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Xu C, Yang S, Xie Y, He J, Chen Y, Pan Y, Xie H. Morphological and Molecular Characterization, Including Parasitic and Pathogenic Studies of a New Spherical Cyst Nematode Species, Globodera vulgaris n. sp. (Nematoda: Heteroderidae), Associated with Potatoes in China. PHYTOPATHOLOGY 2023; 113:1560-1582. [PMID: 36825334 DOI: 10.1094/phyto-12-22-0480-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
In this study, a new spherical cyst nematode belonging to the genus Globodera, herein described as Globodera vulgaris n. sp., was extracted from the roots and rhizosphere soil of potato and circumjacent weeds belonging to different families in three provinces in southwest China. The new species was characterized by 8 to 24 ridges between the anus and fenestra and an average Granek's ratio of 2.8 to 3.8 in cysts, a head with three to four annules, a dorsal knob anteriorly projected, ventral knobs round or anteriorly projected in second stage juveniles, a head with three to five annules, a short spicule with an average length of less than 30.0 μm, and a developed velum in males. Pathogenicity tests showed that G. vulgaris n. sp. infected potato but did not damage or affect the potato yield compared with the control, and it parasitized tomato with a low reproduction rate (RF < 1) while it did not parasitize tobacco (RF = 0). The new species was closely related to G. rostochiensis, based on molecular diagnostic marker sequences and constructed phylogenetic analysis, based on internal transcribed spacers of ribosomal DNA, large-subunit rDNA, and small-subunit rDNA. However, the new species exhibited differences from G. rostochiensis in terms of morphological characteristics, a wide host preference, lack of damage to hosts, and an egg-hatching rate induced by hatching factors.
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Affiliation(s)
- Chunling Xu
- Laboratory of Plant Nematology and Research Center of Nematodes of Plant Quarantine, Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, P.R. China
| | - Sihua Yang
- Laboratory of Plant Nematology and Research Center of Nematodes of Plant Quarantine, Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, P.R. China
| | - Yujia Xie
- Laboratory of Plant Nematology and Research Center of Nematodes of Plant Quarantine, Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, P.R. China
| | - Jin He
- Laboratory of Plant Nematology and Research Center of Nematodes of Plant Quarantine, Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, P.R. China
| | - Yan Chen
- Laboratory of Plant Nematology and Research Center of Nematodes of Plant Quarantine, Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, P.R. China
| | - Yonglang Pan
- Laboratory of Plant Nematology and Research Center of Nematodes of Plant Quarantine, Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, P.R. China
| | - Hui Xie
- Laboratory of Plant Nematology and Research Center of Nematodes of Plant Quarantine, Department of Plant Pathology, College of Plant Protection, South China Agricultural University, Guangzhou, P.R. China
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Lee Y, Cho CH, Noh C, Yang JH, Park SI, Lee YM, West JA, Bhattacharya D, Jo K, Yoon HS. Origin of minicircular mitochondrial genomes in red algae. Nat Commun 2023; 14:3363. [PMID: 37291154 PMCID: PMC10250338 DOI: 10.1038/s41467-023-39084-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 05/30/2023] [Indexed: 06/10/2023] Open
Abstract
Eukaryotic organelle genomes are generally of conserved size and gene content within phylogenetic groups. However, significant variation in genome structure may occur. Here, we report that the Stylonematophyceae red algae contain multipartite circular mitochondrial genomes (i.e., minicircles) which encode one or two genes bounded by a specific cassette and a conserved constant region. These minicircles are visualized using fluorescence microscope and scanning electron microscope, proving the circularity. Mitochondrial gene sets are reduced in these highly divergent mitogenomes. Newly generated chromosome-level nuclear genome assembly of Rhodosorus marinus reveals that most mitochondrial ribosomal subunit genes are transferred to the nuclear genome. Hetero-concatemers that resulted from recombination between minicircles and unique gene inventory that is responsible for mitochondrial genome stability may explain how the transition from typical mitochondrial genome to minicircles occurs. Our results offer inspiration on minicircular organelle genome formation and highlight an extreme case of mitochondrial gene inventory reduction.
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Affiliation(s)
- Yongsung Lee
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Korea
| | - Chung Hyun Cho
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Korea
| | - Chanyoung Noh
- Department of Chemistry, Sogang University, Seoul, 04107, Korea
| | - Ji Hyun Yang
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Korea
| | - Seung In Park
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Korea
| | - Yu Min Lee
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Korea
| | - John A West
- School of Biosciences 2, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Debashish Bhattacharya
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, 08901, USA
| | - Kyubong Jo
- Department of Chemistry, Sogang University, Seoul, 04107, Korea.
| | - Hwan Su Yoon
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Korea.
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Yang J, Ling C, Zhang H, Hussain Q, Lyu S, Zheng G, Liu Y. A Comparative Genomics Approach for Analysis of Complete Mitogenomes of Five Actinidiaceae Plants. Genes (Basel) 2022; 13:genes13101827. [PMID: 36292711 PMCID: PMC9601400 DOI: 10.3390/genes13101827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 10/01/2022] [Accepted: 10/01/2022] [Indexed: 11/04/2022] Open
Abstract
Actinidiaceae, an economically important plant family, includes the Actinidia, Clematoclethra and Saurauia genus. Kiwifruit, with remarkably high vitamin C content, is an endemic species widely distributed in China with high economic value. Although many Actinidiaceae chloroplast genomes have been reported, few complete mitogenomes of Actinidiaceae have been studied. Here, complete circular mitogenomes of the four kiwifruit species and Saurauia tristyla were assembled. Codon usage, sequence repeats, RNA editing, gene transfers, selective pressure, and phylogenetic relationships in the four kiwifruit species and S. tristyla were comparatively analyzed. This research will contribute to the study of phylogenetic relationships within Actiniaceae and molecular barcoding in kiwifruit.
