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So far, Rubrioxytricha guamensis Kumar et al. 2018 is known only from the type locality, namely Guam, USA. Recently, another isolate was recorded from a freshwater habitat in China that is 3500 km from the type locality. Its morphology and molecular phylogeny were investigated using live observation, protargol staining and ribosomal gene sequencing methods. The morphology of the present isolate of R. guamensis corresponds well with that of the type population despite a broad range of morphometric data in the Chinese population. Conspecificity of the two populations is supported by 99.9% 18S rRNA gene sequence similarity. Phylogenetic analysis reveals that these two populations of R. guamensis group together and cluster within the genus. The present study contributes to understanding the wide distribution of the species and helps to circumscribe the species. [ABSTRACT FROM AUTHOR]

One new species of Racovitzaibathynella Serban and Coineau, 1994 and one of Cteniobathynella Schminke, 1973 of the order Bathynellacea Chappuis, 1915 (family Parabathynellidae Noodt, 1065) are described from Benin in West Africa. These represent the first records of Bathynellacea species in Benin following a broad sampling throughout the country. Two species of the genus Racovitzaibathynella are known from South Africa and one is known from Chad and Israel. Specimens of Racovitzaibathynella beninensis Camacho and Lagnika sp. n. and Cteniobathynella boutini Camacho and Lagnika sp. n. have a unique combination of morphological characters and several shared generic features. Racovitzaibathynella beninensissp. n. has a six-segmented antennule with three aesthetascs on segment five; a five-segmented antenna; concave labrum; mandible with only three teeth on the distal endite; no epipod on thoracopods I to III; plumose setae on the exopod of thoracopods I to VII; female thoracopod VIII distal-end bilobed, and two plumose setae on the endopod of the uropod. Cteniobathynella boutinisp. n. has a six-segmented antennula; five-segmented antenna; no epipod on thoracopods I to III; endopod on ThVIII of males as exopod, and five setae on the endopod of the uropod. To complement the morphological description of the two new species, a phylogenetic analysis based on the 18S ribosomal RNA (rRNA) gene was performed to infer their phylogenetic position within the family Parabathynellidae. The phylogenetic reconstruction shows an Afrotropical clade, which includes the new African species, and is clearly distinct from the European, Australian and Asiatic clades. [ABSTRACT FROM AUTHOR]

In eukaryotes, the ribosomal small subunit (40S) is composed of 18S rRNA and 33 ribosomal proteins. 18S rRNA has a special secondary structure and is an indispensable part of the translation process. Herein, a special sequence located in mammalian 18S rRNA named Poly(G)7box, which is composed of seven guanines, was found. Poly(G)7 can form a special and stable secondary structure by binding to the translation elongation factor subunit eEF1D and the ribosomal protein RPL32. Poly(G)7box was transfected into cells, and the translation efficiency of cells was inhibited. We believe that Poly(G)7box is an important translation-related functional element located on mammalian 18S rRNA, meanwhile the Poly(G)7 located on mRNA 5' and 3' box does not affect mRNA translation. [ABSTRACT FROM AUTHOR]

The present study was aimed at the identification, molecular characterization, and risk factor assessment of Theileria infection among sheep of Haryana province, north India. A total of 402 blood samples were collected from three different climatic zones of Haryana from March 2020 to September 2021. Light microscopy of blood smears revealed Theileria spp. infection in 47.26% (n = 190), while 60.94% (n = 245) of blood samples were positive using nested PCR. Extensive molecular characterization of Theileria infection using four pairs of species-specific primers indicated the dominance of T. ovis (29.1%) followed by T. lestoquardi (12.69%), T. luwenshuni (5.97%) and T. annulata (1.49%). Mixed infection was detected in 11.69% of cases. Bidirectional sequencing and phylogeny further confirmed the presence of these four Theileria spp. in the investigated area under study. Hematology indicated a significant (p < 0.01) reduction in various haematological indices of animals infected with T. luwenshuni and T. lestoquardi compared to the healthy control group. Risk factors like age, sex, and zone were significantly associated with Theileria infection in sheep. The present investigation depicts the first comprehensive molecular report of ovine Theileria spp., which warrants further study to develop suitable control strategies against these haemoparasitic infections. [ABSTRACT FROM AUTHOR]

A new freshwater microalgal isolate, CCALA 1135, was characterized using a polyphasic approach (morphology, ultrastructure, fatty acid composition, 18S rRNA gene and rbcL analyses). Non-motile vegetative cells were spherical with thick, smooth cell walls lacking ornamentation, with multiple overlapping chloroplasts and sometimes more than one red globule in the cytoplasm. The nuclear and chloroplast envelopes formed a continuous membrane and there was no pyrenoid. These morphological and ultrastructural features indicated assignment to the class Eustigmatophyceae. The strain was, however, unique in its mode of reproduction: only zoospores were formed, but no autospores were observed (i.e. obligate zoospory, which is rare in the Eustigmatophyceae). The zoospores were relatively fragile and their morphology was similar to those of other members of the clade Goniochloridales (a clade name under the PhyloCode) that have been studied, being uniflagellate and lacking an eyespot. A very high proportion of polyunsaturated fatty acids (up to 57% of total fatty acids) was found, dominated by nutritionally valuable arachidonic and eicosapentaenoic acids, the latter being the most abundant FA (up to 35%) in the total profile. Phylogenetic analysis based on 18S rDNA and rbcL sequences confirmed that CCALA 1135 represents a new member of Goniochloridales clade IIc. Based on cellular morphology, ultrastructure and molecular data we propose this strain as a new species and new genus of the Eustigmatophyceae, Trebonskia zoosporica gen. et sp. nov. Our work is a step toward clarifying the taxonomy of a group of the Eustigmatophyceae with many unnamed strains awaiting characterization. A new genus and species of Eustigmatophyceae is described using a polyphasic approach. This isolate reproduces only by zoospores, a mode rare within Eustigmatophyceae. It contained a high proportion of nutritionally valuable polyunsaturated fatty acids. [ABSTRACT FROM AUTHOR]

