scholarly journals New Insights on Polar Bear (Ursus maritimus) Diet from Faeces based on Next-Generation Sequencing Technologies

ARCTIC ◽  
2021 ◽  
Vol 74 (1) ◽  
pp. 87-99
Author(s):  
Johan Michaux ◽  
Markus Dyck ◽  
Peter Boag ◽  
Stephen Lougheed ◽  
Peter Van Coeverden de Groot

Practical tools to quantify range-wide dietary choices of the polar bear have not been well developed, thus impeding the monitoring of this species in a changing climate. Here we describe our steps toward non-invasive polar bear diet determination with the optimization of 454 pyrosequencing of a 136 base pair (bp) mitochondrial cytochrome b (cytb) fragment amplified from the extracts of captive and wild polar bear faeces. We first determine the efficacy, reliability, and accuracy of our method using five faecal samples from a captive polar bear fed a known diet at the Canadian Polar Bear Habitat in Cochrane, Ontario, Canada; 19 samples from three polar bears at the Metro Toronto Zoo, Toronto, Ontario, Canada; and seven samples from seven wild (unfed) polar bears from a holding facility in Churchill, Manitoba, Canada. We report 91% overall success in amplifying a 136 bp cytb amplicon from the faeces of polar bears. Our DNA analyses accurately recovered the vertebrate diet profiles of captive bears fed known diets. We then characterized multiyear vertebrate prey diet choices from free-ranging polar bears from the sea ice of the M’Clintock Channel polar bear management unit, Nunavut, Canada (n = 117 from an unknown number of bears). These data point to a diet unsurprisingly dominated by ringed seal (Pusa hispida) while including evidence of bearded seal (Erignathus barbatus), harbour seal (Phoca vitulina), muskox (Ovibos moschatus ssp.), Arctic fox (Vulpes lagopus), wolf (Canis lupus), Herring Gull (Larus argentatus), and Willow Ptarmigan (Lagopus lagopus). We found low levels of contamination (< 3% of sequences when present) and suggest specific process improvements to reduce contamination in range-wide studies. Together, these findings indicate that next-generation sequencing-based diet assessments show great promise in monitoring free-ranging polar bears in this time of climate change.   

2008 ◽  
Vol 18 (10) ◽  
pp. 1638-1642 ◽  
Author(s):  
D. R. Smith ◽  
A. R. Quinlan ◽  
H. E. Peckham ◽  
K. Makowsky ◽  
W. Tao ◽  
...  

2011 ◽  
Vol 16 (11-12) ◽  
pp. 512-519 ◽  
Author(s):  
Peter M. Woollard ◽  
Nalini A.L. Mehta ◽  
Jessica J. Vamathevan ◽  
Stephanie Van Horn ◽  
Bhushan K. Bonde ◽  
...  

Genes ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 429 ◽  
Author(s):  
Daniela Barros-Silva ◽  
C. Marques ◽  
Rui Henrique ◽  
Carmen Jerónimo

DNA methylation is an epigenetic modification that plays a pivotal role in regulating gene expression and, consequently, influences a wide variety of biological processes and diseases. The advances in next-generation sequencing technologies allow for genome-wide profiling of methyl marks both at a single-nucleotide and at a single-cell resolution. These profiling approaches vary in many aspects, such as DNA input, resolution, coverage, and bioinformatics analysis. Thus, the selection of the most feasible method according with the project’s purpose requires in-depth knowledge of those techniques. Currently, high-throughput sequencing techniques are intensively used in epigenomics profiling, which ultimately aims to find novel biomarkers for detection, diagnosis prognosis, and prediction of response to therapy, as well as to discover new targets for personalized treatments. Here, we present, in brief, a portrayal of next-generation sequencing methodologies’ evolution for profiling DNA methylation, highlighting its potential for translational medicine and presenting significant findings in several diseases.


