Cis-regulatory element

A cis-regulatory element or cis-element is a region of DNA or RNA which regulates the expression of genes located on that same strand. This term is constructed from the Latin root -cis, which means "on the same side as". These cis-regulatory elements are often binding sites of one or more trans-acting factors. A cis-element may be located in the promoter region 5' to the gene it controls, in the intron, or in the 3' region.

In contrast, trans-regulatory elements are species which may modify the expression of genes distant from the gene that was originally transcribed to create them. To demonstrate the concept (this is not a specific example), a transcription factor which regulates a gene on chromosome 6 might itself have been transcribed from a gene on chromosome 11. This term is constructed from the Latin root -trans, which means "across from".

To summarize, -cis elements are present on the same strand as the gene they regulate whereas -trans elements can regulate genes distant from the gene they were transcribed from.

External references

 * Wray, G. A. 2007. The evolutionary significance of cis-regulatory mutations. Nature Reviews Genetics 8, 206-216
 * Gompel et al. 2005. Chance caught on the wing: cis regulation evolution and the origin of pigmentation patterns in Drosophila. Nature 433: 481-487.
 * Prud'homme et al. 2006. Repeated morphological evolution through cis regulatory changes in a pleiotropic gene. Nature 440: 1050-1053.
 * Stern, D.L. 2000. Perspective: Evolutionary developmental biology and the problem of variation. Evolution 54: 1079-1091.
 * Carroll, S.B., Grenier, J.K. and Weatherbee, S.D. 2005. "From DNA to diversity: Molecular genetics and the evolution of animal design" Blackwell publishing