Name: Dr. George Fox
Institution: University of Houston
Location: Houston, Texas
Tell me a bit about how you came to be interested in Archaea and what your work entails.
Having been there at day 1, the one thing that has always intrigued me is why people are not amazed at how quickly the world of Archaea grew. As we analyzed methanogen 16S rRNA fingerprints (produced largely by technology developed by Mitch Sogin and his lab mates in Carl Woese’s group) it was clear that these organisms were highly unusual. Did they represent a new Domain of life as we wanted to propose? Surely a Domain would have more than one type of organism. Thus, among all known bacterial species Sulfolobus should be a member of the Archaea group too!? The truth is the rapid expansion was both very important to acceptance of the concept and rather fortuitous. It began when Otto Kandler visited the University of Illinois. We shared our ideas with him and learned that the methanogens were rather unique in a second way, in that they lacked peptidoglycan. As it happened, while at Syracuse pursuing my PhD I took a microbiology course from Donald Lundgren, Ralph Slepecky, and Richard Levy, wherein I learned that extreme halophiles lacked peptidoglycan. This memory led to the library where it was learned that the halophiles had unusual ether-linked lipids. Other organisms had these too, mainly Sulfolobus and Thermoplasma. Now we suddenly had multiple candidate Archaea and soon lipid studies on methanogens and 16S studies on these others quickly revealed a growing Domain. For my part, I have continued to focus on the ribosome in efforts to understand the emergence of life as we know it from an earlier progenote world.
Looking back at the last 40 years, what would you describe as the most exciting areas of research linked to the study of the Archaea? And where do you see the field headed in the next decade?
I think without a doubt the most intriguing if not exciting thing about the Archaea are the many similarities with eukaryotes. This is especially true of the ribosomal machinery. Ongoing efforts comparing genomes and individual genes are focused in part on eliminating the idea of a third Domain of life by seeking to demonstrate that the eukaryotic lineages arose from within the Archaea rather than sharing a common ancestor with them. This would promote the Archaea to second. However, I think one must be careful here. It remains difficult to explain the origin of the nucleus. Thus, the older hypothesis of three Domains remains when one considers that the eukaryotic cell may have arisen as a composite of several lineages, at least one of which predated ribosomes. This view has been consistently held by Hyman Hartman.
What would you like the public (and general microbiological audience) to appreciate about Archaea?
The general public should know that there is incredible diversity among microorganisms. Regarding Archaea specifically, they should be aware that these organisms have in many cases pushed the limits of survivability by growing at very high temperatures and under very acidic conditions. Likely of special importance is that there are currently no significant health issues associated with these organisms or the viruses associated with them.
Are there any particular papers that you feel are absolute must reads for those that aren’t necessarily familiar with the field (and briefly, why)?
For a general overview of the history I would strongly recommend Jan Sapp’s book, "The New Foundations of Evolution: On the Tree of Life" (Oxford University Press, 2009)
To see the argument that the eukaryotic cell is more than an amalgam of bacterial and archaeal traits read one or more papers by Hyman Hartman, such as:
Fedorov, A. and Hartman, H., What does the microsporidian E. cuniculi tell us about the origin of the eukaryotic cell?, J Mol Evol 59(5):695-702 (2004)
Hartman, H. and Smith, TF., The evolution of the cilium and the eukaryotic cell, Cell Motil Cytoskeleton. 66(4):215-9 (2009)