ABSTRACT
Tumor heterogeneity presents a challenge for inferring clonal evolution and driver gene identification. Here, we describe a method for analyzing the cancer genome at a single-cell nucleotide level. To perform our analyses, we first devised and validated a high-throughput whole-genome single-cell sequencing method using two lymphoblastoid cell line single cells. We then carried out whole-exome single-cell sequencing of 90 cells from a JAK2-negative myeloproliferative neoplasm patient. The sequencing data from 58 cells passed our quality control criteria, and these data indicated that this neoplasm represented a monoclonal evolution. We further identified essential thrombocythemia (ET)-related candidate mutations such as SESN2 and NTRK1, which may be involved in neoplasm progression. This pilot study allowed the initial characterization of the disease-related genetic architecture at the single-cell nucleotide level. Further, we established a single-cell sequencing method that opens the way for detailed analyses of a variety of tumor types, including those with high genetic complex between patients.
Subject(s)
Clonal Evolution , Gene Expression Profiling , High-Throughput Nucleotide Sequencing/methods , Janus Kinase 2/genetics , Myeloproliferative Disorders/genetics , Myeloproliferative Disorders/pathology , Single-Cell Analysis/methods , Thrombocythemia, Essential/genetics , Exome , Genome, Human , Humans , Male , Middle Aged , MutationABSTRACT
BACKGROUND AND PURPOSE: Multiple system atrophy (MSA) is a progressive, adult-onset neurodegenerative disorder clinically characterized by combinations of autonomic failure, parkinsonism, cerebellar ataxia and pyramidal signs. Although a few genetic factors have been reported to contribute to the disease, its mutational profiles have not been systemically studied. METHODS: To address the genetic profiles of clinically diagnosed MSA patients, exome sequencing and triplet repeat detection was conducted in 205 MSA patients, including one familial case. The pathogenicity of variants was determined according to the American College of Medical Genetics and Genomics and the Association for Molecular Pathology guidelines. RESULTS: In the familial patient, a novel heterozygous COQ2 pathogenic variant (p.Ala351Thr) was identified in the MSA pedigree. In the sporadic patients, 29 pathogenic variants were revealed in 21 genes, and the PARK7 p.Ala104Thr variant was significantly associated with MSA (p = 0.0018). Moreover, burden tests demonstrated that the pathogenic variants were enriched in cerebellar ataxia-related genes in patients. Furthermore, repeat expansion analyses revealed that two patients carried the pathogenic CAG repeat expansion in the CACNA1A gene (SCA6), one patient carried the (ACAGG)exp/(ACAGG)exp expansion in RFC1 and one carried the GAA-pure expansion in FGF14 gene. CONCLUSION: In conclusion, a novel COQ2 pathogenic variant was identified in a familial MSA patient, and repeat expansions in CACNA1A, RFC1 and FGF14 gene were detected in four sporadic patients. Moreover, a PARK7 variant and the burden of pathogenic variants in cerebellar ataxia-related genes were associated with MSA.
ABSTRACT
Both ozone (O3) and UV/O3 treatment processes can effectively remove organic matter in the flocculated membrane filtration concentrate from landfill leachate, but the ozonation byproducts (OBPs) generated in the processes remain unknown. Using electrospray ionization-coupled Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS), this study investigated the molecular characteristics of unknown OBPs and their formation mechanisms during the treatment of flocculated nanofiltration concentrate (FNFC) using the O3 and UV/O3 processes. The results showed that after being treated by the O3 and UV/O3 processes, the average value of the oxygen-to-carbon ratio (O/Cavg) in the FNFC organic matter increased substantially from 0.49 to 0.61-0.64 and 0.63-0.71, respectively, with an O3 dosage of 13.4-54.4 mg/min. The main OBPs were CHO and CHON compounds, which were mainly produced through oxygenation (+O2/+O3 and -H2+O2), oxidative deamination (-NH3+O2), decyclopropyl (-C3H4), and deisopropyl (-C3H6) reactions. The hydroxyl radical (â¢OH) can intensify these reactions, resulting in an abundance of OBPs with a high oxidation degree and low molecular weight. OBPs at five m/z values were fragmented and analyzed with tandem mass spectrometry, and abundant hydroxyl groups, carboxyl groups, and carbonyl groups were tentatively identified, presenting a potential toxicity to aquatic organisms. Due to the high molecular diversity of the OBPs in FNFC, their lower ΔGCoxo compared to natural fulvic acid, and potential toxicity, their impact on the water environment should be given more attention.
