Polymorphic variants of the genes encoding intrleukin-6 and fibrinogen: Risk for ischemic stroke and fibrinogen levels

The occurrence of alleles and genotypes of polymorphic region −174G>C of the gene IL6 (rs1800795) in patients of Russian ethnicity with ischemic stroke (200 cases) and in the control of the same ethnicity similar in sex and age (140 control subjects) has been analyzed. Reliable differences were revealed in the carriage frequency of allele IL6*-174G in homozygous and heterozygous form (p = 0.0029, OR = 2.9, 95% CI: 1.4–5.8), which can be considered a risk factor for the development of ischemic stroke, and in the carriage frequencies of protective genotype IL6*-174C/C (p = 0.0029, OR = 0.35, 95% CI: 0.17–0.69), respectively. After the patients and the control subjects were divided by gender character, similar differences were observed only between women with ischemic stroke and those from the control group, and after division by age, they were only revealed in groups with members older than 60 years. Complex analysis of the association of ischemic stroke with the carriage of alleles and genotypes of IL6 SNP-174G>C in combination with SNP 4266A>G (Thr312Ala) of the gene FGA (rs6050) and -249C>T of the gene FGB (rs1800788) revealed protective combinations of IL6*-174C/C + FGA*4266A and IL6*-174C/C + FGB*-249C, which are slightly more reliably associated with ischemic stroke than the one protective genotype IL6*-174C/C and have nearly the same OR value. At the same time, combinations of alternative allele IL6*-174G and the same alleles FGA*4266A or FGB*-249C were revealed that are characterized by a decrease in both the significance level and the OR value as compared with the carriage of one risk allele IL6*-174G. When there is a combined carriage of the allele IL6*-174G with the genotypes FGA*4266A/A, FGB*-249C/C or with combinations of these alleles/genotypes, the neutralizing effect is enhanced. In other words, we observed the association of IL6, FGA and FGB allele combinations with ischemic stroke in which IL6 plays the key role and FGA and FGB have a modulating function. In analyzing the association of the alleles/genotypes of three polymorphic regions with the fibrinogen level in plasma, no reliable difference was revealed.     

An ecological study of association between coronary heart disease mortality rates in men and the relative frequencies of common allelic variations in the gene coding for apolipoprotein E

Three common alleles, ɛ ₂ , ɛ ₃ , and ɛ ₄ , of the gene coding for apolipoprotein E (apoE) have been identified as predictors of interindividual variation in measures of lipid and lipoprotein metabolism, and ultimately risk of coronary heart disease (CHD), within many populations. Here we evaluated the utility of the geographic distribution of these alleles for prediction of interpopulation variation in average level of serum total cholesterol and other traditional risk factors, and CHD mortality rate. We employed published estimates of the relative frequencies of the three common apoE alleles, average levels of risk factors such as serum total cholesterol, systolic and diastolic blood pressure, body mass index, smoking prevalence and CHD mortality rate for nine population-based samples of middle-aged males studied by the international WHO MONICA Project. There was approximately a 10-fold difference between the highest and lowest CHD mortality rate. Of the traditional risk factors, variation in the average level of serum total cholesterol was the best predictor (approximately 33%) of the observed interpopulation variation in estimates of CHD mortality rate (Pr=0.10). Variation in the relative frequency of the ɛ ₄ allele predicted approximately 50% of interpopulation variation in average serum total cholesterol level (Pr=0.02) and 75% of the variation in CHD mortality rate (Pr=0.002) when information about variation in the other risk factors and the ɛ ₂ andɛ ₃ alleles is ignored. Furthermore, variation in the relative frequency of the ɛ ₄ allele predicted approximately 40% of the variation in CHD mortality rate (Pr=0.02) after considering the contribution of variation in average serum total cholesterol level. Average serum total cholesterol level was estimated to increase by 0.114 mmol/l (4.405 mg/dl), and CHD mortality rate by 24.5/100 000, for an increase of 0.01 in the relative frequency of the ɛ ₄ allele. The predictive utility of the ɛ ₂ andɛ ₃ alleles was considerably less than that of the ɛ ₄ allele. For the sample of populations considered, the geographic distribution of the apoE alleles can be a statistically significant predictor of interpopulation variation in both the average serum total cholesterol level and CHD mortality rate. In particular, the ɛ ₄ allele may confer valuable ecological risk information. Received: 2 December 1997 / Accepted: 28 May 1998     

