1
|
Selifanova M, Demianchenko O, Noskova E, Pitikov E, Skvortsov D, Drozd J, Vatolkina N, Apel P, Kolodyazhnaya E, Ezhova MA, Tzetlin AB, Neretina TV, Knorre DA. ORFans in Mitochondrial Genomes of Marine Polychaete Polydora. Genome Biol Evol 2023; 15:evad219. [PMID: 38019573 PMCID: PMC10721130 DOI: 10.1093/gbe/evad219] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 11/18/2023] [Accepted: 11/24/2023] [Indexed: 11/30/2023] Open
Abstract
Most characterized metazoan mitochondrial genomes are compact and encode a small set of proteins that are essential for oxidative phosphorylation, as well as rRNA and tRNA for their expression. However, in rare cases, invertebrate taxa have additional open reading frames (ORFs) in their mtDNA sequences. Here, we sequenced and analyzed the mitochondrial genome of a polychaete worm, Polydora cf. ciliata, part of whose life cycle takes place in low-oxygen conditions. In the mitogenome, we found three "ORFan" regions (544, 1,060, and 427 bp) that have no resemblance to any standard metazoan mtDNA gene but lack stop codons in one of the reading frames. Similar regions are found in the mitochondrial genomes of three other Polydora species and Bocardiella hamata. All five species share the same gene order in their mitogenomes, which differ from that of other known Spionidae mitogenomes. By analyzing the ORFan sequences, we found that they are under purifying selection pressure and contain conservative regions. The codon adaptation indices (CAIs) of the ORFan genes were in the same range of values as the CAI of conventional protein-coding genes in corresponding mitochondrial genomes. The analysis of the P. cf. ciliata mitochondrial transcriptome showed that ORFan-544, ORFan-427, and a portion of the ORFan-1060 are transcribed. Together, this suggests that ORFan-544 and ORFan-427 encode functional proteins. It is likely that the ORFans originated when the Polydora/Bocardiella species complex separated from the rest of the Spionidae, and this event coincided with massive gene rearrangements in their mitochondrial genomes and tRNA-Met duplication.
Collapse
Affiliation(s)
- Maria Selifanova
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Oleg Demianchenko
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Elizaveta Noskova
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Egor Pitikov
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Denis Skvortsov
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Jana Drozd
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Nika Vatolkina
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Polina Apel
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Ekaterina Kolodyazhnaya
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Margarita A Ezhova
- Pertsov White Sea Biological Station, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Alexander B Tzetlin
- Pertsov White Sea Biological Station, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Tatiana V Neretina
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
- Pertsov White Sea Biological Station, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
- Institute for Information Transmission Problems (Kharkevich Institute), Russian Academy of Science, Moscow, Russia
| | - Dmitry A Knorre
- Pertsov White Sea Biological Station, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| |
Collapse
|
2
|
Kobayashi G. Buried treasure in a public repository: Mining mitochondrial genes of 32 annelid species from sequence reads deposited in the Sequence Read Archive (SRA). PeerJ 2023; 11:e16446. [PMID: 38047014 PMCID: PMC10693233 DOI: 10.7717/peerj.16446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 10/21/2023] [Indexed: 12/05/2023] Open
Abstract
Background The mitochondrial genomes (mitogenomes) of metazoans generally include the same set of protein-coding genes, which ensures the homology of mitochondrial genes between species. The mitochondrial genes are often used as reference data for species identification based on genetic data (DNA barcoding). The need for such reference data has been increasing due to the application of environmental DNA (eDNA) analysis for environmental assessments. Recently, the number of publicly available sequence reads obtained with next-generation sequencing (NGS) has been increasing in the public database (the NCBI Sequence Read Archive, SRA). Such freely available NGS reads would be promising sources for assembling mitochondrial protein-coding genes (mPCGs) of organisms whose mitochondrial genes are not available in GenBank. The present study aimed to