scholarly journals De novo genome assembly and Hi-C analysis reveal an association between chromatin architecture alterations and sex differentiation in the woody plant Jatropha curcas

GigaScience ◽  
2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Mao-Sheng Chen ◽  
Longjian Niu ◽  
Mei-Li Zhao ◽  
Chuanjia Xu ◽  
Bang-Zhen Pan ◽  
...  
Keyword(s):  
Gene Transcription ◽  
Genome Assembly ◽  
Jatropha Curcas ◽  
Woody Plants ◽  
Woody Plant ◽  
De Novo ◽  
Sex Differentiation ◽  
Chromatin Organization ◽  
De Novo Genome Assembly ◽  
Chromatin Architecture

Abstract Background Chromatin architecture is an essential factor regulating gene transcription in different cell types and developmental phases. However, studies on chromatin architecture in perennial woody plants and on the function of chromatin organization in sex determination have not been reported. Results Here, we produced a chromosome-scale de novo genome assembly of the woody plant Jatropha curcas with a total length of 379.5 Mb and a scaffold N50 of 30.7 Mb using Pacific Biosciences long reads combined with genome-wide chromosome conformation capture (Hi-C) technology. Based on this high-quality reference genome, we detected chromatin architecture differences between monoecious and gynoecious inflorescence buds of Jatropha. Differentially expressed genes were significantly enriched in the changed A/B compartments and topologically associated domain regions and occurred preferentially in differential contact regions between monoecious and gynoecious inflorescence buds. Twelve differentially expressed genes related to flower development or hormone synthesis displayed significantly different genomic interaction patterns in monoecious and gynoecious inflorescence buds. These results demonstrate that chromatin organization participates in the regulation of gene transcription during the process of sex differentiation in Jatropha. Conclusions We have revealed the features of chromatin architecture in perennial woody plants and investigated the possible function of chromatin organization in Jatropha sex differentiation. These findings will facilitate understanding of the regulatory mechanisms of sex determination in higher plants.

scholarly journals De Novo Sequencing and Hybrid Assembly of the Biofuel Crop Jatropha curcas L.: Identification of Quantitative Trait Loci for Geminivirus Resistance

Genes ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 69 ◽  
Author(s):  
Nagesh Kancharla ◽  
Saakshi Jalali ◽  
J. Narasimham ◽  
Vinod Nair ◽  
Vijay Yepuri ◽  
...  
Keyword(s):  
Ssr Markers ◽  
Genome Assembly ◽  
Jatropha Curcas ◽  
Quantitative Trait ◽  
De Novo ◽  
Mapping Population ◽  
Single Copy ◽  
Sequencing Data ◽  
De Novo Genome Assembly ◽  
Sequencing Technologies

Jatropha curcas is an important perennial, drought tolerant plant that has been identified as a potential biodiesel crop. We report here the hybrid de novo genome assembly of J. curcas generated using Illumina and PacBio sequencing technologies, and identification of quantitative loci for Jatropha Mosaic Virus (JMV) resistance. In this study, we generated scaffolds of 265.7 Mbp in length, which correspond to 84.8% of the gene space, using Benchmarking Universal Single-Copy Orthologs (BUSCO) analysis. Additionally, 96.4% of predicted protein-coding genes were captured in RNA sequencing data, which reconfirms the accuracy of the assembled genome. The genome was utilized to identify 12,103 dinucleotide simple sequence repeat (SSR) markers, which were exploited in genetic diversity analysis to identify genetically distinct lines. A total of 207 polymorphic SSR markers were employed to construct a genetic linkage map for JMV resistance, using an interspecific F2 mapping population involving susceptible J. curcas and resistant Jatropha integerrima as parents. Quantitative trait locus (QTL) analysis led to the identification of three minor QTLs for JMV resistance, and the same has been validated in an alternate F2 mapping population. These validated QTLs were utilized in marker-assisted breeding for JMV resistance. Comparative genomics of oil-producing genes across selected oil producing species revealed 27 conserved genes and 2986 orthologous protein clusters in Jatropha. This reference genome assembly gives an insight into the understanding of the complex genetic structure of Jatropha, and serves as source for the development of agronomically improved virus-resistant and oil-producing lines.

scholarly journals Chromatin Architectures Are Associated with Response to Dark Treatment in the Oil Crop Sesamum indicum, Based on a High-Quality Genome Assembly

