Mitochondrial Ribosomal RNA Gene Research Articles

A new genus of scutigerid centipede from southern South America with the description of two new species and an updated molecular phylogeny of the myriapod order Scutigeromorpha (Myriapoda: Chilopoda).

Scutigeromorph centipedes are conspicuous, yet often ignored myriapods for which little work has been conducted in southern South America. After examining recent and museum collections from Chile and Argentina, two new species of generic uncertainty were identified. A new genus of scutigerid centipede, Edgethreua , is therefore described with two new species, E. chilensis from Central Chile (type species of the genus) and E. goloboffi from Argentinian Patagonia. The new genus is characterised by the presence of scattered setiform bristles with short paired spines and the absence of simple spinulae and spines on all stomatotergites, the presence of a single spine-bristle in the prefemur of the second maxilla, a patch of cuticular ridges and pores surrounding the sensilla of the proximal labral portion of the epipharynx, the morphology of the sensilla of the distal patch of the hypopharynx and the morphology of the female gonopods. A phylogenetic analysis of the new species using two nuclear ribosomal RNA genes (18S and 28S rRNA), two mitochondrial ribosomal RNA genes (12S and 16S rRNA) and the mitochondrial protein-encoding gene cytochrome c oxidase subunit I show that the new genus does not cluster with any other described genus of scutigeromorph represented in molecular phylogenies. The data indicate that the new genus is probably sister group to a clade including the genera Lassophora , Ballonema and the subfamily Thereuoneminae, although one analysis suggests a position as sister group to Scutigerinae. ZooBank: urn:lsid:zoobank.org:pub:A4D453F3-9031-4E21-84C7-87F16C07AD51.

First Report of Cockscomb Root Rot Caused by Fusarium solani in Iraq

Cockscomb ( Celosia argentea L.) is one of the most important ornamental plants in Iraq. In August 2021, severe root rot of cockscomb plants was observed, with an incidence of 30%, in all of the nurseries surveyed in the Karbala and Babylon provinces, Iraq. The symptoms appeared as severe leaf chlorosis and wilting with brown discoloration of the stem vascular bundle associated with dark brown lesions on the root that extended to the root collar and became extensive rot. The morphological features of 50% of the fungal colonies were identical and similar to those of Fusarium spp. The internal transcribed spacer, translation elongation factor, RNA polymerase I and II, beta-tubulin 1, and mitochondrial small-subunit ribosomal RNA genes were amplified and sequenced. BLASTn analysis of these genetic markers’ sequences found 99.84 to 100% similarity with the corresponding global sequences of Fusarium solani (Mart.). This identification was confirmed by phylogenetic analysis of the concatenated sequences of the genetic markers. Although F. solani has caused economic damage to a broad range of commercially important plants in Iraq, to our knowledge, this is the first report of F. solani causing root rot of cockscomb ( C. argentea) in Iraq.

Comparison of Kato-Katz, PCR and coproantigen for the diagnosis of Taenia solium taeniasis.

Four methods were compared for the diagnosis of human taeniasis caused by Taenia solium. Fecal samples from persons living in a T. solium endemic region of Madagascar were examined for taeniid eggs by the Kato–Katz method. Subsequently, samples positive (n = 16) and negative (n = 200) for T. solium eggs were examined by (i) amplification of the fragment of small subunit of the mitochondrial ribosomal RNA (rrnS) gene using conventional polymerase chain reaction (PCR) and (ii) a nested PCR of a fragment of the T. solium Tso31 gene. Additionally, 12 egg-positive and all egg-negative samples were tested for coproantigen detection. A further 9 egg-positive fecal samples were examined using both PCRs. Of the 12 egg-positive samples tested by PCRs and coproantigen methods, 9 (75%) were positive by rrnS PCR, 3 (25%) using Tso31-nested PCR and 9 (75%) by coproantigen testing. None of the 200 egg-negative fecal samples was positive in either rrnS or Tso31-nested PCR. Twenty of the 25 egg-positive samples (80%) were positive in rrnS PCR, and DNA sequencing of PCR amplicons was obtained from 18 samples, all confirmed to be T. solium. Twelve of the 25 egg-positive samples (48%) were positive in the Tso31-nested PCR, all of which were also positive by rrnS PCR. It is suggested that species-specific diagnosis of T. solium taeniasis may be achieved by either coprological examination to detect eggs or coproantigen testing, followed by rrnS PCR and DNA sequencing to confirm the tapeworm species in egg-positive or coproantigen-positive samples.

