Translating Ribosomal Affinity Purification (TRAP)
Thomas et al. (2012) created stocks for expressing a GFP-tagged ribosomal protein under UAS control. Ribosomes from GAL4-expressing cells can be recovered by immunoprecipitation with an anti-GFP antibody and actively translated mRNAs isolated.
Huang et al. (2019) created a similar stock for expressing a FLAG-tagged ribosomal protein under UAS control and isolating ribosome-associated mRNAs using anti-FLAG antibodies.
TU-tagging and EC-tagging
Miller et al. (2009) and Hida et al., 2017 generated stocks that express either uracil phosphoribosyltransferase (UPRT) or a cytosine deaminase (CD) – UPRT fusion under UAS control. In flies fed 4-thiouracil (4TU), 4TU is modified by UPRT and incorporated into newly synthesized RNA (TU-tagging). In flies fed 5-ethynylcytosine (5EC), 5EC is modified by CD:UPRT and incorporated into newly synthesized RNA (EC-tagging) . Thio- or ethynyl-labeled RNA can be selectively recovered by affinity purification.