scholarly journals Analysis of HLA-G long-read genomic sequences in mother–offspring pairs with preeclampsia

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ayako Nishizawa ◽  
Kazuki Kumada ◽  
Keiko Tateno ◽  
Maiko Wagata ◽  
Sakae Saito ◽  
...  
Keyword(s):  
Single Molecule ◽  
Gene Polymorphisms ◽  
Genomic Dna ◽  
Genomic Sequences ◽  
Genomic Sequencing ◽  
Public Database ◽  
Coding Sequences ◽  
Pacbio Rs Ii ◽  
Potential Association ◽  
Long Read

AbstractPreeclampsia is a pregnancy-induced disorder that is characterized by hypertension and is a leading cause of perinatal and maternal–fetal morbidity and mortality. HLA-G is thought to play important roles in maternal–fetal immune tolerance, and the associations between HLA-G gene polymorphisms and the onset of pregnancy-related diseases have been explored extensively. Because contiguous genomic sequencing is difficult, the association between the HLA-G genotype and preeclampsia onset is controversial. In this study, genomic sequences of the HLA-G region (5.2 kb) from 31 pairs of mother–offspring genomic DNA samples (18 pairs from normal pregnancies/births and 13 from preeclampsia births) were obtained by single-molecule real-time sequencing using the PacBio RS II platform. The HLA-G alleles identified in our cohort matched seven known HLA-G alleles, but we also identified two new HLA-G alleles at the fourth-field resolution and compared them with nucleotide sequences from a public database that consisted of coding sequences that cover the 3.1-kb HLA-G gene span. Intriguingly, a potential association between preeclampsia onset and the poly T stretch within the downstream region of the HLA-G*01:01:01:01 allele was found. Our study suggests that long-read sequencing of HLA-G will provide clues for characterizing HLA-G variants that are involved in the pathophysiology of preeclampsia.

scholarly journals MBRS-47. RAPID MOLECULAR SUBGROUPING OF MEDULLOBLASTOMA BASED ON DNA METHYLATION BY NANOPORE SEQUENCING

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii406-iii406
Author(s):  
Julien Masliah-Planchon ◽  
Elodie Girard ◽  
Philipp Euskirchen ◽  
Christine Bourneix ◽  
Delphine Lequin ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Single Molecule ◽  
Nanopore Sequencing ◽  
Molecular Subgroup ◽  
Group Assignment ◽  
Group 4 ◽  
Methylation Assay ◽  
Tumor Group ◽  
Long Read ◽  
Group 3

Abstract Medulloblastoma (MB) can be classified into four molecular subgroups (WNT group, SHH group, group 3, and group 4). The gold standard of assignment of molecular subgroup through DNA methylation profiling uses Illumina EPIC array. However, this tool has some limitation in terms of cost and timing, in order to get the results soon enough for clinical use. We present an alternative DNA methylation assay based on nanopore sequencing efficient for rapid, cheaper, and reliable subgrouping of clinical MB samples. Low-depth whole genome with long-read single-molecule nanopore sequencing was used to simultaneously assess copy number profile and MB subgrouping based on DNA methylation. The DNA methylation data generated by Nanopore sequencing were compared to a publicly available reference cohort comprising over 2,800 brain tumors including the four subgroups of MB (Capper et al. Nature; 2018) to generate a score that estimates a confidence with a tumor group assignment. Among the 24 MB analyzed with nanopore sequencing (six WNT, nine SHH, five group 3, and four group 4), all of them were classified in the appropriate subgroup established by expression-based Nanostring subgrouping. In addition to the subgrouping, we also examine the genomic profile. Furthermore, all previously identified clinically relevant genomic rearrangements (mostly MYC and MYCN amplifications) were also detected with our assay. In conclusion, we are confirming the full reliability of nanopore sequencing as a novel rapid and cheap assay for methylation-based MB subgrouping. We now plan to implement this technology to other embryonal tumors of the central nervous system.

scholarly journals Survey of the Bradysia odoriphaga Transcriptome Using PacBio Single-Molecule Long-Read Sequencing

Genes ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 481 ◽  
Author(s):  
Chen ◽  
Lin ◽  
Xie ◽  
Zhong ◽  
Zhang ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Single Molecule ◽  
Functional Categories ◽  
Genetic Studies ◽  
Sequencing Technologies ◽  
Clusters Of Orthologous Groups ◽  
Long Read ◽  
Main Gene ◽  
First Time ◽  
Main Factor

