Deletions/insertions, short inverted repeats, sequences resembling att-lambda, and frame shift mutated open reading frames are involved in chloroplast DNA differences in the genus Oenothera subsection Munzia.

A restriction fragment length mutation has been mapped in the large single copy region of the chloroplast DNA from two Munzi-Oenothera species. Fragments containing the deletion/insertion were cloned, further analysed by additional restriction enzymes, and sequenced. A deleted/inserted 136 bp sequence was identified upstream of the 5' end of a tRNA-Leu (UAA) gene and presumably is located in the spacer between this gene and a tRNA-Thr (UGU) gene. The endpoints of the 136 bp sequence are covered by short inverted repeats. Complementary inverted repeats are present in the middle of the deleted/inserted sequence. The repeats are part of sequences resembling the lambda chromosomal attachment site (att-lambda) which is essential for site specific recombination in the lambda/Escherichia coli system. Possible interactions of the repeats during the deletion/insertion process are discussed. The spacer also contains a 1 bp deletion/insertion within an open reading frame (ORF). Due to this frame shift mutation the ORF sizes are quite different between the two Oenothera species.

Chloroplast DNA differences in the genus Oenothera subsection Munzia: a short direct repeat resembling the lambda chromosomal attachment site occurs as a deletion/insertion within an intron of an NADH-dehydrogenase gene.

A small restriction fragment length mutation has been mapped in the large inverted repeats of the chloroplast (cp) DNA of Munzia-Oenothera species (vom Stein and Hachtel 1986). This mutation could be localized within the intron of a reading frame presumably coding for subunit B of an NADH-dehydrogenase (ndhB). Sequence analysis revealed a 24 bp duplication/deletion. The predicted secondary structure of the ndhB-intron is altered by this duplication/deletion. Part of the directly repeated segment shows remarkable similarity to the phage lambda attachment site. Evidence is presented for similar sequences in other plastome regions where deletions/insertions have been found. Furthermore, the locations of the genes for other components of the NADH-dehydrogenase (ndhA, ndhC, ndhD, ndhE, ndhF) were established by heterologous hybridization using gene probes from tobacco cpDNA.

Chloroplast DNA differences between two species of Oenothera subsection Munzia: location in the chloroplast genome and relevance to possible interactions between nuclear and plastid genomes.

The chloroplast DNAs (cpDNAs) of Oenothera berteriana and Oe. odorata (subsection Munzia) were examined by restriction endonuclease analysis with Sal I, Pvu II, Kpn I, Pst I, Hind III, and Bam HI. The fragment patterns show that these cpDNAs have all 133 restriction sites in common as well as a lot of individual bands. Nevertheless the cpDNAs of the two species can be distinguished by distinct differences in size between a small number of fragments. The 42 cleavage sites produced by Sal I, Pvu II and Kpn I were mapped on the circular cpDNAs. This was achieved by an approach which combined experimental and mathematical procedures. The overall serial order of the fragments was found to be the same for both cpDNAs. The size differences of individual fragments in the Sal I, Pvu II and Kpn I patterns between Oe. berteriana and Oe. odorata cpDNA are located within five regions scattered along the plastid chromosome. Two of these regions have been localized in the larger and one in the smaller of the two single-copy parts of the cpDNA molecule. The remaining two overlap the borders between the large single-copy and each of the duplicated parts of the molecule. The positions of distinct restriction sites are altered among the two Oenothera plastome DNAs by 0.02-0.4 MDa (30-600 base pairs). These alterations probably result from insertions/deletions.