Professor completes 21-year evolution project

It took Richard Lenski more than 20 years and help from overseas to examine 40,000 generations of bacteria, but the impact left by the project’s results will last a lifetime. Lenski, a John A. Hannah Distinguished professor of microbial ecology, said understanding how fast a bacteria’s genome changes throughout time is key for researchers hoping to use it for future biotechnology. The experiment’s results were published Sunday in the online edition of the international science journal Nature. “The same thing goes for microbes that cause infectious diseases,” Lenski said. “We need to understand how quickly they change if we want to identify the sources of new outbreaks as well as devise effective strategies for combatting infections and their spread.”

Lenski and Jeffrey Barrick, a postdoctoral research associate in Lenski’s laboratory, worked with scientists from across the globe on the 21-year project. Researchers said understanding the rates of mutation can help others know why there are certain patterns in the progression of some diseases, such as cancer. Dominique Schneider, a molecular genetics professor at the Universit√© Joseph Fourier in France, helped MSU researchers compare individual mutations to a bacterial strain used to begin the experiment.

Jihyun Kim of the Korea Research Institute of Bioscience and Biotechnology and others at the institute performed an independent analysis of the collected genome data to confirm the mutations found by the team at MSU. Kim, who met Lenski at an International Conference of Systems Biology in 2003, wrote in an e-mail the group’s research could allow scientists to improve the productivity of a bacterial strain. “This research is not only useful in understanding the tempo and mode of evolution, but can serve as a nice framework for practical applications in biotechnology, such as improving the performance or productivity of an industrial strain,” Kim said.

Barrick developed several computational tools used to analyze bacteria mutations. “These techniques are so new that people are still developing ways to effectively analyze the data, so I wrote my own computational pipeline for this,” Barrick wrote in an e-mail. Lenski began the project in 1988 — three years before he arrived at MSU — because of an interest in processes such as mutation and natural selection. “Evolution is just such an exciting field,” Lenski said. “It’s like studying our family tree, except at a much, much deeper level. Everybody cares about the evolution of bacteria even if they don’t know they’re interested because evolution affects our ability to combat diseases.”

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