General Information

The "General Information" section of TnPedia offers a comprehensive overview of prokaryotic transposable elements (TEs), which are central to bacterial evolution and adaptation. These mobile genetic elements facilitate the acquisition and dissemination of genes responsible for antibiotic resistance, heavy metal tolerance, and virulence factors.

Fig.1.1. The Busy Genome: Elements of Horizontal Exchange. The genome backbone, which includes housekeeping genes, is shown as the inner circle (blue). The "mobilome" is shown in the outer circle. This includes a number of different types of MGE both intercellular (some genomic islands, prophages, and conjugative transposons) and intracellular (Insertion sequences, compound and unit transposons, integrons, and super integrons). An important class of intercellular MGE, the plasmids, act as transposon vectors and facilitate TE movement within the plasmidome.

This section encompasses several key topics:

• Overview: An introduction to the significance of TEs in bacterial genomes.
• Insertion Sequence History and Early Transposition Models: A historical perspective on the discovery and initial models explaining TE behavior.
• What Is an IS?: Detailed definitions and characteristics of insertion sequences.
• ISfinder and the Growing Number of IS: Insights into the expanding database of known insertion sequences.
• IS Identification, Nomenclature, and Naming Attribution: Guidelines on how insertion sequences are identified and named.
• IS Distribution: Information on the prevalence and distribution patterns of insertion sequences across different bacterial species.
• Major Groups Defined by the Type of Transposase They Use: Classification of TEs based on the transposase enzymes they encode.
• Fuzzy Borders: Discussion on the complexities and ambiguities in defining the boundaries of TEs.
• tIS - IS and Relatives with Passenger Genes: Examination of Insertion Sequences that carry additional genes, known as passenger genes.
• IS Derivatives of Tn3 Family Transposons: Analysis of insertion sequences derived from Tn3 family transposons.
• IS Related to Integrative Conjugative Elements (ICEs): Exploration of the relationship between insertion sequences and ICEs.
• IS91 and ISCR: Specific focus on the IS91 family and ISCR elements.
• Non-autonomous IS Derivatives: Study of insertion sequences that rely on other elements for mobility.
• Relationship Between IS and Eukaryotic TE: Comparative analysis of prokaryotic insertion sequences and eukaryotic transposable elements.
• Impact of IS on Genome Evolution - The Importance of Time Scale: Insights into how insertion sequences influence genome evolution over time.
• Target Choice: Understanding the selection of insertion sites by TEs.
• Influence of Transposition Mechanisms on Genome Impact: Evaluation of how different transposition mechanisms affect genomic architecture.
• IS and Gene Expression: Investigation into how insertion sequences can modulate gene expression.
• IS Organization: Structural organization of insertion sequences within the genome.
• Control of Transposition Activity: Mechanisms that regulate the activity of transposable elements.
• Transposase Expression and Activity: Details on the expression patterns and functionality of transposase enzymes.
• Reaction Mechanisms: Biochemical pathways facilitating transposition events.
• The Casposases: Introduction to casposases and their role in the evolution of CRISPR-Cas systems.

This section serves as a foundational resource for researchers and students aiming to understand the fundamental aspects of transposable elements before delving into specific families of insertion sequences and transposons detailed in other sections of TnPedia.

How to Cite and Download ?

TnPedia Team. (2025). TnPedia: General Information on Prokaryotic Elements. Zenodo. https://doi.org/10.5281/zenodo.15548171