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The palm weevils, Rhynchophorus, have last stage larvae that are highly appreciated by the population of the Democratic Republic of Congo. The population has a poor knowledge of the adult of this insect. We initiated this work to contribute to a better knowledge of the species of Rhynchophorus in the region and, to know their population dynamics. Three sites (Tshopo, Lubunga and Bangboka) on three different axes, 12 km from the city center were chosen. We used erect type traps, mounted on Wild Palms for two years (2012 and 2013). This work revealed the existence of three species of Rhynchophorus in this region: R. phoenicis, R. ferrugineus and R. quadrangulus. R. phoenicis is the most abundant species in the three study sites; R. ferrugineus is a rare species, while R. quadrangulus is relatively absent. The Tshopo and Lubunga sites each have three species, while the Bangboka site has only one (R. phoenicis). The insects are more frequent during the rainy period (March to May). The sex ratio was 0.5 in 2012, while in 2013 it reached 0.6, characterizing a growing population.

Three known compounds were isolated from Virgaria nigra CF-231658; 2,7-dihydroxy naphthalene (1), virgaricin B (2) and virgaricin (3). The isolated compounds was obtained from liquid-state and agar-supported fermentation using Amberlite XAD-16 solid-phase extraction during the cultivation step. Their structures were elucidated on the basis of 1D and 2D NMR as well as HRMS spectroscopic analyses. The isolated compounds were examined for their ability to inhibit elastase using normal human diploid fibroblasts. Compound 2 displayed the most potent activity with 76.7 ± 2.12% inhibition of the enzyme activity at 5 μM concentration. © 2021 Informa UK Limited, trading as Taylor & Francis Group.

Phagocytosis is the mechanism of the internalization of large particles, microorganisms and cellular debris. The complement pathway represents one of the first mechanisms of defense against infection and the complement receptor 3 (CR3), which is highly expressed on macrophages, is a major receptor for many pathogens and debris. Key to dissecting the mechanisms by which CR3-mediated phagocytosis occurs, is understanding how the complex actin binding protein machinery and associated regulators interact with actin during phagocytosis, from triggering of receptor, through to phagosome formation and closure. However, how CR3-mediated phagosome completion and closure are orchestrated is not known. Here, we reveal that dynamin-2 is recruited concomitantly with polymerised actin at the site of the nascent phagosomes and accumulates until membrane scission. Inhibition of dynamin activity leads to stalled phagocytic cups and a decrease in the amount of F-actin at the site of phagocytosis. Acute inhibition of dynamin activity in living phagocytosing cells established that dynamin-2 plays a critical role in the effective scission of the CR3-phagosome from the plasma membrane. Thus, dynamin-2 has two distinct roles in CR3-mediated phagocytosis, in the assembly of the F-actin phagocytic cup and during phagosome scission.

Les moustiques (Diptera, Culicidae) forment une famille d’insectes d’une importance considérable en santé publique. Les mentions de leur présence/absence ont été recherchées dans la littérature et auprès de sites internet spécialisés pour huit pays d’Afrique : Cap-Vert, Mauritanie, Sénégal, Gambie, Mali, Burkina Faso, Niger et Tchad. Au total, 216 espèces ont été répertoriées, appartenant à 13 genres culicidiens : Anopheles (48 espèces), Aedeomyia (2), Aedes (62), Coquillettidia (6), Culex (54), Culiseta (1), Eretmapodites (7), Ficalbia (3), Lutzia (1), Mansonia (2), Mimomyia (7), Toxorhynchites (4) et Uranotaenia (19). La présence de ces espèces dans la zone d’étude est certaine sauf pour trois espèces dont la présence est douteuse. Cette richesse spécifique représente 6% de la richesse mondiale. Les pays hébergeant la plus grande richesse spécifique sont le Burkina Faso (162 espèces), le Sénégal (142) et le Mali (110) ; le pays avec la plus faible est le Cap-Vert (11). Cette richesse est moindre au nord en climat hyper-aride et supérieure au sud en climat sub-humide. Le Tchad est le pays le moins bien inventorié. Toutes les espèces sont considérées comme natives, à l’exception de Aedes (Stegomyia) albopictus (le moustique tigre asiatique) introduit en 2016 au Mali et peut-être Ae. (Ochlerotatus) caspius introduit en Mauritanie et Ae. (Stg.) aegypti introduit à Nouakchott en Mauritanie. Cette synthèse des connaissances pourra être utile en matière de lutte antivectorielle, de santé publique, et de recherches à venir., Médecine Tropicale et Santé Internationale - Bulletin, 2021: Entomologie médicale/Medical entomology

