Chromosomal Evolution of the Talpinae.

In recent years, the number of mole species with species status confirmed by genetic methods has been continuously increasing. Unfortunately, cytogenetic data are not yet available for all species. Here, for the first time, a GTG-banded karyotype of the small-toothed mole from Vietnam, Euroscaptor parvidens, a representative of the Eastern clade of the genus Euroscaptor, has been described. Through comparative analysis of available Euroscaptor (Euroscaptor parvidens, Euroscaptor klossi, and Euroscaptor malayana) and Oreoscaptor (Oreoscaptor mizura) karyotypes, we found cytogenetic signatures for each of the studied species. Zoo-FISH with sorted chromosomes of the Siberian mole (Talpa altaica) on chromosome sets of the small-toothed mole (E. parvidens), the small Japanese mole (Mogera imaizumii) from the closely related genus, and the Japanese shrew mole (Urotrichus talpoides) from the tribe Urotrichini made it possible to identify syntenic regions between these species. We propose a possible ancestral karyotype of the tribe and, based on it, traced the features of chromosomal rearrangements accompanying the divergence of moles. The low rates of chromosomal evolution within the species of the genus Talpa-T. altaica and T. europaea-and the high rates of karyotypic reshuffling within the Asian genera of the tribe were confirmed. The karyotype of the Japanese mountain mole O. mizura seems to be the most conserved among the Asian moles. The most frequently occurring types of chromosomal rearrangements in moles are the pericentric inversions and amplification of heterochromatin. The pericentric inversions on four pairs of autosomes are shared between the closely related genera Euroscaptor, Oreoscaptor, and Mogera, while many more apomorphic rearrangements have occurred in each lineage additionally. The highest rate of chromosomal changes, with five rearrangements occurring over approximately 7 million years, was recorded in the lineage of the small-toothed mole.

Academ Virus, a Novel Hantavirus in the Siberian Mole (Talpa altaica) from Russia.

To date, six hantavirus species have been detected in moles (family Talpidae). In this report, we describe Academ virus (ACDV), a novel hantavirus harbored by the Siberian mole (Talpa altaica) in Western Siberia. Genetic analysis of the complete S-, M-, and partial L-genomic segments showed that ACDV shared a common evolutionary origin with Bruges virus, previously identified in the European mole (Talpa europaea), and is distantly related to other mole-borne hantaviruses. Co-evolution and local adaptation of genetic variants of hantaviruses and their hosts, with possible reassortment events, might have shaped the evolutionary history of ACDV.

Innate and adaptive immunity in wild rodents spontaneously and experimentally infected with the tick-borne encephalitis virus.

