Specific phases of root hair attachment in the Rhizobium trifolii-clover symbiosis.

The time course and orientation of attachment of Rhizobium trifolii 0403 to white clover root hairs was examined in slide cultures by light and electron microscopy. Inocula were grown for 5 days on defined BIII agar medium and represented the large subpopulation of fully encapsulated single cells which uniformly bind the clover lectin trifoliin A. When 10(7) cells or more were added per seedling, bacteria attached within minutes, forming randomly oriented clumps at the root hair tips. Several hours later, single cells attached polarly to the sides of the root hair. This sequence of attachment to clover root hairs was selective for R. trifolii at inoculum sizes of 10(7) to 4 X 10(8) per seedling, specifically inhibited if 2-deoxy-D-glucose, a hapten for trifoliin A, was present in the inoculum, and not observed when 4 X 10(8) cells were added to alfalfa seedling roots or to large clover root cell wall fragments which lacked trifoliin A but still had trifoliin A receptors. Once attached, R. trifolii 0403 became progressively less detachable with 2-deoxy-D-glucose. At smaller inoculum sizes (10(5) to 10(6) cells per seedling), there was no immediate clumping of R. trifolii at clover root hair tips, although polar binding of bacteria along the root hair surface was observed after 4 h. The interface between polarly attached bacteria and the root hair cell wall was shown to contain trifoliin A by immunofluorescence microscopy. Also, this interface was shown by transmission electron microscopy to contain electron-dense granules of host origin. Scanning electron microscopy revealed an accumulation of extracellular microfibrils associated with the lateral and polar surfaces of the attached bacteria, detectable after 12 h of incubation with seedling roots. At this same time, there was a significant reduction in the effectiveness of 2-deoxy-D-glucose in dislodging bacteria already attached to root hairs and an increase in firm attachment of bacteria to the root hair surface, which withstood the hydrodynamic shear forces of high-speed vortexing. These results are interpreted as a sequence of phases in attachment, beginning with specific reversible interactions between bacterial and plant surfaces (phase I attachment), followed by production of extracellular microfibrils which firmly anchor the bacterium to the root hair (phase 2 adhesion). Thus, attachment of R. trifolii to clover root hairs is a specific process requiring more than just the inherent adhesiveness of the bacteria to the plant cell wall.(ABSTRACT TRUNCATED AT 400 WORDS)     

Genetic polymorphism of complement C6 and haplotype analysis between C6 and C7 in a Japanese population

Summary Genetic polymorphism of C6 in the Japanese population has been described using polyacrylamide gel isoelectric focusing electrophoresis followed by the electrophoretic blotting technique, and haplotype analysis between C6 and C7 has also been investigated. In 565 plasma samples five different common patterns and three rare variant patterns were observed, and these were controlled by autosomal codominance at a single locus with three common and one rare alleles. These alleles were designated C6^*B, C6^*A, C6^*B2, and C6^*M, and gene frequencies were estimated to be 0.50265, 0.43186, 0.06018, and 0.00531 for C6^*B, C6^*A, C6^*B2, and C6^*M, respectively. It is noteworthy that C6^*B2 has a polymorphic frequency in the Japanese population. The distribution of phenotypes fitted the Hardy-Weinberg equilibrium. Two combinations between C6 and C7 alleles, namely C6B-C7B and C6M-C7B, were shown to be in significant positive linkage disequilibrium. The presence of allelic combinations showing linkage disequilibrium suggests the close proximity between the C6 and C7 loci.     

G6PD Ube, a glucose-6-phosphate dehydrogenase variant found in four unrelated Japanese families.

A total of 6,120 Japanese males were screened for glucose-6-phosphate dehydrogenase deficiency (G6PD). Five cases with the deficiency were discovered. Two of them and an additional two cases have the same variant, G6PD Ube, characterized by moderate enzyme deficiency, fast moving enzyme activity on electrophoresis, high Ki Nadph, utilization of substrate analogues, kinetics, pH optima, and stability. This variant was distinguished for G6PD A- and from other Oriental variants by biochemical parameters. Differences in the frequency and type of the variants between southern Asia and Japan, suggest that the Japanese who have been isolated on islands where malaria is not endemic, may have developed their own variant traits.     

Partial tetrasomy 9(9pter to 9q2101) due to an extra iso-dicentric chromosome.

A 3-year-old boy with partial No. 9 tetrasomy is described. The patient showed markedly retarded physical and mental development as well as multiple congenital anomalies. Routine chromosome analysis revealed an extra C-group chromosome. It had a pronounced secondary constriction at the proximal part of its long arm. Based on studies by a variety of banding techniques, the extra chromosome was identified to be an iso-dicentric No. 9 chromosome with inactivation of one of the two centromeres, the karyotype being 47,XY, + DIC (9)(Q2101). The value of BrdUrd treatment was emphasized in the detection of a very small piece of euchromatin within a long stretch of constitutive heterochromatin.     