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Affiliation(s)
- Jun Yang
- College of Horticulture, Anhui Agriculture University, Hefei 350002, China
| | - Chengcheng Ling
- College of Horticulture, Anhui Agriculture University, Hefei 350002, China
| | - Huamin Zhang
- College of Horticulture, Anhui Agriculture University, Hefei 350002, China
| | - Quaid Hussain
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, 666 Wusu Street, Hangzhou 311300, China
| | - Shiheng Lyu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, 666 Wusu Street, Hangzhou 311300, China
| | - Guohua Zheng
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Correspondence: (G.Z.); (Y.L.)
| | - Yongsheng Liu
- College of Horticulture, Anhui Agriculture University, Hefei 350002, China
- Correspondence: (G.Z.); (Y.L.)
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Singh PR, van de Vossenberg BTLH, Rybarczyk-Mydłowska K, Kowalewska-Groszkowska M, Bert W, Karssen G. An Integrated Approach for Synonymization of Rotylenchus rhomboides with R. goodeyi (Nematoda: Hoplolaimidae) Reveals High Intraspecific Mitogenomic Variation. PHYTOPATHOLOGY 2022; 112:1152-1164. [PMID: 34818905 DOI: 10.1094/phyto-08-21-0363-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Rotylenchus is a widely distributed, economically important plant-parasitic nematode group whose species-level identification relies largely on limited morphological characters, including character-based tabular keys and molecular data of ribosomal and mitochondrial genes. In this study, a combined morphological and molecular analysis of three populations of Rotylenchus goodeyi from Belgium, Poland, and the Netherlands revealed important character variations of this species, leading to synonymization of R. rhomboides with R. goodeyi and a high nucleotide variation within cox1 gene sequences in these populations. Additional Illumina sequencing of DNA from individuals of the Dutch population revealed two variants of mitogenomes, each approximately 23 Kb in size, differing by approximately 9% and containing 11 protein-coding genes, 2 ribosomal RNA genes, and as many as 29 transfer RNA genes. In addition to the first representative whole-genome shotgun sequence datasets of the genus Rotylenchus, this study also provides the full-length mitogenome and the ribosomal DNA sequences of R. goodeyi.
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Affiliation(s)
| | - Bart T L H van de Vossenberg
- National Plant Protection Organization, National Reference Centre for Plant Health, 6706 EA Wageningen, The Netherlands
| | | | | | - Wim Bert
- Nematology Research Unit, Department of Biology, Ghent University, 9000 Ghent, Belgium
| | - Gerrit Karssen
- Nematology Research Unit, Department of Biology, Ghent University, 9000 Ghent, Belgium
- National Plant Protection Organization, National Reference Centre for Plant Health, 6706 EA Wageningen, The Netherlands
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Complete Mitogenome of Cruznema Tripartitum Confirms Highly Conserved Gene Arrangement within Family Rhabditidae. J Nematol 2022; 54:20220029. [PMID: 36338422 PMCID: PMC9583413 DOI: 10.2478/jofnem-2022-0029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Indexed: 11/09/2022] Open
Abstract
Mitochondrial genomes have widely been used as molecular markers in understanding the patterns and processes of nematode evolution. The species in genus Cruznema are free-living bacterivores as well as parasites of crickets and mollusks. The complete mitochondrial genome of C. tripartitum was determined through high-throughput sequencing as the first sequenced representative of the genus Cruznema. The genome is comprised of 14,067 bp nucleotides, and includes 12 protein-coding, two rRNA, and 22 tRNA genes. Phylogenetic analyses based on amino acid data support C. tripartitum as a sister to the clade containing Caenorhabditis elegans and Oscheius chongmingensis. The analysis of gene arrangement suggested that C. tripartitum shares the same gene order with O. chongmingensis, Litoditis marina, Diplocapter coronatus, genus Caenorhabditis, and Pristionchus pacificus. Thus, the mitochondrial gene arrangement is highly conserved in the family Rhabditidae as well as some species in Diplogasteridae.
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Ma X, Agudelo P, Richards VP, Baeza JA. Genome survey sequencing of the phyto-parasitic nematode Hoplolaimus galeatus. PeerJ 2022; 10:e12749. [PMID: 35111396 PMCID: PMC8781444 DOI: 10.7717/peerj.12749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 12/15/2021] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Hoplolaimus galeatus is a plant-parasite nematode with a broad range of hosts. This nematode is known to damage cotton, corn, and soybean crops. Hoplolaimus galeatus is also an economically important pest of turfgrasses. Despite its economical importance, no genomic resources exist for this parasite. METHODS Using 300 bp paired-end short read sequencing, this study estimated genome size, analyzed a nearly complete mitochondrial chromosome, and explored nuclear repetitive elements, including microsatellites, in H. galeatus for the first time. The phylogenetic placement of H. galeatus in the superfamily Tylenchoidea was also examined. RESULTS The average haploid genome size estimated using a k-mer approach was 517.69 Mbp. The partially assembled mitochondrial genome of H. galeatus is 16,578 bp in length and comprised of 11 protein-coding genes, two ribosomal RNA genes, and 16 transfer RNA genes. A maximum likelihood phylogenetic analysis confirmed the monophyly of the genus Hoplolaimus and the superfamily Tylenchoidea. Repetitive elements constituted 50% of the nuclear genome while half of the genome represented single- or low-copy sequences. A large portion of repetitive sequences could not be assigned to known repeat element families. Considering only annotated repetitive elements, the most ubiquitous belonged to Class II- Subclass 2-Maverick elements, Class I-LTR-Ty-3/Bel-Pao elements, and satellites. 45S ribosomal DNA was also abundant and a total of 36 SSRs were identified.This study developed genomic resources for the plant-parasitic nematode Hoplolaimus galeatus that will contribute to the better understanding of meta-population connectivity and putative genomic mechanisms involved in the exploitation of the broad range of host plants used by H. galeatus.