Two dominant species of wild small rodents trapped in Novosibirsk region, South-Western Siberia, Russia differed in their susceptibility to the tick-borne encephalitis virus (TBEV) infection. TBEV RNA average detection rate for Northern red-backed vole Myodes rutilus (Pallas, 1779) (82.2 ± 5.8% blood samples and 63.1 ± 2.7% organ samples) significantly exceeded the corresponding values for the striped field mouse Apodemus agrarius (Pallas, 1771) (47.0 ± 8.7% blood and 24.5 ± 2.8% organ samples) (p <0.001). Innate immunity may be one of possible reasons of the differences. Th1 cytokine gene expression distinguished between M. rutilus (12.5 ± 8.5%) and A. agrarius (66.6 ± 11.4%), whereas Th2 cytokine frequencies were statistically similar (81.8 ± 12.2% and 100.0%, respectively). Polarization indexes (PI) of the innate immunity calculated as ratio of Th2 to Th1 cytokine RNA detection rates for both M. rutilus (6.5) and A. agrarius (1.5) suggested Th2 mainly humoral immune response against persistent TBEV in natural mammalian hosts. Therefore, the TBEV-induced antibodies were analyzed by ELISA and hemagglutination inhibition (HI) tests. The TBEV-specific antibodies were detected in 74.8 ± 4.3% sera of M. rutilus and 67.3 ± 6.8% of A. agrarius. Among them HI antibodies were found in 4.8 ± 2.1% of the same analyzed sera of M. rutilus and in 6.0 ± 3.4% blood samples of A. agrarius only. To model the TBEV persistence both M. rutilus and A. agrarius were infected with the suspensions of the TBEV-infected ticks with further observations during 4 subsequent months. Detection rate of the TBEV RNA and antigen E remained high during the whole period, however, pathogenic for laboratory suckling mice virus was isolated up to 8 days postinfection. At late stages of the persistent infection (1-4 months) the TBEV RNA detection rate in northern red-backed voles remained high 70.6 ± 7.9% whereas in striped field mice significantly declined to 26.7 ± 9.2% (p < .001). Comparative analysis of the innate immunity of the wild rodents in 2 months postinfection showed similar frequencies of Th2 cytokine gene expression for M. rutilus (77.8 ± 10.1%) and A. agrarius (71.4 ± 12.5%) (p > .05) but Th1 cytokine mRNA detection rates were different (44.4 ± 12.5% and 85.7 ± 9.7%, respectively) (p < .05). In 2 months PI decreased from 6.5 until 1.75 for M. rutilus and from 1.5 until 0.83 for A. agrarius. Nevertheless, Th2 mainly humoral immune response was confirmed by direct detection of the TBEV-specific antibodies. HI and neutralizing antibodies were revealed in blood sera of the small rodents of both studied species in 30 days postinfection and remained at detectable levels during 4 months of observations. Accordingly, Th2 polarized innate immunity of small rodents might facilitate the TBEV intracellular persistence in the presence of HI and neutralization antibodies.

Ixodes persulcatus/pavlovskyi natural hybrids in Siberia: Occurrence in sympatric areas and infection by a wide range of tick-transmitted agents.

Ixodes persulcatus and Ixodes pavlovskyi ticks, two closely related species of the I. ricinus - I. persulcatus group, are widely distributed in the southern part of Western Siberia. Recently, the existence of natural hybrids of I. persulcatus and I. pavlovskyi ticks has been demonstrated. The aim of this study was to evaluate the abundance of I. persulcatus/pavlovskyi hybrids in several locations with different ratios of parental tick species and to investigate the prevalence and genetic variability of a wide range of infectious agents in these hybrids compared to the parental tick species. Natural hybrids of I. persulcatus and I. pavlovskyi ticks were identified in all examined locations in Altai and Novosibirsk, Western Siberia, Russia. The abundance of hybrids varied from 7% to 40% in different locations and was maximal in a location with similar proportions of I. persulcatus and I. pavlovskyi ticks. For the first time, it was shown that hybrids can be infected with the same agents as their parental tick species: tick-borne encephalitis and Kemerovo viruses, Borrelia afzelii, Borrelia bavariensis, Borrelia garinii, Borrelia miyamotoi, Rickettsia helvetica, Rickettsia raoultii, Rickettsia sibirica, "Candidatus Rickettsia tarasevichiae", Anaplasma phagocytophilum, Ehrlichia muris, "Candidatus Neoehrlichia mikurensis", and Babesia microti. The prevalence of most bacterial agents in hybrids was intermediate compared to their parental tick species. Most genetic variants of the identified agents have been previously found in the parental tick species. Wide distribution of I. persulcatus/pavlovskyi natural hybrids implies that I. persulcatus, I. pavlovskyi and their hybrids coexist in all I. persulcatus - I. pavlovskyi sympatric areas.

Detection and genetic characterization of a wide range of infectious agents in Ixodes pavlovskyi ticks in Western Siberia, Russia.