assemble annelid mPCGs from raw data deposited in the SRA. Methods The recent progress in the classification of Annelida was briefly introduced. In the present study, the mPCGs of 32 annelid species of 19 families in clitellates and allies in Sedentaria (echiurans and polychaetes) were newly assembled from the reads deposited in the SRA. Assembly was performed with a recently published pipeline mitoRNA, which includes cycles of Bowtie2 mapping and Trinity assembly. Assembled mPCGs were deposited in GenBank as Third Party Data (TPA) data. A phylogenetic tree was reconstructed with maximum likelihood (ML) analysis, together with other mPCGs deposited in GenBank. Results and Discussion mPCG assembly was largely successful except for Travisia forbesii; only four genes were detected from the assembled contigs of the species probably due to the reads targeting its parasite. Most genes were largely successfully obtained, whereas atp8, nad2, and nad4l were only successful in 22-24 species. The high nucleotide substitution rates of these genes might be relevant to the failure in the assembly although nad6, which showed a similarly high substitution rate, was successfully assembled. Although the phylogenetic positions of several lineages were not resolved in the present study, the phylogenetic relationships of some polychaetes and leeches that were not inferred by transcriptomes were well resolved probably due to a more dense taxon sampling than previous phylogenetic analyses based on transcriptomes. Although NGS data are generally better sources for resolving phylogenetic relationships of both higher and lower classifications, there are ensuring needs for specific loci of the mitochondrial genes for analyses that do not require high resolutions, such as DNA barcoding, eDNA, and phylogenetic analysis among lower taxa. Assembly from publicly available NGS reads would help design specific primers for the mitochondrial gene sequences of species, whose mitochondrial genes are hard to amplify by Sanger sequencing using universal primers.
Collapse
Affiliation(s)
- Genki Kobayashi
- Research Center for Creative Partnerships, Ishinomaki Senshu University, Ishinomaki, Miyagi, Japan
| |
Collapse
|
3
|
Kobayashi G, Itoh H, Nakajima N. First report of the mitogenome of the invasive reef-building polychaete Ficopomatus enigmaticus (Annelida: Serpulidae) and a cryptic lineage from the Japanese Archipelago. Mol Biol Rep 2023; 50:7183-7196. [PMID: 37407804 DOI: 10.1007/s11033-023-08647-3] [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: 03/05/2023] [Accepted: 06/27/2023] [Indexed: 07/07/2023]
Abstract
BACKGROUND The mitochondrial genomes (mitogenomes) of the family Serpulidae are characterized by a high nucleotide sequence divergence and a significant number of gene order rearrangements compared with other families within the phylum Annelida. However, only two of 50 genera of serpulids have mitogenomes already sequenced. In this study, we report the first sequencing and assembly of the complete mitogenome of Ficopomatus, thus providing further knowledge on mitochondrial gene sequences of Serpulidae. METHODS AND RESULTS A mitogenome of the invasive reef-building polychaete Ficopomatus enigmaticus was amplified by long PCR and sequenced using the Illumina MiSeq System. It comprised 15,853 bp and consisted of 12 protein-coding genes (atp8 was not found), 23 tRNA, and two rRNA genes. The AT and GC skew values were infrequent when compared to annelid mitogenomes but similar to other serpulids sequenced to date (i.e., Spirobranchus and Hydroides). The mitochondrial gene order of F. enigmaticus was highly rearranged compared to other serpulids. To amplify 16S rRNA gene sequences, we developed a 16S rRNA primer set by modifying the universal primer set 16SarL/16SbrH. We detected the 16S rRNA sequence of F. enigmaticus deposited in GenBank erroneously characterized as of serpulid origin. We reported for the first time the presence of two lineages of F. enigmaticus in Japan, which have already been identified in California, Australia, and the Mediterranean. CONCLUSIONS The first mitochondrial genome of F. enigmaticus showed a unique gene order rearrangement, corroborating the remarkable diversity in the previously reported mitogenomes of other serpulid species. The presence of the two lineages of F. enigmaticus identified for the first time in Japan represents another case of cryptic invasion. The first 16S rRNA gene sequences of F. enigmaticus obtained in the present study can be used as reference sequences in future DNA metabarcoding studies.
