The Tibetan macaque, which is endemic to China, is currently listed as a Near Endangered primate species by the International Union for Conservation of Nature (IUCN)(2017). Short tandem repeats (STRs) refer to r...The Tibetan macaque, which is endemic to China, is currently listed as a Near Endangered primate species by the International Union for Conservation of Nature (IUCN)(2017). Short tandem repeats (STRs) refer to repetitive elements of genome sequence that range in length from 1-6 bp. They are found in many organisms and are widely applied in population genetic studies. To clarify the distribution characteristics of genome-wide STRs and understand their variation among Tibetan macaques, we conducted a genome-wide survey of STRs with next-generation sequencing of five macaque samples. A total of 1 077 790 perfect STRs were mined from our assembly, with an N50 of 4 966 bp. Mono-nucleotide repeats were the most abundant, followed by tetra- and di-nucleotide repeats. Analysis of GC content and repeats showed consistent results with other macaques. Furthermore, using STR analysis software (IobSTR), we found that the proportion of base pair deletions in the STRs was greater than that of insertions in the five Tibetan macaque individuals (P〈0.05, t-test). We also found a greater number of homozygous STRs than heterozygous STRs (P〈0.05, t-test), with the Emei and Jianyang Tibetan macaques showing more heterozygous loci than Huangshan Tibetan macaques. The proportion of insertions and mean variation of alleles in the Emei and Jianyang individuals were slightly higher than those in the Huangshan individuals, thus revealing differences in STR allele size between the two populations The polymorphic STR loci identified based on the reference genome showed good amplification efficiency and could be used to study population genetics in Tibetan macaques. The neighbor-joining tree classified the five macaques into two different branches according to their geographical origin, indicating high genetic differentiation between the Huangshan and Sichuan populations. We elucidated the distribution characteristics of STRs in the Tibetan macaque genome and provided an effective method for screening polymorphic STRs. Our results also lay a foundation for future genetic variation studies of macaques.展开更多
Objective To establish the northwest database of short tandem repeat(STR) loci in forensic medicine. Methods Bloodstains or whole blood samples were collected from the unrelated prisoners in Xi'an city. Genetic ...Objective To establish the northwest database of short tandem repeat(STR) loci in forensic medicine. Methods Bloodstains or whole blood samples were collected from the unrelated prisoners in Xi'an city. Genetic distribution for 13 STR loci and amelogenin locus were determined in prisons based on GeneScan. One primer for each locus was labeled with the fluorescent by 5 FAM, JOE, or NED. The forensic database were generated by using multiple amplification, GeneScan, genotype, and genetic distribution analysis. Results 113 alleles and 302 genotypes were observed, with the corresponding frequency between 0.0050-0.5250 and 0.0100-0.4100. The mean H was 0.7667. The accumulative DP was 0.9999999,. The accumulative EPP was 0.9999999. The scope of PIC was 0.6036- 0.8562 . PM was less than 10 -11 . The observed and expected genotype frequencies were evaluated using χ 2 test and all were in accordance with Hardy Weinberg equilibrium ( P > 0.05 ). Conclusion STR loci is an ideal genetic marker with powerful polymorphism and stable heredity. It can be used for individual identification and paternity in forensic medicine. The forensic DNA database model can be established successfully.展开更多
Summary: Wilson disease (WD) is an autosomal recessive disorder of copper metabolism. To establish an efficient, accurate and fast diagnostic method for carrier detection and presymptomatic identification of WD in Chi...Summary: Wilson disease (WD) is an autosomal recessive disorder of copper metabolism. To establish an efficient, accurate and fast diagnostic method for carrier detection and presymptomatic identification of WD in Chinese population, we studied haplotypes of short tandem repeat (STR) polymorphisms flanking the WD gene in 40 Chinese WD families. The results suggested that this genetic diagnosis system based on the four STR polymorphisms is of high value for the detection of potential carriers and WD homozygotes in families with at least one previously affected child. It is an efficient, accurate and fast diagnostic method that can be well suited for routine use in clinical laboratories.展开更多
