Dmitry M. Atopkin

Genetic variation and differentiation in striped field mouse Apodemus agrarius inferred from RAPD-PCR analysis

Genetic variation and differentiation of the trans-Palearctic species Apodemus agrarius (striped field mouse), whose range consists of two large isolates—European-Siberian and Far Eastern-Chinese, were examined using RAPD-PCR analysis. The material from the both parts of the range was examined (41 individual of A. agrarius from 18 localities of Russia, Ukraine, Moldova, and Kazakhstan); the Far Eastern-Chinese part was represented by samples from the Amur region, Khabarovsk krai, and Primorye (Russia). Differences in frequencies of polymorphic RAPD loci were found between the European-Siberian and the Far Eastern population groups of striped field mouse. No “fixed” differences between them in RAPD spectra were found, and none of the used statistical methods permitted to distinguish with absolute certainty animals from the two range parts. Thus, genetic isolation of the European-Siberian and the Far Eastern population groups of A. agrarius is not strict. These results support the hypothesis on recent dispersal of striped field mouse from East to West Palearctics (during the Holocene climatic optimum, 7000 to 4500 years ago) and subsequent disjunction of the species range (not earlier than 4000–4500 years ago). The Far Eastern population group is more polymorphic than the European-Siberian one, while genetic heterogeneity is more uniformly distributed within it. This is probably explained by both historical events that happened during the species dispersal in the past, and different environmental conditions for the species in different parts of its range. The Far Eastern population group inhabits the area close to the distribution center of A. agrarius. It is likely that this group preserved genetic variation of the formerly integral ancestral form, while some amount of genetic polymorphism could be lost during the species colonization of the Siberian and European areas. To date, the settlement density and population number in general are higher than within the European-Siberian isolate, which seems to account for closer interpopulation associations, intense genetic exchange, and “smoothing” of polymorphism within the Far Eastern population group of A. agrarius.

Analysis of genetic variation and differentiation in the pygmy wood mouse Sylvaemus uralensis (Rodentia, Muridae) aided by the RAPD-PCR method

The present work ascertains distinct differentiation of the pygmy wood mouse into two groups of populations, which correspond to the European and Asian races, but cannot, however, be considered valid species due to the low values of genetic distances between them. Neither of the used statistical methods explicitly verifies genetic isolation of the East European and South European chromosomal forms, which are close to one another and together constitute the European race. However, these chromosomal forms/races of the pygmy wood mouse differentiates each from other by a character of polymorphism. It can be explained both by the history of their formation (the degree of proximity to the ancestral population complex, isolation, etc.) and by unequal current environmental conditions.

The life cycle of Asymphylodora perccotti sp. n. (Trematoda: Lissorchiidae) in the Russian Southern Far East

Specimens of Asymphylodora perccotti sp. n. (Trematoda: Lissorchidae) were found in the esophagus of the freshwater fish Perccottus glenii (Odobantidae) taken from the Bolshaya Ussurka River Basin (Primorsky Region, Russian Southern Far East). The first intermediate host of this trematode is a gastropod, Parafossarulus manchouricus, and the secondary hosts are the same mollusk and Boreoelona ussuriensis. Specimens of the new species are similar to A. amnicolae identified by Stunkard in 1959, but the mature worms have larger suckers and shorter ceca. The cercariae of these species are distinguished by body, suckers and pharynx size. These organs in A. perccotti sp. n. are more than one-third larger than what is observed in A. amnicolae. In addition, the new species lacks the capacity for progenesis. Finally, the new species is unusual in that it resides in the fish esophagus instead of the intestine, as is common for most Asymphylodora species. Partial ribosomal DNA sequences and phylogenetic reconstruction sequence data indicate that these worms represent a new digenean species.

Phylogenetic position of the genus Gonocerca Manter, 1925 (Trematoda, Hemiuroidea), based on partial sequences of 28S rRNA gene and a reconsideration of taxonomic status of Gonocercinae Skrjabin et Guschanskaja, 1955

Adult trematodes of the genus Gonocerca Manter, 1925, are parasites of marine fishes. Identification of the phylogenetic positions and a revision of the taxonomic status of the subfamily Gonocercinae Skrjabin et Guschanskaja, 1955 (Derogenidae) are the main purposes of this research article. Four Gonocerca species were used in the study, including the type-species G. phycidis Manter, 1925. Molecular phylogenetic analysis, based on partial sequences of 28S rRNA gene, revealed that Gonocerca spp. are phylogenetically distant from other hemiuroid trematodes, including Derogenes varicus (Müller, 1784), representative of the type-genus of the family Derogenidae. The taxonomic rank of Gonocercinae should be raised to the family level. The generic composition of the family Gonocercidae Skrjabin et Guschanskaja, 1955 stat. nov., requires further clarification as the molecular data do not support the inclusion of the genus Hemipera Nicoll, 1913, in this family.