Collapse
Affiliation(s)
- Genki Kobayashi
- Ishinomaki Senshu University, 1 Shinmito Minamisakai, Ishinomaki, Miyagi, 986-8580, Japan.
| | - Hajime Itoh
- National Institute for Environmental Studies, 16-2, Onogawa, Tsukuba, Ibaraki, 305-8506, Japan
| | - Nobuyoshi Nakajima
- National Institute for Environmental Studies, 16-2, Onogawa, Tsukuba, Ibaraki, 305-8506, Japan
| |
Collapse
|
4
|
Szafranski P. New Dielis species and structural dichotomy of the mitochondrial cox2 gene in Scoliidae wasps. Sci Rep 2023; 13:1950. [PMID: 36732536 PMCID: PMC9895450 DOI: 10.1038/s41598-023-27806-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 01/09/2023] [Indexed: 02/04/2023] Open
Abstract
Some mitochondrial protein-coding genes of protists and land plants have split over the course of evolution into complementary genes whose products can form heteromeric complexes that likely substitute for the undivided proteins. One of these genes, cox2, has also been found to have split in animals, specifically in Scoliidae wasps (Hymenoptera: Apocrita) of the genus Dielis (Campsomerini), while maintaining the conventional structure in related Scolia (Scoliini). Here, a hitherto unrecognized Nearctic species of Dielis, D. tejensis, is described based on its phenotype and mtDNA. The mitogenome of D. tejensis sp. nov. differs from that of the sympatric sibling species Dielis plumipes fossulana by the reduced size of the cox2-dividing insert, which, however, still constitutes the fifth part of the mtDNA; an enlarged nad2-trnW intergenic region; the presence of two trnKttt paralogues; and other features. Both species of Dielis have a unique insertion of a threonine in COXIIA, predicted to be involved in COXIIA-COXIIB docking, and substitutions of two hydrophobic residues with redox-active cysteines around the CuA centre in COXIIB. Importantly, the analysis of mtDNA from another Campsomerini genus, Megacampsomeris, shows that its cox2 gene is also split. The presented data highlight evolutionary processes taking place in hymenopteran mitogenomes that do not fall within the mainstream of animal mitochondrion evolution.
Collapse
Affiliation(s)
- Przemyslaw Szafranski
- Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
| |
Collapse
|
5
|
Lubośny M, Śmietanka B, Lasota R, Burzyński A. Confirmation of the first intronic sequence in the bivalvian mitochondrial genome of Macoma balthica (Linnaeus, 1758). Biol Lett 2022; 18:20220275. [PMID: 36196553 PMCID: PMC9532982 DOI: 10.1098/rsbl.2022.0275] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In 2020, the first male-type mitochondrial genome from the clam Macoma balthica was published. Apart from the unusual doubly uniparental inheritance of mtDNA, scientists observed a unique (over 4k bp long) extension in the middle of the cox2 gene. We have attempted to replicate these data by NGS DNA sequencing and explore further the expression of the long cox2 gene. In our study, we report an even longer cox2 gene (over 5.5 kbp) with no stop codon separating conserved cox2 domains, as well as, based on the rtPCR, a lower relative gene expression pattern of the middle part of the gene (5' = 1; mid = 0.46; 3' = 0.89). Lastly, we sequenced the cox2 gene transcript proving the excision of the intronic sequence.
