Candida parapsilosis former groups II and III have recently been established as independent species named C. orthopsilosis and C. metapsilosis, respectively. In this report, 400 isolates (290 patients) previously classified as C. parapsilosis by conventional laboratory tests were screened by BanI digestion profile analysis of the secondary alcohol dehydrogenase gene fragment and by amplification fragment length polymorphism (AFLP). Thirty-three strains collected from 13 patients were identified as C. orthopsilosis, thus giving the first retrospective evidence that C. orthopsilosis was responsible for 4.5% of the infections/colonization attributed to C. parapsilosis. AFLP was proven to unambiguously identify C. orthopsilosis at the species level and efficiently delineate intraspecific genetic relatedness. A high percentage of polymorphic AFLP bands was observed for independent isolates collected from each patient. Statistical analysis of the pairwise genetic distances and bootstrapping revealed that clonal reproduction and recombination both contribute to C. orthopsilosis genetic population structure. AFLP patterns of sequential isolates obtained from two patients demonstrated that a successful strain colonization within the same patient occurred, as revealed by strain maintenance in various body sites. No association between AFLP markers and drug resistance was observed, and none of the clinical C. orthopsilosis isolates were found to produce biofilm in vitro.

No abstract

In previous studies we have identified several mRNAs which accumulate after addition of 2,4-dichlorophenoxyacetic-acid (2,4-D) to auxin-starved tobacco cells. The mRNAs corresponding to cDNA clone pCNT103 were found to accumulate transiently prior to the cell division response due to auxin treatment. In this study we determined the sequences of three 103-like cDNAs and two 103-like genes, GNT1 and GNT35. To further study the regulation of the expression of these genes their 5' regions were translationally fused with the beta-D-glucuronidase reporter gene (GUS). The GNT1 5' region led to GUS expression only in the root tips of transgenic plants. By using transgenic hairy-root cultures and transformed cell suspension cultures it was shown that the 5' regions of both GNT1 and GNT35 lead to 2,4-D-inducible expression of GUS activity. The homology of the 103-like genes with other auxin-regulated genes is evaluated.

A 9.2 kb segment of the maxi-circle of Trypanosoma brucei mitochondrial DNA contains the genes for cytochrome c oxidase subunits I and II (coxI and coxII) and seven Unassigned Reading Frames ("URFs"). The genes for coxI and coxII display considerable homology at the aminoacid level (38 and 25%, respectively) to the corresponding genes in fungal and mammalian mtDNA, the only striking point of divergence being an unusually high cysteine content (about 4.5%). The reading frame coding for cytochrome c oxidase subunit II is discontinuous: the C-terminal portion of about 40 aminoacids, is present in the DNA-sequence in a -1 reading frame with respect to the N-terminal moiety. URF5, 8 and 10, show a low but distinct homology (about 20%) to mammalian mitochondrial URF-1, 4 and 5, respectively. In URF5, the first AUG is found at codon 145, whereas extensive homology to mammalian URF-1 sequences occurs upstream of this position. The possibility exists that UUG can serve as an initiator codon. URF7 and URF9 have a highly unusual aminoacid composition and do not possess AUG or UUG initiator codons. These URFs probably do not have a protein-coding function. The segment does not contain conventional tRNA genes.

To obtain a reproducible efficient procedure for regeneration of rice plants through somatic embryogenesis from callus four published methods of callus induction and regeneration were compared. Callus was initiated from mature embryos of the Japonica cultivar Taipei 309 of rice (Oryza sativa L.). The number, mass and morphology of the callus formed on the scutellum were dependent on the medium used. A limited humidity and an optimal aeration of the culture vessels enhanced the frequency of embryogenesis and plant regeneration. A method described by Poonsapaya et al. (1989) was found to be the most efficient and was slightly modified. As a result 98% of the T309 embryos formed callus, of which 63% regenerated into plants. Each callus yielded an average of 6 plants. Plant morphology, fertility and seed set of the regenerants were found to be normal.