Cell Compartment is a Predictor of Protein Rate of Evolution, but not in the Manner Expected: Evidence Against the Extended Complexity Hypothesis.

What accounts for the variation between proteins in their rate of evolution per synonymous substitution (i.e. dN/dS, alias ω)? Previous analyses suggested that cell location is predictive, with intracellular proteins evolving slower than membrane proteins, a result considered supportive of the extended complexity hypothesis.

Metagenomic analysis of heavy water-adapted bacterial communities.

Micro-organisms can survive and thrive in unusual and extreme environments. Here, we present a metagenomic analysis of living bacteria found in highly pure, deleterious heavy water (>99% DO), stored in sealed plastic containers for more than 30 years, without any external supply. Deep DNA sequencing analyses have revealed that the most abundant genetic signatures were primarily associated with and .

Nitrogen cycling during an Arctic bloom: from chemolithotrophy to nitrogen assimilation.

In the Arctic, phytoplankton blooms are recurring phenomena occurring during the spring-summer seasons and influenced by the strong polar seasonality. Bloom dynamics are affected by nutrient availability, especially nitrogen, which is the main limiting nutrient in the Arctic. This study aimed to investigate the changes in an Arctic microbial community using omics approaches during a phytoplankton bloom focusing on the nitrogen cycle.

Limitations of sequence dissimilarity as a predictor of prokaryotic lineage.

The molecular clock rests upon the assumption that the observed changes among sequences capture the differentiation of lineages, or kinship, as dissimilarity increases with time. Although it has been questioned over the years, this paradigmatic principle continues to underlie the idea that the polymorphic space of a gene is so vast that it is unattainable in evolutionary time. Thus, the molecular clock has been used to obtain taxonomic annotations, proving to be very effective at delivering testable results.

Quantifying microbial guilds.

The ecological role of microorganisms is of utmost importance due to their multiple interactions with the environment. However, assessing the contribution of individual taxonomic groups has proven difficult despite the availability of high throughput data, hindering our understanding of such complex systems. Here, we propose a quantitative definition of guild that is readily applicable to metagenomic data.