scholarly journals Revisiting Orthotospovirus Phylogeny Using Whole Genomic Data and a Hypothesis for their Geographic Origin and Diversification

2020 ◽  
Author(s):  
Anamarija Butković ◽  
Rubén González ◽  
Santiago F. Elena

ABSTRACTThe family Tospoviridae, a member of the Bunyavirales order, is constituted of tri-segmented negative-sense single-stranded RNA viruses that infect plants and are also able of replicating in their insect vectors in a persistent manner. The family is composed of a single genus, the Orthotospovirus, whose type species is Tomato spotted wilt virus (TSWV). Previous studies assessing the phylogenetic relationships within this genus were based upon partial genomic sequences, thus resulting in unresolved clades and a poor assessment of the roles of recombination and genome shuffling during mixed infections. Complete genomic data for most Orthotospovirus species are now available at NCBI genome database. In this study we have used 62 complete genomes from 20 species. Our study confirms the existence of four phylogroups (A to D), grouped in two major clades (A-B and C-D), within the genus. We have estimated the split between the two major clades ∼3,100 years ago shortly followed by the split between the A and B phylogroups ∼2,860 years ago. The split between the C and D phylogroups happened more recently, ∼1,465 years ago. Segment reassortment has been shown to be important in the generation of novel viruses. Likewise, within-segment recombination events have been involved in the origin of new viral species. Finally, phylogeographic analyses of representative viruses suggests the Australasian ecozone as the possible origin of the genus, followed by complex patterns of migration, with rapid global spread and numerous reintroduction events.IMPORTANCEMembers of the Orthotospovirus genus infect a large number of plant families, including food crops and ornamentals, resulting in multimillionaire economical losses. Despite this importance, phylogenetic relationships within the genus were established years ago based in partial genomic sequences. A peculiarity of orthotospoviruses is their tri-segmented negative sense genomes, which makes segment reassortment and within-segment recombination, two forms of viral sex, potential evolutionary forces. Using full genomes from all described orthotospovirus species, we revisited their phylogeny and confirmed the existence of four major phylogroups with uneven geographic distribution. We have also shown a pervasive role of sex in the origin of new viral species. Finally, using Bayesian phylogeographic methods, we assessed the possible geographic origin and historical dispersal of representative viruses from the different phylogroups.

Children ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 601
Author(s):  
Kyung-Sun Park

In this study, two different approaches were applied in the analysis of the GAA gene. One was analyzed based on patients with Pompe disease, and the other was analyzed based on GAA genomic data from unaffected carriers in a general population genetic database. For this, GAA variants in Korean and Japanese patients reported in previous studies and in patients reported in the Pompe disease GAA variant database were analyzed as a model. In addition, GAA variants in the Korean Reference Genome Database (KRGDB), the Japanese Multi Omics Reference Panel (jMorp), and the Genome Aggregation Database (gnomAD) were analyzed. Overall, approximately 50% of the pathogenic or likely pathogenic variants (PLPVs) found in unaffected carriers were also found in real patients with Pompe disease (Koreans, 57.1%; Japanese, 46.2%). In addition, there was a moderate positive correlation (Spearman’s correlation coefficient of 0.45–0.69) between the proportion of certain PLPVs in patients and the minor allele frequency of their variants in a general population database. Based on the analysis of general population databases, the total carrier frequency for Pompe disease in Koreans and Japanese was estimated to be 1.7% and 0.7%, respectively, and the predicted genetic prevalence was 1:13,657 and 1:78,013, respectively.


2002 ◽  
Vol 11 (2) ◽  
pp. 169-174 ◽  
Author(s):  
Peggy S. M. Hill ◽  
Cara Hoffart ◽  
Mark Buchheim

Author(s):  
Andreina I Castillo ◽  
Rodrigo P P Almeida

Abstract Nucleotide composition (GC content) varies across bacteria species, genome regions, and specific genes. In Xylella fastidiosa, a vector-borne fastidious plant pathogen infecting multiple crops, GC content ranges between ∼51-52%; however, these values were gathered using limited genomic data. We evaluated GC content variations across X. fastidiosa subspecies fastidiosa (N = 194), subsp. pauca (N = 107), and subsp. multiplex (N = 39). Genomes were classified based on plant host and geographic origin; individual genes within each genome were classified based on gene function, strand, length, ortholog group, Core vs. Accessory, and Recombinant vs. Non-recombinant. GC content was calculated for each gene within each evaluated genome. The effects of genome and gene level variables were evaluated with a mixed effect ANOVA, and the marginal-GC content was calculated for each gene. Also, the correlation between gene-specific GC content vs. natural selection (dN/dS) and recombination/mutation (r/m) was estimated. Our analyses show that intra-genomic changes in nucleotide composition in X. fastidiosa are small and influenced by multiple variables. Higher AT-richness is observed in genes involved in replication and translation, and genes in the leading strand. In addition, we observed a negative correlation between high-AT and dN/dS in subsp. pauca. The relationship between recombination and GC content varied between core and accessory genes. We hypothesize that distinct evolutionary forces and energetic constraints both drive and limit these small variations in nucleotide composition.


