Cox1 Gene Sequences Research Articles

Molecular characterization of Peronospora variabilis isolates infecting Chenopodium quinoa and Chenopodium album in Spain.

Quinoa is an expanding crop in Southern Spain. Downy mildew, caused by Peronospora variabilis, is the most important quinoa disease in Spain and worldwide. In Spain, this disease has also been observed oin the weed Chenopodium album. The objectives of this study were to unravel the origin of the P. variabilis isolates currently infecting quinoa in Southern Spain and to study their genetic diversity. We hypothesized that P. variabilis isolates infecting quinoa in Spain could have been introduced through the seeds of the quinoa varieties currently grown in the country, or, alternatively, that these isolates are endemic isolates, originally infecting C. album, that jumped to quinoa. In order to test these hypotheses, we sequenced the ITS, cox1 and cox2 regions of 33 P. variabilis isolates infecting C. quinoa and C. album in Southern Spain and analysed their phylogenetic relationship with isolates present in other countries infecting Chenopodium spp. cox1 gene sequences from all the Spanish P. variabilis isolates were identical and exhibited 9 SNPs compared to a single P. variabilis cox1 sequence found at GenBank. Phylogenetic analyses based on ITS rDNA region were not suitable to differentiate isolates according to their geographical origin or host. Cox2 sequences from P. variabilis Spanish isolates collected from C. quinoa and C. album were all identical and had a distinctive SNP in the last of four polymorphic sites that distinguished Spanish isolates from isolates from other countries. These results suggest that P. variabilis infecting quinoa in Southern Spain could be native isolates infecting originally C. album.

Molecular Characterization of Avitellina lahorea Woodland, 1927 (Class Cestoda; Family Anoplocephalidae) Infecting Sheep and Goats Raised in India.

Tapeworms of Avitellina spp. are among those gastrointestinal parasitic helminths which infect wild and domestic ruminants worldwide leading to various clinical manifestations in the ruminant hosts, thereby causing considerable economic losses in livestock production. While these worms are among the major constraints in ruminant livestock raising, there is very meagre molecular information available making their identity error-prone. This study aimed to provide insights into the genetic characterization of these economically important tapeworms. In the present study, we examined 480 guts of slaughtered goats (n = 413) and sheep (n = 67) of which 74 guts were found infected with anoplocephalid cestodes (sheep gut:18; goat gut:56). A total of 27 Avitellina lahorea worms (19 from goat and 8 from sheep) were isolated, fixed, relaxed and stained using Gower's carmine stain. For molecular analyses, the genomic DNA was extracted and fragments of cytochrome c oxidase subunit 1 (cox1) gene, internal transcribed spacer1-5.8S ribosomal RNA (ITS1-5.8S rRNA) gene, and small subunit ribosomal RNA (18S rRNA) gene were amplified and sequenced. Based on snail-shaped paruterine organs and other morphological and morphometric features, the worms were identified as Avitellina lahorea. The phylogenetic analyses, based on our original cox1 gene sequence and those available from NCBI GenBank, showed Avitellina tapeworms as a sister lineage of Thysaniezia with 14 to 17% genetic divergence. Molecular analyses of 18S rRNA gene sequences depicted the present isolate as one of the species of the genus Avitellina clustering with A. centripunctata as a separate species in the phylogenetic tree with 92% homogeneity in sequences. In conjunction with existing data of internal transcribed spacer1-5.8S rRNA (ITS1-5.8S rRNA) gene, the phylogenetic analysis placed the present isolate among the anoplocephalids as one of the species. The present study is the first molecular report on A. lahorea isolated from sheep and goats with the simultaneous use of a morphological approach, and certainly contributes to bridging the existing gaps in the understanding of these economically important parasites.

Taxonomic study of Scytosiphon (Phaeophyceae) from temperate coasts of Argentina.

