Unidirectional Lasing from Mirror-Coupled Dielectric Lattices.

This paper reports how a hybrid system composed of transparent dielectric lattices over a metal mirror can produce high-quality lattice resonances for unidirectional lasing. The enhanced electromagnetic fields are concentrated in the cladding of the periodic dielectric structures and away from the metal. Based on a mirror-image model, we reveal that such high-quality lattice resonances are governed by bound states in the continuum resulting from destructive interference. Using hexagonal arrays of titanium dioxide nanoparticles on a silica-coated silver mirror, we observed lattice resonances with quality factors of up to 2750 in the visible regime. With the lattice resonances as optical feedback and dye solution as the gain medium, we demonstrated unidirectional lasing under optical pumping, where the array size was down to 100 µm × 100 µm. Our scheme can be extended to other spectral regimes to simultaneously achieve strongly enhanced surface fields and high quality factors.

A high-throughput droplet digital PCR system aiming eight DNA methylation targets for age prediction.

The droplet digital Polymerase Chain Reaction (ddPCR) has garnered recognition for its distinctive attribute of absolute quantification. And it has found practical utility in age prediction through DNA methylation profiles. However, a prevalent limitation in current ddPCR methodologies is the restricted capacity to detect only two targets concurrently in most instruments, leading to high costs, sample wastage, and labor-intensive procedures. To address the limitations, a novel high-throughput ddPCR system allowing for the simultaneous detection of eight targets was developed. Through the implementation of a new 8-plex ddPCR assay, coupled with comprehensive linear regression analyses involving primers and probes ratios, diverse inputs of single CpG sites with distinct primers and probes, and varying plex assay configurations, stable DNA methylation values for four CpGs and stable measurement precisions for distinct multiplex systems were consistently observed. These findings pave the way for advancing the field of chemistry science by enabling more efficient and cost-effective methods. Furthermore, the comparative validation of ddPCR and SNaPshot demonstrated a remarkable concordance in results, and the system also displayed well in the field of various aspects, including species specificity, DNA input, and aged samples. In this study, the recommended input of bisulfite-converted DNA was determined to be 10-50 ng due to the double-positive droplets. Notably, the Pearson correlation coefficient squared values of four CpGs were 0.4878 (ASPA), 0.4832 (IGSF1), 0.6881 (COL1A1), and 0.6475 (MEIS1-AS3). And the testing set exhibited a mean absolute error of 4.5923 years, indicating the robustness and accuracy of the age-predictive model.

Explore variation of salivary bacteria across time and geolocations.

Saliva is an informative body fluid that can be found at various crime scenes, and the salivary bacterial community has been revealed it is a potential auxiliary target for forensic identification. However, the variation of salivary bacterial community composition across time and geolocation needs to be explored. The study was designed to be carried out during the winter vacation that was across about 50 days and eight geographic locations. The high throughput sequencing was performed with the V3-V4 region of the16S rRNA gene to explore salivary bacterial community composition. An overall slight fluctuation of the salivary bacteria was observed, which primarily occurred in the relative abundance of the salivary bacterial taxa. The results of principal coordinate analysis and hierarchical clustering showed samples were clustered by the individuals. All individuals could be correctly identified with the random forest model. In summation, although the relative abundance of salivary bacteria varied across the changes of time and geolocation, the individualized characteristic of salivary bacteria remained steady, which is beneficial for the salivary bacterial application in personal identification.

Metabolic variations in root tissues and rhizosphere soils of weak host plants potently lead to distinct host status and chemotaxis regulation of Meloidogyne incognita in intercropping.

