Figure 3. PCR analysis of integration junctions from lariat and linear intron RNA retrohoming in wild-type and mutant strains.

Retrohoming assays with lariat and linear RNPs were done as described in Figure 2A and Materials and Methods, and DNA was extracted from 80 pooled embryos for each strain. 5′- and 3′-integration junctions were amplified by PCR, using primers that flank the junction (5′junction, forward primer P1 and reverse primer LtrB933a; 3′ junction, forward primer P3 and reverse primer P4; see Materials and Methods). The PCR products were analyzed in a 1% agarose gel, which was stained with ethidium bromide. Precise 5′ and 3′ junctions for lariat intron RNA retrohoming and precise 3′ junctions for linear intron RNA retrohoming were confirmed by sequencing junctions from at least 10 randomly selected Tet^R+Amp^R colonies or PCR products from pooled embryos for all strains (not shown).