Development of a novel prostate Cancer-Stroma Sphere (CSS) model for In Vitro tumor microenvironment studies.

Tumor employs non-cancerous cells to gain beneficial features that promote growth and survival of cancer cells. Despite intensive research in the area of tumor microenvironment, there is still a lack of reliable and reproducible in vitro model for tumor and tumor-microenvironment cell interaction studies. Herein we report the successful development of a heterogeneous cancer-stroma sphere (CSS) model composed of prostate adenocarcinoma PC3 cells and immortalized mesenchymal stem cells (MSC). The CSS model demonstrated a structured spatial layout of the cells, with stromal cells concentrated at the center of the spheres and tumor cells located on the periphery. Significant increase in the levels of VEGFA, IL-10, and IL1a has been detected in the conditioned media of CSS as compared to PC3 spheres. Single cell RNA sequencing data revealed that VEGFA was secreted by MSC cells within heterogeneous spheroids. Enhanced expression of extracellular membrane (ECM) proteins was also shown for CSS-derived MSCs. Furthermore, we demonstrated that the multicellular architecture altered cancer cell response to chemotherapeutic agents: the inhibition of sphere formation by topotecan was 74.92 ± 4.56 % for PC3 spheres and 45.95 ± 7.84 % for CSS spheres (p < 0.01), docetaxel showed 37,51± 20,88 % and 15,67± 14,08 % inhibition, respectively (p < 0.05). Thus, CSS present an effective in vitro model for examining the extracellular matrix composition and cell-to-cell interactions within the tumor, as well as for evaluating the antitumor activity of drugs.

Koban culture genome-wide and archeological data open the bridge between Bronze and Iron Ages in the North Caucasus.

The North Caucasus played a key role during the ancient colonization of Eurasia and the formation of its cultural and genetic ancestry. Previous archeogenetic studies described a relative genetic and cultural continuity of ancient Caucasus societies, since the Eneolithic period. The Koban culture, which formed in the Late Bronze Age on the North Caucasian highlands, is considered as a cultural "bridge" between the ancient and modern autochthonous peoples of the Caucasus. Here, we discuss the place of this archeological culture and its representatives in the genetic orbit of Caucasian cultures using genome-wide SNP data from five individuals of the Koban culture and one individual of the early Alanic culture as well as previously published genomic data of ancient and modern North Caucasus individuals. Ancient DNA analysis shows that an ancient individual from Klin-Yar III, who was previously described as male, was in fact a female. Additional studies on well-preserved ancient human specimens are necessary to determine the level of local mobility and kinship between individuals in ancient societies of North Caucasus. Further studies with a larger sample size will allow us gain a deeper understanding of this topic.

In Search of the Elusive North: Evolutionary History of the Arctic Fox (Vulpes lagopus) in the Palearctic from the Late Pleistocene to the Recent Inferred from Mitogenomic Data.

Despite the high level of interest, the population history of arctic foxes during the Late Pleistocene and Holocene remains poorly understood. Here we aimed to fill gaps in the demographic and colonization history of the arctic fox by analyzing new ancient DNA data from fossil specimens aged from 50 to 1 thousand years from the Northern and Polar Urals, historic DNA from museum specimens from the Novaya Zemlya Archipelago and the Taymyr Peninsula and supplementing these data by previously published sequences of recent and extinct arctic foxes from other regions. This dataset was used for reconstruction of a time-calibrated phylogeny and a temporal haplotype network covering four time intervals: Late Pleistocene (ranging from 30 to 13 thousand years bp), Holocene (ranging from 4 to 1 thousand years bp), historical (approximately 150 years), and modern. Our results revealed that Late Pleistocene specimens showed no genetic similarity to either modern or historical specimens, thus supporting the earlier hypothesis on local extinction rather than habitat tracking.

Genetic Diversity of Common Olive (Olea europaea L.) Cultivars from Nikita Botanical Gardens Collection Revealed Using RAD-Seq Method.

