UCLA

Archaea occupy one of the three domains of life and it is recognized that many of their cellular processes bear more similarity to their analogous processes in eukaryotic cells than the comparable processes in prokaryotic cells. However, despite the fact that archaeal cells are similar in complexity to bacterial cells, they have been studied to a much lesser extent, with the majority of species yet to be examined at all in the laboratory. Further study of this domain of life can be expected to contribute to the understanding of the cellular processes in higher organisms, including humans. In particular, very little is known about the structures and morphogenesis of archaeal cells. The studies described here aim to fill this knowledge gap by examining and resolving the structures of archaeal cells under a variety of conditions and with different techniques. Specifically, this work characterized the unique structural components of archaeal cells, analyzed the properties of concentrated inclusion bodies, and examined structural changes throughout cell division in archaeal cells. A combination of biophysical methods, including cryo electron microscopy (cryo EM), cryo electron tomography (cryo ET), scanning transmission EM (STEM) tomography, and energy dispersive x-ray (EDX) spectroscopy, were used to identify and characterize high-density polyphosphate bodies distributed within the Methanospirillum hungatei cell cytoplasm, two distinct high-density inclusion bodies distributed within the Archeaoglobus fulgidus cytoplasm, and the processes of cell division in both M. hungatei and A. fulgidus.