D1 Sequence Research Articles

Probiotic yeast characterization and fungal amplicon metagenomics analysis of fermented bamboo shoot products from Arunachal Pradesh, northeast India

This study investigates the diverse fungal community and their probiotic functions present in ethnic fermented bamboo shoots of Arunachal Pradesh. Among 95 yeast isolates, 13 demonstrated notable probiotic attributes. These included growth at pH 3, bile tolerance, autoaggregation, co-aggregation, hydrophobicity, lysozyme tolerance and antimicrobial activity. Confirmation of some of the probiotic properties through specific primers enabled the detection of genes associated with acid and bile tolerance, antimicrobial activity, and adhesion. Probiotic yeasts were finally identified based on D1 and D2 sequences of large ribosomal subunit as Meyerozyma guilliermondii (BEP1, KGM1_3, NHR3), Meyerozyma caribbica (GEP7), Candida orthopsilopsis (ES1_2, EB1_2, EEGM2_4, GEP2, NEK9), Candida parasilopsis (HD1_1), Pichia kudriavzevii (NHR12), Pichia fermentans (BEP2), and Saccharomyces cerevisiae (NEP2). Fungal amplicon sequencing highlighted the predominance of Ascomycetes, particularly Pestalotiopsis and Penicillium genera. In this study we have perfomed a culture dependent isolation and probiotic study of yeasts and culture independent analysis of the fungal community present during the fermentation of bamboo shoots of Arunachal Pradesh which provides information about the beneficial properties of bamboo shoots as the reservoir of probiotic microorganisms.

Fungi associated with the Asian citrus psyllid, Diaphorina citri Kuwayama, in northeastern Mexico

ABSTRACT Diaphorina citri Kuwayama (Asian citrus psyllid, ACP) is a devastating pest due to transmission of Liberibacter spp. to citrus plants. We identified presumed entomopathogenic fungi (EF) naturally associated with field-collected adult ACP, both killed (mycosed) and alive, at 14 field sites in the Gulf Coastal Plain of NE Mexico. On dead ACP, five species of EF (Hypocreales) were observed: Hirsutella citriformis Speare (Ophiocordycipitaceae), Cordyceps javanica (Frieder. & Bally) Kepler, Shrestha & Spatafora, Beauveria cf. bassiana (Bals.) Vuill., and Akanthomyces cf. lecanii (Cordycipitaceae); also, Niveomyces J.P.M. Araújo & C. de Bekker (Cordycipitaceae), a hyperparasite of Ophiocordycipitaceae, in this case H. citriformis. The most prevalent fungi on field ACP were H. citriformis and C. javanica, on dead and on live, incubated insects, respectively. In laboratory bioassays, C. javanica and H. citriformis conidia from cultures killed >60% of ACP adults. H. citriformis, C. javanica, and A. lecanii killed >60% nymphs. Niveomyces was observed only growing on H. citriformis fructifications on field-killed ACP; it was absent from live incubated insects, indicating Niveomyces is a mycoparasite on H. citriformis. Niveomyces cultures (ARSEF 10230) on agar grew as a Pleurodesmospora synanamorph; its LSU rRNA region D1–D2 sequences (Genbank OM780101) were 99.81% identical to Niveomyces sequences. Conidia from Niveomyces cultures were entomopathogenic on ACP nymphs and adults. These are the first reports of Niveomyces associated with H. citriformis; of the in vitro dimorphic growth (synanamorphs) Niveomyces/Pleurodesmospora; and of experimental verification of entomopathogenicity of Niveomyces. Understanding the interactions of these fungi will support sustainable ACP management.

Exceptional Quantum Efficiency Powers Biomass Production in Halotolerant Algae Picochlorum sp.

