Molecular analysis of the mitochondrial genome of Phytophthoraa

Similarities in Restriction Fragment Patterns of Mitochondrial DNAs ofPhytophthoraSpecies Strongly Depend on the Restriction Enzyme Used Due to Heterogeneous Base Distribution and Sequence Conservation

“…Nevertheless, some results with two enzymes of this kind are available. Förster et al (1987) reported that the digestion of Phytophthora mtDNA with DraI (recognition sequence TTTAAA) resulted in numerous fragments, all of them being smaller than 1.3 kb. We obtained similar results using radioactively labeled AsnI fragments (recognition sequence ATTAAT) separated on a polyacrylamide gel (data not shown).…”

“…The many fragments obtained by restriction digests with DraI (Förster et al, 1987) and AsnI (see above) suggest that sequences with very high AT content are scattered throughout the mitochondrial genome of Phytophthora (Karlovsky and Fartmann, 1992). In order to elucidate whether the different G+C regions are continuous or split into many small domains, we degraded mtDNA of P. nicotianae by ultrasonication into fragments of 200-600 bp and separated the products in a CsCl/H33258 density gradient (Karlovsky and de Cock, 1991).…”

“…2 is a widely applied method in taxonomical and phylogenetic studies of different groups of true fungi (e.g., Bates et al, 1993;Fukuda et al, 1994, Guillamón et al, 1994Varga et al, 1994) as well as the oomycetes, of which Phytophthora has been studied in greatest detail (Förster et al, 1987(Förster et al, , 1988(Förster et al, , 1989(Förster et al, , 1990Förster and Coffey, 1993;Hwang et al, 1991;De Cock et al, 1992;Möller et al, 1993). The principle is simple: in the course of time base substitutions (point mutations) and insertions, deletions, inversions, and transpositions (macromutations) take place in mtDNA molecules.…”

“…This size is in agreement with the published values of 36.2 kb for P. infestans (Klimczak and Prell, 1984), 36.2 to 39.7 kb for P. infestans (Carter et al, 1990), and 39.5 kb for P. parasitica var. nicotianae (P. nicotianae) (Förster et al, 1987). The value of 37.5 kb was subsequently used as the average mtDNA size for the calculation of the mean number of fragments expected (Table 3).…”

Restriction Fragment Length Polymorphisms of Mitochondrial DNAs from the Basidiomycetes Pleurotus Species

“…For the DNA isolation, mycelia were grown in 2 liters of liquid SGYP medium (30 g of soluble starch, 2 g of glucose, 2.5 g of yeast extract, 2.5 g of poly peptone, 1 g ofKH 2 P0 4 , 0.5 g ofCaCl 2 '2H 2 0, 0.5 g of MgS0 4 ' 7H 2 0, 7 g of carboxymethylcellulose and water to 1 liter, adjusted to pH 4.8) in shake cultures for one week at 25°C. Total DNA was extracted from lyophilized mycelium according to the modified cetyltrimethylammoniumbromide (CTAB) procedure as described by Forster et al 8 ) MtDNA was separated from nuclear DNA by two succesive CsCI-bisbenzimide density gradient centrifugations. Digestion patterns for Bg/II, EcoRI and HindIII from the nine isolates of P. ostreatus and from seven isolates of Pleurotus species were all different from each other (Fig.…”