Strategic genetic placement in bacteria provides insight into evolutionary success
During bacterial chromosome replication, multiple copies have genes close to the replication start point (red) and no genes close to the endpoint (blue). Fastest growth will result in stronger effects, reading genes close to the start point simultaneously from up to eight gene copies, resulting in higher expression levels. Depending on how the demand for expression of a particular gene changes with growth rates, natural selection drives its placement along the chromosomes to take advantage of this gene administration effect. (Figure: HHU/XIAO-PAN HU). Credit: HHU/XIAO-PAN HU
The bioinformatics of the Heinrich Heine University Düsseldorf (HHU) and the University of Linköping (Sweden) have established that genes in the bacterial genome are arranged in meaningful order. The journal Science explains that genes are arranged by function. If they become increasingly important for faster growth, they are located near the origin of DNA replication. Therefore, their position affects how growth rates and activity change.
Are genes randomly distributed along bacterial chromosomes, as if they were scattered from a salt shaker? This opinion is held by the majority of researchers and is currently being contested by a team of bioinformaticians led by Dr. Martin Lurcher, director of HHU’s Computational Cell Biology Research Group.
As bacteria replicate genetic material in preparation for cell division, this process begins at a specific point on the bacterial chromosome and continues along the chromosomes in both directions.
Dr. Xiao-Pan hu of HHU said he is the lead author of the study. “During this process, there are more copies of genes that are closer to the origin of replication than those that are shorter and farther away. Therefore, genes that are closer to origin can be read frequently.”
“We have established that these genes are particularly important for cell growth, which is what the product builds bacterial proteins,” adds Professor Lercher, author of the study. In contrast, genes that are rarely needed during the growth stage are usually found on the opposite side of the chromosome and replicated in the process.
Researchers used bioinformatic and mathematical methods to analyze the location of more than 4,400 gene families of more than 900 bacterial species. They found that the location of genes along the chromosome must have been a result of evolutionary pressure, as bacteria that can grow especially rapidly as a result of optimally positioned genes have evolutionary benefits.
Dr. Hu continues. “We have a better understanding of how bacteria regulate their genes. The results really surprised us. They provide a great explanation of the important aspects of bacteria evolution. With correct genomic positioning, bacteria exist more than today’s rivals.”
In more potential applications, Lercher says, “This understanding will also help design more efficient synthetic bacteria, such as biotechnology or medical applications.”
Details: Xiao-Pan Hu et al., most bacterial gene families are biased towards a specific chromosomal location, Science (2025). doi: 10.1126/science.adm9928. www.science.org/doi/10.1126/science.adm9928
Provided by Heinrich-Heine University Duesseldorf
Citation: Bacteria Strategic Gene Placement provides insights into evolutionary success obtained from April 11, 2025 from https:/2025-04–strategic-gene-gene-placement-bacteria-insights.html (April 10, 2025)
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