The green algal genus Picochlorum is of biotechnological interest because of its robust response to multiple environmental stresses. We compared the metabolic performance of P. SE3 and P. oklahomense to diverse microbial phototrophs and observed exceptional performance of photosystem II (PSII) in light energy conversion in both Picochlorum species. The quantum yield (QY) for O2 evolution is the highest of any phototroph yet observed, 32% (20%) by P. SE3 (P. okl) when normalized to total PSII subunit PsbA (D1) protein, and 80% (75%) normalized per active PSII, respectively. Three factors contribute: (1) an efficient water oxidizing complex (WOC) with the fewest photochemical misses of any organism; (2) faster reoxidation of reduced (PQH2)B in P. SE3 than in P. okl. (period-2 Fourier amplitude); and (3) rapid reoxidation of the plastoquinol pool by downstream electron carriers (Cyt b6f/PETC) that regenerates PQ faster in P. SE3. This performance gain is achieved without significant residue changes around the QB site and thus points to a pull mechanism involving faster PQH2 reoxidation by Cyt b6f/PETC that offsets charge recombination. This high flux in P. SE3 may be explained by genomically encoded plastoquinol terminal oxidases 1 and 2, whereas P. oklahomense has neither. Our results suggest two distinct types of PSII centers exist, one specializing in linear electron flow and the other in PSII-cyclic electron flow. Several amino acids within D1 differ from those in the low-light-descended D1 sequences conserved in Viridiplantae, and more closely match those in cyanobacterial high-light D1 isoforms, including changes near tyrosine Yz and a water/proton channel near the WOC. These residue changes may contribute to the exceptional performance of Picochlorum at high-light intensities by increasing the water oxidation efficiency and the electron/proton flux through the PSII acceptors (QAQB).

Heterotrophic nitrifying bacteria from activated sludge in DHS reactor for ammonium removal of natural rubber processing wastewater treatment

Two heterotrophic nitrifying bacterial strains, D2 and D7 were isolated from an activated sludge of sponges in a laboratory-scale downflow hanging sponge reactor. Both strains exhibited efficient ammonium removal ability over a wide range of ammonium loads. At the initial concentration of 100 mg/L, NH4+-N was completely degraded within 20 h by both strains. When the initial concentration was increased to 200 mg/L, the NH4+-N removal efficiency was 99.6 % within 20 h by the strain D2 and 61.3 % by the strain D7. In natural rubber processing wastewater, the ammonium removal efficiencies of strain D2 and D7 were 38 % and 99 % with the initial N-NH4+ concentration of 280 and 380 mg/L after 88 h, respectively. The 16S rRNA gene sequence of D2 and D7 showed the highest similarity to the Pseudomonas aeruginosa and Glutamicibacter nicotianae, respectively. This is the first report to demonstrate the ability to remove ammonium in NRPW by ​heterotrophic nitrifying bacteria isolated from activated sludge in DHS reactor.

Co-pulping of Trewia nudiflora and Trema orientalis

Trewia nudiflora, a fast-growing species, was evaluated as a pulpwood. The α-cellulose content of this species was 40.4% with a Klason lignin of 21.5%. It was characterized by shorter fibers with a thin cell wall. The pulp yield was 40% with a kappa number of 16 at the conditions of 18% active alkali charge and 30% sulfidity for 2 h cooking at 170°C. T. nudiflora was similar to Trema orientalis in anatomical, morphological, and chemical composition; therefore, mixed chips at a 50:50 mixture ratio were cooked under optimum conditions. The pulp yield of mixed chip cooking was 45.4% with a kappa number of 19.4. The tensile and tear index of T. nudiflora pulps were 64.8 N•m/g and 11.5 kPa•m2/g at 35 °SR, respectively. The mixed chips, T. nudiflora, and T. orientalis pulps showed above 81% brightness when bleached by D0(EP)D1 sequence using 20 kg chlorine dioxide (ClO2)/ton of pulp.

Genetic analysis of the tomato russet mite provides evidence of oligophagy and a widespread pestiferous haplotype.

