Members of the mitosporic fungal form-genus Stachybotrys, including common indoor contaminants Stachybotrys chartarum, Stachybotrys echinata and Stachybotrys chlorohalonata, are capable of producing potent, protein synthesis-inhibiting, trichothecene mycotoxins. A combined multi-gene approach was used to investigate relationships among species of Stachybotrys against which the presence/absence of the trichothecene biosynthetic pathway gene, trichodiene synthase (tri5), was evaluated. Phylogenetic analyses partitioned species of Stachybotrys into three strongly supported lineages, two of which contained common indoor taxa.
View Article and Find Full Text PDFComprehensive genomic molecular analyses require relatively large DNA amounts that are often not available from forensic, clinical and other crucial biological samples. Numerous methods to amplify the whole genome have been proposed for cancer, forensic and taxonomic research. Unfortunately, when using truly random primers for the initial priming step, all of these procedures suffer from high background problems for sub-nanogram quantities of input DNA.
View Article and Find Full Text PDFThe small size of miRNAs makes profiling of all the 462 known human miRNAs difficult using single cell samples. Recently, we showed that judicious sequence partitioning between RT primers and second strand synthesis primers permitted multiplexed RT-PCR amplification of miRNA in very small samples to allow individual real time PCR quantification. Here, we show that zip coding the primers and TaqMan probes with sequences specific to each miRNA greatly improves reaction specificity, which permits the profiling of all miRNAs in a single multiplexed RT-PCR reaction.
View Article and Find Full Text PDFBiochem Biophys Res Commun
April 2006
MicroRNAs are short (approximately 22 nucleotides), non-coding RNAs that play critical roles in gene regulation and may be used as rapid precise diagnostic indicators of early stages of cancer. The small size of these RNAs makes detection of multiple microRNA species in very small samples problematic. Here we investigate the parameters associated with multiplexing RT-PCR to obtain relative abundance profiles of multiple microRNAs in small sample sizes down to the amount of RNA found in a single cell.
View Article and Find Full Text PDFWe examined 198 isolates of P. chysogenum recovered from 109 houses in Wallaceburg, Ontario, and 25 culture collection isolates including seven ex-type strains. Multilocus genotypes were determined by heteroduplex mobility assay of regions spanning introns in acetyl co-enzyme A synthase, beta-tubulin, thioredoxin reductase and the internal transcribed spacer regions of the nuclear ribosomal subrepeat.
View Article and Find Full Text PDFThe symbiosis between fungus-growing ants and the fungi they cultivate for food has been shaped by 50 million years of coevolution. Phylogenetic analyses indicate that this long coevolutionary history includes a third symbiont lineage: specialized microfungal parasites of the ants' fungus gardens. At ancient levels, the phylogenies of the three symbionts are perfectly congruent, revealing that the ant-microbe symbiosis is the product of tripartite coevolution between the farming ants, their cultivars, and the garden parasites.
View Article and Find Full Text PDFMicrobiology (Reading)
June 1996
A homologue of the 'ferric uptake regulation' gene (fur) was isolated from the cyanobacterium Synechococcus sp. strain PCC 7942 by an Escherichia coli-based 'in vivo repression assay'. The assay uses a reporter-gene construct containing the promoter region of the iron-regulated cyanobacterial gene isiA, fused to the coding region for chloramphenicol acetyltransferase.
View Article and Find Full Text PDF