Figure 4.
Southern blot analysis of DSBs in a diploid homozygous for ΔAha. (A) The diploid RM206 is homozygous for ΔAha and the rad50S mutation and is congenic to RM169. Cells were removed from sporulation medium at the time noted at the top of each lane. Markers (M) shown are 5.2 kb, 3.9 kb, 3.2 kb, 3.0 kb, 2.9 kb, and 1.9 kb, from top to bottom. Labels and the probe are as in Fig. 2 except band A′ is the parental band from RM206 and is 382 bp smaller than the normal (wild-type) band, which is designated as A (see Fig. 2). (B) Evidence that DSB bands from the ΔAha diploid are the same size as the normal diploid. An enlargement of the DSB bands is shown. DNA from the times in meiosis indicated were analyzed as in A. RM206 is homozygous for ΔAha; RM207 does not contain the deletion. The markers (lane M) in B are a subset of those used in A. [The total amount of counts in the bands A (not shown), B, and C (for RM207) was 1.3 × 106 at 10 hr, 1.4 × 106 at 12 hr, and 2.0 × 106 at 24 hr; the total amount of counts in bands A′ (not shown), B, and C (for RM206) was 1.4 × 106 at 10 hr, 1.2 × 106 at 12 hr, and 1.5 × 106 at 24 hr.]