Early inhibition of BRD4 facilitates iPSC reprogramming via accelerating rDNA dynamic expression.

BACKGROUND: iPSC reprogramming technology exhibits significant promise in the realms of clinical therapeutics, disease modeling, pharmaceutical drug discovery, and various other applications. However, the extensive utilization of this technology has encountered impediments in the form of inefficiency, prolonged procedures, and ambiguous biological processes. Consequently, in order to improve this technology, it is of great significance to delve into the underlying mechanisms involved in iPSC reprogramming. The BET protein BRD4 plays a crucial role in the late stage of reprogramming; however, its precise function in the early stage remains unclear. RESULTS: Our study aims to investigate BRD4's role in the early stages of iPSC reprogramming. Our investigation reveals that early inhibition of BRD4 substantially enhances iPSC reprogramming, whereas its implementation during the middle-late stage impedes the process. During the reprogramming, ribosome DNA expression initially increases before decreasing and then gradually recovers. Early inhibition of BRD4 improved the decline and restoration of rDNA expression in the early and middle-late stages, respectively. Additionally, we uncovered the mechanism of BRD4's regulation of rDNA transcription throughout reprogramming. Specifically, BRD4 interacts with UBF and co-localizes to both the rDNA promoter and enhancer regions. Ultimately, BRD4 facilitates rDNA transcription by promoting the enrichment of histone H3 lysine 27 acetylation in the surrounding chromatin. Moreover, we also discovered that early inhibition of BRD4 facilitates cells' transition out of the somatic cell state and activate pluripotent genes. CONCLUSIONS: In conclusion, our results demonstrate that early inhibition of BRD4 promotes sequential dynamic expression of rDNA, which improves iPSC reprogramming efficiency.

Tick-associated Trypanosoma species (Apicomplexa: Kinetoplastida) from cattle ticks (Acari: Ixodidae) in Peninsular Malaysia.

A Trypanosoma screening was conducted on 130 pools comprising 1,241 ticks, collected from 674 selected farm ruminants in Peninsular Malaysia. Of these, nine pools were tested positive for Trypanosoma. Subsequent BLAST searches revealed that the 18S rRNA gene sequences were closely related to Trypanosoma rhipicephalis isolate Chaco CB, with percentage similarities ranging from 95.56 % to 99.84 %. Phylogenetic analysis showed that three of the nine sequences formed a clade with Trypanosoma rhipicephalis. The remaining six Trypanosoma sequences formed a distinct clade, separate from T. rhipicephalis and other Trypanosoma species, with genetic distances of 4.34 % and 4.33-4.58 %, respectively. This study marks the first report of tick-associated Trypanosoma in Malaysia and underscores significant research gaps regarding trypanosome interactions with tick hosts in the region.

Description of Conchophthirus sinanodontae n. sp. (Ciliophora: Scuticociliatia), a new endocommensal ciliate of the freshwater mussel Sinanodonta woodiana from Korea.

The morphology and molecular phylogeny of a new ciliate, Conchophthirus sinanodontae n. sp., which was discovered in the freshwater mussel Sinanodonta woodiana (Lea, 1834) from the Chilsancheon River, Buyeo-gun, South Korea, were investigated. The new species was characterized and could be distinguished from congeners by a combination of characters including the ovate body outline, four to six oral polykinetids deeply embedded in the upper wall of the buccal cavity, six to ten vestibular kineties, 34-49 ventral and 36-53 dorsal somatic kineties. The genetic differences among C. sinanodontae n. sp. and other congeners with available 18S rDNA sequences further support its distinctness. Moreover, the phylogenetic analyses based on the 18S rDNA sequences show that the new species clusters with other congeners, corroborating the monophyly of the genus Conchophthirus. The Conchophthirus clade nests within the cluster of Dexiotricha spp., Loxocephalus luridus, and Haptophrya spp.

Occurrence rate and species and subtypes of Cryptosporidium spp. in pet dogs in Yunnan Province, China.

