems biology, a holistic approach describing a system emerging from the interactions of its molecular components, critically depends on accurate qualitative determination and quantitative measurements of these components. Development and improvement of large-scale profiling methods ("omics") now facilitates comprehensive measurements of many relevant molecules. For multicellular organisms, such as animals, fungi, algae, and plants, the complexity of the system is augmented by the presence of specialized cell types and organs, and a complex interplay within and between them. Cell type-specific analyses are therefore crucial for the understanding of developmental processes and environmental responses. This review first gives an overview of current methods used for large-scale profiling of specific cell types exemplified by recent advances in plant biology. The focus then lies on suitable model systems to study plant development and cell type specification. We introduce the female gametophyte of flowering plants as an ideal model to study fundamental developmental processes. Moreover, the female reproductive lineage is of importance for the emergence of evolutionary novelties such as an unequal parental contribution to the tissue nurturing the embryo or the clonal production of seeds by asexual reproduction (apomixis). Understanding these processes is not only interesting from a developmental or evolutionary perspective, but bears great potential for further crop improvement and the simplification of breeding efforts. We finally highlight novel methods, which are already available or which will likely soon facilitate large-scale profiling of the specific cell types of the female gametophyte in both model and non-model species. We conclude that it may take only few years until an evolutionary systems biology approach toward female gametogenesis may decipher some of its biologically most interesting and economically most valuable processes. PMID:26579157

  2. The female gametophyte: an emerging model for cell type-specific systems biology in plant development

    PubMed Central

    Schmid, Marc W.; Schmidt, Anja; Grossniklaus, Ueli

    2015-01-01

    Systems biology, a holistic approach describing a system emerging from the interactions of its molecular components, critically depends on accurate qualitative determination and quantitative measurements of these components. Development and improvement of large-scale profiling methods (“omics”) now facilitates comprehensive measurements of many relevant molecules. For multicellular organisms, such as animals, fungi, algae, and plants, the complexity of the system is augmented by the presence of specialized cell types and organs, and a complex interplay within and between them. Cell type-specific analyses are therefore crucial for the understanding of developmental processes and environmental responses. This review first gives an overview of current methods used for large-scale profiling of specific cell types exemplified by recent advances in plant biology. The focus then lies on suitable model systems to study plant development and cell type specification. We introduce the female gametophyte of flowering plants as an ideal model to study fundamental developmental processes. Moreover, the female reproductive lineage is of importance for the emergence of evolutionary novelties such as an unequal parental contribution to the tissue nurturing the embryo or the clonal production of seeds by asexual reproduction (apomixis). Understanding these processes is not only interesting from a developmental or evolutionary perspective, but bears great potential for further crop improvement and the simplification of breeding efforts. We finally highlight novel methods, which are already available or which will likely soon facilitate large-scale profiling of the specific cell types of the female gametophyte in both model and non-model species. We conclude that it may take only few years until an evolutionary systems biology approach toward female gametogenesis may decipher some of its biologically most interesting and economically most valuable processes. PMID:26579157

  3. Reproduction and the pheromonal regulation of sex type in fern gametophytes

    PubMed Central

    Atallah, Nadia M.; Banks, Jo Ann

    2015-01-01

    The fern life cycle includes a haploid gametophyte that is independent of the sporophyte and functions to produce the gametes. In homosporous ferns, the sex of the gametophyte is not fixed but can vary depending on its social environment. In many species, the sexual phenotype of the gametophyte is determined by the pheromone antheridiogen. Antheridiogen induces male development and is secreted by hermaphrodites once they become insensitive to its male-inducing effect. Recent genetic and biochemical studies of the antheridiogen response and sex-determination pathway in ferns, which are highlighted here, reveal many similarities and interesting differences to GA signaling and biosynthetic pathways in angiosperms. PMID:25798139

  4. Phosphoenolpyruvate Provision to Plastids Is Essential for Gametophyte and Sporophyte Development in Arabidopsis thaliana[C][W

    PubMed Central

    Prabhakar, Veena; Löttgert, Tanja; Geimer, Stefan; Dörmann, Peter; Krüger, Stephan; Vijayakumar, Vinod; Schreiber, Lukas; Göbel, Cornelia; Feussner, Kirstin; Feussner, Ivo; Marin, Kay; Staehr, Pia; Bell, Kirsten; Flügge, Ulf-Ingo; Häusler, Rainer E.

    2010-01-01

    Restriction of phosphoenolpyruvate (PEP) supply to plastids causes lethality of female and male gametophytes in Arabidopsis thaliana defective in both a phosphoenolpyruvate/phosphate translocator (PPT) of the inner envelope membrane and the plastid-localized enolase (ENO1) involved in glycolytic PEP provision. Homozygous double mutants of cue1 (defective in PPT1) and eno1 could not be obtained, and homozygous cue1 heterozygous eno1 mutants [cue1/eno1(+/−)] exhibited retarded vegetative growth, disturbed flower development, and up to 80% seed abortion. The phenotypes of diminished oil in seeds, reduced flavonoids and aromatic amino acids in flowers, compromised lignin biosynthesis in stems, and aberrant exine formation in pollen indicate that cue1/eno1(+/−) disrupts multiple pathways. While diminished fatty acid biosynthesis from PEP via plastidial pyruvate kinase appears to affect seed abortion, a restriction in the shikimate pathway affects formation of sporopollonin in the tapetum and lignin in the stem. Vegetative parts of cue1/eno1(+/−) contained increased free amino acids and jasmonic acid but had normal wax biosynthesis. ENO1 overexpression in cue1 rescued the leaf and root phenotypes, restored photosynthetic capacity, and improved seed yield and oil contents. In chloroplasts, ENO1 might be the only enzyme missing for a complete plastidic glycolysis. PMID:20798327

  5. Genes expressed in the male gametophyte of flowering plants and their isolation

    SciTech Connect

    Stinson, J.R.; Eisenberg, A.J.; Willing, R.P.; Pe, M.E.; Hanson, D.D.; Mascarenhas, J.P.

    1987-01-01

    Recombinant cDNA libraries to poly(A)RNA isolated from mature pollen of Zea mays and Tradescantia paludosa have been constructed. Northern blot analyses indicate that several of the clones are unique to pollen and are not expressed in vegetative tissues. The majority, however, are expressed both in pollen and vegetative tissues. Southern hybridizations show that the pollen specific sequences in corn are present in one or a very few copies in the genome. By using several of the clones as probes, it was found that there are at least two different groups of mRNAs with respect to their synthesis. The mRNAs of the first group represented by the pollen specific clones are synthesized after microspore mitosis and increase in concentration up to maturity. The second group, exemplified by actin mRNA, begins to accumulate soon after meiosis, reaches its maximum by later pollen interphase, and decreases thereafter. Although the actin mRNA and the pollen specific mRNAs studied show very different patterns of initiation of synthesis and accumulation during pollen development, the rates of decline in these mRNAs during the first 60 minutes of germination and pollen tube growth in Tradescantia are similar and reflect the previously observed declines in rates of protein synthesis during this period.

  6. Trait evaluation and trial cultivation of Dongfang No. 2, the hybrid of a male gametophyte clone of Laminaria longissima (Laminariales, Phaeophyta) and a female one of L. japonica

    PubMed Central

    Li, Xiaojie; Cong, Yizhou; Shi, Yuanyuan; Qu, Shancun; Li, Zhiling; Wang, Guowen; Zhang, Zhuangzhi; Luo, Shiju; Dai, Hongliang; Xie, Jianzu; Jiang, Guangliang; Liu, Jialiang; Wang, Tongyong

    2006-01-01

    Direct cultivation of the first filial generation of gametophyte clones from different Laminaria species is a highly effective way of utilizing kelp heterozygous vigor (heterosis). A male gametophyte clone of L. longissima Miyabe and a female one of L. japonica Areschoug were hybridized, generating Dongfang No. 2 hybrid kelp. This hybrid kelp was used directly in trial cultivation, and its agronomical traits were evaluated. L. longissima and L. japonica are obviously different and complement each other in their morphological characteristics and ecological performances. The hybrid of their gametophyte clones, Dongfang No. 2, showed 56.8% heterozygous vigor in yield. It also showed increased yields of 41.0 and 76.4% compared to the widely used commercial kelps Variety 1 and Variety 2, respectively. In large-scale cultivation trials at different locations and in different years, Dongfang No. 2 attained significantly higher yields than Varieties 1 and 2, increasing yield by 26.4% on average over Variety 1 and by 65.0% over the other. Dongfang No. 2 has a robust holdfast and a wide, long and deep-brown uniform blade, which shows a distinct middle groove. In addition to yield, Dongfang No. 2 also demonstrates obvious heterozygous vigor in other agronomic traits. It is resistant to strong irradiance, as the two commercial varieties are, has an appropriate vegetative maturation time, and adapts well to a range of different culture conditions. The parentage analysis using AFLP of total DNA and SNP of the ITS region of ribosomal RNA transcription unit showed that Dongfang No. 2 is the real hybrid of L. japonica and L. longissima. PMID:19396352

  7. An Atlas of Type I MADS Box Gene Expression during Female Gametophyte and Seed Development in Arabidopsis[W

    PubMed Central

    Bemer, Marian; Heijmans, Klaas; Airoldi, Chiara; Davies, Brendan; Angenent, Gerco C.

    2010-01-01

    Members of the plant type I MADS domain subfamily have been reported to be involved in reproductive development in Arabidopsis (Arabidopsis thaliana). However, from the 61 type I genes in the Arabidopsis genome, only PHERES1, AGAMOUS-LIKE80 (AGL80), DIANA, AGL62, and AGL23 have been functionally characterized, which revealed important roles for these genes during female gametophyte and early seed development. The functions of the other genes are still unknown, despite the fact that the available single T-DNA insertion mutants have been largely investigated. The lack of mutant phenotypes is likely due to a considerable number of recent intrachromosomal duplications in the type I subfamily, resulting in nonfunctional genes in addition to a high level of redundancy. To enable a breakthrough in type I MADS box gene characterization, a framework needs to be established that allows the prediction of the functionality and redundancy of the type I genes. Here, we present a complete atlas of their expression patterns during female gametophyte and seed development in Arabidopsis, deduced from reporter lines containing translational fusions of the genes to green fluorescent protein and β-glucuronidase. All the expressed genes were revealed to be active in the female gametophyte or developing seed, indicating that the entire type I subfamily is involved in reproductive development in Arabidopsis. Interestingly, expression was predominantly observed in the central cell, antipodal cells, and chalazal endosperm. The combination of our expression results with phylogenetic and protein interaction data allows a better identification of putative redundantly acting genes and provides a useful tool for the functional characterization of the type I MADS box genes in Arabidopsis. PMID:20631316

  8. An atlas of type I MADS box gene expression during female gametophyte and seed development in Arabidopsis.

    PubMed

    Bemer, Marian; Heijmans, Klaas; Airoldi, Chiara; Davies, Brendan; Angenent, Gerco C

    2010-09-01

    Members of the plant type I MADS domain subfamily have been reported to be involved in reproductive development in Arabidopsis (Arabidopsis thaliana). However, from the 61 type I genes in the Arabidopsis genome, only PHERES1, AGAMOUS-LIKE80 (AGL80), DIANA, AGL62, and AGL23 have been functionally characterized, which revealed important roles for these genes during female gametophyte and early seed development. The functions of the other genes are still unknown, despite the fact that the available single T-DNA insertion mutants have been largely investigated. The lack of mutant phenotypes is likely due to a considerable number of recent intrachromosomal duplications in the type I subfamily, resulting in nonfunctional genes in addition to a high level of redundancy. To enable a breakthrough in type I MADS box gene characterization, a framework needs to be established that allows the prediction of the functionality and redundancy of the type I genes. Here, we present a complete atlas of their expression patterns during female gametophyte and seed development in Arabidopsis, deduced from reporter lines containing translational fusions of the genes to green fluorescent protein and beta-glucuronidase. All the expressed genes were revealed to be active in the female gametophyte or developing seed, indicating that the entire type I subfamily is involved in reproductive development in Arabidopsis. Interestingly, expression was predominantly observed in the central cell, antipodal cells, and chalazal endosperm. The combination of our expression results with phylogenetic and protein interaction data allows a better identification of putative redundantly acting genes and provides a useful tool for the functional characterization of the type I MADS box genes in Arabidopsis. PMID:20631316

  9. Expression of the AtSUC1 gene in the female gametophyte, and ecotype-specific expression differences in male reproductive organs.

    PubMed

    Feuerstein, A; Niedermeier, M; Bauer, K; Engelmann, S; Hoth, S; Stadler, R; Sauer, N

    2010-09-01

    Based on analyses in Arabidopsis thaliana ecotype C24, the AtSUC1 protein was previously characterised as a male gametophyte-specific H(+)/sucrose symporter. Later, expression analyses in ecotype Columbia-0 (Col-0) identified AtSUC1 expression also in trichomes (not detected in trichome-less C24 plants) and roots, suggesting ecotype-specific differences in AtSUC1 expression. Here, we present data on additional ecotype-specific differences in AtSUC1 expression in other tissues. Using different AtSUC1 promoter-reporter gene lines, we performed comparative analyses of AtSUC1 expression in floral tissues of C24 and Col-0 plants, and using an AtSUC1-specific antiserum, we performed immunohistochemical analyses on tissue sections from C24, Col-0, Landsberg erecta (Ler) and Wassilewskaija (Ws) ecotypes. We show that AtSUC1 expression occurs in the funicular epidermis of C24, Ler and Ws, but not in Col-0. In contrast, we observed high levels of AtSUC1 protein in pollen grains of Col-0, lower levels in pollen of C24 and Ler, and no AtSUC1 protein in Ws pollen. Moreover, our reporter gene analyses identified a previously undetected expression of AtSUC1 in the female gametophyte, and revealed that AtSUC1 expression in the funicular epidermis is absent from unpollinated siliques and is induced upon successful pollination. The impact of these findings on the potential physiological role of AtSUC1 is discussed. PMID:20712626

  10. Gene Expression Profiles in Rice Developing Ovules Provided Evidence for the Role of Sporophytic Tissue in Female Gametophyte Development.

    PubMed

    Wu, Ya; Yang, Liyu; Cao, Aqin; Wang, Jianbo

    2015-01-01

    The development of ovule in rice (Oryza sativa) is vital during its life cycle. To gain more understanding of the molecular events associated with the ovule development, we used RNA sequencing approach to perform transcriptome-profiling analysis of the leaf and ovules at four developmental stages. In total, 25,401, 23,343, 23,647 and 23,806 genes were identified from the four developmental stages of the ovule, respectively. We identified a number of differently expressed genes (DEGs) from three adjacent stage comparisons, which may play crucial roles in ovule development. The DEGs were then conducted functional annotations and Kyoto encyclopedia of genes and genomes (KEGG) pathway analyses. Genes related to cellular component biogenesis, membrane-bounded organelles and reproductive regulation were identified to be highly expressed during the ovule development. Different expression levels of auxin-related and cytokinin-related genes were also identified at various stages, providing evidence for the role of sporophytic ovule tissue in female gametophyte development from the aspect of gene expression. Generally, an overall transcriptome analysis for rice ovule development has been conducted. These results increased our knowledge of the complex molecular and cellular events that occur during the development of rice ovule and provided foundation for further studies on rice ovule development. PMID:26506227

  11. Gene Expression Profiles in Rice Developing Ovules Provided Evidence for the Role of Sporophytic Tissue in Female Gametophyte Development

    PubMed Central

    Cao, Aqin; Wang, Jianbo

    2015-01-01

    The development of ovule in rice (Oryza sativa) is vital during its life cycle. To gain more understanding of the molecular events associated with the ovule development, we used RNA sequencing approach to perform transcriptome-profiling analysis of the leaf and ovules at four developmental stages. In total, 25,401, 23,343, 23,647 and 23,806 genes were identified from the four developmental stages of the ovule, respectively. We identified a number of differently expressed genes (DEGs) from three adjacent stage comparisons, which may play crucial roles in ovule development. The DEGs were then conducted functional annotations and Kyoto encyclopedia of genes and genomes (KEGG) pathway analyses. Genes related to cellular component biogenesis, membrane-bounded organelles and reproductive regulation were identified to be highly expressed during the ovule development. Different expression levels of auxin-related and cytokinin-related genes were also identified at various stages, providing evidence for the role of sporophytic ovule tissue in female gametophyte development from the aspect of gene expression. Generally, an overall transcriptome analysis for rice ovule development has been conducted. These results increased our knowledge of the complex molecular and cellular events that occur during the development of rice ovule and provided foundation for further studies on rice ovule development. PMID:26506227

  12. The AINTEGUMENTA gene of Arabidopsis required for ovule and female gametophyte development is related to the floral homeotic gene APETALA2.

    PubMed Central

    Klucher, K M; Chow, H; Reiser, L; Fischer, R L

    1996-01-01

    Ovules play a central role in plant reproduction, generating the female gametophyte within sporophytic integuments. When fertilized, the integuments differentiate into the seed coat and support the development of the embryo and endosperm. Mutations in the AINTEGUMENTA (ANT) locus of Arabidopsis have a profound effect on ovule development. Strong ant mutants have ovules that fail to form integuments or a female gametophyte. Flower development is also altered, with a random reduction of organs in the outer three whorls. In addition, organs present in the outer three floral whorls often have abnormal morphology. Ovules from a weak ant mutant contain both inner and outer integuments but generally fail to produce a functional female gametophyte. We isolated the ANT gene by using a mutation derived by T-DNA insertional mutagenesis. ANT is a member of a gene family that includes the floral homeotic gene APETALA2 (AP2). Like AP2, ANT contains two AP2 domains homologous with the DNA binding domain of ethylene response element binding proteins. ANT is expressed most highly in developing flowers but is also expressed in vegetative tissue. Taken together, these results suggest that ANT is a transcription factor that plays a critical role in regulating ovule and female gametophyte development. PMID:8742706

  13. Induction of 2n female gametes in Populus adenopoda Maxim by high temperature exposure during female gametophyte development.

    PubMed

    Lu, Min; Zhang, Pingdong; Kang, Xiangyang

    2013-03-01

    In order to produce triploid plants, 2n female gametes were induced by treating female buds and developing embryo sacs of Populus adenopoda Maxim with high temperature exposure. During megasporogenesis, tests were conducted on the relationship between female gametophyte development and morphological changes of female catkins. In the resulting progeny, 12 triploids were produced, and the highest rate of triploid production was 40%. Cytological observation revealed that the pachytene to diakinesis phase of meiotic stages may be a suitable period for inducing megaspore chromosome doubling through high temperature exposure. On the other hand, catkins of 6-72 h after pollination were treated for inducing embryo sac chromosome doubling. In the offspring seedlings, 51 triploids were detected and the highest efficiency of triploid production was 83.33%. Correlation analysis between the proportion of each embryo sac's developmental stage and the percentage of triploid production indicated that the second mitotic division may be the most effective stage for 2n female gamete induction. Our findings showed that high temperature exposure is an ideal method for 2n female gamete induction. Heterozygous offspring are valuable for breeding programs of P. adenopoda. PMID:23641186

  14. Auxin Import and Local Auxin Biosynthesis Are Required for Mitotic Divisions, Cell Expansion and Cell Specification during Female Gametophyte Development in Arabidopsis thaliana

    PubMed Central

    Panoli, Aneesh; Martin, Maria Victoria; Alandete-Saez, Monica; Simon, Marissa; Neff, Christina; Swarup, Ranjan; Bellido, Andrés; Yuan, Li; Pagnussat, Gabriela C.; Sundaresan, Venkatesan

    2015-01-01

    The female gametophyte of flowering plants, called the embryo sac, develops from a haploid cell named the functional megaspore, which is specified after meiosis by the diploid sporophyte. In Arabidopsis, the functional megaspore undergoes three syncitial mitotic divisions followed by cellularization to form seven cells of four cell types including two female gametes. The plant hormone auxin is important for sporophytic developmental processes, and auxin levels are known to be regulated by biosynthesis and transport. Here, we investigated the role of auxin biosynthetic genes and auxin influx carriers in embryo sac development. We find that genes from the YUCCA/TAA pathway (YUC1, YUC2, YUC8, TAA1, TAR2) are expressed asymmetrically in the developing ovule and embryo sac from the two-nuclear syncitial stage until cellularization. Mutants for YUC1 and YUC2 exhibited defects in cell specification, whereas mutations in YUC8, as well as mutations in TAA1 and TAR2, caused defects in nuclear proliferation, vacuole formation and anisotropic growth of the embryo sac. Additionally, expression of the auxin influx carriers AUX1 and LAX1 were observed at the micropylar pole of the embryo sac and in the adjacent cells of the ovule, and the aux1 lax1 lax2 triple mutant shows multiple gametophyte defects. These results indicate that both localized auxin biosynthesis and auxin import, are required for mitotic divisions, cell expansion and patterning during embryo sac development. PMID:25970627

  15. Auxin Import and Local Auxin Biosynthesis Are Required for Mitotic Divisions, Cell Expansion and Cell Specification during Female Gametophyte Development in Arabidopsis thaliana.

    PubMed

    Panoli, Aneesh; Martin, Maria Victoria; Alandete-Saez, Monica; Simon, Marissa; Neff, Christina; Swarup, Ranjan; Bellido, Andrés; Yuan, Li; Pagnussat, Gabriela C; Sundaresan, Venkatesan

    2015-01-01

    The female gametophyte of flowering plants, called the embryo sac, develops from a haploid cell named the functional megaspore, which is specified after meiosis by the diploid sporophyte. In Arabidopsis, the functional megaspore undergoes three syncitial mitotic divisions followed by cellularization to form seven cells of four cell types including two female gametes. The plant hormone auxin is important for sporophytic developmental processes, and auxin levels are known to be regulated by biosynthesis and transport. Here, we investigated the role of auxin biosynthetic genes and auxin influx carriers in embryo sac development. We find that genes from the YUCCA/TAA pathway (YUC1, YUC2, YUC8, TAA1, TAR2) are expressed asymmetrically in the developing ovule and embryo sac from the two-nuclear syncitial stage until cellularization. Mutants for YUC1 and YUC2 exhibited defects in cell specification, whereas mutations in YUC8, as well as mutations in TAA1 and TAR2, caused defects in nuclear proliferation, vacuole formation and anisotropic growth of the embryo sac. Additionally, expression of the auxin influx carriers AUX1 and LAX1 were observed at the micropylar pole of the embryo sac and in the adjacent cells of the ovule, and the aux1 lax1 lax2 triple mutant shows multiple gametophyte defects. These results indicate that both localized auxin biosynthesis and auxin import, are required for mitotic divisions, cell expansion and patterning during embryo sac development. PMID:25970627

  16. Arabidopsis ubiquitin-conjugating enzyme UBC22 is required for female gametophyte development and likely involved in Lys11-linked ubiquitination.

    PubMed

    Wang, Sheng; Cao, Ling; Wang, Hong

    2016-05-01

    Protein ubiquitination is critical for numerous processes in eukaryotes. The ubiquitin-conjugating enzyme (E2) is required for ubiquitination. The Arabidopsis genome has approximately 37 E2 genes, but in vivo functions for most of them remain unknown. In this study we observed that knockout mutants of Arabidopsis UBC22 had much-reduced silique length and seed number, with nearly 90% of ovules aborted. Analyses revealed that the majority of mutant embryo sacs displayed severe defects and often contained no gamete nuclei. There was no difference between mutant and wild-type Arabidopsis at the megaspore mother cell stage; however, the functional megaspore was either not present or appeared abnormal in a large portion of mutant ovules, suggesting that the defect started with functional megaspore degeneration in the mutants. Degeneration continued during megagametogenesis, such that the percentage of mature embryo sacs without any gamete nuclei was much greater than the percentage of developing ovules without a functional megaspore and, in addition, various abnormalities in megagametogenesis were observed. Additionally, heterozygous plants had only 13.1% of ovules aborted, indicating that the heterozygous sporophytic tissues could affect the development of the mutant female gametophyte. UBC22 is the sole member of an Arabidopsis E2 subfamily, and is more closely related to one type of E2s in animals that catalyzes Lys11-specific ubiquitination. Indeed, our results showed that Arabidopsis UBC22 could catalyze ubiquitin dimer formation in vitro in a Lys11-dependent manner, suggesting that it likely catalyzes Lys11-linked ubiquitination in plants. This study has thus identified one biochemical property of UBC22 and revealed a novel function in female gametophyte development. PMID:27069118

  17. Arabidopsis ubiquitin-conjugating enzyme UBC22 is required for female gametophyte development and likely involved in Lys11-linked ubiquitination

    PubMed Central

    Wang, Sheng; Cao, Ling; Wang, Hong

    2016-01-01

    Protein ubiquitination is critical for numerous processes in eukaryotes. The ubiquitin-conjugating enzyme (E2) is required for ubiquitination. The Arabidopsis genome has approximately 37 E2 genes, but in vivo functions for most of them remain unknown. In this study we observed that knockout mutants of Arabidopsis UBC22 had much-reduced silique length and seed number, with nearly 90% of ovules aborted. Analyses revealed that the majority of mutant embryo sacs displayed severe defects and often contained no gamete nuclei. There was no difference between mutant and wild-type Arabidopsis at the megaspore mother cell stage; however, the functional megaspore was either not present or appeared abnormal in a large portion of mutant ovules, suggesting that the defect started with functional megaspore degeneration in the mutants. Degeneration continued during megagametogenesis, such that the percentage of mature embryo sacs without any gamete nuclei was much greater than the percentage of developing ovules without a functional megaspore and, in addition, various abnormalities in megagametogenesis were observed. Additionally, heterozygous plants had only 13.1% of ovules aborted, indicating that the heterozygous sporophytic tissues could affect the development of the mutant female gametophyte. UBC22 is the sole member of an Arabidopsis E2 subfamily, and is more closely related to one type of E2s in animals that catalyzes Lys11-specific ubiquitination. Indeed, our results showed that Arabidopsis UBC22 could catalyze ubiquitin dimer formation in vitro in a Lys11-dependent manner, suggesting that it likely catalyzes Lys11-linked ubiquitination in plants. This study has thus identified one biochemical property of UBC22 and revealed a novel function in female gametophyte development. PMID:27069118

  18. Directed Synthesis of a Segmental Chromosomal Transposition: An Approach to the Study of Chromosomes Lethal to the Gametophyte Generation of Maize

    PubMed Central

    Birchler, J. A.; Levin, D. M.

    1991-01-01

    Because of the haploid nature of the gametophyte generation of plants, most mutations that are lethal or detrimental to the gametophytes cannot be recovered. Our laboratory is currently developing several techniques to overcome this situation. In this paper, a procedure is described to generate directed segmental chromosomal transpositions. The method involves recovery of recombinants between reciprocal translocation overlaps such that one region of the genome is inserted into a nonhomologous chromosome in a predetermined and directed manner. This duplicated segment then could serve to cover deficiencies or mutations, lethal to the gametophytes, in the region from whence it originated. The manipulation of segmental chromosomal transpositions for analyzing mutants lethal or detrimental to the gametophyte generation is discussed. The procedure to generate transpositions, the translocations between normal A and supernumerary B chromosomes that generate deficiencies in the male gametes, the r-X1 chromosome that generates deficiencies in the female gametes and other techniques available in maize form a system to analyze gametophyte lethal mutations. PMID:2016056

  19. A subunit of the oligosaccharyltransferase complex is required for interspecific gametophyte recognition in Arabidopsis

    PubMed Central

    Müller, Lena M.; Lindner, Heike; Pires, Nuno D.; Gagliardini, Valeria; Grossniklaus, Ueli

    2016-01-01

    Species-specific gamete recognition is a key premise to ensure reproductive success and the maintenance of species boundaries. During plant pollen tube (PT) reception, gametophyte interactions likely allow the species-specific recognition of signals from the PT (male gametophyte) by the embryo sac (female gametophyte), resulting in PT rupture, sperm release, and double fertilization. This process is impaired in interspecific crosses between Arabidopsis thaliana and related species, leading to PT overgrowth and a failure to deliver the sperm cells. Here we show that ARTUMES (ARU) specifically regulates the recognition of interspecific PTs in A. thaliana. ARU, identified in a genome-wide association study (GWAS), exclusively influences interspecific—but not intraspecific—gametophyte interactions. ARU encodes the OST3/6 subunit of the oligosaccharyltransferase complex conferring protein N-glycosylation. Our results suggest that glycosylation patterns of cell surface proteins may represent an important mechanism of gametophyte recognition and thus speciation. PMID:26964640

  20. The Armadillo Repeat Gene ZAK IXIK Promotes Arabidopsis Early Embryo and Endosperm Development through a Distinctive Gametophytic Maternal Effect[C][W][OA

    PubMed Central

    Ngo, Quy A.; Baroux, Celia; Guthörl, Daniela; Mozerov, Peter; Collinge, Margaret A.; Sundaresan, Venkatesan; Grossniklaus, Ueli

    2012-01-01

    The proper balance of parental genomic contributions to the fertilized embryo and endosperm is essential for their normal growth and development. The characterization of many gametophytic maternal effect (GME) mutants affecting seed development indicates that there are certain classes of genes with a predominant maternal contribution. We present a detailed analysis of the GME mutant zak ixik (zix), which displays delayed and arrested growth at the earliest stages of embryo and endosperm development. ZIX encodes an Armadillo repeat (Arm) protein highly conserved across eukaryotes. Expression studies revealed that ZIX manifests a GME through preferential maternal expression in the early embryo and endosperm. This parent-of-origin–dependent expression is regulated by neither the histone and DNA methylation nor the DNA demethylation pathways known to regulate some other GME mutants. The ZIX protein is localized in the cytoplasm and nucleus of cells in reproductive tissues and actively dividing root zones. The maternal ZIX allele is required for the maternal expression of MINISEED3. Collectively, our results reveal a reproductive function of plant Arm proteins in promoting early seed growth, which is achieved through a distinct GME of ZIX that involves mechanisms for maternal allele-specific expression that are independent of the well-established pathways. PMID:23064319

  1. Transcriptomes of Plant Gametophytes Have a Higher Proportion of Rapidly Evolving and Young Genes than Sporophytes

    PubMed Central

    Gossmann, Toni I.; Saleh, Dounia; Schmid, Marc W.; Spence, Michael A.; Schmid, Karl J.

    2016-01-01

    Reproductive traits in plants tend to evolve rapidly due to various causes that include plant-pollinator coevolution and pollen competition, but the genomic basis of reproductive trait evolution is still largely unknown. To characterize evolutionary patterns of genome wide gene expression in reproductive tissues in the gametophyte and to compare them to developmental stages of the sporophyte, we analyzed evolutionary conservation and genetic diversity of protein-coding genes using microarray-based transcriptome data from three plant species, Arabidopsis thaliana, rice (Oryza sativa), and soybean (Glycine max). In all three species a significant shift in gene expression occurs during gametogenesis in which genes of younger evolutionary age and higher genetic diversity contribute significantly more to the transcriptome than in other stages. We refer to this phenomenon as “evolutionary bulge” during plant reproductive development because it differentiates the gametophyte from the sporophyte. We show that multiple, not mutually exclusive, causes may explain the bulge pattern, most prominently reduced tissue complexity of the gametophyte, a varying extent of selection on reproductive traits during gametogenesis as well as differences between male and female tissues. This highlights the importance of plant reproduction for understanding evolutionary forces determining the relationship of genomic and phenotypic variation in plants. PMID:26956888

  2. Transcriptomes of Plant Gametophytes Have a Higher Proportion of Rapidly Evolving and Young Genes than Sporophytes.

    PubMed

    Gossmann, Toni I; Saleh, Dounia; Schmid, Marc W; Spence, Michael A; Schmid, Karl J

    2016-07-01

    Reproductive traits in plants tend to evolve rapidly due to various causes that include plant-pollinator coevolution and pollen competition, but the genomic basis of reproductive trait evolution is still largely unknown. To characterize evolutionary patterns of genome wide gene expression in reproductive tissues in the gametophyte and to compare them to developmental stages of the sporophyte, we analyzed evolutionary conservation and genetic diversity of protein-coding genes using microarray-based transcriptome data from three plant species, Arabidopsis thaliana, rice (Oryza sativa), and soybean (Glycine max). In all three species a significant shift in gene expression occurs during gametogenesis in which genes of younger evolutionary age and higher genetic diversity contribute significantly more to the transcriptome than in other stages. We refer to this phenomenon as "evolutionary bulge" during plant reproductive development because it differentiates the gametophyte from the sporophyte. We show that multiple, not mutually exclusive, causes may explain the bulge pattern, most prominently reduced tissue complexity of the gametophyte, a varying extent of selection on reproductive traits during gametogenesis as well as differences between male and female tissues. This highlights the importance of plant reproduction for understanding evolutionary forces determining the relationship of genomic and phenotypic variation in plants. PMID:26956888

  3. Mycothallic/mycorrhizal symbiosis of chlorophyllous gametophytes and sporophytes of a fern, Pellaea viridis (Forsk.) Prantl (Pellaeaceae, Pteridales).

    PubMed

    Turnau, K; Anielska, T; Jurkiewicz, A

    2005-03-01

    Gametophytes of Pellaea viridis that appeared spontaneously on the surface of substratum originating from an ultramafic area were found to form mycothallic symbiosis with arbuscular mycorrhizal fungi (AMF) under laboratory conditions. In gametophytes and sporophytes grown with Glomus tenue, abundant arbuscule formation was observed at both stages. In gametophytes, the fungus was found in the region where the rhizoids are initiated. If G. intraradices was added to the soil, the gametophytes were colonised mostly by G. tenue, and roots of sporophytes were colonised by G. intraradices. The presence of AM fungi in both gametophytes and sporophytes of P. viridis resulted in the development of larger leaf area and root length of the sporophyte. The analysis of gametophytes from the Botanical Garden in Krakow (Poland) showed that cordate gametophytes of Pteridales, namely Pellaea viridis (Pellaeaceae), Adiantum raddianum and A. formosum (Adiantaceae), were also mycothallic. PMID:15103546

  4. Life history biology of early land plants: Deciphering the gametophyte phase

    PubMed Central

    Taylor, Thomas N.; Kerp, Hans; Hass, Hagen

    2005-01-01

    The ca. 400-million-year-old Rhynie chert biota represents a benchmark for studies of early terrestrial ecosystems. The exquisite preservation of the organisms documents an ancient biodiversity that also includes various levels of biological interaction. Absent from the picture until recently has been detailed information about the development of the gametophyte phase and the alternation of generations of the macroplants in this ecosystem. Here, we trace the development of the gametophyte phase of Aglaophyton, an early land plant with an unusual complement of structural and morphological characters. Mature gametophytes consist of a fleshy protocorm attached to the substrate by basal rhizoids; arising from the upper surface are one to several upright gametangiophores bearing multiple gametangia. Stomata are present on the upper surface of the protocorm and gametangiophore, and endomycorrhizal fungi extend throughout the gametophyte. Gametophytes are unisexual, producing either antheridiophores or archegoniophores. There is no evidence that gametophytes later become hermaphroditic. The sexual dimorphism of the Rhynie chert gametophytes is inconsistent with theoretical ideas about the haploid phase of early land plants. The gametophyte phase of early land plants can now be considered within an ecological and evolutionary framework that, in turn, can be used to develop hypotheses about some aspects of the population dynamics and growth of these early land plants. PMID:15809414

  5. Arabidopsis TAF1 is an MRE11-interacting protein required for resistance to genotoxic stress and viability of the male gametophyte.

    PubMed

    Waterworth, Wanda M; Drury, Georgina E; Blundell-Hunter, George; West, Christopher E

    2015-11-01

    Repair of DNA double-strand breaks (DSBs) by recombination pathways is essential for plant growth and fertility. The recombination endonuclease MRE11 plays important roles in sensing and repair of DNA DSBs. Here we demonstrate protein interaction between Arabidopsis MRE11 and the histone acetyltransferase TAF1, a TATA-binding protein Associated Factor (TAF) of the RNA polymerase II transcription initiation factor complex TFIID. Arabidopsis has two TAF1 homologues termed TAF1 and TAF1b and mutant taf1b lines are viable and fertile. In contrast, taf1 null mutations are lethal, demonstrating that TAF1 is an essential gene. Heterozygous taf1+/- plants display abnormal segregation of the mutant allele resulting from defects in pollen tube development, indicating that TAF1 is important for gamete viability. Characterization of an allelic series of taf1 lines revealed that hypomorphic mutants are viable but display developmental defects and reduced plant fertility. Hypersensitivity of taf1 mutants lacking the C-terminal bromodomain to X-rays and mitomycin C, but not to other forms of abiotic stress, established a specific role for TAF1 in plant DNA repair processes. Collectively these studies reveal a function for TAF1 in plant resistance to genotoxic stress, providing further insight into the molecular mechanisms of the DNA damage response in plants. PMID:26358508

  6. Structural and developmental variability in the female gametophyte of Griffithella hookeriana, Polypleurum stylosum, and Zeylanidium lichenoides and its bearing on the occurrence of single fertilization in Podostemaceae.

    PubMed

    Sehgal, Anita; Mann, Neha; Mohan Ram, H Y

    2014-12-01

    Angiosperms are characterized by the phenomenon of double fertilization with Podostemaceae as an exception that appears to extend to the entire family. Our earlier work demonstrated the cause of failure of double fertilization and ascertained the occurrence of single fertilization in Dalzellia zeylanica (Tristichoideae, Podostemaceae). In continuation with this work, three more members, i.e., Griffithella hookeriana (Tul.) Warming, Polypleurum stylosum (Wight) Hall, and Zeylanidium lichenoides (Kurz) Engl. (Podostemoideae), have been investigated in the present work. We studied the ontogenetic development of female gametophyte and tracked the path of the two sperm cells from the time of their formation in the pollen tube through their entry into the synergid and gamete fusion. We report the occurrence of a remarkably reduced 3-nucleate, 3-celled mature female gametophyte consisting of an egg cell and two synergids in all the three genera. Interestingly, the central cell is formed during female gametophyte development, but exhibits a species-specific, limited life span, and eventually degenerates prior to the entry of the pollen tube into the synergid, resulting in a failure of double fertilization. Sperm dimorphism on the basis of fluorochrome stainability has been recorded in Z. lichenoides. Further, morphogenetic constraints on the part of male (sperm selection, functional reductionism) and female gametophyte (structural reductionism, inaccessibility of central cell) presumably ensure the failure of double fertilization in these species. Thus, loss of double fertilization in this family is likely a derived condition. PMID:25394544

  7. Defects in Peroxisomal 6-Phosphogluconate Dehydrogenase Isoform PGD2 Prevent Gametophytic Interaction in Arabidopsis thaliana.

    PubMed

    Hölscher, Christian; Lutterbey, Marie-Christin; Lansing, Hannes; Meyer, Tanja; Fischer, Kerstin; von Schaewen, Antje

    2016-05-01

    We studied the localization of 6-phosphogluconate dehydrogenase (PGD) isoforms of Arabidopsis (Arabidopsis thaliana). Similar polypeptide lengths of PGD1, PGD2, and PGD3 obscured which isoform may represent the cytosolic and/or plastidic enzyme plus whether PGD2 with a peroxisomal targeting motif also might target plastids. Reporter-fusion analyses in protoplasts revealed that, with a free N terminus, PGD1 and PGD3 accumulate in the cytosol and chloroplasts, whereas PGD2 remains in the cytosol. Mutagenesis of a conserved second ATG enhanced the plastidic localization of PGD1 and PGD3 but not PGD2. Amino-terminal deletions of PGD2 fusions with a free C terminus resulted in peroxisomal import after dimerization, and PGD2 could be immunodetected in purified peroxisomes. Repeated selfing of pgd2 transfer (T-)DNA alleles yielded no homozygous mutants, although siliques and seeds of heterozygous plants developed normally. Detailed analyses of the C-terminally truncated PGD2-1 protein showed that peroxisomal import and catalytic activity are abolished. Reciprocal backcrosses of pgd2-1 suggested that missing PGD activity in peroxisomes primarily affects the male gametophyte. Tetrad analyses in the quartet1-2 background revealed that pgd2-1 pollen is vital and in vitro germination normal, but pollen tube growth inside stylar tissues appeared less directed. Mutual gametophytic sterility was overcome by complementation with a genomic construct but not with a version lacking the first ATG. These analyses showed that peroxisomal PGD2 activity is required for guided growth of the male gametophytes and pollen tube-ovule interaction. Our report finally demonstrates an essential role of oxidative pentose-phosphate pathway reactions in peroxisomes, likely needed to sustain critical levels of nitric oxide and/or jasmonic acid, whose biosynthesis both depend on NADPH provision. PMID:26941195

  8. Study on gametophyte vegetative growth of Undaria pinnatifida and its applications

    NASA Astrophysics Data System (ADS)

    Pang, Shao-Jun; Wu, Chao-Yuan

    1996-09-01

    When cultured under certain environmental conditions (25°C, light intensity 80 μmol/m2·s, LD 12/12, in enriched seawater medium with 7×10-4 mol/L NO3-N, 1.56×10-4 mol/L, PO4-P and supplements of other elements like Mn, Fe, I, etc.), male and female gametophytes of U. pinnatifida kept growing vegetatively and propagated fast at average daily fresh weight increase rate of about 20%. The empirical formula G m= G o·3m was established to estimate the output of vegetative gametophytes. Vigorous vegetative gametophyte cells began to form reproductive structures (oogonium and spermatangium, when the temperature was lower than 25°C and other environmental factors were kept optimal. The sufficient supply of gametophyte cells provided enough seeds for raising Undaria sporelings on production scale. Controlled cross-breeding experiments using selected male and female gametophyte clones which increase their cell number by mitosis instead of meiosis were also carried out in vitro. Juvenile sporophytes from the cross-breeding had almost the same length and width increase rates as those of the control. The fact that vegetative gametophytes can be purposely selected, propagated quickly, cross-bred, with the resulting sporophytes having almost the same characteristics leads to a new way to select desired Undaria strains for long time use without losing the desired economic characteristics.

  9. ABORTED GAMETOPHYTE 1 is required for gametogenesis in Arabidopsis.

    PubMed

    Cui, Hong-Hui; Liao, Hong-Ze; Tang, Yu; Du, Xin-Yu; Chen, Li-Qun; Ye, De; Zhang, Xue-Qin

    2015-12-01

    In flowering plants, the male and female gametogenesis is a crucial step of sexual reproduction. Although many genes have been identified as being involved in the gametogenesis process, the genetic mechanisms underlying gametogenesis remains poorly understood. We reported here characterization of the gene, ABORTED GAMETOPHYTE 1 (AOG1) that is newly identified as essential for gametogenesis in Arabidopsis thaliana. AOG1 is expressed predominantly in reproductive tissues including the developing pollen grains and ovules. The AOG1 protein shares no significant amino acid sequence similarity with other documented proteins and is located mainly in nuclei of the cells. Mutation in AOG1 caused degeneration of pollen at the uninucleate microspore stage and severe defect in embryo sacs, leading to a significant reduction in male and female fertility. Furthermore, the molecular analyses showed that the aog1 mutant significantly affected the expression of several genes, which are required for gametogenesis. Our results suggest that AOG1 plays important roles in gametogenesis at the stage prior to pollen mitosis I (PMI) in Arabidopsis, possibly through collaboration with other genes. PMID:25693728

  10. The impact of environmental stress on male reproductive development in plants: biological processes and molecular mechanisms

    PubMed Central

    de Storme, Nico; Geelen, Danny

    2014-01-01

    In plants, male reproductive development is extremely sensitive to adverse climatic environments and (a)biotic stress. Upon exposure to stress, male gametophytic organs often show morphological, structural and metabolic alterations that typically lead to meiotic defects or premature spore abortion and male reproductive sterility. Depending on the type of stress involved (e.g. heat, cold, drought) and the duration of stress exposure, the underlying cellular defect is highly variable and either involves cytoskeletal alterations, tapetal irregularities, altered sugar utilization, aberrations in auxin metabolism, accumulation of reactive oxygen species (ROS; oxidative stress) or the ectopic induction of programmed cell death (PCD). In this review, we present the critically stress-sensitive stages of male sporogenesis (meiosis) and male gametogenesis (microspore development), and discuss the corresponding biological processes involved and the resulting alterations in male reproduction. In addition, this review also provides insights into the molecular and/or hormonal regulation of the environmental stress sensitivity of male reproduction and outlines putative interaction(s) between the different processes involved. PMID:23731015

  11. Effect of temperature and photon fluence rate on gametophytes and young sporophytes of Laminaria ochroleuca Pylaie

    NASA Astrophysics Data System (ADS)

    Izquierdo, José Luis; Pérez-Ruzafa, Isabel; Gallardo, Tomás

    2002-02-01

    We analysed the effects of temperature and photon fluence rate on meiospore germination, growth and fertility of gametophytes, and growth of young sporophytes of Laminaria ochroleuca. Maximum percentages of germination (91-98%) were obtained at 15°C and 18°C, independent of photon fluence rate. Optimal development of female gametophyte and maximum fecundity and reproductive success of gametophytes occurred at 15°C and 18°C and at 20 and 40 µmol m-2 s-1. Maximum relative growth rate of young sporophytes after 2 weeks of culture was achieved under the same conditions. L. ochroleuca gametophytes cannot reproduce and growth of its sporophytes is not competitive at temperatures close to 10°C.

  12. Analysis of the Female Gametophyte Transcriptome of Arabidopsis by Comparative Expression Profiling1[W

    PubMed Central

    Yu, Hee-Ju; Hogan, Pat; Sundaresan, Venkatesan

    2005-01-01

    The extensive data on the transcription of the plant genome are derived primarily from the sporophytic generation. There currently is little information on genes that are expressed during female gametophyte development in angiosperms, and it is not known whether the female gametophyte transcriptome contains a major set of genes that are not expressed in the sporophyte or whether it is primarily a subset of the sporophytic transcriptome. Because the embryo sac is embedded within the maternal ovule tissue, we have utilized the Arabidopsis (Arabidopsis thaliana) mutant sporocyteless that produces ovules without embryo sacs, together with the ATH1 Arabidopsis whole-genome oligonucleotide array, to identify genes that are preferentially or specifically expressed in female gametophyte development. From analysis of the datasets, 225 genes are identified as female gametophyte genes, likely a lower limit as stringent criteria were used for the analysis, eliminating many low expressed genes. Nearly 45% of the identified genes were not previously detected by sporophytic expression profiling, suggesting that the embryo sac transcriptome may contain a significant fraction of transcripts restricted to the gametophyte. Validation of six candidate genes was performed using promoter∷β-glucuronidase fusions, and all of these showed embryo sac-specific expression in the ovule. The unfiltered expression data from this study can be used to evaluate the possibility of female gametophytic expression for any gene in the ATH1 array, and contribute to identification of the functions of the component of the Arabidopsis genome not represented in studies of sporophytic expression and function. PMID:16299181

  13. Functional Analysis of Sporophytic Transcripts Repressed by the Female Gametophyte in the Ovule of Arabidopsis thaliana

    PubMed Central

    Armenta-Medina, Alma; Huanca-Mamani, Wilson; Sanchez-León, Nidia; Rodríguez-Arévalo, Isaac; Vielle-Calzada, Jean-Philippe

    2013-01-01

    To investigate the genetic and molecular regulation that the female gametophyte could exert over neighboring sporophytic regions of the ovule, we performed a quantitative comparison of global expression in wild-type and nozzle/sporocyteless (spl) ovules of Arabidopsis thaliana (Arabidopsis), using Massively Parallel Signature Sequencing (MPSS). This comparison resulted in 1517 genes showing at least 3-fold increased expression in ovules lacking a female gametophyte, including those encoding 89 transcription factors, 50 kinases, 25 proteins containing a RNA-recognition motif (RRM), and 20 WD40 repeat proteins. We confirmed that eleven of these genes are either preferentially expressed or exclusive of spl ovules lacking a female gametophyte as compared to wild-type, and showed that six are also upregulated in determinant infertile1 (dif1), a meiotic mutant affected in a REC8-like cohesin that is also devoided of female gametophytes. The sporophytic misexpression of IOREMPTE, a WD40/transducin repeat gene that is preferentially expressed in the L1 layer of spl ovules, caused the arrest of female gametogenesis after differentiation of a functional megaspore. Our results show that in Arabidopsis, the sporophytic-gametophytic cross talk includes a negative regulation of the female gametophyte over specific genes that are detrimental for its growth and development, demonstrating its potential to exert a repressive control over neighboring regions in the ovule. PMID:24194852

  14. Functional analysis of sporophytic transcripts repressed by the female gametophyte in the ovule of Arabidopsis thaliana.

    PubMed

    Armenta-Medina, Alma; Huanca-Mamani, Wilson; Sanchez-León, Nidia; Rodríguez-Arévalo, Isaac; Vielle-Calzada, Jean-Philippe

    2013-01-01

    To investigate the genetic and molecular regulation that the female gametophyte could exert over neighboring sporophytic regions of the ovule, we performed a quantitative comparison of global expression in wild-type and nozzle/sporocyteless (spl) ovules of Arabidopsis thaliana (Arabidopsis), using Massively Parallel Signature Sequencing (MPSS). This comparison resulted in 1517 genes showing at least 3-fold increased expression in ovules lacking a female gametophyte, including those encoding 89 transcription factors, 50 kinases, 25 proteins containing a RNA-recognition motif (RRM), and 20 WD40 repeat proteins. We confirmed that eleven of these genes are either preferentially expressed or exclusive of spl ovules lacking a female gametophyte as compared to wild-type, and showed that six are also upregulated in determinant infertile1 (dif1), a meiotic mutant affected in a REC8-like cohesin that is also devoided of female gametophytes. The sporophytic misexpression of IOREMPTE, a WD40/transducin repeat gene that is preferentially expressed in the L1 layer of spl ovules, caused the arrest of female gametogenesis after differentiation of a functional megaspore. Our results show that in Arabidopsis, the sporophytic-gametophytic cross talk includes a negative regulation of the female gametophyte over specific genes that are detrimental for its growth and development, demonstrating its potential to exert a repressive control over neighboring regions in the ovule. PMID:24194852

  15. Mycorrhizal fungi modify element distribution in gametophytes and sporophytes of a fern Pellaeaviridis from metaliferous soils.

    PubMed

    Turnau, Katarzyna; Przybyłowicz, Wojciech J; Ryszka, Przemysław; Orłowska, Elżbieta; Anielska, Teresa; Mesjasz-Przybyłowicz, Jolanta

    2013-08-01

    In the present study, the element distribution within mycothallic and nonmycothallic gametophytes and the early stages of sporophyte development of Pellaea viridis (Pteridaceae) were investigated. Gametophytes of this fern were collected from soil samples originating in the ultramafic area of the Agnes Mine near Barberton, South Africa. The gametophytes were grown on both the original soil and on a plant growth substratum obtained from the local botanical garden. Gametophytes and young sporophytes grown on substratum inoculated with Glomus tenue or non-inoculated were freeze-dried, and the distribution of elements was studied using micro-PIXE. The GeoPIXE II software package was used for quantitative elemental mapping complemented by data extracted from arbitrarily selected micro-areas. The obtained results suggest that although the fern itself avoids the uptake of large amounts of heavy metals, increased levels of Ni, Cr, Fe, Co and Ti were found in the part of the gametophyte that hosted the fungal endophyte. This finding suggests that the fungus might be active in the immobilisation of certain potentially toxic metals that are taken up from the soil by the plant, although other mechanisms cannot be excluded. For the first time, precise, quantitative measurements of the concentration of individual elements in the fern gametophytes and young sporophytes were obtained, along with their distribution within the plant parts. PMID:23714153

  16. Defects in Peroxisomal 6-Phosphogluconate Dehydrogenase Isoform PGD2 Prevent Gametophytic Interaction in Arabidopsis thaliana1[OPEN

    PubMed Central

    Hölscher, Christian; Meyer, Tanja; Fischer, Kerstin

    2016-01-01

    We studied the localization of 6-phosphogluconate dehydrogenase (PGD) isoforms of Arabidopsis (Arabidopsis thaliana). Similar polypeptide lengths of PGD1, PGD2, and PGD3 obscured which isoform may represent the cytosolic and/or plastidic enzyme plus whether PGD2 with a peroxisomal targeting motif also might target plastids. Reporter-fusion analyses in protoplasts revealed that, with a free N terminus, PGD1 and PGD3 accumulate in the cytosol and chloroplasts, whereas PGD2 remains in the cytosol. Mutagenesis of a conserved second ATG enhanced the plastidic localization of PGD1 and PGD3 but not PGD2. Amino-terminal deletions of PGD2 fusions with a free C terminus resulted in peroxisomal import after dimerization, and PGD2 could be immunodetected in purified peroxisomes. Repeated selfing of pgd2 transfer (T-)DNA alleles yielded no homozygous mutants, although siliques and seeds of heterozygous plants developed normally. Detailed analyses of the C-terminally truncated PGD2-1 protein showed that peroxisomal import and catalytic activity are abolished. Reciprocal backcrosses of pgd2-1 suggested that missing PGD activity in peroxisomes primarily affects the male gametophyte. Tetrad analyses in the quartet1-2 background revealed that pgd2-1 pollen is vital and in vitro germination normal, but pollen tube growth inside stylar tissues appeared less directed. Mutual gametophytic sterility was overcome by complementation with a genomic construct but not with a version lacking the first ATG. These analyses showed that peroxisomal PGD2 activity is required for guided growth of the male gametophytes and pollen tube-ovule interaction. Our report finally demonstrates an essential role of oxidative pentose-phosphate pathway reactions in peroxisomes, likely needed to sustain critical levels of nitric oxide and/or jasmonic acid, whose biosynthesis both depend on NADPH provision. PMID:26941195

  17. Cross-Talk Between Sporophyte and Gametophyte Generations Is Promoted by CHD3 Chromatin Remodelers in Arabidopsis thaliana.

    PubMed

    Carter, Benjamin; Henderson, James T; Svedin, Elisabeth; Fiers, Martijn; McCarthy, Kyle; Smith, Amanda; Guo, Changhua; Bishop, Brett; Zhang, Heng; Riksen, Tjitske; Shockley, Allison; Dilkes, Brian P; Boutilier, Kim; Ogas, Joe

    2016-06-01

    Angiosperm reproduction requires the integrated development of multiple tissues with different genotypes. To achieve successful fertilization, the haploid female gametophytes and diploid ovary must coordinate their development, after which the male gametes must navigate through the maternal sporophytic tissues to reach the female gametes. After fertilization, seed development requires coordinated development of the maternal diploid integuments, the triploid endosperm, and the diploid zygote. Transcription and signaling factors contribute to communication between these tissues, and roles for epigenetic regulation have been described for some of these processes. Here we identify a broad role for CHD3 chromatin remodelers in Arabidopsis thaliana reproductive development. Plants lacking the CHD3 remodeler, PICKLE, exhibit various reproductive defects including abnormal development of the integuments, female gametophyte, and pollen tube, as well as delayed progression of ovule and embryo development. Genetic analyses demonstrate that these phenotypes result from loss of PICKLE in the maternal sporophyte. The paralogous gene PICKLE RELATED 2 is preferentially expressed in the endosperm and acts antagonistically with respect to PICKLE in the seed: loss of PICKLE RELATED 2 suppresses the large seed phenotype of pickle seeds. Surprisingly, the alteration of seed size in pickle plants is sufficient to determine the expression of embryonic traits in the seedling primary root. These findings establish an important role for CHD3 remodelers in plant reproduction and highlight how the epigenetic status of one tissue can impact the development of genetically distinct tissues. PMID:27075727

  18. The Arabidopsis transcription factor IIB-related protein BRP4 is involved in the regulation of mitotic cell-cycle progression during male gametogenesis

    PubMed Central

    Hu, Yuxin

    2014-01-01

    Male gametogenesis in angiosperms involves two rounds of mitosis that are essential for the generation of two sperm cells to achieve double fertilization, a distinct event in the sexual reproduction of flowering plants. Precise regulation of mitosis during male gametogenesis is critically important for the establishment of the male germline. However, the molecular mechanisms underlying mitotic division during male gametophyte development have not been characterized fully. Here, we report that the Arabidopsis transcription initiation factor TFIIB-related protein BRP4 is involved in the regulation of mitotic cell-cycle progression during male gametogenesis. BRP4 was expressed predominately in developing male gametophytes. Knockdown expression of BRP4 by a native promoter-driven RNA interference construct in Arabidopsis resulted in arrest of the mitotic progression of male gametophytes, leading to a defect in pollen development. Moreover, we showed that the level of expression of a gene encoding a subunit of the origin recognition complex, ORC6, was decreased in BRP4 knockdown plants, and that the ORC6 knockdown transgenic plants phenocopied the male gametophyte defect observed in BRP4 knockdown plants, suggesting that ORC6 acts downstream of BRP4 to mediate male mitotic progression. Taken together, our results reveal that BRP4 plays an important role in the regulation of mitotic cell-cycle progression during male gametogenesis. PMID:24723406

  19. Cryopreservation of gametophytes of Laminaria japonica (Phaeophyta) using encapsulation-dehydration with two-step cooling method

    NASA Astrophysics Data System (ADS)

    Zhang, Quansheng; Cong, Yizhou; Qu, Shancun; Luo, Shiju; Yang, Guanpin

    2008-02-01

    Gametophytes of Laminaria japonica were cryopreserved in liquid nitrogen using encapsulation-dehydration with two-step cooling method. Gametophytes cultured at 10°C and under continuous irradiance of 30 μmol m-2 s-1 for 3 weeks were encapsulated in calcium alginate beads. The beads were dehydrated in 0.4 molL-1 sucrose prepared with seawater for 6 h, desiccated in an incubator set at 10°C and 70% relative humidity for 4 h, pre-frozen at either -40°C or -60°C for 30 min, and stored in liquid nitrogen for >24 h. As high as 43% of survival rate was observed when gametophytes were thawed by placing the beads in 40°C seawater and re-hydrated in 0.05 molL-1 citrate sodium prepared using 30‰ NaCl 7 d later. More cells of male gametophytes survived the whole procedure in comparison with female gametophytes. The cells of gametophytes surviving the preservation were able to grow asexually and produce morphologically normal sporophytes.

  20. Influence of water availability on gender determination of gametophytes in a diploid-polyploid complex of a xerophytic fern genus.

    PubMed

    Pajarón, Santiago; Pangua, Emilia; Quintanilla, Luis G; Jiménez, Ares

    2015-01-01

    Environmental sex determination (ESD) is present in several animal and plant lineages. Diverse factors such as temperature, light or water availability have been described as sex determinants in these organisms. Among plants, ferns frequently display ESD. This work compares the effect of different levels of water availability in two diploid species of the xerophytic fern genus Cheilanthes and in their derived tetraploid, and if they are sensitive to antheridiogen (i.e. maleness-inducing pheromone). Different watering regimes were applied to isolated gametophyte cultures of the three study species. Gametophyte survival, size, gender and sporophyte production were assessed after 13, 18 and 23 weeks of culture. Cultures combining spores and adult gametophytes were established to test the effect of antheridiogen. Isolated gametophytes had an asexual to female to bisexual sequence that did not depend upon the degree of soil moisture. Both gender expression and growth reduction in response to water scarcity of the allotetraploid were more similar to those of one of the diploid parents. In all watering regimes, survival was higher in the allotetraploid, suggesting hybrid vigour, whereas automixis rate was similar in the three species and reached ∼50 % at high moisture. This breeding system can ensure reproduction in the absence of males. In the three species, female gametophytes produced antheridiogens that enhanced maleness. This promotes a mixed mating system that could be favourable for ferns growing in xeric habitats. PMID:25940203

  1. Influence of water availability on gender determination of gametophytes in a diploid–polyploid complex of a xerophytic fern genus

    PubMed Central

    Pajarón, Santiago; Pangua, Emilia; Quintanilla, Luis G.; Jiménez, Ares

    2015-01-01

    Environmental sex determination (ESD) is present in several animal and plant lineages. Diverse factors such as temperature, light or water availability have been described as sex determinants in these organisms. Among plants, ferns frequently display ESD. This work compares the effect of different levels of water availability in two diploid species of the xerophytic fern genus Cheilanthes and in their derived tetraploid, and if they are sensitive to antheridiogen (i.e. maleness-inducing pheromone). Different watering regimes were applied to isolated gametophyte cultures of the three study species. Gametophyte survival, size, gender and sporophyte production were assessed after 13, 18 and 23 weeks of culture. Cultures combining spores and adult gametophytes were established to test the effect of antheridiogen. Isolated gametophytes had an asexual to female to bisexual sequence that did not depend upon the degree of soil moisture. Both gender expression and growth reduction in response to water scarcity of the allotetraploid were more similar to those of one of the diploid parents. In all watering regimes, survival was higher in the allotetraploid, suggesting hybrid vigour, whereas automixis rate was similar in the three species and reached ∼50 % at high moisture. This breeding system can ensure reproduction in the absence of males. In the three species, female gametophytes produced antheridiogens that enhanced maleness. This promotes a mixed mating system that could be favourable for ferns growing in xeric habitats. PMID:25940203

  2. The RPT2 subunit of the 26S proteasome directs complex assembly, histone dynamics, and gametophyte and sporophyte development in Arabidopsis.

    PubMed

    Lee, Kwang-Hee; Minami, Atsushi; Marshall, Richard S; Book, Adam J; Farmer, Lisa M; Walker, Joseph M; Vierstra, Richard D

    2011-12-01

    The regulatory particle (RP) of the 26S proteasome contains a heterohexameric ring of AAA-ATPases (RPT1-6) that unfolds and inserts substrates into the core protease (CP) for degradation. Through genetic analysis of the Arabidopsis thaliana gene pair encoding RPT2, we show that this subunit plays a critical role in 26S proteasome assembly, histone dynamics, and plant development. rpt2a rpt2b double null mutants are blocked in both male and female gamete transmission, demonstrating that the subunit is essential. Whereas rpt2b mutants are phenotypically normal, rpt2a mutants display a range of defects, including impaired leaf, root, trichome, and pollen development, delayed flowering, stem fasciation, hypersensitivity to mitomycin C and amino acid analogs, hyposensitivity to the proteasome inhibitor MG132, and decreased 26S complex stability. The rpt2a phenotype can be rescued by both RPT2a and RPT2b, indicative of functional redundancy, but not by RPT2a mutants altered in ATP binding/hydrolysis or missing the C-terminal hydrophobic sequence that docks the RPT ring onto the CP. Many rpt2a phenotypes are shared with mutants lacking the chromatin assembly factor complex CAF1. Like caf1 mutants, plants missing RPT2a or reduced in other RP subunits contain less histones, thus implicating RPT2 specifically, and the 26S proteasome generally, in plant nucleosome assembly. PMID:22158466

  3. Genomic Landscape of Developing Male Germ Cells

    PubMed Central

    Lee, Tin-Lap; Pang, Alan Lap-Yin; Rennert, Owen M.; Chan, Wai-Yee

    2010-01-01

    Spermatogenesis is a highly orchestrated developmental process by which spermatogonia develop into mature spermatozoa. This process involves many testis- or male germ cell-specific gene products whose expressions are strictly regulated. In the past decade the advent of high-throughput gene expression analytical techniques has made functional genomic studies of this process, particularly in model animals such as mice and rats, feasible and practical. These studies have just begun to reveal the complexity of the genomic landscape of the developing male germ cells. Over 50% of the mouse and rat genome are expressed during testicular development. Among transcripts present in germ cells, 40% – 60% are uncharacterized. A number of genes, and consequently their associated biological pathways, are differentially expressed at different stages of spermatogenesis. Developing male germ cells present a rich repertoire of genetic processes. Tissue-specific as well as spermatogenesis stage-specific alternative splicing of genes exemplifies the complexity of genome expression. In addition to this layer of control, discoveries of abundant presence of antisense transcripts, expressed psuedogenes, non-coding RNAs (ncRNA) including long ncRNAs, microRNAs (miRNAs) and Piwi-interacting RNAs (piRNAs), and retrogenes all point to the presence of multiple layers of expression and functional regulation in male germ cells. It is anticipated that application of systems biology approaches will further our understanding of the regulatory mechanism of spermatogenesis.† PMID:19306351

  4. A mitochondrial DNA sequence is associated with abnormal pollen development in cytoplasmic male sterile bean plants.

    PubMed Central

    Johns, C; Lu, M; Lyznik, A; Mackenzie, S

    1992-01-01

    Cytoplasmic male sterility (CMS) in common bean is associated with the presence of a 3-kb unique mitochondrial sequence designated pvs. The pvs sequence encodes at least two open reading frames (297 and 720 bp in length) with portions derived from the chloroplast genome. Fertility restoration by the nuclear restorer gene Fr results in the loss of this transcriptionally active unique region. We examined the effect of CMS (pvs present) and fertility restoration by Fr (pvs absent) on the pattern of pollen development in bean. In the CMS line, pollen aborted in the tetrad stage late in microgametogenesis. Microspores maintained cytoplasmic connections throughout pollen development, indicating aberrant or incomplete cytokinesis. Pollen-specific events associated with pollen abortion and fertility restoration imply that a gametophytic factor or event may be involved in CMS. In situ hybridization experiments suggested that significant reduction or complete loss of the mitochondrial sterility-associated sequence occurred in fertile pollen of F2 populations segregating for fertility. These observations support a model of fertility restoration by the loss of a mitochondrial DNA sequence prior to or during microsporogenesis/gametogenesis. PMID:1498602

  5. Postnatal Testosterone Concentrations and Male Social Development

    PubMed Central

    Alexander, Gerianne M.

    2014-01-01

    Converging evidence from over 40 years of behavioral research indicates that higher testicular androgens in prenatal life and at puberty contribute to the masculinization of human behavior. However, the behavioral significance of the transient activation of the hypothalamic–pituitary–gonadal (HPG) axis in early postnatal life remains largely unknown. Although early research on non-human primates indicated that suppression of the postnatal surge in testicular androgens had no measurable effects on the later expression of the male behavioral phenotype, recent research from our laboratory suggests that postnatal testosterone concentrations influence male infant preferences for larger social groups and temperament characteristics associated with the later development of aggression. In later assessment of gender-linked behavior in the second year of life, concentrations of testosterone at 3–4 months of age were unrelated to toy choices and activity levels during toy play. However, higher concentrations of testosterone predicted less vocalization in toddlers and higher parental ratings on an established screening measure for autism spectrum disorder. These findings suggest a role of the transient activation of the HPG axis in the development of typical and atypical male social relations and suggest that it may be useful in future research on the exaggerated rise in testosterone secretion in preterm infants or exposure to hormone disruptors in early postnatal life to include assessment of gender-relevant behavioral outcomes, including childhood disorders with sex-biased prevalence rates. PMID:24600437

  6. Effect of endosulfan on male reproductive development.

    PubMed

    Saiyed, Habibullah; Dewan, Aruna; Bhatnagar, Vijay; Shenoy, Udyavar; Shenoy, Rathika; Rajmohan, Hirehall; Patel, Kumud; Kashyap, Rekha; Kulkarni, Pradip; Rajan, Bagalur; Lakkad, Bhadabhai

    2003-12-01

    There is experimental evidence of adverse effects of endosulfan on the male reproductive system, but there are no human data. Therefore, we undertook a study to examine the relationship between environmental endosulfan exposure and reproductive development in male children and adolescents. The study population was composed of 117 male schoolchildren (10-19 years of age) of a village situated at the foothills of cashew plantations, where endosulfan had been aerially sprayed for more than 20 years, and 90 comparable controls with no such exposure history. The study parameters included recording of clinical history, physical examination, sexual maturity rating (SMR) according to Tanner stages, and estimation of serum levels of testosterone, luteinizing hormone (LH), follicle-stimulating hormone, and endosulfan residues (70 study and 47 control subjects). Mean +/- SE serum endosulfan levels in the study group (7.47 +/- 1.19 ppb) were significantly higher (p < 0.001) than in controls (1.37 +/- 0.40 ppb). Multiple regression analysis showed that SMR scoring for development of pubic hair, testes, penis, and serum testosterone level was positively related to age and negatively related to aerial exposure to endosulfan (AEE; p < 0.01). Serum LH levels were significantly positively related to AEE after controlling for age (p < 0.01). The prevalence of congenital abnormalities related to testicular descent (congenital hydrocele, undescended testis, and congenital inguinal hernia) among study and controls subjects was 5.1% and 1.1%, respectively, but the differences were statistically nonsignificant. Our study results suggest that endosulfan exposure in male children may delay sexual maturity and interfere with sex hormone synthesis. Our study is limited by small sample size and nonparticipation. PMID:14644673

  7. A 610 KB YAC CLONE HARBORS 7 CM OF TOMATO (LYCOPERSICON ESCULENTUM) DNA THAT INCLUDES THE MALE STERILE 14 GENE AND A HOTSPOT FOR RECOMBINATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pollen development requires both sporophytic and gametophytic gene expression. We are using a map-based cloning technique to isolate sporophytic genes which, when mutant, cause pollen abortion and a male sterile (ms) phenotype in tomato (Lycopersicon esculentum). We have genetically characterized on...

