Matters Microbial #98: Nesting Dolls of Endosymbiosis July 3, 2025

Today, Dr. John McCutcheon of Arizona State University joins the #QualityQuorum to discuss the work he and his research group do to investigate the strategies by which microbes become symbionts of other cells. After all, the mitochondria and chloroplasts of eukaryotic cells, including yours, were once bacteria!

Host: Mark O. Martin

Guest: John McCutcheon

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Links for this episode

• A video about the symbiosis of Hydra virdissima, which captured my heart when I was young.  Look at those symbiotic algae!  Here is an overview of this topic.
• A video describing the Rhizobium – legume nitrogen fixing symbiosis in all of its glory—by my PhD advisor, the great Dr. Sharon Long.  Here is an overview of this topic.  
• An appreciation of Paul Buchner’s very important book, “Endosymbiosis of Animals with Plant Microorganisms.”
• A wonderful review by Dr. McCutcheon on how symbioses form.
• A wonderful essay by Ed Yong about an event that made eukaryotic cells possible:  how bacteria became mitochondria.
• A story about an anaerobic protist that lost its mitochondria completely.
• A bacterial symbiont of mitochondria, the “midichlorian.”
• The recent discovery of a new integrated symbiont that has become an organelle, the nitrosome.
• The “X-bacteria” and amoebae story.
• A retrospective on endosymbiosis, and Paramecium based on Tracey Sonneborn’s work.
• An essay on aphids and bacteria.
• An article on the Moranella/Tremblaya symbiosis.
• An article on “bacteria inside other bacteria” found in several symbioses, written by Dr.McCutcheon and colleagues.
• Genomic instability in bacterial endosymbionts.
• An article on cicadas and bacterial endosymbionts from Dr. McCutcheon and colleagues.
• An article on mealybugs and bacterial endosymbionts from Dr. McCutcheon and colleagues.
• Dr. McCutcheon’s thoughts on his career path (so worth reading).
• The Center for Mechanisms of Evolution research institute in which Dr. McCutcheon works.
• Dr. McCutcheon’s faculty website.
• Dr. McCutcheon’s (and his research team’s) wonderful research website.

Intro music is by Reber Clark

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