title: DNA watermarks in non-coding regulatory sequences.
abstract: BACKGROUND
  DNA watermarks can be applied to identify the unauthorized use of genetically modified organisms. It has been shown that coding regions can be used to encrypt information into living organisms by using the DNA-Crypt algorithm. Yet, if the sequence of interest presents a non-coding DNA sequence, either the function of a resulting functional RNA molecule or a regulatory sequence, such as a promoter, could be affected. For our studies we used the small cytoplasmic RNA 1 in yeast and the lac promoter region of Escherichia coli.
  
  
  RESULTS
  The lac promoter was deactivated by the integrated watermark. In addition, the RNA molecules displayed altered configurations after introducing a watermark, but surprisingly were functionally intact, which has been verified by analyzing the growth characteristics of both wild type and watermarked scR1 transformed yeast cells. In a third approach we introduced a second overlapping watermark into the lac promoter, which did not affect the promoter activity.
  
  
  CONCLUSIONS
  Even though the watermarked RNA and one of the watermarked promoters did not show any significant differences compared to the wild type RNA and wild type promoter region, respectively, it cannot be generalized that other RNA molecules or regulatory sequences behave accordingly. Therefore, we do not recommend integrating watermark sequences into regulatory regions.
authors: Department of Experimental Tumorbiology, University of Münster, Badestr, 9, D-48149 Münster, Germany. dominik.heider@uni-due.de
authors: Dominik
authors: D
authors: Heider
authors: Martin
authors: M
authors: Pyka
authors: Angelika
authors: A
authors: Barnekow