The complex hexaploid wheat genome offers many challenges for genomics research. Expressed sequence tags facilitate the analysis of gene-coding regions and provide a rich source of molecular markers for mapping and comparison with model organisms. The objectives of this study were to construct a high-density EST chromosome bin map of wheat homoeologous group 2 chromosomes to determine the distribution of ESTs, construct a consensus map of group 2 ESTs, investigate synteny, examine patterns of duplication, and assess the colinearity with rice (...) of ESTs assigned to the group 2 consensus bin map. A total of 2600 loci generated from 1110 ESTs were mapped to group 2 chromosomes by Southern hybridization onto wheat aneuploid chromosome and deletion stocks. A consensus map was constructed of 552 ESTs mapping to more than one group 2 chromosome. Regions of high gene density in distal bins and low gene density in proximal bins were found. Two interstitial gene-rich islands flanked by relatively gene-poor regions on both the short and long arms and having good synteny with rice were discovered. The map locations of two ESTs indicated the possible presence of a small pericentric inversion on chromosome 2B. Wheat chromosome group 2 was shown to share syntenous blocks with rice chromosomes 4 and 7. (shrink)

The objectives of this study were to develop a high-density chromosome bin map of homoeologous group 7 in hexaploid wheat, to identify gene distribution in these chromosomes, and to perform comparative studies of wheat with rice and barley. We mapped 2148 loci from 919 EST clones onto group 7 chromosomes of wheat. In the majority of cases the numbers of loci were significantly lower in the centromeric regions and tended to increase in the distal regions. The level of duplicated loci (...) in this group was 24% with most of these loci being localized toward the distal regions. One hundred nineteen EST probes that hybridized to three fragments and mapped to the three group 7 chromosomes were designated landmark probes and were used to construct a consensus homoeologous group 7 map. An additional 49 probes that mapped to 7AS, 7DS, and the ancestral translocated segment involving 7BS also were designated landmarks. Landmark probe orders and comparative maps of wheat, rice, and barley were produced on the basis of corresponding rice BAC/PAC and genetic markers that mapped on chromosomes 6 and 8 of rice. Identification of landmark ESTs and development of consensus maps may provide a framework of conserved coding regions predating the evolution of wheat genomes. (shrink)

The concept of human gene therapy came on the heels of fundamental discoveries on the nature and working of the gene. However, realistic prospects to correct the underlying cause of recessive genetic disorders through the transfer of wild‐type alleles of defective genes had to wait for the arrival of recombinant DNA technology. These techniques permitted the isolation and insertion of genes into the first recombinant delivery systems. The realization that viruses are natural gene carriers provided inspiration for gene therapy and, (...) as engineered vectors, viruses became prominent gene delivery vehicles. Nonetheless, when put in the context of human and non‐human primate studies, all vectors fell short of success regardless of their viral or non‐viral origin. Recognition of issues such as inefficient gene transfer and short‐lived or scant expression in the relevant cell type(s) prompted researchers to refine and develop several gene delivery systems, in particular those based on retroviruses, adeno‐associated viruses and adenoviruses. Concomitantly, available technology was deployed to tackle disorders that require few genetically corrected cells to attain therapy. BioEssays 27: 506–517, 2005. © 2005 Wiley periodicals, Inc. (shrink)

Planctomycetes, Verrucomicrobia and Chlamydia are prokaryotic phyla, sometimes grouped together as the PVC superphylum of eubacteria. Some PVC species possess interesting attributes, in particular, internal membranes that superficially resemble eukaryotic endomembranes. Some biologists now claim that PVC bacteria are nucleus‐bearing prokaryotes and are considered evolutionary intermediates in the transition from prokaryote to eukaryote. PVC prokaryotes do not possess a nucleus and are not intermediates in the prokaryote‐to‐eukaryote transition. Here we summarise the evidence that shows why all of the PVC traits (...) that are currently cited as evidence for aspiring eukaryoticity are either analogous (the result of convergent evolution), not homologous, to eukaryotic traits; or else they are the result of horizontal gene transfers. (shrink)

A total of 944 expressed sequence tags generated 2212 EST loci mapped to homoeologous group 1 chromosomes in hexaploid wheat. EST deletion maps and the consensus map of group 1 chromosomes were constructed to show EST distribution. EST loci were unevenly distributed among chromosomes 1A, 1B, and ID with 660, 826, and 726, respectively. The number of EST loci was greater on the long arms than on the short arms for all three chromosomes. The distribution of ESTs along chromosome arms (...) was nonrandom with EST clusters occurring in the distal regions of short arms and middle regions of long arms. Duplications of group 1 ESTs in other homoeologous groups occurred at a rate of 35.5%. Seventy-five percent of wheat chromosome 1 ESTs had significant matches with rice sequences, where large regions of conservation occurred between wheat consensus chromosome 1 and rice chromosome 5 and between the proximal portion of the long arm of wheat consensus chromosome 1 and rice chromosome 10. Only 9.5% of group 1 ESTs showed significant matches to Arabidopsis genome sequences. The results presented are useful for gene mapping and evolutionary and comparative genomics of grasses. (shrink)