BACKGROUND: Cryptosporidium spp. is a ubiquitous, globally distributed intestinal protozoan infecting humans and at least 260 animal hosts. Due to close human contact with pet dogs and identification of zoonotic Cryptosporidium species and subtypes in these animals, dog health is not only a veterinarian issue but also a public health issue. This study aimed to understand occurrence and genetic characterization at both genotype and subtype levels in pet dogs in Yunnan Province, China. RESULTS: A total of 589 fresh fecal specimens were collected from adult pet dogs in the rural areas of eight cities/autonomous prefectures of Yunnan Province, China. 16 fecal specimens were positive for Cryptosporidium spp. by polymerase chain reaction (PCR) amplification and sequence analysis of the small subunit ribosomal RNA (SSU rRNA) gene, with an average occurrence rate of 2.7% (16/589) being observed. Three zoonotic Cryptosporidium species were identified: C. parvum (n = 7), C. suis (n = 5) and C. canis (n = 4). At the 60-kDa glycoprotein (gp60) locus, only three C. parvum and two C. canis specimens were successfully amplified and sequenced, with subtype IIaA17G2R1 (n = 3) and subtypes XXa4 (n = 1) and XXa5 (n = 1) being identified, respectively. CONCLUSIONS: The present finding of three zoonotic Cryptosporidium species in dogs implied that dogs infected with Cryptosporidium spp. may pose a threat to human health. C. suis was identified in dogs in this study for the first time, expanding the host range of this species. Identification of C. parvum subtype IIaA17G2R1 and C. canis subtypes XXa4 and XXa5 will be helpful to explore the source attribution of infection/contamination and assess the transmission dynamics of C. parvum and C. canis in the investigated areas in the future.

Molecular characterization of anopheline species diversity in the Andaman and Nicobar archipelago, with a particular emphasis on Anopheles barbirostris.

This study investigates anopheline species diversity in the Andaman and Nicobar Islands, employing morphological and molecular methods, focusing on the D3 domain of 28S rRNA (D3) and second internal spacer (ITS2). Ten Anopheline species were identified morphologically and confirmed with molecular markers. While the D3 region demonstrated low level of inter- and intra-specific genetic distance in all the species, ITS2 revealed clear barcoding gap. Among the ten species, A. barbirostris exhibited significant diversity when compared with the sequences from other countries available in GenBank. Further analyses of additional samples of A. barbirostris were carried out using ITS2 and cytochrome oxidase I (COI) markers. Limited variations among the sequences from the islands were observed, suggesting a prevalent single molecular form. However, when compared with the GenBank sequences, our samples formed a separate cluster closely related to the A3 species. The genetic distance between our samples and the A3 cluster was 0.02 for COI but very high (0.104) for ITS2, suggesting a potentially new molecular form or species in the island region. This warrants a more comprehensive and detailed analysis of A. barbirostris in these islands at both genetic and morphometric levels. Overall, these observations added-up the new knowledge in the understanding of anopheline diversity in the Andaman and Nicobar archipelago and highlight the necessity for continuous molecular investigations to unravel complexities within mosquito population dynamics.

Phylogeny and ultrastructure of a non-toxigenic dinoflagellate Amphidoma fulgens sp. nov. (Amphidomataceae, Dinophyceae), with a wide distribution across Asian Pacific.

Amphidoma languida, a marine thecate dinoflagellate that produces the lipophilic toxin azaspiracids (AZAs), is primarily found in the Atlantic. Although this species has not been recorded in the Asian Pacific, environmental DNAs related to Am. languida have been widely detected in the region by metabarcoding analysis. Their morphology and AZA production remain unclear. In this study, the morphology, ultrastructure, phylogeny, and AZA production of nine Amphidoma strains isolated from Japan, Malaysia, and Philippines were investigated. Phylogenetic trees inferred from rDNAs (SSU, ITS, and LSU rDNA) showed monophyly of the nine Pacific strains and were sister to the Am. languida clade, including the toxigenic strains from the Atlantic. Cells were ellipsoid, 8.7-16.7 µm in length and 7.4-14.0 µm in width, with a conspicuous apical pore complex. A large nucleus in the hyposome, parietal chloroplast with a spherical pyrenoid in the episome, and refractile bodies were observed. Thecal tabulation was typical of Amphidoma, Po, cp, X, 6', 6'', 6C, 5S, 6''', 2''''. A ventral pore was located on the anterior of 1' plate, beside the suture to 6' plate. The presence of a ventral depression, on the anterior of anterior sulcal plate, was different from Am. languida. A large antapical pore, containing approximately 10 small pores, was observed. Cells were apparently smaller than Am. trioculata, a species possessing three pores (ventral pore, ventral depression, and antapical pore). TEM showed the presence of crystalline structures, resembling guanine crystals, and cytoplasmic invaginations into the pyrenoid matrix. Flagellar apparatus lacking the striated root connective is similar to peridinioids and related dinoflagellates. AZAs were not detected from the Pacific strains by LC-MS/MS. This non-toxigenic Amphidoma species, here we propose as Amphidoma fulgens sp. nov., is widely distributed in the Asian Pacific. Moreover, molecular comparison also suggested that most of the environmental DNA sequences previously reported as Am. languida or related sequences from the Asian Pacific were attributable to Am. fulgens.

