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Background Highly polymorphic autosomal STR loci are useful for understanding population structure better and for forensic application, however the non-CODIS STR loci in the Han population of Shandong, located in Northern China, are not well-characterised. Aim To investigate population genetic polymorphism and forensic efficiency of 21 autosomal STR loci from the Shandong Han population in Northern China and reveal the genetic relationships with other populations both at home and abroad. Subjects and methods In this study, population genetic data of 21 autosomal STR loci included in the Goldeneye DNA ID 22NC Kit that includes four CODIS loci and 17 non-CODIS loci were determined for 523 unrelated Han individuals in Shandong. Results Significant deviations from Hardy–Weinberg equilibrium were not observed. A total of 233 alleles were detected with allele frequencies ranging from 0.0010 to 0.3728. The combined power of discrimination was 0.99999999999999999999999990011134, and the combined power of exclusion was 0.99999999788131. Furthermore, in an analysis of population differentiation Nei’s standard genetic distance and multidimensional scaling analysis, which were conducted based on the overlapping 15 STR loci, revealed that the Shandong Han population was most closely related to populations in close geographic proximity. Conclusions This study demonstrated that the 21 autosomal STR loci included in the GoldeneyeTM DNA ID 22NC system are highly polymorphic and suitable for forensic identification and paternity testing in the Shandong Han population. Additionally, the present results enrich the population genetic database.

Background X-chromosomal short tandem repeats (X-STRs) are a useful supplementary approach to analysing autosomal markers in forensics and kinship studies; such markers are not well-characterised in many populations. Aim To investigate population genetic polymorphism and forensic characterisation of 16 X-STRs in the Jining Han population, and analyse genetic relationships with other Chinese populations. Subjects and methods Allele frequencies for 16 X-STR loci were obtained from a sample set of 527 unrelated individuals from the Jining Han population. Population genetic analyses of Jining Han and another 10 reference populations were conducted using phylogenetic tree, principal component analysis and multidimensional scaling. Results We detected 149 alleles, with frequencies ranging from 0.0013 to 0.8242. The combined powers of discrimination in males and females were 0.999999997194774 and 0.999999999999995, respectively. The combined mean exclusion change (MEC)Krüger, MECKishida, MECDesmarais, and MECDesmarais Duos values were 0.999974632649096, 0.999999976997582, 0.999999977013201, and 0.999993755768423, respectively. We detected relatively high genetic homogeneity in populations with similar ethnic or geographic origins, and a close relationship between the Jining Han and Beijing Han populations. Conclusions The present findings indicate that the 16 X-STR loci examined are highly polymorphic in the Han population of Jining, providing useful information for forensic science and population genetics studies.

Summary: Autophagy is a conserved biological process that maintains cell homeostasis by targeting macromolecules for lysosome-mediated degradation. The levels of autophagy are relatively lower under normal conditions than under stress conditions (e.g., starvation), as autophagy is usually stimulated after multiple stresses. However, many autophagy-related regulators are still expressed under normal conditions. Although these regulators have been studied deeply in autophagy regulation, the nonautophagic roles of these regulators under normal conditions remain incompletely understood. Here, we found that autophagy-related 5 (ATG5), which is a key regulator of autophagy, regulates c-Myc protein degradation under normal conditions through the ubiquitin-proteasome pathway. We also found that ATG5 binds c-Myc and recruits the E3 ubiquitin-protein ligase FBW7 to promote c-Myc degradation. Moreover, ATG5-mediated degradation of c-Myc limits cell growth under normal conditions and is essential for embryonic stem cell differentiation. Therefore, this study reveals a nonautophagic role of ATG5 in regulating of c-Myc protein degradation.

Summary: Histones are main components of chromatin, and the protein levels of histones significantly affect chromatin assembly. However, how histone protein levels are regulated, especially whether and how histones are degraded, is largely unclear. Here, we found that histone H2B is mainly degraded through the proteasome-mediated pathway, and the lysine-120 site of H2B is essential for its K48-linked polyubiquitination and degradation. Moreover, the degradation-impaired H2BK120R mutant shows an increased nucleolus localization, and inhibition of the proteasome results in an elevated nucleolus distribution of wild-type H2B, which is similar to that of H2BK120R mutants. More importantly, the nucleolus fractions can ubiquitinate and degrade the purified H2B in vitro, suggesting that the nucleolus, in addition to its canonical roles regulating ribosome genesis and protein translation, likely associates with H2B degradation. Therefore, these findings revealed a novel mechanism for the regulation of H2B degradation in which a nucleolus-associated proteasome pathway is involved.

Abstract Background Genetic polymorphisms at 23 short tandem repeat (STR) loci were investigated in 1,215 Jining Han individuals from Jining city, Shandong province, eastern China. Methods We used population genetic data of 23 autosomal STR loci included in the Huaxia Platinum system to evaluate 1,215 unrelated Chinese Han individuals in the Jining Han population. Allele frequencies and forensic parameters of the STR loci were determined and genetic relationships among the Jining Han and other Chinese populations were evaluated. Results In total, we observed 321 alleles, with frequencies ranging from 0.00041 to 0.52222. The combined discrimination power and probability of excluding paternity were 0.99999999999999999999999999919 and 0.99999999962, respectively. No deviations from HWE were observed at any loci. Population comparisons showed that the Xinjiang groups (Uyghur and Kazakh) and the Mongolian and Tibetan groups were isolated, while the Jining Han population clustered together with other populations, except the Guizhou Han population. Conclusion This study demonstrated that 23 autosomal STR loci included in the Huaxia Platinum system are highly polymorphic and suitable for personal forensic identification and paternity testing in this population.

Abstract Background Malignant tissue samples may be the only source of biological material for forensic investigations, including individual identification or paternity testing; however, such samples may lead to uncertainties due to frequent genomic aberrations associated with tumors, including alterations of the short tandem repeat (STR) loci used for forensic casework. Methods Short tandem repeat loci routinely used in forensic analysis (n = 23) were analyzed in 68 surgically removed papillary thyroid cancer specimens. Tumor cells and normal stromal cells were separated by laser capture microdissection. Results Four kinds of changes were detected between normal and tumor tissues: partial loss of heterozygosity (pLOH), complete loss of heterozygosity, an additional allele, and a new allele not found in normal tissue. These changes were distributed across 20 of the tested STRs, with no mutations in VWA, D16S539, or Penta D. The most frequently affected locus was D2S1338, and the most frequent type of alteration was pLOH. Samples from patients aged 40–59 years exhibited the highest frequencies of STR variation. Conclusion Our results suggest that great care should be taken in the evaluation of DNA typing results obtained from malignant tissues, particularly when no normal tissue reference samples are available.