Project description:Anthropogenic nutrient inputs alter soil biodiversity; however, it remains largely unknown whether changes in soil microeukaryotes (fungi and protists) are primarily driven by direct effects, such as modifications in soil properties, or by indirect effects, such as plant diversity loss. To disentangle these mechanisms, we investigated the long-term effects (11 years) of fertilization and manipulated plant diversity (1, 2, or 4 plant species) on soil microeukaryote communities in a temperate grassland experiment using long-amplicon rRNA sequencing. Our results indicate that fertilization generally had a stronger influence on microeukaryote communities than plant species richness. Fertilization altered the community composition of fungi and protists, increased OTU richness by 20.8% and 52.7%, respectively, and shifted community dominance from fungi to protists. Regarding plant diversity, we observed an effect exclusively on the protist community. Changes were primarily explained by increased plant biomass (driven by both fertilization and plant diversity) and by higher soil phosphorus and lower soil pH levels (driven exclusively by fertilization). Regarding life strategies, we observed synergistic treatment effects: fertilization primarily enhanced fungal saprophytes (only richness), fungal animal pathogens, and protist consumers, whereas plant diversity affected phototrophic protists (reduction) and protist animal pathogens (enhancement). Notably, fertilization and plant diversity decline together led to a cumulative increase in fungal plant pathogens. In conclusion, we highlight that fertilisation alone has a significant effect on soil microeukaryotes, while the additional decline in plant diversity affects different soil groups that are not directly affected by fertilisation. This synergistic pattern indicates that fertilization can influence the entire microeukaryote community through direct and indirect mechanisms, with a cumulative enhancement on certain groups, such as plant pathogens.
Project description:Zika virus (ZIKV) is a mosquito-transmitted positive-sense RNA virus in the family Flaviviridae. ZIKV infections are associated with neurodevelopmental deficiencies termed Congenital Zika Syndrome. ZIKV strains are grouped into three phylogenetic lineages: East African, West African, and Asian, which contains the American lineage. RNA virus genomes exist as genetically-related sequences. The heterogeneity of these viral populations is implicated in viral fitness, and genome diversity is correlated to virulence. This study examines genetic diversity of representative ZIKV strains from all lineages utilizing next generation sequencing (NGS). Inter-lineage diversity results indicate that ZIKV lineages differ broadly from each other; however, intra-lineage comparisons of American ZIKV strains isolated from human serum or placenta show differences in diversity when compared to ZIKVs from Asia and West Africa. This study describes the first comprehensive NGS analysis of all ZIKV lineages and posits that sub-consensus-level diversity may provide a framework for understanding ZIKV fitness during infection.