Root-knot nematodes (RKNs) inflict extensive damage to global agricultural production. Intercropping has been identified as a viable agricultural tool for combating RKNs, but the mechanisms by which intercropped plants modulate RKN parasitism are still not well understood. Here, we focus on the cucumber-amaranth intercropping system. We used a range of approaches, including the attraction assay, in vitro RNA interference (RNAi), untargeted metabolomics, and hairy root transformation, to unveil the mechanisms by which weak host plants regulate Meloidogyne incognita chemotaxis towards host plants and control infection. Amaranth roots showed a direct repellence to M. incognita through disrupting its chemotaxis. The in vitro RNAi assay demonstrated that the Mi-flp-1 and Mi-flp-18 genes (encoding FMRFamide-like peptides) regulated M. incognita chemotaxis towards cucumber and controlled infection. Moreover, M. incognita infection stimulated cucumber and amaranth to accumulate distinct metabolites in both root tissues and rhizosphere soils. In particular, naringenin and salicin, enriched specifically in amaranth rhizosphere soils, inhibited the expression of Mi-flp-1 and Mi-flp-18. In addition, overexpression of genes involved in the biosynthesis of pantothenic acid and phloretin, both of which were enriched specifically in amaranth root tissues, delayed M. incognita development in cucumber hairy roots. Together, our results reveal that both the distinct host status and disruption of chemotaxis contribute to M. incognita inhibition in intercropping.

Rational Design of a Cross-Linked Composite Solid Electrolyte for Li-Metal Batteries.

The interfacial problem caused by solid-solid contact is an important issue faced by a solid-state electrolyte (SSE). Herein, a cross-linked composite solid electrolyte (CSE) poly(vinylene carbonate) (PVCA)─ethoxylated trimethylolpropane triacrylate (ETPTA)─Li1.5Al0.5Ge1.5(PO4)3 (LAGP) (PEL) is prepared by in situ thermal polymerization. The ionic conductivity and Li+ transference number (tLi+) of PEL increase significantly due to the addition of LAGP, which can reach 1.011 × 10-4 S cm-1 and 0.451 respectively. The electrochemical stable window is also widened to 4.68 V. Benefiting from the integrated interfacial structure, the assembled coin cell shows low interfacial resistance. The all-solid-state NCM622|PEL|Li coin cell exhibits an initial discharge capacity of 169.7 mA h g-1 and 70% capacity retention over 100 cycles at 0.2 C, demonstrating excellent cycling stability.

A forensic population database of autosomal STR and X-STR markers in the Qiang ethnic minority of China.

The Qiang ethnic group is one of the oldest ethnic groups in China and is the most active ethnic group among all the populations along the Tibetan-Yi corridor. They have had a profound impact nationally and internationally. The paternal and maternal genetic feature of the Qiang ethnic group has been revealed, leaving the question of the genetic characteristics from autosomes and X chromosome not answered. The aim of this study was to explore the potential of 36 A-STR (Microreader™ 36A ID System) and 19 X-STR (Microreader™ 19X System) for application in the Qiang population and to elucidate their genetic diversity in southwest China. The cumulative probability of exclusion (CPE) for autosomal STRs is 1-1.3814 × 10-15 and the mean paternity exclusion chance (MEC) for X-STRs is 1-1.7323 × 10-6. Forensic parameters suggest that the STRs analyzed here are well-suited for forensic applications. The results of phylogenetic, interpopulation differentiation, and principal coordinates analysis (PCoA) indicate that the Qiang people have extensive connections with ethnic minorities in China, supporting the view that the Qiang people are the oldest group in the entire Sino-Tibetan language family. The Qiang appeared genetically more associated with most ethnic groups in China, especially the Han. The calculation of random matching probability (RMP) was improved by Fst correction of allele frequencies to make RMP more accurate and reasonable. This study can fill in the gaps in the Qiang STR reference database, providing valuable frequency data for forensic applications and evidence for the Qiang's genetic pattern as an important ancestral position in the Sino-Tibetan populations.

Order-order assembly transition-driven polyamines detection based on iron-sulfur complexes.

Innovative modes of response can greatly push forward chemical sensing processes and subsequently improve sensing performance. Classical chemical sensing modes seldom involve the transition of a delicate molecular assembly during the response. Here, we display a sensing mode for polyamine detection based on an order-order transition of iron-sulfur complexes upon their assembly. Strong validation proves that the unique order-order transition of the assemblies is the driving force of the response, in which the polyamine captures the metal ion of the iron-sulfur complex, leading it to decompose into a metal-polyamine product, accompanied by an order-order transition of the assemblies. This mechanism makes the detection process more intuitive and selective, and remarkably improves the detection efficiency, achieving excellent polyamines specificity, second-level response, convenient visual detection, and good recyclability of the sensing system. Furthermore, this paper also provides opportunities for the further application of the iron-sulfur platform in environment-related fields.

