Researchers have uncovered that even in their most stripped-down forms, cells retain a remarkable ability to adapt and evolve. Professor Jay T. Lennon from the Indiana University Bloomington Department of Biology led a team of researchers in exploring the concept from a new angle. They discovered that even artificially minimized cells maintain the capacity to evolve rapidly, signifying the robust nature of life.
Lennon's team focused their efforts on a synthetic organism, Mycoplasma mycoides JCVI-syn3B. This strain, a stripped-down version of M. mycoides, is a bacterium commonly found in goat intestines and similar animals. Over the years, this parasite has naturally shed many genes, relying on its host for sustenance. Researchers at the J. Craig Venter Institute in California accelerated this process, removing nearly half of the original 901 genes, leaving it with the smallest known set of genes required for independent life.
This significant reduction in genetic information begged the question: Could such a simplified organism evolve successfully? "Every single gene in its genome is essential. One could hypothesize that there is no wiggle room for mutations, which could constrain its potential to evolve," Lennon explains.
To test this, the team subjected M. mycoides JCVI-syn3B to evolutionary forces, allowing it to freely grow and mutate in the lab over 300 days, equivalent to about 40,000 years of human evolution.
They then evaluated the fitness of the evolved minimal cells against their original, non-minimized counterpart and an unevolved minimal cell version. The original, non-minimized strain outperformed the unevolved minimal one, as expected. However, the streamlined cells that had evolved over 300 days significantly improved their fitness levels, effectively recovering their initial genomic reduction.
Furthermore, the scientists identified several genes that showed significant changes during the evolutionary process. Some contributed to the cell surface construction, while the roles of several others remain a mystery.
The research, detailed in a recent paper in Nature, contributes significantly to the understanding of how simplified organisms adapt to evolutionary challenges. This has vital implications for biological issues, from treating pathogens to the origin of life itself. Lennon's research underscores the power of natural selection, even within the simplest autonomous organism, reaffirming that life, indeed, finds a way.
Lennon's team focused their efforts on a synthetic organism, Mycoplasma mycoides JCVI-syn3B. This strain, a stripped-down version of M. mycoides, is a bacterium commonly found in goat intestines and similar animals. Over the years, this parasite has naturally shed many genes, relying on its host for sustenance. Researchers at the J. Craig Venter Institute in California accelerated this process, removing nearly half of the original 901 genes, leaving it with the smallest known set of genes required for independent life.
This significant reduction in genetic information begged the question: Could such a simplified organism evolve successfully? "Every single gene in its genome is essential. One could hypothesize that there is no wiggle room for mutations, which could constrain its potential to evolve," Lennon explains.
To test this, the team subjected M. mycoides JCVI-syn3B to evolutionary forces, allowing it to freely grow and mutate in the lab over 300 days, equivalent to about 40,000 years of human evolution.
They then evaluated the fitness of the evolved minimal cells against their original, non-minimized counterpart and an unevolved minimal cell version. The original, non-minimized strain outperformed the unevolved minimal one, as expected. However, the streamlined cells that had evolved over 300 days significantly improved their fitness levels, effectively recovering their initial genomic reduction.
Furthermore, the scientists identified several genes that showed significant changes during the evolutionary process. Some contributed to the cell surface construction, while the roles of several others remain a mystery.
The research, detailed in a recent paper in Nature, contributes significantly to the understanding of how simplified organisms adapt to evolutionary challenges. This has vital implications for biological issues, from treating pathogens to the origin of life itself. Lennon's research underscores the power of natural selection, even within the simplest autonomous organism, reaffirming that life, indeed, finds a way.