本文選題：Y染色體 + STR��； 參考：《南方醫(yī)科大學》2017年博士論文

【摘要】：Y-STR位于Y染色體的非重組區(qū),是Y染色體上的高多態(tài)性遺傳標記,在有絲分裂中以單倍型的形式由父親遺傳給兒子,是父系親權鑒定和男女混合樣本檢驗的重要遺傳標記,也是群體遺傳學和家族譜系研究的重要工具。國內研發(fā)的Y-STR檢測體系所包含的基因座多,在中國人群中多態(tài)性更好,但很多體系缺乏法醫(yī)學驗證和人群遺傳調查。本研究按照法醫(yī)熒光標記STR復合擴增檢測體系的驗證流程,對AGCU Y24熒光檢測體系進行了法醫(yī)學驗證,發(fā)現(xiàn)AGCU Y24能檢出0.125ng男性DNA樣本的完整分型,對0.065ng的男性DNA樣本能檢出大部分等位基因;體系對PCR抑制劑的耐受性很高,能夠耐受25 ng/μl的鞣酸、或50 ng/μl的腐植酸、或160μmol/L血紅素;體系PCR反應組分濃度變化的冗余度比較大,除在引物和反應液濃度降低50%的情況下出現(xiàn)等位基因丟失外,組分變化的其它情況下均能對樣本進行完整分型;在對0.5ng男性DNA樣本擴增28至32個循環(huán)時,發(fā)現(xiàn)28個循環(huán)下也能獲得峰較低的完整分型,循環(huán)次數(shù)的增加能明顯提高等位基因峰高,擴增平衡性受影響不大,說明體系能通過適當增加PCR循環(huán)數(shù),提高對微量檢材的檢驗能力。在男男混合物測試中,當弱勢供體與優(yōu)勢供體的DNA量比例大于1:4時,AGCU Y24能夠很好地將混合物中弱勢供體的基因型檢驗出。在男女混合樣本測試中,本研究發(fā)現(xiàn),在第一階段退火溫度為60℃的條件下,AGCU Y24體系比較容易受女性成分干擾,會產(chǎn)生固定的非特異性峰;本研究在將第一階段退火溫度優(yōu)化為63 ℃,發(fā)現(xiàn)AGCU Y24能對500ng女性DNA與0.5ng男性DNA的混合樣本進行準確分型,而體系靈敏度變化不大�？傊�,本文通過對AGCU Y24熒光檢測體系進行了法醫(yī)學驗證,認為AGCU Y24體系能滿足法醫(yī)應用的要求。本研究應用AGCUY24和GFS24Y試劑盒,檢測了漢族、廣西瑤族、廣西壯族、廣西仡佬族、廣西苗族、廣西毛南族、廣西京族等7個民族群體共2019名無關男性個體的40個Y-STR,共檢測出337個等位基因和三個多拷貝基因座的142個單體型,觀察到1938個特有單倍型、1863個唯一單倍型,總群體的PD值達0.9994。在總人群中GD值最大的是DYS385ab,為0.9643;最小的是DYS438(0.4102)。AGCUY24比YfilerTM體系多的6個基因座多態(tài)性高,更能滿足法醫(yī)DNA檢驗的需求。40個Y-STR在漢族的多態(tài)性最高,而在廣西瑤族的多態(tài)性最低。本研究認為在應用Y-STR進行法醫(yī)DNA鑒定時,要重視樣本所屬個體的民族背景信息,科學出具鑒定意見。在人群遺傳分析中,廣西瑤族與其它人群的遺傳距離最遠,可能和采樣人群居住在山區(qū)有關。除瑤族以外的七個南方民群體(漢族、廣東漢族、仡佬族、苗族、京族、壯族、毛南族)之間遺傳距離明顯比北方群體之間更近。在系統(tǒng)進化樹上,漢族、廣東漢族、仡佬族、苗族、京族、壯族、毛南族等7個南方群體可以視為一支,而藏族、蒙古族、回族、維吾爾族可以視為另一支,而廣西瑤族和朝鮮族各單獨形成分支。
[Abstract]:Y-STR, located in the non-recombination region of Y chromosome, is a highly polymorphic genetic marker on Y chromosome. It is inherited from father to son in the form of haplotype in mitosis. It is an important genetic marker for paternity test and mixed sample test.It is also an important tool for the study of population genetics and family genealogy.The Y-STR detection system developed in China contains more loci and is more polymorphic in Chinese population, but many systems lack forensic medical verification and population genetic investigation.In this study, according to the verification procedure of forensic fluorescence labeled STR multiplex amplification detection system, the AGCU Y24 fluorescence detection system was verified by forensic medicine. It was found that AGCU Y24 could detect the complete typing of 0.125ng male DNA samples.Most of the alleles could be detected in male DNA samples of 0.065ng; the system had high tolerance to PCR inhibitors and could tolerate tannic acid of 25 ng/ 渭 l, humic acid of 50 ng/ 渭 l, or heme of 160 渭 mol/L.With the exception of alleles lost in the case of 50% reduction in primer and reaction solution concentration, the samples could be completely typed when the components changed, and when 28 to 32 cycles were amplified from 0.5ng male DNA samples,It was found that the complete genotyping with lower peaks could also be obtained under 28 cycles. The increase of cycle times could significantly increase the peak height of alleles, and the amplification equilibrium was not affected, indicating that the system could increase the number of PCR cycles properly.Improve the inspection ability of trace materials.In the test of male and male mixture, when the ratio of DNA of weak donor to dominant donor was greater than 1:4, AGCU Y24 could well test the genotype of weak donor in mixture.In the test of mixed samples of men and women, we found that AGCU Y24 system is more susceptible to female interference under the first stage annealing temperature of 60 鈩，

本文編號：1734284