PT - JOURNAL ARTICLE AU - Leslie Ann Jaramillo Koyama AU - Andrés Aranda-Díaz AU - Yu-Han Su AU - Shruthi Balachandra AU - Judy Lisette Martin AU - William B. Ludington AU - Kerwyn Casey Huang AU - Lucy Erin O’Brien TI - Bellymount enables longitudinal, intravital imaging of abdominal organs and the gut microbiota in adult <em>Drosophila</em> AID - 10.1101/741991 DP - 2019 Jan 01 TA - bioRxiv PG - 741991 4099 - http://biorxiv.org/content/early/2019/08/21/741991.short 4100 - http://biorxiv.org/content/early/2019/08/21/741991.full AB - Cell- and tissue-level processes often occur across days or weeks, but few imaging methods can capture such long timescales. Here we describe Bellymount, a simple, non-invasive method for longitudinal imaging of the Drosophila abdomen at sub-cellular resolution. Bellymounted flies remain live and intact, so the same individual can be imaged serially to yield vivid time series of multi-day processes. This feature opens the door to longitudinal studies of Drosophila internal organs in their native context. Exploiting Bellymount’s capabilities, we track intestinal stem cell lineages and gut microbial colonization in single flies, revealing spatiotemporal dynamics undetectable by previously available methods.