MusD-mediated retrotransposition of the ETn elements. (A) Assay for retrotransposition of neoTNF-marked ETn elements (schematized on the left with their copy number indicated) (see also Table 1) upon transcomplementation with the autonomous MusD-6 copy (+MusD) or a control plasmid (none). Images of the plates and retrotransposition frequencies are given as in Figure 2 (two to three independent experiments, with standard errors indicated). Additional experiments included assays with a neoTNF-marked defective IAP element (marked IAP-IL3) as well as complementation in trans with a functional IAP vector (RP23-92L23; +IAP) (Dewannieux et al. 2004). (B) Four ETn II insertions (originating from the ETn IIβ-1 element) are illustrated as in Figure 3, with the GenBank accession no. and chromosomal localization of each insertion site indicated.
