Project: Linking Modern Microbial Lipid Synthesis and the Primordial Membrane
Membranes are major components of all organisms on Earth and are critical for basic cellular functions. However, the origins of membranes — in particular, the basic chemical structure of the lipids that made up the original (primordial) membrane — are unknown. Many scientists have proposed that the original membrane was composed of a mixture of simple lipid structures that resemble the lipids we see today in modern microbes. However, different microbes use different basic lipids to generate their membranes, and studying these differences can provide clues to the origins of the primordial membrane.
In this study, we propose to modify the lipid profile of specific microbes to determine if a simple, mixed lipid membrane is possible to achieve in a living cell. We will then investigate how a cell responds to harboring this type of membrane and determine if a cell with such a membrane is viable. These studies will provide invaluable insight into the potential composition of the primordial membrane and will guide studies focused on determining how the first cells emerged and evolved.
Bio: Paula Welander received her undergraduate degree from Occidental College in Los Angeles, California. She pursued her Ph.D. studies in microbiology at the University of Illinois at Urbana-Champaign, where she studied the physiology of methanogenic archaea. She was a National Science Foundation Minority Postdoctoral Fellow and a NASA Astrobiology Postdoctoral Fellow at Massachusetts Institute of Technology, where she researched hopanoid and sterol function in bacteria. She joined the Department of Earth System Science in the School of Earth, Energy and the Environment at Stanford University in 2013.