Skip to main content
Figure 1 | Genome Biology

Figure 1

From: Detecting non-allelic homologous recombination from high-throughput sequencing data

Figure 1

Schematic examples of homologous repair. Sister chromatids joined at the centromere are shown. Red and pink regions are homologous LCRs, labeled A and B, respectively. Arrow direction represents LCR orientation. The unique region between the homologous red and pink LCRs is labeled Z. The yellow bolt represents the location of a DSB in the read LCR. Several pathways for homologous repair are shown, with an intermediate stage in each case. In AHR, the red LCR is repaired using the allelic region on the sister chromatid (the other red LCR). The repaired sister chromatid is repaired perfectly, up to polymorphisms. NAHR occurs when a non-allelic but homologous region is used for a template to repair the DSB (that is one of the pink LCRs), and the double Holliday junction is resolved via crossover. This leads to the creation of a new LCR, which is composed of parts of each mediating LCR, called a hybrid LCR. This leads to deletions and/or duplications when the mediating LCRs have the same orientation (that is the arrows point in the same direction). When the LCRs have opposite orientation, NAHR results in an inversion. Finally, it may be that the double Holliday junctions formed during repair are resolved via non-crossover resolution, in which case a gene conversion event occurs. In the schematic example, the pink LCR donates a sequence to the red LCR via gene conversion. AHR, allelic homologous recombination; DSB, double-stranded break; LCR, low-copy repeat; NAHR, non-allelic homologous recombination.

Back to article page