Meeting Abstract
Lakes across the Canadian Precambrian Shield and northern Europe are experiencing declines in ambient phosphorus (P) and calcium (Ca) at unprecedented rates. While these declines may create or exacerbate nutrient-stress in aquatic food webs, our ability to detect and quantify nutrient-stress of these two elements on zooplankton remains limited. Here, we use next generation RNA sequencing technology and differential gene expression analysis to examine the molecular phenotypes produced by single and combined limitation of these two key dietary nutrients in the freshwater zooplankter, Daphnia pulex. Our results reveal an intermediate phenotype in Ca- and P-stressed animals, which provides evidence that D. pulex experiences nutritional co-limitation by both nutrients. We used transcriptome data to identify the most highly up- and down-regulated metabolic pathways, which are presumably involved in mitigating the physiological effects of poor P- and Ca-nutrition. These data provide us with the necessary groundwork to begin unravelling complex multi-nutrient interactions in nature and allow us to start making predictions about the effects of multiple declining nutrients on populations and communities. We believe that nutrigenomics has the potential to address many of the inherent complexities in studying nutritional interactions. Further work is needed however to lay the genomic groundwork necessary to carry out this type of analysis on non-model organisms (i.e. genome sequenced and annotated, gene ontogeny predictions, etc).