Molecular identification of Mymarothecium viatorum and Anacanthorus penilabiatus in extensive native fish farming systems of the Peruvian Amazon.

Piaractus brachypomus (Pacú) is the main native fish species cultivated in Peru and holds great potential for growth in aquaculture from the Peruvian Amazon. Between October 2021 and January 2022 in two fish producing farms in the Amazon region of San Martín in Peru, P. brachypomus individuals were examined for parasite evaluation. A total of 6366 monogeneans were isolated from the gills of 30 fish, revealing a prevalence of 100%, with an abundance and mean intensity of 212 parasites per fish. Monogeneans were morphologically identified as Mymarothecium viatorum and Anacanthorus penilabiatus. The genetic divergence in the 28S rDNA gene found among A. penilabiatus sequences was 0.1% and among Anacanthorus spp. it ranged from 0.9% to 7.5%. The genetic divergence found among the M. viatorum sequences was 0.3%. These finding represents the first molecular data of M. viatorum and A. penilabiatus in Peru using the 28S rDNA gene of these monogeneans. The new sequences obtained will contribute to future studies on the phylogenetic relationships among dactylogyrids. However, further research with a broader range of host-parasite samples and additional genetic markers is needed to clarify these relationships and provide stronger support for the phylogenetic positions.

Hyper-recombination in ribosomal DNA is driven by long-range resection-independent RAD51 accumulation.

Ribosomal DNA (rDNA) encodes the ribosomal RNA genes and represents an intrinsically unstable genomic region. However, the underlying mechanisms and implications for genome integrity remain elusive. Here, we use Bloom syndrome (BS), a rare genetic disease characterized by DNA repair defects and hyper-unstable rDNA, as a model to investigate the mechanisms leading to rDNA instability. We find that in Bloom helicase (BLM) proficient cells, the homologous recombination (HR) pathway in rDNA resembles that in nuclear chromatin; it is initiated by resection, replication protein A (RPA) loading and BRCA2-dependent RAD51 filament formation. However, BLM deficiency compromises RPA-loading and BRCA1/2 recruitment to rDNA, but not RAD51 accumulation. RAD51 accumulates at rDNA despite depletion of long-range resection nucleases and rDNA damage results in micronuclei when BLM is absent. In summary, our findings indicate that rDNA is permissive to RAD51 accumulation in the absence of BLM, leading to micronucleation and potentially global genomic instability.

Trematode species diversity in the faucet snail, Bithynia tentaculata at the western edge of its native distribution, in Ireland.

Trematodes and their snail hosts have developed intimate parasite-host associations, with snails supporting a diverse and often species-specific trematode fauna. In the faucet snail, Bithynia tentaculata (Caenogastropoda, Littorinimorpha), a unique trematode fauna has been recorded recently. However, knowledge of the exact species identity, phylogenetic relationships, and geographical distribution remains limited as many of the species belong to groups with unclear or controversial taxonomical assignment. To contribute to our knowledge of the trematodes, we investigated the trematode fauna of B. tentaculata by examining a total of 556 snails from lakes in County Galway, Ireland. Using an integrative taxonomic approach including DNA sequence data analyses (28S rRNA gene, ITS1-5.8S-ITS2, ITS2, cox1, nad1) and morphological tools (taxonomical drawings and measurements), we identified nine trematode species of seven families, with seven species occurring as cercariae (Cyathocotyle prussica, Lecithodendrium linstowi, Lecithodendrium sp., Asymphylodora progenetica, Sphaerostoma bramae, Metorchis xanthosomus, and Notocotylus sp.) and three species occurring as metacercariae (A. progenetica, Parasymphylodora parasquamosa, and Sphaeridiotrema sp.). Except for S. bramae, all are new species records for Ireland and provide the most western distribution of these trematodes in Europe. The trematode species recorded are known to use a wide range of definitive hosts and have a wide geographical distribution; among them are species members of genera that are zoonotic (Metorchis) and pathogenic to wildlife (Cyathocotyle, Sphaeridiotrema, and Notocotylus). There remains an ongoing need for precise identification of the trematode species to ensure that wider ecological contexts are correctly understood and biodiversity and disease threats can be accurately evaluated.

