Unveiling microbial guilds and symbiotic relationships in Antarctic sponge microbiomes.

Marine sponges host diverse microbial communities. Although we know many of its ecological patterns, a deeper understanding of the polar sponge holobiont is still needed. We combine high-throughput sequencing of ribosomal genes, including the largest taxonomic repertoire of Antarctic sponge species analyzed to date, functional metagenomics, and metagenome-assembled genomes (MAGs).

Ongoing diversification of the global fish pathogen Piscirickettsia salmonis through genetic isolation and transposition bursts.

The management of bacterial pathogens remains a key challenge of aquaculture. The marine gammaproteobacterium Piscirickettsia salmonis is the etiological agent of piscirickettsiosis and causes multi-systemic infections in different salmon species, resulting in considerable mortality and substantial commercial losses. Here, we elucidate its global diversity, evolution, and selection during human interventions.

De novo assembly, characterization of tissue-specific transcriptomes and identification of immune related genes from the scallop Argopecten purpuratus.

The scallop Argopecten purpuratus is one of the most economically important cultured mollusks on the coasts from Chile and Peru but its production has declined, in part, due to the emergence of mass mortality events of unknown origin. Driven by this scenario, increasing progress has been made in recent years in the comprehension of immune response mechanisms in this species. However, it is still not entirely understood how different mucosal interfaces participate and cooperate with the immune competent cells, the hemocytes, in the immune defense.

Selection and validation of reliable housekeeping genes to evaluate Piscirickettsia salmonis gene expression.

Piscirickettsia salmonis is a highly aggressive facultative intracellular bacterium that challenges the sustainability of Chilean salmon production. Due to the limited knowledge of its biology, there is a need to identify key molecular markers that could help define the pathogenic potential of this bacterium. We think a model system should be implemented that efficiently evaluates the expression of putative bacterial markers by using validated, stable, and highly specific housekeeping genes to properly select target genes, which could lead to identifying those responsible for infection and disease induction in naturally infected fish.

In sílico identification and characterization of putative Dot/Icm secreted virulence effectors in the fish pathogen Piscirickettsia salmonis.

Piscirickettsia salmonis seriously affects the Chilean salmon industry. The bacterium is phylogenetically related to Legionella pneumophila and Coxiella burnetii, sharing a Dot/Icm secretion system with them. Although it is well documented that L.