Auswahl der wissenschaftlichen Literatur zum Thema „Silene – Reproduction (biologie) – Fécondation“
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Zeitschriftenartikel zum Thema "Silene – Reproduction (biologie) – Fécondation":
BLESBOIS, E. „Gamètes et fécondation chez les oiseaux“. INRAE Productions Animales 24, Nr. 3 (07.07.2011): 259–72. http://dx.doi.org/10.20870/productions-animales.2011.24.3.3260.
HOUDEBINE, L. M. „Les biotechnologies animales“. INRAE Productions Animales 4, Nr. 1 (02.02.1991): 81–88. http://dx.doi.org/10.20870/productions-animales.1991.4.1.4320.
GROSCLAUDE, F. „Avant-propos“. INRAE Productions Animales 11, Nr. 1 (01.02.1998). http://dx.doi.org/10.20870/productions-animales.1998.11.1.3911.
Dissertationen zum Thema "Silene – Reproduction (biologie) – Fécondation":
Lahiani, Emna. „Dynamique évolutive de la gynodioécie chez Silene nutans et conditions de son maintien en populations“. Electronic Thesis or Diss., Lille 1, 2013. http://www.theses.fr/2013LIL10045.
Gynodioecy - the coexistence of female and hermaphrodite individuals, is one of the most common systems after hermaphroditism in angiosperms. The maintenance and evolution of gynodioecy intrigued many evolutionary biologists. The aim of my thesis was to determine the evolutionary forces involved in maintaining such a sexual polymorphism and study some necessary conditions for the occurrence of a better performance of female and the variation of the magnitude of this advantage in Silene nutans. By population genomics approach, I compared the polymorphism of three genomes (nuclear, mitochondrial and chloroplast) of two species, gynodioïque, S. nutans and dioecious: Silene otites. I showed that gynodioecy is maintained in S. nutans through a frequency-dependent negative selection. A second part of my thesis concerns the occurrence and variation of the amplitude of the female advantage. With biology and genetic of population approach, I compared the reproductive success of females and hermaphrodites. I showed that the female advantage depends on the efficiency of pollination and selfing rates that vary according to the sex ratio in experimental conditions. Furthermore, I showed that natural population pollen flow were mainly restricted in space. I also showed that in the studied natural population the genetic determinism of gynodioecy is nuclear. Finally, I highlighted a greater contribution of nocturnal pollinators to reproductive success in S. nutans in relation to diurnal pollinators of this species
Lahiani, Emna. „Dynamique évolutive de la gynodioécie chez Silene nutans et conditions de son maintien en populations“. Thesis, Lille 1, 2013. http://www.theses.fr/2013LIL10045/document.
Gynodioecy - the coexistence of female and hermaphrodite individuals, is one of the most common systems after hermaphroditism in angiosperms. The maintenance and evolution of gynodioecy intrigued many evolutionary biologists. The aim of my thesis was to determine the evolutionary forces involved in maintaining such a sexual polymorphism and study some necessary conditions for the occurrence of a better performance of female and the variation of the magnitude of this advantage in Silene nutans. By population genomics approach, I compared the polymorphism of three genomes (nuclear, mitochondrial and chloroplast) of two species, gynodioïque, S. nutans and dioecious: Silene otites. I showed that gynodioecy is maintained in S. nutans through a frequency-dependent negative selection. A second part of my thesis concerns the occurrence and variation of the amplitude of the female advantage. With biology and genetic of population approach, I compared the reproductive success of females and hermaphrodites. I showed that the female advantage depends on the efficiency of pollination and selfing rates that vary according to the sex ratio in experimental conditions. Furthermore, I showed that natural population pollen flow were mainly restricted in space. I also showed that in the studied natural population the genetic determinism of gynodioecy is nuclear. Finally, I highlighted a greater contribution of nocturnal pollinators to reproductive success in S. nutans in relation to diurnal pollinators of this species
Gaudette, Julien. „Disponibilité du sperme au cours de la saison de la ponte de l'oursin vert, Strongylocentrotus droebachiensis, dans des populations de différentes tailles“. Thesis, Université Laval, 2004. http://www.theses.ulaval.ca/2004/21737/21737.pdf.
Recent experimental studies with gamete-spawning organisms indicate sperm availability and in turn fertilization success may be sensitive to changes in population abundance. However, the occurrence of sperm limitation is controversial and few studies have measured fertilization rates during natural spawnings. During 2002 and 2003, we used fertilization assays to quantify sperm availability near urchin populations of different abundances. Extensive spawning and fertilization rates near 100% were observed near a large population, whereas smaller populations showed lower and less sustained fertilization rates and no drop in gonad size. Some increases in sperm availability occurred at the same time in different populations, suggesting spawning in response to a large-scale cue. We speculate that mass, synchronous spawning is more likely in large populations where gametes or pheromones from conspecifics reach concentrations that are high enough to trigger spawning in less responsive urchins.