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Affiliation(s)
- Xinyuan Ma
- Department of Biological Sciences, Clemson University, Clemson, SC, United States of America
| | - Paula Agudelo
- Plant and Environmental Sciences Department, Clemson University, Clemson, SC, United States of America
| | - Vincent P. Richards
- Plant and Environmental Sciences Department, Clemson University, Clemson, SC, United States of America
| | - J. Antonio Baeza
- Department of Biological Sciences, Clemson University, Clemson, SC, United States of America,Smithsonian Marine Station at Fort Pierce, Smithsonian Institution, Fort Pierce, FL, United States of America,Departamento de Biologia Marina, Universidad Catolica del Norte, Coquimbo, IV Region, Chile
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Feng S, Pozzi A, Stejskal V, Opit G, Yang Q, Shao R, Dowling DK, Li Z. Fragmentation in mitochondrial genomes in relation to elevated sequence divergence and extreme rearrangements. BMC Biol 2022; 20:7. [PMID: 34996453 PMCID: PMC8742463 DOI: 10.1186/s12915-021-01218-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 12/16/2021] [Indexed: 12/12/2022] Open
Abstract
Background A single circular mitochondrial (mt) genome is a common feature across most metazoans. The mt-genome includes protein-coding genes involved in oxidative phosphorylation, as well as RNAs necessary for translation of mt-RNAs, whose order and number are highly conserved across animal clades, with few known exceptions of alternative mt-gene order or mt-genome architectures. One such exception consists of the fragmented mitochondrial genome, a type of genome architecture where mt-genes are split across two or more mt-chromosomes. However, the origins of mt-genome fragmentation and its effects on mt-genome evolution are unknown. Here, we investigate these origin and potential mechanisms underlying mt-genome fragmentation, focusing on a genus of booklice, Liposcelis, which exhibits elevated sequence divergence, frequent rearrangement of mt-gene order, and fragmentation of the mt genome, and compare them to other Metazoan clades. Results We found this genus Liposcelis exhibits very low conservation of mt-gene order across species, relative to other metazoans. Levels of gene order rearrangement were, however, unrelated to whether or not mt-genomes were fragmented or intact, suggesting mitochondrial genome fragmentation is not affecting mt-gene order directly. We further investigated possible mechanisms underpinning these patterns and revealed very high conservation of non-coding sequences at the edges of multiple recombination regions across populations of one particular Liposcelis species, supportive of a hypothesis that mt-fragmentation arises from recombination errors between mt-genome copies. We propose these errors may arise as a consequence of a heightened mutation rate in clades exhibiting mt-fragmentation. Consistent with this, we observed a striking pattern across three Metazoan phyla (Arthropoda, Nematoda, Cnidaria) characterised by members exhibiting high levels of mt-gene order rearrangement and cases of mt-fragmentation, whereby the mt-genomes of species more closely related to species with fragmented mt-genomes diverge more rapidly despite experiencing strong purifying selection. Conclusions We showed that contrary to expectations, mt-genome fragmentation is not correlated with the increase in mt-genome rearrangements. Furthermore, we present evidence that fragmentation of the mt-genome may be part of a general relaxation of a natural selection on the mt-genome, thus providing new insights into the origins of mt-genome fragmentation and evolution. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01218-7.
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Affiliation(s)
- Shiqian Feng
- Department of Plant Biosecurity, College of Plant Protection, China Agricultural University, Beijing, 100193, China.,School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia
| | - Andrea Pozzi
- School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia
| | - Vaclav Stejskal
- Crop Research Institute, Drnovská 507, 161 06, Prague, Czech Republic.,Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Kamycka 129, 165 00, Prague, Czech Republic
| | - George Opit
- Department of Entomology and Plant Pathology, Oklahoma State University, Oklahoma, 74078, USA
| | - Qianqian Yang
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, 310018, China
| | - Renfu Shao
- GeneCology Research Centre, Centre for Animal Health Innovation, School of Science and Engineering, University of the Sunshine Coast, Maroochydore DC, Queensland, 4556, Australia
| | - Damian K Dowling
- School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia
| | - Zhihong Li
- Department of Plant Biosecurity, College of Plant Protection, China Agricultural University, Beijing, 100193, China.
