71 research outputs found

    Teratozoospermia: spotlight on the main genetic actors in the human

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    BACKGROUND Male infertility affects >20 million men worldwide and represents a major health concern. Although multifactorial, male infertility has a strong genetic basis which has so far not been extensively studied. Recent studies of consanguineous families and of small cohorts of phenotypically homogeneous patients have however allowed the identification of a number of autosomal recessive causes of teratozoospermia. Homozygous mutations of aurora kinase C (AURKC) were first described to be responsible for most cases of macrozoospermia. Other genes defects have later been identified in spermatogenesis associated 16 (SPATA16) and dpy-19-like 2 (DPY19L2) in patients with globozoospermia and more recently in dynein, axonemal, heavy chain 1 (DNAH1) in a heterogeneous group of patients presenting with flagellar abnormalities previously described as dysplasia of the fibrous sheath or short/stump tail syndromes, which we propose to call multiple morphological abnormalities of the flagella (MMAF). METHODS A comprehensive review of the scientific literature available in PubMed/Medline was conducted for studies on human genetics, experimental models and physiopathology related to teratozoospermia in particular globozoospermia, large headed spermatozoa and flagellar abnormalities. The search included all articles with an English abstract available online before September 2014. RESULTS Molecular studies of numerous unrelated patients with globozoospermia and large-headed spermatozoa confirmed that mutations in DPY19L2 and AURKC are mainly responsible for their respective pathological phenotype. In globozoospermia, the deletion of the totality of the DPY19L2 gene represents ∼81% of the pathological alleles but point mutations affecting the protein function have also been described. In macrozoospermia only two recurrent mutations were identified in AURKC, accounting for almost all the pathological alleles, raising the possibility of a putative positive selection of heterozygous individuals. The recent identification of DNAH1 mutations in a proportion of patients with MMAF is promising but emphasizes that this phenotype is genetically heterogeneous. Moreover, the identification of mutations in a dynein strengthens the emerging point of view that MMAF may be a phenotypic variation of the classical forms of primary ciliary dyskinesia. Based on data from human and animal models, the MMAF phenotype seems to be favored by defects directly or indirectly affecting the central pair of axonemal microtubules of the sperm flagella. CONCLUSIONS The studies described here provide valuable information regarding the genetic and molecular defects causing infertility, to improve our understanding of the physiopathology of teratozoospermia while giving a detailed characterization of specific features of spermatogenesis. Furthermore, these findings have a significant influence on the diagnostic strategy for teratozoospermic patients allowing the clinician to provide the patient with informed genetic counseling, to adopt the best course of treatment and to develop personalized medicine directly targeting the defective gene product

    Expression, localization and functions in acrosome reaction and sperm motility of Ca(V)3.1 and Ca(V)3.2 channels in sperm cells: an evaluation from Ca(V)3.1 and Ca(V)3.2 deficient mice.: Cav3.1/3.2 channel functions in sperm physiology

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    International audienceIn spermatozoa, voltage-dependent calcium channels (VDCC) have been involved in different cellular functions like acrosome reaction (AR) and sperm motility. Multiple types of VDCC are present and their relative contribution is still a matter of debate. Based mostly on pharmacological studies, low-voltage-activated calcium channels (LVA-CC), responsible of the inward current in spermatocytes, were described as essential for AR in sperm. The development of Ca(V)3.1 or Ca(V)3.2 null mice provided the opportunity to evaluate the involvement of such LVA-CC in AR and sperm motility, independently of pharmacological tools. The inward current was fully abolished in spermatogenic cells from Ca(V)3.2 deficient mice. This current is thus only due to Ca(V)3.2 channels. We showed that Ca(V)3.2 channels were maintained in sperm by Western-blot and immunohistochemistry experiments. Calcium imaging experiments revealed that calcium influx in response to KCl was reduced in Ca(V)3.2 null sperm in comparison to control cells, demonstrating that Ca(V)3.2 channels were functional. On the other hand, no difference was noticed in calcium signaling induced by zona pellucida. Moreover, neither biochemical nor functional experiments, suggested the presence of Ca(V)3.1 channels in sperm. Despite the Ca(V)3.2 channels contribution in KCl-induced calcium influx, the reproduction parameters remained intact in Ca(V)3.2 deficient mice. These data demonstrate that in sperm, besides Ca(V)3.2 channels, other types of VDCC are activated during the voltage-dependent calcium influx of AR, these channels likely belonging to high-voltage activated Ca(2+) channels family. The conclusion is that voltage-dependent calcium influx during AR is due to the opening of redundant families of calcium channels