The identity of Scolelepis squamata (O.F. Müller, 1806) (Spionidae) has long been under debate. For clarification of this problem a collection of Scolelepis specimens at the type locality of this species, the island of Helgoland (North Sea) and in particular the Helgoland Dunes, has been undertaken. Based on morphological and molecular studies the occurrence of only one Scolelepis species can be reported in the eulittoral zone. The specimens are in good accordance with the morphology of S. squamata. Based on these newly collected specimens S. squamata is redescribed and illustrated comprehensively, and, in addition, molecular information on several markers is provided. A neotype has been designated and deposited in the collection of the Zoological Museum at Hamburg University, Germany. Molecular phylogenetic analyses based on COI, 18S rRNA and 28S rRNA reveal little genetic diversity along the Atlantic coast from Helgoland to Portugal and thus support the occurrence of S. squamata in these coastal regions of the Eastern North Atlantic Ocean. Our results further indicate the presence of a distinct Scolelepis species in the Black Sea, which is closely related to S. squamata. Also, S. mesnili is reinstated as a valid species. Furthermore, it is shown that several earlier genetic studies had misidentified S. squamata specimens wrongly as S. foliosa or S. bonnieri, highlighting the need for the taxonomic redescription as well as for providing DNA barcodes from unambiguously identified specimens. [ABSTRACT FROM AUTHOR]

Over the last decade, our knowledge of the phylogenetic and taxonomic diversity of coralline algae has greatly progressed thanks to the use of DNA sequence data. Despite this, in some geographic regions the knowledge of coralline diversity is still incomplete, because it is entirely based on traditional morpho-anatomical grounds; Antarctica can certainly be included among these regions. During an investigation of the marine phototrophic biodiversity of the Ross Sea, a crustose coralline alga was collected from two sites in Tethys Bay. The alga formed thin crusts adherent to cobbles at ~20 m depth and showed morpho-anatomical features typical of the order Hapalidiales, family Hapalidiaceae (cell fusions, zonate tetrasporangia produced in multiporate conceptacles, and apical plugs). Molecular phylogenies based on the psbA, rbcL and 18S rRNA genes showed that this alga formed a lineage in the family Hapalidiaceae for which a formal assignment at genus level was not yet available. The only other known member of the lineage was a coralline from the Balleny Islands, named as Hapalidiaceae sp. ASG448A, for which psbA and 18S rRNA sequences were deposited in GenBank without identification at genus and species level. Based on our results, we describe this lineage as the new genus Tethysphytum Sciuto, Moschin & Moro, with the single species Tethysphytum antarcticum Sciuto, Moschin & Moro. At present, morpho-anatomical characters do not allow for the discrimination of Tethysphytum from other similar genera of Hapalidiaceae. The discovery of a new genus suggests that the diversity of coralline algae in Antarctica may have been underestimated and that molecular data will be essential for future taxonomic assessments of this group within this region. [ABSTRACT FROM AUTHOR]

During samplings aimed at isolating microalgal strains, a coccoid greyish-green alga was collected along the North Adriatic coasts (Mediterranean Sea, Italy) and grown in culture. The microalgal strain (named strain B1A) was then subjected to an integrative taxonomy approach in order to correctly identify it. Morphological and ultrastructural observations and phycobiliprotein content analysis were carried out, as well as molecular analyses based on the 18S rRNA, rbcL, psbA and plastid-encoded 23S rRNA genes. Phylogenetic placement and ultrastructural observations clearly indicated that strain B1A is a member of the red microalgal genus Dixoniella (Rhodellophyceae, Proteorhodophytina) and is distinct from the only species so far described for this taxon. Therefore, a new species was described to encompass the isolate from the North Adriatic Sea and another isolate from Japan (MF-G2), which was phylogenetically related to strain B1A: Dixoniella giordanoi sp. nov. [ABSTRACT FROM AUTHOR]

Morphological identification of the commonest Indian freshwater calanoid copepod Heliodiaptomus viduus has been facing a lot of controversies. To solve this problem, additional molecular support is needed. Hence, molecular analysis, along with morphological identification of the species using scanning electron microscopy (SEM) and optical microscopy, was carried out. The genetic distance between the intraspecific sequences in the 18SrRNA observed to be 0.000, while the interspecific distance within genus sequences varied from 0.000 to 0.002. Besides, it was noted that both the sequences (intraspecific) were present within a single clade of the phylogenetic trees with 100% bootstrap value. The genetic distance between the intraspecific sequences in the mtCOI observed to be 0.000, while the interspecific distance within genus sequences varied from 0.000 to 0.267 and lay in a separate clade in the phylogenetic tree from the within genus clade. Besides, it was noted that both the sequences (intraspecific) were present within a single clade of the phylogenetic tree with above 75% bootstrap value. Hence, the 18S rRNA (MH145356, MK457456) and mtCOI (MK621900) gene sequences of the present study are well supported the identification of H. viduus and it serves as the first molecular database besides providing morphological authentication (SEM images) of H.viduus. This combined analysis is envisioned to be helpful in selecting the ecologically and nutritionally important species for practical aquaculture [ABSTRACT FROM AUTHOR]