Loss of Y chromosome in leukocytes can be regarded as a male-specific age predictor for age group estimation in forensic genetics.

Age prediction is an important field in forensic and aging research. Traditional methods used DNA methylation, telomere shortening, and mitochondrial DNA mutations to conduct age prediction models. Sex chromosomes, like the Y chromosome, have a significant role in aging as previously reported in hematopoietic disease and many non-reproductive cancers. Until now, there is no age predictor based on the percentage of loss of Y chromosome (LOY). LOY has been previously revealed to be correlated with Alzheimer's disease, short survival, and higher risk of cancer. The possible correlation of LOY between normal aging was not fully explored. In this study, we conducted age prediction by measuring LOY percentage by droplet digital PCR (ddPCR), based on 232 healthy male samples, including 171 blood samples, 49 saliva samples, 12 semen samples. The age group of samples ranges from 0 to 99 years, with two individuals in almost every single age. Pearson correlation method was performed to calculate the correlation index. The result indicated a correlation index of 0.21 (p = 0.0059) between age and LOY percentage in blood samples, with the regression formula being y = - 0.016823 + 0.001098x. The correlation between LOY percentage and age is obvious only when the individuals were divided into different age groups (R = 0.73, p = 0.016). In the studied saliva and semen samples, p-values of the correlation are 0.11 and 0.20, respectively, showing no significant association between age and LOY percentage in these two biological materials. For the first time, we investigated male-specific age predictor based on LOY. The study showed that LOY in leukocytes can be regarded as a male-specific age predictor for age group estimation in forensic genetics. This study might be indicative for forensic applications and aging research.

Characterization of loss of chromosome Y in peripheral blood cells in male Han Chinese patients with schizophrenia.

BACKGROUND: Schizophrenia (SCZ) has a global prevalence of 1% and increases the risk of mortality, reducing life expectancy. There is growing evidence that the risk of this disorder is higher in males than in females and it tends to develop in early adulthood. The Y chromosome is thought to be involved in biological processes other than sex determination and spermatogenesis. Studies have shown that loss of chromosome Y (LOY) in peripheral blood cells is associated with a variety of diseases (including cancer) and increased all-cause mortality. An analysis of the relationship between LOY and schizophrenia is warranted. METHODS: A total of 442 Chinese males (271 patients with schizophrenia vs. 171 controls) were included in this study. The copy numbers of the Y and X chromosomes were detected by positive droplets targeting the amelogenin gene (AMEL) on the Y chromosome and X chromosome (AMELY and AMELX, respectively), using droplet digital PCR (ddPCR). The LOY percentage was defined as the difference between the concentration of AMELX and the concentration of AMELY divided by the concentration of AMELX, denoted as (X - Y)/X. RESULTS: In the Han Chinese population, the LOY percentage was higher in the schizophrenia group than in the control group (p < 0.05), although there was no significant difference in the presence of LOY between the two groups. A strong correlation was found between the average of the disease duration and the average of the LOY percentage (R2 = 0.506, p = 0.032). The logistic regression analysis implied that the risk of LOY increases by 0.058 and 0.057 per year according to age at onset and duration of disease, respectively (ponset = 0.013, pduration = 0.017). CONCLUSIONS: In the Han Chinese population, the LOY percentage of the disease group was significantly different from that of the control group. The age of onset and duration of schizophrenia might be risk factors for LOY in peripheral blood cells. A larger sample size and expanded clinical information are needed for more in-depth and specific analyses.

Integration of GWAS and RNA-Seq Analysis to Identify SNPs and Candidate Genes Associated with Alkali Stress Tolerance at the Germination Stage in Mung Bean.

