Understanding DNA Repair in Hyperthermophilic Archaea: Persistent Gaps and Other Reasons to Focus on the Fork

Figure 3

Patchy recombination in Sulfolobus. Cells transformed with linear DNAs marked at multiple sites (or mated with multiply marked donor cells) produce recombinants that indicate erratic, localized strand loss from heteroduplex intermediates [48, 67]. (a) Markers are acquired from ssDNA as multiple short tracts, some of which consist of a single marker. (b) A preformed heteroduplex, containing two distinct donor alleles at each marked position, generates similar short patches representing all three possible alleles. Semicircular symbols depict “silent” genetic markers (synonymous mutations), and the colors (black, white, and gray) depict different alleles. Different colors opposite to each other indicate a mismatch that is eventually resolved by strand removal and resynthesis.

(a)

(b)