首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
This study developed a new multiplex PCR system that simultaneously amplifies 16 X‐STR loci in the same PCR reaction, and the polymorphism and mutation rates of these 16 X‐STR loci were explored in a Shanghai Han population from China. These loci included DXS10134, DXS10159, DXS6789, DXS6795, DXS6800, DXS6803, DXS6807, DXS6810, DXS7132, DXS7424, DXS8378, DXS9902, GATA165B12, GATA172D05, GATA31E08, and HPRTB. Samples from 591 unrelated individuals (293 males and 298 females) and 400 two‐generation families were successfully analyzed using this multiplex system. Allele frequencies and mutation rates of the 16 loci were investigated, with the comparison of allele frequency distributions among different populations performed. Polymorphism information contents of these loci were all >0.6440 except the locus DXS6800 (0.4706). Nine cases of mutations were detected in the 16 loci from the investigation of 9232 meioses. Pairwise comparisons of allele frequency distributions showed significant differences for most loci among populations from different countries and ethnic groups but not among the Han population living in other areas of China. These results suggest that the 16 X‐STR loci system provides highly informative polymorphic data for paternity testing and forensic identification in the Han population in Shanghai, China, as a complementary tool.  相似文献   

2.
The aim of this study was to investigate a 13 non‐CODIS STR loci database using three national populations from China. A new multiplex PCR system that simultaneously amplified 13 loci in the same PCR reaction was developed. This multiplex system included the 13 STR markers (D3S2402, D3S2452, D3S1766, D3S4554, D3S2388, D3S3051, D3S3053, D4S2364, D4S2404, AC001348A, AC001348B, D17S975, and D17S1294), which were successfully analyzed by using 441 DNA samples from three national populations in China (154 Mongol, 177 Kazakh, and 110 Uigur). Allele frequencies and mutation rates of the 13 non‐CODIS STR loci were investigated. A total of 4–10 alleles at each locus were observed and altogether 84, 88, and 87 alleles for the all selected loci were found in the Mongol, Kazakh, and Uigur, respectively. Eight mutations were detected from the 13 selected loci in 9880 meioses in kinship cases. These results indicate that this multiplex system may provide significant polymorphic information for kinship testing and relationship investigations.  相似文献   

3.
Because of its excellent monodispersity, high throughput, and low volume, microfluidics-based droplet PCR has become the core technology of digital PCR, next-generation sequencing, and other technology platforms. This study constructed a microfluidic water-in-oil droplet PCR system and amplified a commercially available forensic 22-plex short tandem repeat detection system. We analyzed the sensitivity, concordance, amplification efficiency of the droplet PCR, and influence factors of the above aspects. The droplet PCR showed high concordance with conventional bulk PCR and had high sensitivity as 0.125 ng. Furthermore, we observed the performance of droplet PCR in high-order mixed DNA. As the mixture ratios from 10:1 to 30:1, droplet PCR presented more mixture proportion (Mx) increased loci from 11 (57.89%) to 17 (89.47%). In the mixture ratios 20:1, 25:1, and 30:1, significant Mx differences between droplet PCR and bulk PCR were observed (p < 0.05). The results showed that the droplet PCR could improve the identification of the minor contributor's DNA in a two-person mixture and alleviate the imbalanced amplification problem. This study provides a reference and basis for the wide application of droplet PCR in forensic science.  相似文献   

4.
In recent years, the DNA detection of drowning-related diatoms, cyanobacteria, and aeromonas has gradually attracted interest from forensic scientists. In this study, we described the validation and application of a novel multiplex PCR system. This system integrated 12 fluorescently labelled primers designed to amplify specific genes of diatoms, cyanobacteria, and aeromonas. The specificity studies demonstrated that this multiplex PCR system could detect nine species of diatom, seven species of cyanobacteria, and five species of aeromonas, all of which were drowning-related and widely distributed in various water circumstance of southern China. The sensitivity studies indicated that the limit concentration of template DNA was 0.0125 ng. Besides, this multiplex PCR system had good performance in sizing precision and stability, but it is not suitable for degraded DNA samples. The application into forensic casework showed that all the tissue samples from ten nondrowning cases showed negative results, and the positive rates of lung, liver, kidney, and water samples from 30 drowning bodies were 100, 86.7, 90, and 100%, respectively. Combined with results of diatom tests of MD-VF-Auto SEM method, this multiplex PCR system could help rule out nondrowning bodies and provide extra evidences to support drowning diagnosis, especially for those cases with few diatoms observed. It is expected that this multiplex PCR system has great potential for forensic drowning diagnosis.  相似文献   

