Table S1 Summary of experiments comparing retrohoming efficiencies of linear and lariat Ll.LtrB intron RNAs in wild-type and mutant D. melanogaster embryos. Retrohoming assays using lariat and linear RNPs were done in D. melanogaster precellular blastoderm embryos, as described in Figure 2A and Materials and Methods. After incubating the embryos for 1 h at 30uC, nucleic acids were extracted and transformed into E. coli HMS174(DE3) for plating assays of retrohoming efficiency. WT, wild type. aRetrohoming efficiency calculated as (TetR+AmpR)/AmpR colo- nies. bRetrohoming efficiency relative to wild-type w1118 or Or-R assayed in parallel. (DOC) References 1. Lambowitz AM, Zimmerly S (2011) Group II introns: mobile ribozymes that invade DNA. In: Gestland RF, Cech TR, Atkins JF, eds. RNA worlds: from life’s origins to diversity in gene regulation. Cold Spring HarborNY: Cold Spring Harbor Laboratory Press. pp 103–122. 2. 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PLoS Genetics | www.plosgenetics.org 15 February 2012 | Volume 8 | Issue 2 | e1002534