scholarly journals The mitochondrial genomes of bryophytes

2021 ◽  
Vol 43 (1) ◽  
Author(s):  
SHANSHAN DONG ◽  
YANG LIU

In contrast to the highly variable mitogenomes of vascular plants, the composition and architecture of mitogenomes within the three bryophyte lineages appear stable and invariant. Currently, complete mitogenomes are available from 113 bryophyte accessions of 71 genera and 28 orders. Liverworts and mosses hold a rich mitochondrial (mt) gene repertoire among land plants with 40–42 protein-coding genes, whereas hornworts maintain the smallest functional gene set among land plants, of only around two dozen protein-coding genes, with the majority of ribosomal genes pseudogenized and all cytochrome c maturase genes lost. The rRNA and tRNA genes are also conserved and rich in mosses and liverworts, whereas subject to patchy losses in hornworts. In contrast to the conserved gene set, intron content varies significantly with only one intron shared among the three bryophyte lineages. Bryophytes hold relatively compact mitogenomes with narrow size fluctuations. Among the three bryophyte lineages, intergenic spacers and repeat content are smallest in mosses, largest in hornworts, and intermediate in liverworts, mirroring their size differences and levels of structural dynamics among the three lineages. Mosses, with the least repeated sequences, show the most static genome structure; whereas hornworts, with a relatively large set of repeated sequences, experience 1–4 rearrangements; liverworts, with intermediate repeat levels, see only one structural variant that requires two inversions to gain collinearity with the mitogenome of other liverworts. Repeat sequences were evoked to explain the mt gene order rearrangements in hornwort and liverwort mitogenomes; with the latter also supported by sequencing read evidence, which suggests that the conserved mitogenome structure observed in bryophyte lineages might be shaped by low repeat recombination level, and/or along with the intensified nucleus’ surveillance. Mitochondrial RNA editing is abundant in hornworts, with medium frequency and high variation in liverwort species, and generally limited in mosses, reflecting the diversity of nuclear encoded PPR proteins that are functionally related to RNA editing processes.

Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 769
Author(s):  
Pattayampadam Ramakrishnan Shidhi ◽  
Vadakkemukadiyil Chellappan Biju ◽  
Sasi Anu ◽  
Chandrasekharan Laila Vipin ◽  
Kumar Raveendran Deelip ◽  
...  

Mitogenome sequencing provides an understanding of the evolutionary mechanism of mitogenome formation, mechanisms driving plant gene order, genome structure, and migration sequences. Data on the mitochondrial genome for family Convolvulaceae members is lacking. E. alsinoides, also known as shankhpushpi, is an important medicinal plant under the family Convolvulaceae, widely used in the Ayurvedic system of medicine. We identified the mitogenome of E. alsinoides using the Illumina mate-pair sequencing platform, and annotated using bioinformatics approaches in the present study. The mitogenome of E. alsinoides was 344184 bp in length and comprised 46 unique coding genes, including 31 protein-coding genes (PCGs), 12 tRNA genes, and 3 rRNA genes. The secondary structure of tRNAs shows that all the tRNAs can be folded into canonical clover-leaf secondary structures, except three trnW, trnG, and trnC. Measurement of the skewness of the nucleotide composition showed that the AT and GC skew is positive, indicating higher A’s and G’s in the mitogenome of E. alsinoides. The Ka/Ks ratios of 11 protein-coding genes (atp1, ccmC, cob, cox1, rps19, rps12, nad3, nad9, atp9, rpl5, nad4L) were <1, indicating that these genes were under purifying selection. Synteny and gene order analysis were performed to identify homologous genes among the related species. Synteny blocks representing nine genes (nad9, nad2, ccmFc, nad1, nad4, nad5, matR, cox1, nad7) were observed in all the species of Solanales. Gene order comparison showed that a high level of gene rearrangement has occurred among all the species of Solanales. The mitogenome data obtained in the present study could be used as the Convolvulaceae family representative for future studies, as there is no complex taxonomic history associated with this plant.


Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 81
Author(s):  
Jakub Sawicki ◽  
Katarzyna Krawczyk ◽  
Monika Ślipiko ◽  
Monika Szczecińska

The leafy liverwort Nowellia curvifolia is a widespread Holarctic species belonging to the family Cephaloziaceae. It is made up of a newly sequenced, assembled and annotated organellar genomes of two European specimens, which revealed the structure typical for liverworts, but also provided new insights into its microevolution. The plastome of N. curvifolia is the second smallest among photosynthetic liverworts, with the shortest known inverted repeats. Moreover, it is the smallest liverwort genome with a complete gene set, since two smaller genomes of Aneura mirabilis and Cololejeunea lanciloba are missing six and four protein-coding genes respectively. The reduction of plastome size in leafy liverworts seems to be mainly impacted by deletion within specific region between psbA and psbD genes. The comparative intraspecific analysis revealed single SNPs difference among European individuals and a low number of 35 mutations differentiating European and North American specimens. However, the genetic resources of Asian specimen enabled to identify 1335 SNPs in plastic protein-coding genes suggesting an advanced cryptic speciation within N. curvifolia or the presence of undescribed morphospecies in Asia. Newly sequenced mitogenomes from European specimens revealed identical gene content and structure to previously published and low intercontinental differentiation limited to one substitution and three indels. The RNA-seq based RNA editing analysis revealed 17 and 127 edited sites in plastome and mitogenome respectively including one non-canonical editing event in plastid chiL gene. The U to C editing is common in non-seed plants, but in liverwort plastome is reported for the first time.


2019 ◽  
Vol 8 (37) ◽  
Author(s):  
Gareth T. Little ◽  
Muhammad Ehsaan ◽  
Christian Arenas-López ◽  
Kamran Jawed ◽  
Klaus Winzer ◽  
...  

The hydrogen-utilizing strain Cupriavidus necator H16 (DSM 428) was sequenced using a combination of PacBio and Illumina sequencing. Annotation of this strain reveals 6,543 protein-coding genes, 263 pseudogenes, 64 tRNA genes, and 15 rRNA genes.


2018 ◽  
Vol 94 ◽  
Author(s):  
P. Zhang ◽  
R.K. Ran ◽  
A.Y. Abdullahi ◽  
X.L. Shi ◽  
Y. Huang ◽  
...  

AbstractDipetalonema gracile is a common parasite in squirrel monkeys (Saimiri sciureus), which can cause malnutrition and progressive wasting of the host, and lead to death in the case of massive infection. This study aimed to identify a suspected D. gracile worm from a dead squirrel monkey by means of molecular biology, and to amplify its complete mitochondrial genome by polymerase chain reaction (PCR) and sequence analysis. The results identified the worm as D. gracile, and the full length of its complete mitochondrial genome was 13,584 bp, which contained 22 tRNA genes, 12 protein-coding genes, two rRNA genes, one AT-rich region and one small non-coding region. The nucleotide composition included A (16.89%), G (20.19%), T (56.22%) and C (6.70%), among which A + T = 73.11%. The 12 protein-coding genes used TTG and ATT as start codons, and TAG and TAA as stop codons. Among the 22 tRNA genes, only trnS1AGN and trnS2UCN exhibited the TΨC-loop structure, while the other 20 tRNAs showed the TV-loop structure. The rrnL (986 bp) and rrnS (685 bp) genes were single-stranded and conserved in secondary structure. This study has enriched the mitochondrial gene database of Dipetalonema and laid a scientific basis for further study on classification, and genetic and evolutionary relationships of Dipetalonema nematodes.


PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242541
Author(s):  
Lvpei Du ◽  
Shanya Cai ◽  
Jun Liu ◽  
Ruoyu Liu ◽  
Haibin Zhang

Phymorhynchus is a genus of deep-sea snails that are most distributed in hydrothermal vent or cold seep environments. In this study, we presented the complete mitochondrial genome of P. buccinoides, a cold seep snail from the South China Sea. It is the first mitochondrial genome of a cold seep member of the superfamily Conoidea. The mitochondrial genome is 15,764 bp in length, and contains 13 protein-coding genes (PCGs), 2 rRNA genes, and 22 tRNA genes. These genes are encoded on the positive strand, except for 8 tRNA genes that are encoded on the negative strand. The start codon ATG and 3 types of stop codons, TAA, TAG and the truncated termination codon T, are used in the 13 PCGs. All 13 PCGs in the 26 species of Conoidea share the same gene order, while several tRNA genes have been translocated. Phylogenetic analysis revealed that P. buccinoides clustered with Typhlosyrinx sp., Eubela sp., and Phymorhynchus sp., forming the Raphitomidae clade, with high support values. Positive selection analysis showed that a residue located in atp6 (18 S) was identified as the positively selected site with high posterior probabilities, suggesting potential adaption to the cold seep environment. Overall, our data will provide a useful resource on the evolutionary adaptation of cold seep snails for future studies.