2020 ◽  
Vol 61 (5) ◽  
pp. 978-987
Author(s):  
Chaoqiong Li ◽  
Xiaoli Li ◽  
Hongzhan Liu ◽  
Xueqin Wang ◽  
Weifeng Li ◽  
...  
Keyword(s):  
Gene Transcription ◽  
Genome Assembly ◽  
De Novo ◽  
Hierarchical Structures ◽  
Normal Growth ◽  
High Quality ◽  
Dark Treatment ◽  
De Novo Genome Assembly ◽  
Chromosome Conformation ◽  
A Genome

Abstract Eukaryotic chromatin is tightly packed into hierarchical structures, allowing appropriate gene transcription in response to environmental and developmental cues. Here, we provide a chromosome-scale de novo genome assembly of sesame with a total length of 292.3 Mb and a scaffold N50 of 20.5 Mb, containing estimated 28,406 coding genes using Pacific Biosciences long reads combined with a genome-wide chromosome conformation capture (Hi-C) approach. Based on this high-quality reference genome, we detected changes in chromatin architectures between normal growth and dark-treated sesame seedlings. Gene expression level was significantly higher in ‘A’ compartment and topologically associated domain (TAD) boundary regions than in ‘B’ compartment and TAD interior regions, which is coincident with the enrichment of H4K3me3 modification in these regions. Moreover, differentially expressed genes (DEGs) induced by dark treated were enriched in the changed TAD-related regions and genomic differential contact regions. Gene Ontology (GO) enrichment analysis of DEGs showed that genes related to ‘response to stress’ and ‘photosynthesis’ functional categories were enriched, which corresponds to dark treatment. These results suggested that chromatin organization is associated with gene transcription in response to dark treatment in sesame. Our results will facilitate the understanding of regulatory mechanisms in response to environmental cues in plants.

scholarly journals Improved hybrid de novo genome assembly of domesticated apple (Malus x domestica)

GigaScience ◽  
2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Xuewei Li ◽  
Ling Kui ◽  
Jing Zhang ◽  
Yinpeng Xie ◽  
Liping Wang ◽  
...  
Keyword(s):  
Genome Assembly ◽  
De Novo ◽  
Malus X Domestica ◽  
De Novo Genome Assembly

scholarly journals Meraculous: De Novo Genome Assembly with Short Paired-End Reads

PLoS ONE ◽  
2011 ◽  
Vol 6 (8) ◽  
pp. e23501 ◽  
Author(s):  
Jarrod A. Chapman ◽  
Isaac Ho ◽  
Sirisha Sunkara ◽  
Shujun Luo ◽  
Gary P. Schroth ◽  
...  
Keyword(s):  
Genome Assembly ◽  
De Novo ◽  
De Novo Genome Assembly

Ultra Efficient Acceleration for De Novo Genome Assembly via Near-Memory Computing

2021 ◽  
Author(s):  
Minxuan Zhou ◽  
Lingxi Wu ◽  
Muzhou Li ◽  
Niema Moshiri ◽  
Kevin Skadron ◽  
...  
Keyword(s):  
Genome Assembly ◽  
De Novo ◽  
De Novo Genome Assembly

scholarly journals Optimizing de novo genome assembly from PCR-amplified metagenomes

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6902 ◽  
Author(s):  
Simon Roux ◽  
Gareth Trubl ◽  
Danielle Goudeau ◽  
Nandita Nath ◽  
Estelle Couradeau ◽  
...  
Keyword(s):  
Genome Assembly ◽  
De Novo ◽  
Pcr Amplification ◽  
Error Rates ◽  
De Novo Genome Assembly ◽  
Low Input ◽  
Assembly Algorithm ◽  
Coverage Bias ◽  
Size Number ◽  
Assembly Pipeline

