Structural organization and evolution of the plastid genome of Vaucheria sessilis (Xanthophyceae)

Structural organization of the chloroplast genome of the chromophytic algaVaucheria bursata

“…Different evolutionary rates are known, for instance, to occur in plant and animal mitochondrial genomes [32]. In a similar way, restriction site polymorphisms among strains of Vaucheria bursata [22], which are extremely rare in land plant chloroplast genomes [26], could be interpreted as a result of faster substitution rates in chromophytic plastid genome evolution.…”

“…The procedures used to isolate morphologically intact plastids and to extract and purify the DNA were the same as mentioned previously [22]. Restriction enzyme analysis using various endonucleases followed standard protocols.…”

“…One of the most striking features is the highly rearranged gene order which even among closely related genera exceeds the degree of reorientation within the chloroplast genomes of land plants [17]. Even within a single Vaucheria species, strains may exhibit differences in their restriction fragment patterns that are mainly caused by single-base mutations [22]. Since it appears difficult at present to explain this high degree of plastid genome variation within the chlorophyll a + c lineage, it remains speculative as to whether these characters reflect the influence of the second eukaryotic host, or a high degree of phylogenetic distance, or simply specific intramolecular properties.…”

Biogeography of Freshwater Algae

“…It was already shown that chloroplast genomes characterized in such a way may be used as molecular markers (Linne von Berg & Kowallik, 1988). It was already shown that chloroplast genomes characterized in such a way may be used as molecular markers (Linne von Berg & Kowallik, 1988).…”

“…The samples, mostly from terrestrial habitats, were flooded with distilled water and incubated for four to six weeks at 15°C and 14:10 hours light:dark at 120 fJE PAR. Methods to cultivate the algae in 251 aerated vessels for chloroplast isolation, to isolate and purify chloroplast DNA, and to characterize the chloroplast genomes by restriction site and gene mapping experiments were the same as already described (Linne von Berg & Kowallik, 1988). For further studies, fertile filaments were dissected, rinsed, and transferred to Waris medium (Waris, 1953) enriched with vitamins (von Stosch & Drebes, 1964) and trace elements (Braune et aI., 1976).…”