Ribosomal DNA Markers Research Articles

Morphological characteristics and phylogenetic analyses revealed Geastrum yunnanense sp. nov. (Geastrales, Basidiomycota) from Southwest China

A new species (Geastrum yunnanense) from Yunnan Province in Southwest China is described and illustrated based on morphological and molecular evidence. This species is characterized by the globular or ovate endoperidial body, shallowly saccate exoperidium, and spherical basidiospores (2.0–2.5 × 1.9–2.5 µm in diameter). Sequences of the internal transcribed spacers (ITS) and large subunit (nrLSU) of the nuclear ribosomal DNA (rDNA) markers of the studied samples were generated, and the phylogenetic analyses were performed with maximum likelihood, maximum parsimony, and Bayesian inference methods. The phylogenetic analyses inferred from ITS+nrLSU dataset indicated that G. yunnanense nested within the genus Geastrum, forming a monophyletic lineage sister to G. velutinum, and G. javanicum. A full description, illustrations, and phylogenetic analysis results for the new species are provided.

Across a phylogeographic break in the Qinling Mountains-Huaihe River Line: Quaternary evolutionary history of a medicinal and edible homologous plant (Allium macrostemon) in China

Biogeographic barriers to gene flow are central to studies of plant phylogeography. There are many physical and geographic barriers in China, but few studies have used molecular ecological evidence to investigate the natural geographic isolation barrier of the Qinling Mountains-Huaihe River Line (QHL). Allium macrostemon is a precious Chinese perennial herb belonging to the Amaryllidaceae family. It is used as a food and medicine, with a variety of health and healing properties. Five SSR markers, three chloroplast DNA (cpDNA) markers (psbA-trnH, rps16 and trnL-F), one nuclear ribosomal DNA (nrDNA) marker (ITS), and simplified genome GBS sequencing were used to analyse the genetic diversity and structure of A. macrostemon. Combining SSR, cpDNA, nrDNA ITS data and GBS analysis results, we divided A. macrostemon populations into northern and southern groups, with the southern group further divided into southwestern and central-southeastern groups. Niche simulation results reveal that the distribution area of A. macrostemon will reach its maximum in the future. These data indicate that the regional separation of A. macrostemon has been maintained by the combined influence of a geographical barrier and Quaternary climate, and that the back-and-forth fluctuations of QHL and Quaternary climate have played an important role in this process. QHL acts as a north-south dividing line in phylogeography and population genetic structure, promoting physical geographic isolation. This study provides a theoretical basis for the conservation, development, and utilization of A. macrostemon resources. It further provides a reference for understanding the systematic geographical pattern of the large-scale spatial distribution of plants in China and enriches our understanding of Quaternary plant evolution in areas with complex terrain.

Designing A Novel Primer Set for GAPDH Gene to Enhance Taxonomic and Phylogenetic Studies of Golovinomyces Species

Golovinomyces (Erysiphaceae, Ascomycota) is an obligate plant pathogenic group causing powdery mildew on diverse angiosperm plants, including economically significant crops. Despite advancements in the taxonomy and phylogeny of Golovinomyces species using ribosomal DNA markers (ITS and LSU), several taxonomic issues remain unresolved. Previously, the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene, which exhibits higher nucleotide variation, has been proposed as an additional marker for powdery mildew species. In this study, we designed a new primer set (GoGPD-F and GoGPD-R) to improve the PCR success and efficiency of the GAPDH gene across various Golovinomyces species and dried herbarium specimens. The primers were successful in amplifying and sequencing the GAPDH gene in sixteen Golovinomyces species, including six species not previously registered in GenBank and two undescribed species. This development is a significant contribution to future research on the identification, taxonomy, and phylogeny of Golovinomyces species, offering a more robust tool for resolving existing taxonomic issues.

