Characterization and comparison of mitochondrial DNAs and rRNAs from Penicillium urticae and P. chrysogenum

Organization of mitochondrial DNA in the basidiomycetous Dioszegia hungarica (Cryptococcus hungaricus) species

The organization of mitochondrial DNA was investigated in the six collection strains of the basidiomycetous yeast Dioszegia hungarica (Cryptococcus hungaricus) isolated so far. Physical and partial functional maps were constructed. Two strains (CBS 6324 and 6576) were identical while three others (CBS 4214, 5124, 6953) differed not only in the distribution of restriction sites but in gene order as well. Results confirm the hypothesis that these five strains are representatives of different closely related species. The sixth strain CBS 6569 revealed a unique mitochondrial genome organization. Its mtDNA separated into eight bands on agarose gel without enzymatic digestion. These molecules carried mitochondrial genes, and RFLP analysis of the four largest molecules using frequently-cutting restriction enzymes (KpnI and SmaI) showed them to have strongly homologous sequences. This unique mtDNA organization was also observed in a strain of Cystofilobasidium capitatum, providing evidence that CBS 6569 belongs to the Cystofilobasidium clade.

The mitochondrial genome of Mucor piriformis

DNA was purified from the isolated mitochondria of a Mucor piriformis wild-type strain (NRRL 26211). A circular restriction map of the mitochondrial DNA was established on the basis of single and double digests with several restriction endonucleases. The average mitochondrial DNA size calculated from these data was 33.53 kbp; this is in good agreement with the contour length size (33.62 kbp) of the open circular molecules detected by electron microscopy. Heterologous hybridizations with cloned Aspergillus nidulans mitochondrial genes were used to locate some coding regions on the map.

Resolution of four large chromosomes in penicillin-producing filamentous fungi: the penicillin gene cluster is located on chromosome II (9.6 Mb) in Penicillium notatum and chromosome I (10.4 Mb) in Penicillium chrysogenum

Four chromosomes were resolved by pulsed field gel electrophoresis in Penicillium notatum (10.8, 9.6, 6.3 and 5.4 Mb in size) and in five different strains of Penicillium chrysogenum (10.4, 9.6, 7.3 and 6.8 Mb in the wild type). Small differences in size were found between the four chromosomes of the five P. chrysogenum strains. The penicillin gene cluster was localized by hybridization with a pcbAB probe to chromosome II of P. notatum and to chromosome I of all P. chrysogenum strains except the deletion mutant P. chrysogenum npe10, which lacks this DNA region. The pyrG gene was localized to chromosome I in P. notatum and to chromosome II in all P. chrysogenum strains except in the mutant AS-P-78 where the probe hybridized to chromosome III. A major chromosomal rearrangement seems to have occurred in this high penicillin producing strain. A fast moving DNA band observed in all gels corresponds to mitochondrial DNA. The total genome size has been calculated as 32.1 Mb in P. notatum and 34.1 Mb for the P. chrysogenum strains.

Nucleotide sequence of the large mitochondrial rRNA gene of Penicillium chrysogenum

The nucleotide sequence of a large rRNA (1-rRNA) gene and its flanking regions in the cloned fragments of mitochondrial (mt) DNA from Penicillium chrysogenum NRRL1951 (Sekiguchi J., Ohsaki, T., Yamamoto, H., Koichi, K. and Shida, T. (1990) J. Gen. Microbiol. 136, 535-543) was determined and compared with those in Aspergillus nidulans and Neurospora crassa mitochondrial DNAs. The P. chrysogenum mt 1-rRNA gene has a 1678 bp intron which intervenes between a 2835 bp 5' exon and a 581 bp 3' exon, and extensive homology exists between overall sequences of mt 1-rRNA genes of P. chrysogenum and A. nidulans. The P. chrysogenum intron contains a large open reading frame which encodes a polypeptide comprising of 399 amino acids. The intron sequence also suggests that the intron belongs to a self-splicing group IA.