Soil salt-alkalization seriously impacts crop growth and productivity worldwide. Breeding and applying tolerant varieties is the most economical and effective way to address soil alkalization. However, genetic resources for breeders to improve alkali tolerance are limited in mung bean. Here, a genome-wide association study (GWAS) was performed to detect alkali-tolerant genetic loci and candidate genes in 277 mung bean accessions during germination. Using the relative values of two germination traits, 19 QTLs containing 32 SNPs significantly associated with alkali tolerance on nine chromosomes were identified, and they explained 3.6 to 14.6% of the phenotypic variance. Moreover, 691 candidate genes were mined within the LD intervals containing significant trait-associated SNPs. Transcriptome sequencing of alkali-tolerant accession 132-346 under alkali and control conditions after 24 h of treatment was conducted, and 2565 DEGs were identified. An integrated analysis of the GWAS and DEGs revealed six hub genes involved in alkali tolerance responses. Moreover, the expression of hub genes was further validated by qRT-PCR. These findings improve our understanding of the molecular mechanism of alkali stress tolerance and provide potential resources (SNPs and genes) for the genetic improvement of alkali tolerance in mung bean.

In Situ Thermal Polymerization of a Succinonitrile-Based Gel Polymer Electrolyte for Lithium-Oxygen Batteries.

For lithium-oxygen batteries (LOBs), the leakage and volatilization of a liquid electrolyte and its poor electrochemical performance are the main reasons for the slow industrial advancement. Searching for more stable electrolyte substrates and reducing the use of liquid solvents are crucial to the development of LOBs. In this work, a well-designed succinonitrile-based (SN) gel polymer electrolyte (GPE-SLFE) is prepared by in situ thermal cross-linking of an ethoxylate trimethylolpropane triacrylate (ETPTA) monomer. The continuous Li+ transfer channel, formed by the synergistic effect of an SN-based plastic crystal electrolyte and an ETPTA polymer network, endows the GPE-SLFE with a high room-temperature ionic conductivity (1.61 mS cm-1 at 25 °C), a high lithium-ion transference number (tLi+ = 0.489), and excellent long-term stability of the Li/GPE-SLFE/Li symmetric cell at a current density of 0.1 mA cm-2 for over 220 h. Furthermore, cells with the GPE-SLFE exhibit a high discharge specific capacity of 4629.7 mAh g-1 and achieve 40 cycles.

Genome-wide association study of tuberculosis in the western Chinese Han and Tibetan population.

Tuberculosis (TB) remains a serious global public health threat. Accumulated evidence has demonstrated that human susceptibility to TB has a strong genetic basis. And different susceptibility single nucleotide polymorphisms (SNP) have been reported in different studies. To gain greater insight into the host susceptibility to TB, we perform a two-stage genome-wide association study to identify the susceptible loci of TB. In the discovery stage, 3116 (1532 TB patients and 1584 healthy controls) and 439 (211 TB patients and 228 healthy controls) individuals were genome-wide genotyped from a western Chinese Han and Tibetan population, respectively. Based on the additive genetic model, we discovered 14 and three independent loci that had potential associations with TB susceptibility in the Chinese Han and Tibetan populations, respectively (p < 1 × 10-5). Furthermore, we conducted an imputation-based meta-analysis on another two East Asia cohorts to replicate our findings. We identified one independent locus harbored by the human leukocyte antigen (HLA) class II genes that was genome-wide significantly associated with TB (lead SNP rs111875628 with a p-value of 2.20 × 10-9). Our findings suggest a novel mechanism of the interaction with the HLA class II genes and reinforce the importance of the HLA class II alleles in response to TB.

Peat-based hairy root transformation using Rhizobium rhizogenes as a rapid and efficient tool for easily exploring potential genes related to root-knot nematode parasitism and host response.

BACKGROUND: Root-knot nematodes (RKNs) pose a worldwide threat to agriculture of many crops including cucumber. Genetic transformation (GT) has emerged as a powerful tool for exploration of plant-RKN interactions and genetic improvement of RKN resistance. However, it is usually difficult to achieve a highly efficient and stable GT protocol for most crops due to the complexity of this process. RESULTS: Here we firstly applied the hairy root transformation system in exploring root-RKN interactions in cucumber plants and developed a rapid and efficient tool transformation using Rhizobium rhizogenes strain K599. A solid-medium-based hypocotyl-cutting infection (SHI) method, a rockwool-based hypocotyl-cutting infection (RHI) method, and a peat-based cotyledon-node injection (PCI) method was evaluated for their ability to induce transgenic roots in cucumber plants. The PCI method generally outperformed the SHI and RHI methods for stimulating more transgenic roots and evaluating the phenotype of roots during nematode parasitism. Using the PCI method, we generated the CRISPR/Cas9-mediated malate synthase (MS) gene (involved in biotic stress responses) knockout plant and the LATERAL ORGAN BOUNDARIES-DOMAIN 16 (LBD16, a potential host susceptibility gene for RKN) promoter-driven GUS expressing plant. Knockout of MS in hairy roots resulted in effective resistance against RKNs, while nematode infection induced a strong expression of LBD16-driven GUS in root galls. This is the first report of a direct link between these genes and RKN performance in cucumber. CONCLUSION: Taken together, the present study demonstrates that the PCI method allows fast, easy and efficient in vivo studies of potential genes related to root-knot nematode parasitism and host response.

