Study On The Characteristics Of Circular Matched Segments Between Introns Of Ribosomal Protein Genes Of Mus Musculus

With the progress of whole genome sequencing technology,a lot of sequence information has been obtained.The majority of genome sequences are non-coding sequences,and a very small proportion of them are coding sequences.The biological information and functions of these non-coding sequences have attracted more and more attention from researchers.Many researches show that these non-coding sequences may play a very important role in life activities.As non-coding sequence of interrupted gene,the biological significance and function of intron has become a hot topic in biology.Related studies indicate that the circular RNA plays a very important part in gene expression and the origin of some diseases,while the formation of some circular RNA(circRNA)is closely related to the circular matching between introns.We selected the sequences of ribosomal protein genes of Mus musculus as the samples and adopted Smith-Waterman local alignment method to study the ring matching characteristics between intron sequences.The specific research contents are as follows.1.The gene sequences of ribosomal protein genes of Mus musculus was selected as samples,and all nuclear protein gene sequences were extracted.For each gene sequence,the first intron and the second intron...were sorted by their position.On this basis,the length,GC content distribution and other characteristics of each set of intron sequences were figured out.The results indicate that in the ribosomal protein genes of Mus musculus,the lengths of most intron sequences were concentrated around 98 bp and 1200 bp,and the GC content of most introns was 43%-54%.The analysis results indicate that the lengths and GC content distribution of introns at different positions show high similarities,along with some differences of the lengths of introns at different positions.2.For intron sequences in each ribosomal protein gene of Mus musculus,first,one of them is taken as an alignment sequence.The reverse complementary sequences of other intron sequences are then calculated with a computer program.The matching segments between the alignment intron sequences and corresponding reverse complementary sequences are figured out with Smith-Waterman local alignment method to obtain the optimal matching segments and analyze their characteristics.The results indicate that viewed from the length distribution of optimal matching segments,the optimal matching segments of most introns are concentrated around 27 bp,37bp and 42 bp,and the content of GC reaches the highest frequency roughly at the position of 0.5 and 0.53.The analysis results indicate that the distribution patterns are basically consistent with the lengths of optimal matching segments and the content of GC.It is believed that these similarities must be related with the basic unit or basic structure of the interaction between introns.3.On the basis of obtaining the optimal matching segments,the matching rate and relative position of optimal matching segments of introns are figured out.First,in order to compare the distribution of optimal matching segments,the length of optimal matching segments will be standardized at100 bp.Then the relative position of each optimal matching segment in the alignment sequence will be figured out,and the distribution characteristics of relative positions will be analyzed.The optimal matching sequences,after normalization,will be divided into three groups by the content of GC,high GC,medium GC and low GC.Their matching rate and relative position distribution in different optimal matching segments will be analyzed.The results indicate: 1)The matching rate of optimal matching segments of most introns is 60%-90%,and the matching rate of optimal matching segments exceeds 70%.And the matching rate of some optimal matching segments reaches 100%.2)The relative positions of optimal matching segments on the intron sequences generally show a normal distribution.3)The matching rates of optimal matching segments of introns at different positions are highly consistent.4)The maximum value of most high GC sequences appears at26~64bp,and the maximum value of medium GC sequences appears at 6~24bp,30~43bp,51~70bp and 78~87bp and the maximum value of low GC sequences appears at 0~11bp,28~45bp,65~74bp and 82~100bp,which indicates that there are distinctive differences in the relative positions of optimal matching segments in the groups with different contents of GC and means that the GC content of sequences plays a key role in the interaction between introns.