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Hesse CN, Moreno I, Acevedo Pardo O, Pacheco Fuentes H, Grenier E, Dandurand LM, Zasada IA. Characterization of Globodera ellingtonae Populations from Chile Utilizing Whole Genome Sequencing. J Nematol 2021; 53:e2021-88. [PMID: 34761229 PMCID: PMC8574948 DOI: 10.21307/jofnem-2021-088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Indexed: 11/28/2022] Open
Abstract
Globodera ellingtonae was originally described from populations collected in the United States. In the original description, ribosomal DNA loci from Globodera sp. collected in Chile and Argentina were similar to G. ellingtonae, suggesting this nematode originated in this region of South America. In an effort to find additional populations of G. elllingtonae, collection trips were conducted in 2017 and 2020 in the Antofagasta and Arica y Parinacota Regions in Northern Chile, respectively. Globodera sp. were more prevalent in Antofagasta (17 samples collected, 53% positive for Globodera sp.) than in Arica y Parincota (16 samples collected, 13% positive for Globodera sp.). The genomes of single cysts (N ≥ 3) from four fields were sequenced. Additionally, the genomes of the G. ellingtonae population from Oregon and a Globodera sp. population originally collected in Antofagasta Region but maintained in culture in France were also sequenced. Based upon a HSP90 sequenced data mined from WSG data, all of the populations from the Antofagasta Region were G. ellingtonae and grouped in a monophyletic clade. A population collected from the Arica y Parincota Region was identified as G. rostochiensis based upon HSP90 data. Genome-wide SNP patterns of the G. ellingtonae populations showed strong clustering based on geographic location indicating that G. ellingtonae has high genetic diversity within Chile. A phylogenetic tree derived from 168,354 binary SNPs in the nuclear genome showed separate but distinct clustering of the Oregon population and the population from Antofagasta maintained in France. The Oregon G. ellingtonae population subtended the Chilean clades and placed on a long branch representing approximately twice the genetic variation observed among all Chilean G. ellingtonae populations. The possibility remains that G. ellingtonae from Chile may be sufficiently diverged to constitute a new species from G. ellingtonae originally described from a population collected in Oregon.
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Affiliation(s)
- C N Hesse
- USDA ARS Horticultural Crops Research Unit, Corvallis, OR 97330
| | - I Moreno
- Servicio Agrícola y Ganadero (SAG). División de Protección Agrícola y Forestal y Red SAG de Laboratorios, Santiago, Chile
| | - O Acevedo Pardo
- Servicio Agrícola y Ganadero (SAG). División de Protección Agrícola y Forestal y Red SAG de Laboratorios, Santiago, Chile
| | - H Pacheco Fuentes
- Servicio Agrícola y Ganadero (SAG). División de Protección Agrícola y Forestal y Red SAG de Laboratorios, Santiago, Chile
| | - E Grenier
- IGEPP, INRAE, Agrocampus Ouest, Université Rennes 1, 35650, Le Rheu, France
| | - L M Dandurand
- 875 Perimeter Drive MS 2329, University of Idaho, Moscow, ID 83844-2329
| | - I A Zasada
- USDA ARS Horticultural Crops Research Unit, Corvallis, OR 97330
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Ma X, Agudelo P, Richards VP, Baeza JA. The complete mitochondrial genome of the Columbia lance nematode, Hoplolaimus columbus, a major agricultural pathogen in North America. Parasit Vectors 2020; 13:321. [PMID: 32571423 PMCID: PMC7310197 DOI: 10.1186/s13071-020-04187-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 06/13/2020] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND The plant-parasitic nematode Hoplolaimus columbus is a pathogen that uses a wide range of hosts and causes substantial yield loss in agricultural fields in North America. This study describes, for the first time, the complete mitochondrial genome of H. columbus from South Carolina, USA. METHODS The mitogenome of H. columbus was assembled from Illumina 300 bp pair-end reads. It was annotated and compared to other published mitogenomes of plant-parasitic nematodes in the superfamily Tylenchoidea. The phylogenetic relationships between H. columbus and other 6 genera of plant-parasitic nematodes were examined using protein-coding genes (PCGs). RESULTS The mitogenome of H. columbus is a circular AT-rich DNA molecule 25,228 bp in length. The annotation result comprises 12 PCGs, 2 ribosomal RNA genes, and 19 transfer RNA genes. No atp8 gene was found in the mitogenome of H. columbus but long non-coding regions were observed in agreement to that reported for other plant-parasitic nematodes. The mitogenomic phylogeny of plant-parasitic nematodes in the superfamily Tylenchoidea agreed with previous molecular phylogenies. Mitochondrial gene synteny in H. columbus was unique but similar to that reported for other closely related species. CONCLUSIONS The mitogenome of H. columbus is unique within the superfamily Tylenchoidea but exhibits similarities in both gene content and synteny to other closely related nematodes. Among others, this new resource will facilitate population genomic studies in lance nematodes from North America and beyond.
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Affiliation(s)
- Xinyuan Ma
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634 USA
| | - Paula Agudelo
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634 USA
| | - Vincent P. Richards
- Department of Biological Sciences, Clemson University, 132 Long Hall, Clemson, SC 29634 USA
| | - J. Antonio Baeza
- Department of Biological Sciences, Clemson University, 132 Long Hall, Clemson, SC 29634 USA
- Smithsonian Marine Station at Fort Pierce, 701 Seaway Drive, Fort Pierce, Florida 34949 USA
- Departamento de Biología Marina, Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
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Kim T, Lee Y, Kil HJ, Park JK. The mitochondrial genome of Acrobeloides varius (Cephalobomorpha) confirms non-monophyly of Tylenchina (Nematoda). PeerJ 2020; 8:e9108. [PMID: 32440374 PMCID: PMC7229770 DOI: 10.7717/peerj.9108] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 04/10/2020] [Indexed: 01/08/2023] Open
Abstract
The infraorder Cephalobomorpha is a diverse and ecologically important nematode group found in almost all terrestrial environments. In a recent nematode classification system based on SSU rDNA, Cephalobomorpha was classified within the suborder Tylenchina with Panagrolaimomorpha, Tylenchomorpha and Drilonematomorpha. However, phylogenetic relationships among species within Tylenchina are not always consistent, and the phylogenetic position of Cephalobomorpha is still uncertain. In this study, in order to examine phylogenetic relationships of Cephalobomorpha with other nematode groups, we determined the complete mitochondrial genome sequence of Acrobeloides varius, the first sequenced representative of Cephalobomorpha, and used this sequence for phylogenetic analyses along with 101 other nematode species. Phylogenetic analyses using amino acid and nucleotide sequence data of 12 protein-coding genes strongly support a sister relationship between the two cephalobomorpha species A. varius and Acrobeles complexus (represented by a partial mt genome sequence). In this mitochondrial genome phylogeny, Cephalobomorpha was sister to all chromadorean species (excluding Plectus acuminatus of Plectida) and separated from Panagrolaimomorpha and Tylenchomorpha, rendering Tylenchina non-monophyletic. Mitochondrial gene order among Tylenchina species is not conserved, and gene clusters shared between A. varius and A. complexus are very limited. Results from phylogenetic analysis and gene order comparison confirms Tylenchina is not monophyletic. To better understand phylogenetic relationships among Tylenchina members, additional mitochondrial genome information is needed from underrepresented taxa representing Panagrolaimomorpha and Cephalobomorpha.
