scholarly journals Polymorphism within the mitochondrial genome of the ctenophore, Pleurobrachia bachei and its ongoing rapid evolution

2018 ◽  
Author(s):  
Andrea B. Kohn ◽  
Leonid L. Moroz
Keyword(s):  
Mitochondrial Genome ◽  
Gene Loss ◽  
Rapid Evolution ◽  
Mitochondrial Genes ◽  
Mitochondrial Genomes ◽  
Animal Kingdom ◽  
Proteomic Data ◽  
High Level ◽  
Pleurobrachia Bachei ◽  
Fast Evolution

AbstractThe mitochondrial genomes in ctenophores are among the most compact in the animal kingdom with multiple rearrangements and examples of gene loss. Here, by resequencing of the Pleurobrachia bachei mitochondrial genome, we show that the high level of polymorphism (>10%) in Pleurobrachia might contribute to the ongoing fast evolution of ctenophores including the presence of truncated versions of apparently canonical genes such as cox1. Second, the codon interpretations in ctenophores, without robust proteomic data related to mitochondrial genes, is still a challenging issue, which is open for future experimental analyses.

scholarly journals Mitochondrial genome of the nonphotosynthetic mycoheterotrophic plant Hypopitys monotropa, its structure, gene expression and RNA editing

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9309
Author(s):  
Viktoria Yu Shtratnikova ◽  
Mikhail I. Schelkunov ◽  
Aleksey A. Penin ◽  
Maria D. Logacheva
Keyword(s):  
Mitochondrial Genome ◽  
Rna Editing ◽  
Transcriptome Sequencing ◽  
Unique Feature ◽  
Genetic Material ◽  
Mitochondrial Genes ◽  
Vaccinium Macrocarpon ◽  
Mitochondrial Genomes ◽  
Plastid Genomes ◽  
Trans Splicing

Heterotrophic plants—plants that have lost the ability to photosynthesize—are characterized by a number of changes at all levels of organization. Heterotrophic plants are divided into two large categories—parasitic and mycoheterotrophic (MHT). The question of to what extent such changes are similar in these two categories is still open. The plastid genomes of nonphotosynthetic plants are well characterized, and they exhibit similar patterns of reduction in the two groups. In contrast, little is known about the mitochondrial genomes of MHT plants. We report the structure of the mitochondrial genome of Hypopitys monotropa, a MHT member of Ericaceae, and the expression of its genes. In contrast to its highly reduced plastid genome, the mitochondrial genome of H. monotropa is larger than that of its photosynthetic relative Vaccinium macrocarpon, and its complete size is ~810 Kb. We observed an unusually long repeat-rich structure of the genome that suggests the existence of linear fragments. Despite this unique feature, the gene content of the H. monotropa mitogenome is typical of flowering plants. No acceleration of substitution rates is observed in mitochondrial genes, in contrast to previous observations in parasitic non-photosynthetic plants. Transcriptome sequencing revealed the trans-splicing of several genes and RNA editing in 33 of 38 genes. Notably, we did not find any traces of horizontal gene transfer from fungi, in contrast to plant parasites, which extensively integrate genetic material from their hosts.

The plant mitochondrial genome: homologous recombination as a mechanism for generating heterogeneity

1988 ◽  
Vol 319 (1193) ◽  
pp. 149-163 ◽  
Keyword(s):  
Mitochondrial Dna ◽  
Homologous Recombination ◽  
Mitochondrial Genome ◽  
Higher Plants ◽  
Genome Structure ◽  
Rapid Evolution ◽  
Mitochondrial Genomes ◽  
Base Sequence ◽  
Plant Mitochondrial Genome ◽  
Organelle Genomes

The mitochondrial genomes of higher plants are among the largest and most complex organelle genomes described. They are generally multicircular or partly linear; in some species, extrachromosomal plasmids are present. It is proposed that inter- and intramolecular homologous recombination can account for the diversity of the observed genome organizations. The ability of mitochondria to fuse establishes a panmictic mitochondrial DNA population which is in recombinational equilibrium. It is suggested that this suppresses the base mutation rate, and unequal partitioning of the cytoplasm during cell division can lead to the rapid evolution of mitochondrial genome structure. This contrasts with the observed rates of base-sequence and genome evolution in chloroplasts. This difference can be accounted for solely by the inability of chloroplasts to fuse, thereby preventing chloroplast genome panmixis.

scholarly journals The mitochondrial genomes of the mesozoans Intoshia linei, Dicyema sp. and Dicyema japonicum

2018 ◽  
Vol 4 ◽  
Author(s):  
Helen E. Robertson ◽  
Philipp H. Schiffer ◽  
Maximilian J. Telford
Keyword(s):  
Mitochondrial Genome ◽  
Gene Order ◽  
Complete Mitochondrial Genome ◽  
Mitochondrial Protein ◽  
Mitochondrial Genes ◽  
Mitochondrial Genomes ◽  
Protein Coding ◽  
Protein Coding Genes ◽  
Limited Support ◽  
Cell Layers

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.

