simple sequence repeats
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The ReAct (Recovery, Activity) project is an ENFSI (European Network of Forensic Science Institutes) supported initiative comprising a large consortium of laboratories. Here, the results from more than 23 laboratories are presented. The primary purpose was to design experiments simulating typical casework circumstances; collect data and to implement Bayesian networks to assess the value (i.e., likelihood ratio) of DNA results given activity level propositions. Two different experimental designs were used to simulate a robbery, where a screwdriver was used to force a door or window. Propositions and case information were chosen following laboratory feedback listing typical casework circumstances (included in the paper). In a direct transfer experiment, the defendant owned and used the screwdriver, but he did not force the door/window in question. An unknown person used the defendant's stolen screwdriver. In an indirect transfer experiment, the defendant neither owned, saw, nor used the screwdriver, nor did they force the door or window. For the second experiment, given the defence view, the defendant never held the screwdriver. We envisaged the situation where an object manipulated by the defendant (or the defendant himself/herself) would be touched by the unknown offender who would then force the window. It was found for the direct transfer experiment that unless a single contributor profile aligning with the known person's of interest profile was retrieved, the results did not allow to discriminate between propositions. On the other hand, for the indirect transfer experiment, both single and major contributor profiles that aligned with the person of interest (POI) supported the proposition that the person used the tool rather than an unknown person who had touched an object, when indeed the former was true. There was considerable variation in median recoveries of DNA between laboratories (between 200pg-5ng) for a given experiment if quantities are taken into account. These differences affect the likelihood ratios given activity level propositions. More than 2700 samples were analysed in the course of this study. Two different Bayesian Networks are made available via an open source application written in Shiny R: Shiny_React(). For comparison, all datasets were analysed using a qualitative method categorised into absent, single, major or other given contributors. The importance of standardising methods is emphasised, alongside the necessity of developing new approaches to assign the probability of laboratory-dependent DNA recovery. Freely accessible open databases play a crucial role in supporting these efforts.
- MeSH
- Bayesova věta * MeSH
- DNA fingerprinting * MeSH
- DNA * genetika MeSH
- laboratoře * MeSH
- lidé MeSH
- mikrosatelitní repetice MeSH
- pravděpodobnostní funkce MeSH
- soudní genetika metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Abies guatemalensis Rehder, an endangered conifer endemic to Central American highlands, is ecologically vital in upper montane forests. It faces threats from habitat fragmentation, unsustainable logging, and illegal Christmas tree harvesting. While previous genetic studies on mature trees from eighteen populations showed high within-population diversity and limited among-population differentiation, the genetic impact of recent anthropogenic pressures on younger generations has yet to be discovered. Understanding these effects is crucial for developing effective conservation strategies for this vulnerable species. We sampled 170 young trees (< 15 years old) from seven populations across Guatemala. Seven microsatellite markers were used to analyse genetic diversity, population structure, and recent demographic history. Moderate levels of genetic diversity were observed within populations (mean Shannon diversity index = 4.97, mean Simpson's index = 0.51, mean allelic richness = 11.59, mean observed heterozygosity = 0.59). Although genetic structure broadly aligned with mountain corridors, substantial admixture patterns suggest historical connectivity across all populations. Most populations showed evidence of recent bottlenecks (p < 0.05) and inbreeding. The results suggest a potential decline in genetic diversity and increased population structuring (ΦST = 0.274, p < 0.01) over the past decades compared to the previous study on old trees. The observed genetic patterns indicate ongoing impacts of habitat fragmentation and anthropogenic pressures on A. guatemalensis. Conservation efforts should prioritise expanding effective population sizes and facilitating gene flow, particularly for isolated populations. While restoration efforts may be logistically easier within mountain ranges, genetic evidence suggests that increasing overall population connectivity could benefit this species. Management strategies should implement systematic seed collection protocols to maintain genetic diversity in future populations. These findings highlight the urgent need for conservation measures to preserve remaining genetic diversity and promote connectivity among A. guatemalensis populations.
