scholarly journals Novel diversity within marine Mamiellophyceae (Chlorophyta) unveiled by metabarcoding

2018 ◽  
Author(s):  
Margot Tragin ◽  
Daniel Vaulot

ABSTRACTThe Ocean Sampling Day (OSD) project provided metabarcoding data for the V4 hyper-variable regions of the 18S rRNA gene from 157 samples collected at 143 mostly coastal stations. In this paper we focus on the class Mamiellophyceae, which was found at nearly all OSD stations and represented 55 % of the green microalgae (Chlorophyta) reads in the 2014 OSD dataset. We performed phylogenetic analyses of unique OSD metabarcodes (ASV, amplicon single variants) and reference GenBank sequences from cultures and from the environment, focusing on the four most represented genera: Ostreococcus (45 % of the Mamiellophyceae reads), Micromonas (34 %), Bathycoccus (10 %) and Mantoniella (8.7 %). These analyses uncovered novel diversity within each genus except Bathycoccus. In Ostreococcus, a new clade (E) with 2 very clear base pair differences compared to the oceanic clade B in the V4 region was the second most represented clade after the coastal Ostreococcus “lucimarinus”. Within Micromonas, ten clades were found exceeding the 4 species and 2 candidate species already described. Finally, we found 2 new environmental clades of Mantoniella. Each Mamiellophyceae clade had a specific distribution in the OSD dataset suggesting that they are adapted to different ecological niches.

2013 ◽  
Vol 63 (Pt_1) ◽  
pp. 377-387 ◽  
Author(s):  
Jiří Neustupa ◽  
Yvonne Němcová ◽  
Jana Veselá ◽  
Jana Steinová ◽  
Pavel Škaloud

The diversity of green microalgae in subaerial habitats remains largely unexplored and a number of new genus- and species-level lineages have been discovered recently. The traditional green algal genus, Chlorella, which accommodated coccoid unicellular green algal species with globular to oval cells, reproducing entirely by autospores, has been found to be polyphyletic. In this study, we provide a detailed characterization of two strains of microalgae isolated from tree bark in the Mediterranean. These algae share the general Chlorella-like morphology and their 18S rRNA and rbcL gene sequences place them in the Trebouxiophyceae. Strain CAUP H8401 forms an independent trebouxiophycean lineage, together with three previously published 18S rRNA gene environmental sequences of undescribed microalgae, which were retrieved from profoundly different habitats. In contrast, strain CAUP H7902 is related to Kalinella bambusicola in the Watanabea clade of the Trebouxiophyceae on the basis of its 18S rRNA gene sequence. This relationship is also supported by the rbcL gene sequence, acquired from the type strain of K. bambusicola. The investigated strains are described as representatives of a novel species in a new genus, Leptochlorella corticola gen. et sp. nov., and a novel species, Kalinella apyrenoidosa sp. nov., according to the International Code of Nomenclature for Algae, Fungi and Plants.


Nematology ◽  
2018 ◽  
Vol 20 (7) ◽  
pp. 653-669 ◽  
Author(s):  
Oleg Gorgadze ◽  
Elena Fanelli ◽  
Manana Lortkhipanidze ◽  
Alberto Troccoli ◽  
Medea Burjanadze ◽  
...  

Summary A new species of entomopathogenic nematode, Steinernema borjomiense n. sp., was isolated from the body of the host insect, Oryctes nasicornis (Coleoptera: Scarabaeidae), in Georgia, in the territory of Borjomi-Kharagauli. Morphological characters indicate that the new species is closely related to species of the feltiae-group. The infective juveniles are characterised by the following morphological characters: body length of 879 (777-989) μm, distance between the head and excretory pore = 72 (62-80) μm, pharynx length = 132 (122-142) μm, tail length = 70 (60-80) μm, ratio a = 26.3 (23.0-29.3), H% = 45 (40-51), D% = 54 (47-59), E% = 102 (95-115), and lateral fields consisting of seven ridges (eight incisures) at mid-body. Steinernema borjomiense n. sp. was molecularly characterised by sequencing three ribosomal regions (the ITS, the D2-D3 expansion domains and the 18S rRNA gene) and the mitochondrial COI gene. Phylogenetic analyses revealed that S. borjomiense n. sp. differs from all other known species of Steinernema and is a member of the monticolum-group.