    Biphasic Role of Calcium in Mouse Sperm Capacitation Signaling Pathways

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    Mammalian sperm acquire fertilizing ability in the female tract in a process known as capacitation. At the molecular level, capacitation is associated with up-regulation of a cAMP-dependent pathway, changes in intracellular pH, intracellular Ca2+, and an increase in tyrosine phosphorylation. How these signaling systems interact during capacitation is not well understood. Results presented in this study indicate that Ca2+ ions have a biphasic role in the regulation of cAMP-dependent signaling. Media without added Ca2+ salts (nominal zero Ca2+) still contain micromolar concentrations of this ion. Sperm incubated in this medium did not undergo PKA activation or the increase in tyrosine phosphorylation suggesting that these phosphorylation pathways require Ca2+. However, chelation of the extracellular Ca2+ traces by EGTA induced both cAMP-dependent phosphorylation and the increase in tyrosine phosphorylation. The EGTA effect in nominal zero Ca2+ media was mimicked by two calmodulin antagonists, W7 and calmidazolium, and by the calcineurin inhibitor cyclosporine A. These results suggest that Ca2+ ions regulate sperm cAMP and tyrosine phosphorylation pathways in a biphasic manner and that some of its effects are mediated by calmodulin. Interestingly, contrary to wild-type mouse sperm, sperm from CatSper1 KO mice underwent PKA activation and an increase in tyrosine phosphorylation upon incubation in nominal zero Ca2+ media. Therefore, sperm lacking Catsper Ca2+ channels behave as wild-type sperm incubated in the presence of EGTA. This latter result suggests that Catsper transports the Ca2+ involved in the regulation of cAMP-dependent and tyrosine phosphorylation pathways required for sperm capacitation.Fil: Navarrete, Felipe A.. University of Massachusetts; Estados UnidosFil: García Vázquez, Francisco A.. University of Massachusetts; Estados Unidos. Universidad de Murcia; EspañaFil: Alvau, Antonio. University of Massachusetts; Estados UnidosFil: Escoffier, Jessica. University of Massachusetts; Estados UnidosFil: Krapf, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Sánchez Cárdenas, Claudia. Universidad Nacional Autónoma de México; MéxicoFil: Salicioni, Ana M.. University of Massachusetts; Estados UnidosFil: Darszon, Alberto. Universidad Nacional Autónoma de México; MéxicoFil: Visconti, Pablo E.. University of Massachusetts; Estados Unido

    A numerical clone for VeRCoRs mock-up

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    Safety of Nuclear Power Plants (NPP) is EDF main priority. Lifetime Extension Management, which is an industrial and economical objective thus requires solid demonstrations of NPP ability to sustain long term operation. Concerning the reactor containment building, an extensive research program is currently done, centered on a mock-up of a reactor containment building at 1/3 scale. This mock-up named VeRCoRs (VErification Réaliste du COnfinement des RéacteurS) was built near Paris, and is highly instrumented so that its behavior is monitored from the beginning of the construction. One of the main technical objectives of the project is to understand aging of buildings made of prestressed reinforced concrete and its effect on leak tightness evolution. Actually, at a 1/3 scale, the drying process will be nine times faster so that the studies of ageing can be speeded up. In order to verify this speed up, a numerical clone of VeRCoRs is developed at EDF to simulate ageing processes using EDF simulation tools (Salome-Meca, Code_Aster). This numerical model is also necessary to understand the ageing of the mock-up and to analyse on-measurable quantities such as stresses fields. Numerical results are compared to measurements carried out for now in terms of temperature, deformations and displacements. Finally, a first idea of VeRCoRs representativeness is drawn

    Compartmentalization of distinct cAMP signaling pathways in mammalian sperm.

