Temperature gradient DNA-probe column chromatography: as tools for detection and purification of particular DNAs and RNAs

We have developed the temperature-gradient DNA-probe column chromatography as the new method for detecting and purifying particular DNAs or RNAs accurately. The method has high discrimination resolution, and can detect a single-base change in sample base sequences. The method also has high performances in purification of particular DNAs or RNAs, which has been demonstrated by purification of bovine mitochondria serine t-RNA. None of other method can succeed in complete purification of this t-RNA molecule. The present method can be applied not only to molecular biology as basic tools for purifying and picking-up particular sequences but also to the medical field as diagnostic tools.     

A new hereditary single band variant of the Gc system

Summary A new single band variant (Gc Ar) or the Gc subtypes not identical with the known Gc variants has been detected in the plasma of a healthy blood donor by isoelectric focusing. Using this technique the variant is represented by a single band which has a similar isoelectric point to the Gc 1C2 anodal band. It is well known that the single band Gc phenotypes remain unaltered after neuraminidase treatment. Nevertheless, the new single band variant (Gc Ar) is altered after neuraminidase treatment as is Gc 2A3. After neuraminidase treatment, the Gc Ar band is affected and moved to the nearby position of the Gc 2 band. Investigation of the proband's family shows that the variant occurs combined with the common alleles Gc 1F, Gc 1S and that it has an autosomal dominant inheritance.     

Two types of linkage between codon usage and gene-expression levels

The relation between codon usage and gene-expression levels is an intensively investigated and discussed topic in the field of molecular evolution. We statistically analyzed 25 Escherichia coli gene sequences by a new classification of synonymous codons and found that (i) there are two distinct types of linkage between codon usage and gene-expression levels in E. coli, and (ii) one of the two kinds of codon preferences (the codon preference concerned with interaction of GC/AT choice at three codon positions) is observed significantly in weakly expressed genes.     

Isolation and characterization of new cross-linking amino acid "allodesmosine" from hydrolysate of elastin

A new pentafunctional cross-linking amino acid, termed allodesmosine, was isolated from bovine ligamentum nuchae elastin. This compound was a very hygroscopic, white amorphous solid with a faint yellow tinge, soluble in aqueous solvents but not dry methanol; it was characterized by UV, FAB mass and NMR spectroscopy. The compound was shown by UV and 1H-NMR to have a pyridinium ring structure similar to desmosine. Mass spectral analysis indicated a parent compound with a mass of 655. We postulated that it arose by condensation of a reduced aldol condensation product of allysine, allysine and lysine.     

Ancient DNA from pollen: a genetic record of population history in Scots pine

Assessments of plant population dynamics in space and time have depended on dated records of fossil pollen synthesized on a subcontinental scale. Genetic analyses of extant populations have revealed spatial relationships that are indicative of past spatial dynamics, but lack an explicit timescale. Synthesis of these data requires genetic analyses from abundant dated fossil material, and this has hitherto been lacking. Fossil pollen is the most abundant material with which to fill this data gap. Here we report genetic analyses of fossil pollen retrieved from Holtjärnen postglacial lake sediment in Sweden and show that plastid DNA is recoverable from Scots Pine and Norway spruce pollen grains that are 100 and 10 000 years old. By sequencing clones from two short plastid PCR products and by using multiple controls we show that the ancient sequences were endogenous to the fossil grains. Comparison of ancient sequences and those obtained from an extant population of Scots pine establishes the first genetic link between extant and fossil samples in this species, providing genetic continuity through time. The finding of one common haplotype present in modern, 100-year old and 10 000-year old samples suggests that it may have persisted near Holtjärnen throughout the postglacial period. This retrieval of ancient DNA from pollen has major implications for plant palaeoecology in conifer species by allowing direct estimates of population dynamics in space and time.     

Structure of beta-glucan oligomer from laminarin and its effect on human monocytes to inhibit the proliferation of U937 cells

We analyzed the human monocyte-stimulating ability of laminarin from Eisenia bicyclis, lichenan from Cetraria islandica, and their oligomers depolymerized with endo-1,3-beta-glucanase from Arthrobacter sp. The respective beta-glucan oligomers with different degrees of polymerization (DP) were fractionated from hydrolytic products of laminarin and lichenan using gel-filtration chromatography. The monocyte-conditioned medium pre-cultured in the presence of a fraction of beta-glucan oligomer (DP>/=8) from laminarin exhibited inhibitory activity against the proliferation of human myeloid leukemia U937 cells, while those pre-cultured with other beta-glucan oligomers and the original laminarin and lichenan showed little or no activity. NMR analysis indicated that the beta-glucan oligomer (DP>/=8) has an average DP value of 13, and its ratio of beta-1,3- to beta-1,6-linkages in glucopyranose units was estimated to be 1.3:1. These results indicate that the beta-1,3-glucan oligomer with a higher content of beta-1,6-linkage stimulates monocytes to inhibit the proliferation of U937 cells.     

Isolation and characterization of microsatellite loci in a polyploid alpine herb,Callianthemum miyabeanum (Ranunculaceae)

• Premise of the study: Nuclear microsatellite primers were developed to analyze the clonal diversity and population genetic structure of the endemic polyploid herb Callianthemum miyabeanum. • Methods and Results: Using a protocol for constructing microsatellite-enriched libraries, 15 primer sets were developed for use in C. miyabeanum. The number of alleles found ranged from five to 22. The estimated range of expected heterozygosities was 0.574 to 0.907, and the Shannon–Weiner diversity index ranged from 1.061 to 2.733. Cross-amplification of all loci was also successful in the closely related endemic species C. kirigishiense and C. hondoense. • Conclusions: The development of these microsatellite loci will facilitate a deeper understanding of the genetic diversity, mode of reproduction, and population structure of not only C. miyabeanum, but also the other Callianthemum species endemic to Japan.     

Soy protein suppresses gene expression of acetyl-coA carboxylase alpha from promoter PI in rat liver

Dietary soy protein isolate (SPI) reduces hepatic lipogenesis by suppressing gene expression of lipogenic enzymes, including acetyl-CoA carboxylase (ACC). In order to elucidate the mechanism of this regulation, the effect of dietary SPI on promoter (PI and PII) specific gene expression of ACC alpha was investigated. Rats were fed experimental diets containing SPI or casein as a nitrogen source. SPI feeding decreased the hepatic contents of total ACC mRNA as well as triglyceride (TG) content, but dietary SPI affected the amount of sterol-regulatory element binding protein (SREBP)-1 mRNA and protein very little. The amount of ACC mRNA transcribed from PII promoter containing SRE was not significantly affected by dietary protein, while a significant decrease in PI-generated ACC mRNA content was observed in rats fed the SPI diet. These data suggest that SPI feeding decreased the hepatic contents of ACC alpha mRNA mainly by regulating PI promoter via a nuclear factor(s) other than SREBP-1.