Phosphorous (P) that upholds life become unattainable as most of them become unavailable due to the formation of insoluble complexes with cations such as Ca2+, Al3+ and Fe3+ forming a complex calcium phosphate (Ca3(PO4)2), aluminum phosphate (AlPO) and ferrous phosphate (FePO) that results in the decrease of soluble P to a greater extent. There are several reports stating that several rhizospheric fungal species play an important role in solubilizing these insoluble phosphates into a soluble form by the excretion of enzymes like phosphatase, phytase enzymes, and organic acids. In view of this, so we have collected twenty fungal isolates having probable phosphate solubilizing efficiency from different regions of Lucknow, India. Their morphological and biochemical characteristics were tested. Among all, six efficient fungal isolates were further checked at molecular level by using 18S rRNA universal primers and by RAPD means. A dendrogram indicated 40-90% homology i.e., highest similarity was found in between species of Aspergillus flavus and A. biplanus with 33.8% similarity while minimum similarity was observed among A. flavus and Fusarium oxysporum. These findings suggest RAPD proves as, a reliable molecular tool that helps in strain specific discrimination. [ABSTRACT FROM AUTHOR]

Coccomyxa Schmidle (Trebouxiophyceae, Chlorophyta) is a genus of green microalgae that has worldwide distribution, with representatives found in a broad range of terrestrial and aquatic ecosystems. Members of this taxon can be free-living and/or associated with other organisms, establishing different types of relationships (e.g. parasitic, symbiotic). The most frequent organisms forming associations with Coccomyxa are fungi and marine animals, most importantly mussels. Moreover, there is a well-documented association between a Coccomyxa strain and Gingko biloba and some Coccomyxa-like microalgae have been found in the bark of other trees. Here we describe a green algal strain found in association with carnivorous plants of the genus Drosera L. The systematics of Coccomyxa based only on classical methods is problematic, due to the very simple morphology of the genus and its high phenotypic plasticity. Therefore, the microalga associated with Drosera plants was isolated, maintained in culture and subjected to an integrative taxonomy approach, including morphological, ultrastructural and molecular analyses, along with ecological considerations. Phylogenetic reconstructions based on the rbcL and 18S rRNA genes and molecular data obtained from the ITS2 spacer, including both sequence and secondary structure analyses, showed that the investigated microorganism belonged to a lineage distinct from those sequenced so far. An accurate taxonomic comparison between the microalga associated with Drosera and each of the species already described for the genus Coccomyxa was also carried out, considering morphology, ultrastructure and ecology. The results as a whole allowed us to erect a new species inside the genus Coccomyxa: Coccomyxa cimbrica K.Sciuto, B.Baldan & I.Moro [ABSTRACT FROM AUTHOR]

Desmodesmus maximus (West & G.S.West) Hegewald, D. perforatus (Lemmermann) E.Hegewald and D. tropicus (W.B.Crow) E.Hegewald form the series Maximi within the genus Desmodesmus. Desmodesmus tropicus is a rare species although it is widely distributed in tropical regions including South-East Asia, South America and the USA. It is less common in temperate fresh waters, known only from Ukraine. In this study, we report for the first time its presence in the Danube Delta (Puiu Lake), Romania. The morphology and molecular phylogeny of two newly isolated strains were studied in relation to other strains of the genus Desmodesmus, series Maximi. Cell wall structures (rosettes, spines, tubes, honeycomb-shaped mesh with hexagonal units) which are important in the taxonomy of these algae were investigated by light-, scanning- and transmission electron microscopy. The phylogenetic position of the strains in the Algae and Cyanobacteria Culture Collection of the Institute of Biological Research was assessed using 18S rDNA sequences, ITS2 primary and secondary structures and by analysis of Compensatory Base Changes. Morphological traits and measurements of cells, coenobia and spines matched the description of D. tropicus, although some differences from the established morphological key (ridge-like structures resembling fine ribs) were also noticed. Identification as D. tropicus var. longiclathratus (Tell) Jeon & Hegewald was based on the presence of inner spines on four-celled and especially on eight-celled coenobia. The ITS2 sequence and secondary structure phylogeny supported the assignment of both AICB strains to D. tropicus, with no divergence from other D. tropicus sequences to support the identification of var. longiclathratus. Nevertheless, the morphological measurements and the ITS2 primary and secondary structure data indicated two distinct subclusters within D. tropicus, and a new possible taxon within the series Maximi. [ABSTRACT FROM AUTHOR]

The parasites from buffaloes in Guizhou province, southwest China, were suspected to be sarcocysts through morphologic observation. 18S rRNA and the subunit I of cytochrome oxidase (cox1) sequences were amplified, then implemented by phylogenetic analysis. Phylogenetic analyses of 18S rRNA and cox1 genes both indicated the low degree of genetic diversity among the isolated sequences and other sequences of Sarcocystis fusiformis. The result shows that the sarcocysts from these buffaloes in Guizhou province S. fusiformis. This study is the first molecular characterization of S. fusiformis from Chinese buffaloes that used two genetic markers (18S rRNA and cox1 sequences) in China. [ABSTRACT FROM AUTHOR]