5.
With a unique inheritance pattern compared to autosomal short tandem repeats (A-STRs), X chromosomal STRs (X-STRs) have special usage in forensic relationship testing. In this study, we designed a multiplex amplification system (named TYPER-X19 multiplex assay) consisting of 18 STR loci spreading from 7.837 to 149.460 Mb on the X chromosomes (DXS9895, DXS8378, DXS9902, DXS6810, DXS7132, DXS10079, DXS6789, DXS7424, DXS101, DXS6797, DXS7133, DXS6804, GATA165B12, DXS10103, HPRTB, GATA31E08, DXS8377, and DXS7423), and the amelogenin. PCR primers were marked with four kinds of fluorophores including FAM, HEX, TAMRA, and ROX. The multiplex system was optimized and tested for precision, concordance, reproducibility, sensitivity, stability, DNA mixture, and species specificity according to the conventional validation guidelines. The results indicated that the system was accurate, reliable, and sensitive enough, and was suitable for common forensic case-type samples. In the population genetic study, a total of 148 alleles were detected at the 18 X-STR loci in 398 Southern Han Chinese. Relatively high combined power of discrimination in male (PDm), power of discrimination in female (PDf), mean paternity exclusion chance in trios (MECtrio), and mean paternity exclusion chance in duos (MECDuo) by Desmarais were detected, and HPRTB-DXS10103 was in linkage disequilibrium. The results suggested that the TYPER-X19 multiplex assay was suitable for forensic applications.  相似文献   

6.
This paper describes the development and validation of a novel 31-locus, six-dye STR multiplex system, which is designed to meet the needs of the rapidly growing Chinese forensic database. This new assay combines 20 extended-CODIS core loci (D3S1358, D5S818, TPOX, CSF1PO, TH01, vWA, D7S820, D21S11, D8S1179, D18S51, D16S539, D13S317, FGA, D1S1656, D2S441, D2S1338, D10S1248, D12S391, D19S433, and D22S1045), nine highly polymorphic loci in Chinese Han population (D3S3045, D6S1043, D6S477, D8S1132, D10S1435, D15S659, D19S253, Penta D, and Penta E), and two gender determining markers, amelogenin and Y-Indel, which could amplify DNA from extracts, as well as direct amplification from substrates. To demonstrate the suitability for forensic applications, this system was validated by precision and accuracy evaluation, concordance tests, case sample tests, sensitivity, species specificity, stability, stutter calculation, and DNA mixtures, according to the guidelines described by the Scientific Working Group on DNA Analysis Methods (SWGDAM) and regulations published by the China Ministry of Public Security. The validation results indicate the robustness and reliability of this new system, and it could be a potentially helpful tool for human identification and paternity testing in the Chinese population, as well as facilitating global forensic DNA data sharing.  相似文献   

7.
There is growing interest in developing additional DNA typing techniques to provide better investigative leads in forensic analysis. These include inference of genetic ancestry and prediction of common physical characteristics of DNA donors. To date, forensic ancestry analysis has centered on population‐divergent SNPs but these binary loci cannot reliably detect DNA mixtures, common in forensic samples. Furthermore, STR genotypes, forming the principal DNA profiling system, are not routinely combined with forensic SNPs to strengthen frequency data available for ancestry inference. We report development of a 12‐STR multiplex composed of ancestry informative marker STRs (AIM‐STRs) selected from 434 tetranucleotide repeat loci. We adapted our online Bayesian classifier for AIM‐SNPs: Snipper, to handle multiallele STR data using frequency‐based training sets. We assessed the ability of the 12‐plex AIM‐STRs to differentiate CEPH Human Genome Diversity Panel populations, plus their informativeness combined with established forensic STRs and AIM‐SNPs. We found combining STRs and SNPs improves the success rate of ancestry assignments while providing a reliable mixture detection system lacking from SNP analysis alone. As the 12 STRs generally show a broad range of alleles in all populations, they provide highly informative supplementary STRs for extended relationship testing and identification of missing persons with incomplete reference pedigrees. Lastly, mixed marker approaches (combining STRs with binary loci) for simple ancestry inference tests beyond forensic analysis bring advantages and we discuss the genotyping options available.  相似文献   