A Pilot Study on The Population Genetic Structure of the Selected Fish Species from Meenachil River, India

Meenachil River is the only river originating from Southern Western Ghats of India having human settlement right from the headwaters to the mouth. The river is subjected to human-induced stressors to varying extents, resulting in a drastic decline in riverine health and fish diversity. The population genetic structure of two species commonly distributed in different geographical zones of Meenachil River, Dawkinsia filamentosa and Pseudetroplus maculatus were studied using the 16S mitochondrial ribosomal RNA gene sequences. Haplotype clustering and the presence of unique haplotypes were identified by phylogenetic and network analysis. Six haplotypes were identified for D. filamentosa and ten for P. maculatus. The neutrality estimations of the upstream and midstream populations of the species revealed the presence of an excess of common alleles with neutral mutations indicating a population expansion after bottleneck and stabilizing selection. The downstream population revealed the presence of an excess of rare alleles with non-neutral mutations indicating a positive directional selection and population sub-division. Population expansion demonstrated star-like phylogenies with rare haplotypes separated by mutational steps from the ancestral haplotypes. The private haplotypes indicated the existence of selection pressure in the downstream zone of the river.

Insights into the phylogeny of the ciliate of class Colpodea based on multigene data

In the class Colpodea, there are many unresolved evolutionary relationships among taxa. Here, we report 30 new sequences including SSU‐rRNA, ITS1‐5.8S‐ ITS2 rRNA, and the mitochondrial small subunit ribosomal RNA (mtSSU‐rRNA) genes of five colpodeans, and conduct phylogenetic analyses based on each individual gene and a two‐gene concatenated dataset. For the first time, multi‐genes were used to analyze phylogenetic relationships in the class Colpodea. The main findings are: (1) SSU‐rRNA, ITS1‐5.8S‐ ITS2 rRNA, and mtSSU‐rRNA gene sequences of C. reniformis and C. grandis are provided for the first time, and these two species group into the clade including C. inflata, C. lucida, C. cucullus, and C. henneguyi; (2) clustering pattern and morphological similarity indicate that Bresslauides discoideus has a close relation with Colpodidae spp.; (3) Emarginatophrya genus diagnosis is improved to be ‘Hausmanniellidae with sharply shortened and isometric leftmost 1‐4 ciliary rows’ and Colpoda elliotti is transferred to Emarginatophrya; (4) the genus Colpoda is still non‐monophyletic with the addition of 10 populations from five Colpoda species sequences, but there are only two Colpoda groups left based on the present work: Group I comprises C. inflata, C. lucida, C. cucullus, C. henneguyi, C. reniformis, and C. grandis, Group II comprises C. maupasi and C. ecaudata, and the presence of diagonal grooves and the way the vestibular opens might be the two key features that differentiates Colpoda species groups; (5) a close molecular relationship, and highly similar merotelokinetal mode, somatic ciliary pattern, and basic organization of the oral apparatus with P. steinii suggests Bromeliothrix metopoides should be temporarily assigned to Colpodidae.

New contributions to the Cyrtophoria ciliates (Protista, Ciliophora): Establishment of new taxa and phylogenetic analyses using two ribosomal genes.