Association of SULT1A1 and UGT1A1 polymorphisms with breast cancer risk and phenotypes in Russian women

Estrogens are critical for breast cancer initiation and development. Sulfotransferase 1A1 (SULT1A1) and UDP-glucuronosyltransferase 1A1 (UGT1A1) conjugate and inactivate both estrogens and their metabolites, thus preventing estrogen-mediated mitosis and mutagenesis. SULT1A1 and UGT1A1 are both polymorphic, and different alleles encode functionally different allozymes. We hypothesize that low-activity alleles SULT1A1*2 and UGT1A1*28 are associated with higher risk for breast cancer and more severe breast tumor phenotypes. We performed a case-control study, which included 119 women of Russian ancestry with breast cancer and 121 age-matched Russian female controls. We used PCR followed by pyrosequencing to determine the SULT1A1 and UGT1A1 genotypes. Allele UGT1A1*28 was present at a higher frequency than the wild-type UGT1A1*1 allele in breast cancer patients as compared to controls (P = 0.002, OR = 1.79, CI 1.23–2.63). Consistently, the frequency of genotypes that contain allele UGT1A1*28 in the homozygous or the heterozygous state was greater in breast cancer patients as compared with the frequency of the wild-type UGT1A1*1/*1 genotype (P = 0.003, OR = 4.00, CI 1.49–11.11 and P = 0.014, OR = 2.04, CI 1.14–3.57, respectively). Individuals carrying allele UGT1A1*28 in the homo-or heterozygous state had larger breast tumors (>2 cm) as compared to the group with high-activity genotypes (P = 0.011, IR = 3.44, CI 1.42–8.36). No association was observed between any of the SULT1A1 genotypes and breast cancer risk or phenotypes. Our data suggest that UGT1A1, but not SULT1A1, genotypes are important for breast cancer risk and phenotype in Russian women. Published in Russian in Molekulyarnaya Biologiya, 2006, Vol. 40, No. 2, pp. 263–270. The article was translated by the authors.     

Initial step of B12-dependent enzymatic catalysis: energetic implications regarding involvement of the one-electron-reduced form of adenosylcobalamin cofactor

Density functional theory analysis was performed to elucidate the impact of one-electron reduction upon the initial step of adenosylcobalamin-dependent enzymatic catalysis. The transition state (TS) corresponding to the Co–C bond cleavage and subsequent hydrogen abstraction from the substrate was located. The intrinsic reaction coordinate calculations predicted that the reaction consisting of Co–C5′ bond cleavage in [Co^III(corrin^•)]–Rib (where Rib is ribosyl) and hydrogen-atom abstraction from the CH₃–CH₂–CHO substrate occurs in a concerted fashion. The computed activation energy barrier of the reaction (15.0 kcal/mol) was lowered by approximately 54.5% in comparison with the reaction involving the positively charged cofactor model (Im–[Co^III(corrin)]–Rib⁺, where Im is imidazole; energy barrier = 33.0 kcal/mol). The Im base was detached during the TS search in the reaction involving the one-electron-reduced analogue. Thus, to compare the energetics of the two reactions, the axial Im ligand detachment energy for the Im–[Co^III(corrin^•)]–Rib model was computed [7.6 kcal/mol (gas phase); 4.6 kcal/mol (water)]. Consequently, the effective activation energy barrier for the reaction mediated by the Im-off [Co^III(corrin^•)]–Rib was estimated to be 22.6 kcal/mol, which implied an overall 31.5% reduction in the energetic demands of the reaction. Considering that the lengthened Co–N_axial bond has been observed in X-ray crystal structure studies of B₁₂-dependent mutases, the catalytic impact induced by one-electron reduction of the cofactor is expected to be higher in the presence of the enzymatic environment.     

