Les populations néoteniques de Triturus helveticus des causses et du Bas-Languedoc I. Répartition et caractéristiques

Neoteny is common in some populations of Palmate newts Triturus helveticus of Southern France. Population samples have been collected from 117 pools, at three different seasons of the year. Percentages of neotenic individuals have been calculated for 29 of these pools where neotenic newts were found. Neoteny is not evenly distributed over the whole study area. It is more prevalent in the S.E. part of the Causse du Larzac and in the Causse de Blandas, than in the coastal plains of Languedoc. On the “ causses ” (arid limestone tablelands), neoteny only occurs among palmate newts, no neotenic individual having ever been found among the sympatric Triturus marmoratus population. Morphological differences between neotenic and normal popu lations of Triturus helveticus are described. None of them is consistent enough to allow sub-specific status to be given to the neotenic population. Breeding takes place later in the season among the Larzac population and the duration of the aquatic phase of the yearly cycle is also longer in the plateau population than among the newts of the coastal plains. All these differences, morphological as well as biological, disappear when the newts are kept in labo ratory conditions. Metamorphosis occurs normally when the progeny of both newt populations are bred in the laboratory. However mortality is much higher among the progeny of neotenic females, during their first three months of life

Les populations néoténiques de Triturus helveticus Raz. des Causses et du Bas-Languedoc. II. Ecologie

The physical, chemical, and biotic characteristics of the ponds where neotenic populations of Palmate newts are found in Sou thern France are described. The frequency of neoteny is high in permanent ponds, at an altitude ranging from 400 to 700 m, on arid limestone plateaux with a yearly rainfall of 1500-2000 mm. In such areas there are large seasonal variations of water temperature, ranging from + 1 to + 28 °C, water remaining cold (below + 15°C) for 8 to 10 months during the year. The saline content of water is low, as shown by conductivity figures (less than 200 pmhos/cm/cm2) . No iodine deficiency was ever found in the ponds of the study area. A correlation has been found between the frequency of neoteny and the water concentration in Ca, Mg and particularly K (which may account for 35-40 % of the cations) . The aridity of the area surrounding the pools can also contri bute to the selection of neotenic individuals, paedogenesis being of obvious adaptive value in such an environment

Microstructural and mechanical characterization of yarns made from carbon nanotubes for the instrumentation of particle beams at CERN

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Détermination de l'âge par analyse d'images assistée par ordinateur des otolithes des poissons plats Citharus linguatula et Dicologoglossa cuneata de la côte atlantique du Maroc

Deux poissons appartenant au groupe des Pleuronectiformes (Heterosomata), CitharuB linguatula Linné 1758 (Citharidae) etDicologoglossa cuneata Moreau 1881 (Soleidae) étaient échantillonnées de février 1988 à mai 1989 sur le littoral atlantique marocain (Casablanca). L'âge des deux espèces était détenniné par la méthode d'analyse d'images des otolithes sagittae sur ordinateur. Utilisant ces données sur l'âge, les relations entre âgelongueur et âge-poids étaient détenninées. Enfin, l'étude des anneaux des otolithes nous a pennis d'établir les modèles de la croissance pour chaque espèce.Age determination by computer-image analysis of otolith for the tlat fishes Citharus linguatula and Dicologoglossa cuneata from the atlantic coast of MoroccoTwo fishes belonging to the group Pleuronectiform (Heterosomata), namely the spotted flounder (Citharus linguatula Linnaeus 1758, Citharidae) and the wedge sole (Dicologoglossa cuneata Moreau 1881, Soleidae) were sampled from February 1988 to May 1989 off the atlantic coast of morocco (Casablanca), Age of the two species was detenninated by image analysis of otolith sagittae on computer. Using these data on age, the relationships between a age-length and age-weigth were detenninated. Finaly, studies of otolith's rings, enabled us to establish a growht model for each species

Severe hematopoietic stem cell inflammation compromises chronic granulomatous disease gene therapy

X-linked chronic granulomatous disease (CGD) is associated with defective phagocytosis, life-threatening infections, and inflammatory complications. We performed a clinical trial of lentivirus-based gene therapy in four patients (NCT02757911). Two patients show stable engraftment and clinical benefits, whereas the other two have progressively lost gene-corrected cells. Single-cell transcriptomic analysis reveals a significantly lower frequency of hematopoietic stem cells (HSCs) in CGD patients, especially in the two patients with defective engraftment. These two present a profound change in HSC status, a high interferon score, and elevated myeloid progenitor frequency. We use elastic-net logistic regression to identify a set of 51 interferon genes and transcription factors that predict the failure of HSC engraftment. In one patient, an aberrant HSC state with elevated CEBPβ expression drives HSC exhaustion, as demonstrated by low repopulation in a xenotransplantation model. Targeted treatments to protect HSCs, coupled to targeted gene expression screening, might improve clinical outcomes in CGD

MCT Expression and Lactate Influx/Efflux in Tanycytes Involved in Glia-Neuron Metabolic Interaction

