Interactome analysis of Caenorhabditis elegans synapses by TurboID-based proximity labeling

Proximity labeling provides a powerful in vivo tool to characterize the proteome of subcellular structures and the interactome of specific proteins. The nematode Caenorhabditis elegans is one of the most intensely studied organisms in biology, offering many advantages for biochemistry. Using the highly active biotin ligase TurboID, we optimize here a proximity labeling protocol for C. elegans. An advantage of TurboID is that biotin's high affinity for streptavidin means biotin-labeled proteins can be affinity-purified under harsh denaturing conditions. By combining extensive sonication with aggressive denaturation using SDS and urea, we achieved near-complete solubilization of worm proteins. We then used this protocol to characterize the proteomes of the worm gut, muscle, skin, and nervous system. Neurons are among the smallest C. elegans cells. To probe the method's sensitivity, we expressed TurboID exclusively in the two AFD neurons and showed that the protocol could identify known and previously unknown proteins expressed selectively in AFD. The active zones of synapses are composed of a protein matrix that is difficult to solubilize and purify. To test if our protocol could solubilize active zone proteins, we knocked TurboID into the endogenous elks-1 gene, which encodes a presynaptic active zone protein. We identified many known ELKS-1-interacting active zone proteins, as well as previously uncharacterized synaptic proteins. Versatile vectors and the inherent advantages of using C. elegans, including fast growth and the ability to rapidly make and functionally test knock-ins, make proximity labeling a valuable addition to the armory of this model organism

Contribution of Aeromagnetic Data to the Structural Discontinuities Identification of Black Volta Catch-ment Aquifer System in Côte d'Ivoire

This study aims to improve the structural knowledge of the fissured aquifers of the Black Volta catchment in Côte d'Ivoire based on the mapping of magnetic lineaments that represent magnetic discontinuities such as magmatic body contacts or tectonic faults. Four filtering methods: pole reduction (equator), gradient (vertical and hori-zontal), upward extension, and angle tilt were applied to the residual magnetic field map to extract magnetic discontinuities using the Oasis Montaj (Geosoft) program. Euler deconvolution coupled with the analytical signal provided, in addition to the horizontal location of the magnetic contacts, an indication of their depths. The re-sulting structural map contains 458 structures with lengths ranging from 9.03 to 66.54 km. Three directions: NW-SE, E-W and NE-SW were detected, with a predomi-nance of the NW-SE direction. Depths estimated by Euler solutions range from 6.8 to 2847 m. This map is consistent with many faults already recognised or assumed by traditional structural studies and tectonic events affecting the Ivorian basement. These results contribute significantly to the improvement of the structural map of the Black Volta Basin in Côte d'Ivoire. In addition to the major known tectonic faults, numerous lineaments, particularly those at depth, have been highlighted by the pre-sent study.  &nbsp

Contribution of Aeromagnetic Data to the Structural Discontinuities Identification of Black Volta Catch-ment Aquifer System in Côte d'Ivoire

This study aims to improve the structural knowledge of the fissured aquifers of the Black Volta catchment in Côte d'Ivoire based on the mapping of magnetic lineaments that represent magnetic discontinuities such as magmatic body contacts or tectonic faults. Four filtering methods: pole reduction (equator), gradient (vertical and hori-zontal), upward extension, and angle tilt were applied to the residual magnetic field map to extract magnetic discontinuities using the Oasis Montaj (Geosoft) program. Euler deconvolution coupled with the analytical signal provided, in addition to the horizontal location of the magnetic contacts, an indication of their depths. The re-sulting structural map contains 458 structures with lengths ranging from 9.03 to 66.54 km. Three directions: NW-SE, E-W and NE-SW were detected, with a predomi-nance of the NW-SE direction. Depths estimated by Euler solutions range from 6.8 to 2847 m. This map is consistent with many faults already recognised or assumed by traditional structural studies and tectonic events affecting the Ivorian basement. These results contribute significantly to the improvement of the structural map of the Black Volta Basin in Côte d'Ivoire. In addition to the major known tectonic faults, numerous lineaments, particularly those at depth, have been highlighted by the pre-sent study.  &nbsp