Morphometric and molecular analyses of Skrjabinolecithum pyriforme n. sp. (Digenea: Haploporidae) in mullet fish from the Primorsky Region, Russia

A new species of Skrjabinolecithum (Digenea: Waretrematinae), Skrjabinolecithum pyriforme n. sp., has been found in the intestines of Liza haematocheila and Mugil cephalus from the Primorsky Region, Russia. These worms differ from S. vitellosum and S. lobolecithum by the presence of two caeca, as do S. spasskii, S. indicum and S. bengalensis. These species differ morphologically from S. pyriforme n. sp. by a number of features, including body width, oral sucker, pharynx, eggs and ratio of length and width of the body. The most similar species to S. pyriforme n. sp. is Platydidymus flecterotestis (Zhukov, 1971) with some differences in maximal body length, testis and egg sizes. The results of molecular analysis confirmed that this new species belongs to Skrjabinolecithum on the basis of close relationships with S. spasskii-type species.

Life-cycle and genetic characterization of Astiotrema odhneri Bhalerao, 1936 sensu Cho & Seo 1977 from the Primorsky Region (Russian Far East)

Adult Astiotrema odhneri Bhalerao, 1936 sensu Cho & Seo 1977 were found in the intestine of a freshwater turtle, Pelodiscus sinensis (Wiegmann), from the Komissarovka River Basin, Primorsky Region, Russia. It was established that the first intermediate host of this parasite is a snail, Anisus centrifugops, and that the second intermediate hosts include the snails, Helicorbis sujfunensis and A. centrifugops, tadpoles of the frog Rana dybowskii, and the fish Perccottus glenii. The development of A. odhneri includes the formation of sporocyst and xiphidiocercariae, which is typical for species belonging to Plagiorchioidea. Phylogenetic analysis based on 28S rRNA gene sequences showed that A. odhneri, together with Astiotrema monticellii, form a monophyletic clade that was closer to Opisthorchioidea than to any other taxon represented in the tree. However, phylogenetic analysis without outgroup taxon indicated a high degree of differentiation of Astiotrema from both Plagiorchioidea and Opisthorchioidea.

The prevalence of intestinal parasites of domestic cats and dogs in Vladivostok, Russia during 2014–2017

ABSTRACTThe prevalence of intestinal parasites was determined in 144 dogs and 135 cats in Vladivostok, Russia during four years of study. Association between general animal characteristics, such as age and sex, and infections was investigated. The parasitological examination of faecal samples from the dogs and cats was performed by means of the flotation technique using saturated zinc sulfate solution and sedimentation technique. Intestinal parasites were found in 32 (22.1%) of the 144 dogs studied. In total, six different intestinal parasites were identified: Ancylostoma caninum in ten dogs (6.9%), Cystoisospora sp. in seven dogs (4.9%), Uncinaria stenocephala in four dogs (2.8%), Taenia sp. in two dogs (1.3%), Toxocara canis in three dogs (2.1%) and Dipylidium caninum in six dogs (4.2%). Intestinal parasites were found in 25 (18.5%) of the 135 cats studied. In total, six different intestinal parasites were identified: Cystoisospora sp. in eight cats (13.5%), D. caninum in three cats (2.2%), Opisthorchii...

The Identification of Araliaceae Species by ITS2 Genetic Barcoding and Pollen Morphology

The genetic barcode ITS2 (ITS: internal transcribed spacer) and pollen morphology were used for the identification of the pharmacologically valuable wild Araliaceae species Panax ginseng, Oplopanax elatus, Aralia elata, Aralia continentalis, Eleutherococcus senticosus, and Eleutherococcus sessiliflorus inhabiting the natural forests of Primorye, Russia. The ITS2 locus successfully identified all six species, which supports the use of ITS2 as a standard barcode for medicinal plants. However, the ITS2 locus was insufficient for intra-specific discrimination in these species, neither within Primorye nor from other world representatives within GenBank. Araliaceae pollen was confirmed to undergo size-reducing metamorphosis. The final morphotypes were species-specific for each of the six species but could not discriminate intra-species geographic localities within Primorye. The morphologies of the final pollen morphotypes from homologous species inhabiting other parts of the world are not yet known. Therefore, whether pollen is applicable for Araliaceae intra-species discrimination between Primorye and other world localities could not be established. Based on these findings, we propose that the ITS2 genetic barcode and the final pollen morphotypes are suitable for the identification of Araliaceae species. However, further studies will be needed to determine the suitability of genetic and pollen traits for Araliaceae geographic authentication.

Phylogenetic relationships of Hemiuridae (Digenea: Hemiuroidea) with new morphometric and molecular data of Aphanurus mugilis Tang, 1981 (Aphanurinae) from mullet fish of Vietnam

Adult Aphanurus mugilis Tang, 1981 worms were detected in the intestine of Moolgarda engeli in the shallow waters off Cat Ba Island, Vietnam. Tang (1981) first described this species in Mugil cephalus off China. The worms in Vietnamese mullet were identical to Chinese specimens in a number of morphometric characteristics, with the exception of body and ovary size. In the present study, morphological characteristics, and the first molecular data for A. mugilis are provided. Additionally, molecular phylogenetic analysis of the family Hemiuridae was performed. The results of our molecular phylogenetic study indicate that the presence or absence of an ecsoma was not associated with molecular data for hemiurid subfamilies differentiation. The basal position of Bunocotylinae on the molecular-based phylogenetic tree indicated a primordial nature of ecsoma of hemiurid trematodes. Considerable molecular differentiation of Bunocotylinae from other hemiurids indicated the possibility of the recognition of the family Bunocotylidae Dollfus, 1950. Assuming that Machidatrema chilostoma is considered within the Bunocotylinae, the paraphyly of the Lecithasterinae was supported.