Promising applications of human-derived saliva biomarker testing in clinical diagnostics.

Saliva testing is a vital method for clinical applications, for its noninvasive features, richness in substances, and the huge amount. Due to its direct anatomical connection with oral, digestive, and endocrine systems, clinical usage of saliva testing for these diseases is promising. Furthermore, for other diseases that seeming to have no correlations with saliva, such as neurodegenerative diseases and psychological diseases, researchers also reckon saliva informative. Tremendous papers are being produced in this field. Updated summaries of recent literature give newcomers a shortcut to have a grasp of this topic. Here, we focused on recent research about saliva biomarkers that are derived from humans, not from other organisms. The review mostly addresses the proceedings from 2016 to 2022, to shed light on the promising usage of saliva testing in clinical diagnostics. We recap the recent advances following the category of different types of biomarkers, such as intracellular DNA, RNA, proteins and intercellular exosomes, cell-free DNA, to give a comprehensive impression of saliva biomarker testing.

Large fragment Sanger sequencing identifies the newly encountered variant that caused null alleles in parentage testing.

Short tandem repeat (STR) is regarded as a crucial tool for personal identification as well as parentage testing. Thus, genotyping errors of STRs could have negative effects on the reliability of forensic identification. A null allele at the combined DNA index system (CODIS) core loci D2S1338 was found in a father-daughter pair with the AGCU Expressmarker 22 kit which was a commonly used commercial kit during our daily laboratory work. This null allele caused the father and daughter to not conform to the laws of inheritance, thus potentially generating erroneous conclusions that excluded parentage. To figure out the reason for this phenomenon, re-amplification with new primers and then large fragment Sanger sequencing was conducted. We found a G to G/T variation at the position which is fifty-nine bases away from the 3' end of the core repeat in both samples. This probably could be considered a novel variant at the primer binding region which had not been reported that resulted in the emergence of the null allele. We also found that there was more than one single-nucleotide polymorphism (SNP) with minor allele frequency (MAF) greater than 0.1 in the upstream and downstream sequences of D2S1338. When designing primers for amplification of D2S1338, the possible adverse results of these SNPs should be taken into account and avoided.

Population genetics and forensic efficiency of 30 InDel markers in four Chinese ethnic groups residing in Sichuan.

Sichuan Province is located at the transitional junction regions of the Qinghai-Tibet Plateau and the low-altitude plains. It also serves as the corridor of Sino-Tibetan-speaking population migration and expansion since neolithic expansion of Proto-Tibeto-Burman populations from Middle/Upper Yellow River during Majiayao period (3300-2000 BC). However, the population structure and the corresponding genetic diversity of forensic-related markers in this region remain unclear. Thus, we genotyped 30 insertion-deletion (InDel) markers in 444 samples from four ethnic groups (Han, Tibetan, Hui and Yi) from Sichuan Province using the Investigator® DIPplex kit to explore the characteristics of population genetics and forensic genetic focuses. All the loci were found to be in Hardy-Weinberg Equilibrium (HWE) after applying a Bonferroni correction and no pairwise loci showed prominent linkage disequilibrium. The combined matching probability (CMP) and the combined power of discrimination (CPD) are larger than 1.8089 × 10-11 and 0.99999999995, respectively. Principal component analysis, multi-dimensional scaling plots and Neighbour-Joining tree among 65 worldwide populations indicated that Sichuan Hui and Han are genetically close to Hmong-Mien and Tai-Kadai-speaking populations, and Sichuan Tibetan and Yi bear a strong genetic affinity with Tibeto-Burman-speaking populations. The model-based genetic structure further supports the genetic affinity between the studied populations and linguistically close populations.Key PointsForensic parameters of 30 insertion-deletions (InDels) in 444 individuals from four populations are reported, which showed abundant genetic affinity and diversity among populations and high value in personal identification.Genetic similarities existed between the studied populations and ethnically, linguistically close populations.Sichuan Hui and Han are genetically close to Hmong-Mien and Tai-Kadai-speaking populations.Sichuan Tibetan and Yi bear a strong genetic affinity with Tibeto-Burman-speaking populations.

