Rats selectively bred for high intrinsic aerobic endurance capacity are lean, whereas their low-endurance counterparts are overweight and prone to metabolic syndrome and cardiovascular disease. We hypothesized that the lean phenotype is characterized by high endurance and high activity levels. Thus, we focused on these two traits when searching for a biological mechanism underlying the lean phenotype. Competition between species plays a central rolein the activity and structure of communities. Although the phenotypes of mice lacking individual ERM proteins point to a high degree of functional redundancy, biochemical differences suggest that there may be important functional distinctions among these proteins. For example, two known tyrosine phosphorylation sites in ezrin are not conserved in moesin or radixin, and there are differences in protease sensitivity and cargo binding. In T cells, which express moesin and ezrin in a ratio of,3:1, there is evidence that loss of ezrin alone perturbs cell signaling. We recently tested the issue of functional redundancy in mature T cells. We found that ezrin and moesin are differentially tyrosine phosphorylated upon T cell receptor engagement and that these proteins exhibit distinct patterns of movement with respect to the immunological synapse and distal pole complex. In our hands, primary T cells deficient for either ezrin or moesin alone showed modest defects in T cell function. These defects were significantly more profound in cells deficient for both ezrin and moesin, indicating that there is significant functional redundancy between ezrin and moesin in mature T cells. Stable co-existence of diverse organisms in communities is thought to be fostered by individual tradeoffs and optimization of competitive strategies along resource gradients. Outside laboratories microorganisms usually coexist in multicellular communities and compete with one another for limited natural resources. This kind of competition between microbes plays a major role in framing the community structure and, in turn, helps proliferation of certain species in a given niche, where appropriate strategies help it to outcompete others. The strategies include production of LDN-193189 clinical trial various antibiotics, toxins, exo-enzymes, siderophorelike molecules and prophage induction. Amongst others, plasmid acquisition is also known to be employed by microbes while adapting to a new environment. Acquiring plasmid is a gain of function but there is biological cost associated with it, in terms of energy burden, which might make the organism less competitive. Thus, the modulation in the expression of the plasmid-coded genes under specific environmental conditions becomes a necessarystrategy for better survival.