scholarly journals Optimization of high molecular weight DNA extraction methods in shrimp for a long-read sequencing platform

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10340
Author(s):  
Pacharaporn Angthong ◽  
Tanaporn Uengwetwanit ◽  
Wirulda Pootakham ◽  
Kanchana Sittikankaew ◽  
Chutima Sonthirod ◽  
...  

Marine organisms are important to global food security as they are the largest source of animal proteins feeding mankind. Genomics-assisted aquaculture can increase yield while preserving the environment to ensure sufficient and sustainable production for global food security. However, only few high-quality genome sequences of marine organisms, especially shellfish, are available to the public partly because of the difficulty in the sequence assembly due to the complex nature of their genomes. A key step for a successful genome sequencing is the preparation of high-quality high molecular weight (HMW) genomic DNA. This study evaluated the effectiveness of five DNA extraction protocols (CTAB, Genomic-tip, Mollusc DNA, TIANamp Marine Animals DNA, and Sbeadex livestock kits) in obtaining shrimp HMW DNA for a long-read sequencing platform. DNA samples were assessed for quality and quantity using a Qubit fluorometer, NanoDrop spectrophotometer and pulsed-field gel electrophoresis. Among the five extraction methods examined without further optimization, the Genomic-tip kit yielded genomic DNA with the highest quality. However, further modifications of these established protocols might yield even better DNA quality and quantity. To further investigate whether the obtained genomic DNA could be used in a long-read sequencing application, DNA samples from the top three extraction methods (CTAB method, Genomic-tip and Mollusc DNA kits) were used for Pacific Biosciences (PacBio) library construction and sequencing. Genomic DNA obtained from Genomic-tip and Mollusc DNA kits allowed successful library construction, while the DNA obtained from the CTAB method did not. Genomic DNA isolated using the Genomic-tip kit yielded a higher number of long reads (N50 of 14.57 Kb) than those obtained from Mollusc DNA kits (N50 of 9.74 Kb). Thus, this study identified an effective extraction method for high-quality HMW genomic DNA of shrimp that can be applied to other marine organisms for a long-read sequencing platform.

2020 ◽  
Vol 10 (7) ◽  
pp. 2179-2183 ◽  
Author(s):  
Stefan Prost ◽  
Malte Petersen ◽  
Martin Grethlein ◽  
Sarah Joy Hahn ◽  
Nina Kuschik-Maczollek ◽  
...  

Ever decreasing costs along with advances in sequencing and library preparation technologies enable even small research groups to generate chromosome-level assemblies today. Here we report the generation of an improved chromosome-level assembly for the Siamese fighting fish (Betta splendens) that was carried out during a practical university master’s course. The Siamese fighting fish is a popular aquarium fish and an emerging model species for research on aggressive behavior. We updated the current genome assembly by generating a new long-read nanopore-based assembly with subsequent scaffolding to chromosome-level using previously published Hi-C data. The use of ∼35x nanopore-based long-read data sequenced on a MinION platform (Oxford Nanopore Technologies) allowed us to generate a baseline assembly of only 1,276 contigs with a contig N50 of 2.1 Mbp, and a total length of 441 Mbp. Scaffolding using the Hi-C data resulted in 109 scaffolds with a scaffold N50 of 20.7 Mbp. More than 99% of the assembly is comprised in 21 scaffolds. The assembly showed the presence of 96.1% complete BUSCO genes from the Actinopterygii dataset indicating a high quality of the assembly. We present an improved full chromosome-level assembly of the Siamese fighting fish generated during a university master’s course. The use of ∼35× long-read nanopore data drastically improved the baseline assembly in terms of continuity. We show that relatively in-expensive high-throughput sequencing technologies such as the long-read MinION sequencing platform can be used in educational settings allowing the students to gain practical skills in modern genomics and generate high quality results that benefit downstream research projects.


2021 ◽  
Author(s):  
Hollis A Dahn ◽  
Jacquelyn Mountcastle ◽  
Jennifer Balacco ◽  
Sylke Winkler ◽  
Iliana Bista ◽  
...  

Studies in vertebrate genomics require sampling from a broad range of tissue types, taxa, and localities. Recent advancements in long-read and long-range genome sequencing have made it possible to produce high-quality chromosome-level genome assemblies for almost any organism. However, adequate tissue preservation for the requisite ultra-high molecular weight DNA (uHMW DNA) remains a major challenge. Here we present a comparative study of preservation methods for field and laboratory tissue sampling, across vertebrate classes and different tissue types. We find that no single method is best for all cases. Instead, the optimal storage and extraction methods vary by taxa, by tissue, and by down-stream application. Therefore, we provide sample preservation guidelines that ensure sufficient DNA integrity and amount required for use with long-read and long-range sequencing technologies across vertebrates. Our best practices generated the uHMW DNA needed for the high-quality reference genomes for Phase 1 of the Vertebrate Genomes Project (VGP), whose ultimate mission is to generate chromosome-level reference genome assemblies of all ~70,000 extant vertebrate species.