Background:Short tandem repeats(STRs)were recently found to have significant impacts on gene expression and diseases in humans,but their roles on gene expression and complex traits in pigs remain unexplored.This study...Background:Short tandem repeats(STRs)were recently found to have significant impacts on gene expression and diseases in humans,but their roles on gene expression and complex traits in pigs remain unexplored.This study investigates the effects of STRs on gene expression in liver tissues based on the whole-genome sequences and RNA-Seq data of a discovery cohort of 260 F6 individuals and a validation population of 296 F7 individuals from a heterogeneous population generated from crosses among eight pig breeds.Results:We identified 5203 and 5868 significantly expression STRs(eSTRs,FDR<1%)in the F6 and F7 populations,respectively,most of which could be reciprocally validated(π1=0.92).The eSTRs explained 27.5%of the cisheritability of gene expression traits on average.We further identified 235 and 298 fine-mapped STRs through the Bayesian fine-mapping approach in the F6 and F7 pigs,respectively,which were significantly enriched in intron,ATAC peak,compartment A and H3K4me3 regions.We identified 20 fine-mapped STRs located in 100 kb windows upstream and downstream of published complex trait-associated SNPs,which colocalized with epigenetic markers such as H3K27ac and ATAC peaks.These included eSTR of the CLPB,PGLS,PSMD6 and DHDH genes,which are linked with genome-wide association study(GWAS)SNPs for blood-related traits,leg conformation,growth-related traits,and meat quality traits,respectively.Conclusions:This study provides insights into the effects of STRs on gene expression traits.The identified eSTRs are valuable resources for prioritizing causal STRs for complex traits in pigs.展开更多
Objective To study the allele genetic polymorphism of five short tandem repeat (STR) loci on X-chromosome in Ewenke population of north China and to provide basic data for forensic identification. Methods Genomic D...Objective To study the allele genetic polymorphism of five short tandem repeat (STR) loci on X-chromosome in Ewenke population of north China and to provide basic data for forensic identification. Methods Genomic DNA was extracted from EDTA-whole blood of Ewenke population by Chelex-100. The DNA samples were amplified by PCR and were analyzed by polyacrylamide gel electrophoresis and silver staining. The sequence length variations of DXS6799, DXS8378, DXS101, HPRTB, and DXS6789 loci on X-chromosome in 98 unrelated Ewenke individuals were investigated. Results All five loci analyzed showed high polymorphism and genetic stability. The data of the five X-chromosome STR loci in Ewenke ethnic group of China was in accordance with Hardy-Weinberg equilibrium by Chi-square test. Conchusion Allele polymorphism of five X-chromosome STR loci can be used as a genetic marker for forensic identification and population genetic research.展开更多
Objective : To find a simple and rapid way far the prenatal diagnosis of phenyUce-tonuria (PKU) during the first trimester in order to prevent inborn PKU patients as early as possible. Methods :DNA was extracted respe...Objective : To find a simple and rapid way far the prenatal diagnosis of phenyUce-tonuria (PKU) during the first trimester in order to prevent inborn PKU patients as early as possible. Methods :DNA was extracted respectively from the Mood sampleps of 9 families' members and chori-onic tissues of 9 embryoes by cliorionic vittus sampling (CVS). The independent short tandem repeat (STR) alleles of members in 9 families with classic form of PKU were analyzed and prenatal diagnosis were conducted using polymerase chain reaction (PCR) together with denaturing gradient gel elec-trophoresis(DGGE)and silver dyeing. Results-.We identified 1 embryo with PKU, 2 normal individuals and 5 carriers among 9 subjects. Conclusion: Prenatal diagnosis for PKU by STR is available in the first trimester. This procedure was promising and would be widely used in Chinese population.展开更多
Interest in DNA analysis using short tandem repeats (STR) as finger printing tools in forensic medicine has gained tremendous application, as expression of these nuclear factors have enhanced forensic examination. Her...Interest in DNA analysis using short tandem repeats (STR) as finger printing tools in forensic medicine has gained tremendous application, as expression of these nuclear factors have enhanced forensic examination. Here we used this Biochemical characterization after conventional extraction process, polymerase chain reaction (PCR), gel electrophoresiss and a sequencer to distinguish and resolve parental dispute. The differential migration of labeled DNA fragments which attains excitation energy with a laser elicits fluorescent light of different wavelength depending on the dye used. A data collection software (Genemapper) collects raw data (spectrograph) and converts it to an electropherogram that is interpreted. By comparing the DNA profiles, inclusion and exclusion criteria were elucidated to resolve disputes. The inherent discriminating power of STRs used in analysis enhances resolution of cell mixtures, genetic aberration, substantiation of tissue origin and provides genetic distinction which is a robust and reliable approach in resolving parental disputes.展开更多