Worldwide, the tomato russet mite (TRM), Aculops lycopersici (Eriophyidae), is a key pest on cultivated tomato in addition to infesting other cultivated and wild Solanaceae; however, basic information on TRM supporting effective control strategies is still lacking, mainly regarding its taxonomic status and genetic diversity and structure. As A. lycopersici is reported on different species and genera of host plants, populations associated with different host plants may constitute specialized cryptic species, as shown for other eriophyids previously considered generalists. The main aims of this study were to (i) confirm the TRM taxonomic unity of populations from different host plants and localities as well as the species' oligophagy, and (ii) to advance the understanding of TRM host relationship and invasion history. For this purpose, we evaluated the genetic variability and structure of populations from different host plants along crucial areas of occurrence, including the area of potential origin, based on DNA sequences of mitochondrial (cytochrome c oxidase subunit I) and nuclear (internal transcribed spacer, D2 28S) genomic regions. Specimens from South America (Brazil) and Europe (France, Italy, Poland, The Netherlands) were collected from tomato and other solanaceous species from the genera Solanum and Physalis. Final TRM datasets were composed of 101, 82 and 50 sequences from the COI (672bp), ITS (553bp) and D2 (605bp) regions, respectively. Distributions and frequencies of haplotypes (COI) and genotypes (D2 and ITS1) were inferred; pairwise genetic distance comparisons, and phylogenetic analysis were performed, including Bayesian Inference (BI) combined analysis. Our results showed that genetic divergences for mitochondrial and nuclear genomic regions from TRM associated with different host plants were lower than those observed in other eriophyid taxa, confirming conspecificity of TRM populations and oligophagy of this eriophyid mite. Four haplotypes (cH) were identified from the COI sequences with cH1 being the most frequent, representing 90% of all sequences occurring in all host plants studied (Brazil, France, The Netherlands); the other haplotypes were present exclusively in Brazilian populations. Six variants (I) were identified from the ITS sequences: I-1 was the most frequent (76.5% of all sequences), spread in all countries and associated with all host plants, except S. nigrum. Just one D2 sequence variant was found in all studied countries. The genetic homogeneity among populations highlights the occurrence of a highly invasive and oligophagous haplotype. These results failed to corroborate the hypothesis that differential symptomatology or damage intensity among tomato varieties and solanaceous host plants could be due to the genetic diversity of the associated mite populations. The genetic evidence, along with the history of spread of cultivated tomato, corroborates the hypothesis of a South American origin of TRM.

Performance prediction of F1 crosses in eggplant (Solanum melongena L.) based on morphological and molecular divergence

Identifying potential F1 hybrid combinations based on the parental diversity can increase the breeding efficiency and saves the opportunity cost of time. In this work, the genetic diversity between eggplant genotypes was measured by Mahalanobis D2 statistics and Sequence Related Amplified Polymorphism (SRAP) molecular markers. The genetic distances (GD) were correlated with heterosis and trait wise mean performance of F1 crosses generated in a line ? tester mating design for prediction of F1 performance for agronomically important traits. The cluster analysis performed based on the Mahalanobis D2 distance grouped all the eleven genotypes into two clusters and three clusters were formed based on the SRAP marker data. The polymorphic information content value generated by the 30 SRAP marker combinations ranged from 0.09 to 0.77 with a mean value of 0.38. For yield, the F1 combinations exhibited the mid parent heterosis ranged from 3.99% to 83.34% and the heterobeltiosis from -35.67% to 57.19%. GD based on both phenotypic values and molecular marker data successfully predicted the heterotic patterns in the number of fruits per plant and other fruit morphological traits such as fruit length and fruit breadth which is a significant outcome of the study. A multiple linear regression model that included GD, GCA and SCA was more significantly correlated with heterosis for fruit yield than any genetic parameter alone.

First Report of Pratylenchoides leiocauda parasitic on Perilla frutescenes in the Republic of Korea.

