[Evolution of non-Coding RNAs in Drosophila melanogaster Genome]

Non-coding RNAs are important regulatory molecules that function due to their specific RNA secondary structure. The secondary RNA structure depends on RNA sequence. It can be represented as a combination of loops, stems and pseudoknot regions. By the structure formation, each separate local part of a RNA structure as well as the whole molecule tend to achieve the minimum of free energy. New mutations may change the free energy of the current RNA structure and thus change the optimal one and change the function of the molecule. The chance to change the structure for a mutation depends on where it is located in the secondary RNA structure. In this research we studied natural selection acting on loop and stem regions of ncRNA of five classes. We tried to associate their selection characteristics to the changes of free energy value. We considered Drosophila melanogaster genome.