Periphytic ciliates play a vital role in the material cycle and energy flow of microbial food web, however, their taxonomy and biodiversity are inadequately studied given their high species richness. Two new and one little known species, viz. Derouxella lembodes gen. et sp. nov., Cyrtophoron multivacuolatum sp. nov., and Cyrtophoron apsheronica Aliev, 1991, collected from coastal waters of China, were investigated using modern methods. Derouxella gen. nov. can be recognized by having dorsoventrally flattened body, a podite, one fragmented preoral kinety, two parallel circumoral kineties, and somatic kineties progressively shortened from right to left. Morphological classification and phylogenetic analyses based on nuclear small subunit ribosomal RNA (nSSU rRNA) and mitochondrial small subunit ribosomal RNA (mtSSU rRNA) gene sequence data inferred that Derouxella gen. nov. occupies an intermediate position between Hartmannulidae and Dysteriidae. Cyrtophoron multivacuolatum sp. nov. is characterized by large body size, the numbers of somatic kineties and nematodesmal rods, and having numerous contractile vacuoles. The genus Cyrtophoron and the poorly known species C. apsheronica were redefined. Even with the addition of newly obtained nSSU rRNA and mtSSU rRNA gene sequencesof Cyrtophoron, the family Chlamydodontidae was still recovered as a monophyletic group, the monophyly of Cyrtophoron was supported too.

Redescription of Venezillo stuckchensis (Crustacea: Oniscidea: Armadillidae), a terrestrial isopod from the Baja California Peninsula, Mexico

For the Mexican oniscideans of the family Armadillidae, 6 species of the genus Cubaris Brandt, 1833 and 18 species of the genus Venezillo Verhoeff, 1928 have been recorded. Of them, only Venezillo stuckchensis (Mulaik, 1960) has been registered for the Baja California Peninsula (BCP). This species was described upon a single male and no biological studies exist on this taxonomic entity since its original description in 1960. In this work, we redescribe V. stuckchensisincluding the designation of a neotype and paratopotypes using specimens from the type locality. We report this species from 5 additional wetlands of southern BCP in the state of Baja California Sur. The type locality is corrected in its formal name and its geographical location. The morphological identity of V. stuckchensis is documented using SEM micrographs, and data on its molecular identity with 16S ribosomal RNA mitochondrial gene fragments are given.

Phylogenetic Diversity and Phenotypic Characterization of Phlyctema vagabunda (syn. Neofabraea alba) and Neofabraea kienholzii Causing Postharvest Bull's Eye Rot of Apple in Northern Italy.

Bull's eye rot, caused by Phlyctema vagabunda and Neofabraea species, is one of the most important postharvest diseases of apple. South Tyrol (northern Italy) is the largest continuous apple-producing area in Europe, with approximately 1 million tons being produced yearly and conserved in technologically advanced storage facilities for several months. Still, studies on the pathogen species causing postharvest bull's eye rot of apple, as well as their diversity and biology, are lacking for this region. Therefore, the main purpose of the present work was to identify and characterize fungal isolates obtained from decayed apple fruit with symptoms of bull's eye rot that were collected in 2018 and 2019 in different packinghouses in South Tyrol. Among more than 1,000 fungal isolates that were obtained, 419 could be assigned to the genera Phlyctema and/or Neofabraea based on rot symptoms on apple fruit and colony morphology on potato dextrose agar. A smaller subset of 101 representative isolates was further analyzed by DNA sequencing of the internal transcribed spacer region. Furthermore, partial segments of the β-tubulin gene, the translation elongation factor 1α gene, and the 16S mitochondrial ribosomal RNA gene were studied. The phylogenetic analyses, including sequences of reference species, showed that P. vagabunda is the dominant species associated with bull's eye rot of apple in the study area, whereas Neofabraea kienholzii was found only on a small number of apple fruit samples. The combination of multilocus sequence data revealed 11 unique genotypes that belonged to P. vagabunda and four to N. kienholzii. To the best of our knowledge, this study is the first to report N. kienholzii as a postharvest pathogen of apple in Italy. Finally, a pathogenicity test demonstrated different degrees of virulence among selected isolates of P. vagabunda and N. kienholzii on the cultivar Golden Delicious. The present study emphasizes the importance of accurate species identification, because different species may vary in their biological and pathogenic characteristics, and consequently require distinct disease management strategies, both in the field and during the postharvest stages.[Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Rhipicephalus capensis (Acari: Ixodidae), A geographically restricted South African tick, returning with a human traveler to the United States