Collapse
Affiliation(s)
- Marek Lubośny
- Department of Genetics and Marine Biotechnology, Institute of Oceanology Polish Academy of Sciences, Sopot 81-712, Poland
| | - Beata Śmietanka
- Department of Genetics and Marine Biotechnology, Institute of Oceanology Polish Academy of Sciences, Sopot 81-712, Poland
| | - Rafał Lasota
- Faculty of Oceanography and Geography, Division of Marine Ecosystems Functioning, University of Gdańsk, Gdynia 81-378, Poland
| | - Artur Burzyński
- Department of Genetics and Marine Biotechnology, Institute of Oceanology Polish Academy of Sciences, Sopot 81-712, Poland
| |
Collapse
|
6
|
Mitochondrial genomes provide insight into interfamilial relationships within Pycnogonida. Polar Biol 2022. [DOI: 10.1007/s00300-022-03085-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
7
|
Unprecedented frequency of mitochondrial introns in colonial bilaterians. Sci Rep 2022; 12:10889. [PMID: 35764672 PMCID: PMC9240083 DOI: 10.1038/s41598-022-14477-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 06/07/2022] [Indexed: 11/16/2022] Open
Abstract
Animal mitogenomes are typically devoid of introns. Here, we report the largest number of mitochondrial introns ever recorded from bilaterian animals. Mitochondrial introns were identified for the first time from the phylum Bryozoa. They were found in four species from three families (Order Cheilostomatida). A total of eight introns were found in the complete mitogenome of Exechonella vieirai, and five, 17 and 18 introns were found in the partial mitogenomes of Parantropora penelope, Discoporella cookae and Cupuladria biporosa, respectively. Intron-encoded protein domains reverse transcriptase and intron maturase (RVT-IM) were identified in all species. Introns in E. vieirai and P. penelope had conserved Group II intron ribozyme domains V and VI. Conserved domains were lacking from introns in D. cookae and C. biporosa, preventing their further categorization. Putative origins of metazoan introns were explored in a phylogenetic context, using an up-to-date alignment of mitochondrial RVT-IM domains. Results confirmed previous findings of multiple origins of annelid, placozoan and sponge RVT-IM domains and provided evidence for common intron donor sources across metazoan phyla. Our results corroborate growing evidence that some metazoans with regenerative abilities (i.e. placozoans, sponges, annelids and bryozoans) are susceptible to intron integration, most likely via horizontal gene transfer.
Collapse
|
8
|
Kobayashi G, Itoh H, Nakajima N. First mitochondrial genomes of Capitellidae and Opheliidae (Annelida) and their phylogenetic placement. Mitochondrial DNA B Resour 2022; 7:577-579. [PMID: 35386629 PMCID: PMC8979498 DOI: 10.1080/23802359.2022.2056537] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Affiliation(s)
- Genki Kobayashi
- Seto Marine Biological Laboratory, Field Science Education and Research Center, Kyoto University, Nishimuro, Japan
| | - Hajime Itoh
- National Institute for Environmental Studies, Tsukuba, Japan
| | | |
Collapse
|
9
|
Cejp B, Ravara A, Aguado MT. First mitochondrial genomes of Chrysopetalidae (Annelida) from shallow-water and deep-sea chemosynthetic environments. Gene 2022; 815:146159. [PMID: 34995739 DOI: 10.1016/j.gene.2021.146159] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 11/30/2021] [Accepted: 12/10/2021] [Indexed: 02/07/2023]
Abstract
Among Annelida, Chrysopetalidae is an ecologically and morphologically diverse group, which includes shallow-water, deep-sea, free-living, and symbiotic species. Here, the four first mitochondrial genomes of this group are presented and described. One of the free-living shallow-water species Chrysopetalum debile (Chrysopetalinae), one of the yet undescribed free-living deep-sea species Boudemos sp., and those of the two deep-sea bivalve endosymbionts Craseoschema thyasiricola and Iheyomytilidicola lauensis (Calamyzinae). An updated phylogeny of Chrysopetalidae is performed, which supports previous phylogenetic hypotheses within Chrysopetalinae and indicates a complex ecological evolution within Calamyzinae. Additionally, analyses of natural selection pressure in the four mitochondrial genomes and additional genes from the two shallow-water species Bhawania goodei and Arichlidon gathofi were performed. Relaxed selection pressure in the mitochondrion of deep-sea and symbiotic species was found, with many sites under selection identified in the COX3 gene of deep-sea species.
