ABP1 is required for organized cell elongation and division in Arabidopsis embryogenesis

To directly address the function of a putative auxin receptor designated ABP1, a reverse genetic approach was taken to identify and characterize ABP1 mutant alleles in Arabidopsis. A homozygous null mutation in ABP1 confers embryo lethality. Null mutant embryos develop normally until the early stages of the globular embryo but are unable to make the transition to a bilaterally symmetrical structure because cells fail to elongate. Cell division was also aberrant both in the suspensor and embryo proper. Antisense suppression of ABP1 in tobacco cells causes slow proliferation and eliminates auxin-induced cell elongation and reduces cell division. The complete lack of auxin-inducible elongation in individual cells confirms the results observed in embryos, indicates a cell autonomous function, and, taken together with biochemical evidence that ABP1 binds auxins, suggests that ABP1 mediates auxin-induced cell elongation and, directly or indirectly, cell division.

Furazolidone toxicosis in female Japanese quail (Coturnix coturnix japonica): pathomorphological changes in reproductive tract and reversibility of the induced changes

Female Japanese quail (Coturnix coturnix Japonica) placed in 3 equal groups were given 600, 400 or 0 mg furazolidone (Fz)/kg feed for 4 w and then withdrawn for another 4 w. Another (pair-fed) group of same size was given basal feed as much as was consumed by the quail fed 600 mg Fz/kg feed. Fz feeding decreased body weight, feed intake and egg production. Ovaries of the Fz-fed quail decreased in weight and size and were studded with small follicles. Magnum, isthmus and uterus in Fz-fed groups had decreased area, height and number of mucosal folds compared with the control group. Microscopically, in Fz-fed groups, the mucosal glands in magnum and isthmus had decreased cell height with centrally located nuclei and foamy cytoplasm. In the 600 mg Fz-fed group, some birds had atrophy of the glandular tissue in the mucosa and infiltration of mononuclear cells and fibroblasts. Upon cessation of the Fz feeding, all parameters reversed gradually and became non-significantly different from control quail. These observations suggested that Fz-induced changes in mature female quail were reversible.

Solubilization of Amphiphilic Hemicyanine Dyes by a Cationic Surfactant, Cetyltrimethylammonium Bromide

The solubilization of amphiphilic hemicyanine dyes by the micelles of a cationic surfactant, cetyltrimethylammonium bromide (CTAB), was studied as a function of surfactant concentration above the critical micelle concentration (CMC). The micelle-water partition coefficient, Kx, and the standard free energy of solubilization, DeltaG0, of these dyes in CTAB micelles was determined at 25.0°C by a differential spectroscopic method. The CMCs of CTAB in the presence of small amounts of these dyes were determined by a conductivity method at 25.0°C. The values of Kx and DeltaG0 for all six dyes were determined by an improved method that incorporates both conductance and differential absorbance data.