Subject(s)
Ozone , Water Pollutants, Chemical , Water Purification , Ozone/analysis , Water Pollutants, Chemical/analysis , Oxidation-Reduction , Tandem Mass Spectrometry , Hydroxyl Radical , Water Purification/methodsABSTRACT
The actin cytoskeleton is regulated by many proteins including capping proteins that stabilize actin filaments (F-actin) by inhibiting actin polymerization and depolymerization. Here, we report two pediatric probands who carry damaging heterozygous de novo mutations in CAPZA2 (HGNC: 1490) and exhibit neurological symptoms with shared phenotypes including global motor development delay, speech delay, intellectual disability, hypotonia and a history of seizures. CAPZA2 encodes a subunit of an F-actin-capping protein complex (CapZ). CapZ is an obligate heterodimer consisting of α and ß heterodimer conserved from yeast to human. Vertebrate genomes contain three α subunits encoded by three different genes and CAPZA2 encodes the α2 subunit. The single orthologue of CAPZA genes in Drosophila is cpa. Loss of cpa leads to lethality in early development and expression of the human reference; CAPZA2 rescues this lethality. However, the two CAPZA2 variants identified in the probands rescue this lethality at lower efficiency than the reference. Moreover, expression of the CAPZA2 variants affects bristle morphogenesis, a process that requires extensive actin polymerization and bundling during development. Taken together, our findings suggest that variants in CAPZA2 lead to a non-syndromic neurodevelopmental disorder in children.
Subject(s)
CapZ Actin Capping Protein/genetics , Developmental Disabilities/genetics , Genetic Predisposition to Disease , Intellectual Disability/genetics , Actin Cytoskeleton/genetics , Amino Acid Sequence , Child , Child, Preschool , Developmental Disabilities/pathology , Female , Heterozygote , Humans , Intellectual Disability/pathology , Mutation/genetics , PhenotypeABSTRACT
The brains of some insects can encode and decode polarization information and obtain heading angle information. Referring to the encoding ability of insects, exponential function encoding is designed to improve the stability of the polarized light compass artificial neural network. However, in the decoding process, only neurons with the largest activation degree are used for decoding (maximum value decoding), so the heading information contained in other neurons is not used. Therefore, average value decoding (AVD) and weighted AVD are proposed to use the heading information contained in multiple neurons to determine the heading. In addition, concerning the phenomenon of threshold activation of insect neurons, threshold value decoding (TVD) and weighted TVD are proposed, which can effectively eliminate the interference of neurons with low activation. Moreover, this paper proposes to improve the heading determination accuracy of the artificial neural network through pre-training. The simulation and experimental results show that the new, to the best of our knowledge, decoding methods and pre-training can effectively improve the heading determination accuracy of the artificial neural network.
Subject(s)
Brain , Neural Networks, Computer , Brain/physiology , Computer SimulationABSTRACT
To explore the influence of different wax components and the shear effect exerted by the pump and pipe wall in the process of crude oil pipeline transportation on the microbehavior of wax aggregation in crude oil at low temperatures, molecular dynamics models of binary and multivariate systems of crude oil with different wax components are established in this paper. The simulation results are compared with the existing experimental results and the NIST database to verify the rationality and accuracy of the models. By using the established binary model to simulate four crude oil systems containing different wax components, it can be found that the longer the wax molecular chain, the more easily the wax molecules aggregate. The influence of temperature on the aggregation process of wax molecules with different chain lengths is also studied. The lower the temperature, the greater the difference in wax molecular aggregation degree caused by the difference in molecular chain length. Nonequilibrium molecular dynamics is used to simulate the shear process of a multivariate system of crude oil, and the micromechanisms of the shear effect on the aggregation process of wax molecules are studied. Shearing can destroy the stable structure of crude oil, resulting in the orientation and conformational transformation of wax molecules, and obtaining the region of wax molecules sensitive to temperature and shear effects, the temperatures of which are below the wax precipitation point and the shear rate of which is lower than the maximum shear rate to prevent the molecular structure from being destroyed. At the same time, the sensitivity of wax components with different chain lengths to the shear effect is studied. The research results provide theoretical guidance for ensuring the safe and economic operation of waxy crude oil production.