  8. The PTI1-like kinase ZmPti1a from maize (Zea mays L.) co-localizes with callose at the plasma membrane of pollen and facilitates a competitive advantage to the male gametophyte

    PubMed Central

    Herrmann, Markus M; Pinto, Sheena; Kluth, Jantjeline; Wienand, Udo; Lorbiecke, René

    2006-01-01

    Background The tomato kinase Pto confers resistance to bacterial speck disease caused by Pseudomonas syringae pv. tomato in a gene for gene manner. Upon recognition of specific avirulence factors the Pto kinase activates multiple signal transduction pathways culminating in induction of pathogen defense. The soluble cytoplasmic serine/threonine kinase Pti1 is one target of Pto phosphorylation and is involved in the hypersensitive response (HR) reaction. However, a clear role of Pti1 in plant pathogen resistance is uncertain. So far, no Pti1 homologues from monocotyledonous species have been studied. Results Here we report the identification and molecular analysis of four Pti1-like kinases from maize (ZmPti1a, -b, -c, -d). These kinase genes showed tissue-specific expression and their corresponding proteins were targeted to different cellular compartments. Sequence similarity, expression pattern and cellular localization of ZmPti1b suggested that this gene is a putative orthologue of Pti1 from tomato. In contrast, ZmPti1a was specifically expressed in pollen and sequestered to the plasma membrane, evidently owing to N-terminal modification by myristoylation and/or S-acylation. The ZmPti1a:GFP fusion protein was not evenly distributed at the pollen plasma membrane but accumulated as an annulus-like structure which co-localized with callose (1,3-β-glucan) deposition. In addition, co-localization of ZmPti1a and callose was observed during stages of pollen mitosis I and pollen tube germination. Maize plants in which ZmPti1a expression was silenced by RNA interference (RNAi) produced pollen with decreased competitive ability. Hence, our data provide evidence that ZmPti1a plays an important part in a signalling pathway that accelerates pollen performance and male fitness. Conclusion ZmPti1a from maize is involved in pollen-specific processes during the progamic phase of reproduction, probably in crucial signalling processes associated with regions of callose deposition

  9. A bacterial pathogen infecting gametophytes of Saccharina japonica (Laminariales, Phaeophyceae)

    NASA Astrophysics Data System (ADS)

    Peng, Yanting; Li, Wei

    2013-03-01

    A newly identified bacterial disease of kelp ( Saccharina japonica) gametophytes was found in clone cultures. It is characterized by swollen gametophyte cells in the early period of infection followed by filamentous fading. An alginolytic marine bacterium referred to as A-1 was isolated from the diseased gametophytes. On the basis of 16S rDNA sequencing and morphological, physiological and biochemical characteristics, the bacterium was identified as a strain of the genus Alteromonas. By testing Koch's postulates, Alteromonas sp. A-1 was further confirmed as the pathogen. The infection process was also investigated using both scanning electron and light microscopy.

  10. A22316 Gametophyte and sporophyte (version 2.0)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gametogenesis is the process of gamete formation, which includes micro- and megagametogenesis. Gametogenesis initiates after specialized cells in the sporophyte undergo meiosis, and subsequent mitotic divisions yield the gametophytic phase of the plant life cycle. In higher plants, microgametogenesi...

  11. Gene expression by Onoclea Sensibilis gametophytes under different light conditions

    SciTech Connect

    Chansa-ngavej, K.; Raghavan, V.

    1987-04-01

    Gametophytes of the fern Onoclea sensibilis grow as filaments in red light or in complete darkness by divisions perpendicular to the long axis of the cell. When transferred to blue light the gametophytes exhibit a plate-like structure as a result of both transverse and longitudinal cell divisions. Both 1-D and 2-D SDS-polyacrylamide gel electrophoresis revealed quantitative and qualitative differences in the polypeptide patterns of the gametophytes grown in red and blue light regimes and in complete darkness. NAD/sup +/-Glyceraldehyde-3-phosphate dehydrogenase activity was found to increase sharply within 4 hours of transfer of the gametophytes from red light to blue light and to complete darkness. /sup 3/H-Leucine was incorporated at a higher rate into proteins of gametophytes after 2 hours of transfer from red light to blue light and to complete darkness. These results seem to indicate possible involvement of differential protein synthesis and hence differential gene expression during growth of gametophytes under different light conditions.

  12. Development of male-sterile lines for breeding hybrid rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice is a self-pollinated crop that depends on male-sterility for F1 hybrid seed production. As an alternative to accessing existing male-sterile lines from other hybrid breeding programs, the program in Arkansas has created its own novel male-sterile sources. These were developed out of germplasm...

  13. Pattern formation in miniature: the female gametophyte of flowering plants.

    PubMed

    Sundaresan, Venkatesan; Alandete-Saez, Monica

    2010-01-01

    Plant reproduction involves gamete production by a haploid generation, the gametophyte. For flowering plants, a defining characteristic in the evolution from the 'naked-seed' plants, or gymnosperms, is a reduced female gametophyte, comprising just seven cells of four different types--a microcosm of pattern formation and gamete specification about which only little is known. However, several genes involved in the differentiation, fertilization and post-fertilization functions of the female gametophyte have been identified and, recently, the morphogenic activity of the plant hormone auxin has been found to mediate patterning and egg cell specification. This article reviews recent progress in understanding the pattern formation, maternal effects and evolution of this essential unit of plant reproduction. PMID:20040485

  14. Arsenic Toxicity in Male Reproduction and Development

    PubMed Central

    Kim, Yoon-Jae; Kim, Jong-Min

    2015-01-01

    Arsenic is a toxic metalloid that exists ubiquitously in the environment, and affects global health problems due to its carcinogenicity. In most populations, the main source of arsenic exposure is the drinking water. In drinking water, chronic exposure to arsenic is associated with increased risks of various cancers including those of skin, lung, bladder, and liver, as well as numerous other non-cancer diseases including gastrointestinal and cardiovascular diseases, diabetes, and neurologic and cognitive problems. Recent emerging evidences suggest that arsenic exposure affects the reproductive and developmental toxicity. Prenatal exposure to inorganic arsenic causes adverse pregnancy outcomes and children’s health problems. Some epidemiological studies have reported that arsenic exposure induces premature delivery, spontaneous abortion, and stillbirth. In animal studies, inorganic arsenic also causes fetal malformation, growth retardation, and fetal death. These toxic effects depend on dose, route and gestation periods of arsenic exposure. In males, inorganic arsenic causes reproductive dysfunctions including reductions of the testis weights, accessory sex organs weights, and epididymal sperm counts. In addition, inorganic arsenic exposure also induces alterations of spermatogenesis, reductions of testosterone and gonadotrophins, and disruptions of steroidogenesis. However, the reproductive and developmental problems following arsenic exposure are poorly understood, and the molecular mechanism of arsenic-induced reproductive toxicity remains unclear. Thus, we further investigated several possible mechanisms underlying arsenic-induced reproductive toxicity. PMID:26973968

  15. Arsenic Toxicity in Male Reproduction and Development.

    PubMed

    Kim, Yoon-Jae; Kim, Jong-Min

    2015-12-01

    Arsenic is a toxic metalloid that exists ubiquitously in the environment, and affects global health problems due to its carcinogenicity. In most populations, the main source of arsenic exposure is the drinking water. In drinking water, chronic exposure to arsenic is associated with increased risks of various cancers including those of skin, lung, bladder, and liver, as well as numerous other non-cancer diseases including gastrointestinal and cardiovascular diseases, diabetes, and neurologic and cognitive problems. Recent emerging evidences suggest that arsenic exposure affects the reproductive and developmental toxicity. Prenatal exposure to inorganic arsenic causes adverse pregnancy outcomes and children's health problems. Some epidemiological studies have reported that arsenic exposure induces premature delivery, spontaneous abortion, and stillbirth. In animal studies, inorganic arsenic also causes fetal malformation, growth retardation, and fetal death. These toxic effects depend on dose, route and gestation periods of arsenic exposure. In males, inorganic arsenic causes reproductive dysfunctions including reductions of the testis weights, accessory sex organs weights, and epididymal sperm counts. In addition, inorganic arsenic exposure also induces alterations of spermatogenesis, reductions of testosterone and gonadotrophins, and disruptions of steroidogenesis. However, the reproductive and developmental problems following arsenic exposure are poorly understood, and the molecular mechanism of arsenic-induced reproductive toxicity remains unclear. Thus, we further investigated several possible mechanisms underlying arsenic-induced reproductive toxicity. PMID:26973968

  16. Review on research of suppression male fertility and male contraceptive drug development by natural products.

    PubMed

    Bajaj, Vijay Kumar; Gupta, Radhey S

    2013-08-01

    Male contraceptive development in the present scenario is most viable aspect of research due to uncontrolled population growth in the world. In this respect investigators are busy to find out a safe male contraceptive drug. Researchers have started their finding for a suitable drug from natural sources because these are safe and easily acceptable for common man, most of natural sources are plants and their products. In this review 137 plants and their effects on reproduction and reproductive physiology are summarized. Some of them have intense effect on male reproductive system and do not produce any side effects. Reproductive toxicological studies are also important aspects of these kinds of researches, so it is important that drugs are safe and widely acceptable. An ideal male contraceptive can influence semen, testes, hormone level, accessory reproductive organs and general physiology of animals and produced some alterations. Many plants in this review are showing antifertility as well as antispermatogenic effects, so these may be used for further study for contraceptives development but it is important to find out the mechanism of reaction and further laboratory and clinical research on some plants are needed for final male contraceptive drug development. In conclusion this review will help for finding suitable plant products for male contraceptive clinical and laboratory studies. PMID:24079200

  17. Exploration of cryo-methods to preserve fern gametophytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fern gametophytes, derived from in vitro cultures, are a useful source of germplasm for scientific research using genetic stocks, mass production of individuals for plantings, ex situ conservation of endangered populations and reproduction of species or hybrids that produce short-lived or nonfunctio...

  18. The alpha-N-acetyl-glucosaminidase gene is transcriptionally activated in male and female gametes prior to fertilization and is essential for seed development in Arabidopsis.

    PubMed

    Ronceret, Arnaud; Gadea-Vacas, Jose; Guilleminot, Jocelyne; Devic, Martine

    2008-01-01

    Sugar residues in proteoglycan complexes carry important signalling and regulatory functions in biology. In humans, heparan sulphate is an example of such a complex polymer containing glucosamine and N-acetyl-glucosamine residues and is present in the extracellular matrix. Although heparan sulphate has not been found in plants, the At5g13690 gene encoding the alpha-N-acetyl-glucosaminidase (NAGLU), an enzyme involved in its catabolism, is present in the Arabidopsis genome. Among our collection of embryo-defective lines, a plant was identified in which the T-DNA had inserted into the AtNAGLU gene. The phenotype of atnaglu is an early arrest of seed development without apparent male or female gametophytic effects. These data demonstrated the essential function in Arabidopsis consistent with the contribution of NAGLU to the Sanfilippo syndrome in human. Expression of AtNAGLU in plants was shown to be prevalent during reproductive development. The presence of AtNAGLU mRNA was observed during early and late male gametogenesis and in each cell of the embryo sac at the time of fertilization. After fertilization, AtNAGLU was expressed in the embryo, suspensor, and endosperm until the cotyledonary stage embryo. This precise pattern of expression identifies the cells and tissues where a remodelling of the N-acetyl-glucosamine residues of proteoglycan complexes is occurring. This work provides original evidence of the important role of N-acetyl-glucosamines in plant reproductive development. PMID:18782908

  19. Expression of CP4 EPSPS in microspores and tapetum cells of cotton (Gossypium hirsutum) is critical for male reproductive development in response to late-stage glyphosate applications.

    PubMed

    Chen, Yun-Chia Sophia; Hubmeier, Christopher; Tran, Minhtien; Martens, Amy; Cerny, R Eric; Sammons, R Doug; CaJacob, Claire

    2006-09-01

    Plants expressing Agrobacterium sp. strain CP4 5-enolpyruvylshikimate-3-phosphate synthase (CP4 EPSPS) are known to be resistant to glyphosate, a potent herbicide that inhibits the activity of the endogenous plant EPSPS. The RR1445 transgenic cotton line (current commercial line for Roundup Ready Cotton) was generated using the figwort mosaic virus (FMV) 35S promoter to drive the expression of the CP4 EPSPS gene, and has excellent vegetative tolerance to glyphosate. However, with high glyphosate application rates at developmental stages later than the four-leaf stage (late-stage applications: applications that are inconsistent with the Roundup labels), RR1445 shows male sterility. Another transgenic cotton line, RR60, was generated using the FMV 35S promoter and the Arabidopsis elongation factor-1alpha promoter (AtEF1alpha) for the expression of CP4 EPSPS. RR60 has excellent vegetative and reproductive tolerance to applications of glyphosate at all developmental stages. Histochemical analyses were conducted to examine the male reproductive development at the cellular level of these cotton lines in response to glyphosate applications, and to investigate the correlation between glyphosate injury and the expression of CP4 EPSPS in male reproductive tissues. The expression of CP4 EPSPS in RR60 was found to be strong in all male reproductive cell types. Conversely, CP4 EPSPS expression in RR1445 was low in pollen mother cells, male gametophytes and tapetum, three crucial male reproductive cell types. Our results indicate that the FMV 35S promoter, although expressing strongly in most vegetative tissues in plants, has extremely low activity in these cell types. PMID:17309724

  20. Novel roles of Pkd2 in male reproductive system development

    PubMed Central

    Nie, Xuguang; Arend, Lois J

    2016-01-01

    Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common inherited genetic diseases, caused by mutations in PKD1 and/ or PKD2. Infertility and reproductive tract abnormalities in male ADPKD patients are very common and have higher incidence than in the general population. In this work, we reveal novel roles of Pkd2 for male reproductive system development. Disruption of Pkd2 caused dilation of mesonephric tubules/efferent ducts, failure of epididymal coiling, and defective testicular development. Deletion of Pkd2 in the epithelia alone was sufficient to cause reproductive tract defects seen in Pkd2−/− mice, suggesting that epithelial Pkd2 plays a pivotal role for development and maintenance of the male reproductive tract. In the testis, Pkd2 also plays a role in interstitial tissue and testicular cord development. In-depth analysis of epithelial-specific knockout mice revealed that Pkd2 is critical to maintain cellular phenotype and developmental signaling in the male reproductive system. Taken together, our data for the first time reveal novel roles for Pkd2 in male reproductive system development and provide new insights in male reproductive system abnormality and infertility in ADPKD patients. PMID:24951251

  1. Pkd1 is Required for Male Reproductive tract Development

    PubMed Central

    Nie, Xuguang; Arend, Lois J.

    2016-01-01

    Reproductive tract abnormalities and male infertility have higher incidence in autosomal dominant polycystic kidney disease (ADPKD) patients than in general population. In this work, we revealed that Pkd1, whose mutations account for 85% of ADPKD cases, is essential for male reproductive tract development. Disruption of Pkd1 caused a spectrum of defects in the murine male reproductive tract. The earliest visible defect in Pkd1-/- reproductive tract was cystic dilation of the efferent ducts, which are derivatives of the mesonephric tubules. Epididymis development was delayed or arrested in the Pkd1-/- mice. No sign of epididymal coiling was seen in the Pkd1 null mice. Disruption of Pkd1 in epithelia alone using the Pax2-cre mice was sufficient to cause efferent duct dilation and coiling defect in the epididymis, suggesting that Pkd1 is critical for epithelial development and maintenance in male reproductive tract. In-depth analysis showed that Pkd1 is required to maintain tubulin cytoskeleton and important for Tgf-β/Bmp signal transduction in the epithelia of male reproductive tract. Altogether, our results provide the first direct evidence for developmental roles of Pkd1 in male reproductive tract and provide new insights in reproductive tract abnormalities and infertility in ADPKD patients. PMID:23933588

  2. The sperm of aging male bustards retards their offspring's development.

    PubMed

    Preston, Brian T; Saint Jalme, Michel; Hingrat, Yves; Lacroix, Frederic; Sorci, Gabriele

    2015-01-01

    Understanding whether the sperm of older males has a diminished capacity to produce successful offspring is a key challenge in evolutionary biology. We investigate this issue using 10 years of reproductive data on captive long-lived houbara bustards (Chlamydotis undulata), where the use of artificial insemination techniques means parents can only influence offspring quality via their gametes. Here we show that paternal aging reduces both the likelihood that eggs hatch and the rate at which chicks grow, with older males producing the lightest offspring after the first month. Surprisingly, this cost of paternal aging on offspring development is of a similar scale to that associated with maternal aging. Fitting with predictions on germline aging, the sperm of immature males produce the fastest growing offspring. Our findings thus indicate that any good genes benefit that might be offered by older 'proven' males will be eroded by aging of their germline DNA. PMID:25647605

  3. The sperm of aging male bustards retards their offspring's development

    PubMed Central

    Preston, Brian T.; Saint Jalme, Michel; Hingrat, Yves; Lacroix, Frederic; Sorci, Gabriele

    2015-01-01

    Understanding whether the sperm of older males has a diminished capacity to produce successful offspring is a key challenge in evolutionary biology. We investigate this issue using 10 years of reproductive data on captive long-lived houbara bustards (Chlamydotis undulata), where the use of artificial insemination techniques means parents can only influence offspring quality via their gametes. Here we show that paternal aging reduces both the likelihood that eggs hatch and the rate at which chicks grow, with older males producing the lightest offspring after the first month. Surprisingly, this cost of paternal aging on offspring development is of a similar scale to that associated with maternal aging. Fitting with predictions on germline aging, the sperm of immature males produce the fastest growing offspring. Our findings thus indicate that any good genes benefit that might be offered by older ‘proven' males will be eroded by aging of their germline DNA. PMID:25647605

  4. Development of a Denial Scale for Male Incest Offenders.

    ERIC Educational Resources Information Center

    Guthrie, James T.; Canada, Richard M.; Lim, Mee-Gaik; Jennings, Glen H.

    1998-01-01

    A scale to measure denial among sexual offenders was developed for male incest offenders (N=265). Validity and reliability were tested. Four subscales correspond to the domains of denial: facts, awareness, impact, and responsibility. Development strategy and psychometric analysis are reported. Recommendations for further research are included.…

  5. Ego development in female-to-male transsexual couples.

    PubMed

    Fleming, M; Costos, D; MacGowan, B

    1984-12-01

    The ego development of 22 postoperative female-to-male transsexuals and their spouses or lovers with whom they had been living for a year or more was investigated. The transsexuals, their spouses, and a control group of 22 couples were administered the Washington University Sentence Completion Test of Ego Development, a projective measure of ego functioning. Ego development refers to the framework of meaning that the individual brings to an experience. The construct of ego development incorporates a series of sequential stages that integrate various frames of reference including cognitive style, interpersonal style, conscious preoccupation, and impulse control. These processes have received little attention in studies on female-to-male transsexuals who have successfully negotiated the social barrier of cross-living to the extent that they are living the male role in a heterosexual relationship. No significant differences in the distribution of ego development scores were found between the transsexuals and the control males, or between the transsexuals' spouses and the control spouses. Over 93% of the transsexuals and their spouses scored above the conformist level of ego development. These findings are discussed in terms of some of the previous literature on conformist thinking by transsexuals. PMID:6517690

  6. Identification and bioinformatics analysis of microRNAs from the sporophyte and gametophyte of Pyropia haitanensis

    NASA Astrophysics Data System (ADS)

    Huang, Aiyou; Wang, Guangce

    2016-05-01

    Pyropia haitanensis (T. J. Chang et B. F. Zheng) N. Kikuchi et M. Miyata ( Porphyra haitanensis) is an economically important genus that is cultured widely in China. P. haitanensis is cultured on a larger scale than Pyropia yezoensis, making up an important part of the total production of cultivated Pyropia in China. However, the majority of molecular mechanisms underlying the physiological processes of P. haitanensis remain unknown. P. haitanensis could utilize inorganic carbon and the sporophytes of P. haitanensis might possess a PCK-type C4-like carbon-fixation pathway. To identify microRNAs and their probable roles in sporophyte and gametophyte development, we constructed and sequenced small RNA libraries from sporophytes and gametophytes of P. haitanensis. Five microRNAs were identified that shared no sequence homology with known microRNAs. Our results indicated that P. haitanensis might posses a complex sRNA processing system in which the novel microRNAs act as important regulators of the development of different generations of P. haitanensis.

  7. Identification and bioinformatics analysis of microRNAs from the sporophyte and gametophyte of Pyropia haitanensis

    NASA Astrophysics Data System (ADS)

    Huang, Aiyou; Wang, Guangce

    2015-09-01

    Pyropia haitanensis (T. J. Chang et B. F. Zheng) N. Kikuchi et M. Miyata (Porphyra haitanensis) is an economically important genus that is cultured widely in China. P. haitanensis is cultured on a larger scale than Pyropia yezoensis, making up an important part of the total production of cultivated Pyropia in China. However, the majority of molecular mechanisms underlying the physiological processes of P. haitanensis remain unknown. P. haitanensis could utilize inorganic carbon and the sporophytes of P. haitanensis might possess a PCK-type C4-like carbon-fixation pathway. To identify microRNAs and their probable roles in sporophyte and gametophyte development, we constructed and sequenced small RNA libraries from sporophytes and gametophytes of P. haitanensis. Five microRNAs were identified that shared no sequence homology with known microRNAs. Our results indicated that P. haitanensis might posses a complex sRNA processing system in which the novel microRNAs act as important regulators of the development of different generations of P. haitanensis.

  8. Leadership Development and the African American Male College Student Experience

    ERIC Educational Resources Information Center

    Oaks, D'Arcy John; Duckett, Kirstan; Suddeth, Todd; Kennedy-Phillips, Lance

    2013-01-01

    Qualitative interviews were employed to assess the effectiveness of a leadership program geared toward African American male personal and professional development, and to examine the relationship between program participation and connectedness. Elements of both social engagement (mentoring and being mentored, peer-to-peer relationships, and…

  9. Gametophytic and zygotic selection leads to segregation distortion through in vivo induction of a maternal haploid in maize

    PubMed Central

    Chen, Shaojiang

    2013-01-01

    Production of maternal haploids via a male inducer can greatly accelerate maize breeding and is an interesting biological phenomenon in double fertilization. However, the mechanism behind haploid induction remains elusive. Segregation distortion, which is increasingly recognized as a potentially powerful evolutionary force, has recently been observed during maternal haploid induction in maize. The results present here showed that both male gametophytic and zygotic selection contributed to severe segregation distortion of a locus, named segregation distortion 1 (sed1), during maternal haploid induction in maize. Interestingly, analysis of reciprocal crosses showed that sed1 is expressed in the male gametophyte. A novel mapping strategy based on segregation distortion has been used to fine-map this locus. Strong selection for the presence of the sed1 haplotype from inducers in kernels with haploid formation and defects could be detected in the segregating population. Dual-pollination experiments showed that viable pollen grains from inducers had poor pollen competitive ability against pollen from normal genotypes. Although defective kernels and haploids have different phenotypes, they are most probably caused by the sed1 locus, and possible mechanisms for production of maternal haploids and the associated segregation distortion are discussed. This research also provides new insights into the process of double fertilization. PMID:23349137

  10. Development and Validation of a Male Specific Body Checking Questionnaire

    PubMed Central

    Hildebrandt, Tom; Walker, D. Catherine; Alfano, Lauren; Delinsky, Sherrie; Bannon, Katie

    2010-01-01

    Objective Body checking may be an important behavioral consequence of body image disturbance. Despite the importance of body checking, few measurements of this construct exist, particularly for males. This study describes the development and validation of the Male Body Checking Questionnaire (MBCQ). Method Convergent and divergent validity, factor structure, and reliability were tested in three separate samples of men and women. Results Factor analyses suggested a reliable four-factor structure with evidence of a higher order global checking factor for men, but not women. The MBCQ demonstrated good concurrent and divergent validity. Short-term test-retest reliability was good with high internal consistency across time. Discussion Interpretation of psychometrics and recommendations for subsequent research are discussed. The MBCQ is likely to be an appropriate tool for investigating body image-based pathology in males. PMID:19247988

  11. Synthesizing research and education: Ecology and genetics of independent fern gametophytes and teaching science inquiry and content through simulations

    NASA Astrophysics Data System (ADS)

    Duffy, Aaron M.

    Two of the main areas of focus in university academics are research and education. The mission statements of Utah State University and the Department of Biology emphasize both areas, as do the requirements of funding agencies. I attempted to integrate research and education by using tools that I developed to support and inform my biological research projects to teach science. Ferns have a life cycle with alternating haploid and diploid life stages, both of which are free-living and potentially long-lived. The haploid gametophytes of some ferns reproduce asexually and may have different environmental requirements than the diploid sporophytes, so it is possible for populations of gametophytes to exist without sporophytes. This dissertation includes a description of surveys for Hymenophyllum wrightii, a fern with independent gametophytes in the Pacific Northwest, and improves our understanding of the range, distribution, and habitat requirements of these plants which were previously assumed to be rare. It also describes an attempt to explore the population genetics of gametophytes of Crepidomanes intricatum, a widespread fern in the Appalachian Mountains for which no sporophytes have ever been found. To help visualize evolutionary processes in independent gametophyte populations I developed the Virtual Population Genetics Simulator (VPGsim) to simulate populations of ferns in a 3-dimensional environment. This dissertation includes a description of VPGsim, a learning module using it to teach undergraduate genetics, and a study demonstrating its effectiveness at improving students' understanding of science content and confidence in their ability to perform science inquiry. That simulation tool led to a collaboration to find other ways to teach science with simulations, and to the development of a Virtual Plant Community simulator (VPCsim) for teaching middle school students about the effects of the environment and human impacts on living organisms. This dissertation

  12. Early development of Costaria costata (C. Agardh) Saunders and cultivation trials

    NASA Astrophysics Data System (ADS)

    Fu, Gang; Liu, Jidong; Wang, Gaoge; Yao, Jianting; Wang, Xiuliang; Duan, Delin

    2010-07-01

    Costaria costata (C. Agardh) Saunders is one of common kelps distributed in many coastal areas worldwide; however, in China, no reports have been made on cultivation of the genus. To investigate potential cultivation of the species in the northern part of China, trials on isolation and preservation of the gametophytes were conducted using C. costata from Korea; growth and development of the gametophytes were observed. We showed that at 10±1°C, 60 μmol m-2s-1 and 12:12 h (L:D), freshly released zoospores settled down within 1 hour, and then developed into the primary cell during the following 2 days. After a vegetative growth phase lasting 6-8 days, female gametophytes became 3-4 times larger in diameter than that of the primary cell, but still remained at a unicellular stage, while male gametophytes divided into 4-10 cells with only a slight change in size. Fertilization occurred within 10 days after the zoospores were released from the sporangia, and the apical and basal tissues of the juvenile sporophyte divided and differentiated into the blade and stipe. Temperature and irradiance influenced gametophytic vegetative growth and developmental patterns. Generally, low irradiance (15 μmol m-2s-1 and 30 μmol m-2s-1) was unfavorable to the induction of fertility, but it enhanced female gametophyte division. The optimal conditions for vegetative growth were 15°C and 30 μmol m-2s-1. After transplantation of the juvenile seedlings and after eight months cultivation, the harvested mature blade reached 194 cm in length and 32.7 cm in width. Our study proves that it is feasible to implement propagation and large scale cultivation of C. costata in northern China.

  13. Genomic localization of the maize cross-incompatibility gene, Gametophyte factor 1 (ga1)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gametophyte factors in maize (Zea mays L.) mediate pollen-pistil interactions that confer preferential fertilization of some pistil genotypes by pollen carrying compatible alleles. Non-Mendelian segregation ratios caused by gametophyte factors have been observed in maize since the early 1920’s. In t...

  14. Examining the Development and Sexual Behavior of Adolescent Males

    PubMed Central

    Ott, Mary A.

    2010-01-01

    A careful examination of young men's sexuality by health professionals in pediatrics, primary care and reproductive health is foundational to adolescent male sexual health and healthy development. Through a review of existing literature, this article provides background and a developmental framework for sexual health services for adolescent boys. The article first defines and provides an overview of adolescent boys’ sexual health, and then discusses developmentally focused research on the following topics: (1) early romantic relationships and the evolution of power and influence within these relationships; (2) developmental “readiness” for sex and curiosity; (3) boys’ need for closeness and intimacy; (4) adopting codes of masculinity; (5) boys’ communicating about sex; and (6) contextual influences from peers, families, and providers. This article concludes by examining the implications of these data for sexual health promotion efforts for adolescent males, including HPV vaccination. PMID:20307842

  15. trnL-F is a powerful marker for DNA identification of field vittarioid gametophytes (Pteridaceae)

    PubMed Central

    Chen, Cheng Wei; Huang, Yao Moan; Kuo, Li Yaung; Nguyen, Quoc Dat; Luu, Hong Truong; Callado, John Rey; Farrar, Donald R.; Chiou, Wen Liang

    2013-01-01

    Background and Aims The gametophyte phase of ferns plays an important role in habitat selection, dispersal, adaptation and evolution. However, ecological studies on fern gametophytes have been impeded due to the difficulty of species identification of free-living gametophytes. DNA barcoding provides an alternative approach to identifying fern gametophytes but is rarely applied to field studies. In this study, an example of field vittarioid gametophyte identification using DNA barcoding, which has not been done before, is given. Methods A combination of distance-based and tree-based approaches was performed to evaluate the discriminating power of three candidate barcodes (matK, rbcL and trnL-F) on 16 vittarioid sporophytes. Sequences of the trnL-F region were generated from 15 fern gametophyte populations by tissue-direct PCR and were compared against the sporophyte dataset, using BLAST. Key Results trnL-F earns highest primer universality and discriminatory ability scores, whereas PCR success rates were very low for matK and rbcL regions (10·8 % and 41·3 %, respectively). BLAST analyses showed that all the sampled field gametophytes could be successfully identified to species level. Three gametophyte populations were also discovered to be living beyond the known occurrence of their sporophyte counterparts. Conclusions This study demonstrates that DNA barcoding (i.e. reference databasing, tissue-direct PCR and molecular analysis), especially the trnL-F region, is an efficient tool to identify field gametophytes, and has considerable potential in exploring the ecology of fern gametophytes. PMID:23380240

  16. Two-step oligoclonal development of male germ cells.

    PubMed

    Ueno, Hiroo; Turnbull, Brit B; Weissman, Irving L

    2009-01-01

    During mouse development, primordial germ cells (PGCs) that give rise to the entire germ line are first identified within the proximal epiblast. However, long-term tracing of the fate of the cells has not been done wherein all cells in and around the germ-cell lineage are identified. Also, quantitative estimates of the number of founder PGCs using different models have come up with various numbers. Here, we use tetrachimeric mice to show that the progenitor numbers for the entire germ line in adult testis, and for the initiating embryonic PGCs, are both 4 cells. Although they proliferate to form polyclonal germ-cell populations in fetal and neonatal testes, germ cells that actually contribute to adult spermatogenesis originate from a small number of secondary founder cells that originate in the fetal period. The rest of the "deciduous" germ cells are lost, most likely by apoptosis, before the reproductive period. The second "actual" founder germ cells generally form small numbers of large monoclonal areas in testes by the reproductive period. Our results also demonstrate that there is no contribution of somatic cells to the male germ cell pool during development or in adulthood. These results suggest a model of 2-step oligoclonal development of male germ cells in mice, the second step distinguishing the heritable germ line from cells selected not to participate in forming the next generation. PMID:19098099

  17. Ultrastructure of the sporophyte foot-gametophyte vaginula complex inTimmiella barbuloides (Brid.) Moenk.

    PubMed

    Ligrone, R; Gambardella, R; de Lucia Sposito, M L

    1982-09-01

    The sporophyte foot of the mossTimmiella barbuloides consists of an unistratose epidermis of transfer cells, a parenchymatous cortex, and a small central strand consisting only of hydroids. The parenchymatous tissue of the vaginula develops one layer of transfer cells opposite the foot, whose lower extremity extends into the gametophyte stem's central strand. From the bottom to the top of the foot the ultrastructure of the sporophyte transfer cells shows some gradual changes that appear related to a functional specialization of these cells. According to a centripetal gradient, the quantity of plastid starch progressively lessens in both vaginula parenchyma and foot cortex. the observed morphological patterns suggest that in the foot-vaginula complex nutrients are translocated radially up to the sporophyte central strand. PMID:24276269

  18. Roles of autophagy in male reproductive development in plants

    PubMed Central

    Hanamata, Shigeru; Kurusu, Takamitsu; Kuchitsu, Kazuyuki

    2014-01-01

    Autophagy, a major catabolic pathway in eukaryotic cells, is essential in development, maintenance of cellular homeostasis, immunity and programmed cell death (PCD) in multicellular organisms. In plant cells, autophagy plays roles in recycling of proteins and metabolites including lipids, and is involved in many physiological processes such as abiotic and biotic stress responses. However, its roles during reproductive development had remained poorly understood. Quantitative live cell imaging techniques for the autophagic flux and genetic studies in several plant species have recently revealed significant roles of autophagy in developmental processes, regulation of PCD and lipid metabolism. We here review the novel roles of autophagic fluxes in plant cells, and discuss their possible significance in PCD and metabolic regulation, with particular focus on male reproductive development during the pollen maturation. PMID:25309556

  19. Arbuscular mycorrhiza formation in cordate gametophytes of two ferns, Angiopteris lygodiifolia and Osmunda japonica.

    PubMed

    Ogura-Tsujita, Yuki; Sakoda, Aki; Ebihara, Atsushi; Yukawa, Tomohisa; Imaichi, Ryoko

    2013-01-01

    Mycorrhizal symbiosis is common among land plants including pteridophytes (monilophytes and lycophytes). In pteridophytes with diplohaplontic life cycle, mycorrhizal formations were mostly reported for sporophytes, but very few for gametophytes. To clarify the mycorrhizal association of photosynthetic gametophytes, field-collected gametophytes of Angiopteris lygodiifolia (Marattiaceae, n = 52) and Osmunda japonica (Osmundaceae, n = 45) were examined using microscopic and molecular techniques. Collected gametophytes were mostly cut into two pieces. One piece was used for light and scanning microscopic observations, and the other for molecular identification of plant species (chloroplast rbcL sequences) and mycorrhizal fungi (small subunit rDNA sequences). Microscopic observations showed that 96 % (50/52) of Angiopteris and 95 % (41/43) of Osmunda gametophytes contained intracellular hyphae with arbuscules and/or vesicles and fungal colonization was limited to the inner tissue of the thick midribs (cushion). Fungal DNA analyses showed that 92 % (48/52) of Angiopteris and 92 % (35/38) of Osmunda have sequences of arbuscular mycorrhizal fungi, which were highly divergent but all belonged to Glomus group A. These results suggest that A. lygodiifolia and O. japonica gametophytes consistently form arbuscular mycorrhizae. Mycorrhizal formation in wild fern gametophytes, based on large-scale sampling with molecular identification of host plant species, was demonstrated for the first time. PMID:22806582

  20. Effects of cadmium metal on young gametophytes of Gelidium floridanum: metabolic and morphological changes.

    PubMed

    Simioni, Carmen; Schmidt, Éder C; Rover, Ticiane; dos Santos, Rodrigo; Filipin, Elisa P; Pereira, Debora T; Costa, Giulia Burle; Oliveira, Eva Regina; Chow, Fungyi; Ramlov, Fernanda; Ouriques, Luciane; Maraschin, Marcelo; Bouzon, Zenilda L

    2015-09-01

    By evaluating carotenoid content, photosynthetic pigments and changes in cellular morphology, growth rates, and photosynthetic performance, this study aimed to determine the effect of cadmium (Cd) on the development of young gametophytes of Gelidium floridanum. Plants were exposed to 7.5 and 15 μM of Cd for 7 days. Control plants showed increased formation of new filamentous thallus, increased growth rates, presence of starch grains in the cortical and subcortical cells, protein content distributed regularly throughout the cell periphery, and intense autofluorescence of chloroplasts. On the other hand, plants treated with Cd at concentrations of 7.5 and 15 μM showed few formations of new thallus with totally depigmented regions, resulting in decreased growth rates. Plants exposed to 7.5 μM Cd demonstrated alterations in the cell wall and an increase in starch grains in the cortical and subcortical cells, while plants exposed to 15 μM Cd showed changes in medullary cells with no organized distribution of protein content. The autofluorescence and structure of chloroplasts decreased, forming a thin layer on the periphery of cells. Cadmium also affected plant metabolism, as visualized by a decrease in photosynthetic pigments, in particular, phycoerythrin and phycocyanin contents, and an increase in carotenoids. This result agrees with decreased photosynthetic performance and chronic photoinhibition observed after treatment with Cd, as measured by the decrease in electron transport rate. Based on these results, it was concluded that exposure to Cd affects cell metabolism and results in significant toxicity to young gametophytes of G. floridanum. PMID:25666304

  1. High genetic diversity in gametophyte clones of Undaria pinnatifida from Vladivostok, Dalian and Qingdao revealed using microsatellite analysis

    NASA Astrophysics Data System (ADS)

    Shan, Tifeng; Pang, Shaojun; Liu, Feng; Xu, Na; Zhao, Xiaobo; Gao, Suqin

    2012-03-01

    Breeding practice for Undaria pinnatifida (Harvey) Suringar requires the screening of a large number of offspring from gametophyte crossings to obtain an elite variety for large-scale cultivation. To better understand the genetic relationships of different gametophyte cultures isolated from different sources, 20 microsatellite loci were screened and 53 gametophyte clone cultures analyzed for U. pinnatifida isolated from wild sporophytes in Vladivostok, Russia and from cultivated sporophytes from Dalian and Qingdao, China. One locus was abandoned because of poor amplification. At the sex-linked locus of Up-AC-2A8, 3 alleles were detected in 25 female gametophyte clones, with sizes ranging from 307 to 316 bp. At other loci, 3 to 7 alleles were detected with an average of 4.5 alleles per locus. The average number of alleles at each locus was 1.3 and 3.7 for Russian and Chinese gametophyte clones, respectively. The average gene diversity for Russian, Chinese, and for the combined total of gametophyte clones was 0.1, 0.4, and 0.5, respectively. Russian gametophyte clones had unique alleles at 7 out of the 19 loci. In cluster analysis, Russian and Chinese gametophyte clones were separated into two different groups according to genetic distance. Overall, high genetic diversity was detected in gametophyte clones isolated from the two countries. These gametophyte cultures were believed to be appropriate parental materials for conducting breeding programs in the future.

  2. Regulation of protein synthesis during photomorphogenesis of gametophytes of the fern Onoclea sensibilis

    SciTech Connect

    Chansa-Ngavej, K.; Raghavan, V. )

    1989-08-01

    Gametophytes of the fern Onoclea sensibilis grow as filaments in the dark and in red light and become planar in blue light. Pulse-labeling 4-day-old gametophytes with ({sup 35}S)methionine at different times after transfer to dark, red, and blue light environments revealed higher rates of amino acid uptake and protein synthesis in blue light than in red light or in the dark. Characterization of the extant and newly synthesized soluble proteins by one- and two-dimensional gel electrophoresis showed that the patterns of protein accumulation and synthesis in gametophytes exposed to short periods of red or blue light were qualitatively indistinguishable from those of gametophytes maintained in the dark. However, some striking increases and decreases in the levels of certain polypeptides were noted and these changes were accentuated during continued growth of gametophytes in the different environments. The results show that photomorphogenesis of gametophytes of O. sensibilis is associated with quantitative rather than qualitative changes in the population of mRNAs available for translation.

  3. RLKs orchestrate the signaling in plant male-female interaction.

    PubMed

    Li, Hongju; Yang, Wei-Cai

    2016-09-01

    Different from animals, sessile plants are equipped with a large receptor-like kinase (RLK) superfamily. RLKs are a family of single trans-membrane proteins with divergent N-terminal extracellular domains capped by a signal peptide and C-terminal intracellular kinase. Researches in the last two decades have uncovered an increasing number of RLKs that regulate plant development, stress response and sexual reproduction, highlighting a dominant role of RLK signaling in cell-to-cell communications. Sexual reproduction in flowering plants is featured by interactions between the male gametophyte and the female tissues to facilitate sperm delivery and fertilization. Emerging evidences suggest that RLKs regulate almost every aspect of plant reproductive process, especially during pollination. Therefore, in this review we will focus mainly on the function and signaling of RLKs in plant male-female interaction and discuss the future prospects on these topics. PMID:27525988

  4. REPRODUCTIVE DEVELOPMENT IN MALE DEER MICE EXPOSED TO AGGRESSIVE BEHAVIOR

    EPA Science Inventory

    Male deer mice (Peromyscus maniculatus bairdii) were reared in a long photoperiod and housed individually from 3 weeks of age until they were killed 2, 4, or 6 weeks later. Males that were exposed to aggressive females for 2 min, three times per week, were of normal body weight a...

  5. Analysis of fatigue development during elite male handball matches.

    PubMed

    Póvoas, Susana C A; Ascensão, António A M R; Magalhães, José; Seabra, André F T; Krustrup, Peter; Soares, José M C; Rebelo, António N C

    2014-09-01

    This study aimed at describing the physiological demands and fatigue development during elite male handball matches. Our hypothesis was that players perform multiple high-intensity activities during periods of the game and develop temporary and end-match neuromuscular fatigue. Time-motion analyses and heart rate (HR) recordings were performed in 40 players during 12 competitive matches. Blood samples were collected, and sprint, jump, and intermittent exercise performance (Yo-Yo Intermittent Endurance level 2 test [YYIE2]) was assessed for 18 players at baseline conditions and after 2 competitive matches, and additional blood sampling and testing were performed for 12 of these players during a friendly match. The time spent with high-intensity running (4.4 ± 2.0 to 3.1 ± 1.7%), the frequency of demanding actions (61 ± 5 to 54 ± 6), and the time with HR above 80% HRmax (62 ± 21 to 41 ± 17%) were lowered from the first to the second half. Average blood lactate during the match was 3.6 ± 2.1 (1.3-8.6) mM. Plasma free fatty acids (FFA), glycerol, glucose, and uric acid increased (p ≤ 0.05) during the first half and plasma FFA and glycerol increased further (p ≤ 0.05) during the second half. After an intense period in the second half, sprint performance was decreased by 3.9 ± 4.9%. After the match, YYIE2 (33.4 ± 8.7%), vertical jump (7.4 ± 6.5%), and 20-m sprint performance (1.6 ± 2.6%) was lower (p ≤ 0.05) than at baseline. This study showed that the intensity is high in certain periods during elite male handball games and that physical performance is impaired both temporarily during and toward the end of games confirming our hypothesis. These findings enables physical trainers and coaches to plan and design proper game-specific training exercises aiming at delaying both temporary and end-game fatigue and strengthen the physiological rationale for the need for substitutions in various stages of match-play. PMID:24552799

  6. The UV-absorbing compounds in gametophytic blades of Porphyra haitanensis and the effect on formation of sporangial branchlets of conchocelis

    NASA Astrophysics Data System (ADS)

    Chen, Ye; Yan, Xiaojun

    2007-07-01

    Endogenous levels of UVAC in different parts of matured gametophytic blades of Porphyra haitanensis and the effect of exogenous UVAC on sporangial branchlet formation are studied. The UVAC value in vegetative (36. 78 mg/g) and reproductive (29.25 mg/g) parts of female thallus is higher than their counterparts in male thallus (34.68 mg/g and 20.46 mg/g). The UVAC value of reproductive parts is higher than vegetative parts of same sexual thallus. The optimal UVAC concentration for sporangial branchlet formation is 0.1 mg/g.

  7. Aniline Is Rapidly Converted Into Paracetamol Impairing Male Reproductive Development.

    PubMed

    Holm, Jacob Bak; Chalmey, Clementine; Modick, Hendrik; Jensen, Lars Skovgaard; Dierkes, Georg; Weiss, Tobias; Jensen, Benjamin Anderschou Holbech; Nørregård, Mette Marie; Borkowski, Kamil; Styrishave, Bjarne; Martin Koch, Holger; Mazaud-Guittot, Severine; Jegou, Bernard; Kristiansen, Karsten; Kristensen, David Møbjerg

    2015-11-01

    Industrial use of aniline is increasing worldwide with production estimated to surpass 5.6 million metric tons in 2016. Exposure to aniline occurs via air, diet, and water augmenting the risk of exposing a large number of individuals. Early observations suggest that aniline is metabolized to paracetamol/acetaminophen, likely explaining the omnipresence of low concentrations of paracetamol in European populations. This is of concern as recent studies implicate paracetamol as a disrupter of reproduction. Here, we show through steroidogenic profiling that exposure to aniline led to increased levels of the Δ4 steroids, suggesting that the activity of CYP21 was decreased. By contrast, paracetamol decreased levels of androgens likely through inhibition of CYP17A1 activity. We confirm that aniline in vivo is rapidly converted to paracetamol by the liver. Intrauterine exposure to aniline and paracetamol in environmental and pharmaceutical relevant doses resulted in shortening of the anogenital distance in mice, a sensitive marker of fetal androgen levels that in humans is associated with reproductive malformations and later life reproductive disorders. In conclusion, our results provide evidence for a scenario where aniline, through its conversion into antiandrogenic paracetamol, impairs male reproductive development. PMID:26259604

  8. Arbuscular mycorrhizal colonization in field-collected terrestrial cordate gametophytes of pre-polypod leptosporangiate ferns (Osmundaceae, Gleicheniaceae, Plagiogyriaceae, Cyatheaceae).

    PubMed

    Ogura-Tsujita, Yuki; Hirayama, Yumiko; Sakoda, Aki; Suzuki, Ayako; Ebihara, Atsushi; Morita, Nana; Imaichi, Ryoko

    2016-02-01

    To determine the mycorrhizal status of pteridophyte gametophytes in diverse taxa, the mycorrhizal colonization of wild gametophytes was investigated in terrestrial cordate gametophytes of pre-polypod leptosporangiate ferns, i.e., one species of Osmundaceae (Osmunda banksiifolia), two species of Gleicheniaceae (Diplopterygium glaucum, Dicranopteris linearis), and four species of Cyatheales including tree ferns (Plagiogyriaceae: Plagiogyria japonica, Plagiogyria euphlebia; Cyatheaceae: Cyathea podophylla, Cyathea lepifera). Microscopic observations revealed that 58 to 97% of gametophytes in all species were colonized with arbuscular mycorrhizal (AM) fungi. Fungal colonization was limited to the multilayered midrib (cushion) tissue in all gametophytes examined. Molecular identification using fungal SSU rDNA sequences indicated that the AM fungi in gametophytes primarily belonged to the Glomeraceae, but also included the Claroideoglomeraceae, Gigasporaceae, Acaulosporaceae, and Archaeosporales. This study provides the first evidence for AM fungal colonization of wild gametophytes in the Plagiogyriaceae and Cyatheaceae. Taxonomically divergent photosynthetic gametophytes are similarly colonized by AM fungi, suggesting that mycorrhizal associations with AM fungi could widely occur in terrestrial pteridophyte gametophytes. PMID:26047572

  9. Effects of ultraviolet radiation (UVA+UVB) on young gametophytes of Gelidium floridanum: growth rate, photosynthetic pigments, carotenoids, photosynthetic performance, and ultrastructure.

    PubMed

    Simioni, Carmen; Schmidt, Eder C; Felix, Marthiellen R de L; Polo, Luz Karime; Rover, Ticiane; Kreusch, Marianne; Pereira, Debora T; Chow, Fungyi; Ramlov, Fernanda; Maraschin, Marcelo; Bouzon, Zenilda L

    2014-01-01

    This study investigated the effects of radiation (PAR+UVA+UVB) on the development and growth rates (GRs) of young gametophytes of Gelidium floridanum. In addition, photosynthetic pigments were quantified, carotenoids identified, and photosynthetic performance assessed. Over a period of 3 days, young gametophytes were cultivated under laboratory conditions and exposed to photosynthetically active radiation (PAR) at 80 μmol photons m(-2) s(-1) and PAR+UVA (0.70 W m(-2))+UVB (0.35 W m(-2)) for 3 h per day. The samples were processed for light and electron microscopy to analyze the ultrastructure features, as well as carry out metabolic studies of GRs, quantify the content of photosynthetic pigments, identify carotenoids and assess photosynthetic performance. PAR+UVA+UVB promoted increase in cell wall thickness, accumulation of floridean starch grains in the cytoplasm and disruption of chloroplast internal organization. Algae exposed to PAR+UVA+UVB also showed a reduction in GR of 97%. Photosynthetic pigments, in particular, phycoerythrin and allophycocyanin contents, decreased significantly from UV radiation exposure. This result agrees with the decrease in photosynthetic performance observed after exposure to ultraviolet radiation, as measured by a decrease in the electron transport rate (ETR), where values of ETRmax declined approximately 44.71%. It can be concluded that radiation is a factor that affects the young gametophytes of G. floridanum at this stage of development. PMID:24893751

  10. The Anaphase-Promoting Complex Is a Dual Integrator That Regulates Both MicroRNA-Mediated Transcriptional Regulation of Cyclin B1 and Degradation of Cyclin B1 during Arabidopsis Male Gametophyte Development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The anaphase-promoting complex/cyclosome (APC/C), an essential ubiquitin protein ligase, regulates mitotic progression and exit by enhancing degradation of cell cycle regulatory proteins, such as CYCB1;1, whose transcripts are upregulated by DUO POLLEN1 (DUO1). DUO1 is required for cell division in ...

  11. The Anaphase-Promoting Complex is a dual integrator that regulates both microRNA-mediated transcriptional regulation of Cyclin B1 and degradation of Cyclin B1 during Arabidopsis male gametophyte development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The anaphase-promoting complex/cyclosome (APC/C), an essential ubiquitin protein ligase, regulates mitotic progression and exit by enhancing degradation of cell cycle regulatory proteins, such as CYCB1;1, whose transcripts are upregulated by DUO POLLEN1 (DUO1). DUO1 is required for cell division in ...

  12. Developing a Latino Mentoring Program: Project MALES (Mentoring to Achieve Latino Educational Success)

    ERIC Educational Resources Information Center

    Sáenz, Victor B.; Ponjuan, Luis; Segovia, Jorge, Jr.; Del Real Viramontes, José

    2015-01-01

    This chapter highlights the development of Project MALES (Mentoring to Achieve Latino Educational Success). At the center of Project MALES is a mentoring program that aims to cultivate an engaged support network for males of color at the University of Texas at Austin and across surrounding communities. Specifically, there is a discussion of the…

  13. Host specificity and growth of kelp gametophytes symbiotic with filamentous red algae (Ceramiales, Rhodophyta)

    NASA Astrophysics Data System (ADS)

    Hubbard, Charlene B.; Garbary, David J.; Kim, Kwang Young; Chiasson, David M.

    2004-02-01

    Kelp gametophytes were previously observed in nature living endophytically in red algal cell walls. Here we examine the interactions of two kelp species and six red algae in culture. Gametophytes of Nereocystis luetkeana (Mertens) Postels et Ruprecht became endophytic in the cell walls of Griffithsia pacifica Kylin and Antithamnion defectum Kylin, and grew epiphytically in high abundance on G. japonica Okamura and Aglaothamnion oosumiense Itono. Alaria esculenta (Linnaeus) Greville from the Atlantic coast of Nova Scotia became endophytic in Aglaothamnion oosumiense, Antithamnion defectum, Callithamnion sp., G. japonica, G. pacifica, and Pleonosporium abysicola Gardner, all from the Pacific Ocean. Some cultures were treated with phloroglucinol before infection to thicken the cell walls. The endophytic gametophytes were smaller and grew more slowly than gametophytes epiphytic on the same host. N. luetkeana failed to become endophytic in some of the potential hosts, and this may reflect host specificity, or culture artifacts. This work improves our understanding of the process of infection of red algae by kelp gametophytes, and broadens our knowledge of host specificity in endophytic symbioses.

  14. Differential responses of tetrasporophytes and gametophytes of Mazzaella laminarioides (Gigartinales, Rhodophyta) under solar UV radiation.

    PubMed

    Navarro, Nelso P; Figueroa, Félix L; Korbee, Nathalie; Mansilla, Andrés; Plastino, Estela M

    2016-06-01

    The effects of solar UV radiation on mycosporine-like amino acids (MAAs), growth, photosynthetic pigments (Chl a, phycobiliproteins), soluble proteins (SP), and C and N content of Mazzaella laminarioides tetrasporophytes and gametophytes were investigated. Apical segments of tetrasporophytes and gametophytes were exposed to solar radiation under three treatments (PAR [P], PAR+UVA [PA], and PAR+UVA+UVB [PAB]) during 18 d in spring 2009, Punta Arenas, Chile. Samples were taken after 2, 6, 12, and 18 d of solar radiation exposure. Most of the parameters assessed on M. laminarioides were significantly influenced by the radiation treatment, and both gametophytes and tetrasporophytes seemed to respond differently when exposed to high UV radiation. The two main effects promoted by UV radiation were: (i) higher synthesis of MAAs in gametophytes than tetrasporophytes at 2 d, and (ii) a decrease in phycoerythrin, phycocyanin, and SPs, but an increase in MAA content in tetrasporophytes at 6 and 12 d of culture. Despite some changes that were observed in biochemical parameters in both tetrasporophytes and gametophytes of M. laminarioides when exposed to UVB radiation, these changes did not promote deleterious effects that might interfere with the growth in the long term (18 d). The tolerance and resistance of M. laminarioides to higher UV irradiance were expected, as this intertidal species is exposed to variation in solar radiation, especially during low tide. PMID:26990026

  15. Sexual selection on male size drives the evolution of male-biased sexual size dimorphism via the prolongation of male development.

    PubMed

    Rohner, Patrick T; Blanckenhorn, Wolf U; Puniamoorthy, Nalini

    2016-06-01

    Sexual size dimorphism (SSD) arises when the net effects of natural and sexual selection on body size differ between the sexes. Quantitative SSD variation between taxa is common, but directional intraspecific SSD reversals are rare. We combined micro- and macroevolutionary approaches to study geographic SSD variation in closely related black scavenger flies. Common garden experiments revealed stark intra- and interspecific variation: Sepsis biflexuosa is monomorphic across the Holarctic, while S. cynipsea (only in Europe) consistently exhibits female-biased SSD. Interestingly, S. neocynipsea displays contrasting SSD in Europe (females larger) and North America (males larger), a pattern opposite to the geographic reversal in SSD of S. punctum documented in a previous study. In accordance with the differential equilibrium model for the evolution of SSD, the intensity of sexual selection on male size varied between continents (weaker in Europe), whereas fecundity selection on female body size did not. Subsequent comparative analyses of 49 taxa documented at least six independent origins of male-biased SSD in Sepsidae, which is likely caused by sexual selection on male size and mediated by bimaturism. Therefore, reversals in SSD and the associated changes in larval development might be much more common and rapid and less constrained than currently assumed. PMID:27168489

  16. RNA Sequencing Analysis of the Gametophyte Transcriptome from the Liverwort, Marchantia polymorpha

    PubMed Central

    Sharma, Niharika; Jung, Chol-Hee; Bhalla, Prem L.; Singh, Mohan B.

    2014-01-01

    The liverwort Marchantia polymorpha is a member of the most basal lineage of land plants (embryophytes) and likely retains many ancestral morphological, physiological and molecular characteristics. Despite its phylogenetic importance and the availability of previous EST studies, M. polymorpha’s lack of economic importance limits accessible genomic resources for this species. We employed Illumina RNA-Seq technology to sequence the gametophyte transcriptome of M. polymorpha. cDNA libraries from 6 different male and female developmental tissues were sequenced to delineate a global view of the M. polymorpha transcriptome. Approximately 80 million short reads were obtained and assembled into a non-redundant set of 46,533 transcripts (> = 200 bp) from 46,070 loci. The average length and the N50 length of the transcripts were 757 bp and 471 bp, respectively. Sequence comparison of assembled transcripts with non-redundant proteins from embryophytes resulted in the annotation of 43% of the transcripts. The transcripts were also compared with M. polymorpha expressed sequence tags (ESTs), and approximately 69.5% of the transcripts appeared to be novel. Twenty-one percent of the transcripts were assigned GO terms to improve annotation. In addition, 6,112 simple sequence repeats (SSRs) were identified as potential molecular markers, which may be useful in studies of genetic diversity. A comparative genomics approach revealed that a substantial proportion of the genes (35.5%) expressed in M. polymorpha were conserved across phylogenetically related species, such as Selaginella and Physcomitrella, and identified 580 genes that are potentially unique to liverworts. Our study presents an extensive amount of novel sequence information for M. polymorpha. This information will serve as a valuable genomics resource for further molecular, developmental and comparative evolutionary studies, as well as for the isolation and characterization of functional genes that are involved in

  17. Direction of illumination controls gametophyte orientation in seedless plants and related algae.

    PubMed

    Cardona-Correa, Christopher; Ecker, Alice; Graham, Linda E

    2015-01-01

    The environmental influences that determine dorsiventral or axial gametophyte orientation are unknown for most modern seedless plants. To fill this gap, an experimental laboratory system was employed to evaluate the relative effects of light direction and gravity on body orientation of the dorsiventral green alga Coleochaete orbicularis, and gametophytes of liverworts Blasia pusilla and Marchantia polymorpha, early-diverging moss Sphagnum compactum, and fern Ceratopteris richardii, the latter functioning as experimental control. Replicate clonal cultures were experimentally illuminated only from above, only from below, or from multiple directions, with the same near-saturation PAR level for periods brief enough to minimize nutrient limitation effects, and orientation of new growth was evaluated. For all species tested, direction of illumination exerted stronger control over gametophyte body orientation than gravity. When illuminated only from below: 1) axial Sphagnum gametophores that had initially grown into an overlying air space inverted growth by 180°, burrowing into the substrate; 2) new growth of dorsiventral Blasia, Marchantia, and Ceratopteris gametophytes-whose ventral rhizoids initially penetrated agar substrate and dorsal surfaces initially faced overlying airspace-twisted 180° so that ventral surfaces bearing rhizoids faced overlying air space and rhizoids extended into the air; and 3) Coleochaete lost typical dorsiventral organization and diagnostic dorsal hairs. Direction of illumination also exerted stronger control over orientation of liverwort new growth than surface contact did. These results indicate that early land plants likely inherited light-directed gametophyte body orientation from ancestral streptophyte algae and suggest a mechanism for reorientation of gametophyte-dominant land plants after spatial disturbance. PMID:26237278

  18. Selection of sporophytic and gametophytic self-incompatibility in the absence of a superlocus.

    PubMed

    Schoen, Daniel J; Roda, Megan J

    2016-06-01

    Self-incompatibility (SI) is a complex trait that enforces outcrossing in plant populations. SI generally involves tight linkage of genes coding for the proteins that underlie self-pollen detection and pollen identity specification. Here, we develop two-locus genetic models to address the question of whether sporophytic SI (SSI) and gametophytic SI (GSI) can invade populations of self-compatible plants when there is no linkage or weak linkage of the underlying pollen detection and identity genes (i.e., no S-locus supergene). The models assume that SI evolves as a result of exaptation of genes formerly involved in functions other than SI. Model analysis reveals that SSI and GSI can invade populations even when the underlying genes are loosely linked, provided that inbreeding depression and selfing rate are sufficiently high. Reducing recombination between these genes makes conditions for invasion more lenient. These results can help account for multiple, independent evolution of SI systems as seems to have occurred in the angiosperms. PMID:27111063

  19. Masculinity Identity Development and Its Relevance to Supporting Talented Black Males

    ERIC Educational Resources Information Center

    Henfield, Malik S.

    2012-01-01

    The purpose of the article is to provide a brief introduction to Black male masculine identity development and relate it to the field of gifted education. It will begin with information related to identity development that is applicable to Black males. Next, the phenomenological variant of ecological systems theory (PVEST) will be explored and…

  20. Male Archetypes as Resources for Homosexual Identity Development in Gay Men.

    ERIC Educational Resources Information Center

    McFarland, William P.; McMahon, Timothy R.

    1999-01-01

    The male archetypes of king, lover, magician, and warrior provide important and timeless insights into mature masculine qualities. Homosexual identity development models describe tasks that confront gay men as they move through the identity development process. Proposes that by understanding the metaphor of male archetypes, gay men will discover…

  1. Methoprene and protein supplements accelerate reproductive development and improve mating success of male tephritid flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have been studying the physiological mechanisms responsible for coordination of reproductive maturity and sex pheromone communication in males of tephritid flies in order to develop methods for acceleration of reproductive maturity among sterilized males. Our studies revealed that the juvenile ho...

  2. African American Males and Literacy Development in Contexts That Are Characteristically Urban

    ERIC Educational Resources Information Center

    Tatum, Alfred W.; Muhammad, Gholnecsar E.

    2012-01-01

    Advancing the literacy development of African American males in contexts that are characteristically urban has been a challenging task for educators across the P-12 spectrum. Frames that have been traditionally used to improve the reading achievement of African American males have not reversed trends in reading achievement that find many of these…

  3. Ethical issues in male sterilization in developing countries.

    PubMed

    Rizvi, S A; Naqvi, S A; Hussain, Z

    1995-11-01

    The history of sterilization dates back to the time of Hippocrates, when female sterilization was recommended for preventing hereditary mental diseases. James Blundell introduced surgical sterilization in 1823 for the prevention of high risk pregnancies. Vasectomy was first performed in the US at the end of the 19th century, mainly to prevent hereditary disorders. Male sterilization was a means of genocide during Nazi rule in Germany. Religious beliefs have the most powerful impact on the practice or nonpractice of family planning. In the teachings of Islam, Christianity, and Judaism, only sporadic references explicitly prohibit contraception, yet various religious edicts have interpreted these references too broadly by advocating prohibition of most contraceptive methods. Recently, the world community endorsed the basic right of couples to decide the number of children they want and the right to family planning with free informed choice. An integral part of a successful family planning program is voluntarism. In Europe and North America sterilization is legal, except in Italy, France, and Turkey. In Latin America sterilization is illegal in a number of countries; in Burma and Vietnam restrictions are in place; and in Africa fertility regulation is illegal in one-third of the countries. Informed consent before sterilization during counseling by a skilled, unbiased counselor is indispensable. All family planning services should be part of the national health care system including the voluntary contraception services. Incentives may compromise voluntarism. Most programs require a minimum age and a minimum number of children, marital status, and spousal consent. For sterilization, a waiting period of 1-30 days has been recommended. The exclusion of childless and single individuals has been challenged as a violation of human rights. For mentally retarded people parents or guardians provide consent. Major ethical issues in the future could emerge concerning novel

  4. Direction of illumination controls gametophyte orientation in seedless plants and related algae

    PubMed Central

    Cardona-Correa, Christopher; Ecker, Alice; Graham, Linda E

    2015-01-01

    The environmental influences that determine dorsiventral or axial gametophyte orientation are unknown for most modern seedless plants. To fill this gap, an experimental laboratory system was employed to evaluate the relative effects of light direction and gravity on body orientation of the dorsiventral green alga Coleochaete orbicularis, and gametophytes of liverworts Blasia pusilla and Marchantia polymorpha, early-diverging moss Sphagnum compactum, and fern Ceratopteris richardii, the latter functioning as experimental control. Replicate clonal cultures were experimentally illuminated only from above, only from below, or from multiple directions, with the same near-saturation PAR level for periods brief enough to minimize nutrient limitation effects, and orientation of new growth was evaluated. For all species tested, direction of illumination exerted stronger control over gametophyte body orientation than gravity. When illuminated only from below: 1) axial Sphagnum gametophores that had initially grown into an overlying air space inverted growth by 180°, burrowing into the substrate; 2) new growth of dorsiventral Blasia, Marchantia, and Ceratopteris gametophytes–whose ventral rhizoids initially penetrated agar substrate and dorsal surfaces initially faced overlying airspace–twisted 180° so that ventral surfaces bearing rhizoids faced overlying air space and rhizoids extended into the air; and 3) Coleochaete lost typical dorsiventral organization and diagnostic dorsal hairs. Direction of illumination also exerted stronger control over orientation of liverwort new growth than surface contact did. These results indicate that early land plants likely inherited light-directed gametophyte body orientation from ancestral streptophyte algae and suggest a mechanism for reorientation of gametophyte-dominant land plants after spatial disturbance. PMID:26237278

  5. Traditional Wisdom and Male Adolescent Development on Marathon Bicycle Rides.

    ERIC Educational Resources Information Center

    McClelland, Gary W.

    The challenge of the Australian lifestyle has historically led bushmen on journeys of arduous adventure which actively developed unfettered spirits and extraordinary endurance. These qualities have contributed to the development of the Australian psyche. As a way of passing on the qualities and values of Australian bushmen of years ago, an…

  6. Pollen wall development: the associated enzymes and metabolic pathways.

    PubMed

    Jiang, J; Zhang, Z; Cao, J

    2013-03-01

    Pollen grains are surrounded by a sculpted wall, which protects male gametophytes from various environmental stresses and microbial attacks, and also facilitates pollination. Pollen wall development requires lipid and polysaccharide metabolism, and some key genes and proteins that participate in these processes have recently been identified. Here, we summarise the genes and describe their functions during pollen wall development via several metabolic pathways. A working model involving substances and catalytic enzyme reactions that occur during pollen development is also presented. This model provides information on the complete process of pollen wall development with respect to metabolic pathways. PMID:23252839

  7. Transgenic studies on the involvement of cytokinin and gibberellin in male development.

    PubMed

    Huang, Shihshieh; Cerny, R Eric; Qi, Youlin; Bhat, Deepti; Aydt, Carrie M; Hanson, Doris D; Malloy, Kathleen P; Ness, Linda A

    2003-03-01

    Numerous plant hormones interact during plant growth and development. Elucidating the role of these various hormones on particular tissue types or developmental stages has been difficult with exogenous applications or constitutive expression studies. Therefore, we used tissue-specific promoters expressing CKX1 and gai, genes involved in oxidative cytokinin degradation and gibberellin (GA) signal transduction, respectively, to study the roles of cytokinin and GA in male organ development. Accumulation of CKX1 in reproductive tissues of transgenic maize (Zea mays) resulted in male-sterile plants. The male development of these plants was restored by applications of kinetin and thidiazuron. Similarly, expression of gai specifically in anthers and pollen of tobacco (Nicotiana tabacum) and Arabidopsis resulted in the abortion of these respective tissues. The gai-induced male-sterile phenotype exhibited by the transgenic plants was reversible by exogenous applications of kinetin. Our results provide molecular evidence of the involvement of cytokinin and GA in male development and support the hypothesis that the male development is controlled in concert by multiple hormones. These studies also suggest a potential method for generating maintainable male sterility in plants by using existing agrochemicals that would reduce the expense of seed production for existing hybrid crops and provide a method to produce hybrid varieties of traditionally non-hybrid crops. PMID:12644677

  8. Transgenic Studies on the Involvement of Cytokinin and Gibberellin in Male Development

    PubMed Central

    Huang, Shihshieh; Cerny, R. Eric; Qi, Youlin; Bhat, Deepti; Aydt, Carrie M.; Hanson, Doris D.; Malloy, Kathleen P.; Ness, Linda A.

    2003-01-01

    Numerous plant hormones interact during plant growth and development. Elucidating the role of these various hormones on particular tissue types or developmental stages has been difficult with exogenous applications or constitutive expression studies. Therefore, we used tissue-specific promoters expressing CKX1 and gai, genes involved in oxidative cytokinin degradation and gibberellin (GA) signal transduction, respectively, to study the roles of cytokinin and GA in male organ development. Accumulation of CKX1 in reproductive tissues of transgenic maize (Zea mays) resulted in male-sterile plants. The male development of these plants was restored by applications of kinetin and thidiazuron. Similarly, expression of gai specifically in anthers and pollen of tobacco (Nicotiana tabacum) and Arabidopsis resulted in the abortion of these respective tissues. The gai-induced male-sterile phenotype exhibited by the transgenic plants was reversible by exogenous applications of kinetin. Our results provide molecular evidence of the involvement of cytokinin and GA in male development and support the hypothesis that the male development is controlled in concert by multiple hormones. These studies also suggest a potential method for generating maintainable male sterility in plants by using existing agrochemicals that would reduce the expense of seed production for existing hybrid crops and provide a method to produce hybrid varieties of traditionally non-hybrid crops. PMID:12644677

  9. Ploidy manipulation of the gametophyte, endosperm and sporophyte in nature and for crop improvement: a tribute to Professor Stanley J. Peloquin (1921–2008)

    PubMed Central

    Ortiz, Rodomiro; Simon, Philipp; Jansky, Shelley; Stelly, David

    2009-01-01

    Background Emeritus Campbell-Bascom Professor Stanley J. Peloquin was an internationally renowned plant geneticist and breeder who made exceptional contributions to the quantity, quality and sustainable supply of food for the world from his innovative and extensive scientific contributions. For five decades, Dr Peloquin merged basic research in plant reproduction, cytology, cytogenetics, genetics, potato (Solanum tuberosum) improvement and education at the University of Wisconsin-Madison. Successive advances across these five decades redefined scientific comprehension of reproductive variation, its genetic control, genetic effects, evolutionary impact and utility for breeding. In concert with the International Potato Center (CIP), he and others translated the advances into application, resulting in large benefits on food production worldwide, exemplifying the importance of integrated innovative university research and graduate education to meet domestic and international needs. Scope Dr Peloquin is known to plant breeders, geneticists, international agricultural economists and potato researchers for his enthusiastic and incisive contributions to genetic enhancement of potato using haploids, 2n gametes and wild Solanum species; for his pioneering work on potato cultivation through true seed; and as mentor of a new generation of plant breeders worldwide. The genetic enhancement of potato, the fourth most important food crop worldwide, benefited significantly from expanded germplasm utilization and advanced reproductive genetic knowledge, which he and co-workers, including many former students, systematically transformed into applied breeding methods. His research on plant sexual reproduction included subjects such as haploidization and polyploidization, self- and cross-incompatibility, cytoplasmic male sterility and restorer genes, gametophytic/sporophytic heterozygosity and male fertility, as well as endosperm dosages and seed development. By defining methods of

  10. Evaluation of Reference Genes for RT qPCR Analyses of Structure-Specific and Hormone Regulated Gene Expression in Physcomitrella patens Gametophytes

    PubMed Central

    Le Bail, Aude; Scholz, Sebastian; Kost, Benedikt

    2013-01-01

    The use of the moss Physcomitrella patens as a model system to study plant development and physiology is rapidly expanding. The strategic position of P. patens within the green lineage between algae and vascular plants, the high efficiency with which transgenes are incorporated by homologous recombination, advantages associated with the haploid gametophyte representing the dominant phase of the P. patens life cycle, the simple structure of protonemata, leafy shoots and rhizoids that constitute the haploid gametophyte, as well as a readily accessible high-quality genome sequence make this moss a very attractive experimental system. The investigation of the genetic and hormonal control of P. patens development heavily depends on the analysis of gene expression patterns by real time quantitative PCR (RT qPCR). This technique requires well characterized sets of reference genes, which display minimal expression level variations under all analyzed conditions, for data normalization. Sets of suitable reference genes have been described for most widely used model systems including e.g. Arabidopsis thaliana, but not for P. patens. Here, we present a RT qPCR based comparison of transcript levels of 12 selected candidate reference genes in a range of gametophytic P. patens structures at different developmental stages, and in P. patens protonemata treated with hormones or hormone transport inhibitors. Analysis of these RT qPCR data using GeNorm and NormFinder software resulted in the identification of sets of P. patens reference genes suitable for gene expression analysis under all tested conditions, and suggested that the two best reference genes are sufficient for effective data normalization under each of these conditions. PMID:23951063

  11. The POWER campaign for promotion of female and male condoms: audience research and campaign development.

    PubMed

    Bull, Sheana Salyers; Cohen, Jennifer; Ortiz, Charlene; Evans, Tom

    2002-01-01

    In this study, we conducted and content analyzed 12 focus groups with women aged 15-25 living in inner city Denver as a process of audience research to develop a male and female condom promotion campaign. We recruited 89 women from school and community sites in central Denver neighborhoods to discuss their knowledge, attitudes, and practices regarding both male and female condoms, then solicited opinions about how to increase knowledge about and familiarity with female condoms, increase positive attitudes toward both male and female condoms, and how to increase access to and use of both male and female condoms. Opinions on these topics drove the development of a targeted media campaign promoting condom use in this population. We report here on the general findings from focus groups and provide details about the campaign the participants helped to develop. PMID:12375772

  12. Barriers to male transmission of mitochondrial DNA in sperm development.

    PubMed

    DeLuca, Steven Z; O'Farrell, Patrick H

    2012-03-13

    Across the eukaryotic phylogeny, offspring usually inherit their mitochondrial genome from only one of two parents: in animals, the female. Although mechanisms that eliminate paternally derived mitochondria from the zygote have been sought, the developmental stage at which paternal transmission of mitochondrial DNA is restricted is unknown in most animals. Here, we show that the mitochondria of mature Drosophila sperm lack DNA, and we uncover two processes that eliminate mitochondrial DNA during spermatogenesis. Visualization of mitochondrial DNA nucleoids revealed their abrupt disappearance from developing spermatids in a process requiring the mitochondrial nuclease, Endonuclease G. In Endonuclease G mutants, persisting nucleoids are swept out of spermatids by a cellular remodeling process that trims and shapes spermatid tails. Our results show that mitochondrial DNA is eliminated during spermatogenesis, thereby removing the capacity of sperm to transmit the mitochondrial genome to the next generation. PMID:22421049

  13. THE DEVELOPMENT OF SEXUAL DIMORPHISM: STUDIES OF THE C. ELEGANS MALE

    PubMed Central

    Emmons, Scott W.