Accelerated frequency of recreational travel, globalization of business, and legal and illegal plant and animal trades have contributed to enduring introductions of exotic ticks into the United States. We herein report a new incursion of a female Rhipicephalus capensis on a human traveler returning to Connecticut from South Africa. Natural distribution of R. capensis is restricted to the Western Cape Province and southwestern portion of the Northern Cape Province of South Africa, an area called the Fynbos Biome, and adults of this species primarily parasitize large, wild ungulate hosts. Only one previous international introduction of this tick is documented on imported South African plant material into the United States in 1985. The specimen described here was identified initially by morphological means and subsequently, a partial DNA sequence for the mitochondrial ribosomal RNA gene was generated in a PCR assay, which showed 94.86% identity to an R. capensis sequence in GenBank. We also provide information on several other previously unreported or under-reported incursions by South African ticks into the United States in association with imported Fynbos floricultural materials and speckled Cape tortoises, Chersobius signatus. Documentation of these additional exotic tick species incursions highlights ongoing challenges of the international movement of humans, animals, and other goods carrying ticks of human and veterinary importance.

Characterization of mitogenomes from four Mucorales species and insights into pathogenicity.

Mucorales, as one major order of Zygomycetes fungi, can infect human beings and cause serious consequence. We have noticed the pathogenicity of Mucorales is closely related to energy metabolism, while mitochondria play the role of energy factories in almost all biological activities. Virulence of M irregularis, M hiemalis, L corymbifera and R arrhizus were verified in Galleria mellonella larvae, as well as mitochondrial gene copies analysed with RT-qPCR. Mitogenomes of the four Mucorales species were sequenced based on illumina NovaSeq technology to study their characteristic features and functional regions. Variant virulence of M irregularis, M hiemalis, L corymbifera and R arrhizu were verified by clinical retrospective data and our G mellonella infection models, also copies of mitochondrial genes indicated the significant associations with pathogenicity. A total of 274.18 clean reads were generated to be assembled; the complete mitogenomes of the four Mucorales species were obtained with totally different length. After the genomes annotated and compared, M irregularis was found more similar with M hiemalis than those of L corymbifera and R arrhizus, especially the small (rrns) and large (rrnl) subunits of mitochondrial ribosomal RNA (rRNA) genes. The GC content, ncRNAs and the distribution of the SNPs and InDels were also compared, and the GC content rate of fungi seems to be related to the fungal thermal adaptability. In addition, linear mitogenomes of these four Mucorales showed diverse arrangements of orf genes and directionality of some conserved gene elements. This study uncovered the pathogenicity variances among the four Mucorales species and the relationship between their mitogenomic features and clinical pathogenicity. Further studies like spatial structure of mitochondrial genomes and the comprehensive analysis of transcription regulation are needed.

The Caspian red deer, Cervus elaphus maral (Mammalia: Cervidae): a new host record for Rhipicephalus (Boophilus) annulatus (Acari: Ixodidae) in northern Iran

Thirty tick samples were collected from a Caspian red deer in forested areas of Talesh County, Lisar protected area, Gilan province, northern Iran. Tick samples were examined according to morphological characters. In order to specific identification, a fragment (ca. 800-bp) of internal transcribed spacer 2 (ITS2) and a 340-bp fragment of mitochondrial large subunit ribosomal RNA (16S rRNA) gene were amplified by PCR. Nucleotide sequences were analyzed with BLASTn in GenBank. Adult tick samples were identified as female of the genus (subgenus): Rhipicephalus (Boophilus). The results of BLASTn showed that the female ticks belonged to the species Rhipicephalus (Boophilus) annulatus. Our results confirmed the presence of Rhipicephalus (Boophilus) annulatus on Cervus elaphus maral representing the first tick infestation record of the Caspian red deer in Iran. The results suggest a possible establishment of this vector species in a wildlife environment.