8.
We evaluated the efficacy of PCR-RFLP, competitive multiplex PCR, and a commercially available system of multiplex ligation-dependent probe amplification (MLPA) for the determination of deletion and duplication genotypes of the PMP22 gene. We compared the methods for efficiency, sensitivity, and specificity. We determined the gene dosage of the PMP22 gene via PCR-RFLP, competitive multiplex PCR, and MLPA. To demonstrate the sensitivity and accuracy of these three methods, a total of 185 samples from 42 patients with hereditary neuropathy with liability to pressure palsies (HNPP), 57 patients with Charcot-Marie-Tooth disease type 1A (CMT1A), and 86 unaffected individuals, were analyzed. Molecular diagnosis by PCR-RFLP was performed on all 185 samples; 24 HNPP deletions and 33 CMT1A duplications were identified. In contrast, 25 HNPP deletions and 38 CMT1A duplications were identified correctly using competitive multiplex PCR and MLPA. Six samples were incorrectly identified by PCR-RFLP (one HNPP deletion and five CMT1A duplications). Competitive multiplex PCR and MLPA demonstrated reliability and relative speed compared to PCR-RFLP; they were superior to PCR-RFLP for gene dosage quantification. Multiplex PCR and MLPA should be the methods of choice for detection of deletion and duplication genotypes in molecular genetic diagnoses.  相似文献   

9.
X‐chromosomal STRs (X‐STRs) have been used as complements of autosomal STR application in recent years. In this work, we present population genetic data of 12 X‐STRs including DXS101, DXS10159, DXS10162, DXS10164, DXS6789, DXS7133, DXS7423, DXS7424, DXS8378, DXS981, GATA165B12, and GATA31E08 loci in a sample of 231 unrelated healthy individuals from the Hui ethnic group in Ningxia Hui Autonomous Region, China. Allelic frequencies of the 12 X‐STR loci and haplotypic frequencies of the reported linkage groups (DXS7424‐DXS101 and DXS10159‐DXS10164‐DXS10162) were investigated in the group, respectively. No STR loci showed significant deviations from the Hardy–Weinberg equilibriums and no linkage disequilibriums of pairwise loci were found after Bonferroni correction, respectively. A combined power of discrimination in female individuals was 0.999999999985 and that in male individuals was 0.99999967, respectively. The combined mean exclusion chance in deficiency cases, normal trios and duo cases were 0.999934, 0.995754, and 0.999796, respectively. Significant differences were observed from 0 to 8 loci, when making comparisons between the data of Hui ethnic group and previously reported data from other 16 populations. The results indicated the new panel of 12 X‐STR loci might be useful for forensic science application.  相似文献   

10.
Single nucleotide polymorphisms (SNPs) are one of the most common markers in mammals. Rapid, accurate, and multiplex typing of SNPs is critical for subsequent biological and genetic research. In this study, we have developed a novel method for multiplex genotyping SNPs in mice. The method involves allele‐specific PCR amplification of genomic DNA with two stem‐loop primers accompanied by two different universal fluorescent primers. Blue and green fluorescent signals were conveniently detected on a DNA sequencer. We verified four SNPs of 65 mice based on the novel method, and it is well suited for multiplex genotyping as it requires only one reaction per sample in a single tube with multiplex PCR. The use of universal fluorescent primers greatly reduces the cost of designing different fluorescent probes for each SNP. Therefore, this method can be applied to many biological and genetic studies, such as multiple candidate gene testing, genome‐wide association study, pharmacogenetics, and medical diagnostics.  相似文献   