A six-color fluorescent multiplex amplification system for 31 Y-chromosomal short tandem repeats(Y-STRs)(DYS19,DYS390,DYS391,DYF399S1,DYF404S1,DYS439,DYS444,DYS449,DYS452,DYS456,DYS458,DYS460,DYS481,DYS508,DYS513,DYS5...A six-color fluorescent multiplex amplification system for 31 Y-chromosomal short tandem repeats(Y-STRs)(DYS19,DYS390,DYS391,DYF399S1,DYF404S1,DYS439,DYS444,DYS449,DYS452,DYS456,DYS458,DYS460,DYS481,DYS508,DYS513,DYS516,DYS518,DYS543,DYS547,DYS549,DYS552,DYS557,DYS570,DYS576,DYS612,DYS622,DYS626,DYS627,DYS630,DYS635,and Y-GATA-A10)was developed for investigating the mutation rates of 31 highly mutated Y-STR genes in the Han population of northern China.The mutation rates of the 31 highly mutated Y-STRs were calculated using the father-son pair study method after typing 526 Northern Han father-son pairs with this system.Statistically,148 Y-STR mutations were found,with mutation rates ranging from 0(95%confidence interval[CI]0 to 9.0×10^(−3),DYS622)to 7.0×10^(−2)(95%CI 5.1×10^(−2)to 9.7×10^(−2),DYF399S1).Out of these,126 father-son pairs were successfully identified,with a distinction rate of 24.0%(95%CI 20.4%-27.9%).The ability of the 31 highly mutated Y-STRs to distinguish closely related males from the same paternal lineage in the Northern Han population is extremely valuable for criminal investigations and other purposes.展开更多
Background:Exploring and identifying novel alleles of noncombined DNAIndex System(CODIS)short tandem repeat(STR)loci in different ethnic groups is important for the establishment of forensic reference databases and st...Background:Exploring and identifying novel alleles of noncombined DNAIndex System(CODIS)short tandem repeat(STR)loci in different ethnic groups is important for the establishment of forensic reference databases and study of population genetics.Aim:This study is aimed to explore the genetic polymorphism of 22 non-CODIS autosomal STR loci(D6S477,D18S535,D19S253,D15S659,D11S2368,D20S470,D1S1656,D22-GATA198B05,D8S1132,D4S2366,D21S1270,D13S325,D9S925,D3S3045,D14S608,D10S1435,D12S391,D7S3048,D17S1290,D5S2500,D2S1338,and D16S539)in Sierra Leone population and analyze the population genetic relationships in comparison with otherpopulations.Materialsand ethods:The amples of a total of 495 unrelated individuals(274 females and 221 males)from Sierra Leonewere examined by the Microreader^(TM)23SPID System,and their genetic polymorphisms and associated forensic parameters were calculated.The genetic relationships between Sierra Leonepopulation and other populations were evaluated as well.Results:Atotal of 287 alleles were observed with allelic frequencies ranging from 0.001 to 0.399.The cumulative power of discrimination(CPD)of the 22 autosomal STR loci was 0.99999999999999999999999999999538.The cumulative probability of exclusion(CPE)of the 22 autosomal STR loci was 0.9999998514(CPEdous)and 0.9999999999826(CPEtrios).All of the STR loci reached the Hardy–Weinberg equilibrium after Bonferroni correction.The population genetics analysis results demonstrated that Sierra Leone population exhibited distinctive genetic characteristics compared to those of East Asian populations and it had relatively close genetic distances to the Uygur population.Conclusion:The results of this study could enrich the forensic databases with Sierra Leone population.The 22 STR loci are highly polymorphic and could be used for forensic practice and population genetics studies.展开更多
目的探讨短串联重复序列(short tandem repeat,STR)三带型基因座同一认定似然比(likelihood ratio,LR)的不同计算策略。方法通过忽略三带型基因座、基于人群中不同类型的观测值、基于三带型基因座形成机制推导公式三个模型,对三带型基...目的探讨短串联重复序列(short tandem repeat,STR)三带型基因座同一认定似然比(likelihood ratio,LR)的不同计算策略。方法通过忽略三带型基因座、基于人群中不同类型的观测值、基于三带型基因座形成机制推导公式三个模型,对三带型基因座似然比进行计算。结果得到三个模型六种策略的LR计算方法,并分析其保守性与局限性。结论根据三体综合征发生机制推导的三带型基因座LR计算公式,可得到较为准确且可用于司法鉴定的LR值。展开更多
