Computational Tools for the Analysis of Uncultivated Phage Genomes.

Over a century of bacteriophage research has uncovered a plethora of fundamental aspects of their biology, ecology, and evolution. Furthermore, the introduction of community-level studies through metagenomics has revealed unprecedented insights on the impact that phages have on a range of ecological and physiological processes. It was not until the introduction of viral metagenomics that we began to grasp the astonishing breadth of genetic diversity encompassed by phage genomes.

Informative Regions In Viral Genomes.

Viruses, far from being just parasites affecting hosts' fitness, are major players in any microbial ecosystem. In spite of their broad abundance, viruses, in particular bacteriophages, remain largely unknown since only about 20% of sequences obtained from viral community DNA surveys could be annotated by comparison with public databases. In order to shed some light into this genetic dark matter we expanded the search of orthologous groups as potential markers to viral taxonomy from bacteriophages and included eukaryotic viruses, establishing a set of 31,150 ViPhOGs (Eukaryotic Viruses and Phages Orthologous Groups).

Defining a Core Genome for the Herpesvirales and Exploring their Evolutionary Relationship with the Caudovirales.

The order Herpesvirales encompasses a wide variety of important and broadly distributed human pathogens. During the last decades, similarities in the viral cycle and the structure of some of their proteins with those of the order Caudovirales, the tailed bacterial viruses, have brought speculation regarding the existence of an evolutionary relationship between these clades. To evaluate such hypothesis, we used over 600 Herpesvirales and 2000 Caudovirales complete genomes to search for the presence or absence of clusters of orthologous protein domains and constructed a dendrogram based on their compositional similarities.

Virome Diversity Correlates with Intestinal Microbiome Diversity in Adult Monozygotic Twins.

The virome is one of the most variable components of the human gut microbiome. Within twin pairs, viromes have been shown to be similar for infants, but not for adults, indicating that as twins age and their environments and microbiomes diverge, so do their viromes. The degree to which the microbiome drives the vast virome diversity is unclear.

GenSeed-HMM: A Tool for Progressive Assembly Using Profile HMMs as Seeds and its Application in Alpavirinae Viral Discovery from Metagenomic Data.

This work reports the development of GenSeed-HMM, a program that implements seed-driven progressive assembly, an approach to reconstruct specific sequences from unassembled data, starting from short nucleotide or protein seed sequences or profile Hidden Markov Models (HMM). The program can use any one of a number of sequence assemblers. Assembly is performed in multiple steps and relatively few reads are used in each cycle, consequently the program demands low computational resources.