Vitamin A receptors. I. Comparison of retinol binding to serum retinol-binding protein and to tissue receptors in chick retina and pigment epithelium.

1. A simple, efficient three-step method for purification of serum retinol-binding-protein is described with homogeneity obtained after chromatography on DEAE-Sephadex, CM-Sephadex and Sephadex G-100. 2. Evidence is presented indicating that retinol receptors present in the cytosol fraction of chick retina and pigment epithelium are separate and distinct from purified retinol-binding protein. Fluorescence characteristics are different in tissue cytosol and serum as assessed by sucrose density gradient analysis. Tissue retinol receptors do not interact with human serum prealbumin although the prealbumin readily complexes with purified chicken retinol-binding protein. Likewise, no binding to serum retinol-binding protein antibody could be detected by sucrose density gradient analysis, in immunoprecipitation experiments or by double immunodiffusion. It thus appears that specific retinol receptors are present in neural retina and pigment epithelium that are different from serum retinol-binding protein.     

Vitamin A receptors. II. Characteristics of retinol binding in chick retina and pigment epithelium

Gel filtration studies demonstrate that retinol receptors of chick retinal and pigment epithelial cytosols are (1) of very similar nature (2) of small molecular size (about 18000 daltons) and are different in character from serum proteins. Citral inhibits the binding of [3H]retinol to the retinal 2 S receptor. Retinol acetate competes with retinol for binding to 2 S receptor in both retina and pigment epithelium whereas retinol palmitate is an effective competitor only in the pigment epithelium. Dithiothreitol maximizes 2 S binding in retina and pigment epithelial cytosol; its absence does not lead to receptor aggregation however. A limited number of high affinity binding sites (2 S receptor) appear to be present in retina and pigment epithelium. A 5 S binding species is also present in pigment epithelium; it is similar in character to [3H]retinol binding in serum and may arise from serum contamination of the pigment epithelial preparation. Binding affinity in retina is high with possibly two classes of retinol binding sites present of KD about 1 - 10(-9) and 4 - 10(-8).     

Isolation and identification of 25-hydroxy-24-oxocholecalciferol: A metabolite of 25-hydroxycholecalciferol

A metabolite of 25-hydroxycholecalciferol has been isolated in pure form from chicken kidney homogenates. It has been identified as 25-hydroxy-24-oxocholecalciferol by means of ultraviolet absorption spectrophotometry, mass spectrometry, infrared spectrometry, nuclear magnetic resonance spectrometry, and specific chemical reactions.     

A compound possessing antitumor and interferon-inducing activities derived from the common antigen (OEP) of Pseudomonas aeruginosa.

OEP, a component consisting mainly of protein with small amounts of lipids and sugars, has been isolated from the autolysate of Pseudomonas aeruginosa and purified by physicochemical methods. It possesses remarkable biological properties, showing antitumor and interferon-inducing activities. As regards the antitumor activity of the sample, the ED50 value against ascites sarcoma-180 was 1 microgram/kg mouse/day, and its interferon-inducing activity amounted to 15 units at a concentration of 0.01 microgram/ml. Both activities increased after protease digestion, reaching about ten times those of the sample which had not undergone digestion. The protease-treated OEP contained 17% protein, 14.5% total sugars, 31% lipids, 12.5% hexosamine, 3.8% KDO, and 2.7% phosphorus. Neutral sugars consisted of 12.4% rhamnose, 2.7% mannose, 66.9% glucose, and other unidentified material. Total lipids derived from OEP consisted of 65% loosely-bound and 35% covalently-bound lipids; the former contained C14:10, C16:0, C16:1, C18:0, and C15:1 acids and the latter, beta-OH C10:0, C12:0, alpha-OH C12:0, beta-OH C12:0, C16:0, and C16:1 acids. The antitumor and interferon-inducing activities of OEP remained after the removal of loosely-bound lipids from OEP.     

Abscisic acid from Pinus densiflora pollen

(+)-Abscisic acid was isolated as the methyl ester from Pinus densiflora pollen and identified spectroscopically.     

Novel p-coumaric acid esters from Pinus densiflora pollen

Solvent-extractable lipids in Pinus densiflora pollen were investigated. The cis- and trans-isomers of 1,16-dioxo-, 1-hydroxy-16-oxo- and 1, 16-dihydroxyhexadecan-7-yl p-coumarates were identified.