scholarly journals De Novo Assembly of a High-Quality Reference Genome for the Horned Lark (Eremophila alpestris)

2019 ◽  
Vol 10 (2) ◽  
pp. 475-478 ◽  
Author(s):  
Nicholas A. Mason ◽  
Paulo Pulgarin ◽  
Carlos Daniel Cadena ◽  
Irby J. Lovette

The Horned Lark (Eremophila alpestris) is a small songbird that exhibits remarkable geographic variation in appearance and habitat across an expansive distribution. While E. alpestris has been the focus of many ecological and evolutionary studies, we still lack a highly contiguous genome assembly for the Horned Lark and related taxa (Alaudidae). Here, we present CLO_EAlp_1.0, a highly contiguous assembly for E. alpestris generated from a blood sample of a wild, male bird captured in the Altiplano Cundiboyacense of Colombia. By combining short-insert and mate-pair libraries with the ALLPATHS-LG genome assembly pipeline, we generated a 1.04 Gb assembly comprised of 2713 scaffolds, with a largest scaffold size of 31.81 Mb, a scaffold N50 of 9.42 Mb, and a scaffold L50 of 30. These scaffolds were assembled from 23685 contigs, with a largest contig size of 1.69 Mb, a contig N50 of 193.81 kb, and a contig L50 of 1429. Our assembly pipeline also produced a single mitochondrial DNA contig of 14.00 kb. After polishing the genome, we identified 94.5% of single-copy gene orthologs from an Aves data set and 97.7% of single-copy gene orthologs from a vertebrata data set, which further demonstrates the high quality of our assembly. We anticipate that this genomic resource will be useful to the broader ornithological community and those interested in studying the evolutionary history and ecological interactions of larks, which comprise a widespread, yet understudied lineage of songbirds.

2019 ◽  
Author(s):  
Nicholas A. Mason ◽  
Paulo Pulgarin ◽  
Carlos Daniel Cadena ◽  
Irby J. Lovette

AbstractThe Horned Lark (Eremophila alpestris) is a species of small songbird that exhibits remarkable geographic variation in appearance and habitat across an expansive distribution. While E. alpestris and related species have been the focus of many ecological and evolutionary studies, we still lack a highly contiguous genome assembly for horned larks and related taxa (Alaudidae). Here, we present CLO_EAlp_1.0, a highly contiguous assembly for horned larks generated from blood samples of a wild, male bird captured in the Altiplano Cundiboyacense of Colombia. By combining short-insert and mate-pair libraries with the ALLPATHS-LG genome assembly pipeline, we generated a 1.04 Gb assembly comprised of 2708 contigs with an N50 of 10.58 Mb and a L50 of 29. After polishing the genome, we were able to identify 94.5% of single-copy gene orthologs from an Aves data set and 97.7% of single-copy gene orthologs from a vertebrata data set, indicating that our de novo assembly is near complete. We anticipate that this genomic resource will be useful to the broader ornithological community and those interested in studying the evolutionary history and ecological interactions of a widespread, yet understudied lineage of songbirds.


1992 ◽  
Vol 84 (4) ◽  
pp. 561-567 ◽  
Author(s):  
Poul E. Jensen ◽  
Michael Kristensen ◽  
Tine Hoff ◽  
Jan Lehmbeck ◽  
Bjarne M. Stummann ◽  
...  

Genomics ◽  
1998 ◽  
Vol 48 (2) ◽  
pp. 163-170 ◽  
Author(s):  
Yu-Ker Wang ◽  
Luis A. Pérez-Jurado ◽  
Uta Francke

2021 ◽  
Vol 9 (8) ◽  
pp. 1610
Author(s):  
Christian Klotz ◽  
Elke Radam ◽  
Sebastian Rausch ◽  
Petra Gosten-Heinrich ◽  
Toni Aebischer

