MAR 04, 2015 03:49 PM PST

Researchers Watch Evolution in Near Real Time

WRITTEN BY: Judy O'Rourke
Evolution brings improvements, but it's also a hotbed for lots of diseases that defy treatment.

We see this in pathogens like bacteria and parasites, which fend off our defenses and antimicrobial drugs. Cancer evolves, with rogue cells changing, spreading outside their limits, roaming far and wide in the body, where chemotherapy may not reach.
Saccharomyces cerevisiae (Yeast)
Researchers have devised a new technology called high-resolution lineage tracking, which allows them to keep close track of how populations of cells evolve.

"The technology has the potential to help us understand many processes important to infection and disease," says Sasha Levy, PhD, assistant professor of physical and quantitative biology, Lewis and Beatrice Laufer Center, Stony Brook University, New York.

"One avenue we are pursuing is to place it into pathogenic microbes to study how they develop resistance to antibiotics," he says. "We are looking into placing it into cancer cells to try to understand the fundamental rules by which cancer cells adapt and metastasize. We hope that gaining better understanding of the evolutionary dynamics of these disease processes will allow us to optimize treatment to slow their rates of progression."

Levy and his team created the genetic apparatus to place millions of unique, chance DNA sequences at a particular genomic spot in Saccharomyces cerevisiae (yeast). They then observed adaptive evolution take place.

He explains the process by comparing it to a review of history by using a tally of surnames, collected each year over a period of thousands of years. "Even with this limited information, you would be able to say a lot about history-you could tell which families were successful and when, which families were wiped out because of competition or war, and how families migrated," he says. "We did a similar thing in competing cell populations. But instead of tracking last names, we track DNA barcodes-tiny identifiers we place in the genome that allow us to uniquely identify a cell and its descendants."

"By taking a census of these barcodes over time, we can discover when a cell lineage becomes more fit and expands within the population," says Levy, who's also a professor in the Department of Biochemistry & Cell Biology, and the study's lead author. "By doing this on a massive scale-we tracked 500,000 cell lineages simultaneously-we can understand some fundamental properties about how cell populations compete with one another and evolve."

The project, which brings together biology and theoretical and applied physics, has logged key discoveries. "We have developed a general system to track cell lineages at high resolution," Levy says. "And we have developed the theory to make sense of this type of data, in order to study evolution in a more quantitative way."

The finding is significant as the evolution of sizable cell populations is the basis of about 30% of deaths worldwide-some as a result of bacteria, parasites, fungi, and cancer.

"I have always been excited to learn about how evolution works, but disappointed by our lack of tools to study it quantitatively," Levy says. "This caused a big chasm between what theorists were capable of predicting and what biologists could actually measure. I saw this project as an opportunity to narrow that chasm, just a little bit."

The study, titled "Quantitative evolutionary dynamics using high-resolution lineage tracking," is published in the journal Nature.
About the Author
  • Judy O'Rourke worked as a newspaper reporter before becoming chief editor of Clinical Lab Products magazine. As a freelance writer today, she is interested in finding the story behind the latest developments in medicine and science, and in learning what lies ahead.
You May Also Like
OCT 14, 2019
Cell & Molecular Biology
OCT 14, 2019
Variations in tRNA Genes are More Common Than Thought
It had been thought that there was not much of interest happening in the genes that code for tRNA; new work changes that view....
OCT 14, 2019
Genetics & Genomics
OCT 14, 2019
Do You Inherit Your Morals?
Morality is usually a subject discussed by philosophers, not biologists. But is it really a purely philosophical issues? After all, what makes us more susc...
OCT 14, 2019
Technology
OCT 14, 2019
Bioprinting Complex Tissues
Tissue engineering is a quickly growing field that involves the development of artificial organs and tissues that can be utilized to test the efficacy of d...
OCT 14, 2019
Cell & Molecular Biology
OCT 14, 2019
Dysfunctional Mitochondria Cause Telomere Damage
"I like to call it 'the Chernobyl effect' -- you've turned the reactor on and now you can't turn it off," said senior author Bennett Van Houten, Ph.D....
OCT 14, 2019
Genetics & Genomics
OCT 14, 2019
A 3D Look at the Genome Reveals a Super Enhancer
We can write out the sequence of the genome, but the three-dimensional structure of the molecule is important to its function as well....
OCT 14, 2019
Neuroscience
OCT 14, 2019
Neuroscientists discover gut-brain superhighway
The gut and brain communicate - typically through hormones. Throughout the day, your gut releases hormones that travel through the bloodstream and, over the course of about 10 minutes, reach...
Loading Comments...