1.A study on the application of methylation-microhaplotypes in the identification of synthetic human DNA samples
Yue WANG ; Dan WEN ; Xuan TANG ; Yi LIU ; Ruyi XU ; Siqi CHEN ; Xiaoyi FU ; Xue LI ; Yuepeng WANG ; Chudong WANG ; Weifeng QU ; Hongtao JIA ; Jienan LI ; Lagabaiyila ZHA
Chinese Journal of Forensic Medicine 2025;40(1):40-48,55
Objective Advances in synthetic DNA technology have made it much easier to fake human DNA samples.There are literature reports that fake human DNA can be synthesized by different methods and implanted in the field to confuse the investigation or mislead the trial.Therefore,distinguishing authentic human DNA from synthetic DNA and performing individual identification has become a critical scientific challenge.Methods We define a novel composite genetic marker(methylation-microhaplotype)by combining CpG sites stably hypermethylated or hypomethylated in natural human DNA and nearby immediately adjacent microhaplotype sites.A total of 19 locis were obtained according to the screening criteria,and a composite detection system for methylation-microhaplotypes was established using MPS technology.Random volunteer DNA samples were extracted and synthetic DNA samples were prepared based on whole genome amplification techniques.Population DNA samples were analyzed to evaluate forensic parameters and methylation variability of the methylation-microhaplotype markers.Comparative analyses of human and synthetic DNA were conducted to assess the markers'ability to discriminate between the two and to detect/type both components in mixed mixed samples.Results The composite detection system composed of 19 locis demonstrated high individual identification ability,achieving a cumulative individual identification probability of 0.999 999 999 996 86.12 hypermethylated locis and 7 hypomethylated locis had relatively stable methylation levels in 57 human DNA samples.According to the allele methylation rate(Ram)value,the system can effectively identify natural and synthetic DNA samples.Meanwhile,for mixed DNA samples,the presence of human and synthetic DNA samples can be found and genotyped.Conclusion Methylation-microhaplotype genetic markers,which can discover human DNA and synthetic DNA and can detect the presence and genotyping of them from mixed samples,is a potential useful tool for forensic DNA analysis.
2.A study on the application of methylation-microhaplotypes in the identification of synthetic human DNA samples
Yue WANG ; Dan WEN ; Xuan TANG ; Yi LIU ; Ruyi XU ; Siqi CHEN ; Xiaoyi FU ; Xue LI ; Yuepeng WANG ; Chudong WANG ; Weifeng QU ; Hongtao JIA ; Jienan LI ; Lagabaiyila ZHA
Chinese Journal of Forensic Medicine 2025;40(1):40-48,55
Objective Advances in synthetic DNA technology have made it much easier to fake human DNA samples.There are literature reports that fake human DNA can be synthesized by different methods and implanted in the field to confuse the investigation or mislead the trial.Therefore,distinguishing authentic human DNA from synthetic DNA and performing individual identification has become a critical scientific challenge.Methods We define a novel composite genetic marker(methylation-microhaplotype)by combining CpG sites stably hypermethylated or hypomethylated in natural human DNA and nearby immediately adjacent microhaplotype sites.A total of 19 locis were obtained according to the screening criteria,and a composite detection system for methylation-microhaplotypes was established using MPS technology.Random volunteer DNA samples were extracted and synthetic DNA samples were prepared based on whole genome amplification techniques.Population DNA samples were analyzed to evaluate forensic parameters and methylation variability of the methylation-microhaplotype markers.Comparative analyses of human and synthetic DNA were conducted to assess the markers'ability to discriminate between the two and to detect/type both components in mixed mixed samples.Results The composite detection system composed of 19 locis demonstrated high individual identification ability,achieving a cumulative individual identification probability of 0.999 999 999 996 86.12 hypermethylated locis and 7 hypomethylated locis had relatively stable methylation levels in 57 human DNA samples.According to the allele methylation rate(Ram)value,the system can effectively identify natural and synthetic DNA samples.Meanwhile,for mixed DNA samples,the presence of human and synthetic DNA samples can be found and genotyped.Conclusion Methylation-microhaplotype genetic markers,which can discover human DNA and synthetic DNA and can detect the presence and genotyping of them from mixed samples,is a potential useful tool for forensic DNA analysis.
3.Inhibition of winter seedling raising in greenhouse of premature bolting in Angelica sinensis.
Yan'an WU ; Xiaorui LIU ; Zhanfeng CAO ; Jienan JIA
China Journal of Chinese Materia Medica 2010;35(3):283-287
OBJECTIVETo study the inhibition effect of winter seedling raising in sunlight-greenhouse on premature bolting of Angelica sinensis.
METHODOne factor of sowing date with 4 levels was tested at random design with 3 repeats.
RESULTSowing date of winter seedling raising had an important effect on seedling growth, seedling mature, plant growth, premature bolting, yield, quality, and extreme significant effect on yield. The bolting date of winter raised seedlings started in middle of July, 50 d later than tranditional seedlings, and bolting peck date was in the last ten days of July, 40 d later than the traditional seedlings. The highest ratio of premature bolting for winter raised seedlings was 1%, and the lowest was 0. A. sinensis roots sowed in November 28 had the highest yield, root dry ratio, ethanol extract, essential oil and ferulic acid contents compared to that in other sowing dates. The best sowing time was from end of November to middle of December.
CONCLUSIONPremature bolting of A. sinensis could be greatly inhibited by winter seedling raising, end of November to middle of December would be the best sowing time for winter seedling raising in greenhouse.
Angelica sinensis ; growth & development ; Plants, Medicinal ; growth & development ; Seasons ; Seedlings ; growth & development

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