The introduction of exogenous DNA sequences into cultured cells is a cornerstone in the study of mammalian gene expression. For most cell types, the efficiency of stable gene transfer is usually quite low, which mandates the use of selectable markers to isolate a population of transfected cells with the desired phenotype. In simple gene expression experiments, only one type of selectable marker...

Cassava is an important subsistence crop grown only in the tropics, and represents a major source of calories for many people in developing countries. Improvements in the areas of resistance to insects and viral diseases, enhanced nutritional qualities, reduced cyanogenic content and modified starch characteristics are urgently needed. Traditional breeding is hampered by the nature of the crop,...

When fused to the ligand binding domain (LBD) of steroid hormone nuclear receptors, site-specific recombinases (SSRs) acquire a ligand-dependent activity. Here, we describe the use of SSR-LBD fusion proteins in an inducible expression system, introduced into cells in a single step. A single transgene contains a constitutively active, bi-directional enhancer/promoter, which directs expression, o...

Chlorimuronethyl resistance gene is increasingly used as a selectable marker for transformation, especially fungal transformation. Magnaporthe grisea is an important model organism for investigating fungal pathogenicity, and Agrobacterium tumefaciens-mediated transformation (ATMT) is used for functional mutagenesis of the fungus. However, our results showed that rice blast strains collected fro...

Background: The objective of this study was to develop an efficient selectable marker for transgenic Dunaliella salina. Results: Tests of the sensitivity of D. salina to the antibiotic chloramphenicol and the herbicide Basta® showed that cells (1.0 × 10 cells/ml) treated with 1000 or 1500 μg/ml chloramphenicol died in 8 or 6 days, respectively, whereas D. salina cells (1.0 × 10 cells/ml) treate...

Transformation-associated recombination (TAR) is a cloning technique that allows specific chromosomal regions or genes to be isolated directly from genomic DNA without prior construction of a genomic library. This technique involves homologous recombination during spheroplast transformation between genomic DNA and a TAR vector that has 5' and 3' gene targeting sequences (hooks). Typically, TAR ...

Stable cell transfection is used for the expression of exogenous genes or cDNAs in eukaryotic cells. Selection of these transfectants requires a dominant selectable marker. A variety of such markers has been identified and is currently in use. However, many of these are not suitable for all cell types or require unique conditions. Here we describe a simple and versatile dominant selectable mark...

Secretion of recombinant proteins is a common strategy for heterologous protein expression using the yeast Kluyveromyces lactis. However, a common problem is degradation of a target recombinant protein by secretory pathway aspartyl proteases. In this study, we identified five putative pfam00026 aspartyl proteases encoded by the K. lactis genome. A set of selectable marker-free protease deletion...