Volume 4 Issue 2, February 2019

A secreted effector from the plant pathogenic fungus Ustilago maydis has evolved to acquire a new function that contributes to the unique lifestyle of this species, highlighting the utility of using comparative genetic analyses to address current questions in plant–microorganism interactions.

Only a tiny fraction of bacterial species can be cultured and engineered in the laboratory, limiting our ability to deploy bacteria in harsh environments or use them to produce important compounds. Recent work has opened this frontier by developing new methods to characterize and engineer diverse, undomesticated bacterial species.

Sterols are a hallmark of eukaryotes. So how do hordes of primitive eukaryotes survive and thrive without a key enzyme for making these crucial lipids? We now learn what solution evolution arrived at — invention of an alternative enzyme that does the same job.

Following cleavage by ADAM10, the vaccinia virus epidermal growth factor homologue, VGF, promotes infected cell motility at the leading edge of infection and spread of the virus.

The discovery of an alternative squalene epoxidase (AltSQE) belonging to the fatty acid hydroxylase superfamily in the diatom Phaeodactylum tricornutum and other eukaryotic lineages solves the mystery of the existence of a steroid biosynthesis pathway in eukaryotes that lack the canonical flavoprotein SQE.

Thaumarchaeota isolates are capable of utilizing urea and cyanate for nitrification in vitro. Here, the authors show that this occurs in situ and that Thaumarchaeota are able to use urea and cyanate as an energy and nitrogen source in the marine environment.

The development of mobile CRISPR interference (CRISPRi), a modular dCas9-based system that facilitates blocking of gene expression and is easily transferred via conjugation, enables genetic investigations in non-model bacteria.

Comparison of Ustilago maydis and Sporisorium reilianum, two smut fungi that parasitize maize, reveals that their Tin2 effectors target different protein kinase paralogues and activity of an ancestral allele indicates Tin2 neofunctionalization in U. maydis.

The synthesis of NPY and its receptor Y1R increases in lung phagocytes during severe influenza virus infection, leading to the induction of SOCS3 and impaired antiviral response and increased pro-inflammatory cytokine production.

Clostridium difficile toxins TcdA and TcdB enhance pathogenesis by inducing vascular endothelial growth factor A (VEGF-A) production and promoting colonic vascular permeability.

Many enterovirus genomes harbour an upstream ORF (uORF) that is subject to strong purifying selection and encodes a protein (UP) that associates with membranes and facilitates virus release. UP-knockout echoviruses are attenuated at late stages of infection in human intestinal organoids.

Using metabolomics and shotgun metagenomics on stool samples from individuals with and without inflammatory bowel disease, metabolites, microbial species and genes associated with disease were identified and validated in an independent cohort.

Structural and functional characterization of H7-reactive monoclonal neutralizing antibodies from donors naturally infected with H7N9 influenza virus reveals overlapping epitopes around the receptor binding site of haemagglutinin and antigenic change in virus lineages isolated in 2013/14 versus 2016/17, indicating a need to update H7N9 vaccines.

Two distinct pathways control inflammasome activation during Aspergillus fumigatus infection. The C-type lectin receptor (CLR) pathway activates MAPK and NF-κB signalling, whereas Toll-like receptor (TLR) signalling is activated through MyD88 and TRIF. Both pathways activate transcription factor IRF1, which induces antifungal effector IRGB10.

A genome-wide association study using evolutionarily coupled loci identifies epistatic pairs impacting antibiotic resistance in Neisseria gonorrhoeae.

Hepatitis C virus (HCV) infection blunts induction of hepcidin expression by bone morphogenetic protein 6 (BMP6), probably via TNF-mediated downregulation of the BMP co-receptor HJV, while BMP6 regulates a gene repertoire reminiscent of type I IFN signalling. BMP6 and related activin proteins potently block replication of HCV, hepatitis B virus and Zika virus independently of IFN.

Metagenomes from hydraulically fractured wells over time identified viral operational taxonomic units predicted to actively infect dominant bacteria, and in vitro experiments show that viral lysis of these hosts can release metabolites important for fermentation.

The Bacillus cereus enterotoxin haemolysin BL induces pore formation and activation of the NLRP3 inflammasome, leading to enhanced lethality during infection.