Evolutionary and dynamic stability in continuous population games

 Asymptotic stability under the replicator dynamics over a continuum of pure strategies is shown to crucially depend on the choice of topology over the space of mixed population strategies, namely probability measures over the real line. Thus, Strong Uninvadability, proved by Bomze (1990) to be a sufficient condition for asymptotic stability under the topology of variational distance between probability measures, implies convergence to fixation over a pure strategy x ^* only when starting from a population strategy which assigns to x ^* a probability sufficiently close to one. It does not imply convergence to x ^* when starting from a distribution of small deviations from x ^* , regardless of how small these deviations are. It is, therefore, suggested that when a metric space of pure strategies is involved, another topology, hence another stability condition, may prove more relevant to the process of natural selection. Concentrating on the case of a one dimensional continuous quantitative trait, we resort to the natural Maximum Shift Topology in which an ɛ-vicinity of the fixation on a pure strategy x ^* consists of all mixed population strategies with support which includes x ^* and is in the ɛ-neighborhood of x ^* . Under this topology, a relatively simple necessary and sufficient condition for replicator asymptotic stability, namely Continuous Replicator Stability (CRSS), is demonstrated. This condition is closely related to the static stability condition of Neighbor Invadability (Apaloo 1997), and slightly stronger than the condition of Continuous Stability (Eshel and Motro 1981). Received: 9 July 2002 / Revised version: 12 November 2002 / Published online: 19 March 2003 Key words or phrases: CSS – ESS – NIS – Strong uninvadability – Weak topology – Replicator dynamics – Long-term evolution – Continuous population games – Continuous replicator stability – Asymptotic stability     

Diversity associated with the second expressed H L A - D R B locus in the human population

Although diversity within the HLA-DRB region is predominantly focused in the DRB1 gene, the second expressed DRB loci, DRB3, DRB4, and DRB5, also exhibit variation. Within DRB1 ^* 15 or DRB1 ^* 16 haplotypes, four new variants were identified: 1) two new DRB5 alleles, DRB5 ^* 0104 and DRB5 ^* 0204, 2) a haplotype carrying a DRB1 ^* 15 or ^* 16 allele without the usual accompanying DRB5 allele, and 3) a haplotype carrying a DRB5^* 0101 allele without a DRB1 ^* 15 or ^* 16 allele. The evolutionary origins of these haplotypes were postulated based on their associations with the DRB6 pseudogene. Within HLA haplotypes which carry DRB3, a new DRB3 ^* 0205 allele and one unusual DRB3 association were identified. Finally, two new null DRB4 alleles are described: DRB4 ^* 0201N, which exhibits a deletion in the second exon, and a second allele, DRB4 ^* null, which lacks the second exon completely. Gene conversion-like events and variation in the number of functional genes through reciprocal recombination and inactivation contribute to the diversity observed in the second expressed HLA-DRB loci. Received: 2 November 1996 / Revised: 23 December 1996     

The Influence of Nutrigenetics on the Lipid Profile: Interaction Between Genes and Dietary Habits

Nutrigenetics is a new field with few studies in Latin America. Our aim is to investigate the way in which different genes related to the lipid profile influence the response to specific dietary habits. Eight polymorphisms on seven genes were investigated in a sample (n = 567) from Porto Alegre, RS, Brazil. All the volunteers completed a food diary that was then assessed and classified into nine food groups. A number of nutrigenetic interactions were detected primarily related to the apolipoprotein E (apoE) gene. For example, frequent consumption of foods rich in polyunsaturated fat resulted in the beneficial effect of increasing HDL-C only in individuals who were not carriers of the E*4 allele of the APOE gene, whereas variations in eating habits of E*4 carriers did not affect their HDL-C (P = 0.018). Our data demonstrate for the first time nutrigenetic interactions in a Brazilian population.     

A phylogenetic analysis of cattle DRB3 alleles with a deletion of codon 65

 One of the most common cattle major histocompatibility complex DRB3 alleles, ^* 0201, includes a deletion of codon 65 encoding one residue in the α-helical chain. The mutation is functionally interesting and is likely to influence peptide binding. Exon 2 of two additional del65 alleles, ^* 3301 and ^* 4101, have now been sequenced with the aim to investigate the evolutionary relationship of this allelic group. Despite a fairly large genetic distance between the three alleles (11–17 nucleotide substitutions causing 8–11 amino acid substitutions) we found clear indications of a common ancestry. The α-helical region was very similar or identical among the alleles whereas the β-strand region was quite divergent. The results indicated that interallelic recombination has contributed to the diversification of the del65 group. Deletion of codon 65 has also been found in a roe deer DRB1 allele and a cattle DQB3 allele. Sequence comparisons of the cattle and roe deer DRB del65 alleles refuted the possibility of a trans-species persistence of a del65 allelic lineage but the two species may share a short ancestral sequence motif including del65. In addition to del65, the cattle DQB3 allele did not show any striking sequence similarities to the DRB alleles. Received: 20 March 1997 / Revised: 17 June 1997     

Stomach contents of bowhead whales (Balaena mysticetus) from four locations in the Canadian Arctic