A one-megabase physical map provides insights on gene organization in the enormous mitochondrial genome of cucumber

Genome ◽  
2009 ◽  
Vol 52 (4) ◽  
pp. 299-307 ◽  
Author(s):  
Grzegorz Bartoszewski ◽  
Piotr Gawronski ◽  
Marek Szklarczyk ◽  
Henk Verbakel ◽  
Michael J. Havey
Keyword(s):  
Mitochondrial Dna ◽  
Mitochondrial Genome ◽  
Physical Map ◽  
Mitochondrial Gene ◽  
Mitochondrial Genes ◽  
Gene Organization ◽  
Mitochondrial Genomes ◽  
Bac Contig ◽  
Repetitive Dnas ◽  
Dna Motifs

Cucumber ( Cucumis sativus ) has one of the largest mitochondrial genomes known among all eukaryotes, due in part to the accumulation of short 20 to 60 bp repetitive DNA motifs. Recombination among these repetitive DNAs produces rearrangements affecting organization and expression of mitochondrial genes. To more efficiently identify rearrangements in the cucumber mitochondrial DNA, we built two nonoverlapping 800 and 220 kb BAC contigs and assigned major mitochondrial genes to these BACs. Polymorphism carried on the largest BAC contig was used to confirm paternal transmission. Mitochondrial genes were distributed across BACs and physically distant, although occasional clustering was observed. Introns in the nad1, nad4, and nad7 genes were larger than those reported in other plants, due in part to accumulation of short repetitive DNAs and indicating that increased intron sizes contributed to mitochondrial genome expansion in cucumber. Mitochondrial genes atp6 and atp9 are physically close to each other and cotranscribed. These physical contigs will be useful for eventual sequencing of the cucumber mitochondrial DNA, which can be exploited to more efficiently screen for unique rearrangements affecting mitochondrial gene expression.

scholarly journals Complete mitochondrial genome sequences of the northern spotted owl (Strix occidentalis caurina) and the barred owl (Strix varia; Aves: Strigiformes: Strigidae) confirm the presence of a duplicated control region

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3901 ◽  
Author(s):  
Zachary R. Hanna ◽  
James B. Henderson ◽  
Anna B. Sellas ◽  
Jérôme Fuchs ◽  
Rauri C.K. Bowie ◽  
...  
Keyword(s):  
Mitochondrial Genome ◽  
Sequence Data ◽  
Complete Mitochondrial Genome ◽  
Mitochondrial Genes ◽  
Mitochondrial Genomes ◽  
Genome Sequences ◽  
Spotted Owl ◽  
Strix Occidentalis ◽  
Strix Occidentalis Caurina ◽  
Control Regions

We report here the successful assembly of the complete mitochondrial genomes of the northern spotted owl (Strix occidentalis caurina) and the barred owl (S. varia). We utilized sequence data from two sequencing methodologies, Illumina paired-end sequence data with insert lengths ranging from approximately 250 nucleotides (nt) to 9,600 nt and read lengths from 100–375 nt and Sanger-derived sequences. We employed multiple assemblers and alignment methods to generate the final assemblies. The circular genomes of S. o. caurina and S. varia are comprised of 19,948 nt and 18,975 nt, respectively. Both code for two rRNAs, twenty-two tRNAs, and thirteen polypeptides. They both have duplicated control region sequences with complex repeat structures. We were not able to assemble the control regions solely using Illumina paired-end sequence data. By fully spanning the control regions, Sanger-derived sequences enabled accurate and complete assembly of these mitochondrial genomes. These are the first complete mitochondrial genome sequences of owls (Aves: Strigiformes) possessing duplicated control regions. We searched the nuclear genome of S. o. caurina for copies of mitochondrial genes and found at least nine separate stretches of nuclear copies of gene sequences originating in the mitochondrial genome (Numts). The Numts ranged from 226–19,522 nt in length and included copies of all mitochondrial genes except tRNAPro, ND6, and tRNAGlu. Strix occidentalis caurina and S. varia exhibited an average of 10.74% (8.68% uncorrected p-distance) divergence across the non-tRNA mitochondrial genes.

