Automated detection of spontaneous calcium signaling events in prohemocytes of the Drosophila melanogaster lymph gland

Calcium signaling is an important regulator of stem cell maintenance and differentiation. Here we report the development of an image processing pipeline for <i>ex vivo</i> time-lapse microscopy data that enables the unbiased, automated detection of calcium signaling events in prohemocytes of the <i>Drosophila melanogaster</i> lymph gland. We also show that heterogeneity in gene expression driven by Tep4-Gal4, which is used to mark prohemocytes, accounts for most of the cell-to-cell variability in the signal, and that spontaneous calcium signaling events in the lymph gland can last from a few seconds to well over a minute.