    2014-01-01

    Studies of the development of the C. elegans male have been carried out with the aim of understanding the basis of sexual dimorphism. Postembryonic development of the two C. elegans sexes differs extensively. Development along either the hermaphrodite or male pathway is specified initially by the X to autosome ratio. The regulatory events initiated by this ratio include a male-determining paracrine intercellular signal. Expression of this signal leads to different consequences in three regions of the body: the non-gonadal soma, the somatic parts of the gonad, and the germ line. In the non-gonadal soma, activity of the key Zn-finger transcription factor TRA 1 determines hermaphrodite development; in its absence, the male pathway is followed. Only a few genes directly regulated by TRA 1 are currently known, including members of the evolutionarily conserved, male-determining DM domain Zn-finger transcription factors. In the somatic parts of the gonad and germ line, absence of TRA 1 activity is not sufficient for full expression of the male pathway. Several additional transcription factors involved have been identified. In the germ line, regulatory genes for sperm development that act at the level of RNA in the cytoplasm play a prominent role. PMID:25262817

  14. Testicular function, secondary sexual development, and social status in male mandrills (Mandrillus sphinx).

    PubMed

    Wickings, E J; Dixson, A F

    1992-11-01

    Positive correlations between dominance rank and plasma testosterone levels have been described for adult males of several primate species in captivity, but the relevance of such observations to free-ranging animals is unclear. CIRMF in Gabon maintains a breeding group of 45 mandrills in a six hectare, naturally rainforested enclosure. This study describes correlations between dominance rank (in agonistic encounters), levels of plasma testosterone, testicular volume, body weight, and development of secondary sexual characteristics (red and blue sexual skin on the muzzle and rump areas) in male mandrills under semifree ranging conditions. Two morphological and social variants of adult male mandrill were identified. Large-rumped or fatted adult males (n = 3) remained in the social group and exhibited maximal development of sexual skin coloration as well as large testicular size and highest plasma testosterone levels. By contrast, slimmer-rumped or nonfatted males (n = 3) lived a peripheral or solitary existence and these exhibited less development of their secondary sexual coloration and had smaller testes and lower plasma testosterone levels. Longitudinal studies of gonadal development in these six males revealed that testicular volumes and plasma testosterone levels increased most rapidly during pubertal development (4-5 years of age) in the three animals which proceeded to the fatted condition. These included the highest ranking, group-associated male which exhibited the most intense sexual skin coloration and had higher testosterone levels, although this was not correlated with testicular volume. This study shows that in the male mandrill social factors and reproductive development are interrelated.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1484847

  15. The development of male prostitution activity among gay and bisexual adolescents.

    PubMed

    Coleman, E

    1989-01-01

    The current research literature regarding male-juvenile prostitution activity is reviewed. An attempt is made to develop some theoretical understanding of the development of this activity among gay and bisexual adolescents. A predisposition, resulting from faulty psychosexual and psychosocial development, appears to make these boys vulnerable to the situational variables that they encounter. More severe disruptions in psychosexual and psychosocial development seem to result in more destructive and non-ego-enhancing prostitution activities. A clinical case study is presented which illustrates the development of this activity. Recommendations are made to help reduce the amount of self-destructive prostitution activity among male adolescents. PMID:2760444

  16. Development of avian external genitalia: interspecific differences and sexual differentiation of the male and female phallus.

    PubMed

    Herrera, Ana M; Brennan, Patricia L R; Cohn, Martin J

    2015-01-01

    Avian genitalia, particularly in waterfowl, are extremely diverse. Penis morphology varies among species, and penis length and elaboration are associated with the frequency of forced extra-pair copulations, yet the developmental mechanisms responsible for this variation are unknown. In addition, females have a small phallic structure that is homologous to the male phallus, but little is known about when or how sexual differentiation takes place. To determine whether species-specific genital morphologies and sexual differentiation occur during duck embryonic development, we characterized development from the onset of genital tubercle initiation through stages of sexual differentiation in 3 species. Pekin and Laysan ducks have long, thick penises, whereas those of Mandarin ducks are shorter and thinner. Development of the genital tubercle is similar throughout the pre-hatching period across the 3 species, suggesting that differences in penis morphology arise post-hatching. We observed that male and female phallus development is similar at early stages, but the female phallus later regresses. Then, we compared male and female genital development between ducks and chickens, which develop a non-intromittent penis. We found that external genital development in male and female chickens resembles that of female ducks, which raises the possibility that male phallus development became feminized during galliform evolution. PMID:25011524

  17. Environmental influences on kelp performance across the reproductive period: an ecological trade-off between gametophyte survival and growth?

    PubMed

    Mohring, Margaret B; Kendrick, Gary A; Wernberg, Thomas; Rule, Michael J; Vanderklift, Mathew A

    2013-01-01

    Most kelps (order Laminariales) exhibit distinct temporal patterns in zoospore production, gametogenesis and gametophyte reproduction. Natural fluctuations in ambient environmental conditions influence the intrinsic characteristics of gametes, which define their ability to tolerate varied conditions. The aim of this work was to document seasonal patterns in reproduction and gametophyte growth and survival of Ecklonia radiata (C. Agardh) J. Agardh in south-western Australia. These results were related to patterns in local environmental conditions in an attempt to ascertain which factors explain variation throughout the season. E. radiata was fertile (produced zoospores) for three and a half months over summer and autumn. Every two weeks during this time, gametophytes were grown in a range of temperatures (16-22 °C) in the laboratory. Zoospore densities were highly variable among sample periods; however, zoospores released early in the season produced gametophytes which had greater rates of growth and survival, and these rates declined towards the end of the reproductive season. Growth rates of gametophytes were positively related to day length, with the fastest growing recruits released when the days were longest. Gametophytes consistently survived best in the lowest temperature (16 °C), yet exhibited optimum growth in higher culture temperatures (20-22 °C). These results suggest that E. radiata releases gametes when conditions are favourable for growth, and E. radiata gametophytes are tolerant of the range of temperatures observed at this location. E. radiata releases the healthiest gametophytes when day length and temperature conditions are optimal for better germination, growth, and sporophyte production, perhaps as a mechanism to help compete against other species for space and other resources. PMID:23755217

  18. Flavonoids, Antioxidant Potential, and Acetylcholinesterase Inhibition Activity of the Extracts from the Gametophyte and Archegoniophore of Marchantia polymorpha L.

    PubMed

    Wang, Xin; Cao, Jianguo; Wu, Yuhuan; Wang, Quanxi; Xiao, Jianbo

    2016-01-01

    Marchantia polymorpha L. is a representative bryophyte used as a traditional Chinese medicinal herb for scald and pneumonia. The phytochemicals in M. polymorpha L. are terpenoids and flavonoids, among which especially the flavonoids show significant human health benefits. Many researches on the gametophyte of M. polymorpha L. have been reported. However, as the reproductive organ of M. polymorpha L., the bioactivity and flavonoids profile of the archegoniophore have not been reported, so in this work the flavonoid profiles, antioxidant and acetylcholinesterase inhibition activities of the extracts from the archegoniophore and gametophyte of M. polymorpha L. were compared by radical scavenging assay methods (DPPH, ABTS, O(2-)), reducing power assay, acetylcholinesterase inhibition assay and LC-MS analysis. The results showed that the total flavonoids content in the archegoniophore was about 10-time higher than that of the gametophyte. Differences between the archegoniophore and gametophyte of M. polymorpha L. were observed by LC-MS analysis. The archegoniophore extracts showed stronger bio-activities than those of the gametophyte. The archegoniophore extract showed a significant acetylcholinesterase inhibition, while the gametophyte extract hardly inhibited it. PMID:26999088

  19. Plant Development & the Fern Life Cycle: Using "Ceratopteris richardii."

    ERIC Educational Resources Information Center

    Renzaglia, Karen S.; And Others

    1995-01-01

    Presents laboratory activities focusing on the development of sexually mature gametophytes from single-celled spores. Includes techniques for culture and manipulation of gametophyte development from spores that are applicable for hands-on activities for students at all levels. (MKR)

  20. Follicle Development of Xenotransplanted Sheep Ovarian Tissue into Male and Female Immunodeficient Rats

    PubMed Central

    Tahaei, Leila Sadat; Eimani, Hussein; Hajmusa, Ghazaleh; Fathi, Rouhollah; Rezazadeh Valojerdi, Mojtaba; Shahverdi, Abdolhossein; Eftekhari-Yazdi, Poopak

    2015-01-01

    Background This study aimed to assess follicle survival after xenotransplantation of sheep ovarian tissue into male and female immunodeficient rats. We evaluated the effects of gonadotropin treatment on follicular development in the transplanted tissue. Materials and Methods In this experimental study, sheep ovarian cortical strips were transplanted into the neck back muscles of 8 male and 8 female immunodeficient, castrated rats. Fourteen days after surgery, each rat was treated with human menopausal gonadotropin (hMG) for 9 weeks. One day after the last injection, ovarian tissues were removed and fixed for histology assessment. Histology analyses were performed before and after grafting. Estradiol (E2) levels were measured before and after gonadectomy, and at the end of the experiment. The control group consisted of 7 male and 7 female noncastrated/non-grafted rats and the sham group comprised 7 male and 7 female castrated/ non-grafted rats for comparison of serum E2 concentrations. Results The percentage of primordial follicles decreased after transplantation in male (25.97%) and female (24.14%) rats compared to the control group (ovarian tissue nongrafted; 37.51%). Preantral follicles increased in the male (19.5%) and female (19.49%) transplanted rats compared to the control group (11.4%). Differences in antral follicles between male (0.06 ± 0.0%) and female (0.06 ± 0.0%) rats were not noticeable compared to control (1.25 ± 0.0%) rats. We observed a significantly higher percent of mean E2 secretion in grafted males compared to grafted females (P˂0.05). Conclusion Despite significant differences in E2 secretion between xenografted male and female rats, we observed no statistical differences in terms of follicular development. PMID:26644859

  1. Differential Expression of Rubisco in Sporophytes and Gametophytes of Some Marine Macroalgae

    PubMed Central

    Wang, Guangce; Niu, Jianfeng; Zhou, Baicheng

    2011-01-01

    Rubisco (ribulose-1, 5-bisphosphate carboxylase/oxygenase), a key enzyme of photosynthetic CO2 fixation, is one of the most abundant proteins in both higher plants and algae. In this study, the differential expression of Rubisco in sporophytes and gametophytes of four seaweed species — Porphyra yezoensis, P. haitanensis, Bangia fuscopurpurea (Rhodophyte) and Laminaria japonica (Phaeophyceae) — was studied in terms of the levels of transcription, translation and enzyme activity. Results indicated that both the Rubisco content and the initial carboxylase activity were notably higher in algal gametophytes than in the sporophytes, which suggested that the Rubisco content and the initial carboxylase activity were related to the ploidy of the generations of the four algal species. PMID:21283730

  2. [Genesis of cells of apical meristems and realization of gametophytic apomixis in flowering plants].

    PubMed

    Kashin, A S

    2012-01-01

    Based on our own and literature data on peculiarities of caryotypical variability, we concluded that gametophytic apomixis is naturally accompanied with phenomena of poly-, aneu-, and mixoploidy and that apomicts have genome instability manifesting at the level of meristematic somatic cells. In this connection, a hypothesis is substantiated that realization of this mode of seed reproduction in flowering plants is caused by modification of systems of cell cycle control, following after acts of hybridogenesis and/or polyploidization. It is concluded that instability of the seed reproduction system by gametophytic apomixis manifests not only at the stage of choice of a seed reproduction pathway (apomeiosis-euspory; apozygosis-zygosis) but also in all the cycles of reproduction of the cells of a germ line in plant ontogenesis. PMID:22650078

  3. Genetic and phenotypic analyses of carpel development in Arabidopsis.

    PubMed

    Balanzà, Vicente; Ballester, Patricia; Colombo, Monica; Fourquin, Chloé; Martínez-Fernández, Irene; Ferrándiz, Cristina

    2014-01-01

    Carpels are the female reproductive organs of the flower, organized in a gynoecium, which is arguably the most complex organ of a plant. The gynoecium provides protection for the ovules, helps to discriminate between male gametophytes, and facilitates successful pollination. After fertilization, it develops into a fruit, a specialized organ for seed protection and dispersal. To carry out all these functions, coordinated patterning and tissue specification within the developing gynoecium have to be achieved. In this chapter, we describe different methods to characterize defects in carpel patterning and morphogenesis associated with developmental mutations as well as a list of reporter lines that can be used to facilitate genetic analyses. PMID:24395260

  4. Non-hormonal male contraception: A review and development of an Eppin based contraceptive.

    PubMed

    O'Rand, Michael G; Silva, Erick J R; Hamil, Katherine G

    2016-01-01

    Developing a non-hormonal male contraceptive requires identifying and characterizing an appropriate target and demonstrating its essential role in reproduction. Here we review the development of male contraceptive targets and the current therapeutic agents under consideration. In addition, the development of EPPIN as a target for contraception is reviewed. EPPIN is a well characterized surface protein on human spermatozoa that has an essential function in primate reproduction. EPPIN is discussed as an example of target development, testing in non-human primates, and the search for small organic compounds that mimic contraceptive antibodies; binding EPPIN and blocking sperm motility. Although many hurdles remain before the success of a non-hormonal male contraceptive, continued persistence should yield a marketable product. PMID:26593445

  5. Bisphenol-A promotes antiproliferative effects during neonatal prostate development in male and female gerbils.

    PubMed

    de Lima, Rodrigo Fernandes; Rodriguez, Daniel Andrés Osório; Campos, Mônica Souza; Biancardi, Manoel Francisco; dos Santos, Iana Figueiredo Ferreira Roriz; de Oliveira, Wendyson Duarte; Cavasin, Gláucia Maria; Marques, Mara Rubia; Taboga, Sebastião Roberto; Santos, Fernanda Cristina Alcantara

    2015-12-01

    The aim of this study was to evaluate the development of male and female neonatal gerbil prostate under normal conditions and exposed to bisphenol-A (BPA). Normal postnatal development of the female gerbil prostate occurs earlier than and is morphologically distinct from that occurring in males. In BPA-exposed PND8 gerbils, we have not observed evidence of alterations in the ductal branching in either gender. However, the exposure to BPA alters the immunolabeling pattern of AR, ERα, and PCNA. In males, the exposure to high dosages of BPA resulted in a decrease in the proliferative status of the developing ventral prostate. In females, both high and low dosages were sufficient to decrease the proliferation of paraurethral buds in the branching process by more than 50%. Therefore, the obtained data indicate that BPA promotes antiproliferative effects during the neonatal development of the gerbil prostate, with more sensitivity to this endocrine disruptor in females. PMID:26529182

  6. The Forms of Capital and the Developed Achievement of Black Males

    ERIC Educational Resources Information Center

    Dixon-Román, Ezekiel J.

    2013-01-01

    This study sought to examine the association of the various forms of capital on the developed achievement of Black males. As one of the richest longitudinal family economic data sets, the Child Development Supplement to the Panel Study of Income Dynamics is used to estimate multilevel growth models of the math and reading achievement of Black…

  7. Effects of CO2 and seawater acidification on the early stages of Saccharina japonica development.

    PubMed

    Xu, Dong; Wang, Dongsheng; Li, Bin; Fan, Xiao; Zhang, Xiao W; Ye, Nai H; Wang, Yitao; Mou, Shanli; Zhuang, Zhimeng

    2015-03-17

    In this paper, we demonstrated that ocean acidification (OA) had significant negative effects on the microscopic development of Saccharina japonica in a short-term exposure experiment under a range of light conditions. Under elevated CO2, the alga showed a significant reduction in meiospore germination, fecundity, and reproductive success. Larger female and male gametophytes were noted to occur under high CO2 conditions and high light magnified these positive effects. Under conditions of low light combined with high PCO2, the differentiation of gametophytes was delayed until the end of the experiment. In contrast, gametophytes were able to survive after having been subjected to a long-term acclimation period, of 105 days. Although the elevated PCO2 resulted in a significant increase in sporophyte length, the biomass abundance (expressed as individual density attached to the seed fiber) was reduced significantly. Further stress resistance experiments showed that, although the acidified samples had lower resistance to high light and high temperature conditions, they displayed higher acclimation to CO2-saturated seawater conditions compared with the control groups. These combined results indicate that OA has a severe negative effect on S. japonica, which may result in future shifts in species dominance and community structure. PMID:25695307

  8. Agonistic onset during development differentiates wild house mouse males (Mus domesticus)

    NASA Astrophysics Data System (ADS)

    Krackow, Sven

    2005-02-01

    Wild house mouse populations have been suggested to locally adapt to varying dispersal regimes by expressing divergent aggressivity phenotypes. This conjecture implies, first, genetic polymorphism for dispersive strategies which is supported by the finding of heritable variation for male dispersal tendency in feral house mice. Secondly, aggressivity is assumed to translate into dispersal rates. This speculation is reinforced by experimental evidence showing that non-agonistic males display lower dispersal propensity than same-aged males that have established agonistic dominance. However, the actual ontogenetic behavioural pattern and its variability among populations remain unknown. Hence, in this study the timing of agonistic onset is quantified within laboratory-reared fraternal pairs, and compared between descendants from two different feral populations. Males from the two populations (G and Z) differed strongly in agonistic development, as Z fraternal pairs had a 50% risk of agonistic onset before 23.5±2.7 days of age, while this took 57.3±5.4 days in males from population G. This difference coincided with significant genetic differentiation between the males of the two populations as determined by 11 polymorphic microsatellite markers. Furthermore, in population G, males from agonistic and amicable fraternal pairs exhibited significant genetic differentiation. These results corroborate the supposition of genetic variability for dispersive strategies in house mice, and identify the ontogenetic timing of agonistic phenotype development as the potential basis for genetic differentiation. This opens a unique opportunity to study the genetic determination of a complex mammalian behavioural syndrome in a life history context, using a simple laboratory paradigm.

  9. Temporal and spatial characteristics of male cone development in Metasequoia glyptostroboides Hu et Cheng

    PubMed Central

    Jin, Biao; Tang, Liang; Lu, Yan; Wang, Di; Zhang, Min; Ma, Jiuxia

    2012-01-01

    Metasequoia glyptostroboides, a famous relic species of conifer that survived in China, has been successfully planted in large numbers across the world. However, limited information on male cone development in the species is available. In this study, we observed the morphological and anatomical changes that occur during male cone development in M. glyptostroboides using semi-thin sections and scanning electron microscopy. The male cones were borne oppositely on one-year-old twigs that were mainly located around the outer and sunlit parts of crown. Male cones were initiated from early September and shed pollen in the following February. Each cone consisted of spirally arranged microsporophylls subtended by decussate sterile scales, and each microsporophyll commonly consisted of three microsporangia and a phylloclade. The microsporangial wall was composed of an epidermis, endothecium, and tapetum. In mid-February, the endothecium and tapetum layers disintegrated, and in the epidermal layer the cell walls were thickened with inner protrusions. Subsequently, dehiscence of the microsporangia occurred through rupturing of the microsporangial wall along the dehiscence line. These results suggest that the structure, morphology, architecture and arrangement of male cones of M. glyptostroboides are mainly associated with the production, protection and dispersal of pollen for optimization of wind pollination. PMID:23221679

  10. Temporal and spatial characteristics of male cone development in Metasequoia glyptostroboides Hu et Cheng.

    PubMed

    Jin, Biao; Tang, Liang; Lu, Yan; Wang, Di; Zhang, Min; Ma, Jiuxia

    2012-12-01

    Metasequoia glyptostroboides, a famous relic species of conifer that survived in China, has been successfully planted in large numbers across the world. However, limited information on male cone development in the species is available. In this study, we observed the morphological and anatomical changes that occur during male cone development in M. glyptostroboides using semi-thin sections and scanning electron microscopy. The male cones were borne oppositely on one-year-old twigs that were mainly located around the outer and sunlit parts of crown. Male cones were initiated from early September and shed pollen in the following February. Each cone consisted of spirally arranged microsporophylls subtended by decussate sterile scales, and each microsporophyll commonly consisted of three microsporangia and a phylloclade. The microsporangial wall was composed of an epidermis, endothecium, and tapetum. In mid-February, the endothecium and tapetum layers disintegrated, and in the epidermal layer the cell walls were thickened with inner protrusions. Subsequently, dehiscence of the microsporangia occurred through rupturing of the microsporangial wall along the dehiscence line. These results suggest that the structure, morphology, architecture and arrangement of male cones of M. glyptostroboides are mainly associated with the production, protection and dispersal of pollen for optimization of wind pollination. PMID:23221679

  11. Synergistic Disruption of External Male Sex Organ Development by a Mixture of Four Antiandrogens

    PubMed Central

    Christiansen, Sofie; Scholze, Martin; Dalgaard, Majken; Vinggaard, Anne Marie; Axelstad, Marta; Kortenkamp, Andreas; Hass, Ulla

    2009-01-01

    Background By disrupting the action of androgens during gestation, certain chemicals present in food, consumer products, and the environment can induce irreversible demasculinization and malformations of sex organs among male offspring. However, the consequences of simultaneous exposure to such chemicals are not well described, especially when they exert their actions by differing molecular mechanisms. Objectives To fill this gap, we investigated the effects of mixtures of a widely used plasticizer, di(2-ethylhexyl) phthalate (DEHP); two fungicides present in food, vinclozolin and prochloraz; and a pharmaceutical, finasteride, on landmarks of male sexual development in the rat, including changes in anogenital distance (AGD), retained nipples, sex organ weights, and malformations of genitalia. These chemicals were chosen because they disrupt androgen action with differing mechanisms of action. Results Strikingly, the effect of combined exposure to the selected chemicals on malformations of external sex organs was synergistic, and the observed responses were greater than would be predicted from the toxicities of the individual chemicals. In relation to other hallmarks of disrupted male sexual development, including changes in AGD, retained nipples, and sex organ weights, the combined effects were dose additive. When the four chemicals were combined at doses equal to no observed adverse effect levels estimated for nipple retention, significant reductions in AGD were observed in male offspring. Conclusions Because unhindered androgen action is essential for human male development in fetal life, these findings are highly relevant to human risk assessment. Evaluations that ignore the possibility of combination effects may lead to considerable underestimations of risks associated with exposures to chemicals that disrupt male sexual differentiation. PMID:20049201

  12. Effects of altered food intake during pubertal development in male and female Wistar rats

    EPA Science Inventory

    The U.S.EPA is currently validating assays that will be used in a Tier I Screening Battery to detect endocrine disrupting chemicals. A primary concern with the Protocols for the Assessment of Pubertal Development and Thyroid Function in Juvenile Male and Female Rats is that a non...

  13. CHARACTERIZATION OF THE PERIOD OF SENSITIVITY OF FETAL MALE SEXUAL DEVELOPMENT TO VINCLOZOLIN

    EPA Science Inventory

    Characterization of the period of sensitivity of fetal male sexual development to vinclozolin.

    Wolf CJ, LeBlanc GA, Ostby JS, Gray LE Jr.

    Endocrinology Branch, MD 72, Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U....

  14. Student Organizations as Venues for Black Identity Expression and Development among African American Male Student Leaders

    ERIC Educational Resources Information Center

    Harper, Shaun R.; Quaye, Stephen John

    2007-01-01

    Ways in which membership in student organizations, both predominantly Black and mainstream, provide space for Black identity expression and development were explored in this study. Based on individual interviews conducted with African American male student leaders at six predominantly White universities, findings reveal a nexus between Black…

  15. Simvastatin reduces fetal testosterone production and permanently alters reproductive tract development in the male rat

    EPA Science Inventory

    Androgen signaling by fetal Leydig cells is critical in the proper development of the male reproductive tract. As cholesterol is a precursor for hormone biosynthesis,inhibition of the cholesterol pathway during sex differentiation may reduce testosterone {T). We hypothesized tha...

  16. THE DEVELOPMENT AND TESTING OF A SCALE TO IDENTIFY MALE DROPOUTS AT LIBERAL ARTS COLLEGES.

    ERIC Educational Resources Information Center

    MERIGOLD, FRANK A.

    TWO FORMS OF A SCALE FOR THE COLLEGE INTEREST INVENTORY THAT WERE INTENDED TO IDENTIFY MALE STUDENTS WHO WOULD DROP OUT OF LIBERAL ARTS COLLEGES WERE DEVELOPED AND TESTED. THE PREDICTIVE VALIDITY OF THE SCALES WAS EVALUATED BY COMPARISON WITH THE "SO,""SC," AND "AC" SCALES OF THE CALIFORNIA PSYCHOLOGICAL INVENTORY THAT HAVE BEEN USED TO PREDICT…

  17. IPRODIONE DELAYS MALE RAT PUBERTAL DEVELOPMENT, REDUCING SERUM TESTOSTERONE AND EX VIVO TESTOSTERONE PRODUCTION

    EPA Science Inventory

    Iprodione (IPRO) is a dichlorophenyl dicarboximide fungicide similar to the androgen receptor (AR) antagonist vinclozolin. The current studies were designed to determine if IPRO would delay male rat pubertal development like vinclozolin and to identify the mechanism(s) of action...

  18. Developing Argument Skills in Severely Disadvantaged Adolescent Males in a Residential Correctional Setting

    ERIC Educational Resources Information Center

    De Fuccio, MaryAnne; Kuhn, Deanna; Udell, Wadiya; Callender, Kerry

    2009-01-01

    We investigate whether the intervention designed by Kuhn and Udell (2003) to develop argument skills could be implemented productively among adolescent males in a residential juvenile detention facility--boys who were educationally disengaged and severely disadvantaged academically as well as socially. Compared to a control group from the same…

  19. Finding "Los Científicos" within: Latino Male Science Identity Development in the First College Semester

    ERIC Educational Resources Information Center

    Lu, Charles

    2015-01-01

    Latino males are the lowest male ethnic subgroup to attain a four-year STEM college degree. This phenomenological qualitative research study used two rounds of interviews with twelve Latino male students in Central Texas to examine their first semester science experiences using a science identity framework. Findings indicate that developing a…

  20. The Racial Identity Development of Male Student-Athletes when Blacks Are the Majority and Whites Are the Minority

    ERIC Educational Resources Information Center

    Henry, Wilma J.; Closson, Rosemary B.

    2012-01-01

    Focus groups were used in the present study to explore the racial identity development of Black male and White male student-athletes on a predominantly Black, Division IA football team at a predominantly White institution (PWI). Findings indicate that the Black male football players demonstrated positive indicators of Black racial identity. The…

  1. Identification of microRNAs differentially expressed involved in male flower development.

    PubMed

    Wang, Zhengjia; Huang, Jianqin; Sun, Zhichao; Zheng, Bingsong

    2015-03-01

    Hickory (Carya cathayensis Sarg.) is one of the most economically important woody trees in eastern China, but its long flowering phase delays yield. Our understanding of the regulatory roles of microRNAs (miRNAs) in male flower development in hickory remains poor. Using high-throughput sequencing technology, we have pyrosequenced two small RNA libraries from two male flower differentiation stages in hickory. Analysis of the sequencing data identified 114 conserved miRNAs that belonged to 23 miRNA families, five novel miRNAs including their corresponding miRNA*s, and 22 plausible miRNA candidates. Differential expression analysis revealed 12 miRNA sequences that were upregulated in the later (reproductive) stage of male flower development. Quantitative real-time PCR showed similar expression trends as that of the deep sequencing. Novel miRNAs and plausible miRNA candidates were predicted using bioinformatic analysis methods. The miRNAs newly identified in this study have increased the number of known miRNAs in hickory, and the identification of differentially expressed miRNAs will provide new avenues for studies into miRNAs involved in the process of male flower development in hickory and other related trees. PMID:25576251

  2. Neither male gonadal androgens nor female reproductive costs drive development of sexual size dimorphism in lizards.

    PubMed

    Starostová, Zuzana; Kubička, Lukáš; Golinski, Alison; Kratochvíl, Lukáš

    2013-05-15

    Sexual size dimorphism (SSD) is an extensively studied phenomenon in animals, including reptiles, but the proximate mechanism of its development is poorly understood. The most pervasive candidates are: (1) androgen-mediated control of growth, i.e. a positive effect of gonadal androgens (testosterone) on male growth in male-larger species, and a negative effect in female-larger species; and (2) sex-specific differences in energy allocation to growth, e.g. sex with larger reproductive costs should result in smaller body size. We tested these hypotheses in adults of the male-larger lizard Paroedura picta by conducting castrations with and without testosterone implants in males and manipulating reproductive status in females. Castration or testosterone replacement had no significant effect on final body length in males. High investment to reproduction had no significant effect on final body length in intact females. Interestingly, ovariectomized females and females with testosterone implants grew to larger body size than intact females. We did not find support for either of the above hypotheses and suggest that previously reported effects of gonadal androgens on growth in male lizards could be a consequence of altered behaviour or social status in manipulated individuals. Exogenous testosterone in females led to decreased size of ovaries; its effect on body size may be caused by interference with normal ovarian function. We suggest that ovarian factors, perhaps estrogens, not reproductive costs, can modify growth in female lizards and may thus contribute to the development of SSD. This hypothesis is largely supported by published results on the effect of testosterone treatment or ovariectomy on body size in female squamates. PMID:23393279

  3. Novel function of LHFPL2 in female and male distal reproductive tract development

    PubMed Central

    Zhao, Fei; Zhou, Jun; Li, Rong; Dudley, Elizabeth A.; Ye, Xiaoqin

    2016-01-01

    Congenital reproductive tract anomalies could impair fertility. Female and male reproductive tracts are developed from Müllerian ducts and Wolffian ducts, respectively, involving initiation, elongation and differentiation. Genetic basis solely for distal reproductive tract development is largely unknown. Lhfpl2 (lipoma HMGIC fusion partner-like 2) encodes a tetra-transmembrane protein with unknown functions. It is expressed in follicle cells of ovary and epithelial cells of reproductive tracts. A spontaneous point mutation of Lhfpl2 (LHFPL2G102E) leads to infertility in 100% female mice, which have normal ovarian development, ovulation, uterine development, and uterine response to exogenous estrogen stimulation, but abnormal upper longitudinal vaginal septum and lower vaginal agenesis. Infertility is also observed in ~70% mutant males, which have normal mating behavior and sperm counts, but abnormal distal vas deferens convolution resulting in complete and incomplete blockage of reproductive tract in infertile and fertile males, respectively. On embryonic day 15.5, mutant Müllerian ducts and Wolffian ducts have elongated but their duct tips are enlarged and fail to merge with the urogenital sinus. These findings provide a novel function of LHFPL2 and a novel genetic basis for distal reproductive tract development; they also emphasize the importance of an additional merging phase for proper reproductive tract development. PMID:26964900

  4. Novel function of LHFPL2 in female and male distal reproductive tract development.

    PubMed

    Zhao, Fei; Zhou, Jun; Li, Rong; Dudley, Elizabeth A; Ye, Xiaoqin

    2016-01-01

    Congenital reproductive tract anomalies could impair fertility. Female and male reproductive tracts are developed from Müllerian ducts and Wolffian ducts, respectively, involving initiation, elongation and differentiation. Genetic basis solely for distal reproductive tract development is largely unknown. Lhfpl2 (lipoma HMGIC fusion partner-like 2) encodes a tetra-transmembrane protein with unknown functions. It is expressed in follicle cells of ovary and epithelial cells of reproductive tracts. A spontaneous point mutation of Lhfpl2 (LHFPL2(G102E)) leads to infertility in 100% female mice, which have normal ovarian development, ovulation, uterine development, and uterine response to exogenous estrogen stimulation, but abnormal upper longitudinal vaginal septum and lower vaginal agenesis. Infertility is also observed in ~70% mutant males, which have normal mating behavior and sperm counts, but abnormal distal vas deferens convolution resulting in complete and incomplete blockage of reproductive tract in infertile and fertile males, respectively. On embryonic day 15.5, mutant Müllerian ducts and Wolffian ducts have elongated but their duct tips are enlarged and fail to merge with the urogenital sinus. These findings provide a novel function of LHFPL2 and a novel genetic basis for distal reproductive tract development; they also emphasize the importance of an additional merging phase for proper reproductive tract development. PMID:26964900

  5. Systems Toxicology of Male Reproductive Development: Profiling 774 Chemicals for Molecular Targets and Adverse Outcomes

    PubMed Central

    Leung, Maxwell C.K.; Phuong, Jimmy; Baker, Nancy C.; Sipes, Nisha S.; Klinefelter, Gary R.; Martin, Matthew T.; McLaurin, Keith W.; Setzer, R. Woodrow; Darney, Sally Perreault; Judson, Richard S.; Knudsen, Thomas B.

    2015-01-01

    Background: Trends in male reproductive health have been reported for increased rates of testicular germ cell tumors, low semen quality, cryptorchidism, and hypospadias, which have been associated with prenatal environmental chemical exposure based on human and animal studies. Objective: In the present study we aimed to identify significant correlations between environmental chemicals, molecular targets, and adverse outcomes across a broad chemical landscape with emphasis on developmental toxicity of the male reproductive system. Methods: We used U.S. EPA’s animal study database (ToxRefDB) and a comprehensive literature analysis to identify 774 chemicals that have been evaluated for adverse effects on male reproductive parameters, and then used U.S. EPA’s in vitro high-throughput screening (HTS) database (ToxCastDB) to profile their bioactivity across approximately 800 molecular and cellular features. Results: A phenotypic hierarchy of testicular atrophy, sperm effects, tumors, and malformations, a composite resembling the human testicular dysgenesis syndrome (TDS) hypothesis, was observed in 281 chemicals. A subset of 54 chemicals with male developmental consequences had in vitro bioactivity on molecular targets that could be condensed into 156 gene annotations in a bipartite network. Conclusion: Computational modeling of available in vivo and in vitro data for chemicals that produce adverse effects on male reproductive end points revealed a phenotypic hierarchy across animal studies consistent with the human TDS hypothesis. We confirmed the known role of estrogen and androgen signaling pathways in rodent TDS, and importantly, broadened the list of molecular targets to include retinoic acid signaling, vascular remodeling proteins, G-protein coupled receptors (GPCRs), and cytochrome P450s. Citation: Leung MC, Phuong J, Baker NC, Sipes NS, Klinefelter GR, Martin MT, McLaurin KW, Setzer RW, Darney SP, Judson RS, Knudsen TB. 2016. Systems toxicology of male

  6. A potential mate influences reproductive development in female, but not male, pine siskins.

    PubMed

    Watts, Heather E; Edley, Bruce; Hahn, Thomas P

    2016-04-01

    The role of photoperiod in avian reproductive timing has been well studied, and we are increasingly recognizing the roles of other environmental cues such as social cues. However, few studies have evaluated the extent to which males and females of the same species respond similarly to the same type of cue. Moreover, previous studies have rarely examined how variation in the quality or nature of a given social cue might modulate its effect. Here, we examine the sensitivity of male and female pine siskins (Spinus pinus) to a potential mate as a stimulatory cue for gonadal recrudescence, and we investigate whether variation in the relationship between a bird and its potential mate modulates the effect of that potential mate. Birds were initially housed without opposite sex birds on a 12L:12D photoperiod with ad libitum food. After gonadal recrudescence had begun males and females were randomly paired with an opposite sex bird or housed alone. An additional group of males was paired with estradiol-implanted females. In males, these social treatments had no effect on testis length, cloacal protuberance length, luteinizing hormone (LH) levels, or testosterone levels. In females, presence of a potential mate had a significant and positive effect on ovary score, defeathering of the brood patch, and LH levels. Among paired birds, the degree of affiliation within a pair corresponded to the extent of reproductive development in females, but not males. Thus, reproductive timing in females appears to be sensitive to both the presence of a potential mate and her relationship with him. PMID:26836771

  7. Changes in gametophyte physiology of Pteris multifida induced by the leaf leachate treatment of the invasive Bidens pilosa.

    PubMed

    Zhang, Kai-Mei; Shen, Yu; Fang, Yan-Ming; Liu, Ying

    2016-02-01

    In recent years, the response of fern gametophytes to environment has raised much attention. However, studies on the influence of plant invasion to fern gametophytes are scarce. Allelopathy plays an important role in biological invasion. Hence, it is necessary to study the allelopathic effects of invasive plants on fern gametophytes and elucidate the mechanisms by which invasive plants cause phytotoxicity. As one of the main invasive plants in China, Bidens pilosa exhibits allelopathic effects on spermatophyte growth. Field investigation shows that many ferns are threatened by the invasion of B. pilosa. The distribution of Pteris multifida overlaps with that of B. pilosa in China. To examine the potential involvement of allelopathic mechanisms of B. pilosa leaves, changes in the physiology in P. multifida gametophytes are analyzed. We found that cell membrane and antioxidant enzyme activities as well as photosynthesis pigment contents of the gametophytes were affected by B. pilosa leachates. Gametophytes of P. multifida exposed to B. pilosa had increased damages to cell membranes, expressed in thiobarbituric acid reacting substance (TBARS) concentrations, malondialdehyde (MDA), electrolyte leakage (membrane permeability), and degree of injury. Enzyme activities, assessed by superoxide dismutase (SOD) and catalase (CAT) as well as guaiacol peroxidase (GPX) enhanced with the increase in leachate concentration after 2-day exposure. Meanwhile, lower chlorophyll a (Chl a), chlorophyll b (Chl b), carotenoid (Car), and the total chlorophyll were measured as leachate concentrations increased. At day 10, leaf leachates of B. pilosa exhibited the greatest inhibition. These results suggest that the observed inhibitory or stimulatory effects on the physiology studied can have an adverse effect on P. multifida and that allelopathic interference seems to have involved in this process. PMID:26490937

  8. Primary male development of two sequentially hermaphroditic groupers, Epinephelus akaara and Epinephelus awoara (Perciformes: Epinephelidae).

    PubMed

    Liu, M; Wang, Y-Y; Shan, X-J; Kang, B; Ding, S-X

    2016-04-01

    Gonad ontogeny of the Hong Kong grouper Epinephelus akaara (a bi-directional sex changer) and the yellow grouper Epinephelus awoara (a protogynous hermaphrodite) was examined for the first time from post-larval phase until first sexual maturation, by histology. Approximately 20 specimens of each species were collected randomly every 2-7 weeks from rearing tanks with natural sea water and temperature between June 2013 and June 2014. The paired gonadal primordia (GP) were observed at 6 weeks after hatching (wah) for both species; however, gonia were first observed in GP at 16 wah for E. akaara and at 8 wah for E. awoara. The timings for the appearance of primary-growth stage oocytes (O1) and the completion of ovarian lumen (OL) varied; both at 27 wah for E. akaara, and at 18 and 23 wah for E. awoara respectively. A bisexual-phase gonad with an OL, O1 and scattered spermatogenic cysts (SC) was observed at 27-29 wah for both E. akaara and E. awoara. Sexual differentiation was subsequently observed from the bisexual-phase gonad at 34 wah for E. akaara, and 41 wah for E. awoara, with the appearance of cortical-alveolus stage oocytes (O2) for developing female and the proliferation of SC for developing primary male (i.e. from juvenile directly). Ovaries of mature females contained the vitellogenic stage oocytes (O3) and scattered SC; testes of mature primary males had sperm in sperm sinuses within the gonadal wall and remained O1. Minimum age of first sexual maturation for both female and primary male of E. akaara was at 41 wah; minimum total length (LT ) of female (143 mm) was larger than that of primary male (137 mm LT ). Minimum age and size of first sexual maturation for female of E. awoara (47 wah and 149 mm LT , respectively) were larger than those of E. akaara. Developing primary males of E. awoara were found at 41-58 wah, however, mature males were not observed, indicating inconsistency in first sexual maturation for E. awoara. This

  9. Myo-inositol hexakisphosphate, isolated from female gametophyte tissue of loblolly pine, inhibits growth of early-stage somatic embryos.

    PubMed

    Wu, Di; Sullards, M Cameron; Oldham, Charlie D; Gelbaum, Les; Lucrezi, Jacob; Pullman, Gerald S; May, Sheldon W

    2012-01-01

    • Myo-inositol hexakisphosphate (InsP(6)), abundant in animals and plants, is well known for its anticancer activity. However, many aspects of InsP(6) function in plants remain undefined. We now report the first evidence that InsP(6) can inhibit cellular proliferation in plants under growth conditions where phosphorus is not limited. • A highly anionic molecule inhibitory to early-stage somatic embryo growth of loblolly pine (LP) was purified chromatographically from late-stage LP female gametophytes (FGs), and then characterized structurally using mass spectrometry (MS) and nuclear magnetic resonance (NMR) analyses. • Exact mass and mass spectrometry-mass spectrometry (MS-MS) fragmentation identified the bioactive molecule as an inositol hexakisphosphate. It was then identified as the myo-isomer (i.e. InsP(6)) on the basis of (1)H-, (31)P- and (13)C-NMR, (1)H-(1)H correlation spectroscopy (COSY), (1)H-(31)P heteronuclear single quantum correlation (HSQC) and (1)H-(13)C HSQC. Topical application of InsP(6) to early-stage somatic embryos indeed inhibits embryonic growth. • Recently evidence has begun to emerge that InsP(6) may also play a regulatory role in plant cells. We anticipate that our findings will help to stimulate additional investigations aimed at elucidating the roles of inositol phosphates in cellular growth and development in plants. PMID:22023391

  10. Overexpressing the Multiple-Stress Responsive Gene At1g74450 Reduces Plant Height and Male Fertility in Arabidopsis thaliana

    PubMed Central

    Visscher, Anne M.; Belfield, Eric J.; Vlad, Daniela; Irani, Niloufer; Moore, Ian; Harberd, Nicholas P.

    2015-01-01

    A subset of genes in Arabidopsis thaliana is known to be up-regulated in response to a wide range of different environmental stress factors. However, not all of these genes are characterized as yet with respect to their functions. In this study, we used transgenic knockout, overexpression and reporter gene approaches to try to elucidate the biological roles of five unknown multiple-stress responsive genes in Arabidopsis. The selected genes have the following locus identifiers: At1g18740, At1g74450, At4g27652, At4g29780 and At5g12010. Firstly, T-DNA insertion knockout lines were identified for each locus and screened for altered phenotypes. None of the lines were found to be visually different from wildtype Col-0. Secondly, 35S-driven overexpression lines were generated for each open reading frame. Analysis of these transgenic lines showed altered phenotypes for lines overexpressing the At1g74450 ORF. Plants overexpressing the multiple-stress responsive gene At1g74450 are stunted in height and have reduced male fertility. Alexander staining of anthers from flowers at developmental stage 12–13 showed either an absence or a reduction in viable pollen compared to wildtype Col-0 and At1g74450 knockout lines. Interestingly, the effects of stress on crop productivity are most severe at developmental stages such as male gametophyte development. However, the molecular factors and regulatory networks underlying environmental stress-induced male gametophytic alterations are still largely unknown. Our results indicate that the At1g74450 gene provides a potential link between multiple environmental stresses, plant height and pollen development. In addition, ruthenium red staining analysis showed that At1g74450 may affect the composition of the inner seed coat mucilage layer. Finally, C-terminal GFP fusion proteins for At1g74450 were shown to localise to the cytosol. PMID:26485022

  11. Gene expression profiles in testis of developing male Xenopus laevis damaged by chronic exposure of atrazine.

    PubMed

    Sai, Linlin; Dong, Zhihua; Li, Ling; Guo, Qiming; Jia, Qiang; Xie, Lin; Bo, Cunxiang; Liu, Yanzhong; Qu, Binpeng; Li, Xiangxin; Shao, Hua; Ng, Jack C; Peng, Cheng

    2016-09-01

    As a widely used herbicide, atrazine (AZ) has been extensively studied for its adverse effects on the reproductive system, especially feminization in male animals. However, the relationship of gene expression changes and associated toxicological endpoints remains unclear. In this study, developing Xenopus laevis tadpoles were exposed to concentration of AZ at 0.1, 1, 10 or 100 μg/L continuously. Compared with froglets in the control group, there were no significant differences in body length, body weight, liver weight and hepatosomatic index (HSI) of males in groups treated with AZ for 90 d. At 100 μg/L AZ treatment caused a significant reduction of gonad weight and gonadosomatic index (GSI) of males (p < 0.01). In addition, AZ at all dose levels caused testicular degeneration, especially in froglets from the groups with 0.1 and 100 μg/L which exhibited U-shaped dose-response trend. We further investigated the gene expression changes associated with the testicular degeneration induced by AZ. We found that the expression of 1165 genes was significantly altered with 616 upregulated and 549 downregulated compared to the expression profile of the control animals. KEGG analysis showed that genes which were significantly affected by AZ are mainly involved in arginine and proline metabolism, cell cycle, riboflavin metabolism, spliceosome, base excision repair and progesterone-mediated oocyte maturation pathway. Our results show that AZ may affect reproductive and immune systems by interference with the related gene expression changes during the male X. laevis development. The findings may help to clarify the feminization mechanisms of AZ in male X. laevis. PMID:27288644

  12. Tomato Male sterile 1035 is essential for pollen development and meiosis in anthers

    PubMed Central

    Jeong, Hee-Jin; Kang, Jin-Ho; Zhao, Meiai; Kwon, Jin-Kyung; Choi, Hak-Soon; Bae, Jung Hwan; Lee, Hyun-ah; Joung, Young-Hee; Choi, Doil; Kang, Byoung-Cheorl

    2014-01-01

    Male fertility in flowering plants depends on proper cellular differentiation in anthers. Meiosis and tapetum development are particularly important processes in pollen production. In this study, we showed that the tomato male sterile (ms10 35) mutant of cultivated tomato (Solanum lycopersicum) exhibited dysfunctional meiosis and an abnormal tapetum during anther development, resulting in no pollen production. We demonstrated that Ms10 35 encodes a basic helix–loop–helix transcription factor that is specifically expressed in meiocyte and tapetal tissue from pre-meiotic to tetrad stages. Transgenic expression of the Ms10 35 gene from its native promoter complemented the male sterility of the ms10 35 mutant. In addition, RNA-sequencing-based transcriptome analysis revealed that Ms10 35 regulates 246 genes involved in anther development processes such as meiosis, tapetum development, cell-wall degradation, pollen wall formation, transport, and lipid metabolism. Our results indicate that Ms10 35 plays key roles in regulating both meiosis and programmed cell death of the tapetum during microsporogenesis. PMID:25262227

  13. 3. Impact of altered gravity on CNS development and behavior in male and female rats

    NASA Astrophysics Data System (ADS)

    Sajdel-Sulkowska, E. M.; Nguon, K.; Ladd, B.; Sulkowski, V. A.; Sulkowski, Z. L.; Baxter, M. G.

    The present study examined the effect of altered gravity on CNS development. Specifically, we compared neurodevelopment, behavior, cerebellar structure and protein expression in rat neonates exposed perinatally to hypergravity. Pregnant Sprague-Dawley rats were exposed to 1.5G-1.75G hypergravity on a 24-ft centrifuge starting on gestational day (G) 10, through giving birth on G22/G23, and nursing their offspring through postnatal day (P) 21. Cerebellar mass on P6 was decreased in 1.75G-exposed male pups by 27.5 percent; in 1.75G-exposed female pups it was decreased by 22.5 percent. The observed cerebellar changes were associated with alterations in neurodevelopment and motor behavior. Exposure to hypergravity impaired performance on the following neurocognitive tests: (1) righting time on P3 was more than doubled in 1.75G-exposed rats and the effect appeared more pronounced in female pups, (2) startle response on P10 was delayed in both male and female HG pups; HG pups were one-fifth as likely to respond to a clapping noise as SC pups, and (3) performance on a rotorod on P21 was decreased in HG pups; the duration of the stay on rotorod recorded for HG pups of both sexes was one tenth of the SC pups. Furthermore, Western blot analysis of selected cerebellar proteins suggested gender-specific changes in glial and neuronal proteins. On P6, GFAP expression was decreased by 59.2 percent in HG males, while no significant decrease was observed in female cerebella. Synaptophysin expression was decreased in HG male neonates by 29.9 percent and in HG female neonates by 20.7 percent as compared to its expression in SC cerebella. The results of this experiment suggest that perinatal exposure to hypergravity affects cerebellar development and behavior differently in male and female neonates. If one accepts that hypergravity is a good paradigm to study the effect of microgravity on the CNS, and since males and females were shown to respond differently to hypergravity, it can be

  14. Normal female carrier and affected male half-sibs with t(X;5)(q13;p15). Location of a gene determining male genital development.

    PubMed

    Callen, D F; Sutherland, G R

    1986-07-01

    A unique family in which half-brothers have a maternally derived t(X;5)(q13;p15) and similar genital malformations is described. This family provides evidence for a gene required for male genital development located at Xq13. PMID:3757297

  15. Varieties of male-sexual-identity development in clinical practice: a neuropsychoanalytic model.

    PubMed

    Stortelder, Frans

    2014-01-01

    Variations of sexual identity development are present in all cultures, as well as in many animal species. Freud - founding father of psychoanalysis - believed that all men have an inherited, bisexual disposition, and that many varieties of love and desire are experienced as alternative pathways to intimacy. In the neuropsychoanalytic model, psychic development starts with the constitutional self. The constitutional self is comprised of the neurobiological factors which contribute to sexual identity development. These neurobiological factors are focused on biphasic sexual organization in the prenatal phase, based on variations in genes, sex hormones, and brain circuits. This psychosocial construction of sexual identity is determined through contingent mirroring by the parents and peers of the constitutional self. The development of the self-or personal identity-is linked with the development of sexual identity, gender-role identity, and procreative identity. Incongruent mirroring of the constitutional self causes alienation in the development of the self. Such alienation can be treated within the psychoanalytic relationship. This article presents a contemporary, neuropsychoanalytic, developmental theory of male-sexual identity relating to varieties in male-sexual-identity development, with implications for psychoanalytic treatment, and is illustrated with three vignettes from clinical practice. PMID:25566168

  16. Varieties of male-sexual-identity development in clinical practice: a neuropsychoanalytic model

    PubMed Central

    Stortelder, Frans

    2014-01-01

    Variations of sexual identity development are present in all cultures, as well as in many animal species. Freud – founding father of psychoanalysis – believed that all men have an inherited, bisexual disposition, and that many varieties of love and desire are experienced as alternative pathways to intimacy. In the neuropsychoanalytic model, psychic development starts with the constitutional self. The constitutional self is comprised of the neurobiological factors which contribute to sexual identity development. These neurobiological factors are focused on biphasic sexual organization in the prenatal phase, based on variations in genes, sex hormones, and brain circuits. This psychosocial construction of sexual identity is determined through contingent mirroring by the parents and peers of the constitutional self. The development of the self—or personal identity—is linked with the development of sexual identity, gender-role identity, and procreative identity. Incongruent mirroring of the constitutional self causes alienation in the development of the self. Such alienation can be treated within the psychoanalytic relationship. This article presents a contemporary, neuropsychoanalytic, developmental theory of male-sexual identity relating to varieties in male-sexual-identity development, with implications for psychoanalytic treatment, and is illustrated with three vignettes from clinical practice. PMID:25566168

  17. Maternal lead exposure during lactation persistently impairs testicular development and steroidogenesis in male offspring.

    PubMed

    Wang, Hua; Ji, Yan-Li; Wang, Qun; Zhao, Xian-Feng; Ning, Huan; Liu, Ping; Zhang, Cheng; Yu, Tao; Zhang, Ying; Meng, Xiu-Hong; Xu, De-Xiang

    2013-12-01

    Lead (Pb) is a testicular toxicant. In the present study, we investigated the effects of maternal Pb exposure during lactation on testicular development and steroidogenesis in male offspring. Maternal mice were exposed to different concentration of lead acetate (200 or 2000 ppm) through drinking water from postnatal day (PND) 0 to PND21. As expected, a high concentration of Pb was measured in the kidneys and liver of pups whose mothers were exposed to Pb during lactation. In addition, maternal Pb exposure during lactation elevated, to a less extent, Pb content in testes of weaning pups. Testis weight in weaning pups was significantly decreased when maternal mice were exposed to Pb during lactation. The level of serum and testicular T was reduced in Pb-exposed pups. The expression of P450scc, P450(17α) and 17β-HSD, key enzymes for T synthesis, was down-regulated in testes of weaning pups whose mothers were exposed to Pb during lactation. Interestingly, the level of serum and testicular T remained decreased in adult offspring whose mothers were exposed to Pb during lactation. Importantly, the number of spermatozoa was significantly reduced in Pb-exposed male offspring. Taken together, these results suggest that Pb could be transported from dams to pups through milk. Maternal Pb exposure during lactation persistently disrupts testicular development and steroidogenesis in male offspring. PMID:22806249

  18. Genetic Map-Based Location of the Red Clover (Trifolium pratense L.) Gametophytic Self-incompatibility Locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Red clover is a hermaphadidic allogamous diploid (2n = 2x = 14) with a homomorphic gametophytic self-incompatibility (GSI) system red clover (Trifolium pratense L.). Red clover GSI has long been studied and it is thought that the genetic control of GSI constitutes a single locus. Although GSI gene...

  19. Identification of SSR Markers Linked to the Gametophytic Self-Incompatibility Locus in Red Clover (Trifolium pratense)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Self-pollination is prevented in red clover by a gametophytic self-incompatibility system (SI). This SI system is likely controlled by two tightly linked genes, effectively creating a single locus. While SI genes have been identified in some plants, they have not been identified in red clover or o...

  20. Resistance to the Gal-M gametophyte factor in maize: A genetic solution to an undervalued risk

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to maize’s wind-driven pollination, non-target pollen contamination is problematic for producers and breeders. Maize gametophyte factors have long been used to produce selectively pollinating phenotypes. The use of these factors is the cornerstone of commercial popcorn production, and they are u...

  1. The development of stimulus-specific auditory responses requires song exposure in male but not female zebra finches

    PubMed Central

    Maul, Kristen K.; Voss, Henning U.; Parra, Lucas C.; Salgado-Commissariat, Delanthi; Ballon, Douglas; Tchernichovski, Ofer; Helekar, Santosh A.

    2013-01-01

    Juvenile male zebra finches develop their song by imitation. Females do not sing but are attracted to males' songs. With functional Magnetic Resonance Imaging (fMRI) and Event Related Potentials (ERPs) we tested how early auditory experience shapes responses in the auditory forebrain of the adult bird. Adult male birds kept in isolation over the sensitive period for song learning showed no consistency in auditory responses to conspecific songs, calls, and syllables. Thirty seconds of song playback each day over development, which is sufficient to induce song imitation, was also sufficient to shape stimulus-specific responses. Strikingly, adult females kept in isolation over development showed responses similar to those of males that were exposed to songs. We suggest that early auditory experience with songs may be required to tune perception towards conspecific songs in males, whereas in females song selectivity develops even without prior exposure to song. PMID:19937773

  2. Baseline sacroiliac joint magnetic resonance imaging abnormalities and male sex predict the development of radiographic sacroiliitis.

    PubMed

    Akar, Servet; Isik, Sibel; Birlik, Bilge; Solmaz, Dilek; Sari, Ismail; Onen, Fatos; Akkoc, Nurullah

    2013-10-01

    We evaluated the relationship between the baseline sacroiliac joint (SIJ) magnetic resonance imaging (MRI) findings and the development of radiographic sacroiliitis and tested their prognostic significance in cases of ankylosing spondylitis. Patients who had undergone an SIJ MRI at the rheumatology department were identified. Individuals for whom pelvic X-rays were available after at least 1 year of MRI were included in the analysis. All radiographs and MRI examinations were scored by two independent readers. Medical records of the patients were reviewed to obtain potentially relevant demographic and clinical data. We identified 1,069 SIJ MRIs, and 328 fulfilled our inclusion criteria. Reliability analysis revealed moderate to good inter- and intra-observer agreement. On presentation data, 14 cases were excluded because they had unequivocal radiographic sacroiliitis at baseline. After a mean of 34.8 months of follow-up, 24 patients developed radiographic sacroiliitis. The presence of active sacroiliitis (odds ratio (OR) 15.1) and structural lesions on MRI (OR 8.3), male sex (OR 4.7), fulfillment of Calin's inflammatory back pain criteria (P = 0.001), and total MRI activity score (P < 0.001) were found to be related to the development of radiographic sacroiliitis. By regression modeling, the presence of both active inflammatory and structural damage lesions on MRI and male sex were found to be predictive factors for the development of radiographic sacroiliitis. Our present results suggest that the occurrence of both active inflammatory and structural lesions in SIJs revealed by MRI is a significant risk factor for radiographic sacroiliitis, especially in male patients with early inflammatory back pain. PMID:23765093

  3. Apilarnil reduces fear and advances sexual development in male broilers but has no effect on growth.

    PubMed

    Altan, O; Yücel, B; Açikgöz, Z; Seremet, C; Kösoğlu, M; Turgan, N; Ozgönül, A M

    2013-06-01

    1. An experiment was conducted to determine the possibility of stimulating sexual development at an early age in male and female broiler chickens by administration of apilarnil, a natural bee product, in the pre-pubertal period. 2. From 28 to 55 d of age, birds were given apilarnil orally. The effects of low (2.5 g/bird) and high (7.5 g/bird) doses of apilarnil on growth performance, testicular weight, secondary sexual characteristics, blood lipids, testosterone and fearful behaviour were evaluated. 3. Apilarnil administration did not cause a positive effect on growth performance of male and female broilers suggesting that apilarnil did not have an anabolic effect. 4. Apilarnil administration suppressed blood glucose and cholesterol. 5. Birds receiving apilarnil remained immobile for a shorter period in a tonic imobiliy test and showed less home-cage avoidance responses suggesting a lower level of fearfulness. 6. Increases in testicular weight, testosterone concentration and comb growth in males receiving apilarnil implied that it stimulates the sexual maturation at an early age. However, a similar stimulation of secondary sexual characteristics was not observed in females. PMID:23796118

  4. The development and initial validation of a new measure of male body dissatisfaction.

    PubMed

    Ochner, Christopher N; Gray, James A; Brickner, Katrina

    2009-12-01

    The purpose of this research was to develop, and establish the initial psychometric properties of, the Male Body Dissatisfaction Scale (MBDS). Ninety-five male students were recruited over three phases. An item-remainder analysis was performed in phase I, convergent and discriminant validity assessed in phase II, and test-retest reliability and factor structure assessed in phase III. The MBDS achieved an alpha level of 0.93 and was inversely related to body esteem (p=0.02) and self-esteem (p=0.03), and positively related to how much participants' opinion of themselves was based on their body shape and weight (p<0.01). The MBDS was not related to measures of affect, and was able to distinguish between males endorsing, and not endorsing, elevated body shape and weight concerns (p<0.05). Finally, the MBDS displayed a test-retest reliability coefficient of 0.96 (p<0.01). Findings suggest that the MBDS may fill the need for a reliable and valid measure of body dissatisfaction that allows men to weight particular aspects of their body image according to personal importance. PMID:19778747

  5. Hypogonadism predisposes males to the development of behavioural and neuroplastic depressive phenotypes.

    PubMed

    Wainwright, Steven R; Lieblich, Stephanie E; Galea, Liisa A M

    2011-10-01

    The incidence of depression is 2-3× higher in women particularly during the reproductive years, an occurrence that has been associated with levels of sex hormones. The age-related decline of testosterone levels in men corresponds with the increased acquisition of depressive symptoms, and hormone replacement therapy can be efficacious in treating depression in hypogonadal men. Although it is not possible to model depression in rodents, it is possible to model some of the symptoms of depression including a dysregulated stress response and altered neuroplasticity. Among animal models of depression, chronic mild unpredictable stress (CMS) is a common paradigm used to induce depressive-like behaviours in rodents, disrupt the hypothalamic-pituitary adrenal axis and decrease hippocampal neuroplasticity. The purpose of this study was to assess the effect of hypogonadism, produced by gonadectomy, on the acquisition of depressive-like behaviours and changes in hippocampal neuroplasticity in adult male Sprague-Dawley rats. A 21-day unpredictable CMS protocol was used on gonadectomised (GDX) and sham-operated males which produced an attenuation of weight gain in the GDX males receiving CMS treatment (GDX-CMS). Behavioural analysis was carried out to assess anxiety- and depressive-like behaviours. The combination of GDX and CMS produced greater passive behaviours within the forced swim test than CMS exposure alone. Similarly, hippocampal cell proliferation, neurogenesis and the expression of the neuroplastic protein polysialated neural cell adhesion molecule (PSA-NCAM) were all significantly reduced in the GDX-CMS group compared to all other treatment groups. These findings indicate that testicular hormones confer resiliency to chronic stress in males therefore reducing the likelihood of developing putative physiological, behavioural or neurological depressive-like phenotypes. PMID:21481538

  6. Development of motor coordination and cerebellar structure in male and female rat neonates exposed to hypergravity

    NASA Astrophysics Data System (ADS)

    Nguon, K.; Ladd, B.; Baxter, M. G.; Sajdel-Sulkowska, E. M.

    2006-01-01

    We previously reported that the developing rat cerebellum is affected by exposure to hypergravity. In the present study, we explored the hypothesis that the changes in cerebellar structure in hypergravity-exposed rat neonates may affect their motor coordination. Furthermore, we hypothesized that the changes observed at 1.5G will be magnified at higher gravitational loading. To test this hypothesis, we compared motor behavior, cerebellar structure, and protein expression in rat neonates exposed to 1.5 1.75G on a 24-ft centrifuge daily for 22.5 h starting on gestational day (G) 10, through birth on G22/G23 and through postnatal day (P) 21. Exposure to hypergravity impacted the neurodevelopmental process as indicated by: (1) impaired righting response on P3, more than doubling the righting time at 1.75G, and (2) delayed onset of the startle response by one day, from P9 in controls to P10 in hypergravity-exposed pups. Hypergravity exposure resulted in impaired motor functions as evidenced by performance on a rotarod on P21; the duration of the stay on the rotarod recorded for 1.75G pups of both sexes was one tenth that of the stationary control (SC) pups. These changes in motor behavior were associated with cerebellar changes: (1) cerebellar mass on P6 was decreased by 7.5% in 1.5G-exposed male pups, 27.5% in 1.75G-exposed male pups, 17.5% in 1.5G-exposed female pups, and 22.5% in 1.75G female pups and (2) changes in the expression of glial and neuronal proteins. The results of this study suggest that perinatal exposure to hypergravity affects cerebellar development as evidenced by decreased cerebellar mass and altered cerebellar protein expression; cerebellar changes observed in hypergravity-exposed rat neonates are associated with impaired motor behavior. Furthermore, the response to hypergravity appears to be different in male and female neonates. If one accepts that the hypergravity paradigm is a useful animal model with which to predict those biological processes

  7. Promoting positive youth development by examining the career and educational aspirations of African American males: implications for designing educational programs.

    PubMed

    Lee, Felecia A; Lewis, Rhonda K; Sly, Jamilia R; Carmack, Chakema; Roberts, Shani R; Basore, Polly

    2011-01-01

    African American males experience poor academic performance, high absenteeism at school, and are at increased risk of being involved in violence than other racial groups. Given that the educational outlook for African American males appears bleak, it is important to assess the aspirations of these adolescent males in order to find the gap between aspirations and educational attainment. In order to promote positive development within this population, it is essential that factors that affect African American males be identified. A survey was administered to male students attending elementary, middle, and high schools in a local school district. A cross-sectional study was conducted to examine the career and educational aspirations of African American males. A total of 473 males were surveyed: 45% African American, 22% Caucasian, 13% biracial, and 19% Other (including Asian American, Hispanic, Native American). The results revealed that African American males aspired to attend college at the same rate as other ethnic groups. Also, African American males were more likely to aspire to be professional athletes than males from other ethnic groups. Important factors to consider when designing a program are discussed as well as future research and limitations. PMID:21992020

  8. Segmental Neuropathic Pain Does Not Develop in Male Rats with Complete Spinal Transections

    PubMed Central

    Kaddumi, Ezidin G.; Johnson, Richard D.

