NSF Postdoctoral Fellowship in Biology FY 2017: Incidence and Consequences of Prokaryotic Polyploidy

Moore Kristin A, Superior CO

Investigators

Abstract

This is an NSF Postdoctoral Research Fellowship in Biology, under the program Broadening Participation of Groups Under-represented in Biology. The fellow, Kristin A. Moore, is conducting research and receiving training that is increasing the participation of groups underrepresented in biology. The fellow is being mentored by Jeffrey C. Cameron at the University of Colorado. The fellow's research aims to increase our understanding of a fundamental question regarding life, namely, how do cells with varying amounts of DNA ensure that their descendants receive the correct amount of DNA? Control of genetic inheritance, the faithful copying and division of DNA, is an essential process for all living organisms. Disruptions that alter cell DNA content can result in abnormal development and disease. For example, in humans one additional copy of chromosome 21 results in Down syndrome. Historically, it has been assumed that bacteria contain a single circular chromosome. However, recent studies indicate that many bacterial species contain multiple chromosomes, and that the number of copies can even vary between individual cells in a population. Furthermore, the consequences of variable DNA content in bacteria are unknown, even though bacteria that are important medically, ecologically, and industrially, have all been shown to have multiple chromosome copies. The fellow's research aims to bolster our understanding of the extent, causes, and significance of chromosome number variation in bacteria. This research aims to identify the molecular mechanisms that regulate genome copy number as well as the physiological and evolutionary consequences of polyploidy (multiple identical chromosomes) in a phylogenetically diverse subset of cyanobacteria. Cyanobacteria, a phylum comprised of photosynthetic microbes that play critical roles in many biogeochemical cycles, can be either monoploid (one copy of chromosomes per cell) or polyploid (2-20 copies per cell). The natural variation in chromosome number, fully sequenced genomes, genetically tractable model species, and an extensive synthetic biology toolkit make cyanobacteria an ideal system to study the causes and consequences of polyploidy in bacteria. Over the course of this multidisciplinary project, the fellow will gain experience in advanced microscopy, computational biology, synthetic biology, ecology, and mathematical modeling. The fellow will also gain experience mentoring students from under-represented groups that will be involved in the research. Additionally, a unique set of teaching modules will be created based on the fellow's studies that will provide educators with real-world projects and data that they can incorporate into their own classrooms.