Genes (ebrAB) responsible for ethidium resistance were cloned from chromosomal DNA of Bacillus subtilis ATCC 9372. The recombinant plasmid produced elevated resistance against ethidium bromide, acriflavine, pyronine Y, and safranin O not only in Escherichia coli but also in B. subtilis. It also caused an elevated energy-dependent efflux of ethidium in E. coli. EbrA and EbrB showed high sequence...

Washed mature spermatozoa from bulls incorporate ribonucleoside triphosphates into RNA using an endogenous template. Maximum incorporation was observed at 31 degrees C in the presence of MgCl2, all four ribonucleoside triphosphates, beta-mercaptoethanol, and glycine sodium hydroxide buffer at pH 9.0. The amount of synthesis was linearly dependent upon the concentration of spermatozoa and contin...

A miniature fiber optic endomicroscope with built-in dynamic focus scanning capability is developed for the first time for 3-D two-photon fluorescence (TPF) imaging of biological samples. Fast 2-D lateral beam scanning is realized by resonantly vibrating a double-clad fiber cantilever with a tubular piezoactuator. Slow axial scanning is achieved by moving the distal end of the imaging probe wit...

A new synthesized acridine derivative, 3,6-diamino-10-methyl-9, 10-dihydroacridine (AcrH), was tested for in vitro reverse mutations with Salmonella TA strains, chromosome aberrations and sister chromatid exchanges (SCE) in human lymphocytes, and for in vivo chromosome aberrations in bone marrow of mice. Using the classic plate incorporation method, mutagenicity of AcrH in bacterial cells (TA97...

Mutations in the acrB gene, which were originally selected through their resistance to acriflavine, also result in reduced growth on a range of sole carbon sources, including fructose, cellobiose, raffinose, and starch, and reduced utilization of omega-amino acids, including GABA and beta-alanine, as sole carbon and nitrogen sources. The acrB2 mutation suppresses the phenotypic effects of mutat...

A dominant gene Su(kau-2) partially suppresses the effect of an apparently unlinked recessive kau-2. Gene kau-2 blocks chemical induction of conjugation in Paramecium aurelia syngen 8 when solutions of acriflavine + either KCl or MgCl-2 are used. Wild-type cells are induced to conjugate in either solution. When cells homozygous for kau-2 also have gene Su(kau-2), they are still uninducible in t...