scholarly journals Evolutionary Patterns of the Mitochondrial Genome in Metazoa: Exploring the Role of Mutation and Selection in Mitochondrial Protein–Coding Genes

2011 ◽  
Vol 3 ◽  
pp. 1067-1079 ◽  
Author(s):  
S. Castellana ◽  
S. Vicario ◽  
C. Saccone
Genes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 115
Author(s):  
Yuxin Hu ◽  
Weiyue Xing ◽  
Zhengyu Hu ◽  
Guoxiang Liu

We sequenced the mitochondrial genome of six colonial volvocine algae, namely: Pandorina morum, Pandorina colemaniae, Volvulina compacta, Colemanosphaera angeleri, Colemanosphaera charkowiensi, and Yamagishiella unicocca. Previous studies have typically reconstructed the phylogenetic relationship between colonial volvocine algae based on chloroplast or nuclear genes. Here, we explore the validity of phylogenetic analysis based on mitochondrial protein-coding genes. We found phylogenetic incongruence of the genera Yamagishiella and Colemanosphaera. In Yamagishiella, the stochastic error and linkage group formed by the mitochondrial protein-coding genes prevent phylogenetic analyses from reflecting the true relationship. In Colemanosphaera, a different reconstruction approach revealed a different phylogenetic relationship. This incongruence may be because of the influence of biological factors, such as incomplete lineage sorting or horizontal gene transfer. We also analyzed the substitution rates in the mitochondrial and chloroplast genomes between colonial volvocine algae. Our results showed that all volvocine species showed significantly higher substitution rates for the mitochondrial genome compared with the chloroplast genome. The nonsynonymous substitution (dN)/synonymous substitution (dS) ratio is similar in the genomes of both organelles in most volvocine species, suggesting that the two counterparts are under a similar selection pressure. We also identified a few chloroplast protein-coding genes that showed high dN/dS ratios in some species, resulting in a significant dN/dS ratio difference between the mitochondrial and chloroplast genomes.


2018 ◽  
Author(s):  
Helen. E. Robertson ◽  
Philipp. H. Schiffer ◽  
Maximilian. J. Telford

AbstractThe 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 divergent gene order compared to other metazoans. The data we present 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 across 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.Key FindingsWe report the first almost-complete mitochondrial genome from an orthonectid parasite, Intoshia linei, including 12 protein-coding genes; 20 tRNAs and putative sequences for large and small subunit rRNAs. We find that the I. linei mitochondrial genome is exceptionally AT-rich and has a novel gene order compared to other published metazoan mitochondrial genomes. These findings are indicative of the rapid rate of evolution that has occurred in the I. linei mitochondrial genome.We also report nine and eight protein-coding genes, respectively, from the dicyemid species Dicyema sp. and Dicyema japonicum, and use the cox1 genes from both species for phylogenetic inference of the internal phylogeny of the dicyemids.We find that the cox1 gene from dicyemids has a series of four conserved in-frame deletions which appear to be unique to this group.


2018 ◽  
Vol 4 ◽  
Author(s):  
Helen E. Robertson ◽  
Philipp H. Schiffer ◽  
Maximilian J. Telford

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.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7532 ◽  
Author(s):  
Yin-Yin Cai ◽  
Shi-Qi Shen ◽  
Li-Xu Lu ◽  
Kenneth B. Storey ◽  
Dan-Na Yu ◽  
...  

