Virulence as a Side Effect of Interspecies Interaction in Coral Pathogens.

The increase in prevalence and severity of coral disease outbreaks produced by pathogens, and related to global warming, has seriously impacted reef-building corals throughout the oceans. The coral has been used as a model system to study coral bleaching produced by infection. Previous data demonstrated that when two coral pathogens ( and ) simultaneously infected the coral , their pathogenicity was greater than when each bacterium was infected separately.

Transcriptome dynamics of the multicellular developmental program.

The bacterium exhibits a complex multicellular life cycle. In the presence of nutrients, cells prey cooperatively. Upon starvation, they enter a developmental cycle wherein cells aggregate to produce macroscopic fruiting bodies filled with resistant myxospores.

Recovering microbial genomes from metagenomes in hypersaline environments: The Good, the Bad and the Ugly.

Current metagenomic tools allow the recovery of microbial genomes directly from the environment. This can be accomplished by binning metagenomic contigs according to their coverage and tetranucleotide frequency, followed by an estimation of the bin quality. The public availability of bioinformatics tools, together with the decreasing cost of next generation sequencing, are democratizing this powerful approach that is spreading from specialized research groups to the general public.

Transcriptome analysis of Haloquadratum walsbyi: vanity is but the surface.

Background: Haloquadratum walsbyi dominates saturated thalassic lakes worldwide where they can constitute up to 80-90% of the total prokaryotic community. Despite the abundance of the enigmatic square-flattened cells, only 7 isolates are currently known with 2 genomes fully sequenced and annotated due to difficulties to grow them under laboratory conditions. We have performed a transcriptomic analysis of one of these isolates, the Spanish strain HBSQ001 in order to investigate gene transcription under light and dark conditions.

Metagenome sequencing of prokaryotic microbiota from two hypersaline ponds of a marine saltern in santa pola, Spain.

Marine salterns are composed of several shallow ponds with a salinity gradient, from seawater to salt saturation, with gradually changing microbial populations. Here, we report the metagenome sequencing of the prokaryotic microbiota of two ponds with 13% and 33% salinity from a saltern in Santa Pola, Spain.

The bacterial pan-genome:a new paradigm in microbiology.

Bacterial strains belonging to the same species vary considerably in gene content. Thus, the genetic repertoire of a given species (its "pan-genome") is much larger than the gene content of individual strains. These variations in DNA material, together with differences in genomic structure and nucleotide polymorphisms among strains, confer upon prokaryotic species a phenomenal adaptability.

Characterization of glycoside hydrolase family 5 proteins in Schizosaccharomyces pombe.

In yeast, enzymes with β-glucanase activity are thought to be necessary in morphogenetic events that require controlled hydrolysis of the cell wall. Comparison of the sequence of the Saccharomyces cerevisiae exo-β(1,3)-glucanase Exg1 with the Schizosaccharomyces pombe genome allowed the identification of three genes that were named exg1(+) (locus SPBC1105.05), exg2(+) (SPAC12B10.

The Schizosaccharomyces pombe endo-1,3-beta-glucanase Eng1 contains a novel carbohydrate binding module required for septum localization.

Cell separation in Schizosaccharomyces pombe is achieved through the concerted action of the Eng1 endo-beta-1,3-glucanase and the Agn1 endo-alpha-1,3-glucanase, which are transported to the septum and localize to a ring-like structure that surrounds the septum. Correct localization of these hydrolases requires the presence of both the septins and the exocyst. In this work, we show that the glucanase Eng1 contains a region at the C-terminus that acts as a carbohydrate-binding module (CBM) and that it is not present in other members of glycoside hydrolases family 81 (GH81).

Rho4 GTPase is involved in secretion of glucanases during fission yeast cytokinesis.

Rho GTPases are regulators of signaling pathways that control actin organization and cell polarity processes in all eukaryotic cells. In Schizosaccharomyces pombe, Rho4p is involved in the regulation of septum degradation during cytokinesis. Here we show that Rho4p participates in the secretion of the glucanases Eng1p and Agn1p, which are responsible for the septum degradation.

Role of septins and the exocyst complex in the function of hydrolytic enzymes responsible for fission yeast cell separation.

Cell separation in Schizosaccharomyces pombe is achieved by the concerted action of the Eng1 endo-beta-1,3-glucanase and the Agn1 endo-alpha-1,3-glucanase, which are transported to the septum and localize to a ringlike structure that surrounds the septum. The requirements for the correct localization of both hydrolases as a ring were analyzed using green fluorescent protein fusion proteins. Targeting to the septum required a functional exocyst, because both proteins failed to localize correctly in sec8-1 or exo70delta mutants, suggesting that Agn1 and Eng1 might be two of the cargo proteins present in the vesicles that accumulate in exocyst mutants.

Ace2p controls the expression of genes required for cell separation in Schizosaccharomyces pombe.

Schizosaccharomyces pombe cells divide by medial fission through contraction of an actomyosin ring and deposition of a multilayered division septum that must be cleaved to release the two daughter cells. Here we describe the identification of seven genes (adg1(+), adg2(+), adg3(+), cfh4(+), agn1(+), eng1(+), and mid2(+)) whose expression is induced by the transcription factor Ace2p. The expression of all of these genes varied during the cell cycle, maximum transcription being observed during septation.

The endo-beta-1,3-glucanase eng1p is required for dissolution of the primary septum during cell separation in Schizosaccharomyces pombe.

Schizosaccharomyces pombe cells divide by medial fission throughout contraction of an actomyosin ring and deposition of a multilayered division septum that must be cleaved to release the two daughter cells. Although many studies have focused on the actomoysin ring and septum assembly, little information is available concerning the mechanism of cell separation. Here we describe the characterization of eng1+, a new gene that encodes a protein with detectable endo-beta-1,3-glucanase activity and whose deletion is not lethal to the cells but does interfere in their separation.

Eng1p, an endo-1,3-beta-glucanase localized at the daughter side of the septum, is involved in cell separation in Saccharomyces cerevisiae.

ENG1 (YNR067c), a gene encoding a new endo-1,3-beta-glucanase, was cloned by screening a genomic library with a DNA probe obtained by PCR with synthetic oligonucleotides designed according to conserved regions found between yeast exo-1,3-beta-glucanases (Exglp, Exg2p, and Ssglp). Eng1p shows strong sequence similarity to the product of the Saccharomyces cerevisiae ACF2 gene, involved in actin assembly "in vitro," and to proteins present in other yeast and fungal species. It is also related to plant glucan-binding elicitor proteins, which trigger the onset of a defense response upon fungal infection.