2021 ◽  
Author(s):  
Ahmed S Fahad ◽  
Cheng Yu Chung ◽  
Sheila N. Lopez Acevedo ◽  
Nicoleen Boyle ◽  
Bharat Madan ◽  
...  

Functional analyses of the T cell receptor (TCR) landscape can reveal critical information about protection from disease and molecular responses to vaccines. However, it has proven difficult to combine advanced next-generation sequencing technologies with methods to decode the peptide-major histocompatibility complex (pMHC) specificity of individual TCRs. Here we developed a new high-throughput approach to enable repertoire-scale functional evaluations of natively paired TCRs. In particular, we leveraged the immortalized nature of physically linked TCRα:β amplicon libraries to analyze binding against multiple recombinant pMHCs on a repertoire scale. To exemplify the utility of this approach, we also performed affinity-based functional mapping in conjunction with quantitative next-generation sequencing to track antigen- specific TCRs. These data successfully validated a new immortalization and screening platform to facilitate detailed molecular analyses of human TCRs against diverse antigen targets associated with health, vaccination, or disease.


2018 ◽  
Vol 15 (2) ◽  
pp. 367-372
Author(s):  
Lê Ngọc Giang ◽  
Lưu Hàn Ly ◽  
Nguyễn Mai Phương ◽  
Lê Tùng Lâm ◽  
Đỗ Thị Huyền ◽  
...  

Microorganisms, particularly bacteria, in the ruminant's rumen are valuable genetic resources that many scientists interested in. In recent years, the application of next-generation sequencing technologies allows direct decoding an extracted DNA metagenome in each ecological community without culture, increasing the efficiency of exploiting interested genes. Notably, the quantity and quality of extracted DNA play an important role in getting a reliable metagenome database. In this study, DNA metagenome from goat rumen fluid was extracted by five different methods RBB (repeated bead beating plus column), RBBC (repeated bead beating), PSP1, PSP2 (PSP®Spin Stool DNA Kit, protocol 1, 2, Germany) và QIA (QIAamp® DNA Stool Mini Kit, Germany). The results showed that DNA metagenome obtained by all methods had A260/280 greater than 1.8. DNA extracted by the RBB method had high DNA concentration but low A260/230 values (less than 1.4) and still contained Taq polymerase inhibitor. After purifying by QIA column, A260/230 values of RBB-extracted DNA significantly increased up to 2.0 and Taq polymerase inhibitor in samples were removed. However, the concentrations decreased by 57% that nearly equivalent to concentration of DNA metagenome obtained by QIA. The method using PSP®Spin Stool DNA kit produced the highest DNA concentrations (from 149.7 to 195.5 ng/µl) with A260/280 ratios of 1.9 and A260/230 ratios of 1.8 to 1.9. Morever, this method was able to remove polymerase inhibitor and be performed on short time. Therefore, the PSP®Spin Stool DNA kit is a suitable method for DNA metagenome extraction of bacteria from goat rumen. DNA obtained by this method fulfilled all criteria about quality and concentration for sequencing by next-generation sequencing Illumina.


2017 ◽  
Vol 1 (Special Issue-Supplement) ◽  
pp. 237-237
Author(s):  
Reddaiah Bodanapu ◽  
Krishna Lalam ◽  
Durga Khandekar ◽  
Navitha Kokkonda ◽  
Sivarama Prasad Lekkala ◽  
...  

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7170
Author(s):  
Daniel Liu

Next-generation sequencing technologies create large, multiplexed DNA sequences that require preprocessing before any further analysis. Part of this preprocessing includes demultiplexing and trimming sequences. Although there are many existing tools that can handle these preprocessing steps, they cannot be easily extended to new sequence schematics when new pipelines are developed. We present Fuzzysplit, a tool that relies on a simple declarative language to describe the schematics of sequences, which makes it incredibly adaptable to different use cases. In this paper, we explain the matching algorithms behind Fuzzysplit and we provide a preliminary comparison of its performance with other well-established tools. Overall, we find that its matching accuracy is comparable to previous tools.


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