Interactions Between Introns and Corresponding mRNA Sequences In 5'UTR Region of Complete Genome Sequences in D.melanogaster

【摘要】：正Background:Introns constitute the largest portion of eukaryotic genomes.There are much indication that spliced introns play a important role in the process of mRNA export and regulating gene expression.And several studies have suggested distinct biological functions following length variation of introns and location within genes.On this condition,we have proposed that intron sequence and its corresponding mRNA sequence are existed interaction or co-evolution relations,and hoped to get location distribution and sequence characterization of the best matching area from the interaction between 5'UTR region and intron. Methods:1878 intron sequences,which are only one intron in the 5'UTR region,and 1878 fraction of corresponding mRNA sequences to identical genes(from TSS to the first exon after translational start code) were selected in D.melanogaster genome from EID.Then the matching local alignment between introns and the fraction of corresponding mRNA(FmRNA) sequences were done with Smith-Waterman local alignment software.Next keeping original length and base contents of intron sequences and mRNA sequences as them,we generated their random sequences to the same gene.As before,random sequences were aligned.For getting best matching regions,targeting sequences were standardized by the most suited lengths.After eliminating matching regions within random matching range relative shorter matching length and smaller marking value,F- mRNA sequences were classified to many groups by interval 40bp according to their length.End,we counted matching frequencies and analyzed results. Results:The results show that there are really the interaction regions.Inside the FmRNA length of 400bp,the two significant interaction regions are displayed.The first regions are located in about 15%～30%of their length,and relative matching frequencies have reached about 25%.The positions of second peak undergo great changes,but their relative matching frequencies are lower than the first peak.During the length range of 400bp to 800bp,several peaks are presented.Among them,the outstanding interaction regions are near 5'UTR ends, which are agree with previous 400bp,and relative matching frequencies are about 15%. Conclusion:Intron sequences in 5'UTR regions correlate closely with their mRNA in 5'UTR regions or the kinds of sequence segments are existed co-evolution relation.