Fig. 3.

PCR analysis of integration junctions for retrohoming of Ll.LtrB Lin RNPs in X. laevis oocyte nuclei. Retrohoming assays with Lin, GG-Lin, and Lar RNPs were done in X. laevis oocyte nuclei as in Fig. 2, except that the extracted nucleic acids were analyzed directly by PCR without transformation into E. coli. (A) PCR of the 5′ junction using primers P1 and P2, and PCR of the 3′ junction using primers P3 and P4 (Materials and Methods). The control lanes show parallel PCR of X. laevis genomic DNA and a water blank. (B) Sequences of 5′ integration junctions for retrohoming of Lin RNPs. PCR products corresponding to regions a, b, and c of the gel were cloned into pCRII-TOPO and sequenced (Materials and Methods). Intron and exon sequences are depicted as in Fig. 2. Mutations in the intron are highlighted in gray.