A New, Morphologically Cryptic Species of Fanged Frog, Genus Limnonectes (Amphibia: Anura: Dicroglossidae), from Mindoro Island, Central Philippines

We describe a new species of fanged frog (genus Limnonectes) from Mindoro and Semirara Islands, of the Mindoro Pleistocene Aggregate Island Complex, of the central Philippines. Although morphologically indistinguishable from its closest relative, Limnonectes acanthi, of the Palawan faunal region, the two species can be readily diagnosed on the basis of spectral (dominant frequency) and temporal (pulse number and structure) properties of their advertisement calls, and their allopatric insular geographic ranges on permanently separate geological platforms which have not been connected by dry land in the recent geological past—all of which we interpret as congruent and independent lines of evidence supporting our recognition of two independently evolving evolutionary lineages (species). Ribosomal RNA mitochondrial gene sequences were used to provide genetic identification of specimens and estimate phylogenetic relationships; genetic divergences between Palawan and Mindoro faunal regions exceed those estimated among other, uncontroversial, phenotypically distinct Philippine species with equivalent levels of allopatry and biogeographic isolation. The recognition of the new species further emphasizes the degree to which even well-studied Philippine landmasses still harbor unrecognized biodiversity, and suggests that other widespread Philippine fanged frogs should be scrutinized for non-traditional diagnostic character differences (mate-recognition signal divergence, ecological differences, larval characteristics, life-history trait variation), especially when their geographic ranges span the archipelago's permanent, deep-water trenches, which define its well-characterized Pleistocene Aggregate Island Complexes.

Genetic diversity of Pneumocystis jirovecii isolates among Turkish population based on mitochondrial large subunit ribosomal RNA and dihydropteroate synthase gene typing.

Pneumocystis jirovecii (P. jirovecii) is an atypical fungus that can cause life-threatening pneumonia in immunocompromised patients. In this study, we investigated the mtLSU-rRNA and DHPS gene polymorphisms in P. jirovecii isolates from both hospital and autopsy cases.

First molecular characterization of the small subunit ribosomal RNA gene of Hysterothylacium fabri larvae (Nematoda: Raphidascarididae) from Mediterranean Sea

Hysterothylacium fabri is commonly reported in various Mediterranean fish. However, there is no data on the mitochondrial ribosomal RNA (rrnS) gene sequence of H. fabri larvae in the Mediterranean Sea waters. Therefore, we aimed to reveal molecular characterization of H. fabri based on the rrnS gene sequence in the current study. Firstly, the fourth stage of H. fabri larvae were identified at parasitological examination from Mullus barbatus in the Mediterranean Sea. Morphologically identified H. fabri larvae herein were also supported by the sequencing of the nuclear ribosomal ITS gene regions. In the next step, the rrnS gene of these larvae was molecularly analysed. Our H. fabri isolate (MK886659) showed 96.42% identity with H. fabri reported from China (MF140349) based on the rrnS gene. The nucleotide difference based on the rrnS gene between Chinese isolate (MF140349) and our H. fabri isolate (MK886659) was determined as 3.2%. Consequently, for the first time, the mitochondrial rrnS gene sequencing of H. fabri from the Mediterranean waters were performed in the current study.

Fast and Accurate Pneumocystis Pneumonia Diagnosis in Human Samples Using a Label-Free Plasmonic Biosensor.

Pneumocystis jirovecii is a fungus responsible for human Pneumocystis pneumonia, one of the most severe infections encountered in immunodepressed individuals. The diagnosis of Pneumocystis pneumonia continues to be challenging due to the absence of specific symptoms in infected patients. Moreover, the standard diagnostic method employed for its diagnosis involves mainly PCR-based techniques, which besides being highly specific and sensitive, require specialized personnel and equipment and are time-consuming. Our aim is to demonstrate an optical biosensor methodology based on surface plasmon resonance to perform such diagnostics in an efficient and decentralized scheme. The biosensor methodology employs poly-purine reverse-Hoogsteen hairpin probes for the detection of the mitochondrial large subunit ribosomal RNA (mtLSU rRNA) gene, related to P. jirovecii detection. The biosensor device performs a real-time and label-free identification of the mtLSU rRNA gene with excellent selectivity and reproducibility, achieving limits of detection of around 2.11 nM. A preliminary evaluation of clinical samples showed rapid, label-free and specific identification of P. jirovecii in human lung fluids such as bronchoalveolar lavages or nasopharyngeal aspirates. These results offer a door for the future deployment of a sensitive diagnostic tool for fast, direct and selective detection of Pneumocystis pneumonia disease.