Scytosiphon is a common intertidal genus widely distributed on temperate coasts worldwide. Recently, eight species have been delimited with molecular tools. Although S. lomentaria is the only species that predominates in the macroalgal literature of the Southwestern Atlantic Ocean (SwAO), unpublished molecular data obtained for a population study of S. lomentaria revealed hidden species diversity of Scytosiphon among the individuals collected from four localities at the SwAO. The aim of this study was to revise the identity and phylogenetic relationships of Scytosiphon from temperate coasts of the SwAO using DNA data. Thalli were collected from the Argentinean coast between 39° S and 43° S, from which cox1 and rbcL gene sequences were obtained. Phylogenies and haplotype networks were inferred and morphology of gametophytes was studied. Four species were recognized, S. lomentaria, S. promiscuus, S. shibazakiorum, and one species that belongs to a complex of species known as "Scytosiphon Atlantic complex." This complex was known to occur only in the North Atlantic, however, the results found in this study revealed that it has an extended distribution range that includes the southern hemisphere, where its populations have high genetic diversity and unique haplotypes. The morphological differences among the four species were subtle; denoting that previous Scytosiphon records from the SwAO attributed to the renowned S. lomentaria could represent different species. In addition, sex ratio and genome-wide single nucleotide polymorphisms (SNPs) analyses were done for populations of S. promiscuus presumably introduced to the SwAO, and the results indicated that they included female-dominant parthenogenetic populations, which were probably introduced from Japan.

The Surveillance of Borrelia Species in Camelus dromedarius and Associated Ticks: The First Detection of Borrelia miyamotoi in Egypt

A total of 133 blood samples and 1596 adult hard ticks were collected from Camelus dromedaries at Cairo and Giza slaughterhouses in Egypt. Tick species were identified by examining their morphology and sequencing the cytochrome C oxidase subunit 1 (cox1) gene. Borrelia spp. was detected using nested PCR on the IGS (16S-23S) gene, and positive samples were genotyped using 16S rRNA and glpQ spp. genes specific for Borrelia burgdorferi and Borrelia miyamotoi, respectively. The positive PCR products were sequenced and analyzed by phylogenetic tree. Analysis of the cox1 gene sequence revealed that the adult ticks belonged to three genera; Hyalomma (H), Amblyomma (Am), and Rhipicephalus (R), as well as 12 species, including H. dromedarii, H. marginatum, H. excavatum, H. anatolicum, R. annulatus, R. pulchellus, Am. testudinarium, Am. hebraeum, Am. lipidium, Am. variegatum, Am. cohaerens and Am. gemma. Borrelia spp. was found in 8.3% (11/133) of the camel blood samples and 1.3% (21/1596) of the ticks, respectively. Sequencing of the IGS (16S-23S) gene found that B. afzelii, detected from H. dromedarii and H. marginatum, and B. crocidurae, which belongs to the RF group, was detected from one blood sample. B. burgdorferi and B. miyamotoi were discovered in the blood samples and tick species. Phylogenetic analysis of the glpQ gene showed that the B. miyamotoi in this study was of the Asian and European types. These results suggest that the camels can be infected by Lyme borrelia and other Borrelia bacteria species. This study also provides the first insight into the presence of Borrelia miyamotoi and B. afzelii DNA in camels and associated ticks in Egypt.

Identification and molecular classification of passeriform birds in Kabul province