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Affiliation(s)
- Taeho Kim
- Division of EcoScience, Ewha Womans University, Seoul, Republic of Korea
| | - Yucheol Lee
- Division of EcoScience, Ewha Womans University, Seoul, Republic of Korea
| | - Hyun-Jong Kil
- Animal Resources Division, National Institute of Biological Resources, Incheon, Republic of Korea
| | - Joong-Ki Park
- Division of EcoScience, Ewha Womans University, Seoul, Republic of Korea
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Zou H, Jakovlić I, Zhang D, Hua CJ, Chen R, Li WX, Li M, Wang GT. Architectural instability, inverted skews and mitochondrial phylogenomics of Isopoda: outgroup choice affects the long-branch attraction artefacts. ROYAL SOCIETY OPEN SCIENCE 2020; 7:191887. [PMID: 32257344 PMCID: PMC7062073 DOI: 10.1098/rsos.191887] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 01/14/2020] [Indexed: 05/13/2023]
Abstract
The majority strand of mitochondrial genomes of crustaceans usually exhibits negative GC skews. Most isopods exhibit an inversed strand asymmetry, believed to be a consequence of an inversion of the replication origin (ROI). Recently, we proposed that an additional ROI event in the common ancestor of Cymothoidae and Corallanidae families resulted in a double-inverted skew (negative GC), and that taxa with homoplastic skews cluster together in phylogenetic analyses (long-branch attraction, LBA). Herein, we further explore these hypotheses, for which we sequenced the mitogenome of Asotana magnifica (Cymothoidae), and tested whether our conclusions were biased by poor taxon sampling and inclusion of outgroups. (1) The new mitogenome also exhibits a double-inverted skew, which supports the hypothesis of an additional ROI event in the common ancestor of Cymothoidae and Corallanidae families. (2) It exhibits a unique gene order, which corroborates that isopods possess exceptionally destabilized mitogenomic architecture. (3) Improved taxonomic sampling failed to resolve skew-driven phylogenetic artefacts. (4) The use of a single outgroup exacerbated the LBA, whereas both the use of a large number of outgroups and complete exclusion of outgroups ameliorated it.
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Affiliation(s)
- Hong Zou
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, and State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
| | - Ivan Jakovlić
- Bio-Transduction Lab, Wuhan 430075, People's Republic of China
| | - Dong Zhang
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, and State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Cong-Jie Hua
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, and State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
- Department of Pathogenic Biology, School of Medicine, Jianghan University, Wuhan 430056, People's Republic of China
| | - Rong Chen
- Bio-Transduction Lab, Wuhan 430075, People's Republic of China
| | - Wen-Xiang Li
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, and State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Ming Li
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, and State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Gui-Tang Wang
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, and State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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Skantar AM, Handoo ZA, Kantor MR, Carta LK, Faghihi J, Ferris V. Characterization of Vittatidera zeaphila (Nematoda: Heteroderidae) from Indiana with molecular phylogenetic analysis of the genus. J Nematol 2020; 52:1-8. [PMID: 32227749 PMCID: PMC7266014 DOI: 10.21307/jofnem-2020-024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Indexed: 01/06/2023] Open
Abstract
In the summer of 2016, a field of corn (Zea mays) in Spencer County, Indiana was observed with heavily stunted plants, and from the affected roots a large number of cysts were recovered. Soil samples were submitted to one of us (JF), who extracted the nematode cysts and sent them to the USDA-ARS, Mycology and Nematology Genetic Diversity and Biology Laboratory (MNGDBL), Beltsville, MD for morphological and molecular identification. Cysts and the recovered second-stage juveniles (J2) that were examined morphologically conformed to the measurements of Vittatidera zeaphila, the goose cyst nematode originally described from Tennessee, USA in 2010. The molecular analysis of J2 showed the sample from Spencer County matched exactly with V. zeaphila according to ribosomal DNA markers ITS, 28S, and 18S, and with mitochondrial cytochrome oxidase I (COI). The nuclear marker heat shock protein 90 (Hsp90) was also analyzed for the first time from the Indiana population of V. zeaphila. Similarities to existing cyst nematode sequences are reported herein. Geographically, although the county is across the Ohio River from Kentucky, the previously reported Hickman County, Kentucky location and Indiana detection are approximately 200 miles apart. To the best of our knowledge, this is the first report of V. zeaphila in Indiana. In the summer of 2016, a field of corn (Zea mays) in Spencer County, Indiana was observed with heavily stunted plants, and from the affected roots a large number of cysts were recovered. Soil samples were submitted to one of us (JF), who extracted the nematode cysts and sent them to the USDA-ARS, Mycology and Nematology Genetic Diversity and Biology Laboratory (MNGDBL), Beltsville, MD for morphological and molecular identification. Cysts and the recovered second-stage juveniles (J2) that were examined morphologically conformed to the measurements of Vittatidera zeaphila, the goose cyst nematode originally described from Tennessee, USA in 2010. The molecular analysis of J2 showed the sample from Spencer County matched exactly with V. zeaphila according to ribosomal DNA markers ITS, 28S, and 18S, and with mitochondrial cytochrome oxidase I (COI). The nuclear marker heat shock protein 90 (Hsp90) was also analyzed for the first time from the Indiana population of V. zeaphila. Similarities to existing cyst nematode sequences are reported herein. Geographically, although the county is across the Ohio River from Kentucky, the previously reported Hickman County, Kentucky location and Indiana detection are approximately 200 miles apart. To the best of our knowledge, this is the first report of V. zeaphila in Indiana.