Vianey-Liaud, Marc. „Biologie de la reproduction de Biomphalaria glabrata (Say, 1818) (Mollusque, Gastéropode, Planorbidae)“. Montpellier 2, 1990. http://www.theses.fr/1990MON20245.
Martin, Hélène. „Processus de spéciation et impact des systèmes de reproduction dans le genre Silene : spéciation rapide chez l’espèce gynodioïque Silene nutans et labilité des chromosomes sexuels dans la section Otites“. Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10191/document.
Speciation reflects the origins and further development of reproductive barriers. The study of speciation thus requires answering three main questions: which processes lead to reproductive barriers; how effective these barriers are to maintain the genetic integrity of populations; and what are their genetic basis. The goal of my thesis is to attempt to answer these questions in the context of the Silene genus, and to evaluate the potential impact of breeding systems in the speciation process. In the first part, I focused on S. nutans, a gynodioecious species which exhibits two genetic lineages that differentiate in allopatry. Nowadays in secondary contact, the reproductive isolation between these lineages is almost complete. The heterogeneity of selection along the genome has shaped the heterogeneity of genetic differentiation. Therefore, I was not able to propose candidate regions of the genetic basis of the reproductive barriers. In a second part, I focused on the impact of dioecy on population divergence and species adaptation. The discovery of distinct sex determination in close species allowed me to propose to associate the genetic basis of the reproductive isolation to sex chromosome lability. My work furthers the understanding how reproductive barriers developed between two taxas and shows that taking into account the breeding system of taxa and associate genetic conflicts (sex chromosome, cyto-nuclear conflicts) can be important in the study of speciation
Langlois, Isabelle. „Analyse de la différenciation de la granulosa de brebis et de truie in vitro : aspects cellulaire, moléculaire et génétique“. Toulouse 3, 1995. http://www.theses.fr/1995TOU30005.
Delmas, Chloé. „Interactions plantes-pollinisateurs et reproduction sexuée en habitat fragmenté : le cas d'un arbuste à floraison massive“. Toulouse 3, 2012. http://thesesups.ups-tlse.fr/1603/.
There is increasing evidence that global changes negatively impact plant and pollinator populations. However, the ecological and evolutionary consequences of pollinator and mate limitations on plant mating system have been poorly studied. To contribute to this scientific challenge, we study the importance of pollination failure in a self-compatible and mass-flowering shrub (Rhododendron ferrugineum) along a gradient of floral display size. To explore the causes of pollination failure and the consequences on the reproductive success of this focal species, we used an integrative approach including: the study of plant-pollinator interactions at the community scale, pollinator and stigmatic pollen load analyses and the pollination and mating system of the focal species. We also examine, at the species and community levels, the ecological and evolutionary processes that might be able to alleviate pollination failure. We evidence that pollinator abundance substantially decreased with decreasing R. Ferrugineum floral display size. Nevertheless, this highly attractive species monopolizes pollinators from the surrounding community, mitigating the negative consequences of plant isolation. Pollination failure, assessed by pollen transfer limitation in R. Ferrugineum, is due to low pollinator availability in patches with large floral display sizes (intraspecific competition) while it is due to low conspecific plant availability in patches with small floral display sizes. Our study highlights that pollinator versus mate limitation resulted in contrasted pollination modes (allogamy / facilitated autogamy, respectively), reproductive success (low / high) and selfing rate (low / high). Contrary to our expectations, no evolutionary shift has been observed towards a higher frequency of spontaneous self-fertilization in response to pollen transfer limitation due to either pollinator or mate limitation. This study clearly demonstrates the relevance of using holistic approaches to assess global changes consequences on mating system evolution and adaptive potential of plant species. High inbreeding depression and selective pressures on pollinator attractive structures, allowing both facilitated selfing and outcrossing, are likely to prevent mating system evolution in long-lived mass-flowering species
Meslin, Camille. „Analyse de l'évolution de gènes impliqués dans la reproduction“. Thesis, Tours, 2011. http://www.theses.fr/2011TOUR4030.
Genes involved in reproduction evolve rapidly and are often under positive selection. The objective of this work was to study the evolution of some of these genes, potentially involved in speciation, through their involvement in prezygotic barriers.Our results show that for the SAL1 gene, involved in pheromonal recognition in pig, three amino acids under positive selection participate in the specific binding of the pig pheromone. We also perform an evolutionary analysis of genes experimentally shown to be involved in the sperm-oocyte interaction during fertilization. Each of the nineteen species studied exhibit a particular pattern of evolution, characterized by gene gains and losses, as well as the position of amino acids under positive selection. The divergent evolution of all these genes could be involved in speciation or at least in the reinforcement of species barriers.Finally, the PhyleasProg web server was designed during the thesis. This tool permits to scientists with no experience in phylogenetic analyses to acquire a large number of results quickly and easily on the evolutionary history of their genes of interest
Mazin, Benjamin Damien. „Exploration du rôle de signalisation des Mitogen-Activated Protein Kinases lors de la fécondation chez les plantes“. Thesis, 2020. http://hdl.handle.net/1866/25575.
