In a recent publication, d'Alençon et al.(1) presented evidence that a form of non‐homologous DNA recombination involving direct repeats is dependent upon the replication of the DNA. In addition, density‐labeling experiments showed that after recombination was stimulated, progenies were present only in molecules that had undergone complete replication. These observations are consistent with a replicative and not a breakage‐and‐rejoining model for the DNA recombination events. These two models had of course been contrasted many years ago in mechanistic (...) studies of homologous DNA recombination. It is therefore interesting to place the latest findings of d'Alençon et al. in this historical context. (shrink)

Science; Ethics; Politics; Beyond recombinant dna.

The nuclear pore complex (NPC) is emerging as a center for recruitment of a class of “difficult to repair” lesions such as double‐strand breaks without a repair template and eroded telomeres in telomerase‐deficient cells. In addition to such pathological situations, a recent study by Su and colleagues shows that also physiological threats to genome integrity such as DNA secondary structure‐forming triplet repeat sequences relocalize to the NPC during DNA replication. Mutants that fail to reposition the triplet repeat locus to the (...) NPC cause repeat instability. Here, we review the types of DNA lesions that relocalize to the NPC, the putative mechanisms of relocalization, and the types of recombinational repair that are stimulated by the NPC, and present a model for NPC‐facilitated repair. (shrink)

The debate over recombinant DNA research is a unique event, perhaps a turning point, in the history of science. For the first time in modern history there has been widespread public discussion about whether and how a promising though potentially dangerous line of research shall be pursued. At root the debate is a moral debate and, like most such debates, requires proper assessment of the facts at crucial stages in the argument. A good deal of the controversy over recombinant DNA (...) research arises because some of the facts simply are not yet known. There are many empirical questions we would like to have answered before coming to a decision-questions about the reliability of proposed containment facilities, about the viability of enfeebled strains of E. coli, about the ways in which pathogenic organisms do their unwelcome work, and much more. But all decisions cannot wait until the facts are available; some must be made now. It is to be expected that people with different hunches about what the facts will turn out to be will urge different decisions on how recombinant DNA research should be regulated. However, differing expectations about the facts have not been the only fuel for controversy. A significant part of the current debate can be traced to differences over moral principles. Also, unfortunately, there has been much unnecessary debate generated by careless moral reasoning and a failure to attend to the logical structure of some of the moral arguments that have been advanced. (shrink)

Recombinant DNA technology is an essential area of life engineering. The main aim of research in this field is to experimentally explore the possibilities of repairing damaged human DNA, healing or enhancing future human bodies. Based on ethnographic research in a Czech biochemical laboratory, the article explores biotechnological corporealities and their specific ontology through dealings with bio-objects, the bodywork of scientists. Using the complementary concepts of utopia and heterotopia, the text addresses the situation of bodies and bio-objects in a laboratory. (...) Embodied utopias are analyzed as material semiotic phenomena that are embodied by scientists in their visions and emotions and that are related to potential bodies and to future, not-yet-actualized embodiments. As a counterpart to this, the text explores embodied heterotopias, which are always the other spaces, like biotechnological bio-objects that are simulated in computers or stored in special solutions. (shrink)

The introduction of recombinant DNA technology into the field of genetics has led to a rapid advancement of our knowledge of genes and genome structure. Such technology, applied to the human genome, has provided valuable information concerning the nature and possible treatment of inherited disorders. The possibility that this knowledge will pave the way for the correction of at least some of these disorders has captured the imagination of the informed public. In this review we look at the accomplishments of (...) molecular pathologists to date and how new techniques are being applied to the study of inherited disease. (shrink)

The recent finding of a role for the recA gene in DNA replication restart does not negate previous data showing the existence of recA‐dependent recombinational DNA repair, which occurs when there are two DNA duplexes present, as in the case for recA‐dependent excision repair, for postreplication repair (i.e., the repair of DNA daughter‐strand gaps), and for the repair of DNA double‐strand breaks. Recombinational DNA repair is critical for the survival of damaged cells. BioEssays 26:1322–1326, 2004. © 2004 Wiley Periodicals, Inc.

Graphical AbstractThe finding that viruses with RNA and DNA genomes can recombine to produce chimeric entities provides valuable insights into the origin and evolution of viruses. It also substantiates the hypothesis that certain groups of DNA viruses could have emerged from plasmids via acquisition of capsid protein-coding genes from RNA viruses.

The existing literature on the development of recombinant DNA technology and genetic engineering tends to focus on Stanley Cohen and Herbert Boyer's recombinant DNA cloning technology and its commercialization starting in the mid-1970s. Historians of science, however, have pointedly noted that experimental procedures for making recombinant DNA molecules were initially developed by Stanford biochemist Paul Berg and his colleagues, Peter Lobban and A. Dale Kaiser in the early 1970s. This paper, recognizing the uneasy disjuncture between scientific authorship and legal invention (...) in the history of recombinant DNA technology, investigates the development of recombinant DNA technology in its full scientific context. I do so by focusing on Stanford biochemist Berg's research on the genetic regulation of higher organisms. As I hope to demonstrate, Berg's new venture reflected a mass migration of biomedical researchers as they shifted from studying prokaryotic organisms like bacteria to studying eukaryotic organisms like mammalian and human cells. It was out of this boundary crossing from prokaryotic to eukaryotic systems through virus model systems that recombinant DNA technology and other significant new research techniques and agendas emerged. Indeed, in their attempt to reconstitute 'life' as a research technology, Stanford biochemists' recombinant DNA research recast genes as a sequence that could be rewritten thorough biochemical operations. The last part of this paper shifts focus from recombinant DNA technology's academic origins to its transformation into a genetic engineering technology by examining the wide range of experimental hybridizations which occurred as techniques and knowledge circulated between Stanford biochemists and the Bay Area's experimentalists. Situating their interchange in a dense research network based at Stanford's biochemistry department, this paper helps to revise the canonized history of genetic engineering's origins that emerged during the patenting of Cohen-Boyer's recombinant DNA cloning procedures. (shrink)

