Related Experiment Video
Updated: May 20, 2026
10:23
A Concoction Pipeline for Generating Molecular Operational Taxonomic Units (MOTUs) Among Riparian and Aquatic Beetles
Published on: July 11, 2025
Molecular phylogenetics in 2D: ITS2 rRNA evolution and sequence-structure barcode from Veneridae to Bivalvia
Daniele Salvi1, Paolo Mariottini
1CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Campus Agrário de Vairão, 4485-661 Vairão, Portugal. danielesalvi.bio@gmail.com
Molecular Phylogenetics and Evolution
|August 1, 2012
Summary
The internal transcribed spacer 2 (ITS2) marker effectively resolves bivalve family trees, offering a powerful tool for molecular diagnosis and understanding evolutionary relationships in Veneridae and other bivalve taxa.
Area of Science:
- Molecular Biology
- Evolutionary Biology
- Taxonomy
Background:
- The internal transcribed spacer 2 (ITS2) region of ribosomal DNA is widely used in molecular systematics.
- Its utility for resolving phylogenetic relationships within Bivalvia, particularly the Veneridae family, requires further investigation.
Purpose of the Study:
- To evaluate the phylogenetic resolution and molecular diagnostic potential of the ITS2 marker in Veneridae.
- To compare the ITS2 marker's performance with other commonly used genetic markers in Bivalvia.
- To explore the role of ITS2 secondary structure in phylogenetic inference.
Main Methods:
- Analysis of nuclear ITS2 rRNA primary sequences and secondary structures in Veneridae and 20 other Bivalvia taxa.
- Phylogenetic analyses using Maximum Likelihood, Bayesian inference, and Neighbor-Joining methods.
- Comparative analysis of sequence-structure evolution models.
Main Results:
- ITS2 demonstrated high phylogenetic resolution below the subfamily level, comparable to longer gene fragments.
- Secondary structure elements, including specific base pairings and compensatory changes, supported monophyly and phylogenetic relationships.
- Specific ITS2 sequence-structure features in Veneridae were identified, with some shared across superfamilies, potentially challenging the monophyly of Myoida and Veneroida orders.
Conclusions:
- The ITS2 marker is validated as a suitable tool for Veneridae phylogenetics and taxonomy.
- Incorporating ITS2 secondary structure information enhances phylogenetic analyses and taxonomic applications within Bivalvia.
- ITS2 analysis provides valuable insights into bivalve systematic relationships at various taxonomic levels.
Related Concept Videos
02:54Evolutionary Relationships through Genome Comparisons
Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse...
01:29Modern Molecular Taxonomy
Advancements in molecular biology have revolutionized the identification and characterization of bacteria, with multiple methods leveraging DNA sequencing for enhanced precision. As sequencing technologies improve and costs decline, these approaches are increasingly used in clinical, environmental, and evolutionary studies.Multilocus Sequence Typing (MLST) examines several housekeeping genes, essential chromosomal genes encoding cellular functions, to distinguish strains. Approximately...
02:05Gene Evolution - Fast or Slow?
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
02:05Gene Evolution - Fast or Slow?
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
01:20Applications of Molecular Taxonomy
Molecular taxonomy has revolutionized the understanding and classification of bacteria, providing precise insights into their diversity, evolutionary relationships, and ecological roles. By utilizing molecular techniques such as DNA sequencing and fingerprinting, researchers have made significant strides in various fields related to bacterial studies.Resolving Taxonomic AmbiguitiesMolecular taxonomy has been instrumental in distinguishing closely related bacterial species initially thought to...
01:28Microbial Phylogeny
Understanding the evolutionary relationships among microorganisms is fundamental to microbial ecology and taxonomy. Phylogenetic trees are essential tools for inferring these relationships, relying primarily on comparative analyses of molecular sequences such as DNA, RNA, or proteins. In microbial studies, these trees typically depict the evolutionary paths of diverse bacterial and archaeal species by mapping genetic differences accumulated over time.Phylogenetic trees are composed of tips,...