The accumulation of nitrate in freshwater and coastal marine ecosystems is one of the consequences of the worldwide production of artificial fertilizers. Here it is shown that nitrate accumulation in ecosystems shows consistent and negative nonlinear correlations with organic carbon availability, along a continuum from soils, through freshwater systems and coastal margins, to the open ocean. This pattern can be explained by carbon:nitrate ratios, which influence nitrate accumulation by regulating microbial processes

Variation in the regulation of gene transcription between individuals is thought to be a major cause of phenotypic diversity. Here, individual differences in the binding of transcription-factor proteins are studied. A well-known transcription factor in the yeast pheromone pathway is used as an example, and the underlying genetic loci responsible for variation in its binding are mapped. The study reveals new insights into the mechanisms of gene regulation, and new regulators of the yeast pheromone pathway

During embryonic development, blood vessels remodel in response to blood flow. Here, a genetic pathway is described through which this mechanosensory stimulus is integrated with early developmental signals to remodel vessels of the aortic arch in zebrafish. It is found that the flow-induced transcription factor klf2a is required to induce the expression of an endothelial-specific microRNA, activating signalling through the growth factor Vegf