Rapid, one-step DNA extraction for the identification of German cockroach, Blattella germanica (L.) (Dictyoptera: Blattellidae) using DNA sequence of mitochondrial ribosomal RNA gene (16S rRNA gene)

In this study, DNA sequencing was used to study species identification and phylogeny of German cockroach that has medical importance, So, the comparisons can be made with specific region of mitochondrial ribosomal RNA gene (16S rRNA gene) of two collected Blattella germanica the first from central city of Mashhad (GM), Iran, and the second from city of Tehran (GT), Iran, and other individuals of B. germanica from different areas, that already have been recorded in the BLAST database, on the basis of the Single Nucleotide Polymorphisms (SNPs), nucleotide substitutions, and DNA and putative amino acid sequence data. Also, a phylogeny for these cockroaches based on the DNA sequence of the 16S rRNA genes is offered. Our results indicated that the nucleotide sequence of the B. germanica (GM) matched with sequences from other subspecies, except the (thymine–adenine) SNPs at position 15 and 19 of the 376-bp, and the nucleotide sequence of B. germanica (GT), also, matched with sequences from other subspecies, except (adenine-guanine) SNP at position 360-bp, and (thymine-guanine) SNP at position 368-bp of a portion of the 16s rRNA gene. Therefore, the B. germanica (GM), B. germanica (GT), and B. germanica isolates in BLAST database were different among them. Furthermore, we found that the forward (LR-J-13017) primer and reverse (LR-N-13398) primer were very impressive to distinguish among cockroaches belong sub-order Dictyoptera especially German cockroach. As well, these primers were produced a small DNA fragment of the 16S rRNA gene that includes all SNPs required for B. germanica isolates identification.

Insight Into the Microbial Co-occurrence and Diversity of 73 Grapevine (Vitis vinifera) Crown Galls Collected Across the Northern Hemisphere.

Crown gall (CG) is a globally distributed and economically important disease of grapevine and other important crop plants. The causal agent of CG is Agrobacterium or Allorhizobium strains that harbor a tumor-inducing plasmid (pTi). The microbial community within the CG tumor has not been widely elucidated and it is not known if certain members of this microbial community promote or inhibit CG. This study investigated the microbiotas of grapevine CG tumor tissues from seven infected vineyards located in Hungary, Japan, Tunisia, and the United States. Heavy co-amplification of grapevine chloroplast and mitochondrial ribosomal RNA genes was observed with the widely used Illumina V3–V4 16S rRNA gene primers, requiring the design of a new reverse primer to enrich for bacterial 16S rRNA from CG tumors. The operational taxonomic unit (OTU) clustering approach is not suitable for CG microbiota analysis as it collapsed several ecologically distinct Agrobacterium species into a single OTU due to low interspecies genetic divergence. The CG microbial community assemblages were significantly different across sampling sites (ANOSIM global R = 0.63, p-value = 0.001) with evidence of site-specific differentially abundant ASVs. The presence of Allorhizobium vitis in the CG microbiota is almost always accompanied by Xanthomonas and Novosphingobium, the latter may promote the spread of pTi plasmid by way of acyl-homoserine lactone signal production, whereas the former may take advantage of the presence of substrates associated with plant cell wall growth and repair. The technical and biological insights gained from this study will contribute to the understanding of complex interaction between the grapevine and its microbial community and may facilitate better management of CG disease in the future.

Molecular characterization of Hysterothylacium aduncum (Nematoda: Raphidascarididae) larvae infecting Merlangius merlangus euxinus (Linnaeus, 1758) from the Turkish Black Sea coast based on mitochondrial small subunit ribosomal RNA gene analysis