Perilla (Perilla frutescens (L.) Britton var. japonica) is an annual herbaceous crop belonging to Lamiaceae. It is one of the most important crops in Korea. A survey of plant parasitic nematodes was carried out in 70 perilla fields in Geumsan and Miryang, Korea in 2020. Migratory endo-parasitic nematodes were extracted from the perilla roots using modified root incubation methods (Mountain and Patrick, 1959). False root-lesion nematodes (Pratylenchoides) were recovered from 41.4% of the fields. They were identified using morphological and molecular analyses. Among the Pratylenchoides species, Pratylenchoides leiocauda was described in France from soil around non-identified grass and weeds. P. leiocauda is reported to weaken the root systems of tomato, potato and strawberry (Sher, 1970; Li et al., 2020). The morphological characteristics of males and females from the 2020 survey were very similar to P. leiocauda. The lateral field contained six incisures and the pharyngeal glands overlapped the intestine dorsally for 1-2 times the body width. Additionally, they had a second nucleus near the pharyngeal intestine valve, female tails with incisures, and a smooth conical tail with 18-23 annules. Measurements and micrographs with the light-microscope (DM5000, Leica, Germany) and camera (DFC450, Leica, Germany) were taken from females (n=23) for mean, standard deviation and range of body length: 824.5 ± 71.0 (657.7-993.8) µm, maximum body width: 28.4 ± 2.7 (24.8-36.2) µm, stylet length: 22.8 ± 0.7 (21.4-24.0) µm and percent of distance from anterior end to vulva / body length: 57.7 ± 1.4 (54.0-60.3). Males (n=5) were characterized by a body length: 653.5 ± 64.3 (555.3-714.7) µm, a stylet length: 20.9 ± 1.0 (19.7-22.0) µm and a spicule length: 26.1 ± 2.5 (22.3-28.5) µm. Morphological measurements and characteristics (Fig. 1A-F) were compared to previous descriptions of P. leiocauda. As a result, the Korean population was larger than that of the originally described population from France, and was more similar to the Chinese population (Sher, 1970; Azizi et al., 2016; Li et al., 2020). In addition, PCR was performed for the COⅠ, LSU rRNA D2-D3 and ITS region using the primers (Mwesige et al., 2020). The sequenced COⅠ, LSU rRNA D2-D3 segments and ITS region are 447, 776 and 777 bp, respectively. The newly obtained sequences were submitted to GenBank database under accession numbers MZ418130, MZ414163 and MZ418133 of ITS region. A BLASTn search of the LSU rRNA D2-D3 sequence was most similar to P. leiocauda (MN539650), which is the species isolated from tomato in China (Li et al., 2020). The identities of these two sequences were 99.9% (775/776), with no insertions/deletions. The phylogenetic relationships strongly support P. leiocauda (Fig. 1G). Symptoms of perilla associated with P. leiocauda under field conditions included small and curled leaves, chlorosis of leaf edges, dark brown root epidermis and root necrosis (Fig. 2A, B). Koch's postulates were completed by inoculating 100 P. leiocauda into ten 45-cm-in-diameter pots filled with sterilized sandy loam soil and planted with perilla cultivar 'Ipdeulkkae 1-ho'. The potted plants were maintained for 50 days at 25℃ under greenhouse conditions. A P. leiocauda reproduction factor was 1.45 ± 0.20 was observed at the end of the trial, with 106 ± 21.6 recovered from soil and 39 ± 6.7 from root tissue. The root and shoot symptoms in the greenhouse trial were the same as those observed under field conditions (Fig. 2C, D). This, therefore, is the first record of P. leiocauda associated with perilla in Korea and management is warranted.

Mutual Cooperativity of Three Allosteric Sites on the Dopamine D1 Receptor.

