Novel DNA polymorphism in the mouse tumor necrosis factor receptors type 1 and type 2

The introduction of the polymerase chain reaction (PCR) provides an entirely new means of analyzing DNA polymorphism and makes practical the analysis of length variation in simple-sequence tandem repeats of dinucleotides. In the process of cloning and sequencing the mouse genomic DNA for tumor necrosis factor (TNF) receptors type 1 and type 2, we identified two simple dinucleotide repeats within the noncoding regions of TNF receptor type 1 and three such sequences within TNF receptor type 2. PCR analysis of these sequences, using genomic DNA from 21 different inbred and wild mouse strains, as demonstrated by running the amplified products on sequencing gels, showed that the repeats are highly polymorphic. We identified seven alleles of TNF receptor type 2 and five alleles of TNF receptor type 1. Using these polymorphic markers in two sets of recombinant inbred strains of mice, the chromosomal localization of Tnfr-1 was mapped to mouse chromosome 6 and Tnfr-2 was located to the distal portion of mouse chromosome 4.     

Characteristics of the energy-transducing NADH-quinone oxidoreductase ofParacoccus denitrificans as revealed by biochemical,biophysical, and molecular biological approaches

A comparison of the mitochondrial NADH-ubiquinone oxidoreductase and the energy-transducing NADH-quinone oxidoreductase (NDH-1) ofParacoccus denitrificans revealed that both systems have similar electron-transfer and energy-transduction pathways. In addition, both complexes are sensitive to the same inhibitors and contain similar electron carriers, suggesting that theParacoccus NDH-1 may serve as a useful model system for the study of the human enzyme complex. The gene cluster encoding theParacoccus NDH-1 has been cloned and sequenced. It is composed of 18,106 base pairs and contains 14 structural genes and six unidentified reading frames (URFs). The structural genes, URFs, and their polypeptides have been characterized. We also discuss nucleotide sequences which are believed to play a role in the regulation of the NDH-1 gene cluster andParacoccus NDH-1 subunits which may contain the binding sites of substrates and/or electron carriers.     

Determination of non-protein-bound iron in human synovial fluid by high-performance liquid chromatography with electrochemical detection

Non-protein-bound iron in human synovial fluid was determined using high-performance liquid chromatography with electrochemical detection. The procedure was based on the separation of the iron—diethylenetriaminepentaacetic acid (DPTA) complex formed directly on a chromatographic column containing an anion-exchange resin followed by electrochemical detection. The method enabled more than 0.1 μM Fe(III) to be determined with an injection volume of 10 μl. A mixture of synovial fluid, 20 μM DTPA and acetate buffer was incubated in the presence and absence of superoxide (O⁻₂) generated by a xanthine—xanthine oxidase system and was ultrafiltered through a 30 000 molecular mass cut-off filter. No iron was detected in the ultrafiltrate at physiological pH. However, the presence of iron was observed in the ultrafiltrate at low pH, and O⁻₂ and decreased pH, iron may be released into the synovial fluid.     

Biosynthesis of brassinolide from castasterone in cultured cells of Catharanthus roseus

Feeding experiments with tritium- and deuterium-labeled castasterone (CS) were conducted with three cell lines of Catharanthus roseus, including crown gall cells and nontransformed cells. In all three cell lines, the conversion of CS to brassinolide (BL) was observed and unequivocally confirmed by gas chromatography/mass spectrometry (GC/MS). This is the first conclusive evidence that CS is the biosynthetic precursor of BL.Biosynthesis of brassinosteroids in Catharanthus roseus. Part II. Part I of this series: Yokota et al. (1990a).     

The Chromosomal Organization of the Human Endogenous Retrovirus-like Sequence HERV-H: Clustering of the HERV-H Sequences in a 300-kb Region Close to the GRPR Locus on the X Chromosome

Within the haploid genome there are approximately 1,000 copiesof the human endogenous retroviruslike sequence, HERV-H. Althoughthese sequences are scattered throughout the entire genome,in situ hybridization experiments revealed that there are discreteclusters positioned on chromosomes 1p and 7q. In this study,we have located three HERV-H sequences which were unexpectedlyclustered within a 300-kilobase region close to the GRPR locuson the X chromosome. In previous studies, no clusteringof thissequence has been reported at this locus. Our finding demonstratesthat, like other repetitive sequences, clustering of HERV-Hoccurs in the human genome, although these sequences may notalways be detected by in situ hybridization methods.     

Application of leaf extract causes repetitive action potentials inBiophytum sensitivum

A wound stimulus evoked a number of repetivite action potentials in the leaf ofBiophytum sensitivum. When the cut end of a leaf was immersed in a leaf extract, the resulting repetitive action potentials continue for a long time. These repetitive action potentials disappeared immediately when the leaf extract, which contains a proposed stimulant, was removed and the cut end was washed with water.     

Influence of Axis Removal on Amino-, Carboxy- and Endopeptidase Activities in Cotyledons of Germinating Vigna mungo Seeds

Endopeptidase (azocaseolytic enzyme) and carboxypeptidase activitiesin cotyledons of germinating Vigna mungo seeds increased until3 days after the onset of imbibition and decreased thereafter.In detached and incubated cotyledons, the endopeptidase activityincreased only a little while the carboxypeptidase activitycontinued increasing even after 3 days of incubation. The activitiesof leucine-aminopeptidase and alanine-aminopeptidase, exceptfor that of one leucine-aminopeptidase isoenzyme relativelyabundantly present in unimbibed dry cotyledons, increased slightlyon the first day and declined during germination. In detachedcotyledons, the activities maintained their initial levels throughoutthe incubation period. When cotyledons were detached from germinatingseedlings on days 2 and 4 then incubated, the endopeptidaseactivity started to decrease just after removal of the axisbut the carboxypeptidase activity increased more markedly thanwhen the axis remained attached. Exogenously supplied GA₃, kinetin,IAA, or their combinations, showed no significant effect onthe developmental patterns of the endopeptidase and carboxypeptidaseactivities in cotyledons. These results are discussed in relationto the role of the axis in controlling peptidase formation incotyledons of germinating V. mungo seeds. (Received November 18, 1983; Accepted February 28, 1984)