1. Meiotic DNA Breaks Associated with Recombination in S. pombe
Marcella D Cervantes, Joseph A Farah, Gerald R Smith 
Molecular Cell 
Volume 5, Issue 5, Pages (May 2000)
DOI: /S (00)

2. Figure 1
Synchrony of Meiotic DNA Replication in an S. pombe pat1 Mutant
Cells of the rec+ diploid strain GP338 were induced for meiosis as described in the Experimental Procedures. At the indicated times after induction, samples of cells were analyzed for DNA content by flow cytometry. DNA replication occurred between 1 and 2 hr. Additional samples from this induction were analyzed for DNA integrity (see Figure 2A and Figure 3).
Molecular Cell 2000 5, DOI: ( /S (00) )

3. Figure 2 DNA Breakage during Meiosis Requires rec Gene Products
S. pombe cells were harvested at the indicated times (hr) after the induction of meiosis, and their DNA was analyzed by pulsed-field gel electrophoresis and staining with ethidium bromide as described in the Experimental Procedures. (A) Diploid rec+ strain GP338; (B) haploid rec+ strain GP535; (C) diploid rec strain GP2740; (D) haploid rec6-103 strain GP701. The bands in the mitotic (0 hr) samples are, from top to bottom, the wells into which the DNA was loaded, chromosome I (5.7 Mb), chromosome II (4.6 Mb), and chromosome III (3.5 Mb). The smear (*) is broken DNA apparent during meiosis in the rec+ strains but not in the rec mutant strains. The arrow at the left indicates occasionally observed mechanically broken DNA due to premature lysis of the spheroplasts during preparation.
Molecular Cell 2000 5, DOI: ( /S (00) )

4. Figure 3
Meiotic DNA Breakage Occurs at a Limited Number of Prominent Sites
Cells of strain GP338 (rec+ diploid) were induced for meiosis, and their DNA was analyzed as in Figure 2, using altered electrophoresis conditions. (A) Ethidium bromide–stained gel. S. cerevisiae chromosomal DNA markers are in lane M. The arrow indicates mechanically broken DNA (see Figure 2). Intact S. pombe chromosomal DNA is unresolved, in the region from the top of the wells to the 1.6 Mb marker. (B) Southern blot hybridization with a radioactive probe containing the ura1 gene located about 0.75 Mb from the left end of chromosome I. The band marked with an asterisk (*) is deduced to extend from the left telomere, through the ura1 gene, to the meiotic break site. The band marked with a caret (>) is inferred to result from two meiotic breakages (see Results). The band in the rightmost lane reflects cross-hybridization of the ura1 probe to the S. cerevisiae URA2 gene on chromosome X (0.75 Mb). (C) Southern blot hybridization with a radioactive probe containing the rae1 gene located about 0.2 Mb from the right end of chromosome II.
Molecular Cell 2000 5, DOI: ( /S (00) )