Cytogenetic analysis and visualization of genetic relationships in wild lilies.

Lilies are highly regarded for their ornamental appeal and striking flowers, which are of significant importance in horticulture. Understanding the genetic makeup of these plants is crucial for breeding and developing new cultivars. This study presents a comprehensive cytogenetic analysis of 45 S and 5 S rDNA loci in 34 wild Lilium species. To reveal the genetic relationships within the genus, advanced visualization methods, such as heatmaps and 3D network plots, were utilized. The results of this study identified both conserved and divergent genetic features, which offer insights into the evolutionary history and potential genetic compatibility of these species. Notably, the clustering of species based on rDNA locus patterns highlights the need for potential taxonomic re-evaluation and reveals candidates for cross-breeding. This integrated approach emphasizes the importance of combining cytogenetic data with traditional morphological classifications to refine our understanding of the Lilium species. Future research should expand the range of analyzed species, incorporate additional molecular markers to further elucidate genetic relationships, and support the development of resilient and diverse ornamental crops. The findings of this study provide a novel framework for genetic analysis of Lilium, offering valuable insights for both scientific understanding and practical breeding programs.

PHF8 facilitates transcription recovery following DNA double-strand break repair.

Transient halting of transcription activity on the damaged chromatin facilitates DNA double-strand break (DSB) repair. However, the molecular mechanisms that facilitate transcription recovery following DSB repair remain largely undefined. Notably, failure to restore gene expression in a timely manner can compromise transcriptome signatures and may impose deleterious impacts on cell identity and cell fate. Here, we report PHF8 as the major demethylase that reverses transcriptionally repressive epigenetic modification laid down by the DYRK1B-EHMT2 pathway. We found that PHF8 concentrates at laser-induced DNA damage tracks in a DYRK1B-dependent manner and promotes timely resolution of local H3K9me2 to facilitate the resumption of transcription. Moreover, PHF8 also assists in the recovery of ribosomal DNA (rDNA) transcription following the repair of nucleolar DSBs. Taken together, our findings uncover PHF8 as a key mediator that coordinates transcription activities during the recovery phase of DSB responses.

Taxonomy and molecular phylogeny of genus Plagiocampa (Ciliophora, Prostomatea), with redescriptions of two poorly known species.

Prostomateans, as common inhabitants in diverse aquatic environments, are among the simplest ciliate lineages, and serve as trophic links in food webs. However, only a few members are well-known and thoroughly studied, and the diversity of this group remains elusive. The unique genus Plagiocampa has a long history of research, but few studies have been performed using up-to-date methods. In the present work, Plagiocampa longis Kahl, 1927 and Plagiocampa minima Kahl, 1927, collected from Chinese coastal habitats, were investigated based on microscopical observation, protargol staining, and SSU rRNA gene sequencing. Their ciliature and morphometric data as well as gene sequences are documented. Phylogenetic analyses revealed that the family Plagiocampidae is likely monophyletic and has a closer relationship with parasitic Cryptocaryon.

Paronatrema davidbowiei n. sp. (Trematoda: Syncoeliidae), a new parasite of the pelagic thresher (Alopias pelagicus) and its phylogenetic relationships within the suborder Hemiurata Skrjabin & Guschanskaja, 1954.

A new species of hemiurid trematode found on the gills and in the aorta of the pelagic thresher Alopias pelagicus from the eastern Pacific, off Costa Rica, is described based on an integrative taxonomic approach that includes the use of light and scanning electron microscopy, and 28S rDNA sequencing. Phylogenetic analysis was also performed to explore, for the first time, the relationships of a member of the subfamily Otiotrematinae within the suborder Hemiurata. Paronatrema davidbowiei n. sp. can be distinguished from the congeners by having tegumental spines on the dorsal surface of the forebody, papillae on the oral sucker, and different morphology or number of testicular follicles. BLAST analysis revealed that sequences of Paronatrema davidbowiei n. sp. had the highest degree of similarity with Hirudinella spp. (Hirudinellidae). Results from Maximum Likelihood and Bayesian phylogenetic analyses, returning trees with the exact same topology and strong branch support, distinguished between the two superfamilies included in the suborder Hemiurata: Azygioidea and Hemiuroidea. Our analysis placed the new species in a clade with Copiatestes filiferus, the only existing sequence of the family Syncoeliidae.

