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We have developed a DNA extraction procedure for milligram amounts of plant tissue. Yields ranged from 0.3–200 nanograms of DNA per milligram of tissue. The factors affecting yield are discussed. Fresh tissue, as well as herbarium specimens (22–118 years old) and mummified seeds and embryos (500 to greater than 44 600 years old) were used. All tissues(More)
Ribosomal RNA genes in plants are highly variable both in copy number and in intergenic spacer (IGS) length. This variability exists not only between distantly related species, but among members of the same genus and also among members of the same population of a single species. Analysis of inheritance indicates that copy number change is rapid, occurring(More)
When samples are collected in the field and transported to the lab, degradation of the nucleic acids contained in the samples is frequently observed. Immediate extraction and precipitation of the nucleic acids reduces degradation to a minimum, thus preserving accurate sequence information. An extraction method to obtain high quality DNA in field studies is(More)
A family of optional group-I introns was found near the 3′ end of the nuclear small subunit rRNA genes in 61 out of 70 isolates of the deuteromycete mycorrhizal fungusCenococcum geophilum. DNA sequence polymorphisms among the introns (termedCgSSU introns) from ten of the isolates were studied. The sequences, ranging in size from 488 to 514 nucleotides, were(More)
Here we report the characterization of fungi from 10 accretion ice sections (3300-5100 y old) as well as two deep glacial ice sections that are close to the bottom of the glacier (1,000,000-2,000,000 y old) from the Vostok, Antarctica, 5G ice core. Fungi were characterized by fluorescence microscopy culturing and sequence analyses of ribosomal DNA internal(More)
Cenococcum geophilum is an ecologically important mycorrhizal fungus with a global distribution and a wide host range. It has been difficult to study since it forms only sterile mycelia and, occasionally, sclerotial bodies. Because of its lack of morphological variability, its taxonomy and phylogenetic origins have until recently remained unclear. To better(More)
Despite an expanding array of molecular approaches for detecting microorganisms in a given sample, rapid and robust means of assessing the differential viability of the microbial cells, as a function of phylogenetic lineage, remain elusive. A propidium monoazide (PMA) treatment coupled with downstream quantitative polymerase chain reaction (qPCR) and(More)
Influenza A virus infects a large proportion of the human population annually, sometimes leading to the deaths of millions. The biotic cycles of infection are well characterized in the literature, including in studies of populations of humans, poultry, swine, and migratory waterfowl. However, there are few studies of abiotic reservoirs for this virus. Here,(More)
We have compared the restriction patterns and copy numbers of ribosomal RNA genes (rDNA) between and within individuals of Vicia faba . While the EcoRI blot-hybridization patterns changed only after one to two generations, copy number changes were found among different tissues of the same plant. Copy number differences among individuals in the population(More)