It is thought that the passiform order of bird has monophyletic origin.. However, new studies show that many passerine families are not monophyletic in traditional classifications, and a more complete understanding of Passeriform phylogeny is possible only by conducting extensive molecular studies. Therefore, this molecular study was conducted to evaluate the passiform birds of Kabul Province, Afghanistan. Samplings were collected from ten already marked stations during three stages in Kabul province in 2019 and 2021 years, including Deh Sabz, Bagrami, Sarubi, Khak Jabar, Shekar Dara, Gol Dara, Paghman, Char Asiyab, Andrabi Road and Kafroshi. Totally 190 samples were taken using a net. Miss net was collected and 110 samples were taken to the laboratory. After the morphological studies, it was identified by the identification key that all the species belong to the Passeriform order. These species belong to 13 families, 23 genera and 35 species, of which the family of yellow-winged moths is the most diverse with 7 species and the family of sparrows is the most abundant with 45 individuals. After performing morphometry, the samples were transferred to the laboratory for molecular studies and DNA extraction and COX1 gene sequencing to identify the species in the tree drawn by Bayesian method which shows the position of genera and species within families and superfamilies. In this study, genus Passer with four species, genus Motacilla with one species, genus Carduelis with one species, genus Emberiza with six species and genus Serinusa with one species were included in the superfamily Passerioiodea. The genus Corvus with one species and the genus Lanius with one species were included in the Corvida clade. Two species of the genus Luscinia with one species of the genus Muscicapa and one species of the genus Acridotheres were included in the superfamily Muscicapoidea. Two species of the genus Hirundo, one species of the genus Phylloscopus, one species of the genus Ripria, one species of the genus Sitta, one species of the genus Sylvia and one species of the genus Eremophila were included in the superfamily Sylvioidea.

New record of Tylodelphys metacercariae (Diplostomidae) from Perccottus glenii (Odontobutidae) and their phylogenetic assessment.

Metacercariae of Tylodelphys sp. were found in the abdominal cavity of the Chinese sleeper (Perccottus glenii) collected in Liaoning Province and Inner Mongolia Autonomous Region of China. The sequences of the mitochondrial cox1 gene and ribosomal ITS1-5.8S rDNA-ITS2 region were obtained and used for molecular identification and phylogenetic assessment of this parasite species. Results of phylogenetic analyses based on ITS and cox1 markers showed that the metacercariae of Tylodelphys sp.ex P. glenii from China were conspecific with specimens of Tylodelphys sp. collected by Sokolov etal. (2013) from the same fish-host species captured earlier in West Siberia, Russia. The examined Tylodelphys sp. ex. P. glenii is the only member of the genus whose metacercariae parasitise the abdominal cavity of fish in northern Eurasia. Tylodelphys sp. ex P. glenii clustered with T. darbyi, T. immer, T.podicipina, and Tylodelphys sp. of Soldánová etal., 2017 based on mitochondrial DNA markers, and with T. darbyi, T. immer, T. kuerepus, and T. schreuringi using nuclear DNA markers.

The prevalence and risk factors of Spirocerca lupi in domestic dogs in the Mekong Delta of Vietnam

Spirocercosis is caused by Spirocerca spp., which is a chronic disease and might cause life-threatening due to forming cancer in oesophagus in canid carnivores. There are limited studies involving spirocercosis in domestic dogs. Thus, this study aims to investigate the prevalence and analyse risk factors involved in the S. lupi infection in Mekong Delta in Vietnam. In total, 400 fecal samples from domestic dogs were collected from May 2020 to May 2021. The overall prevalence of spirocercosis in domestic dogs in the Mekong Delta was 10.50% by copromicroscope and PCR methods. PCR targeted to the housekeeping gene cytochrome c oxidase I (cox-1) was applied to identify species of Spirocerca spp. and analyse the phylogenetic tree. Outdoor dogs had 5.48 times (CI 95% = 2.45-11.690, p < 0.001) higher risks of S. lupi infection compared to indoor dogs. Besides, seasons and age showed a correlation to the increase the risk of S. lupi infection, while neither dog breeds nor gender influenced the prevalence of this species. The cytochrome c oxidase I (cox-1) gene sequence of S. lupi in the Mekong Delta showed the high homologues to the S. lupi isolates in India, Israel, and the North of Vietnam and belonged to the S. lupi genotype 2.

