The twin spot generator for differential Drosophila lineage analysis

Abstract

This technique, adapted from mosaic analysis with double markers in mice, relies on mitotic recombination to reconstitute sequences encoding EGFP or mRFP1. After cell division, each daughter cell contains one fluorescent marker, causing a green and a red twin spot that can be traced through development. In Drosophila melanogaster, widely used mitotic recombination–based strategies generate mosaic flies with positive readout for only one daughter cell after division. To differentially label both daughter cells, we developed the twin spot generator (TSG) technique, which through mitotic recombination generates green and red twin spots that are detectable after the first cell division as single cells. We propose wide applications of TSG to lineage and genetic mosaic studies.