In this article we describe a newParamacrobiotusspecies of theareolatusgroup by means of integrative taxonomy. Together with the detailed morphological and morphometric data (obtained from light and scanning electron microscopy) we also provide DNA sequences of four universal molecular markers used in tardigrade taxonomy (three nDNA fragments: 18S rRNA, 28S rRNA, ITS-2, and one mtDNA fragment: COI). The animals ofParamacrobiotus lachowskaesp. nov. are similar to several species of theareolatuscomplex and the eggshell ornamentation is similar to that of two species of therichtersigroup. Therefore, the new species can be easily distinguished from theareolatusgroup species by egg morphology (dome-like, wrinkled processes with long flexible spines/filaments covered by fine short hairs) and from species of therichtersicomplex by the absence of the microplacoid.Paramacrobiotus lachowskaesp. nov. is the 43rd species reported from Colombia and fifthParamacrobiotusspecies from this South American country. http://zoobank.org/urn:lsid:zoobank.org:pub:FEDC11D3-DCCF-4699-A704-CE6DEA1CDED4 [ABSTRACT FROM AUTHOR]

The early detection and correct identification of polydorid polychaete species is essential as they are often encountered as invasive alien pests in aquaculture facilities or the intertidal where they may modify the ecosystem. Accurate identification is, however, often hampered by high levels of morphological similarity among species. This taxon will therefore benefit from the development of a library of sequences, such as COI barcodes, to aid identification. However, the universal primers for the cytochromecoxidase I (COI) DNA barcoding marker has failed to consistently amplify this gene for polydorids, greatly hampering the development of such a library. We describe the development of unique PCR primers for the COI gene that work across four genera and nine species of polydorids. We also compared its efficacy with sequence data for mitochondrial cytochromeband nuclear 18S rRNA, and a concatenated dataset consisting of all three markers. The nuclear 18S rRNA gene showed the least variation both intra- (0.0–1.2%) and interspecifically (0.6–4.3%), and was the most accurate for species identifications among the three markers. Although COI was characterised by higher intraspecific variation compared with Cytb(0.0–14.5% and 0.0–4.2%, respectively), Cytbshowed considerably higher levels of interspecific variation (16.6–30.2%) compared with COI (2.2–20.7%). Of the two mitochondrial DNA markers, COI was actually less accurate for species identifications, having suggested two species withinBoccardia pseudonatrixthat was not supported by the other markers. Overall, the concatenated dataset yielded the most consistent intraspecific groupings, suggesting that this is the most accurate means of identifying polydorids using DNA sequence data. Thus, there may not be a quick and easy way to identify these species accurately using only molecular data. [ABSTRACT FROM PUBLISHER]

Using laboratory cultures, we have documented the life cycle ofAnisolpidium ectocarpii, a pathogen ofEctocarpusand other filamentous brown algae, and presented preliminary observations onAnisolpidium rosenvingei, a pathogen ofPylaiella littoralis. Consistent with earlier reports, the zoospores of both species have a single anterior flagellum, which justified the placement ofAnisolpidiumamongst the Hyphochytriales (Hyphochytridiomycota). We have also shown thatA. ectocarpiican complete its infection cycle in a broad selection of species from various brown algal orders, whereasA. rosenvingeiseemingly exhibits a strict specificity for unilocular sporangia ofP. littoralis. Unexpectedly, nuclear (18S rRNA) and mitochondrial (cox1,cox2) markers regroupA. ectocarpiiandA. rosenvingei, into a hitherto unrecognized monophyletic clade within the oomycetes (Oomycota), most closely related to the Olpidiopsidales. TheAnisolpidiumgenus is therefore entirely distinct from the Hyphochytridiomycota and represents the first confirmed instance of an anteriorly uniciliate oomycete. Finally, we suggest that a valid morphological criterion to separate true hyphochytrids from oomycetes is the timing of zoospore cleavage. Given the evidence, we propose to transfer the Anisolpidiales from the Hyphochytriales to the Oomycetes. [ABSTRACT FROM PUBLISHER]

Mesocristais a Holarctic tardigrade genus currently classified within the subfamily Itaquasconinae (Eutardigrada: Parachela: Hypsibiidae). The position of the genus has been so far inferred solely on the basis of light microscopy observations. Here, we present the first-ever scanning electron microscopy images of a dissected bucco-pharyngeal apparatus and DNA sequences forMesocristafrom Spitsbergen, mainland Norway and Poland. The new data allowed an integrative redescription of the nominalM. spitzbergensisfrom thelocus typicusand uncovered a new species,M. revelata, from the European localities. The two species differ phenotypically by the oral cavity armature and claw morphology as well as by a number of morphometric traits, and they are also distinct genetically in all sequenced DNA markers, three nuclear (18S rRNA, 28S rRNA, ITS-2) and one mitochondrial (COI). Both molecular and morphometric data presented in this paper suggest that previous records ofM. spitzbergensisshould be treated with caution, since most probably some of them signify differentMesocristaspecies. Our phylogenetic analysis confirmed thatMesocristais indeed a member of the Itaquasconinae. We also found that the most closely related, among genera for which there are molecular data available, isAdropion, from whichMesocristadiffers by the shape of the apophyses for insertion of stylet muscles and the width of the bucco-pharyngeal tube. Finally, we advocate thatDiphascon marcusi, a rare species hypothesised to represent eitherMesocristaorAdropion, should be transferred to the latter genus and that the species should be redescribed to confirm its validity and systematic position. http://zoobank.org/urn:lsid:zoobank.org:pub:6515D58D-8469-4854-8687-177232112BDA [ABSTRACT FROM PUBLISHER]