Fleas from the Silk Road in Central Asia: identification of Ctenocephalides canis and Ctenocephalides orientis on owned dogs in Uzbekistan using molecular identification and geometric morphometrics

BackgroundThe Silk Road connected the East and West for over 1500 years. Countries in Central Asia are valuable in addressing the hypothesis that parasites on domestic animals were introduced along the Silk Road. Adult fleas are obligate parasites, having worldwide distribution. In dogs, Ctenocephalides canis, C. felis and C. orientis are the most common species identified. The distribution of the Oriental cat flea, C. orientis, is restricted to southeast Asia. The purpose of this study was to determine the diversity of dog fleas from Uzbekistan, a country in Central Asia, with particular reference to C. orientis.MethodsFleas were collected from 77 dogs from 5 locations in Uzbekistan. The cox1 gene sequences from Ctenocephalides spp. were compared to global collection of Ctenocephalides cox1 haplotypes. Landmark-based geometric morphometrics have been applied to the head and curvature to compare C. canis and C. canis using canonical variate analysis and discriminant function analysis.ResultsOverall, 199 fleas were collected and identified as C. canis (n = 115, 58%), C. orientis (n = 53, 27%) and Pulex irritans (n = 22, 11%). None of the fleas were C. felis. All Ctenocephalides spp. fleas were subject to cox1 amplification and 95% (166/175) yielded DNA sequence. There were 25 cox1 haplotypes; 14 (22/25, 88%) were C. canis cox1 haplotypes and 3 (3/25, 12%) were C. orientis cox1 haplotypes. Molecular analysis confirmed the absence of C. felis. Four (4/22) and one (1/3) cox1 haplotypes were identical to cox1 haplotypes belonging to C. canis and C. orientis cox1 haplotypes identified elsewhere, respectively. Overall morphometric analysis confirmed significant differences between the head shape of C. canis and C. orientis and improved four–fivefold the species identification compared to traditional morphological key.ConclusionWe report for the first time the presence of C. orientis in Uzbekistan. Differentiation of C. orientis from C. canis and C. felis remains difficult in regions where these species coexist. Studies in Central and Southeast Asia should confirm species identity using cox1 locus to enable retracing of the distribution of the Ctenocephalides in Asia. The presence of C. orientis suggests that this species may have been introduced from the east along the ancient Silk Road.Graphical

Spatial Pattern of Genetic Diversity in the Blood Fluke Aporocotyle argentinensis (Digenea, Aporocotylidae) from South American Hakes (Pisces: Merluccidae)

Distribution of blood fluke Aporocotyle spp. parasitizing Merluccius species from the coasts of South America (Peru, Chile and Argentina) constitutes an excellent opportunity to evaluate the geographical amplitude in which a parasite can exploit the same host species. Phylogenetic analyses (partial sequences of SSU rDNA, LSU rDNa, and cox1 gene) were performed to characterize the genetic lineage of Aporocotyle species described from South American Hake: Merluccius australis, M. gayi, and M. hubbsi. The Phylogenetic analyses (SSUrDNA and LSUrDNA) revealed an absence of genetic variability in Aporocotyle obtained over a gradient of 6800 km, covering two oceans and three closely related hosts. Consequently, the species infecting Merluccius spp. in South America is Aporocotyle argentinensis Smith 1969, by priority law. Phylogeographic analysis suggests a pattern of spatial differentiation and genetic population structure associated with the geographical distribution of the host’s species. A specimen with a haplotype found in M. gayi was collected from M. australis from Puerto Montt, and three worms (from Coquimbo, Constitución and Talcahuano, host M. gayi) harbored a haplotype found in M. australis + M. hubbsi, suggesting that the gene flow between different hosts and geographical distributions occurs when the distribution of adequate hosts overlaps, avoiding speciation in blood flukes from South American hakes.

Molecular characterisation of the Monogenea parasites of blue mackerel Scomber australasicus (Perciformes: Scombridae) in Australian waters

