Matters Microbial: International Edition - Exploring Host-Microbe Interactions with Cryo-Electron Tomography
0:00:30 Introduction: Dr. Mark Martin introduces the episode, highlighting the history of microbiology and the importance of learning from both good and bad stories. He mentions Esther Lederberg as a microbial hero and shares personal anecdotes about her.
0:01:09 Microbial Cell Structure: Discusses the lack of respect for bacteria and archaea from ukar researchers and illustrates the complexity of microbial cell structure using electron cryotomography. Ariana Bgal, a former guest, now leads an integrative structural cell biology unit at the Pasteur Institute.
0:04:26 Exploring Squid-Vibrio Symbiosis: Ariana describes the awesomely cute Hawaiian bobtail squid and the bioluminescent Vibrio fischeri. She notes that Cryo-EM has gone from "nice pictures" to a technique that allows us now to really start to understand microbes.
0:06:30 Cryo-Electron Tomography Explanation: Ariana explains the tomography principle using a video, emphasizing the need to rotate the object of interest to collect a series of 2D projections for creating a 3D volume.
0:07:57 Importance of Vitrification: Ariana and Mark discuss the necessity of cryo-preservation to prevent water crystallization and preserve the native state of biological samples in electron microscopy.
0:13:30 High Pressure Freezing and INB Milling: Ariana discusses overcoming the challenge of thick samples through high-pressure freezing and focused ion beam milling.
0:16:45 Moore Foundation Grant: Ariana expresses appreciation for the Gordon and Betty Moore Foundation for funding research into host-microbe interactions, acknowledging the ambitious nature of the project.
0:16:45 Squid Research Team: A team, including Margaret McFall-Ngai, Ned Ruby, Alicia Septer and Katrina Gund, researches the squid-Vibrio system, which offers a simplified model with one host and one microbe. Katrina is a former postu in Ariana's lab, now an assistant prof at pacific university.
0:21:37 Details of the Hawaiian Bobtail Squid System: Adult squids have to be collected um uh from the wild uh from a beach in uh Oahu in Hawaii in the evening when it's getting dark. Squid egg clutches are shipped internationally to build squid labs and hatch them.
0:27:56 Spatial Interactions with Squid Tomogram: The squid system allows for analysis of the spatial interaction of the host and microbe. Analysis of over 300 tomograms showed both outer membrane vesicles from the bacteria and vesicles derived from host tissue.
0:28:36 Complexity of the Light Organ: The simple understanding about the light organ isn't true. Traditional EM revealed a more complex architecture.
0:30:45 Target Cryo Tomograms carefully: With Cryo Tomograms, you have to really Target this this specific spot correctly, else you will miss interaction.
0:32:02 Collaboration with Jurgen plitzko and UDA: The group collaborated with pioneers of large-volume technology to start studying the light organ.
0:34:20 Squid "In C2" Studies: By studying squid cells in C2, one is able to study the nucleopore, cytoskeleton, and even start using protein signs.
0:35:21 Bacterial-Host Vesicle Interactions: Cryo-EM reveals both bacterial and host-derived vesicles, facilitating the study of spatial interactions at a molecular level.
0:37:17 Directional Communication, and the Three Stages of Science: There's the three stages of science (silly idea, relevant, and I said it first!). Some systems are hyper complex, like neurobiology.
0:41:51 The I is to study diseases, like microbacterial infections: What next? the main limitation is the challenges. What what needs to happen in the next few years is to streamline this workflow.
0:50:00 artifact Real or Not, defining what you mean: How can cryom be sure that the images are not due to artifacts? What is the solution.
0:50:51 Hyper Complexity of Ecological Interactions: It may not be possible to look at them all, and it still comes down to "one change and impact".
0:53:00 The Future lies with Pasteurs, Not Leiden: Ariana details her move from Leiden to the Pasture institute, with great infrastructure in nanoimaging. Most of her lab decided to join.
0:56:44 Final Thanks and Closing Remarks: Ariana thanks Mark for having her on the podcast.