b'Carnegie Science|Fall 2020 11Bellymount, First Real-Time Views of the GutIn another collaboration, led by Lucy OBrien and K.C. Huang of Stanford University with Ludington, the team developed a new tool to watch the real time cell-renewal process that keeps gut tissue healthy and the interactions between bacterial species that make up the microbiome. The system, dubbed Bellymount, allowed researchers to peer into the live tissue of the fruit fly gut to better understand the many complex, overlapping processes occurring there. PLOS Biology published the work.OBrien developed Bellymount to understand how stem cells in the gastrointestinal system drive the tissue- Bellymount allows researchers to peer into the live tissue of the fruit fly gut and other visceral organs in real time. It renewal process that gets rid of sick cellsprovides researchers with massive amounts of time-series imaging data, which is revolutionary in the biological sciences. and replaces them with new, healthy ones.Image courtesy Leslie Koyama and Lucy OBrienWhen this process is disrupted, it has an aging effect. Understanding it could drivepace, said lead author Leslie Koyama ofare more like a reservoir. improvements in medicine and regenerativeStanford.It makes you wonder how gut stem therapies.Beyond the gut, Bellymount will allowcells and gut bacteria are talking to each Before now, no one has ever watchedresearchers to spy on other fruit fly organs,other and possibly coordinating their how gut renewal progresses because itwatching them communicate duringactions, said Huang. Now we have the occurs over many days and happens deepwhole-body processes.power to actually eavesdrop on their inside the body, OBrien explained. It also enabled Ludington to betterconversations. Using Bellymount, the researchers wereunderstand how the guts bacteriaBecause Bellymount allows able to watch stem cells coordinating duringcontribute to many of its functions byinvestigators to peek at the activity of all the organ renewal process and discoveredwatching them unfold for the first time.of the flies visceral organs, this crosstalk that the rate at which individual stem cellsThey found that there are regionalcan be monitored across tissues and generate adult replacement cells variesdifferences in microbiome stability thatinform how they understand whole-body greatly. No one had seen the gut renewalactually mimic the regionality of the stemprocesses, such as immune surveillance, process play out in real time before this.cell activity. Some parts of the microbiomereproduction, aging, and cancerEach stem cell seems to work at its ownare continuously turned over, and others Will Ludington, right, joined the Carnegie staff in June 2018. He is working in his lab at the Department of Embryology.Image courtesy Navid Marvi, Carnegie Institution for Science'