    2008-01-01

    Abstract In a previous study using male rats, a correlation was found between the development of “at-level” allodynia in T6-7 dermatomes following severe T8 spinal contusion injury and the sparing of some myelinated axons within the core of the lesion epicenter. To further test our hypothesis that this sparing is important for the expression of allodynia and the supraspinal plasticity that ensues, an injury that severs all axons (i.e., a complete spinal cord transection) was made in 15 male rats. Behavioral assessments were done at level throughout the 30-day recovery period followed by terminal electrophysiological recordings (urethane anesthesia) from single medullary reticular formation (MRF) neurons receiving convergent nociceptive inputs from receptive fields above, at, and below the lesion level. None of the rats developed signs of at-level allodynia (versus 18 of 26 male rats following severe contusion). However, the terminal recording (206 MRF neurons) data resembled those obtained previously post-contusion. That is, there was evidence of neuronal hyper-excitability (relative to previous data from intact controls) to high- and low-threshold mechanical stimulation for “at-level” (dorsal trunk) and “above-level” (eyelids and face) cutaneous territories. These results, when combined with prior data on intact controls and severe/moderate contusions, indicate that (1) an anatomically incomplete injury (some lesion epicenter axonal sparing) following severe contusion is likely important for the development of allodynia and (2) the neuronal hyper-excitability at the level of the medulla is likely involved in nociceptive processes that are not directly related to the conscious expression of pain-like avoidance behaviors that are being used as evidence of allodynia. PMID:18986225

  9. How Do Black Male College Students Develop Supportive Relationships with White Faculty Members and Advisors at a Predominately White Institution

    ERIC Educational Resources Information Center

    Franco, Karina Elizabeth

    2012-01-01

    This qualitative study examined how Black male students develop supportive relationships with White faculty members and advisors at a predominately White urban institution in the Southeastern United State. A multiple-case study method was used to explore how Black males define support, what faculty and advisor characteristics attract Black male…

  10. Sexual and Ethnic Identity Development among Gay/Bisexual/Questioning (GBQ) Male Ethnic Minority Adolescents

    PubMed Central

    Jamil, Omar B.; Harper, Gary W.; Fernandez, M. Isabel

    2010-01-01

    Identity development is a critical task of adolescence and occurs across multiple areas of self identification. Though research on the identity development process among individuals who are ethnic and sexual minorities has been conducted for individuals who have one minority status or the other, few studies have examined these processes in persons who are both ethnic and sexual minorities. This qualitative study examined the dual identity development processes related to ethnic and sexual identity among gay/bisexual/questioning (GBQ) Latino and African American male adolescents. Results indicated that the processes associated with the development of sexual orientation and ethnic identity occur concurrently. However, the actual processes involved with the development of each identity not only differed, but seemed to be independent of each other since neither process was referenced in the development of the other. Overall, the process of ethnic identity development involved the process of becoming aware of one’s ethnic and cultural heritage, while sexual identity development involved finding one’s own personally relevant sexual orientation label and connecting to that community. The implications of these findings for the development of interventions to assist in the healthy development of GBQ adolescents are discussed. PMID:19594249

  11. Development and evaluation of male-only strains of the Australian sheep blowfly, Lucilia cuprina

    PubMed Central

    2014-01-01

    The Australian sheep blowfly Lucilia cuprina (Wiedemann) is a major pest of sheep in Australia and New Zealand. From the 1960s to the 1980s there was a major effort to develop "field female killing" or FFK strains of L. cuprina that could be used for a cost-effective genetic control program. The FFK strains carried eye color mutations that were lethal to females in the field but not under conditions in the mass rearing facility. Males did not die in the field as normal copies of the eye color genes had been translocated to the Y chromosome and an autosome. Although the FFK strains showed some promise in field tests, a genetic control program in mainland Australia was never implemented for several reasons including instability of the FFK strains during mass rearing. A stable transgenic strain of L. cuprina that carried one or more dominant repressible female lethal genes offered the potential for efficient genetic control of blowfly populations. Here I review our research on tetracycline-repressible female lethal genetic systems, Lucilia germ-line transformation and sex determination genes that ultimately led to the successful development of transgenic "male-only" strains of L. cuprina. The technology developed for L. cuprina should be directly transferable to other blowfly livestock pests including L. sericata and the New World and Old World screwworm. 29 PMID:25472415

  12. Arabidopsis PLC2 is involved in auxin-modulated reproductive development.

    PubMed

    Li, Lin; He, Yuqing; Wang, Yarui; Zhao, Shujuan; Chen, Xi; Ye, Tiantian; Wu, Yuxuan; Wu, Yan

    2015-11-01

    Phospholipase C (PLC) is an enzyme that plays crucial roles in various signal transduction pathways in mammalian cells. However, the role of PLC in plant development is poorly understood. Here we report involvement of PLC2 in auxin-mediated reproductive development in Arabidopsis. Disruption of PLC2 led to sterility, indicating a significant role for PLC2 in reproductive development. Development of both male and female gametophytes was severely perturbed in plc2 mutants. Moreover, elevated auxin levels were observed in plc2 floral tissues, suggesting that the infertility of plc2 plants may be associated with increased auxin concentrations in the reproductive organs. We show that expression levels of the auxin reporters DR5:GUS and DR5:GFP were elevated in plc2 anthers and ovules. In addition, we found that expression of the auxin biosynthetic YUCCA genes was increased in plc2 plants. We conclude that PLC2 is involved in auxin biosynthesis and signaling, thus modulating development of both male and female gametophytes in Arabidopsis. PMID:26340337

  13. Cytochemical Analysis of Pollen Development in Wild-Type Arabidopsis and a Male-Sterile Mutant.

    PubMed Central

    Regan, SM; Moffatt, BA

    1990-01-01

    Microsporogenesis has been examined in wild-type Arabidopsis thaliana and the nuclear male-sterile mutant BM3 by cytochemical staining. The mutant lacks adenine phosphoribosyltransferase, an enzyme of the purine salvage pathway that converts adenine to AMP. Pollen development in the mutant began to diverge from wild type just after meiosis, as the tetrads of microspores were released from their callose walls. The first indication of abnormal pollen development in the mutant was a darker staining of the microspore wall due to an incomplete synthesis of the intine. Vacuole formation was delayed and irregular in the mutant, and the majority of the mutant microspores failed to undergo mitotic divisions. Enzyme activities of alcohol dehydrogenase and esterases decreased in the mutant soon after meiosis and were undetectable in mature pollen grains of the mutant. RNA accumulation was also diminished. These results are discussed in relation to the possible role(s) of adenine salvage in pollen development. PMID:12354970

  14. Pollen Semi-Sterility1 Encodes a Kinesin-1–Like Protein Important for Male Meiosis, Anther Dehiscence, and Fertility in Rice[W

    PubMed Central

    Zhou, Shirong; Wang, Yang; Li, Wanchang; Zhao, Zhigang; Ren, Yulong; Wang, Yong; Gu, Suhai; Lin, Qibing; Wang, Dan; Jiang, Ling; Su, Ning; Zhang, Xin; Liu, Linglong; Cheng, Zhijun; Lei, Cailin; Wang, Jiulin; Guo, Xiuping; Wu, Fuqing; Ikehashi, Hiroshi; Wang, Haiyang; Wan, Jianmin

    2011-01-01

    In flowering plants, male meiosis produces four microspores, which develop into pollen grains and are released by anther dehiscence to pollinate female gametophytes. The molecular and cellular mechanisms regulating male meiosis in rice (Oryza sativa) remain poorly understood. Here, we describe a rice pollen semi-sterility1 (pss1) mutant, which displays reduced spikelet fertility (~40%) primarily caused by reduced pollen viability (~50% viable), and defective anther dehiscence. Map-based molecular cloning revealed that PSS1 encodes a kinesin-1–like protein. PSS1 is broadly expressed in various organs, with highest expression in panicles. Furthermore, PSS1 expression is significantly upregulated during anther development and peaks during male meiosis. The PSS1–green fluorescent protein fusion is predominantly localized in the cytoplasm of rice protoplasts. Substitution of a conserved Arg (Arg-289) to His in the PSS1 motor domain nearly abolishes its microtubule-stimulated ATPase activity. Consistent with this, lagging chromosomes and chromosomal bridges were found at anaphase I and anaphase II of male meiosis in the pss1 mutant. Together, our results suggest that PSS1 defines a novel member of the kinesin-1 family essential for male meiotic chromosomal dynamics, male gametogenesis, and anther dehiscence in rice. PMID:21282525

  15. Mosaicism for the FMR1 gene influences adaptive skills development in fragile X-affected males

    SciTech Connect

    Cohen, I.L.; Sudhalter, V.; Nolin, S.L.

    1996-08-09

    Fragile X syndrome is one of the most common forms of inherited mental retardation, and the first of a new class of genetic disorders associated with expanded trinucleotide repeats. Previously, we found that about 41% of affected males are mosaic for this mutation in that some of their blood cells have an active fragile X gene and others do not. It has been hypothesized that these mosaic cases should show higher levels of functioning than those who have only the inactive full mutation gene, but previous studies have provided negative or equivocal results. In the present study, the cross-sectional development of communication, self-care, socialization, and motor skills was studied in 46 males with fragile X syndrome under age 20 years as a function of two variables: age and the presence or absence of mosaicism. The rate of adaptive skills development was 2-4 times as great in mosaic cases as in full mutation cases. There was also a trend for cases with autism to be more prevalent in the full-mutation group. These results have implications for prognosis, for the utility of gene or protein replacement therapies for this disorder, and for understanding the association between mental retardation, developmental disorders, and fragile X syndrome. 21 refs., 3 figs.

  16. Histological Description of Gonadal Development of Females and Males of Callinectes sapidus Rathbun, 1896 (Decapoda: Portunidae).

    PubMed

    Carvalho-Saucedo, Liliana; Ramírez-Santiago, Cecilia; Pérez, Carlos

    2015-04-01

    This paper describes the characteristics of male and female germ cells during gonadal development and the gonadal maturity scale of the blue crab, Callinectes sapidus. A total of 20 specimens were collected monthly from June to November 2012, in two areas off the coast of the Gulf of Mexico: the San Andrés Lagoon and Alvarado Lagoon. The gonads were removed and processed following the standard technique of hematoxylin and eosin staining. An important event in oogenesis (pre-vitellogenesis) was the appearance of a perinuclear vesicle in the cytoplasm and the accumulation of yolk granules. Later, vitellogenesis began and there was an accumulation of nutritive droplets and fragmentation of the perinuclear vesicle. During spermatogenesis, the accumulation of two fluids was observed that were involved in the formation of the spermatophore and the delay of spermiogenesis. Based on the histological features of gonad maturity, five stages were described (inactive, early gametogenesis, development, maturity, and resorption), in females and males. This proposal can be useful for the study of reproductive seasonality of this species. PMID:25826069

  17. TOXICOLOGY OF MALE REPRODUCTIVE DEVELOPMENT: PROFILING 774 CHEMICALS FOR MOLECULAR TARGETS AND ADVERSE OUTCOMES (SOT)

    EPA Science Inventory

    Adverse trends in male reproductive health have been reported for increased rates of testicular germ cell tumor, low semen quality, cryptorchidism, and hypospadias. An association with prenatal environmental exposure has been inferred from human and animal studies underlying male...

  18. Systems Toxicology of Male Reproductive Development: Profiling 774 Chemicals for Molecular Targets and Adverse Outcomes

    EPA Science Inventory

    Adverse trends in male reproductive health have been reported for increased rates of testicular germ cell tumor, low semen quality, cryptorchidism, and hypospadias. An association with prenatal environmental exposure has been inferred from human and animal studies underlying male...

  19. RAN-Binding Protein 9 is Involved in Alternative Splicing and is Critical for Male Germ Cell Development and Male Fertility

    PubMed Central

    Bao, Jianqiang; Tang, Chong; Li, Jiachen; Zhang, Ying; Bhetwal, Bhupal P.; Zheng, Huili; Yan, Wei

    2014-01-01

    As a member of the large Ran-binding protein family, Ran-binding protein 9 (RANBP9) has been suggested to play a critical role in diverse cellular functions in somatic cell lineages in vitro, and this is further supported by the neonatal lethality phenotype in Ranbp9 global knockout mice. However, the exact molecular actions of RANBP9 remain largely unknown. By inactivation of Ranbp9 specifically in testicular somatic and spermatogenic cells, we discovered that Ranbp9 was dispensable for Sertoli cell development and functions, but critical for male germ cell development and male fertility. RIP-Seq and proteomic analyses revealed that RANBP9 was associated with multiple key splicing factors and directly targeted >2,300 mRNAs in spermatocytes and round spermatids. Many of the RANBP9 target and non-target mRNAs either displayed aberrant splicing patterns or were dysregulated in the absence of Ranbp9. Our data uncovered a novel role of Ranbp9 in regulating alternative splicing in spermatogenic cells, which is critical for normal spermatogenesis and male fertility. PMID:25474150

  20. Effects of Strength Training on Muscle Development in Prepubescent, Pubescent, and Postpubescent Males.

    ERIC Educational Resources Information Center

    Pfeiffer, Ronald D.; Francis, Rulon S.

    1986-01-01

    Thirty-three males from ages 8 to 21 years participated in a nine-week resistive exercise program to test the hypothesis that pubescent males respond better to strength training than older or younger males do. Results are discussed. (Author/MT)

  1. Progress in development of male sterile germplasm for hybrid rice breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Currently, there are two types of male sterility mainly commercialized in hybrid rice production, three-line type or cytoplasmic male sterility (CMS) and two-line type or environmental male sterility (EMS). The great majority belongs to the CMS and there are four strategies that have been proven suc...

  2. Effect of three larval diets on larval development and male sexual performance of Anopheles gambiae s.s.

    PubMed

    Yahouédo, Gildas A; Djogbénou, Luc; Saïzonou, Jacques; Assogba, Bénoît S; Makoutodé, Michel; Gilles, Jeremie R L; Maïga, Hamidou; Mouline, Karine; Soukou, Bhonna K; Simard, Frédéric

    2014-04-01

    Population replacement/elimination strategies based on mass-release of sterile or otherwise genetically modified (male) mosquitoes are being considered in order to expand the malaria vector control arsenal on the way to eradication. A challenge in this context, is to produce male mosquitoes that will be able to compete and mate with wild females more efficiently than their wild counterparts, i.e. high fitness males. This study explored the effect of three larval food diets developed by the International Atomic Energy Agency on the overall fitness and mating performance of male Anopheles gambiae s.s. mosquitoes (Kisumu strain). Larval development (pupation and emergence rate, development time) was monitored, and adult wing length and energy reserves at emergence (i.e. lipids, sugars, glycogen and proteins) were measured. Male sexual performance was assessed through an insemination test whereby one male and 10 virgin females were maintained together in the same cage in order to record the number of inseminated females per 24h. Our results show that males reared on Diets 2 and 3 performed best during larval development. Males provided with treatment 2.2 had a shorter development time and performed best in insemination tests. However, these males had the lowest overall lifespan, suggesting a trade-off between longevity and sexual performances which needs to be taken into consideration when planning release. The results from this work were discussed in the context of sterile insect techniques or genetic control methods which is today one of the strategy in the overall mosquito control and elimination efforts. PMID:24291460

  3. Development of photoperiod- and thermo-sensitive male sterility rice expressing transgene Bacillus thuringiensis

    PubMed Central

    Liu, Xin; Zhang, Jiwen; Zhang, Cuicui; Wang, Liangchao; Chen, Hao; Zhu, Zengrong; Tu, Jumin

    2015-01-01

    Stem borers and leaffolders are the main pests that cause severe damage in rice (Oryza sativa L.) production worldwide. We developed the first photoperiod- and thermo-sensitive male sterility (PTSMS) rice 208S with the cry1Ab/1Ac Bacillus thuringiensis (Bt) gene, through sexual crossing with Huahui 1 (elite line with the cry1Ab/1Ac gene). The novel 208S and its hybrids presented high and stable resistance to stem borers and leaffolders, and the content of Cry1Ab/1Ac protein in chlorophyllous tissues achieved the identical level as donor and showed little accumulation in non-chlorophyllous tissue. No dominant dosage effect in the Bt gene was observed in 208S and its derived hybrids. An analysis of fertility transition traits indicated that 208S was completely sterile under long day length/high temperature, but partially fertile under short day length/low temperature. With fine grain quality and favorable combining ability, 208S had no observed negative effects on fertility and agronomic traits from Bt (cry1Ab/1Ac). Additionally, 208S as a male sterile line showed no fertility decrease caused by Bt transgenic process, as it is the case in Huahui 1. Thus, 208S has great application value in two-line hybrid production for insect resistance, and can also be used as a bridge material in rice Bt transgenic breeding. PMID:26366116

  4. Cystic fibrosis transmembrane conductance regulator protein expression in the male excretory duct system during development.

    PubMed

    Marcorelles, Pascale; Gillet, Danièle; Friocourt, Gaëlle; Ledé, Françoise; Samaison, Laura; Huguen, Geneviève; Ferec, Claude

    2012-03-01

    Sterility due to bilateral destruction in utero or in early infancy resulting in congenital absence of the vas deferens is the rule in male patients with cystic fibrosis. To understand the developmental pattern of this anomaly, the microscopic morphology of the male excretory system was analyzed during development and the expression of the cystic fibrosis transmembrane conductance regulator protein was explored by immunohistochemistry. We observed that cystic fibrosis fetuses had no excretory ducts agenesis or obstruction until 22 weeks of gestation. However, a focal inflammatory pattern and mucinous plugs in the oldest cystic fibrosis case suggested a disruptive mechanism. Immunolabeling of cytoplasmic epithelial cystic fibrosis transmembrane conductance regulator protein was demonstrated in all cystic fibrosis and control cases with a similar pattern of expression of the protein between age-matched controls and cystic fibrosis cases. At midgestation, an apical intensification appeared in both cystic fibrosis and control cases and was stable during the remainder of fetal life. No gradient of intensity could be detected between the different segments of the excretory tract. These findings are different from those reported in adults. The absence of any morphologic anomaly until 22 weeks of gestation, the focal destruction of the epithelial structures during the second trimester, and the chronological pattern of expression of cystic fibrosis transmembrane conductance regulator are of interest for a better understanding of the pathophysiology of this disease. PMID:21840567

  5. Male circumcision and common sexually transmissible diseases in a developed nation setting.

    PubMed Central

    Donovan, B; Bassett, I; Bodsworth, N J

    1994-01-01

    OBJECTIVE--To determine whether the circumcision status of men affected their likelihood of acquiring sexually transmissible diseases (STDs). DESIGN--A cross-sectional study employing an anonymous questionnaire, clinical examination and type specific serology for herpes simplex virus type 2 (HSV-2). SETTING--A public STD clinic in Sydney, Australia. SUBJECTS--300 consecutive heterosexual male patients. MAIN OUTCOME MEASURES--Associations between circumcision status and past or present diagnoses of STDs including HSV-2 serology and clinical pattern of genital herpes. RESULTS--185 (62%) of the men were circumcised and they reported similar ages, education levels and lifetime partner numbers as men who were uncircumcised. There were no significant associations between the presence or absence of the male prepuce and the number diagnosed with genital herpes, genital warts and non-gonococcal urethritis. Men who were uncircumcised were no more likely to be seropositive for HSV-2 and reported symptomatic genital herpes outbreaks of the same frequency and severity as men who were circumcised. Gonorrhoea, syphilis and acute hepatitis B were reported too infrequently to reliably exclude any association with circumcision status. Human immunodeficiency virus infection (rare among heterosexual men in the clinic) was an exclusion criterion. CONCLUSIONS--From the findings of this study, circumcision of men has no significant effect on the incidence of common STDs in this developed nation setting. However, these findings may not necessarily extend to other setting where hygiene is poorer and the spectrum of common STDs is different. PMID:8001942

  6. A Phenomenological Investigation on the Role of Mentoring in the Academic Development of African American Male Secondary Students

    NASA Astrophysics Data System (ADS)

    Inge, Jillian

    The purpose of this phenomenological study was to examine how the construct of mentoring by African American males can support the academic development of African American male students. Since African American male students perform significantly lower in academic subjects than their counterparts of other ethnicities, there is an exigent need for change in this area. Built upon the conceptual framework of communal interactions and identity, the inquiry questioned the experiences of mentors for African American male secondary students, and their perceptions of the influence of a mentoring relationship when the mentor and mentee are of similar backgrounds. Participants in this study were 7 African American males who had mentored or were currently mentoring African American male students. Data, obtained through semi structured interviews and focus group interviews, were coded for themes that reflected the experiences of mentors in mentoring African American males. Mentors in this study reported that students with whom they share similar backgrounds and experiences were better able to relate to them than those who had dissimilar backgrounds and experiences. In addition, mentors reported their mentees were more likely to envision themselves in professional areas beyond their perceived cultural norm when they routinely interact with successful African American males from various fields; thus, it was important for mentors to provide opportunities for students to interact with professionals. Contributions to social change will emerge as African American male mentors understand and employ their roles as a fundamental component in the academic development of African American male secondary students and thus empower this population of students to achieve academic success and to serve in a capacity that nurtures their immediate surroundings.

  7. Impact of Male Partner Antenatal Accompaniment on Perinatal Health Outcomes in Developing Countries: A Systematic Literature Review.

    PubMed

    Aguiar, Carolina; Jennings, Larissa

    2015-09-01

    Encouraging male partners to accompany women to antenatal care (ANC) is an important first step in engaging men on maternal and newborn health. However, little is known regarding the impact of male partner antenatal accompaniment beyond HIV-related perinatal outcomes. A systematic review was conducted to synthesize the evidence on the influence of male accompaniment on non-HIV outcomes during pregnancy and into the postpartum period. Eligible studies were published in English from 2003 to 2013 and evaluated the effect of male antenatal accompaniment on perinatal health in a developing country. Four electronic databases and selected reference lists were searched. Out of 84 potential citations retrieved, seven publications were retained for the assessment of male antenatal accompaniment's influence using iterative thematic analysis. During pregnancy, male antenatal accompaniment positively impacted women's knowledge of danger signs, but did not affect birth preparedness, ANC utilization, or miscarriages. During labor and delivery, men's ANC presence was associated with increases in institutional delivery and skilled birth attendance, but with no effect for birth-related outcomes. During the early postnatal period, male antenatal accompaniment was associated with higher uptake of postnatal services, but with mixed effects on breastfeeding and newborn survival. Couples' increased communication on pregnancy care and men's subsequent motivation to ensure safe delivery may explain these observed benefits. Inadequate communication, late accompaniment, or partner type may explain the lack of influence on some outcomes. More efforts are needed to expand the implementation and evaluation of male involvement strategies to improve perinatal health. PMID:25656727

  8. Pituitary and testis responsiveness of young male sheep exposed to testosterone excess during fetal development.

    PubMed

    Recabarren, Mónica P; Rojas-Garcia, Pedro P; Einspanier, Ralf; Padmanabhan, Vasantha; Sir-Petermann, Teresa; Recabarren, Sergio E

    2013-06-01

    Prenatal exposure to excess testosterone induces reproductive disturbances in both female and male sheep. In females, it alters the hypothalamus-pituitary-ovarian axis. In males, prenatal testosterone excess reduces sperm count and motility. Focusing on males, this study tested whether pituitary LH responsiveness to GNRH is increased in prenatal testosterone-exposed males and whether testicular function is compromised in the testosterone-exposed males. Control males (n=6) and males born to ewes exposed to twice weekly injections of 30  mg testosterone propionate from days 30 to 90 and of 40  mg testosterone propionate from days 90 to 120 of gestation (n=6) were studied at 20 and 30 weeks of age. Pituitary and testicular responsiveness was tested by administering a GNRH analog (leuprolide acetate). To complement the analyses, the mRNA expression of LH receptor (LHR) and that of steroidogenic enzymes were determined in testicular tissue. Basal LH and testosterone concentrations were higher in the testosterone-exposed-males. While LH response to the GNRH analog was higher in the testosterone-exposed males than in the control males, testosterone responses did not differ between the treatment groups. The testosterone:LH ratio was higher in the control males than in the testosterone-exposed males of 30 weeks of age, suggestive of reduced Leydig cell sensitivity to LH in the testosterone-exposed males. The expression of LHR mRNA was lower in the testosterone-exposed males, but the mRNA expression of steroidogenic enzymes did not differ between the groups. These findings indicate that prenatal testosterone excess has opposing effects at the pituitary and testicular levels, namely increased pituitary sensitivity to GNRH at the level of pituitary and decreased sensitivity of the testes to LH. PMID:23579187

  9. Transcriptomic Analysis of Differentially Expressed Genes during Flower Organ Development in Genetic Male Sterile and Male Fertile Tagetes erecta by Digital Gene-Expression Profiling

    PubMed Central

    Ai, Ye; Zhang, Qinghua; Wang, Weining; Zhang, Chunling; Cao, Zhe; Bao, Manzhu; He, Yanhong

    2016-01-01

    Tagetes erecta is an important commercial plant of Asteraceae family. The male sterile (MS) and male fertile (MF) two-type lines of T. erecta have been utilized in F1 hybrid production for many years, but no report has been made to identify the genes that specify its male sterility that is caused by homeotic conversion of floral organs. In this study, transcriptome assembly and digital gene expression profiling were performed to generate expression profiles of MS and MF plants. A cDNA library was generated from an equal mixture of RNA isolated from MS and MF flower buds (1 mm and 4 mm in diameter). Totally, 87,473,431 clean tags were obtained and assembled into 128,937 transcripts among which 65,857 unigenes were identified with an average length of 1,188 bp. About 52% of unigenes (34,176) were annotated in Nr, Nt, Pfam, KOG/COG, Swiss-Prot, KO (KEGG Ortholog database) and/or GO. Taking the above transcriptome as reference, 125 differentially expressed genes were detected in both developmental stages of MS and MF flower buds. MADS-box genes were presumed to be highly related to male sterility in T. erecta based on histological and cytological observations. Twelve MADS-box genes showed significantly different expression levels in flower buds 4 mm in diameter, whereas only one gene expressed significantly different in flower buds 1 mm in diameter between MS and MF plants. This is the first transcriptome analysis in T. erecta and will provide a valuable resource for future genomic studies, especially in flower organ development and/or differentiation. PMID:26939127

  10. Transcriptomic Analysis of Differentially Expressed Genes during Flower Organ Development in Genetic Male Sterile and Male Fertile Tagetes erecta by Digital Gene-Expression Profiling.

    PubMed

    Ai, Ye; Zhang, Qinghua; Wang, Weining; Zhang, Chunling; Cao, Zhe; Bao, Manzhu; He, Yanhong

    2016-01-01

    Tagetes erecta is an important commercial plant of Asteraceae family. The male sterile (MS) and male fertile (MF) two-type lines of T. erecta have been utilized in F1 hybrid production for many years, but no report has been made to identify the genes that specify its male sterility that is caused by homeotic conversion of floral organs. In this study, transcriptome assembly and digital gene expression profiling were performed to generate expression profiles of MS and MF plants. A cDNA library was generated from an equal mixture of RNA isolated from MS and MF flower buds (1 mm and 4 mm in diameter). Totally, 87,473,431 clean tags were obtained and assembled into 128,937 transcripts among which 65,857 unigenes were identified with an average length of 1,188 bp. About 52% of unigenes (34,176) were annotated in Nr, Nt, Pfam, KOG/COG, Swiss-Prot, KO (KEGG Ortholog database) and/or GO. Taking the above transcriptome as reference, 125 differentially expressed genes were detected in both developmental stages of MS and MF flower buds. MADS-box genes were presumed to be highly related to male sterility in T. erecta based on histological and cytological observations. Twelve MADS-box genes showed significantly different expression levels in flower buds 4 mm in diameter, whereas only one gene expressed significantly different in flower buds 1 mm in diameter between MS and MF plants. This is the first transcriptome analysis in T. erecta and will provide a valuable resource for future genomic studies, especially in flower organ development and/or differentiation. PMID:26939127

  11. Male circumcision, religion, and infectious diseases: an ecologic analysis of 118 developing countries

    PubMed Central

    Drain, Paul K; Halperin, Daniel T; Hughes, James P; Klausner, Jeffrey D; Bailey, Robert C

    2006-01-01

    Background Both religious practices and male circumcision (MC) have been associated with HIV and other sexually-transmitted infectious diseases. Most studies have been limited in size and have not adequately controlled for religion, so these relationships remain unclear. Methods We evaluated relationships between MC prevalence, Muslim and Christian religion, and 7 infectious diseases using country-specific data among 118 developing countries. We used multivariate linear regression to describe associations between MC and cervical cancer incidence, and between MC and HIV prevalence among countries with primarily sexual HIV transmission. Results Fifty-three, 14, and 51 developing countries had a high (>80%), intermediate (20–80%), and low (<20%) MC prevalence, respectively. In univariate analyses, MC was associated with lower HIV prevalence and lower cervical cancer incidence, but not with HSV-2, syphilis, nor, as expected, with Hepatitis C, tuberculosis, or malaria. In multivariate analysis after stratifying the countries by religious groups, each categorical increase of MC prevalence was associated with a 3.65/100,000 women (95% CI 0.54-6.76, p = 0.02) decrease in annual cervical cancer incidence, and a 1.84-fold (95% CI 1.36-2.48, p < 0.001) decrease in the adult HIV prevalence among sub-Saharan African countries. In separate multivariate analyses among non-sub-Saharan African countries controlling for religion, higher MC prevalence was associated with a 8.94-fold (95% CI 4.30-18.60) decrease in the adult HIV prevalence among countries with primarily heterosexual HIV transmission, but not, as expected, among countries with primarily homosexual or injection drug use HIV transmission (p = 0.35). Conclusion Male circumcision was significantly associated with lower cervical cancer incidence and lower HIV prevalence in sub-Saharan Africa, independent of Muslim and Christian religion. As predicted, male circumcision was also strongly associated with lower HIV

  12. Maternal cypermethrin exposure during the perinatal period impairs testicular development in C57BL male offspring.

    PubMed

    Huang, Chaobin; Li, Xiangdong

    2014-01-01

    Numerous studies have demonstrated that endocrine-disrupting compounds (EDC) are a possible cause of male reproductive organ malfunction and malformation. Cypermethrin (CYP) is a widely used synthetic pyrethroid and a potential EDC. This study aimed to examine the effects of perinatal exposure to low-dose CYP on the development and function of the offspring testes. Pregnant mice were intragastrically administered 0.12 to 12 mg/kg/day CYP from embryonic day 0.5 (E0.5) to weaning (PD21.5, postnatal day 21.5). Maternal exposure to 0.12, 1.2, and 12 mg/kg/day CYP affected the body and organ weight of the offspring. Exposure of CYP led to a dose-dependent decrease in the male-to-female sex ratio. A histopathological analysis revealed a thinner seminiferous epithelium layer at PD21.5, interstitial hyperplasia at PD45.5, and germ cell vacuolization at PD90.5 in the 12 mg/kg/day CYP group. The TUNEL assay results revealed increased germ cell apoptosis in the 12 mg/kg/day CYP group. The serum testosterone (T) level decreased, whereas the estradiol level increased with age in the 1.2 and 12 mg/kg/day CYP groups. The RT-PCR analysis demonstrated decreased expression of T production-related, mitosis-related, and meiosis-related genes in the 1.2 and 12 mg/kg/day CYP groups. The in vitro experimental results demonstrated reduced expression of steroidogenesis genes and decreased T levels. It is concluded that perinatal exposure to low-dose CYP affects testes development and function in adults. PMID:24810582

  13. Maternal Cypermethrin Exposure during the Perinatal Period Impairs Testicular Development in C57BL Male Offspring

    PubMed Central

    Huang, Chaobin; Li, Xiangdong

    2014-01-01

    Numerous studies have demonstrated that endocrine-disrupting compounds (EDC) are a possible cause of male reproductive organ malfunction and malformation. Cypermethrin (CYP) is a widely used synthetic pyrethroid and a potential EDC. This study aimed to examine the effects of perinatal exposure to low-dose CYP on the development and function of the offspring testes. Pregnant mice were intragastrically administered 0.12 to 12 mg/kg/day CYP from embryonic day 0.5 (E0.5) to weaning (PD21.5, postnatal day 21.5). Maternal exposure to 0.12, 1.2, and 12 mg/kg/day CYP affected the body and organ weight of the offspring. Exposure of CYP led to a dose-dependent decrease in the male-to-female sex ratio. A histopathological analysis revealed a thinner seminiferous epithelium layer at PD21.5, interstitial hyperplasia at PD45.5, and germ cell vacuolization at PD90.5 in the 12 mg/kg/day CYP group. The TUNEL assay results revealed increased germ cell apoptosis in the 12 mg/kg/day CYP group. The serum testosterone (T) level decreased, whereas the estradiol level increased with age in the 1.2 and 12 mg/kg/day CYP groups. The RT-PCR analysis demonstrated decreased expression of T production-related, mitosis-related, and meiosis-related genes in the 1.2 and 12 mg/kg/day CYP groups. The in vitro experimental results demonstrated reduced expression of steroidogenesis genes and decreased T levels. It is concluded that perinatal exposure to low-dose CYP affects testes development and function in adults. PMID:24810582

  14. Estrogenic Environmental Chemicals and Drugs: Mechanisms for Effects on the Developing Male Urogenital System

    PubMed Central

    Taylor, Julia A.; Richter, Catherine A.; Ruhlen, Rachel L.; vom Saal, Frederick S.

    2011-01-01

    Development and differentiation of the prostate from the fetal urogenital sinus (UGS) is dependent on androgen action via androgen receptors (AR) in the UGS mesenchyme. Estrogens are not required for prostate differentiation but do act to modulate androgen action. In mice exposure to exogenous estrogen during development results in permanent effects on adult prostate size and function, which is mediated through mesenchymal estrogen receptor (ER) alpha. For many years estrogens were thought to inhibit prostate growth because estrogenic drugs studied were administered at very high concentrations that interfered with normal prostate development. There is now extensive evidence that exposure to estrogen at very low concentrations during the early stages of prostate differentiation can stimulate fetal/neonatal prostate growth and lead to prostate disease in adulthood. Bisphenol A (BPA) is an environmental endocrine disrupting chemical that binds to both ER receptor subtypes as well as to AR. Interest in BPA has increased because of its prevalence in the environment and its detection in over 90% of people in the USA. In tissue culture of fetal mouse UGS mesenchymal cells, BPA and estradiol stimulated changes in the expression of several genes. We discuss here the potential involvement of estrogen in regulating signaling pathways affecting cellular functions relevant to steroid hormone signaling and metabolism and to inter- and intra-cellular communications that promote cell growth. The findings presented here provide additional evidence that BPA and the estrogenic drug ethinylestradiol disrupt prostate development in male mice at administered doses relevant to human exposures. PMID:21827855

  15. Profiling of androgen response in rainbow trout pubertal testis: relevance to male gonad development and spermatogenesis.

    PubMed

    Rolland, Antoine D; Lardenois, Aurélie; Goupil, Anne-Sophie; Lareyre, Jean-Jacques; Houlgatte, Rémi; Chalmel, Frédéric; Le Gac, Florence

    2013-01-01

    The capacity of testicular somatic cells to promote and sustain germ cell differentiation is largely regulated by sexual steroids and notably androgens. In fish species the importance of androgens is emphasized by their ability to induce sex reversal of the developing fries and to trigger spermatogenesis. Here we studied the influence of androgens on testicular gene expression in trout testis using microarrays. Following treatment of immature males with physiological doses of testosterone or 11-ketotestosterone, 418 genes that exhibit changes in expression were identified. Interestingly, the activity of testosterone appeared stronger than that of 11-ketotestosterone. Expression profiles of responsive genes throughout testis development and in isolated germ cells confirmed androgens to mainly affect gene expression in somatic cells. Furthermore, specific clusters of genes that exhibit regulation coincidently with changes in the natural circulating levels of androgens during the reproductive cycle were highlighted, reinforcing the physiological significance of these data. Among somatic genes, a phylogenetic footprinting study identified putative androgen response elements within the proximal promoter regions of 42 potential direct androgen target genes. Finally, androgens were also found to alter the germ line towards meiotic expression profiles, supporting the hypothesis of a role for the somatic responsive genes in driving germ cell fate. This study significantly increases our understanding of molecular pathways regulated by androgens in vertebrates. The highly cyclic testicular development in trout together with functions associated with regulated genes reveal potential mechanisms for androgen actions in tubule formation, steroid production, germ cell development and sperm secretion. PMID:23301058

  16. Parallel evolution of male germline epigenetic poising and somatic development in animals.

    PubMed

    Lesch, Bluma J; Silber, Sherman J; McCarrey, John R; Page, David C

    2016-08-01

    Changes in gene regulation frequently underlie changes in morphology during evolution, and differences in chromatin state have been linked with changes in anatomical structure and gene expression across evolutionary time. Here we assess the relationship between evolution of chromatin state in germ cells and evolution of gene regulatory programs governing somatic development. We examined the poised (H3K4me3/H3K27me3 bivalent) epigenetic state in male germ cells from five mammalian and one avian species. We find that core genes poised in germ cells from multiple amniote species are ancient regulators of morphogenesis that sit at the top of transcriptional hierarchies controlling somatic tissue development, whereas genes that gain poising in germ cells from individual species act downstream of core poised genes during development in a species-specific fashion. We propose that critical regulators of animal development gained an epigenetically privileged state in germ cells, manifested in amniotes by H3K4me3/H3K27me3 poising, early in metazoan evolution. PMID:27294618

  17. Pollen Performance in Clarkia Taxa with Contrasting Mating Systems: Implications for Male Gametophytic Evolution in Selfers and Outcrossers

    PubMed Central

    Hove, Alisa A.; Mazer, Susan J.

    2013-01-01

    We tested three predictions regarding the joint evolution of pollen performance and mating system. First, due to the potential for intense intrasexual competition in outcrossing populations, we predicted that outcrossers would produce faster-growing pollen than their selfing relatives. Second, if elevated competition promotes stronger selection on traits that improve pollen performance, then, among-plant variation in pollen performance would be lower in outcrossers than in selfers. Third, given successive generations of adaptation to the same maternal genotype in selfers, we predicted that, in selfing populations (but not in outcrossing ones), pollen would perform better following self- than cross-pollinations. We tested these predictions in field populations of two pairs of Clarkia (Onagraceae) sister taxa. Consistent with our predictions, one outcrosser (C. unguiculata) exhibited faster pollen germination and less variation in pollen tube growth rate (PTGR) among pollen donors than its selfing sister species, C. exilis. Contrary to our predictions, the selfing C. xantiana ssp. parviflora exhibited faster PTGR than the outcrossing ssp. xantiana, and these taxa showed similar levels of variation in this trait. Pollen performance following self- vs. cross-pollinations did not differ within either selfing or outcrossing taxa. While these findings suggest that mating system and pollen performance may jointly evolve in Clarkia, other factors clearly contribute to pollen performance in natural populations. PMID:27137375

  18. Dynamics of asymmetrical hybridization in North American wood ferns: reconciling patterns of inheritance with gametophyte reproductive biology.

    PubMed

    Testo, Weston L; Watkins, James E; Barrington, David S

    2015-04-01

    Hybridization is an important evolutionary force in plants, but the mechanisms underlying it have not been well studied for many groups. In particular, the drivers of non-random patterns of interspecific gene flow (asymmetrical hybridization) remain poorly understood, especially in the seed-free vascular plants. Here, we examine patterns of asymmetrical hybridization in two widespread fern hybrids from eastern North America and study the role of gametophyte ecology in the determination of hybridization bias. We characterized the maternal parentage of > 140 hybrid sporophytes by sequencing a c. 350-bp region of chloroplast DNA (cpDNA). To identify factors contributing to patterns of asymmetrical hybridization, we cultured gametophytes of the parental species and evaluated critical aspects of their reproductive biology. We found that asymmetrical hybridization was prevalent across the populations of both hybrids. Reproductive traits varied across species and suggest that selfing potential, antheridiogen responsiveness, sperm dispersal capacity and gamete size all contribute to the mediation of the direction of hybridization in this group. Our findings suggest that asymmetrical hybridization in ferns is driven by an array of reproductive traits. This study helps to sharpen and define a mechanistic understanding of patterns of hybridization in this group and demonstrates the importance of considering gametophyte biology when studying evolutionary processes in ferns. PMID:25443156

  19. In utero exposure to chloroquine alters sexual development in the male fetal rat

    SciTech Connect

    Clewell, Rebecca A. Pluta, Linda; Thomas, Russell S.; Andersen, Melvin E.

    2009-06-15

    Chloroquine (CQ), a drug that has been used extensively for the prevention and treatment of malaria, is currently considered safe for use during pregnancy. However, CQ has been shown to disrupt steroid homeostasis in adult rats and similar compounds, such as quinacrine, inhibit steroid production in the Leydig cell in vitro. To explore the effect of in utero CQ exposure on fetal male sexual development, pregnant Sprague-Dawley rats were given a daily dose of either water or chloroquine diphosphate from GD 16-18 by oral gavage. Chloroquine was administered as 200 mg/kg CQ base on GD 16, followed by two maintenance doses of 100 mg/kg CQ base on GD 16 and 18. Three days of CQ treatment resulted in reduced maternal and fetal weight on GD 19 and increased necrosis and steatosis in the maternal liver. Fetal livers also displayed mild lipid accumulation. Maternal serum progesterone was increased after CQ administration. Fetal testes testosterone, however, was significantly decreased. Examination of the fetal testes revealed significant alterations in vascularization and seminiferous tubule development after short-term CQ treatment. Anogenital distance was not altered. Microarray and RT-PCR showed down-regulation of several genes associated with cholesterol transport and steroid synthesis in the fetal testes. This study indicates that CQ inhibits testosterone synthesis and normal testis development in the rat fetus at human relevant doses.

  20. Evaluation of the presence of arabinogalactan proteins and pectins during Quercus suber male gametogenesis

    PubMed Central

    Costa, Mário Luís; Sobral, Rómulo; Costa, Maria Manuela Ribeiro; Amorim, Maria Isabel; Coimbra, Sílvia

    2015-01-01

    Background and Aims Quercus suber (cork oak) is a dominant tree of the Fagaceae in forests of the south-west Iberian Peninsula. It is monoecious with a long progamic phase that provides a comprehensive system for comparative studies in development and sexual reproduction. In this study the distribution of arabinogalactan protein (AGPs) and pectin epitopes in anthers of Q. suber was assessed to map these hydroxyproline-rich glycoproteins and the galacturonate-rich acidic polysaccharides during pollen development. Methods Immunolocalization in male flowers was performed with a set of monoclonal antibodies directed against the carbohydrate moiety that recognizes AGPs and pectins. To identify AGP genes involved in cork oak male flower development, a search was conducted for annotated AGP genes in the available transcriptome data of the Cork Oak EST Consortium database (www.corkoakdb.org). Key Results Ubiquitous labelling in all cell types was obtained with anti-homogalacturan antibodies for methyl-esterified pectins. In contrast, the antibody that labelled non-methyl-esterified homogalacturans had a preferential presence in microsporocyte cells walls at the beginning of pollen development. Intense labelling was obtained with anti-AGP antibodies both in the tapetum and in the intine wall near the pollen apertures and later in the generative cell wall and vegetative cell. Evaluation of the putative AGPs highly expressed in the male gametophyte was achieved by quantitative RT-PCR analysis in male and female cork oak flowers. Conclusions Four putative AGP genes were identified that are preferentially expressed in the male flower compared with the female flower. The putative Arabidopsis thaliana orthologues of these genes are associated with preferential expression in pollen, suggesting that the AGPs probably play a significant role in cork oak reproduction. PMID:25452249

  1. Male pubertal development: are endocrine-disrupting compounds shifting the norms?

    PubMed

    Zawatski, William; Lee, Mary M

    2013-01-01

    Endocrine-disrupting compounds (EDCs) are synthetic or natural compounds that interfere with endogenous endocrine action. The frequent use of chemicals with endocrine active properties in household products and contamination of soil, water, and food sources by persistent chemical pollutants result in ubiquitous exposures. Wildlife observations and animal toxicological studies reveal adverse effects of EDCs on reproductive health. In humans, a growing number of epidemiological studies report an association with altered pubertal timing and progression. While these data are primarily reported in females, this review will focus on the small number of studies performed in males that report an association of polychlorinated biphenyls with earlier sexual maturity rating and confirm subtle effects of lead, dioxins, and endosulfan on delaying pubertal onset and progression in boys. Recent studies have also demonstrated that EDC exposure may affect pubertal testosterone production without having a noticeable effect on sexual maturity rating. A limitation to understand the effects of EDCs in humans is the potential for confounding due to the long temporal lag from early-life exposures to adult outcomes. The complex interplay of multiple environmental exposures over time also complicates the interpretation of human studies. These studies have identified critical windows of vulnerability during development when exposures to EDCs alter critical pathways and affect postnatal reproductive health. Contemporaneous exposures can also disrupt the hypothalamic-pituitary-gonadal axis. This paper will review the normal process of puberty in males and summarize human data that suggest potential perturbations in pubertal onset and tempo with early-life exposures to EDCs. PMID:23709001

  2. Male pubertal development: are endocrine-disrupting compounds shifting the norms?

    PubMed

    2013-01-01

    Endocrine-disrupting compounds (EDCs) are synthetic or natural compounds that interfere with endogenous endocrine action. The frequent use of chemicals with endocrine active properties in household products and contamination of soil, water, and food sources by persistent chemical pollutants result in ubiquitous exposures. Wildlife observations and animal toxicological studies reveal adverse effects of EDCs on reproductive health.In humans, a growing number of epidemiological studies report an association with altered pubertal timing and progression. While these data are primarily reported in females,this review will focus on the small number of studies performed in males that report an association of polychlorinated biphenyls with earlier sexual maturity rating and confirm subtle effects of lead, dioxins, and endosulfan on delaying pubertal onset and progression in boys. Recent studies have also demonstrated that EDC exposure may affect pubertal testosterone production without having a noticeable effect on sexual maturity rating.A limitation to understand the effects of EDCs in humans is the potential for confounding due to the long temporal lag from early-life exposures to adult outcomes. The complex interplay of multiple environmental exposures over time also complicates the interpretation of human studies. These studies have identified critical windows of vulnerability during development when exposures to EDCs alter critical pathways and affect postnatal reproductive health. Contemporaneous exposures can also disrupt the hypothalamic-pituitary-gonadal axis. This paper will review the normal process of puberty in males and summarize human data that suggest potential perturbations in pubertal onset and tempo with early-life exposures to EDCs. PMID:23977686

  3. A critical evaluation of arguments opposing male circumcision for HIV prevention in developed countries

    PubMed Central

    Morris, Brian J.; Bailey, Robert C.; Klausner, Jeffrey D.; Leibowitz, Arleen; Wamai, Richard G.; Waskett, Jake H.; Banerjee, Joya; Halperin, Daniel T.; Zoloth, Laurie; Weiss, Helen A.; Hankins, Catherine A.

    2013-01-01

    A potential impediment to evidence-based policy development on medical male circumcision (MC) for HIV prevention in all countries worldwide is the uncritical acceptance by some of arguments used by opponents of this procedure. Here we evaluate recent opinion-pieces of 13 individuals opposed to MC. We find that these statements misrepresent good studies, selectively cite references, some containing fallacious information, and draw erroneous conclusions. In marked contrast, the scientific evidence shows MC to be a simple, low-risk procedure with very little or no adverse long-term effect on sexual function, sensitivity, sensation during arousal or overall satisfaction. Unscientific arguments have been recently used to drive ballot measures aimed at banning MC of minors in the USA, eliminate insurance coverage for medical MC for low-income families, and threaten large fines and incarceration for health care providers. Medical MC is a preventative health measure akin to immunisation, given its protective effect against HIV infection, genital cancers and various other conditions. Protection afforded by neonatal MC against a diversity of common medical conditions starts in infancy with urinary tract infections and extends throughout life. Besides protection in adulthood against acquiring HIV, MC also reduces morbidity and mortality from multiple other sexually transmitted infections (STIs) and genital cancers in men and their female sexual partners. It is estimated that over their lifetime one-third of uncircumcised males will suffer at least one foreskin-related medical condition. The scientific evidence indicates that medical MC is safe and effective. Its favourable risk/benefit ratio and cost/benefit support the advantages of medical MC. PMID:22452415

  4. Reproductive and sexual behaviour development of dam or artificially reared male lambs.

    PubMed

    Damián, Juan Pablo; Beracochea, Florencia; Hötzel, Maria José; Banchero, Georgget; Ungerfeld, Rodolfo

    2015-08-01

    The objective of this study was to determine if artificially reared male lambs differ from those reared by their mothers in their reproductive development and sexual behaviour during the first breeding season and in their serum testosterone to a GnRH challenge at the end of the first breeding season. Lambs were assigned to two experimental groups: 1) artificially reared lambs, separated from their dams 24-36h after birth (Week 0) and fed sheep milk until 10weeks of age (group AR, n=14); and 2) lambs reared by their dams until 10weeks of age (group DR, n=13). Reproductive parameters and sexual behaviour were recorded from Weeks 9 to 39. The GnRH challenge was performed on Week 40. Body weight, scrotal circumference, gonado-somatic index, testosterone concentration and sperm parameters were unaffected by group, but increased with age (P<0.0001). Lambs reared by their mothers had greater values of gonado-somatic index on Weeks 9, 16 and 19 (P<0.05), and tended to reach puberty earlier than AR (22.9±0.7 vs. 25.1±1.1weeks, respectively, P=0.087). Lambs reared by their mothers presented more lateral approaches and mount attempts than AR (P<0.05), and DR lambs presented more mounts on Weeks 32 and 39 than AR (P<0.05). Blood testosterone concentrations 3.5 and 4h after the GnRH challenge were higher in AR than in DR lambs (P<0.05). In conclusion mother rearing promoted sexual behaviour and reproductive performance of male lambs. PMID:25846838

  5. Testicular dysgenesis syndrome and the development and occurrence of male reproductive disorders

    SciTech Connect

    Virtanen, H.E.; Rajpert-De Meyts, E.; Main, K.M.; Skakkebaek, N.E.; Toppari, J. . E-mail: jorma.toppari@utu.fi

    2005-09-01

    Patients with 45,X0/46XY karyotype often present with intersex phenotype and testicular dysgenesis. These patients may also have undescended testes (cryptorchidism), hypospadias and their spermatogenesis is severely disrupted. They have a high risk for testicular cancer. These patients have the most severe form of testicular dysgenesis syndrome (TDS). We have hypothesized that testicular cancer, cryptorchidism, hypospadias and poor spermatogenesis are all signs of a developmental disturbance that was named as testicular dysgenesis syndrome. The hypothesis is based on clinical and epidemiological findings and on biological and experimental evidence. Signs of TDS share several risk factors, such as small birth weight (particularly being small for gestational age), and they are risk factors for each other. All of them have background in fetal development. They show strong epidemiological links so that countries with high incidence of testicular cancer, such as Denmark, tend to also have high prevalence rates of cryptorchidism and hypospadias and poor semen quality. Vice versa, in countries with good male reproductive health, e.g., in Finland, all these aspects are better than in Denmark. Although genetic abnormalities can cause these disorders, in the majority of cases, the reasons remain unclear. Adverse trends in the incidence of male reproductive disorders suggest that environmental and life style factors contribute to the problem. Endocrine disrupters are considered as prime candidates for environmental influence. Fetal exposure to high doses of dibutyl phthalate was shown to cause a TDS-like phenotype in the rats. Studies are underway to assess whether there is any exposure-outcome relation with selected chemicals (persistent organic pollutants, pesticides, phthalates) and cryptorchidism00.

  6. Spatial heterogeneity in response of male greater sage-grouse lek attendance to energy development.

    PubMed

    Gregory, Andrew J; Beck, Jeffrey L

    2014-01-01

    Landscape modification due to rapidly expanding energy development, in particular oil and gas, in the westernUSA, have prompted concerns over how such developments may impact wildlife. One species of conservation concern across much of the Intermountain West is the greater sage-grouse (Centrocercusurophasianus). Sage-grouse have been petitioned for listing under provisions of the Endangered Species Act 7 times and the state of Wyoming alone represents 64% of the extant sage-grouse population in the eastern portion of their range. Consequently, the relationship between sage-grouse populations and oil and gas development in Wyoming is an important component to managing the long-term viability of this species. We used 814 leks from the Wyoming Game and Fish Department's lek survey database and well pad data from the Wyoming Oil and Gas Conservation Commission to evaluate changes in sage-grouse lek counts as a function of oil and gas development since 1991.From 1991-2011 we found that oil and gas well-pad density increased 3.6-fold across the state and was associated with a 24% decline in the number of male sage-grouse. Using a spatial and temporally structured analysis via Geographically Weighted Regression, we found a 1-to-4 year time lag between development density and lek decline. Sage-grouse also responded to development densities at multiple spatial neighborhoods surrounding leks, including broad scales of 10 km. However, sage-grouse lek counts do not always decline as a result of oil and gas development. We found similar development densities resulting in different sage-grouse lek count responses, suggesting that development density alone is insufficient to predict the impacts that oil and gas development have on sage-grouse. Finally, our analysis suggests a maximum development density of 1 well-pad within 2 km of leks to avoid measurable impacts within 1 year, and <6 well-pads within 10 km of leks to avoid delayed impacts. PMID:24918922

  7. Spatial Heterogeneity in Response of Male Greater Sage-Grouse Lek Attendance to Energy Development

    PubMed Central

    Gregory, Andrew J.; Beck, Jeffrey L.

    2014-01-01

    Landscape modification due to rapidly expanding energy development, in particular oil and gas, in the westernUSA, have prompted concerns over how such developments may impact wildlife. One species of conservation concern across much of the Intermountain West is the greater sage-grouse (Centrocercusurophasianus). Sage-grouse have been petitioned for listing under provisions of the Endangered Species Act 7 times and the state of Wyoming alone represents 64% of the extant sage-grouse population in the eastern portion of their range. Consequently, the relationship between sage-grouse populations and oil and gas development in Wyoming is an important component to managing the long-term viability of this species. We used 814 leks from the Wyoming Game and Fish Department's lek survey database and well pad data from the Wyoming Oil and Gas Conservation Commission to evaluate changes in sage-grouse lek counts as a function of oil and gas development since 1991.From 1991–2011 we found that oil and gas well-pad density increased 3.6-fold across the state and was associated with a 24% decline in the number of male sage-grouse. Using a spatial and temporally structured analysis via Geographically Weighted Regression, we found a 1-to-4 year time lag between development density and lek decline. Sage-grouse also responded to development densities at multiple spatial neighborhoods surrounding leks, including broad scales of 10 km. However, sage-grouse lek counts do not always decline as a result of oil and gas development. We found similar development densities resulting in different sage-grouse lek count responses, suggesting that development density alone is insufficient to predict the impacts that oil and gas development have on sage-grouse. Finally, our analysis suggests a maximum development density of 1 well-pad within 2 km of leks to avoid measurable impacts within 1 year, and <6 well-pads within 10 km of leks to avoid delayed impacts. PMID:24918922

  8. Androgen action during male sex differentiation includes suppression of cranial suspensory ligament development.

    PubMed

    Emmen, J M; McLuskey, A; Grootegoed, J A; Brinkmann, A O

    1998-05-01

    The cranial suspensory ligament is located on the border of the cranial (mesonephric) mesentery in adult female mammals, which runs between the cranial pole of the internal genitalia and the dorsal abdominal wall. Absence of the cranial suspensory ligament in male mammals depends upon exposure of its primordium to fetal testicular androgens and is a prerequisite for testis descent. Female rats were exposed to 5alpha-dihydrotestosterone propionate at different stages of genital development, and cranial suspensory ligament development was studied in neonatal and in adult animals. Androgens suppressed cranial suspensory ligament development when exposure started during the early stages of genital development, until day 19 postconception (pc). Androgen receptor expression was immunohistochemically detected in the cranial mesentery of both sexes from day 16 pc onwards. A decrease of androgen receptor expression in female fetuses from day 18 pc onwards coincided with the appearance of a differentiated cranial suspensory ligament, as evidenced by the expression of two cell differentiation markers: alpha-smooth muscle (alpha-SM) actin and desmin. alpha-SM actin was located on the outer border of the cranial mesentery of both sexes at day 17 pc, and expression increased only in female fetuses. On day 19 pc, desmin expression was also detectable in the a-SM actin-positive cells. Proliferation and apoptosis indices of cells in the cranial mesentery, as analysed by 5'-bromodeoxyuridine incorporation and by detection of DNA strand breaks (TUNEL method) respectively, did not show any difference between the sexes, neither on day 17 nor on day 18 pc. Since primordial cells of the cranial suspensory ligament highly express the androgen receptor during the period of gestation when androgens can suppress cranial suspensory development, altered morphogenesis of these cells may be a direct consequence of androgen action. PMID:9647559

  9. A Preliminary Study of College Room-Bound Male Students: Concept Exploration and Instrument Development

    ERIC Educational Resources Information Center

    Chou, Chien; Wu, Huan-Chueh; Wang, Mei-Hung

    2011-01-01

    From time to time, cases of over-dependence on the Internet have been observed on college campuses. Some students, especially male students, remain connected to the Internet as long as they are awake. In Chinese, the emerging term (chai-nan) is used to describe this kind of young man, meaning "room-bound male," who seldom leaves his residence and…

  10. Teaching Young Men in Correctional Education: Issues and Interventions in Male Identity Development

    ERIC Educational Resources Information Center

    Pleasants, Robert K.

    2007-01-01

    Because of the disproportionate number of violent males in American society (particularly in the juvenile justice system), teachers and researchers should afford greater scrutiny to the relationship between masculinity and violence. Incarcerated male youth have unique issues not only because of their incarceration, but also because of their…

  11. Lifting Up Our Kings: Developing Black Males in a Positive and Safe Space

    ERIC Educational Resources Information Center

    Chatmon, Chris; Gray, Richard

    2015-01-01

    African American males are three times more likely than their White male counterparts to be suspended or expelled in public schools. Changing these odds requires not only addressing disparities in discipline practices, but also lifting up a new narrative of hope, possibility, and brilliance so that young Black men can see and realize their…

  12. Effect of Marine Collagen Peptides on Physiological and Neurobehavioral Development of Male Rats with Perinatal Asphyxia

    PubMed Central

    Xu, Linlin; Dong, Wenhong; Zhao, Jie; Xu, Yajun

    2015-01-01

    Asphyxia during delivery produces long-term deficits in brain development. We investigated the neuroprotective effects of marine collagen peptides (MCPs), isolated from Chum Salmon skin by enzymatic hydrolysis, on male rats with perinatal asphyxia (PA). PA was performed by immersing rat fetuses with uterine horns removed from ready-to-deliver rats into a water bath for 15 min. Caesarean-delivered pups were used as controls. PA rats were intragastrically administered with 0.33 g/kg, 1.0 g/kg and 3.0 g/kg body weight MCPs from postnatal day 0 (PND 0) till the age of 90-days. Behavioral tests were carried out at PND21, PND 28 and PND 90. The results indicated that MCPs facilitated early body weight gain of the PA pups, however had little effects on early physiological development. Behavioral tests revealed that MCPs facilitated long-term learning and memory of the pups with PA through reducing oxidative damage and acetylcholinesterase (AChE) activity in the brain, and increasing hippocampus phosphorylated cAMP-response element binding protein (p-CREB) and brain derived neurotrophic factor (BDNF) expression. PMID:26058015

  13. Developing an AIDS prevention intervention for incarcerated male adolescents in Brazil.

    PubMed

    Peres, Camila Alves; Peres, Rodrigo Alves; da Silveira, Fernando; Paiva, Vera; Hudes, Esther Sid; Hearst, Norman

    2002-10-01

    The objective of this study was to investigate knowledge, attitudes, and practices regarding AIDS among incarcerated male adolescents in Brazil and to develop an AIDS prevention intervention for this population. A questionnaire administered to 275 boys in São Paulo covered demographic and social characteristics, drugs, and HIV risk perception and behavior. Subsequently, we collected qualitative data on the development and implementation of a prevention program. Ninety-eight percent of adolescents were sexually experienced, most initiating by age 13; 22% were fathers. Injection drug use was reported by 5.5%, 12% had exchanged sex for money, 35% had more than 15 partners and 8% had homosexual experience. Although 72% had used condoms, only 9% used them consistently, and only 35% used one in their last intercourse before incarceration. Predictors of condom use included carrying condoms and endorsing the statement "I would use condoms with my girlfriend." Many said their lives include other risks more important than AIDS, such as survival in the crime scene. Initial efforts at prevention based on commonly used approaches of providing information to guide future rational decisions generated limited participation. However, when we worked with them to develop interventions based on their interests and needs, using modalities such as music, hip-hop arts, graffiti, and helping them to create an AIDS prevention compact disk, they responded with enthusiasm. These incarcerated adolescents are at extremely high social risk and report high levels of risk behavior for HIV infection. Interventions for these youth were better received when developed in collaboration with them and based on their beliefs, aspirations, and culture. The intervention that resulted went beyond AIDS to include issues such as violence, drugs, sexuality and human rights. PMID:12413191

  14. The Impact of Racial Identity and Consciousness Development of African American Male Academic Achievement: Implications for Counseling

    ERIC Educational Resources Information Center

    Whiteside, Dora

    2007-01-01

    The purpose of this study was to examine the effect of racial identity/consciousness development on the academic achievement of African American male college freshmen. In the late 1900s Black identity models were developed to help African Americans grasp hold of who they were, as they lived in the residues of the peculiar institution of slavery.…

  15. GermlncRNA: a unique catalogue of long non-coding RNAs and associated regulations in male germ cell development.

    PubMed

    Luk, Alfred Chun-Shui; Gao, Huayan; Xiao, Sizhe; Liao, Jinyue; Wang, Daxi; Tu, Jiajie; Rennert, Owen M; Chan, Wai-Yee; Lee, Tin-Lap

    2015-01-01

    Spermatogenic failure is a major cause of male infertility, which affects millions of couples worldwide. Recent discovery of long non-coding RNAs (lncRNAs) as critical regulators in normal and disease development provides new clues for delineating the molecular regulation in male germ cell development. However, few functional lncRNAs have been characterized to date. A major limitation in studying lncRNA in male germ cell development is the absence of germ cell-specific lncRNA annotation. Current lncRNA annotations are assembled by transcriptome data from heterogeneous tissue sources; specific germ cell transcript information of various developmental stages is therefore under-represented, which may lead to biased prediction or fail to identity important germ cell-specific lncRNAs. GermlncRNA provides the first comprehensive web-based and open-access lncRNA catalogue for three key male germ cell stages, including type A spermatogonia, pachytene spermatocytes and round spermatids. This information has been developed by integrating male germ transcriptome resources derived from RNA-Seq, tiling microarray and GermSAGE. Characterizations on lncRNA-associated regulatory features, potential coding gene and microRNA targets are also provided. Search results from GermlncRNA can be exported to Galaxy for downstream analysis or downloaded locally. Taken together, GermlncRNA offers a new avenue to better understand the role of lncRNAs and associated targets during spermatogenesis. Database URL: http://germlncrna.cbiit.cuhk.edu.hk/ PMID:25982314

  16. GermlncRNA: a unique catalogue of long non-coding RNAs and associated regulations in male germ cell development

    PubMed Central

    Luk, Alfred Chun-Shui; Gao, Huayan; Xiao, Sizhe; Liao, Jinyue; Wang, Daxi; Tu, Jiajie; Rennert, Owen M.; Chan, Wai-Yee; Lee, Tin-Lap

    2015-01-01

    Spermatogenic failure is a major cause of male infertility, which affects millions of couples worldwide. Recent discovery of long non-coding RNAs (lncRNAs) as critical regulators in normal and disease development provides new clues for delineating the molecular regulation in male germ cell development. However, few functional lncRNAs have been characterized to date. A major limitation in studying lncRNA in male germ cell development is the absence of germ cell-specific lncRNA annotation. Current lncRNA annotations are assembled by transcriptome data from heterogeneous tissue sources; specific germ cell transcript information of various developmental stages is therefore under-represented, which may lead to biased prediction or fail to identity important germ cell-specific lncRNAs. GermlncRNA provides the first comprehensive web-based and open-access lncRNA catalogue for three key male germ cell stages, including type A spermatogonia, pachytene spermatocytes and round spermatids. This information has been developed by integrating male germ transcriptome resources derived from RNA-Seq, tiling microarray and GermSAGE. Characterizations on lncRNA-associated regulatory features, potential coding gene and microRNA targets are also provided. Search results from GermlncRNA can be exported to Galaxy for downstream analysis or downloaded locally. Taken together, GermlncRNA offers a new avenue to better understand the role of lncRNAs and associated targets during spermatogenesis. Database URL: http://germlncrna.cbiit.cuhk.edu.hk/ PMID:25982314

  17. Male reproductive development: gene expression profiling of maize anther and pollen ontogeny

    PubMed Central

    Ma, Jiong; Skibbe, David S; Fernandes, John; Walbot, Virginia

    2008-01-01

    Background During flowering, central anther cells switch from mitosis to meiosis, ultimately forming pollen containing haploid sperm. Four rings of surrounding somatic cells differentiate to support first meiosis and later pollen dispersal. Synchronous development of many anthers per tassel and within each anther facilitates dissection of carefully staged maize anthers for transcriptome profiling. Results Global gene expression profiles of 7 stages representing 29 days of anther development are analyzed using a 44 K oligonucleotide array querying approximately 80% of maize protein-coding genes. Mature haploid pollen containing just two cell types expresses 10,000 transcripts. Anthers contain 5 major cell types and express >24,000 transcript types: each anther stage expresses approximately 10,000 constitutive and approximately 10,000 or more transcripts restricted to one or a few stages. The lowest complexity is present during meiosis. Large suites of stage-specific and co-expressed genes are identified through Gene Ontology and clustering analyses as functional classes for pre-meiotic, meiotic, and post-meiotic anther development. MADS box and zinc finger transcription factors with constitutive and stage-limited expression are identified. Conclusions We propose that the extensive gene expression of anther cells and pollen represents the key test of maize genome fitness, permitting strong selection against deleterious alleles in diploid anthers and haploid pollen. Because flowering plants show a substantial bias for male-sterile compared to female-sterile mutations, we propose that this fitness test is general. Because both somatic and germinal cells are transcriptionally quiescent during meiosis, we hypothesize that successful completion of meiosis is required to trigger maturation of anther somatic cells. PMID:19099579

  18. Development and Internal Validation of the Male Osteoporosis Risk Estimation Score

    PubMed Central

    Shepherd, Angela J.; Cass, Alvah R.; Carlson, Carol A.; Ray, Laura

    2007-01-01

    PURPOSE We wanted to develop and validate a clinical prediction rule to identify men at risk for osteoporosis and subsequent hip fracture who might benefit from dual-energy x-ray absorptiometry (DXA). METHODS We used risk factor data from the National Health and Nutrition Examination Survey III to develop a best fitting multivariable logistic regression model in men aged 50 years and older randomized to either the development (n = 1,497) or validation (n = 1,498) cohorts. The best fitting model was transformed into a simplified scoring algorithm, the Male Osteoporosis Risk Estimation Score (MORES). We validated the MORES, comparing sensitivity, specificity, and area under the receiver operating characteristics (ROC) curve in the 2 cohorts and assessed clinical utility with an analysis of the number needed-to-screen (NNS) to prevent 1 additional hip fracture. RESULTS The MORES included 3 variables—age, weight, and history of chronic obstructive pulmonary disease—and showed excellent predictive validity in the validation cohort. A score of 6 or greater yielded an overall sensitivity of 0.93 (95% CI, 0.85–0.97), a specificity of 0.59 (95% CI, 0.56–0.62), and an area under the ROC curve of 0.832 (95% CI, 0.807–0.858). The overall NNS to prevent 1 additional hip fracture was 279 in a cohort of men representative of the US population. CONCLUSIONS Osteoporosis is a major predictor of hip fractures. Experts believe bisphosphonate treatment in men should yield results similar to that in women and reduce hip fracture rates associated with osteoporosis. In men aged 60 years and older, the MORES is a simple approach to identify men at risk for osteoporosis and refer them for confirmatory DXA scans. PMID:18025492

  19. Callose synthesis during reproductive development in monocotyledonous and dicotyledonous plants

    PubMed Central

    Shi, Xiao; Han, Xiao; Lu, Tie-gang

    2016-01-01

    Callose, a linear β-1,3-glucan molecule, plays important roles in a variety of processes in angiosperms, including development and the response to biotic and abiotic stress. Despite the importance of callose deposition, our understanding of the roles of callose in rice reproductive development and the regulation of callose biosynthesis is limited. GLUCAN SYNTHASE-LIKE genes encode callose synthases (GSLs), which function in the production of callose at diverse sites in plants. Studies have shown that callose participated in plant reproductive development, and that the timely deposition and degradation of callose were essential for normal male gametophyte development. In this mini-review, we described conserved sequences found in GSL family proteins from monocotyledonous (Oryza sativa and Zea mays) and dicotyledonous (Arabidopsis thaliana and Glycine max) plants. We also describe the latest findings on callose biosynthesis and deposition during reproductive development and discuss future challenges in unraveling the mechanism of callose synthesis and deposition in higher plants. PMID:26451709

  20. Callose synthesis during reproductive development in monocotyledonous and dicotyledonous plants.

    PubMed

    Shi, Xiao; Han, Xiao; Lu, Tie-Gang

    2016-02-01

    Callose, a linear β-1,3-glucan molecule, plays important roles in a variety of processes in angiosperms, including development and the response to biotic and abiotic stress. Despite the importance of callose deposition, our understanding of the roles of callose in rice reproductive development and the regulation of callose biosynthesis is limited. GLUCAN SYNTHASE-LIKE genes encode callose synthases (GSLs), which function in the production of callose at diverse sites in plants. Studies have shown that callose participated in plant reproductive development, and that the timely deposition and degradation of callose were essential for normal male gametophyte development. In this mini-review, we described conserved sequences found in GSL family proteins from monocotyledonous (Oryza sativa and Zea mays) and dicotyledonous (Arabidopsis thaliana and Glycine max) plants. We also describe the latest findings on callose biosynthesis and deposition during reproductive development and discuss future challenges in unraveling the mechanism of callose synthesis and deposition in higher plants. PMID:26451709

  1. Development and Psychometric Evaluation of the Gay Male Sexual Difficulties Scale.

    PubMed

    McDonagh, Lorraine K; Stewart, Ian; Morrison, Melanie A; Morrison, Todd G

    2016-08-01

    Sexual difficulties (i.e., disturbances in normal sexual responding) have the potential to significantly and negatively affect men's social and psychological well-being. However, a review of published measurement tools indicates that most have limited applicability to gay men, and none offer a nuanced understanding of sexual difficulties, as experienced by members of this population. To address this omission, the Gay Male Sexual Difficulties Scale (GMSDS) was developed using a sequential mixed-methods approach. The 25-item GMSDS uses a 6-point frequency Likert-type response format and examines: difficulties with receptive and insertive anal intercourse (5 items each); erectile difficulties (4 items); foreskin difficulties (4 items); body embarrassment (4 items); and seminal fluid concerns (3 items). The measure's scale score dimensionality, assessed using both exploratory and confirmatory factor analyses, as well as scale score reliability and validity (e.g., known-groups and convergent) was tested and deemed to be satisfactory. Limitations of the current series of studies and directions for future research are discussed. PMID:26728054

  2. Effects of Nuclear Genomes on Anther Development in Cytoplasmic Male Sterile Chicories (Cichorium intybus L.): Morphological Analysis

    PubMed Central

    Habarugira, Ildephonse; Hendriks, Theo; Quillet, Marie-Christine; Hilbert, Jean-Louis; Rambaud, Caroline

    2015-01-01

    The Cichorium intybus flower development in fertile, cytoplasmic male sterility (CMS 524) and various phenotypes carrying the 524 male sterile cytoplasm was investigated macroscopically and by light microscopy. The development was similar in fertile and in male sterile florets up to meiosis, and then it was affected in anther wall structure and pollen grain development in male sterile floret. In the male sterile plants, the tapetum intrusion after meiosis was less remarkable, the microspores started to abort at vacuolate stage, the connective tissue collapsed, and endothecium failed to expand normally and did not undergo cell wall lignification, which prevented anther opening since the septum and stomium were not disrupted. Crosses undertaken in order to introduce the CMS 524 into two different nuclear backgrounds gave rise to morphologically diversified progenies due to different nuclear-mitochondrial interactions. Macroscopic and cytological investigations showed that pollen-donor plants belonging to Jupiter population had potential capacity to restore fertility while the CC line could be considered as a sterility maintainer. PMID:25861678

  3. Effects of nuclear genomes on anther development in cytoplasmic male sterile chicories (Cichorium intybus L.): morphological analysis.

