A chloroplast DNA mutational hotspot and gene conversion in a noncoding region near rbcL in the grass family (Poaceae)

摘要: The noncoding DNA region of the chloroplast genome, flanked by genes rbcL and psaI (ORF36), has been sequenced for seven species grass family (Poaceae). This had previously observed as a hotspot area length mutations. Sequence comparison reveals that short duplications, probably resulting from slipped-strand mispairing, account many small differences between sequences but major mutational hotspots are localized in three areas, two which show potential secondary structure. Mutation one these appears to be result more complex recombination events. All contain pseudogene rpl23 evidence is presented this being maintained gene conversion with functional gene. Different transition/transversion biases AT contents surrounding noted. In subfamily Panicoideae there deletion almost 1 kb ancestral sequence, including 3' end pseudogene, replaced non-homologous 60-base sequence unknown origin. Two other deletions same have occurred family. deleted compositional properties similar coding pseudogene. independent deletions, well pattern mutation hotspots, indicate such may misleading studies phylogenetic inference.