Endosymbiosis morphological reorganization during metamorphosis diverges in weevils

Virtually all animals associate with beneficial symbiotic bacteria. Whether and how these associations are modulated across a host’s lifecycle is an important question in disentangling animal-bacteria interactions. We recently reported a case of complete morphological reorganization of symbiosis during metamorphosis of the cereal weevil, Sitophilus oryzae. In this model, the bacteriome, a specialized organ that houses the intracellular bacterium Sodalis pierantonius, undergoes a two-phase remodeling program synchronously driven by host and endosymbiont, resulting in a localization shift and the formation of multiple new bacteriomes. Here, we provide comparative data in a closely-related coleopteran, the red palm weevil Rhynchophorus ferrugineus, which is associated with the ancestral endosymbiont Nardonella. Using cell imaging experiments, we show that the red pal weevil bacteriome remains unchanged during metamorphosis, hence contrasting with what we reported in the cereal weevil S. oryzae. These findings highlight the complexity and divergence of host-symbiont interactions and their intertwining with host development, even in closely-related species. Abbreviations: DAPI: 4′,6-diamidino-2-phenylindole; FISH: Fluorescence in situ hybridization; T3SS: Type III secretion system

Modulation of fecal clostridiales bacteria and butyrate by probiotic intervention with Lactobacillus paracasei DG varies among healthy adults

Background: The modulation of gut microbiota is considered to be the first target to establish probiotic efficacy in a healthy population. Objective: This study was conducted to determine the impact of a probiotic on the intestinal microbial ecology of healthy volunteers. Methods: High-throughput 16S ribosomal RNA gene sequencing was used to characterize the fecal microbiota in healthy adults (23-55 y old) of both sexes, before and after 4 wk of daily consumption of a capsule containing at least 24 billion viable Lactobacillus paracasei DG cells, according to a randomized, double-blind, crossover placebo-controlled design. Results: Probiotic intake induced an increase in Proteobacteria (P = 0.006) and in the Clostridiales genus Coprococcus (P = 0.009), whereas the Clostridiales genus Blautia (P = 0.036) was decreased; a trend of reduction was also observed for Anaerostipes (P = 0.05) and Clostridium (P = 0.06). We also found that the probiotic effect depended on the initial butyrate concentration. In fact, participants with butyrate >100 mmol/kg of wet feces had a mean butyrate reduction of 49 ± 21% and a concomitant decrease in the sum of 6 Clostridiales genera, namely Faecalibacterium, Blautia, Anaerostipes, Pseudobutyrivibrio, Clostridium, and Butyrivibrio (P = 0.021), after the probiotic intervention. In contrast, in participants with initial butyrate concentrations <25 mmol/kg of wet feces, the probiotic contributed to a 329 ± 255% (mean ± SD) increment in butyrate concomitantly with an ~55% decrease in Ruminococcus (P = 0.016) and a 150% increase in an abundantly represented unclassified Bacteroidales genus (P = 0.05). Conclusions: The intake of L. paracasei DG increased the Blautia:Coprococcus ratio, which, according to the literature, can potentially confer a health benefit on the host. The probiotic impact on themicrobiota and on short-chain fatty acids, however, seems to strictly depend on the initial characteristics of the intestinal microbial ecosystem. In particular, fecal butyrate concentrations could represent an important biomarker for identifying subjects who may benefit from probiotic treatment

Assessing the impact of agricultural strategies on soil Artropods: a case study using environmental DNA

Elucidating how agricultural practices affect soil arthropod\u2019s communities is of relevant for both scientific and economic interests. Thus, using DNA metabarcoding approach, Arthropods communities inhabiting soil of organic and conventional farms were characterized. Soil samples were collected from organic and conventional farms, covering the margin and three levels towards the center of a stable meadow and a barley field in both farms; each sample consisted of 10 homogenized cores of soil (~560 cm3), sampling was performed in spring, summer and autumn Soil texture, pH, N and C parameters were measured. DNA was extracted from three replicates of each soil sample. A fragment mitochondrial cox1 was amplified using three primer pairs and sequenced using Illumina Miseq. Raw sequences were processed and analyzed using Qiime to obtain Operational Taxonomic Units (OTUs) table. Approximately 75% of the obtained reads were identified as Animalia, and among these ~80% as Arthropods. \u3b1-diversity indices barley field in conventional farming were significantly lower (OTUs= 854, H'= 5.34\ub10.53, Pielou\u2019s evenness= 0,77\ub10,06) comparing with the other samples (OTUs> 1100, H'> 6 and Pielou\u2019s evenness> 0,8). Fitting the farming system, the field, position as factors in NMDS showed that Arthropods communities were not affected by the collecting season and the farming system (organic vs conventional), instead crop vs stable meadows and the position in the field (margin vs middle) have a strong effect. Soil properties affected the Arthropods communities, especially the pH on Chilopoda and Diplopoda and the C/N ratio on Arachnida and Insecta. Our results pointing out that the strategy of farm management does not affect the arthropod communities of the soil as much as the soil properties itself, while the position in the filed had a major effect, highlighting the importance of green corridors for maintaining the soil biodiversity and the agroecosystem functioning