scholarly journals Homologous recombination changes the context of Cytochrome b transcription in the mitochondrial genome of Silene vulgaris KRA

2018 ◽  
Author(s):  
Helena Štorchová ◽  
James D. Stone ◽  
Daniel B. Sloan ◽  
Oushadee Abeyawardana ◽  
Karel Müller ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Mitochondrial Genome ◽  
Rna Editing ◽  
Cytochrome B ◽  
Mitochondrial Genes ◽  
Mitochondrial Genomes ◽  
Silene Vulgaris ◽  
Fertility Restorer ◽  
Restorer Genes ◽  
Fertility Restorer Genes

AbstractBackgroundSilene vulgaris (bladder campion) is a gynodioecious species existing as two genders – male-sterile females and hermaphrodites. Cytoplasmic male sterility (CMS) is generally encoded by mitochondrial genes, which interact with nuclear fertility restorer genes. Mitochondrial genomes of this species vary in DNA sequence, gene order and gene content. Multiple CMS genes are expected to exist in S. vulgaris, but little is known about their molecular identity.ResultsWe assembled the complete mitochondrial genome from the haplotype KRA of S. vulgaris. It consists of five chromosomes, two of which recombine with each other. Two small non-recombining chromosomes exist in linear, supercoiled and relaxed circle forms. We compared the mitochondrial transcriptomes from females and hermaphrodites and confirmed the differentially expressed chimeric gene bobt as the strongest CMS candidate gene in S. vulgaris KRA. The chimeric gene bobt is co-transcribed with the Cytochrome b (cob) gene in some genomic configurations. The co-transcription of a CMS factor with an essential gene may constrain transcription inhibition as a mechanism for fertility restoration because of the need to maintain appropriate production of the necessary protein. Homologous recombination places the gene cob outside the control of bobt, which allows for the suppression the CMS gene by the fertility restorer genes. In addition, by analyzing RNA editing, we found the loss of three editing sites in the KRA mitochondrial genome and identified four sites with highly distinct editing rates between KRA and another S. vulgaris haplotypes (KOV). Three of these highly differentially edited sites were located in the transport membrane protein B (mttB) gene. They resulted in differences in MttB protein sequences between haplotypes despite completely identical gene sequences.ConclusionsFrequent homologous recombination events that are widespread in plant mitochondrial genomes may change chromosomal configurations and also the control of gene transcription including CMS gene expression. Posttranscriptional processes, e.g RNA editing shall be evaluated in evolutionary and co-evolutionary studies of mitochondrial genes, because they may change protein composition despite the sequence identity of the respective genes. The investigation of natural populations of wild species such as S. vulgaris are necessary to reveal important aspects of CMS missed in domesticated crops, the traditional focus of the CMS studies.

scholarly journals Mitochondrial genome of non-photosynthetic mycoheterotrophic plant Hypopitys monotropa,its structure, gene expression and RNA editing

2019 ◽  
Author(s):  
Viktoria Y. Shtratnikova ◽  
Mikhail I. Schelkunov ◽  
Aleksey A. Penin ◽  
Maria D. Logacheva
Keyword(s):  
Mitochondrial Genome ◽  
Rna Editing ◽  
Unique Feature ◽  
Genetic Material ◽  
Mitochondrial Genes ◽  
Vaccinium Macrocarpon ◽  
Mitochondrial Genomes ◽  
Plastid Genomes ◽  
Trans Splicing ◽  
Mycoheterotrophic Plants

AbstractHeterotrophic plants – the plants that lost the ability to photosynthesis – are characterized by a number of changes at all levels of organization. Heterotrophic plants divide into two large categories – parasitic and mycoheterotrophic. The question of to what extent these changes are similar in these two categories is still open. Plastid genomes of non-photosynthetic plants are well characterized and they demonstrate similar patterns of reduction in both groups. In contrast, little is known about mitochondrial genomes of mycoheterotrophic plants. We report the structure of the mitochondrial genome of Hypopitys monotropa, a mycoheterotrophic member of Ericaceae, and the expression of mitochondrial genes. In contrast to its highly reduced plastid genome, the mitochondrial genome of H. monotropa is larger than that of its photosynthetic relative Vaccinium macrocarpon, its complete size is ~810 Kbp. We found an unusually long repeat-rich structure of the genome that suggests the existence of linear fragments. Despite this unique feature, the gene content of the H. monotropa mitogenome is typical of flowering plants. No acceleration of substitution rates is observed in mitochondrial genes, in contrast to previous observations on parasitic non-photosynthetic plants. Transcriptome sequencing revealed trans-splicing of several genes and RNA editing in 33 genes of 38. Notably, we did not find any traces of horizontal gene transfer from fungi, in contrast to plant parasites which extensively integrate genetic material from their hosts.