The family Pyxicephalidae including two subfamilies (Cacosterninae and Pyxicephalinae) is an ecologically important group of frogs distributed in sub-Saharan Africa. However, its phylogenetic position among the Anura has remained uncertain. The present study determined the complete mitochondrial genome sequence of Pyxicephalus adspersus, the first representative mitochondrial genome from the Pyxicephalinae, and reconstructed the phylogenetic relationships within Ranoidae using 10 mitochondrial protein-coding genes of 59 frog species. The P. adspersus mitochondrial genome showed major gene rearrangement and an exceptionally long length that is not shared with other Ranoidae species. The genome is 24,317 bp in length, and contains 15 protein-coding genes (including extra COX3 and Cyt b genes), four rRNA genes (including extra 12S rRNA and 16S rRNA genes), 29 tRNA genes (including extra tRNALeu (UAG), tRNALeu (UUR), tRNAThr, tRNAPro, tRNAPhe, tRNAVal, tRNAGln genes) and two control regions (CRs). The Dimer-Mitogenome and Tandem duplication and random loss models were used to explain these gene arrangements. Finally, both Bayesian inference and maximum likelihood analyses supported the conclusion that Pyxicephalidae was monophyletic and that Pyxicephalidae was the sister clade of (Petropedetidae + Ptychadenidae).


2017 ◽  
Vol 92 (4) ◽  
pp. 524-529 ◽  
Author(s):  
S.-L. Song ◽  
H.-S. Yong ◽  
P. Eamsobhana

AbstractAngiostrongylus mackerrasae is a parasitic nematode of rats found in Australia. When first reported, it was referred to as A. cantonensis. Recent molecular studies, including the mitochondrial genome, indicate that it is highly similar to A. cantonensis. These studies did not include A. malaysiensis, another member of the A. cantonensis species complex, for comparison. The present study examined the genetic distance and phylogenetic relationship between the component taxa (A. cantonensis, A. mackerrasae and A. malaysiensis) of the A. cantonensis species complex, based on the 12 protein-coding genes (PCGs) of their mitochondrial genome. Both the nucleotide and amino acid sequences were analysed. Angiostrongylus mackerrasae and A. cantonensis are members of the same genetic lineage and both are genetically distinct from A. malaysiensis. The genetic distance based on concatenated nucleotide sequences of 12 mt-PCGs between A. mackerrasae and A. cantonensis from Thailand is p = 1.73%, while that between the Thai and Chinese taxa of A. cantonensis is p = 3.52%; the genetic distance between A. mackerrasae and A. cantonensis from China is p = 3.70%. The results indicate that A. mackerrasae and A. cantonensis belong to the same genetic lineage, and that A. mackerrasae may be conspecific with A. cantonensis. It remains to be resolved whether A. mackerrasae is conspecific with A. cantonensis or undergoing incipient speciation.


2018 ◽  
Vol 64 (5) ◽  
pp. 339-348 ◽  
Author(s):  
Talal George Abboud ◽  
Abdullah Zubaer ◽  
Alvan Wai ◽  
Georg Hausner

Ophiostoma novo-ulmi, a member of the Ophiostomatales (Ascomycota), is the causal agent of the current Dutch elm disease pandemic in Europe and North America. The complete mitochondrial genome (mtDNA) of Ophiostoma novo-ulmi subsp. novo-ulmi, the European component of O. novo-ulmi, has been sequenced and annotated. Gene order (synteny) among the currently available members of the Ophiostomatales was examined and appears to be conserved, and mtDNA size variability among the Ophiostomatales is due in part to the presence of introns and their encoded open reading frames. Phylogenetic analysis of concatenated mitochondrial protein-coding genes yielded phylogenetic estimates for various members of the Ophiostomatales, with strong statistical support showing that mtDNA analysis may provide valuable insights into the evolution of the Ophiostomatales.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Hee-seung Hwang ◽  
Jongwoo Jung ◽  
Juan Antonio Baeza

