CAREER: Investigation of Conserved Global Regulatory Systems Using Cross-organism Comparison

University Of Mississippi, University MS

Investigators

Abstract

Bacteria are the most abundant life-form on Earth, but much of how bacteria work on a molecular level is still a mystery. Are there ways that molecular systems work in bacteria that are similar to systems in higher organisms? Or do bacteria have their own unique systems? Do some bacteria have systems different even from other bacteria? In this study, molecular systems in two bacteria, Caulobacter crescentus and Brevundimonas subvibrioides, will be investigated to determine how much they have in common with systems found in related bacteria or in higher organisms. By investigating these systems, the extent to which evolution has reused the same blueprints to build complexity will be determined. Part of this research will be performed by college undergraduates in the classroom, allowing a great many students, who normally would not have the opportunity, to conduct their own biological research study. Additionally, high school students will be exposed to the wonders of the biological world as seen through the lens of a microscope. Prokaryotic analogs of eukaryotic cellular systems have been found in a number of bacteria. Yet, how much these systems are conserved from bacterium to bacterium, how similar these prokaryotic systems are to their eukaryotic versions, or how much they have been adapted to suit the unique needs of each organism is largely unknown. This research will study the GcrA/CcrM epigenetic regulatory system and the DivK/CtrA cell cycle regulatory system, both of which are conserved throughout the Alphaproteobacterial clade. These systems will be investigated in the bacterium Brevundimonas subvibrioides where they display important operational variation from the model organism Caulobacter crescentus, using modern genetic and cell biology techniques, including ChIP-Seq and single-molecule sequencing. The comparisons of regulatory systems between related bacteria will aid in showing how systems evolve to better suit the needs of different organisms, what fundamental principles must be conserved between them, and assess just how translatable models can be across evolutionary distance. Part of this research will be performed by undergraduates in an upper level class, providing the opportunity for many students to work on an original research project. This study also includes the development of a single day program designed to expose high school students to microscopy in order to visually draw students into STEM fields.