Production of Hydroxyl Radicals and α-dicarbonyl Compounds Associated with Amadori Compound-Cu 2+ Complex Degradation

The chemical properties of Amadori compounds in the presence of transition metal ions were studied, using the analogs 1-deoxy-1- n -butylamino- d -fructose (DBF) and N &#102 -formyl-fructoselysine (fFL). The following characteristics were revealed: (a) DBF combined easily with Cu 2+ (but no other transition metal ions) to form a DBF-Cu 2+ complex in phosphate buffer, pH 7.4; (b) the complex was unstable, and degraded with the release of Cu + during incubation at 37°C; (c) degradation of the complex was associated with the production of hydroxyl radicals by the Fenton reaction and &#102 -dicarbonyl compounds by non-autoxidative degradation; and (d) properties of DBF were similar to those of fFL. The above properties were additionally observed in glycated poly-Lys (GPL). Our findings indicate a novel mechanism for the generation of hydroxyl radicals and &#102 -dicarbonyl compounds from Amadori adducts in the presence of Cu 2+ .     

Plasmid-borne mercury resistance in aquatic bacteria

Abstract Bacteria isolated from the River Mersey were analysed for their tolerance to mercury (HgCl₂). About 40% of the population was tolerant to mercury and in 13 of 52 mercury-tolerant isolates tested the mercury resistance (Hg^®) was transferred to Escherichia coli in conjugal matings. These 13 isolates represented a range of gram-negative genera and in each case mercury resistance was coded by a conjugative plasmid. These plasmids (75 kb to > 250 kb in size) all expressed mercury resistance of the narrow spectrum variety, volatilised HgCl₂ to elemental Hg° vapour and showed some degree of temperature sensitivity of transfer. None expressed resistance to nine different antibiotics. These 13 Hg^R plasmids were classified by restriction mapping into three distinct groups typified by pMER11, pMER327 and pMER610. The eight pMER610 group plasmids are identical and belong to the IncHI-2 group. Two of the four pMER327 group plasmids are closely related while the other two contain some common restriction fragments. pMER11 is quite distinct from the other groups. These results imply that within this aquatic environment plasmids play an important role in the response of bacteria to contaminating mercury and that there is widespread plasmid transfer and considerable genetic rearrangement.     

Simple sequence repeat genetic linkage maps of A-genome diploid cotton (Gossypium arboreum)

This study introduces the construction of the first intraspacific genetic linkage map of the A-genome diploid cotton with newly developed simple sequence repeat (SSR) markers using 189 F2 plants derived from the cross of two Asiatic parents were detected using 6 092 pairs of SSR primers. Two-hundred and sixty-eight pairs of SSR pdmers with better polymorphisms were picked out to analyze the F2 population. In total, 320 polymorphic bands were generated and used to construct a linkage map with JoinMap3.0. Two-hundred and sixty-seven loci, Including three phenotypic traits were mapped at a logarithms of odds ratio (LOD) ≥ 3.0 on 13 linkage groups. The total length of the map was 2 508.71 cM, and the average distance between adjacent markers was 9.40 cM. Chromosome assignments were according to the association of linkages with our backbone tetraploid specific map using the 89 similar SSR loci. Comparisons among the 13 suites of orthologous linkage groups revealed that the A-genome chromosomes are largely collinear with the At and Dt sub-genome chromosomes. Chromosomes associated with inversions suggested that allopolyploidization was accompanied by homologous chromosomal rearrangement. The inter-chromosomal duplicated loci supply molecular evidence that the A-genome diploid Asiatic cotton is paleopolyploid.     