ABSTRACT
BACKGROUND: Several genetic susceptibility loci associated with diabetic nephropathy have been documented, but no causative variants implying novel pathogenetic mechanisms have been elucidated. METHODS: We carried out whole-genome sequencing of a discovery cohort of Finnish siblings with type 1 diabetes who were discordant for the presence (case) or absence (control) of diabetic nephropathy. Controls had diabetes without complications for 15-37 years. We analyzed and annotated variants at genome, gene, and single-nucleotide variant levels. We then replicated the associated variants, genes, and regions in a replication cohort from the Finnish Diabetic Nephropathy study that included 3531 unrelated Finns with type 1 diabetes. RESULTS: We observed protein-altering variants and an enrichment of variants in regions associated with the presence or absence of diabetic nephropathy. The replication cohort confirmed variants in both regulatory and protein-coding regions. We also observed that diabetic nephropathy-associated variants, when clustered at the gene level, are enriched in a core protein-interaction network representing proteins essential for podocyte function. These genes include protein kinases (protein kinase C isoforms ε and ι) and protein tyrosine kinase 2. CONCLUSIONS: Our comprehensive analysis of a diabetic nephropathy cohort of siblings with type 1 diabetes who were discordant for kidney disease points to variants and genes that are potentially causative or protective for diabetic nephropathy. This includes variants in two isoforms of the protein kinase C family not previously linked to diabetic nephropathy, adding support to previous hypotheses that the protein kinase C family members play a role in diabetic nephropathy and might be attractive therapeutic targets.
Subject(s)
Diabetes Mellitus, Type 1/complications , Diabetic Nephropathies/genetics , Whole Genome Sequencing/methods , Adolescent , Adult , Animals , Child , Child, Preschool , Diabetes Mellitus, Type 1/genetics , Female , HEK293 Cells , Humans , Male , Polymorphism, Single Nucleotide , Protein Kinase C/physiology , Siblings , Young Adult , ZebrafishABSTRACT
Evaporation is a typical heat and mass transfer process, which is important in both nature and industry. Here, the evaporation of five fluid samples (pure Ar, pure Kr and Ar/Kr mixtures with molar ratio Ar : Kr = 1 : 3, Ar : Kr = 1 : 1 and Ar : Kr = 3 : 1) on Pt surface was investigated using molecular dynamics simulations. Colligative properties of the mixtures led to the melting of the Ar/Kr mixtures (Ar : Kr = 1 : 1, Ar : Kr = 3 : 1) at 70 K below the triple point of Ar. Furthermore, under the same condition, the other systems were frozen as the solid state. The Pt surface at 90 K, over the boiling point of Ar, triggered the evaporation of Ar atoms in all the systems while the Kr atoms remained in the condensed state. Kr atoms were reported to be evaporated to a large extent when the Pt surface was heated to 120 K near the boiling point of Kr. The presence of Kr could reduce the evaporation of the Ar atoms, especially when the mole ratio of Ar : Kr in the mixture was 1 : 1 because the Ar : Kr = 1 : 1 system can effectively reduce the temperature of the gas-liquid interface. The temperature of the fluid samples then decreased with increase in distance between Pt and fluid atoms because the evaporated atoms could take the thermal energy away from the condensed films. Moreover, both Ar and Kr atoms, which were close to the Pt surface, hardly changed during evaporation because of the strong attractive force from the Pt substrate.