The stomach contents of four bowhead whales (Balaena mysticetus) harvested between 1994 and 2008 from the Canadian Arctic were examined to assess diet composition. Three samples were collected from bowhead whales of the Eastern Canada–West Greenland (EC–WG) population and represent, according to our knowledge, the first diet analysis from this bowhead whale stock. We also examined the stomach content of one bowhead whale from the Bering-Chukchi-Beaufort (BCB) population hunted in 1996. All four whales had food in their stomachs and their diet varied from exclusively pelagic (BCB whale), with Limnocalanus macrurus being the main prey, to epibenthic and benthic (EC–WG) with Mysis oculata playing an important role. These results indicate broad foraging spectrum of the bowhead whales and add to a basic knowledge of their diet.     

Apolipoprotein E and A-IV Polymorphisms in Ethnic Russians Living in Estonia

To determine the distribution of genetic variations in apolipoprotein E (apoE) and apolipoprotein A-IV (apoA-IV) genes, 137 Russians living in Estonia was screened by isoelectric focusing and immunoblotting procedures. The apoA-IV-2 allele and apoE4 allele frequency of the Russians tended to be lower than in most other European populations.     

MHC class II DRB1 gene polymorphism in the pathogenesis of Maedi–Visna and pulmonary adenocarcinoma viral diseases in sheep

Ovine pulmonary adenocarcinoma (OPA) and Maedi–Visna (Maedi) are two chronic respiratory diseases of retroviral origin which occur worldwide. It is known that different host genetic factors influence the outcome of viral infections. To determine if variation in the Mhc-DRB1 gene was associated with progression to these ovine diseases, sheep lungs with and without OPA and Maedi lesions were collected. A sequence-based method was applied and 40 different alleles were detected in the sample analysed. In the allele-by-allele association analysis, allele DRB1*0325 had a significant association with susceptibility to Maedi (P = 0.045). For OPA, DRB1*0143 and DRB1*0323 were significantly associated with susceptibility (P = 0.024 and P = 0.029), and allele DRB1*0702 was significantly associated with resistance (P = 0.012). Based on these results, the Mhc-DRB1 alleles were classified by effect in three categories—susceptible (S), resistant (R) and neutral (N)—and animals were reassigned the genotypes as S/S, S/R, S/N, R/R, R/N and N/N. In a second analysis, penalised logistic regression models including a flock effect were run. In Maedi, significant association was detected for the N/S heterozygote (P = 0.0007), but not for the S/S homozygote, probably as a result of the low number of S/S animals. In OPA, association was detected for both the S/S and R/R homozygotes (P = 0.005 and P = 0.047). This allele grouping method may be applied in association studies with highly variable genes. This is the first study demonstrating significant associations between sheep Mhc-DRB1 alleles and susceptibility to OPA and Maedi. Therefore, both diseases are suitable candidates for more comprehensive genetic studies.     

Computational (DFT and TD DFT) study of the electron structure of the tautomers/conformers of uridine and deoxyuridine and the processes of intramolecular proton transfers

Six uridine and six deoxyuridine isomers were studied at the B3LYP and TD B3LYP theoretical level and 6–31+G(d) basis function. The stability and the excited states of the isomers were studied in order to clarify some known experimental data. It was established that the rotation of the oxo uracil ring in uridine is energetically more likely to occur in the excited state than in the ground state, driven by the bright ¹ ππ* state and the dark charge transfer ¹nπ* state. Very high energy barriers (on the S_o) were found for thermal intramolecular proton transfer processes.     

Bioenergetics and diet in a simple community of shrubsteppe birds

Summary Simulation model estimates of bioenergetics are coupled with observations of diet selection and arthropod prey abundances to assess (1) the role of bird populations in trophic energy fluxes in a temporally heterogeneous shrubsteppe ecosystem, and (2) the degree to which those populations may be limited by food.The model estimates a total annual energy demand of 2.91 kcal m^-2 yr^-1 by the entire passerine avifauna during 1974, with daily demands varying from 0.0025 to 0.0260 kcal m^-2. Coupling energy requirements with estimates of arthropod availability implies that bird demands on the insect standing crop never exceeded 0.7% per day of that standing crop during the breeding season or summer.Overall, the bioenergetic estimates imply that these birds are unlikely to be important in ecosystem processes and, reciprocally, are unlikely to be limited by food resources even during peak energy demands. As a consequence, I suggest that biological interactions such as competition play a relatively minor role in structuring the bird community in this variable environment.     

