Barcoding a can of worms: testing cox1 performance as a DNA barcode of Nematoda

Genome ◽  
2021 ◽  
Author(s):  
Leonardo Tresoldi Gonçalves ◽  
Filipe Michels Bianchi ◽  
Maríndia Deprá ◽  
Cláudia Calegaro-Marques

Accurate taxonomic identifications and species delimitations are a fundamental problem in biology. The complex taxonomy of Nematoda is primarily based on morphology, which is often dubious. DNA barcoding emerged as a handy tool to identify specimens and assess diversity, but its applications in Nematoda are incipient. We evaluated cytochrome c oxidase subunit I (cox1) efficiency as a DNA barcode for nematodes scrutinising 5,241 sequences retrieved from BOLD and GenBank. The samples included genera with medical, agricultural, or ecological relevance: Anguillicola, Caenorhabditis, Heterodera, Meloidogyne, Onchocerca, Strongyloides, and Trichinella. We assessed cox1 performance through barcode gap and Probability of Correct Identification (PCI) analyses, and estimated species richness through Automatic Barcode Gap Discovery (ABGD). Each genus presented distinct gap ranges, mirroring the evolutionary diversity within Nematoda. Thus, to survey the diversity of the phylum, a careful definition of thresholds for lower taxonomic levels should be considered. PCIs were around 70% for both databases, highlighting operational biases and challenges in nematode taxonomy. ABGD inferred higher richness than the taxonomic labels informed by databases. The prevalence of specimen misidentifications and dubious species delimitations emphasise the value of integrative approaches to nematode taxonomy and systematics. Overall, cox1 is a relevant tool for integrative taxonomy of nematodes.

Zootaxa ◽  
2022 ◽  
Vol 5091 (4) ◽  
pp. 546-558
Author(s):  
ZHAOYANG CHEN ◽  
FENGXIANG LIU ◽  
DAIQIN LI ◽  
XIN XU

This paper reports four new species of the primitively segmented spider genus Songthela from Chongqing Municipality, China, based on morphological characters of both males and females: S. jinyun sp. nov., S. longbao sp. nov., S. serriformis sp. nov. and S. wangerbao sp. nov. We also provide the GenBank accession codes of mitochondrial DNA barcode gene, cytochrome c oxidase subunit I (COI), for the holotype of four new species for future identification.  


Zootaxa ◽  
2020 ◽  
Vol 4803 (3) ◽  
pp. 561-575
Author(s):  
ADRIAN ARDILA-CAMACHO ◽  
CALEB CALIFRE MARTINS ◽  
JORGE ARI NORIEGA

Isostenosmylus Krüger, 1913 is the richest genus of Osmylidae of the Neotropical region, with 17 described species so far, which are distributed mainly in the Andean region and in the South of Brazil and Paraguay. A new remarkable Colombian species of Isostenosmylus—I. ammirabilis sp. nov.—is herein described and illustrated. DNA barcode of mitochondrial gene cytochrome c oxidase subunit I (COI) for this species is also provided. Taxonomic keys for the genus are updated. 


Genome ◽  
2020 ◽  
Vol 63 (6) ◽  
pp. 291-305 ◽  
Author(s):  
Cameron M. Nugent ◽  
Tyler A. Elliott ◽  
Sujeevan Ratnasingham ◽  
Sarah J. Adamowicz

Biological conclusions based on DNA barcoding and metabarcoding analyses can be strongly influenced by the methods utilized for data generation and curation, leading to varying levels of success in the separation of biological variation from experimental error. The 5′ region of cytochrome c oxidase subunit I (COI-5P) is the most common barcode gene for animals, with conserved structure and function that allows for biologically informed error identification. Here, we present coil ( https://CRAN.R-project.org/package=coil ), an R package for the pre-processing and frameshift error assessment of COI-5P animal barcode and metabarcode sequence data. The package contains functions for placement of barcodes into a common reading frame, accurate translation of sequences to amino acids, and highlighting insertion and deletion errors. The analysis of 10 000 barcode sequences of varying quality demonstrated how coil can place barcode sequences in reading frame and distinguish sequences containing indel errors from error-free sequences with greater than 97.5% accuracy. Package limitations were tested through the analysis of COI-5P sequences from the plant and fungal kingdoms as well as the analysis of potential contaminants: nuclear mitochondrial pseudogenes and Wolbachia COI-5P sequences. Results demonstrated that coil is a strong technical error identification method but is not reliable for detecting all biological contaminants.


Zootaxa ◽  
2008 ◽  
Vol 1691 (1) ◽  
pp. 67 ◽  
Author(s):  
M. ALEX SMITH

The 5' end (Folmer or Barcode region) of cytochrome c oxidase 1 (CO1) has been proposed as the gene region of choice for a standardized animal DNA barcode (Hebert et al. 2003). Concerns have been raised regarding the decision to utilize this particular mitochondrial gene region as a barcode. Nevertheless, widely divergent taxonomic groups have reported success using CO1 for both species identification and discovery. The utility of CO1 for barcoding amphibians was raised early on (Vences, et al. 2005) and concerns for this group were reported widely (Waugh 2007)—although some considered that the reporting of the concerns outstripped the data that had been analyzed at that point (Smith et al. 2008). Indeed, our analysis of CO1 for a small group of Holarctic amphibians was neither more difficult to generate nor to analyze than for other groups where we have utilized the technique.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9726
Author(s):  
Ana Paula Goulart Araujo ◽  
Fernando Carbayo ◽  
Marta Riutort ◽  
Marta Álvarez-Presas

