The Research On Investigation And Application Of Gene Frequency Of Chinese Han Population In Laiwu, Shandong Province

Short tandem repeat (STR for short), or simple sequence repeats, also known as microsatellite repeat, is a class of DNA sequence of length polymorphism widely present in the human genome. It has been widely used in genetic linkage analysis, paternity testing, genetic mapping, disease gene mapping ,species polymorphism, tissue transplantation evaluation and other areas. With the rapid development of STR analysis, it is playing an increasing role in forensic science. In particular, the combination of fluorescent STR multiplex amplification technology and automatic genetic analysis instrument makes STR analysis digitalized and standardized. The combination also produce such result that an amplification can be up to 16 loci and the accumulative discrimination power reaches the level of DNA fingerprinting. STR testing technology has greatly broadened the scope of forensic tests and has promoted the development of the criminal DNA database in the forensic sciences, so it has become the most direct and most important means of identification of material evidence. Every year there are tens of thousands of DNA conclusions adopted by the court, which play an increasingly important role in the fight against crimes.In the paper, 100 samples are randomly selected from the residence of Han population in LaiWu, Shandong province during which sample extraction, amplification, detection, classification, the data storage and the actual proceeding are carried out under the same conditions for standardization and quality control. 15 STR loci typing tests are done on the samples in which SinofilerTM fluorescence is used to mark multiplex amplification system, the direct counting method to calculate the genotype and gene frequencies of the locus, PowerstatsV12 software to calculate the forensic data. A total of 44 alleles are detected from these 15 loci, among which D19S433 has the most, up to 15 alleles and D7S820,CSF1PO,D3S1358,D5S818,D13S317,D16S539,vWA has the least, 7 alleles. The accumulative discrimination power is 1-4.81×10-18.Through HWE test, except vWA loca whose p value is less than 0.05, other locus such as D8S1179,D21S11,D7S820,CSF1PO,D3S1358,D5S818,D13S317,D16S539,D2S1338,D19S433,D12S391,D18S51,D6S1043 and FGA all have the p value more than 0.05. This result notes that 14 sites are in line with Hardy-Weinberg equilibrium and are suited for genetic markers in forensic science.Population polymorphism frequency data are those that can accurately calculate the parameters of forensic science and assess its effectiveness. This paper gets the allele frequency data of STR loci in the survey of Han population in LaiWu, Shandong province, which provide a scientific basis on the accurate calculation of the individual discrimination, non-paternity exclusion, polymorphism information content, parental authority probability and other important forensic parameters. The data can also be used to calculate the likelihood ratio of the paternity test in the region. The ratio provides important basic data in forensic identification,the paternity test,DNA data technology, as well as population genetics studies.