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Affiliation(s)
- Andrea M Skantar
- Mycology and Nematology Genetic Diversity and Biology Laboratory , USDA, ARS, BARC-West, Bldg. 010A, Rm. 111 , Beltsville, MD , 20705
| | - Zafar A Handoo
- Mycology and Nematology Genetic Diversity and Biology Laboratory , USDA, ARS, BARC-West, Bldg. 010A, Rm. 111 , Beltsville, MD , 20705
| | - Mihail R Kantor
- Mycology and Nematology Genetic Diversity and Biology Laboratory , USDA, ARS, BARC-West, Bldg. 010A, Rm. 111 , Beltsville, MD , 20705
| | - Lynn K Carta
- Mycology and Nematology Genetic Diversity and Biology Laboratory , USDA, ARS, BARC-West, Bldg. 010A, Rm. 111 , Beltsville, MD , 20705
| | - Jamal Faghihi
- Department of Entomology , Purdue University , 901 West State St. West Lafayette, IN, 47907-2089
| | - Virginia Ferris
- Department of Entomology , Purdue University , 901 West State St. West Lafayette, IN, 47907-2089
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14
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Mishmar D, Levin R, Naeem MM, Sondheimer N. Higher Order Organization of the mtDNA: Beyond Mitochondrial Transcription Factor A. Front Genet 2019; 10:1285. [PMID: 31998357 PMCID: PMC6961661 DOI: 10.3389/fgene.2019.01285] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 11/21/2019] [Indexed: 01/09/2023] Open
Abstract
The higher order organization of eukaryotic and prokaryotic genomes is pivotal in the regulation of gene expression. Specifically, chromatin accessibility in eukaryotes and nucleoid accessibility in bacteria are regulated by a cohort of proteins to alter gene expression in response to diverse physiological conditions. By contrast, prior studies have suggested that the mitochondrial genome (mtDNA) is coated solely by mitochondrial transcription factor A (TFAM), whose increased cellular concentration was proposed to be the major determinant of mtDNA packaging in the mitochondrial nucleoid. Nevertheless, recent analysis of DNase-seq and ATAC-seq experiments from multiple human and mouse samples suggest gradual increase in mtDNA occupancy during the course of embryonic development to generate a conserved footprinting pattern which correlate with sites that have low TFAM occupancy in vivo (ChIP-seq) and tend to adopt G-quadruplex structures. These findings, along with recent identification of mtDNA binding by known modulators of chromatin accessibility such as MOF, suggest that mtDNA higher order organization is generated by cross talk with the nuclear regulatory system, may have a role in mtDNA regulation, and is more complex than once thought.
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Affiliation(s)
- Dan Mishmar
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Rotem Levin
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Mansur M Naeem
- Institute of Medical Sciences and the Department of Paediatrics, The University of Toronto, Toronto, ON, Canada
| | - Neal Sondheimer
- Institute of Medical Sciences and the Department of Paediatrics, The University of Toronto, Toronto, ON, Canada
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15
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Hogan RI, Hopkins K, Wheeler AJ, Allcock AL, Yesson C. Novel diversity in mitochondrial genomes of deep-sea Pennatulacea (Cnidaria: Anthozoa: Octocorallia). Mitochondrial DNA A DNA Mapp Seq Anal 2019; 30:764-777. [PMID: 31317811 DOI: 10.1080/24701394.2019.1634699] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We present the first documented complete mitogenomes of deep-sea Pennatulacea, representing nine genera and eight families. These include one species each of the deep-sea genera Funiculina, Halipteris, Protoptilum and Distichoptilum, four species each of Umbellula and Pennatula, three species of Kophobelemnon and two species of Anthoptilum, as well as one species of the epi- and mesobenthic genus Virgularia. Seventeen circular genomes ranged from 18,513 bp (Halipteris cf. finmarchica) to 19,171 bp (Distichoptilum gracile) and contained all genes standard to octocoral mitochondrial genomes (14 protein-coding genes, two ribosomal RNA genes and one transfer RNA). We found at least three different gene orders in Pennatulacea: the ancestral gene order, the gene order found in bamboo corals (Family Isididae), and a novel gene order. The mitogenome of one species of Umbellula has a bipartite genome (∼13 kbp and ∼5 kbp), with good evidence that both parts are circular.