Soil DNA metabarcoding: evaluating the efficiency of multiplex primer sets in recovering the soil invertebrate's community as soil quality indicators

DNA Metabarcoding was used to investigate the efficiency of two sets of primers (combinations A and B) for characterizing the soil invertebrate\u2019s communities in different farming management systems. Soil samples were taken from three different sites in the South-West of Milan and DNA was extracted directly. PCR was applied by using 4 pairs of previously published primers targeting invertebrate\u2019s cox1, followed by Illumina Miseq sequencing. The results showed that the presence of the most popular primer pair used in barcoding studies (LCOI490-HCO2198) has affected negatively the taxonomic assignment of OTUs, since about 67.88 % of the obtained sequences where not identified. Our analysis showed that a higher percentage of Arthropoda, Annelida, Nematoda and Rotifera &Tardigrada (41.6, 5.9, 0.8 and 1% of total reads, respectively) was obtained with primer combination B; thus this primers set can be considered a promising method to evaluate the soil arthropods community

Widespread presence of Wolbachia in an Alpine population of the viviparous leaf beetle Oreina cacaliae (Coleoptera: Chrysomelidae)

Oreina cacaliae (Coleoptera: Chrysomelidae) is a rare example of viviparous insect, able to feed on toxic plants and sequester toxic compounds. Here we present the results of a study on the microbiota associated with O. cacaliae, based on 16S rRNA bacterial gene sequencing. Wolbachia resulted as the dominant bacterium, both in males (100%) and in females (91.9%). Based on multilocus sequence typing, the detected Wolbachia was described as a new sequence type (Wolbachia Ocac_A_wVdO). Phylogenetic analyses assigned Wolbachia Ocac_A_wVdO to supergroup-A. In situ hybridization and electron microscopy confirmed the presence of Wolbachia within O. cacaliae oocytes, indicating its transovarial transmission. PCR specific for Wolbachia was performed on representatives of six species of Oreina; the presence / absence of Wolbachia was then mapped on a cladogram representing the phylogeny of the insect host. Finally, since viviparous species of Oreina were either infected or non-infected by Wolbachia, we cannot derive any conclusion about the possibility that this symbiont played some role in the evolution of viviparity

Midgut microbiota of the malaria mosquito vector Anopheles gambiae and Interactions with plasmodium falciparum Infection

The susceptibility of Anopheles mosquitoes to Plasmodium infections relies on complex interactions between the insect vector and the malaria parasite. A number of studies have shown that the mosquito innate immune responses play an important role in controlling the malaria infection and that the strength of parasite clearance is under genetic control, but little is known about the influence of environmental factors on the transmission success. We present here evidence that the composition of the vector gut microbiota is one of the major components that determine the outcome of mosquito infections. A. gambiae mosquitoes collected in natural breeding sites from Cameroon were experimentally challenged with a wild P. falciparum isolate, and their gut bacterial content was submitted for pyrosequencing analysis. The meta-taxogenomic approach revealed a broader richness of the midgut bacterial flora than previously described. Unexpectedly, the majority of bacterial species were found in only a small proportion of mosquitoes, and only 20 genera were shared by 80% of individuals. We show that observed differences in gut bacterial flora of adult mosquitoes is a result of breeding in distinct sites, suggesting that the native aquatic source where larvae were grown determines the composition of the midgut microbiota. Importantly, the abundance of Enterobacteriaceae in the mosquito midgut correlates significantly with the Plasmodium infection status. This striking relationship highlights the role of natural gut environment in parasite transmission. Deciphering microbe-pathogen interactions offers new perspectives to control disease transmission.Institut de Recherche pour le Developpement (IRD); French Agence Nationale pour la Recherche [ANR-11-BSV7-009-01]; European Community [242095, 223601]info:eu-repo/semantics/publishedVersio

Structure and functional characterization of pyruvate decarboxylase from Gluconacetobacter diazotrophicus