BACKGROUND: The Ixodes pavlovskyi tick species, a member of the I. persulcatus/I. ricinus group, was discovered in the middle of the 20th century in the Russian Far East. Limited data have been reported on the detection of infectious agents in this tick species. The aim of this study was to investigate the prevalence and genetic variability of a wide range of infectious agents in I. pavlovskyi ticks collected in their traditional and recently invaded habitats, the Altai Mountains and Novosibirsk Province, respectively, which are both located within the Western Siberian part of the I. pavlovskyi distribution area. RESULTS: This study reports the novel discovery of Borrelia bavariensis, Rickettsia helvetica, R. heilongjiangensis, R. raoultii, "Candidatus Rickettsia tarasevichiae", Anaplasma phagocytophilum, Ehrlichia muris, "Candidatus Neoehrlichia mikurensis" and Babesia microti in I. pavlovskyi ticks. In addition, we confirmed the previous identification of B. afzelii, B. garinii and B. miyamotoi, as well as tick-borne encephalitis and Kemerovo viruses in this tick species. The prevalence and some genetic characteristics of all of the tested agents were compared with those found in I. persulcatus ticks that were collected at the same time in the same locations, where these tick species occur in sympatry. It was shown that the prevalence and genotypes of many of the identified pathogens did not significantly differ between I. pavlovskyi and I. persulcatus ticks. However, I. pavlovskyi ticks were significantly more often infected by B. garinii and less often by B. bavariensis, B. afzelii, "Ca. R. tarasevichiae", and E. muris than I. persulcatus ticks in both studied regions. Moreover, new genetic variants of B. burgdorferi (sensu lato) and Rickettsia spp. as well as tick-borne encephalitis and Kemerovo viruses were found in both I. pavlovskyi and I. persulcatus ticks. CONCLUSION: Almost all pathogens that were previously detected in I. persulcatus ticks were identified in I. pavlovskyi ticks; however, the distribution of species belonging to the B. burgdorferi (sensu lato) complex, the genus Rickettsia, and the family Anaplasmataceae was different between the two tick species. Several new genetic variants of viral and bacterial agents were identified in I. pavlovskyi and I. persulcatus ticks.

Occurrence and genetic variability of Kemerovo virus in Ixodes ticks from different regions of Western Siberia, Russia and Kazakhstan.

Kemerovo virus (KEMV), a member of the Reoviridae family, Orbivirus genus, is transmitted by Ixodes ticks and can cause aseptic meningitis and meningoencephalitis. Recently, this virus was observed in certain provinces of European part of Russia, Ural, and Western and Eastern Siberia. However, the occurrence and genetic diversity of KEMV in Western Siberia remain poorly studied. Therefore, the aim of this work was to investigate the prevalence and genetic variability of KEMV in Ixodes ticks from Western Siberia. A total of 1958 Ixodes persulcatus, I. pavlovskyi ticks and their hybrids from Novosibirsk and Omsk provinces, Altai Republic (Russia) and East Kazakhstan province (Kazakhstan) were analyzed for the presence of KEMV and tick-borne encephalitis virus (TBEV) RNA. It was observed that the KEMV distribution area in Western Siberia was wider than originally thought and included Northern and Northeastern Altai in addition to the Omsk and Novosibirsk provinces. For the first time, this virus was found in Kazakhstan. The occurrence of KEMV was statistically lower than TBEV in most locations in Western Siberia. KEMV was found both in I. persulcatus and I. pavlovskyi ticks and in their hybrids. Notably, KEMV variants observed in the 2010s were genetically different from those isolated in the 1960s, which indicated the ongoing process of evolution of the Kemerovo virus group. Moreover, the possibility of reassortment for KEMV was demonstrated for the first time.

Tick-Borne Encephalitis Virus Diversity in Ixodid Ticks and Small Mammals in South-Western Siberia, Russia.