Two new species of the generaHaplophallonellaSerban and Coineau, 1975a andRacovitzaibathynellaSerban and Coineau, 1994 are described from Africa. This is the first record of the members of the order Bathynellacea Chappuis, 1915 from Chad. Representatives of the genusHaplophallonellahave hitherto been known only from the Ivory Coast type locality, andRacovitzaibathynellaonly from South Africa. Representatives ofHaplophallonella irenaesp. nov. andRacovitzaibathynella dumontisp. nov. have a unique combination of morphological characters.Haplophallonella irenaesp. nov. includes: seven-segmented antennule; five-segmented antenna; labrum with special morphology, clefted; mandible without proximal tooth; no epipodite on thoracopod I; bidentated exopod of male thoracopod VIII; triangular female thoracopod VIII; presence of basal seta on exopod of uropod and three plumose setae on endopod of uropod.Racovitzaibathynella dumontisp. nov. includes: seven-segmented antennule; five-segmented antenna with sexual dimorphism and without seta on segment two; no epipodite on thoracopods I and II; outer lobe of male thoracopod VIII almost square, does not cover the posterior part of dentate lobe; the posterior lobe covers one part of dentate lobe, exopod with pointed distal end, basipod with distal end bilobed and endopod as two unequal smooth setae; almost triangular female thoracopod VIII and five to seven similar spines on sympod of uropod. Sequences of the 18S ribosomal RNA (rRNA) gene from 12 specimens ofRacovitzaibathynella dumontisp. nov. and two specimens ofHaplophallonella irenaesp. nov. were obtained and analysed to complete the morphological description with molecular data. We have used these data to make a preliminary phylogenetic analysis with all genera of the world for those whose sequences are available (18S). Phylogenetic reconstruction of the Parabathynellidae family shows how the new African species remain clearly separated from European and Australian genus groups. http://zoobank.org/urn:lsid:zoobank.org:pub:4E7EB201-8922-403C-9546-AF8E9A409776 [ABSTRACT FROM PUBLISHER]

Sea ice is a large and diverse ecosystem contributing significantly to primary production in ice-covered regions. In the Arctic Ocean, sea ice consists of mixed multi-year ice (MYI), often several metres thick, and thinner first-year ice (FYI). Current global warming is most severe in Arctic regions; as a consequence, summer sea ice cover is decreasing and MYI is disappearing at an alarming rate. Despite its apparent hostility, sea ice is inhabited by a diverse microbial community of bacteria and protists, many of which are photosynthetic. Here we present an assessment of eukaryotic biodiversity in MYI and FYI from the central Arctic Ocean using high-throughput 454 sequencing of 18S rRNA and rDNA amplicons. We compared the rDNA-based ‘total’ biodiversity with the ‘active’ biodiversity from rRNA amplicons and found differences between them including an over-representation of Ciliophora, Bicosoecida and Bacillariophyceae operational taxonomic units (OTUs) in the active part of the community. Differences between the two libraries are more pronounced at the lower taxonomic level: certain genera, such asMelosira, are more abundant in the rRNA library, indicating activity of these genera. Furthermore, we found that one FYI station showed a higher activity of potential grazers which was probably due to the advanced stage of melt evident by higher ice temperatures and highly porous ice compared with the other stations. [ABSTRACT FROM AUTHOR]

A new widespread myxomycete species, Physarum pseudonotabile, inhabiting the arid regions of the Eurasia, South and North America is described and illustrated. Tentatively assigned to Ph. notabile T. Macbr., a phylogeny based on the small ribosomal subunit (SSU) and elongation factor 1 alpha (EFla) genes placed the new species in a clade far from Ph. notabile. Ph. pseudonotabile was found to be frequent in surveys based on the moist chamber culture technique with samples of litter, bark and herbivore dung collected in dry steppe and deserts of the Caspian lowland (Russia), Kazakhstan, Mongolia, China, Spain, Argentina and USA. The main morphological difference between Ph. pseudonotabile and Ph. notabile lies in spore ornamentation. Spores of the former species display irregularly distributed verrucae, whereas the latter species possesses spores with dense and regularly arranged spinulae. In addition, the ecological preferences of the two species differ. Ph. pseudonotabile inhabits the bark of living plants and ground litter in arid regions, whereas Ph. notabile is found on coarse woody debris in boreal and temperate forests. Although the new species appears to be closest to Ph. notabile morphologically, the phylogenetic analysis reveals Ph. pusillum and Ph. nivale as the closest relatives. In addition, the molecular investigations revealed a considerable amount of hidden diversity within species of Physarum with gray lime flakes. Currently we have only sufficient material to assess the morphological variation of Ph. pseudonotabile but expect that more taxa within this clade may emerge within studies combining morphological and molecular analyses. [ABSTRACT FROM AUTHOR]

Strain QD001, previously identified as Chlorella, was examined using molecular phylogenetic analysis (nuclear-encoded 18S rRNA, ITS, rbch), ITS2 secondary structure, light and electron microscopy, high-performance liquid chromatography pigment analysis, and fatty acid analysis. The strain was shown to be phylogenetically distinct from all described taxa, and the strain was named Nannochloropsis oceanica var. sinensis var. nov. DNA sequences from the new variety were very similar to GenBank sequences for N. maritima nomen nudum [ABSTRACT FROM AUTHOR]

A new genus and species of Kinorhyncha,Franciscideres kalenesosgen. et sp. nov., is described from tidal and subtidal sandy habitats in Brazil. The new genus and species is characterized by an extremely flexible trunk without pachycycli that appears perfectly circular in cross-section, segments 1, 2 and 11 consisting of closed rings and 3 to 10 of single, bent plates with midventral articulations, a neck without placids that resembles an additional segment, densely packed scale-like, cuticular hairs, and a terminal segment with a middorsal spine and two sets of lateral terminal spines, but no midterminal spine. Phylogenetic analyses of 18S rRNA ofFranciscideres kalenesosgen. et sp. nov. and 47 other kinorhynch ingroup taxa suggest that the new genus is a basal homalorhagid, whereas comparison of morphological characters indicates affinities between the new genus and the peculiar cyclorhagidCateria. http://zoobank.org/urn:lsid:zoobank.org:pub:64E29D97-DE1D-4511-8683-C969DD2EED43 [ABSTRACT FROM AUTHOR]