Post-translational non-enzymatic modification of proteins I. Chromatography of marker adducts with special emphasis to glycation reactions

Analytical methods for marker compounds formed during post-translational modifications of proteins are reviewed. Only adducts arising either in vivo or under in vitro conditions simulating the in vivo situations are discussed. All of these compounds stem from either the reaction of free amino groups (i.e., lysine, arginine or N-terminal amino acid). In most cases the reactive counterpart is an aldehydic moiety containing endogenous compound; however, other functional groups containing metabolites are considered as well. The main demand put upon such marker compounds is that they are stable in acid or enzymatic hydrolysis or, alternatively, can be stabilized by simple sample pretreatment (e.g., by reduction). Practically all categories of separation procedures can be applied provided that the chemical characteristics of a particular marker are adequately respected; frequently combination of two different separation procedures based on different principles must be used. Because of the low level of such marker compounds under in vivo conditions, an appropriate sample enrichment step must be involved. Emphasis is put upon the analysis of Amadori products, pentosidine (and pentosidine related compounds), pyrraline, furosine, N-carboxymethylamino acids, amino acid hydantoins and stabilized dicarbonyl intermediates     

An efficient Oligo-FISH painting system for revealing chromosome rearrangements and polyploidization in Triticeae

A chromosome-specific painting technique has been developed which combines the most recent approaches of the companion disciplines of molecular cytogenetics and genome research. We developed seven oligonucleotide (oligo) pools derivd from single-copy sequences on chromosomes 1 to 7 of barley (Hordeum vulgare L.) and corresponding collinear regions of wheat (Triticum aestivum L.). The seven groups of pooled oligos comprised between 10 986 and 12 496 45-bp monomers, and these then produced stable fluorescence in situ hybridization (FISH) signals on chromosomes of each linkage group of wheat and barley. The pooled oligo probes were applied to high-throughput karyotyping of the chromosomes of other Triticeae species in the genera Secale, Aegilops, Thinopyrum, and Dasypyrum, and the study also extended to some wheat-alien amphiploids and derived lines. We demonstrated that a complete set of whole-chromosome oligo painting probes facilitated the study of inter-species chromosome homologous relationships and visualized non-homologous chromosomal rearrangements in Triticeae species and some wheat-alien species derivatives. When combined with other non-denaturing FISH procedures using tandem-repeat oligos, the newly developed oligo painting techniques provide an efficient tool for the study of chromosome structure, organization, and evolution among any wild Triticeae species with non-sequenced genomes.     

Kinase gene fusions in defined subsets of melanoma

Genomic rearrangements resulting in activating kinase fusions have been increasingly described in a number of cancers including malignant melanoma, but their frequency in specific melanoma subtypes has not been reported. We used break‐apart fluorescence in situ hybridization (FISH) to identify genomic rearrangements in tissues from 59 patients with various types of malignant melanoma including acral lentiginous, mucosal, superficial spreading, and nodular. We identified four genomic rearrangements involving the genes BRAF, RET, and ROS1. Of these, three were confirmed by Immunohistochemistry (IHC) or sequencing and one was found to be an ARMC10‐BRAF fusion that has not been previously reported in melanoma. These fusions occurred in different subtypes of melanoma but all in tumors lacking known driver mutations. Our data suggest gene fusions are more common than previously thought and should be further explored particularly in melanomas lacking known driver mutations.     

Genetic diversity among perennial wild rice Oryza rufipogon Griff., in the Mekong Delta

Oryza rufipogon Griff. is a perennial species of wild rice widely distributed along the channels and rivers of the Mekong Delta, Vietnam. This study attempted to find centers of diversity among wild rice populations in this area and their inter‐relationships. The highest genetic diversity was found in the Dong Thap population and the lowest in the Can Tho population. Maternal diversity evaluated using chloroplast INDELs detected ten plastid types, five of which were novel relative to other Asian countries. The mitochondrial genome suggested two unique deletions. One 699‐bp deletion via short tandem repeats was accompanied by another deletion including orf153. All accessions carrying the mitochondrial type were found in a particular plastid type. This unique maternal lineage was confined to specific channels where it showed vigorous vegetative growth in comparison to upstream areas where various maternal lineages and maximum genetic diversity occurred. This area along the Mekong Delta is a center of not only nuclear but also maternal diversity.