Image: The team's research showed experimentally that epigenetic-clocks recapitulate known divergence times of intra-species phylogenetic or evolutionary trees in the self-fertilizing plant A. thaliana, a small plant in the mustard family, and the clonal seagrass Z. marina, which represent two major modes of plant reproduction. "We further strengthened the existence of a plant epigenetic clock using a variety of experimental evolution populations of A. thaliana with known pedigrees" said Robert Schmitz, UGA Foundation Professor in Plant Sciences, Lars G. Ljungdahl Distinguished Investigator in the department of genetics, and co-author on the study. These plants were grown by single-seed descent for up to 32 generations from wild type exposed to different environments or from natural strains from distinct geographical origins. "Using DNA methylome data from hundreds of individuals from throughout these populations, we identified a subset of epimutations that are 'clock-like' and accurately estimated time of the pedigree," said Zhilin Zhang, doctoral student from the Technical University of Munich and co-lead author on the study along with Nan Yao, a doctoral student in the UGA Franklin College of Arts and Sciences department of genetics. "We showed this epigenetic clock was more accurate at dating a recently diverged North American population of A. thaliana, approximately 140 years old, compared to a molecular clock using DNA mutations of the same individuals," Yao said. Read More: Franklin College Article
