FIG. 2.

Recombination substrates. In all substrates, 12-RSSs occur at sites 1 or 2, and the canonical 23-RSS is inserted at site 3. The frequency with which a given test RSS positioned at site 1 recombines is tested relative to the frequency with which the invariant sequence at site 2 is rearranged. In each section of the figure, labeled bars represent the oligonucleotide probes that are used in the typing of recombinants (see Materials and Methods). (A) The SJΔ substrate and two possible recombinant deletion products, involving either the site 1 or site 2 RSS. (B) Inv substrate with the inversional recombinant resulting from site-1-to-site-3 rearrangement and site 2 deletion product. (C) The CJΔ substrate is shown with the deleted coding joint product. This plasmid is cotransfected with the site 2 control plasmid, which gives rise to the site 2 deletion product.