Genes in the Organelles Affects Cell Metabolism

New research from the University of California, Davis, shows that the tiny proportion of a cell's DNA that is located outside the cell nucleus has a disproportionately large effect on a cell's metabolism. Plant and animal cells carry most of their genes on chromosomes in the nucleus, separated from the rest of the cell. However, they also contain a small number of genes in organelles that lie outside the nucleus. These are the mitochondria, which generate energy for animal and plant cells, and chloroplasts, which carry out photosynthesis in plant cells.

Working with the model plant Arabidopsis, the researchers studied how variation in 25,000 nuclear genes and 200 organellar genes affect the levels of thousands of individual chemicals, or metabolites, in leaf tissue from 316 individual Arabidopsis plants. They found that 80 percent of the metabolites measured were directly affected by variation in the organellar genes — about the same proportion that were affected by variation among the much larger number of nuclear genes. There were also indirect effects, where organellar genes regulated the activity of nuclear genes that in turn affected metabolism.

See UC Davis' news release at http://www.caes.ucdavis.edu/news/articles/2013/10/outside-influence-genes-outside-nucleus-have-disproportionate-effect.