This study describes the occurrence and molecular identification of Monogenea from blue mackerel Scomber australasicus (Cuvier) (Perciformes: Scombridae), an edible fish, from Australian waters. Previous studies have provided either morphological or genetic results, whereas this study combines both methods of species identification. A total of 50 fish sourced from the waters off the south-eastern Australian coastline were examined and 71 Monogenea were recovered from the gills. The overall prevalence, mean intensity, and mean abundance were 64%, 2.22, and 1.42, respectively. Monogenea were initially classified morphologically as five species belonging to two families. Family Mazocraeidae was represented by Kuhnia scombri (Kuhn, 1829) Sproston, 1945, K. scombercolias Nasir & Fuentes Zambrano, 1983 and Pseudokuhnia minor (Goto, 1894) Rohde & Watson, 1985 and family Gastrocotylidae by Gastrocotyle kurra Unnithan, 1968 and Allogastrocotyle bivaginalis Nasir & Fuentes Zambrano, 1983. Molecular identification of Monogenea was conducted through sequencing of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. The host S. australasicus was barcoded (cox1) to confirm the specific identity. There was no comparable sequence available in GenBank for K. scombercolias. Also, limited sequences were available in GenBank for the gastrocotylid Monogenea identified in this study. However, phylogenetic analyses of cox1 sequences of the Monogenea identified in this study clustered according to their familial groups. Gastrocotyle kurra and A. bivaginalis were identified for the first-time on S. australasicus in Australian waters. This study provides the first sequencing of cox1 gene for K. scombercolias. The outcomes of the study provide a basis for future Monogenea research in Australian waters, as well as for other Scomber spp.

Species complexes and life cycles of digenetic trematodes from the family Derogenidae.

The best way to study digenean diversity combines molecular genetic methods, life-cycle studies and elaborate morphological descriptions. This approach has been barely used for one of the most widespread digenean taxa parasitizing fish – the superfamily Hemiuroidea. Here, we applied the integrative approach to the hemiuroideans from the family Derogenidae parasitizing fish at the White and Barents Seas. Analysis of 28S, 18S, 5.8S rDNA, ITS2 and cox1 gene sequences from sexually adult worms (maritae) showed genetic heterogeneity for 2 derogenid species known from this area: Derogenes varicus and Progonus muelleri. Thus, 2 pairs of genetic lineages were found: DV1 and DV2, PM1 and PM2, respectively. Data from other regions indicate that 2 more lineages of D. varicus probably exist. Based on previous records from the White and Barents Seas, we hypothesized that the cercariae found in the moonsnails (family Naticidae) belong to the Derogenidae and may help to differentiate these lineages as species. According to our results, Cercaria appendiculata from Cryptonatica affinis matched DV1, similar nameless cercariae from Euspira pallida and Amauropsis islandica matched DV2, and Cercaria octocauda from C. affinis matched PM1. We provide new data on the structure of these cercariae and discuss the life-cycle pattern of the studied digeneans.

From Argentine Abyssal Plain to farmed turbot in Spain: A ubiquitous amoeba species Vannella robusta sp. nov. (Amoebozoa, Vannellida)

A strain with the characters of the genus Vannella was isolated from the water layer immediately above the deep-sea sediment collected in the south-western Atlantic Ocean, ca. 4.6 km deep. Small-subunit ribosomal RNA (SSU rRNA) and cytochrome c oxidase (Cox1) gene phylogenetic analyses showed that the new strain branches within the clade of previously isolated unnamed Vannella strains from different marine fish and invertebrate hosts. Although the SSU rRNA gene sequences of these strains show variability within 2% of all nucleotide positions without any regular pattern, the available Cox1 gene sequences from within this clade are identical. Given the morphological homogeneity of the revealed clade, all of its strains can be assigned under the same species name, and the variation of their SSU rRNA is comparable to its intragenomic variation, as shown by molecular cloning of the PCR amplicons. High variability of the SSU rRNA gene sequences within and between independently isolated morphologically identical strains in combination with highly conserved Cox1 gene sequences may be a feature in some clades of Vannella, but is not a general rule for this genus, as SSU rRNA genes conserved between different morphospecies occur in several other clades within Vannella.

Phylogenetic relationships of Ochoterenatrema Caballero, 1943 (Digenea: Lecithodendriidae) with descriptions of two new species.