2005 ◽  
Vol 26 (2) ◽  
pp. 139-147 ◽  
Author(s):  
Francisca do Val ◽  
Paulo Nuin

AbstractThe systematics and phylogenetic relationships of the family Leptodactylidae are controversial as is the intrafamilial phylogeny of the leptodactylids. Here we analyze the relationships of the leptodactylid subfamily Hylodinae. This subfamily has been considered to be monophyletic and composed of three genera, Hylodes, Crossodactylus and Megaelosia. In the present study 49 characters were used, based on different studies on Leptodactylidae phylogeny. Maximum parsimony methods with unweighted and successively weighted characters were used to estimate the phylogeny of the Hylodinae. Upon analysis, the data provided further evidence of the monophyletic status of the three genera, with Megaelosia being the basal genus and the other two genera being sister taxa. The analysis with successive weighting results in a more resolved topology of the species subgroups of the genus Hylodes and separates this genus from Crossodactylus and confirms that the hylodines are monophyletic.


Author(s):  
Sooyeon Park ◽  
Jung-Sook Lee ◽  
Wonyong Kim ◽  
Jung-Hoon Yoon

Two Gram-stain-negative and non-flagellated bacteria, YSTF-M3T and YSTF-M6T, were isolated from a tidal flat from Yellow Sea, Republic of Korea, and subjected to a polyphasic taxonomic study. Neighbour-joining phylogenetic tree of 16S rRNA gene sequences showed that strains YSTF-M3T and YSTF-M6T belong to the genera Kordia and Olleya of the family Flavobacteriaceae , respectively. The 16S rRNA gene sequence similarities between strain YSTF-M3T and the type strains of Kordia species and between strain YSTF-M6T and the type strains of Olleya species were 94.1–98.4 and 97.3–98.3 %, respectively. The ANI and dDDH values between genomic sequences of strain YSTF-M3T and the type strains of five Kordia species and between those of strain YSTF-M6T and the type strains of three Olleya species were in ranges of 77.0–83.2 and 20.7–27.1 % and 79.4–81.5 and 22.3–23.9 %, respectively. The DNA G+C contents of strain YSTF-M3T and YSTF-M6T from genomic sequences were 34.1 and 31.1 %, respectively. Both strains contained MK-6 as predominant menaquinone and phosphatidylethanolamine as only major phospholipid identified. Differential phenotypic properties, together with the phylogenetic and genetic distinctiveness, revealed that strains YSTF-M3T and YSTF-M6T are separated from recognized species of the genera Kordia and Olleya , respectively. On the basis of the data presented, strains YSTF-M3T (=KACC 21639T=NBRC 114499T) and YSTF-M6T (=KACC 21640T=NBRC 114500T) are considered to represent novel species of the genera Kordia and Olleya , respectively, for which the names Kordia aestuariivivens sp. nov. and Olleya sediminilitoris sp. nov. are proposed.


Zootaxa ◽  
2021 ◽  
Vol 4990 (1) ◽  
pp. 192-200
Author(s):  
SIMONE MARIA DE ALBUQUERQUE LIRA ◽  
CYNTHIA DAYANNE MELLO DE LIMA ◽  
IGOR DE ÁVILA TEIXEIRA ◽  
RALF SCHWAMBORN

The objective of this paper is to describe and illustrate the first zoeal stage of the largest land crab of the Tropical Atlantic, Johngarthia lagostoma (Milne Edwards, 1837) (Brachyura: Gecarcinidae). A larval description of J. lagostoma was previously not available. Larvae were obtained from ovigerous females on Rocas Atoll and Fernando de Noronha Archipelago, Brazil. Twenty larvae were randomly chosen to be dissected and described in detail, while 40 others (20 larvae from each island) were measured only. The published description of the congener J. planatus (Stimpson, 1860) larvae was used for a comparison of larval morphology. Some morphological differences between the first zoeal stage of these two species were: The absence or presence of a simple shorter seta on antennule, number of the minute terminal spines on the antenna, setation of the coxal endite of the maxilla, exopod unsegmented of the first and second maxilliped, and a single mid-dorsal seta on first pleonite. These results and differences observed between these species can assist in studies on phylogenetic relationships within the Family Gecarcinidae MacLeay, 1838, as well as in the identification of the larvae of J. Lagostoma in plankton samples from the tropical Atlantic.  


IAWA Journal ◽  
2021 ◽  
pp. 1-11
Author(s):  
Kishore S. Rajput ◽  
Amit D. Gondaliya ◽  
Roger Moya

Abstract The lianas in the family Sapindaceae are known for their unique secondary growth which differs from climbing species in other plant families in terms of their cambial variants. The present study deals with the stem anatomy of self-supporting and lianescent habit, development of phloem wedges, the ontogeny of cambial variants and structure of the secondary xylem in the stems of Serjania mexicana (L.) Willd. Thick stems (15–20 mm) were characterized by the presence of distinct phloem wedges and tangentially wide neo-formed cambial cylinders. As the stem diameter increases, there is a proportional increase in the number of phloem wedges and neo-formed vascular cylinders. The parenchymatous (pericyclic) cells external to phloem wedges that are located on the inner margin of the pericyclic fibres undergo dedifferentiation, become meristematic and form small segments of cambial cylinders. These cambia extend tangentially into wide and large segments of neoformations. Structurally, the secondary xylem and phloem of the neo-formed vascular cylinders remain similar to the derivatives produced by the regular vascular cambium. The secondary xylem is composed of vessels (wide and narrow), fibres, axial and ray parenchyma cells. The occurrence of perforated ray cells is a common feature in both regular and variant xylem.


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