An amine-containing molecule called Compound A has been reported by a group from Bristol-Myers Squibb to act as a positive allosteric modulator (PAM) at the dopamine D1 receptor. We synthesized the more active enantiomer of Compound A (BMS-A1) and compared it with the D1 PAMs DETQ and MLS6585, which are known to bind to intracellular loop 2 and the extracellular portion of transmembrane helix 7, respectively. Results from D1/D5 chimeras indicated that PAM activity of BMS-A1 tracked with the presence of D1 sequence in the N-terminal/extracellular region of the D1 receptor, a unique location compared with either of the other PAMs. In pairwise combinations, BMS-A1 potentiated the small allo-agonist activity of each of the other PAMs, while the triple PAM combination (in the absence of dopamine) produced a cAMP response about 64% of the maximum produced by dopamine. Each of the pairwise PAM combinations produced a much larger leftward shift of the dopamine EC50 than either single PAM alone. All three PAMs in combination produced a 1000-fold leftward shift of the dopamine curve. These results demonstrate the presence of three non-overlapping allosteric sites that cooperatively stabilize the same activated state of the human D1 receptor. SIGNIFICANCE STATEMENT: Deficiencies in dopamine D1 receptor activation are seen in Parkinson disease and other neuropsychiatric disorders. In this study, three positive allosteric modulators of the dopamine D1 receptor were found to bind to distinct and separate sites, interacting synergistically with each other and dopamine, with the triple combination causing a 1000-fold leftward shift of the response to dopamine. These results showcase multiple opportunities to modulate D1 tone and highlight new pharmacological approaches for allosteric modulation of G-protein-coupled receptors.

Cyanophages as an important factor in the early evolution of oxygenic photosynthesis

Cyanophages are viruses that infect cyanobacteria. An interesting feature of many of them is the presence of psbA and psbD, genes that encode D1 and D2 proteins, respectively. The D1 and D2 are core proteins of the photosystem II (PSII) in cyanobacteria, algae and plants and influence the proper function of oxygenic photosynthesis (OP) in all oxyphototrophs on Earth. The frequent occurrence of psbA and psbD in cyanophages raises the question whether these genes coevolved with hosts during the early stages of cyanophage and cyanobacterial evolution, or whether they are direct descendants of genes adopted from the genomes of cyanobacterial hosts. The phylogeny of D1/D2 proteins encoded in the genomes of selected cyanophages and oxyphototrophs was reconstructed. In addition, common ancestral sequences of D1 and D2 proteins were predicted for cyanophages and oxyphototrophs. Based on this, the reconstruction of the 3D structures of D1 and D2 proteins was performed. In addition, the ratio of non-synonymous to synonymous (dN/dS) nucleotide substitutions in the coding sequences (CDSs) of psbA and psbD was determined. The results of the predicted spatial structures of the D1 and D2 proteins and purifying selection for the CDSs of psbA and psbD suggest that they belong to the ancient proteins, which may have formed the primordial PSII. It cannot be ruled out that they involved in water oxidation in cyanobacteria-like organisms at early stages of the evolution of life on Earth and coevolved with ancient cyanophages. The data are also discussed in the context of the origin of viruses.

Phylogenetic and drug- and vaccine-resistance profiles of Hepatitis B Virus among children with HIV co-infection in Pakistan.

HIV-1 and hepatitis B virus (HBV) share common routes of transmission and therefore co-infection is common. In 2019, an HIV-1 outbreak that resulted in >1000 children being infected, predominantly through nosocomial transmission, occurred in Sindh, Pakistan. We conducted a phylogenetic and drug resistance analysis of the HBV Reverse Transcriptase (RT) gene in children with HIV-1 and HBV co-infection. Blood samples were collected from 321 children with HIV who were recruited as part of a study to investigate the HIV-1 outbreak. All samples were tested for HBV surface antigen (HBsAg) using an ELISA assay, and positive samples were used to amplify and sequence the HBV RT gene. The phylogenetic relationship between sequences was analyzed, and drug- and vaccine- resistance mutations in the RT gene were explored. Of 321 samples, 23% (n=75) were positive for HBsAg on ELISA. Phylogenetic analysis of the sequences revealed that 63.5% of HBV sequences were sub-genotype D1, while the rest were sub-genotype D2. Cluster analysis revealed grouping of sub-genotype D1 sequences exclusively with Pakistani sequences, while clustering of sub-genotypes D2 predominantly with global sequences. The 236Y mutation associated with resistance to tenofovir was observed in 2.8% of HBV sequences. Additionally, seven vaccine escape mutations were observed, the most common being 128V. Our study suggests ongoing transmission of HBV D1 and D2 sub-genotypes in the HIV-1 co-infected population, likely nosocomially, given common routes of HVB and HIV-1 transmission. The prevalence of major HBV drug- and vaccine-resistant mutations remains low. Surveillance for further transmissions and the possible emergence of major drug- or vaccine-resistant variants is required.

