Many human diseases are related to changes in the level of gene expression, and therefore the amount of gene product produced, without any obvious alteration of the gene product itself or the timing of gene expression. However, these types of changes have been notoriously difficult to study in the laboratory because traditional methods for changing levels of gene expression tend to also disrupt multiple elements that are required for gene function, thereby making it nearly impossible to draw conclusions related solely to quantitative differences in gene expression. Dr. Oliver Smithies and colleagues from the University of North Carolina at Chapel Hill tried to overcome these problems by developing a totally new procedure that can be used to alter expression levels while retaining essential control elements.
The researchers altered a region of the gene, called the 3' untranslated region (UTR), that does not specifically control gene function but ultimately influences how much protein product the gene produces. As an initial test of the new method, the researchers used a gene for a protein that glows green as a reporter system. By using protein fluorescence as a quantitative indicator of gene expression, the researchers determined that modification of the 3' UTR changes expression of the gene in a predictable fashion in mice. These results were confirmed in different types of cells and by increasing or decreasing expression of functionally different native mouse genes. This technique may be very useful for construction of animal models that can be used to better understand complex human genetic diseases.
Masao Kakoki, Yau-Sheng Tsai, Hyung-Suk Kim, Seigo Hatada, Dominic J. Ciavatta, Nobuyuki Takahashi, Larry W. Arnold, Nobuyo Maeda, and Oliver Smithies: "Altering the Expression in Mice of Genes by Modifying Their 3' Regions"
Published in Developmental Cell, Volume 6, Number 4, April 2004, page 597-606.
Journal
Developmental Cell