Genomic DNA extraction is the starting point for various downstream molecular biology applications viz. PCR, restriction analysis, hybridisation etc. Numerous problems like DNA degradation, co-isolation of viscous polysaccharides, polyphenols and other secondary metabolites causing damage to DNA, inhibiting restriction enzymes, DNA polymerases etc, are routinely encountered during DNA isolation from plants. Quinone compounds resulting from oxidation of polyphenols lead brown the DNA preparations and can also damage proteins and DNA’s due to their oxidizing properties. This results in a poor yield of high molecular weight DNA. The protocol below explains the extraction of DNA via the CTAB method, involving three major steps viz lysis of cell wall and membranes, extraction of genomic DNA and precipitation of DNA.


2020 ◽  
Author(s):  
Anna Cusco ◽  
Daniel Perez ◽  
Joaquim Viñes ◽  
Olga Francino

Abstract Background. Metagenomics is a powerful and rapidly developing approach that provides new biological insights into the microbes inhabiting underexplored environments, such as canine fecal microbiome. We investigate long-read metagenomics with Nanopore sequencing to profile the fecal microbiome and to retrieve high-quality metagenome-assembled genomes (HQ MAGs) from a healthy dog.Results. More than 99% of total classified reads corresponded to Bacteria. The most abundant phylum was Bacteroidetes (~80% of total reads), followed by Firmicutes, Proteobacteria, and Fusobacteria. Prevotella (>50%) and Bacteroides (>20%) are the more abundant genera, followed by Fusobacterium, Megamonas, Sutterella, and other fecal-related genera, (each representing <5% of the total bacterial composition). We retrieved eight single-contig HQ MAGs and three medium-quality MAGs, after combining several metagenome dataset assemblies. The HQ MAGs corresponded to Succinivibrio, Sutterella, Prevotellamassilia, Phascolarctobacterium, Enterococcus, Blautia, and Catenibacterium genera. Succinivibrio HQ MAG represents a novel candidate bacterial species. Sutterella HQ MAG is potentially the first reported genome assembly for Sutterella stercoricanis, as assigned by 16S rRNA gene similarity. Prevotellamassilia, Phascolarctobacterium, Catenibacterium, and Blautia sp900541345 HQ MAGs improved the contiguity of previously reported genome assemblies in their respective genera, and the number of rRNA genes and tRNA genes. Finally, Enterococcus hirae and Blautia sp003287895 HQ MAGs represented species that already have a complete reference genome. At the technical level, we demonstrated that a high-molecular weight DNA extraction improved the taxonomic classification of the raw unassembled reads, the metagenomics assembly contiguity, and the retrieval of longer and circular contigs, which are potential HQ MAGs. Conclusions. Long-read metagenomics allowed us to recover HQ MAGs from canine feces of a healthy dog. The high-molecular weight DNA extraction to improve contiguity and the correction of the insertions and deletions to reduce frameshift errors ensure the retrieval of complete single-contig HQ MAGs.


2012 ◽  
Vol 14 (1) ◽  
pp. 138 ◽  
Author(s):  
Muh Restu ◽  
Mukrimin Mukrimin ◽  
Gusmiaty Gusmiaty

The species of trees have different secondary compounds that need optimum extraction techniques. Appropriate extraction techniquesdetermine the quality and quantity of DNA produced. This research aims to found optimal of extraction methods and DNA isolation, thento created genome DNA in high quality and quantity, so that it can be using for genetic variation analyses in Suren (Toona sureni Merr.) byRandom Amplified Polymorphic DNA (RAPD). This study shows that DNA concentrates were 763.3 μg/ml, 180.0 μg/ml, 383.3 μg/ml, and436.7 μg/ml. While based on the results of PCR amplification using the primers OPD 03 shows that the four extraction methods used, the extraction method of number 3 has been able to produce genomic DNA with better quality and more number of bands, although the quantityis lower.


2020 ◽  
Author(s):  
Stefan Prost ◽  
Malte Petersen ◽  
Martin Grethlein ◽  
Sarah Joy Hahn ◽  
Nina Kuschik-Maczollek ◽  
...  