scholarly journals The mitochondrial genomes of the acoelomorph worms Paratomella rubra and Isodiametra pulchra

2017 ◽  
Author(s):  
Helen E Robertson ◽  
François Lapraz ◽  
Bernhard Egger ◽  
Maximilian J Telford ◽  
Philipp H. Schiffer
Keyword(s):  
Mitochondrial Genome ◽  
Phylogenetic Trees ◽  
Large Degree ◽  
Mitochondrial Genes ◽  
Mitochondrial Genomes ◽  
Long Branch Attraction ◽  
Protein Coding ◽  
Simple Body ◽  
Mitochondrial Sequences ◽  
Marine Worms

AbstractAcoels are small, ubiquitous, but understudied, marine worms with a very simple body plan. Their internal phylogeny is still in parts unresolved, and the position of their proposed phylum Xenacoelomorpha (Xenoturbella+Acoela) is still debated.Here we describe mitochondrial genome sequences from two acoel species: Paratomella rubra and Isodiametra pulchra. The 14,954 nucleotide-long P. rubra sequence is typical for metazoans in size and gene content. The larger I. pulchra mitochondrial genome contains both ribosomal genes, 21 tRNAs, but only 11 protein-coding genes. We find evidence suggesting a duplicated sequence in the I. pulchra mitochondrial genome.Mitochondrial sequences for both P. rubra and I. pulchra have a unique genome organisation in comparison to other published metazoan mitochondrial genomes. We found a large degree of protein-coding gene and tRNA overlap in P. rubra, with little non-coding sequence making the genome compact. Conversely, the I. pulchra mitochondrial genome has many long non-coding sequences between genes, likely driving the genome size expansion. Phylogenetic trees inferred from concatenated alignments of mitochondrial genes grouped the fast-evolving Acoela and Tunicata, almost certainly due to the systematic error of long branch attraction: a reconstruction artefact that is probably compounded by the fast substitution rate of mitochondrial genes in this taxon.

scholarly journals Rapid evolution of the compact and unusual mitochondrial genome in the ctenophore, Pleurobrachia bachei

2012 ◽  
Vol 63 (1) ◽  
pp. 203-207 ◽  
Author(s):  
Andrea B. Kohn ◽  
Mathew R. Citarella ◽  
Kevin M. Kocot ◽  
Yelena V. Bobkova ◽  
Kenneth M. Halanych ◽  
...  
Keyword(s):  
Mitochondrial Genome ◽  
Rapid Evolution ◽  
Pleurobrachia Bachei

scholarly journals Highly rearranged mitochondrial genome in Nycteria parasites (Haemosporidia) from bats

2016 ◽  
Vol 113 (35) ◽  
pp. 9834-9839 ◽  
Author(s):  
Gregory Karadjian ◽  
Alexandre Hassanin ◽  
Benjamin Saintpierre ◽  
Guy-Crispin Gembu Tungaluna ◽  
Frederic Ariey ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Mitochondrial Genome ◽  
Evolutionary History ◽  
Complete Mitochondrial Genome ◽  
Molecular Data ◽  
Mitochondrial Genes ◽  
Mitochondrial Genomes ◽  
History Of ◽  
Generation Sequencing ◽  
Complete Mitochondrial Genomes

Haemosporidia parasites have mostly and abundantly been described using mitochondrial genes, and in particular cytochrome b (cytb). Failure to amplify the mitochondrial cytb gene of Nycteria parasites isolated from Nycteridae bats has been recently reported. Bats are hosts to a diverse and profuse array of Haemosporidia parasites that remain largely unstudied. There is a need to obtain more molecular data from chiropteran parasites. Such data would help to better understand the evolutionary history of Haemosporidia, which notably include the Plasmodium parasites, malaria’s agents. We use next-generation sequencing to obtain the complete mitochondrial genome of Nycteria parasites from African Nycteris grandis (Nycteridae) and Rhinolophus alcyone (Rhinolophidae) and Asian Megaderma spasma (Megadermatidae). We report four complete mitochondrial genomes, including two rearranged mitochondrial genomes within Haemosporidia. Our results open outlooks into potentially undiscovered Haemosporidian diversity.

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