Abstract Background Stomatopod crustaceans are aggressive marine predators featuring complex compound eyes and powerful raptorial appendages used for “smashing” or “spearing” prey and/or competitors. Among them, parasquilloids (superfamily Parasquilloidea) possess eyes with 2-3 midband rows of hexagonal ommatidia and spearing appendages. Here, we assembled and analyzed the complete mitochondrial genome of the parasquilloid Faughnia haani and explored family- and superfamily-level phylogenetic relationships within the Stomatopoda based on mitochondrial protein coding genes (PCGs). Results The mitochondrial genome of F. haani is 16,089 bp in length and encodes 13 protein coding genes (PCGs), 22 transfer RNA genes, 2 ribosomal RNA genes, and a control region that is relatively well organized, containing 2 GA-blocks, 4 poly-T stretches, various [TA(A)]n-blocks, and 2 hairpin structures. This organized control region is likely a synapomorphic characteristic in the Stomatopoda. Comparison of the control region among superfamilies shows that parasquilloid species are more similar to gonodactyloids than to squilloids and lysiosquilloids given the presence of various  poly-T stretches between the hairpin structures and [TA(A)]n-blocks. Synteny is identical to that reported for other stomatopods and corresponds to the Pancrustacea ground pattern. A maximum-likelihood phylogenetic tree based on PCGs revealed that Parasquilloidea is sister to Lysiosquilloidea and Gonodactyloidea and not to Squilloidea, contradicting previous phylogenetic studies. Conclusions The novel phylogenetic position of Parasquilloidea revealed by our study indicates that ‘spearing’ raptorial appendages are plesiomorphic and that the ‘smashing’ type is either derived (as reported in previous studies) or apomorphic. Our results raise the possibility that the spearing raptorial claw may have independently evolved twice. The superfamily Parasquilloidea exhibits a closer relationship with other stomatopod superfamilies with a different raptorial claw type and with dissimilar numbers of midband rows of hexagonal ommatidia. Additional studies focusing on the assembly of mitochondrial genomes from species belonging to different genera, families, and superfamilies within the order Stomatopoda are warranted to reach a robust conclusion regarding the evolutionary history of this iconic clade based on mitochondrial PCGs.


PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0255091
Author(s):  
Sadaf Habib ◽  
Shanshan Dong ◽  
Yang Liu ◽  
Wenbo Liao ◽  
Shouzhou Zhang

Mitochondrial genomes of vascular plants are well known for their liability in architecture evolution. However, the evolutionary features of mitogenomes at intra-generic level are seldom studied in vascular plants, especially among gymnosperms. Here we present the complete mitogenome of Cycas debaoensis, an endemic cycad species to the Guangxi region in southern China. In addition to assemblage of draft mitochondrial genome, we test the conservation of gene content and mitogenomic stability by comparing it to the previously published mitogenome of Cycas taitungensis. Furthermore, we explored the factors such as structural rearrangements and nuclear surveillance of double-strand break repair (DSBR) proteins in Cycas in comparison to other vascular plant groups. The C. debaoensis mitogenome is 413,715 bp in size and encodes 69 unique genes, including 40 protein coding genes, 26 tRNAs, and 3 rRNA genes, similar to that of C. taitungensis. Cycas mitogenomes maintained the ancestral intron content of seed plants (26 introns), which is reduced in other lineages of gymnosperms, such as Ginkgo biloba, Taxus cuspidata and Welwitschia mirabilis due to selective pressure or retroprocessing events. C. debaoensis mitogenome holds 1,569 repeated sequences (> 50 bp), which partially account for fairly large intron size (1200 bp in average) of Cycas mitogenome. The comparison of RNA-editing sites revealed 267 shared non-silent editing site among predicted vs. empirically observed editing events. Another 33 silent editing sites from empirical data increase the total number of editing sites in Cycas debaoensis mitochondrial protein coding genes to 300. Our study revealed unexpected conserved evolution between the two Cycas species. Furthermore, we found strict collinearity of the gene order along with the identical set of genomic content in Cycas mt genomes. The stability of Cycas mt genomes is surprising despite the existence of large number of repeats. This structural stability may be related to the relative expansion of three DSBR protein families (i.e., RecA, OSB, and RecG) in Cycas nuclear genome, which inhibit the homologous recombinations, by monitoring the accuracy of mitochondrial chromosome repair.


2019 ◽  
Vol 07 (02) ◽  
Author(s):  
Saira Bibi ◽  
Muhammad Fiaz Khan ◽  
Aqsa Rehman ◽  
Faisal Nouroz

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