AbstractBackgroundEver decreasing costs along with advances in sequencing and library preparation technologies enable even small research groups to generate chromosome-level assemblies today. Here we report the generation of an improved chromosome-level assembly for the Siamese fighting fish (Betta splendens) that was carried out during a practical university Master’s course. The Siamese fighting fish is a popular aquarium fish and an emerging model species for research on aggressive behaviour. We updated the current genome assembly by generating a new long-read nanopore-based assembly with subsequent scaffolding to chromosome-level using previously published HiC data.FindingsThe use of nanopore-based long-read data sequenced on a MinION platform (Oxford Nanopore Technologies) allowed us to generate a baseline assembly of only 1,276 contigs with a contig N50 of 2.1 Mbp, and a total length of 441 Mbp. Scaffolding using previously published HiC data resulted in 109 scaffolds with a scaffold N50 of 20.7 Mbp. More than 99% of the assembly is comprised in 21 scaffolds. The assembly showed the presence of 95.8% complete BUSCO genes from the Actinopterygii dataset indicating a high quality of the assembly.ConclusionWe present an improved full chromosome-level assembly of the Siamese fighting fish generated during a university Master’s course. The use of ~35× long-read nanopore data drastically improved the baseline assembly in terms of continuity. We show that relatively in-expensive high-throughput sequencing technologies such as the long-read MinION sequencing platform can be used in educational settings allowing the students to gain practical skills in modern genomics and generate high quality results that benefit downstream research projects.


2020 ◽  
Author(s):  
Rhosener Bhea Lu Koh ◽  
Cris Francis Cortez Barbosa ◽  
Vermando Masinsin Aquino ◽  
Leny Calano Galvez

Abstract Background The abaca (Musa textilis Née) is a fiber crop native to the Philippines with high economic value because of its fiber - the Manila hemp, known to be the strongest of all the natural fibers. DNA extraction in abaca is difficult due to its fibrous nature, high cellulose content and polyphenol compounds. Thus an optimized DNA extraction method is required for extracting high quality abaca DNA for next-generation sequencing applications. Results In this study, we have compared five different methods for the extraction of high molecular weight DNA from abaca leaves. The methods are the traditional CTAB method (Protocol 1), the CTAB with PVP method (Protocol 2), the CTAB with 0.3% β-mercaptoethanol method (Protocol 3), SDS-method (Protocol 4) and CTAB with Triton X-100 and PVP method (Protocol 5). Out of the five methods tested, traditional CTAB-method (Protocol 1), CTAB with 0.3% β-mercaptoethanol method (Protocol 3) and SDS-method (Protocol 4) have shown to be the most consistent in giving high molecular weight DNA with good yield and purity based on A260/A280 and A260/A230 absorption values. TissueLyserII was also utilized for homogenization for the three extraction protocols for applications in high-throughput DNA extraction. DNA from two abaca varieties were extracted using the CTAB with 0.3% β-mercaptoethanol method (Protocol 3) and were sent for NGS based on Illumina HiSeq platform having both passed the quality control for library preparation. Conclusion The CTAB with 0.3% β-mercaptoethanol method (Protocol 3) was found to be the simplest and most consistent method for extracting average yield DNA with high quality for NGS applications. The SDS-method (Protocol 4) was determined to have the shortest processing time and together with TissueLyserII is the most appropriate method for high-throughput extraction of abaca samples which will be useful for genotyping-by-sequencing (GBS) studies.


Author(s):  
Joanna M. Feehan ◽  
Katherine E. Scheibel ◽  
Salim Bourras ◽  
William Underwood ◽  
Beat Keller ◽  
...  

Biologia ◽  
2014 ◽  
Vol 69 (2) ◽  
Author(s):  
Mohammad Uddin ◽  
Wenli Sun ◽  
Xinhua He ◽  
Jaime Teixeira da Silva ◽  
Qi Cheng

AbstractHigh quality genomic DNA is the first step in the development of DNA-based markers for fingerprinting and genetic diversity of crops, including mango (Mangifera indica L.), a woody perennial. Poor quality genomic DNA hinders the successful application of analytical DNA-based tools. Standard protocols for DNA extraction are not suitable for mango since the extracted genomic DNA often contains secondary metabolites that interfere with analytical applications. In this study, we employed an additional step to remove polysaccharides, polyphenols and secondary metabolites from genomic DNA extracted from young or mature leaf tissue; then a modified traditional cetyl trimethyl ammonium bromide (CTAB) method was applied. The use of 0.4 M glucose improved DNA quality and avoided contamination and browning by polyphenolics, relative to the traditional CTAB method. This is an easy and efficient method for genomic DNA extraction from both young and mature leaves of mango. The isolated DNA was free of polysaccharides, polyphenols, RNA and other major contaminants, as judged by its clear colour, its viscosity, A260/A280 ratio and suitability for PCR-based reactions. This modified protocol was also used to extract high quality genomic DNA from other woody perennials, including walnut, guava, lychee, pear, grape and sugarcane.


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