ABSTRACT
The effect of biochar on the removal of organic and nitrogen contaminants from leachate in a semi-aerobic aged refuse biofilter (SAARB) was investigated. A preset amount of biochar was mixed with the aged refuse to explore the enhancement ability of pollutant removal by characterizing the leachate effluent and gas. The results showed that biochar contributed to the removal of organic and nitrogen pollutants from the leachate and that increasing the amount of biochar added led to higher colour number, chemical oxygen demand, ammonia nitrogen, and total nitrogen removal efficiencies. Furthermore, the addition of biochar significantly increased the removal of large molecule organic pollutants from the leachate. The improved removal of organics was due to the considerable number of surface functional groups and the large surface area of the biochar, which effectively absorbed and removed a significant amount of the organic matter from the leachate. Biochar elevated the dissolved oxygen concentration in the semi-aerobic system, which facilitated the completion of the nitrification reaction. It also promoted denitrification by acting as a supplementary carbon source. The nitrous oxide (N2O) emissions decreased as the amount of biochar added increased. When the biochar proportion reached 3%, the N2O emission was only 1.11% of the original total nitrogen and the di-nitrogen emission was 19.61%. The findings of this study can be used to improve the treatment of leachate using biochar combined with a SAARB.
Subject(s)
Environmental Pollutants , Water Pollutants, Chemical , Bioreactors , Charcoal , Denitrification , Nitrogen , Water Pollutants, Chemical/analysisABSTRACT
Lupus nephritis (LN) is one of the most prevalent and serious complications of SLE, with significant effects on patient and renal survival. Although a large number of genetic variants associated with SLE have been identified, biomarkers that correlate with LN are extremely limited. In this study, we performed a comprehensive sequencing analysis of the whole MHC region in 1331 patients with LN and 1296 healthy controls and validated the independent associations in another 950 patients with LN and 1000 controls. We discovered five independent risk variants for LN within the MHC region, including HLA-DRß1 amino acid 11 (Pomnibus<0.001), HLA-DQß1 amino acid 45 (P<0.001; odds ratio, 0.58; 95% confidence interval, 0.52 to 0.65), HLA-A amino acid 156 (Pomnibus<0.001), HLA-DPß1 amino acid 76 (Pomnibus<0.001), and a missense variant in PRRC2A (rs114580964; P<0.001; odds ratio, 0.38; 95% confidence interval, 0.30 to 0.49) at genome-wide significance. These data implicate aberrant peptide presentation by MHC classes 1 and 2 molecules and sex hormone modulation in the development of LN.
Subject(s)
Genome-Wide Association Study , Lupus Nephritis/genetics , Major Histocompatibility Complex/genetics , Adult , Female , Humans , MaleABSTRACT
Initial results from sequencing studies suggest that there are relatively few low-frequency (<5%) variants associated with large effects on common phenotypes. We performed low-pass whole-genome sequencing in 680 individuals from the InCHIANTI study to test two primary hypotheses: (i) that sequencing would detect single low-frequency-large effect variants that explained similar amounts of phenotypic variance as single common variants, and (ii) that some common variant associations could be explained by low-frequency variants. We tested two sets of disease-related common phenotypes for which we had statistical power to detect large numbers of common variant-common phenotype associations-11 132 cis-gene expression traits in 450 individuals and 93 circulating biomarkers in all 680 individuals. From a total of 11 657 229 high-quality variants of which 6 129 221 and 5 528 008 were common and low frequency (<5%), respectively, low frequency-large effect associations comprised 7% of detectable cis-gene expression traits [89 of 1314 cis-eQTLs at P < 1 × 10(-06) (false discovery rate â¼5%)] and one of eight biomarker associations at P < 8 × 10(-10). Very few (30 of 1232; 2%) common variant associations were fully explained by low-frequency variants. Our data show that whole-genome sequencing can identify low-frequency variants undetected by genotyping based approaches when sample sizes are sufficiently large to detect substantial numbers of common variant associations, and that common variant associations are rarely explained by single low-frequency variants of large effect.