Most endogenous viruses, an important proportion of eukaryote genomes, are doomed to slowly decay. Little is known, however, on how they evolve when they confer a benefit to their host. Bracoviruses are essential for the parasitism success of parasitoid wasps, whose genomes they integrated ~103 million years ago. Here we show, from the assembly of a parasitoid wasp genome, for the first time at a chromosomal scale, that symbiotic bracovirus genes spread to and colonized all the chromosomes. Moreover, large viral clusters are stably maintained suggesting strong evolutionary constraints. Genomic comparison with another wasps revealed that this organization was already established ~53 mya. Transcriptomic analyses highlight temporal synchronization of viral gene expression, leading to particle production. Immune genes are not induced, however, indicating the virus is not perceived as foreign by the wasp. This recognition suggests that no conflicts remain between symbiotic partners when benefits to them converge.

Aging research aims at developing therapies that delay normal aging processes and some related pathologies. Recently, many compounds and extracts from natural products have been shown to slow aging and/or extend lifespan. Marine sponges and their associated microorganisms have been found to produce a wide variety of bioactive secondary metabolites; however, those from the Southwest of the Indian Ocean are much less studied, especially regarding anti-aging activities. In this study, the microbial diversity of the marine sponge Scopalina hapalia was investigated by metagenomic analysis. Twenty-six bacterial and two archaeal phyla were recovered from the sponge, of which the Proteobacteria phylum was the most abundant. In addition, 30 isolates from S. hapalia were selected and cultivated for identification and secondary metabolites production. The selected isolates were affiliated to the genera Bacillus, Micromonospora, Rhodoccocus, Salinispora, Aspergillus, Chaetomium, Nigrospora and unidentified genera related to the family Thermoactinomycetaceae. Crude extracts from selected microbial cultures were found to be active against seven clinically relevant targets (elastase, tyrosinase, catalase, sirtuin 1, Cyclin-dependent kinase 7 (CDK7), Fyn kinase and proteasome). These results highlight the potential of microorganisms associated with a marine sponge from Mayotte to produce anti-aging compounds. Future work will focus on the isolation and the characterization of bioactive compounds. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.

Infection of Arabidopsis thaliana by the ascomycete fungus Colletotrichum higginsianum is characterized by an early symptomless biotrophic phase followed by a destructive necrotrophic phase. The fungal genome contains 77 secondary metabolism-related biosynthetic gene clusters, whose expression during the infection process is tightly regulated. Deleting CclA, a chromatin regulator involved in the repression of some biosynthetic gene clusters through H3K4 trimethylation, allowed overproduction of three families of terpenoids and isolation of 12 different molecules. These natural products were tested in combination with methyl jasmonate, an elicitor of jasmonate responses, for their capacity to alter defence gene induction in Arabidopsis. Higginsianin B inhibited methyl jasmonate-triggered expression of the defence reporter VSP1p:GUS, suggesting it may block bioactive jasmonoyl isoleucine (JA-Ile) synthesis or signalling in planta. Using the JA-Ile sensor Jas9-VENUS, we found that higginsianin B, but not three other structurally related molecules, suppressed JA-Ile signalling by preventing the degradation of JAZ proteins, the repressors of jasmonate responses. Higginsianin B likely blocks the 26S proteasome-dependent degradation of JAZ proteins because it inhibited chymotrypsin- and caspase-like protease activities. The inhibition of target degradation by higginsianin B also extended to auxin signalling, as higginsianin B treatment reduced auxin-dependent expression of DR5p:GUS. Overall, our data indicate that specific fungal secondary metabolites can act similarly to protein effectors to subvert plant immune and developmental responses. © 2020 The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Experimental Biology.

2,4-Dichlorophenol (2,4-DCP) is a ubiquitous environmental pollutant categorized as a priority pollutant by the United States (US) Environmental Protection Agency, posing adverse health effects on humans and wildlife. Bioremediation is proposed as an eco-friendly, cost-effective alternative to traditional physicochemical remediation techniques. In the present study, fungal strains were isolated from marine invertebrates and tested for their ability to biotransform 2,4-DCP at a concentration of 1 mM. The most competent strains were studied further for the expression of catechol dioxygenase activities and the produced metabolites. One strain, identified as Tritirachium sp., expressed high levels of extracellular catechol 1,2-dioxygenase activity. The same strain also produced a dechlorinated cleavage product of the starting compound, indicating the assimilation of the xenobiotic by the fungus. This work also enriches the knowledge about the mechanisms employed by marine-derived fungi in order to defend themselves against chlorinated xenobiotics. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.

