dissection-mosquito-ovaries-midgut-salivary-glands-for-microbiome

Dissection of Mosquito Ovaries, Midgut, and Salivary Glands for Microbiome Analyses at the Organ Level

The global burden of mosquito-transmitted diseases, including malaria, dengue, West Nile, Zika, Usutu, and yellow fever, continues to increase, posing a ...

University of Montpellier, INRAe, CNRS, IRD

Free-living and symbiotic chemosynthetic microbial communities support primary production and higher trophic levels in deep-sea hydrothermal vents. The shrimp Rimicaris exoculata, which dominates animal communities along the Mid-Atlantic Ridge, houses a complex bacterial community in its enlarged cephalothorax. The dominant bacteria present are from the taxonomic groups Campylobacteria, Desulfobulbia (formerly Deltaproteobacteria), Alphaproteobacteria, Gammaproteobacteria, and some recently discovered iron oxyhydroxide-coated Zetaproteobacteria. This epibiotic consortium uses iron, sulfide, methane, and hydrogen as energy sources. Here, we generated shotgun metagenomes from Rimicaris exoculata cephalothoracic epibiotic communities to reconstruct and investigate symbiotic genomes. We collected specimens from three geochemically contrasted vent fields, TAG, Rainbow, and Snake Pit, to unravel the specificity, variability, and adaptation of Rimicaris-microbe associations.

Niche partitioning in the Rimicaris exoculata holobiont: the case of the first symbiotic Zetaproteobacteria.

Correction to: Niche partitioning in the Rimicaris exoculata holobiont: the case of the first symbiotic Zetaproteobacteria.

In deep-sea hydrothermal vent areas, deprived of light, most animals rely on chemosynthetic symbionts for their nutrition. These symbionts may be located on their cuticle, inside modified organs, or in specialized cells. Nonetheless, many of these animals have an open and functional digestive tract. The vent shrimp Rimicaris exoculata is fueled mainly by its gill chamber symbionts, but also has a complete digestive system with symbionts. These are found in the shrimp foregut and midgut, but their roles remain unknown. We used genome-resolved metagenomics on separate foregut and midgut samples, taken from specimens living at three contrasted sites along the Mid-Atlantic Ridge (TAG, Rainbow, and Snake Pit) to reveal their genetic potential.

A novel and dual digestive symbiosis scales up the nutrition and immune system of the holobiont Rimicaris exoculata.

Mosquitoes represent the most important pathogen vectors and are responsible for the spread of a wide variety of poorly treatable diseases. Wolbachia are obligate intracellular bacteria that are widely distributed among arthropods and collectively represents one of the most promising solutions for vector control. In particular, Wolbachia has been shown to limit the transmission of pathogens, and to dramatically affect the reproductive behavior of their host through its phage WO. While much research has focused on deciphering and exploring the biocontrol applications of these WO-related phenotypes, the extent and potential impact of the Wolbachia mobilome remain poorly appreciated. Notably, several Wolbachia plasmids, carrying WO-like genes and Insertion Sequences (IS), thus possibly interrelated to other genetic units of the endosymbiont, have been recently discovered. Here we investigated the diversity and biogeography of the first described plasmid of Wolbachia in Culex pipiens (pWCP) in several islands and continental countries around the world-including Cambodia, Guadeloupe, Martinique, Thailand, and Mexico-together with mosquito strains from colonies that evolved for 2 to 30 years in the laboratory. We used PCR and qPCR to determine the presence and copy number of pWCP in individual mosquitoes, and highly accurate Sanger sequencing to evaluate potential variations. Together with earlier observation, our results show that pWCP is omnipresent and strikingly conserved among Wolbachia populations within mosquitoes from distant geographies and environmental conditions. These data suggest a critical role for the plasmid in Wolbachia ecology and evolution, and the potential of a great tool for further genetic dissection and possible manipulation of this endosymbiont.

Article	Year
Niche partitioning in the Rimicaris exoculata holobiont: the case of the first symbiotic Zetaproteobacteria. Microbiome\| PubMed ID: 33845886	2021
Correction to: Niche partitioning in the Rimicaris exoculata holobiont: the case of the first symbiotic Zetaproteobacteria. Microbiome\| PubMed ID: 35303955	2022
A novel and dual digestive symbiosis scales up the nutrition and immune system of the holobiont Rimicaris exoculata. Microbiome\| PubMed ID: 36333777	2022
pWCP is a widely distributed and highly conserved Wolbachia plasmid in Culex pipiens and Culex quinquefasciatus mosquitoes worldwide. ISME communications\| PubMed ID: 37117399	2023

Julie Reveillaud

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