scholarly journals Moramonas marocensis gen. nov., sp. nov.: a jakobid flagellate isolated from desert soil with a bacteria-like, but bloated mitochondrial genome

Open Biology ◽  
2016 ◽  
Vol 6 (2) ◽  
pp. 150239 ◽  
Author(s):  
Jürgen F. H. Strassert ◽  
Denis V. Tikhonenkov ◽  
Jean-François Pombert ◽  
Martin Kolisko ◽  
Vera Tai ◽  
...  

A new jakobid genus has been isolated from Moroccan desert soil. The cyst-forming protist Moramonas marocensis gen. nov., sp. nov. has two anteriorly inserted flagella of which one points to the posterior cell pole accompanying the ventral feeding groove and is equipped with a dorsal vane—a feature typical for the Jakobida. It further shows a flagellar root system consisting of singlet microtubular root, left root (R1), right root (R2) and typical fibres associated with R1 and R2. The affiliation of M. marocensis to the Jakobida was confirmed by molecular phylogenetic analyses of the SSU rRNA gene, five nuclear genes and 66 mitochondrial protein-coding genes. The mitochondrial genome has the high number of genes typical for jakobids, and bacterial features, such as the four-subunit RNA polymerase and Shine–Dalgarno sequences upstream of the coding regions of several genes. The M. marocensis mitochondrial genome encodes a similar number of genes as other jakobids, but is unique in its very large genome size (greater than 264 kbp), which is three to four times higher than that of any other jakobid species investigated yet. This increase seems to be due to a massive expansion in non-coding DNA, creating a bloated genome like those of plant mitochondria.

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.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8033
Author(s):  
Siuli Mitra ◽  
Vaishnavi Kunteepuram ◽  
Klaus-Peter Koepfli ◽  
Neha Mehra ◽  
Wajeeda Tabasum ◽  
...  

The binturong (Arctictis binturong) is classified as a member of the subfamily Paradoxurinae within the family Viverridae (Carnivora: Mammalia) and comprises nine subspecies spread across Southern and Southeast Asia. Here, we describe the complete mitochondrial genome of the Indian subspecies A. b. albifrons using next-generation sequencing methods. The total length of the A. b. albifrons mitogenome was 16,642 bp. Phylogenetic analyses based on 13 mitochondrial protein-coding genes placed the binturong as a sister taxon to Paguma larvata within the Paradoxurinae and supported the clustering of Genettinae and Viverrinae and the monophyly of Viverridae and six other families of feliforms, consistent with previous studies. Divergence time estimates suggest that the Viverridae diversified during the Miocene (22.62 Mya: 95% CI [20.78–24.54] Mya) and that Arctictis and Paguma split 12.57 Mya (95% CI [8.66–15.67] Mya). Further molecular studies are required to test the distinctiveness and diversity of the nine putative subspecies of binturong.


Genetics ◽  
1996 ◽  
Vol 144 (3) ◽  
pp. 1165-1180 ◽  
Author(s):  
Katharina Noack ◽  
Rafael Zardoya ◽  
Axel Meyer

Abstract The evolutionary position of bichirs is disputed, and they have been variously aligned with ray-finned fish (Actinopterygii) or lobe-finned fish (Sarcopterygii), which also include tetrapods. Alternatively, they have been placed into their own group, the Brachiopterygii. The phylogenetic position of bichirs as possibly the most primitive living bony fish (Osteichthyes) made knowledge about their mitochondrial genome of considerable evolutionary interest. We determined the complete nucleotide sequence (16,624 bp) of the mitochondrial genome of a bichir, Polypterus ornatipinnis. Its genome contains 13 protein-coding genes, 22 tRNAS, two rRNAs and one major noncoding region. The genome's structure and organization show that this is the most basal vertebrate that conforms to the consensus vertebrate mtDNA gene order. Bichir mitochondrial protein-coding and ribosomal RNA genes have greater sequence similarity to ray-finned fish than to either lamprey or lungfish. Phylogenetic analyses suggest the bichir's placement as the most basal living member of the ray-finned fish and rule out its classification as a lobe-finned fish. Hence, its lobe-fins are probably not a shared-derived trait with those of lobe-finned fish (Sarcopterygii).


