Intragenic vectors for gene transfer without foreign DNA

The intragenic vector system involves identifying functional equivalents of vector components from the genome of a specific crop species (or related species to which it can be hybridised) and using these DNA sequences to assemble vectors for transformation of that plant species. This system offers an attractive alternative to current genetic engineering strategies where vectors are based on DNA sequences that usually originate from bacteria. The construction of intragenic vectors enables the well-defined genetic improvement of plants with all transferred DNA originating from within the gene pool already available to plant breeders. In this manner genes can be introgressed into elite cultivars in a single step without linkage drag and without the incorporation of foreign DNA. The resulting plants are non-transgenic, although they are derived using the tools of molecular biology and plant transformation. The use of intragenic vectors for the transfer of genes from within the gene pools of crops may help to alleviate some of the major public concerns over the deployment of GM crops in agriculture, notably the ethical issue associated with the transfer of DNA across wide taxonomic boundaries. This paper reviews the progress toward the development and use of intragenic vectors and the implications of their use for the genetic improvement of crops

The location behavior of the multinational enterprise: some analytical issues

In the international business literature location behavior has traditionally been analyzed using Dunning's (1977) OLI framework, which focuses on the nature, role, and behavior of multinational enterprise (MNE). In this paper it is argued that this approach is now no longer appropriate for discussing the spatial behavior of MNEs, because of the fundamental changes which have taken place either in MNE organization or in the global and institutional environment for foreign direct investment (FDI). At the same time, the paper argues that current location theory from regional economics and economic geography is also largely unsuitable for discussing these issues, such that the spatial behavior of the MNE provides a set of difficult challenges to location analysts. There appears to have been some response to these issues from the international business and management literature, most notably the Porter literature on clusters. However, it is also argued here that this literature provides few, if any, real answers to the problems set by the geographical behavior of the MNE. It is concluded that a fusion of traditional economic geography approaches with a focus on the information and organizational aspects of the firm and the region under consideration may be a way forward for both theory and empirical analysis. Copyright 2004 Gatton College of Business and Economics, University of Kentucky..

An integrated encyclopedia of DNA elements in the human genome.

The human genome encodes the blueprint of life, but the function of the vast majority of its nearly three billion bases is unknown. The Encyclopedia of DNA Elements (ENCODE) project has systematically mapped regions of transcription, transcription factor association, chromatin structure and histone modification. These data enabled us to assign biochemical functions for 80% of the genome, in particular outside of the well-studied protein-coding regions. Many discovered candidate regulatory elements are physically associated with one another and with expressed genes, providing new insights into the mechanisms of gene regulation. The newly identified elements also show a statistical correspondence to sequence variants linked to human disease, and can thereby guide interpretation of this variation. Overall, the project provides new insights into the organization and regulation of our genes and genome, and is an expansive resource of functional annotations for biomedical research

The Female Gametophyte

The angiosperm female gametophyte is critical for plant reproduction. It contains the egg cell and central cell that become fertilized and give rise to the embryo and endosperm of the seed, respectively. Female gametophyte development begins early in ovule development with the formation of a diploid megaspore mother cell that undergoes meiosis. One resulting haploid megaspore then develops into the female gametophyte. Genetic and epigenetic processes mediate specification of megaspore mother cell identity and limit megaspore mother cell formation to a single cell per ovule. Auxin gradients influence female gametophyte polarity and a battery of transcription factors mediate female gametophyte cell specification and differentiation. The mature female gametophyte secretes peptides that guide the pollen tube to the embryo sac and contains protein complexes that prevent seed development before fertilization. Post-fertilization, the female gametophyte influences seed development through maternal-effect genes and by regulating parental contributions. Female gametophytes can form by an asexual process called gametophytic apomixis, which involves formation of a diploid female gametophyte and fertilization-independent development of the egg into the embryo. These functions collectively underscore the important role of the female gametophyte in seed and food production