Taxonomic Re-Evaluation of the Genus Fuscoporia in the Republic of Korea Including Three Unrecorded Species

The genus Fuscoporia (Hymenochaetaceae, Basidiomycota) comprises poroid white-rot fungi characterized by dark brown hymenial setae, a dimitic hyphal system, and encrusted generative hyphae. Despite the ecological and commercial significance of Fuscoporia species, their identification has been challenging owing to their morphological overlap with other genera of Hymenochaetaceae and to the limited resolution of nuclear ribosomal DNA markers. With the advances in molecular research, Fuscoporia has been revised to include species from Inonotus sensu lato and Phellinus sensu lato, and 71 new species have been reported over the past decade. In Korea, a comprehensive taxonomic study elucidating the true diversity of Fuscoporia is yet to be conducted. Among the 11 Fuscoporia species reported in Korea, two were identified solely based on morphological characteristics, and four were identified based on nuclear ribosomal DNA regions, which have limited resolution for species identification in Fuscoporia. To investigate the current status of Fuscoporia species native to Korea, we conducted a phylogenetic study using four genetic markers (ITS + nrLSU + RPB2 + TEF1), along with morphological characteristics, and re-analyzed the GenBank records deposited from Korea. Ten Fuscoporia species were identified, including three previously unrecorded species. A detailed description of the unrecorded species and a list of proposed Korean names for all Fuscoporia species in Korea are provided. This study will guide further taxonomic and applied research of Fuscoporia by providing a species identification key and a verified multigenetic database, in addition to confirming the sequences in public database.

Unveiling genotypic diversity of Theileria orientalis in lethal outbreaks among bovines in Karnataka, India.

Theileria orientalis, the causal agent of oriental theileriosis, is known to cause mild disease in cattle and buffalo across the world. Recently, different genotypes of T. orientalis have emerged as pathogenic, causing high reported morbidity in cattle. This study focuses on investigating three suspected outbreaks of oriental theileriosis that resulted in fatalities among crossbred and indigenous bulls in Karnataka, India. Examination of blood smears revealed the presence of T. orientalis piroplasms within erythrocytes. The genetic characterization of T. orientalis was conducted by targeting specific markers, including the mpsp gene, p23 gene, and ribosomal DNA markers (18S rRNA gene, ITS-1, and ITS-2). Analysis based on the 18S rRNA gene unveiled the presence of both Type A and Type E genotypes of T. orientalis in the outbreaks. The mpsp gene-based analysis identified genotype 7 of T. orientalis in crossbred cows, whereas genotype 1 (Chitose B) was found to be present in indigenous bulls. Haplotype network analysis based on the mpsp gene revealed the presence of 39 distinct haplotypes within the 12 defined genotypes of T. orientalis with a high haplotype diversity of 0.9545 ± 0.017. Hematological and biochemical analysis revealed a decrease in calcium, hemoglobin levels, red blood cell counts, and phosphorus. This study constitutes the initial documentation of a clinical outbreak of oriental theileriosis in indigenous bulls with genotype 1 (Chitose 1B). Substantial epidemiological investigations are imperative to gain a comprehensive understanding of the geographical distribution of distinct genotypes and the diverse clinical manifestations of the disease across various hosts.

New insights into the chromosomes of stoneflies: I. Karyotype, C-banding and localization of ribosomal and telomeric DNA markers in Skwalacompacta (McLachlan, 1872) (Polyneoptera, Plecoptera, Perlodidae) from Siberia.

This study provides data on chromosome number (2n♂♀=26), sex determination mechanism (XY♂/XX♀), C-banding pattern, distribution of clusters of telomeric TTAGG repeats and 18S ribosomal DNA in the karyotype of the stonefly Skwalacompacta (McLachlan, 1872). For the first time in the history of stoneflies cytogenetics, we provide photos of the chromosomes of the Plecoptera insects. The karyotype of males and females of S.compacta consists of 12 pairs of autosomes. Three pairs of large autosomes and four pairs of medium-sized autosomes are subacrocentric. The remaining pairs of autosomes are small, with unclear morphology. Pericentromeric C-bands were revealed in all autosomes. The sex chromosomes are also subacrocentric. The short arms of X and Y chromosomes are entirely heterochromatic and are rich in ribosomal DNA sequences. In the X chromosome this arm is larger than in the Y chromosome. It is likely that this arm associated with the nucleolar organizer (NOR). Telomeric DNA (TTAGG)n repeats were detected in the terminal regions of all chromosomes.

Taxonomy and phylogeny of Auriculariales (Agaricomycetes, Basidiomycota) with descriptions of four new species from south-western China.