Subject(s)
Genetic Association Studies/methods , Genetic Markers , Phenotype , Adult , Aged , Aged, 80 and over , Female , Gene Frequency , Genetic Variation , Genome, Human , Genotyping Techniques , High-Throughput Nucleotide Sequencing , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide , Quantitative Trait Loci , Young AdultABSTRACT
The evolution mechanism of a vent pipe diameter on a waste-stabilization process in semi-aerobic bioreactor landfills was analyzed from the organic-matter concentration, biodegradability, spectral characteristics of dissolved organic matter, correlations and principal-component analysis. Waste samples were collected at different distances from the vent pipe and from different landfill layers in semi-aerobic bioreactor landfills with different vent pipe diameters. An increase in vent pipe diameter favored waste degradation. Waste degradation in landfills can be promoted slightly when the vent pipe diameter increases from 25 to 50 mm. It could be promoted significantly when the vent pipe diameter was increased to 75 mm. The vent pipe diameter is important in waste degradation in the middle layer of landfills. The dissolved organic matter in the waste is composed mainly of long-wave humus (humin), short-wave humus (fulvic acid) and tryptophan. The humification levels of the waste that was located at the center of vent pipes with 25-, 50- and 75-mm diameters were 2.2682, 4.0520 and 7.6419 Raman units, respectively. The appropriate vent pipe diameter for semi-aerobic bioreactor landfills with an 800-mm diameter was 75 mm. The effect of different vent pipe diameters on the degree of waste stabilization is reflected by two main components. Component 1 is related mainly to the content of fulvic acid, biologically degradable material and organic matter. Component 2 is related mainly to the content of tryptophan and humin from the higher vascular plants.
Subject(s)
Bioreactors , Waste Disposal Facilities , Refuse Disposal , SoilABSTRACT
It has been hypothesized that, in aggregate, rare variants in coding regions of genes explain a substantial fraction of the heritability of common diseases. We sequenced the exomes of 1,000 Danish cases with common forms of type 2 diabetes (including body mass index > 27.5 kg/m(2) and hypertension) and 1,000 healthy controls to an average depth of 56×. Our simulations suggest that our study had the statistical power to detect at least one causal gene (a gene containing causal mutations) if the heritability of these common diseases was explained by rare variants in the coding regions of a limited number of genes. We applied a series of gene-based tests to detect such susceptibility genes. However, no gene showed a significant association with disease risk after we corrected for the number of genes analyzed. Thus, we could reject a model for the genetic architecture of type 2 diabetes where rare nonsynonymous variants clustered in a modest number of genes (fewer than 20) are responsible for the majority of disease risk.
Subject(s)
Diabetes Mellitus, Type 2/genetics , Exome , Genetic Variation , Open Reading Frames , Computational Biology , Denmark , Genetic Association Studies , Genotype , High-Throughput Nucleotide Sequencing , Humans , Models, Statistical , Polymorphism, Single Nucleotide , White PeopleABSTRACT
UNLABELLED: In the past 50 years there have been considerable efforts to identify the cellular receptor of hepatitis B virus (HBV). Recently, in vitro evidence from several groups has shown that the sodium-taurocholate cotransporting polypeptide (NTCP, which is encoded by SLC10A1 and transports bile acids into hepatic cells in enterohepatic recirculation) is a strong candidate. In particular, in vitro the p.Ser267Phe variation of SLC10A1 results in loss of HBV receptor function. We tested the role of NTCP as a receptor for HBV in chronic hepatitis B patients using a genetic association study. We selected SLC10A1 variants from 189 exomes. We used Sanger sequencing to follow up the association of the various SLC10A1 variants in a Han Chinese cohort of 1899 chronic hepatitis B patients and 1828 healthy controls. We further investigated the potential impact of the p.Ser267Phe variant on NTCP function using structural analysis. The p.Ser267Phe variant was associated with healthy status (P = 5.7 × 10(-23) , odds ratio = 0.36) irrespective of hepatitis B virus surface antibody status (P = 6.2 × 10(-21) and 1.5 × 10(-10) , respectively, when the cases were compared with hepatitis B virus surface antibody-positive and -negative controls). The variation was also associated with a lower incidence of acute-on-chronic liver failure (P = 0.007). The estimated heritability explained by this single variation was â¼3.2%. The population prevented fraction was around 13.0% among the southern Chinese. Our structural modeling showed that the p.Ser267Phe variant might interfere with ligand binding, thereby preventing HBV from cellular entry. CONCLUSION: The p.Ser267Phe NTCP variant is significantly associated with resistance to chronic hepatitis B and a lower incidence of acute-on-chronic liver failure. Our results support that NTCP is a cellular receptor for HBV in human infection.
