Letter to the Editor

Genomic Noncoding Sequences and the Size of Eukaryotic Cell Nucleus as Important Factors of Gene Protection from Chemical Mutagens

I. G. Minkevich1 and L. I. Patrushev2 #

#Phone/fax: (495) 429-86-10; e-mail: patrush@mail.ibch.ru

1Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow oblast, 142290, Russia;
2Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia

Received: December 8, 2006;  in final form: January 15, 2007

Abstract.  An improved quantitative model describing a protective function of eukaryotic genomic noncoding sequences was developed. In this new model, two factors affecting gene protection from chemical mutagensare considered: (1) the ratio of the total lengths of coding and noncoding genomic sequences and (2) the volume of the cell nucleus. An increase in the noncoding DNA in the genome reduces the number of mutagen-damaged nucleotides in the coding region, whereas an increase in the volume of the nucleus decreases the flow of mutagens per unit of nuclear volume that attacks its surface.

Key words:  coding sequences, genome, mutations, noncoding sequences, nuclear volume, paradox C

Russian Journal of Bioorganic Chemistry 2007, 33 (4): 439-442