Ochoterenatrema is a small genus of lecithodendriid digeneans that includes six species parasitic in Neotropical bats in North and South America. Members of this genus are characterized by the presence of a pseudogonotyl formed by thickened tegument on the left side of the ventral sucker. We examined morphology of specimens belonging to five species of Ochoterenatrema from Brazil, Ecuador and the USA and describe two new Ochoterenatrema spp. (Ochoterenatrema sphaerula n. sp. and Ochoterenatrema gracilis n. sp.). These new species are readily differentiated from their congeners by a combination of morphological characters, including the distribution of vitelline follicles and the body shape. We have provided the first DNA sequences for Ochoterenatrema. Newly generated partial nuclear 28S rDNA and mitochondrial cox1 gene sequences were used to differentiate among species and study the phylogenetic affinities of Ochoterenatrema spp., including one of the new species, O. gracilis n. sp., as well as Ochoterenatrema diminutum, Ochoterenatrema fraternum and Ochoterenatrema cf. labda. The phylogeny of the Microphalloidea based on 28S had well-supported topology, particularly at the family level. The Ochoterenatrema clade was strongly supported; however, the internal topology of the clade was weakly supported. Comparison of sequences revealed 0.4-1.3% interspecific divergence in 28S and 9.1-19.7% interspecific divergence in cox1 among Ochoterenatrema spp. We hypothesize that extremely diverse fauna of bats in South and Central America harbors multiple undescribed species of Ochoterenatrema. Several lecithodendriid genera from bats and other hosts are yet to be included in future molecular phylogenetic analyses to test the monophyly of this extremely diverse digenean family and analyze evolutionary affinities of its constituent taxa.

Finding a needle in a haystack: larval stages of Didymozoidae (Trematoda: Digenea) parasitizing marine zooplankton.

Larval didymozoids (Trematoda: Digenea) were discovered parasitizing the hemocoel of the heteropod Firoloida desmarestia (redia mean intensity = 13) and the chaetognaths Flaccisagitta enflata and Flaccisagitta hexaptera (metacercaria mean intensity = 1) during a 2014-2016 systematic study of parasites of zooplankton collected in the central and southern regions of the Gulf of California, Mexico. Didymozoid infection route during the early life cycle was inferred combining morphological (light microscopy) and molecular (mitochondrial cytochrome c oxidase subunit I gene, cox1) evidence. Didymozoid rediae parasitizing F. desmarestia were observed, just after field collection of the host, containing hundredths of completely developed cystophorous cercariae, releasing them though the birth pore at approximately one cercaria every 12s. Cercariae lost their tails developing into a 'young metacercaria' in 1 d at 22°C without need of an intermediate host. Molecular analysis of cox1 showed that rediae found in F. desmarestia belong to two distinct didymozoid species (Didymozoidae sp. 1 and sp. 2). Metacercariae parasitizing chaetognaths were morphologically identified as Didymozoidae type Monilicaecum and cox1 sequences showed that metacercariae of chaetognaths matched with these two Didymozoidae sp.1, and sp. 2 species found parasitizing F. desmarestia, plus a third distinct Didymozoidae sp. 3. These are the first DNA sequences of cox1 gene from didymozoid larvae for any zooplankton taxonomic group in the world. We concluded that F. desmarestia is the first intermediate host of rediae and cercariae, and the chaetognaths are the second intermediate hosts where non-encysted metacercariae were found. The definitive host is still unknown because cox1 sequences of present study did not genetically match with any available cox1 sequence of adult didymozoid. Our results demonstrate a potential overlap in the distribution of two carnivorous zooplankton taxonomic groups that are intermediate hosts of didymozoids in the pelagic habitat. The didymozoid specimens were not identified to species level because any of the cox1 sequences generated here matched with the sequences of adult didymozoids currently available in GenBank and Bold System databases. This study provides baseline information for the future morphological and molecular understanding of the Didymozoidae larvae that has been previously based on the recognition of the 12 known morphotypes.