Reproduction is a crucial event for plant life. This process requires the formation of pollen and ovules. The germ cells will undergo meiosis and then a succession of mitosis, two for the pollen and three for the ovule, which will allow them to acquire their final structures. Once formed, these two gametes must meet each other. For this, the pollen grain will germinate on the stigmas to form the pollen tube. The growth of the pollen tube will pass through the different female tissues and thus pull the two sperm cells to the ovum for reproduction. An important cellular signaling network is necessary to allow these events to occur. The Mitogen-Activated Protein Kinase (MAPKs) cascades are one of the most studied signaling networks in plants. These kinases are involved in a wide range of developmental processes such as embryo formation and stomata. However, their roles remain poorly characterized during fertilization. The aim of this project is to better understand the role played by MAPKs during the formation of male and female gametes as well as during the growth of pollen tubes. Several members of the MAPK superfamily have been characterized for their role in the sexual reproduction of plants. Previous work in Daniel P. Matton's laboratory has demonstrated the involvement of two MAPK Kinases (MAP3K), Solanum chacoense Fertilization-Related Kinase 1 (ScFRK1) and ScFRK2. These two kinases are necessary for egg and pollen development in S. chacoense, a diploid wild potato species. In a first step, we studied the functionality of a new ScFRK, ScFRK3. This third member of the class of FRKs in S. chacoense, is also involved in the development of male and female gametophytes. From the expression pattern to the establishment of a potential signaling pathway, through the phenotypic characterization of mutants, several experiments have been performed in order to understand the role of ScFRK3 in the formation of gametes in S. chacoense. We show that ScFRK3 is involved in the formation of pollen as well as that of the embryonic sac. We then continued our research by refining the phenotyping of the overexpression mutant ScFRK2. Indeed, previous studies have shown that ScFRK2 overexpression leads the ovular primordium to the formation of carpeloid structures. However, the sets of ovular primordia have not become capeloid structures. We show here that only 10% of the eggs in the ovary have become carpeloid. Our study shows that in addition to the carpeloid structures, a large number of ova do not have an embryonic sac in the anthesis, which explains the low number of seeds per fruit. The analysis of the development of the embryonic sacs shows that 7 overexpression of ScFRK2 leads to the cessation of the functional megaspore stage. This phenotype is similar to what has been observed in interfering RNA lines reducing expression of ScFRK1 and ScFRK3. Previous studies in Arabidopsis thaliana suggest that members of the MAPK superfamily are not essential for pollen tube growth. To understand the role that MAPKs play in pollen tube elongation, we used a MAP Kinase Kinase (MKK) inhibitor called U0126. The presence of this drug in the growth medium of pollen grains causes a decrease in germination and elongation of the pollen tube. The use of the semi in vivo method shows a loss of polarization of the pollen tube growth caused by the inhibition of MKK. The presence of the inhibitor leads to a decrease in the number of actin filaments and their disorganization at the apex of the tube. Exocytosis is also affected by MKK inhibition. We show in this chapter that MAPK cascades are necessary for polarized pollen tube growth in Arabidopsis thaliana. Finally, we wanted to identify some members of the MAPK superfamily involved in pollen tube growth. We were first interested in the ScFRK family orthologs in Arabidopsis thaliana. AtMAP3K19-20-21 are the closest orthologs to ScFRK3. These AtMAP3K are expressed during the development of pollen grains and during the elongation of the pollen tube. Pollen analysis of the different mutant lines shows that in their absence the pollen does not present any development problems unlike ScFRK3. On the other hand, double mutants and triple mutant for AtMAP3K19-20-21 show a decrease in germination capacity. Pollen tube elongation is affected when at least one of the AtMAP3Ks is mutated. These two studies demonstrate that MAPKs are essential for the formation and elongation of the pollen tube and that AtMAP3K19-20-21 participate in these biological processes.
Bücher zum Thema "Silene – Reproduction (biologie) – Fécondation":
Patricia, Spallone, und Steinberg Deborah Lynn, Hrsg. Made to order: The myth of reproductive and genetic progress. Oxford [Oxfordshire]: Pergamon Press, 1987.
Clos, Jean, und Yves Muller. La reproduction humaine, tome 1 : Gonades, gamètes et fécondation - Sujets corrigés de biologie, IUFM, Capes, Agreg. Nathan Université, 1999.
Photographer), Patricia Spallone (Editor, und Deborah L. Steinberg (Editor), Hrsg. Made to Order: The Myth of Reproductive and Genetic Progress (Athene Series). Pergamon, 1987.
Photographer), Patricia Spallone (Editor, und Deborah L. Steinberg (Editor), Hrsg. Made to Order: The Myth of Reproductive and Genetic Progress (Athene Series). Pergamon, 1987.