    PubMed

    Habarugira, Ildephonse; Hendriks, Theo; Quillet, Marie-Christine; Hilbert, Jean-Louis; Rambaud, Caroline

    2015-01-01

    The Cichorium intybus flower development in fertile, cytoplasmic male sterility (CMS 524) and various phenotypes carrying the 524 male sterile cytoplasm was investigated macroscopically and by light microscopy. The development was similar in fertile and in male sterile florets up to meiosis, and then it was affected in anther wall structure and pollen grain development in male sterile floret. In the male sterile plants, the tapetum intrusion after meiosis was less remarkable, the microspores started to abort at vacuolate stage, the connective tissue collapsed, and endothecium failed to expand normally and did not undergo cell wall lignification, which prevented anther opening since the septum and stomium were not disrupted. Crosses undertaken in order to introduce the CMS 524 into two different nuclear backgrounds gave rise to morphologically diversified progenies due to different nuclear-mitochondrial interactions. Macroscopic and cytological investigations showed that pollen-donor plants belonging to Jupiter population had potential capacity to restore fertility while the CC line could be considered as a sterility maintainer. PMID:25861678

  4. The mouse homolog of Drosophila Vasa is required for the development of male germ cells

    PubMed Central

    Tanaka, Satomi S.; Toyooka, Yayoi; Akasu, Ryuko; Katoh-Fukui, Yuko; Nakahara, Yoko; Suzuki, Rika; Yokoyama, Minesuke; Noce, Toshiaki

    2000-01-01

    Restricted expression of a mouse Vasa homolog gene (Mvh) expression is first detected in primordial germ cells (PGCs) after colonization of the genital ridges. Subsequently, Mvh is maintained until postmeiotic germ cells are formed. Here, we demonstrate that male mice homozygous for a targeted mutation of Mvh exhibit a reproductive deficiency. Male homozygotes produce no sperm in the testes, where premeiotic germ cells cease differentiation by the zygotene stage and undergo apoptotic death. In addition, the proliferation of PGCs that colonize homozygous male gonads is significantly hampered, and OCT-3/4 expression appears to be reduced. These results indicate that the loss of Mvh function causes a deficiency in the proliferation and differentiation of mouse male germ cells. PMID:10766740

  5. Wnt and EGF pathways act together to induce C. elegans male hook development

    PubMed Central

    Yu, Hui; Seah, Adeline; Herman, Michael A.; Ferguson, Edwin L.; Horvitz, H. Robert; Sternberg, Paul W.

    2009-01-01

    Comparative studies of vulva development between Caenorhabditis elegans and other nematode species have provided some insight into the evolution of patterning networks. However, molecular genetic details are available only in C. elegans and Pristionchus pacificus. To extend our knowledge on the evolution of patterning networks, we studied the C. elegans male hook competence group (HCG), an equivalence group that has similar developmental origins to the vulval precursor cells (VPCs), which generate the vulva in the hermaphrodite. Similar to VPC fate specification, each HCG cell adopts one of three fates (1°, 2°, 3°), and 2°HCG fate specification is mediated by LIN-12/Notch. We show that 2° HCG specification depends on the presence of a cell with the 1° fate. We also provide evidence that Wnt signaling via the Frizzled-like Wnt receptor LIN-17 act to specify the 1° and 2° HCG fate. A requirement for EGF signaling during 1° fate specification is seen only when LIN-17 activity is compromised. In addition, activation of the EGF pathway decreases dependence on LIN-17 and causes ectopic hook development. Our results suggest that WNT plays a more significant role than EGF signaling in specifying HCG fates, whereas in VPC specification EGF signaling is the major inductive signal. Nonetheless, the overall logic is similar in the VPCs and the HCG: EGF and/or WNT induce a 1° lineage, and LIN-12/NOTCH induces a 2° lineage. Wnt signaling is also required for execution of the 1° and 2°HCG lineages. lin-17 and bar-1/β-catenin are preferentially expressed in the presumptive 1° cell P11.p. The dynamic subcellular localization of BAR-1–GFP in P11.p is concordant with the timing of HCG fate determination. PMID:19154732

  6. The male genital system of the cellar spider Pholcus phalangioides (Fuesslin, 1775) (Pholcidae, Araneae): development of spermatozoa and seminal secretion

    PubMed Central

    Michalik, Peter; Uhl, Gabriele

    2005-01-01

    Background Most arthropods pass through several molting stages (instars) before reaching sexual maturity. In spiders, very little is known about the male genital system, its development and seminal secretions. For example, it is unknown whether spermatozoa exist prior to-, or only after the final molt. Likewise, it is unclear whether sperm are produced throughout male adulthood or only once in a lifetime, as is whether seminal secretions contain factors capable of manipulating female behavior. In order to shed light on these aspects of the reproductive biology of spiders, we investigated the male genital system of the common cellar spider Pholcus phalangioides, with special emphasis on its development and seminal secretions. Results Testes already display all stages of spermatogenesis in subadult males (about four weeks before the final molt). Their vasa deferentia possess proximally a very voluminous lumen containing dense seminal fluid and few spermatozoa, whereas the distal part is seemingly devoid of contents. Spermatoza of P. phalangioides are typical cleistospermia with individual secretion sheaths. In male stages approximately two weeks prior to the final molt, the lumina of the testes are wider and filled with a dense secretion. The wide, proximal portion of the vasa deferentia is filled with secretion and a large number of spermatozoa, and the narrow distal part also contains secretion. In adult males, the wide lumina of the testes are packed with spermatozoa and secretions. The latter are produced by the somatic cells that bear microvilli and contain many vesicles. The lumina of the vasa deferentia are narrow and filled with spermatozoa and secretions. We could identify a dense matrix of secretion consisting of mucosubstances and at least three types of secretion droplets, likely consisting of proteinaceous substances. Conclusion This study reveals that spermatogenesis begins weeks before maturity and takes place continuously in the long-lived males of P

  7. The role of Arabidopsis thaliana NAR1, a cytosolic iron-sulfur cluster assembly component, in gametophytic gene expression and oxidative stress responses in vegetative tissue.

    PubMed

    Nakamura, Miyuki; Buzas, Diana Mihaela; Kato, Akira; Fujita, Masahiro; Kurata, Nori; Kinoshita, Tetsu

    2013-09-01

    Iron-sulfur proteins have iron-sulfur clusters as a prosthetic group and are responsible for various cellular processes, including general transcriptional regulation, photosynthesis and respiration. The cytosolic iron-sulfur assembly (CIA) pathway of yeast has been shown to be responsible for regulation of iron-sulfur cluster assembly in both the cytosol and the nucleus. However, little is known about the roles of this pathway in multicellular organisms. In a forward genetic screen, we identified an Arabidopsis thaliana mutant with impaired expression of the endosperm-specific gene Flowering Wageningen (FWA). To characterize this mutant, we carried out detailed phenotypic and genetic analyses during reproductive and vegetative development. The mutation affects NAR1, which encodes a homolog of a yeast CIA pathway component. Comparison of embryo development in nar1-3 and other A. thaliana mutants affected in the CIA pathway showed that the embryos aborted at a similar stage, suggesting that this pathway potentially functions in early seed development. Transcriptome analysis of homozygous viable nar1-4 seedlings showed transcriptional repression of a subset of genes involved in 'iron ion transport' and 'response to nitrate'. nar1-4 also exhibited resistance to the herbicide paraquat. Our results indicate that A. thaliana NAR1 has various functions including transcriptional regulation in gametophytes and abiotic stress responses in vegetative tissues. PMID:23734982

  8. The MSP1 Gene Is Necessary to Restrict the Number of Cells Entering into Male and Female Sporogenesis and to Initiate Anther Wall Formation in Rice

    PubMed Central

    Nonomura, Ken-Ichi; Miyoshi, Kazumaru; Eiguchi, Mitsugu; Suzuki, Tadzunu; Miyao, Akio; Hirochika, Hirohiko; Kurata, Nori

    2003-01-01

    The function of the novel gene MSP1 (MULTIPLE SPOROCYTE), which controls early sporogenic development, was elucidated by characterizing a retrotransposon-tagged mutation of rice. The MSP1 gene encoded a Leu-rich repeat receptor–like protein kinase. The msp1 mutation gave rise to an excessive number of both male and female sporocytes. In addition, the formation of anther wall layers was disordered and the tapetum layer was lost completely. Although the mutation never affected homologous chromosome pairing and chiasma maintenance, the development of pollen mother cells was arrested at various stages of meiotic prophase I, which resulted in complete male sterility. Meanwhile, plural megaspore mother cells in a mutant ovule generated several megaspores, underwent gametogenesis, and produced germinable seeds when fertilized with wild-type pollen despite disorganized female gametophytes. In situ expression of MSP1 was detected in surrounding cells of male and female sporocytes and some flower tissues, but never in the sporocytes themselves. These results suggest that the MSP1 product plays crucial roles in restricting the number of cells entering into male and female sporogenesis and in initiating anther wall formation in rice. PMID:12897248

  9. Intellectual development is positively related to intrinsic motivation and course grades for female but not male students.

    PubMed

    Cortright, Ronald N; Lujan, Heidi L; Cox, Julie H; Cortright, Maria A; Langworthy, Brandon M; Petta, Lorene M; Tanner, Charles J; DiCarlo, Stephen E

    2015-09-01

    We hypothesized that the intellectual development of students, i.e., their beliefs about the nature of knowledge and learning, affects their intrinsic motivation and class performance. Specifically, we hypothesized that students with low intellectual development (i.e., the naive beliefs that knowledge is simple, absolute, and certain) have low intrinsic motivation and low class performance, whereas students with high intellectual development (i.e., more sophisticated beliefs that knowledge is complex, tentative, and evolving) have high intrinsic motivation and class performance. To test this hypothesis, we administered the Learning Context Questionnaire to measure intellectual development. In addition, we administered the Intrinsic Motivation Inventory to assess our students' intrinsic motivation. Furthermore, we performed regression analyses between intellectual development with both intrinsic motivation and class performance. The results document a positive relationship among intellectual development, intrinsic motivation, and class performance for female students only. In sharp contrast, there was a negative relationship between intellectual development, intrinsic motivation, and class performance for male students. The slope comparisons documented significant differences in the slopes relating intellectual development, intrinsic motivation, and class performance between female and male students. Thus, female students with more sophisticated beliefs that knowledge is personally constructed, complex, and evolving had higher intrinsic motivation and class performance. In contrast, male students with the naive beliefs that the structure of knowledge is simple, absolute, and certain had higher levels of intrinsic motivation and class performance. The results suggest that sex influences intellectual development, which has an effect on intrinsic motivation for learning a specific topic. PMID:26330034

  10. Convergent evolution at the gametophytic self-incompatibility system in Malus and Prunus.

    PubMed

    Aguiar, Bruno; Vieira, Jorge; Cunha, Ana E; Fonseca, Nuno A; Iezzoni, Amy; van Nocker, Steve; Vieira, Cristina P

    2015-01-01

    S-RNase-based gametophytic self-incompatibility (GSI) has evolved once before the split of the Asteridae and Rosidae. This conclusion is based on the phylogenetic history of the S-RNase that determines pistil specificity. In Rosaceae, molecular characterizations of Prunus species, and species from the tribe Pyreae (i.e., Malus, Pyrus, Sorbus) revealed different numbers of genes determining S-pollen specificity. In Prunus only one pistil and pollen gene determine GSI, while in Pyreae there is one pistil but multiple pollen genes, implying different specificity recognition mechanisms. It is thus conceivable that within Rosaceae the genes involved in GSI in the two lineages are not orthologous but possibly paralogous. To address this hypothesis we characterised the S-RNase lineage and S-pollen lineage genes present in the genomes of five Rosaceae species from three genera: M. × domestica (apple, self-incompatible (SI); tribe Pyreae), P. persica (peach, self-compatible (SC); Amygdaleae), P. mume (mei, SI; Amygdaleae), Fragaria vesca (strawberry, SC; Potentilleae), and F. nipponica (mori-ichigo, SI; Potentilleae). Phylogenetic analyses revealed that the Malus and Prunus S-RNase and S-pollen genes belong to distinct gene lineages, and that only Prunus S-RNase and SFB-lineage genes are present in Fragaria. Thus, S-RNase based GSI system of Malus evolved independently from the ancestral system of Rosaceae. Using expression patterns based on RNA-seq data, the ancestral S-RNase lineage gene is inferred to be expressed in pistils only, while the ancestral S-pollen lineage gene is inferred to be expressed in tissues other than pollen. PMID:25993016

  11. Convergent Evolution at the Gametophytic Self-Incompatibility System in Malus and Prunus

    PubMed Central

    Cunha, Ana E.; Fonseca, Nuno A.; Iezzoni, Amy; van Nocker, Steve; Vieira, Cristina P.

    2015-01-01

    S-RNase-based gametophytic self-incompatibility (GSI) has evolved once before the split of the Asteridae and Rosidae. This conclusion is based on the phylogenetic history of the S-RNase that determines pistil specificity. In Rosaceae, molecular characterizations of Prunus species, and species from the tribe Pyreae (i.e., Malus, Pyrus, Sorbus) revealed different numbers of genes determining S-pollen specificity. In Prunus only one pistil and pollen gene determine GSI, while in Pyreae there is one pistil but multiple pollen genes, implying different specificity recognition mechanisms. It is thus conceivable that within Rosaceae the genes involved in GSI in the two lineages are not orthologous but possibly paralogous. To address this hypothesis we characterised the S-RNase lineage and S-pollen lineage genes present in the genomes of five Rosaceae species from three genera: M. × domestica (apple, self-incompatible (SI); tribe Pyreae), P. persica (peach, self-compatible (SC); Amygdaleae), P. mume (mei, SI; Amygdaleae), Fragaria vesca (strawberry, SC; Potentilleae), and F. nipponica (mori-ichigo, SI; Potentilleae). Phylogenetic analyses revealed that the Malus and Prunus S-RNase and S-pollen genes belong to distinct gene lineages, and that only Prunus S-RNase and SFB-lineage genes are present in Fragaria. Thus, S-RNase based GSI system of Malus evolved independently from the ancestral system of Rosaceae. Using expression patterns based on RNA-seq data, the ancestral S-RNase lineage gene is inferred to be expressed in pistils only, while the ancestral S-pollen lineage gene is inferred to be expressed in tissues other than pollen. PMID:25993016

  12. Biological Maturation in Adolescence and the Development of Drinking Habits and Alcohol Abuse among Young Males: A Prospective Longitudinal Study.

    ERIC Educational Resources Information Center

    Andersson, Tommy; Magnusson, David

    1990-01-01

    The relationship between biological maturation, as evidenced by skeletal growth, during adolescence and the development of drinking habits and alcohol abuse was studied for a representative group of Swedish males (N=88). Early and late maturers had more advanced drinking habits at age 14 years than did normally maturing subjects. (TJH)

  13. Gestational Atrazine Exposure: Effects on Male Reproductive Development and Metabolite Distribution in the Dam, Fetus, and Neonate

    EPA Science Inventory

    Few studies have investigated the long-term effects of atrazine (ATR)following in utero exposure. We evaluated the effects of gestational exposure of Sprague Dawley dams to ATR (0, 1, 5.20, or 100 mg/Kg-d) on the reproductive development of male offspring. We also quantified the...

  14. EFFECTS OF PRENATAL TESTOSTERONE PROPIONATE ON THE SEXUAL DEVELOPMENT OF MALE AND FEMALE RATS: A DOSE-RESPONSE STUDY

    EPA Science Inventory

    Effects of Prenatal Testosterone Propionate on the Sexual Development of Male and Female Rats: A Dose-Response Study
    Cynthia J. Wolf1,2, Andrew Hotchkiss3, Joseph S. Ostby1, Gerald A. LeBlanc2 and
    L. Earl Gray1,4, Jr.

    ABSTRACT
    Testosterone plays a major role in ...

  15. EFFECTS OF PRENATAL TESTOSTERONE PROPIONATE ON SEXUAL DEVELOPMENT OF MALE AND FEMALE RATS: A DOSE-RESPONSE STUDY

    EPA Science Inventory

    Effects of Prenatal Testosterone Propionate on Sexual Development of Male and Female Rats: A Dose-Response Study
    Cynthia Wolf1,2, Joe Ostby1*, Andrew Hotchkiss3, Gerald LeBlanc2, and L. Earl Gray, Jr.1
    1USEPA, NHEERL, Reproductive Toxicology Division, RTP, NC; 2Dept. of To...

  16. PERIPUBERTAL DI (2-ETHYLHEXYL) PHTHALATE EXPOSURE INHIBITS ANDROGEN SENSITIVE TISSUE DEVELOPMENT AND DELAYS PUBERTY IN MALE SPRAGUE-DAWLEY RATS

    EPA Science Inventory

    PERIPUBERTAL DI (2-ETHYLHEXYL) PHTHALATE EXPOSURE INHIBITS ANDROGEN SENSITIVE TISSUE DEVELOPMENT AND DELAYS PUBERTY IN MALE SPRAGUE-DAWLEY RATS

    Nigel Noriega, Jonathan Furr, Christy Lambright, Vickie Wilson, L. Earl Gray Jr.

    The plasticizer Di (2-ethylhexyl) phtha...

  17. EFFECTS OF PRENATAL TESTOSTERONE PROPIONATE AND VINCLOZOLIN ON PERINATAL AND INFANTILE DEVELOPMENT OF MALE AND FEMALE RATS

    EPA Science Inventory

    Effects of Prenatal Testosterone Propionate and Vinclozolin on Perinatal and Infantile Development of Male and Female Rats
    Cynthia Wolf1,2, Jonathan Furr1, Gerald A. LeBlanc2, and L. Earl Gray, Jr.1
    1USEPA, NHEERL, RTD, EB, RTP, NC 27711, 2Dept. of Environmental and Molecu...

  18. Isolation of candidate genes for apomictic development in buffelgrass (Pennisetum ciliare)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Asexual reproduction through seeds, or apomixis, is a process that holds much promise for agricultural advances. However, the molecular mechanisms underlying apomixis are currently poorly understood. To identify genes related to female gametophyte development in apomictic ovaries of buffelgrass (P...

  19. Evaluation of the effect of clinostat rotation on pollen germination and tube development as a tool for selection of plants in Space

    NASA Astrophysics Data System (ADS)

    De Micco, Veronica; Scala, Michele; Aronne, Giovanna

    2006-05-01

    The choice of species and cultivar on which rely to sustain Close Loop Environmental Systems is generally approached by analysing the behaviour of plants in presence of stress (sporophytic selection). In this paper, we investigated the possibility to conduct the selection among genotypes in Space through the male gametophytic selection. Thus, we studied the effect of simulated microgravity on pollen germination and tube development of both woody and herbaceous crop species: Prunus armeniaca (apricot), P. dulcis (almond), Malus domestica (apple) and Vicia faba (broad bean). Pollen collected from just bloomed flowers was assessed for viability and incubated on the optimal growing medium in petri dishes both on a uni-axial clinostat and stationary in 1g. Then, pollen was observed under a light microscope to detect percent germination and growth direction. Histochemical analyses were performed to verify the presence and distribution of storage substances. Moreover, specific stainings and epifluorescent microscopy were applied to count nuclei, follow the migration of sperm cells and investigate the presence, size and morphology of callose plugs. Results showed that simulated microgravity affected pollen tube development. The different response showed by the various species indicates that male-gametophytic selection could be useful for the selection of plants in microgravity.

  20. Comparative morphology, biology and histology of reproductive development in three lines of Manihot esculenta Crantz (Euphorbiaceae: Crotonoideae)

    PubMed Central

    Perera, P. I. P.; Quintero, M.; Dedicova, B.; Kularatne, J. D. J. S.; Ceballos, H.

    2012-01-01

    Background and aims Cassava (Manihot esculenta), a major food staple in the tropics and subtropics, thrives even in environments undergoing threatening climate change. To satisfy the increasing demand for crop improvement and overcome the limitations of conventional breeding, the introduction of inbreeding techniques such as the production of doubled haploid lines via androgenesis or gynogenesis offers advantages. However, comprehensive studies on cassava flower bud biology or structural development are lacking and precise structural and biological information is a prerequisite to enhance the efficiency of these techniques. Methodology The floral biology of three selected cassava lines was studied, focusing on morphology, phenology and pollen biology (quantity, viability and dimorphism). Histological studies were also conducted on microsporogenesis/microgametogenesis and megasporogenesis/megagameto-genesis to generate precise developmental data for these lines. Principal results Male and female cyathia have distinct developmental phases. Pollen viability was high during immature stages of plant development; however, pollen mortality was common at later stages. Pollen trimorphism in male gametophytes towards the larger or smaller pollen size, as compared with normal size, was observed. Ten characteristic events were identified in male gametogenesis and six in female gametogenesis that were correlated with flower bud diameter. Male gametophyte diameter at different developmental stages was also determined. Conclusions Results indicate that the three lines did not differ significantly, except regarding a few morphological aspects such as plant height, flower colour and number of male cyathia. Pollen grains were initially viable, but viability decreased drastically at later stages of growth. Abnormal meiosis or mitosis triggered pollen trimorphism. The demonstrated sequential events of reproductive development generated valuable information at the cellular level, which

  1. Arabidopsis thaliana GEX1 has dual functions in gametophyte development and early embryogenesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    GEX1 is a plasma membrane protein conserved among plant species, and was previously shown to be expressed in sperm cells and some sporophytic tissues. Here we show that GEX1 is also expressed in the embryo sac before cellularization, in the egg cell after cellularization, in the zygote/embryo immedi...

  2. A tuber calcanei avulsion fracture developed on the basis of idiopathic osteoporosis in a young male: a case report.

    PubMed

    Terzi, R; Özer, T

    2015-09-01

    Calcaneus fractures constitute 1.2 % of all fractures. Tuber calcanei avulsion fractures constitute 1.3-2.7 % of calcaneus fractures. Osteoporosis, osteomalacia, and diabetes mellitus have been reported to increase the risk of development of these fractures. It has been reported that tuber calcanei avulsion fractures in elderly females might develop due to osteoporosis. As far as we know, no tuber calcanei avulsion fracture developing on the basis of osteoporosis without presence of a trauma has been reported in young males in the literature. In the current case report, a 41-year-old male patient who was admitted with complaints of pain in the left heel and diagnosed with calcaneal avulsion fracture that developed on the basis of idiopathic osteoporosis and who was treated with conservative methods was presented. PMID:25851698

  3. Ethical Behavior and Human Development among Male and Female Graduate and Undergraduate College Students.

    ERIC Educational Resources Information Center

    Sottile, James M., Jr.; Brozik, Dallas

    The purpose of this research was to describe and better understand the ethical experiences of graduate and undergraduate, male and female college students attending a university in a rural location of a mid-eastern state. A survey was created to determine the ethical activities of college students. A total of 2,718 surveys were completed.…

  4. The male-taller norm: Lack of evidence from a developing country.

    PubMed

    Sohn, K

    2015-08-01

    In general, women prefer men taller than themselves; this is referred to as the male-taller norm. However, since women are shorter than men on average, it is difficult to determine whether the fact that married women are on average shorter than their husbands results from the norm or is a simple artifact generated by the shorter stature of women. This study addresses the question by comparing the rate of adherence to the male-taller norm between actual mating and hypothetical random mating. A total of 7954 actually married couples are drawn from the last follow-up of the Indonesian Family Life Survey, a nationally representative survey. Their heights were measured by trained nurses. About 10,000 individuals are randomly sampled from the actual couples and randomly matched. An alternative random mating of about 100,000 couples is also performed, taking into account an age difference of 5 years within a couple. The rate of adherence to the male-taller norm is 93.4% for actual couples and 88.8% for random couples. The difference between the two figures is statistically significant, but it is emphasized that it is very small. The alternative random mating produces a rate of 91.4%. The male-taller norm exists in Indonesia, but only in a statistical sense. The small difference suggests that the norm is mostly explained by the fact that women are shorter than men on average. PMID:25983077

  5. Phospholipase C zeta (PLCζ) and male infertility: Clinical update and topical developments.

    PubMed

    Amdani, Siti Nornadhirah; Yeste, Marc; Jones, Celine; Coward, Kevin

    2016-05-01

    The development of a mammalian embryo is initiated by a sequence of molecular events collectively referred to as 'oocyte activation' and regulated by the release of intracellular calcium in the ooplasm. Over the last decade, phospholipase C zeta (PLCζ), a sperm protein introduced into the oocyte upon gamete fusion, has gained almost universal acceptance as the protein factor responsible for initiating oocyte activation. A large body of consistent and reproducible evidence, from both biochemical and clinical settings, confers support for the role of PLCζ in this fundamental biological context, which has significant ramifications for the management of human male infertility. Oocyte activation deficiency (OAD) and total fertilisation failure (TFF) are known causes of infertility and have both been linked to abnormalities in the structure, expression, and localisation pattern of PLCζ in human sperm. Assisted oocyte activators (AOAs) represent the only therapeutic option available for OAD at present, although these agents have been the source of much debate recently, particularly with regard to their potential epigenetic effects upon the embryo. Consequently, there is much interest in the deployment of sensitive PLCζ assays as prognostic/diagnostic tests and human recombinant PLCζ protein as an alternative form of therapy. Although PLCζ deficiency has been directly linked to a cohort of infertile cases, we have yet to identify the specific causal mechanisms involved. While two genetic mutations have been identified which link defective PLCζ protein to an infertile phenotype, both were observed in the same patient, and have yet to be described in other patients. Consequently, some researchers are investigating the possibility that genetic variations in the form of single nucleotide polymorphisms (SNPs) could provide some explanation, especially since >6000 SNPs have been identified in the PLCζ gene. As yet, however, there is no consistent data to suggest that any

  6. Testicular Development in Male Rats Is Sensitive to a Soy-Based Diet in the Neonatal Period1

    PubMed Central

    Napier, India D.; Simon, Liz; Perry, Devin; Cooke, Paul S.; Stocco, Douglas M.; Sepehr, Estatira; Doerge, Daniel R.; Kemppainen, Barbara W.; Morrison, Edward E.; Akingbemi, Benson T.

    2014-01-01

    ABSTRACT Approximately 30% of infants in the United States are exposed to high doses of isoflavones resulting from soy infant formula consumption. Soybeans contain the isoflavones genistin and daidzin, which are hydrolyzed in the gastrointestinal tract to their genistein and daidzein aglycones. Both aglycones possess hormonal activity and may interfere with male reproductive development. Testosterone, which supports male fertility, is mainly produced by testicular Leydig cells. Our previous studies indicated that perinatal exposure of male rats to isoflavones induced proliferative activity in Leydig cells and increased testosterone concentrations into adulthood. However, the relevance of the neonatal period as part of the perinatal window of isoflavone exposure remains to be established. The present study examined the effects of exposure to isoflavones on male offspring of dams maintained on a casein-based control or whole soybean diet in the neonatal period, that is, Days 2 to 21 postpartum. The results showed that the soybean diet stimulated proliferative activity in developing Leydig cells while suppressing their steroidogenic capacity in adulthood. In addition, isoflavone exposure decreased production of anti-Müllerian hormone by Sertoli cells. Similar to our previous in vitro studies of genistein action in Leydig cells, daidzein induced proliferation and interfered with signaling pathways to suppress steroidogenic activity. Overall, the data showed that the neonatal period is a sensitive window of exposure to isoflavones and support the view that both genistein and daidzein are responsible for biological effects associated with soy-based diets. PMID:24451983

  7. Biomechanical and neuromuscular characteristics of male athletes: implications for the development of anterior cruciate ligament injury prevention programs.

    PubMed

    Sugimoto, Dai; Alentorn-Geli, Eduard; Mendiguchía, Jurdan; Samuelsson, Kristian; Karlsson, Jon; Myer, Gregory D

    2015-06-01

    Prevention of anterior cruciate ligament (ACL) injury is likely the most effective strategy to reduce undesired health consequences including reconstruction surgery, long-term rehabilitation, and pre-mature osteoarthritis occurrence. A thorough understanding of mechanisms and risk factors of ACL injury is crucial to develop effective prevention programs, especially for biomechanical and neuromuscular modifiable risk factors. Historically, the available evidence regarding ACL risk factors has mainly involved female athletes or has compared male and female athletes without an intra-group comparison for male athletes. Therefore, the principal purpose of this article was to review existing evidence regarding the investigation of biomechanical and neuromuscular characteristics that may imply aberrant knee kinematics and kinetics that would place the male athlete at risk of ACL injury. Biomechanical evidence related to knee kinematics and kinetics was reviewed by different planes (sagittal and frontal/coronal), tasks (single-leg landing and cutting), situation (anticipated and unanticipated), foot positioning, playing surface, and fatigued status. Neuromuscular evidence potentially related to ACL injury was reviewed. Recommendations for prevention programs for ACL injuries in male athletes were developed based on the synthesis of the biomechanical and neuromuscular characteristics. The recommendations suggest performing exercises with multi-plane biomechanical components including single-leg maneuvers in dynamic movements, reaction to and decision making in unexpected situations, appropriate foot positioning, and consideration of playing surface condition, as well as enhancing neuromuscular aspects such as fatigue, proprioception, muscle activation, and inter-joint coordination. PMID:25663251

  8. Photosynthetic electron-transfer reactions in the gametophyte of Pteris multifida reveal the presence of allelopathic interference from the invasive plant species Bidens pilosa.

    PubMed

    Zhang, Kai-Mei; Shen, Yu; Zhou, Xiao-Qi; Fang, Yan-Ming; Liu, Ying; Ma, Lena Q

    2016-05-01

    To date, the response of the fern gametophyte to its environment has received considerable attention. However, studies on the influence of plant invasion on the fern gametophyte are fewer. Allelopathy has been hypothesized to play an important role in biological invasion. Hence, it is necessary to study the allelopathy of invasive plant species to the fern gametophyte and elucidate the mechanisms by which invasive plants cause phytotoxicity. As one of the main invasive plants in China, Bidens pilosa exhibits allelopathic effects on the gametophytic growth of Pteris multifida. The root exudate plays an important role among various allelochemical delivery mechanisms in B. pilosa. The effect invasive plant species has on photosynthesis in native species is poorly understood. To elucidate this effect, the changes in photosynthesis in the gametophytes of P. multifida are analyzed to examine the mechanisms of the root exudates of B. pilosa. Meanwhile, a non-invasive plant, Coreopsis basalis, was also applied to investigate the effects on fluorescence and pigments in P. multifida gametophytes. We found that gametophytes exposed to both B. pilosa and C. basalis had decreased fluorescence parameters in comparison with the control, except for non-photochemical quenching. Furthermore, it was found that these parameters were markedly affected from day 2 to day 10 in the presence of both exudates at a concentration of 25% or above. B. pilosa exudate had a negative dose-dependent effect on chlorophyll a, chlorophyll b, carotenoid, and the total chlorophyll in the gametophyte. The inhibitory effects increased with increasing exudate concentrations of both species, exhibiting the greatest inhibition at day 10. In conclusion, B. pilosa irreversibly affected the photosynthesis of P. multifida on both PS I and PS II. Root exudates caused the primary damage with respect to the decrease of the acceptors and donors of photon and electron in photosynthetic units and the production and

  9. Growth and reproductive development of male piglets are more vulnerable to midgestation maternal stress than that of female piglets.

    PubMed

    Mack, L A; Lay, D C; Eicher, S D; Johnson, A K; Richert, B T; Pajor, E A

    2014-02-01

    In many mammalian species, prenatal stress masculinizes female and feminizes male offspring impairing their reproductive capacity. Regrouping gestating sows is a common, stressful production practice, but its impact on the developing pigs of the sow is not fully known. This study examined the effects of regrouping gestating sows and the administration of exogenous glucocorticoids on the growth and external reproductive morphology of pigs. At 37.2 ± 0.26 d of gestation, 6 cohorts of 18 sows (N = 108) were placed in 1 of 3 treatments: socially stable (Stable), hydrocortisone acetate (HCA), or mixed (Mixed). The HCA sows were administered 70 mg HCA, a synthetic glucocorticoid, twice daily during the 21 d experimental period. Each Mixed sow was penned with 2 companion sows (Companion) and regrouped on d 7 and 14 with 2 different Companion sows in a new pen. Stable and HCA sows were penned in treatment groups of 3 sows. Sow social rank was assessed weekly during feeding. After the 21 d experimental period, all sows were housed in gestation stalls for the duration of pregnancy. During the 21 d, Companion sows gained more weight than HCA and Mixed sows (P < 0.05) with Stable sows intermediate. High ranked sows gained more weight than middle and low ranked sows (P < 0.05). Mixed sows had greater head lesion scores than Stable and HCA sows (P < 0.05) with Companion sows intermediate. Head lesions increased with lower social rank (P < 0.001). Sow treatment did not affect farrowing rate, litter size, or sex ratio (P > 0.10). Social rank also had no effect on farrowing rate (P > 0.10), but affected total litter size (P = 0.03). High ranked sows bore and weaned more live females than low ranked sows (P < 0.05), in part due to differential preweaning mortality among female pigs (P = 0.01). Only male pigs were affected by sow treatment. Preweaning mortality was higher among male pigs from HCA than from Mixed sows (P = 0.04) with other treatments intermediate. Despite no weight

  10. Female and Male Interns and Their Mentors? Perception of Workforce Skill Development

    NASA Technical Reports Server (NTRS)

    Hall, Cathy W.; Pinelli, Thomas E.; Brush, Kimberly M.

    2013-01-01

    Participants in this study were student interns and mentors taking part in the 2012, 10- week Langley Aerospace Research Student Scholars (LARSS) summer internship program in Hampton, Virginia. The study examined mentors and student interns' ratings of their preparedness in basic knowledge and skills. The study focused on three primary areas: 1) overall evaluation of knowledge and skills by mentors and interns; 2) male and female interns' perceptions of their own skills in these key areas; and 3) mentors' perceptions of their student interns' knowledge and skills in the same areas by gender. Overall mentors were more positive about their interns' improvement in 12 of 17 areas assessed than were the student interns. There were no significant gender differences in how mentors rated their male and female interns' abilities in these workforce skills, but there were four key areas where female interns rated their own abilities lower than did their male peers: analytical thinking, computational skills, computer skills and technical skills. Implications of these findings are discussed.

  11. Improving seedless kelp (Saccharina japonica) during its domestication by hybridizing gametophytes and seedling-raising from sporophytes

    PubMed Central

    Li, Xiaojie; Zhang, Zhuangzhi; Qu, Shancun; Liang, Guangjin; Sun, Juan; Zhao, Nan; Cui, Cuiju; Cao, Zengmei; Li, Yan; Pan, Jinhua; Yu, Shenhui; Wang, Qingyan; Li, Xia; Luo, Shiju; Song, Shaofeng; Guo, Li; Yang, Guanpin

    2016-01-01

    Dongfang no.7 (Saccharina japonica) was bred and maintained by hybridizing gametophytes, self-crossing the best individuals, selecting the best self-crossing line and seedling-raising from yearly reconstructed sporophytes. It increased the air dry yield by 43.2% in average over 2 widely farmed controls. Dongfang no.7 was seedling-raised from bulked sporophytes reconstructed from its representative gametophyte clones. Such strategy ensured it against variety contamination due to possible cross fertilization and occasional mixing and inbred depletion due to self-crossing number-limited sporophytes year after year. It derived from an intraspecific hybrid through 4 rounds of self-crossing and selection and retained a certain degree of genetic heterozygosity, thus being immune to inbred depletion due to purification of unknown detrimental alleles. Most importantly, it can be farmed in currently available system as the seedlings for large scale culture can be raised from reconstructed Dongfang no.7 sporophytes. Breeding and maintaining Dongfang no.7 provided a model that other varieties of kelp (S. japonica) and brown algae may follow during their domestication. PMID:26887644

  12. Improving seedless kelp (Saccharina japonica) during its domestication by hybridizing gametophytes and seedling-raising from sporophytes.

    PubMed

    Li, Xiaojie; Zhang, Zhuangzhi; Qu, Shancun; Liang, Guangjin; Sun, Juan; Zhao, Nan; Cui, Cuiju; Cao, Zengmei; Li, Yan; Pan, Jinhua; Yu, Shenhui; Wang, Qingyan; Li, Xia; Luo, Shiju; Song, Shaofeng; Guo, Li; Yang, Guanpin

    2016-01-01

    Dongfang no.7 (Saccharina japonica) was bred and maintained by hybridizing gametophytes, self-crossing the best individuals, selecting the best self-crossing line and seedling-raising from yearly reconstructed sporophytes. It increased the air dry yield by 43.2% in average over 2 widely farmed controls. Dongfang no.7 was seedling-raised from bulked sporophytes reconstructed from its representative gametophyte clones. Such strategy ensured it against variety contamination due to possible cross fertilization and occasional mixing and inbred depletion due to self-crossing number-limited sporophytes year after year. It derived from an intraspecific hybrid through 4 rounds of self-crossing and selection and retained a certain degree of genetic heterozygosity, thus being immune to inbred depletion due to purification of unknown detrimental alleles. Most importantly, it can be farmed in currently available system as the seedlings for large scale culture can be raised from reconstructed Dongfang no.7 sporophytes. Breeding and maintaining Dongfang no.7 provided a model that other varieties of kelp (S. japonica) and brown algae may follow during their domestication. PMID:26887644

  13. Reproductive development of male goat kids reared with or without permanent contact with adult females until 10 months of age.

    PubMed

    Lacuesta, L; Orihuela, A; Ungerfeld, R

    2015-01-01

    Adult male ruminants that were reared in contact with females display greater sexual behavior than those reared in single male groups. The aim of the experiment was to compare the reproductive development of prepubertal male kids reared with or without direct permanent contact with adult females until they were 10 months old. Seventeen Saanen male kids were maintained in two groups until 44 weeks of age: kids reared in permanent direct contact with four adult goats (group FEM, N = 8) and kids that remained isolated from females (group ISO, N = 9). All goats in the FEM group became pregnant approximately when bucks attained 28 weeks of age. Scrotal circumference and testosterone concentration were measured, and semen was obtained by electroejaculation to avoid female contact in the ISO group. Scrotal circumference was greater in FEM kids at 12 and 14 weeks of age (P < 0.0001) and testosterone when they were 20 and 22 weeks old (P < 0.0001). Testosterone concentration was greater in ISO kids from 28 to 44 weeks of age. All semen characteristics increased with age (P < 0.0001). Individual motility was greater in FEM kids than that in ISO kids at 15 and 17 weeks (P < 0.005); mass motility was greater in ISO than that in FEM kids at 32 weeks (P < 0.05); total number of spermatozoa/ejaculate was greater in ISO kids at 30, 32, and 40 weeks and in FEM kids at 43 weeks (P < 0.005); total number of motile spermatozoa was greater in ISO kids at 32 and 40 weeks, whereas at 43 weeks, it was greater in FEM kids (P < 0.005). It was concluded that permanent contact with adult goats had transient and short-time positive effects in male kids' reproductive traits during prepubertal development. However, positive effects stopped after goats used as stimulus became pregnant. PMID:25277528

  14. The effects of inbreeding, genetic dissimilarity and phenotype on male reproductive success in a dioecious plant

    PubMed Central

    Austerlitz, Frédéric; Gleiser, Gabriela; Teixeira, Sara; Bernasconi, Giorgina

    2012-01-01

    Pollen fate can strongly affect the genetic structure of populations with restricted gene flow and significant inbreeding risk. We established an experimental population of inbred and outbred Silene latifolia plants to evaluate the effects of (i) inbreeding depression, (ii) phenotypic variation and (iii) relatedness between mates on male fitness under natural pollination. Paternity analysis revealed that outbred males sired significantly more offspring than inbred males. Independently of the effects of inbreeding, male fitness depended on several male traits, including a sexually dimorphic (flower number) and a gametophytic trait (in vitro pollen germination rate). In addition, full-sib matings were less frequent than randomly expected. Thus, inbreeding, phenotype and genetic dissimilarity simultaneously affect male fitness in this animal-pollinated plant. While inbreeding depression might threaten population persistence, the deficiency of effective matings between sibs and the higher fitness of outbred males will reduce its occurrence and counter genetic erosion. PMID:21561968

  15. Severe impairment of male reproductive organ development in a low SMN expressing mouse model of spinal muscular atrophy

    PubMed Central

    Ottesen, Eric W.; Howell, Matthew D.; Singh, Natalia N.; Seo, Joonbae; Whitley, Elizabeth M.; Singh, Ravindra N.

    2016-01-01

    Spinal muscular atrophy (SMA) is caused by low levels of survival motor neuron (SMN), a multifunctional protein essential for higher eukaryotes. While SMN is one of the most scrutinized proteins associated with neurodegeneration, its gender-specific role in vertebrates remains unknown. We utilized a mild SMA model (C/C model) to examine the impact of low SMN on growth and development of mammalian sex organs. We show impaired testis development, degenerated seminiferous tubules, reduced sperm count and low fertility in C/C males, but no overt sex organ phenotype in C/C females. Underscoring an increased requirement for SMN expression, wild type testis showed extremely high levels of SMN protein compared to other tissues. Our results revealed severe perturbations in pathways critical to C/C male reproductive organ development and function, including steroid biosynthesis, apoptosis, and spermatogenesis. Consistent with enhanced apoptosis in seminiferous tubules of C/C testes, we recorded a drastic increase in cells with DNA fragmentation. SMN was expressed at high levels in adult C/C testis due to an adult-specific splicing switch, but could not compensate for low levels during early testicular development. Our findings uncover novel hallmarks of SMA disease progression and link SMN to general male infertility. PMID:26830971

  16. MALE REPRODUCTIVE PHYSIOLOGY AND THE DEVELOPMENT OF ARTIFICIAL INSEMINATION IN THE MAGELLANIC PENGUIN (SPHENISCUS MAGELLANICUS) USING CHILLED-STORED SEMEN.

    PubMed

    O'Brien, Justine K; Nollens, Hendrik H; Schmitt, Todd L; Steinman, Karen J; Dubach, Jean M; Robeck, Todd R

    2016-03-01

    Research was performed to increase our understanding of male Magellanic penguin (Spheniscus magellanicus) reproductive biology and to develop artificial insemination (AI) technology to assist with maintaining the species' genetic diversity. Seminal traits were characterized from seven males with noncontaminated ejaculates (n = 123) displaying high in vitro motion parameters, membrane integrity, and morphology. Seven females were maintained in nest sites that permitted visual, auditory, and tactile contact with their paired male but not copulation for 18.3 ± 2.4 days before egg lay. After cloacal AI (2.6 ± 0.4 inseminations/female) with semen chilled for up to 20.5 hr at 5°C, all females produced one to two fertile eggs, with the first oviposition occurring within 7 days of plasma progesterone concentrations exceeding 0.8 ng/ml. Overall fertility was 91.7%, hatchability was 63.6%, and genetic analyses confirmed that all embryos and hatchlings were sired by AI males. The heterospermic AI design demonstrated that eggs were fertilized by spermatozoa chilled for 1.5-19.8 hr before AI and were laid 4.5-11.5 days post AI. These results contribute new data on Magellanic penguin sperm biology and demonstrate that high fertility rates after AI of chilled semen can be achieved with females remaining in proximity to their paired mate. PMID:27010281

  17. Expression of fragile X mental retardation protein within the vocal control system of developing and adult male zebra finches

    PubMed Central

    Winograd, Claudia; Clayton, David; Ceman, Stephanie

    2008-01-01

    Individuals with fragile X syndrome (FXS) are cognitively impaired and have marked speech delays and deficits. Our goal was to characterize expression of FMRP, the fragile X mental retardation protein, encoded by the gene FMR1, in an animal model that learns to vocalize, namely the zebra finch Taeniopygia guttata (Tgu). We cloned and sequenced the zebra finch ortholog of FMR1 (TguFmr1) and developed an antibody that recognizes TguFmrp specifically. TguFmrp has structural features similar to its human ortholog FMRP. Because FXS patients exhibit sensorimotor deficits, we examined TguFmrp expression prior to, during, and after sensorimotor song learning in zebra finches. We found that TguFmrp is expressed throughout the brain and in four major song nuclei of the male zebra finch brain, primarily in neurons. Additionally, prior to sensorimotor learning, we observed elevated TguFmrp expression in the RA of post-hatch day 30 males, compared to the surrounding telencephalon, suggesting a preparation for this stage of song learning. Finally, we observed variable TguFmrp expression in the RA of adolescent and adult males: in some males it was elevated and in others it was comparable to the surrounding telencephalon. In summary, we have characterized the zebra finch ortholog of FMRP and found elevated levels in the premotor nucleus RA at a key developmental stage for vocal learning. PMID:18835331

  18. The Internet’s Multiple Roles in Facilitating the Sexual Orientation Identity Development of Gay and Bisexual Male Adolescents

    PubMed Central

    Harper, Gary W.; Serrano, Pedro A.; Bruce, Douglas; Bauermeister, Jose A.

    2016-01-01

    One emerging avenue for the exploration of adolescents’ sexual orientation identity development is the Internet since it allows for varying degrees of anonymity and exploration. The purpose of this phenomenological study was to examine the role of the Internet in facilitating the sexual orientation identity development process of gay and bisexual male adolescents. Qualitative interviews were conducted with an ethnically diverse sample of 63 gay/bisexual male adolescents (ages 15–23). Participants reported using a range of Internet applications as they explored and came to accept their sexual orientation identity, with the intended purpose and degree of anonymity desired determining which applications were used. Youth reported that the Internet provided a range of functions with regard to the exploration and acceptance of their sexual orientation identity, including: 1) increasing self awareness of sexual orientation identity; 2) learning about gay/bisexual community life; 3) communicating with other gay/bisexual people; 4) meeting other gay/bisexual people; 5) finding comfort and acceptance with sexual orientation; and 6) facilitating the coming out process. Future research and practice may explore the Internet as a platform for promoting the healthy development of gay and bisexual male adolescents by providing a developmentally and culturally appropriate venue for the exploration and subsequent commitment to an integrated sexual orientation identity. PMID:25585861

  19. The Internet's Multiple Roles in Facilitating the Sexual Orientation Identity Development of Gay and Bisexual Male Adolescents.

    PubMed

    Harper, Gary W; Serrano, Pedro A; Bruce, Douglas; Bauermeister, Jose A

    2016-09-01

    One emerging avenue for the exploration of adolescents' sexual orientation identity development is the Internet, since it allows for varying degrees of anonymity and exploration. The purpose of this phenomenological study was to examine the role of the Internet in facilitating the sexual orientation identity development process of gay and bisexual male adolescents. Qualitative interviews were conducted with an ethnically diverse sample of 63 gay/bisexual male adolescents (ages 15-23). Participants reported using a range of Internet applications as they explored and came to accept their sexual orientation identity, with the intended purpose and degree of anonymity desired determining which applications were used. Youth reported that the Internet provided a range of functions with regard to the exploration and acceptance of their sexual orientation identity, including (1) increasing self-awareness of sexual orientation identity, (2) learning about gay/bisexual community life, (3) communicating with other gay/bisexual people, (4) meeting other gay/bisexual people, (5) finding comfort and acceptance with sexual orientation, and (6) facilitating the coming out process. Future research and practice may explore the Internet as a platform for promoting the healthy development of gay and bisexual male adolescents by providing a developmentally and culturally appropriate venue for the exploration and subsequent commitment to an integrated sexual orientation identity. PMID:25585861

  20. Correction of Hormonal and Metabolic Disorders in Male Rats with Developing Experimental Diabetes.

    PubMed

    Didebulidze, N A; Kakabadze, M Sh; Gordadze, N G; Latsabidze, I N; Kordzaya, M E; Sikharulidze, I T

    2015-05-01

    Synthetic radioinert androgen methyltrienolone administered daily for 2 weeks to male rats with severe diabetes led to a sharp increase in blood testosterone and was accompanied by reduction in glucose level due to an increase in tissue sensitivity to insulin. Normalization of plasma testosterone concentration contributed to saturation of active androgen receptors in the myocardium with testosterone; the number of free receptors decreased by 1.8 times. Testosterone that diminishes the catabolic effects of glucocorticoids improved the state of the myocardium, which was confirmed by activation of DNA and RNA synthesis. PMID:26033581

  1. The elusiveness of masculinity: primordial vulnerability, lack, and the challenges of male development.

    PubMed

    Diamond, Michael J

    2015-01-01

    Reaching beyond the Oedipus prototype to address the unrepresentable vulnerability founded on the boy's infantile helplessness in contact with the mother's body, the author aims to identify the inherent tensions and enigmas of being male. He proposes that both the repudiation of femininity and the overvaluation of phallicity are unconsciously constructed to withstand the fundamental deficiency grounded in the asymmetry of the boy's prephallic relation with his primary object. This bodily based primordial vulnerability, marked by absence and lack, remains elusive-an unsymbolizable experience that provides the archaic matrix for adaptive and defensive phallicism, the oedipal complex, and genital progression. A clinical vignette is presented to illustrate these concepts. PMID:25619366

  2. Individual and Family Factors Associated with Intention to Quit among Male Vietnamese American Smokers: Implications for Intervention Development

    PubMed Central

    Tsoh, Janice Y.; Tong, Elisa K.; Gildengorin, Ginny; Nguyen, Tung T.; Modayil, Mary V.; Wong, Ching; McPhee, Stephen J.

    2011-01-01

    Smoking prevalence among Vietnamese American males remains higher than the U.S. general population. This study examined the associations of individual and family factors with quit intention among Vietnamese male smokers in California to guide intervention development to reduce their smoking prevalence. Data for Vietnamese male current smokers (n = 234) in the 2008 California Vietnamese Adult Tobacco Use Survey (N=1,101 males) were analyzed to describe quit intention and previous quit attempts. One-third of Vietnamese male smokers (33%) had no intention to quit at any time, 36% intended to quit soon (in the next 30 days), and 31% intended to quit later (beyond the next 30 days). Half (51.7%) of the sample was in “precontemplation,” indicating no intention to quit within 6 months. Many (71%) had made a serious quit attempt in the past year, but 68% of those who tried to quit used no cessation assistance. Multivariate logistic regression adjusting for age, depression, smoking intensity, nicotine dependence, health knowledge, children in the household and home smoking ban revealed that having smoking-related family conflicts and a quit attempt in the past year with or without assistance were independently associated with an intention to quit either in the next 30 days or later. Higher education was associated with no intention to quit. Findings underscore the importance of designing strategic interventions that meet the needs of smokers at both individual and family levels to promote quit intention and to facilitate successful quitting in this population. PMID:21177041

  3. Development of a nursing care problems coping scale for male caregivers for people with dementia living at home

    PubMed Central

    Nishio, Midori; Ono, Mitsu

    2015-01-01

    Objective: The number of male caregivers has increased, but male caregivers face several problems that reduce their quality of life and psychological condition. This study focused on the coping problems of men who care for people with dementia at home. It aimed to develop a coping scale for male caregivers so that they can continue caring for people with dementia at home and improve their own quality of life. The study also aimed to verify the reliability and validity of the scale. Patients/Material and Methods: The subjects were 759 men who care for people with dementia at home. The Care Problems Coping Scale consists of 21 questions based on elements of questions extracted from a pilot study. Additionally, subjects completed three self-administered questionnaires: the Japanese version of the Zarit Caregiver Burden Scale, the Depressive Symptoms and the Self-esteem Emotional Scale, and Rosenberg Self-Esteem Scale. Results: There were 274 valid responses (36.1% response rate). Regarding the answer distribution, each average value of the 21 items ranged from 1.56 to 2.68. The median answer distribution of the 21 items was 39 (SD = 6.6). Five items had a ceiling effect, and two items had a floor effect. The scale stability was about 50%, and Cronbach’s α was 0.49. There were significant correlations between the Care Problems Coping Scale and total scores of the Japanese version of the Zarit Caregiver Burden Scale, the Depressive Symptoms and Self-esteem Emotional Scale, and the Rosenberg Self-Esteem Scale. Conclusion: The answers provided on the Care Problems Coping Scale questionnaire indicated that male caregivers experience care problems. In terms of validity, there were significant correlations between the external questionnaires and 19 of the 21 items in this scale. This scale can therefore be used to measure problems with coping for male caregivers who care for people with dementia at home. PMID:26380589

  4. Male pattern baldness (image)

    MedlinePlus

    Male pattern baldness is a sex-linked characteristic that is passed from mother to child. A man can more accurately predict his chances of developing male pattern baldness by observing his mother's father than by looking ...

  5. Male pattern baldness (image)

    MedlinePlus

    Male pattern baldness is a sex-linked characteristic that is passed from mother to child. A man can more accurately predict his chances of developing male pattern baldness by observing his mother's father than ...

  6. Effects of perinatal bisphenol A exposure during early development on radial arm maze behavior in adult male and female rats

    PubMed Central

    Sadowski, Renee N.; Park, Pul; Neese, Steven L.; Ferguson, Duncan C.; Schantz, Susan L.; Juraska, Janice M.

    2014-01-01

    Previous work has shown that exposure to bisphenol A (BPA) can affect anxiety behavior. However, no studies have examined whether administration of this endocrine disruptor during the perinatal period has the potential to induce alterations in cognitive behavior in both adult males and females as assessed in an appetitive task. The goal of the current study was to determine whether exposure to different doses of BPA during early development alters performance on the 17-arm radial maze in adulthood in Long-Evans rats. Oral administration of corn oil (vehicle), 4 μg/kg, 40 μg/kg, or 400 μg/kg BPA to the dams occurred daily throughout pregnancy, and the pups received direct oral administration of BPA between postnatal days 1-9. Blood was collected from offspring at weaning age to determine levels of several hormones (thyroxine, thyroid stimulating hormone, follicle stimulating hormone, luteinizing hormone). One male and one female from each litter were evaluated on the 17-arm radial maze, a working/reference memory task, in adulthood. Results indicated that after exposure to BPA at both 4 and 400 μg/kg/day, rats of both sexes had decreased levels of FSH at weaning. There were no significant effects of BPA on performance on the radial arm maze in males or females. In conclusion, exposure to BPA during early development had modest effects on circulating hormones but did not affect a spatial learning and memory task. PMID:24440629

  7. The effects of prenatal and early postnatal tocotrienol-rich fraction supplementation on cognitive function development in male offspring rats

    PubMed Central

    2013-01-01

    Background Recent findings suggest that the intake of specific nutrients during the critical period in early life influence cognitive and behavioural development profoundly. Antioxidants such as vitamin E have been postulated to be pivotal in this process, as vitamin E is able to protect the growing brain from oxidative stress. Currently tocotrienols are gaining much attention due to their potent antioxidant and neuroprotective properties. It is thus compelling to look at the effects of prenatal and early postnatal tocotrienols supplementation, on cognition and behavioural development among offsprings of individual supplemented with tocotrienols. Therefore, this study is aimed to investigate potential prenatal and early postnatal influence of Tocotrienol-Rich Fraction (TRF) supplementation on cognitive function development in male offspring rats. Eight-week-old adult female Sprague Dawley (SD) rats were randomly assigned into five groups of two animals each. The animals were fed either with the base diet as control (CTRL), base diet plus vehicle (VHCL), base diet plus docosahexanoic acid (DHA), base diet plus Tocotrienol-Rich fraction (TRF), and base diet plus both docosahexaenoic acid, and tocotrienol rich fraction (DTRF) diets for 2 weeks prior to mating. The females (F0 generation) were maintained on their respective treatment diets throughout the gestation and lactation periods. Pups (F1 generation) derived from these dams were raised with their dams from birth till four weeks post natal. The male pups were weaned at 8 weeks postnatal, after which they were grouped into five groups of 10 animals each, and fed with the same diets as their dams for another eight weeks. Learning and behavioural experiments were conducted only in male off-spring rats using the Morris water maze.Eight-week-old adult female Sprague Dawley (SD) rats were randomly assigned into five groups of two animals each. The animals were fed either with the base diet as control (CTRL), base

  8. [Thr arteries of the male sex organs of Japanese quail (Coturnix coturnix japonica) and their development after hatching].

    PubMed

    Okamoto, T; Vollmerhaus, B; Roos, H; Waibl, H; König, H E

    1992-06-01

    A total of 83 male Japanese quails of the following age groups were used for this study: 11, 18, 25, 32, 35, 37, 39, 41, 43 days, and 7, 9, 17 weeks after hatching. Neoprene-Latex, Tensol-Cement, and the china ink were injected via the aortic arch. In most of male Japanese quails, the testes are supplied by the A. testicularis originated from the Aorta descendens through a common trunk with the A. renalis cranialis. But in only 3 quails had this artery originated directly from the Aorta descendens on either side. In 9 quails had the A. testicularis accessoria originating independently from the Aorta descendens and running cranially or caudally in short distance to the normal A. testicularis. The arteries for the Ductus deferens were divided into 3 categories. The Rami ureterodeferentiales craniales were spread out from A. testicularis or Rami epididymales. The Rami ureterodeferentiales medii came from the A. renalis media and the A. renalis caudalis. The Rami ureterodeferentiales caudales originated from the A. caudae lateralis and A. pudenda. The Receptaculum ductus deferentis, the Corpus vasculare paracloacalis and the Phallus nonprotrudens in the Cloaca were supplied from the thick Ramus cloacalis of the A. pudenda. The Ramus bursalis of this artery supplied the Glandula proctodaealis and the Bursa cloacalis, and was also thick. The arteries to the genital organs were observed in the 11 day old male quail. The A. pudenda began developing at about 30 days after hatching when the quail's body matured. While the A. testicularis began developing at about 40 days after hatching when the male Japanese quail was full of the spermatogenic activity. PMID:1497141

  9. Genetic and Biochemical Mechanisms of Pollen Wall Development.

    PubMed

    Shi, Jianxin; Cui, Meihua; Yang, Li; Kim, Yu-Jin; Zhang, Dabing

    2015-11-01

    The pollen wall is a specialized extracellular cell wall matrix that surrounds male gametophytes and plays an essential role in plant reproduction. Uncovering the mechanisms that control the synthesis and polymerization of the precursors of pollen wall components has been a major research focus in plant biology. We review current knowledge on the genetic and biochemical mechanisms underlying pollen wall development in eudicot model Arabidopsis thaliana and monocot model rice (Oryza sativa), focusing on the genes involved in the biosynthesis, transport, and assembly of various precursors of pollen wall components. The conserved and divergent aspects of the genes involved as well as their regulation are addressed. Current challenges and future perspectives are also highlighted. PMID:26442683

  10. Changes in certain diurnal hormonal rhythms in developing male rats exposed to adiurnal environmental cues.

    PubMed

    Ooka-Souda, S

    1981-03-01

    It has traditionally been thought that diurnal rhythmicities cannot be entrained to follow adiurnal environmental cues that deviate greatly from a 24-hour periodicity. In this study, exposure of male rats pre- and postnatally to an adiurnal lighting schedule of 9 hours light: 9 hours dark resulted in the entertainment of certain hormonal rhythms (such as plasma corticosterone and plasma TSH) but not of others (such as pituitary TSH and plasma T3). Even though thyroid rhythms were influenced only partially by the shorter, 18-hour day, absolute levels of pituitary TSH and plasma T3 were significantly higher in experimental rats (9 hours light:9 hours dark) than controls (12 hours light:12 hours dark). Whole-body and kidney weights and tail length were also significantly increased in the 9 hours light:9 hours dark animals, suggesting a possible relationship of shorter day cycles to faster growth and higher thyroid hormone levels. PMID:7195965

  11. Suppression of male reproduction in rats after exposure to sodium fluoride during early stages of development

    NASA Astrophysics Data System (ADS)

    Reddy, P. Sreedhar; Pushpalatha, T.; Reddy, P. Sreenivasula

    2007-07-01

    Sodium fluoride (NaF), a widespread natural pollutant was given to sperm-positive female rats throughout gestation and lactation at a dose of 4.5 and 9.0 ppm via drinking water. The neonates were allowed to grow up to 90 days on tap water, and then sperm parameters, testicular steroidogenic marker enzyme activity levels, and circulatory hormone levels were studied. The sperm count, sperm motility, sperm coiling (hypoosmotic swelling test), and sperm viability were decreased in experimental rats when compared with controls. The activity levels of testicular steroidogenic marker enzymes (3β hydroxysteroid dehydrogenase and 17β hydroxysteroid dehydrogenase) were significantly decreased in experimental animals indicating decreased steroidogenesis. The serum testosterone, follicle stimulating hormone and luteinizing hormone levels were also significantly altered in experimental animals. Our data indicate that exposure to NaF during gestation and lactation affects male reproduction in adult rats by decreasing spermatogenesis and steroidogenesis.

  12. The FRK1 mitogen-activated protein kinase kinase kinase (MAPKKK) from Solanum chacoense is involved in embryo sac and pollen development

    PubMed Central

    Lafleur, Edith; Kapfer, Christelle; Joly, Valentin; Liu, Yang; Tebbji, Faiza; Daigle, Caroline; Gray-Mitsumune, Madoka; Cappadocia, Mario; Nantel, André; Matton, Daniel P.

    2015-01-01

    The fertilization-related kinase 1 (ScFRK1), a nuclear-localized mitogen-activated protein kinase kinase kinase (MAPKKK) from the wild potato species Solanum chacoense, belongs to a small group of pMEKKs that do not possess an extended N- or C-terminal regulatory domain. Initially selected based on its highly specific expression profile following fertilization, in situ expression analyses revealed that the ScFRK1 gene is also expressed early on during female gametophyte development in the integument and megaspore mother cell and, later, in the synergid and egg cells of the embryo sac. ScFRK1 mRNAs are also detected in pollen mother cells. Transgenic plants with lower or barely detectable levels of ScFRK1 mRNAs lead to the production of small fruits with severely reduced seed set, resulting from a concomitant decline in the number of normal embryo sacs produced. Megagametogenesis and microgametogenesis were affected, as megaspores did not progress beyond the functional megaspore (FG1) stage and the microspore collapsed around the first pollen mitosis. As for other mutants that affect embryo sac development, pollen tube guidance was severely affected in the ScFRK1 transgenic lines. Gametophyte to sporophyte communication was also affected, as observed from a marked change in the transcriptomic profiles of the sporophytic tissues of the ovule. The ScFRK1 MAPKKK is thus involved in a signalling cascade that regulates both male and female gamete development. PMID:25576576

  13. The FRK1 mitogen-activated protein kinase kinase kinase (MAPKKK) from Solanum chacoense is involved in embryo sac and pollen development.

    PubMed

    Lafleur, Edith; Kapfer, Christelle; Joly, Valentin; Liu, Yang; Tebbji, Faiza; Daigle, Caroline; Gray-Mitsumune, Madoka; Cappadocia, Mario; Nantel, André; Matton, Daniel P

    2015-04-01

    The fertilization-related kinase 1 (ScFRK1), a nuclear-localized mitogen-activated protein kinase kinase kinase (MAPKKK) from the wild potato species Solanum chacoense, belongs to a small group of pMEKKs that do not possess an extended N- or C-terminal regulatory domain. Initially selected based on its highly specific expression profile following fertilization, in situ expression analyses revealed that the ScFRK1 gene is also expressed early on during female gametophyte development in the integument and megaspore mother cell and, later, in the synergid and egg cells of the embryo sac. ScFRK1 mRNAs are also detected in pollen mother cells. Transgenic plants with lower or barely detectable levels of ScFRK1 mRNAs lead to the production of small fruits with severely reduced seed set, resulting from a concomitant decline in the number of normal embryo sacs produced. Megagametogenesis and microgametogenesis were affected, as megaspores did not progress beyond the functional megaspore (FG1) stage and the microspore collapsed around the first pollen mitosis. As for other mutants that affect embryo sac development, pollen tube guidance was severely affected in the ScFRK1 transgenic lines. Gametophyte to sporophyte communication was also affected, as observed from a marked change in the transcriptomic profiles of the sporophytic tissues of the ovule. The ScFRK1 MAPKKK is thus involved in a signalling cascade that regulates both male and female gamete development. PMID:25576576

  14. Predicting recidivism among adult male child pornography offenders: Development of the Child Pornography Offender Risk Tool (CPORT).

    PubMed

    Seto, Michael C; Eke, Angela W

    2015-08-01

    In this study, we developed a structured risk checklist, the Child Pornography Offender Risk Tool (CPORT), to predict any sexual recidivism among adult male offenders with a conviction for child pornography offenses. We identified predictors of sexual recidivism using a 5-year fixed follow-up analysis from a police case file sample of 266 adult male child pornography offenders in the community after their index offense. In our 5-year follow-up, 29% committed a new offense, and 11% committed a new sexual offense, with 3% committing a new contact sexual offense against a child and 9% committing a new child pornography offense. The CPORT items comprised younger offender age, any prior criminal history, any contact sexual offending, any failure on conditional release, indication of sexual interest in child pornography material or prepubescent or pubescent children, more boy than girl content in child pornography, and more boy than girl content in other child depictions. The CPORT was significantly associated with any sexual recidivism, with moderate predictive accuracy, and thus has promise in the risk assessment of adult male child pornography offenders with further cross-validation. PMID:25844514

  15. Male-specific region of the bovine Y chromosome is gene rich with a high transcriptomic activity in testis development.

    PubMed

    Chang, Ti-Cheng; Yang, Yang; Retzel, Ernest F; Liu, Wan-Sheng

    2013-07-23

    The male-specific region of the mammalian Y chromosome (MSY) contains clusters of genes essential for male reproduction. The highly repetitive and degenerative nature of the Y chromosome impedes genomic and transcriptomic characterization. Although the Y chromosome sequence is available for the human, chimpanzee, and macaque, little is known about the annotation and transcriptome of nonprimate MSY. Here, we investigated the transcriptome of the MSY in cattle by direct testis cDNA selection and RNA-seq approaches. The bovine MSY differs radically from the primate Y chromosomes with respect to its structure, gene content, and density. Among the 28 protein-coding genes/families identified on the bovine MSY (12 single- and 16 multicopy genes), 16 are bovid specific. The 1,274 genes identified in this study made the bovine MSY gene density the highest in the genome; in comparison, primate MSYs have only 31-78 genes. Our results, along with the highly transcriptional activities observed from these Y-chromosome genes and 375 additional noncoding RNAs, challenge the widely accepted hypothesis that the MSY is gene poor and transcriptionally inert. The bovine MSY genes are predominantly expressed and are differentially regulated during the testicular development. Synonymous substitution rate analyses of the multicopy MSY genes indicated that two major periods of expansion occurred during the Miocene and Pliocene, contributing to the adaptive radiation of bovids. The massive amplification and vigorous transcription suggest that the MSY serves as a genomic niche regulating male reproduction during bovid expansion. PMID:23842086

  16. Plasmodium AdoMetDC/ODC bifunctional enzyme is essential for male sexual stage development and mosquito transmission.