Biofouling in water treatment processes represents one of the most frequent causes of plant performance decline. Investigation of clogged membranes (reverse osmosis membranes, microfiltration membranes and ultrafiltration membranes) is generally performed on fresh membranes. In the present study, a multidisciplinary autopsy of a reverse osmosis membrane (ROM) was conducted. The membrane, which was used in sulfate-rich river water purification for drinking purposes, had become inoperative after 6 months because of biofouling and was later stored for 18 months in dry conditions before analysis. SSU rRNA gene library construction, clone sequencing, T-RFLP, light microscope, and scanning electron microscope (SEM) observations were used to identify the microorganisms present on the membrane and possibly responsible for biofouling at the time of removal. The microorganisms were mainly represented by bacteria belonging to the phylum Actinobacteria and by a single protozoan species belonging to the Lobosea group. The microbiological analysis was interpreted in the context of the treatment plant operations to hypothesize as to the possible mechanisms used by microorganisms to enter the plant and colonize the ROM surface. [ABSTRACT FROM PUBLISHER]

The endophytic fungal populations of different tissues of Taxus baccata grown at high altitudes in West Bengal, India were explored. These isolated fungal populations represented different genera, which were screened for taxol production using immunoassay technique. The culture AAT-TS-41 that produced taxol was identified as Gliocladium sp. based on its cultural, morphological characteristics, internal transcribed spacer, and 18S rRNA sequence analysis. Kinetics of taxol production as a function of culture growth were investigated [ABSTRACT FROM AUTHOR]

Molecular analyses of the 18S ribosomal RNA gene and the psbA gene of Membranella nitens and Smithora naiadum from Pacific North America show that both taxa are genetically identical. The variability of the characters distinguishing these two genera has not been well documented. The generic name Smithora Hollenberg has priority over Membranella Hollenberg & Abbott; therefore, M. nitens is placed in taxonomic synonymy as S. naiadum. [ABSTRACT FROM AUTHOR]

In this study the authors examined the sequences of the ribosomal 18S rRNA of Drosophila and man and 16 mRNA sequences coding for different members of the family of the mammalian formyl peptide receptors (FPRs). The positions in the sequences of all ≥7-base oligonucleotide identities occurring in at least one of the 18S rRNAs and one of the FPR mRNAs were recorded. On the basis of the positional data, the Drosophila 18S-FPR and human 18S-FPR distances (in nucleotides) were determined for each identity. Then the actual frequency distribution of the distances (grouped into 200-unit classes) was derived. The theoretical frequency distribution of distances was also calculated under the assumption of non-relatedness between the 18S and FPR sequences. Comparison between the theoretical and the actual distributions showed that at class -500 (range from - 400 to - 600) of the 18S-FPR values the actual frequency was significantly (p < 0.01) higher than the theoretical frequency, in both Drosophila and man, suggesting that the second section of the FPR genes (approximately from nucleotide 400 to the end of sequence) may be structurally related to the first section of the ribosomal 18S genes (approximately nucelotides 1-650). The authors advance the hypothesis that the two families of genes may have used common ancestral raw genetic materials in the building of the extant sequences. [ABSTRACT FROM AUTHOR]

Comparisons between the sequences of insect and vertebrate 18S rRNAs and the sequences of mammalian formyl peptide and some vertebrate chemokine receptor mRNAs demonstrated non-random structural similarities between these two groups of RNAs. It has been proposed that sections of the more ancient and conserved rRNA genes could have participated in the building of these more recent genes involved in immune responses. Here we analyze the sequence architecture of the 18S rRNA in insects (Drosophila simulans) and vertebrates (man), in terms of similarities between selected segments within the individual molecules. The insect and vertebrate 18S rRNAs are basically similar, but show specific insertions/deletions and base changes. In spite of these differences, in both sequences a significantly higher-than-expected (by random occurrence) number of 7-or-more-base oligonucleotide repeats was observed between segments roughly corresponding to nt 350-1050 and nt 1150-1850, with mutual between-repeats distances comprised in the range 700-900 nt. Based on this result we performed a multialignment of segments 317-1035 of Drosophila, 360-1005 of man, 1096-1864 of Drosophila, and 1066-1736 of man, the first two segments covering the region of first occurrence of the repeats and the last two the region of recurrences. At both ends of these segments the four sequences could be aligned with relatively minor gaps and the number of base identities in all four sequences was significantly higher than expected by random coincidences. These results support the hypothesis that an ancestral gene structure, composed of a chain of about 700 nt, duplicated to form a two-unit tandem repeat which still represents the most substantial part of the 18S rRNA molecule in extant insects and vertebrates. [ABSTRACT FROM AUTHOR]

We sequenced the nuclear 18S ribosomal RNA (rRNA) genes of 23 strains of the genus Chlorogonium, to re-evaluate the status of C. euchlorum, C. elongatum, and C. capillatum, which had previously been classified using morphological criteria and gene sequence data from the large subunit of chloroplast Rubisco (rbcL). Although C. capillatum CCAP 12/2A and SAG 12-2a had been considered parts of the same strain of C. capillatum, we identified SAG 12-2a as C. euchlorum. We observed no intraspecific variation of the 18S rRNA gene sequence within C. euchlorum and C. capillatum. Some variations in 18S rRNA gene sequences were observed among strains of C. elongatum, but these sequences constituted a monophyletic group. Thus, taxonomic delimitation using chloroplast rbcL gene sequences produced monophyletic groupings of Chlorogonium species, which are supported by nuclear gene sequence analysis. [ABSTRACT FROM AUTHOR]