The damage caused by Bradysia odoriphaga is the main factor threatening the production of vegetables in the Liliaceae family. However, few genetic studies of B. odoriphaga have been conducted because of a lack of genomic resources. Many long-read sequencing technologies have been developed in the last decade; therefore, in this study, the transcriptome including all development stages of B. odoriphaga was sequenced for the first time by Pacific single-molecule long-read sequencing. Here, 39,129 isoforms were generated, and 35,645 were found to have annotation results when checked against sequences available in different databases. Overall, 18,473 isoforms were distributed in 25 various Clusters of Orthologous Groups, and 11,880 isoforms were categorized into 60 functional groups that belonged to the three main Gene Ontology classifications. Moreover, 30,610 isoforms were assigned into 44 functional categories belonging to six main Kyoto Encyclopedia of Genes and Genomes functional categories. Coding DNA sequence (CDS) prediction showed that 36,419 out of 39,129 isoforms were predicted to have CDS, and 4319 simple sequence repeats were detected in total. Finally, 266 insecticide resistance and metabolism-related isoforms were identified as candidate genes for further investigation of insecticide resistance and metabolism in B. odoriphaga.

scholarly journals Hapo-G, haplotype-aware polishing of genome assemblies with accurate reads

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Jean-Marc Aury ◽  
Benjamin Istace
Keyword(s):  
Single Molecule ◽  
Direct Consequence ◽  
High Quality ◽  
Sequencing Errors ◽  
Coding Regions ◽  
Sequencing Technologies ◽  
Long Reads ◽  
Oxford Nanopore ◽  
Long Read ◽  
Genome Assemblies

Abstract Single-molecule sequencing technologies have recently been commercialized by Pacific Biosciences and Oxford Nanopore with the promise of sequencing long DNA fragments (kilobases to megabases order) and then, using efficient algorithms, provide high quality assemblies in terms of contiguity and completeness of repetitive regions. However, the error rate of long-read technologies is higher than that of short-read technologies. This has a direct consequence on the base quality of genome assemblies, particularly in coding regions where sequencing errors can disrupt the coding frame of genes. In the case of diploid genomes, the consensus of a given gene can be a mixture between the two haplotypes and can lead to premature stop codons. Several methods have been developed to polish genome assemblies using short reads and generally, they inspect the nucleotide one by one, and provide a correction for each nucleotide of the input assembly. As a result, these algorithms are not able to properly process diploid genomes and they typically switch from one haplotype to another. Herein we proposed Hapo-G (Haplotype-Aware Polishing Of Genomes), a new algorithm capable of incorporating phasing information from high-quality reads (short or long-reads) to polish genome assemblies and in particular assemblies of diploid and heterozygous genomes.

scholarly journals Biological Nanopores: Engineering on Demand

Life ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 27
Author(s):  
Ana Crnković ◽  
Marija Srnko ◽  
Gregor Anderluh
Keyword(s):  
Molecular Biology ◽  
Single Molecule ◽  
Enzymatic Reactions ◽  
Label Free ◽  
Natural Sources ◽  
On Demand ◽  
Label Free Detection ◽  
Long Read ◽  
Inorganic Molecules ◽  
Standard Molecular Biology

Nanopore-based sensing is a powerful technique for the detection of diverse organic and inorganic molecules, long-read sequencing of nucleic acids, and single-molecule analyses of enzymatic reactions. Selected from natural sources, protein-based nanopores enable rapid, label-free detection of analytes. Furthermore, these proteins are easy to produce, form pores with defined sizes, and can be easily manipulated with standard molecular biology techniques. The range of possible analytes can be extended by using externally added adapter molecules. Here, we provide an overview of current nanopore applications with a focus on engineering strategies and solutions.