    PubMed

    Hart, Robert J; Ghaffar, Atif; Abdalal, Shaymaa; Perrin, Benjamin; Aly, Ahmed S I

    2016-01-01

    Polyamines are positively-charged organic molecules that are important for cellular growth and division. Polyamines and their synthesizing enzymes are particularly abundant in rapidly proliferating eukaryotic cells such as parasitic protozoa and cancer cells. Polyamine biosynthesis inhibitors, such as Elfornithine, are now being considered for cancer prevention and have been used effectively against Trypanosoma brucei Inhibitors of polyamine biosynthesis have caused growth arrest of Plasmodium falciparum blood stages in vitro, but in P. berghei only partial inhibition has been observed. While polyamine biosynthesis enzymes are characterized and conserved in Plasmodium spp., little is known on the biological roles of these enzymes inside malaria parasite hosts. The bifunctional polyamine biosynthesis enzyme S-adenosyl methionine decarboxylase/ornithine decarboxylase (AdoMetDC/ODC) was targeted for deletion in P. yoelii Deletion of AdoMetDC/ODC significantly reduced blood stage parasitemia but Anopheles transmission was completely blocked. We showed that male gametocytogenesis and male gamete exflagellation were abolished and consequently no ookinetes or oocyst sporozoites could be generated from adometdc/odc(-) parasites. Supplementation of putrescine and spermidine did not rescue the defective phenotypes of male gametocytes and gametes of the knockout parasites. These results highlight the crucial role of polyamine homeostasis in the development and functions of Plasmodium erythrocytic stages in the blood and in the mosquito vector and validate polyamine biosynthesis pathway enzymes as drug targeting candidates for malaria parasite transmission blocking. PMID:27387533

  17. Plasmodium AdoMetDC/ODC bifunctional enzyme is essential for male sexual stage development and mosquito transmission

    PubMed Central

    Hart, Robert J.; Ghaffar, Atif; Abdalal, Shaymaa; Perrin, Benjamin

    2016-01-01

    ABSTRACT Polyamines are positively-charged organic molecules that are important for cellular growth and division. Polyamines and their synthesizing enzymes are particularly abundant in rapidly proliferating eukaryotic cells such as parasitic protozoa and cancer cells. Polyamine biosynthesis inhibitors, such as Elfornithine, are now being considered for cancer prevention and have been used effectively against Trypanosoma brucei. Inhibitors of polyamine biosynthesis have caused growth arrest of Plasmodium falciparum blood stages in vitro, but in P. berghei only partial inhibition has been observed. While polyamine biosynthesis enzymes are characterized and conserved in Plasmodium spp., little is known on the biological roles of these enzymes inside malaria parasite hosts. The bifunctional polyamine biosynthesis enzyme S-adenosyl methionine decarboxylase/ornithine decarboxylase (AdoMetDC/ODC) was targeted for deletion in P. yoelii. Deletion of AdoMetDC/ODC significantly reduced blood stage parasitemia but Anopheles transmission was completely blocked. We showed that male gametocytogenesis and male gamete exflagellation were abolished and consequently no ookinetes or oocyst sporozoites could be generated from adometdc/odc(–) parasites. Supplementation of putrescine and spermidine did not rescue the defective phenotypes of male gametocytes and gametes of the knockout parasites. These results highlight the crucial role of polyamine homeostasis in the development and functions of Plasmodium erythrocytic stages in the blood and in the mosquito vector and validate polyamine biosynthesis pathway enzymes as drug targeting candidates for malaria parasite transmission blocking. PMID:27387533

  18. Application of Radial Basis Function Methods in the Development of a 95th Percentile Male Seated FEA Model.

    PubMed

    Vavalle, Nicholas A; Schoell, Samantha L; Weaver, Ashley A; Stitzel, Joel D; Gayzik, F Scott

    2014-11-01

    Human body finite element models (FEMs) are a valuable tool in the study of injury biomechanics. However, the traditional model development process can be time-consuming. Scaling and morphing an existing FEM is an attractive alternative for generating morphologically distinct models for further study. The objective of this work is to use a radial basis function to morph the Global Human Body Models Consortium (GHBMC) average male model (M50) to the body habitus of a 95th percentile male (M95) and to perform validation tests on the resulting model. The GHBMC M50 model (v. 4.3) was created using anthropometric and imaging data from a living subject representing a 50th percentile male. A similar dataset was collected from a 95th percentile male (22,067 total images) and was used in the morphing process. Homologous landmarks on the reference (M50) and target (M95) geometries, with the existing FE node locations (M50 model), were inputs to the morphing algorithm. The radial basis function was applied to morph the FE model. The model represented a mass of 103.3 kg and contained 2.2 million elements with 1.3 million nodes. Simulations of the M95 in seven loading scenarios were presented ranging from a chest pendulum impact to a lateral sled test. The morphed model matched anthropometric data to within a rootmean square difference of 4.4% while maintaining element quality commensurate to the M50 model and matching other anatomical ranges and targets. The simulation validation data matched experimental data well in most cases. PMID:26192960

  19. POLYPRENOL REDUCTASE2 Deficiency Is Lethal in Arabidopsis Due to Male Sterility[OPEN

    PubMed Central

    Gutkowska, Malgorzata; Buczkowska, Anna; Lichocka, Malgorzata; Nowakowska, Julita

    2015-01-01

    Dolichol is a required cofactor for protein glycosylation, the most common posttranslational modification modulating the stability and biological activity of proteins in all eukaryotic cells. We have identified and characterized two genes, PPRD1 and -2, which are orthologous to human SRD5A3 (steroid 5α reductase type 3) and encode polyprenol reductases responsible for conversion of polyprenol to dolichol in Arabidopsis thaliana. PPRD1 and -2 play dedicated roles in plant metabolism. PPRD2 is essential for plant viability; its deficiency results in aberrant development of the male gametophyte and sporophyte. Impaired protein glycosylation seems to be the major factor underlying these defects although disturbances in other cellular dolichol-dependent processes could also contribute. Shortage of dolichol in PPRD2-deficient cells is partially rescued by PPRD1 overexpression or by supplementation with dolichol. The latter has been discussed as a method to compensate for deficiency in protein glycosylation. Supplementation of the human diet with dolichol-enriched plant tissues could allow new therapeutic interventions in glycosylation disorders. This identification of PPRD1 and -2 elucidates the factors mediating the key step of the dolichol cycle in plant cells which makes manipulation of dolichol content in plant tissues feasible. PMID:26628744

  20. Impaired pubertal development and testicular hormone function in males with sickle cell anemia.

    PubMed

    Martins, Paulo Roberto Juliano; Kerbauy, José; Moraes-Souza, Helio; Pereira, Gilberto de Araújo; Figueiredo, Maria Stella; Verreschi, Ieda Therezinha

    2015-01-01

    Changes in weight/height ratio, delayed sexual maturation, hypogonadism and impaired fertility have been demonstrated in sickle cell disease (SCD). This study aimed to evaluate the clinical and laboratory views of the Leydig cells function after stimulation with hCG in adults with sickle cell disease. We studied 15 patients with SCD (18 to 40 years; median=27 years old), fourteen homozygous S, and one with SC disease. The control group, composed by adult males, was divided into two groups: I - 10 relatives (18-39 years, median=26 years) with the same socioeconomic level of the patients, and II - 9 normal individuals (23-28, median=31 years) randomly chosen. Clinically it was observed a slight degree of malnutrition, important puberty delay, rarefaction of chest, underarm and pubic hair, and important reduction of the testis and penis size, featuring a mild hypogonadism in patients with SCD. The hormonal level assessment of testosterone at baseline and at 24, 48 and 72 h after hCG stimulation showed no significant differences between the groups studied. We can presume that adult men with SCD showed clinical hypoandrogenism with normal testicular hormonal function, a fact inconsistent with the hypothesis of primary hypogonadism. PMID:25190051

  1. A role for 5alpha-reductase activity in the development of male homosexuality?

    PubMed

    Alias, A G

    2004-12-01

    Higher body hair with lower mesmorphism ratings were observed in Caucasian homosexual men compared with the general male population, reflecting elevated 5alpha-reductase (5alphaR) activity, and higher dihydrotestosterone-to-testosterone (DHT-to-T) ratio, in sharp contrast to 46,XY 5alphaR 2 deficiency subjects, who are often born with ambiguous, or female genitalia, but tend to grow up to be muscular, heterosexual men with very little body hair, or beard. One study also showed them scoring around dull normal IQs. A greater prevalence of liberal body hair growth in men with higher IQs and/or educational levels was also observed in several samples. The exceptions to this statistical trend are too unsettling, however. Nevertheless, the results of a number of published studies, including one showing higher DHT-to-T ratio in homosexual men, done with different objectives over a span of 80 years, together strongly support these findings. Furthermore, in an animal model, "cognitive-enhancing effects" of "5alpha-reduced androgen [metabolites]" were recently demonstrated. PMID:15677419

  2. GPSy: a cross-species gene prioritization system for conserved biological processes—application in male gamete development

    PubMed Central

    Britto, Ramona; Sallou, Olivier; Collin, Olivier; Michaux, Grégoire; Primig, Michael; Chalmel, Frédéric

    2012-01-01

    We present gene prioritization system (GPSy), a cross-species gene prioritization system that facilitates the arduous but critical task of prioritizing genes for follow-up functional analyses. GPSy’s modular design with regard to species, data sets and scoring strategies enables users to formulate queries in a highly flexible manner. Currently, the system encompasses 20 topics related to conserved biological processes including male gamete development discussed in this article. The web server-based tool is freely available at http://gpsy.genouest.org. PMID:22570409

  3. Growth pattern and carcase development in male ducks selected for growth rate.

    PubMed

    Maruyama, K; Akbar, M K; Turk, C M

    1999-05-01

    1. Growth patterns of the whole body, eviscerated carcases, breast muscle, leg and thigh muscles and abdominal fat pads were compared in 4 lines (Lines A, B, C, and D) of male ducks selected for market weight (n = 1305) using growth curve analysis, allometric growth analysis and repeated measure analysis. At 49 d of age, Line A was heaviest, followed by Line B, Line C and Line D. 2. Ducks were fed ad libitum under 24-h lighting and 12 or 24 ducks were killed to determine body, carcase, breast-muscle, leg and thigh-muscle, and abdominal fat weights at time points from hatching until 53 d of age. 3. The Weibull function was chosen for growth curve analysis. The asymptote and inflection point from the Weibull growth curves identified 3 lines (Lines B, C, and D) with discrete body and carcase growth patterns but did not distinguish Line A from Line B. In all 4 lines the asymptote ranged from 4437 g to 3008 g for body weight and from 3334 g to 2098 g for carcase weight; the inflection point ranged from 22.5 d to 25.3 d for body weight and from 25.4 d to 29.6 d for carcase weight. 4. The allometric growth coefficient, relative to whole-body growth, was higher than 1.00 for breast muscle and lower than 1.00 for leg and thigh muscles during from 4 d to 53 d of age. 5. Body fat accumulation was estimated by abdominal fat. Line D accumulated more abdominal fat than other lines. The pattern of fat accumulation in Line D was different from Lines A, B and C and there were no differences between Lines A, B and C. PMID:10465391

  4. Attentional control and interpretation of facial expression after oxytocin administration to typically developed male adults.

    PubMed

    Hirosawa, Tetsu; Kikuchi, Mitsuru; Okumura, Eiichi; Yoshimura, Yuko; Hiraishi, Hirotoshi; Munesue, Toshio; Takesaki, Natsumi; Furutani, Naoki; Ono, Yasuki; Higashida, Haruhiro; Minabe, Yoshio

    2015-01-01

    Deficits in attentional-inhibitory control have been reported to correlate to anger, hostility, and aggressive behavior; therefore, inhibitory control appears to play an important role in prosocial behavior. Moreover, recent studies have demonstrated that oxytocin (OT) exerts a prosocial effect (e.g., decreasing negative behaviors, such as aggression) on humans. However, it is unknown whether the positively valenced effect of OT on sociality is associated with enhanced attentional-inhibitory control. In the present study, we hypothesized that OT enhances attentional-inhibitory control and that the positively valenced effect of OT on social cognition is associated with enhanced attentional-inhibitory control. In a single-blind, placebo-controlled crossover trial, we tested this hypothesis using 20 healthy male volunteers. We considered a decrease in the hostility detection ratio, which reflects the positively valenced interpretation of other individuals' facial expressions, to be an index of the positively valenced effects of OT (we reused the results of our previously published study). As a measure of attentional-inhibitory control, we employed a modified version of the flanker task (i.e., a shorter conflict duration indicated higher inhibitory control). These results failed to demonstrate any significant behavioral effects of OT (i.e., neither a positively valenced effect on facial cognition nor an effect on attentional-inhibitory control). However, the enhancement of attentional-inhibitory control after OT administration significantly correlated to the positively valenced effects on the interpretation of uncertain facial cognition (i.e., neutral and ambiguous facial expressions). PMID:25659131

  5. Attentional Control and Interpretation of Facial Expression after Oxytocin Administration to Typically Developed Male Adults

    PubMed Central

    Hirosawa, Tetsu; Kikuchi, Mitsuru; Okumura, Eiichi; Yoshimura, Yuko; Hiraishi, Hirotoshi; Munesue, Toshio; Takesaki, Natsumi; Furutani, Naoki; Ono, Yasuki; Higashida, Haruhiro; Minabe, Yoshio

    2015-01-01

    Deficits in attentional-inhibitory control have been reported to correlate to anger, hostility, and aggressive behavior; therefore, inhibitory control appears to play an important role in prosocial behavior. Moreover, recent studies have demonstrated that oxytocin (OT) exerts a prosocial effect (e.g., decreasing negative behaviors, such as aggression) on humans. However, it is unknown whether the positively valenced effect of OT on sociality is associated with enhanced attentional-inhibitory control. In the present study, we hypothesized that OT enhances attentional-inhibitory control and that the positively valenced effect of OT on social cognition is associated with enhanced attentional-inhibitory control. In a single-blind, placebo-controlled crossover trial, we tested this hypothesis using 20 healthy male volunteers. We considered a decrease in the hostility detection ratio, which reflects the positively valenced interpretation of other individuals’ facial expressions, to be an index of the positively valenced effects of OT (we reused the results of our previously published study). As a measure of attentional-inhibitory control, we employed a modified version of the flanker task (i.e., a shorter conflict duration indicated higher inhibitory control). These results failed to demonstrate any significant behavioral effects of OT (i.e., neither a positively valenced effect on facial cognition nor an effect on attentional-inhibitory control). However, the enhancement of attentional-inhibitory control after OT administration significantly correlated to the positively valenced effects on the interpretation of uncertain facial cognition (i.e., neutral and ambiguous facial expressions). PMID:25659131

  6. Genome-wide transcriptomic analysis of the effects of sub-ambient atmospheric oxygen and elevated atmospheric carbon dioxide levels on gametophytes of the moss, Physcomitrella patens.

    PubMed

    Shinde, Suhas; Behpouri, Ali; McElwain, Jennifer C; Ng, Carl K-Y

    2015-07-01

    It is widely accepted that atmospheric O2 has played a key role in the development of life on Earth, as evident from the coincidence between the rise of atmospheric O2 concentrations in the Precambrian and biological evolution. Additionally, it has also been suggested that low atmospheric O2 is one of the major drivers for at least two of the five mass-extinction events in the Phanerozoic. At the molecular level, our understanding of the responses of plants to sub-ambient O2 concentrations is largely confined to studies of the responses of underground organs, e.g. roots to hypoxic conditions. Oxygen deprivation often results in elevated CO2 levels, particularly under waterlogged conditions, due to slower gas diffusion in water compared to air. In this study, changes in the transcriptome of gametophytes of the moss Physcomitrella patens arising from exposure to sub-ambient O2 of 13% (oxygen deprivation) and elevated CO2 (1500 ppmV) were examined to further our understanding of the responses of lower plants to changes in atmospheric gaseous composition. Microarray analyses revealed that the expression of a large number of genes was affected under elevated CO2 (814 genes) and sub-ambient O2 conditions (576 genes). Intriguingly, the expression of comparatively fewer numbers of genes (411 genes) was affected under a combination of both sub-ambient O2 and elevated CO2 condition (low O2-high CO2). Overall, the results point towards the effects of atmospheric changes in CO2 and O2 on transcriptional reprogramming, photosynthetic regulation, carbon metabolism, and stress responses. PMID:25948702

  7. Gross Motor Development of Malaysian Hearing Impaired Male Pre- and Early School Children

    ERIC Educational Resources Information Center

    Zawi, Khairi; Lian, Denise Koh Choon; Abdullah, Rozlina Tan

    2014-01-01

    Acquisition of gross motor skill is a natural developmental process for children. This aspect of human development increases with one's chronological age, irrespective of any developmental conditions. The purpose of this study was to assess the level of gross motor skill development among pre- and early school-aged children with motor disability.…

  8. Minority Male Participation in Educational Research and Development: A Recruitment Selection Dilemma.

    ERIC Educational Resources Information Center

    Braithwaite, Ronald L.; Beatty, Lula

    1981-01-01

    Despite Federal efforts to increase minority participation in university level research and development (R & D), there is a disproportionate underrepresentation of minority men as trainees. Reasons seem to lie in R & D recruitment strategies and practices. (Author/GC)

  9. Social stress, coping strategies and tumor development in male mice: behavioral, neuroendocrine and immunological implications.

    PubMed

    Vegas, Oscar; Fano, Eduardo; Brain, Paul Fredric; Alonso, Ana; Azpiroz, Arantza

    2006-01-01

    The relationships between acute social stress, immunological alterations and the development of pulmonary metastases of B16F10 melanoma were analyzed. In particular, the effects of different behavioral coping strategies on the development of the metastases were studied. Tumor bearing and tumor non-bearing mice were subjected for 24h to a sensory contact social stress model. This included two 5 min sessions of direct social interaction with their resident cagemates (which had been selected for consistent levels of aggression). The subjects' behavior was videotaped and assessed. Corticosterone, IL-2, IL-12 and splenic cell proliferation responses to Con-A were determined 1h and 3 days post-stress. Lung metastatic foci numbers were determined 21 days after inoculation (15 days post-stress). Social stress increased the number of pulmonary metastases and the serum level of corticosterone but decreased the splenic proliferative capacity. No direct relationship could be established between the development of the metastases and the assayed interleukin response. A combination of cluster and discriminant analyses established that there were three types of coping strategies. Subjects engaging in a strategy characterized by an absence of attack, low non-social exploration levels and high levels of defense, subordination and avoidance, developed most pulmonary metastases. Social stress effects on tumor development appear to depend on the subject's coping strategy in such situations (although one cannot rule out the possibility that differences in the development of the disease per se are responsible for the different behavioral patterns observed). PMID:16046077

  10. Analysis of gene expression profile in pollen development of recessive genic male sterile Brassica napus L. line S45A.

    PubMed

    Chen, Yuning; Lei, Shaolin; Zhou, Zhengfu; Zeng, Fangqin; Yi, Bin; Wen, Jing; Shen, Jinxiong; Ma, Chaozhi; Tu, Jinxing; Fu, Tingdong

    2009-09-01

    Male sterility in a near-isogenic line S45AB after 25 generations of subcrossing is controlled by two pairs of duplicate genes. The genotype of S45A is Bnms1Bnms1Bnms2Bnms2, and that of S45B is BnMs1Bnms1Bnms2Bnms2, respectively. Histological observations revealed that abnormal anther development appeared in the tapetum and pollen exine during the tetrad stage. This male sterility was characterized by hypertrophy of the tapetal cells at the tetrad stage and a complete lack of microspore exine after the release of microspores from the tetrads. To elucidate the mechanism of this recessive genic male sterility, the flower bud expression profiles of the S45A and S45B lines were analyzed using an Arabidopsis thaliana ATH1 oligonucleotide array. When compared with the S45B line, 69 genes were significantly downregulated, and 46 genes were significantly upregulated in the S45A line. Real-time polymerase chain reaction (PCR) was then used to verify the results of the microarray analysis, and the majority of the downregulated genes in the S45A line were abundantly and specifically expressed in the anther. The results of the real-time PCR suggest that Bnms1 might be involved in the metabolism of lipid/fatty acids, and the homologous mutation of Bnms1 may either block the biosynthesis of sporopollenin or block sporopollenin from being deposited on the microspore surface, thus, preventing pollen exine formation. The role of Bnms1 in the regulatory network of exine formation is also discussed as well. PMID:19562345

  11. Male contraception.

    PubMed

    Chao, Jing; Page, Stephanie T; Anderson, Richard A

    2014-08-01

    Clear evidence shows that many men and women would welcome new male methods of contraception, but none have become available. The hormonal approach is based on suppression of gonadotropins and thus of testicular function and spermatogenesis, and has been investigated for several decades. This approach can achieve sufficient suppression of spermatogenesis for effective contraception in most men, but not all; the basis for these men responding insufficiently is unclear. Alternatively, the non-hormonal approach is based on identifying specific processes in sperm development, maturation and function. A range of targets has been identified in animal models, and targeted effectively. This approach, however, remains in the pre-clinical domain at present. There are, therefore, grounds for considering that safe, effective and reversible methods of contraception for men can be developed. PMID:24947599

  12. Male contraception

    PubMed Central

    Chao, Jing; Page, Stephanie T.; Anderson, Richard A.

    2015-01-01

    Clear evidence shows that many men and women would welcome new male methods of contraception, but none have become available. The hormonal approach is based on suppression of gonadotropins and thus of testicular function and spermatogenesis, and has been investigated for several decades. This approach can achieve sufficient suppression of spermatogenesis for effective contraception in most men, but not all; the basis for these men responding insufficiently is unclear. Alternatively, the nonhormonal approach is based on identifying specific processes in sperm development, maturation and function. A range of targets has been identified in animal models, and targeted effectively. This approach, however, remains in the pre-clinical domain at present. There are, therefore, grounds for considering that safe, effective and reversible methods of contraception for men can be developed. PMID:24947599

  13. Differential Pathways to Generic Skills Development of Male and Female College Students in Korea

    ERIC Educational Resources Information Center

    Rhee, Byung Shik; Kim, Sooji

    2012-01-01

    This study analyzed a stratified random sample of 1,707 senior students at 60 four-year universities in South Korea to explore the gender-specific pathways to Korean students' development of generic skills--analytical thinking and problem-solving skills. Multiple regression analyses were performed to investigate the involvement factors…

  14. DEVELOPING IMPROVED STRATEGIES TO DETERMINE MALE REPRODUCTIVE RISK FROM ENVIRONMENTAL TOXINS

    EPA Science Inventory

    It is important that evaluation procedures for chemicals incorporate measures suitable to detect a wide range of potential effects from those chemicals. he reproductive systems are among the most sensitive to toxic insult, so it is important that effective methods be developed an...

  15. Low-Dose, Gestational Exposure to Atrazine Does Not Alter Postnatal Reproductive Development of Male Offspring

    EPA Science Inventory

    There is growing evidence that xenobiotic exposure during the perinatal period may result in a variety of adverse outcomes when the developing organism attains adulthood. Maternal stress and subsequent exposure of the fetus to excess glucocorticoids may underlie these effects. Pr...

  16. Elucidating human male germ cell development by studying germ cell cancer.

    PubMed

    Nettersheim, Daniel; Jostes, Sina; Schneider, Simon; Schorle, Hubert

    2016-10-01

    Human germ cell development is regulated in a spatio-temporal manner by complex regulatory networks. Here, we summarize results obtained in germ cell tumors and respective cell lines and try to pinpoint similarities to normal germ cell development. This comparison allows speculating about the critical and error-prone mechanisms, which when disturbed, lead to the development of germ cell tumors. Short after specification, primordial germ cells express markers of pluripotency, which, in humans, persists up to the stage of fetal/infantile spermatogonia. Aside from the rare spermatocytic tumors, virtually all seminomas and embryonal carcinomas express markers of pluripotency and show signs of pluripotency or totipotency. Therefore, it appears that proper handling of the pluripotency program appears to be the most critical step in germ cell development in terms of tumor biology. Furthermore, data from mice reveal that germline cells display an epigenetic signature, which is highly similar to pluripotent cells. This signature (poised histone code, DNA hypomethylation) is required for the rapid induction of toti- and pluripotency upon fertilization. We propose that adult spermatogonial cells, when exposed to endocrine disruptors or epigenetic active substances, are prone to reinitiate the pluripotency program, giving rise to a germ cell tumor. The fact that pluripotent cells can be derived from adult murine and human testicular cells further corroborates this idea. PMID:27512122

  17. Pubertal Development, Choice of Friends, and Smoking Initiation among Adolescent Males

    ERIC Educational Resources Information Center

    Drapela, Laurie A.; Gebelt, Janet L.; McRee, Nick

    2006-01-01

    Prior research has indicated that pubertal development and peer associations are important determinants of adolescent smoking behavior. However, more remains to be learned about "why" these variables matter or how they may be related to one another in ways that lead to the initiation of smoking. Using contractual data from the National…

  18. Effects of Prenatal Exposure to a Low Dose Atrazine Metabolite Mixture on pubertal timing and prostrate Development of Male Long Evans Rats.

    EPA Science Inventory

    The present study examines the postnatal reproductive development of male rats following prenatal exposure to an atrazine metabolite mixture (AMM) consisting of the herbicide atrazine and its environmental metabolites diaminochlorotriazine, hydroxyatrazine, deethylatrazine, and d...

  19. The effect of carotenoid supplementation on immune system development in juvenile male veiled chameleons (Chamaeleo calyptratus)

    PubMed Central

    2014-01-01

    Introduction Nutrient availability, assimilation, and allocation can have important and lasting effects on the immune system development of growing animals. Though carotenoid pigments have immunostimulatory properties in many animals, relatively little is known regarding how they influence the immune system during development. Moreover, studies linking carotenoids to health at any life stage have largely been restricted to birds and mammals. We investigated the effects of carotenoid supplementation on multiple aspects of immunity in juvenile veiled chameleons (Chamaeleo calyptratus). We supplemented half of the chameleons with lutein (a xanthophyll carotenoid) for 14 weeks during development and serially measured multiple aspects of immune function, including: agglutination and lysis performance of plasma, wound healing, and plasma nitric oxide concentrations before and after wounding. Results Though lutein supplementation effectively elevated circulating carotenoid concentrations throughout the developmental period, we found no evidence that carotenoid repletion enhanced immune function at any point. However, agglutination and lysis scores increased, while baseline nitric oxide levels decreased, as chameleons aged. Conclusions Taken together, our results indicate that body mass and age, but not carotenoid access, may play an important role in immune performance of growing chameleons. Hence, studying well-understood physiological processes in novel taxa can provide new perspectives on alternative physiological processes and nutrient function. PMID:24655326

  20. Long-term cortisol treatment inhibits pubertal development in male common carp, Cyprinus carpio L.

    PubMed

    Consten, D; Bogerd, J; Komen, J; Lambert, J G; Goos, H J

    2001-04-01

    The onset and regulation of puberty is determined by functional development of the brain-pituitary-gonad (BPG) axis. Stress has been shown to interfere with reproduction and the functioning of the BPG axis. The response to chronic and severe stress may require much energy and force the organism to make adaptive choices. Energy that is normally available for processes like growth, immune response, or reproduction will be channeled into restoration of the disturbed homeostasis. Cortisol plays a key role in the homeostatic adaptation during or after stress. In the present study, immature common carp were fed with cortisol-containing food pellets covering the pubertal period. We showed that cortisol caused an inhibition of pubertal development, by affecting directly or indirectly all components of the BPG axis. The salmon GnRH content of the brain was decreased. Luteinizing hormone- and FSH-encoding mRNA levels in the pituitary and LH plasma levels were diminished by long-term cortisol treatment, as was the testicular androgen secretion. Testicular development, reflected by gonadosomatic index and the first wave of spermatogenesis, was retarded. PMID:11259251

  1. A Putative Homologue of CDC20/CDH1 in the Malaria Parasite Is Essential for Male Gamete Development

    PubMed Central

    Guttery, David S.; Ferguson, David J. P.; Poulin, Benoit; Xu, Zhengyao; Straschil, Ursula; Klop, Onny; Solyakov, Lev; Sandrini, Sara M.; Brady, Declan; Nieduszynski, Conrad A.; Janse, Chris J.; Holder, Anthony A.; Tobin, Andrew B.; Tewari, Rita

    2012-01-01

    Cell-cycle progression is governed by a series of essential regulatory proteins. Two major regulators are cell-division cycle protein 20 (CDC20) and its homologue, CDC20 homologue 1 (CDH1), which activate the anaphase-promoting complex/cyclosome (APC/C) in mitosis, and facilitate degradation of mitotic APC/C substrates. The malaria parasite, Plasmodium, is a haploid organism which, during its life-cycle undergoes two stages of mitosis; one associated with asexual multiplication and the other with male gametogenesis. Cell-cycle regulation and DNA replication in Plasmodium was recently shown to be dependent on the activity of a number of protein kinases. However, the function of cell division cycle proteins that are also involved in this process, such as CDC20 and CDH1 is totally unknown. Here we examine the role of a putative CDC20/CDH1 in the rodent malaria Plasmodium berghei (Pb) using reverse genetics. Phylogenetic analysis identified a single putative Plasmodium CDC20/CDH1 homologue (termed CDC20 for simplicity) suggesting that Plasmodium APC/C has only one regulator. In our genetic approach to delete the endogenous cdc20 gene of P. berghei, we demonstrate that PbCDC20 plays a vital role in male gametogenesis, but is not essential for mitosis in the asexual blood stage. Furthermore, qRT-PCR analysis in parasite lines with deletions of two kinase genes involved in male sexual development (map2 and cdpk4), showed a significant increase in cdc20 transcription in activated gametocytes. DNA replication and ultra structural analyses of cdc20 and map2 mutants showed similar blockage of nuclear division at the nuclear spindle/kinetochore stage. CDC20 was phosphorylated in asexual and sexual stages, but the level of modification was higher in activated gametocytes and ookinetes. Changes in global protein phosphorylation patterns in the Δcdc20 mutant parasites were largely different from those observed in the Δmap2 mutant. This suggests that CDC20 and MAP2 are both

  2. A putative homologue of CDC20/CDH1 in the malaria parasite is essential for male gamete development.

    PubMed

    Guttery, David S; Ferguson, David J P; Poulin, Benoit; Xu, Zhengyao; Straschil, Ursula; Klop, Onny; Solyakov, Lev; Sandrini, Sara M; Brady, Declan; Nieduszynski, Conrad A; Janse, Chris J; Holder, Anthony A; Tobin, Andrew B; Tewari, Rita

    2012-02-01

    Cell-cycle progression is governed by a series of essential regulatory proteins. Two major regulators are cell-division cycle protein 20 (CDC20) and its homologue, CDC20 homologue 1 (CDH1), which activate the anaphase-promoting complex/cyclosome (APC/C) in mitosis, and facilitate degradation of mitotic APC/C substrates. The malaria parasite, Plasmodium, is a haploid organism which, during its life-cycle undergoes two stages of mitosis; one associated with asexual multiplication and the other with male gametogenesis. Cell-cycle regulation and DNA replication in Plasmodium was recently shown to be dependent on the activity of a number of protein kinases. However, the function of cell division cycle proteins that are also involved in this process, such as CDC20 and CDH1 is totally unknown. Here we examine the role of a putative CDC20/CDH1 in the rodent malaria Plasmodium berghei (Pb) using reverse genetics. Phylogenetic analysis identified a single putative Plasmodium CDC20/CDH1 homologue (termed CDC20 for simplicity) suggesting that Plasmodium APC/C has only one regulator. In our genetic approach to delete the endogenous cdc20 gene of P. berghei, we demonstrate that PbCDC20 plays a vital role in male gametogenesis, but is not essential for mitosis in the asexual blood stage. Furthermore, qRT-PCR analysis in parasite lines with deletions of two kinase genes involved in male sexual development (map2 and cdpk4), showed a significant increase in cdc20 transcription in activated gametocytes. DNA replication and ultra structural analyses of cdc20 and map2 mutants showed similar blockage of nuclear division at the nuclear spindle/kinetochore stage. CDC20 was phosphorylated in asexual and sexual stages, but the level of modification was higher in activated gametocytes and ookinetes. Changes in global protein phosphorylation patterns in the Δcdc20 mutant parasites were largely different from those observed in the Δmap2 mutant. This suggests that CDC20 and MAP2 are both

  3. Targeted disruption of the mouse prosaposin gene affects the development of the prostate gland and other male reproductive organs.

    PubMed

    Morales, C R; Zhao, Q; El-Alfy, M; Suzuki, K

    2000-01-01

    The prosaposin gene encodes a 65-70 kilodalton (kd) protein, which is secreted or targeted to lysosomes. In lysosomes, prosaposin is the precursor of 4 activator proteins, designated saposins A, B, C, and D, which promote by acidic hydrolases, the degradation of glycosphingolipids with short oligosaccharide chains. Mutations of the prosaposin gene have been linked to several lysosomal storage disorders. An animal model was recently developed by creating a null allele in embryonic stem cells through gene targeting in order to investigate the phenotypic diversity of prosaposin mutations, the involvement of this protein in lysosomal storage diseases, and to develop potential therapeutic approaches. Mutant homozygous mice die at 35-40 days of age and neurological disorders contribute to their early death. Secreted prosaposin is present in milk and in cerebrospinal and seminal fluids. In the nervous system, prosaposin exhibits a trophic activity. Examination of reproduc-tive organs in homozygous mutant males shows several abnormalities such as a decrease in testis size with reduced spermiogenesis, and an involution of the prostate, seminal vesicle, and epididymis, although levels of testosterone in blood remain normal. In the prostate of homozygous mutants, only basal cells appear to be present, whereas secretory cells are absent. The epithelia in efferent ducts is formed by ciliated cells, whereas heterozygotes exhibit a majority of nonciliated cells. Our data indicate that prosaposin is involved in the development and maintenance of male reproductive organs. In prostatic epithelium, targeted disruption of the prosaposin gene appears to inactivate the mitogen-activated protein kinase pathway and to interfere with differentiation of secretory cells. PMID:11105903

  4. Transcription and imprinting dynamics in developing postnatal male germline stem cells

    PubMed Central

    Hammoud, Saher Sue; Low, Diana H.P.; Yi, Chongil; Lee, Chee Leng; Oatley, Jon M.; Payne, Christopher J.; Carrell, Douglas T.; Guccione, Ernesto; Cairns, Bradley R.

    2015-01-01

    Postnatal spermatogonial stem cells (SSCs) progress through proliferative and developmental stages to populate the testicular niche prior to productive spermatogenesis. To better understand, we conducted extensive genomic profiling at multiple postnatal stages on subpopulations enriched for particular markers (THY1, KIT, OCT4, ID4, or GFRa1). Overall, our profiles suggest three broad populations of spermatogonia in juveniles: (1) epithelial-like spermatogonia (THY1+; high OCT4, ID4, and GFRa1), (2) more abundant mesenchymal-like spermatogonia (THY1+; moderate OCT4 and ID4; high mesenchymal markers), and (3) (in older juveniles) abundant spermatogonia committing to gametogenesis (high KIT+). Epithelial-like spermatogonia displayed the expected imprinting patterns, but, surprisingly, mesenchymal-like spermatogonia lacked imprinting specifically at paternally imprinted loci but fully restored imprinting prior to puberty. Furthermore, mesenchymal-like spermatogonia also displayed developmentally linked DNA demethylation at meiotic genes and also at certain monoallelic neural genes (e.g., protocadherins and olfactory receptors). We also reveal novel candidate receptor–ligand networks involving SSCs and the developing niche. Taken together, neonates/juveniles contain heterogeneous epithelial-like or mesenchymal-like spermatogonial populations, with the latter displaying extensive DNA methylation/chromatin dynamics. We speculate that this plasticity helps SSCs proliferate and migrate within the developing seminiferous tubule, with proper niche interaction and membrane attachment reverting mesenchymal-like spermatogonial subtype cells back to an epithelial-like state with normal imprinting profiles. PMID:26545815

  5. Transcription and imprinting dynamics in developing postnatal male germline stem cells.

    PubMed

    Hammoud, Saher Sue; Low, Diana H P; Yi, Chongil; Lee, Chee Leng; Oatley, Jon M; Payne, Christopher J; Carrell, Douglas T; Guccione, Ernesto; Cairns, Bradley R

    2015-11-01

    Postnatal spermatogonial stem cells (SSCs) progress through proliferative and developmental stages to populate the testicular niche prior to productive spermatogenesis. To better understand, we conducted extensive genomic profiling at multiple postnatal stages on subpopulations enriched for particular markers (THY1, KIT, OCT4, ID4, or GFRa1). Overall, our profiles suggest three broad populations of spermatogonia in juveniles: (1) epithelial-like spermatogonia (THY1(+); high OCT4, ID4, and GFRa1), (2) more abundant mesenchymal-like spermatogonia (THY1(+); moderate OCT4 and ID4; high mesenchymal markers), and (3) (in older juveniles) abundant spermatogonia committing to gametogenesis (high KIT(+)). Epithelial-like spermatogonia displayed the expected imprinting patterns, but, surprisingly, mesenchymal-like spermatogonia lacked imprinting specifically at paternally imprinted loci but fully restored imprinting prior to puberty. Furthermore, mesenchymal-like spermatogonia also displayed developmentally linked DNA demethylation at meiotic genes and also at certain monoallelic neural genes (e.g., protocadherins and olfactory receptors). We also reveal novel candidate receptor-ligand networks involving SSCs and the developing niche. Taken together, neonates/juveniles contain heterogeneous epithelial-like or mesenchymal-like spermatogonial populations, with the latter displaying extensive DNA methylation/chromatin dynamics. We speculate that this plasticity helps SSCs proliferate and migrate within the developing seminiferous tubule, with proper niche interaction and membrane attachment reverting mesenchymal-like spermatogonial subtype cells back to an epithelial-like state with normal imprinting profiles. PMID:26545815

  6. 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.

  7. The Effect of Exposure to Atrazine on Dopaminergic Development in Pubertal Male SD Rats.

    PubMed

    Li, Yan-Shu; He, Xi; Ma, Kun; Wu, Yan-Ping; Li, Bai-Xiang

    2015-10-01

    Atrazine (ATR, 2-chloro-4-ethylamino-6-isopropylamino-s-triazine) is used worldwide as a herbicide, and its presence in the environment has resulted in documented human exposure. A lack of strong evidence for genetic heritability of idiopathic Parkinson's disease has focused attention on environmental toxicants in the disease etiology, particularly agrichemicals. Parkinson's disease is associated with advanced age and is characterized by the degeneration of dopaminergic neurons, but it is unclear whether specific neuronal damage could result from insults during development. The juvenile period is particularly vulnerable to environmental agent, therefore, we evaluated the effects of a 28-day exposure to ATR on the dopaminergic system in pubertal rats. Sprague-Dawley rats were treated orally with ATR at 50, 100, and 200 mg/kg bw, daily from postnatal days 27 to 54. In this study, we examined the hypothesis that pubertal exposure to ATR would disrupt the development of the nigrostriatal dopamine (DA) system. The content of DA and levodopa (L-DA) were examined in striatum samples by HPLC-FL, and the mRNA and protein expression of tyrosine hydroxylase, orphan nuclear hormone receptor (Nurr1), Nurr1 interacting protein (NuIP), and cyclin-dependent kinase inhibitors of the Cip̲Kip family (p57kip2) were examined in samples of the nigrostriatum by use of fluorescence Real-Time quantitative polymerase chain reaction (PCR). Exposure of juvenile rats to the high dose of ATR led to reduced levels of DA and L-DA, genes expression of NuIP, Nurr1, and p57kip2 in animals. PMID:26331294

  8. Maternal Flaxseed Oil During Lactation Enhances Bone Development in Male Rat Pups.

    PubMed

    Pereira, Aline D'Avila; Ribeiro, Danielle Cavalcante; de Santana, Fernanda Carvalho; de Sousa Dos Santos, Aline; Mancini-Filho, Jorge; do Nascimento-Saba, Celly Cristina Alves; Velarde, Luis Guillermo Coca; da Costa, Carlos Alberto Soares; Boaventura, Gilson Teles

    2016-08-01

    Flaxseed oil is an alpha linolenic acid source important in the growth and body development stage; furthermore, this acid acts on adipose tissue and bone health. The aim of this study was to evaluate body composition, fatty acid composition, hormone profile, retroperitoneal adipocyte area and femur structure of pups at weaning, whose mothers were fed a diet containing flaxseed oil during lactation. After birth, pups were randomly assigned: control (C, n = 12) and flaxseed oil (FO, n = 12), rats whose mothers were treated with diet containing soybean or flaxseed oil. At 21 days, the pups were weaned and body mass, length, body composition, biochemical parameter, leptin, osteoprotegerin, osteocalcin, fatty acids composition, intra-abdominal fat mass and femur structure were analyzed. FO showed (p < 0.05): higher body mass (+12 %) and length (+9 %); body fat mass (g, +45 %); bone mineral density (+8 %), bone mineral content (+55 %) and bone area (+35 %), osteocalcin (+173 %) and osteoprotegerin (+183 %). Arachidonic acid was lower (p < 0.0001), alpha-linolenic and eicosapentaenoic were higher (p < 0.0001). Intra-abdominal fat mass was higher (+25 %), however, the retroperitoneal adipocytes area was lower (-44 %). Femur mass (+10 %), distance between epiphyses (+4 %) and bone mineral density (+13 %) were higher. The study demonstrates that adequate flaxseed oil content during a lactation diet plays an important role in the development of pups. PMID:27256330

  9. Longitudinal development of match-running performance in elite male youth soccer players.

    PubMed

    Saward, C; Morris, J G; Nevill, M E; Nevill, A M; Sunderland, C

    2016-08-01

    This study longitudinally examined age-related changes in the match-running performance of retained and released elite youth soccer players aged 8-18 years. The effect of playing position on age-related changes was also considered. Across three seasons, 263 elite youth soccer players were assessed in 1-29 competitive matches (988 player-matches). For each player-match, total distance and distances covered at age group-specific speed zones (low-speed, high-speed, sprinting) were calculated using 1 Hz or 5 Hz GPS. Mixed modeling predicted that match-running performance developed nonlinearly, with age-related changes best described with quadratic age terms. Modeling predicted that playing position significantly modified age-related changes (P < 0.05) and retained players covered significantly more low-speed distance compared with released players (P < 0.05), by 75 ± 71 m/h (mean ± 95% CI; effect size ± 95% CI: 0.35 ± 0.34). Model intercepts randomly varied, indicating differences between players in match-running performance unexplained by age, playing position or status. These findings may assist experts in developing training programs specific to the match play demands of players of different ages and playing positions. Although retained players covered more low-speed distance than released players, further study of the actions comprising low-speed distance during match play is warranted to better understand factors differentiating retained and released players. PMID:26302717

  10. The impact of football training on motor development in male children.

    PubMed

    Erceg, Marko; Zagorac, Nebojsa; Katić, Ratko

    2008-03-01

    The aim of the study was to determine the effect of football school program and physical education curriculum on changes in the motor abilities of 7- and 8-year-old boys. The study included a sample of 180 boys divided into group 1 (7-year-old boys), subdivided to experimental (n = 40) and control (n = 50) groups, and group 2 (8-year-old boys), subdivided to experimental (n = 40) and control (n = 50) groups. Experimental groups included children attending three training units of football training over a 9-month period, in addition to the conventional physical education curriculum. Control groups included children attending only conventional physical education curriculum. All study subjects underwent testing with a battery of 12 motor tests at the beginning and at the end of the study. Results obtained by discriminative canonic analysis showed no statistically significant between-group difference in motor abilities at the beginning of the study. However, significant differences in favor of experimental groups were recorded at the end of the study. Favorable changes in all motor variables were observed in both experimental and control groups of children from the initial through the final state. These changes were more pronounced in experimental groups. Analysis of variance for difference variables (final to initial measurement) indicated programmed education in the form of football training in addition to regular physical education curriculum to predominantly influence the development of aerobic endurance, agility, speed and flexibility in 7-year-old boys, and of explosive strength, aerobic endurance, flexibility and speed in 8-year-old boys. In the latter, football training led to the formation of a motor complex integrating explosiveness, speed, coordination, endurance and flexibility as a general motor factor determining future quality development in football. PMID:18494210

  11. Neonatal allopregnanolone or finasteride administration modifies hippocampal K(+) Cl(-) co-transporter expression during early development in male rats.

    PubMed

    Mòdol, Laura; Casas, Caty; Llidó, Anna; Navarro, Xavier; Pallarès, Marc; Darbra, Sònia

    2014-09-01

    The maintenance of levels of endogenous neurosteroids (NS) across early postnatal development of the brain, particularly to the hippocampus, is crucial for their maturation. Allopregnanolone (Allop) is a NS that exerts its effect mainly through the modulation of the GABAA receptor (GABAAR). During early development, GABA, acting through GABAAR, that predominantly produces depolarization shifts to hyperpolarization in mature neurons, around the second postnatal week in rats. Several factors contribute to this change including the progressive increase of the neuron-specific K(+)/Cl(-) co-transporter 2 (KCC2) (a chloride exporter) levels. Thus, we aimed to analyze whether a different profile of NS levels during development is critical and can alter this natural progression of KCC2 stages. We administrated sustained Allop (20mg/kg) or Finasteride (5α-reductase inhibitor, 50mg/kg) from the 5th postnatal day (PD5) to PD9 and assessed changes in the hippocampal expression of KCC2 at transcript and protein levels as well as its active phosphorylated state in male rats. Taken together data indicated that manipulation of NS levels during early development influence KCC2 levels and point out the importance of neonatal NS levels for the hippocampal development. PMID:24861264

  12. Cut-Off Value of Total Adiponectin for Managing Risk of Developing Metabolic Syndrome in Male Japanese Workers

    PubMed Central

    Hata, Akiko; Yonemoto, Koji; Shikama, Yosuke; Aki, Nanako; Kosugi, Chisato; Tamura, Ayako; Ichihara, Takako; Minagawa, Takako; Kuwamura, Yumi; Miyoshi, Masashi; Nakao, Takayuki; Funaki, Makoto

    2015-01-01

    Aim To determine the optimal cut-off value of serum total adiponectin for managing the risk of developing metabolic syndrome (MetS) in male Japanese workers. Methods A total of 365 subjects without MetS aged 20–60 years were followed up prospectively for a mean of 3.1 years. The accelerated failure-time model was used to estimate time ratio (TR) and cut-off value for developing MetS. Results During follow-up, 45 subjects developed MetS. Age-adjusted TR significantly declined with decreasing total adiponectin level (≤ 4.9, 5.0–6.6, 6.7–8.8 and ≥ 8.9 μg/ml, P for trend = 0.003). In multivariate analyses, TR of MetS was 0.12 (95% CI 0.02–0.78; P = 0.03) in subjects with total adiponectin level of 5.0–6.6 μg/ml, and 0.15 (95% CI 0.02–0.97; P = 0.047) in subjects with total adiponectin level ≤ 4.9 μg/ml compared with those with total adiponectin level ≥ 8.9 μg/ml. The accelerated failure-time model showed that the optimal cut-off value of total adiponectin for managing the risk of developing MetS was 6.2 μg/ml. In the multivariate-adjusted model, the mean time to the development of MetS was 78% shorter for total adiponectin level ≤ 6.2 μg/ml compared with > 6.2 μg/ml (TR 0.22, 95% CI: 0.08–0.64, P = 0.005). Conclusion Our findings suggest that the cut-off value for managing the risk of developing MetS is 6.2 μg/ml in male Japanese workers. Subjects with total adiponectin level ≤ 6.2 μg/ml developed MetS more rapidly than did those with total adiponectin level > 6.2 μg/ml. PMID:25705909

  13. The role of OsMSH4 in male and female gamete development in rice meiosis

    PubMed Central

    Wang, Chaolong; Wang, Yang; Cheng, Zhijun; Zhao, Zhigang; Chen, Jun; Sheng, Peike; Yu, Yang; Ma, Weiwei; Duan, Erchao; Wu, Fuqing; Liu, Linglong; Qin, Ruizhen; Zhang, Xin; Guo, Xiuping; Wang, Jiulin; Jiang, Ling; Wan, Jianmin

    2016-01-01

    Meiosis is essential for gametogenesis in sexual reproduction in rice (Oryza sativa L.). We identified a MutS-homolog (MSH) family gene OsMSH4 in a trisomic plant. Cytological analysis showed that developments of both pollen and embryo sacs in an Osmsh4 mutant were blocked due to defective chromosome pairing. Compared with the wild type, the Osmsh4 mutant displayed a significant ~21.9% reduction in chiasma frequency, which followed a Poisson distribution, suggesting that class I crossover formation in the mutant was impaired. Temporal and spatial expression pattern analyses showed that OsMSH4 was preferentially expressed in meiocytes during their meiosis, indicating a critical role in gametogenesis. Subcellular localization showed that OsMSH4–green fluorescent protein was predominantly located in the nucleus. OsMSH4 could interact with another MSH member (OsMSH5) through the N-terminus and C-terminus, respectively. Direct physical interaction between OsMSH5, OsRPA1a, OsRPA2b, OsRPA1c, and OsRPA2c was identified by yeast two-hybrid assays and further validated by pull-down assays. Our results supported the conclusion that the OsMSH4/5 heterodimer plays a key role in regulation of crossover formation during rice meiosis by interaction with the RPA complex. PMID:26712826

  14. The negative effect of heavy work life during adolescence on height development of young males.

    PubMed

    Ozener, Baniş; Ertuğrul, Berna

    2012-03-01

    The aim of this study was to determine the physical development level of post-adolescent automotive repair workers who had been employed in heavy work during adolescence, a critical developmental period. Young workers (Group 1, N = 106, Mean age = 18.33, SD = 0.65) employed an average of 6 years in workshops in the capital of Turkey, Ankara. For the control group, two groups of the same age but having a difference in terms of socioeconomic status were chosen. The first one of these was comprised of individuals who had the same socioeconomic status as the laborers (Group 2, N = 106, Mean age = 18.33, SD = 0.65) but were not laborers. The second control group was composed of individuals from the higher socioeconomic levels of society (Group 3, N = 100, Mean Age = 18.45 SD = 0.63). Weight, height and measures were taken from the individuals and the body mass index (kg/m2) was calculated. The results of the analysis show that, although all the variables of the labor group were lower than Group 2, the difference is only significant for the height variable (p < 0.05). These findings reveal that, having completed a critical developmental period such as adolescence after being employed in heavy work, the automotive repair youngsters are prone to chronic developmental retardation. PMID:22816205

  15. The role of OsMSH4 in male and female gamete development in rice meiosis.

    PubMed

    Wang, Chaolong; Wang, Yang; Cheng, Zhijun; Zhao, Zhigang; Chen, Jun; Sheng, Peike; Yu, Yang; Ma, Weiwei; Duan, Erchao; Wu, Fuqing; Liu, Linglong; Qin, Ruizhen; Zhang, Xin; Guo, Xiuping; Wang, Jiulin; Jiang, Ling; Wan, Jianmin

    2016-03-01

    Meiosis is essential for gametogenesis in sexual reproduction in rice (Oryza sativa L.). We identified a MutS-homolog (MSH) family gene OsMSH4 in a trisomic plant. Cytological analysis showed that developments of both pollen and embryo sacs in an Osmsh4 mutant were blocked due to defective chromosome pairing. Compared with the wild type, the Osmsh4 mutant displayed a significant ~21.9% reduction in chiasma frequency, which followed a Poisson distribution, suggesting that class I crossover formation in the mutant was impaired. Temporal and spatial expression pattern analyses showed that OsMSH4 was preferentially expressed in meiocytes during their meiosis, indicating a critical role in gametogenesis. Subcellular localization showed that OsMSH4-green fluorescent protein was predominantly located in the nucleus. OsMSH4 could interact with another MSH member (OsMSH5) through the N-terminus and C-terminus, respectively. Direct physical interaction between OsMSH5, OsRPA1a, OsRPA2b, OsRPA1c, and OsRPA2c was identified by yeast two-hybrid assays and further validated by pull-down assays. Our results supported the conclusion that the OsMSH4/5 heterodimer plays a key role in regulation of crossover formation during rice meiosis by interaction with the RPA complex. PMID:26712826

  16. Changes in Thyroid Status During Perinatal Development of MCT8-Deficient Male Mice

    PubMed Central

    Ferrara, Alfonso Massimiliano; Liao, Xiao-Hui; Gil-Ibáñez, Pilar; Marcinkowski, Teresa; Bernal, Juan; Weiss, Roy E.; Dumitrescu, Alexandra M.

    2013-01-01

    Patients with the monocarboxylate transporter 8 (MCT8) deficiency syndrome present with a severe psychomotor retardation and abnormal serum thyroid hormone (TH) levels, consisting of high T3 and low T4 and rT3. Mice deficient in Mct8 replicate the thyroid phenotype of patients with the MCT8 gene mutations. We analyzed the serum TH levels and action in the cerebral cortex and in the liver during the perinatal period of mice deficient in Mct8 to assess how the thyroid abnormalities of Mct8 deficiency develop and to study the thyroidal status of specific tissues. During perinatal life, the thyroid phenotype of Mct8-deficient mice is different from that of adult mice. They manifest hyperthyroxinemia at embryonic day 18 and postnatal day 0. This perinatal hyperthyroxinemia is accompanied by manifestations of TH excess as evidenced by a relative increase in the expression of genes positively regulated by T3 in both the cerebral cortex and liver. An increased tissue accumulation of T4 and T3 and the expression of TH alternative transporters, including Lat1, Lat2, Oatp1c1, and Oatp3a1 in the cortex and Lat2 and Oatp1b2 in the liver, suggested that Mct8 deficiency either directly interferes with tissue efflux of TH or indirectly activates other transporters to increase TH uptake. This report is the first to identify that the ontogenesis of TH abnormalities in Mct8-deficient mice manifests with TH excess in the perinatal period. PMID:23696569

  17. Dietary amino acid levels and feed restriction affect small intestinal development, mortality, and weight gain of male broilers.

    PubMed

    Wijtten, P J A; Hangoor, E; Sparla, J K W M; Verstegen, M W A

    2010-07-01

    This study investigated the effect of 2 different dietary amino acid treatments and feed restriction in early life versus a control treatment on development of the small intestine segments (weights), mortality, and broiler performance. Each treatment was applied to 6 cages with Ross 308 male broilers and to 6 cages with Cobb 500 male broilers with 24 birds per cage. A control treatment (100% ideal protein) was compared with a treatment with 30% extra ideal protein, a treatment with daily adjustment of the dietary amino acid level and profile, and a feed restriction treatment. The protein treatments were applied from 0 to 14 d of age. The feed restriction was applied from 4 to 21 d of age. Restriction was 15% from d 4 to 14 of age and diminished with equal daily steps thereafter to 5% at 21 d of age. Birds were weighed and dissected for evaluation of small intestine weights at 6, 9, 14, and 36 d of age. Feed intake restriction reduced leg problems in Ross and Cobb broilers. Extra dietary protein reduced leg problems in Ross broilers only. The present experiment does not show that small intestinal weight development is related to mortality. Thirty percent extra dietary ideal protein increased duodenum weight between 6 and 9 d of age. This was not further increased by the daily optimization of the dietary amino acid level and profile. The increased duodenum weights coincided with an improved BW gain. This indicates that duodenum weight may be important in facilitating BW gain in young broilers. Thus, it may be worthwhile to pay more attention to the relation between nutrition and duodenum weight and duodenum function in further studies. PMID:20548070

  18. Development and psychometric properties of a self-regulation scale about leisure time physical activity in Iranian male adolescents

    PubMed Central

    Abasi, Mohammad Hadi; Eslami, Ahmad Ali; Rakhshani, Fatemeh; Shiri, Mansoor

    2016-01-01

    Background: Self-regulation is one of the current psychological concepts that have been known as a determinant of leisure time physical activity. Due to cultural and social diversity in different societies and age groups, application of specific questionnaires is essential to perform investigations about physical activities. The aim of this study is development and evaluation of psychometric properties of a self-regulation questionnaire about leisure time physical activity in Iranian male adolescents. Materials and Methods: This cross-sectional study was conducted in 2013, and data of 603 male students from 12 high schools in Isfahan were collected. A comprehensive literature review and similar questionnaire review were conducted and 25 items were selected or developed to measure self-regulation. Comprehensibility of items was evaluated in a pilot study and an expert panel evaluated face and content validity. Exploratory factors analysis (EFA) was used for evaluation of construct validity and extraction of sub-constructs of self-regulation. Leisure time physical activity was assessed using International Physical Activity Questionnaire (IPAQ). Results: The mean age of the participants was 16.3 years (SD =1.0) and the range was 15-19 years. Cronbach's α coefficient of the questionnaire in the pilot and main study was 0.84 and 0.90, respectively. EFA resulted in four sub-constructs including “enlistment of social support”, “goal setting”, “self-construction”, and “self-monitoring”, which explained 63.6% of the variance of self-regulation. Conclusions: Results of this investigation provide some support to the validity and reliability of the 16-item questionnaire of self-regulation abut leisure time physical activity in the target group. PMID:27095993

  19. Aerobic Fitness Linked to Cortical Brain Development in Adolescent Males: Preliminary Findings Suggest a Possible Role of BDNF Genotype

    PubMed Central

    Herting, Megan M.; Keenan, Madison F.; Nagel, Bonnie J.

    2016-01-01

    Aerobic exercise has been shown to impact brain structure and cognition in children and adults. Exercise-induced activation of a growth protein known as brain derived neurotrophic factor (BDNF) is thought to contribute to such relationships. To date, however, no study has examined how aerobic fitness relates to cortical brain structure during development and if BDNF genotype moderates these relationships. Using structural magnetic resonance imaging (MRI) and FreeSurfer, the current study examined how aerobic fitness relates to volume, thickness, and surface area in 34 male adolescents, 15 to 18 years old. Moreover, we examined if the val66met BDNF genotype moderated these relationships. We hypothesized that aerobic fitness would relate to greater thickness and volumes in frontal, parietal, and motor regions, and that these relationships would be less robust in individuals carrying a Met allele, since this genotype leads to lower BDNF expression. We found that aerobic fitness positively related to right rostral middle frontal cortical volume in all adolescents. However, results also showed BDNF genotype moderated the relationship between aerobic fitness and bilateral medial precuneus surface area, with a positive relationship seen in individuals with the Val/Val allele, but no relationship detected in those adolescents carrying a Met allele. Lastly, using self-reported levels of aerobic activity, we found that higher-fit adolescents showed larger right medial pericalcarine, right cuneus and left precuneus surface areas as compared to their low-fit peers. Our findings suggest that aerobic fitness is linked to cortical brain development in male adolescents, and that more research is warranted to determine how an individual’s genes may influence these relationships. PMID:27445764

  20. Exposure to monocrotophos pesticide during sexual development causes the feminization/demasculinization of the reproductive traits and a reduction in the reproductive success of male guppies (Poecilia reticulata)

    SciTech Connect

    Tian, Hua; Li, Yun; Wang, Wei; Wu, Peng; Ru, Shaoguo

    2012-09-01

    Monocrotophos is a highly toxic organophosphorus pesticide that has been confirmed to be an endocrine‐disrupting chemical. To evaluate the influence of this pollutant on the reproductive system of male fish, we studied the sex steroid levels, reproductive traits, sex ratio, and reproductive success in male guppies (Poecilia reticulata) exposed to 40% monocrotophos pesticide at the nominal concentrations of 0.01, 0.10, and 1.00 mg/L for 90 days from birth to adulthood in a semi‐static exposure system. Radioimmunoassay and western blot analyses demonstrated that the long‐term exposure to monocrotophos pesticide during the sexual development of male guppies caused a significant increase in 17β‐estradiol levels and consequently induced vitellogenin synthesis, suggesting the feminization of the males. Monocrotophos pesticide also caused a significant decrease in testosterone levels, which consequently inhibited testis growth and reduced the sperm count and the area and intensity of their sexually attractive orange spots, which collectively indicated the significant demasculinization of the male sexual characteristics. Furthermore, these changes in the sexual characteristics at the cellular and organ levels translated into ecologically important effects on the reproductive success at the individual level, as measured by a decrease in offspring production and survival rate. The present study provides the first evidence that monocrotophos pesticide can cause severe reproductive abnormalities in fish due to its endocrine‐disrupting action. -- Highlights: ► Monocrotophos pesticide caused an increase in 17β‐estradiol levels of male guppies. ► Monocrotophos pesticide induced vitellogenin synthesis of male guppies. ► Monocrotophos pesticide caused a decrease in testosterone levels of male guppies. ► Monocrotophos pesticide caused demasculinization of male sexual characteristics. ► Monocrotophos pesticide caused a reduction in reproductive success of male

  1. Condoms - male

    MedlinePlus

    ... Rubbers; Male condoms; Contraceptive - condom; Contraception - condom; Barrier method - condom ... infections.) Latex rubber Polyurethane Condoms are the only method of birth control for men that are not ...

  2. The role of sexually explicit material in the sexual development of same-sex-attracted Black adolescent males.

    PubMed

    Arrington-Sanders, Renata; Harper, Gary W; Morgan, Anthony; Ogunbajo, Adedotun; Trent, Maria; Fortenberry, J Dennis

    2015-04-01

    Sexually explicit material (SEM) (including Internet, video, and print) may play a key role in the lives of Black same-sex sexually active youth by providing the only information to learn about sexual development. There is limited school- and/or family-based sex education to serve as models for sexual behaviors for Black youth. We describe the role SEM plays in the sexual development of a sample of Black same-sex attracted (SSA) young adolescent males ages 15-19. Adolescents recruited from clinics, social networking sites, and through snowball sampling were invited to participate in a 90-min, semi-structured qualitative interview. Most participants described using SEM prior to their first same-sex sexual experience. Participants described using SEM primarily for sexual development, including learning about sexual organs and function, the mechanics of same-gender sex, and to negotiate one's sexual identity. Secondary functions were to determine readiness for sex; to learn about sexual performance, including understanding sexual roles and responsibilities (e.g., "top" or "bottom"); to introduce sexual performance scripts; and to develop models for how sex should feel (e.g., pleasure and pain). Youth also described engaging in sexual behaviors (including condom non-use and/or swallowing ejaculate) that were modeled on SEM. Comprehensive sexuality education programs should be designed to address the unmet needs of young, Black SSA men, with explicit focus on sexual roles and behaviors that may be inaccurately portrayed and/or involve sexual risk-taking (such as unprotected anal intercourse and swallowing ejaculate) in SEM. This work also calls for development of Internet-based HIV/STI prevention strategies targeting young Black SSA men who may be accessing SEM. PMID:25677334

  3. Effects of commercial in ovo injection of 25-hydroxycholecalciferol on bone development and mineralization in male and female broilers.

    PubMed

    Bello, A; Hester, P Y; Gerard, P D; Zhai, W; Peebles, E D

    2014-11-01

    Improved bone development and mineralization in broilers have been attributed to the use of 25-hydroxylcholecalceiferol [25(OH)D3] as a dietary supplement. In this study, effects of the in ovo injection of 25(OH)D3 delivered in commercial diluent on 18 d of incubation (doi) on subsequent bone development and mineralization in male and female Ross × Ross 708 broilers were investigated. The variables investigated included bone mineral density and breaking strength, bone ash concentration, and calcium and phosphorus bone ash concentrations. In a single-stage incubator, with 6 treatments on each of the 10 tray levels, a total of 2,400 experimental broiler hatching eggs were evenly and randomly set. Eggs were treatment-injected and transferred to corresponding hatching baskets on 18 doi. Experimental treatment groups were those that received 0.2, 0.6, 1.8, or 5.4 µg of 25(OH)D3 that were delivered in 100 µL of commercial diluent. Noninjected and diluent-injected controls were also included. On 21 doi, chicks were pulled and placed in corresponding floor pens, and on each of d 0, 14, and 28 posthatch (poh), 2 birds of each sex from each pen were randomly selected for necropsy and extraction of both of their tibia bones. Bones from the right leg were subjected to mineral density analysis and those from the left leg were used to determine breaking strength and residual bone ash concentration. Furthermore, ash calcium and phosphorus concentrations on d 14 and 28 poh were determined. There was a treatment × sex × age interaction for bone breaking strength. Bone breaking strength in male birds on d 28 poh was higher in the 0.20, 0.60, and 1.80 µg of 25(OH)D3-injected treatment groups than in the diluent-injected control group. In conclusion, although the in ovo injection of 25(OH)D3 had no positive effect on the bone development of Ross × Ross 708 broilers through d 28 poh compared with noninjected controls, it may provide a benefit to those subjected to an injection

  4. A receptor heteromer mediates the male perception of female attractants in plants.

    PubMed

    Wang, Tong; Liang, Liang; Xue, Yong; Jia, Peng-Fei; Chen, Wei; Zhang, Meng-Xia; Wang, Ying-Chun; Li, Hong-Ju; Yang, Wei-Cai

    2016-03-10

    Sexual reproduction requires recognition between the male and female gametes. In flowering plants, the immobile sperms are delivered to the ovule-enclosed female gametophyte by guided pollen tube growth. Although the female gametophyte-secreted peptides have been identified to be the chemotactic attractant to the pollen tube, the male receptor(s) is still unknown. Here we identify a cell-surface receptor heteromer, MDIS1-MIK, on the pollen tube that perceives female attractant LURE1 in Arabidopsis thaliana. MDIS1, MIK1 and MIK2 are plasma-membrane-localized receptor-like kinases with extracellular leucine-rich repeats and an intracellular kinase domain. LURE1 specifically binds the extracellular domains of MDIS1, MIK1 and MIK2, whereas mdis1 and mik1 mik2 mutant pollen tubes respond less sensitively to LURE1. Furthermore, LURE1 triggers dimerization of the receptors and activates the kinase activity of MIK1. Importantly, transformation of AtMDIS1 to the sister species Capsella rubella can partially break down the reproductive isolation barrier. Our findings reveal a new mechanism of the male perception of the female attracting signals. PMID:26863186

  5. CUMULATIVE EFFECTS OF DIBUTYL PHTHALATE AND DIETHYLHEXYL PHTHALATE ON MALE RAT REPRODUCTIVE TRACT DEVELOPMENT: ALTERED FETAL STEROID HORMONES AND GENES.

    EPA Science Inventory

    Exposure to the plasticizers diethylhexyl phthalate (DEHP) and di(n-butyl) phthalate (DBP) during sexual differentiation causes male reproductive tract malformations in rats and rabbits. In the fetal male rat, these two phthalate esters decrease testosterone (T) production and i...

  6. Chronic Exendin-4 treatment prevents the development of cancer cachexia symptoms in male rats bearing the Yoshida Sarcoma

    PubMed Central

    Honors, Mary Ann; Kinzig, Kimberly P.

    2013-01-01

    Cancer cachexia is the syndrome of weight loss, loss of appetite, and wasting of skeletal muscle and adipose tissue experienced by many individuals with cancer. Currently, few effective treatment and prevention strategies are available for these patients, due in part to a poor understanding of the mechanisms contributing to cachexia. Insulin resistance has been associated with cancer cachexia in epidemiological, human, and animal research. The present experiment was designed to examine the ability of Exendin-4, a GLP-1 agonist and insulin sensitizing agent, to prevent the development of cachexia symptoms in male Sprague Dawley rats bearing the Yoshida sarcoma. Following tumor implantation or sham surgery, rats received daily treatment with saline or Exendin-4 (3 μg/kg body weight/day) and were monitored for tumor growth and cachexia symptoms for 21-23 days. As a result of large variability in treatment effects, data were analyzed separately for animals with large and small tumors. Exendin-4 treatment reduced tumor growth and prevented the development of cancer cachexia symptoms in animals with small, but not large, tumors. In addition, insulin levels were preserved in Exendin-4-treated tumor-bearing animals. The results of this experiment demonstrate a novel preventative therapy for cancer cachexia, and a novel use of Exendin-4. Further research is necessary to determine the mechanisms through which Exendin-4 exerts these potent effects. PMID:24101584

  7. Altered testicular development as a consequence of increase number of sertoli cell in male lambs exposed prenatally to excess testosterone.

    PubMed

    Rojas-García, Pedro P; Recabarren, Mónica P; Sir-Petermann, Teresa; Rey, Rodolfo; Palma, Sergio; Carrasco, Albert; Perez-Marin, Carlos C; Padmanabhan, Vasantha; Recabarren, Sergio E

    2013-06-01

    The reprograming effects of prenatal testosterone (T) treatment on postnatal reproductive parameters have been studied extensively in females of several species but similar studies in males are limited. We recently found that prenatal T treatment increases Sertoli cell number and reduced spermatogenesis in adult rams. If such disruptions are manifested early in life and involve changes in testicular paracrine environment remain to be explored. This study addresses the impact of prenatal T excess on testicular parameters in infant males, including Sertoli cell number and expression of critical genes [FSH receptor (FSHR), androgen receptor (AR), transforming growth factor beta 1 (TGFB1), 3 (TGFB3), transforming growth factor beta type 1 receptor, (TGFBR1), and anti-Müllerian hormone (AMH)] modulating testicular function. At 4 week of age, male lambs born to dams treated with 30 mg of T propionate twice weekly from day 30 to 90, followed by 40 mg of T propionate from day 90 to 120 of pregnancy (T-males), had a higher number of Sertoli cells/testis (P = 0.035) than control males (C-males) born to dams treated with the vehicle. While no differences were observed in the expression of FSHR and TGFB3, testicular TGFBR1 expression was found to be lower in T-males (P = 0.03) compared to C-males. Expression level of AMH, TGFB1, and AR also tended to be lower in T-males. These findings provide evidence that impact of fetal exposure to T excess is evident early in postnatal life, mainly characterized by an increase in Sertoli cell number. This could explain the testicular dysfunction observed in adult rams. PMID:23076741

  8. Differential Flight Muscle Development in Workers, Queens and Males of the Eusocial Bees, Apis mellifera and Scaptotrigona postica

    PubMed Central

    Correa-Fernandez, Fernanda; Cruz-Landim, Carminda

    2010-01-01

    The flight capability of the adult eusocial bees, Apis mellifera L. and Scaptotrigona postica Latreille (Hymenoptera: Apidae), is intrinsically linked to their colonial functions, such as the nuptial flight for mating in the case of queens and males, and the exploration of new habitats for nesting and food sources in the case of workers. Flight is achieved by the contraction of indirect flight muscles that produce changes in thoracic volume and, therefore, wing movement. The purpose of this work is to examine possible differences in muscle development that may be associated with the flying activity of individuals in a given life stage considering the behavioral and physiological differences among the stages and between the two species studied. Measurements of the muscle fibers obtained from light microscopy preparations of muscle were submitted to statistical analysis in order to detect the differences at a given time, or throughout the life of the individual. The results show that muscle morphology is similar in both species, but in A. mellifera the muscle fibers are thicker and more numerous than in S. postica. Differences in the fiber thickness according to life stage in all classes of individuals of both species were detected. These results are discussed in relation to the need for flying in each life stage. PMID:20673070

  9. Testicular disorder of sex development in four cats with a male karyotype (38,XY; SRY-positive).

    PubMed

    Nowacka-Woszuk, Joanna; Szczerbal, Izabela; Salamon, Sylwia; Kociucka, Beata; Jackowiak, Hanna; Prozorowska, Ewelina; Slaska, Brygida; Rozanska, Dorota; Orzelski, Maciej; Ochota, Malgorzata; Dzimira, Stanislaw; Lipiec, Magdalena; Nizanski, Wojciech; Switonski, Marek

    2014-12-10

    The molecular background of disorders of sex development (DSD) in cats is poorly recognized. In this study we present cytogenetic, molecular and histological analyses of four cats subjected for the analysis due to ambiguous external genitalia. Three cases, with rudimentary penises and an abnormal position of the urethral orifice, represented different types of hypospadias. The fourth case had a normal penis, a blind vulva and spermatogenetically active testes. Histological studies showed structures typical of testes, but spermatogenic activity was observed in two cats only. All the cats had a normal male chromosome complement (38,XY) and the Y-chromosome linked genes (SRY and ZFY) were also detected. Fluorescent in situ hybridization (FISH), with the use of the feline BAC probe harboring the SRY gene, excluded the possibility of chromosome translocation of the Y chromosome fragment carrying the SRY gene onto another chromosome. Sequencing of four candidate genes (SRY--sex determining region Y; AR--androgen receptor; SRD5A2--steroid-5-alfa reductase 2 and MAMLD1--mastermind-like domain containing (1) revealed one SNP in the SRY gene, one common polymorphism in exon 1 of the AR gene (tandem repeat of a tri-nucleotide motif--CAG), six polymorphisms (5 SNPs and 1 indel) in the SRD5A2 gene and one SNP in the MAMLD1 gene. Molecular studies of the candidate genes showed no association with the identified polymorphisms, thus molecular background of the studied DSD phenotypes remains unknown. PMID:25455261

  10. Development of a short version of the Aging Males' Symptoms scale: Mokken scaling analysis and Rasch analysis.

    PubMed

    Lee, Chin-Pang; Chen, Yu; Jiang, Kun-Hao; Chu, Chun-Lin; Chiu, Yu-Wen; Chen, Jiun-Liang; Chen, Ching-Yen

    2016-06-01

    The aim of this study was to develop a psychometrically sound short version of the 17-item Aging Males' Symptoms (AMS) scale using Mokken scale analysis (MSA) and Rasch analysis. We recruited a convenient sample of 1787 men (age: mean (SD) = 43.8 (11.5) years) who visited a men's health polyclinic in Taiwan and completed the AMS scale. The scale was first assessed using MSA. The remaining items were assessed using Rasch analysis. We used a stepwise approach to remove items with χ(2) item statistics and mean square values while monitoring unidimensionality. The item reduction process resulted in a 6-item version of the AMS scale (AMS-6). The AMS-6 scale included a 5-item psychosomatic subscale (original items 1, 4, 5, 8, and 9) and a 1-item sexual subscale (original item 16). Analyses confirmed that the 5-item psychosomatic subscale was a Rasch scale. The AMS-6 correlated well with the AMS scales: the 5-item psychosomatic subscale correlated with the AMS scale (r between 0.50 and 0.92); the 1-item sexual subscale correlated with the sexual subscale of the AMS scale (r = 0.81). A 6-item short form of the AMS scale had satisfactory measurement properties. This version may be useful for estimating psychosomatic and sexual symptoms as well as health-related quality of life with a minimal burden on respondents. PMID:26984738

  11. Transgenic mice with inactive alleles for procollagen N-proteinase (ADAMTS-2) develop fragile skin and male sterility.

