Posted by Jim:
Our long-time collaborators Puni Jeysasingh, Bob Sterner, and Larry Weider have published a nifty paper showing how the genotype for Pgi (a gene controlling phosphoglucose isomerase, an enzyme involved in energy processing) is closely linked to an animal’s sensitivity to poor stoichiometric food quality (high C:P in algae). Pgi homozygotes outcompete pgi heterozygotes because they are energetically INEFFICIENT, which is an advantage when food has high C:P ratio (C in excess). The discovery is quite remarkable, as Pgi has long been used as some kind of “neutral” marker for identifying different populations of Daphnia. So, it’s quite a coincidence that Pgi seems to be closely involved in how Daphnia copes with poor food quality.
Members of the Elser group should read this paper immediately.