Cryo-electron tomography for microbial ecology and evolution

The cryo-electron microscopy (cryoEM) modalities of single particle analysis and cryo-electron tomography (cryoET) have revolutionized the fields of structural biology and cellular biochemistry, and they enabled groundbreaking insights into primarily hypothesis-driven, mechanistic problems, using well-established model systems.

High-throughput sequencing technologies have revolutionized microbial community studies and changed our view of the diversity of life.

In order to understand how microbes function and interact with other cells, however, sequencing- and cultivation-based techniques must be complemented with experiments that elucidate phenotypes in situ at the single-cell level. In Aim 1, we will develop cryoET methods for their application to problems in microbial ecology.

We will resolve technical challenges of cryoET application to complex environmental samples, including aspects of sample preparation, data collection, data analysis and data integration.In Aim 2, we will apply the new methods to outstanding biological questions to advance our understanding of cell-cell interactions.

We will study the role of unique bacterial tubulins in a bacterium-ciliate symbiosis, aspects of multicellularity in magnetotactic bacteria, and the diversity and roles of bacterial contractile injection systems.This project resides at the interface of structural biology/biophysics and environmental/evolutionary biology.

We will leverage the power of cryoET to generate three-dimensional images of cells in a frozen-hydrated life-like state, and at macromolecular resolution.

The complementation with high-throughput and single-cell approaches from microbial ecology will allow us to make progress on specific biological questions. CryoET offers a new “sense” for the analysis of complex environmental samples.

Our efforts will establish cryoET as a discovery tool that enables us to conceive how genetic variations manifest in structural and functional diversity.