The intMEMOIR system for lineage tracing is composed of an array of 10 unique barcodes under the control of UAS. Each barcode is flanked by unique attP/attB sites recognized by Bxb1 integrase. In the presence of Bxb1:int, integrase activity can result in stochastic deletion or inversion of individual barcodes. Readout of each barcode status (deleted, inverted or no change) is accomplished by sequential rounds of single molecule FISH.
For more information see Ke-Huan et al., (2020).