Developmental validation of the Microreader Group Y Direct ID System: A novel six-dye typing system with 54 Y-chromosomal loci for forensic application.

Y-chromosome, as a gender-determined biological marker, is inherited only between fathers and sons. The Y-chromosome short tandem repeats (Y-STRs) play an essential role in paternity lineage tracing as well as sexual assault cases. The Microreader Group Y Direct ID System as a six-dye multiplex amplification kit, including 53 Y-STR and one Y-Indel locus, would improve performance and aid in obtaining more information through a greater number of loci with high polymorphism. In the present study, to verify the accuracy and efficiency of the kit, developmental validation was conducted by investigating sensitivity, species specificity, PCR inhibition, male-male and male-female mixtures, and reproducibility. The kit was tested using 311 male samples from Han and Qiang populations in Sichuan Province. The results showed that this kit had fairly high power for forensic discrimination (Han: haplotype diversity [HD] = 1, Qiang: HD = 0.999944). Additionally, 44 confirmed father-son pairs were also genotyped, among which 69 distinct haplotypes could be obtained. These father-son pairs cannot be distinguished by commonly used Y-STR panels, indicating that adding these extra Y-STRs to a single panel can achieve better discrimination performance. Collectively, the Microreader Group Y Direct ID System is robust and informative for forensic applications.

Paternal genetic structure of the Qiang ethnic group in China revealed by high-resolution Y-chromosome STRs and SNPs.

The Qiang population mainly lived in Beichuan Qiang Autonomous County of Sichuan Province. It is one of the nomads in China, distributed along the Minjiang River. The Qiang population was assumed to have great affinity with the Han, the largest ethnic group in China, when it refers to the genetic origin. Whereas, it is deeply understudied, especially from the Y chromosome. Here in this study, we used validated high-resolution Y-chromosome single nucleotide polymorphisms (Y-SNPs) and short tandem repeats (Y-STRs) panels to study the Qiang ethnic group to unravel their paternal genetic, forensic and phylogenetic characteristics. A total of 422 male samples of the Qiang ethnic group were genotyped by 233 Y-SNPs and 29 Y-STRs. Haplogroup O-M175 (N = 312) was the most predominant haplogroup in the Qiang ethnic group, followed by D-M174 (N = 32) and C-M130 (N = 32), N-M231 (N = 27), and Q-M242 (N = 15). After further subdivision, O2a-M324 (N = 213) accounted for the majority of haplogroup O. Haplogroup C2b-Z1338 (N = 29), D1a-CTS11577 (N = 30). O2a2b1a1a1-F42 (N = 48), O2a1b1a1a1a-F11 (N = 35), and O2a2b1a1-M117 (N = 21) represented other large terminal haplogroups. The results unveiled that Qiang ethnic group was a population with a high percentage of haplogroup O2a2b1a1a1-F42 (48/422) and O2a1b1a1a1a-F11 (35/422), and O2a2b1a1-M117 (21/422), which has never been reported. Its haplogroup distribution pattern was different from any of the Han populations, implying that the Qiang ethnic group had its unique genetic pattern. Mismatch analysis indicated that the biggest mismatch number in haplogroup O2a2b1a1a1-F42 was 21, while that of haplogroup O2a1b1a1a1a-F11 was 20. The haplotype diversity of the Qiang ethnic group equaled 0.999788, with 392 haplotypes observed, of which 367 haplotypes were unique. The haplogroup diversity of the Qiang ethnic group reached 0.9767, and 53 terminal haplogroups were observed (The haplogroup diversity of the Qiang ethnic group was the highest among Qiang and all Han subgroups, indicating the larger genetic diversity of the Qiang ethnic group.). Haplogroup O2a2b1a1a1-F42 was the most predominant haplogroup, including 11.37 % of the Qiang individuals. Median-joining trees showed gene flow between the Qiang and Han individuals. Our results indicated that 1) the highest genetic diversity was observed in the Qiang ethnic group compared to any of the former studied Chinese population, suggesting that the Qiang might be an older paternal branch; 2) the haplogroup D-M174 individuals of Qiang, Tibetans and Japanese distributed in three different subclades, which was unable to identify through low-resolution Y-SNP panel; and 3) the Qiang had lower proportion of haplogroup D compared to Yi and Tibetan ethnic groups, showing that the Qiang had less genetic communication with them than with Han Chinese.