11.
X‐chromosomal short tandem repeats (X‐STRs) have been proved to be useful for some deficiency paternity cases in recent years. Here, we studied the genetic polymorphisms of 19 X‐STR loci (DXS10148‐DXS10135‐DXS8378, DXS10159‐DXS10162‐DXS10164, DXS7132‐DXS10079‐DXS10074‐DXS10075, DXS6809‐DXS6789, DXS7424‐DXS101, DXS10103‐HPRTB‐DXS10101 and DXS7423‐DXS10134) in 252 male and 222 female individuals from Guanzhong Han population, China. No deviation for all 19 loci was observed from the Hardy–Weinberg equilibrium. The polymorphism information content values of the panel of 19 loci were more than 0.5 with the exception of the locus DXS7423. The combined power of discrimination were 0.9999999999999999999994340 in females and 0.9999999999997662 in males, respectively; and the combined mean exclusion chances were 0.999999993764 in duos and 0.999999999997444 in trios, respectively. The haplotype diversities for all the seven clusters of linked loci were more than 0.9. The results showed that the panel of 19 X‐STR loci were powerful for forensic applications in Guanzhong Han population. Locus by locus population comparisons showed significant differences at more than seven loci between Guanzhong Han population and the groups from North America, Europe and Africa.  相似文献   

12.
This study reports the methodology used to search, select and characterize STR loci on the canine X chromosome using publicly available genome resources and following the current guidelines for human and non‐human forensic testing. After several rounds of selection, 12 X‐STR markers were optimized for simultaneous co‐amplification in a single PCR, and genetic profiles were determined in a sample of 103 unrelated dogs. Mendelian inheritance was verified and mutation rates were assessed using family groups. Alleles that varied in size were sequenced to create a standardized nomenclature proposal based on the number of repeats. All loci conformed to Hardy–Weinberg expectations. The resulting panel showed high forensic efficiency, presenting high values of power of discrimination (in males and females) and mean exclusion chance, both in trios involving female offspring and in duos composed of dam and male offspring. Its use may complement the information obtained by autosomal STR analysis and contribute to the resolution of complex cases of kinship in dogs. The presented methodology for the de novo construction of an STR multiplex may also provide a helpful framework for analogous work in other animal species. As an increasing number of reference genomes become available, convenient tools for individual identification and parentage testing based on STR loci selected from autosomes or sex chromosomes' sequences may be created following this strategy.  相似文献   

13.
Many genetic diseases are caused by the presence of point mutations, small insertions, and deletions in respective genes, and the number of diseases known to be caused by deletions and duplications involving large DNA genomes is increasing. These changes lead to underexpression or overexpression of the gene, according to changes in gene dosage. The methods for the detection of point mutations, small insertions, and deletions are well established, but the detection of larger genomic deletions or duplications is more difficult. Due to the lack of efficient and technically feasible protocols for gene dosage quantification, we describe a diagnostic protocol employing a combination of available methods. The efficient and accurate gene dosage quantification platform is combined with multiplex PCR and CE, and applied to detect dosages of several genes, including SMN, PMP22, and alpha-globin genes. The reliability of this novel methodology shows that it is a relatively speedy and low-cost procedure and a significant tool for genetic diagnosis. Its sensitivity and specificity for identifying deletion and duplication genotypes approach 100%. Moreover, once we establish this powerful system, we will further apply this technique to the rapid detection of trisomy syndromes and microdeletion syndromes, including trisomy 13, Down syndrome, DiGeorge syndrome, and others.  相似文献   

14.
In the present study, 24 Y‐chromosomal short tandem repeat (Y‐STR) loci were analyzed in 115 unrelated Hui male individuals from Haiyuan county or Tongxin county, Ningxia Hui Autonomous Region, China, to evaluate the forensic application of the 24 STR loci and to analyze interpopulation differentiations by making comparisons between the Hui group data and previously published data of other 13 populations. A total of 115 different haplotypes were observed on these 24 Y‐STR loci. The gene diversities ranged from 0.4049 (DYS437) to 0.9729 (DYS385a, b). The overall haplotype diversity was 1 at AGCU 24 Y‐STR loci level, while the values were reduced to 0.999237, 0.996949, and 0.996644 at the Y‐filer 17 loci, 11 Y‐STR loci of extended haplotype and 9 Y‐STR loci of minimal haplotype levels, respectively; whereas, haplotype diversity for additional 7 loci (not included in Y‐filer 17 loci) was 0.995271. The pairwise FST, multidimensional scaling plot and neighbor‐joining tree indicated the Hui group had the closest genetic relationship with Sala in the paternal lineage in the present study. In summary, the results in our study indicated the 24 Y‐STRs had a high level of polymorphism in Hui group and hence could be a powerful tool for forensic application and population genetic study.  相似文献   

