[Polymorphism of the coxl mtDNA gene from cercarian isolates of the avian schistosome Bilharziella polonica (Trematoda: Schistosomatidae) from Belarussian lakes].

We have studied the phylogeographic structure of avian schistosomes Bilharziella polonica (class Trematoda, family Schistosomatidae), parasites of 18 molluscs Planorbius corneus (family Planorbidae) from three Belarussian lakes. Low nucleotide (pi<0.5%) and high haplotype (h=85.6%) diversity of the gene encoding the cytochrome C oxidase first subunit (coxl) was found on the part of the species range studied. The phylogeographic reconstructions showed that the sample examined consists of at least two lineages ofhaplotypes A and C. Haplotype diversity was somewhat higher in lineage C. The genetic divergence between these genealogical lines reached 0.55%, while the time of possible divergence was 180,000-270,000 years. Possible evolutionary scenarios for differentiation of the B. polonica lines and effectiveness of using coxl for barcoding trematode populations and finding coevolutionary parasite-host relationships are discussed.

[Polymorphism of the cox1 gene in bird schistosome cercaria isolates (Trematoda, Schistosomatidae) from ponds of Moscow and Moscow oblast].

Polymorphism of a 8 10-bp mitochondrial cox1 gene region was studied in 16 cercaria isolates of bird schistosomes (family Schistosomatidae), which were collected in water bodies of Moscow and Moscow oblast and represented three species: Trichobilharzia szidati, T. franki, and T. regenti. A substantial predominance of AT (65.4%) was characteristic of the cox1 sequences in all three species. Rare single nucleotide substitutions determined low (0.2-0.9%) intraspecific nucleotide and amino acid sequence diversity. Haplotype diversity h was high (80-100%) in all three species, suggesting a unique character for almost all cox1 sequences in the sample. Phylogenetic trees based on the nucleotide and amino acid sequence variations were constructed to study the relationships of the three schistosome species. A high support was observed for the main branching node that reflects differentiation of the monophyletic group Trichobilharzia and species of the genera Bilharziella (B. polonica), Dendritobilharzia (D. pulverulenta), and Gigantobilharzia (G. huronensis). Based on the nucleotide substitutions and amino acid polymorphisms, two groups of isolates, which infect Lymnaea stagnalis (T. szidati) and snails of the group Radix (T. franki and T. regenti) respectively, were isolated in the genus Trichobilharzia. The time of divergence between the two schistosome groups infecting snails of the genera Radix and Lymnaea was calculated from the cox1 nucleotide substitution rate, which is known for Asian and Indian blood flukes from the genus Schistosoma and is 2-3% per million years on average. Divergence of the three bird schistosome species under study and divergence of the Asian species of mammalian schistosome were almost concurrent, dating back to 2.5-3.8 Myr ago. Factors responsible for the lack of intraspecific subdivision with respect to the cox1 gene in bird schistosomes and the lack of separation between two species (T. franki and T. regenti) are discussed.

[Phylogenetic relationships among schistosomatidae].

According updates on molecular genetics, the development of human schistosomes in Asia with subsequent migration to the African continent is considered to be the most probable course of events. Generally, there are 2 hypotheses of the genus Schistoma. A hypothesis of Gondvana origin was based on snail host phylogeny and paleonthology and considered first schistosomes to originate on this continent to and appear in Asia from the Indian subcontinent platform 70-150 million years ago and in South America before Gondvana's split 60-120 million years ago. The recent data of molecular genetics show a high similarity between ITS2 sequences of S.bovis and S.intercalatum, with slightly lesser one between S.bovis and S.matthei. The similar pattern with slightly fewer differences can be seen in variability of cytochrome C subunit 1. Webster et al. 2006 noted a generally high similarity among species of the African group of schistosomes and considered it to originate from interspecies hybridization inside this group. Such hydridization occurring in both nature and a laboratory can make uncertain the determination of schistosome species based on a certain single gene marker.

[Polymorphism of microsatellite markers in breeds of common carp (Cyprinus carpio L.) of Russian breeding].