Background Cratera is a genus of land planarians endemic to the Brazilian Atlantic forest. The species of this genus are distinguished from each other by a series of external and internal characters, nonetheless they represent a challenging taxonomic issue due to the extreme alikeness of the species analysed in the present work. To resolve these difficulties, we have performed morphological analyses and used three nuclear markers (ribosomal 18S and 28S, Elongation Factor, a new anonymous marker named Tnuc813) and two mitochondrial fragments (Cytochrome c oxidase subunit I gene, and a fragment encompasing NADH deshydrogenase subunit 4 gene, trnF and the beginning of the Cytochrome c oxidase I gene) in an integrative taxonomic study. Methods To unveil cryptic species, we applied a molecular species delimitation approach based on molecular discovery methods, followed by a validation method. The putative species so delimited were then validated on the basis of diagnostic morphological features. Results We discovered and described four new species, namely Cratera assu, C. tui, C. boja, and C. imbiri. A fifth new species, C. paraitinga was not highly supported by molecular evidence, but was described because its morphological attributes are unique. Our study documents for the genus Cratera the presence of a number of highly similar species, a situation that is present also in other genera of land planarians. The high number of poorly differentiated and presumably recent speciation events might be explained by the recent geological history of the area.


ZooKeys ◽  
2021 ◽  
Vol 1037 ◽  
pp. 57-71
Author(s):  
Zhaoyang Chen ◽  
Dengqing Li ◽  
Daiqin Li ◽  
Xin Xu

We diagnose and describe three new species of the primitively segmented spider genus Songthela from Guizhou Province, China, based on morphological characters and molecular data: S. liuisp. nov. (♂♀), S. tianzhusp. nov. (♂♀), and S. yupingsp. nov. (♂♀). We provide the genetic distances within and among the three new species based on the DNA barcode gene, cytochrome c oxidase subunit I (COI) to support our descriptions. We also provide the COI GenBank accession codes for the three new species for future identification.


ZooKeys ◽  
2021 ◽  
Vol 1009 ◽  
pp. 123-138
Author(s):  
Li Yu ◽  
Fengxiang Liu ◽  
Zengtao Zhang ◽  
Daiqin Li ◽  
Xin Xu

We report three new species of the segmented trapdoor spider genus Qiongthela Xu & Kuntner, 2015 collected from Hainan Island, China based on morphological characters: Q. dongfangsp. nov. (♂♀), Q. nankaisp. nov. (♂♀), Q. yalinsp. nov. (♂♀). We also provide the GenBank accession codes of the DNA barcode gene, cytochrome c oxidase subunit I (COI), of the type specimens of all three new species to aid future identification.


Author(s):  
Cameron M. Nugent ◽  
Tyler A. Elliott ◽  
Sujeevan Ratnasingham ◽  
Sarah J. Adamowicz

AbstractBiological conclusions based on DNA barcoding and metabarcoding analyses can be strongly influenced by the methods utilized for data generation and curation, leading to varying levels of success in the separation of biological variation from experimental error. The five-prime region of cytochrome c oxidase subunit I (COI-5P) is the most common barcode gene for animals, with conserved structure and function that allows for biologically informed error identification. Here, we present coil (https://CRAN.R-project.org/package=coil), an R package for the pre-processing and error assessment of COI-5P animal barcode and metabarcode sequence data. The package contains functions for placement of barcodes into a common reading frame, accurate translation of sequences to amino acids, and highlighting insertion and deletion errors. The analysis of 10,000 barcode sequences of varying quality demonstrated how coil can place barcode sequences in reading frame and distinguish sequences containing indel errors from error-free sequences with greater than 97.5% accuracy. Package limitations were tested through the analysis of COI-5P sequences from the plant and fungal kingdoms as well as the analysis of potential contaminants: nuclear mitochondrial pseudogenes and Wolbachia COI-5P sequences. Results demonstrated that coil is a strong technical error identification method but is not reliable for detecting all biological contaminants.


2021 ◽  
Vol 86 ◽  
pp. 63-77
Author(s):  
Sangjin Kim ◽  
Željko Tomanović ◽  
Yeonghyeok Yu ◽  
JuHyeong Sohn ◽  
Yunjong Han ◽  
...  

Several species of the genus Aphidius are well known as commercial biocontrol agents of pest aphids, and more than 130 species of the genus have been recorded worldwide. To date, only 15 Aphidius species have been recorded in South Korea. Using the DNA barcode region (ca. 658 bp) of mitochondrial cytochrome c oxidase subunit I (COI), we amplified sequences of 15 Aphidius Korean species, aligned them in combination with 23 reference species retrieved from GenBank for comparison and identification, and then reconstructed a barcode phylogeny by the neighbour-joining method. As a result, three Aphidius species were found to be new to Science. Descriptions and illustrations of the three species new to Science – Aphidius longicarpussp. nov., A. longistigmussp. nov., and A. asiaticussp. nov. – are provided, together with their phylogenetic position within the genus Aphidius. In addition, a redescription of A. areolatus, a parasitoid of maple aphids (Peryphillus spp.), is also given.


Sign in / Sign up

Export Citation Format

Share Document