15.
Beta (β)‐thalassemia is one of the most common monogenic diseases worldwide. Affected pregnancies can be avoided through preimplantation genetic diagnosis (PGD), which commonly involves customized assays to detect the different combinations of β‐globin (HBB) gene mutations present in couples, in conjunction with linkage analysis of flanking microsatellite markers. Currently, the limited number of reported closely linked markers hampers their utility in indirect linkage‐based PGD for this disorder. To increase the available markers closely flanking the HBB gene, an in silico search was performed to identify all markers within 1 Mb flanking the HBB gene. Fifteen markers with potentially high polymorphism information content (PIC) and heterozygosity values were selected and optimized into a single‐tube pentadecaplex PCR panel. Allele frequencies and polymorphism and heterozygosity indices of each marker were assessed in five populations. A total of 238 alleles were observed from the 15 markers. PIC was >0.7 for all markers, with expected heterozygosity and observed heterozygosity values ranging from 0.74 to 0.90 and 0.72 to 0.88, respectively. Greater than 99% of individuals were heterozygous for at least seven markers, with at least two heterozygous markers on either side of the HBB gene. The pentadecaplex marker assay also performed reliably on single cells either directly or after whole genome amplification, thus validating its use in standalone linkage‐based β‐thalassemia PGD or in conjunction with HBB mutation detection.  相似文献   

16.
Kyrgyz ethnic group is one of the nomads in China, with the majority in Xinjiang and a small part of them living in Heilongjiang province. Historically, they have went through five migrations westward due to the wars. The name “Kyrgyz” means 40 tribes, originating from the primary groups of Kyrgyz. However, it is a largely understudied population, especially from the Y chromosome. In this study, we used a previously validated high-resolution Y-chromosome single nucleotide polymorphisms (Y-SNPs) and short tandem repeats (Y-STRs) system to study Kyrgyz ethnic group. A total of 314 male samples of Kyrgyz ethnic group were genotyped by 173 Y-SNPs and 27 Y-STRs. After data analysis, the results unveiled that Kyrgyz ethnic group was a population with high percentage of both haplogroup C2a1a3a1d∼-F10091 (91/134) and R1a1a1b2a2-Z2124 (109/134), which has never been reported. This implied that Kyrgyz ethnic group might have gone through bottleneck effects twice, with these two main lineages left. Mismatch analysis indicated that the biggest mismatch number in haplogroup C2a1a3a1d∼-F10091 was 10, while that of haplogroup R1a1a1b2a2-Z2124 was 20. This huge difference reflected the different substructure in two lineages, suggesting that haplogroup C2a1a3a1d∼-F10091 might have the least admixture compared to the other two lineages. After admixture modelling with other datasets, the conclusion could be drawn that Kyrgyz ethnic group had great genetic affinity with Punjabi from Lahore, Pakistan, which supported that Kyrgyz ethnic group in China was close to central Asian.  相似文献   

17.
One rapid CE method was established to diagnose Duchenne muscular dystrophy (DMD). DMD is a severe recessive inherited disorder frequently caused by gene deletions. Among them, exons 1–20 account for nearly 30% of occurrences. In this study, the universal multiplex PCR was used to enhance the fluorescently labeling efficiency, which was performed only by one universal fluorescent primer. After PCR, a short‐end injection CE (short‐end CE) speeded up the genotyping of the DMD gene. This method involved no extra purification, and was completed within 9 min. The CE conditions contained a polymer solution of 1.5% hydroxylethylcellulose in 1× TBE buffer at 6 kV for separation. This method was applied to test six DMD patients and one healthy male person. The results showed good agreement with those of multiplex ligation‐dependent probe amplification. This method can be applied for clinical diagnosis of DMD disease. Accurate diagnosis of the DMD gene is the best way to prevent the disease.  相似文献   