The wood-inhabiting fungi play an integral role in wood degradation and the cycle of matter in the ecological system. They are considered as the "key player" in wood decomposition, because of their ability to produce lignocellulosic enzymes that break down woody lignin, cellulose and hemicellulose. In the present study, four new wood-inhabiting fungal species, Adustochaetealbomarginata, Ad.punctata, Alloexidiopsisgrandinea and Al.xantha collected from southern China, are proposed, based on a combination of morphological features and molecular evidence. Adustochaetealbomarginata is characterised by resupinate basidiomata with cream to buff, a smooth, cracked, hymenial surface, a monomitic hyphal system with clamped generative hyphae and subcylindrical to allantoid basidiospores (12-17.5 × 6.5-9 µm). Adustochaetepunctata is characterised by resupinate basidiomata with cream, a smooth, punctate hymenial surface, a monomitic hyphal system with clamped generative hyphae and subcylindrical to allantoid basidiospores (13.5-18 × 6-8.2 µm). Alloexidiopsisgrandinea is characterised by resupinate basidiomata with buff to slightly yellowish, a grandinioid hymenial surface, a monomitic hyphal system with clamped generative hyphae and allantoid basidiospores (10-12.3 × 5-5.8 µm). Additionally, Alloexidiopsisxantha is characterised by resupinate basidiomata with cream to slightly buff, a smooth hymenial surface, a monomitic hyphal system with clamped generative hyphae and subcylindrical to allantoid basidiospores measuring 20-24 × 5-6.2 µm. Sequences of the internal transcribed spacers (ITS) and the large subunit (nrLSU) of the nuclear ribosomal DNA (rDNA) markers of the studied samples were generated. Phylogenetic analyses were performed with the Maximum Likelihood, Maximum Parsimony and Bayesian Inference methods. The phylogram, based on the ITS+nLSU rDNA gene regions, revealed that four new species were assigned to the genera Adustochaete and Alloexidiopsis within the order Auriculariales, individually. The phylogenetic tree inferred from the ITS sequences highlighted that Ad.albomarginata was retrieved as a sister to Ad.yunnanensis and the species Ad.punctata was sister to Ad.rava. The topology, based on the ITS sequences, showed that Al.grandinea was retrieved as a sister to Al.schistacea and the taxon Al.xantha formed a monophyletic lineage. Furthermore, two identification keys to Adustochaete and Alloexidiopsis worldwide are provided.

Discovery of Formicomyces microglobosus gen. et sp. nov. strengthens the hypothesis of independent evolution of ant-associated fungi in Trichomeriaceae

Different groups of fungi have been reported to interact with ants. Recent studies have shown that fungi of the order Chaetothyriales are important components of ant–fungus networks, including members of the family Trichomeriaceae, which is particularly rich in fungi isolated from carton ants nests. One of the still understudied ant-related environments are ants' infrabuccal pockets and pellets, which often contain fungal matter. The aim of this work was to determine the systematic and phylogenetic position of two slow growing strains of Trichomeriaceae isolated from infrabuccal pellets of Formica polyctena ants. Molecular analyses based on maximum likelihood and bayesian inference, using sequences of two ribosomal DNA markers: ITS and LSU have shown that the isolated strains form a monophyletic clade within the family Trichomeriaceae, sister to a clade formed by representatives of the genus Trichomerium. Morphological analyses additionally justified distinctiveness of the isolated strains, which have different morphology of conidia and conidiophores than Trichomerium representatives. Therefore, our results show that the isolated strains represent a new species within a not yet described fungal genus. Due to the strains’ isolation source and their close relatedness to a fungal strain isolated from a carton nest of Lasius fuliginosus, we propose a name Formicomyces microglobosus Siedlecki & Piątek for this fungus. While our discovery strengthens a hypothesis of the multiple, independent evolution of ant-associated fungi in the family Trichomeriaceae, the ecology of F. microglobosus still remains to be characterized.

Widespread infection, diversification and old host associations of Nosema Microsporidia in European freshwater gammarids (Amphipoda).