UNLABELLED: The persistence of tick-borne encephalitis virus (TBEV) in nature is maintained by numerous species of reservoir hosts, multiple transmissions between vertebrates and invertebrates, and the virus adaptation to its hosts. Our Aim: was to compare TBEV isolates from ticks and small wild mammals to estimate their roles in the circulation of the viral subtypes. METHODS: TBEV isolates from two species of ixodid ticks, four species of rodents, and one species of shrews in the Novosibirsk region, South-Western Siberia, Russia, were analyzed using bioassay, hemagglutination, hemagglutination inhibition, neutralization tests, ELISA, reverse transcription with real-time PCR, and phylogenetic analysis. RESULTS: TBEV RNA and/or protein E were found in 70.9% ± 3.0% of mammals and in 3.8% ± 0.4% of ticks. The TBEV infection rate, main subtypes, and neurovirulence were similar between ixodid tick species. However, the proportions of the virus that were pathogenic for laboratory mice and of the Far-Eastern (FE) subtype, as well as the viral loads with the Siberian and the European subtypes for the TBEV in Ixodes pavlovskyi Pomerantsev, 1946 were higher than in Ixodes persulcatus (P. Schulze, 1930). Percentages of infected Myodes rutilus, Sicista betulina, and Sorex araneus exceeded those of Apodemus agrarius and Myodes rufocanus. Larvae and nymphs of ticks were found mainly on rodents, especially on Myodes rufocanus and S. betulina. The proportion of TBEV-mixed infections with different subtypes in the infected ticks (55.9% ± 6.5%) was higher than in small mammals (36.1% ± 4.0%) (p < 0.01). CONCLUSIONS: Molecular typing revealed mono- or mixed infection with three main subtypes of TBEV in ticks and small mammals. The Siberian subtype was more common in ixodid ticks, and the FE subtype was more common in small mammals (p < 0.001). TBEV isolates of the European subtype were rare. TBEV infection among different species of small mammals did not correlate with their infestation rate with ticks in the Novosibirsk region, Russia.

First detection of Kemerovo virus in Ixodes pavlovskyi and Ixodes persulcatus ticks collected in Novosibirsk region, Russia.

Kemerovo group viruses are tick-transmitted members of Orbivirus genus of the Reoviridae family that can cause infections of the central nervous system of humans. In this work, Kemerovo virus (KEMV) RNA was detected for the first time in Novosibirsk region of Western Siberia, Russia, in Ixodes pavlovskyi and Ixodes persulcatus ticks.

Genetic variability of Anaplasma phagocytophilum in Ixodes persulcatus ticks and small mammals in the Asian part of Russia.

The specimens of 3552 questing adult Ixodes persulcatus and 1698 blood/tissue samples of small mammals collected in Ural, Siberia, and Far East of Russia were assayed for the presence of Anaplasma phagocytophilum by nested PCR based on the 16S rRNA gene. Totally, A. phagocytophilum was detected in 112 tick and 88 mammalian samples. The nucleotide sequences of the 16S rRNA gene and groESL operon (1244-1295 bp) were determined for A. phagocytophilum samples from 65 ticks and 25 small mammals. Six different 16S rRNA gene variants differing by 1-5 nucleotide substitutions were detected, and only one variant matched the sequences deposited in GenBank. Analysis of groESL sequences allowed the A. phagocytophilum samples to be divided into three groups; moreover, the samples from different groups also differed in the 16S rRNA gene sequences. The A. phagocytophilum sequences from group I were detected in 11 Myodes spp. samples from West Siberia and Far East and in 19 I. persulcatus samples from all examined regions; from group II, in 10 samples of Myodes spp. and common shrews (Sorex araneus) from Ural; and from group III, in four samples of Asian chipmunks (Tamias sibiricus) from West Siberia and Far East; and in 46 I. persulcatus samples from all examined regions. The nucleotide sequences of A. phagocytophilum groESL operon from groups I and II were strictly conserved and formed with A. phagocytophilum groESL sequence from a Swiss bank vole (Myodes glareolus) (GenBank accession no. AF192796), a separate cluster on the phylogenetic tree with a strong bootstrap support. The A. phagocytophilum groESL operon sequences from group III differed from one another by 1-4 nucleotides and formed a separate branch in the cluster generated by European A. phagocytophilum strains from roe deer (Capreolus capreolus) and Ixodes ricinus ticks.

