scholarly journals Phylogenomic analyses confirm a novel invasive North American Corbicula (Bivalvia: Cyrenidae) lineage

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7484 ◽  
Author(s):  
Amanda E. Haponski ◽  
Diarmaid Ó Foighil

The genus Corbicula consists of estuarine or freshwater clams native to temperate/tropical regions of Asia, Africa, and Australia that collectively encompass both sexual species and clonal (androgenetic) lineages. The latter have become globally invasive in freshwater systems and they represent some of the most successful aquatic invasive lineages. Previous studies have documented four invasive clonal lineages, Forms A, B, C, and Rlc, with varying known distributions. Form A (R in Europe) occurs globally, Form B is found solely in North America, mainly the western United States, Form C (S in Europe) occurs both in European watersheds and in South America, and Rlc is known from Europe. A putative fifth invasive morph, Form D, was recently described in the New World from the Illinois River (Great Lakes watershed), where it occurs in sympatry with Forms A and B. An initial study showed Form D to be conchologically distinct: possessing rust-colored rays and white nacre with purple teeth. However, its genetic distinctiveness using standard molecular markers (mitochondrial cytochrome c oxidase subunit I and nuclear ribosomal 28S RNA) was ambiguous. To resolve this issue, we performed a phylogenomic analysis using 1,699–30,027 nuclear genomic loci collected via the next generation double digested restriction-site associated DNA sequencing method. Our results confirmed Form D to be a distinct invasive New World lineage with a population genomic profile consistent with clonality. A majority (7/9) of the phylogenomic analyses recovered the four New World invasive Corbicula lineages (Forms A, B, C, and D) as members of a clonal clade, sister to the non-clonal Lake Biwa (Japan) endemic, Corbicula sandai. The age of the clonal clade was estimated at 1.49 million years (my; ± 0.401–2.955 my) whereas the estimated ages of the four invasive lineage crown clades ranged from 0.27 to 0.44 my. We recovered very little evidence of nuclear genomic admixture among the four invasive lineages in our study populations. In contrast, 2/6 C. sandai individuals displayed partial nuclear genomic Structure assignments with multiple invasive clonal lineages. These results provide new insights into the origin and maintenance of clonality in this complex system.

Coral Reefs ◽  
2021 ◽  
Author(s):  
Bar Feldman ◽  
Lutfi Afiq-Rosli ◽  
Noa Simon-Blecher ◽  
Elena Bollati ◽  
Benjamin John Wainwright ◽  
...  

2020 ◽  
Vol 70 (9) ◽  
pp. 5032-5039 ◽  
Author(s):  
Jae-Chan Lee ◽  
Kyung-Sook Whang

A Gram-stain-positive actinobacterial strain, designated ANK073T, was isolated from rhizosphere soil sampled at a spinach farming field in Shinan, Republic of Korea. Cells of strain ANK073T were found to be aerobic, non-motile, non-spore-forming rods which could grow at 20–40 °C (optimum, 30 °C), at pH 6.0–10.0 (optimum, pH 6.5–7.5) and at salinities of 0–4 % (w/v) NaCl (optimum, 0 % NaCl). The 16S rRNA gene sequence analysis showed that strain ANK073T belongs to the genus Agromyces with high sequence similarities to Agromyces humatus CD5T (98.8 %), Agromyces tardus SJ-23T (98.5 %) and Agromyces iriomotensis IY07-20T (98.4 %). The phylogenetic analysis indicated that strain ANK073T formed a distinct phyletic line in the genus Agromyces and the results of DNA–DNA relatedness and phylogenomic analysis based on whole genome sequences demonstrated that strain ANK073T could be separated from its closest relatives in the genus Agromyces . The strain contained 2,4-diaminobutylic acid, glycine, d-glutamic acid and d-alanine in the peptidoglycan. The predominant menaquinones were identified as MK-12 and MK-11, and the major fatty acids were anteiso-C17 : 0, anteiso-C15 :  0 and iso-C15:0. The major polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The G+C content of the genome was determined to be 70.2 mol%. On the basis of its phenotypic and chemotaxonomic properties and the results of phylogenetic and phylogenomic analyses, strain ANK073T is considered to represent a novel species in the genus Agromyces , for which the name Agromyces humi sp. nov. is proposed. The type strain is ANK073T (=KACC 18683T=NBRC 111825T).