    PubMed Central

    Li, S W; Arita, M; Fertala, A; Bao, Y; Kopen, G C; Långsjö, T K; Hyttinen, M M; Helminen, H J; Prockop, D J

    2001-01-01

    Transgenic mice were prepared with inactive alleles for procollagen N-proteinase (ADAMTS-2; where ADAMTS stands for a disintegrin and metalloproteinase with thrombospondin repeats). Homozygous mice were grossly normal at birth, but after 1-2 months they developed thin skin that tore after gentle handling. Although the gene was inactivated, a large fraction of the N-propeptides of type I procollagen in skin and the N-propeptides of type II procollagen in cartilage were cleaved. Therefore the results suggested the tissues contained one or more additional enzymes that slowly process the proteins. Electron microscopy did not reveal any defects in the morphology of collagen fibrils in newborn mice. However, in two-month-old mice, the collagen fibrils in skin were seen as bizarre curls in cross-section and the mean diameters of the fibrils were approx. half of the controls. Although a portion of the N-propeptides of type II procollagen in cartilage were not cleaved, no defects in the morphology of the fibrils were seen by electron microscopy or by polarized-light microscopy. Female homozygous mice were fertile, but male mice were sterile with a marked decrease in testicular sperm. Therefore the results indicated that ADAMTS-2 plays an essential role in the maturation of spermatogonia. PMID:11284712

  12. Androgen-mediated development of irradiation-induced thyroid tumors in rats: dependence on animal age during interval of androgen replacement in castrated males

    SciTech Connect

    Hofmann, C.; Oslapas, R.; Nayyar, R.; Paloyan, E.

    1986-07-01

    When male Long-Evans rats at age 8 weeks were radiation treated (40 microCi Na131I), thyroid follicular adenomas and carcinomas were observed at age 24 months with a high incidence of 94%. Castration of males prior to irradiation significantly reduced this tumor incidence to 60%. When testosterone (T) was replaced in castrated, irradiated male rats, differentially increased incidences of thyroid tumors occurred. Immediate (age 2-6 mo) or early (age 6-12 mo) T replacement at approximate physiologic levels led to thyroid follicular tumor incidences of 100 and 82%, respectively, whereas intermediate (12-18 mo) or late (18-24 mo) T treatment led to only 70 and 73% incidences, respectively. Continuous T replacement (2-24 mo) in castrated irradiated male rats raised thyroid tumor incidence to 100%. Since elevated thyroid-stimulating hormone (TSH) is a reported requisite for development of radiation-associated thyroid tumors, the effects of T on serum TSH levels were examined. Mean serum TSH values in all irradiated animal groups were significantly elevated above age-matched nonirradiated animals at 6, 12, 18, and 24 months. Serum TSH levels were higher in continuous T-replaced irradiated castrates than in intact, irradiated males, whereas such intact male TSH levels were greater than those for irradiated castrates without T treatment. Interval T replacement in castrated male rats was associated with increased serum TSH levels during the treatment interval and with lowered TSH levels after discontinuation of T treatment, particularly in irradiated rats. However, when irradiated, castrated males received late T replacement (age 18-24 mo), there was no elevation of TSH at the end of the treatment interval. An indirect effect of T via early stimulation of TSH may be partly responsible for the high incidence of irradiation-induced thyroid tumors in rats.

  13. Condoms - male

    MedlinePlus

    ... PREGNANCY? If the sperm contained in a male's semen reach a woman's vagina, pregnancy may occur. Condoms ... receptacle) on the end of it (to collect semen), place the condom against the top of the ...

  14. Perinatal exposure to bisphenol-A inhibits synaptogenesis and affects the synaptic morphological development in offspring male mice.

    PubMed

    Xu, Xiaohong; Xie, Lingdan; Hong, Xing; Ruan, Qin; Lu, Hongfei; Zhang, Qin; Zhang, Guangxia; Liu, Xingyi

    2013-05-01

    Our previous study indicated that perinatal exposure to low-dose BPA, one of the most common environmental endocrine disrupters, alters behavioral development in offspring mice. Given that synaptic structure of the hippocampus is closely related to behaviors, in the present study, we examined the effects of perinatal exposure to BPA (0.04, 0.4, and 4.0 mg kg(-1) day(-1)) on the synaptic density and the synaptic structural modification of pyramidal cells in hippocampus region CA1 and the expressions of synaptic proteins such as synapsin I and PSD-95 and glutamate NMDA and AMPA receptors in male offspring mice on postnatal day (PND) 14, 21, and 56. The results of electron microscope measurement showed that BPA significantly reduced the numeric synaptic density and altered the structural modification of synaptic interface of pyramidal cells with the enlarged synaptic cleft, the shortened active zone, and the thinned postsynaptic density (PSD) on PND 14, 21, and 56 and the increased curvature of synaptic interface on PND 14 and 21. Further analyses of Western blot indicated that BPA markedly reduced the levels of synapsin I and PSD-95 on PND 14, 21, and 56 and down-regulated NMDA receptor subunit NR1 and AMPA receptor subunit GluR1 during development and young adulthood. These results suggest that perinatal exposure to low level of BPA inhibits synaptogenesis and affects synaptic structural modification after birth. The reduced expressions of synaptic proteins synapsin I and PSD-95 and glutamate NMDA and AMPA receptors may be involved in the negative changes in the synaptic plasticity. PMID:23490186

  15. Relations between different coping strategies for social stress, tumor development and neuroendocrine and immune activity in male mice.

    PubMed

    Azpiroz, A; De Miguel, Z; Fano, E; Vegas, O

    2008-07-01

    This study analyzes the effects of acute social stress and different coping strategies employed in response to it on the development of B16F10 melanoma pulmonary metastases, the activation of the HPA axis and the NKG2D receptor expression. To this end, male OF1 mice were subjected to 24h of social stress using the sensorial contact model. This model includes three 5-min sessions of direct social interaction with resident cagemates selected for consistent levels of aggression. Subjects' behavior was videotaped and assessed. Six days after the first social interaction (1st social stress), the animals were inoculated with tumor cells or vehicle, and six days later, both tumor-bearing and non tumor-bearing mice were subjected to a second 24h sensorial contact social stress session (2nd social stress). One hour after the 2nd social interaction, corticosterone levels and NKG2D receptor expression were determined. Lung metastatic foci numbers were determined 21 days after inoculation (15 days post-stress). Social stress increased the number of pulmonary metastases and the serum corticosterone level. A combination of cluster and discriminant analyses established the existence of two types of coping strategies: (1) a passive-reactive strategy characterized by subjects dedicating a greater percentage of time to submission, flee and avoidance behaviors; and (2) an active-proactive strategy, characterized by subjects dedicating a greater percentage of time to attack and non social exploration behaviors. Subjects belonging to the passive-reactive group were found to have a higher number of tumor foci, a higher level of corticosterone and a lower NKG2D receptor expression than subjects in the active-proactive group. These data indicate the relationship between different coping strategies for social stress and tumor development. PMID:18061400

  16. Abnormalities of sexual development in male rats with in utero and lactational exposure to the antiandrogenic plasticizer Di(2-ethylhexyl) phthalate.

    PubMed Central

    Moore, R W; Rudy, T A; Lin, T M; Ko, K; Peterson, R E

    2001-01-01

    Several members of the phthalate ester family have antiandrogenic properties, yet little is known about how exposure to these ubiquitous environmental contaminants early in development may affect sexual development. We conducted experiments to determine effects of in utero and lactational exposure to the most prevalent phthalate ester, di(2-ethylhexyl) phthalate (DEHP), on male reproductive system development and sexual behavior. Sprague-Dawley rats were dosed with corn oil or DEHP (0, 375, 750, or 1,500 mg/kg/day, per os) from gestation day 3 through postnatal day (PND) 21. Dose-related effects on male offspring included reduced anogenital distance, areola and nipple retention, undescended testes, and permanently incomplete preputial separation. Testis, epididymis, glans penis, ventral prostate, dorsolateral prostate, anterior prostate, and seminal vesicle weights were reduced at PND 21, 63, and/or 105-112. Additional dose-related effects included a high incidence of anterior prostate agenesis, a lower incidence of partial or complete ventral prostate agenesis, occasional dorsolateral prostate and seminal vesicle agenesis, reduced sperm counts, and testicular, epididymal, and penile malformations. Many DEHP-exposed males were sexually inactive in the presence of receptive control females, but sexual inactivity did not correlate with abnormal male reproductive organs. These results suggest that in utero and lactational DEHP exposure also inhibited sexually dimorphic central nervous system development. No major abnormalities were found in any of eight control litters, but DEHP caused severe male reproductive system toxicity in five of eight litters at 375 mg/kg/day, seven of eight litters at 750 mg/kg/day, and five of five litters at 1,500 mg/kg/day. These results demonstrate that the male reproductive system is far more sensitive to DEHP early in development than when animals are exposed as juveniles or adults. The effects of DEHP on male reproductive organs and

  17. Down-regulation of OsSPX1 caused semi-male sterility, resulting in reduction of grain yield in rice.

    PubMed

    Zhang, Kang; Song, Qian; Wei, Qiang; Wang, Chunchao; Zhang, Liwei; Xu, Wenying; Su, Zhen

    2016-08-01

    OsSPX1, a rice SPX domain gene, involved in the phosphate (Pi)-sensing mechanism plays an essential role in the Pi-signalling network through interaction with OsPHR2. In this study, we focused on the potential function of OsSPX1 during rice reproductive phase. Based on investigation of OsSPX1 antisense and sense transgenic rice lines in the paddy fields, we discovered that the down-regulation of OsSPX1 caused reduction of seed-setting rate and filled grain number. Through examination of anthers and pollens of the transgenic and wild-type plants by microscopy, we found that the antisense of OsSPX1 gene led to semi-male sterility, with lacking of mature pollen grains and phenotypes with a disordered surface of anthers and pollens. We further conducted rice whole-genome GeneChip analysis to elucidate the possible molecular mechanism underlying why the down-regulation of OsSPX1 caused deficiencies in anthers and pollens and lower seed-setting rate in rice. The down-regulation of OsSPX1 significantly affected expression of genes involved in carbohydrate metabolism and sugar transport, anther development, cell cycle, etc. These genes may be related to pollen fertility and male gametophyte development. Our study demonstrated that down-regulation of OsSPX1 disrupted rice normal anther and pollen development by affecting carbohydrate metabolism and sugar transport, leading to semi-male sterility, and ultimately resulted in low seed-setting rate and grain yield. PMID:26806409

  18. Gay and bisexual identity development among female-to-male transsexuals in North America: emergence of a transgender sexuality.

    PubMed

    Bockting, Walter; Benner, Autumn; Coleman, Eli

    2009-10-01

    We studied a North American sample of female-to-male (FtM) transsexuals sexually attracted to men, aiming to understand their identity and sexuality in the context of a culture of transgender empowerment. Sex-reassigned FtM transsexuals, 18 years or older and attracted to men, were recruited via an FtM community conference and listserv. Participants (N = 25) responded to open-ended questions about identity development, sexual behavior, and social support. Data were analyzed by content analysis. Scores for sexual identity, self esteem, sexual functioning, and psychological adjustment were compared to those of a comparison group (N = 76 nontransgender gay and bisexual men). Of the 25 FtMs, 15 (60%) identified as gay, 8 (32%) as bisexual, and 2 (8%) as queer. All were comfortable with their gender identity and sexual orientation. The FtM group was more bisexual than the nontransgender gay and bisexual controls. No significant group differences were found in self esteem, sexual satisfaction, or psychological adjustment. For some FtMs, sexual attractions and experiences with men affirmed their gender identity; for others, self-acceptance of a transgender identity facilitated actualization of their attractions toward men. Most were "out" as transgender among friends and family, but not on the job or within the gay community. Disclosure and acceptance of their homosexuality was limited. The sexual identity of gay and bisexual FtMs appears to mirror the developmental process for nontransgender homosexual men and women in several ways; however, participants also had experiences unique to being both transgender and gay/bisexual. This signals the emergence of a transgender sexuality. PMID:19330439

  19. Influence of fat/carbohydrate ratio on progression of fatty liver disease and on development of osteopenia in male rats fed alcohol via total enteral nutrition (TEN)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alcohol abuse is associated with the development of fatty liver disease and also with significant bone loss in both genders. In this study, we examined ethanol (EtOH)-induced pathology in response to diets with differing fat/carbohydrate ratios. Male Sprague-Dawley rats were fed intragastrically wit...

  20. Growth and reproductive development of male piglets are more vulnerable to mid-gestation maternal stress than that of female piglets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In many mammalian species, prenatal stress masculinizes female and feminizes male offspring impairing their reproductive capacity. Regrouping gestating sows is a common, stressful production practice, but its impact on the sow’s developing piglets is not fully known. This study examined the effects ...

  1. From Boys to KINGS: Examining the Perceptions and Perspectives of African American Male Participants of the 100 KINGS Youth Development Program

    ERIC Educational Resources Information Center

    Smith, Rodney D.

    2011-01-01

    This study explored the perceptions and perspectives of African American male students with regard to their experiences in a youth development initiative sponsored by a community-based organization. This examination aimed to ascertain the aspects of the program that, first, prompted the students to be a part of the initiative, but also those…

  2. EFFECTS OF GESTATIONAL PROCHLORAZ ADMINISTRATION ON MALE REPRODUCTIVE DEVELOPMENT IN RATS. IN VIVO ASSESSMENTS OF A FUNGICIDE WITH MULTIPLE IN VITRO EFFECTS

    EPA Science Inventory

    Effects of Gestational Prochloraz Administration on Male Reproductive Development in Rats. In Vivo Assessments of a Fungicide with multiple In Vitro effects.

    Nigel C. Noriega, Joseph Ostby, Christy Lambright, Vickie S. Wilson,and L. Earl Gray Jr.,
    noriega.nigel@epa.gov<...

  3. EFFECTS OF GESTATIONAL PROCHLORAZ ADMINISTRATION ON MALE REPRODUCTIVE DEVELOPMENT IN RATS: IN VIVO ASSESSMENTS OF A FUNGICIDE WITH MULTIPLE IN VITRO EFFECTS

    EPA Science Inventory

    Effects of Gestational Prochloraz Administration on Male Reproductive Development in Rats. In Vivo Assessments of a Fungicide with multiple In Vitro effects.

    Nigel C. Noriega, Joseph Ostby, Christy Lambright, Vickie S. Wilson,and L. Earl Gray Jr.,
    noriega.nigel@epa.gov<...

  4. EFFECTS OF GESTATIONAL PROCHLORAZ ADMINISTRATION ON MALE REPRODUCTIVE DEVELOPMENT IN RATS. IN VIVO ASSESSMENTS OF A FUNGICIDE WITH MULTIPLE IN VITRO EFFECTS

    EPA Science Inventory

    Effects of Gestational Prochloraz Administration on Male Reproductive Development in Rats. In Vivo Assessments of a Fungicide with multiple In Vitro effects.

    Nigel C. Noriega, Joseph Ostby, Christy Lambright, Vickie S. Wilson, and L. Earl Gray Jr.,
    noriega.nigel@epa.go...

  5. Male Role Norms Inventory--Short Form (MRNI-SF): Development, Confirmatory Factor Analytic Investigation of Structure, and Measurement Invariance across Gender

    ERIC Educational Resources Information Center

    Levant, Ronald F.; Hall, Rosalie J.; Rankin, Thomas J.

    2013-01-01

    The current study reports the development from the Male Role Norms Inventory-Revised (MRNI-R; Levant, Rankin, Williams, Hasan, & Smalley, 2010) of the 21-item MRNI-Short Form (MRNI-SF). Confirmatory factor analysis of MRNI-SF responses from a sample of 1,017 undergraduate participants (549 men, 468 women) indicated that the best fitting "bifactor"…

  6. A Case Study of the Identity Development of an Adolescent Male with Emotional Disturbance and 48, XYYY Karyotype in an Institutional Setting

    ERIC Educational Resources Information Center

    Rausch, John L.

    2012-01-01

    The goal of this study was to utilize a phenomenological case study design to investigate the individual and social identity development of an adolescent male who had been placed in a high-security group home setting. The participant had been identified with emotional disturbance (ED), and 48, XYYY karyotype. The participant described his social…

  7. DEVELOPMENT OF A PROGRAM FOR THE RE-EDUCATION AND REHABILITATION OF EMOTIONALLY HANDICAPPED MALE ADOLESCENTS WITHIN A PUBLIC SCHOOL SETTING.

    ERIC Educational Resources Information Center

    DEEM, MICHAEL A.; PORTER, WILLIAM R.

    MAJOR OBJECTIVES OF THIS DEMONSTRATION PROJECT WERE (1) TO CONTINUE DEVELOPING A PROTOTYPE SPECIAL CLASS PROGRAM FOR EMOTIONALLY HANDICAPPED PUPILS (18 MALE ADOLESCENTS), (2) TO DEVISE METHODS OF EVALUATION FOR THE PROGRAM, AND (3) TO IDENTIFY SIGNIFICANT VARIABLES FOR FURTHER INVESTIGATION AND RESEARCH. IN PLANNING THE PROJECT DURING THE FIRST…

  8. Male Sterile2 Encodes a Plastid-Localized Fatty Acyl Carrier Protein Reductase Required for Pollen Exine Development in Arabidopsis

    SciTech Connect

    Chen, W.; Shanklin, J.; Yu, X.-H.; Zhang, K.; Shi, J.; De Oliveira, S.; Schreiber, L.; Zhang, D.

    2011-10-01

    Male Sterile2 (MS2) is predicted to encode a fatty acid reductase required for pollen wall development in Arabidopsis (Arabidopsis thaliana). Transient expression of MS2 in tobacco (Nicotiana benthamiana) leaves resulted in the accumulation of significant levels of C16 and C18 fatty alcohols. Expression of MS2 fused with green fluorescent protein revealed that an amino-terminal transit peptide targets the MS2 to plastids. The plastidial localization of MS2 is biologically important because genetic complementation of MS2 in ms2 homozygous plants was dependent on the presence of its amino-terminal transit peptide or that of the Rubisco small subunit protein amino-terminal transit peptide. In addition, two domains, NAD(P)H-binding domain and sterile domain, conserved in MS2 and its homologs were also shown to be essential for MS2 function in pollen exine development by genetic complementation testing. Direct biochemical analysis revealed that purified recombinant MS2 enzyme is able to convert palmitoyl-Acyl Carrier Protein to the corresponding C16:0 alcohol with NAD(P)H as the preferred electron donor. Using optimized reaction conditions (i.e. at pH 6.0 and 30 C), MS2 exhibits a K{sub m} for 16:0-Acyl Carrier Protein of 23.3 {+-} 4.0 {mu}m, a V{sub max} of 38.3 {+-} 4.5 nmol mg{sup -1} min{sup -1}, and a catalytic efficiency/K{sub m} of 1,873 m{sup -1} s{sup -1}. Based on the high homology of MS2 to other characterized fatty acid reductases, it was surprising that MS2 showed no activity against palmitoyl- or other acyl-coenzyme A; however, this is consistent with its plastidial localization. In summary, genetic and biochemical evidence demonstrate an MS2-mediated conserved plastidial pathway for the production of fatty alcohols that are essential for pollen wall biosynthesis in Arabidopsis.

  9. Liver-specific ablation of KRAB Associated Protein 1 in mice leads to male-predominant hepatosteatosis and development of liver adenoma

    PubMed Central

    Bojkowska, Karolina; Kapopoulou, Adamandia; Santoni de Sio, Francesca; Aloisio, Fabio; Cassano, Marco; Zangger, Nadine; Offner, Sandra; Cartoni, Cristina; Thomas, Charles; Quenneville, Simon; Johnsson, Kai; Trono, Didier

    2016-01-01

    The liver is characterized by sexually dimorphic gene expression translating into sex-specific differences in lipid, drug, steroid hormone and xenobiotic metabolism, with distinct responses of males and females to environmental challenges. Here, we investigated the role of the KRAB-associated protein 1 (KAP1) epigenetic regulator in this process. Liver-specific KAP1 knockout led to strikingly sexually dimorphic phenotypic disturbances, including male-predominant steatosis and hepatic tumors. This correlated with sex-specific transcriptional dysregulation of a wide range of metabolic genes, notably those involved in retinol and sex hormone processing as well as in detoxification. Furthermore, chromatin immunoprecipitation followed by deep sequencing indicated that a number of dysregulated genes are direct targets of the KRAB/KAP1 repression system. Those genes include sexually dimorphic Cyp2d9, Gstπ, Slp Cyp2a, Cyp2b and Cyp3a gene clusters. Additionally, we identified a male-restricted KAP1 binding site in the fsp27 (fat specific protein 27) gene, correlating with its male-predominant upregulation upon Kap1 deletion, suggesting that the latter might be an important trigger in the development of male-specific hepatosteatosis and secondary tumorigenesis. Conclusion This work reveals KRAB/KAP1-mediated transcriptional regulation as a central event in the metabolic control hormones, drugs and xenobiotics in the liver, and further links disturbances in these processes with hepatic carcinogenesis. PMID:22684873

  10. Development of male gender identity/role and a sexual orientation towards women in a 46,XY subject with an incomplete form of the androgen insensitivity syndrome.

    PubMed

    Gooren, L; Cohen-Kettenis, P T

    1991-10-01

    Transsexualism and homosexuality have been theorized to originate in the male from insufficient androgenization of the brain. For verification of this hypothesis clinical science must rely on subjects with an abnormal prenatal/perinatal endocrine history. A case of a 33-year-old 46,XY subject with an incomplete form of androgen insensitivity syndrome (AIS) is presented. In adulthood the only genital sign of masculinization is a clitoris of 4 cm; the vagina is normal size. The diagnosis AIS was verified by androgen receptor studies. At birth there was confusion as to the sex of the newborn. Originally, the subject was assigned to the male sex, but this decision was reversed 5 days after birth and the subject was reared as a girl. At age 30 the subject applied for gender reassignment treatment to the male sex. Upon psychological evaluation the gender identity was unambiguously male and the sexual orientation was exclusively towards women. The estrogen feedback effect on LH, regarded by some as a marker of the sexual differentiation of the neuroendocrinium was negative before orchiectomy but positive after orchiectomy. Our observation demonstrates that in 46,XY subjects a male gender identity and a sexual orientation towards women can develop with a strikingly lower-than-normal level of biological action of androgens. PMID:1747041

  11. Bypassing genomic imprinting allows seed development.

    PubMed

    Nowack, Moritz K; Shirzadi, Reza; Dissmeyer, Nico; Dolf, Andreas; Endl, Elmar; Grini, Paul E; Schnittger, Arp

    2007-05-17

    In developing progeny of mammals the two parental genomes are differentially expressed according to imprinting marks, and embryos with only a uniparental genetic contribution die. Gene expression that is dependent on the parent of origin has also been observed in the offspring of flowering plants, and mutations in the imprinting machinery lead to embryonic lethality, primarily affecting the development of the endosperm-a structure in the seed that nourishes the embryo, analogous to the function of the mammalian placenta. Here we have generated Arabidopsis thaliana seeds in which the endosperm is of uniparental, that is, maternal, origin. We demonstrate that imprinting in developing seeds can be bypassed and viable albeit smaller seedlings can develop from seeds lacking a paternal contribution to the endosperm. Bypassing is only possible if the mother is mutant for any of the FIS-class genes, which encode Polycomb group chromatin-modifying factors. Thus, these data provide functional evidence that the action of the FIS complex balances the contribution of the paternal genome. As flowering plants have evolved a special reproduction system with a parallel fusion of two female with two male gametes, our findings support the hypothesis that only with the evolution of double fertilization did the action of the FIS genes become a requirement for seed development. Furthermore, our data argue for a gametophytic origin of endosperm in flowering plants, thereby supporting a hypothesis raised in 1900 by Eduard Strasburger. PMID:17468744

  12. Arabidopsis SOMATIC EMBRYOGENESIS RECEPTOR KINASES1 and 2 are essential for tapetum development and microspore maturation.

    PubMed

    Colcombet, Jean; Boisson-Dernier, Aurélien; Ros-Palau, Roc; Vera, Carlos E; Schroeder, Julian I

    2005-12-01

    Among the >200 members of the leucine-rich repeat receptor kinase family in Arabidopsis thaliana, only a few have been functionally characterized. Here, we report a critical function in anther development for the SOMATIC EMBRYOGENESIS RECEPTOR KINASE1 (SERK1) and SERK2 genes. Both SERK1 and SERK2 are expressed widely in locules until stage 6 anthers and are more concentrated in the tapetal cell layer later. Whereas serk1 and serk2 single insertion mutants did not show developmental phenotypes, serk1 serk2 double mutants were not able to produce seeds because of a lack of pollen development in mutant anthers. In young buds, double mutant anthers developed normally, but serk1 serk2 microsporangia produced more sporogenous cells that were unable to develop beyond meiosis. Furthermore, serk1 serk2 double mutants developed only three cell layers surrounding the sporogenous cell mass, whereas wild-type anthers developed four cell layers. Further confocal microscopic and molecular analyses showed that serk1 serk2 double mutant anthers lack development of the tapetal cell layer, which accounts for the microspore abortion and male sterility. Taken together, these findings demonstrate that the SERK1 and SERK2 receptor kinases function redundantly as an important control point for sporophytic development controlling male gametophyte production. PMID:16284306

  13. Development of PCR‐Based Markers to Determine the Sex of Kelps

    PubMed Central

    Lipinska, Agnieszka P.; Ahmed, Sophia; Peters, Akira F.; Faugeron, Sylvain; Cock, J. Mark; Coelho, Susana M.

    2015-01-01

    Sex discriminating genetic markers are commonly used to facilitate breeding programs in economically and ecologically important animal and plant species. However, despite their considerable economic and ecological value, the development of sex markers for kelp species has been very limited. In this study, we used the recently described sequence of the sex determining region (SDR) of the brown algal model Ectocarpus to develop novel DNA-based sex-markers for three commercially relevant kelps: Laminaria digitata, Undaria pinnatifida and Macrocystis pyrifera. Markers were designed within nine protein coding genes of Ectocarpus male and female (U/V) sex chromosomes and tested on gametophytes of the three kelp species. Seven primer pairs corresponding to three loci in the Ectocarpus SDR amplified sex-specific bands in the three kelp species, yielding at least one male and one female marker for each species. Our work has generated the first male sex-specific markers for L. digitata and U. pinnatifida, as well as the first sex markers developed for the genus Macrocystis. The markers and methodology presented here will not only facilitate seaweed breeding programs but also represent useful tools for population and demography studies and provide a means to investigate the evolution of sex determination across this largely understudied eukaryotic group. PMID:26496392

  14. The Satellite Cell in Male and Female, Developing and Adult Mouse Muscle: Distinct Stem Cells for Growth and Regeneration

    PubMed Central

    Neal, Alice; Boldrin, Luisa; Morgan, Jennifer Elizabeth

    2012-01-01

    Satellite cells are myogenic cells found between the basal lamina and the sarcolemma of the muscle fibre. Satellite cells are the source of new myofibres; as such, satellite cell transplantation holds promise as a treatment for muscular dystrophies. We have investigated age and sex differences between mouse satellite cells in vitro and assessed the importance of these factors as mediators of donor cell engraftment in an in vivo model of satellite cell transplantation. We found that satellite cell numbers are increased in growing compared to adult and in male compared to female adult mice. We saw no difference in the expression of the myogenic regulatory factors between male and female mice, but distinct profiles were observed according to developmental stage. We show that, in contrast to adult mice, the majority of satellite cells from two week old mice are proliferating to facilitate myofibre growth; however a small proportion of these cells are quiescent and not contributing to this growth programme. Despite observed changes in satellite cell populations, there is no difference in engraftment efficiency either between satellite cells derived from adult or pre-weaned donor mice, male or female donor cells, or between male and female host muscle environments. We suggest there exist two distinct satellite cell populations: one for muscle growth and maintenance and one for muscle regeneration. PMID:22662253

  15. A Comparative Study of the Career Development Patterns of Male and Female Library Administrators in Large Public Libraries.

    ERIC Educational Resources Information Center

    Greiner, Joy M.

    1985-01-01

    This nationwide study, conducted to investigate extent to which sex of individual is controlling factor relating to salaries, career progression, and library support, compared the careers of male and female public library directors serving populations of 100,000 or more in continental United States. Questionnaire is appended. (21 references) (EJS)

  16. Comparative Transcript Profiling of a Male Sterile Cybrid Pummelo and Its Fertile Type Revealed Altered Gene Expression Related to Flower Development

    PubMed Central

    Zheng, Bei-Bei; Wu, Xiao-Meng; Ge, Xiao-Xia; Deng, Xiu-Xin; Grosser, Jude W.; Guo, Wen-Wu

    2012-01-01

    Male sterile and seedless characters are highly desired for citrus cultivar improvement. In our breeding program, a male sterile cybrid pummelo, which could be considered as a variant of male fertile pummelo, was produced by protoplast fusion. Herein, ecotopic stamen primordia initiation and development were detected in this male sterile cybrid pummelo. Histological studies revealed that the cybrid showed reduced petal development in size and width, and retarded stamen primordia development. Additionally, disorganized cell proliferation was also detected in stamen-like structures (fused to petals and/or carpel). To gain new insight into the underlying mechanism, we compared, by RNA-Seq analysis, the nuclear gene expression profiles of floral buds of the cybrid with that of fertile pummelo. Gene expression profiles which identified a large number of differentially expressed genes (DEGs) between the two lines were captured at both petal primordia and stamen primordia distinguishable stages. For example, nuclear genes involved in nucleic acid binding and response to hormone synthesis and metabolism, genes required for floral bud identification and expressed in particular floral whorls. Furthermore, in accordance with flower morphology of the cybrid, expression of PISTILLATA (PI) was reduced in stamen-like structures, even though it was restricted to correct floral whorls. Down-regulated expression of APETALA3 (AP3) coincided with that of PI. These finding indicated that, due to their whorl specific effects in flower development, citrus class-B MADS-box genes likely constituted ‘perfect targets’ for CMS retrograde signaling, and that dysfunctional mitochondria seemed to cause male sterile phenotype in the cybrid pummelo. PMID:22952758

  17. Male skin care needs.

    PubMed

    Weber, Stephen M; Ford, Kay

    2008-08-01

    Male skin care has undergone significant development over the past decade, with many companies now marketing skin care products directly to the male consumer. Despite the claims of many of these companies, few over-the-counter products have data to support their efficacy at a clinical level. A basic, effective regimen for preventive male skin care should include twice-daily facial cleansing and twice-daily moisturizer application, which should include sunscreen during the day. This article focuses on topical therapies directed at the maintenance and repair of photoaged male skin. The future holds promise for new developments in skin care. However, in the absence of significant scientific breakthroughs, the most cost-effective intervention will continue to be prevention. PMID:18620985

  18. Critical Roles of Vacuolar Invertase in Floral Organ Development and Male and Female Fertilities Are Revealed through Characterization of GhVIN1-RNAi Cotton Plants1[OPEN

    PubMed Central

    2016-01-01

    Seed number and quality are key traits determining plant fitness and crop yield and rely on combined competence in male and female fertilities. Sucrose metabolism is central to reproductive success. It remains elusive, though, how individual sucrose metabolic enzymes may regulate the complex reproductive processes. Here, by silencing vacuolar invertase (VIN) genes in cotton (Gossypium hirsutum) reproductive organs, we revealed diverse roles that VIN plays in multiple reproductive processes. A set of phenotypic and genetic studies showed significant reductions of viable seeds in GhVIN1-RNAi plants, attributed to pollination failure and impaired male and female fertilities. The former was largely owing to the spatial mismatch between style and stamen and delayed pollen release from the anthers, whereas male defects came from poor pollen viability. The transgenic stamen exhibited altered expression of the genes responsible for starch metabolism and auxin and jasmonic acid signaling. Further analyses identified the reduction of GhVIN expression in the seed coat as the major cause for the reduced female fertility, which appeared to disrupt the expression of some key genes involved in trehalose and auxin metabolism and signaling, leading to programmed cell death or growth repression in the filial tissues. Together, the data provide an unprecedented example of how VIN is required to synchronize style and stamen development and the formation of male and female fertilities for seed development in a crop species, cotton. PMID:26969720

  19. Critical Roles of Vacuolar Invertase in Floral Organ Development and Male and Female Fertilities Are Revealed through Characterization of GhVIN1-RNAi Cotton Plants.

    PubMed

    Wang, Lu; Ruan, Yong-Ling

    2016-05-01

    Seed number and quality are key traits determining plant fitness and crop yield and rely on combined competence in male and female fertilities. Sucrose metabolism is central to reproductive success. It remains elusive, though, how individual sucrose metabolic enzymes may regulate the complex reproductive processes. Here, by silencing vacuolar invertase (VIN) genes in cotton (Gossypium hirsutum) reproductive organs, we revealed diverse roles that VIN plays in multiple reproductive processes. A set of phenotypic and genetic studies showed significant reductions of viable seeds in GhVIN1-RNAi plants, attributed to pollination failure and impaired male and female fertilities. The former was largely owing to the spatial mismatch between style and stamen and delayed pollen release from the anthers, whereas male defects came from poor pollen viability. The transgenic stamen exhibited altered expression of the genes responsible for starch metabolism and auxin and jasmonic acid signaling. Further analyses identified the reduction of GhVIN expression in the seed coat as the major cause for the reduced female fertility, which appeared to disrupt the expression of some key genes involved in trehalose and auxin metabolism and signaling, leading to programmed cell death or growth repression in the filial tissues. Together, the data provide an unprecedented example of how VIN is required to synchronize style and stamen development and the formation of male and female fertilities for seed development in a crop species, cotton. PMID:26969720

  20. Dipentyl Phthalate Dosing during Sexual Differentiation Disrupts Fetal Testis Function and Postnatal Development of the Male Sprague-Dawley Rat with Greater Relative Potency than Other Phthalates

    PubMed Central

    Hannas, Bethany R.; Furr, Johnathan; Lambright, Christy S.; Wilson, Vickie S.; Foster, Paul M. D.; Gray, L. Earl

    2011-01-01

    Phthalate esters (PEs) constitute a large class of plasticizer compounds that are widely used for many consumer product applications. Ten or more members of the PE class of compounds are known to induce male fetal endocrine toxicity and postnatal reproductive malformations by disrupting androgen production during the sexual differentiation period of development. An early study conducted in the rat pubertal model suggested that dipentyl phthalate (DPeP) may be a more potent testicular toxicant than some more extensively studied phthalates. Regulatory agencies require dose-response and potency data to facilitate risk assessment; however, very little data are currently available for DPeP. The goal of this study was to establish a more comprehensive data set for DPeP, focusing on dose-response and potency information for fetal and postnatal male reproductive endpoints. We dosed pregnant rats on gestational day (GD) 17 or GD 14–18 and subsequently evaluated fetal testicular testosterone (T) production on GD 17.5 and GD 18, respectively. We also dosed pregnant rats on GD 8–18 and evaluated early postnatal endpoints in male offspring. Comparison of these data to data previously obtained under similar conditions for di (2-ethylhexyl) phthalate indicates that DPeP is approximately eightfold more potent in reducing fetal T production and two- to threefold more potent in inducing development of early postnatal male reproductive malformations. Additionally, fetal testicular T production was more sensitive to inhibitory effects of DPeP exposure than was gene expression of target genes involved in male reproductive development, supporting the use of this endpoint as a critical effect in the risk assessment process. PMID:21177253

  1. Male Osteoporosis

    PubMed Central

    Drake, Matthew T.; Khosla, Sundeep

    2013-01-01

    Synopsis Osteoporosis is now recognized as a major threat to health in aging men. Morbidity and mortality, particularly following hip fracture, are substantial. Whereas trabecular bone loss starts in early adulthood, loss of cortical bone only appears to occur from mid-life onwards. Declining bioavailable estradiol levels play an integral role in male age-associated bone loss. Both pharmacologic and supportive care interventions are important for optimal care in men at increased fracture risk. PMID:22877433

  2. Development of an Improved Animal Model of Overactive Bladder: Transperineal Ligation versus Transperitoneal Ligation in Male Rats

    PubMed Central

    Kim, Woo Hyun; Bae, Woong Jin; Park, Jung Woo; Choi, Jin Bong; Kim, Su Jin; Cho, Hyuk Jin; Ha, U Syn; Hong, Sung Hoo; Lee, Ji Youl; Hwang, Sung Yeoun

    2016-01-01

    Purpose We compared a transperineal ligation model and a transperitoneal ligation model in male rats to determine which animal model of overactive bladder (OAB) was more useful based on cystometrography, estimations of oxidative stress, and measurements of pro-inflammatory cytokine levels. Materials and Methods Male rats were randomly divided into three groups (n=15 in each): the control group, the transperineal ligation group, and the transperitoneal ligation group. Four weeks after the ligation procedure, cystometrography was performed and oxidative stress, pro-inflammatory cytokine levels, and histologic changes were evaluated. Oxidative stress was assessed by measuring 8-hydroxy-20-deoxyguanosine and superoxide dismutase, and pro-inflammatory cytokine activity was investigated by measuring levels of interleukin (IL)-6, IL-8, and tumor necrosis factor-α. Results The transperineal model led to results similar to those observed for the transperitoneal model, namely (1) increased voiding frequency and reductions in the non-voiding contraction interval and the maximal vesical pressure, (2) increased levels of oxidative stress markers, (3) increased pro-inflammatory cytokine levels, and (4) fibrotic changes in the bladder tissue. Conclusions We suggest that the transperineal procedure can be used as an alternative OAB model in male rats. PMID:27574597

  3. Development of a novel recessive genetic male sterility system for hybrid seed production in maize and other cross-pollinating crops.

    PubMed

    Wu, Yongzhong; Fox, Tim W; Trimnell, Mary R; Wang, Lijuan; Xu, Rui-Ji; Cigan, A Mark; Huffman, Gary A; Garnaat, Carl W; Hershey, Howard; Albertsen, Marc C

    2016-03-01

    We have developed a novel hybridization platform that utilizes nuclear male sterility to produce hybrids in maize and other cross-pollinating crops. A key component of this platform is a process termed Seed Production Technology (SPT). This process incorporates a transgenic SPT maintainer line capable of propagating nontransgenic nuclear male-sterile lines for use as female parents in hybrid production. The maize SPT maintainer line is a homozygous recessive male sterile transformed with a SPT construct containing (i) a complementary wild-type male fertility gene to restore fertility, (ii) an α-amylase gene to disrupt pollination and (iii) a seed colour marker gene. The sporophytic wild-type allele complements the recessive mutation, enabling the development of pollen grains, all of which carry the recessive allele but with only half carrying the SPT transgenes. Pollen grains with the SPT transgenes exhibit starch depletion resulting from expression of α-amylase and are unable to germinate. Pollen grains that do not carry the SPT transgenes are nontransgenic and are able to fertilize homozygous mutant plants, resulting in nontransgenic male-sterile progeny for use as female parents. Because transgenic SPT maintainer seeds express a red fluorescent protein, they can be detected and efficiently separated from seeds that do not contain the SPT transgenes by mechanical colour sorting. The SPT process has the potential to replace current approaches to pollen control in commercial maize hybrid seed production. It also has important applications for other cross-pollinating crops where it can unlock the potential for greater hybrid productivity through expanding the parental germplasm pool. PMID:26442654

  4. Effects of prenatal exposure to a low dose atrazine metabolite mixture on pubertal timing and prostate development of male Long-Evans rats

    SciTech Connect

    Stanko, Jason; Enoch, Rolondo; Rayner, Jennifer L; Davis, Christine; Wolf, Douglas; Malarkey, David; Fenton, Suzanne

    2010-12-01

    The present study examines the postnatal reproductive development of male rats following prenatal exposure to an atrazine metabolite mixture (AMM) consisting of the herbicide atrazine and its environmental metabolites diaminochlorotriazine, hydroxyatrazine, deethylatrazine, and deisopropylatrazine. Pregnant Long-Evans rats were treated by gavage with 0.09, 0.87, or 8.73 mg AMM/kg body weight (BW), vehicle, or 100 mg ATR/kg BW positive control, on gestation days 15 19. Preputial separation was significantly delayed in 0.87 mg and 8.73 mg AMM-exposed males. AMM-exposed males demonstrated a significant treatment-related increase in incidence and severity of inflammation in the prostate on postnatal day (PND) 120. A dose-dependent increase in epididymal fat masses and prostate foci were grossly visible in AMM-exposed offspring. These results indicate that a short, late prenatal exposure to mixture of chlorotriazine metabolites can cause chronic prostatitis in male LE rats. The mode of action for these effects is presently unclear.

  5. Prenatal exposure to sodium valproate alters androgen receptor expression in the developing cerebellum in a region and age specific manner in male and female rats.

    PubMed

    Perez-Pouchoulen, Miguel; Miquel, Marta; Saft, Paul; Brug, Brenda; Toledo, Rebeca; Hernandez, Maria Elena; Manzo, Jorge

    2016-10-01

    Valproic acid (VPA) is an anti-epileptic drug with teratogenicity activity that has been related to autism. In rodents, exposure to VPA in utero leads to brain abnormalities similar than those reported in the autistic brain. Particularly, VPA reduces the number of Purkinje neurons in the rat cerebellum parallel to cerebellar abnormalities found in autism. Thus, we injected pregnant females on embryonic day 12 either with VPA (600mg/kg, i.p.) or 0.9% saline solution and obtained the cerebellum from their offspring at different postnatal time points. Testosterone has been linked to autism and plays an important role during brain development. Therefore, we identified and analyzed the androgen receptor (AR) by immunohistochemistry and densitometry, respectively. We found VPA decreases AR density in the superficial Purkinje layer only in cerebellar lobule 8 at PN7, but increased it at PN14 compared to control in males. In females, VPA decreased AR density in the superficial Purkinje layer in cerebellar lobule 6 at PN14, but increased it in lobule 9 at the same time point. No differences were found in the deep Purkinje layer of any cerebellar lobule in terms of AR density neither in males nor females. We additionally found a particular AR density decreasing in both superficial and deep regions across development in the majority of cerebellar lobules in males, but in all cerebellar lobules in females. Thus, our results indicate that VPA disrupts the AR ontogeny in the developing cerebellum in an age and region specific manner in male and female rats. Future epigenetic studies including the evaluation of histone deacetylases (HDAC's) might shed light these results as HDAC's are expressed by Purkinje neurons, interact with the AR and are VPA targets. This work contributes to the understanding of the cerebellar development and it might help to understand the role of the cerebellum in neurodevelopmental disorders such as autism. PMID:27423376

  6. Gametophyte and Sporophyte

    Technology Transfer Automated Retrieval System (TEKTRAN)

    All land plants are believed to have had their origin in a unicellular green algal ancestor. The major innovations in the evolution of early land plants from their primitive ancestors were, not surprisingly, adaptations that allowed plants to reproduce in the absence of water. Besides a more sophist...

  7. Comprehensive Analysis of Genic Male Sterility-Related Genes in Brassica rapa Using a Newly Developed Br300K Oligomeric Chip

    PubMed Central

    Dong, Xiangshu; Feng, Hui; Xu, Ming; Lee, Jeongyeo; Kim, Yeon Ki; Lim, Yong Pyo; Piao, Zhongyun; Park, Young Doo; Ma, Hong; Hur, Yoonkang

    2013-01-01

    To identify genes associated with genic male sterility (GMS) that could be useful for hybrid breeding in Chinese cabbage (Brassicarapa ssp. pekinensis), floral bud transcriptome analysis was carried out using a B. rapa microarray with 300,000 probes (Br300K). Among 47,548 clones deposited on a Br300K microarray with seven probes of 60 nt length within the 3' 150 bp region, a total of 10,622 genes were differentially expressed between fertile and sterile floral buds; 4,774 and 5,848 genes were up-regulated over 2-fold in fertile and sterile buds, respectively. However, the expression of 1,413 and 199 genes showed fertile and sterile bud-specific features, respectively. Genes expressed specifically in fertile buds, possibly GMS-related genes, included homologs of several Arabidopsis male sterility-related genes, genes associated with the cell wall and synthesis of its surface proteins, pollen wall and coat components, signaling components, and nutrient supplies. However, most early genes for pollen development, genes for primexine and callose formation, and genes for pollen maturation and anther dehiscence showed no difference in expression between fertile and sterile buds. Some of the known genes associated with Arabidopsis pollen development showed similar expression patterns to those seen in this study, while others did not. BrbHLH89 and BrMYP99 are putative GMS genes. Additionally, 17 novel genes identified only in B. rapa were specifically and highly expressed only in fertile buds, implying the possible involvement in male fertility. All data suggest that Chinese cabbage GMS might be controlled by genes acting in post-meiotic tapetal development that are different from those known to be associated with Arabidopsis male sterility. PMID:24039743

  8. Maternal substrate utilization programs the development of the metabolic syndrome in male mice exposed to high fat in utero.

    PubMed

    Hartil, Kirsten; Vuguin, Patricia M; Kruse, Michael; Schmuel, Esther; Fiallo, Ariana; Vargas, Carlos; Warner, Matthew J; Durand, Jorge L; Jelicks, Linda A; Charron, Maureen J

    2009-10-01

    Studies were conducted to determine whether maternal substrate utilization during pregnancy affects fetal growth and predisposes offspring to metabolic disease. Female wild-type (WT) and glucose transporter 4 heterozygous mice (G4+/-, a model of altered peripheral substrate utilization) were fed high-fat diet (HFD, 35.5% fat) or control chow (C, 9.5% fat) for 2 wk before mating, throughout pregnancy and lactation (IU/L). WT HFD females exhibited increased serum nonesterified fatty acid and lactate levels and increased hepatic mRNA expression of peroxisome proliferator-activated receptor gamma coactivator-1-beta and SREBP-1c, consistent with increased lipogenesis. G4+/- HFD females exhibited enhanced lipid clearance, and exposure to HFD did not increase hepatic gene expression. HFD independent of maternal genotype decreased fetal growth and birth weight. WT offspring were weaned onto a low-fat diet (5.6% fat). Male offspring of WT mothers exposed to HFD exhibited "catch-up" growth accompanied by increased adiposity, impaired glucose tolerance, and insulin sensitivity. In contrast, male offspring of G4+/- HFD mothers did not exhibit any characteristics of metabolic syndrome. These data suggest that differences in maternal substrate utilization influence offspring metabolic phenotype. PMID:19581843

  9. Rice Undeveloped Tapetum1 Is a Major Regulator of Early Tapetum DevelopmentW⃞

    PubMed Central

    Jung, Ki-Hong; Han, Min-Jung; Lee, Yang-Seok; Kim, Yong-Woo; Hwang, Inhwan; Kim, Min-Jeong; Kim, Yeon-Ki; Nahm, Baek Hie; An, Gynheung

    2005-01-01

    The tapetum, the innermost of four sporophytic layers in the anther wall, comes in direct contact with the developing male gametophyte and is thought to play a crucial role in the development and maturation of microspores. Here, we report the identification of rice (Oryza sativa) Undeveloped Tapetum1 (Udt1), which is required for the differentiation of secondary parietal cells to mature tapetal cells. T-DNA or retrotransposon Tos17 insertions in the Udt1 gene caused male sterility. The anther walls and meiocytes of the mutants were normal during the early premeiosis stage, but their tapeta failed to differentiate and became vacuolated during the meiotic stage. In addition, meiocytes did not develop to microspores, and middle layer degeneration was inhibited. Consequently, the anther locules contained no pollen. The UDT1:green fluorescent protein fusion protein was localized to the nucleus. This, together with its homology with other basic helix-loop-helix proteins, suggests that UDT1 is a transcription factor. DNA microarray analysis identified 958 downregulated and 267 upregulated genes in the udt1-1 anthers, suggesting that Udt1 plays a major role in maintaining tapetum development, starting in early meiosis. PMID:16141453

  10. Human X-linked Intellectual Disability Factor CUL4B Is Required for Post-meiotic Sperm Development and Male Fertility

    PubMed Central

    Lin, Chien-Yu; Chen, Chun-Yu; Yu, Chih-Hsiang; Yu, I-Shing; Lin, Shu-Rung; Wu, June-Tai; Lin, Ying-Hung; Kuo, Pao-Lin; Wu, Jui-Ching; Lin, Shu-Wha

    2016-01-01

    In this study, we demonstrate that an E3-ubiquitin ligase associated with human X-linked intellectual disability, CUL4B, plays a crucial role in post-meiotic sperm development. Initially, Cul4bΔ/Y male mice were found to be sterile and exhibited a progressive loss in germ cells, thereby leading to oligoasthenospermia. Adult Cul4b mutant epididymides also contained very low numbers of mature spermatozoa, and these spermatazoa exhibited pronounced morphological abnormalities. In post-meiotic spermatids, CUL4B was dynamically expressed and mitosis of spermatogonia and meiosis of spermatocytes both appeared unaffected. However, the spermatids exhibited significantly higher levels of apoptosis during spermiogenesis, particularly during the acrosome phase through the cap phase. Comparative proteomic analyses identified a large-scale shift between wild-type and Cul4b mutant testes during early post-meiotic sperm development. Ultrastructural pathology studies further detected aberrant acrosomes in spermatids and nuclear morphology. The protein levels of both canonical and non-canonical histones were also affected in an early spermatid stage in the absence of Cul4b. Thus, X-linked CUL4B appears to play a critical role in acrosomal formation, nuclear condensation, and in regulating histone dynamics during haploid male germ cell differentiation in relation to male fertility in mice. Thus, it is possible that CUL4B-selective substrates are required for post-meiotic sperm morphogenesis. PMID:26832838

  11. Do men need empowering too? A systematic review of entrepreneurial education and microenterprise development on health disparities among inner-city black male youth.

    PubMed

    Jennings, Larissa

    2014-10-01

    Economic strengthening through entrepreneurial and microenterprise development has been shown to mitigate poverty-based health disparities in developing countries. Yet, little is known regarding the impact of similar approaches on disadvantaged U.S. populations, particularly inner-city African-American male youth disproportionately affected by poverty, unemployment, and adverse health outcomes. A systematic literature review was conducted to guide programming and research in this area. Eligible studies were those published in English from 2003 to 2014 which evaluated an entrepreneurial and microenterprise initiative targeting inner-city youth, aged 15 to 24, and which did not exclude male participants. Peer-reviewed publications were identified from two electronic bibliographic databases. A manual search was conducted among web-based gray literature and registered trials not yet published. Among the 26 papers retrieved for review, six met the inclusion criteria and were retained for analysis. None of the 16 registered microenterprise trials were being conducted among disadvantaged populations in the U.S. The available literature suggests that entrepreneurial and microenterprise programs can positively impact youth's economic and psychosocial functioning and result in healthier decision-making. Young black men specifically benefited from increased autonomy, engagement, and risk avoidance. However, such programs are vastly underutilized among U.S. minority youth, and the current evidence is insufficiently descriptive or rigorous to draw definitive conclusions. Many programs described challenges in securing adequate resources, recruiting minority male youth, and sustaining community buy-in. There is an urgent need to increase implementation and evaluation efforts, using innovative and rigorous designs, to improve the low status of greater numbers of African-American male youth. PMID:25135594

  12. Continuation of all-trans retinoic acid despite the development of scrotal ulcerations in a black male.

    PubMed

    Sutherland, Jennifer; Kempton, Christine L; Curry, Marjorie Adams

    2015-10-01

    Acute promyelocytic leukemia, an aggressive subtype of acute myeloid leukemia, is characterized by the t(15;17) translocation. Standard induction chemotherapy consists of (ATRA) in combination with anthracycline-based chemotherapy with or without the addition of cytarabine. Rare and serious side effects of ATRA have been reported including painful lip and scrotal ulcerations. Of 20 previous reports of genital ulceration, 17 patients had ATRA discontinued and corticosteroids initiated; however, the corticosteroid regimens and duration of therapy were not well described. Herein we present the first known case of a Black male with ATRA-associated scrotal ulcerations who was successfully managed with corticosteroids without cessation of all-trans retinoic acid. We report this case to highlight its rarity and to note that ATRA can be continued in combination with corticosteroids throughout induction. PMID:24876163

  13. Genistein Exposure During the Early Postnatal Period Favors the Development of Obesity in Female, But Not Male Rats

    PubMed Central

    Helferich, William G.

    2014-01-01

    Genistein (Gen), the primary isoflavone in soy, has been shown to adversely affect various endocrine-mediated endpoints in rodents and humans. Soy formula intake by human infants has been associated with early age at menarche and decreased female-typical behavior in girls. Adipose deposition and expansion are also hormonally regulated and Gen has been shown to alter these processes. However, little is known about the impact of early-life soy intake on metabolic homeostasis in adulthood. The current study examined the impact of early-life Gen exposure on adulthood body composition (by magnetic resonance imaging) and the molecular signals mediating adipose expansion. From postnatal day (PND) 1 to 22, rat pups were daily orally dosed with 50mg/kg Gen to mimic blood Gen levels in human infants fed soy formula. Female but not male Gen-exposed rats had increased fat/lean mass ratio, fat mass, adipocyte size and number, and decreased muscle fiber perimeter. PND22 Gen-exposed females, but not males, had increased expression of adipogenic factors, including CCAAT/enhancer binding protein alpha (Cebpα), CCAAT/enhancer binding protein beta (Cebpβ), and peroxisome proliferator-activated receptor gamma (Pparγ). Furthermore, Wingless-related MMTV integration site 10b (Wnt10b), a critical regulator of adipogenic cell fate determination, was hypermethylated and had decreased expression in adipose of PND22 Gen-exposed females. These data suggest that developmental Gen exposure in rats has gender-specific effects on adiposity that closely parallel the effects of a postweaning high-fat diet and underscore the importance of considering timing of exposure and gender when establishing safety recommendations for early-life dietary Gen intake. PMID:24361872

  14. Use of genomic data in risk assessment case study: I. Evaluation of the dibutyl phthalate male reproductive development toxicity data set

    SciTech Connect

    Makris, Susan L.; Euling, Susan Y.; Gray, L. Earl; Benson, Robert; Foster, Paul M.D.

    2013-09-15

    A case study was conducted, using dibutyl phthalate (DBP), to explore an approach to using toxicogenomic data in risk assessment. The toxicity and toxicogenomic data sets relative to DBP-related male reproductive developmental outcomes were considered conjointly to derive information about mode and mechanism of action. In this manuscript, we describe the case study evaluation of the toxicological database for DBP, focusing on identifying the full spectrum of male reproductive developmental effects. The data were assessed to 1) evaluate low dose and low incidence findings and 2) identify male reproductive toxicity endpoints without well-established modes of action (MOAs). These efforts led to the characterization of data gaps and research needs for the toxicity and toxicogenomic studies in a risk assessment context. Further, the identification of endpoints with unexplained MOAs in the toxicity data set was useful in the subsequent evaluation of the mechanistic information that the toxicogenomic data set evaluation could provide. The extensive analysis of the toxicology data set within the MOA context provided a resource of information for DBP in attempts to hypothesize MOAs (for endpoints without a well-established MOA) and to phenotypically anchor toxicogenomic and other mechanistic data both to toxicity endpoints and to available toxicogenomic data. This case study serves as an example of the steps that can be taken to develop a toxicological data source for a risk assessment, both in general and especially for risk assessments that include toxicogenomic data.

  15. Impact of 4-methylbenzylidene-camphor (4-MBC) during embryonic and fetal development in the neuroendocrine regulation of testicular axis in prepubertal and peripubertal male rats.

    PubMed

    Carou, M E; Szwarcfarb, B; Deguiz, M L; Reynoso, R; Carbone, S; Moguilevsky, J A; Scacchi, P; Ponzo, O J

    2009-10-01

    4-Methylbenzylidene-camphor (4-MBC), an UV-B ray filter, belongs to the endocrine disrupters involved with alterations in the reproductive axis. Our target was to study the effect of 4-MBC on the neuroendocrine parameters that regulate reproduction in prepubertal and peripubertal male rats, which received this disrupter during embryonic and fetal development. 4-MBC was administered (sc) to female rats since pregnancy onset in doses of 20, 100 and 500 mg/kg/day. The litters were sacrificed at 15 or 30 days old to determine testicular weight, gonadotropin and prolactin serum levels and also GnRH and amino acids release from the hypothalamus. The exposure to 20 mg/kg/day only increased the LH serum levels in 30-day-old males. Doses of 100 and 500 mg/kg/day caused a decrease in testicular weight and in LH, GnRH and glutamate levels, in prepubertal rats (15-day-old specimens), and an increase in, gonadotropin (LH and FSH) con-centration and aspartate levels in peripubertal rats (30-day-old specimens), without changes in testicular weight. Prolactinaemia remained unaltered in all groups. Results obtained show that the administration of high doses of 4-MBC during embryonic and fetal stage inhibits the testicular axis in male rats during the prepubertal stage and stimulates it during peripubertad stage. On the other hand in the case of low doses no significant effects were observed. PMID:19885997

  16. Development of medium-size half-mask facepiece for male workers at a shipyard and its fit performance in Korea.

    PubMed

    Han, Don-Hee; Kim, David

    2014-01-01

    Ten years ago, three differently sized half-mask facepiece prototypes were constructed from silicon using computer graphics and statistical analysis to fit them according to Korean facial dimensions. The purpose of this study was to complete the medium-size half-mask respirator based on the prototype, which would provide an adequate fit performance for male workers at a shipyard, Hyundai Samho Heavy Industry Co., in Korea. The complete respirator--the hardness 55--was manufactured with existing accessories such as a filter, exhalation valve, and strap attached. The fit performance test was conducted by performing a quantitative fit-test on 48 male subjects: workers who usually wear half-mask respirators (Dobulife Tech Co., Model DM-911, Gwangju, Gyeonggi-do, Korea). The results showed that the hardness 55 provided male subject workers with much better fit performance than the existing mask constructed by the same company. Because softness of the material of the facepiece, in particular the inner part, influenced faceseal leakage, further research on developing better-fit respirator facepieces should consider carefully the fine control of material softness. PMID:24467771

  17. Disruption of reproductive development in male rat offspring following gestational and lactational exposure to di-(2-ethylhexyl) phthalate and genistein.

    PubMed

    Zhang, Lian-Dong; Deng, Qian; Wang, Zi-Ming; Gao, Ming; Wang, Lei; Chong, Tie; Li, He-Cheng

    2013-01-01

    Studies of developmental effects of mixtures of endocrine disrupters on the male reproductive system are of great concern. In this study, the reproductive effects of the co-administration of di-2-(ethylhexyl) phthalate (DEHP) and genistein (GEN) during pregnancy and lactation were studied in male rat offspring. Pregnant Sprague-Dawley rats were gavaged from gestation day 3 to postnatal day 21 with vehicle control, DEHP 250 mg/kg body weight (bwyday, GEN 50 mg/kg bwday, GEN 400 mg/kg bwday, and two combinations of the two compounds (DEHP 250 mg/kg bwday + GEN 50 mg/kg bwday, DEHP 250 mg/kg bwday + GEN 400 mg/kg bwday). The outcomes studied were general morphometry (weight, AGD), testicular histology, testosterone levels, and expression at the mRNA level of genes involved in steroidogenesis. Organ coefficient, AGD / body weight1/3 י, serum testosterone concentration and genes involved in steroidogenic pathway expression when exposed to DEHP (250mg/kg bwday), GEN(50mg/kg bwday) or GEN(400mg/kg bwday) alone were not significantly different from the control group. When exposed to (DEHP 250mg/kg bwday +GEN 50mg/kg bwday) together during pregnancy and lactation, serum testosterone concentration, epididymis coefficient and Cypal17a1,Scarb1 m RNA expression significantly decreased compared to the control and GEN(50mg/kg bwday). When exposed to (DEHP 250mg/kg bwday +GEN 400mg/kg bwday) together during pregnancy and lactation, AGD / body weight1/3 י, serum testosterone concentration, testis and epididymis coefficient and Star, Cypal17a1 mRNA expression appeared significantly decreased compared to the control and DEHP/GEN single exposure, together with developmental impairment of seminiferous tubules and seminiferous epithelium. Overall, co-administration of DEHP and GEN during gestation and lactation seem to acts in a cumulative manner to induce the most significant alterations in the neonate, especially with GEN at high dose, although the effect of the DEHP-GEN mixture on

  18. Genetically-induced Estrogen Receptor Alpha mRNA (Esr1) Overexpression Does Not Adversely Affect Fertility or Penile Development in Male Mice

    PubMed Central

    Heath, John; Abdelmageed, Yazeed; Braden, Tim D.; Williams, Carol S.; Williams, John W.; Paulose, Tessie; Hernandez-Ochoa, Isabel; Gupta, Rupesh; Flaws, Jodi A.; Goyal, Hari O.

    2011-01-01

    Previously, we reported that estrogen receptor alpha mRNA (Esr1) or protein (ESR1) overexpression resulting from neonatal exposure to estrogens in rats was associated with infertility and mal-developed penis characterized by reduced length and weight and abnormal accumulation of fat cells. The objective of this study was to determine if mutant male mice overexpressing Esr1 are naturally infertile or have reduced fertility and/or develop abnormal penis. The fertility parameters, including fertility and fecundity indices, numbers of days from the day of cohabitation to the day of delivery, and numbers of pups per female, were not altered from controls, as a result of Esr1 overexpression. Likewise, penile morphology, including the length, weight, and diameter and os penis development, was not altered from controls. Conversely, weights of the seminal vesicles and bulbospongiosus and levator ani (BS/LA) muscles were significantly (P < 0.05) lower as compared to controls; however, the weight of the testis, the morphology of the testis and epididymis, and the plasma and testicular testosterone concentration were not different from controls. Hence, the genetically-induced Esr1 overexpression alone, without an exogenous estrogen exposure during the neonatal period, is unable to adversely affect the development of the penis as well as other male reproductive organs, except limited, but significant, reductions in weights of the seminal vesicles and BS/LA muscles. PMID:20930192

  19. Cold exposure inhibits hypothalamic Kiss-1 gene expression, serum leptin concentration, and delays reproductive development in male Brandt's vole ( Lasiopodomys brandtii)

    NASA Astrophysics Data System (ADS)

    Zhang, Qiang; Lin, Yi; Zhang, Xue-Ying; Wang, De-Hua

    2015-06-01

    Cold commonly affects growth and reproductive development in small mammals. Here, we test the hypothesis that low ambient temperature will affect growth and puberty onset, associated with altered hypothalamic Kiss-1 gene expression and serum leptin concentration in wild rodents. Male Brandt's voles ( Lasiopodomys brandtii) were exposed to cold (4 ± 1 °C) and warm (23 ± 1 °C) conditions from the birth and sacrificed on different developmental stages (day 26, day 40, day 60, and day 90, respectively). Brandt's voles increased the thermogenic capacity of brown adipose tissue, mobilized body fat, decreased serum leptin levels, and delayed the reproductive development especially on day 40 in the cold condition. They increased food intake to compensate for the high energy demands in the cold. The hypothalamic Kiss-1 gene expression on day 26 was decreased, associated with lower wet testis mass and testis testosterone concentration on day 40, in the cold-exposed voles compared to that in the warm. Serum leptin was positively correlated with body fat, testis mass, and testosterone concentration. These data suggested that cold exposure inhibited hypothalamic Kiss-1 gene expression during the early stage of development, decreased serum leptin concentration, and delayed reproductive development in male Brandt's voles.

  20. Exposure to altered gravity during specific developmental periods differentially affects growth, development, the cerebellum and motor functions in male and female rats

    NASA Astrophysics Data System (ADS)

    Nguon, K.; Ladd, B.; Sajdel-Sulkowska, E. M.

    2006-01-01

    We previously reported that perinatal exposure to hypergravity affects cerebellar structure and motor coordination in rat neonates. In the present study, we explored the hypothesis that neonatal cerebellar structure and motor coordination may be particularly vulnerable to the effects of hypergravity during specific developmental stages. To test this hypothesis, we compared neurodevelopment, motor behavior and cerebellar structure in rat neonates exposed to 1.65 G on a 24-ft centrifuge during discrete periods of time: the 2nd week of pregnancy [gestational day (G) 8 through G15; group A], the 3rd week of pregnancy (G15 through birth on G22/G23; group B), the 1st week of nursing [birth through postnatal day (P) 6; group C], the 2nd and 3rd weeks of nursing (P6 through P21; group D), the combined 2nd and 3rd weeks of pregnancy and nursing (G8 through P21; group E) and stationary control (SC) neonates (group F). Prenatal exposure to hypergravity resulted in intrauterine growth retardation as reflected by a decrease in the number of pups in a litter and lower average mass at birth. Exposure to hypergravity immediately after birth impaired the righting response on P3, while the startle response in both males and females was most affected by exposure during the 2nd and 3rd weeks after birth. Hypergravity exposure also impaired motor functions, as evidenced by poorer performance on a rotarod; while both males and females exposed to hypergravity during the 2nd and 3rd weeks after birth performed poorly on P21, male neonates were most dramatically affected by exposure to hypergravity during the second week of gestation, when the duration of their recorded stay on the rotarod was one half that of SC males. Cerebellar mass was most reduced by later postnatal exposure. Thus, for the developing rat cerebellum, the postnatal period that overlaps the brain growth spurt is the most vulnerable to hypergravity. However, male motor behavior is also affected by midpregnancy exposure to

  1. Targeting the adolescent male.

    PubMed

    Pitt, E

    1986-01-01

    The National Urban League regards too early parenting among adolescents as an issue requiring high level, active attention from all segments of the Black community. Poverty, single parent households and adolescent pregnancies are not exclusively female problems. The role that males play has been missing from too many studies of these phenomena. In light of the fact that most sexual activity is male initiated, and most sexual behavior is male influenced, it becomes clear that there will be no resolution of the problem of teenage pregnancy without directing greater attention to the male. The issue of male responsibility is skirted too often due to parental pride on the part of mothers and fathers when their male children seek sexual relations with female partners. It is viewed as a sign that they are developing sexually within the norm. This is especially true, in many instances, in female headed households where the mother is concerned that she may not be providing her son with an adequate male role model. Sexual activity by female adolescents, however, is generally not condoned. This confusing double standard is further compounded by the disjointed fashion in which American society responds to adolescent sexuality on the whole. Although the home should be the focal point, many parents reluctantly admit an inability to communicate effectively about sex with their pre-adolescent children. Thus, the school, church, community and social agencies have all been enlisted in this task. The National Urban League's initiative in this area is expected to have significant impact on the course of adolescent sexuality and reproductive responsibility.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3745498

  2. Eating disorders in males.

    PubMed

    Robb, Adelaide S; Dadson, Michele J

    2002-04-01

    Eating disorders are one of the rare psychiatric disorders with a large preponderance of female patients. The other articles in this issue review eating disorders in children and adolescents and focus primarily on female patients. This article reviews the eating disorders that occur in male children and teenagers, including anorexia nervosa, bulimia nervosa, binge eating disorder, a subtype of body dysmorphic disorder named muscle dysmorphobia, and obesity. This article reviews subgroups of boys who are at higher risk for developing eating disorders. The article commences with the difference in male perceptions of body image and dieting behaviors. PMID:12109328

  3. Brain abnormalities in male children and adolescents with hemophilia: detection with MR imaging. The Hemophilia Growth and Development Study Group.