The microsporidian genus Nosema is primarily known to infect insects of economic importance stimulating high research interest, while other hosts remain understudied. Nosema granulosis is one of the formally described Nosema species infecting amphipod crustaceans, being known to infect only two host species. Our first aim was to characterize Nosema spp. infections in different amphipod species from various European localities using the small subunit ribosomal DNA (SSU) marker. Second, we aimed to assess the phylogenetic diversity, host specificity and to explore the evolutionary history that may explain the diversity of gammarid-infecting Nosema lineages by performing a phylogenetic reconstruction based on RNA polymerase II subunit B1 (RPB1) gene sequences. For the host species Gammarus balcanicus, we also analyzed whether parasites were in excess in females to test for sex ratio distortion in relation with Nosema infection. We identified Nosema spp. in 316 individuals from nine amphipod species being widespread in Europe. The RPB1-based phylogenetic reconstruction using newly reported sequences and available data from other invertebrates identified 39 haplogroups being associated with amphipods. These haplogroups clustered into five clades (A-E) that did not form a single amphipod-infecting monophyletic group. Closely related sister clades C and D correspond to Nosema granulosis. Clades A, B and E might represent unknown Nosema species infecting amphipods. Host specificity seemed to be variable with some clades being restricted to single hosts, and some that could be found in several host species. We show that Nosema parasite richness in gammarid hosts is much higher than expected, illustrating the advantage of the use of RPB1 marker over SSU. Finally, we found no hint of sex ratio distortion in Nosema clade A infecting G. balcanicus. This study shows that Nosema spp. are abundant, widespread and diverse in European gammarids. Thus, Nosema is as diverse in aquatic as in terrestrial hosts.

Phylogenetic structure and molecular species delimitation hint a complex evolutionary history in an Alpine endemic Niphargus clade (Crustacea, Amphipoda)

Subterranean fauna is an important contributor to the global fauna, but it is still understudied and a large part of its taxonomy is not yet resolved. One species complex with unresolved taxonomy is the groundwater amphipod Niphargus ruffoi, endemic to the Alpine chain. Here, we used new samples from across the Alpine arc to review the taxonomic status of the entire clade, including the species N. ruffoi and Niphargus arolaensis. We sequenced four genetic markers from the collected specimens, assessed the phylogenetic position of N. ruffoi within the genus, and studied the structure of this species complex using four molecular species delimitation methods. We tested for recombination using the alignments of the concatenated nuclear rDNA genes. The phylogenetic analyses revealed high support for the monophyly of the studied species complex, defining two lineages (i.e., N. arolaensis and N. ruffoi) within the clade. Molecular species delimitation methods suggested that N. arolaensis is a single species, while N. ruffoi should be considered as a species complex of three (using ITS) to eight (using COI) putative species. Moreover, we found a discrepancy between the different nuclear ribosomal DNA markers, indicating a possible recombination with fragments of 28S DNA of N. ruffoi s. lat. present in the genome of N. arolaensis. For the above-mentioned reasons, the internal phylogenetic structure of N. ruffoi s. lat. could not be fully resolved. Moreover, no clear morphological evidence supported the molecular species delimitation. Consequently, no taxonomic changes were proposed. We postulate that this complex scenario was influenced by Pleistocene climate oscillations with subsequent fragmentation events and secondary contacts, making this an interesting study system to investigate the evolution and biogeography of Alpine clades.

Biomarkers of aging through the life course: A Recent Literature Update.

The development of biomarkers of aging has greatly advanced epidemiological studies of aging processes. However, much debate remains on the timing of aging onset and the causal relevance of these biomarkers. In this review, we discuss the most recent biomarkers of aging that have been applied across the life course. The most recently developed aging biomarkers that have been applied across the life course can be designated into three categories: epigenetic clocks, epigenetic markers of chronic inflammation, and mitochondrial DNA copy number. While these have been applied at different life stages, the development, validation, and application of these markers has been largely centered on populations of older adults. Few studies have examined trajectories of aging biomarkers across the life course. As the wealth of molecular and biochemical data increases, emerging biomarkers may be able to capture complex and system-specific aging processes. Recently developed biomarkers include novel epigenetic clocks; clocks based on ribosomal DNA, transcriptomic profiles, proteomics, metabolomics, and inflammatory markers; clonal hematopoiesis of indeterminate potential gene mutations; and multi-omics approaches. Attention should be placed on aging at early and middle life stages to better understand trajectories of aging biomarkers across the life course. Additionally, novel biomarkers will provide greater insight into aging processes. The specific mechanisms of aging reflected by these biomarkers should be considered when interpreting results.

