Molecular evidence for extensive discontinuity between peracarid (Crustacea) fauna of Macaronesian islands and nearby continental coasts: over fifty candidate endemic species

Oceanic islands are recognized evolutionary hotspots for terrestrial organisms, but little is known about their impact on marine organisms' evolution and biogeography. The volcanic archipelagos of Macaronesia occupy a vast and complex region in the Atlantic Ocean and may be particularly suitable to investigate marine island biogeography. In this study, we used mitochondrial DNA sequences (cytochrome c oxidase subunit I DNA barcoding region) to investigate the genetic differentiation between the populations from Webbnesia (i.e. Madeira, Selvagens and Canary Islands) and adjacent coasts (Azores, Continental Iberian Peninsula and Morocco) of 23 intertidal peracarid species. All species had high intraspecific genetic distances (>3%), reaching more than 20% in some cases. Between 79 and 95 Molecular Operational Taxonomic Units (MOTUs) were found in these species. Webbnesia populations displayed high genetic diversity and high endemicity, with 83% of the MOTUs being private to these islands, particularly La Palma and Madeira. Artificial community network analyses based on MOTU occurrence suggested higher similarity between Webbnesia and Azores than with adjacent continental coasts. These results reveal an unanticipated and strong biogeographic discontinuity of peracaridean fauna between Webbnesia and the Iberian Peninsula, a pattern that may occur in other groups of marine invertebrates in the region. We emphasize the unique genetic heritage hosted by these islands, underlining the need to consider the fine scale endemicity in marine conservation efforts.The authors wish to thank the colleagues who helped during fieldwork, sample processing and/or laboratory work: Tavares M and Santos R (University of Algarve, Portugal), Ladeiro B, Peteiro L, Gomes I, Albuquerque R, GuimarAes B and Fuente N (University of Aveiro, Portugal) and Gomes N (University of Minho, Portugal). Additionally, thanks to Carvalho D in the name of the Portuguese Museum of Natural History and Science of Lisbon for supplying material from the EMEPC/M@rBis/Selvagens2010 and EMAM/PEPC_M@rBis/2011 campaigns to Selvagens. Thanks to Bellisario B for feedback regarding network analysis. Finally, thanks to Ferreira EL for the use of some equipments. This work was supported by the project "DiverseShores-Testing associations between genetic and community diversity in European rocky shore environments (PTDC/BIA-BIC/114526/2009)" funded by the Fundacao para a Ciencia e Tecnologia (FCT) under the COMPETE programme supported by the European Regional Development Fund. FCT also supported a PhD grant to PEV (SFRH/BD/86536/2012). Thanks to FCT/MCTES are also due for the financial support to CESAM (UIDP/50017/2020+UIDB/50017/2020), through national funds. PE was funded through FCT in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23 of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19

Synergistic Parasite-Pathogen Interactions Mediated by Host Immunity Can Drive the Collapse of Honeybee Colonies

The health of the honeybee and, indirectly, global crop production are threatened by several biotic and abiotic factors, which play a poorly defined role in the induction of widespread colony losses. Recent descriptive studies suggest that colony losses are often related to the interaction between pathogens and other stress factors, including parasites. Through an integrated analysis of the population and molecular changes associated with the collapse of honeybee colonies infested by the parasitic mite Varroa destructor, we show that this parasite can de-stabilise the within-host dynamics of Deformed wing virus (DWV), transforming a cryptic and vertically transmitted virus into a rapidly replicating killer, which attains lethal levels late in the season. The de-stabilisation of DWV infection is associated with an immunosuppression syndrome, characterized by a strong down-regulation of the transcription factor NF-κB. The centrality of NF-κB in host responses to a range of environmental challenges suggests that this transcription factor can act as a common currency underlying colony collapse that may be triggered by different causes. Our results offer an integrated account for the multifactorial origin of honeybee losses and a new framework for assessing, and possibly mitigating, the impact of environmental challenges on honeybee health

The genome sequence of Dyella jiangningensis FCAV SCS01 from a lignocellulose-decomposing microbial consortium metagenome reveals potential for biotechnological applications

<div><p>Abstract Cellulose and its associated polymers are structural components of the plant cell wall, constituting one of the major sources of carbon and energy in nature. The carbon cycle is dependent on cellulose- and lignin-decomposing microbial communities and their enzymatic systems acting as consortia. These microbial consortia are under constant exploration for their potential biotechnological use. Herein, we describe the characterization of the genome of Dyella jiangningensis FCAV SCS01, recovered from the metagenome of a lignocellulose-degrading microbial consortium, which was isolated from a sugarcane crop soil under mechanical harvesting and covered by decomposing straw. The 4.7 Mbp genome encodes 4,194 proteins, including 36 glycoside hydrolases (GH), supporting the hypothesis that this bacterium may contribute to lignocellulose decomposition. Comparative analysis among fully sequenced Dyella species indicate that the genome synteny is not conserved, and that D. jiangningensis FCAV SCS01 carries 372 unique genes, including an alpha-glucosidase and maltodextrin glucosidase coding genes, and other potential biomass degradation related genes. Additional genomic features, such as prophage-like, genomic islands and putative new biosynthetic clusters were also uncovered. Overall, D. jiangningensis FCAV SCS01 represents the first South American Dyella genome sequenced and shows an exclusive feature among its genus, related to biomass degradation.</p></div