Pulvinus veneticus gen. et sp. nov. is a small (< 500 μm in diameter), cushion shaped epiphyte isolated into culture from Caloglossa vieillardii that was collected from Vanuatu. Molecular analysis places Pulvinus veneticus in the Compsopogonales. It has prostrate-adherent filaments or free filaments with one or more discoid to spiral bluish-green plastids without pyrenoids per cell. Pulvinus is euryhaline, growing and reproducing in salinities of 2 to 30 practical salinity units (psu). Monosporangia are formed successively by terminal branch cells or when a sector of a thallus gelatinises, releasing masses of spores. Monospores are round (6–10 μm diameter) and glide at speeds up to 4.5 μm s-1. Some monospores have an extracellular polysaccharide tail and move more slowly, 0.25 to 1.0 μm s-1. Spores avoid contact with other objects and do not require substrate contact during movement. The ultrastructure of Pulvinus is very similar to that of Compsopogon and Boldia in that the cis-region of Golgi bodies is not associated with a mitochondrion and plastids have a peripheral thylakoid. No pit connections occur between derivative cells. [ABSTRACT FROM AUTHOR]

The gene encoding the 18S rRNA is an ancient molecule and its basic structure has been highly conserved from fish to mammals. Recently, we compared the nucleotide sequences of the human 18S rRNA and the human formyl peptide receptor 1 mRNA and concluded that selected segments of the two sequences exhibit similarities that are unlikely to be due simply to chance. Other data suggest the existence of nonrandom similarities between the 18S rRNA and the chemokine CXC receptor 4 mRNA. Therefore we advance the hypothesis that some groups of genes encoding 7-transmembrane G-coupled receptors of immunological interest may be evolutionarily related to the 18S gene. In this article we analyze the base-sequence architecture of the human 18S rRNA in terms of similarities between selected segments within the molecule. The method of study was based on the recording of the positions of 7- to 11-base oligonucleotide repeats, followed by a probabilistic analysis of the random occurrence of the repeats. Herein we show that most of the 18S rRNA molecule appears to be composed of two long tandem quasirepeats. We hypothesize that an ancestral gene structure composed of a chain of about 850 nucleotides duplicated to form a two-unit tandem repeat. Then the two units diverged as a consequence of independent nucleotide mutations, deletions, and insertions, but still retaining recognizable homologies. In addition, further nonduplicated shorter segments were added to build up the complete sequence. [ABSTRACT FROM AUTHOR]

Selected segments of the nucleotide sequences of the human 18S rRNA and the human formyl peptide receptor 1 mRNA exhibit structural similarities that are unlikely to be due simply to chance. Herein we analyze the structural similarities between the human 18S rRNA gene and the vertebrate chemokine CXC receptor 4 (CXCR4) gene that encodes a class A (rhodopsin-like) seven-transmembrane G-protein coupled receptor belonging to the same superfamily of formyl peptide receptors. The method of study was based on the recording of the positions of the 7-or-more-base oligonucleotide identities encountered in the 18S and CXCR4 genes and the construction of scatter-plots (abscissa-18S; ordinate-CXCR4) displaying the identity points positions. Analysis of the distribution of distances between identity points (abscissa-ordinate in the scatter-plot) demonstrated distinct peaks of frequency around 1200. Series of identities arranged near diagonal lines at 45° in the scatter-plot (quasialignments) were evaluated for their probabilistic level of random occurrence. Results of this analysis demonstrated nonrandom quasialignments between (i) a 900-nt ca. section of the human CXCR4 intron that immediately precedes almost the whole of the coding sequence and the 18S gene from nt 125 to 1025 ca.; and (ii) a 425-nt ca. section of the CXCR4 vertebrate genes, corresponding to nt 137–560 of the coding sequence, and the 18S gene from nt 1300 to 1730 ca. In both instances significant quasialignments are evidenced when CXCR4 nt sequences are shifted to the right by about 1200 nt with respect to the 18S nt sequence, as confirmed by analysis of the abscissa - ordinate differences. Taken together, these results indicate that, at least in humans, a continuous nonrandom quasialignment extends for some 1600 nt, from the second part of the (single) intron to the first part of the coding sequence. We hypothesize that the relatively more recent CXCR4 vertebrate gene might be evolutionarily related to the more ancient and highly conserved 18S gene. [ABSTRACT FROM AUTHOR]

Over the past decade molecular sequence data and phylogenetic analyses have provided strong evidence that the order Bangiales is monophyletic, but that Porphyra and Bangia as currently understood are not. Previous research on the Bangiales has focused primarily on taxa from the North Pacific and North Atlantic. Recent exploration of Bangiales diversity in other regions, particularly the southern hemisphere, has revealed deep divergences in the order in phylogenetic analyses employing the slowly evolving 18S rRNA gene. The presence of high diversity in New Zealand raises the prospect that the southern hemisphere, and particularly eastern Gondwana, is not only a centre of diversity but a centre of origin for the Bangiales. Although the need for new generic concepts within this order is clear, it is our conclusion that approaches to revising the Bangiales based solely on regional approaches will not succeed: the completion of a modern and robust taxonomic revision of this order requires a global collaborative effort. Enhanced taxon sampling and verifiable application of names, based on vouchered specimens, will be essential for this to be achieved. The determination of phylogenetic relationships in the Bangiales has implications for the quantification of biodiversity. The number of taxa in the evolutionarily diverse Bangiales has been significantly underestimated, and the diversity in this group has been obscured by the recognition of only two genera. Based on the analyses completed to date, in a revised Bangiales there will be at least 10 genera, 5 of which are currently recognised (Bangia, Dione, Minerva, Pseudohangia and Porphyra), as well as further genera yet to be circumscribed. The majority of species currently placed in Porphyra, including species of commercial value, will not remain in Porphyra sensu stricto. [ABSTRACT FROM AUTHOR]

