Encephalitozoon (Nosema) infection of the cornea in a cat.
The distribution of cytoplasmic microtubules throughout the cell cycle of the centric diatom Stephanopyxis turris: their...
The cell cycle of the marine centric diatom Stephanopyxis turris consists of a series of spatially and temporally well-ordered events. We have used immunofluorescence microscopy to examine the role of cytoplasmic microtubules in these events. At interphase, microtubules radiate out from the microtubule-organizing center, forming a network around th...
The mechanism of anaphase spindle elongation: uncoupling of tubulin incorporation and microtubule sliding during in vitr...
To study tubulin polymerization and microtubule sliding during spindle elongation in vitro, we developed a method of uncoupling the two processes. When isolated diatom spindles were incubated with biotinylated tubulin (biot-tb) without ATP, biot-tb was incorporated into two regions flanking the zone of microtubule overlap, but the spindles did not ...
A clonal theory of parasitic protozoa: the population structures of Entamoeba, Giardia, Leishmania, Naegleria, Plasmodiu...
We propose a general theory of clonal reproduction for parasitic protozoa, which has important medical and biological consequences. Many parasitic protozoa have been assumed to reproduce sexually, because of diploidy and occasional sexuality in the laboratory. However, a population genetic analysis of extensive data on biochemical polymorphisms ind...
Are eukaryotic microorganisms clonal or sexual? A population genetics vantage.
We argue that the mode of reproduction of microorganisms in nature can only be decided by population genetic information. The evidence available indicates that many parasitic protozoa and unicellular fungi have clonal rather than sexual population structures, which has major consequences for medical research and practice. Plasmodium falciparum, the...
Development of flow cytometry-based algal bioassays for assessing toxicity of copper in natural waters
Copper toxicity to the freshwater algae Selenastrum capricornutum and Chlorella sp. and the marine algae Phaeodactylum tricornutum and Dunaliella tertiolecta was investigated using different parameters measured by flow cytometry: cell division rate inhibition, chlorophyll a fluorescence, cell size (i.e., light-scattering), and enzyme activity. Thes...
Repair of oxidized proteins: Identification of a new methionine sulfoxide reductase
Oxidation of methionine residues to methionine sulfoxide can lead to inactivation of proteins. Methionine sulfoxide reductase (MsrA) has been known for a long time, and its repairing function well characterized. Here we identify a new methionine sulfoxide reductase, which we referred to as MsrB, the gene of which is present in genomes of eubacteria...
ENCORE: The effect of nutrient enrichment on coral reefs. Synthesis of results and conclusions
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Coral reef degradation resulting from nutrient enrichment of coastal waters is of increasing global concern. Although effects of nutrients on coral reef organisms have been demonstrated in the laboratory, there is little direct evidence of nutrient effects on coral reef biota in situ. The ENCORE experiment investigated responses of coral reef organ...
Development of an improved rapid enzyme inhibition bioassay with marine and freshwater microalgae using flow cytometry
A rapid toxicity test based on inhibition of esterase activity in marine and freshwater microalgae (Selenastrum capricornutum, Chlorella sp., Dunaliella tertiolecta, Phaeodactylum tricornutum, Tetraselmis sp., Entomoneis cf. punctulata, Nitzschia cf. paleacea) was developed using flow cytometry. Uptake of fluorescein diacetate (FDA) was optimized f...
N-glycosylation in sugarcane
The N-linked glycosylation of secretory and membrane proteins is the most complex posttranslational modification known to occur in eukaryotic cells. It has been shown to play critical roles in modulating protein function. Although this important biological process has been extensively studied in mammals, much less is known about this biosynthetic p...