Luminescence dating applied to medieval architecture

Avranches’ keep remains constitute a witness of Anglo-Norman knowledge on castle building. Their similarity with other buildings such as Ivry-la-Bataille castle or London Tower required determining the place of Avranches keep in this group: pioneer or imitation? Therefore, samples of brick for luminescence dating were taken from the remaining little tower. Results indicate a chronology later than assumed: second part of the 12th century and first part of 13th century. These dates tend to prove that north-east tower remains would correspond to a reconstruction phase and not to the original construction.Le donjon d’Avranches représente un des rares témoins de l’architecture castrale anglo-normande. Son plan présente d’importantes resemblance avec d’autres edifices de du même contexte chrono-culturel, comme le donjon d’Ivry-la-Bataille ou la Tour de Londres. Ces ressemblances posent la question de la place du donjon d’Avranches dans cet ensemble : s’agit-il d’un édifice précurseur ou d’une imitation ? C’est pourquoi plusieurs prélèvements de brique ont été prélevés dans les vestiges de ce bâtiment, afin de procéder à la datation de la sa construction. Les résultats semblent suggérer une construction plus tardive qu’on ne l’envisageait, entre la deuxième moitié du xiie siècle et la première moitié du xiiie siècle. Ces dates pourraient suggérer une reconstruction partielle du donjon, sans correspondre à la phase de construction originale du château

Culicidae diversity, malaria transmission and insecticide resistance alleles in malaria vectors in Ouidah-Kpomasse-Tori district from Benin (West Africa): A pre-intervention study

<p>Abstract</p> <p>Background</p> <p>To implement an Insecticide Resistance Management (IRM) strategy through a randomized controlled trial (phase III), 28 villages were selected in southern Benin. No recent entomological data being available in these villages, entomological surveys were performed between October 2007 and May 2008, before vector control strategies implementation, to establish baseline data.</p> <p>Methods</p> <p>Mosquitoes were sampled by human landing collection (16 person-nights per village per survey per village) during 5 surveys. Mosquitoes were identified morphologically and by molecular methods. The <it>Plasmodium falciparum </it>circumsporozoïte indexes were measured by ELISA, and the entomological inoculation rates (EIRs) were calculated. Molecular detection of pyrethroid knock down resistance (<it>Kdr</it>) and of insensitive acetylcholinesterase were performed.</p> <p>Results</p> <p>44,693 mosquitoes belonging to 28 different species were caught from October 2007 to May 2008. Among mosquitoes caught, 318 were <it>An. gambiae s.s</it>., 2 were <it>An. nili</it>, 568 were <it>An. funestus s.s</it>., and one individual was <it>An. leesoni</it>. EIR was 2.05 ± 1.28 infective bites per human per 100 nights on average, of which 0.67 ± 0.60 were from <it>An. funestus </it>and 1.38 ± 0.94 infective bites were from <it>An. gambiae</it>. Important variations were noted between villages considering mosquito density and malaria transmission indicating a spatial heterogeneity in the study area. The <it>kdr </it>allelic frequency was 28.86% in <it>An. gambiae s.s</it>. on average and significantly increases from October 2007 (10.26%) to May 2008 (33.87%) in M molecular form of <it>An. gambiae s.s</it>. <it>Ace 1 </it>mutation was found in S molecular of <it>An. gambiae s.s </it>at a low frequency (< 1%).</p> <p>Conclusion</p> <p>This study updates information on mosquito diversity and malaria risk in rural villages from south Benin. It showed a high spatial heterogeneity in mosquito distribution and malaria transmission and underlines the need of further investigations of biological, ecological, and behavioral traits of malaria vectors species and forms. This study is a necessary prerequisite to cartography malaria risk and to improve vector control operations in southern Benin.</p