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Project Progress

VPL Team members made progress this year improving our understanding of environmental influences on horizontal gene transfer and the implications for microbial evolution and adaptation to environments on other worlds. Team members also initiated research on fundamental chemical affinities that may have assisted the origin of life.

Siefert continued long-term work at the Mexican field site, the Cuatro Ciénegas basin, in collaboration with Jim Elser and the Follow the Elements NAI Team, ASU. The scientific goal is to understand stromatolite formation in present conditions as a proxy for evaluating early Earth and extraterrestrial microbiological formations as biosignatures. We were on site during February, and again in May. The May trip involved an all-hands meeting with our Mexican collaborators and the planning of eight papers to come from our efforts there. In February we continued sampling and worked with the team that is handling the bioinformatics platform, so that all of the sequence data is in the same format and available through a web interface. The May meeting was held in Mexico City and was a brainstorming session for the papers, in an attempt to place all of the experimental data into a global context. We also beta-tested the bioinformatics web interface. (All papers are currently in progress, with two nearly ready for submission). Siefert also attended the Astrobiology Grand Tour in Western Australia which was instrumental in understanding the context, geology, and history of microbialites on early and current Earth. As an astrobiological application of her work on horizontal gene transfer at Cuatro Cienegas, Siefert explored the viability of microbial contamination of the Mars environment by microbes carried on manned and unmanned vehicles (Siefert, 2012).

At UW, Black and Keller performed laboratory studies that suggest that the joining of RNA and fatty acids to form the first cells may have been assisted by a natural chemical affinity between these components (Black et al., 2013). Their research showed that the four bases in RNA had a preferential affinity for decanoic acid, which was likely a key component of prebiotic vesicles. In turn, the RNA bases bonded to decanoic acid vesicles protected the vesicles from aggregation in salty solutions, providing mutually reinforcing mechanisms that could have driven the emergence of primitive cells.