Figure 3.

Mapping the presence of Sly1-1 in the pedigree of FGSC 2489 and related strains. A cross of Lindegren 1A and the presumed Abbott 12a strain (see Newmeyer et al. 1987) yielded Emerson 5297a. One copy of Sly1-1 is present in Emerson 5297a as shown by Southern blot analysis; it remains unknown if Sly1-1 was introduced from Abbott 12a as the strain may be lost. Lindegren 25a and Abbott 4A produced Emerson 5256A and neither of them carries Sly1-1. FGSC 2489 was derived via several backcrosses from a cross between Emerson 5297a and Emerson 5256a. Two copies of Sly1-1, instead of just one in Emerson 5297a, are present in the genome of FGSC 2489, as shown in the Southern blots, indicating that Sly1-1 is potentially active and may have transposed at least once. The FGSC 2489 lineage resulted from multiple back-crosses to Emerson parents, indicated by the dotted line. Genomic DNAs were digested by the restriction endonuclease XhoI for Southern blotting analysis. Digested DNA fragments were hybridized with three probes whose positions are illustrated: probe A and probe B hybridized with the 5531-bp fragment of Sly1-1 at the 5′ end; probe C hybridized with the 4292-bp fragment of Sly1-1 at the 3′ end.