A supposed sporulation-deficient mutation of Saccharomyces cerevisiae is found to affect mating in haploids and in diploids, and to be inseparable from the mating-type locus by recombination. The mutation is regarded as a defective a allele and is designated a*. This is confirmed by its dominance relations in diploids, triploids, and tetraploids. Tetrad analysis of tetraploids and of their spor...

Eyeglass lenses are commonly composed of allyl-diglycol carbonate (CR-39), an alpha-particle detecting plastic, thus making such lenses personal radon dosimeters. Samples of such lenses have been etched to reveal that radon and radon progeny alpha tracks can be seen in abundance, and sensitivities have been calibrated in radon chambers as a primary calibration and with a uranium-based source of...

BACKGROUND Candida species are microbial pathogens originally thought to be asexual, but several are now recognized as sexual or parasexual. Candida albicans, the most common fungus infecting humans, is an obligate diploid with a parasexual cycle involving mating, recombination, and genome reduction but no recognized meiosis. Others (C. lusitaniae, C. guilliermondii) are haploid, and their mati...

We investigated the ability of a new type of biological material, the self-assembling peptide scaffold, to foster tissue-like function by a putative adult rat hepatocyte progenitor cell line, Lig-8. In conventional adherent petri-dish cultures, Lig-8 cells divide exponentially, express markers for definitive endoderm HNF3 beta and hepatocyte lineage, including CK8 and alpha-fetoprotein, but lac...

IFN-alpha has been shown to prolong survival in chronic myeloid leukemia patients, but its mechanism of action is still not understood. The human cobblestone area-forming cell (CAFC) assay allows for the measurement of the concentration of normal as well as malignant stem cells, while their progeny can be measured in parallel long-term culture (LTC) in flasks. Using CAFC and LTC assays, we have...

The mechanism(s) by which alpha (alpha) particles like those emitted from inhaled radon and radon progeny cause their carcinogenic effects in the lung remains unclear. Although direct nuclear traversals by alpha-particles may be involved in mediating these outcomes, increasing evidence indicates that a particles can cause alterations in DNA in the absence of direct hits to cell nuclei. Using th...