Short tandem repeats (STRs) are short tandemly repeated DNA sequences that involve a repetitive unit of 1-6 bp. Because of their polymorphisms and high mutation rates, STRs are widely used in biological research. St...Short tandem repeats (STRs) are short tandemly repeated DNA sequences that involve a repetitive unit of 1-6 bp. Because of their polymorphisms and high mutation rates, STRs are widely used in biological research. Strand-slippage replication is the predominant mutation mechanism of STRs, and the stepwise mutation model is regarded as the main mutation model. STR mutation rates can be influenced by many factors. Moreover, some trinucleotide repeats are associated with human neurodegenerative diseases. In order to deepen our knowledge of these diseases and broaden STR application, it is essential to understand the STR mutation process in detail. In this review, we focus on the current known information about STR mutation.展开更多
基金supported by the State Key Program of National Natural Science Foundation of China(31530068)National Natural Science Foundation of China(31770415)Sichuan Application Foundation Project(2015JY0268)
文摘The Tibetan macaque, which is endemic to China, is currently listed as a Near Endangered primate species by the International Union for Conservation of Nature (IUCN)(2017). Short tandem repeats (STRs) refer to repetitive elements of genome sequence that range in length from 1-6 bp. They are found in many organisms and are widely applied in population genetic studies. To clarify the distribution characteristics of genome-wide STRs and understand their variation among Tibetan macaques, we conducted a genome-wide survey of STRs with next-generation sequencing of five macaque samples. A total of 1 077 790 perfect STRs were mined from our assembly, with an N50 of 4 966 bp. Mono-nucleotide repeats were the most abundant, followed by tetra- and di-nucleotide repeats. Analysis of GC content and repeats showed consistent results with other macaques. Furthermore, using STR analysis software (IobSTR), we found that the proportion of base pair deletions in the STRs was greater than that of insertions in the five Tibetan macaque individuals (P〈0.05, t-test). We also found a greater number of homozygous STRs than heterozygous STRs (P〈0.05, t-test), with the Emei and Jianyang Tibetan macaques showing more heterozygous loci than Huangshan Tibetan macaques. The proportion of insertions and mean variation of alleles in the Emei and Jianyang individuals were slightly higher than those in the Huangshan individuals, thus revealing differences in STR allele size between the two populations The polymorphic STR loci identified based on the reference genome showed good amplification efficiency and could be used to study population genetics in Tibetan macaques. The neighbor-joining tree classified the five macaques into two different branches according to their geographical origin, indicating high genetic differentiation between the Huangshan and Sichuan populations. We elucidated the distribution characteristics of STRs in the Tibetan macaque genome and provided an effective method for screening polymorphic STRs. Our results also lay a foundation for future genetic variation studies of macaques.
基金ThisworkwassupportedbytheScientificResearchItemofXi’ancity (No .2 0 0 2 3 9)
文摘Objective To establish the northwest database of short tandem repeat(STR) loci in forensic medicine. Methods Bloodstains or whole blood samples were collected from the unrelated prisoners in Xi'an city. Genetic distribution for 13 STR loci and amelogenin locus were determined in prisons based on GeneScan. One primer for each locus was labeled with the fluorescent by 5 FAM, JOE, or NED. The forensic database were generated by using multiple amplification, GeneScan, genotype, and genetic distribution analysis. Results 113 alleles and 302 genotypes were observed, with the corresponding frequency between 0.0050-0.5250 and 0.0100-0.4100. The mean H was 0.7667. The accumulative DP was 0.9999999,. The accumulative EPP was 0.9999999. The scope of PIC was 0.6036- 0.8562 . PM was less than 10 -11 . The observed and expected genotype frequencies were evaluated using χ 2 test and all were in accordance with Hardy Weinberg equilibrium ( P > 0.05 ). Conclusion STR loci is an ideal genetic marker with powerful polymorphism and stable heredity. It can be used for individual identification and paternity in forensic medicine. The forensic DNA database model can be established successfully.
文摘Summary: Wilson disease (WD) is an autosomal recessive disorder of copper metabolism. To establish an efficient, accurate and fast diagnostic method for carrier detection and presymptomatic identification of WD in Chinese population, we studied haplotypes of short tandem repeat (STR) polymorphisms flanking the WD gene in 40 Chinese WD families. The results suggested that this genetic diagnosis system based on the four STR polymorphisms is of high value for the detection of potential carriers and WD homozygotes in families with at least one previously affected child. It is an efficient, accurate and fast diagnostic method that can be well suited for routine use in clinical laboratories.