Molecular characterization of Fasciola spp. from ruminants in Duhok province using the ITS1 ribosomal DNA marker

This study aimed to characterize and identify the genotypes of Fasciola spp. isolated from sheep, goats, and cattle in Duhok province based on the ITS1 region of rDNA. About 54 adult Fasciola flukes were individually isolated from the livers of naturally infected ruminants. After morphological identification, the genomic DNA of 54 isolated Fasciola spp. was successfully extracted, and the ITS1segment (518 bp) of rDNA was amplified. The amplicons were confirmed by gel electrophoresis and yielded mono cleared bands. Five amplicons from these samples (2 sheep, 2 cattle, and 1 goat) were selected for sequencing and then compared with NCBI-GenBank sequences for genotyping and phylogenetic analysis. Sequencing analysis and the BLAST results revealed that 3/5 of the resultant sequences were F. hepatica and 2/5 were F. gigantica. The ITS1 sequences were submitted to NCBI-GenBank with accession numbers: OM920533, OM920534, OM948733, OM948683, and OM918714. Alignment analysis of the current study and GenBank ITS1 sequences showed the presence of nucleotide variations between F. hepatica and F. gigantica species (interspecific), which were enough to separate them. At the same time, they were not observed within the same species of Fasciola (intraspecific). The pairwise identity percentage of intraspecific and interspecific Fasciola isolates was 100% and 99.2-99.6%, respectively. Phylogenetic analysis of the ITS1 sequences demonstrated that the Fasciola isolates of this study were clustered into two clades (hepatica and gigantica clades). The present study concluded that both Fasciola spp. (F. hepatica and F. gigantica) existed among the infected ruminants in Duhok province and are closely related to intraspecific Fasciola isolates from different countries in the Middle East, Asia, Europe, and Africa.

Species of Ergasilus von Nordmann, 1832 (Copepoda: Ergasilidae) from cichlid fishes in Lake Tanganyika.

Ergasilus (von Nordmann, 1832) (Ergasilidae) is a species-rich group of parasitic copepods with a wide distribution in freshwater, marine and brackish environments. Up to now, 9 species of Ergasilus are known from cichlid fishes in Africa. In this study, 5 species, including 3 new, were collected from the gills of 12 cichlid species (11 genera: Bathybates, Ctenochromis, Eretmodus, Gnathochromis, Lamprologus, Neolamprologus, Ophthalmotilapia, Perissodus, Simochromis, Spathodus and Tanganicodus) of the northeastern shore of Lake Tanganyika in Burundi, namely E. macrodactylus (Sars, 1909), E. megacheir (Sars, 1909), E. caparti n. sp., E. parasarsi n. sp. and E. parvus n. sp. All species found were identified and described on the basis of adult female specimens using an integrative taxonomy approach mixing morphological characterization and molecular analyses of 2 ribosomal DNA markers (partial 18S and 28S rDNA sequences). An identification key for Ergasilus species from Lake Tanganyika is included. This study provides the first molecular data for Ergasilus species in Africa. The phylogenetic analyses suggest that the Ergasilus species parasitizing Lake Tanganyikan cichlids form a well-supported clade within the Ergasilidae. However, their phylogenetic relationships with other congeners still remain unclear due to a lack of molecular data for this diverse genus.

Diversity of coral-associated pit crabs (Crustacea: Decapoda: Cryptochiridae) from Hong Kong, with description of two new species of Lithoscaptus A. Milne-Edwards, 1862

Highly specialized cryptochirid crabs are obligate symbionts of scleractinian corals in tropical and subtropical seas. General morphologies of cryptochirid crabs remain poorly described due to their small size and difficulties in collection; thus, the current inventory is probably an underestimation. In the present study, we sampled cryptochirid crabs from coral communities in Hong Kong. In the literature, onlyCryptochirus hongkongensis(nowNeotroglocarcinus hongkongensis) with unknown hosts had been recorded in Hong Kong since 1936. In addition to morphological examination, identification in the present study is further supported by sequence divergence of mitochondrial cytochrome c oxidase I (COI) and 16S ribosomal DNA markers. Six operative taxonomic units (OTUs), representing four species and one species complex with two species, were revealed among our material:Cryptochirus coralliodytes,Lithoscaptus paradoxus,Lithoscaptus doughnutsp. nov.,Lithoscaptus scottaesp. nov., andXynomaia shenispecies complex. Morphological description of these species is provided, including description of the two new pseudocryptic species. The hosts of the genusLithoscaptusbelong largely to the Merulinidae, whileL. doughnutsp. nov. inhabits the Plesiastreidae.

