Related Experiment Video
Updated: Feb 18, 2026
09:40
Generation of Genomic Deletions in Mammalian Cell Lines via CRISPR/Cas9
Published on: January 3, 2015
96.6K
The independent loss model with ordered insertions for the evolution of CRISPR spacers
F Baumdicker1, A M I Huebner1, P Pfaffelhuber1
1Department of Mathematical Stochastics, Albert-Ludwigs-University of Freiburg, Germany.
Theoretical Population Biology
|November 28, 2017
Summary
This study models the CRISPR immune system in microbes, estimating the rate at which genetic elements are lost from CRISPR arrays. The findings help understand microbial adaptive immunity evolution.
Area of Science:
- Microbiology
- Genomics
- Evolutionary Biology
Background:
- CRISPR (clustered regularly interspaced short palindromic repeats) regions in bacteria and archaea function as adaptive immune systems.
- Previous models, like the ordered independent loss model (Kupczok & Bollback, 2013), describe CRISPR array evolution.
Purpose of the Study:
- To compute the distribution of spacer distances within CRISPR arrays for a sample size of n.
- To estimate the spacer loss rate (ρ) from CRISPR array data using a mathematical model.
Main Methods:
- Utilized the ordered independent loss model for CRISPR array evolution.
- Focused on the dynamics of spacers entering and being lost from CRISPR arrays.
- Calculated the distribution of spacer distances for sample sizes n=2 and n=3.
Main Results:
- Derived a method to estimate the spacer loss rate (ρ) in microbial CRISPR systems.
- The model provides a quantitative approach to analyze spacer array data.
Conclusions:
- The study offers a new method for estimating crucial evolutionary parameters of CRISPR-Cas adaptive immunity.
- This research contributes to understanding the evolutionary dynamics of microbial defense mechanisms.
Related Concept Videos
01:09Mutation, Gene Flow, and Genetic Drift
64.7K
In a population that is not at Hardy-Weinberg equilibrium, the frequency of alleles changes over time. Therefore, any deviations from the five conditions of Hardy-Weinberg equilibrium can alter the genetic variation of a given population. Conditions that change the genetic variability of a population include mutations, natural selection, non-random mating, gene flow, and genetic drift (small population size).
64.7K
01:20Mismatch Repair
6.7K
Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes.
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
6.7K
02:08Gene Conversion
10.7K
Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new...
10.7K
01:59CRISPR
58.1K
Genome editing technologies allow scientists to modify an organism’s DNA via the addition, removal, or rearrangement of genetic material at specific genomic locations. These types of techniques could potentially be used to cure genetic disorders such as hemophilia and sickle cell anemia. One popular and widely used DNA-editing research tool that could lead to safe and effective cures for genetic disorders is the CRISPR-Cas9 system. CRISPR-Cas9 stands for Clustered Regularly Interspaced...
58.1K
02:53Conservative Site-specific Recombination and Phase Variation
6.9K
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...
6.9K
01:30Spontaneous and Induced Mutations
2.4K
Spontaneous mutations arise infrequently during DNA replication due to errors in the process. A key factor behind these errors is tautomeric shifts in nitrogenous bases, where bases transition from keto to enol forms or amino to imino forms. This shift can alter base-pairing rules, leading to mutations. Additionally, reactive oxygen species (ROS) arising from aerobic metabolism can damage DNA, resulting in depurination (loss of a purine base) or depyrimidination (loss of a pyrimidine base).
2.4K