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Isolation of marine compounds from living invertebrates represents a major challenge for sustainable and environmentally friendly exploitation of marine bio-resources. To develop innovative technology to trap invertebrate compounds in the open sea, the proof of concept of a system combining external continuous circulation of water with XAD-amberlite solid-phase extraction was validated in an aquarium. In this work, we reported the elicitation of guanidine alkaloid production of Crambe crambe in the presence of Anemonia sulcata, both collected from the Mediterranean Sea. Besides the previously reported crambescidin 359 (1), and crambescidin acid (2), three new compounds were isolated; one carboxylated analog of 1 named crambescidin 401 (3), and two analogs of crambescin B, crambescin B 281 (4) and crambescin B 253 (5). Based on these results, a technology named Somartexfi for “Self Operating MARine Trapping Extractor” was patented and built to transfer the concept from closed aquarium systems to open marine ecosystems. © 2018 by the authors.

Emergence of polyphagous herbivorous insects entails significant adaptation to recognize, detoxify and digest a variety of host-plants. Despite of its biological and practical importance - since insects eat 20% of crops - no exhaustive analysis of gene repertoires required for adaptations in generalist insect herbivores has previously been performed. The noctuid moth Spodoptera frugiperda ranks as one of the world’s worst agricultural pests. This insect is polyphagous while the majority of other lepidopteran herbivores are specialist. It consists of two morphologically indistinguishable strains (“C” and “R”) that have different host plant ranges. To describe the evolutionary mechanisms that both enable the emergence of polyphagous herbivory and lead to the shift in the host preference, we analyzed whole genome sequences from laboratory and natural populations of both strains. We observed huge expansions of genes associated with chemosensation and detoxification compared with specialist Lepidoptera. These expansions are largely due to tandem duplication, a possible adaptation mechanism enabling polyphagy. Individuals from natural C and R populations show significant genomic differentiation. We found signatures of positive selection in genes involved in chemoreception, detoxification and digestion, and copy number variation in the two latter gene families, suggesting an adaptive role for structural variation.

International audience; The Vistre river (France) is a hardly damaged stream, affected by a combination of both chemical and hydromorphological pressures. In order to improve its global quality and its ecological functioning, 2 kinds of action were led on 2 different reaches separated by 5 km. In 2004, a 2-km-long reach was morphologically restored, including meandering work and pebbles addition. In 2008, inputs of an old wastewater treatment plant (WWTP) were stopped due to the close of the WWTP whereas a new one, equipped with modern techniques and respecting the Europeans standards, was built 1 km downstream. Our objectives were to follow and compare the recovery of the aquatic ecosystem functioning after such modifications. Focusing on macroinvertebrate communities, we aim to first assess biological responses of such chemical and physical improvement and second to compare their respective responses. Invertebrates and environmental parameters were collected each September during the last 3 years on 6 sites : 1 reference site, 1 non-restored site reflecting the river before restoration works, 2 morphologically restored sites and 2 sites respectively downstream the old and the new WWTP inputs. Downstream these inputs, global water quality, macroinvertebrate richness and diversity improve rapidly in time and tend to be closest to the reference site. Even if in terms of current velocity and habitat structure, the two morphologically restored sites are very comparable to reference site, the water quality of this reach seems not good enough to observe significant recovery of macroinvertebrate community. Reference and restored sites show a higher proportion of Ephemeroptera and Trichoptera taxa, diversity and richness than non-restored site. Observed modifications in the functional structure suggest that ecological traits could be useful to assess the effect of morphological restoration management. Our results suggest that chemical and physical restoration works led separately limit the biological recovery.

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The anopheline vectors and malaria transmission were investigated in the Middle West of Madagascar, in the village of Ambohimena (at the altitude of 940 meters) during two years (August 1996 to July 1998). This village is located outside the vector control area, where yearly DDT house spraying campaigns have been conducted between 1993 and 1998. Collection of mosquitoes was mainly based on all night man billing collections (650 man-nights), pyrethrum spray catches (224 bedrooms) and direct collections in outdoor resting places (140 toilets, 61 pigsties, 33 holes, 19 sheds, 79 sisal hedges, 70 cart shelters). Blood fed anophelines allowed analysis of the origin of blood with an ELISA method. Presence of circum-sporozoite protein was assessed with another ELISA method. The total number of collected anophelines was 14,280. Two malaria vectors were identified: Anopheles funestus Giles, 1900 and An. arabiensis Patton, 1902. An. funestus was the most abundant mosquito, especially during the hot rainy season. Two peaks of abundance were observed (in December and April). Endophagic rate (for mosquitoes aggressive for man) of 35.3%, an endophilic rate (for resting mosquitoes) of 78.0% and an anthropophilic rate (for indoor resting mosquitoes) of 64.0% were calculated. The average parity rate was relatively low (61.2%). The Plasmodium falciparum immunological sporozoite rate was 0.20%. An. funestus presented a higher vectorial capacity during the first round of rice cultivation (January) than during the second round (April-May). An. arabiensis was mostly abundant in December and January at the beginning of the rainy season. This species was exophagic (endophagic rate = 27.5%) and zoophilic (anthropophilic rate = 7.8%). The sporozoitic index was determined as zero (number of examined mosquitoes = 871). In this village, An. arabiensis presented only marginal importance for malaria transmission. Malaria transmission occurred from December to April. Annual entomological inoculation rate, only due to An. funestus, was 8.96 during the first year, and 3.17 during the second year. In this area where transmission is moderately stable, we suggest an extension of vector imagocidal control activities up to the western fringes of the Highlands.