Diagnosis and characterization of the ribosomal DNA-ITS of potato rot nematode (Ditylenchus destructor) populations from Chinese medicinal herbs

The potato rot nematode (Ditylenchus destructor) is a very economically important nematode in agronomic and horticultural plants worldwide. In this study, 43 populations of D. destructor were collected from different hosts across China, including 37 populations from Chinese herbal medicine plants. Obtained sequences of ITS-rDNA and D2–D3 of 28S-rDNA genes of D. destructor were compared and analyzed. Nine types of significant length variations in ITS sequences were observed among all populations. The differences in ITS1 length were mainly caused by the presence of repetitive elements with substantial base substitutions. Reconstructions of ITS1 secondary structures showed that the minisatellites formed a stem structure. Ten haplotypes were observed in all populations based on mutations and variations of helix H9. Among them, 3 known haplotypes (A–C) were found in 7 populations isolated from potato, sweet potato, and Codonopsis pilosula, and 7 unique haplotypes were found in other 36 populations collected from C. pilosula and Angelica sinensis compared with 7 haplotypes (A–G) according to Subbotin’ system. These unique haplotypes were different from haplotypes A–G, and we named them as haplotypes H–N. The present results showed that a total of 14 haplotypes (A–N) of ITS-rDNA have been found in D. destructor. Phylogenetic analyses of ITS-rDNA and D2–D3 showed that all populations of D. destructor were clustered into two major clades: one clade only containing haplotype A from sweet potato and the other containing haplotypes B–N from other plants. For further verification, PCR-ITS-RFLP profiles were conducted on 7 new haplotypes. Collectively, our study suggests that D. destructor populations on Chinese medicinal materials are very different from those on other hosts and this work provides a paradigm for relevant researches.

Novel Freshwater Ascomycetes from Spain.

Freshwater ascomycetes are a group of fungi of great ecological importance because they are involved in decomposition processes and the recycling of organic matter in aquatic ecosystems. The taxonomy of these fungi is complex, with representatives in several orders of the phylum Ascomycota. In the present study, we collected ninety-two samples of plant debris submerged in freshwater in different locations in Spain. The plant specimens were placed in wet chambers and developed several fungi that were later isolated in pure culture. A main phylogenetic tree using the nucleotide sequences of D1–D2 domains of the 28S nrRNA gene (LSU) was built to show the taxonomic placement of all our fungal strains, and, later, individual phylogenies for the different families were built using single or concatenated nucleotide sequences of the most suitable molecular markers. As a result, we found a new species of Amniculicola that produces a coelomycetous asexual state, a new species of Elongatopedicellata that produces an asexual state, a new species of Neovaginatispora that forms both sexual and asexual states in vitro, and the sexual states of two species of Pyrenochaetopsis, none of which have been reported before for these genera. In addition, we describe a new species of Pilidium characterized by the production of copper-colored globose conidiomata, and of Pseudosigmoidea, which produces well-developed conidiophores.

Microbial production of hydroxy fatty acids utilizing crude glycerol

Strain D2 was isolated from a natural sample as a crude glycerol-assimilating microorganism. The ITS-5.8S rDNA sequence of strain D2 was most similar to that of Fusarium solani deposited in the NCBI database. Strain D2 accumulated 10-hydroxy-cis-12-octadecenoic acid (HYA), 10-hydroxyoctadecanoic acid (HYB), and 10-oxooctadecanoic acid (KetoB) in a medium containing crude glycerol, as a carbon source, and yeast extract, named CG medium. The growth and HYB production of strain D2 depended on the crude glycerol concentration in the medium. Strain D2 produced 2.20 g/L (40% of total fatty acids) of HYB on cultivation in CG medium containing 8% crude glycerol. When strain D2 was cultivated in CG medium containing 6% crude glycerol, the yield of HYB on cultivation under 4 days-shaking and 3 days-static conditions reached 1.19 g/L, which was 2.2 times higher than that under 7 days-shaking conditions and accounted for 53% of total fatty acids. The fungus was found not only to efficiently produce fatty acids utilizing crude glycerol, but also to be the first filamentous fungus to produce hydroxy and oxo fatty acids such as HYB, HYA, and KetoB.

