Fig. 5

Model of targeted and guided NCO recombination. a Targeted NCO recombination. 5hmC is enriched in functional regions such as UTRs and exons (compare Fig. 4b). Thus, utilization of marks like 5hmC would allow to target the NCO recombination machinery towards function-related loci, which would in turn undergo more frequent recombination than quiescent or non-functional regions. b Guided NCO recombination. 5hmC is also a product of oxidative C-demethylation and indicative of recently opened chromatin. As this process can also occur in response to environmental signals, newly formed 5hmC marks would direct the recombination machinery preferably to these sites. In this model, the environmental pressure would therefore “guide” genetic evolution in a Lamarckian sense