2020 ◽  
Vol 70 (3) ◽  
pp. 1785-1792 ◽  
Author(s):  
Jae-Chan Lee ◽  
Kyung-Sook Whang

A Gram-stain-positive actinobacterial strain, designated YJ01T, was isolated from a spinach farming field soil at Shinan in Korea. Strain YJ01T was aerobic, non-motile, non-spore-forming cocci with diameters of 1.5–1.9 µm, and was able to grow at 10–37 °C (optimum, 28–30 °C), at pH 4.5–9.0 (optimum, pH 7.0–8.0) and at salinities of 0–7.5 % (w/v) NaCl (optimum, 1.0 % NaCl). Sequence similarities of the 16S rRNA gene of strain YJ01T with closely related relatives were in the range 96.2–92.8 %, and the results of phylogenomic analysis indicated that strain YJ01T was clearly separated from species of genera in the family Intrasporangiaceae showing average nucleotide identity values of 84.2–83.4 %. The predominant isoprenoid quinone was identified as MK-8(H4) and the major fatty acids were iso-C15 : 0, iso-C16:1 h, iso-C16 : 0 and anteiso-C17 : 1ω9c. The diagnostic diamino acid of the peptidoglycan was ornithine, and the interpeptide bridge was l-Orn–Gly2–d-Glu. The major polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylserine, an unidentified phosphatidylglycolipid, two unidentified phosphoaminolipids and an unidentified phosphoglycoaminolipid. The G+C content of the genome was 70.1 mol%. On the basis of phenotypic and chemotaxonomic properties and phylogenetic and phylogenomic analyses using 16S rRNA gene sequences and whole-genome sequences, strain YJ01T is considered to represent a novel species of a new genus in the family Intrasporangiaceae , for which the name Segeticoccus rhizosphaerae gen. nov. sp. nov. is proposed. The type strain of Segeticoccus rhizosphaerae is YJ01T (=KACC 19547T=NBRC 113173T).


Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1143 ◽  
Author(s):  
Hang Ran ◽  
Yanyan Liu ◽  
Cui Wu ◽  
Yanan Cao

Phylogenetic analyses of complete chloroplast genome sequences have yielded significant improvements in our understanding of relationships in the woody flowering genus Viburnum (Adoxaceae, Dipsacales); however, these relationships were evaluated focusing only on Viburnum species within Central and South America and Southeast Asia. By contrast, despite being a hotspot of Viburnum diversity, phylogenetic relationships of Viburnum species in China are less well known. Here, we characterized the complete chloroplast (cp) genomes of 21 Viburnum species endemic to China, as well as three Sambucus species. These 24 plastomes were highly conserved in genomic structure, gene order and content, also when compared with other Adoxaceae. The identified repeat sequences, simple sequence repeats (SSRs) and highly variable plastid regions will provide potentially valuable genetic resources for further population genetics and phylogeographic studies on Viburnum and Sambucus. Consistent with previous combined phylogenetic analyses of 113 Viburnum species, our phylogenomic analyses based on the complete cp genome sequence dataset confirmed the sister relationship between Viburnum and the Sambucus-Adoxa-Tetradoxa-Sinadoxa group, the monophyly of four recognized sections in Flora of China (i.e., Viburnum sect. Tinus, Viburnum sect. Solenotinus, Viburnum sect. Viburnum and Viburnum sect. Pseudotinus) and the nonmonophyly of Viburnum sect. Odontotinus and Viburnum sect. Megalotinus. Additionally, our study confirmed the sister relationships between the clade Valvatotinus and Viburnum sect. Pseudotinus, as well as between Viburnum sect. Opulus and the Odontotinus-Megalotinus group. Overall, our results clearly document the power of the complete cp genomes in improving phylogenetic resolution, and will contribute to a better understanding of plastome evolution in Chinese Adoxaceae.


Author(s):  
Robert S de Moya ◽  
Kazunori Yoshizawa ◽  
Kimberly K O Walden ◽  
Andrew D Sweet ◽  
Christopher H Dietrich ◽  
...  