Some properties of the inverse degree index and coindex of trees

Let G = (V, E), V = {v1, v2,..., vn}, be a simple graph without isolated vertices, with the sequence of vertex degrees d1 ? d2 ?...? dn > 0, di = d(vi). If vertices vi and vj are adjacent in G, we write i ~ j, otherwise we write i ~/ j. The inverse degree topological index of G is defined to be ID(G) = ?ni=1 1/di = ? i~j (1/d2i + 1/d2j), and the inverse degree coindex ?ID(G) = ? i~/j(1/d2i + 1/d2j). We obtain a number of inequalities which determine bounds for the ID(G) and ?ID(G) when G is a tree.

On the identity of the genus Epacrolaimus Andrássy, 2000 (Nematoda, Dorylaimida), with new insights into its phylogeny.

The type species of the genus Epacrolaimus, Epacrolaimus declinatoaculeatus, is studied from the re-examination of type material of Aporcelaimus vorax, its junior synonym, and the observation of several Iberian populations and a few Iranian specimens. Morphologically, it displays a recognizable morphological pattern characterized by, among other features, the incurved nature of its odontostyle aperture, presence of perioral liplets or lobes, lip region 24-31 μm wide, odontostyle 21-25 μm long and comparatively anterior location of S2N pharyngeal gland nuclei. Nevertheless, variations in some morphological traits (vagina shape and tail shape) and in several morphometrics (body length, uterus length, vulva position, tail length and spicule length) are also noted. Sequences of D2-D3 domains of the 28S rDNA, 18S rDNA and COI mtDNA were obtained from several Iberian populations. Their analyses, in particular those from D2-D3 sequences, revealed the existence of a highly supported clade ((Epacrolaimus + Sectonema) + Metaporcelaimus), with a closer relationship between Epacrolaimus and Palaearctic populations of Sectonema, whereas the remaining aporcelaimid genera occupied placements in other clades. These results are discussed, with especial emphasis on the intricate separation of Epacrolaimus and Sectonema, which display significantly different protruding stomatal structure in spite of their close evolutionary relationship as derived from molecular trees.

Description of Basiria iranica sp. nov. (Nematoda: Tylenchidae) from Southwestern Iran and its Phylogenetic Relationships

Basiria iranicasp. nov., recovered from the rhizospheric soil of pomegranate in Khuzestan province, southwestern Iran, is described and illustrated based upon morphological and molecular characters. The new species is characterized by its lateral fields composed of four incisures, with non areolated bands, lip region smooth and continuous with body contour, stylet 11–13 µm long, basal bulb pyriform to slightly cylindrical, V = 62 (60.3–63.3), tail elongate-conoid, tail tip pointed to filiform and males with 20 (19–21) µm long spicules. Morphologically, the new species comes close to B. berylla, B. duplexa, B. elegans, B. graminophila, B. hissariensis, B. khouzestanensis and B. paraobliqua. Morphological comparisons with these species are discussed. The sequence of the D2–D3 expansion segments of 28S rDNA gene for the new species was also used for molecular phylogenetic analysis. The phylogenetic relationships of the new species in relation to representatives of the family Tylenchidae, obtained from Bayesian inference (BI) analysis of the D2–D3 sequences, are presented and discussed. The new species clusters in a subclade containing B. aberrans, three unidentified species of the genus Basiria and B. khouzestanensis with high support.