Two new subspecies of Crocus biflorus L. (Iridaceae) from the Iraqi Kurdistan region using morphological and molecular methods

Species belonging to the Crocus genus are considered among the most attractive horticultural species and valuable economic plants in the world. Crocus plants are present at several locations in the Iraqi Kurdistan region. However, a comprehensive study has not been conducted yet in recognition of the species in this area. In the current work we used Internal Transcribed Spacers of nuclear ribosomal DNA (ITSnr) markers and morphological traits to provide information on this genus. The study revealed two new subspecies within species Crocus biflorus; Crocus biflorus subsp. penjwenii and Crocus biflorus subsp. qaradaghii. In addition, the circumscriptions of Crocus cancellatus and Crocus pallasii, as well as their subspecies ranks (haussknechtii and cancellatus) respectively, are confirmed in Iraq for the first time by using molecular means.

Paleobiogeographical origins of Fasciola hepatica and F. gigantica in light of new DNA sequence characteristics of F. nyanzae from hippopotamus.

Fascioliasis is a highly pathogenic disease affecting humans and livestock worldwide. It is caused by the liver flukes Fasciola hepatica transmitted by Galba/Fossaria lymnaeid snails in Europe, Asia, Africa, the Americas and Oceania, and F. gigantica transmitted by Radix lymnaeids in Africa and Asia. An evident founder effect appears in genetic studies as the consequence of their spread by human-guided movements of domestic ruminants, equines and Old World camelids in the post-domestication period from the beginning of the Neolithic. Establishing the geographical origins of fasciolid expansion is multidisciplinary crucial for disease assessment. Sequencing of selected nuclear ribosomal and mitochondrial DNA markers of F. nyanzae infecting hippopotamuses (Hippopotamus amphibius) in South Africa and their comparative analyses with F. hepatica and F. gigantica, and the two Fascioloides species, Fs. jacksoni from Asian elephants and Fs. magna from Holarctic cervids, allow to draw a tuned-up evolutionary scenario during the pre-domestication period. Close sequence similarities indicate a direct derivation of F. hepatica and F. gigantica from F. nyanzae by speciation after host capture phenomena. Phylogenetic reconstruction, genetic distances and divergence estimates fully fit fossil knowledge, past interconnecting bridges between continents, present fasciolid infection in the wild fauna, and lymnaeid distribution. The paleobiogeographical analyses suggest an origin for F. gigantica by transfer from primitive hippopotamuses to grazing bovid ancestors of Reduncinae, Bovinae and Alcelaphinae, by keeping the same vector Radix natalensis in warm lowlands of southeastern Africa in the mid-Miocene, around 13.5 mya. The origin of F. hepatica should have occurred after capture from primitive, less amphibious Hexaprotodon hippopotamuses to mid-sized ovicaprines as the wild bezoar Capra aegagrus and the wild mouflon Ovis gmelini, and from R. natalensis to Galba truncatula in cooler areas and mountainous foothills of Asian Near East in the latest Miocene to Early Pliocene, around 6.0 to 4.0 mya and perhaps shortly afterwards.

Host genotype controls ecological change in the leaf fungal microbiome.

Leaf fungal microbiomes can be fundamental drivers of host plant success, as they contain pathogens that devastate crop plants and taxa that enhance nutrient uptake, discourage herbivory, and antagonize pathogens. We measured leaf fungal diversity with amplicon sequencing across an entire growing season in a diversity panel of switchgrass (Panicum virgatum). We also sampled a replicated subset of genotypes across 3 additional sites to compare the importance of time, space, ecology, and genetics. We found a strong successional pattern in the microbiome shaped both by host genetics and environmental factors. Further, we used genome-wide association (GWA) mapping and RNA sequencing to show that 3 cysteine-rich receptor-like kinases (crRLKs) were linked to a genetic locus associated with microbiome structure. We confirmed GWAS results in an independent set of genotypes for both the internal transcribed spacer (ITS) and large subunit (LSU) ribosomal DNA markers. Fungal pathogens were central to microbial covariance networks, and genotypes susceptible to pathogens differed in their expression of the 3 crRLKs, suggesting that host immune genes are a principal means of controlling the entire leaf microbiome.

