Genetic and environmental factors affect gene expression in yeast
Individuals frequently encounter different environmental conditions, and the physiological and behavioral responses to these conditions can depend on an individual’s genetic makeup. This phenomenon is known as gene–environment interaction. For example, individuals who are infected with the Plasmodium falciparum parasite are susceptible to malaria, but not if they carry the sickle-cell allele of hemoglobin. The general properties of gene–environment interaction are poorly understood, and a better understanding is essential if individuals are to make informed health choices guided by their genomic information. A new paper just published in the open-access journal PLoS Biology shows that there is a balance between inherited genes and the environment in determining thousands of traits in yeast.
The authors investigated gene–environment interaction on a genomic level, characterizing its role in over 4,000 traits at once by investigating natural variation in yeast gene expression. They compared lab and vineyard strains of yeast growing in two conditions (glucose and ethanol as carbon sources) in which they adopt two different metabolic states: fermentation and aerobic respiration, respectively. This showed that gene–environment interaction is a common phenomenon, and provides detailed molecular examples of these interactions.
As we approach the age of personal genomics, in which each of us knows something about the genetic variations we carry, it is important to understand how genes and the environment interact in order to draw medically sound conclusions from the information available e.g. whether exercise can reduce risks that are increased because of a genetic predisposition towards a certain illness. The phenomenon of gene/environment interaction has been documented before, that the environment affects the ways it genes are expressed so that genes that are on in one condition may be downregulated or switched off in other environments. What the new research adds is the ability to study thousands of gene expression patterns simultaneously, to understand the general properties of these previously poorly understood interactions. The expression of many genes is under the control of other genes. This paper shows that the environment often has a bigger effect on these regulated genes than on ones that are switched on and off by other, more direct mechanisms. Intriguingly, sometimes a control gene that positively affects another gene in one environment may have the opposite effect in another environment.
Gene environment interaction in yeast gene expression. PLoS Biol 6(4): e83
Tags: Biology, Biotechnology, Environment, Genetics, Malaria, Microbiology, Mycology, Science