Metabolic interaction via lactate between glial cells and neurons has been proposed as one of the mechanisms involved in hypothalamic glucosensing. We have postulated that hypothalamic glial cells, also known as tanycytes, produce lactate by glycolytic metabolism of glucose. Transfer of lactate to neighboring neurons stimulates ATP synthesis and thus contributes to their activation. Because destruction of third ventricle (III-V) tanycytes is sufficient to alter blood glucose levels and food intake in rats, it is hypothesized that tanycytes are involved in the hypothalamic glucose sensing mechanism. Here, we demonstrate the presence and function of monocarboxylate transporters (MCTs) in tanycytes. Specifically, MCT1 and MCT4 expression as well as their distribution were analyzed in Sprague Dawley rat brain, and we demonstrate that both transporters are expressed in tanycytes. Using primary tanycyte cultures, kinetic analyses and sensitivity to inhibitors were undertaken to confirm that MCT1 and MCT4 were functional for lactate influx. Additionally, physiological concentrations of glucose induced lactate efflux in cultured tanycytes, which was inhibited by classical MCT inhibitors. Because the expression of both MCT1 and MCT4 has been linked to lactate efflux, we propose that tanycytes participate in glucose sensing based on a metabolic interaction with neurons of the arcuate nucleus, which are stimulated by lactate released from MCT1 and MCT4-expressing tanycytes

Étude expérimentale du développement larvaire d’

L’étude comparée du développement larvaire d’Hymenolepis stylosa (Rudolphi, 1809) (Cestode, Cyclophyllide), parasite de Corvidés, a été réalisée expérimentalement chez trois Insectes. L’observation du développement chez un Coléoptère, Tenebrio molitor, montre que le scolex se différencie avant l’invagination du métacestode dans la vésicule cystique, et que le cysticercoïde est pourvu d’un cercomère long et flexueux. Par sa morphologie et son évolution, le cysticercoïde d’H. stylosa est semblable aux cysticercoïdes des autres Hymenolepis d’Oiseaux dont le développement est connu. Le développement chez un Orthoptère, Locusta migratoria, est identique à celui observé chez T. molitor, mais l’invagination du scolex intervient plus rapidement. Chez un autre Coléoptère, Dermestes frischi, l’oncosphère est bloquée au niveau de la paroi de l’intestin. Il résulte de ces observations qu’une étude comparée de la structure des cysticercoïdes d’Hymenolepis de Mammifères et d’Oiseaux s’impose pour rechercher des affinités entre les espèces appartenant à ce genre

Les populations néoténiques de Triturus helveticus des Causses et du Bas-Languedoc. I. Répartition et caractéristiques

Neoteny is common in some populations of Palmate newts Triturus helveticus of Southern France. Population samples have been collected from 117 pools, at three different seasons of the year. Percentages of neotenic individuals have been calculated for 29 of these pools where neotenic newts were found. Neoteny is not evenly distributed over the whole study area. It is more prevalent in the S.E. part of the Causse du Larzac and in the Causse de Blandas, than in the coastal plains of Languedoc. On the “causses” (arid limestone tablelands), neoteny only occurs among palmate newts, no neotenic individual having ever been found among the sympatric Triturus marmoratus population. Morphological differences between neotenic and normal populations of Triturus helveticus are described. None of them is consistent enough to allow sub-specific status to be given to the neotenic population. Breeding takes place later in the season among the Larzac population and the duration of the aquatic phase of the yearly cycle is also longer in the plateau population than among the newts of the coastal plains. All these differences, morphological as well as biological, disappear when the newts are kept in laboratory conditions. Metamorphosis occurs normally when the progeny of both newt populations are bred in the laboratory. However mortality is much higher among the progeny of neotenic females, during their first three months of life.Gabrion J., Sentein P., Gabrion C. Les populations néoténiques de Triturus helveticus des Causses et du Bas-Languedoc. I. Répartition et caractéristiques. In: La Terre et La Vie, Revue d'Histoire naturelle, tome 31, n°3, 1977. pp. 489-506

Les populations néoténiques de Triturus helveticus Raz. des Causses et du Bas-Languedoc. II. Écologie

The physical, chemical, and biotic characteristics of the ponds where neotenic populations of Palmate newts are found in Southern France are described. The frequency of neoteny is high in permanent ponds, at an altitude ranging from 400 to 700 m, on arid limestone plateaux with a yearly rainfall of 1500-2000 mm. In such areas there are large seasonal variations of water temperature, ranging from + 1 to + 28°C, water remaining cold (below + 15°C) for 8 to 10 months during the year. The saline content of water is low, as shown by conductivity figures (less than 200 μmhos/cm/cm²). No iodine deficiency was ever found in the ponds of the study area. A correlation has been found between the frequency of neoteny and the water concentration in Ca, Mg and particularly K (which may account for 35-40 % of the cations). The aridity of the area surrounding the pools can also contri¬ bute to the selection of neotenic individuals, paedogenesis being of obvious adaptive value in such an environment.Gabrion J., Sentein P., Gabrion C. Les populations néoténiques de Triturus helveticus Raz. des Causses et du Bas-Languedoc. II. Écologie. In: La Terre et La Vie, Revue d'Histoire naturelle, tome 32, n°4, 1978. pp. 577-610