Mutation analysis for newly suggested 30 Y-STR loci with high mutation rates in Chinese father-son pairs.

Rapidly mutating Y-STRs (RM Y-STRs) harbor great potential to distinguish male relatives and achieve male identification. However, forensic applications were greatly limited by the small number of the initially identified 14 RM Y-STRs. Recently, with the emergence of 12 novel RM Y-STRs, an integrated panel named RMplex was introduced, which contains all 26 RM Y-STRs and four fast mutating Y-STRs (FM Y-STRs). To obtain the first data on the mutation rates and father-son differentiation rates of the 30 newly proposed Y-STRs in Chinese populations, we performed an empirical mutation study on 307 DNA-confirmed Chinese paternal pairs. Previously reported mutation rates for 14 RM Y-STRs in Chinese and European populations were pooled and merged with our data. The highest meiosis number for the two groups reached 4771 and 2687, respectively. Five loci showed significant differences between the populations (DYS570, DYS399S1, DYS547, DYS612, and DYF403S1b). For the new panel covering 30 Y-STR loci, our results show extensive differences in the mutation rates between the two populations, as well. 10 RM Y-STR loci showed relatively low mutation rates (10-3-10-2 per meiosis) and 2 FM Y-STR loci had rapid mutation rates (> 10-2 per meiosis) in the Chinese population. Several-fold differences in mutation rates were found in nine Y-STR loci between the Chinese and reference populations, with two loci having significantly higher mutation rates and one locus with a significantly lower mutation rate in the Chinese population (P < 0.05). Eighteen RM Y-STRs (> 10-2 per meiosis), 8 FM Y-STR loci (5×10-3-10-2 per meiosis), 3 moderately mutating Y-STRs (MM Y-STRs, 10-3-5×10-3 per meiosis), and one locus with no observed mutation events were identified in the Chinese population. 40.06% of the Chinese paternity pairs were discriminated with RMplex while only 20.84% with the initial 14 RM Y-STRs, indicating that RMplex is beneficial for distinguishing paternally related males. Future studies on populations of different genetic backgrounds are necessary to obtain comprehensive estimates of mutation rates at these new loci.

Inference of population structure and admixture proportion from Y chromosomal data of Chinese population.

In the past two decades, Y chromosome data has been generated for human population genetic studies. These Y chromosome datasets were produced with various testing methods and markers, thus difficult to combine them for a comprehensive analysis. In this study, we combine four human Y chromosomal datasets of Han, Tibetan, Hui, and Li ethnic groups. The dataset contains 27 microsatellites and 137 single nucleotide polymorphisms these populations share in common. We assembled a single dataset containing 2439 individuals from 25 nationwide populations in China. A systematic analysis of genetic distance and clustering was performed. To determine the gene flow of the studied population with worldwide populations, we modeled the ancestry informative markers. The reference panel was regarded as a mixture of South Asian (SAS), East Asian (EAS), European (EUR), African (AFR), and American (AMR) populations from 1000 Genomes data of Y chromosome using nonlinear data-fitting. We then calculated the admixture proportion of these four studied populations with 26 worldwide populations. The results showed that the Han and Hui have great genetic affinity, and Hui is the most admixed ethnic group, with 61.53% EAS, 34.65% SAS, 1.91% AFR, 1.56% AMR, and 0.04% EUR ancestry component (the AMR is highly admixed and thus should be ignored). All the other three ethnic groups contained more than 97% EAS ancestry component. The Li is the least admixed population in this study. The combined dataset in this study is the largest of this kind reported to date and proposes reference population data for use in future paternal genetic studies and forensic genealogical identification.