18.
CYP2D6 (cytochrome P450 2D6) is one of the most important enzymes involved in drug metabolism, and CYP2D6 gene variants may cause toxic effects of therapeutic drugs or treatment failure. In this research, a rapid and simple method for genotyping the most common mutant alleles in the Asian population (CYP2D6*1/*1, CYP2D6*1/*10, CYP2D6*10/*10, CYP2D6*1/*5, CYP2D6*5/*10, and CYP2D6*5/*5) was developed by allele-specific polymerase chain reaction (AS-PCR) combined with capillary electrophoresis (CE). We designed a second mismatch nucleotide next to the single nucleotide polymorphism (SNP) site in allele-specific primers to increase the difference in PCR amplification. Besides, we established simulation equations to predict the CYP2D6 genotypes by analyzing the DNA patterns in the CE chromatograms. The multiplex PCR combined with CE method was applied to test 50 patients, and all of the test results were compared with the DNA sequencing method, long-PCR method and real-time PCR method. The correlation of the analytical results between the proposed method and other methods were higher than 90%, and the proposed method is superior to other methods for being able to simultaneous detection of SNPs and copy number variations (CNV). Furthermore, we compared the plasma concentration of aripiprazole (a CYP2D6 substrate) and its major metabolites with the genotype of 25 patients. The results demonstrate the proposed genotyping method is effective for estimating the activity of the CYP2D6 enzyme and shows potential for application in personalized medicine. Similar approach can be applied to simultaneous detection of SNPs and CNVs of other genes.  相似文献   

19.
Metastable Germanium–tin (GeSn) layers with rather high Sn content between 15% and 18% grown on Si substrates by molecular beam epitaxy were analyzed for the morphological changes on a surface before and after reaching critical layer parameters (thickness, Sn content, and growth temperature) for surface roughening. Atomic‐force microscopy investigations were performed as a function of thickness and separately for varying Sn concentrations in the GeSn layer. Epitaxial growth of metastable, uniform GeSn (15% Sn content) layers is obtained up to a critical thickness which increases from about 80 to above 200 nm by reducing the nominal growth temperature from 160 to 140 °C. Phase separation of the complete layer into tin‐rich surface protrusions and a Ge‐rich matrix takes place beyond the critical thickness. This surface roughening via phase separation was not observed in earlier investigations with lower Sn concentrations (<6%). Tin depletion in the GeSn matrix was confirmed by using energy‐dispersive X‐ray spectroscopy measurements showing residual Sn concentration below 5%. Additionally, creation of droplets with high concentration of tin on the surfaces was confirmed by energy‐dispersive X‐ray spectroscopy. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

20.
From 35 species of marine fishes (n = 327) from the South China Sea, 237 nematode larvae were collected and identified morphologically as Anisakis. Genomic DNA was isolated from each larva and subjected to PCR‐based RFLP and targeted sequencing of a nuclear ribosomal DNA region between the 3′‐end of the small subunit and 5′‐end of the large subunit of the rRNA genes (= internal transcribed spacers, ITS+). Four different RFLP profile combinations (sets) were detected for all restriction endonucleases (HinfI, HhaI, and TaqI), of which three were characteristic of Anisakis typica, A. pegreffii, and A. physeteris, respectively. One profile set (for sample CA‐2012) was linked to an ITS+ sequence that was identical to a previously published sequence of Anisakis sp. (sample HC‐2005; originating from the African shelf) and another sequence (PH‐2010; Madeira, Portugal). Phylogenetic analysis was carried out using the ITS+ sequence data from this study and reference sequences from the GenBank database. Neighbor joining and maximum parsimony trees displayed three clades. Clades I and II included nine described species of Anisakis, including all type I and type II larvae; clade III represented some undescribed species of Anisakis. Morphological comparison showed that Anisakis sp. CA‐2012 was distinct from type I and type II larvae based on its tail shape and ratio of tail length to body length. The phylogenetic analysis and morphological characters suggest that Anisakis sp. CA‐2012 represents a new record, now called Anisakis type III larvae.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号