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    Fertilization competence is acquired in the female tract in a process known as capacitation. Capacitation is needed for the activation of motility (e.g. hyperactivation) and to prepare the sperm for an exocytotic process known as acrosome reaction. While the HCO3--dependent soluble adenylyl cyclase Adcy10 plays a role in motility, less is known about the source of cAMP in the sperm head. Transmembrane adenylyl cyclases (tmACs) are another possible source of cAMP. These enzymes are regulated by stimulatory heterotrimeric Gs proteins; however, the presence of Gs or tmACs in mammalian sperm has been controversial. In this manuscript, we used Western blotting and cholera toxin-dependent ADP ribosylation to show Gs presence in the sperm head. Also, we showed that forskolin, a tmAC specific activator, induces cAMP accumulation in sperm from both WT and Adcy10 null mice. This increase is blocked by the tmAC inhibitor SQ-22536 but not by the Adcy10 inhibitor KH7. While Gs immunoreactivity and tmAC activity are detected in the sperm head, PKA is only found in the tail, where Adcy10 was previously shown to reside. Consistent with an acrosomal localization, Gs reactivity is lost in acrosome reacted sperm, and forskolin is able to increase intracellular Ca2+ and induce the acrosome reaction. Altogether, these data suggest that cAMP pathways are compartmentalized in sperm, with Gs and tmAC in the head and Adcy10 and PKA in the flagellum.Fil: Wertheimer Hermitte, Eva Victoria. University Of Massachussets; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Krapf, Dario. Universidad Nacional de Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: de la Vega Beltran, José L.. Universidad Nacional Autónoma de México; MéxicoFil: Sánchez Cárdenas, Claudia. Universidad Nacional Autónoma de México; MéxicoFil: Navarrete, Felipe. University Of Massachussets; Estados UnidosFil: Haddad, Douglas. University Of Massachussets; Estados UnidosFil: Escoffier, Jessica. University Of Massachussets; Estados UnidosFil: Salicioni, Ana M.. University Of Massachussets; Estados UnidosFil: Levin, Lonny R.. Cornell University; Estados UnidosFil: Buck, Jochen. Cornell University; Estados UnidosFil: Mager, Jesse. University Of Massachussets; Estados UnidosFil: Darszon, Alberto. Universidad Nacional Autónoma de México; MéxicoFil: Visconti, Pablo E.. University Of Massachussets; Estados Unido

    Predicting leakage of the VERCORS mock-up and concrete containment buildings - a digital twin approach

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    EDF operates a nuclear power generation fleet made up of 56 reactors. This fleet contains 24 reactors designed as double-walled concrete containment building. The inner concrete containment vessel has no metallic liner and is a prestressed reinforced concrete building. The inner concrete containment vessel is designed to withstand a severe accident, in terms of mechanical and sealing behaviour. The tightness of the containment is tested every 10 years, by carrying out a pressurization test and by measuring the leak rate. The leak rate is required to be below a regulatory threshold to continue operation of the concrete containment building for the next ten years. Ageing of concrete due to drying, creep and shrinkage leads to increase prestress loss and then leak rate with time. For some containment buildings, the leak rate gets closer to the regulatory threshold with time, so important coating programs are planned to mitigate and limit the leak rate under the regulatory threshold. Therefore, it is very important for EDF to have a concrete containment building leak rate prediction tool. To address this issue, an important research program around a 1/3 scale concrete containment building mock-up called "VERCORS" have been launched at EDF. The mock-up is heavily instrumented, and its materials (concrete, prestressing cables) have been widely characterized and studied. An important numerical effort has also been made to implement structural computations of the mock-up and to capitalize these computations as well as their post-processing (so as to compare automatically with the monitoring data) in what can be called a digital twin of the mock-up. This digital twin is now used to predict the leakage of VERCORS mock-up before yearly pressure test, and also to optimize the repair programs on the real containments