基金supported by National Natural Science Foundation of China(31790413)supported by National Natural Science Foundation of China(31760657)。
文摘Background:Short tandem repeats(STRs)were recently found to have significant impacts on gene expression and diseases in humans,but their roles on gene expression and complex traits in pigs remain unexplored.This study investigates the effects of STRs on gene expression in liver tissues based on the whole-genome sequences and RNA-Seq data of a discovery cohort of 260 F6 individuals and a validation population of 296 F7 individuals from a heterogeneous population generated from crosses among eight pig breeds.Results:We identified 5203 and 5868 significantly expression STRs(eSTRs,FDR<1%)in the F6 and F7 populations,respectively,most of which could be reciprocally validated(π1=0.92).The eSTRs explained 27.5%of the cisheritability of gene expression traits on average.We further identified 235 and 298 fine-mapped STRs through the Bayesian fine-mapping approach in the F6 and F7 pigs,respectively,which were significantly enriched in intron,ATAC peak,compartment A and H3K4me3 regions.We identified 20 fine-mapped STRs located in 100 kb windows upstream and downstream of published complex trait-associated SNPs,which colocalized with epigenetic markers such as H3K27ac and ATAC peaks.These included eSTR of the CLPB,PGLS,PSMD6 and DHDH genes,which are linked with genome-wide association study(GWAS)SNPs for blood-related traits,leg conformation,growth-related traits,and meat quality traits,respectively.Conclusions:This study provides insights into the effects of STRs on gene expression traits.The identified eSTRs are valuable resources for prioritizing causal STRs for complex traits in pigs.
基金Supported by the National Natural Science Foundation of China(39970401).
文摘Objective To study the allele genetic polymorphism of five short tandem repeat (STR) loci on X-chromosome in Ewenke population of north China and to provide basic data for forensic identification. Methods Genomic DNA was extracted from EDTA-whole blood of Ewenke population by Chelex-100. The DNA samples were amplified by PCR and were analyzed by polyacrylamide gel electrophoresis and silver staining. The sequence length variations of DXS6799, DXS8378, DXS101, HPRTB, and DXS6789 loci on X-chromosome in 98 unrelated Ewenke individuals were investigated. Results All five loci analyzed showed high polymorphism and genetic stability. The data of the five X-chromosome STR loci in Ewenke ethnic group of China was in accordance with Hardy-Weinberg equilibrium by Chi-square test. Conchusion Allele polymorphism of five X-chromosome STR loci can be used as a genetic marker for forensic identification and population genetic research.
文摘Objective : To find a simple and rapid way far the prenatal diagnosis of phenyUce-tonuria (PKU) during the first trimester in order to prevent inborn PKU patients as early as possible. Methods :DNA was extracted respectively from the Mood sampleps of 9 families' members and chori-onic tissues of 9 embryoes by cliorionic vittus sampling (CVS). The independent short tandem repeat (STR) alleles of members in 9 families with classic form of PKU were analyzed and prenatal diagnosis were conducted using polymerase chain reaction (PCR) together with denaturing gradient gel elec-trophoresis(DGGE)and silver dyeing. Results-.We identified 1 embryo with PKU, 2 normal individuals and 5 carriers among 9 subjects. Conclusion: Prenatal diagnosis for PKU by STR is available in the first trimester. This procedure was promising and would be widely used in Chinese population.
文摘Interest in DNA analysis using short tandem repeats (STR) as finger printing tools in forensic medicine has gained tremendous application, as expression of these nuclear factors have enhanced forensic examination. Here we used this Biochemical characterization after conventional extraction process, polymerase chain reaction (PCR), gel electrophoresiss and a sequencer to distinguish and resolve parental dispute. The differential migration of labeled DNA fragments which attains excitation energy with a laser elicits fluorescent light of different wavelength depending on the dye used. A data collection software (Genemapper) collects raw data (spectrograph) and converts it to an electropherogram that is interpreted. By comparing the DNA profiles, inclusion and exclusion criteria were elucidated to resolve disputes. The inherent discriminating power of STRs used in analysis enhances resolution of cell mixtures, genetic aberration, substantiation of tissue origin and provides genetic distinction which is a robust and reliable approach in resolving parental disputes.
基金supported by the Fundamental Research Funds for the Central Universities.In addition,this study was also supported by opening research grants from Shanghai Key Lab of Forensic Medicine,Key Lab of Forensic Science,the Ministry of Justice,PR.China(Academy of Forensic Science)(No.KF202111).
