With the binary vectors pBIG and pBIB it is possible to: i) exchange the plant selectable marker/promoter fusion and the reporter gene, ii) use one vector and Agrobacterium strain system, thus reducing variables associated with using different vectors and strains, iii) allow for divergent transcription of the selectable marker gene and of promoter/reporter gene fusions. The two plasmids are der...

Isolation of recombinant viruses after DNA transfection remains the most time-consuming and labor-intensive feature in the production of vaccinia virus (VV) recombinants. This procedure has been aided by the design and incorporation of both positive and negative selectable markers into the insertion vectors. Use of these selectable markers is not always feasible or desirable. In the absence of ...

Several of parameters seeking to increase the infection frequency of normal haemopoietic cells by recombinant retroviruses containing a drug selectable marker and/or a haemopoietic growth factor gene have been compared. By using bone marrow cells pretreated with 5-fluorouracil, cocultivation of cells for at least 4 days with virus producing fibroblasts, and addition of pokeweed mitogen stimulat...

background genetic manipulation of chloroplast in higher plants offers a number of unique prerogatives, including; undesirable of pleiotropic genome and gene silencing effects and also use as an important agronomic trait for producing essential biomaterials and industrial enzymes. in order to manipulate chloroplast genome, specific vectors are required. these vectors can be transformed and expr...

The nitrate reductase gene (niaD) is the most frequently utilized as a selectable marker for homologous integration at the niaD locus of Aspergillus oryzae. In this study we developed a method for curing of the niaD-based plasmid integrated on the A. oryzae genome. Positive selection using a modified chlorate medium containing leucine as a nitrogen source enabled efficient isolation of the stra...

A new expression plasmid containing the fla operon promoter and a staphylococcal chloramphenicol resistance gene, was constructed to help assess the role of fliG in Treponema denticola motility. Deletion of fliG resulted in a nonmotile mutant with a markedly decreased number of flagellar filaments. Wild-type fliG genes from T. denticola and from Treponema pallidum were cloned into this expressi...

Bacillus subtilis has been a model for gram-positive bacteria and it has long been exploited for industrial and biotechnological applications. However, the availability of facile genetic tools for physiological analysis has generally lagged substantially behind traditional genetic models such as Escherichia coli and Saccharomyces cerevisiae. In this work, we have developed an efficient, precise...

Plant genetic engineering has, until now, relied on the incorporation of foreign DNA into plant genomes. Public concern about the extent to which transgenic crops differ from their traditionally bred counterparts has resulted in molecular strategies and gene choices that limit, but not eliminate, the introduction of foreign DNA. Here, we demonstrate that a plant-derived (P-) DNA fragment can be...

A new genetic technique for constructing mutants of Methanosarcina acetivorans C2A by using hpt as a counterselectable marker was developed. Mutants with lesions in the hpt gene, encoding hypoxanthine phosphoribosyltransferase, were shown to be >35-fold more resistant to the toxic base analog 8-aza-2,6-diaminopurine (8ADP) than was the wild type. Reintroduction of the hpt gene into a Delta hpt ...