The focus of this study was to analyze the content, distribution, and comparative genome relationships of 996 chromosome bin-mapped expressed sequence tags accounting for 2266 restriction fragments on the homoeologous group 3 chromosomes of hexaploid wheat. Of these loci, 634, 884, and 748 were mapped on chromosomes 3A, 3B, and 3D, respectively. The individual chromosome bin maps revealed bins with a high density of mapped ESTs in the distal region and bins of low density in the proximal region of the (...) chromosome arms, with the exception of 3DS and 3DL. These distributions were more localized on the higher-resolution group 3 consensus map with intermediate regions of high-mapped-EST density on both chromosome arms. Gene ontology classification of mapped ESTs was not significantly different for homoeologous group 3 chromosomes compared to the other groups. A combined analysis of the individual bin maps using 537 of the mapped ESTs revealed rearrangements between the group 3 chromosomes. Approximately 232 of the consensus mapped ESTs matched sequences on rice chromosome 1 and revealed large- and small-scale differences in gene order. Of the group 3 mapped EST unigenes ∼21 and 32% matched the Arabidopsis coding regions and proteins, respectively, but no chromosome-level gene order conservation was detected. (shrink)

This report describes the rationale, approaches, organization, and resource development leading to a large-scale deletion bin map of the hexaploid wheat genome. Accompanying reports in this issue detail results from chromosome bin-mapping of expressed sequence tags representing genes onto the seven homoeologous chromosome groups and a global analysis of the entire mapped wheat EST data set. Among the resources developed were the first extensive public wheat EST collection. Described are protocols for sequencing, sequence processing, EST nomenclature, and the assembly of (...) ESTs into contigs. These contigs plus singletons were used for selection of distinct sequence motif unigenes. Selected ESTs were rearrayed, validated by 5′ and 3′ sequencing, and amplified for probing a series of wheat aneuploid and deletion stocks. Images and data for all Southern hybridizations were deposited in databases and were used by the coordinators for each of the seven homoeologous chromosome groups to validate the mapping results. Results from this project have established the foundation for future developments in wheat genomics. (shrink)

The problem of immediate intuitive knowledge occupied Hegel throughout his life. The problem of the relation of immediate to mediate knowledge, of intuition to proof, was one that Hegel solved for himself at the outset of his development as a philosopher. He remained true to this solution in all the years that followed.

1. The characterization of Hegel's teaching as dialectical is usually associated with a critique of the logic that preceded his and that was dominant in his time: that of the Wolffians and, in particular, of Kant and the Kantians. All in all, to characterize Hegel's teaching in this way is entirely in accord with the facts. However, when stated in so general a form, it leaves much unclarified and undoubtedly demands further concreteness. The article we offer here for the reader's (...) consideration is an attempt at a concretization of this order. Central to this matter is the question of formal thinking: did Hegel accept the rights of formal thinking, and, if so, to what degree? (shrink)

Chastʹ I. Ėsteticheskie uchenii︠a︡ filosofov antichnogo mira -- Chastʹ II. Iskusstvo v suzhdenni︠a︡kh pisateleĭ antichnogo mira.

OBJECTIVES: To investigate the need for hospital clinical ethics committees by studying the frequency with which ethical dilemmas arose, the perceived adequacy of the process of their resolution, and the teaching and training of staff in medical ethics. DESIGN: Interviews with individuals and three multidisciplinary teams; questionnaire to randomly selected individuals. SETTING: Two major London children's hospitals. RESULTS: Ethical dilemmas arose frequently but were resolved in a relatively unstructured fashion. Ethical concerns included: the validity of consent for investigations and treatment; (...) lack of children's involvement in consent; initiation of heroic or futile treatments; resource allocation. Staff expressed the need for a forum which would provide consultation on ethical issues, develop guidelines for good ethical practice, undertake teaching and training, and provide ethical reflection outside the acute clinical setting. CONCLUSION: Multidisciplinary, accountable and audited clinical ethics committees with predominantly advisory, practice development and educational roles could provide a valuable contribution to UK clinical practice and perhaps in other countries that have not developed hospital clinical ethics committees. (shrink)