BACKGROUND: Bacterial pyruvate decarboxylases (PDC) are rare. Their role in ethanol production and in bacterially mediated ethanologenic processes has, however, ensured a continued and growing interest. PDCs from Zymomonas mobilis (ZmPDC), Zymobacter palmae (ZpPDC) and Sarcina ventriculi (SvPDC) have been characterized and ZmPDC has been produced successfully in a range of heterologous hosts. PDCs from the Acetobacteraceae and their role in metabolism have not been characterized to the same extent. Examples include Gluconobacter oxydans (GoPDC), G. diazotrophicus (GdPDC) and Acetobacter pasteutrianus (ApPDC). All of these organisms are of commercial importance. RESULTS: This study reports the kinetic characterization and the crystal structure of a PDC from Gluconacetobacter diazotrophicus (GdPDC). Enzyme kinetic analysis indicates a high affinity for pyruvate (KM 0.06 mM at pH 5), high catalytic efficiencies, pHopt of 5.5 and Topt at 45 degrees C. The enzyme is not thermostable (T of 18 minutes at 60 degrees C) and the calculated number of bonds between monomers and dimers do not give clear indications for the relatively lower thermostability compared to other PDCs. The structure is highly similar to those described for Z. mobilis (ZmPDC) and A. pasteurianus PDC (ApPDC) with a rmsd value of 0.57 A for C? when comparing GdPDC to that of ApPDC. Indole-3-pyruvate does not serve as a substrate for the enzyme. Structural differences occur in two loci, involving the regions Thr341 to Thr352 and Asn499 to Asp503. CONCLUSIONS: This is the first study of the PDC from G. diazotrophicus (PAL5) and lays the groundwork for future research into its role in this endosymbiont. The crystal structure of GdPDC indicates the enzyme to be evolutionarily closely related to homologues from Z. mobilis and A. pasteurianus and suggests strong selective pressure to keep the enzyme characteristics in a narrow range. The pH optimum together with reduced thermostability likely reflect the host organisms niche and conditions under which these properties have been naturally selected for. The lack of activity on indole-3-pyruvate excludes this decarboxylase as the enzyme responsible for indole acetic acid production in G. diazotrophicus.IS

Molecular Tools for Monitoring the Ecological Sustainability of a Stone Bio-Consolidation Treatment at the Royal Chapel, Granada

Background: Biomineralization processes have recently been applied in situ to protect and consolidate decayed ornamental stone of the Royal Chapel in Granada (Spain). While this promising method has demonstrated its efficacy regarding strengthening of the stone, little is known about its ecological sustainability.Methodology/Principal Findings: Here, we report molecular monitoring of the stone-autochthonous microbiota before and at 5, 12 and 30 months after the bio-consolidation treatment (medium/long-term monitoring), employing the well-known molecular strategy of DGGE analyses. Before the bio-consolidation treatment, the bacterial diversity showed the exclusive dominance of Actinobacteria (100%), which decreased in the community (44.2%) after 5 months, and Gamma-proteobacteria (30.24%) and Chloroflexi (25.56%) appeared. After 12 months, Gamma-proteobacteria vanished from the community and Cyanobacteria (22.1%) appeared and remained dominant after thirty months, when the microbiota consisted of Actinobacteria (42.2%) and Cyanobacteria (57.8%) only. Fungal diversity showed that the Ascomycota phylum was dominant before treatment (100%), while, after five months, Basidiomycota (6.38%) appeared on the stone, and vanished again after twelve months. Thirty months after the treatment, the fungal population started to stabilize and Ascomycota dominated on the stone (83.33%) once again. Members of green algae (Chlorophyta, Viridiplantae) appeared on the stone at 5, 12 and 30 months after the treatment and accounted for 4.25%, 84.77% and 16.77%, respectively.Conclusions: The results clearly show that, although a temporary shift in the bacterial and fungal diversity was observed during the first five months, most probably promoted by the application of the bio-consolidation treatment, the microbiota tends to regain its initial stability in a few months. Thus, the treatment does not seem to have any negative side effects on the stone-autochthonous microbiota over that time. The molecular strategy employed here is suggested as an efficient monitoring tool to assess the impact on the stone-autochthonous microbiota of the application of biomineralization processes as a restoration/conservation procedure.This work was supported by the European Regional Development Fund (ERDF), Junta de Andalucía (Spain) and the “Fortalecimiento de la I+D+i” program from the University of Granada, co-financed by grant RNM-3493 and Research Group BIO-103 from Junta de Andalucía, as well as by the Spanish Government through “José Castillejo” program from the “Ministerio de Educación, Cultura y Deporte” (I+D+i 2008-2011), and by the Austrian Science Fund (FWF) under Grant “Elise-Richter V194-B20”

Endosymbiosis morphological reorganization during metamorphosis diverges in weevils.

Virtually all animals associate with beneficial symbiotic bacteria. Whether and how these associations are modulated across a host's lifecycle is an important question in disentangling animal-bacteria interactions. We recently reported a case of complete morphological reorganization of symbiosis during metamorphosis of the cereal weevil, Sitophilus oryzae. In this model, the bacteriome, a specialized organ that houses the intracellular bacterium Sodalis pierantonius, undergoes a two-phase remodeling program synchronously driven by host and endosymbiont, resulting in a localization shift and the formation of multiple new bacteriomes. Here, we provide comparative data in a closely-related coleopteran, the red palm weevil Rhynchophorus ferrugineus, which is associated with the ancestral endosymbiont Nardonella. Using cell imaging experiments, we show that the red pal weevil bacteriome remains unchanged during metamorphosis, hence contrasting with what we reported in the cereal weevil S. oryzae. These findings highlight the complexity and divergence of host-symbiont interactions and their intertwining with host development, even in closely-related species. Abbreviations: DAPI: 4',6-diamidino-2-phenylindole; FISH: Fluorescence in situ hybridization; T3SS: Type III secretion system