Beth Rowan

Lab member

2016-present

Education

2008 Ph.D. Biology University of Washington

Research Topic

Structure of mitochondrial DNA in lettuce.

Research Summary

When most people talk about "the genome" of an organism, they are referring to only one of multiple genomes that encode all of the information necessary for sustaining life -- the one that is present within the nucleus, the master organizer of the basic unit of life: the cell. In plants, there are two smaller genomes present in other compartments of the cell. The chloroplasts, which are the site of photosynthesis, and the mitochondria, which are responsible for energy production, each have their own genome that encodes some of the necessary components to maintain their functions. Despite the important role of the genomes in these organelles in supporting the basic metabolic activity in plants, there is surprisingly little information about how the genes within those genomes are organized in physical molecules of DNA. DNA sequence information and genetic mapping suggest a single circular structure representing the entire genome. Although other physical forms can give rise to circular sequence assemblies and circular genetic maps, most people assume that the DNA molecules are single genome-sized circles in vivo. The lettuce mitochondrial genome is unusual because data from high-quality long read sequencing has suggested that there are several different circular forms that are each less than the size of the genome. Each of these circular sequences has a different sequence composition and order. Does this mean that there are several subgenomic circular molecules in vivo? Or might these circular sequence arrangements exist in a more complex physical structure within the mitochondria? I am currently investigating the answers to these questions using pulsed-field gel electrophoresis, visualization of individual molecules using fluorescence and electron microscopy, and adopting a CRISPR/Cas9-based strategy to label specific sequences of the mitochondria to determine how the DNA sequence maps on to the physical molecules.

I am also currently pursuing independent projects on the subject of meiotic recombination. For more information, please see my website: rowan.openwetware.org.