Morphological, histopathological and molecular characterization of parasitic ciliate Ichthyophthirius multifiliis infecting an indigenous and endangered fish, Schizothorax macropogon (Cyprinidae: Schizothoracinae) in high plateau, Tibet, China

Ichthyophthirius multifiliis Fouquet, 1876 is an important parasitic pathogen of freshwater fish, with low host specificity and broad geographical distribution. However, the epizootic occurrence of ichthyophthiriasis in high plateau has been rarely reported. In the present study, infection of I. multifiliis was found in juvenile fish of an indigenous and endangered fish Schizothorax macropogon Regan, 1905 (Cyprinidae: Schizothoracinae) in high plateau of Tibet, China, which caused mass mortality of the host. To understand the characteristics of this I. multifiliis isolate in Tibet, a morphological, histopathological and molecular study was performed to compare with another isolate of I. multifiliis from Tachysurus fulvidraco Richardson, 1846 in Guangdong province, China. Despite the distribution in different altitudes, obvious difference was not found in the two isolates in relation with infection site, morphology, ultrastructure and histopathology. The analysis of COX-1 gene, SSU rDNA and ITS1-5.8S rDNA-ITS2 sequences cloned from the two isolates in the present study showed that variable sites were found only in COX-1 gene sequences, which indicated that COX-1 gene was the most effective marker to distinguish different isolates of I. multifiliis. Phylogenetically, all I. multifiliis isolates can be divided into three genetically distinct groups, and the two isolates identified in the present study were placed in different groups. In consideration of the high plateau and low water temperature in Tibet, the possible differentiation of I. multifiliis is of interest for further investigation.

A re-evaluation of conflicting taxonomic structures of EurasianTriaenophorusspp. (Cestoda, Bothriocephalidea: Triaenophoridae) based on partialcox1mtDNA and 28S rRNA gene sequences

Cestodes of the genus Triaenophorus Rudolphi, 1793 are widely distributed parasites of Esocidae, Percidae, Salmonidae, Thimallidae, Cobitidae, Osmeridae, Cyprinidae, Cottiidae, Lotidae, and several others in the Holarctic. The taxonomic arrangements of different authors, based on morphological and ecological–biogeographic characters, suggest the presence of two to five species of this genus in Eurasia. The genetic variation of Eurasian Triaenophorus spp. was evaluated using DNA barcoding ( cox1 and 28S gene sequences). This confirmed the validity of five Triaenophorus species: T. amurensis, T. crassus, T. meridionalis, T. nodulosus, and T. orientalis. We demonstrated systematic concordance between traditional meristic criteria and DNA sequence data. Phylogenetic reconstructions support the monophyletic origin of the group of species with a long basal plate of the scolex hook ( T. crassus, T. meridionalis, and T. orientalis). Triaenophorus crassus is represented by two haplogroups, associated with Siberia and northwestern Russia. Our results show differences between T. nodulosus, T. amurensis, and T. crassus in terms of the haplotype diversity level, which are probably related to the Quaternary history of the development of their ranges, as well as the degree of euryxeny to the second intermediate host.

Characterization of the complete mitochondrial genome of Dendroctonus valens and elimination of nuclear mitochondrial pseudogene interference

AbstractNuclear mitochondrial pseudogenes (numts) are short, nonfunctional DNA sequences resulting from mitochondrial gene transfer to the nuclear genome; these sequences seriously affect the accuracy of mitochondrial gene for population genetic and phylogenetic analyses. The nuclear genome of Dendroctonus valens (Coleoptera: Curculionidae: Scolytidae), a major forest quarantine pest that seriously threatens the ecological security of pine forests, contains a large number of numts, and these interfere with analyses of genetic variation based on the mitochondrial cox1 gene. To eliminate interference by numts, we sequenced, assembled and analysed the complete mitochondrial genome of D. valens. The mitogenome is a circular molecule of 16,547 bp and shows typical gene content and arrangement. We identified its codon preference, tRNA secondary structure and nucleotide evolution rate. Furthermore, we designed primers for long fragment amplification to eliminate numts in the mitochondrial cox1 gene. Finally, amplified products were sequenced with universal primers, and cox1 gene sequences (464 bp) without numts were successfully obtained. The Heilihe Nature Reserve (harbouring Pinus tabulaeformis) in Inner Mongolia, is in the early stage of D. valens northward invasion, with a high population genetic diversity. We hypothesized that the high genetic diversity was related to human activities around the reserve and the reproductive characteristics in the early stage of D. valens invasion. The newly developed method resolves the issue of numt interference and lays a foundation for the analyses of genetic diversity in D. valens populations in the region as well as its invasion routes.

