In addition, a transcription component, Odd Skipped is expressed during the Stat92E GFP domain, in nearby cells on the two sides of it, and in both little and big nuclei. wg Gal4/UAS GFP and Patched, a regulator in the Hh signal transduction pathway may also be expressed from the Stat92E GFP domain. Stat92E GFP is really a stem cell marker in a number of other organs. 17,36 Ptc continues to be proven to mark the hub and cyst progenitor cells in Drosophila testis. 37 We located that in addition to testis CPCs, ptc lacz also express inside the F/M junction during the cardia. This cellular organization and expression of markers at the F/M junction are extremely related to those that have been reported with the junction of your posterior midgut and hindgut. 17 Stem cells are actually identi fied at the junction with the posterior midgut and hindgut and in close by tissues. 15 17,36 These findings led us to examine no matter if the F/M junction also includes stem cells.
The F/M junction cells are proliferating. So as to search for that F/M cell exercise, we performed five bromodeoxyuridine incorporation experiments. Cells instantly upcoming for the Stat92E GFP zone in both foregut and anterior midgut additional resources showed strong BrdU incorporation. In contrast, cells during the Stat92E GFP zone showed weak BrdU incor poration. We additional analyzed the stability of BrdU labeled cells at the F/M junction, applying the pulse chase technique. Right after a 5 day chase, the BrdU label was retained only in the Stat92E GFP expressing cells. We also chased the flies for 17 days and observed that all BrdU labeled cells on the F/M junc tion were gone. In invertebrates, BrdU is incorporated into quite a few differentiated cells that endoreplicate. 38 We even further stained the tissue for phospho histone H3 to distinguish endoreplicating from dividing cells while in the cardia.
Whilst BrdU labeled various forms of cells within the cardia, the PH3 staining was only detected in a pretty unusual population of cells with little nuclei within the STAT92E GFP and wg Gal4/UAS GFP areas of the cardia. These observations indicate the Stat92E expressing and a part of wg Gal4/UAS GFP cells may possibly be stem cells and selleck chemicals the close by cells at the two foregut and anterior midgut sides are their proliferative progenitors. We further examined the cell death by utilizing an Apoptag kit. We detected quite handful of dying cells during the Stat92E GFP zone or wg Gal4/UAS GFP zone. On the other hand, a signifi cant quantity of dying cells have been detected in the esophagus, ante rior midgut, and crop, indicating that the stem cells from the Stat92E GFP zone and their proliferat ing progenitors are creating replacement cells for the dead cells within the esophagus, anterior midgut and crop.
The F/M junction cells are multipotent stem cells. To deter mine whether or not the F/M junction cells included functional stem cells, we conducted 3 types of lineage tracing experiments.