Resistance Gene Candidate2 (RGC2) genes belong to a large, highly duplicated family of nucleotide binding site-leucine rich repeat (NBS-LRR) encoding disease resistance genes located at a single locus in lettuce (Lactuca sativa). To investigate the genetic events occurring during the evolution of this locus, approximately 1.5- to 2-kb 3' fragments of 126 RGC2 genes from seven genotypes were seq...

Chronic obstructive pulmonary disease, which by this point we define COPD, is understood as a situation of progressive airflow limitation, sometimes reversible, whose pathogenetic mechanisms responsible are to be attributed, on the one hand, to the progressive obstruction of the central and peripheral airways, with structural modification of their histological status and, secondly, to a progres...

Site-specific recombination provides a powerful tool for studying gene function at predetermined chromosomal sites. Here we describe the use of a blasticidin resistance system to select for recombination in mammalian cells using the yeast enzyme FLP. The vector is designed so that site-specific recombination reconstructs the antibiotic resistance marker within the sequences flanked by the FLP t...

The toxic action of environmental chemicals on reproduction and the toxiclike effects of ovarian hormones have been shown by numerous investigators. Some toxic effects of environmental chemicals on reproduction are through their action on hormonal secretion. Such effects on the endocrine system could provide additional approaches to investigations of toxicity of compounds. A better understandin...

Genetic exchange occurs via horizontal gene transfer in bacteria and archea or sexual reproduction in fungal and parasitic eukaryotic microbes. Sexual reproduction is universal, or nearly so, in eukaryotes. Until recently, most eukaryotic microbial pathogens were thought to be clonal and asexual due to the absence of a compatible partner or the lack of morphological or population genetic eviden...