Seewis virus: phylogeography of a shrew-borne hantavirus in Siberia, Russia.

BACKGROUND: Hantaviral antigens were originally reported more than 20 years ago in tissues of the Eurasian common shrew (Sorex araneus), captured in European and Siberian Russia. The recent discovery of Seewis virus (SWSV) in this soricid species in Switzerland provided an opportunity to investigate its genetic diversity and geographic distribution in Russia. METHODS: Lung tissues from 45 Eurasian common shrews, 4 Laxmann's shrews (Sorex caecutiens), 3 Siberian large-toothed shrews (Sorex daphaenodon), 9 pygmy shrews (Sorex minutus), 28 tundra shrews (Sorex tundrensis), and 6 Siberian shrews (Crocidura sibirica), captured in 11 localities in Western and Eastern Siberia during June 2007 to September 2008, were analyzed for hantavirus RNA by reverse transcription-polymerase chain reaction. RESULTS: Hantavirus L and S segment sequences, detected in 11 S. araneus, 2 S. tundrensis, and 2 S. daphaenodon, were closely related to SWSV, differing from the prototype mp70 strain by 16.3-20.2% at the nucleotide level and 1.4-1.7% at the amino acid level. Alignment and comparison of nucleotide and amino acid sequences showed an intrastrain difference of 0-11.0% and 0% for the L segment and 0.2-8.5% and 0% for the S segment, respectively. Phylogenetic analysis, using neighbor-joining, maximum-likelihood, and Bayesian methods, showed geographic-specific clustering of SWSV strains in Western and Eastern Siberia. CONCLUSIONS: This is the first definitive report of shrew-borne hantaviruses in Siberia, and demonstrates the impressive distribution of SWSV among phylogenetically related Sorex species. Coevolution and local adaptation of SWSV genetic variants in specific chromosomal races of S. araneus may account for their geographic distribution.

Genetic diversity of Anaplasma and Ehrlichia in the Asian part of Russia.

Totally, 2590 questing adult Ixodes persulcatus ticks and 1458 small mammals from Ural, Siberia, and the Far East as well as 53 Haemaphysalis concinna, 136 Haem. japonica, and 43 Dermacentor silvarum ticks--exclusively adults--from the Far East were examined for the presence of Ehrlichia and Anaplasma by nested PCR based on the 16S rRNA gene. Both Anaplasma phagocytophilum and Ehrlichia muris were found in I. persulcatus and small mammals from all the studied regions. Myodes spp., Microtus spp., Sorex araneus, Apodemus peninsulae, and Tamias sibiricus were naturally infected with An. phagocytophilum and E. muris. Five of the examined I. persulcatus and 5 of the examined wild rodents from Siberia and the Far East were infected with 'Candidatus Neoehrlichia mikurensis'. The determined 16S rRNA gene sequences of 'Candidatus Neoehrlichia mikurensis' were identical to the sequences of Japanese isolates, while the determined groESL sequences were unique. A new Ehrlichia sp. variant closely related to the Ehrlichia sp. EHf669 found in Haem. flava from Japan was detected in 11% of Haem. japonica ticks. New Anaplasmataceae bacteria genetically distinct from the known species of this family were found in 3 adult Derm. silvarum from the Far East and in 2 I. persulcatus from Siberia and the Far East. In the Far East, about 15% of the captured small mammals were naturally infected with recently discovered Ehrlichia sp. Khabarovsk. Ehrlichia sp. Khabarovsk was found in about 20% of Myodes spp. and S. araneus but was undetectable in any of the 236 studied Ap. peninsulae. A three-year study has demonstrated that An. phagocytophilum and E. muris were detectable in small mammals from the Far East captured only after the beginning of the tick activity season, from May to November. Ehrlichia sp. Khabarovsk was found in mammals trapped in all the examined periods, from February to November.