DNA fiber FISH using pools of long PCR products at gap 2 prior to final closure by long PCR. (a) Schematic representation of the three long PCR products from either side of the gap that were labeled and hybridized to DNA fibers. See Figure S5 in Additional data file 7 for identities. Note that non-repetitive sequence represented 71% of 19,858 kb on the left-hand side of the gap and only 50% of 6,239 kb on the right-hand side, as determined by Repeatmasker. (b) Three example DNA fibers showing detection by FISH of hybridized centromeric and telomeric PCR product pools in red (Texas Red) and green (FITC), respectively. Estimation from the DNA fiber FISH images suggested that the remaining gap was 2-3 kb in size and this was closed by the PCR product c658c926rcL (sequence CU210860).