On the utilization of food by planktophage fishes

Making some plausible assumptions about the over-all mechanism of food catching and consumption by fishes and evaluating in the light of those assumptions some available experimental data, it is possible to calculate from those data the variation of several important factors with the concentration of food. The factors considered are: total rate of metabolism, total diurnal energy expenditure in the process of feeding, average number of hours per day during which the fish feeds, average length of path traveled by a fish per day, and the so-called “energetic coefficient of growth.” A possible relation with the work of N. Rashevsky (Bull. Math. Biophysics,20, 299–308, 1959) is discussed.     

Population structure of <Emphasis Type="Italic">Apis cerana</Emphasis> in Thailand reflects biogeography and current gene flow rather than <Emphasis Type="Italic">Varroa</Emphasis> mite association

Concordance between the mitochondrial haplotypes of the Eastern honey bee, Apis cerana, and its ectoparasitic Varroa mites across the Isthmus of Kra in Thailand has suggested that local host–pathogen co-evolution may be responsible for the geographic distribution of particular genotypes. To investigate nuclear microsatellites population structure in A. cerana, single workers of A. cerana colonies from Thailand were genotyped at 18 microsatellite loci. The loci showed intermediate to high levels of heterozygosity and a range of allele numbers. The analyses confirmed a fundamental subdivision of the Thai A. cerana population into the “Asia Mainland” and “Sundaland” regions at the Isthmus of Kra. However, the nuclear microsatellite differentiation was less distinct than mtDNA haplotype differences, suggesting male-biased dispersal and population admixture. Overall, samples showed a weak isolation-by-distance effect. The isolated population on Samui island was most differentiated from the other samples. The results do not support our initial hypothesis of local host–pathogen co-evolution, which predicts a strict correspondence between the nuclear genome and the lineage of parasitic Varroa mite of the A. cerana samples, because the gene flow indicated by our nuclear microsatellite markers should also mix potential Varroa resistance alleles among subpopulations. Instead, our study suggests that the coincidental distribution of Varroa lineages and A. cerana population structure in Thailand are the result of biogeographic history and current migration patterns.     

HLA-G gene polymorphism in a Japanese population

 Polymorphism of the HLA-G gene in a Japanese population was investigated employing polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) analysis, PCR sequence-specific oligonucleotide (SSO) analysis, and DNA direct sequencing. Nucleotide sequence variations in exons 2, 3, and 4 of the HLA-G gene in 54 healthy Japanese individuals were examined. In addition, seven Japanese samples carrying common HLA haplotypes were analyzed. In total, nine single-base substitutions compared with the sequence of G ^* 01011 were identified: one in intron 1 (nucleotide position 970), one in exon 2 (the third base of codon 57: G → A), three in intron 2 (1264, 1276, and 1292), three in exon 3 (the third base of codon 93: C → T, the third base of codon 107: A → T, and the first base of codon 110: C → A), and one in intron 3 (2334). The substitution at codon 110 was non-synonymous and led to an amino acid substitution from leucine to isoleucine. The other three nucleotide substitutions in exons were synonymous. Through analysis of combinations of the exon 2, 3, and 4 nucleotide sequences we identified four alleles, which we provisionally designated GJ1, GJ2, GJ3, and GJ4. The allele frequencies were estimated to be 0.33, 0.16, 0.45, and 0.06, respectively. Nucleotide sequences of GJ1, GJ2, and GJ4 were identical to G ^* 01011, the clone 7.0E, and G ^* 01013, respectively. GJ3 was a newly observed allele and was officially designated G ^* 0104 by the WHO Nomenclature Committee in January 1996. Strong positive associations were observed between HLA-G alleles and HLA-A, -B, or -DRB1 alleles. Received: 15 February 1996 / Revised: 26 March 1996     

Interactions in pseudorotoxanes based on crown ether-secondary ammonium motifs. A theoretical study

A theoretical analysis of the nature of the interactions in dibenzo[24]crown-8 (DB24C8)-n-dibutylammonium (DBM)—pseudorotaxane complex at the MP2 and DFT levels shows that the main contribution to the binding energy is the electrostatic interaction with moderate (20–25%) correlation stabilization. The total binding energy in the DB24C8-DBM complex represents a sum of the binding energies of two NH–O and one CH–O hydrogen bonds and the latter constitutes about 25% of the total interaction energy, giving the total binding energy of −41.2 kcal mol⁻¹ at the BHandHLYP/6-311++G** level. Deprotonation of the DB24C8-DBM complex reduces the binding energy by some 50 kcal mol⁻¹, giving metastable complexes DB24C8-DBA-1 or DB24C8-DBA-2, which will dissociate to give free crown ether and n-dibutylamine because of the strong exchange repulsion that prevails in neutral complexes. Figure Formation of DB24C8-DBM pseudorotoxane complex     

