Characteristics of Chi distribution on different bacterial genomes
Related Experiment Video
Updated: Oct 17, 2026

Characterizing Microbiome Dynamics – Flow Cytometry Based Workflows from Pure Cultures to Natural Communities
Published on: July 12, 2018
M El Karoui1, V Biaudet, S Schbath
1Laboratoire de génétique azppliquée-URLGA, INRA, Domaine de Vilvert, Jouy en Josas, France.
Abstract:
The availability of full genome sequences provides the bases for analyzing global properties of the genetic text. For example, oligonucleotide sequences that are over- or underrepresented can be identified by taking into account the overall genome composition and organization. One of the most overrepresented oligonucleotides in Escherichia coli is the Chi site, an octanucleotide that stimulates DNA repair by homologous recombination. Here we analyze the genomic distribution of Chi in E. coli and in the three other bacteria where a Chi sequence has been identified; note that Chi is a different sequence in each organism. For each bacterial genome, Chi sequences are frequent, regularly distributed, and overrepresented. This suggests that selection for Chi may have occurred during evolution to favor efficient repair of a damaged chromosome. Other characteristics of Chi distribution are not conserved and might reflect specific features of DNA repair in each host. The different sequence and characteristics of Chi in each microorganism suggest that selection for Chi occurred independently in different bacteria.
More Related Videos
Related Concept Videos
Chi-square Distribution
Genomic DNA in Prokaryotes
Genomic Diversity in Bacteria
Although bacterial genomes are much...
Modern Molecular Taxonomy
Evolution of Microbial Genome
Microbial Morphologies
Chi-square Analysis
The chi-square test was developed by Pearson in 1990.
The first step of performing a Chi-square analysis is to establish a null hypothesis, which assumes that there is no real...

