APR 04, 2016 3:18 PM PDT

DNA Supercoiling Combats Environmental Challenges

WRITTEN BY: Kara Marker
DNA, the diverse combination of just four nucleotide letters that writes our genetic code, can do more than just form a double helix. In a new study from the National Institutes of Health (NIH) and the National Center for Biological Sciences (NCBS), scientists look at the pattern of gene expression that could potentially be impacted by various supercoiling arrangements.
 
To fit into tight-knit cells, DNA has to be packed in to the small space. However, during events like regular DNA replication and reproduction, the genetic material has to be unpacked and unwound in order for other compounds to be able to read and create RNA and proteins from DNA.

"An artistic rendering of DNA supercoiling/"
 
In the NIH/NCBS study published in the journal Nature Communications, the authors described a “constant state of structural flux” that goes hand in hand with the state of cellular activity, indicating that the genetic code can respond to changes in order to improve body-wide function.
 
Studies in human and yeast cells investigating the supercoiling of DNA have been completed, but the present study looks at the genome of a favorite model organism, Escherichia coli.
 
In addition to being a commonly used model organism, E. coli cause bacterial infections, often from contaminated food or drink, leading to diarrhea, urinary tract infections, pneumonia, and more (Centers for Disease Control and Prevention).
 
Bacteria experience environmental influences just like humans do, and the current study is considering the possibility that by altering their gene expression, bacteria could increase their chance of survival despite any environmental hardships like starvation, lack of oxygen, or unusual temperatures. Scientists believe that there is a supercoiling connection to bacterial sensitivity to changes in environmental influences.
 
The method presented in the study started with exposing E. coli genetic material to a chemical called trimethylpsoralem, whose bondage to DNA is a representation of how much DNA supercoiling is occurring. Next comes ultraviolet light and microarray technology, focused on two different populations of E. coli bacteria so the researchers could visualize a distinction between the activity of DNA under two opposite environmental conditions.
 
After securing a fine-scale resolution view of supercoiling patterns, researchers soon gained insight into section-specific genomic information.
 
One group of bacteria were cultured in a nutrient-rich environment, one which promoted active division and a continuously growing population. The other group struggled to grow in a nutrient-poor environment and existed as a stationary population as opposed to actively growing.
 
For the health, actively dividing group of bacteria, the entire genome appeared supercoiled, while the nutrient-deprived group showed a diverse gradient of supercoiling.
 
This study provides proof-of-concept that the supercoiling of a genome is not uniform and that it varies locally across genes,” said first author of the study, Avantika Lal, PhD. “It also provides evidence to support the hypothesis that bacterial cells could be regulating gene expression and their own physiologies by altering the structure of their genomes."
 
 
Source: National Center for Biological Sciences
 
About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
OCT 24, 2020
Genetics & Genomics
Cord Blood Samples Reveal More About the Genetics of Autism
OCT 24, 2020
Cord Blood Samples Reveal More About the Genetics of Autism
The activity of genes in our genome is controlled by many factors, one of which are chemical tags or structural changes ...
DEC 15, 2020
Genetics & Genomics
Can a Brain Look Lonely?
DEC 15, 2020
Can a Brain Look Lonely?
Many isolated individuals have been isolated this year, and the holidays may only exacerbate feelings of loneliness.
DEC 24, 2020
Genetics & Genomics
After Chromosomes Shatter, Cancer Cells Can Become Drug-Resistant
DEC 24, 2020
After Chromosomes Shatter, Cancer Cells Can Become Drug-Resistant
Many types of cells have to be replenished throughout our lives, and cells divide to replace those that are damaged or w ...
DEC 29, 2020
Microbiology
How CRISPR Can Help Create a Vaccine for a Common Parasite
DEC 29, 2020
How CRISPR Can Help Create a Vaccine for a Common Parasite
The parasite Toxoplasma gondii is thought to infect a third of the people on the planet as well as a wide range of other ...
DEC 30, 2020
Drug Discovery & Development
Gene Therapy Cures Mice of Deafness
DEC 30, 2020
Gene Therapy Cures Mice of Deafness
Currently, around half a billion people suffer from hearing loss around the world. In about half of these cases, genetic ...
JAN 01, 2021
Genetics & Genomics
Common Brain Disorder Has a Genetic Influence
JAN 01, 2021
Common Brain Disorder Has a Genetic Influence
It's thought that as many as one in one hundred people are born with a brain disorder known as Chiari 1 malformation, bu ...
Loading Comments...