Fatal Respiratory Diphtheria Caused by ß-Lactam–Resistant Corynebacterium diphtheriae

2020 ◽  
Author(s):  
Brian M Forde ◽  
Andrew Henderson ◽  
Elliott G Playford ◽  
David Looke ◽  
Belinda C Henderson ◽  
...  
Keyword(s):  
Single Molecule ◽  
Genomic Analysis ◽  
Carbapenem Resistance ◽  
Corynebacterium Diphtheriae ◽  
Penicillin Binding Protein ◽  
Long Read ◽  
Amoxicillin Clavulanic Acid ◽  
Resistance To Penicillin ◽  
High Level

Abstract Background Diphtheria is a potentially fatal respiratory disease caused by toxigenic Corynebacterium diphtheriae. Although resistance to erythromycin has been recognized, β-lactam resistance in toxigenic diphtheria has not been described. Here, we report a case of fatal respiratory diphtheria caused by toxigenic C. diphtheriae resistant to penicillin and all other β-lactam antibiotics, and describe a novel mechanism of inducible carbapenem resistance associated with the acquisition of a mobile resistance element. Methods Long-read whole-genome sequencing was performed using Pacific Biosciences Single Molecule Real-Time sequencing to determine the genome sequence of C. diphtheriae BQ11 and the mechanism of β-lactam resistance. To investigate the phenotypic inducibility of meropenem resistance, short-read sequencing was performed using an Illumina NextSeq500 sequencer on the strain both with and without exposure to meropenem. Results BQ11 demonstrated high-level resistance to penicillin (benzylpenicillin minimum inhibitory concentration [MIC] ≥ 256 μg/ml), β-lactam/β-lactamase inhibitors and cephalosporins (amoxicillin/clavulanic acid MIC ≥ 256 μg/mL; ceftriaxone MIC ≥ 8 μg/L). Genomic analysis of BQ11 identified acquisition of a novel transposon carrying the penicillin-binding protein (PBP) Pbp2c, responsible for resistance to penicillin and cephalosporins. When strain BQ11 was exposed to meropenem, selective pressure drove amplification of the transposon in a tandem array and led to a corresponding change from a low-level to a high-level meropenem-resistant phenotype. Conclusions We have identified a novel mechanism of inducible antibiotic resistance whereby isolates that appear to be carbapenem susceptible on initial testing can develop in vivo resistance to carbapenems with repeated exposure. This phenomenon could have significant implications for the treatment of C. diphtheriae infection, and may lead to clinical failure.

Cloning of taxane 2α-O-benzoyltransferase (TBT) genomic DNA from Taxus

Biologia ◽  
2006 ◽  
Vol 61 (3) ◽  
Author(s):  
Dongli Zhao ◽  
Le Li ◽  
Qian Wang ◽  
Guoyin Kai ◽  
Xiang Wang ◽  
...  
Keyword(s):  
Genomic Dna ◽  
Cdna Sequence ◽  
Gene Diversity ◽  
Genomic Sequences ◽  
Taxus Yunnanensis ◽  
Sequence Encoding ◽  
First Time

AbstractBased on the cDNA sequence encoding taxane 2α-O-benzoyltransferase (TBT) from Taxus yunnanensis (Gen-Bank Accession No.: AY970522), genomic sequences of TBTs from T. yunnanensis (TyTBT) and T. cuspidata (TcuTBT) were cloned for the first time. They both contain only one intron. The finding that the introns of TyTBT and TcuTBT are more diverse than their exons implies that the gene diversity is more within introns than within exons, which may be important for keeping the functions of the genes.

scholarly journals Gene prediction by multiple syntenic alignment

2005 ◽  
Vol 2 (1) ◽  
pp. 38-47
Author(s):  
Said S. Adi ◽  
Carlos E. Ferreira
Keyword(s):  
Computer Program ◽  
Genomic Dna ◽  
Gene Prediction ◽  
Genomic Sequences ◽  
Prediction Problem ◽  
Huge Amount ◽  
Protein Coding ◽  
Coding Regions ◽  
Conserved Regions ◽  
Similarity Information

Summary Given the increasing number of available genomic sequences, one now faces the task of identifying their functional parts, like the protein coding regions. The gene prediction problem can be addressed in several ways. One of the most promising methods makes use of similarity information between the genomic DNA and previously annotated sequences (proteins, cDNAs and ESTs). Recently, given the huge amount of newly sequenced genomes, new similarity-based methods are being successfully applied in the task of gene prediction. The so-called comparative-based methods lie in the similarities shared by regions of two evolutionary related genomic sequences. Despite the number of different gene prediction approaches in the literature, this problem remains challenging. In this paper we present a new comparative-based approach to the gene prediction problem. It is based on a syntenic alignment of three or more genomic sequences. With syntenic alignment we mean an alignment that is constructed taking into account the fact that the involved sequences include conserved regions intervened by unconserved ones. We have implemented the proposed algorithm in a computer program and confirm the validity of the approach on a benchmark including triples of human, mouse and rat genomic sequences.

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