Zootaxa ◽  
2021 ◽  
Vol 4995 (2) ◽  
pp. 334-344
Author(s):  
QIAN ZHOU ◽  
FAHUI TANG ◽  
YUANJUN ZHAO

During a survey of parasitic ciliates in Chongqing, China, Trichodina matsu Basson & Van As, 1994 was isolated from gills of Tachysurus fulvidraco. Furthermore, the 18S rRNA gene and ITS-5.8S rRNA region of T. matsu were sequenced for the first time and applied for the species identification and comparison with similar species in the present study. Based on the morphological and molecular comparisons, the results indicate that T. matsu is an ectoparasite specific for the Siluriformes catfish. Based on the analyses of genetic distance, multiple sequence alignments, and phylogenetic analyses, no obvious differentiation within populations of T. matsu was found. In addition, the ‘Trichodina hyperparasitis’ (KX904933) in GenBank is a misidentification and appears to be conspecific with T. matsu according to the comparison of morphological and molecular data.  


Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1433
Author(s):  
Claire Bonsergent ◽  
Marie-Charlotte de Carné ◽  
Nathalie de la Cotte ◽  
François Moussel ◽  
Véronique Perronne ◽  
...  

In Europe, Babesia divergens is responsible for most of the severe cases of human babesiosis. In the present study, we describe a case of babesiosis in a splenectomized patient in France and report a detailed molecular characterization of the etiological agent, named Babesia sp. FR1, as well as of closely related Babesia divergens, Babesia capreoli and Babesia sp. MO1-like parasites. The analysis of the conserved 18S rRNA gene was supplemented with the analysis of more discriminant markers involved in the red blood cell invasion process: rap-1a (rhoptry-associated-protein 1) and ama-1 (apical-membrane-antigen 1). The rap-1a and ama-1 phylogenetic analyses were congruent, placing Babesia sp. FR1, the new European etiological agent, in the American cluster of Babesia sp. MO1-like parasites. Based on two additional markers, our analysis confirms the clear separation of B. divergens and B. capreoli. Babesia sp. MO1-like parasites should also be considered as a separate species, with the rabbit as its natural host, differing from those of B. divergens (cattle) and B. capreoli (roe deer). The natural host of Babesia sp. FR1 remains to be discovered.


2017 ◽  
Vol 54 (1) ◽  
pp. 87-96 ◽  
Author(s):  
C. Verma ◽  
A. Chaudhary ◽  
H. S. Singh

Summary Two species of Thaparocleidus Jain (1952a) were found harboring W. attu from the Ganga River at two localities, Meerut and Farrukhabad, Uttar Pradesh, India, during the period of 2013-2015. Morphology and morphometric study of specimens identified as Thaparocleidus gomtius (Jain, 1952a) Lim, 1996 and T. sudhakari (Gusev, 1976) Lim, 1996. Molecular analyses using the 18S rRNA gene confirmed the validity of T. gomtius and T. sudhakari and demonstrated that both the species clustered with other Thaparocleidus species from different geographical regions. We aim at reassessing the taxonomy and establishing the phylogenetic relationships among these two redescribed species with other representatives of the genus Thaparocleidus.


Nematology ◽  
2015 ◽  
Vol 17 (8) ◽  
pp. 953-966 ◽  
Author(s):  
Alberto Troccoli ◽  
Monica Oreste ◽  
Eustachio Tarasco ◽  
Elena Fanelli ◽  
Francesca De Luca

Several juvenile and adult nematodes were isolated after dissection of pupae and adults of the red palm weevil,Rhynchophorus ferrugineus, recovered from an infestedPhoenix canariensisChabaud exemplar in Bari, Italy. Two species of nematodes were recovered,Teratorhabditis synpapillataandMononchoides macrospiculumn. sp. which is described herein. The mitochondrial cytochrome oxidase I (COI), the ITS-containing region, the 18S rRNA gene (SSU) and the D2-D3 expansion domains of the 28S rRNA gene (LSU) were amplified and sequenced. The new species,M. macrospiculumn. sp., is described at morphological and molecular level. Phylogenetic analyses using SSU and LSU sequences placedM. macrospiculumn. sp. together withM. composticolaandM. striatus. The sequences of the Italian population ofT. synpapillataare identical to those ofT. synpapillatafrom Japan. This is the first report on the association ofM. macrospiculumn. sp. andT. synpapillatawith the red palm weevil in Europe.


2006 ◽  
Vol 56 (4) ◽  
pp. 913-922 ◽  
Author(s):  
Fabio Rindi ◽  
Juan M. López-Bautista ◽  
Alison R. Sherwood ◽  
Michael D. Guiry

Spongiochrysis hawaiiensis gen. et sp. nov. is described from material collected at two sites on O'ahu, Hawaiian Islands. This alga produced golden-yellow crusts on the bark of Casuarina trees and consisted of globular cells with an axial stellate chloroplast. The only form of reproduction was a specialized type of autosporulation in which a budding-like division of the mother cell produced daughter cells of different sizes. Phylogenetic analyses of the 18S rRNA gene showed that Spongiochrysis hawaiiensis is a member of the freshwater clade of the Cladophorales/Siphonocladales lineage in the green algal class Ulvophyceae. On the basis of its unicellular habit and terrestrial habitat, this species is well differentiated from all other members of the same lineage and can be considered as the first known successful step of a member of the order Cladophorales into terrestrial habitats. The implications of the description of this species with regard to both green algal evolution and conservation of little-known tropical habitats are discussed. The holotype specimen of Spongiochrysis hawaiiensis is GALW015489 and isotype specimens have also been deposited in the BISH and BM herbaria.