Using five microsatellite loci, genotyping and genetic diversity estimates were obtained for nine samples representing seven common carp breeds most widespread in Russia. For comparison, the samples of Amur wild common carp (Cyprinus carpio haematopterus) and a sample of European Hungarian common carp were used. In the samples examined (n = 148) a total of 78 alleles were revealed. The highest mean allele number per locus (4.3) was identified in Amur wild common carp, while the lowest number was found in Cherepets carps (4.0). In different breeds, the observed heterozygosities varied from 0.819 (Altai carp) to 0.651 (Cherepets scaly carp). Three out of five microsatellite loci (MFW-24, MFW-28, and MFW-19) revealed a high level of population differentiation. In the dendrogram of genetic differences, all breeds clustered into two groups. One of these groups was composed of the two strains of Ropsha common carp, Stavropol common carp, Amur wild common carp, and the two samples of Cherepets common carp. The second cluster included Altai common carp (Cis-Ob' and Chumysh populations), two Angelinskii common carp breeds (mirror and scaly), and Hungarian common carp. The pairs of breeds/populations/strains, having common origin, were differentiated. Specifically, these were two populations of Altai common carp, two strains of Ropsha common carp, as well as the breeds of Angelinskii and Cherepets common carps. The reasons for genetic differentiation of Russian common carp breeds, as well as the concordance of the evolutionary histories of these breeds, some of which originated from the European breeds, while the others contain substantial admixture of the Amur wild common carp, are discussed.

[Genetic variability and differentiation of three Russian populations of yellow potato cyst nematode Globodera rostochiensis as revealed by nuclear markers].

Genetic variability of yellow potato cyst nematode G. rostochiensis from three Russian populations (Karelia, Vladimir oblast, and Moscow oblast) was investigated using two types of nuclear markers. Using RAPD markers identified with the help of six random primers (P-29, OPA-10, OPT-14, OPA-11, OPB-11, and OPH-20), it was possible to distinguish Karelian population from the group consisting of the populations from two adjacent regions (Moscow oblast and Vladimir oblast). Based on the combined matrix, containing 294 RAPD fragments, dendrogram of genetic differences was constructed, and the indices of genetic divergence and partition (P, H, and G(st)), as well as the gene flow indices N(m) between the nematode samples examined, were calculated. The dendrogram structure, genetic diversity indices, and variations of genetic distances between single individuals in each population from Karelia and Central Russia pointed to genetic isolation and higher genetic diversity of the nematodes from Karelia. Based on polymorphism of rDNA first intergenic spacer ITS1, attribution of all populations examined to the species G. rostochiensis was proved. Small variations of the ITS1 sequence in different geographic populations of nematodes from different regions of the species world range did not allow isolation of separate groups within the species. Possible factors (including interregional transportations of seed potato) affecting nematode population structure in Russia are discussed.

[Genetic diversity and differentiation of Russian common carp (Cyprinus carpio L.) breeds inferred from RAPD markers].

Polymorphic components of the common carp Cyprinus carpio L. genome were examined by means of polymerase chain reaction with random primers (RAPD-PCR). Using four primers, genetic diversity estimates were obtained for 12 populations and seven strains of Russian common carp breeds, as well as for European Hungarian common carp and Amur wild common carp (N = 87). The highest number of polymorphic loci was revealed in Angelinskii common carp, as well as in the samples of Altai common carp and Amur wild common carp (P = 23.8-18.7%), while the lowest number of polymorphic loci was in the BB strain of Ropsha common carp. The index of genetic diversity, H, was high (11%) in Amur wild common carp, as well as in Altai and Angelinskii common carps. In the remaining breeds, the value of this index varied from 4 to 8%. Based on summarized RAPD profile (132 bands), a dendrogram of genetic differences was constructed. In this dendrogram, all breeds examined grouped into two clusters. One of the clusters was formed by Hungarian and Angelinskii common carps, and the three samples of Altai common carp. The second cluster was formed by the group consisting of the representatives of Cherepetskskii, Stavropol, and Ropsha common carps, along with the differing from them Amur wild common carp. The observed differentiation was confirmed by the analysis of the polymorphic markers variance by the method of principle components. Evolutionary history and the reasons for genetic differentiation of Russian common carp breeds are discussed.

[Individual and population variation in cercariae of bird schistosomes of the Trichobilharzia ocellata species group as revealed with the polymerase chain reaction].

The polymerase chain reaction with arbitrary (RAPD-PCR) or specific primers was used to study the population variation and to identify the species in cercariae of schistosomes of the Trichobilharzia ocellata species group (Trematoda, Schistosomatidae). In total, 28 cercariae were obtained from two spontaneously invaded mollusks Lymnaea stagnalis (LS) and L. ovata (LO), which were collected in different water bodies of Moscow. RAPD-PCR was carried out with two arbitrary primers, OPA9 and OPB11, which each detected different levels of individual and among-group variation and revealed considerable genetic differentiation of cercariae from different host mollusks. To check whether the cercariae of the two samples belong to one species, sequencing was performed with a region corresponding to intergenic transcribed spacer 2 (ITS2), which was earlier proposed for cercaria identification in three European species of bird schistosomes of the genus Trichobilharzia (T. franki, T. regenti, and T. szidati). The ITS2 sequences of two LO cercariae were identical, each consisted of 319 bp, and showed 100% homology to the T. franki ITS2 sequence. The ITS2 sequences of two LS cercariae were identical, each consisted of 323 bp, and showed 99.4% homology to the T. szidati counterpart. The causes of genetic variation in cercariae and prospects of using RAPD markers to study different stages of the life cycle in trematodes are discussed.