2021 ◽  
Vol 10 (41) ◽  
Author(s):  
Darien Brown ◽  
Shannon Isenhart ◽  
Auremie Kleven ◽  
Adam Gillison ◽  
Lee Anne Martínez ◽  
...  

We report the discovery and genome sequence of phage Adumb2043, a siphovirus infecting Arthrobacter globiformis , B2979-SEA. Adumb2043 was isolated from soil collected in Colorado Springs, Colorado. The genome has a length of 43,100 bp and contains 68 predicted protein-coding genes and no tRNA genes. Adumb2043 is related to actinobacteriophages Elezi and London.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8450 ◽  
Author(s):  
Sunan Huang ◽  
Xuejun Ge ◽  
Asunción Cano ◽  
Betty Gaby Millán Salazar ◽  
Yunfei Deng

The genus Dicliptera (Justicieae, Acanthaceae) consists of approximately 150 species distributed throughout the tropical and subtropical regions of the world. Newly obtained chloroplast genomes (cp genomes) are reported for five species of Dilciptera (D. acuminata, D. peruviana, D. montana, D. ruiziana and D. mucronata) in this study. These cp genomes have circular structures of 150,689–150,811 bp and exhibit quadripartite organizations made up of a large single copy region (LSC, 82,796–82,919 bp), a small single copy region (SSC, 17,084–17,092 bp), and a pair of inverted repeat regions (IRs, 25,401–25,408 bp). Guanine-Cytosine (GC) content makes up 37.9%–38.0% of the total content. The complete cp genomes contain 114 unique genes, including 80 protein-coding genes, 30 transfer RNA (tRNA) genes, and four ribosomal RNA (rRNA) genes. Comparative analyses of nucleotide variability (Pi) reveal the five most variable regions (trnY-GUA-trnE-UUC, trnG-GCC, psbZ-trnG-GCC, petN-psbM, and rps4-trnL-UUA), which may be used as molecular markers in future taxonomic identification and phylogenetic analyses of Dicliptera. A total of 55-58 simple sequence repeats (SSRs) and 229 long repeats were identified in the cp genomes of the five Dicliptera species. Phylogenetic analysis identified a close relationship between D. ruiziana and D. montana, followed by D. acuminata, D. peruviana, and D. mucronata. Evolutionary analysis of orthologous protein-coding genes within the family Acanthaceae revealed only one gene, ycf15, to be under positive selection, which may contribute to future studies of its adaptive evolution. The completed genomes are useful for future research on species identification, phylogenetic relationships, and the adaptive evolution of the Dicliptera species.


2021 ◽  
Vol 46 (1) ◽  
pp. 162-174
Author(s):  
Ming-Hui Yan ◽  
Chun-Yang Li ◽  
Peter W. Fritsch ◽  
Jie Cai ◽  
Heng-Chang Wang

Abstract—The phylogenetic relationships among 11 out of the 12 genera of the angiosperm family Styracaceae have been largely resolved with DNA sequence data based on all protein-coding genes of the plastome. The only genus that has not been phylogenomically investigated in the family with molecular data is the monotypic genus Parastyrax, which is extremely rare in the wild and difficult to collect. To complete the sampling of the genera comprising the Styracaceae, examine the plastome composition of Parastyrax, and further explore the phylogenetic relationships of the entire family, we sequenced the whole plastome of P. lacei and incorporated it into the Styracaceae dataset for phylogenetic analysis. Similar to most others in the family, the plastome is 158189 bp in length and contains a large single-copy region of 88085 bp and a small single-copy region of 18540 bp separated by two inverted-repeat regions of 25781 bp each. A total of 113 genes was predicted, including 79 protein-coding genes, 30 tRNA genes, and four rRNA genes. Phylogenetic relationships among all 12 genera of the family were constructed with 79 protein-coding genes. Consistent with a previous study, Styrax, Huodendron, and a clade of Alniphyllum + Bruinsmia were successively sister to the remainder of the family. Parastyrax was strongly supported as sister to an internal clade comprising seven other genera of the family, whereas Halesia and Pterostyrax were both recovered as polyphyletic, as in prior studies. However, when we employed either the whole plastome or the large- or small-single copy regions as datasets, Pterostyrax was resolved as monophyletic with 100% support, consistent with expectations based on morphology and indicating that non-coding regions of the Styracaceae plastome contain informative phylogenetic signal. Conversely Halesia was still resolved as polyphyletic but with novel strong support.


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