Fig. 6.

Sources of environmental influences on gene expression levels. a Effects of the developmental environment, typically in the range of weeks–years. Size and development are positively correlated. If size is used as a proxy for development, it may give confounding effects if two individuals with the same size but with different developmental rates are compared. b Effects of the immediate environment, usually in the range of hours–days. An experiment is carried out (delimited by the two vertical dashed lines in time) and RNA is harvested at the end. Comparing mRNA levels of a population with a certain level of stimulus (red or green bar with the duration of the experiment) against a control population (blue) will give different results depending on the immediate environment prior the start of the experiment. c Effects of RNA harvest (in the range of minutes–hours). Factors that affect mRNA levels are listed