2020 ◽  
Vol 44 (1) ◽  
pp. 1-40
Author(s):  
W.M. Jaklitsch ◽  
H. Voglmayr

Fresh collections and their ascospore and conidial isolates backed up by type studies and molecular phylogenetic analyses of a multigene matrix of partial nuSSU-, complete ITS, partial LSU rDNA, rpb2, tef1 and tub2 sequences were used to evaluate the boundaries and species composition of Fenestella and related genera of the Cucurbitariaceae. Eight species, of which five are new, are recognised in Fenestella s.str., 13 in Parafenestella with eight new species and two in the new genus Synfenestella with one new species. Cucurbitaria crataegi is combined in Fenestella, C. sorbi in Synfenestella, Fenestella faberi and Thyridium salicis in Parafenestella. Cucurbitaria subcaespitosa is distinct from C. sorbi and combined in Neocucurbitaria. Fenestella minor is a synonym of Valsa tetratrupha, which is combined in Parafenestella. Cucurbitaria marchica is synonymous with Parafenestella salicis, Fenestella bavarica with S. sorbi, F. macrospora with F. media, and P. mackenziei is synonymous with P. faberi, and the latter is lectotypified. Cucurbitaria sorbi, C. subcaespitosa and Fenestella macrospora are lecto- and epitypified, Cucurbitaria crataegi, Fenestella media, F. minor and Valsa tetratrupha are epitypified in order to stabilise the names in their phylogenetic positions. A neotype is proposed for Thyridium salicis. A determinative key to species is given. Asexual morphs of fenestelloid fungi are phoma-like and do not differ from those of other representatives of the Cucurbitariaceae. The phylogenetic structure of the fenestelloid clades is complex and can only be resolved at the species level by protein-coding genes, such as rpb2, tef1 and tub2. All fungal species studied here occur, as far as has been possible to determine, on members of Diaporthales, most frequently on asexual and sexual morphs of Cytospora.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10364
Author(s):  
Natalia I. Abramson ◽  
Fedor N. Golenishchev ◽  
Semen Yu. Bodrov ◽  
Olga V. Bondareva ◽  
Evgeny A. Genelt-Yanovskiy ◽  
...  

In this article, we present the nearly complete mitochondrial genome of the Subalpine Kashmir vole Hyperacrius fertilis (Arvicolinae, Cricetidae, Rodentia), assembled using data from Illumina next-generation sequencing (NGS) of the DNA from a century-old museum specimen. De novo assembly consisted of 16,341 bp and included all mitogenome protein-coding genes as well as 12S and 16S RNAs, tRNAs and D-loop. Using the alignment of protein-coding genes of 14 previously published Arvicolini tribe mitogenomes, seven Clethrionomyini mitogenomes, and also Ondatra and Dicrostonyx outgroups, we conducted phylogenetic reconstructions based on a dataset of 13 protein-coding genes (PCGs) under maximum likelihood and Bayesian inference. Phylogenetic analyses robustly supported the phylogenetic position of this species within the tribe Arvicolini. Among the Arvicolini, Hyperacrius represents one of the early-diverged lineages. This result of phylogenetic analysis altered the conventional view on phylogenetic relatedness between Hyperacrius and Alticola and prompted the revision of morphological characters underlying the former assumption. Morphological analysis performed here confirmed molecular data and provided additional evidence for taxonomic replacement of the genus Hyperacrius from the tribe Clethrionomyini to the tribe Arvicolini.


Author(s):  
Xiao-Xian Huang ◽  
Jia Shang ◽  
Lian Xu ◽  
Rui Yang ◽  
Ji-Quan Sun

A Gram-stain-negative, non-motile, rod-shaped bacterial strain, named SJ-16T, was isolated from desert soil collected in Inner Mongolia, northern PR China. Strain SJ-16T grew at pH 6.0–11.0 (optimum, pH 8.0–9.0), 4–40 °C (optimum, 30–35 °C) and in the presence of 0–8 % (w/v) NaCl (optimum, 0–2 %). The strain was negative for catalase and positive for oxidase. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain SJ-16T clustered with Luteimonas chenhongjianii 100111T and Luteimonas terrae THG-MD21T, and had 98.8, 98.6, 98.3 and <97.9 % of 16S rRNA gene sequence similarity to strains L. chenhongjianii 100111T, L. terrae THG-MD21T, L. aestuarii B9T and all other type strains of the genus Luteimonas , respectively. The major cellular fatty acids were iso-C15 : 0, iso-C16 : 0, summed feature 3 (C16 : 1  ω7c and/or C16 : 1  ω6c) and summed feature 9 (C16 : 0 10-methyl and/or iso-C17 : 1  ω9c). Diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine were the major polar lipids, and ubiquinone-8 was the only respiratory quinone. The genomic DNA G+C content was 69.3 mol%. The digital DNA–DNA hybridization and average nucleotide identity values of strain SJ-16T to L. chenhongjianii 100111T, L. terrae THG-MD21T, L. rhizosphaerae 4-12T and L. aestuarii B9T were 36.9, 37.5, 24.0 and 21.1 %, and 80.9, 80.6, 80.7 and 76.3 %, respectively. Based on phenotypic, physiological and phylogenetic results, strain SJ-16T represents a novel species of the genus Luteimonas , for which the name Luteimonas deserti is proposed. The type strain is SJ-16T (=CGMCC 1.17694T=KCTC 82207T).