- MeSH
- ekosystém * MeSH
- genetická variace * MeSH
- jedle * genetika MeSH
- mikrosatelitní repetice * genetika MeSH
- ohrožené druhy * MeSH
- populační genetika MeSH
- zachování přírodních zdrojů MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Guatemala MeSH
Echinococcus granulosus (Batsch, 1786), a cestode of the Teniidae family, causes human cystic echinococcosis (CE) also known as hydatid disease. Echinococcus granulosus sensu lato includes the G1, G3, G4, G5, G6/7 and G8/10 genotypes which are known to cause human CE. This study aimed to differentiate genotypes of E. granulosus s.l. complex by employing EmsB, a tandemly repeated multilocus microsatellite, using next-generation sequencing (MIC-NGS). Human and animal histopathology-confirmed hydatid cyst tissue samples and reference DNA samples of E. granulosus G1, G3, G4, G5, G6/7 and G10 underwent MIC-NGS assay with custom primers amplifying a 151 bp EmsB DNA fragment. NGS data were analysed using online Galaxy analysis pipeline, a phylogenetic tree was constructed by MEGA software, and haplotype networking was performed with PopArt 1.7. All sixty samples (49 from animals and 11 from humans) included were successfully identified and genotyped with a 100 % success rate. The study showed improved discrimination power to distinguish all study samples including closely related E. granulosus s.s. genotypes G1-G3. The maximum likelihood tree reaffirmed the monophyly of E. granulosus s.l. The median-joining haplotype networking revealed 12 distinct haplotypes. In conclusion, MIC-NGS assay was shown to be sensitive, specific and simple to apply to clinical samples offering a powerful discriminatory tool for the genotyping of E. granulosus s.l.
- MeSH
- Echinococcus granulosus * genetika MeSH
- echinokokóza * veterinární parazitologie MeSH
- fylogeneze MeSH
- genotyp * MeSH
- genotypizační techniky veterinární MeSH
- lidé MeSH
- mikrosatelitní repetice * MeSH
- vysoce účinné nukleotidové sekvenování * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
... didn\'t tell us and the goal of identifying all functional human DNA sequences -- 37 -- 2.4 A QUICK ... ... TOUR OF SOME -- ELECTRONIC RESOURCES USED -- TO INTERROGATE THE HUMAN -- GENOME SEQUENCE AND GENE -- ... ... TRIGGERED BY -- LONG TANDEM REPEATS AND -- INTERSPERSED REPEATS 198 -- Pathogenic exchanges between ... ... Pathogenic sequence exchanges between chromatids at mispaired tandem repeats -- 198 -- 199 -- Disease ... ... arising from sequence exchanges between distantly located repeats in nuclear DNA.202 -- 7.5 CHROMOSOME ...
2nd ed. 534 s. : il.
"Genetics and Genomics in Medicine is a new textbook written for undergraduate and graduate students, as well as medical researchers, which explains the science behind the uses of genetics and genomics in medicine today. It is not just about rare inherited and chromosomal disorders, but how genetics affects the whole spectrum of human health and disease. DNA technologies are explained, with emphasis on the modern techniques that have revolutionized the use of genetic information in medicine and are indicating the role of genetics in common complex diseases. The detailed, integrative coverage of genetic approaches to treatment and prevention includes pharmacogenomics and the prospects for personalized medicine. Cancers are essentially genetic diseases and are given a dedicated chapter that includes new insights from cancer genome sequencing. Clinical disorders are covered throughout and there are extensive end-of-chapter questions and problems"--Provided by publisher.
Hazelnut (Corylus), which has high commercial and nutritional benefits, is an important tree for producing nuts and nut oil consumed as ingredient especially in chocolate. While Corylus avellana L. (Euro-pean hazelnut, Betulaceae) and Corylus colurna L. (Turkish hazelnut, Betulaceae) are the two common hazelnut species in Europe, C. avellana L. (Tombul hazelnut) is grown as the most widespread hazelnut species in Turkey, and C. colurna L., which is the most important genetic resource for hazelnut breeding, exists naturally in Anatolia. We generated the transcriptome data of these two Corylus species and used these data for gene discovery and gene expression profiling. Total RNA from young leaves, flowers (male and female), buds, and husk shoots of C. avellana and C. colurna were used for two different libraries and were sequenced using Illumina HiSeq4000 with 100 bp paired-end reads. The transcriptome data 10.48 and 10.30 Gb of C. avellana and C. colurna, respectively, were assembled into 70,265 and 88,343 unigenes, respectively. These unigenes were functionally annotated using the TRAPID platform. We identified 25,312 and 27,051 simple sequen-ce repeats (SSRs) for C. avellana and C. colurna, respectively. TL1, GMPM1, N, 2MMP, At1g29670, CHIB1 unigenes were selected for validation with qPCR. The first de novo transcriptome data of C. co-lurna were used to compare data of C. avellana of commercial importance. These data constitute a valuable extension of the publicly available transcriptomic resource aimed at breeding, medicinal, and industrial research studies.