Subject(s)
Hepatitis B, Chronic/genetics , Organic Anion Transporters, Sodium-Dependent/genetics , Symporters/genetics , Adult , Female , Genetic Association Studies , Humans , Male , Middle AgedABSTRACT
The demographic history of the isolated population of the Faroe Islands may have induced enrichment of variants rarely seen in outbred European populations, including enrichment of risk variants for panic disorder (PD). PD is a common mental disorder, characterized by recurring and unprovoked panic attacks, and genetic factors have been estimated to explain around 40% of the risk. In this study the potential enrichment of PD risk variants was explored based on whole-exome sequencing of 54 patients with PD and 211 control individuals from the Faroese population. No genome-wide significant associations were found, however several single variants and genes showed strong association with PD, where DGKH was found to be the strongest PD associated gene. Interestingly DGKH has previously demonstrated genome-wide significant association with bipolar disorder as well as evidence of association to other mental disorders. Additionally, we found an enrichment of PD risk variants in the Faroese population; variants with otherwise low frequency in more outbreed European populations. © 2016 Wiley Periodicals, Inc.
Subject(s)
Diacylglycerol Kinase/genetics , Panic Disorder/genetics , Adult , Denmark , Diacylglycerol Kinase/metabolism , Ethnicity/genetics , Exome , Female , Gene Frequency/genetics , Genetic Predisposition to Disease/genetics , Genetic Variation/genetics , Genome-Wide Association Study/methods , Haplotypes/genetics , Humans , Male , Panic Disorder/psychology , Polymorphism, Single Nucleotide/genetics , Risk Factors , White People/geneticsABSTRACT
There is accumulating evidence that the number of multiple-nucleotide substitutions (MNS) occurring in closely spaced sites in eukaryotic genomes is significantly higher than would be predicted from the random accumulation of independently generated single-nucleotide substitutions (SNS). Although this excess can in principle be accounted for by the concept of transient hypermutability, a general mutational signature of concurrent MNS mutations has not so far been evident. Employing a dataset (N = 449) of "concurrent" double MNS mutations causing human inherited disease, we have identified just such a mutational signature: concurrently generated double MNS mutations exhibit a >twofold lower transition/transversion ratio (termed RTs/Tv ) than independently generated de novo SNS mutations (<0.80 vs. 2.10; P = 2.69 × 10(-14) ). We replicated this novel finding through a similar analysis employing two double MNS variant datasets with differing abundances of concurrent events (150,521 variants with both substitutions on the same haplotypic lineage vs. 94,875 variants whose component substitutions were on different haplotypic lineages) plus 5,430,874 SNS variants, all being derived from the whole-genome sequencing of seven Chinese individuals. Evaluation of the newly observed mutational signature in diverse contexts provides solid support for the postulated role of translesion synthesis DNA polymerases in transient hypermutability.
Subject(s)
Genome, Human , Nucleotides/metabolism , Point Mutation , Genetic Diseases, Inborn/genetics , HumansABSTRACT
BACKGROUND: Massively parallel cDNA sequencing (RNA-seq) experiments are gradually superseding microarrays in quantitative gene expression profiling. However, many biologists are uncertain about the choice of differentially expressed gene (DEG) analysis methods and the validity of cost-saving sample pooling strategies for their RNA-seq experiments. Hence, we performed experimental validation of DEGs identified by Cuffdiff2, edgeR, DESeq2 and Two-stage Poisson Model (TSPM) in a RNA-seq experiment involving mice amygdalae micro-punches, using high-throughput qPCR on independent biological replicate samples. Moreover, we sequenced RNA-pools and compared their results with sequencing corresponding individual RNA samples. RESULTS: False-positivity rate of Cuffdiff2 and false-negativity rates of DESeq2 and TSPM were high. Among the four investigated DEG analysis methods, sensitivity and specificity of edgeR was relatively high. We documented the pooling bias and that the DEGs identified in pooled samples suffered low positive predictive values. CONCLUSIONS: Our results highlighted the need for combined use of more sensitive DEG analysis methods and high-throughput validation of identified DEGs in future RNA-seq experiments. They indicated limited utility of sample pooling strategies for RNA-seq in similar setups and supported increasing the number of biological replicate samples.