Ligation of N-formyl-methionyl-leucyl-phenylalanine (fMLP) to its specific cell surface receptors triggers different cascades of biochemical events, eventually leading to cellular activation. The formyl peptide receptors (FPRs) are members of the seven-transmembrane, G-protein coupled receptors superfamily, expressed at high levels on polymorphonuclear and mononuclear phagocytes. The main responses elicited upon ligation of formylated peptides, referred to as cellular activation, are those of morphological polarization, locomotion, production of reactive-oxygen species and release of proteolytic enzymes. FPRs have in recent years been shown to be expressed also in several non myelocytic populations, suggesting other unidentified functions for this receptor family, independent of the inflammatory response. Finally, a number of ligands acting as exogenous or host-derived agonists for FPRs, as well as ligands acting as FPRs antagonists, have been described, indicating that these receptors may be differentially modulated by distinct molecules. [ABSTRACT FROM AUTHOR]

A method to quantify induction of vitellogenin (Vtg) mRNA in adult male mosquitofish was developed. Male mosquitofish were exposed to 0, 1, 20 and 250 ng l -1 17β-oestradiol (E 2 ) for 4 and 8 days in static exposures, and liver Vtg mRNA and 18S rRNA expression were quantified in duplex RT-PCR. Liver 18S rRNA expression was very consistent among individuals, and there was a highly significant increase in Vtg mRNA expression after exposure of mosquitofish for just 4 days at 250 ng l -1 E 2 . Lower doses did not induce Vtg mRNA expression even at 4 or 8 days. This method could be used as a rapid test to detect exposure of mosquitofish to oestrogenic chemicals. Further work is needed to determine if increased Vtg mRNA levels in male mosquitofish induce Vtg synthesis, and to determine the usefulness of the method in field sampling. [ABSTRACT FROM AUTHOR]

Formyl peptides released by some bacteria are powerful chemoattractants and activators of mammalian granulocytes and monocytes, acting through 7-transmembrane specific formyl peptide receptors (FPRs). Three distinct segments of the formyl peptide receptor 1 (FPR1) mRNA of Man share probabilistically significant homologies with segments of the 18S rRNA which are highly conserved from Drosophila to Man. Overall, the three segments cover ≈ 24% that of the 18S rRNA sequence and ≈ 36% of the FPR1 sequence. The three segments are, however, arranged in different orders in the 18S rRNAs and in the FPR1 mRNA, the segment appearing in the first location in the 18S rRNAs is located at the end of the FPR1 mRNA sequence. The hypothesis is advanced that the three “conserved” segments either derive from an ancestral gene that is the forerunner of both the ribosomal 18S genes and the FPR genes or that at some stage of evolution the FPR genes derived, at least in part, from the more ancient ribosomal 18S genes. The extant 18S rRNA sequences exhibit obvious signs of a number of breaks that occurred during evolution, especially in the transition from insects to vertebrates. Some of these events may have resulted in differential rearrangements of segments in the groups of FPR genes and ribosomal 18S genes. [ABSTRACT FROM AUTHOR]

A group I intron of 418 base pairs in the Monilinia fructicola ribosomal small-subunit sequence was characterized. The absence of such an intron in M. laxa and M. fructigena led to a PCR test for M. fructicola identification based on the presence of this intron. The failure to amplify a PCR fragment for some isolates of M. fructicola recently lead to speculation that the intron might not be present always in M. fructicola. In this study, we analyzed 13 isolates of M. fructicola and found that the intron was absent in four isolates and we determined from sequence analysis that there are several nucleotide variations that allow the M. fructicola ribosomal SSU intron to be grouped into 6 polymorphic types. [ABSTRACT FROM AUTHOR]

Purpose. GAPDH, β-actin, HPRT and 18S rRNA are constitutively expressed in all mammalian cells. In accordance with the nature of invariant control, these genes have been used to standardize genes of interest in expression studies. Recent studies have suggested that GAPDH, β-actin and HPRT in special situations may come under temporary regulatory control, but that 18S rRNA may be more likely to remain constitutive. However, little is known about the quantitative expression of these genes in fibroblasts and in particular during early postnatal development, a time of rapid changes in cell metabolism. In this study we have examined the differential expression of these genes in association with scleral development from an early postnatal age up to young adult status. Methods. GAPDH, β-actin, HPRT, and 18S rRNA gene expression were analyzed in the rabbit sclera from 1 day to 8 weeks postnatally by real-time, comparative PCR. Results. Real-time PCR analysis showed that the expression levels of GAPDH, β-actin, and HPRT were higher in the first postnatal week and then declined. However, from 2 to 8 weeks, the mRNA levels of these three genes underwent significant variations (P < 0.01) in their levels of expression. In contrast, the expression level of 18S rRNA showed no significant variation (P ≥ 0.5) over this time period. Conclusions.. The present study shows that GAPDH, β actin and HPRT gene were differentially expressed in early postnatal scleral development. It also suggests that these gene products could be implicated in the developmental process and have a crucial role in the early postnatal period. This study demonstrates that 18S rRNA may be preferable to normalize genes of interest in studies of early development. [ABSTRACT FROM AUTHOR]