The existing literature on the development of recombinant DNA technology and genetic engineering tends to focus on Stanley Cohen and Herbert Boyer's recombinant DNA cloning technology and its commercialization starting in the mid-1970s. Historians of science, however, have pointedly noted that experimental procedures for making recombinant DNA molecules were initially developed by Stanford biochemist Paul Berg and his colleagues, Peter Lobban and A. Dale Kaiser in the early 1970s. This paper, recognizing the uneasy disjuncture between scientific authorship and legal invention (...) in the history of recombinant DNA technology, investigates the development of recombinant DNA technology in its full scientific context. I do so by focusing on Stanford biochemist Berg's research on the genetic regulation of higher organisms. As I hope to demonstrate, Berg's new venture reflected a mass migration of biomedical researchers as they shifted from studying prokaryotic organisms like bacteria to studying eukaryotic organisms like mammalian and human cells. It was out of this boundary crossing from prokaryotic to eukaryotic systems through virus model systems that recombinant DNA technology and other significant new research techniques and agendas emerged. Indeed, in their attempt to reconstitute 'life' as a research technology, Stanford biochemists' recombinant DNA research recast genes as a sequence that could be rewritten thorough biochemical operations. The last part of this paper shifts focus from recombinant DNA technology's academic origins to its transformation into a genetic engineering technology by examining the wide range of experimental hybridizations which occurred as techniques and knowledge circulated between Stanford biochemists and the Bay Area's experimentalists. Situating their interchange in a dense research network based at Stanford's biochemistry department, this paper helps to revise the canonized history of genetic engineering's origins that emerged during the patenting of Cohen-Boyer's recombinant DNA cloning procedures. (shrink)

This paper examines the use of language and metaphor in the reception of recombinant DNA in the USA between 1973 and 1988. The Archives of Stanford University are used to show how changing images of production were conveyed, and how academic–industrial policies were shaped, in a rapidly advancing field of biotechnology.

This survey of 430 recombinant DNA scientists currently engaged in research assesses the impact of public attention, political advocacy, and litigation on their work. The findings show that most researchers feel they have benefited from public attention to the field, but 34% feel they have been negatively affected. Sixty-one percent agree that as a result of litigation by activists, greater social responsibility on the part of scientists working in the field is required. Considerable concern is expressed regarding public ignorance, uninformed (...) controversy, and the future impact of activist-inspired litigation, especially on the possible loss of the U.S. competitive edge. Recommendations are made for a public education campaign focused on priority-target audiences. (shrink)

Unlike the most well‐characterized prokaryotic polymerase, E. Coli DNA pol I, none of the eukaryotic polymerases have their own 5′ to 3′ exonuclease domain for nick translation and Okazaki fragment processing. In eukaryotes, FEN‐1 is an endo‐and exonuclease that carries out this function independently of the polymerase molecules. Only seven nucleases have been cloned from multicellular eukaryotic cells. Among these, FEN‐1 is intriguing because it has complex structural preferences; specifically, it cleaves at branched DNA structures. The cloning of FEN‐1 permitted (...) establishment of the first eukaryotic nuclease family, predicting that S. cerevisiae RAD2 (S. pombe Rad13) and its mammalian homolog, XPG, would have similar structural specficity. The FEN‐1 nuclease family includes several similar enzymes encoded by bacteriophages. The crystal structures of two enzymes in the FEN‐1 nuclease family have been solved and they provide a structural basis for the interesting steric requirements of FEN‐1 substrates. Because of their unique structural specificities, FEN‐1 and its family members have important roles in DNA replication, repair and, potentially, recombination. Recently, FEN‐1 was found to specifically associate with PCNA, explaining some aspects of FEN‐1 function during DNA replication and potentially in DNA repair. (shrink)

DNA junctions are by‐products of recombinational repair, during which a damaged DNA sequence, assisted by RecA filament, invades an intact homologous DNA to form a joint molecule. The junctions are three‐strand or four‐strand depending on how many single DNA strands participate in joint molecules. In E. coli, at least two independent pathways to remove the junctions are proposed to operate. One is via RuvAB‐promoted migration of four‐strand junctions with their subsequent resolution by RuvC. In vivo, RuvAB and RuvC enzymes might (...) work in a single complex, a resolvasome, to clean DNA from used RecA filaments and to resolve four‐strand junctions. An alternative pathway for junction removal could be via RecG‐promoted branch migration of three‐strand junctions, provided that an as yet uncharacterized endonuclease activity incises one of the strands in the joint molecules. (shrink)