Processing of Ordinal Information in Math-Anxious Individuals

This study aimed to investigate whether the ordinal judgments of high math-anxious (HMA) and low math-anxious (LMA) individuals differ. Two groups of 20 participants with extreme scores on the Shortened Mathematics Anxiety Rating Scale (sMARS) had to decide whether a triplet of numbers was presented in ascending order. Triplets could contain one-digit or two-digit numbers and be formed by consecutive numbers (counting condition), numbers with a constant distance of two or three (balanced) or numbers with variable distances between them (neutral). All these triplets were also presented unordered: sequence order in these trials could be broken at the second (D2) or third (D3) number. A reverse distance effect (worse performance for ordered balanced than for counting trials) of equal size was found in both anxiety groups. However, HMA participants made more judgment errors than their LMA peers when they judged one-digit counting ordered triplets. This effect was related to worse performance of HMA individuals on a symmetry span test and might be related to group differences on working memory. Importantly, HMAs were less accurate than LMA participants at rejecting unordered D2 sequences. This result is interpreted in terms of worse cognitive flexibility in HMA individuals.

Nematode epibionts on skin of the Florida manatee, Trichechus manatus latirostris

A survey for the presence of nematodes on the skin of the native Florida manatee, Trichechus manatus latirostris from Crystal River, Florida was conducted during annual manatee health assessments. A putative isolate of Cutidiplogaster manati (Diplogastridae) and two other nematodes belonging to the same family were recovered from mid-dorsal tail skin-scrapings from all sampled winter-collected healthy wild adult manatees during two successive years (2018–2019). Qualitative abundance estimates of these three species of diplogastrid nematodes suggest that an average wild Florida manatee adult might possess between 30,000 and 120,000 nematodes on its tail dorsum and that the entire body dorsum including the tail might possess 160,000–640,000 nematodes in roughly equal ratios. Attempts to culture these nematodes on a variety of different culture media were unsuccessful but examination of the mouth (stomatal) morphology suggests specialized feeding on microbes such as diatoms or predation on other nematodes. No skin lesions were observed during the 2018–2019 samplings suggesting that under normal conditions these nematodes are highly specialized free-living epibionts of the skin that are tightly bound to this niche and horizontally transferred between individual manatees in an analogous fashion to human skin mites (Demodex folliculorum and D. brevis). Molecular phylogenetic inferences using sequences of near full length SSU and D2–D3 expansion segments of LSU rRNA genes revealed a putative new morphospecies in Cutidiplogaster sister to C. manati that was monophyletic with several named Mononchoides species, and another putative new morphospecies that formed a clade with several undescribed species similar in appearance to Mononchoides as well as Tylopharyx, Eudiplogasterium, Paroigolaimella and Sachsia.

Description of Longidorella (Saevadorella) caspica n. sp. (Dorylaimida: Nordiidae) from north Iran.

This contribution provides the morphological and molecular identification of a new species of the genus Longidorella (Saevadorella). L. (S.) caspica n. sp., was recovered from the rhizospheric soil of grasses in Mazandaran province in the seashore of the Caspian Sea. It is characterized by females with a length of 788 to 874 μm and a cephalic region with prominent papillae; and separated from the rest of the body by a remarkable constriction, an odontostyle of 32 to 33 μm, vulva at 52.5 to 59.0%, and a tail of 33 to 38 μm with a rounded tip. Males have 32 to 35 μm long spicules of dorylaimoid form and five to seven ventral supplements ending at 48 to 55 μm distance from cloacal pair. The new species was morphologically compared with seven nominal species viz. L. (S.) arenicola, L. (S.) cuspidata, L. (S.) magna, L. (S.) perplexa, L. (S.) saadi, L. (S.) saevae, and L. (S.) tharensis. It was further compared with similar species under the subgenus Longidorella (Enchodorella) viz. L. (E.) deliblatica and L. (E.) murithi. Besides morphological studies, molecular phylogenetic studies using partial sequences of D2 to D3 expansion fragments of 28S rDNA were performed for the new species and its phylogenetic relationships with other species and genera were discussed.