Giardiasis in humans is a gastrointestinal disease transmitted by the potentially zoonotic Giardia duodenalis genotypes (assemblages) A and B. Small wild rodents such as mice and voles are discussed as potential reservoirs for G. duodenalis but are predominantly populated by the two rodent species Giardia microti and Giardia muris. Currently, the detection of zoonotic and non-zoonotic Giardia species and genotypes in these animals relies on cumbersome PCR and sequencing approaches of genetic marker genes. This hampers the risk assessment of potential zoonotic Giardia transmissions by these animals. Here, we provide a workflow based on newly developed real-time PCR schemes targeting the small ribosomal RNA multi-copy gene locus to distinguish G. muris, G. microti and G. duodenalis infections. For the identification of potentially zoonotic G. duodenalis assemblage types A and B, an established protocol targeting the single-copy gene 4E1-HP was used. The assays were specific for the distinct Giardia species or genotypes and revealed an analytical sensitivity of approximately one or below genome equivalent for the multi-copy gene and of about 10 genome equivalents for the single-copy gene. Retesting a biobank of small rodent samples confirmed the specificity. It further identified the underlying Giardia species in four out of 11 samples that could not be typed before by PCR and sequencing. The newly developed workflow has the potential to facilitate the detection of potentially zoonotic and non-zoonotic Giardia species in wild rodents.


1989 ◽  
Vol 9 (1) ◽  
pp. 329-331
Author(s):  
M Winey ◽  
I Edelman ◽  
M R Culbertson

Saccharomyces cerevisiae glutamine tRNA(CAG) is encoded by an intronless, single-copy gene, SUP60. We have imposed a requirement for splicing in the biosynthesis of this tRNA by inserting a synthetic intron in the SUP60 gene. Genetic analysis demonstrated that the interrupted gene produces a functional, mature tRNA product in vivo.


1985 ◽  
Vol 5 (5) ◽  
pp. 1151-1162
Author(s):  
D J Bergsma ◽  
K S Chang ◽  
R J Schwartz

We identified a novel chicken actin gene. The actin protein deduced from its nucleotide sequence very closely resembles the vertebrate cytoplasmic actins; accordingly, we classified this gene as a nonmuscle type. We adopted the convention for indicating the nonmuscle actins of the class Amphibia (Vandekerckhove et al., J. Mol. Biol. 152:413-426) and denoted this gene as type 5. RNA blot analysis demonstrated that the type 5 actin mRNA transcripts accumulate in adult tissues in a pattern indicative of a nonmuscle actin gene. Genomic DNA blots indicated that the type 5 actin is a single copy gene and a distinct member of the chicken actin multigene family. Inspection of the nucleotide sequence revealed many features that distinguished the type 5 gene from all other vertebrate actin genes examined to date. These unique characteristics include: (i) an initiation Met codon preceding an Ala codon, a feature previously known only in plant actins, (ii) a single intron within the 5' untranslated region, with no interruptions in the coding portion of the gene, and (iii) an atypical Goldberg-Hogness box (ATAGAA) preceding the mRNA initiation terminus. These unusual features have interesting implications for actin gene diversification during evolution.


2015 ◽  
Vol 84 ◽  
pp. 205-219 ◽  
Author(s):  
Sebastian Müller ◽  
Karsten Salomo ◽  
Jackeline Salazar ◽  
Julia Naumann ◽  
M. Alejandra Jaramillo ◽  
...  

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6902 ◽  
Author(s):  
Simon Roux ◽  
Gareth Trubl ◽  
Danielle Goudeau ◽  
Nandita Nath ◽  
Estelle Couradeau ◽  
...  

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.


Author(s):  
Yuanchao Liu ◽  
Longhua Huang ◽  
Huiping Hu ◽  
Manjun Cai ◽  
Xiaowei Liang ◽  
...  

Abstract Ganoderma leucocontextum, a newly discovered species of Ganodermataceae in China, has diverse pharmacological activities. G. leucocontextum was widely cultivated in southwest China, but the systematic genetic study has been impeded by the lack of a reference genome. Herein, we present the first whole-genome assembly of G. leucocontextum based on the Illumina and Nanopore platform from high-quality DNA extracted from a monokaryon strain (DH-8). The generated genome was 50.05 Mb in size with a N50 scaffold size of 3.06 Mb, 78,206 coding sequences and 13,390 putative genes. Genome completeness was assessed using the Benchmarking Universal Single-Copy Orthologs (BUSCO) tool, which identified 96.55% of the 280 Fungi BUSCO genes. Furthermore, differences in functional genes of secondary metabolites (terpenoids) were analyzed between G. leucocontextum and G. lucidum. G. leucocontextum has more genes related to terpenoids synthesis compared to G. lucidum, which may be one of the reasons why they exhibit different biological activities. This is the first genome assembly and annotation for G. leucocontextum, which would enrich the toolbox for biological and genetic studies in G. leucocontextum.


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