Ichthyosporea: a window into the origin of animals.

Ichthyosporea is an underexplored group of unicellular eukaryotes closely related to animals. Thanks to their phylogenetic position, genomic content, and development through a multinucleate coenocyte reminiscent of some animal embryos, the members of Ichthyosporea are being increasingly recognized as pivotal to the study of animal origins. We delve into the existing knowledge of Ichthyosporea, identify existing gaps and discuss their life cycles, genomic insights, development, and potential to be model organisms.

Shotgun metagenomes from productive lakes in an urban region of Sweden.

Urban lakes provide multiple benefits to society while influencing life quality. Moreover, lakes and their microbiomes are sentinels of anthropogenic impact and can be used for natural resource management and planning. Here, we release original metagenomic data from several well-characterized and anthropogenically impacted eutrophic lakes in the vicinity of Stockholm (Sweden).

Gene gain facilitated endosymbiotic evolution of Chlamydiae.

Chlamydiae is a bacterial phylum composed of obligate animal and protist endosymbionts. However, other members of the Planctomycetes-Verrucomicrobia-Chlamydiae superphylum are primarily free living. How Chlamydiae transitioned to an endosymbiotic lifestyle is still largely unresolved.

Genomic diversity and biosynthetic capabilities of sponge-associated chlamydiae.

Sponge microbiomes contribute to host health, nutrition, and defense through the production of secondary metabolites. Chlamydiae, a phylum of obligate intracellular bacteria ranging from animal pathogens to endosymbionts of microbial eukaryotes, are frequently found associated with sponges. However, sponge-associated chlamydial diversity has not yet been investigated at the genomic level and host interactions thus far remain unexplored.

Chlamydial contribution to anaerobic metabolism during eukaryotic evolution.

The origin of eukaryotes is a major open question in evolutionary biology. Multiple hypotheses posit that eukaryotes likely evolved from a syntrophic relationship between an archaeon and an alphaproteobacterium based on H exchange. However, there are no strong indications that modern eukaryotic H metabolism originated from archaea or alphaproteobacteria.

Marine Sediments Illuminate Chlamydiae Diversity and Evolution.

The bacterial phylum Chlamydiae is so far composed of obligate symbionts of eukaryotic hosts. Well known for Chlamydiaceae, pathogens of humans and other animals, Chlamydiae also include so-called environmental lineages that primarily infect microbial eukaryotes. Environmental surveys indicate that Chlamydiae are found in a wider range of environments than anticipated previously.

Virus Genomes from Deep Sea Sediments Expand the Ocean Megavirome and Support Independent Origins of Viral Gigantism.

The nucleocytoplasmic large DNA viruses (NCLDV) of eukaryotes (proposed order, "Megavirales") include the families , , , , , , and , as well as still unclassified pithoviruses, pandoraviruses, molliviruses, and faustoviruses. Several of these virus groups include giant viruses, with genome and particle sizes exceeding those of many bacterial and archaeal cells. We explored the diversity of the NCLDV in deep sea sediments from the Loki's Castle hydrothermal vent area.

Changes in expression profiles of genes associated with DNA repair following induction of DNA damage in larval zebrafish Danio rerio.

DNA repair is initiated by transcription of genes in response to specific types of damage. Breaks in DNA strands (single and double) are repaired predominantly through non-homologous end-joining (NHEJ) or homologous recombination (HR), but progression of repair and changes in expression profiles of genes involved are unknown. DNA damage was induced in zebrafish larvae by brief exposure (10min) to hydrogen peroxide (H2O2; 100mM), and induction of DNA strand breaks was assessed by single-cell gel electrophoresis (comet) assay over 24h.

Enhanced metal and metalloid concentrations in the gut system comparing to remaining tissues of Gammarus pulex L.

Invertebrate shredders such as Gammarus pulex are key species in contaminated stream ecosystems. Although a number of previous studies examining differences in metal accumulation between the gut system and remaining tissues of invertebrates exist, few focus on wide range of metals and metalloids that are relevant to contaminated systems. This study compared accumulation of the commonest (at study site) 15 metals and metalloids between the gut system including feces and remaining tissues of G.