Background Metagenomics has transformed our understanding of microbial diversity across ecosystems, with recent advances enabling de novo assembly of genomes from metagenomes. These metagenome-assembled genomes are critical to provide ecological, evolutionary, and metabolic context for all the microbes and viruses yet to be cultivated. Metagenomes can now be generated from nanogram to subnanogram amounts of DNA. However, these libraries require several rounds of PCR amplification before sequencing, and recent data suggest these typically yield smaller and more fragmented assemblies than regular metagenomes. Methods Here we evaluate de novo assembly methods of 169 PCR-amplified metagenomes, including 25 for which an unamplified counterpart is available, to optimize specific assembly approaches for PCR-amplified libraries. We first evaluated coverage bias by mapping reads from PCR-amplified metagenomes onto reference contigs obtained from unamplified metagenomes of the same samples. Then, we compared different assembly pipelines in terms of assembly size (number of bp in contigs ≥ 10 kb) and error rates to evaluate which are the best suited for PCR-amplified metagenomes. Results Read mapping analyses revealed that the depth of coverage within individual genomes is significantly more uneven in PCR-amplified datasets versus unamplified metagenomes, with regions of high depth of coverage enriched in short inserts. This enrichment scales with the number of PCR cycles performed, and is presumably due to preferential amplification of short inserts. Standard assembly pipelines are confounded by this type of coverage unevenness, so we evaluated other assembly options to mitigate these issues. We found that a pipeline combining read deduplication and an assembly algorithm originally designed to recover genomes from libraries generated after whole genome amplification (single-cell SPAdes) frequently improved assembly of contigs ≥10 kb by 10 to 100-fold for low input metagenomes. Conclusions PCR-amplified metagenomes have enabled scientists to explore communities traditionally challenging to describe, including some with extremely low biomass or from which DNA is particularly difficult to extract. Here we show that a modified assembly pipeline can lead to an improved de novo genome assembly from PCR-amplified datasets, and enables a better genome recovery from low input metagenomes.

scholarly journals Accurate long-read de novo assembly evaluation with Inspector

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yu Chen ◽  
Yixin Zhang ◽  
Amy Y. Wang ◽  
Min Gao ◽  
Zechen Chong
Keyword(s):  
Genome Assembly ◽  
De Novo Assembly ◽  
In Silico ◽  
Large Scale ◽  
De Novo ◽  
Small Scale ◽  
De Novo Genome Assembly ◽  
Consensus Sequences ◽  
Assembly Evaluation ◽  
Long Read

AbstractLong-read de novo genome assembly continues to advance rapidly. However, there is a lack of effective tools to accurately evaluate the assembly results, especially for structural errors. We present Inspector, a reference-free long-read de novo assembly evaluator which faithfully reports types of errors and their precise locations. Notably, Inspector can correct the assembly errors based on consensus sequences derived from raw reads covering erroneous regions. Based on in silico and long-read assembly results from multiple long-read data and assemblers, we demonstrate that in addition to providing generic metrics, Inspector can accurately identify both large-scale and small-scale assembly errors.

scholarly journals Gene Annotation and Transcriptome Delineation on a De Novo Genome Assembly for the Reference Leishmania major Friedlin Strain

Genes ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1359
Author(s):  
Esther Camacho ◽  
Sandra González-de la Fuente ◽  
Jose C. Solana ◽  
Alberto Rastrojo ◽  
Fernando Carrasco-Ramiro ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Genome Assembly ◽  
Molecular Mechanisms ◽  
High Throughput Sequencing ◽  
Leishmania Major ◽  
De Novo ◽  
Gene Annotation ◽  
Leishmania Species ◽  
De Novo Genome Assembly ◽  
Sequencing Platforms

Leishmania major is the main causative agent of cutaneous leishmaniasis in humans. The Friedlin strain of this species (LmjF) was chosen when a multi-laboratory consortium undertook the objective of deciphering the first genome sequence for a parasite of the genus Leishmania. The objective was successfully attained in 2005, and this represented a milestone for Leishmania molecular biology studies around the world. Although the LmjF genome sequence was done following a shotgun strategy and using classical Sanger sequencing, the results were excellent, and this genome assembly served as the reference for subsequent genome assemblies in other Leishmania species. Here, we present a new assembly for the genome of this strain (named LMJFC for clarity), generated by the combination of two high throughput sequencing platforms, Illumina short-read sequencing and PacBio Single Molecular Real-Time (SMRT) sequencing, which provides long-read sequences. Apart from resolving uncertain nucleotide positions, several genomic regions were reorganized and a more precise composition of tandemly repeated gene loci was attained. Additionally, the genome annotation was improved by adding 542 genes and more accurate coding-sequences defined for around two hundred genes, based on the transcriptome delimitation also carried out in this work. As a result, we are providing gene models (including untranslated regions and introns) for 11,238 genes. Genomic information ultimately determines the biology of every organism; therefore, our understanding of molecular mechanisms will depend on the availability of precise genome sequences and accurate gene annotations. In this regard, this work is providing an improved genome sequence and updated transcriptome annotations for the reference L. major Friedlin strain.

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