Related Experiment Video
Updated: Jun 18, 2026
06:18
Frequency and Distribution of Crossovers in Caenorhabditis elegans Meiosis by SNP Genotyping using Real-time PCR
Published on: July 11, 2025
Coalescent simulation of intracodon recombination
1Departamento de Bioquímica, Genética e Inmunología, Universidad de Vigo, 36310 Vigo, Spain.
Genetics
|November 26, 2009
Summary
This study introduces a new algorithm for simulating genetic sequences, allowing recombination within codons. This improves models of molecular evolution for genes and pathogens like HIV-1.
Area of Science:
- Molecular Population Genetics
- Computational Biology
- Evolutionary Genetics
Background:
- Coalescent theory is crucial for molecular population genetics, simulating genetic sequence evolution.
- Existing algorithms often restrict recombination to between codons, which is biologically inaccurate.
- Recombination is known to occur frequently within codons.
Purpose of the Study:
- To develop a novel algorithm for simulating coding sequences that incorporates intracodon recombination.
- To analyze the impact of intracodon recombination on estimates of evolutionary rates, particularly the nonsynonymous/synonymous substitution ratio (omega).
- To provide a more realistic model for studying the evolution of nuclear coding genes and rapidly evolving pathogens.
Main Methods:
- Modified Hudson's coalescent algorithm to track recombination events within codons.
- Developed an algorithm to simulate ancestral recombination graphs with intracodon recombination.
- Implemented the algorithm in a software package named NetRecodon.
Main Results:
- Intracodon recombination introduces a small number of nonsynonymous changes at typical substitution rates.
- The overall nonsynonymous/synonymous substitution ratio (omega) is not generally inflated by intracodon recombination.
- Recombination can bias omega estimates at specific codons, leading to spurious detection of positive selection.
- Allowing for variable synonymous rates across sites significantly reduces false positives and increases statistical power.
Conclusions:
- The developed algorithm provides a more accurate model for molecular evolution by allowing intracodon recombination.
- The findings highlight the importance of considering intracodon recombination for accurate evolutionary rate estimation and selection detection.
- This approach can enhance simulations for nuclear coding genes and fast-evolving viruses like HIV-1.
More Related Videos
07:48Protocols for Analyzing the Role of Paneth Cells in Regenerating the Murine Intestine using Conditional Cre-lox Mouse Models
Published on: November 21, 2015
15:00Daily Transfers, Archiving Populations, and Measuring Fitness in the Long-Term Evolution Experiment with Escherichia coli
Published on: August 18, 2023
Related Concept Videos
00:57Viral Recombination
Cells are sometimes infected by more than one virus at once. When two viruses disassemble to expose their genomes for replication in the same cell, similar regions of their genomes can pair together and exchange sequences in a process called recombination. Alternatively, viruses with segmented genomes can swap segments in a process called reassortment.
02:53Conservative Site-specific Recombination and Phase Variation
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
02:31Homologous Recombination
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
02:31Homologous Recombination
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
02:32Exon Recombination
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Exon shuffling follows “splice frame rules.” Each exon has three reading...
02:13Overview of Transposition and Recombination
Transposons make up a significant part of genomes of various organisms. Therefore, it is believed that transposition played a major evolutionary role in speciation by changing genome sizes and modifying gene expression patterns. For example, in bacteria, transposition can lead to conferring antibiotic resistance. Movement of transposable elements within the genetic pool of pathogenic bacteria can aid in transfer of antibiotic-resistant genetic elements. In eukaryotes, transposons can carry out...