When Does Microenvironmental Variation Modulate Developmental Stability?

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

This project examines microenvironmental causes of developmental instability. This project hypothesizes that developmental instability results in part from the sensitivity of metabolism and development to (generally unmeasured) micro-environmental variation This project tests the hypothesis that trait sensitivities to small-scale changes in environmental conditions will explain a significant fraction of developmental instability. Thirty five ecotypes of Arabidopsis thaliana will be grown in controlled environmental conditions. Each plant will experience one of four macro-scale environments: High Light (HL)/High Nitrogen (HN); HL/LowNitrogen(LN); LowLight (LL)/HN; LL/LN. Within these macroenvironments, each plant will receive a slight increase or decrease in light or nitrogen relative to the macro-scale target levels. Using a quantitative genetics approach, the comparison of 1) the sensitivity of trait measurements to small changes in environmental conditions and 2) the extent of developmental instability, will test the hypothesis. Developmental instability is thought to play a number of important roles in the processes by which organisms adapt to changing environments. Perhaps most importantly, developmental instability obscures the roles of genes in the variation between individuals. For crop breeding, this means that the response to selection for economically important traits is reduced. In natural populations, developmental instability reduces the abilty of the organism to both maintain a stable phenotype, and to adapt to changing environments.