[RAPD fingerprinting of common bream Abramis brama L., roach Rutilus rutilus L., and their F1 hybrids]. / RAPD-fingerprinting leshcha ( Abramis brama L.), plotvy (Rutilus rutilus L.) i gibridov pervogo pokoleniia leshch x plotva i plotva X leshch.

The polymerase chain reaction with arbitrary primers (RAPD-PCR) was used to study and to evaluate the genetic variation in the hybrid progeny of two Cyprinidae species, common bream Abramis brama and roach Rutilus rutilus. Genetic polymorphism was studied in 20 fishes (young of the current year) obtained in four individual crosses: R. rutilus x R. rutilus (RR), A. brama x A. brama (AA), R. rutilus x A. brama (RA), and A. brama x R. rutilus (AR). Amplification spectra obtained with eight primers contained 288 fragments, 97.6% of which proved to be polymorphic. The proportion of polymorphic fragments was 75.0% in the RR progeny, 58.1% in the AA progeny, 84.9% in the AR progeny, and 77.8% in the RA progeny. Classification analysis in the space of principal components was performed with the first four components, which together accounted for 64% of the total variance of the character under study. The individual contributions of components I, II, III, and IV were 26.8, 16.8, 11.5, and 8.9%, respectively. Fishes of the two pure species and the hybrid progeny (direct and reverse hybrids together) were clearly differentiated in the space of principal components I and II. The best differentiation of the four samples (RR, AA, RA, and AR) was observed in the space of principal components II and IV. Possible causes of high genetic variation in interspecific hybrids are discussed.

[Polymorphism of the ND1 and CO1 mitochondrial genes in populations of liver fluke Fasciola hepatica]. / Polimorfizm mitokhondrial'nykh genov ND1 i SD1 v populiatsiiakh pechenochnogo sosal'shchika Fasciola hepatica.

Polymorphism of fragments of the ND1 and CO1 mitochondrial genes was for the first time found in four liver fluke Fasciola hepatica samples from Ukraine, Belarus, Moscow region, and Mordovia. The ND1 and CO1 fragments were respectively 292 and 433 bp in size, with polymorphic sites accounting for 2.7 and 0.9% of the total sequence. Seven haplotypes were found in the four samples; two haplotypes (A and B) were most common (29.1 and 45.8%, respectively) in the pooled sample. The haplotype frequency distribution differed among the four populations. Haplotype B prevailed in the Mordovian and Moscow region samples. In addition, these samples had a higher number of unique haplotypes (A2, A3, B2). The results testify to genetic divergence of the four geographically distant populations of F. hepatica.

[Genetic variability of Trichinella spiralis Oven, 1835, and Trichinella pseudospiralis Garkavi, 1972, detected by polymerase chain reaction with random primers]. / Geneticheskaia izmenchivost' Trichinella spiralis Oven, 1835, i Trichenella pseudospiralis Garkavi, 1972, vyiavliaemaia metodom polimeraznoi tsepnoi reaktsii so sluchainymi praimerami.

DNA polymorphisms in two parasitic nematode species, Trichinella spiralis Oven, 1835, and Trichinella pseudospiralis Garkavi, 1972, were revealed via random amplification of polymorphic DNA by the polymerase chain reaction (RAPD PCR). The diagnostic value of seven 10-bp oligonucleotide primers was evaluated, and the extent of the homology between the genomes of the two species was estimated. The intraspecific variation of RAPD markers was revealed in larvae of both species isolated from experimentally infected white rats. The variation was higher in larvae from nonlinear rats than in larvae from linear rats. When animals were infected with both Trichinella species simultaneously, "hybrid" progeny were obtained that had capsule that somewhat differed in shape from one characteristic of the parental species, T. spiralis. In RAPD spectra, the hybrids showed higher similarity of T. spiralis than to T. pseudospiralis. Intra- and interspecific differentiation, genome divergence, and factors inducing the intraspecific variation in Trichinella species are discussed.