Abstract The insect order Psocodea is a diverse lineage comprising both parasitic (Phthiraptera) and non-parasitic members (Psocoptera). The extreme age and ecological diversity of the group may be associated with major genomic changes, such as base compositional biases expected to affect phylogenetic inference. Divergent morphology between parasitic and non-parasitic members has also obscured the origins of parasitism within the order. We conducted a phylogenomic analysis on the order Psocodea utilizing both transcriptome and genome sequencing to obtain a data set of 2,370 orthologous genes. All phylogenomic analyses, including both concatenated and coalescent methods suggest a single origin of parasitism within the order Psocodea, resolving conflicting results from previous studies. This phylogeny allows us to propose a stable ordinal level classification scheme that retains significant taxonomic names present in historical scientific literature and reflects the evolution of the group as a whole. A dating analysis, with internal nodes calibrated by fossil evidence, suggests an origin of parasitism that predates the K-Pg boundary. Nucleotide compositional biases are detected in third and first codon positions and result in the anomalous placement of the Amphientometae as sister to Psocomorpha when all nucleotide sites are analyzed. Likelihood-mapping and quartet sampling methods demonstrate that base compositional biases can also have an effect on quartet-based methods.


2009 ◽  
Vol 83 (18) ◽  
pp. 9347-9355 ◽  
Author(s):  
Muhammad Shah Nawaz-ul-Rehman ◽  
Shahid Mansoor ◽  
Rob W. Briddon ◽  
Claude M. Fauquet

ABSTRACT Begomoviruses (family Geminiviridae) cause major losses to crops throughout the tropical regions of the world. Begomoviruses originating from the New World (NW) and the Old World (OW) are genetically distinct. Whereas the majority of OW begomoviruses have monopartite genomes and whereas most of these associate with a class of symptom-modulating satellites (known as betasatellites), the genomes of NW begomoviruses are exclusively bipartite and do not associate with satellites. Here, we show for the first time that a betasatellite (cotton leaf curl Multan betasatellite [CLCuMuB]) associated with a serious disease of cotton across southern Asia is capable of interacting with a NW begomovirus. In the presence of CLCuMuB, the symptoms of the NW cabbage leaf curl virus (CbLCuV) are enhanced in Nicotiana benthamiana. However, CbLCuV was unable to interact with a second betasatellite, chili leaf curl betasatellite. Although CbLCuV can transreplicate CLCuMuB, satellite accumulation levels in plants were low. However, progeny CLCuMuB isolated after just one round of infection with CbLCuV contained numerous mutations. Reinoculation of one such progeny CLCuMuB with CbLCuV to N. benthamiana yielded infections with significantly higher satellite DNA levels. This suggests that betasatellites can rapidly adapt for efficient transreplication by a new helper begomovirus, including begomoviruses originating from the NW. Although the precise mechanism of transreplication of betasatellites by begomoviruses remains unknown, an analysis of betasatellite mutants suggests that the sequence(s) required for maintenance of CLCuMuB by one of its cognate begomoviruses (cotton leaf curl Rajasthan virus) differs from the sequences required for maintenance by CbLCuV. The significance of these findings and, particularly, the threat that betasatellites pose to agriculture in the NW, are discussed.


2019 ◽  
Vol 36 (4) ◽  
pp. 757-765 ◽  
Author(s):  
Jürgen F H Strassert ◽  
Mahwash Jamy ◽  
Alexander P Mylnikov ◽  
Denis V Tikhonenkov ◽  
Fabien Burki

AbstractThe resolution of the broad-scale tree of eukaryotes is constantly improving, but the evolutionary origin of several major groups remains unknown. Resolving the phylogenetic position of these “orphan” groups is important, especially those that originated early in evolution, because they represent missing evolutionary links between established groups. Telonemia is one such orphan taxon for which little is known. The group is composed of molecularly diverse biflagellated protists, often prevalent although not abundant in aquatic environments. Telonemia has been hypothesized to represent a deeply diverging eukaryotic phylum but no consensus exists as to where it is placed in the tree. Here, we established cultures and report the phylogenomic analyses of three new transcriptome data sets for divergent telonemid lineages. All our phylogenetic reconstructions, based on 248 genes and using site-heterogeneous mixture models, robustly resolve the evolutionary origin of Telonemia as sister to the Sar supergroup. This grouping remains well supported when as few as 60% of the genes are randomly subsampled, thus is not sensitive to the sets of genes used but requires a minimal alignment length to recover enough phylogenetic signal. Telonemia occupies a crucial position in the tree to examine the origin of Sar, one of the most lineage-rich eukaryote supergroups. We propose the moniker “TSAR” to accommodate this new mega-assemblage in the phylogeny of eukaryotes.


2019 ◽  
Vol 10 (1) ◽  
pp. 11-25
Author(s):  
Christophe Verwimp ◽  
Lies Vansteenbrugge ◽  
Sofie Derycke ◽  
Thomas Kerkhove ◽  
Hilde Muylle ◽  
...  

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