[Genetic Polymorphisms of 27 Y-STR Loci in Dongxiang Population of Gansu Province].

OBJECTIVES: To investigate the genetic polymorphisms of 27 Y-STR in Dongxiang population of Gansu province, and to explore the population genetic relationship and the value of forensic application. METHODS: The genotyping of 27 Y-STR loci in 526 unrelated male individuals in Dongxiang population of Gansu province were detected by STRtyper-27Y kit. The allele frequencies and haplotype diversity were also calculated. Combining with other genetics data of 14 loci in same populations, which have been published at home and abroad, the genetic distance and clustering relationship in Dongxiang population of Gansu province were calculated. RESULTS: Totally 55 haplotypes were found in the DYS385a/b biallelic loci, 39 haplotypes in DYF387S1 loci, and 4-16 alleles in the rest 23 single copy STR loci. The GD value was from 0.453 9 （DYS391） to 0.957 5 （DYS385a/b）. Totally 471 haplotypes were observed in 27 Y-STR loci in 526 individuals, and the value of haplotypes diversity was 0.999 5. The genetic distance between Dongxiang and Tibetan populations of Gansu province was the closest （0.068 2）, while it was the longest between Dongxiang population in Gansu province and Han population in Henan province （0.084 7）. The result of dimensional analysis established upon the genetic distance was basically matched with that of the cluster analysis. CONCLUSIONS: The 27 Y-STR loci show a high genetic polymorphism in Dongxiang population of Gansu province, which has significance for the Y-STR database establishment, population genetics study and forensic practice.

[Forensic Application of 16 X-STR Loci in Henan Han Population].

OBJECTIVES: To investigate the genetic data of 16 X-STR loci in Henan Han population and to assess the application value in forensic science. METHODS: The DNA of 326 unrelated individuals in Henan Han population were amplified using Goldeneye™ DNA identification system 17X kit, and the PCR products were analyzed by electrophoresis through 3130xl genetic analyzer. The fragment sizes of alleles were analyzed subsequently by GeneMapper® ID-X. Allele frequencies and population genetics parameters of 16 X-STR loci were analyzed statistically and compared with the available data of other Han populations from different regions. RESULTS: Among the 16 X-STR loci, DXS6800 were found to be moderately polymorphic and the other 15 X-STR loci were highly polymorphic. The cumulative discrimination power in females and males were 0.999 999 999 999 992 and 0.999 999 996 577 712, respectively. The combined power of exclusion in trios and in duos were 0.999 999 971 and 0.999 992 574, respectively. CONCLUSIONS: The 16 X-STR loci meet the application requires of forensic genetics, especially for testing the special paternity cases.

Impairment of hippocampal neurogenesis in streptozotocin-treated diabetic rats.

OBJECTIVES: Adult neurogenesis in dentate gyrus (DG) is an evolutionarily preserved trait in most mammals examined thus far. Neuronal proliferation and subsequent integration of new neurons into the hippocampal circuit are regulated processes that can have profound effects on an animal's behaviour. A streptozotocin model of type I diabetes, characterized by low insulin and high plasma glucose levels, affects not only body's overall metabolism but also brain activity. MATERIALS AND METHODS: Neurogenesis was measured within the DG of the hippocampus using immunohistochemical markers Ki67, Doublecortin, Calbindin (CaBP) and bromodeoxyuridine (BrdU). RESULTS: Cell proliferation, measured with the endogenous marker Ki67, was reduced by 45%, and cell survival, measured with BrdU, was reduced by 64% of the control. Combined effects on proliferation and survival produced dramatically lower neuronal production. Among the surviving cells only 33% matured normally as judged by the co-labelling of BrdU and CaBP. CONCLUSION: Such a reduction lowered the number of surviving cells with neuronal phenotype by over 80% of the control values and this is expected to cause a significant functional impairment of learning and memory in diabetic animals. These results may shed light on causes of diabetic neuropathology and provide an explanation for the memory deficiencies seen in some diabetic patients.