Diversity and evolution of viroids and viroid-like agents with circular RNA genomes revealed by metatranscriptome mining.

Viroids, the agents of several plant diseases, are the smallest and simplest known replicators that consist of covalently closed circular (ccc) RNA molecules between 200 and 400 nucleotides in size. Viroids encode no proteins and rely on host RNA polymerases for replication, but some contain ribozymes involved in replication intermediate processing. Although other viroid-like agents with cccRNAs genomes, such as satellite RNAs, ribozyviruses and retrozymes, have been discovered, until recently, the spread of these agents in the biosphere appeared narrow, and their actual diversity and evolution remained poorly understood.

, a novel ribovirian phylum for viruses with viroid-like properties.

Fungi harbor a vast diversity of mobile genetic elements (MGEs). Recently, novel fungal MGEs, tentatively referred to as 'ambiviruses,' were described. 'Ambiviruses' have single-stranded RNA genomes of about 4-5 kb in length that contain at least two open reading frames (ORFs) in non-overlapping ambisense orientation.

Mining metatranscriptomes reveals a vast world of viroid-like circular RNAs.

Viroids and viroid-like covalently closed circular (ccc) RNAs are minimal replicators that typically encode no proteins and hijack cellular enzymes for replication. The extent and diversity of viroid-like agents are poorly understood. We developed a computational pipeline to identify viroid-like cccRNAs and applied it to 5,131 metatranscriptomes and 1,344 plant transcriptomes.

Viroids and Viroid-like Circular RNAs: Do They Descend from Primordial Replicators?

Viroids are a unique class of plant pathogens that consist of small circular RNA molecules, between 220 and 450 nucleotides in size. Viroids encode no proteins and are the smallest known infectious agents. Viroids replicate via the rolling circle mechanism, producing multimeric intermediates which are cleaved to unit length either by ribozymes formed from both polarities of the viroid genomic RNA or by coopted host RNAses.

ViroidDB: a database of viroids and viroid-like circular RNAs.

We introduce ViroidDB, a value-added database that attempts to collect all known viroid and viroid-like circular RNA sequences into a single resource. Spanning about 10 000 unique sequences, ViroidDB includes viroids, retroviroid-like elements, small circular satellite RNAs, ribozyviruses, and retrozymes. Each sequence's secondary structure, ribozyme content, and cluster membership are predicted via a custom pipeline optimized for handling circular RNAs.

A Modified SpeedBridge Technique for Retracted or Delaminated Rotator Cuff Repairs.

Treatment of full-thickness rotator cuff tears vary in surgical technique dependent on the amount of retraction of the rotator cuff and/or delamination of the soft tissue. The described technique addresses both of those concerns. We present a modification of the SpeedBridge technique used to address retracted or delaminated repairs and effectively expand the indications for use of the double-row knotless technique.

DNAvisualization.org: a serverless web tool for DNA sequence visualization.

Raw DNA sequences contain an immense amount of meaningful biological information. However, these sequences are hard for humans to intuitively interpret. To solve this problem, a number of methods have been proposed to transform DNA sequences into two-dimensional visualizations.

Squiggle: a user-friendly two-dimensional DNA sequence visualization tool.

Summary: Squiggle is a software tool that automatically generates interactive web-based two-dimensional graphical representations of raw DNA sequences. Built with ease of use in mind, Squiggle implements several prior sequence visualization algorithms and introduces novel visualization methods designed to maximize human usability.

Availability And Implementation: Squiggle is written in Python 3 and freely available under the permissive MIT license.