2009 ◽  
Vol 57 (4) ◽  
pp. 167 ◽  
Author(s):  
Gavin Huttley

Did the mammal radiation arise through initial divergence of prototherians from a common ancestor of metatherians and eutherians, the Theria hypothesis, or of eutherians from a common ancestor of metatherians and prototherians, the Marsupionta hypothesis? Molecular phylogenetic analyses of point substitutions applied to this problem have been contradictory – mtDNA-encoded sequences supported Marsupionta, nuclear-encoded sequences and RY (purine–pyrimidine)-recoded mtDNA supported Theria. The consistency property of maximum likelihood guarantees convergence on the true tree only with longer alignments. Results from analyses of genome datasets should therefore be impervious to choice of outgroup. We assessed whether important hypotheses concerning mammal evolution, including Theria/Marsupionta and the branching order of rodents, carnivorans and primates, are resolved by phylogenetic analyses using ~2.3 megabases of protein-coding sequence from genome projects. In each case, only two tree topologies were being compared and thus inconsistency in resolved topologies can only derive from flawed models of sequence divergence. The results from all substitution models strongly supported Theria. For the eutherian lineages, all models were sensitive to the outgroup. We argue that phylogenetic inference from point substitutions will remain unreliable until substitution models that better match biological mechanisms of sequence divergence have been developed.


Zootaxa ◽  
2019 ◽  
Vol 4671 (4) ◽  
pp. 571-580 ◽  
Author(s):  
YUE SHEN ◽  
YU-ZHOU DU

The nearly complete mitochondrial genome (mitogenome) of Leuctra sp. (Plecoptera: Leuctridae) was sequenced. The 14,585-bp long mitogenome of L. sp. contained 37 genes including 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs), and a control region (CR). The mitochondrial gene arrangement of L. sp. was identical with other stoneflies and the putative ancestral mitogenome of Drosophila yakuba Burla. Most PCGs used standard ATN start codons and TAN termination codons. Twenty-one of the 22 tRNAs in each mitogenome exhibited the cloverleaf secondary structures, while the dihydrouridine (DHU) arm of trnSer (AGN) was reduced. Phylogenetic analyses using our new Leuctra sp. genome and all other publicly available genomes for Plecoptera and Bayesian inference (BI) and maximum likelihood methods (ML) generated identical topologies, both supporting the monophyly of all stonefly families for which tests were possible and the infraorder Systellognatha. Scopuridae and Gripopterygidae were grouped with the infraorder Euholognatha. The final relationships within Plecoptera were recovered as (((((Perlodidae + Chloroperlidae) + Perlidae) + Pteronarcyidae) + Peltoperlidae) + Styloperlidae) + (((((Capniidae + Taeniopterygidae) + Nemouridae) + Scopuridae) + Leuctridae) + Gripopterygidae). 


Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1042 ◽  
Author(s):  
Tanapan Sukee ◽  
Anson V. Koehler ◽  
Ross Hall ◽  
Ian Beveridge ◽  
Robin B. Gasser ◽  
...  

Nematodes of the genus Macropostrongyloides inhabit the large intestines or stomachs of macropodid (kangaroos and wallabies) and vombatid (wombats) marsupials. This study established the relationships of seven species of Macropostrongyloides using mitochondrial (mt) protein amino acid sequence data sets. Phylogenetic analyses revealed that species of Macropostrongyloides (M. lasiorhini, M. baylisi, M. yamagutii, M. spearei, M. mawsonae and M. woodi) from the large intestines of their hosts formed a monophyletic assemblage with strong nodal support to the exclusion of M. dissimilis from the stomach of the swamp wallaby. Furthermore, the mitochondrial protein-coding genes provided greater insights into the diversity and phylogeny of the genus Macropostrongyloides; such data sets could potentially be used to elucidate the relationships among other parasitic nematodes of Australian marsupials.


Genome ◽  
2017 ◽  
Vol 60 (2) ◽  
pp. 128-138 ◽  
Author(s):  
Li-Shang Dai ◽  
Sheng Li ◽  
Hui-min Yu ◽  
Guo-Qing Wei ◽  
Lei Wang ◽  
...  

In the present study, we sequenced the complete mitochondrial genome (mitogenome) of Agrius convolvuli (Lepidoptera: Sphingidae) and compared it with previously sequenced mitogenomes of lepidopteran species. The mitogenome was a circular molecule, 15 349 base pairs (bp) long, containing 37 genes. The order and orientation of genes in the A. convolvuli mitogenome were similar to those in sequenced mitogenomes of other lepidopterans. All 13 protein-coding genes (PCGs) were initiated by ATN codons, except for the cytochrome c oxidase subunit 1 (cox1) gene, which seemed to be initiated by the codon CGA, as observed in other lepidopterans. Three of the 13 PCGs had the incomplete termination codon T, while the remainder terminated with TAA. Additionally, the codon distributions of the 13 PCGs revealed that Asn, Ile, Leu2, Lys, Phe, and Tyr were the most frequently used codon families. All transfer RNAs were folded into the expected cloverleaf structure except for tRNASer(AGN), which lacked a stable dihydrouridine arm. The length of the adenine (A) + thymine (T)-rich region was 331 bp. This region included the motif ATAGA followed by a 19-bp poly-T stretch and a microsatellite-like (TA)8 element next to the motif ATTTA. Phylogenetic analyses (maximum likelihood and Bayesian methods) showed that A. convolvuli belongs to the family Sphingidae.


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