    The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey

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    The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July. In addition, the stellar parameters pipeline, which determines radial velocities, surface temperatures, surface gravities, and metallicities of stars, has been updated and refined with improvements in temperature estimates for stars with T_eff<5000 K and in metallicity estimates for stars with [Fe/H]>-0.5. DR9 includes new stellar parameters for all stars presented in DR8, including stars from SDSS-I and II, as well as those observed as part of the SDSS-III Sloan Extension for Galactic Understanding and Exploration-2 (SEGUE-2). The astrometry error introduced in the DR8 imaging catalogs has been corrected in the DR9 data products. The next data release for SDSS-III will be in Summer 2013, which will present the first data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) along with another year of data from BOSS, followed by the final SDSS-III data release in December 2014.Comment: 9 figures; 2 tables. Submitted to ApJS. DR9 is available at http://www.sdss3.org/dr

    The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar and APOGEE-2 Data

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    This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library (MaStar) accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) survey which publicly releases infra-red spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the sub-survey Time Domain Spectroscopic Survey (TDSS) data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey (SPIDERS) sub-survey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated Value Added Catalogs (VACs). This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper (MWM), Local Volume Mapper (LVM) and Black Hole Mapper (BHM) surveys

    Des sPLA2 de venins de serpents à leurs homologues de Mammifères: Rôles de ces enzymes dans la fécondation

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    The fall of the world male fertility these last decades became alarming. Thus, a man on fifteen is subfertile. If the causes of the fall of fertility seem to be mainly related on the environment and the lifestyle, it is essential to understand all the mechanisms which control the fertilizing ability of spermatozoon in order to optimize the techniques of procreation medically assisted. The development of new research orientations, experimental and theoretical, to identify the subjacent mechanisms of male infertility is essential. In this context, development of new experimental strategies that is situated this work of thesis. The strategy that I employed here is research new pharmacological tools starting from venom of animals by tests of biological activities. This research allowed us to discover a new regulatory pathway of sperm physiology involving secreted phospholipases A2. Thus, we showed for the first time that secreted phospholipases A2 regulate four key events of sperm physiology: Capacitation Acrosome reaction, sperm motility and gamete interaction.La baisse de la fertilité masculine mondiale ces dernières décennies est devenue préoccupante. Ainsi, un homme sur quinze est subfertile. Si les causes de la baisse de fertilité semblent être essentiellement liés à l'environnement et au mode de vie, il est essentiel de comprendre tous les mécanismes qui régulent le pouvoir fécondant du spermatozoïde afin d'optimiser les techniques de procréation médicalement assistée. Le développement de nouveaux axes de recherche, expérimentaux et théoriques, pour identifier les mécanismes sous-jacents de l'infertilité masculine est indispensable. C'est dans ce contexte, de développement de nouvelles stratégies expérimentales que se situe ce travail de thèse. La stratégie que j'ai employée ici est la recherche de nouveaux outils pharmacologiques à partir de venin d'animaux par des tests d'activités biologiques. Cette recherche nous a permis de mettre en évidence une nouvelle voie de régulation de la physiologie spermatique : la voie des phospholipases A2 secrétées. Ainsi, nous avons montré pour la première fois que les phospholipases A2 secrétées, régulent 4 étapes clé de la fécondation : la capacitation, la mobilité spermatique, la réaction acrosomique et l'interaction gamétique

    Mutations in CFAP43 and CFAP44 cause male infertility and flagellum defects in Trypanosoma and human

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    Spermatogenesis defects concern millions of men worldwide, yet the vast majority remains undiagnosed. Here we report men with primary infertility due to multiple morphological abnormalities of the sperm flagella with severe disorganization of the sperm axoneme, a microtubule-based structure highly conserved throughout evolution. Whole-exome sequencing was performed on 78 patients allowing the identification of 22 men with bi-allelic mutations in DNAH1 (n = 6), CFAP43 (n = 10), and CFAP44 (n = 6). CRISPR/Cas9 created homozygous CFAP43/44 male mice that were infertile and presented severe flagellar defects confirming the human genetic results. Immunoelectron and stimulated-emission-depletion microscopy performed on CFAP43 and CFAP44 orthologs in Trypanosoma brucei evidenced that both proteins are located between the doublet microtubules 5 and 6 and the paraflagellar rod. Overall, we demonstrate that CFAP43 and CFAP44 have a similar structure with a unique axonemal localization and are necessary to produce functional flagella in species ranging from Trypanosoma to human
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