Subject(s)
DNA, Complementary/genetics , High-Throughput Nucleotide Sequencing/methods , Sequence Analysis, RNA , Animals , Mice , SoftwareABSTRACT
Copy number variations (CNVs) have increasingly been reported to cause, or predispose to, human disease. However, a large fraction of these CNVs have not been accurately characterized at the single-base-pair level, thereby hampering a better understanding of the mutational mechanisms underlying CNV formation. Here, employing a composite pipeline method derived from various inference-based programs, we have characterized 26 deletion CNVs [including three novel pathogenic CNVs involving an autosomal gene (EXT2) causing hereditary osteochondromas and an X-linked gene (CLCN5) causing Dent disease, as well as 23 CNVs previously identified by inference from a cohort of Canadian autism spectrum disorder families] to the single-base-pair level of accuracy from whole-genome sequencing data. We found that breakpoint-flanking micro-mutations (within 22 bp of the breakpoint) are present in a significant fraction (5/26; 19%) of the deletion CNVs. This analysis also provided evidence that a recently described error-prone form of DNA repair (i.e., repair of DNA double-strand breaks by templated nucleotide sequence insertions derived from distant regions of the genome) not only causes human genetic disease but also impacts on human genome evolution. Our findings illustrate the importance of precise CNV breakpoint delineation for understanding the underlying mutational mechanisms and have implications for primer design in relation to the detection of deletion CNVs in clinical diagnosis.
Subject(s)
Child Development Disorders, Pervasive/genetics , DNA Breaks, Double-Stranded , DNA Copy Number Variations , Genetic Diseases, Inborn/genetics , Genome, Human , Sequence Deletion , Canada , Chloride Channels/genetics , Family , Female , Humans , Male , N-Acetylglucosaminyltransferases/geneticsABSTRACT
Nano bubbles and films are important in theory and various applications, such as the specific ion effect of bubble coalescence, flotation and porous medium seepage; these rely greatly on the fundamental aspects of extended-DLVO surface forces. However, the origin and validation of the non-DLVO forces are still obscure, especially at the nano scale (1-5 nm). Herein, we report the first determination of the disjoining pressures of aqueous electrolyte nano-films using molecular dynamics (MD) simulations. Our results showed that adding salt does not lead to a decrease in the disjoining pressure. On the contrary, higher concentrations results in greater disjoining pressures. In addition, the temperature was found to significantly change the pattern of the disjoining pressure isotherm. These results aid the understanding of a number of underlying mechanisms, involving nano solid-liquid-gas surfaces.
ABSTRACT
Here we present the first diploid genome sequence of an Asian individual. The genome was sequenced to 36-fold average coverage using massively parallel sequencing technology. We aligned the short reads onto the NCBI human reference genome to 99.97% coverage, and guided by the reference genome, we used uniquely mapped reads to assemble a high-quality consensus sequence for 92% of the Asian individual's genome. We identified approximately 3 million single-nucleotide polymorphisms (SNPs) inside this region, of which 13.6% were not in the dbSNP database. Genotyping analysis showed that SNP identification had high accuracy and consistency, indicating the high sequence quality of this assembly. We also carried out heterozygote phasing and haplotype prediction against HapMap CHB and JPT haplotypes (Chinese and Japanese, respectively), sequence comparison with the two available individual genomes (J. D. Watson and J. C. Venter), and structural variation identification. These variations were considered for their potential biological impact. Our sequence data and analyses demonstrate the potential usefulness of next-generation sequencing technologies for personal genomics.