Prevalence and molecular characterization of Dirofilaria immitis in road killed canids of northern Iran

BackgroundDirofilaria immitis is a mosquito-borne filarial nematode, which infects primarily wild and domestic canids, causing cardiopulmonary dirofilariasis. The aim of the present study was to determine the prevalence and characterize molecular features of D. immitis in road killed canids, northern Iran.MethodsThe carcasses of 53 road killed canids including 18 dogs (Canis familiaris), and 35 golden jackals (C. aureus) were necropsied in both Mazanderan and Guilan provinces, northern Iran. The molecular analyses were conducted based on the cytochrome oxidase (Cox) 1 and 18S ribosomal RNA (rRNA) genes.ResultsThe heartworm infection was found in 55.6% of dogs and 22.9% of jackals. Our study revealed significantly higher prevalence of D. immitis in dogs compared to jackals (P = 0.031). The prevalence of D. immitis was no statistically significant between males and females in both dogs and jackal (P > 0.05). Comparison of the Cox1 gene sequences with available data in the GenBank illustrated 100% similarity with D. immitis isolates from different hosts in European, Asian, and South American continents. Moreover, the 18S rRNA gene sequences showed 100% identity with dog isolates from Japan and French Guiana.ConclusionsThis study confirms the high prevalence of D. immitis in dogs and jackals of northern Iran. Developing control programs to prevent transmission of the disease is necessary for dogs and humans in the study areas.

Diversity and Pathogenicity of Pythium Species Associated with Reduced Yields of Processing Tomatoes (Solanum lycopersicum) in Victoria, Australia.

Yield decline associated with poor crop establishment, stunting, wilting, and diminished root systems was reported in processing tomato crops in Victoria, Australia. During surveys between 2016 and 2018 Pythium species were isolated by soil baiting and by culturing from the diseased roots and collars of plants exhibiting these symptoms. Eleven species of Pythium were identified based on cultural characteristics and phylogenetic analysis with ITS, Cox-1, and Cox-2 gene sequences. None of the 11 Pythium species had been reported previously from processing or fresh tomatoes in Australia. Pythium dissotocum was the most abundant and widespread species isolated during surveys in each of two growing seasons. In pathogenicity tests, these Pythium species ranged from nonpathogenic to highly aggressive. P. aphanidermatum, P. ultimum, and P. irregulare were consistently the most aggressive species, causing serious damage or death at the pregermination, postgermination, and later stages of plant growth. Five processing tomato cultivars varied significantly in their susceptibility to Pythium disease. These results suggest that Pythium species could be contributing to yield loss in processing tomatoes in Victoria both in the crop establishment phase and through the season.

Prevalence and genetic variance of Taenia hydatigena in goats and sheep from northern Ghana: Preliminary data on a globally neglected livestock parasite.

Cysticercosis caused by the larval stages of Taenia hydatigena has a significant global impact on livestock production, particularly of goats and sheep. Despite this, global data on prevalence and genetic variance of this parasite are still scarce. In Ghana, as in most African countries, numerous anecdotal observations agree that it is widespread and frequent. To obtain baseline data, we screened 251 goats and 248 sheep in northern Ghana (Upper East Region) for T. hydatigena metacestode and molecularly characterized the isolates using the mtDNA cox1 gene sequence. Prevalence was 58.57% in goats and 60.48% in sheep, confirming the abundance of this parasite in the region. Gene sequences revealed high diversity (π 0.00346, hd 0.809) and significant negative Tajima D and Fu's Fs values, a characteristic of a population experiencing an expansion after a recent bottleneck. This is the first account of the genetic structure of T. hydatigena in Ghana, intended as a basis for subsequent studies in the region.