J. Mergliano, R. Namba, S. Cambridge, J. Minden. Fate mapping the procephalic region of the Drosophila embryos has been a difficult process due to the complex morphogenetic movements of this region of the embryo. We have used the caged GAL4VP16 cell labeling system to begin analyzing the fates of these cells according to their mitotic domain residency.
Mitotic domains are groups of cells that divide in a stereotypic pattern.
This cell labeling method relies on the removal of photolabile blocking groups on the chemically modified transcriptional activator, caged GAL4VP16, with a brief pulse of a UV micro-beam. The photoactivation of caged GAL4VP16 was used to mark selected cells and their progeny by driving the expression of a UAS-lacZ transgene. The progeny of the photoactivated cells was determined by immunolocalization of lacZ. Mitotic domain 2 gave rise to the pharyngeal ectoderm and macrophages. Midgut endoderm originated from mitotic domain 8. Mitotic domain 15 produced the esophagus, proventriculus, and the anterior midgut endoderm.