The taxonomy of Hysterothylacium genus remains incomplete and unclear in Turkish waters. In the present study, H. adumcum larvae were morphologically identified from Merlangius merlangus euxinus in the Black Sea, Turkey. The nuclear ribosomal ITS regions (ITS-1, 5.8S subunit, ITS-2) and the small subunit of the mitochondrial ribosomal RNA (rrnS) gene of H. aduncum were amplified and sequenced. The BLAST analysis indicated that present ITS sequences of H. aduncum were identical to that of the reference sequence of H. aduncum (accession no JX413596) recorded previously from the Black Sea, Turkey. The present rrnS gene of H. aduncum from the Black Sea, Turkey (MK886768) showed 97.94 to 99.56% identity with isolates of H. aduncum from the Mediterranean Sea (MF000685-MF000691) and the Chinese waters (MF140344). Moreover, pairwise comparison between the rrnS sequences of the H. aduncum from the Black Sea, Turkey (MK886768) and others H. aduncum isolates from the Mediterranean Sea (MF000685-MF000691), the Chinese waters (MF140344) showed differences ranged from 0.2 and 1.7%. With the present study, H. aduncum from the Black Sea was characterized for the first time by sequencing of the mitochondrial rrnS gene.

Mitocondrial COI and 16S rDNA sequences support morphological identification and biogeography of deep-sea red crabs of the genus Chaceon (Crustacea, Decapoda, Geryonidae) in the Eastern Central and South Atlantic Ocean.

The geographical spreading of new fishing activities and the increasingly deeper locations of these activities have shown the worldwide distribution of gerionid crabs and new descriptions of Chaceon taxa. However, incomplete penetrance, variable expressivity, and phenotypic overlap make the morphometric identification of these species difficult. In this study, partial sequences of the cytochrome c oxidase subunit 1 (COI) and 16S mitochondrial ribosomal RNA (16S rRNA) genes have been analyzed in Chaceon species from the Eastern Central and South Atlantic and compared with sequences of species from Western Atlantic. Our results corroborate the proposed morphological species and highlight the significant separation of the Eastern Atlantic species and those from Atlantic coasts of South America for both markers (97% Bayesian posterior probability, BPP / 83% Bootstrap replicates, BT). Interestingly, Chaceon sanctaehelenae shows a closer relationship with the species of the American coast than with those from the Eastern Atlantic. On the other hand, while COI marker clearly separates Chaceon atopus and Chaceon erytheiae species (99 BPP / 91% BT), these species share haplotypes for the 16S rRNA marker, pointing to a recent speciation process. Moreover, a close relationship was observed between Chaceon maritae and Chaceon affinis (94% BPP / 77% BT). The topologies of the trees obtained indicate that the ancestor of this genus was closer related to those species from South America than to those from the Eastern Atlantic.

Molecular detection of Pneumocystis in the lungs of cats.

The genus Pneumocystis comprises potential pathogens that reside normally in the lungs of a wide range of mammals. Although they generally behave as transient or permanent commensals, they can occasionally cause life-threatening pneumonia (Pneumocystis pneumonia; PCP) in immunosuppressed individuals. Several decades ago, the presence of Pneumocystis morphotypes (trophic forms and cysts) was described in the lungs of normal cats and cats with experimentally induced symptomatic PCP (after immunosuppression by corticosteroids); yet to date spontaneous or drug-induced PCP has not been described in the clinical feline literature, despite immunosuppression of cats by long-standing retrovirus infections or after kidney transplantation. In this study, we describe the presence of Pneumocystis DNA in the lungs of normal cats (that died of various unrelated causes; n = 84) using polymerase chain reactions (PCRs) targeting the mitochondrial small and large subunit ribosomal RNA gene (mtSSU rRNA and mtLSU rRNA). The presence of Pneumocystis DNA was confirmed by sequencing in 24/84 (29%) cats, with evidence of two different sequence types (or lineages). Phylogenetically, lineage1 (L1; 19 cats) and lineage 2 (L2; 5 cats) formed separate clades, clustering with Pneumocystis from domestic pigs (L1) and carnivores (L2), respectively. Results of the present study support the notion that cats can be colonized or subclinically infected by Pneumocystis, without histological evidence of damage to the pulmonary parenchyma referable to pneumocystosis. Pneumocystis seems most likely an innocuous pathogen of cats’ lungs, but its possible role in the exacerbation of chronic pulmonary disorders or viral/bacterial coinfections should be considered further in a clinical setting.