- MeSH
- líska * genetika metabolismus MeSH
- ořechy MeSH
- stanovení celkové genové exprese MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Turecko MeSH
Human ribosomal DNA is represented by hundreds of repeats in each cell. Every repeat consists of two parts: a 13 kb long 47S DNA with genes encoding 18S, 5.8S, and 28S RNAs of ribosomal particles, and a 30 kb long intergenic spacer (IGS). Remarkably, transcription does not take place in all the repeats. The transcriptionally silent genes are characterized by the epigenetic marks of the inactive chromatin, including DNA hypermethylation of the promoter and adjacent areas. However, it is still unknown what causes the differentiation of the genes into active and silent. In this study, we examine whether this differentiation is related to the nucleotide sequence of IGS. We isolated ribosomal DNA from the nucleoli of human-derived HT1080 cells, and separated methylated and non-methylated DNA by chromatin immunoprecipitation. Then, we used PCR to amplify a 2 kb long region upstream of the transcription start and sequenced the product. We found that six SNVs and a series of short deletions in a region of simple repeats correlated with the DNA methylation status. These data indicate that variability of IGS sequence may initiate silencing of the ribosomal genes. Our study also suggests a number of pathways to this silencing that involve micro-RNAs and/or non-canonical DNA structures.
- MeSH
- intergenová DNA MeSH
- lidé MeSH
- mezerníky ribozomální DNA genetika MeSH
- ribozomální DNA genetika MeSH
- ribozomy * MeSH
- RNA ribozomální 28S genetika MeSH
- sekvence nukleotidů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Many approaches aimed at improving next-generation sequencing output for clinical purposes exist. However, sequencing gaps or misalignments for regions that are difficult to cover because of their low complexity or high homology still exist. Our aim was to improve the yield of sequencing data. A hybridization-based next-generation sequencing library was pooled with custom add-on amplicon-based libraries processed by the same commercial test and run in parallel and sequenced simultaneously. Formulas and steps for proper amplicon pooling (250 to 7000 bp) and final library merging are presented. The novel strategy was tested on selected archetypal situations: diagnostics of a gene with many pseudogenes, a genomic region surrounded by Alu repeats, simple one-time addition of an extra gene, and mosaicism detection. The sequence of all supplemented genomic regions was traced with reasonable coverage at the background of a hybridization captured library. The flexible add-on module expands the possibilities of routine diagnostics. The technical solution makes it possible to mix amplicons that differ significantly in size and process them in one tube simultaneously with samples of the hybridization-based panel. The proposed approach reduces turnaround time and increases diagnostic yield.
- MeSH
- genomika * MeSH
- genová knihovna MeSH
- hybridizace nukleových kyselin MeSH
- lidé MeSH
- vysoce účinné nukleotidové sekvenování * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Wilt (Fusarium oxysporum f. sp. lentis; Fol) is one of the major diseases of lentil worldwide. Two hundred and thirty-five isolates of the pathogen collected from 8 states of India showed substantial variations in morphological characters such as colony texture and pattern, pigmentation and growth rate. The isolates were grouped as slow (47 isolates), medium (118 isolates) and fast (70 isolates) growing. The macroconidia and microconidia (3.0-77.5 × 1.3-8.8 μm for macroconidia and 1.8-22.5 × 0.8-8.0 μm for microconidia for length × width) were variable in size and considering the morphological features, the populations were grouped into 12 categories. Seventy representative isolates based on their morphological variability and place of origin were selected for further study. A set of 10 differential genotypes was identified for virulence analysis and based on virulence patterns on these 10 genotypes, 70 Fol isolates were grouped into 7 races. Random amplified polymorphic DNA (RAPD), universal rice primers (URPs), inter simple sequence repeats (ISSR) and sequence-related amplified polymorphism (SRAP) were used for genetic diversity analysis. URPs, ISSR and SRAP markers gave 100% polymorphism while RAPD gave 98.9% polymorphism. The isolates were grouped into seven clusters at genetic similarities ranging from 21 to 80% using unweighted paired group method with arithmetic average analysis. The major clusters include the populations from northern and central regions of India in distinct groups. All these three markers proved suitable for diversity analysis, but their combined use was better to resolve the area specific grouping of the isolates. The sequences of rDNA ITS and TEF-1α genes of the representative isolates were analysed. Phylogenetic analysis of ITS region grouped the isolates into two major clades representing various races. In TEF-1α analysis, the isolates were grouped into two major clades with 28 isolates into one clade and 4 remaining isolates in another clade. The molecular groups partially correspond to the lentil growing regions of the isolates and races of the pathogen.
