Observations of low response of patients infected with Onchocerca volvulus to ivermectin suggest that the parasite may be under a selection process toward potential resistance. To limit the extension of this phenomenon, it is crucial to characterize the genes of O. volvulus that are involved. For this, O. volvulus adult worms collected before the introduction of ivermectin in an onchocerciasis ...

A recessive male sterile mutation (B2t8) that encodes a stable variant of the testis-specific beta 2-tubulin of Drosophila causes the assembly of aberrant microtubules both in vivo and in vitro. The B2t8 mutation appears to cause defects in the formation of interprotofilament bonds. In testes from homozygous mutant males, the most commonly observed aberrant structures were sheets of protofilame...

Arabidopsis contains six alpha-tubulin and nine beta-tubulin genes that are expressed in a tissue-specific and developmentally regulated manner. We analyzed the effects of light on tubulin mRNA abundance in Arabidopsis seedlings using RNA gel blot hybridizations and gene-specific probes. Transcript levels of all 15 tubulin genes were decreased by continuous white light, although to different de...

The epothilones (Epos) are a group of natural products isolated from the myxobacterium, Sorangium cellulosum. They have a mechanism of action similar to that of Taxol, i.e., they stabilize microtubules and induce the formation of microtubule bundles in cells. Because they are simpler in structure than Taxol and preserve their activity in P-glycoprotein-expressing cells, they are being studied a...

The surface topography of opened-up microtubule walls (sheets) decorated with monomeric and dimeric kinesin motor domains was investigated by freeze-drying and unidirectional metal shadowing. Electron microscopy of surface-shadowed specimens produces images with a high signal/noise ratio, which enable a direct observation of surface features below 2 nm detail. Here we investigate the inner and ...

The treatment of advanced ovarian cancer with taxol is hindered by the development of drug resistance. The cellular target for taxol is the microtubule that is stabilized by the drug. Taxol preferentially binds to the beta subunit of tubulin of which there are six distinct isotypes in mammalian cells. We have used highly specific oligonucleotides and polymerase chain reaction to analyze express...

Chilodonella uncinata, like all ciliates, contains two distinct nuclei in every cell: a germline micronucleus and a somatic macronucleus. During development of the macronucleus from a zygotic nucleus, the genome is processed in several ways, including elimination of internal sequences. In this study, we analyze micronuclear and macronuclear copies of beta-tubulin in C. uncinata and find at leas...

A systematic strategy was used to create a synoptic set of mutations that are distributed throughout the single beta-tubulin gene of Saccharomyces cerevisiae. Clusters of charged amino acids were targeted for mutagenesis and converted to alanine to maximize alterations on the protein's surface and minimize alterations that affect protein folding. Of the 55 mutations we constructed, three confer...

OBJECTIVES This study investigates how the tumor necrosis factor (TNF-alpha) and interleukin-1beta (IL-1beta) affect the morphology, organization, and expression of actin, beta-actin and tubulin in microglia. MATERIALS AND METHODS Microglia cultures were prepared from neopallia of newborn mice. Immunofluorescence, immunoblotting, and ELISA studies were used. RESULTS When microglia are treat...