文摘A six-color fluorescent multiplex amplification system for 31 Y-chromosomal short tandem repeats(Y-STRs)(DYS19,DYS390,DYS391,DYF399S1,DYF404S1,DYS439,DYS444,DYS449,DYS452,DYS456,DYS458,DYS460,DYS481,DYS508,DYS513,DYS516,DYS518,DYS543,DYS547,DYS549,DYS552,DYS557,DYS570,DYS576,DYS612,DYS622,DYS626,DYS627,DYS630,DYS635,and Y-GATA-A10)was developed for investigating the mutation rates of 31 highly mutated Y-STR genes in the Han population of northern China.The mutation rates of the 31 highly mutated Y-STRs were calculated using the father-son pair study method after typing 526 Northern Han father-son pairs with this system.Statistically,148 Y-STR mutations were found,with mutation rates ranging from 0(95%confidence interval[CI]0 to 9.0×10^(−3),DYS622)to 7.0×10^(−2)(95%CI 5.1×10^(−2)to 9.7×10^(−2),DYF399S1).Out of these,126 father-son pairs were successfully identified,with a distinction rate of 24.0%(95%CI 20.4%-27.9%).The ability of the 31 highly mutated Y-STRs to distinguish closely related males from the same paternal lineage in the Northern Han population is extremely valuable for criminal investigations and other purposes.
基金This work was supported by the Key Program of National Natural Science Foundation of China(NSFC)(grant number 82230064)the General Program of National Natural Science Foundation of China(NSFC)(grant number 82271928).
文摘Background:Exploring and identifying novel alleles of noncombined DNAIndex System(CODIS)short tandem repeat(STR)loci in different ethnic groups is important for the establishment of forensic reference databases and study of population genetics.Aim:This study is aimed to explore the genetic polymorphism of 22 non-CODIS autosomal STR loci(D6S477,D18S535,D19S253,D15S659,D11S2368,D20S470,D1S1656,D22-GATA198B05,D8S1132,D4S2366,D21S1270,D13S325,D9S925,D3S3045,D14S608,D10S1435,D12S391,D7S3048,D17S1290,D5S2500,D2S1338,and D16S539)in Sierra Leone population and analyze the population genetic relationships in comparison with otherpopulations.Materialsand ethods:The amples of a total of 495 unrelated individuals(274 females and 221 males)from Sierra Leonewere examined by the Microreader^(TM)23SPID System,and their genetic polymorphisms and associated forensic parameters were calculated.The genetic relationships between Sierra Leonepopulation and other populations were evaluated as well.Results:Atotal of 287 alleles were observed with allelic frequencies ranging from 0.001 to 0.399.The cumulative power of discrimination(CPD)of the 22 autosomal STR loci was 0.99999999999999999999999999999538.The cumulative probability of exclusion(CPE)of the 22 autosomal STR loci was 0.9999998514(CPEdous)and 0.9999999999826(CPEtrios).All of the STR loci reached the Hardy–Weinberg equilibrium after Bonferroni correction.The population genetics analysis results demonstrated that Sierra Leone population exhibited distinctive genetic characteristics compared to those of East Asian populations and it had relatively close genetic distances to the Uygur population.Conclusion:The results of this study could enrich the forensic databases with Sierra Leone population.The 22 STR loci are highly polymorphic and could be used for forensic practice and population genetics studies.
文摘目的探讨短串联重复序列(short tandem repeat,STR)三带型基因座同一认定似然比(likelihood ratio,LR)的不同计算策略。方法通过忽略三带型基因座、基于人群中不同类型的观测值、基于三带型基因座形成机制推导公式三个模型,对三带型基因座似然比进行计算。结果得到三个模型六种策略的LR计算方法,并分析其保守性与局限性。结论根据三体综合征发生机制推导的三带型基因座LR计算公式,可得到较为准确且可用于司法鉴定的LR值。
文摘Short tandem repeats (STRs) are short tandemly repeated DNA sequences that involve a repetitive unit of 1-6 bp. Because of their polymorphisms and high mutation rates, STRs are widely used in biological research. Strand-slippage replication is the predominant mutation mechanism of STRs, and the stepwise mutation model is regarded as the main mutation model. STR mutation rates can be influenced by many factors. Moreover, some trinucleotide repeats are associated with human neurodegenerative diseases. In order to deepen our knowledge of these diseases and broaden STR application, it is essential to understand the STR mutation process in detail. In this review, we focus on the current known information about STR mutation.