Figure 4
Two hypotheses for the evolutionary derivation of the trnH-rps19 cluster in IRs of monocots from an Amborella- like ancestor. Arrow lines coded by different colors indicate distinct evolutionary pathways. Arrowheads denote possible breakpoints when DSB events occurred (different DSB colors are associated with different IR expansions). The light blue arrow line refers to a scenario in which a type II IR-LSC junction was established (see Fig. 1) in some eudicots (note that the rps19 residue is situated between rpl2 and trnH in IRA). The grey area in each cpDNA molecule highlights the IRs at all evolutionary stages.