    PubMed

    Wilson, D A; Nelson, M D; Fenstermacher, M J; Bohan, T P; Hopper, K D; Tilton, A; Mitchell, W G; Contant, C F; Maeder, M A; Donfield, S M

    1992-11-01

    Cranial magnetic resonance (MR) imaging was performed in 124 male patients (aged 7-19 years), from 14 institutions, in whom a diagnosis of moderate to severe hemophilia was made. Blood tests in all subjects were negative for human immunodeficiency virus. Findings in MR studies were abnormal in 25 (20.2%) subjects. Six lesions in five subjects were classified as congenital. The most commonly identified congenital lesion was a posterior fossa collection of cerebrospinal fluid (five cases). Twenty-two subjects had acquired lesions that were probably related to the hemophilia or its treatment. The most commonly acquired lesions were single- or multifocal areas of high signal intensity within the white matter on T2-weighted images noted in 14 (11.3%) subjects. Two subjects had large focal areas of brain atrophy, and six had some degree of diffuse cerebral cortical atrophy. Three subjects (2.4%) had hemorrhagic lesions. To the authors' knowledge, the unexpected finding of small, focal, nonhemorrhagic white matter lesions has not previously been reported. PMID:1410372

  4. Adaptor Protein Complex 2–Mediated Endocytosis Is Crucial for Male Reproductive Organ Development in Arabidopsis[W

    PubMed Central

    Kim, Soo Youn; Xu, Zheng-Yi; Song, Kyungyoung; Kim, Dae Heon; Kang, Hyangju; Reichardt, Ilka; Sohn, Eun Ju; Friml, Jiří; Juergens, Gerd; Hwang, Inhwan

    2013-01-01

    Fertilization in flowering plants requires the temporal and spatial coordination of many developmental processes, including pollen production, anther dehiscence, ovule production, and pollen tube elongation. However, it remains elusive as to how this coordination occurs during reproduction. Here, we present evidence that endocytosis, involving heterotetrameric adaptor protein complex 2 (AP-2), plays a crucial role in fertilization. An Arabidopsis thaliana mutant ap2m displays multiple defects in pollen production and viability, as well as elongation of staminal filaments and pollen tubes, all of which are pivotal processes needed for fertilization. Of these abnormalities, the defects in elongation of staminal filaments and pollen tubes were partially rescued by exogenous auxin. Moreover, DR5rev:GFP (for green fluorescent protein) expression was greatly reduced in filaments and anthers in ap2m mutant plants. At the cellular level, ap2m mutants displayed defects in both endocytosis of N-(3-triethylammonium-propyl)-4-(4-diethylaminophenylhexatrienyl) pyridinium dibromide, a lypophilic dye used as an endocytosis marker, and polar localization of auxin-efflux carrier PIN FORMED2 (PIN2) in the stamen filaments. Moreover, these defects were phenocopied by treatment with Tyrphostin A23, an inhibitor of endocytosis. Based on these results, we propose that AP-2–dependent endocytosis plays a crucial role in coordinating the multiple developmental aspects of male reproductive organs by modulating cellular auxin level through the regulation of the amount and polarity of PINs. PMID:23975898

  5. Increased gene copy number of the vesicle SNARE VAMP7 disrupts human male urogenital development through altered estrogen action

    PubMed Central

    Tannour-Louet, Mounia; Han, Shuo; Louet, Jean-Francois; Zhang, Bin; Romero, Karina; Addai, Josephine; Sahin, Aysegul; Cheung, Sau Wai; Lamb, Dolores J

    2014-01-01

    Vesicle transport is intimately connected with key nuclear functions and transcriptional regulation. Here, children born with congenital genitourinary tract masculinization disorders were analyzed by array-Comparative Genomic Hybridization, which revealed the presence of de novo copy number gains on Xq28 encompassing the VAMP7 gene encoding a vesicle-trafficking protein. Humanized VAMP7 BAC transgenic mice displayed cryptorchidism, urethral defects, and hypospadias. Mutant mice exhibited reduced penile length, focal spermatogenic anomalies, diminished sperm motility, and subfertility. VAMP7 colocalized with estrogen receptor alpha (ESR1) in the presence of ligand. Elevated levels of VAMP7 markedly intensified ESR1 transcriptional activity by increasing ESR1 protein cellular content upon ligand stimulation and up-regulated the expression of estrogen-responsive genes including ATF3, CYR61, and CTGF, all of which are implicated in human hypospadias. Hence, increased gene dosage of the SNARE protein, VAMP7, enhances estrogen receptor action in male genitourinary tissues, affects the virilization of the reproductive tract, and results in genitourinary birth defects in humans. PMID:24880616

  6. The Effect of Using Brainstorming Strategy in Developing Creative Problem Solving Skills among Male Students in Kuwait: A Field Study on Saud Al-Kharji School in Kuwait City

    ERIC Educational Resources Information Center

    AlMutairi, Abdullahi Naser Mohammad

    2015-01-01

    The purpose of this study is to investigate the effect of using brainstorm strategy in developing creative problem solving skills among male students in Saud Al-Kharji School in Kuwait. The sample of the study consisted of (98) male students. The sample was distributed into two classes, the first represents the experimental group totaling (47)…

  7. Chronic kisspeptin administration stimulated gonadal development in pre-pubertal male yellowtail kingfish (Seriola lalandi; Perciformes) during the breeding and non-breeding season.

    PubMed

    Nocillado, Josephine N; Zohar, Yonathan; Biran, Jakob; Levavi-Sivan, Berta; Elizur, Abigail

    2013-09-15

    The kisspeptin system is now accepted as a key regulator of vertebrate reproductive function, particularly the onset of puberty. In teleosts, the stimulatory effect of exogenous kisspeptins has been demonstrated mainly at the hypothalamic and pituitary levels of the reproductive axis, with very limited information pertaining to gonadal response. We determined the effect of chronic peripheral administration of the conserved kisspeptin decapeptides (YNLNSFGLRY or Kiss1-10; and FNFNPFGLRF or Kiss2-10) on gonadal development of pre-pubertal yellowtail kingfish (Seriola lalandi), a Perciform teleost, during the breeding and non-breeding season. We utilized slow-release implants to chronically deliver the synthesized peptides, which were based on the yellowtail kingfish kiss1 and kiss2 cDNA sequences that we isolated. The expression level of kiss2r and gnrh1 in the brain or hypothalamus did not vary between treated and control groups. Pituitary expression of fshβ and lhβ was upregulated only with Kiss1-10 treatment regardless of the season. Based on histological evidence, gonadal development was stimulated in male fish with either Kiss1-10 or Kiss2-10, with Kiss2-10 being more effective during the non-breeding period. Overall, our results suggest that kisspeptins modulate the early gonadal development of male yellowtail kingfish, however that may vary with the breeding season. PMID:23791760

  8. Effectiveness of injury prevention programs on developing quadriceps and hamstrings strength of young male professional soccer players.

    PubMed

    Daneshjoo, Abdolhamid; Rahnama, Nader; Mokhtar, Abdul Halim; Yusof, Ashril

    2013-12-18

    Muscular strength is an important factor which is crucial for performance and injury prevention in most sports. The purpose of this study was to evaluate the effects of the FIFA's Medical Assessment and Research Centre 11+ and HarmoKnee injury prevention programs on knee strength of young professional male soccer players. Thirty-six soccer players (age: 18.9 ± 1.4 years) were divided equally into three groups; the 11+, HarmoKnee and control groups. The programs were performed for 24 sessions. Hamstring and quadriceps strength was measured using the Biodex System 3 at 30°, 60° and 90° of knee flexion. The 11+ increased quadriceps strength in the dominant leg by 19.7% and 47.8% at 60°and 90° knee flexion, respectively, and in the non-dominant leg by 16%, 35.3% and 78.1 % at 30°, 60° and 90° knee flexion, respectively. The HarmoKnee group, however, showed increased quadriceps strength only at 90° i.e., by 85.7% in the dominant leg and 73.8% in the non-dominant leg. As for hamstring strength, only the 11+ group demonstrated an increment by 24.8% and 19.8% at 30° and 60° knee flexion in the dominant leg, and in the non-dominant leg, by 28.7% and 13.7% at 30° and 60° knee flexion, respectively. In conclusion, both warm-up programs improve quadriceps strength. The 11+ demonstrated improvement in hamstring strength while the HarmoKnee program did not indicate any improvement. We suggest adding eccentric hamstring components such as Nordic hamstring exercise to the HarmoKnee program in order to enhance hamstring strength. PMID:24511347

  9. Plasma Membrane-Targeted PIN Proteins Drive Shoot Development in a Moss

    PubMed Central

    Bennett, Tom A.; Liu, Maureen M.; Aoyama, Tsuyoshi; Bierfreund, Nicole M.; Braun, Marion; Coudert, Yoan; Dennis, Ross J.; O’Connor, Devin; Wang, Xiao Y.; White, Chris D.; Decker, Eva L.; Reski, Ralf; Harrison, C. Jill

    2014-01-01

    Summary Background Plant body plans arise by the activity of meristematic growing tips during development and radiated independently in the gametophyte (n) and sporophyte (2n) stages of the life cycle during evolution. Although auxin and its intercellular transport by PIN family efflux carriers are primary regulators of sporophytic shoot development in flowering plants, the extent of conservation in PIN function within the land plants and the mechanisms regulating bryophyte gametophytic shoot development are largely unknown. Results We have found that treating gametophytic shoots of the moss Physcomitrella patens with exogenous auxins and auxin transport inhibitors disrupts apical function and leaf development. Two plasma membrane-targeted PIN proteins are expressed in leafy shoots, and pin mutants resemble plants treated with auxins or auxin transport inhibitors. PIN-mediated auxin transport regulates apical cell function, leaf initiation, leaf shape, and shoot tropisms in moss gametophytes. pin mutant sporophytes are sometimes branched, reproducing a phenotype only previously seen in the fossil record and in rare natural moss variants. Conclusions Our results show that PIN-mediated auxin transport is an ancient, conserved regulator of shoot development. PMID:25448003

  10. Positive Youth Development: Minority Male Participation in a Sport-Based Afterschool Program in an Urban Environment

    ERIC Educational Resources Information Center

    Fuller, Rhema D.; Percy, Vernon E.; Bruening, Jennifer E.; Cotrufo, Raymond J.

    2013-01-01

    Purpose: As there is little research that investigates the experiences of minority boys participating in youth development programs (Fashola, 2003), the current research focused on a sport-based youth development program for early adolescent Black and Latino boys in Hartford, CT. Specifically, the present study explored (a) what attracted minority…

  11. Intellectual Development Is Positively Related to Intrinsic Motivation and Course Grades for Female but Not Male Students

    ERIC Educational Resources Information Center

    Cortright, Ronald N.; Lujan, Heidi L.; Cox, Julie H.; Cortright, Maria A.; Langworthy, Brandon M.; Petta, Lorene M.; Tanner, Charles J.; DiCarlo, Stephen E.

    2015-01-01

    We hypothesized that the intellectual development of students, i.e., their beliefs about the nature of knowledge and learning, affects their intrinsic motivation and class performance. Specifically, we hypothesized that students with low intellectual development (i.e., the naive beliefs that knowledge is simple, absolute, and certain) have low…

  12. Dream Chasers: An Exploration of How Role Identity Is Related to Career Development Attitudes among African American Male Collegiate Athletes

    ERIC Educational Resources Information Center

    Small, Charles Lamar

    2013-01-01

    In order to develop an identity, individuals undergo the process of role-taking. During this process, they slowly develop an identity as they gain greater comprehension of social meanings in the culture. The individual is able to assume the group culture or perspective as they interact with others and better understand their role in those…

  13. Comparison of Toxicity of CdSe: ZnS Quantum Dots on Male Reproductive System in Different Stages of Development in Mice

    PubMed Central

    Amiri, Gholamreza; Valipoor, Akram; Parivar, Kazem; Modaresi, Mehrdad; Noori, Ali; Gharamaleki, Hamideh; Taheri, Jafar; Kazemi, Ali

    2016-01-01

    Background Quantum dots (QDs) are new types of fluorescent materials for biological labeling. QDs toxicity study is an essential requirement for future clinical applications. Therefore, this study aimed to evaluate cytotoxic effects of CdSe: ZnS QDs on male reproductive system. Materials and Methods In this experimental study, the different concentrations of CdSe: ZnS QDs (10, 20 and 40 mg/kg) were injected to 32 male mice (adult group) and 24 pregnant mice (embryo group) on day 8 of gestation. The histological changes of testis and epididymis were studied by a light microscopy, and the number of seminiferous tubules between two groups was compared. One-way analysis of variance (one-way Anova) using the Statistical Package for the Social Sciences (SPSS, SPSS Inc., USA) version 16 were performed for statistical analysis. Results In adult group, histological studies of testis tissues showed a high toxicity of CdSe: ZnS in 40 mg/kg dose followed by a decrease in lamina propria; destruction in interstitial tissue; deformation of seminiferous tubules; and a reduction in number of spermatogonia, spermatocytes, and spermatids. However, there was an interesting result in fetal testis development, meaning there was no significant effect on morphology and structure of the seminiferous tubules and number of sperm stem cells. Also histological study of epididymis tissues in both groups (adult and embryo groups) showed no significant effect on morphology and structure of tubule and epithelial cells, but there was a considerable reduction in number of spermatozoa in the lumen of the epididymal duct in 40 mg/kg dose of adult group. Conclusion The toxicity of QDs on testicular tissue of the mice embryo and adult are different before and after puberty. Due to lack of research in this field, this study can be an introduction to evaluate the toxicity of QDs on male reproduction system in different stages of development. PMID:26985339

  14. Cigarette smoking and male sex are independent and age concomitant risk factors for the development of ocular sarcoidosis in a new orleans sarcoidosis population

    PubMed Central

    Janot, Adam C.; Huscher, Dörte; Walker, McCall; Grewal, Harmanjot K.; Yu, Mary; Lammi, Matthew R.; Saketkoo, Lesley Ann

    2016-01-01

    Introduction Sarcoidosis is a multi-organ system granulomatous disease of unknown origin with an incidence of 1–40/100,000. Though pulmonary manifestations are predominant, ocular sarcoidosis (OS) affects 25–50% of patients with sarcoidosis and can lead to blindness. Methods A retrospective, single-center chart review of sarcoidosis cases investigated variables associated with the development of OS. Inclusion criteria were biopsy-proven sarcoidosis, disease duration greater than 1 year, documented smoking status on chart review and documentation of sarcoid-related eye disease. Multivariate analysis identified independent risk factors for OS. Results Of 269 charts reviewed, 109 patients met inclusion criteria. The OS group had a significantly higher proportion of smokers (71.4%) than without OS (42.0%, p=0.027) with no difference (p=0.61) in median number of pack years. Male sex was significantly higher in the OS group (57.1% versus 26.1%, p=0.009). Median duration of sarcoidosis was higher in the OS group (10 versus 4 years, p=0.031). Multivariate regression identified tobacco exposure (OR=5.25, p=0.007, 95% CI 1.58–17.41), male sex (OR=7.48, p=0.002, 95% CI 2.15–26.01), and age (OR=1.114, p=0.002, 95% CI 1.04–1.19) as concomitant risk factors for the development of OS. Conclusion To date, there are few dedicated investigations of risk factors for OS, especially smoking. This investigation identified male sex, age, and tobacco exposure as independent risk factors for OS. Though disease duration did not withstand regression analysis in this moderately sized group, age at chart review suggests screening for OS should not remit but rather intensify in aging patients with sarcoidosis. PMID:26278693

  15. Microanatomy and Development of the Dwarf Male of Symbion pandora (Phylum Cycliophora): New Insights from Ultrastructural Investigation Based on Serial Section Electron Microscopy

    PubMed Central

    Neves, Ricardo Cardoso; Reichert, Heinrich

    2015-01-01

    Cycliophorans have a complex life cycle that involves several sexual and asexual stages. One of the sexual stages is the 40 μm-long dwarf male, which is among the smallest free-living metazoans. Although the dwarf male has a highly complex body plan, this minute organism is composed of a very low number of somatic cells (~50). The developmental processes that give rise to this unique phenotype are largely unknown. Here we use high resolution serial block face—scanning electron microscopy to analyze the anatomy and morphogenesis of three cycliophoran dwarf males at different developmental stages ranging from internal bud to mature male. The anatomical and morphological features of the mature dwarf male stage reported here largely correspond to those reported in earlier studies. Interestingly, the organs that typically characterize the anatomy of the mature dwarf male, e.g., muscles, brain, testis and glands, are already formed in the young male. However, there are striking differences between the mature male and young male stages at the level of cellular architecture. Thus, while the young male stage, like the internal bud stage, possesses approximately 200 nucleated cells, the mature male stage comprises only around 50 nucleated cells; muscle and epidermal cells of the mature male lack nuclei. Moreover, the total body volume of the mature male is only 63% of the body of the young male implying that the maturation of the young male into a mature male involves a marked reduction of internal body volume, mainly by massive nuclei loss. Our comparative analysis of these dwarf male specimens reveals unprecedented insight into the striking morphological and developmental differences that characterize these highly miniaturized male stages both at the level of body organization and at the level of cellular ultrastructure. PMID:25875482

  16. Microanatomy and development of the dwarf male of Symbion pandora (Phylum Cycliophora): new insights from ultrastructural investigation based on serial section electron microscopy.

    PubMed

    Neves, Ricardo Cardoso; Reichert, Heinrich

    2015-01-01

    Cycliophorans have a complex life cycle that involves several sexual and asexual stages. One of the sexual stages is the 40 μm-long dwarf male, which is among the smallest free-living metazoans. Although the dwarf male has a highly complex body plan, this minute organism is composed of a very low number of somatic cells (~50). The developmental processes that give rise to this unique phenotype are largely unknown. Here we use high resolution serial block face-scanning electron microscopy to analyze the anatomy and morphogenesis of three cycliophoran dwarf males at different developmental stages ranging from internal bud to mature male. The anatomical and morphological features of the mature dwarf male stage reported here largely correspond to those reported in earlier studies. Interestingly, the organs that typically characterize the anatomy of the mature dwarf male, e.g., muscles, brain, testis and glands, are already formed in the young male. However, there are striking differences between the mature male and young male stages at the level of cellular architecture. Thus, while the young male stage, like the internal bud stage, possesses approximately 200 nucleated cells, the mature male stage comprises only around 50 nucleated cells; muscle and epidermal cells of the mature male lack nuclei. Moreover, the total body volume of the mature male is only 63% of the body of the young male implying that the maturation of the young male into a mature male involves a marked reduction of internal body volume, mainly by massive nuclei loss. Our comparative analysis of these dwarf male specimens reveals unprecedented insight into the striking morphological and developmental differences that characterize these highly miniaturized male stages both at the level of body organization and at the level of cellular ultrastructure. PMID:25875482

  17. Arabidopsis SOMATIC EMBRYOGENESIS RECEPTOR KINASES1 and 2 Are Essential for Tapetum Development and Microspore MaturationW⃞ 111111111111111111111111 100000000000000000000001 100001111000000001000001 100010000100000010100001 100100000010000010100001 101000000001000100010001 101000000001000100010001 101000000001001111111001 101000000001001000001001 100100000010001000001001 100010000100010000000101 100001111000010000000101 100000000000000000000001 111111111111111111111111

    PubMed Central

    Colcombet, Jean; Boisson-Dernier, Aurélien; Ros-Palau, Roc; Vera, Carlos E.; Schroeder, Julian I.

    2005-01-01

    Among the >200 members of the leucine-rich repeat receptor kinase family in Arabidopsis thaliana, only a few have been functionally characterized. Here, we report a critical function in anther development for the SOMATIC EMBRYOGENESIS RECEPTOR KINASE1 (SERK1) and SERK2 genes. Both SERK1 and SERK2 are expressed widely in locules until stage 6 anthers and are more concentrated in the tapetal cell layer later. Whereas serk1 and serk2 single insertion mutants did not show developmental phenotypes, serk1 serk2 double mutants were not able to produce seeds because of a lack of pollen development in mutant anthers. In young buds, double mutant anthers developed normally, but serk1 serk2 microsporangia produced more sporogenous cells that were unable to develop beyond meiosis. Furthermore, serk1 serk2 double mutants developed only three cell layers surrounding the sporogenous cell mass, whereas wild-type anthers developed four cell layers. Further confocal microscopic and molecular analyses showed that serk1 serk2 double mutant anthers lack development of the tapetal cell layer, which accounts for the microspore abortion and male sterility. Taken together, these findings demonstrate that the SERK1 and SERK2 receptor kinases function redundantly as an important control point for sporophytic development controlling male gametophyte production. PMID:16284306

  18. Male Infertility

    MedlinePlus

    ... the cause, treatments may include medicines, surgery, or assisted reproductive technology. Happily, many couples treated for infertility are able to have babies. NIH: National Institute of Child Health and Human Development

  19. The presence of macrophages and inflammatory responses in an in vitro testicular co-culture model of male reproductive development enhance relevance to in vivo conditions.

    PubMed

    Harris, Sean; Shubin, Sara Pacheco; Wegner, Susanna; Van Ness, Kirk; Green, Foad; Hong, Sung Woo; Faustman, Elaine M

    2016-10-01

    Our 3-dimensional testis co-culture system (3D-TCS) represents a promising model of male reproductive toxicity which captures sensitive processes of male reproductive development and contains the main testes cell types (germ, Leydig and Sertoli cells). Macrophages are another cell type important for testicular function and help to modulate immuno-endocrine processes during testes development. Chemicals such as phthalate esters (PE's) affect macrophage function and testosterone production in the testes in vivo. The aim of this study was to determine whether macrophages were present in the 3D-TCS and investigate responses in our model that may be related to immuno-endocrine functions. We observed consistent expression of the resident macrophage marker ED2 as well as increases in inflammatory cytokines produced by macrophages and testes cells (IL-6, TNF-α and KC/GRO) after exposure to toxic PE's. Pathway analysis of gene expression changes after exposure to PE's showed that IL-6 and TNF-α signaling pathways were enriched after treatment with reproductively toxic, but not non-reproductively toxic phthalates. These results indicate that macrophages and inflammatory processes are captured in the 3D-TCS and that these processes are impacted by exposure to reproductive toxicants. These processes represent a major mode of action for in vivo testis toxicity for a variety of compounds and our novel in vitro model is able to capture toxicant perturbation of immune function. PMID:27511800

  20. Effects of Strength Training Combined with Specific Plyometric exercises on body composition, vertical jump height and lower limb strength development in elite male handball players: a case study

    PubMed Central

    Carvalho, Alberto; Mourão, Paulo; Abade, Eduardo

    2014-01-01

    The purpose of the present study was to identify the effects of a strength training program combined with specific plyometric exercises on body composition, vertical jump (VJ) height and strength development of lower limbs in elite male handball players. A 12-week program with combined strength and specific plyometric exercises was carried out for 7 weeks. Twelve elite male handball players (age: 21.6 ± 1.73) competing in the Portuguese Major League participated in the study. Besides the anthropometric measurements, several standardized jump tests were applied to assess VJ performance together with the strength development of the lower limbs in an isokinetic setting. No significant changes were found in body circumferences and diameters. Body fat content and fat mass decreased by 16.4 and 15.7% respectively, while lean body mass increased by 2.1%. Despite small significance, there was in fact an increase in squat jump (SJ), counter movement jump (CMJ) and 40 consecutive jumps after the training period (6.1, 3.8 and 6.8%, respectively). After the applied protocol, peak torque increased in lower limb extension and flexion in the majority of the movements assessed at 90ºs-1. Consequently, it is possible to conclude that combining general strength-training with plyometric exercises can not only increase lower limb strength and improve VJ performance but also reduce body fat content. PMID:25114739

  1. Male breast cancer.

    PubMed

    Ottini, Laura; Palli, Domenico; Rizzo, Sergio; Federico, Mario; Bazan, Viviana; Russo, Antonio

    2010-02-01

    Male breast cancer (MaleBC) is a rare disease, accounting for <1% of all male tumors. During the last few years, there has been an increase in the incidence of this disease, along with the increase in female breast cancer (FBC). Little is known about the etiology of MaleBC: hormonal, environmental and genetic factors have been reported to be involved in its pathogenesis. Major risk factors include clinical disorders carrying hormonal imbalances, radiation exposure and, in particular, a positive family history (FH) for BC, the latter suggestive of genetic susceptibility. Rare mutations in high-penetrance genes (BRCA1 and BRCA2) confer a high risk of BC development; low-penetrance gene mutations (i.e. CHEK-2) are more common but involve a lower risk increase. About 90% of all male breast tumors have proved to be invasive ductal carcinomas, expressing high levels of hormone receptors with evident therapeutic returns. The most common clinical sign of BC onset in men is a painless palpable retroareolar lump, which should be evaluated by means of mammography, ultrasonography and core biopsy or fine needle aspiration (FNA). To date, there are no published data from prospective randomized trials supporting a specific therapeutic approach in MaleBC. Tumor size together with the number of axillary nodes involved are the main prognostic factors and should guide the treatment choice. Locoregional approaches include surgery and radiotherapy (RT), depending upon the initial clinical presentation. When systemic treatment (adjuvant, neoadjuvant and metastatic) is delivered, the choice between hormonal and or chemotherapy (CT) should depend upon the clinical and biological features, according to the FBC management guidelines. However great caution is required because of high rates of age-related comorbidities. PMID:19427229

  2. Mild Thyroid Hormone Insufficiency During Development Compromises Activity-Dependent Neuroplasticity in the Hippocampus of Adult Male Rats.

    PubMed

    Gilbert, M E; Sanchez-Huerta, K; Wood, C

    2016-02-01

    Severe thyroid hormone (TH) deficiency during critical phases of brain development results in irreversible neurological and cognitive impairments. The mechanisms accounting for this are likely multifactorial, and are not fully understood. Here we pursue the possibility that one important element is that TH affects basal and activity-dependent neurotrophin expression in brain regions important for neural processing. Graded exposure to propylthiouracil (PTU) during development produced dose-dependent reductions in mRNA expression of nerve growth factor (Ngf) in whole hippocampus of neonates. These changes in basal expression persisted to adulthood despite the return to euthyroid conditions in blood. In contrast to small PTU-induced reductions in basal expression of several genes, developmental PTU treatment dramatically reduced the activity-dependent expression of neurotrophins and related genes (Bdnft, Bdnfiv, Arc, and Klf9) in adulthood and was accompanied by deficits in hippocampal-based learning. These data demonstrate that mild TH insufficiency during development not only reduces expression of important neurotrophins that persists into adulthood but also severely restricts the activity-dependent induction of these genes. Considering the importance of these neurotrophins for sculpting the structural and functional synaptic architecture in the developing and the mature brain, it is likely that TH-mediated deficits in these plasticity mechanisms contribute to the cognitive deficiencies that accompany developmental TH compromise. PMID:26606422

  3. Implications of Our Developing Understanding of Risk and Protective Factors in the Treatment of Adult Male Sexual Offenders

    ERIC Educational Resources Information Center

    Thornton, David

    2013-01-01

    This paper summarizes our developing knowledge of factors that contribute added risk of sexual recidivism (risk factors) and factors that are associated with a reduced risk of sexual recidivism (protective factors). Specific implications for the design of future treatment programs are drawn. This information is contrasted with the common foci of…

  4. Comparative transcript profiling of gene expression between seedless Ponkan mandarin and its seedy wild type during floral organ development by suppression subtractive hybridization and cDNA microarray

    PubMed Central

    2012-01-01

    Background Seedlessness is an important agronomic trait for citrus, and male sterility (MS) is one main cause of seedless citrus fruit. However, the molecular mechanism of citrus seedlessness remained not well explored. Results An integrative strategy combining suppression subtractive hybridization (SSH) library with cDNA microarray was employed to study the underlying mechanism of seedlessness of a Ponkan mandarin seedless mutant (Citrus reticulata Blanco). Screening with custom microarray, a total of 279 differentially expressed clones were identified, and 133 unigenes (43 contigs and 90 singletons) were obtained after sequencing. Gene Ontology (GO) distribution based on biological process suggested that the majority of differential genes are involved in metabolic process and respond to stimulus and regulation of biology process; based on molecular function they function as DNA/RNA binding or have catalytic activity and oxidoreductase activity. A gene encoding male sterility-like protein was highly up-regulated in the seedless mutant compared with the wild type, while several transcription factors (TFs) such as AP2/EREBP, MYB, WRKY, NAC and C2C2-GATA zinc-finger domain TFs were down-regulated. Conclusion Our research highlighted some candidate pathways that participated in the citrus male gametophyte development and could be beneficial for seedless citrus breeding in the future. PMID:22897898

  5. MALE OSTEOPOROSIS

    PubMed Central

    Oliveira, Lindomar Guimarães; Guimarães, Mara Lucia Rassi

    2015-01-01

    ABSTRACT Population aging is a reality that is being faced worldwide, and Brazil is no different. Osteoporosis was considered to be a postmenopausal women's disease for many years. Men have many development and hormonal factors that differentiate their skeletal maturation, which affects the incidence of osteoporosis and fractures. An up-to-date review of the specific literature within the Medline system is presented. PMID:27022584

  6. Physiologically based pharmacokinetic (PBPK) models for lifetime exposure to PCB 153 in male and female harbor porpoises (Phocoena phocoena): model development and evaluation.

    PubMed

    Weijs, Liesbeth; Yang, Raymond S H; Covaci, Adrian; Das, Krishna; Blust, Ronny

    2010-09-15

    Physiologically based pharmacokinetic (PBPK) models were developed for the most persistent polychlorinated biphenyl (PCB 153) in male and female harbor porpoises (Phocoena phocoena) to elucidate processes such as uptake, distribution, and elimination. Due to its limited metabolic capacities, long life span, and top position in marine food chains, this species is highly sensitive to pollution. The models consist of 5 compartments, liver, blubber, kidney, brain, and a compartment which accounts for the rest of the body, all connected through blood. All physiological and biochemical parameters were extracted from the literature, except for the brain/blood partition coefficient and rate of excretion, which were both fitted to data sets used for validation of the models. These data sets were compiled from our own analyses performed with GC-MS on tissue samples of harbor porpoises. The intake of PCB 153 was from milk from birth to 4 months, and after weaning fish was the main food source. Overall, these models reveal that concentrations of PCB 153 in males increase with age but suggest that, as the animals grow older, metabolic transformation can be a possible pathway for elimination as well. In contrast, the model for females confirms that gestation and lactation are key processes for eliminating PCB 153 as body burdens decrease with age. These PBPK models are capable of simulating the bioaccumulation of PCB 153 during the entire life span of approximately 20 years of the harbor porpoises. PMID:20718467

  7. Active immunization with GnRH-tandem-dimer peptide in young male rats reduces serum reproductive hormone concentrations, testicular development and spermatogenesis.

    PubMed

    Han, Xing-Fa; Li, Jun-Li; Zhou, Yu-Qin; Ren, Xiao-Hua; Liu, Gong-Cheng; Cao, Xiao-Han; Du, Xiao-Gang; Zeng, Xian-Yin

    2016-01-01

    GnRH sterilization vaccines have been developed for various practical and clinical reasons. However, conjugation of GnRH peptide to carrier protein has many drawbacks, hampering the further commercialization of GnRH vaccines. In this study, a new nonconjugated GnRH vaccine, D-Lys6-GnRH-tandem-dimer peptide (TDK), emulsified in Specol adjuvant was investigated for its immunocastration efficacy in young male rats. Prepubertal male rats were randomly allocated into three groups (n = 12): control (no treatment), surgically castrated or immunized against 100 μg TDK in Specol adjuvant at 6 weeks of age (with a booster 8 weeks later). Blood samples (for antibody titers and hormone concentrations) were collected at 2-week intervals until rats were killed (18 weeks of age). Compared to intact controls, active immunization against TDK reduced (P < 0.05) serum concentrations of testosterone, inhibin B, LH and FSH, prevented the onset of spermatogenesis at puberty. Furthermore, mRNA expressions of GnRH receptor, LH-β and FSH-β in the pituitary, LH receptor, FSH receptor, inhibin α, βA and βB subunit in the testes were decreased in immunocastrated rats compared to intact controls (P < 0.05). These results demonstrate for the first time that GnRH-tandem-dimer peptide emulsified in Specol is a promising veterinary sterilization medicine. PMID:26208395

  8. Development of an inhalation physiologically based pharmacokinetic (PBPK) model for 2,2, 4-trimethylpentane (TMP) in male Long-Evans rats using gas uptake experiments.

    PubMed

    El-Masri, Hisham A; Dowd, Sean; Pegram, Rex A; Harrison, Randy; Yavanhxay, Sisouphanh J; Simmons, Jane Ellen; Evans, Marina

    2009-12-01

    2,2,4-Trimethylpentane (TMP) is a volatile colorless liquid used primarily to increase the octane rating of combustible fuels. TMP is released in the environment through the manufacture, use, and disposal of products associated with the gasoline and petroleum industry. Short-term inhalation exposure to TMP (< 4 h; > 1000 ppm) caused sensory and motor irritations in rats and mice. Like many volatile hydrocarbons, acute exposure to TMP may also be expected to alter neurological functions. To estimate in vivo metabolic kinetics of TMP and to predict its target tissue dosimetry during inhalation exposures, a physiologically based pharmacokinetic (PBPK) model was developed for the chemical in Long-Evans male rats using closed-chamber gas-uptake experiments. Gas-uptake experiments were conducted in which rats (80-90 days old) were exposed to targeted initial TMP concentrations of 50, 100, 500, and 1000 ppm. The model consisted of compartments for the closed uptake chamber, lung, fat, kidney, liver, brain, and rapidly and slowly perfused tissues. Physiological parameters were obtained from literature. Partition coefficients for the model were experimentally determined for air/blood, fat, liver, kidney, muscle, and brain using vial equilibration methods. Common to other hydrocarbons, metabolism of TMP via oxidative reactions is assumed to mainly occur in the liver. The PBPK model simulations of the closed chamber data were used to estimate in vivo metabolic parameters for TMP in male Long-Evans rats. PMID:19922404

  9. Expression of the androgen receptor in the testes and the concentrations of gonadotropins and sex steroid hormones in male turkeys (Meleagris gallopavo) during growth and development.

    PubMed

    Kiezun, J; Leska, A; Kaminska, B; Jankowski, J; Dusza, L

    2015-04-01

    Androgens, including testosterone (T) and androstenedione (A4), are essential for puberty, fertility and sexual functions. The biological activity of those hormones is mediated via the androgen receptor (AR). The regulation of androgen action in birds is poorly understood. Therefore, the present study analysed mRNA and protein expression of AR in the testes, plasma concentrations of the luteinizing hormone (LH), follicle-stimulating hormone (FSH), T, A4 and oestradiol (E2), as well as the levels of T, A4 and E2 in testicular homogenates of male turkeys (Meleagris gallopavo) at the age of 4, 8, 12, 16, 20, 24 and 28weeks. Plasma concentrations of LH and FSH, as well as plasma and testicular levels of T and A4 began to increase at 20weeks of age. The lowest plasma levels of E2 were noted at 20weeks relative to other growth stages. The 20th week of life seems to be the key phase in the development of the reproductive system of turkeys. The AR protein was found in the nuclei of testicular cells in all examined growth stages. Higher expression of AR protein in the testes beginning at 20weeks of age was accompanied by high plasma concentrations of LH and high plasma and testicular levels of androgens. This relationship seems to be necessary to regulate male sexual function. PMID:25072891

  10. Ethinylestradiol differentially interferes with IGF-I in liver and extrahepatic sites during development of male and female bony fish.

    PubMed

    Shved, Natallia; Berishvili, Giorgi; D'Cotta, Helena; Baroiller, Jean-François; Segner, Helmut; Eppler, Elisabeth; Reinecke, Manfred

    2007-12-01

    Growth and sexual development are closely interlinked in fish; however, no reports exist on potential effects of estrogen on the GH/IGF-I-axis in developing fish. We investigate whether estrogen exposure during early development affects growth and the IGF-I system, both at the systemic and tissue level. Tilapia were fed from 10 to 40 days post fertilization (DPF) with 17alpha-ethinylestradiol (EE(2)). At 50, 75, 90, and 165 DPF, length, weight, sex ratio, serum IGF-I (RIA), pituitary GH mRNA and IGF-I, and estrogen receptor alpha (ERalpha) mRNA in liver, gonads, brain, and gills (real-time PCR) were determined and the results correlated to those of in situ hybridization for IGF-I. Developmental exposure to EE(2) had persistent effects on sex ratio and growth. Serum IGF-I, hepatic IGF-I mRNA, and the number of IGF-I mRNA-containing hepatocytes were significantly decreased at 75 DPF, while liver ERalpha mRNA was significantly induced. At 75 DPF, a transient decline of IGF-I mRNA and a largely reduced number of IGF-I mRNA-containing neurons were observed in the female brain. In both sexes, pituitary GH mRNA was significantly suppressed. A transient downregulation of IGF-I mRNA occurred in ovaries (75 DPF) and testes (90 DPF). In agreement, in situ hybridization revealed less IGF-I mRNA signals in granulosa and germ cells. Our results show for the first time that developmental estrogen treatment impairs GH/IGF-I expression in fish, and that the effects persist. These long-lasting effects both seem to be exerted indirectly via inhibition of pituitary GH and directly by suppression of local IGF-I in organ-specific cells. PMID:18000313

  11. Male-male homosexology: seven short discourses.

    PubMed

    Money, John

    2004-09-01

    Homosexology is that branch of the science of sexology that deals with same sex relationships. It is subdivided into ideation, imagery, and praxis. Praxeology is the science of praxis. There are two doctrines by which homosexuality is defined: elective and developmental. Elective is like joining a political party and is more likely bisexual than exclusively homosexual. Complete developmental homosexuality is a state of being and is characteristically immutable. Both types of homosexuality are determined multivariately and sequentially, not univariately. Male and female mammals are phylogenically programmed to be reciprocal, not identical, in the praxeology of their courtship and mating. In primate, notably human, evolution, the eyes have taken over from the nose as organs of erotic arousal, but the molecular biology of how this happens in individual development, gay, straight or ambivalent, remains to be ascertained. The different personal histories of homosexual development also remain to be ascertained and cataloged. PMID:15506674

  12. The male germline of angiosperms: repertoire of an inconspicuous but important cell lineage

    PubMed Central

    Russell, Scott D.; Jones, Daniel S.

    2015-01-01

    The male germline of flowering plants constitutes a specialized lineage of diminutive cells initiated by an asymmetric division of the initial microspore cell that sequesters the generative cell from the pollen vegetative cell. The generative cell subsequently divides to form the two male gametes (non-motile sperm cells) that fuse with the two female gametophyte target cells (egg and central cells) to form the zygote and endosperm. Although these male gametes can be as little as 1/800th of the volume of their female counterpart, they encode a highly distinctive and rich transcriptome, translate proteins, and display a novel suite of gamete-distinctive control elements that create a unique chromatin environment in the male lineage. Sperm-expressed transcripts also include a high proportion of transposable element-related sequences that may be targets of non-coding RNA including miRNA and silencing elements from peripheral cells. The number of sperm-encoded transcripts is somewhat fewer than the number present in the egg cell, but are remarkably distinct compared to other cell types according to principal component and other analyses. The molecular role of the male germ lineage cells is just beginning to be understood and appears more complex than originally anticipated. PMID:25852722

  13. Tumor necrosis factor-alpha during neonatal brain development affects anxiety- and depression-related behaviors in adult male and female mice.

    PubMed

    Babri, Shirin; Doosti, Mohammad-Hossein; Salari, Ali-Akbar

    2014-03-15

    A nascent literature suggests that neonatal infection is a risk factor for the development of brain, behavior and hypothalamic-pituitary-adrenal axis which can affect anxiety- and depression-related behaviors in later life. It has been documented that neonatal infection raises the concentrations of tumor necrosis factor-alpha (TNF-α) in neonate rodents and such infections may result in neonatal brain injury, at least in part, through pro-inflammatory cytokines. In addition, previous studies have shown that TNF-α is involved in cellular differentiation, neurogenesis and programmed cell death during the development of the central nervous system. We investigated for the first time whether neonatal exposure to TNF-α can affect body weight, stress-induced corticosterone (COR), anxiety- and depression-related behaviors in adult mice. In the present study, neonatal mice were treated to recombinant mouse TNF-α (0.2, 0.4, 0.7 and 1 μg/kg) or saline on postnatal days 3 and 5, then adult male and female mice were exposed to different behavioral tests. The results indicated that neonatal TNF-α treatment reduced body weight in neonatal period in both sexes. In addition, this study presents findings indicating that high doses of TNF- increase stress-induced COR levels, anxiety- and depression-related behaviors in adult males, but increase levels of anxiety without significantly influencing depression in adult female mice [corrected]. Our findings suggest that TNF-α exposure during neonatal period can alter brain and behavior development in a dose and sex-dependent manner in mice. PMID:24398264

  14. Development of the gonads in the triploid (ZZW and ZZZ) fowl, Gallus domesticus, and comparison with normal diploid males (ZZ) and females (ZW).

    PubMed

    Lin, M; Thorne, M H; Martin, I C; Sheldon, B L; Jones, R C

    1995-01-01

    Gonadal development in fowls aged from 1 day to more than 4.5 years was studied in 63 ZZW and 16 ZZZ triploid crossbreds and compared with normal diploid males (ZZ) and females (ZW). In the ZZW fowl, the right gonad developed into a testis (although this occurred earlier in the ZZ genotype), and a structurally-abnormal excurrent duct system containing some malformed spermatids and spermatozoa was associated with the gonad of young adults. The left gonad was an ovotestes at hatching and no excurrent ducts were associated with it. The ovarian component was much less developed than that in the ZW genotype-it started to degenerate by 1 week of age, and most of the oocytes had disappeared by about 3 weeks of age. The seminiferous tubules developed in the medullary region, but only abnormal spermatozoa were produced. Leukocytes infiltrated both gonads at about 9 months of age and the seminiferous epithelium had degenerated in most fowls over 1 year old. In ZZZ fowl, gonadal and excurrent duct development was normal, but occurred earlier than in the ZZ genotype. However, meiosis and spermiogenesis were abnormal and malformed spermatozoa were produced. The heads of spermatozoa from the ducts deferens were about 1.4-times longer in the ZZZ genotype than in the ZZ genotype, indicating that the former may be producing some diploid spermatozoa. PMID:8848586

  15. Social Isolation During Postweaning Development Causes Hypoactivity of Neurons in the Medial Nucleus of the Male Rat Amygdala.

    PubMed

    Adams, Thomas; Rosenkranz, J Amiel

    2016-06-01

    Children exposed to neglect or social deprivation are at heightened risk for psychiatric disorders and abnormal social patterns as adults. There is also evidence that prepubertal neglect in children causes abnormal metabolic activity in several brain regions, including the amygdala area. The medial nucleus of the amygdala (MeA) is a key region for performance of social behaviors and still undergoes maturation during the periadolescent period. As such, the normal development of this region may be disrupted by social deprivation. In rodents, postweaning social isolation causes a range of deficits in sexual and agonistic behaviors that normally rely on the posterior MeA (MeAp). However, little is known about the effects of social isolation on the function of MeA neurons. In this study, we tested whether postweaning social isolation caused abnormal activity of MeA neurons. We found that postweaning social isolation caused a decrease of in vivo firing activity of MeAp neurons, and reduced drive from excitatory afferents. In vitro electrophysiological studies found that postweaning social isolation caused a presynaptic impairment of excitatory input to the dorsal MeAp, but a progressive postsynaptic reduction of membrane excitability in the ventral MeAp. These results demonstrate discrete, subnucleus-specific effects of social deprivation on the physiology of MeAp neurons. This pathophysiology may contribute to the disruption of social behavior after developmental social deprivation, and may be a novel target to facilitate the treatment of social disorders. PMID:26677945

  16. Early vulnerability in the development of the sense of maleness: Castration depression in the phallic-narcissistic phase.

    PubMed

    Bell, Silvia M

    2004-01-01

    This paper considers Brenner's (1975, 1979, 1982) modification of Freud's theory that anxiety is the only signal affect. Brenner introduced the notion that castration depressive affect also can trigger psychic conflict, defense, and symptom formation. Clinical material from the first year of treatment of a three-year-old boy who suffered a regression in daytime bladder control is presented. The focus is threefold: First, to show that the often cited but poorly studied symptom of regression in bladder control may be an indicator of the child 's struggle with the three calamities of childhood (object loss, loss of love, and castration); second, to present data that support the importance in early symptom formation of both anxiety and depressive affect tied to the ideation of castration as well as of object loss; third, to suggest that vulnerability to castration depression is a concept more pertinent to the stage presently labeled the phallic-narcissistic phase, rather than to the oedipal phase of development. The discussion addresses the importance of castration depressive affect as a concept in guiding therapeutic intervention. Vulnerability to castration depressive affect is postulated to be more prominent in the phallic-narcissistic phase because phallic self representation is not yet consolidated. PMID:16240608

  17. MedlinePlus: Male Infertility

    MedlinePlus

    ... Male Infertility? (National Institute of Child Health and Human Development) Living With How a Man's Diet Affects Fertility Too (Academy of Nutrition and Dietetics) Related Issues Finasteride (Propecia/Proscar) and ...

  18. ECHIDNA protein impacts on male fertility in Arabidopsis by mediating trans-Golgi network secretory trafficking during anther and pollen development.

    PubMed

    Fan, Xinping; Yang, Caiyun; Klisch, Doris; Ferguson, Alison; Bhaellero, Rishi P; Niu, Xiwu; Wilson, Zoe A

    2014-03-01

    The trans-Golgi network (TGN) plays a central role in cellular secretion and has been implicated in sorting cargo destined for the plasma membrane. Previously, the Arabidopsis (Arabidopsis thaliana) echidna (ech) mutant was shown to exhibit a dwarf phenotype due to impaired cell expansion. However, ech also has a previously uncharacterized phenotype of reduced male fertility. This semisterility is due to decreased anther size and reduced amounts of pollen but also to decreased pollen viability, impaired anther opening, and pollen tube growth. An ECH translational fusion (ECHPro:ECH-yellow fluorescent protein) revealed developmentally regulated tissue-specific expression, with expression in the tapetum during early anther development and microspore release and subsequent expression in the pollen, pollen tube, and stylar tissues. Pollen viability and production, along with germination and pollen tube growth, were all impaired. The ech anther endothecium secondary wall thickening also appeared reduced and disorganized, resulting in incomplete anther opening. This did not appear to be due to anther secondary thickening regulatory genes but perhaps to altered secretion of wall materials through the TGN as a consequence of the absence of the ECH protein. ECH expression is critical for a variety of aspects of male reproduction, including the production of functional pollen grains, their effective release, germination, and tube formation. These stages of pollen development are fundamentally influenced by TGN trafficking of hormones and wall components. Overall, this suggests that the fertility defect is multifaceted, with the TGN trafficking playing a significant role in the process of both pollen formation and subsequent fertilization. PMID:24424320

  19. Treatment with protein kinase C activator is effective for improvement of male pronucleus formation and further embryonic development of sperm-injected oocytes in pigs.

    PubMed

    Nakai, M; Ito, J; Kashiwazaki, N; Men, N T; Tanihara, F; Noguchi, J; Kaneko, H; Onishi, A; Kikuchi, K

    2016-03-01

    To assist the process of oocyte activation, which is essential for promotion of fertilization events, i.e., resumption of meiosis, extrusion of the second polar body and formation of the pronucleus (PN), artificial stimuli such as an electrical pulse have been applied to porcine oocytes after injection of sperm. However, the efficiency of fertilization and embryonic development remains low. It is well known that in vertebrates, inactivation of mitogen-activated protein (MAP) kinase is required for oocyte activation. We have hypothesized that even after electrical stimulation of sperm-injected oocytes, MAP kinase may not be inactivated. As it has been reported that MAP kinase activity is regulated by protein kinase C, we examined the effectiveness of phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator, for improvement of fertilization and embryonic development of sperm-injected porcine oocytes. First, we examined the concentrations (0, 0.01, 0.1, 1, and 10 μM) and durations (0, 1, 3, 5 hours) of PMA treatment that were efficient for the extrusion of two polar bodies and formation of two PNs (2PB+2PN) and embryonic development. When the sperm-injected oocytes were treated with 0.01-μM PMA for 3 hours after electrical stimulation, the rates of 2PB+2PN and embryonic development were higher than those in the other treatment groups. We then examined the effect of PMA treatment (0.01 μM, 3 hours) on MAP kinase activity. Unexpectedly, after electrical stimulation, the activity remained low until PN formation, irrespective of whether or not the oocytes had been treated with PMA. On the other hand, transformation of the injected sperm nucleus into the male PN was accelerated after the PMA treatment. Our present results suggest that the low efficiency of fertilization and embryonic development in sperm-injected oocytes is not due to high activity of MAP kinase but due to poor transformation of the injected sperm nucleus into the male PN. Furthermore, a

  20. Male pattern baldness

    MedlinePlus

    Alopecia in men; Baldness - male; Hair loss in men; Androgenetic alopecia ... Male pattern baldness is related to your genes and male sex hormones. It usually follows a pattern of receding hairline and ...

  1. Expression of heavy metal tolerance in pollen and implications for gametophytic selection. [The plants used were clones of Silene dioica and Mimulus guttatus

    SciTech Connect

    Searcy, K.B.

    1984-01-01

    Many genes are expressed in both sporophytic and microgametophytic phases of the angiosperm life cycle. Thus, selection in one phase could modify gene frequency in both phases. An attempt was made to investigate microgametophytic selection in response to toxic concentrations of heavy metals and the effect of this selection upon the resultant sporophyte generation. The plants used were clones of a zinc-tolerant Silene dioica, closely related nontolerant S. alba, and copper tolerant and non-tolerant clones of Mimulus guttatus. First, the expression of metal tolerance in pollen was established by in vitro pollen germination and tube growth, and was found to be associated with the tolerance of the pollen source. Second, to test the extent to which the parallel expression of metal tolerance was determined by the gametophytic genotype, tolerant but segregating clones were grown with and without added metals. Finally, selection was applied during pollen germination, tube growth and fertilization. In Silene, neither the tolerance of the pollen nor the metal content of the styles affected pollen tube growth rate. In Mimulus, pollen from the nontolerant source grew faster, but the metal content of the floral tissue had no significant effect on pollen tube growth rate, and only slightly reduced the fertilization ability of pollen from the nontolerant clone.

  2. [Clinical characteristics of male osteoporosis].

    PubMed

    Yamauchi, Mika; Sugimoto, Toshitsugu

    2016-07-01

    As men are less likely than women to develop osteoporosis, male osteoporosis remains poorly understood. However, elderly men have a clearly reduced bone mineral density and increased risk for fractures. In Japan, one in four patients with osteoporosis is male. Male osteoporosis is associated with not only reduction in androgen, but also estrogen, and differs from postmenopausal osteoporosis in that decreased bone formation is involved and that age-related changes in cortical bone structure and perforation of the trabeculae of cancellous bone are unlikely to occur. The proportion of secondary osteoporosis is higher for men than women;therefore, differential diagnosis is important in the diagnosis of male osteoporosis. In addition, it is recommended that bone mineral density be measured at the femoral neck or total hip in men. Men have a worse prognosis following fractures than women, and management of male osteoporosis is highly important for extending healthy life expectancy. PMID:27346307

  3. Thyroid, spermatogenesis, and male infertility.

    PubMed

    Rajender, Singh; Monica, Marie Gray; Walter, Lee; Agarwal, Ashok

    2011-01-01

    Since the identification of thyroid hormone receptors on the testes, thyroid has been suggested to have a significant impact on the male reproductive tract, spermatogenesis, and male fertility. Several research articles on the role of thyroid in spermatogenesis or male infertility have been published in the last three decades. We conducted an exhaustive literature search was conducted in order to create an up-to-date review of literature. This review aims to discuss the impact of thyroid on testicular development, spermatogenesis, hypo- or hyper- thyroidism and male infertility, and the management of thyroid related abnormal semen profile. The literature revealed that thyroid significantly impacts testicular development and that abnormal thyroid profile affects semen quality and male fertility by compromising testicular size, sperm motility and ejaculate volume. A clear link exists between thyroid hormones, testicular development and spermatogenesis. Thyroid disease negatively affects spermatogenesis and consequently may cause male infertility. In such cases, infertility is reversible, but more studies need to be conducted, especially in post-pubertal males to cement the current findings. PMID:21622096

  4. Flower development: the evolutionary history and functions of the AGL6 subfamily MADS-box genes.

    PubMed

    Dreni, Ludovico; Zhang, Dabing

    2016-04-01

    AGL6 is an ancient subfamily of MADS-box genes found in both gymnosperms and angiosperms. Its functions remained elusive despite the fact that the MADS-box genes and the ABC model have been studied for >20 years. Nevertheless, recent discoveries in petunia, rice, and maize support its involvement in the 'E' function of floral development, very similar to the closely related AGL2 (SEPALLATA) subfamily which has been well characterized. The known functions of AGL6 span from ancient conserved roles to new functions acquired in specific plant families. The AGL6 genes are involved in floral meristem regulation, in floral organs, and ovule (integument) and seed development, and have possible roles in both male and female germline and gametophyte development. In grasses, they are also important for the development of the first whorl of the flower, whereas in Arabidopsis they may play additional roles before floral meristem formation. This review covers these recent insights and some other aspects that are not yet fully elucidated, which deserve more studies in the future. PMID:26956504

  5. Male-specific alteration in excitatory post-synaptic development and social interaction in pre-natal valproic acid exposure model of autism spectrum disorder.

    PubMed

    Kim, Ki Chan; Kim, Pitna; Go, Hyo Sang; Choi, Chang Soon; Park, Jin Hee; Kim, Hee Jin; Jeon, Se Jin; Dela Pena, Ike Campomayor; Han, Seol-Heui; Cheong, Jae Hoon; Ryu, Jong Hoon; Shin, Chan Young

    2013-03-01

    Autism spectrum disorder (ASD) is a pervasive developmental disorder characterized by three main behavioral symptoms including social deficits, impaired communication, and stereotyped and repetitive behaviors. ASD prevalence shows gender bias to male. Prenatal exposure to valproic acid (VPA), a drug used in epilepsy and bipolar disorder, induces autistic symptoms in both human and rodents. As we reported previously, prenatally VPA-exposed animals at E12 showed impairment in social behavior without any overt reproductive toxicity. Social interactions were not significantly different between male and female rats in control condition. However, VPA-exposed male offspring showed significantly impaired social interaction while female offspring showed only marginal deficits in social interaction. Similar male inclination was observed in hyperactivity behavior induced by VPA. In addition to the ASD-like behavioral phenotype, prenatally VPA-exposed rat offspring shows crooked tail phenotype, which was not different between male and female groups. Both male and female rat showed reduced GABAergic neuronal marker GAD and increased glutamatergic neuronal marker vGluT1 expression. Interestingly, despite of the similar increased expression of vGluT1, post-synaptic marker proteins such as PSD-95 and α-CAMKII expression was significantly elevated only in male offspring. Electron microscopy showed increased number of post-synapse in male but not in female at 4 weeks of age. These results might suggest that the altered glutamatergic neuronal differentiation leads to deranged post-synaptic maturation only in male offspring prenatally exposed to VPA. Consistent with the increased post-synaptic compartment, VPA-exposed male rats showed higher sensitivity to electric shock than VPA-exposed female rats. These results suggest that prenatally VPA-exposed rats show the male preponderance of ASD-like behaviors including defective social interaction similar to human autistic patients, which

  6. Development and Validation of an Older Occupant Finite Element Model of a Mid-Sized Male for Investigation of Age-related Injury Risk.

    PubMed

    Schoell, Samantha L; Weaver, Ashley A; Urban, Jillian E; Jones, Derek A; Stitzel, Joel D; Hwang, Eunjoo; Reed, Matthew P; Rupp, Jonathan D; Hu, Jingwen

    2015-11-01

    The aging population is a growing concern as the increased fragility and frailty of the elderly results in an elevated incidence of injury as well as an increased risk of mortality and morbidity. To assess elderly injury risk, age-specific computational models can be developed to directly calculate biomechanical metrics for injury. The first objective was to develop an older occupant Global Human Body Models Consortium (GHBMC) average male model (M50) representative of a 65 year old (YO) and to perform regional validation tests to investigate predicted fractures and injury severity with age. Development of the GHBMC M50 65 YO model involved implementing geometric, cortical thickness, and material property changes with age. Regional validation tests included a chest impact, a lateral impact, a shoulder impact, a thoracoabdominal impact, an abdominal bar impact, a pelvic impact, and a lateral sled test. The second objective was to investigate age-related injury risks by performing a frontal US NCAP simulation test with the GHBMC M50 65 YO and the GHBMC M50 v4.2 models. Simulation results were compared to the GHBMC M50 v4.2 to evaluate the effect of age on occupant response and risk for head injury, neck injury, thoracic injury, and lower extremity injury. Overall, the GHBMC M50 65 YO model predicted higher probabilities of AIS 3+ injury for the head and thorax. PMID:26660751

  7. Development of burnout over time and the causal order of the three dimensions of burnout among male and female GPs. A three-wave panel study

    PubMed Central

    2011-01-01

    Background A good understanding of the aetiology and development of burnout facilitates its early recognition, prevention and treatment. Since the prevalence and onset of this health problem is thought to differ between men and women, sex must be taken into account. This study aims to assess the prevalence and development of burnout among General Practitioners (GPs). In this population the prevalence of burnout is high. Methods We performed a three-wave longitudinal study (2002, 2004, 2006) in a random sample of Dutch GPs. Data were collected by means of self-report questionnaires including the Maslach Burnout Inventory. Our final sample consisted of 212 GPs of which 128 were male. Data were analyzed by means of SPSS and LISREL. Results Results indicate that about 20% of the GPs is clinically burned out (but still working). For both sexes, burnout decreased after the first wave, but increased again after the second wave. The prevalence of depersonalization is higher among men. With regard to the process of burnout we found that for men burnout is triggered by depersonalization and by emotional exhaustion for women. Conclusions As regards the developmental process of burnout, we found evidence for the fact that the aetiological process of burnout, that is the causal order of the three burnout dimensions, differs between men and women. These sex differences should be taken into account in vocational training and policy development, especially since general practice is feminizing rapidly. PMID:21501467

  8. Cytochrome P450 1B1 Contributes to the Development of Angiotensin II-Induced Aortic Aneurysm in Male Apoe(-/-) Mice.

    PubMed

    Thirunavukkarasu, Shyamala; Khan, Nayaab S; Song, Chi Young; Ghafoor, Hafiz U; Brand, David D; Gonzalez, Frank J; Malik, Kafait U

    2016-08-01

    Cytochrome P450 (CYP) 1B1 is implicated in vascular smooth muscle cell migration, proliferation, and hypertension. We assessed the contribution of CYP1B1 to angiotensin (Ang) II-induced abdominal aortic aneurysm (AAA). Male Apoe(-/-)/Cyp1b1(+/+) and Apoe(-/-)/Cyp1b1(-/-) mice were infused with Ang II or its vehicle for 4 weeks; another group of Apoe(-/-)/Cyp1b1(+/+) mice was coadministered the CYP1B1 inhibitor 2,3',4,5'-tetramethoxystilbene (TMS) every third day for 4 weeks. On day 28 of Ang II infusion, AAAs were analyzed by ultrasound and ex vivo by Vernier calipers, mice were euthanized, and tissues were harvested. Ang II produced AAAs in Apoe(-/-)/Cyp1b1(+/+) mice; mice treated with TMS or Apoe(-/-)/Cyp1b1(-/-) mice had reduced AAAs. Ang II enhanced infiltration of macrophages, T cells, and platelets and increased platelet-derived growth factor D, Pdgfrb, Itga2, and matrix metalloproteinases 2 and 9 expression in aortic lesions; these changes were inhibited in mice treated with TMS and in Apoe(-/-)/Cyp1b1(-/-) mice. Oxidative stress resulted in cyclooxygenase-2 expression in aortic lesions. These effects were minimized in Apoe(-/-)/Cyp1b1(+/+) mice treated with TMS and in Apoe(-/-)/Cyp1b1(-/-) mice and by concurrent treatment with the superoxide scavenger 4-hydroxyl-2,2,6,6-tetramethylpiperidine-1-oxyl. CYP1B1 contributed to the development of Ang II-induced AAA and associated pathogenic events in mice, likely by enhancing oxidative stress and associated signaling events. Thus, CYP1B1 may serve as a target for therapeutic agents for AAA in males. PMID:27301358

  9. Beyond the Condom: Frontiers in Male Contraception.

    PubMed

    Roth, Mara Y; Amory, John K

    2016-05-01

    Nearly half of all pregnancies worldwide are unplanned, despite numerous contraceptive options available. No new contraceptive method has been developed for men since the invention of condom. Nevertheless, more than 25% of contraception worldwide relies on male methods. Therefore, novel effective methods of male contraception are of interest. Herein we review the physiologic basis for both male hormonal and nonhormonal methods of contraception. We review the history of male hormonal contraception development, current hormonal agents in development, as well as the potential risks and benefits of male hormonal contraception options for men. Nonhormonal methods reviewed will include both pharmacological and mechanical approaches in development, with specific focus on methods which inhibit the testicular retinoic acid synthesis and action. Multiple hormonal and nonhormonal methods of male contraception are in the drug development pathway, with the hope that a reversible, reliable, safe method of male contraception will be available to couples in the not too distant future. PMID:26947703

  10. Australian scientists develop male contraceptive.

    PubMed

    1974-05-20

    The Australian Information Service in Canberra reports that Australian scientists have formulated a contraceptive pill to temporarily stop spermatogenesis in man, thus producing infertility. The research was done by a team consisting of Dr. Henry Burger, director of the Medical Reserach Center at Prince Henry's Hospital in Melbourne, Dr. Bryan Hudson, Principal Research Fellow at the Howard Florey Institute of Experimental Medicine at the Univeristy of Melbourne, and Dr. David de Kretser, senior lecturer in Monash University's Department of Medicine at Prince Henry's Hospital. The contraceptive pill consists of progestagen (d-norgestrel) with androgen (methyltestosterone), a combination that suppresses the production of the sperm but conserves libido and potency. The testing program has yet to be undertaken in human volunteers. There will be three phases to the drug trial: pretreatment, during which the health of the volunteers and the safety of the drug will be established; the treatment phase, lasting six months, during which the volunteers will be given daily oral dose of the drugs; and the recovery phase, lasting at least three months, during which the restoration of normal spermatogenesis will be observed. PMID:12333267

  11. Low temperatures are required to induce the development of fertile flowers in transgenic male and female early flowering poplar (Populus tremula L.).

    PubMed

    Hoenicka, Hans; Lehnhardt, Denise; Briones, Valentina; Nilsson, Ove; Fladung, Matthias

    2016-05-01

    Until now, artificial early flowering poplar systems have mostly led to the development of sterile flowers. In this study, several strategies aimed at inducting fertile flowers in pHSP::AtFT transgenic poplar were evaluated, in particular the influence of temperature and photoperiod. Our results provide evidence that temperature, and not photoperiod, is the key factor required for the development of fertile flowers in early flowering poplar. Fertile flowers were only obtained when a cold treatment phase of several weeks was used after the heat treatment phase. Heat treatments induced AtFT gene activity through activation of the heat-shock promoter (pHSP). Photoperiod did not show a similar influence on flower fertility as pollen grains were obtained under both long- and short-day conditions. Fertility was confirmed in flowers of both male and female plants. For the first time, crosses were successfully performed with transgenic female early flowering poplar. All mature flowers obtained after 8 weeks of inductive treatments were fertile. Gene expression studies also confirmed that cold temperatures influenced expression of poplar genes homologous to 'pollen development genes' from Arabidopsis thaliana (L.) Heynh. Homology and expression patterns suggested a role for PtTDF1, PtBAM1, PtSERK1/2 and PtMS1 on anther and pollen development in poplar flowers. The system developed in this study allows a fast and very reliable induction of fertile poplar flowers in a very short period of time. The non-reproductive phase, usually 7-10 years, can now be shortened to 6-10 months, and fertile flowers can be obtained independently of the season. This system is a reliable tool for breeding purposes (high-speed breeding technology), genomics and biosafety research. PMID:27052434

  12. Transfer of plastid DNA to the nucleus is elevated during male gametogenesis in tobacco.

    PubMed

    Sheppard, Anna E; Ayliffe, Michael A; Blatch, Laura; Day, Anil; Delaney, Sven K; Khairul-Fahmy, Norfarhana; Li, Yuan; Madesis, Panagiotis; Pryor, Anthony J; Timmis, Jeremy N

    2008-09-01

    In eukaryotes, many genes were transferred to the nucleus from prokaryotic ancestors of the cytoplasmic organelles during endosymbiotic evolution. In plants, the transfer of genetic material from the plastid (chloroplast) and mitochondrion to the nucleus is a continuing process. The cellular location of a kanamycin resistance gene tailored for nuclear expression (35SneoSTLS2) was monitored in the progeny of reciprocal crosses of tobacco (Nicotiana tabacum) in which, at the start of the experiments, the reporter gene was confined either to the male or the female parental plastid genome. Among 146,000 progeny from crosses where the transplastomic parent was male, 13 transposition events were identified, whereas only one atypical transposition was identified in a screen of 273,000 transplastomic ovules. In a second experiment, a transplastomic beta-glucuronidase reporter gene, tailored to be expressed only in the nucleus, showed frequent stochastic expression that was confined to the cytoplasm in the somatic cells of several plant tissues. This gene was stably transferred in two out of 98,000 seedlings derived from a male transplastomic line crossed with a female wild type. These data demonstrate relocation of plastid DNA to the nucleus in both somatic and gametophytic tissue and reveal a large elevation of the frequency of transposition in the male germline. The results suggest a new explanation for the occurrence of uniparental inheritance in eukaryotes. PMID:18660434

  13. Graduating Black Males

    ERIC Educational Resources Information Center

    Bell, Edward Earl

    2010-01-01

    Background: The graduation numbers for Black males are dismal, chilling, and undeniably pathetic. The nation graduates only 47% of Black males who enter the 9th grade. The infusion of federal dollars and philanthropic support will not stop the trajectory of Black males who drop out of school. Black males face an upheaval educational battle;…

  14. Male Sexual Development and the Androgenic Gland: Novel Insights through the de novo Assembled Transcriptome of the Eastern Spiny Lobster, Sagmariasus verreauxi.

    PubMed

    Chandler, Jennifer C; Aizen, Joseph; Elizur, Abigail; Battaglene, Stephen C; Ventura, Tomer

    2015-01-01

    The Eastern spiny lobster, Sagmariasus verreauxi, is commercially important in fisheries, with growing aquaculture potential, driving an interest to better understand male sexual differentiation. Amongst the Decapoda, the androgenic gland (AG) and the insulin-like androgenic gland hormone (IAG) have a well-defined function in male sexual differentiation. However, IAG is not a sex determinant and therefore must be considered as part of a broader, integrated pathway. This work uses a transcriptomic, multi-tissue approach to provide an integrated description of male-biased expression as mediated through the AG. Transcriptomic analyses demonstrate that IAG expression is stage- and eyestalk-regulated (low in immature, high in mature and 6-times higher in hypertrophied glands), with IAG being the predominant AG-specific factor. The low expression of this key factor in immature males suggests the involvement of other tissues in male sexual differentiation. Across tissues, the gonad (87.8%) and antennal gland (73.5%) show the highest male-biased differential expression of transcripts and also express 4 sex-determination regulators, known as Dmrts, with broader expression of Sv-Sxl and Sv-TRA-2. In order to better understand male sexual differentiation, tissues other than the AG must also be considered. This research highlights the gonad and antennal gland as showing significant male-biased expression patterns, including the Sv-Dmrts. PMID:26927314

  15. Role of testosterone in resistance to development of stress-related vascular diseases in male and female organisms: models of hypertension and ulcer bleeding

    NASA Astrophysics Data System (ADS)

    Semyachkina-Glushkovskaya, O.; Pavlov, A.; Semyachkin-Glushkovskiy, I.; Zinchenko, E.; Kassim, M.; Al-Fatle, F.; Al Hassani, L.; Ulanova, M.; Gekaluk, A.

    2015-03-01

    In this paper, we discuss a relationship between stress-induced formation of hypertension and ulcer bleeding and the level of serum testosterone in female and male rats. We show that the secretion of testosterone is an important sign of severity of stress-induced damages of vascular homeostasis in males but not in females.

  16. Conservation of Male Sterility 2 function during spore and pollen wall development supports an evolutionarily early recruitment of a core component in the sporopollenin biosynthetic pathway.

    PubMed

    Wallace, Simon; Chater, Caspar C; Kamisugi, Yasuko; Cuming, Andrew C; Wellman, Charles H; Beerling, David J; Fleming, Andrew J

    2015-01-01

    The early evolution of plants required the acquisition of a number of key adaptations to overcome physiological difficulties associated with survival on land. One of these was a tough sporopollenin wall that enclosed reproductive propagules and provided protection from desiccation and UV-B radiation. All land plants possess such walled spores (or their derived homologue, pollen). We took a reverse genetics approach, consisting of knock-out and complementation experiments to test the functional conservation of the sporopollenin-associated gene MALE STERILTY 2 (which is essential for pollen wall development in Arabidopsis thaliana) in the bryophyte Physcomitrella patens. Knock-outs of a putative moss homologue of the A. thaliana MS2 gene, which is highly expressed in the moss sporophyte, led to spores with highly defective walls comparable to that observed in the A. thaliana ms2 mutant, and extremely compromised germination. Conversely, the moss MS2 gene could not rescue the A. thaliana ms2 phenotype. The results presented here suggest that a core component of the biochemical and developmental pathway required for angiosperm pollen wall development was recruited early in land plant evolution but the continued increase in pollen wall complexity observed in angiosperms has been accompanied by divergence in MS2 gene function. PMID:25195943

  17. Genetics Home Reference: familial male-limited precocious puberty

    MedlinePlus

    ... and luteinizing hormone triggers these cells to produce androgens. Androgens, including testosterone, are the hormones that control male ... chorionic gonadotropin. In males, the overactive receptor causes excess production of testosterone, which triggers male sexual development ...