2018 ◽  
Vol 66 (1) ◽  
pp. 107-115 ◽  
Author(s):  
Sándor Hornok ◽  
Alexandra Corduneanu ◽  
Jenő Kontschán ◽  
Katinka Bekő ◽  
Krisztina Szőke ◽  
...  

Babesia vesperuginis is the only piroplasm known to infect bats. Unlike most members of the genus Babesia, it is probably transmitted by a soft tick species (i.e. Argas vespertilionis). Recently, two studies have been conducted to clarify the phylogenetic status of this species, and both agreed on placing it into a basal position among Babesia sensu stricto (s.s.). However, several important groups of piroplasms were not included in the already reported phylogenetic trees of B. vesperuginis isolates. Therefore, the aim of the present study was to amplify an approx. 950-bp fragment of the cytochrome c oxidase subunit 1 (cox1) gene of B. vesperuginis from A. vespertilionis specimens, and to compare its sequences with those from other piroplasmid groups in a broader phylogenetic context. Sequence comparisons focusing on either 18S rRNA or cox1 genes, as well as phylogenetic analyses involving separate and concatenated 18S rRNA and cox1 sequences indicate that B. vesperuginis is more closely related to the phylogenetic group of Theileriidae than to Babesia s.s. In particular, B. vesperuginis clustered closest to Cytauxzoon felis and the ‘prototheilerid’ B. conradae. The results of this study highlight that B. vesperuginis is a unique and taxonomically important species, which should be included in future studies aimed at resolving the comprehensive phylogeny of Piroplasmida.


2021 ◽  
Vol 9 (9) ◽  
pp. 1842
Author(s):  
Sara Laetitia Elphège Gnangui ◽  
Romain Kouakou Fossou ◽  
Anicet Ebou ◽  
Chiguié Estelle Raïssa Amon ◽  
Dominique Kadio Koua ◽  
...  

Over the past decade, many projects have been initiated worldwide to decipher the composition and function of the soil microbiome, including the African Soil Microbiome (AfSM) project that aims at providing new insights into the presence and distribution of key groups of soil bacteria from across the African continent. In this national study, carried out under the auspices of the AfSM project, we assessed the taxonomy, diversity and distribution of rhizobial genera in soils from the tropical savannah zones in Northern Côte d’Ivoire. Genomic DNA extracted from seven sampled soils was analyzed by sequencing the V4-V5 variable region of the 16S rDNA using Illumina’s MiSeq platform. Subsequent bioinformatic and phylogenetic analyses showed that these soils harbored 12 out of 18 genera of Proteobacteria harboring rhizobia species validly published to date and revealed for the first time that the Bradyrhizobium genus dominates in tropical savannah soils, together with Microvirga and Paraburkholderia. In silico comparisons of different 16S rRNA gene variable regions suggested that the V5-V7 region could be suitable for differentiating rhizobia at the genus level, possibly replacing the use of the V4-V5 region. These data could serve as indicators for future rhizobial microbiome explorations and for land-use decision-making.


2019 ◽  
Vol 186 (4) ◽  
pp. 892-914 ◽  
Author(s):  
Diana Delicado ◽  
Beatriz Arconada ◽  
Amanda Aguado ◽  
Marian A Ramos

Abstract Valvatiform gastropods of the family Hydrobiidae are frequently found in European spring-fed systems. Their simplified and sometimes convergent morphological structures and restricted geographical ranges make the description and identification of valvatiform species challenging. In the Iberian Peninsula, to date, 20 valvatiform species have been described morphologically. To test morphological species delimitations and to evaluate the role of physical geography on their evolutionary history, we analysed two mitochondrial (COI and 16S rRNA) and two nuclear (28S rRNA and 18S rRNA) gene fragments of 16 valvatiform species from the Iberian Peninsula. Molecular species delimitation methods consistently inferred 11 of the nominal species. Our phylogenetic analyses recovered the species Islamia azarum as an independent lineage, distantly related to other genera, which we place in the new genus Deganta. Furthermore, Iberian valvatiform hydrobiids do not form a monophyletic subunit, but they are included in two distinct clades of Hydrobiidae. Divergence times indicate that speciation in these clades is likely to have coincided with the formation of major Iberian mountain ranges and river basins. Similarities of geographical subdivision and divergent times between this assemblage and the non-valvatiform genus Corrosella provide strong evidence for the role of the Iberian geographical barriers in shaping the biogeography of these springsnails.


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