BACKGROUND: Current SARS-CoV-2 detection platforms lack the ability to differentiate among variants of concern (VOCs) in an efficient manner. CRISPR/Cas (Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated) based detection systems have the potential to transform the landscape of COVID-19 diagnostics due to their programmability; however, most of these methods are reliant on either a multi-step process involving amplification or elaborate guide RNA designs. METHODS: Three Cas12b proteins from Alicyclobacillus acidoterrestris (AacCas12b), Alicyclobacillus acidiphilus (AapCas12b), and Brevibacillus sp. SYP-B805 (BrCas12b) were expressed and purified, and their thermostability was characterised by differential scanning fluorimetry, cis-, and trans-cleavage activities over a range of temperatures. The BrCas12b was then incorporated into a reverse transcription loop-mediated isothermal amplification (RT-LAMP)-based one-pot reaction system, coined CRISPR-SPADE (CRISPR Single Pot Assay for Detecting Emerging VOCs). FINDINGS: Here we describe a complete one-pot detection reaction using a thermostable Cas12b effector endonuclease from Brevibacillus sp. to overcome these challenges detecting and discriminating SARS-CoV-2 VOCs in clinical samples. CRISPR-SPADE was then applied for discriminating SARS-CoV-2 VOCs, including Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2), and Omicron (B.1.1.529) and validated in 208 clinical samples. CRISPR-SPADE achieved 92·8% sensitivity, 99·4% specificity, and 96·7% accuracy within 10-30 min for discriminating the SARS-CoV-2 VOCs, in agreement with S gene sequencing, achieving a positive and negative predictive value of 99·1% and 95·1%, respectively. Interestingly, for samples with high viral load (Ct value ≤ 30), 100% accuracy and sensitivity were attained. To facilitate dissemination and global implementation of the assay, a lyophilised version of one-pot CRISPR-SPADE reagents was developed and combined with an in-house portable multiplexing device capable of interpreting two orthogonal fluorescence signals. INTERPRETATION: This technology enables real-time monitoring of RT-LAMP-mediated amplification and CRISPR-based reactions at a fraction of the cost of a qPCR system. The thermostable Brevibacillus sp. Cas12b offers relaxed primer design for accurately detecting SARS-CoV-2 VOCs in a simple and robust one-pot assay. The lyophilised reagents and simple instrumentation further enable rapid deployable point-of-care diagnostics that can be easily expanded beyond COVID-19. FUNDING: This project was funded in part by the United States-India Science & Technology Endowment Fund- COVIDI/247/2020 (P.K.J.), Florida Breast Cancer Foundation- AGR00018466 (P.K.J.), National Institutes of Health- NIAID 1R21AI156321-01 (P.K.J.), Centers for Disease Control and Prevention- U01GH002338 (R.R.D., J.A.L., & P.K.J.), University of Florida, Herbert Wertheim College of Engineering (P.K.J.), University of Florida Vice President Office of Research and CTSI seed funds (M.S.), and University of Florida College of Veterinary Medicine and Emerging Pathogens Institute (R.R.D.).
- MeSH
- Brevibacillus * genetika MeSH
- COVID-19 * diagnóza MeSH
- guide RNA, Kinetoplastida MeSH
- lidé MeSH
- SARS-CoV-2 genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Analysis of histone variants and epigenetic marks is dominated by genome-wide approaches in the form of chromatin immunoprecipitation-sequencing (ChIP-seq) and related methods. Although uncontested in their value for single-copy genes, mapping the chromatin of DNA repeats is problematic for biochemical techniques that involve averaging of cell populations or analysis of clusters of tandem repeats in a single-cell analysis. Extending chromatin and DNA fibers allows us to study the epigenetics of individual repeats in their specific chromosomal context, and thus constitutes an important tool for gaining a complete understanding of the epigenetic organization of genomes. We report that using an optimized fiber extension protocol is essential in order to obtain more reproducible data and to minimize the clustering of fibers. We also demonstrate that the use of super-resolution microscopy is important for reliable evaluation of the distribution of histone modifications on individual fibers. Furthermore, we introduce a custom script for the analysis of methylation levels on DNA fibers and apply it to map the methylation of telomeres, ribosomal genes and centromeres.