International audience; To evaluate the determining factors of the malaria transmission in the northwest region of Madagascar, transversal studies were carried out through one year, from March 1997 to April 1998, in two villages located near Mandritsara, at less than 300 meters above sea level. The rice-growingregion forms an intermediate zone between the central highlands with epidemic and instable malaria and the coastal zone with endemic and stable malaria. Mosquitoes were collected when landing on humans during the night and by pyrethrum spray catches as regards endophilic mosquitoes. Three vectors were identified : Anopheles arabiensis, An.gambiae and An. funestus. An. arabiensis and An. gambiae were exophagic and zoophilic.An.funestus was endo-exophagic and anthropophilic but this species shows also a zoophilic trophic deviation. In both villages, An. funestus is the main vector of human malaria. Malaria transmission was estimated to be around 50 and 70 infective bites/person/year in each village.; Pour évaluer les facteurs qui déterminent la transmission du paludisme dans la région nord-est de Madagascar, des enquêtes entomologiques ont été menées d’avril 1997 à mars 1998 dans deux villages situés dans la région de Mandritsara, à moins de 300 mètres d’altitude. Cette région est une zone rizicole importante et fait partie de la zone intermédiaire entre les Hautes terres à paludisme instable, épidémique et la région côtière à paludisme stable endémique.Les moustiques ont été récoltés par des captures sur hommes volontaires et par des collectes matinales des moustiques endophiles. Les vecteurs ont été Anopheles arabiensis, An. gambiae et An. funestus. An. funestus a été le vecteur majeur du paludisme; il n'a pas présenté d'aptitude particulière pour l'endophagie ou l'exophagie; il a essentiellement présenté une anthropophilie mais avec une tendance zoophile marquée. Le taux entomologique d’inoculation a été d’environ 50 piqûres infectantes par homme et par an dans le premier village et 70 dans le deuxième.

For malaria vector control in Madagascar, the efficacy of lambda-cyhalothrin 10% wettable powder (ICON 10 WP) was compared with DDT 75% WP for house-spraying. This evaluation was conducted from November 1997 to September 1998 in highland villages of Vakinankaratra Region, at the fringe of the malaria epidemic zone, outside the zone covered by routine DDT house-spraying (Opération de pulvérisation intro-domiciliaire de DDT: OPID zone). Treatments were compared by house-spraying in four areas: 1) application of DDT 2g ai/m2 and 2) lambda-cyhalothrin 30 mg ai/m2 in previously unsprayed villages; 3) no intervention (control); 4) OPID 5th cycle of DDT 2g ai/m2. The prevalent vector Anopheles funestus almost disappeared from both the DDT and ICON sprayed areas, whereas in the unsprayed (control) area An. funeslus density went up to 60 females per room in April and there were two seasonal peaks of malaria transmission in January and March (see following paper). In the area sprayed with ICON, the parous rate of An. funestus decreased from 47% pre-spray to 39% six months post-spraying, while the parous rate increased in DDT-sprayed area (from 57% pre-spray to 64% six months post-spray). Bioassays of An. funestus on treated walls, six months post-spray, gave mortality rates of 100% on DDT and 90% on ICON. Conversely, ICON appeared to be more effective than DDT on thatched roofs (66% versus 100%, respectively, six months post-spray). In areas sprayed with DDT or ICON the density of An. arabiensis were little affected. This study demonstrated that, under equivalent conditions, both DDT and lambda-cyhalothrin were effective in reducing malaria transmission on the western fringes of the malaria epidemic zone of the malagasy highlands, with a residual effect lasting at least for six months. Lambda-cyhalothrin appeared to be more effective than DDT in reducing the longevity of malaria vectors. In addition to efficacy, the choice of insecticide for malaria vector control should take into account their acceptability by human populations and their toxicity and persistence in the environment.

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