Biomedical subjects

Jian-qiang Deng

Publications and source records attributed to Jian-qiang Deng.

7 recordsLinked to original sources

PubMed2006

[Constructing of STR slippage model by optimizing some factors].

OBJECTIVE: To construct STR slippage model and study factors involved in this procedure. METHODS: DNA samples were amplified with the technology of Degenerate oligonucleotide- primed PCR, then their products were taken as later DNA template and their STR genotype were analyzed by optimizing several factors. RESULTS: STR slippage model was constructed. CONCLUSION: Several factors were involved in the produce of STR slippage, such as amount of modulate DNA, concentration of MgCl2, property of DNA polymerase, motif sequence of STR loci, sample, etc.

DNA↗

PubMed2005

[Constructing standard allelic ladders for four short tandem repeat loci and employing them in a population study on Han Nationality of Chengdu in China].

OBJECTIVE: To solve the problems in the accuracy and standardization of short tandem repeats-polymerase chain reaction (STR-PCR) typing, the authors adopted the molecular clone technology in producing the standard allelic ladders of D1S1676, D2S2735, D11S1977 and D22S444 loci and applied them in a population study on the Hans in Chengdu, China. METHODS: PCR was used to produce several different allelic fragments of these loci. PCR products were eluted from the gel and re-amplified by PCR. The purified allelic fragments were then blunt-end subcloned individually into the pGEMR-T plasmid vectors and the recombinant were transfected into competent E.coli DH5alpha TM cells. The results of sequencing confirmed that the size and the construction of the inserts were correct. The recombinant plasmids DNA with the inserts were then used as template for re-amplification to generate the four loci standard ladders. RESULTS: The authors succeeded in producing large quantity of standard allelic ladder of these four loci, with which the genetic polymorphisms of these loci in Chengdu Han population of China were studied. CONCLUSION: This method is of high value for forensic DNA typing to construct standard ladders. D1S1676, D2S2735 loci are robust for forensic analysis in Chinese Han population, whereas the value of D11S1977 and D22S444 loci is limited.

Alleles↗

PubMed2005

[DNA samples preparation from single cell and its application in sensitivity test].

OBJECTIVE: To establish a reliable, exact and practical method to prepare DNA samples for sensitivity-test purposes. METHODS: The micromanipulation method was employed to prepare exact quantity DNA samples used to study the sensitivity of Profiler Plus Kit-ABI PRISM 310 system. RESULTS: We succeed in establishing a micromanipulation method to prepare groups of DNA samples, which contain 1-11 cells in turn, and also succeed in using them to study the sensitivity of Profiler Plus Kit-ABI310 system. CONCLUSION: The method we have established is proved to be a reliable, exact and practical way to prepare DNA samples for sensitivity-test purposes.

DNA↗

PubMed2005

[Forensic applications of the sequencing of mitochondrial DNA cytochrome oxidase subunit I and II gene for idenfication of Sarcosaphagous flies (diptera)].

OBJECTIVE: This study was based on a 278 and 635 bp region of the gene for cytochrome oxidase subunit I and I (CO I and CO II ) encoding region of mtDNA; the aim was to solve the problems in identifying Sarcosaphagous flies, particularly in the flies' larvae and eggs which could not be identified only by use of their morphologyical features. METHODS: Samples of sarcosaphagous flies and larvae were collected from those on the corps of rabbits on the grassland in the Huhhot district and of a pig on the sandy ground in the Dunhuang district. The mtDNA of flies and their larvae and eggs was extracted using the Chelex technique. Polymerase chain reactions were conducted on a Perkin-Elmer 9600 thermal cycler, followed by vertical non-denaturing polyacrylamide gelectrophoresis. PCR products were purified using the Nucleic Acid Purification Kit. Sequences of both strands were obtained by direct sequencing of the double-stranded PCR product using one of the PCR primers and the ABI PRISM Big Dye Terminator Cycle Sequencing Kit. Sequence reactions were electrophoresed on ABI Model 377 DNA Sequencers. A neighbour-joining tree using the Tamura and Nei model of nucleotide substitution was constructed using the MEGA2. 1 package. RESULTS: A 278 and 635 bp region of the gene for CO I and CO II encoding region of mtDNA of Sarcosaphagous flies and their larvae and eggs was noted to show the percentages for the sequence divergence within species (less than 1%) and the sequence divergence between species (above 3%). For species that diverged from all others by a relatively large percentage and had small within-species variation, the least percentages of sequence divergence were given which distinguished any individual within that species from any other species. CONCLUSION: A 278 and 635 bp region of the gene for CO I and CO II encoding region of mtDNA of Sarcosaphagous flies and their larvae and eggs has been effectively used for the molecular phylogeny and the identification of their species group. CO I and CO II, or CO II, is better than CO I.

Animals↗

PubMed2005

Genetic polymorphisms of four STR loci on chromosome X and their forensic applications in a Chinese Han population.

OBJECTIVE: To add DXS7133, GATA198A10, DXS9896 and DXS6797 to the panel of forensically validated X chromosome markers, and apply the multiplex amplification system to a population study and forensic analysis on the Hans of Chengdu. METHODS: The PCR products were detected by the polyacrylamide gel electrophoresis and silver staining method. Hardy-Weinberg equilibrium of females was tested and every forensically interested value was calculated. RESULTS: Sequencing revealed that their common sequence motifs were tetranucleotide repeats. Population genetic data were obtained by analyzing 120 unrelated females and 100 males from Chengdu Han ethnic group. In this population, DXS7133, GATA198A10, DXS9896 and DXS6797 exhibited 6, 6, 11, 8 distinguishable alleles respectively. Chi-square test demonstrated that genotype frequencies in females did not depart from Hardy-Weinberg equilibrium. Power of discrimination for female samples for the four loci were 0.7962, 0.8021, 0.9675, and 0.9444. The parentage testing in 32 cases revealed a typical X-linked inheritance and no mutations. CONCLUSION: DXS7133, GATA198A10, DXS9896 and DXS6797, which are highly polymorphic in Chengdu Han population, are appropriate for individual identification and paternity testing involving a female child.

Asian People↗

PubMed2005

[Practice value of whole genome amplification technology to be used in forensic science and analysis of its result].

Genetic analysis from forensic microsamples is a urgent, difficult task in forensic science, because it is frequently limited by the amount of specimen available in forensic practice, much effort has been carried out to resolve this difficulty. Whole genome amplification (WGA) technology, which was developing quickly in these years, has been thought to be a powerful, reliable and efficient strategy in analysis of minute amount DNA on many fields. In this review, we discuss its application in forensic science.

DNA↗

PubMed2004

[Genetic polymorphisms of three STR loci on chromosome X and their forensic application in a Chinese Han population].

OBJECTIVE: To understand the allele structure and genetic polymorphism at three STR loci on chromosome X in Chinese Han population and make an evalution of their forensic application. METHODS: EDTA-blood samples were collected from the unrelated individuals in Chengdu, China. After being extracted with Chelex method, the DNA samples were amplified by PCR technique. The PCR products were analyzed by PAG electrophoresis and the approach of automated fluorescence detection. Hardy-Weinberg equilibrium of females was tested and every forensic interested value was calculated. RESULTS: The polymorphisms of all 3 STR loci were obtained from 100 unrelated females and 120 unrelated males from Chinese Han ethnic group. Chi-square tests on the genotype frequencies in females did not reveal deviations from Hardy-Weinberg equilibrium. CONCLUSION: The obtained data are beneficial to understanding the population genetics of the three STR loci in Chinese Han population. For forensic genetics, the obtained data can be used to calculate the probabilities dealing with the paternity test and the individual identification.

China↗