The Analysis Of The Heterogeneous Distribution Of SSRs In The Human Genome Y Chromosome Reference Sequence

The completion of the human genome sequencing project has promoted the rapid development of sequencing technology,and has promoted the completion of large-scale sequencing projects of various other species.Now with the continuous development of high-throughput sequencing technologies,continuously shortening of the sequencing time,the sequencing cost is greatly reduced,and all these also promoted the rapid development of personalized medicine,single gene disease rapid screening,accurate medical treatment,large-scale species group evolution research and other related research.Meanwhile vast amounts of sequence generated by genomic high-throughput sequencing also pose a new challenge.how to analyze and explain the composition characteristics of the large number of sequences and how to explore their biological significance in depth are huge challenges in the current biology field.At present,most researches on genome in the world focus on gene expression and regulation.Since the completion of human whole genome sequencing,it has been found that the actual coding gene sequence is less than 2%of the genome,and the sequence fragments of up to 46%are repetitive sequences.In fact,repetitive sequences were found to be unphenotypic and junk DNA sequences in the 1980s.Recent studies have found that some repetitive sequences are closely related to genetic diseases and gene regulation.The human genome also has a large number of microsatellites,which are more likely to be distributed in intergenic regions,introns and promoters(International Human Genome Sequencing Consortium,2001).The current researches related to human genome microsatellites are mainly in the following aspects:(1)Some studies have shown that microsatellites in some sites in the human genome are associated with genetic diseases,such as huntington’s disease and muscle atrophy.(2)Many studies associated with cancer have shown that some of the microsatellites of cancer patients are unstable,such as colon cancer,breast cancer and stomach cancer patients often being detected the instability of microsatellites in some sites,and studies using microsatellite instability as one of the marker of cancer detection.(3)Some loci of microsatellites have higher mutation rates than other sites in the genome,so they are often used as genetic markers for paternity tests,forensic identification and population studies.These studies are generally based on some specific microsatellite sites in the human genome,however,the number of microsatellites in the human genome is huge.So many microsatellites in different chromosomes of the human genome has what kind of distribution characteristics and patterns?And the distribution characteristics and patterns have what kind of biological significance?There is a lack of systematic research.Since the human genome sequence data is too big,the system analysis of the distribution characteristics of the human genome sequence is also a great project.So i have written a software(microsatellites differential calculator,DCM 2.0)with C language,use it to chromosome DNA sequence of the human genome for differential treatment,and calculate the number of microsatellites,the number of repetitions and the length of microsatellites in each differential range,achieving the observation of dozens of kilobytes and even smaller statistical units,at the same time reducing the artificial statistical workload and time,realizing the innovation of research method.In this study,a preliminary analysis of smaller Y chromosome DNA sequences of the human genome was carried out.The results show that in the completely sequenced area of the human Y chromosome reference sequence has more than 190000 microsatellite fragments.Currently on the international and domestic,a handful of microsatellite locus on the Y chromosome have certain research,at the same time as a genetic marker tool-Y-STR used in paternity test,the difference of population and forensic identification,etc.In this study,a systematic analysis was carried out on the distribution characteristics of more than 190,000 microsatellites screened on the Y chromosome sequence.This study based on the human Y chromosome reference sequence from NCBI,and i extracted,counted and classified the microsatellite types,physical site,combination method of the sequenced region on the Y chromosome,finally establishing the physical maps of characteristics distribution of microsatellites based on human Y chromosome reference sequence.From these physical maps,i found that the distribution of microsatellites on the human Y chromosome is extremely heterogeneous.Results of the study lays the foundation for further exploring the biological significance of microsatellite in the Y chromosome sequence,and will provide reference for studying the evolution laws of microsatellite in the Y chromosome sequence,and will provide theoretical support for the forensic medicine identification and population studies,and will also help with the discovery and research of genetic diseases associated with Y chromosome microsatellites.