Detection Of9miniSTR Loci In Burned Bones And Its Genetic Polymorphism In Tibetan Population

ObjectiveTo detect and type the9miniSTR loci（D20S1082、D6S474、D12ATA63、D9S1122、D2S1776、D1S1627、D3S4529、D2S441、Amelogenin） in femoralbones incinerated at300℃,so as to reveal the advantages of it in highlydegraded samples such as burned bones.And to investigate the geneticpolymorphism of it in Tibetan population in order to learn more about it in theapplication of forensic science.MethodsThe DNA of burned bones was extracted by improvedphenol-chloroform,and the DNA from blood samples of96unrelated individualsin Tibetan population was extracted by Chelex-100method.The concentration and purity of DNA were determined by eppendorfBioPhotometer plus.Amplification of9miniSTR loci was performed on thegradient PCR respectively.Data were collected by the3130gene analyzer,thelength of the amplification fragments was calculated and the genotyping wasmade using GeneMarkerV2.2.0software. The detection rates of9miniSTR lociand IdentifilerTMPCR kit in8samples were compared with Chi-square testthrough SPSS16.0software.And the genetic polymorphism of9miniSTR lociwere calculated by Modified-Powerstates software in Tibetan population.ResultsIn femoral bones incinerated at300℃,the average concentration of DNA extracted from8samples was25ng/μl,and its value of D260/D280was between1.7and1.9. The detection rates of9miniSTR loci in8samples were89﹪,89﹪,100﹪,89﹪,100﹪,78﹪,89﹪,100﹪，respectively.Most of the9miniSTR locican be detected and typed successfully,but few loci were still lost in somesamples randomly. And the9miniSTR loci showed respectively5,5,6,7,6,4,5,6,and2alleles in Tibetan population. All loci were inHardy–Weinberg equilibrium.The heterozygosity of it were between0.531and0.742.The polymorphism information content(PIC) were from0.510to0.720.The discrimination powers (DP) were from0.750to0.903.The totalprobability of discrimination power（TPD）was0.999998, and the cumulateexclusion probability of paternity（CPE）was0.984083.ConclusionsThe9miniSTR loci can be used as basic loci for individual identification andpaternity testing in the burned bones incinerated at300℃.It is more valuablethan IdentifilerTMPCR kit in burned bones.And it shows high geneticpolymorphism and great discrimination power in Tibetan population, and playsan important role in forensic practice.