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Affiliation(s)
- Raissa I Hogan
- Department of Zoology, Ryan Institute, National University of Ireland , Galway , Ireland
| | - Kevin Hopkins
- Institute of Zoology, Zoological Society of London, Regent's Park , London , UK
| | - Andrew J Wheeler
- School of Biological, Earth and Environmental Sciences/iCRAG/ERI, University College Cork , Cork , Ireland
| | - A Louise Allcock
- Department of Zoology, Ryan Institute, National University of Ireland , Galway , Ireland
| | - Chris Yesson
- Institute of Zoology, Zoological Society of London, Regent's Park , London , UK
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Feng S, Li H, Song F, Wang Y, Stejskal V, Cai W, Li Z. A novel mitochondrial genome fragmentation pattern in Liposcelis brunnea, the type species of the genus Liposcelis (Psocodea: Liposcelididae). Int J Biol Macromol 2019; 132:1296-1303. [DOI: 10.1016/j.ijbiomac.2019.04.034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 03/22/2019] [Accepted: 04/05/2019] [Indexed: 10/27/2022]
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17
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Barshad G, Marom S, Cohen T, Mishmar D. Mitochondrial DNA Transcription and Its Regulation: An Evolutionary Perspective. Trends Genet 2018; 34:682-692. [DOI: 10.1016/j.tig.2018.05.009] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 05/19/2018] [Accepted: 05/31/2018] [Indexed: 12/15/2022]
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The mitochondrial genomes of the mesozoans Intoshia linei, Dicyema sp. and Dicyema japonicum. ACTA ACUST UNITED AC 2018; 4. [PMID: 30105092 DOI: 10.1017/pao.2018.12] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The Dicyemida and Orthonectida are two groups of tiny, simple, vermiform parasites that have historically been united in a group named the Mesozoa. Both Dicyemida and Orthonectida have just two cell layers and appear to lack any defined tissues. They were initially thought to be evolutionary intermediates between protozoans and metazoans but more recent analyses indicate that they are protostomian metazoans that have undergone secondary simplification from a complex ancestor. Here we describe the first almost complete mitochondrial genome sequence from an orthonectid, Intoshia linei, and describe nine and eight mitochondrial protein-coding genes from Dicyema sp. and Dicyema japonicum, respectively. The 14,247 base pair long I. linei sequence has typical metazoan gene content, but is exceptionally AT-rich, and has a unique gene order. The data we have analysed from the Dicyemida provide very limited support for the suggestion that dicyemid mitochondrial genes are found on discrete mini-circles, as opposed to the large circular mitochondrial genomes that are typical of the Metazoa. The cox1 gene from dicyemid species has a series of conserved, in-frame deletions that is unique to this lineage. Using cox1 genes from across the genus Dicyema, we report the first internal phylogeny of this group.
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Kim T, Kern E, Park C, Nadler SA, Bae YJ, Park JK. The bipartite mitochondrial genome of Ruizia karukerae (Rhigonematomorpha, Nematoda). Sci Rep 2018; 8:7482. [PMID: 29749383 PMCID: PMC5945635 DOI: 10.1038/s41598-018-25759-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 04/27/2018] [Indexed: 11/24/2022] Open
Abstract
Mitochondrial genes and whole mitochondrial genome sequences are widely used as molecular markers in studying population genetics and resolving both deep and shallow nodes in phylogenetics. In animals the mitochondrial genome is generally composed of a single chromosome, but mystifying exceptions sometimes occur. We determined the complete mitochondrial genome of the millipede-parasitic nematode Ruizia karukerae and found its mitochondrial genome consists of two circular chromosomes, which is highly unusual in bilateral animals. Chromosome I is 7,659 bp and includes six protein-coding genes, two rRNA genes and nine tRNA genes. Chromosome II comprises 7,647 bp, with seven protein-coding genes and 16 tRNA genes. Interestingly, both chromosomes share a 1,010 bp sequence containing duplicate copies of cox2 and three tRNA genes (trnD, trnG and trnH), and the nucleotide sequences between the duplicated homologous gene copies are nearly identical, suggesting a possible recent genesis for this bipartite mitochondrial genome. Given that little is known about the formation, maintenance or evolution of abnormal mitochondrial genome structures, R. karukerae mtDNA may provide an important early glimpse into this process.
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Affiliation(s)
- Taeho Kim
- Division of Environmental Science and Ecological Engineering, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Elizabeth Kern
- Division of EcoScience, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Chungoo Park
- School of Biological Sciences and Technology, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Steven A Nadler
- Department of Entomology and Nematology, University of California, Davis, CA, 95616, USA
| | - Yeon Jae Bae
- Division of Environmental Science and Ecological Engineering, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Joong-Ki Park
- Division of EcoScience, Ewha Womans University, Seoul, 03760, Republic of Korea.
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The Highly Divergent Mitochondrial Genomes Indicate That the Booklouse, Liposcelis bostrychophila (Psocoptera: Liposcelididae) Is a Cryptic Species. G3-GENES GENOMES GENETICS 2018; 8:1039-1047. [PMID: 29352078 PMCID: PMC5844292 DOI: 10.1534/g3.117.300410] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The booklouse, Liposcelis bostrychophila is an important storage pest worldwide. The mitochondrial (mt) genome of an asexual strain (Beibei, China) of the L. bostrychophila comprises two chromosomes; each chromosome contains approximate half of the 37 genes typically found in bilateral animals. The mt genomes of two sexual strains of L. bostrychophila, however, comprise five and seven chromosomes, respectively; each chromosome contains one to six genes. To understand mt genome evolution in L. bostrychophila, and whether L. bostrychophila is a cryptic species, we sequenced the mt genomes of six strains of asexual L. bostrychophila collected from different locations in China, Croatia, and the United States. The mt genomes of all six asexual strains of L. bostrychophila have two chromosomes. Phylogenetic analysis of mt genome sequences divided nine strains of L. bostrychophila into four groups. Each group has a distinct mt genome organization and substantial sequence divergence (48.7–87.4%) from other groups. Furthermore, the seven asexual strains of L. bostrychophila, including the published Beibei strain, are more closely related to two other species of booklice, L. paeta and L. sculptilimacula, than to the sexual strains of L. bostrychophila. Our results revealed highly divergent mt genomes in the booklouse, L. bostrychophila, and indicate that L. bostrychophila is a cryptic species.