Diversity of ribosomes at the level of rRNA variation associated with human health and disease.

With hundreds of copies of rDNA, it is unknown whether they possess sequence variations that form different types of ribosomes. Here, we developed an algorithm for long-read variant calling, termed RGA, which revealed that variations in human rDNA loci are predominantly insertion-deletion (indel) variants. We developed full-length rRNA sequencing (RIBO-RT) and in situ sequencing (SWITCH-seq), which showed that translating ribosomes possess variation in rRNA. Over 1,000 variants are lowly expressed. However, tens of variants are abundant and form distinct rRNA subtypes with different structures near indels as revealed by long-read rRNA structure probing coupled to dimethyl sulfate sequencing. rRNA subtypes show differential expression in endoderm/ectoderm-derived tissues, and in cancer, low-abundance rRNA variants can become highly expressed. Together, this study identifies the diversity of ribosomes at the level of rRNA variants, their chromosomal location, and unique structure as well as the association of ribosome variation with tissue-specific biology and cancer.

DESCRIPTIONS AND PHYLOGENETIC AFFINITIES OF TWO NEW SPECIES OF RHABDIAS STILES AND HASSALL, 1905 (NEMATODA: RHABDIASIDAE) FROM NORTH AMERICAN FROGS: ARE WE STILL ONLY SCRATCHING THE SURFACE?

Two new species of lung-dwelling nematodes are described from North American frogs: Rhabdias aurorae n. sp. from Rana aurora and Rhabdias conni n. sp. from Rana clamitans and Rana catesbeiana from Arkansas; the latter species was also found in Oklahoma and Georgia. Rhabdias aurorae n. sp. differs from other Nearctic congeners in the combination of the following characteristics: buccal capsule 22-25 µm wide, elongated tail covered with inflated cuticle, esophagus with prominent dilatation in anterior part and 6 small circumoral lips. Rhabdias conni n. sp. is morphologically closest to Rhabdias ranae Walton, 1929 and Rhabdias joaquinensisIngles, 1936; it differs from them in the shape of lateral pseudolabia, the dimensions of the body, and the egg size. Both new species were found to be significantly different from the Nearctic congeners in the nucleotide sequences of nuclear ribosomal DNA (18S-ITS-28S region), 12S, and CO1 mitochondrial genes. The 2 new species differ from other currently sequenced Nearctic congeners by 1.1-2.7% of nucleotide positions in the nuclear rDNA region, 1.3-3.4% in the 12S gene, and 3.4-9.4% in CO1 gene. Molecular phylogenetic analysis based on nuclear ribosomal DNA sequences placed both new species into the clade consisting of Nearctic and Neotropical Rhabdias spp. The position of Rh. aurorae n. sp. within the clade is uncertain because of a polytomy, but Rh. conni n. sp. is nested within the "Rh. joaquinensis complex" related to Rh. ranae and Rhabdias tarichaeKuzmin, Tkach, and Snyder, 2003. The phylogenetic analysis based on nuclear ribosomal DNA sequences has revealed 3 evolutionary host-switching events from anuran to caudatan hosts among Rhabdias spp. that occurred in the Nearctic and Palearctic. The molecular phylogeny also suggests that Rhabdias may have originally evolved in what is now Africa.

Comparative molecular and conventional cytogenetic analyses of three species of Rhinella (Anura; Bufonidae).