Collapse
Affiliation(s)
- Benjamin Cejp
- Animal Evolution and Biodiversity, Johann-Friedrich-Blumenbach Institute for Zoology & Anthropology, Georg-August-University Göttingen, 37073, Germany.
| | - Ascensão Ravara
- Departamento de Biologia & CESAM, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
| | - M Teresa Aguado
- Animal Evolution and Biodiversity, Johann-Friedrich-Blumenbach Institute for Zoology & Anthropology, Georg-August-University Göttingen, 37073, Germany.
| |
Collapse
|
10
|
Kobayashi G, Itoh H, Kojima S. Mitogenome of a stink worm (Annelida: Travisiidae) includes degenerate group II intron that is also found in five congeneric species. Sci Rep 2022; 12:4449. [PMID: 35292662 PMCID: PMC8924214 DOI: 10.1038/s41598-022-08103-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 02/25/2022] [Indexed: 12/05/2022] Open
Abstract
Mitogenomes are useful for inferring phylogenetic relationships between organisms. Although the mitogenomes of Annelida, one of the most morphologically and ecologically diverse metazoan groups have been well sequenced, those of several families remain unexamined. This study determined the first mitogenome from the family Travisiidae (Travisia sanrikuensis), analyzed its mitogenomic features, and reconstructed a phylogeny of Sedentaria. The monophyly of the Terebellida + Arenicolida + Travisiidae clade is supported by molecular phylogenetic analysis. The placement of Travisiidae is unclear because of the lack of mitogenomes from closely related lineages. An unexpected intron appeared within the cox1 gene of T. sanrikuensis and in the same positions of five undescribed Travisia spp. Although the introns are shorter (790–1386 bp) than other group II introns, they can be considered degenerate group II introns due to type II intron maturase open reading frames, found in two of the examined species, and motifs characteristic of group II introns. This is likely the first known case in metazoans where mitochondrial group II introns obtained by a common ancestor are conserved in several descendants. Insufficient evolutionary time for intron loss in Travisiidae, or undetermined mechanisms may have helped maintain the degenerate introns.
Collapse
Affiliation(s)
- Genki Kobayashi
- Seto Marine Biological Laboratory, Field Science Education and Research Center, Kyoto University, 459 Shirahama, Nishimuro, Wakayama, 649-2211, Japan.
| | - Hajime Itoh
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan
| | - Shigeaki Kojima
- Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8564, Japan
| |
Collapse
|
11
|
Mukhopadhyay J, Hausner G. Organellar Introns in Fungi, Algae, and Plants. Cells 2021; 10:cells10082001. [PMID: 34440770 PMCID: PMC8393795 DOI: 10.3390/cells10082001] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/31/2021] [Accepted: 08/05/2021] [Indexed: 12/16/2022] Open
Abstract
Introns are ubiquitous in eukaryotic genomes and have long been considered as ‘junk RNA’ but the huge energy expenditure in their transcription, removal, and degradation indicate that they may have functional significance and can offer evolutionary advantages. In fungi, plants and algae introns make a significant contribution to the size of the organellar genomes. Organellar introns are classified as catalytic self-splicing introns that can be categorized as either Group I or Group II introns. There are some biases, with Group I introns being more frequently encountered in fungal mitochondrial genomes, whereas among plants Group II introns dominate within the mitochondrial and chloroplast genomes. Organellar introns can encode a variety of proteins, such as maturases, homing endonucleases, reverse transcriptases, and, in some cases, ribosomal proteins, along with other novel open reading frames. Although organellar introns are viewed to be ribozymes, they do interact with various intron- or nuclear genome-encoded protein factors that assist in the intron RNA to fold into competent splicing structures, or facilitate the turn-over of intron RNAs to prevent reverse splicing. Organellar introns are also known to be involved in non-canonical splicing, such as backsplicing and trans-splicing which can result in novel splicing products or, in some instances, compensate for the fragmentation of genes by recombination events. In organellar genomes, Group I and II introns may exist in nested intronic arrangements, such as introns within introns, referred to as twintrons, where splicing of the external intron may be dependent on splicing of the internal intron. These nested or complex introns, with two or three-component intron modules, are being explored as platforms for alternative splicing and their possible function as molecular switches for modulating gene expression which could be potentially applied towards heterologous gene expression. This review explores recent findings on organellar Group I and II introns, focusing on splicing and mobility mechanisms aided by associated intron/nuclear encoded proteins and their potential roles in organellar gene expression and cross talk between nuclear and organellar genomes. Potential application for these types of elements in biotechnology are also discussed.
