David Romero

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Symbiotic bacteria known as rhizobia interact with the roots of legumes and induce the formation of nitrogen-fixing nodules. In rhizobia, essential genes for symbiosis are compartmentalized either in symbiotic plasmids or in chromosomal symbiotic islands. To understand the structure and evolution of the symbiotic genome compartments (SGCs), it is necessary(More)
Gene conversion is defined as the non-reciprocal transfer of information between homologous sequences. Despite methodological problems to establish non-reciprocity, gene conversion has been demonstrated in a wide variety of bacteria. Besides examples of high-frequency reversion of mutations in repeated genes, gene conversion in bacterial genomes has been(More)
(R)-3-[1-(2,6-Dichloro-3-fluoro-phenyl)-ethoxy]-5-(1-piperidin-4-yl-1H-pyrazol-4-yl)-pyridin-2-ylamine (PF02341066) was identified as an orally available, ATP-competitive small molecule inhibitor of cMet receptor tyrosine kinase. The objectives of the present studies were to characterize 1) the pharmacokinetic-pharmacodynamic relationship of the plasma(More)
Replicon architecture in bacteria is commonly comprised of one indispensable chromosome and several dispensable plasmids. This view has been enriched by the discovery of additional chromosomes, identified mainly by localization of rRNA and/or tRNA genes, and also by experimental demonstration of their requirement for cell growth. The genome of Rhizobium(More)
Bean-nodulating Rhizobium etli originated in Mesoamerica, while soybean-nodulating Sinorhizobium fredii evolved in East Asia. S. fredii strains, such as GR64, have been isolated from bean nodules in Spain, suggesting the occurrence of conjugative transfer events between introduced and native strains. In R. etli CFN42, transfer of the symbiotic plasmid(More)
Virtual Breeding Environments (VBEs) are long-term strategic alliances of organisations aimed at offering the conditions to support the rapid and fluid configuration of Virtual Organisations (VOs). VBE reference models play a guiding role to conceptualise a set of business processes to enhance the responsiveness and flexibility of networks to react to a(More)
Alchichica is a saline crater-lake located in Mexico. Tufa grows on its periphery and a wind-driven Nodularia cf. spumigena bloom occurs annually. Fixation rates were assayed by the acetylene reduction method. Here, we describe the patterns of nitrogen fixation on two tufa forms before, during and after the bloom, as well as those from the planktonic(More)
This work centres on the genomic comparisons of two closely-related nitrogen-fixing symbiotic bacteria, Rhizobium leguminosarum biovar viciae 3841 and Rhizobium etli CFN42. These strains maintain a stable genomic core that is also common to other rhizobia species plus a very variable and significant accessory component. The chromosomes are highly syntenic,(More)
Plasmid p42a from Rhizobium etli CFN42 is self-transmissible and indispensable for conjugative transfer of the symbiotic plasmid (pSym). Most pSym transconjugants also inherit p42a. pSym transconjugants that lack p42a always contain recombinant pSyms, which we designated RpSyms*. RpSyms* do not contain some pSym segments and instead have p42a sequences,(More)