Analysis Of Microsatellite-specific Cluster Fragments On Human Y Chromosome

Since the completion of human genome sequencing,there are many single human chromosomes whose total number of bases is over 100 million pairs,and in the face of such a huge amount of data,previous studies were some rough statistics on the total number of SSRs?Simple Sequence Repeats?,or only focused on some local genomic regions,while there were few comprehensive analysis of SSRs in human genomes.Chromosome Y is one of short human chromosome,and human reference Y-DNA NC₀000.24.10,which has the largest sequenced region,was selected to process the systematic analysis here.Based on sequenced regions of human chromosome Y,totally190000 SSRs were detected and found unevenly occurred in this chromosomal sequence,furthermore,many same or similar SSRs specifically clustered together,and some included hundreds of these special repeats,some included dozens or a few of microsatellites.According to this phenomenon,they are divided into clusters,mini clusters,and micro clusters of microsatellites.Cluster consisted of more than 25 consecutive or identical microsatellites.The mini cluster composed with 9 to 25 similar or identical microsatellites.The micro cluster included a continuously 3-8 similar or identical microsatellites.It was also found in the statistics that there were totally 8110 microsatellite-specific clusters,and the number of microsatellites in those cluster fragments accounts for about 30% of the total microsatellite number?over 190 kilos?in the sequenced region,among which the number of microsatellite cluster was 204,the mini cluster is 354,and the number of micro clusters is 7552.Owing to the proportion of the cluster being the largest,the next research in our group is also on these microsatellite clusters,so the distributions of the microsatellite specific clusters in different regions was mainly analyzed here,and provided a data foundation for future research.In this paper,we analyzed the distribution of three types of microsatellite-specific clusters on the genome at first;Then,the statistics of microsatellite-specific clusters with different repeat types and motifs,and in different regions were processed and analyzed comparatively.Finally,the different features of the microsatellite-specific clusters were analyzed,which could reflect the specificity inside those fragments to indicate the important biological significance.The above results indicated that these microsatellite-specific clusters might have biological importance,moreover,they laid a deeper foundation for understanding the structure of the human Y chromosome,and provide assistance forevolution of microsatellites.