Collapse
MESH Headings
- Evolution, Molecular
- Gene Expression Regulation, Fungal
- Gene Expression Regulation, Plant
- Genome, Fungal
- Genome, Plant
- Introns
- Organelles/genetics
- Organelles/metabolism
- RNA Splicing
- RNA Stability
- RNA, Algal/genetics
- RNA, Algal/metabolism
- RNA, Fungal/genetics
- RNA, Fungal/metabolism
- RNA, Plant/genetics
- RNA, Plant/metabolism
- RNA, Untranslated/genetics
- RNA, Untranslated/metabolism
- Transcription, Genetic
Collapse
|
12
|
Mitochondrial genomes of two Polydora (Spionidae) species provide further evidence that mitochondrial architecture in the Sedentaria (Annelida) is not conserved. Sci Rep 2021; 11:13552. [PMID: 34193932 PMCID: PMC8245539 DOI: 10.1038/s41598-021-92994-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 06/18/2021] [Indexed: 12/15/2022] Open
Abstract
Contrary to the early evidence, which indicated that the mitochondrial architecture in one of the two major annelida clades, Sedentaria, is relatively conserved, a handful of relatively recent studies found evidence that some species exhibit elevated rates of mitochondrial architecture evolution. We sequenced complete mitogenomes belonging to two congeneric shell-boring Spionidae species that cause considerable economic losses in the commercial marine mollusk aquaculture: Polydora brevipalpa and Polydora websteri. The two mitogenomes exhibited very similar architecture. In comparison to other sedentarians, they exhibited some standard features, including all genes encoded on the same strand, uncommon but not unique duplicated trnM gene, as well as a number of unique features. Their comparatively large size (17,673 bp) can be attributed to four non-coding regions larger than 500 bp. We identified an unusually large (putative) overlap of 14 bases between nad2 and cox1 genes in both species. Importantly, the two species exhibited completely rearranged gene orders in comparison to all other available mitogenomes. Along with Serpulidae and Sabellidae, Polydora is the third identified sedentarian lineage that exhibits disproportionally elevated rates of mitogenomic architecture rearrangements. Selection analyses indicate that these three lineages also exhibited relaxed purifying selection pressures.
Collapse
|
13
|
Sun Y, Daffe G, Zhang Y, Pons J, Qiu JW, Kupriyanova EK. Another blow to the conserved gene order in Annelida: Evidence from mitochondrial genomes of the calcareous tubeworm genus Hydroides. Mol Phylogenet Evol 2021; 160:107124. [PMID: 33610649 DOI: 10.1016/j.ympev.2021.107124] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 01/15/2021] [Accepted: 02/11/2021] [Indexed: 01/07/2023]
Abstract
Mitochondrial genomes are frequently applied in phylogenetic and evolutionary studies across metazoans, yet they are still poorly represented in many groups of invertebrates, including annelids. Here, we report ten mitochondrial genomes from the annelid genus Hydroides (Serpulidae) and compare them with all available annelid mitogenomes. We detected all 13 protein coding genes in Hydroides spp., including the atp8 which was reported as a missing gene in the Christmas Tree worm Spirobranchus giganteus, another annelid of the family Serpulidae. All available mitochondrial genomes of Hydroides show a highly positive GC skew combined with a highly negative AT skew - a feature consistent with that found only in the mitogenome of S. giganteus. In addition, amino acid sequences of the 13 protein-coding genes showed a high genetic distance between the Hydroides clade and S. giganteus, suggesting a fast rate of mitochondrial sequence evolution in Serpulidae. The gene order of protein-coding genes within Hydroides exhibited extensive rearrangements at species level, and were different from the arrangement patterns of other annelids, including S. giganteus. Phylogenetic analyses based on protein-coding genes recovered Hydroides as a monophyletic group sister to Spirobranchus with a long branch, and sister to the fan worm Sabellidae. Yet the Serpulidae + Sabellidae clade was unexpectedly grouped with Sipuncula, suggesting that mitochondrial genomes alone are insufficient to resolve the phylogenetic position of Serpulidae within Annelida due to its high base substitution rates. Overall, our study revealed a high variability in the gene order arrangement of mitochondrial genomes within Serpulidae, provided evidence to question the conserved pattern of the mitochondrial gene order in Annelida and called for caution when applying mitochondrial genes to infer their phylogenetic relationships.