First record of the diatom Nitzschia navis-varingica (Bacillariophyceae) producing amnesic shellfish poisoning-toxins from Papua New Guinea

To determine the species distribution of an amnesic shellfish poisoning (ASP) toxins-producing diatom Nitzschia navis-varingica outside its current restricted geographical distribution range in Asian coastal waters, samples were collected from two sites of Bootless Bay, located on southwest coast of Papua New Guinea near Port Moresby. A total of twenty-one strains of N. navis-varingica were isolated and the clonal cultures established. The species identity was confirmed by molecular characterization based on the ribosomal DNA markers. The LSU rDNA phylogenetic inference revealed a monophyletic clade of all strains, clustered with N. navis-varingica with high bootstrap supports. ASP toxin production in the strains was investigated by HPLC with fluorescence detection and subsequently confirmed for the representative isolates by LC-MS/MS with multiple reaction monitoring (MRM) mode. All eleven strains from site A showed presence of domoic acid (DA) and isodomoic acid (IB); the toxin quota ranged from 0.70 to 4.63 pg cell−1 (average 2.75 ± 1.26 pg cell−1, n = 11), with the composition of DA and IB of 21 DA: 79 IB. While for strains from site B, four out of ten strains showed presence of DA and IB, with the toxin quota ranged from 1.40 to 3.84 (average 2.57 ± 1.17 pg cell−1, n = 4); the composition was 52 DA: 48 IB. The strains examined in this study were divided into toxic and probably non-toxic groups in ITS2 phylogeny. This represents the first record of domoic acid-producing Nitzschia navis-varingica from Papua New Guinea.

Siphoderina hustoni n. sp. (Platyhelminthes: Trematoda: Cryptogonimidae) from the Maori snapper Lutjanus rivulatus (Cuvier) on the Great Barrier Reef

A new cryptogonimid trematode, Siphoderina hustonin. sp., is reported, collected off Lizard Island, Queensland, Australia, from the Maori snapper Lutjanus rivulatus (Cuvier). The new species is moderately distinctive within the genus. It is larger and more elongate than most other species of Siphoderina Manter, 1934, has the shortest forebody of any, a relatively large ventral sucker, a long post-testicular zone, and is perhaps most recognisable for the substantial space in the midbody between the ventral sucker and ovary devoid of uterine coils and vitelline follicles, the former being restricted to largely posterior to the ovary and the latter distributed from the level of the anterior testis to the level of the ovary. In phylogenetic analyses of 28S ribosomal DNA, the new species resolved with the other nine species of Siphoderina for which sequence data are available, all of which are from Queensland waters and from lutjanid and haemulid fishes. Molecular barcode data were also generated, for the ITS2 ribosomal DNA and cox1 mitochondrial DNA markers. The new species is the first cryptogonimid known from L. rivulatus and the first metazoan parasite reported from that fish in Australian waters.

Phylogeny and Ecology of Trebouxia Photobionts From Bolivian Lichens.

In the past few years, new phylogenetic lineages in Trebouxia were detected as a result of molecular approaches. These studies included symbiont selectivity in lichen communities, transects along altitudinal gradients at local and global scales and the photobiont diversity in local populations of lichen-forming fungal species. In most of these studies, phylogenetic and haplotype analyses based on the internal transcribed spacer (ITS) locus have continuously allowed the recognition of new monophyletic lineages, which suggests that still numerous undiscovered Trebouxia lineages can be hidden in lichens from unexplored areas, especially in the tropics. Here, we estimated the biodiversity of photobionts in Bolivian Andean vegetation and assessed their specificity. About 403 lichen samples representing 42 genera, e.g., Haematomma, Heterodermia, Hypotrachyna, Lecanora, Lepra, Leucodermia, Parmotrema, Pertusaria, Polyblastidium, and Usnea, containing Trebouxia photobionts, were analyzed. ITS ribosomal DNA (rDNA) and rbcL markers were used. We obtained Trebouxia sequences from Bolivian samples belonging to already described clades A, C, I, and S. Thirty-nine Trebouxia lineages were distinguished within these clades, while 16 were new. To reveal the structure of the community of Bolivian photobionts and their relationships with mycobionts, the comparative effects of climate, altitude, geographical distances, substrate, and habitat type, as well as functional traits of lichens such as growth forms, propagation mode and secondary metabolites, were analyzed. Furthermore, new Bolivian records were included in analysis on a global scale. In our study, the mycobiont genus or even species are the most important factors correlated with photobiont identity. Moreover, we revealed that the community of Bolivian photobionts is shaped by altitude.