The genus Rhinella corresponds to a group of anurans characterized by numerous taxonomic and systemic challenges, leading to their organization into species complexes. Cytogenetic data for this genus thus far are limited to the diploid number and chromosome morphology, which remain highly conserved among the species. In this study, we analyse the karyotypes of three species of the genus Rhinella (Rhinella granulosa, Rhinella margaritifera, and Rhinella marina) using both classical (conventional staining and C-banding) and molecular (FISH-fluorescence in situ hybridization with 18S rDNA, telomeric sequences, and microsatellite probes) cytogenetic approaches. The aim of this study is to provide data that can reveal variations in the distribution of repetitive sequences that can contribute to understanding karyotypic diversification in these species. The results revealed a conserved karyotype across the species, with 2n = 22 and FN = 44, with metacentric and submetacentric chromosomes. C-banding revealed heterochromatic blocks in the pericentromeric region for all species, with a proximal block on the long arms of pairs 3 and 6 in R. marina and on the short arms of pairs 4 and 6 in R. margaritifera. Additionally, 18S rDNA probes hybridized to pair 5 in R. granulosa, to pair 7 in R. marina, and to pair 10 in R. margaritifera. Telomeric sequence probes displayed signals exclusively in the distal region of the chromosomes, while microsatellite DNA probes showed species-specific patterns. These findings indicate that despite a conserved karyotypical macrostructure, chromosomal differences exist among the species due to the accumulation of repetitive sequences. This variation may be attributed to chromosome rearrangements or differential accumulation of these sequences, highlighting the dynamic role of repetitive sequences in the chromosomal evolution of Rhinella species. Ultimately, this study emphasizes the importance of the role of repetitive DNAs in chromosomal rearrangements to elucidate the evolutionary mechanisms leading to independent diversification in the distinct phylogenetic groups of Rhinella.

TWO NEW CERATOMYXA SPECIES (MYXOSPOREA: CERATOMYXIDAE) INFECTING THE GALL BLADDER OF MARINE FISHES FROM THE SOUTH-CENTRAL COAST OF VIETNAM.

Myxospores discovered floating free in the bile of marine fishes from the south-central coast of Vietnam were identified using morphological and molecular methods, leading to the description of 2 new species. Ceratomyxa chauvanminhi n. sp. was detected in 16% (8/50) of cultured barramundi Lates calcarifer (Bloch) specimens, and Ceratomyxa sekoi n. sp. was found in 20% (5/25) of wild largehead hairtail Trichiurus lepturus Linnaeus specimens. The spores of C. chauvanminhi n. sp. are very shallowly ovoid, slightly crescent shaped, and 11.5 ± 0.5 (10.7-12.4) µm thick, 5.8 ± 0.2 (5.4-6.1) µm long, and 5.5 ± 0.2 (5.2-5.7) µm wide. Their posterior angles are slightly concave at 158.7° ± 4.2° (151.3°-164.8°), and they possess 2 equal spherical polar capsules 2.5 ± 0.2 (2.1-2.9) µm in diameter. The spores of C. sekoi n. sp. are 5.6 ± 0.2 (5.0-6.1) µm long, 75.5 ± 4.8 (68.9-90.0) µm thick, and 5.5 ± 0.1 (5.4-5.6) µm wide, with 2 equal, slightly anterior spherical polar capsules 2.1 ± 0.2 (1.7-2.4) µm in diameter. Although C. sekoi n. sp. spores resemble those of species of MyxodavisiaZhao, Zhou, Kent, and Whipps, 2008, characterized by long tapering valves, genetic analyses distinctly place this new species within the Ceratomyxa Thélohan, 1892 lineage. This study contributes to the understanding myxosporean diversity in Vietnamese waters and highlights the difficulty associated with distinguishing between the genera Ceratomyxa and Myxodavisia.

Distribution, morphological and molecular characterization of root-lesion nematodes (Pratylenchus spp.) (Tylenchida: Pratylenchidae) in maize (Zea mays L.) (Poales: Poaceae) in Türkiye.

BACKGROUND: Root-lesion nematodes (RLN) are the most economically important pathogenic nematodes attacking maize. Significant economic losses due to lesion nematodes have been reported in maize producing countries in the world. METHODS AND RESULTS: This study was conducted to determine the distribution and identity of root-lesion nematodes (Pratylenchus spp.) (Tylenchida: Hoplolaimidae) in maize (Zea mays L.) (Poales: Poaceae) fields of the Black Sea region of Türkiye. For this purpose, 39 locations were surveyed and soil samples were taken from 17 regional provinces. Nematodes were extracted using the modified Baerman funnel technique. The species were identified based on sequences of the Internal Transcribed Spacer (ITS) region of ribosomal DNA, as well as morphological characters and morphometrics. In addition, species identifications were confirmed using species-specific primers in the D3 expansion region of 26 S rDNA. At the end of the study, 51.3% of the maize production areas sampled in the region were infected with root-lesion nematode species. Pratylenchus agilis, P. mediterraneus, P. neglectus, P. penetrans, P. thornei, and P. vulnus were identified, and were present in 25%, 5%, 25%, 10%, 15%, and 20% of samples, respectively. To our knowledge, this is the first report of P. agilis in Türkiye. CONCLUSION: The present study concluded that the molecular analysis of Pratylenchus sequences based on the ITS and D3 region of ribosomal RNA genes allowed the identification of six root lesion nematode species. This study is of great importance in terms of adding additional species to the root-lesion nematode fauna in Turkey and will provide data for future research on the management of these nematodes.