Collapse
Affiliation(s)
- Yanan Sun
- Department of Biology and Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Hong Kong Baptist University, 224 Waterloo Road, Hong Kong; Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney, NSW 2010, Australia
| | - Guillemine Daffe
- Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney, NSW 2010, Australia; Universite de Bordeaux, CNRS, INRAE, La Rochelle Universite, UMS 2567 POREA, 33615 Pessac, France
| | - Yanjie Zhang
- Department of Biology and Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Hong Kong Baptist University, 224 Waterloo Road, Hong Kong
| | - Joan Pons
- Diversidad Animal y Microbiana, Instituto Mediterráneo de Estudios Avanzados IMEDEA (CSIC-UIB), Esporles, Balearic Islands, Spain
| | - Jian-Wen Qiu
- Department of Biology and Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Hong Kong Baptist University, 224 Waterloo Road, Hong Kong
| | - Elena K Kupriyanova
- Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney, NSW 2010, Australia; Department of Biological Sciences, Macquarie University, Sydney, NSW 2109, Australia.
| |
Collapse
|
14
|
Mitogenomics reveals phylogenetic relationships of Arcoida (Mollusca, Bivalvia) and multiple independent expansions and contractions in mitochondrial genome size. Mol Phylogenet Evol 2020; 150:106857. [PMID: 32473333 DOI: 10.1016/j.ympev.2020.106857] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 04/09/2020] [Accepted: 05/21/2020] [Indexed: 11/24/2022]
Abstract
Arcoida, comprising about 570 species of blood cockles, is an ecologically and economically important lineage of bivalve molluscs. Current classification of arcoids is largely based on morphology, which shows widespread homoplasy. Despite two recent studies employing multi-locus analyses with broad sampling of Arcoida, evolutionary relationships among major lineages remain controversial. Interestingly, mitochondrial genomes of several ark shell species are 2-3 times larger than those found in most bilaterians, and are among the largest bilaterian mitochondrial genomes reported to date. These results highlight the need of detailed phylogenetic study to explore evolutionary relationships within Arcoida so that the evolution of mitochondrial genome size can be understood. To this end, we sequenced 17 mitochondrial genomes and compared them with publicly available data, including those from other lineages of Arcoida with emphasis on the subclade Arcoidea species. Our phylogenetic analyses indicate that Noetiidae, Cucullaeidae and Glycymerididae are nested within a polyphyletic Arcidae. Moreover, we find multiple independent expansions and potential contractions of mitochondrial genome size, suggesting that the large mitochondrial genome is not a shared ancestral feature in Arcoida. We also examined tandem repeats and inverted repeats in non-coding regions and investigated the presence of such repeats with relation to genome size variation. Our results suggest that tandem repeats might facilitate intraspecific mitochondrial genome size variation, and that inverted repeats, which could be derived from transposons, might be responsible for mitochondrial genome expansions and contractions. We show that mitochondrial genome size in Arcoida is more dynamic than previously understood and provide insights into evolution of mitochondrial genome size variation in metazoans.
Collapse
|