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Zou H, Jakovlić I, Chen R, Zhang D, Zhang J, Li WX, Wang GT. The complete mitochondrial genome of parasitic nematode Camallanus cotti: extreme discontinuity in the rate of mitogenomic architecture evolution within the Chromadorea class. BMC Genomics 2017; 18:840. [PMID: 29096600 PMCID: PMC5669012 DOI: 10.1186/s12864-017-4237-x] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 10/24/2017] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Complete mitochondrial genomes are much better suited for the taxonomic identification and phylogenetic studies of nematodes than morphology or traditionally-used molecular markers, but they remain unavailable for the entire Camallanidae family (Chromadorea). As the only published mitogenome in the Camallanina suborder (Dracunculoidea superfamily) exhibited a unique gene order, the other objective of this research was to study the evolution of mitochondrial architecture in the Spirurida order. Thus, we sequenced the complete mitogenome of the Camallanus cotti fish parasite and conducted structural and phylogenomic comparative analyses with all available Spirurida mitogenomes. RESULTS The mitogenome is exceptionally large (17,901 bp) among the Chromadorea and, with 46 (pseudo-) genes, exhibits a unique architecture among nematodes. Six protein-coding genes (PCGs) and six tRNAs are duplicated. An additional (seventh) tRNA (Trp) was probably duplicated by the remolding of tRNA-Ser2 (missing). Two pairs of these duplicated PCGs might be functional; three were incomplete and one contained stop codons. Apart from Ala and Asp, all other duplicated tRNAs are conserved and probably functional. Only 19 unique tRNAs were found. Phylogenomic analysis included Gnathostomatidae (Spirurina) in the Camallanina suborder. CONCLUSIONS Within the Nematoda, comparable PCG duplications were observed only in the enoplean Mermithidae family, but those result from mitochondrial recombination, whereas characteristics of the studied mitogenome suggest that likely rearrangement mechanisms are either a series of duplications, transpositions and random loss events, or duplication, fragmentation and subsequent reassembly of the mitogenome. We put forward a hypothesis that the evolution of mitogenomic architecture is extremely discontinuous, and that once a long period of stasis in gene order and content has been punctuated by a rearrangement event, such a destabilised mitogenome is much more likely to undergo subsequent rearrangement events, resulting in an exponentially accelerated evolutionary rate of mitogenomic rearrangements. Implications of this model are particularly important for the application of gene order similarity as an additive source of phylogenetic information. Chromadorean nematodes, and particularly Camallanina clade (with C. cotti as an example of extremely accelerated rate of rearrangements), might be a good model to further study this discontinuity in the dynamics of mitogenomic evolution.
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Affiliation(s)
- Hong Zou
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, and State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072 People’s Republic of China
| | - Ivan Jakovlić
- Bio-Transduction Lab, Wuhan Institute of Biotechnology, Wuhan, 430075 People’s Republic of China
| | - Rong Chen
- Bio-Transduction Lab, Wuhan Institute of Biotechnology, Wuhan, 430075 People’s Republic of China
| | - Dong Zhang
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, and State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072 People’s Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049 People’s Republic of China
| | - Jin Zhang
- Bio-Transduction Lab, Wuhan Institute of Biotechnology, Wuhan, 430075 People’s Republic of China
| | - Wen-Xiang Li
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, and State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072 People’s Republic of China
| | - Gui-Tang Wang
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, and State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072 People’s Republic of China
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Mitochondrial genome diversity in dagger and needle nematodes (Nematoda: Longidoridae). Sci Rep 2017; 7:41813. [PMID: 28150734 PMCID: PMC5288807 DOI: 10.1038/srep41813] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 12/30/2016] [Indexed: 11/23/2022] Open
Abstract
Dagger and needle nematodes included in the family Longidoridae (viz. Longidorus, Paralongidorus, and Xiphinema) are highly polyphagous plant-parasitic nematodes in wild and cultivated plants and some of them are plant-virus vectors (nepovirus). The mitochondrial (mt) genomes of the dagger and needle nematodes, Xiphinema rivesi, Xiphinema pachtaicum, Longidorus vineacola and Paralongidorus litoralis were sequenced in this study. The four circular mt genomes have an estimated size of 12.6, 12.5, 13.5 and 12.7 kb, respectively. Up to date, the mt genome of X. pachtaicum is the smallest genome found in Nematoda. The four mt genomes contain 12 protein-coding genes (viz. cox1-3, nad1-6, nad4L, atp6 and cob) and two ribosomal RNA genes (rrnL and rrnS), but the atp8 gene was not detected. These mt genomes showed a gene arrangement very different within the Longidoridae species sequenced, with the exception of very closely related species (X. americanum and X. rivesi). The sizes of non-coding regions in the Longidoridae nematodes were very small and were present in a few places in the mt genome. Phylogenetic analysis of all coding genes showed a closer relationship between Longidorus and Paralongidorus and different phylogenetic possibilities for the three Xiphinema species.
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