DNA sequence analysis of the C4 antigen WH: evidence for two mechanisms of expression

 Amino acid and protein analyses have allowed the construction of a model for the C4-based Rodgers and Chido blood group antigens. The single low-frequency allele (WH) in this blood group system, however, has not been characterized at the molecular level. Two WH⁺ donors were studied by C4 agarose gel electrophoreses, immunoblot studies using monoclonal anti-Rg: 1 or anti-Ch: 1, serological phenotyping, polymerase chain reaction-restriction fragment length polymorphism of their C4 genes, and DNA sequencing of the WH allele. The first donor had the C4A1, A3 phenotype; the C4A1 carried Ch: 1, 3, 6 (thus exhibiting reversed antigenicity) and the C4A3 carried the WH antigen. The amino acid sequence of the WH allele was PCPVLD at positions 1101 – 1106, S at position 1157, and VDLL at positions 1188 – 1191. A second donor typed as C4A2, A4, B1 and was also WH⁺. Immunoblot analysis showed that a C4B1 protein expressed Rg: 1. Sequence analysis of the C4B genes showed the amino acids LSPVIH at positions 1101 – 1106, S at position 1157, and ADLR at positions 1188 – 1191. Thus, the WH antigen is a conformational epitope that can arise through different mechanisms on either a C4A or C4B gene. Received: 22 November 1995 / Revised: 19 February 1996     

Scramble Competition Among <Emphasis Type="Italic">Colobus vellerosus</Emphasis> at Boabeng-Fiema,Ghana

We investigated the occurrence of scramble competition among Colobus vellerosus at Boabeng-Fiema, Ghana. If scramble competition had an impact on feeding efficiency among females, we expected a positive relationship between group size and the proportion of time spent feeding, day journey length, or home range size assuming resource availability is similar among the groups compared. We collected focal data on the feeding behavior of adult females and males over 11 mo (September 2000–August 2001) on 2 study groups: WW (n = 31–33 individuals) and B (n = 8–16 individuals). We also collected ranging data on group movements at half-hour intervals. The large group (WW1) had a significantly longer day journey length than the small group (B1), and females in the large group spent a significantly greater proportion of time feeding in the wet season, a period of low food availability, which suggests it may be a bottleneck period when food resources are scarce and Colobus vellerosus is close to being energy limited. The proximity data suggested females may be able to reduce or adjust for competition by having fewer neighbors when they feed and by spreading out when in a larger group. However, we found no relationship between home range size and group size or that females spent a greater proportion of time feeding than adult males did. Our results highlight the need to factor in differences in food availability when investigating scramble competition. Though equivocal, our results suggest scramble competition occurs among Colobus vellerosus, leading us to suggest there was a match with the potential competitive regime, i.e., food distribution.     

Geographical Variation of Allele Frequencies at the LDH-A* Locus in the Arctic Grayling Thymallus arcticus Pall. and in the European Grayling Thymallus thymallus L.

The allele frequencies of LDH-A* locus were studied in the populations of Siberian grayling from the Kozhym River (Pechora basin) and in the population of European grayling from Pechora, Mezen', and Vym' rivers (Northern Dvina basin). In samples of both species (n = 134), three LDH-A phenotypes have been identified in total, which proved to be under the control of two alleles: LDH-A*100 and LDH-A*50. The alternative alleles of LDH-A* locus were identified in the populations of Siberian grayling from Kozhym River and in the population of European grayling from the same river and other Pechora tributaries, namely, LDH-A*100 and LDH-A*50 in the Siberian and the European grayling, respectively. However, in the European grayling populations from the Mezen' and Vym' rivers, both alleles occur at the frequencies of the rare LDH-A*100 allele of 0.143 and 0.222, respectively. According to the published data, the frequency of LDH-A*100 allele increases in the European grayling populations of northwestern (Finland) and southern Europe (France) rivers, reaching 0.872 and 1.000 in Rhone and Loire, respectively, i.e., the values characteristic of the Siberian grayling populations.