Morphological and Molecular Analyses of Aponurus laguncula Looss, 1907 (Digenea: Lecithasteridae) Parasitic in Atlantic Spadefish Chaetodipterus faber (Broussonet, 1782) (Acanthuriformes: Ephippidae) from Brazilian Coastal Zone.

OBJECTIVES: An integrative taxonomic description of Aponurus laguncula (Lecithasteridae), a digenean parasitic species of Chaetodipterus faber (Acanthuriformes) from Brazilian Southeast, is provided. Morphological techniques, as whole mounted slides, histology and scanning electron microscopy, and molecular analyses supported that integrative description. METHODS: Fifteen digenean specimens were stained in hydrochloric carmine and mounted on permanent slides. Two specimens were stained in hematoxylin and eosin following histological routine processing. Four parasites were dehydrated through a graded ethanol series, critical point dried with carbon dioxide and coated with gold to scanning electron microscopy analysis. Sequence of the large ribosomal subunit (28S rDNA) gene was generated and used to construct a phylogeny based on maximum likelihood and Bayesian inference analyses. RESULTS: Morphological description and morphometric data obtained in present study were in accordance with previous studies of the species. Use of another morphological techniques, as scanning electron microscopy and histology, corroborated the observed features of whole mounted slides. Also, they provided a better observation of previous reported characteristics and new features reporting, such as an elongated hermaphroditic duct, a smooth tegument and cells that compose the prostatic gland. The molecular sequence obtained in the present study formed a robust clade with available sequences of species of Aponurus. CONCLUSIONS: The integrative taxonomic approach successfully combined morphological observations, including both previously reported features and new descriptions from histological and electron microscopy analyses, with molecular data to identify these specimens as A. laguncula. Moreover, the detailed characterization of structures, such as the gonads in A. laguncula, that would be challenging to analyze using a single technique, was possible. Further molecular studies with less conserved genetic markers should be conducted to understand phylogenetic relationships between Aponurus species.

Morphological and molecular identification of metacestodes infecting teleost fishes of Moreton Bay, Australia.

In a parasitological survey of fishes from Moreton Bay (southeastern Queensland, Australia), 169 teleost fishes, representing 54 species from 28 families, were examined for larval cestodes. Of these 54 species, 36 were found to be infected by metacestodes. Metacestodes were characterised by morphological and molecular data (the D1-D3 region of the 28S rDNA gene); these data were analysed in parallel to inform larval type allocation. Metacestodes collected represented eight morphological types, seven previously reported (Types I, II, IV, V, VI, VII, and X) and one novel type (Type XVI). Phylogenetic analyses were conducted to genetically match larval types to adult cestodes. Six of the eight larval types found were matched to adult forms: Type I metacestodes matched species of Phoreiobothrium Linton, 1889 (Onchobothriidae); Type II metacestodes matched species of Acanthobothrium van Beneden, 1849 (Onchobothriidae); Type IV metacestodes matched species of Scyphophyllidium Woodland, 1927 and Alexandercestus Ruhnke & Workman, 2013 (Phyllobothriidae); Type VI metacestodes matched species of Anthobothrium van Beneden, 1850 (Tetraphyllidea incertae sedis); Type X metacestodes matched species of Ambitalveolus Caira & Jensen, 2022 (Tetraphyllidea incertae sedis); and Type XVI metacestodes matched species of Platybothrium Linton, 1890 (Onchobothriidae). Based on phylogenetic topology, Type V metacestodes are inferred to match Pedibothrium Linton, 1909 (Balanobothriidae) and Type VII metacestodes are inferred to match Spongiobothrium Linton, 1889 (Rhinebothriidae). These findings support and extend the unified morphological type system proposed previously, but suggest that morphological types will ultimately be informative to identify metacestodes to a group of related genera rather than any distinct genus.