In different countries, interest in the commercial cultivation of the olive has recently greatly increased, which has led to the expansion of its range. The Crimean Peninsula is the northern limit of the common olive (Olea europaea L.) range. A unique collection of common olive's cultivars and hybrids has been collected in the Nikitsky Botanical Gardens (NBG). The aim of this study was to assess the genetic diversity of 151 samples (total of several biological replicates of 46 olive cultivars including 29 introduced and 11 indigenous genotypes) using the ddRAD sequencing method. Structural analysis showed that the studied samples are divided into ten groups, each of which mainly includes cultivars of the same origin. Cultivars introduced to the Crimean Peninsula from different regions formed separate groups, while local cultivars joined different groups depending on their origin. Cultivars of Crimean origin contain admixtures of mainly Italian and Caucasian cultivars' genotypes. Our study showed that the significant number of Crimean cultivars contains an admixture of the Italian cultivar "Coreggiolo". Genetic analysis confirmed the synonymy for the cv. "Otur" and "Nikitskaya 2", but not for the other four putative synonyms. Our results revealed the genetic diversity of the olive collection of NBG and provided references for future research studies, especially in selection studies for breeding programs.

Ancient DNA of the Don-Hares Assumes the Existence of Two Distinct Mitochondrial Clades in Northeast Asia.

Paleoclimatic changes during the Pleistocene-Holocene transition is suggested as a main factor that led to species extinction, including the woolly mammoth (Mammuthus primigenius), Steller's sea cow (Hydrodamalis gigas) and the Don-hare (Lepus tanaiticus). These species inhabited the territory of Eurasia during the Holocene, but eventually went extinct. The Don-hare is an extinct species of the genus Lepus (Leporidae, Lagomorpha), which lived in the Late Pleistocene-Early Holocene in Eastern Europe and Northern Asia. For a long time, the Don-hare was considered a separate species, but at the same time, its species status was disputed, taking into account both morphological data and mitochondrial DNA. In this study, mitochondrial genomes of five Don-hares, whose remains were found on the territory of Northeastern Eurasia were reconstructed. Firstly, we confirm the phylogenetic proximity of the "young" specimens of Don-hare and mountain or white hare, and secondly, that samples older than 39 Kya form a completely distinct mitochondrial clade.

Ancient DNA Reveals Maternal Philopatry of the Northeast Eurasian Brown Bear (Ursus arctos) Population during the Holocene.

Significant palaeoecological and paleoclimatic changes that took place during Late Pleistocene-Early Holocene transition are considered important factors that led to megafauna extinctions. Unlike many other species, the brown bear (Ursus arctos) has survived this geological time. Despite the fact that several mitochondrial DNA clades of brown bears became extinct at the end of the Pleistocene, this species is still widely distributed in Northeast Eurasia. Here, using the ancient DNA analysis of a brown bear individual that inhabited Northeast Asia in the Middle Holocene (3460 ± 40 years BP) and comparative phylogenetic analysis, we show a significant mitochondrial DNA similarity of the studied specimen with modern brown bears inhabiting Yakutia and Chukotka. In this study, we clearly demonstrate the maternal philopatry of the Northeastern Eurasian U. arctos population during the several thousand years of the Holocene.

Genome-Wide Association Study of Exercise-Induced Fat Loss Efficiency.

There is a wide range of individual variability in the change of body weight in response to exercise, and this variability partly depends on genetic factors. The study aimed to determine DNA polymorphisms associated with fat loss efficiency in untrained women with normal weight in response to a 12-week aerobic training program using the GWAS approach, followed by a cross-sectional study in athletes. The study involved 126 untrained young Polish women (age 21.4 ± 1.7 years; body mass index (BMI): 21.7 (2.4) kg/m2) and 550 Russian athletes (229 women, age 23.0 ± 4.1; 321 men, age 23.9 ± 4.7). We identified one genome-wide significant polymorphism (rs116143768) located in the ACSL1 gene (acyl-CoA synthetase long-chain family member 1, implicated in fatty acid oxidation), with a rare T allele associated with higher fat loss efficiency in Polish women (fat mass decrease: CC genotype (n = 122) -3.8%; CT genotype (n = 4) -31.4%; p = 1.18 × 10-9). Furthermore, male athletes with the T allele (n = 7) had significantly lower BMI (22.1 (3.1) vs. 25.3 (4.2) kg/m2, p = 0.046) than subjects with the CC genotype (n = 314). In conclusion, we have shown that the rs116143768 T allele of the ACSL1 gene is associated with higher fat loss efficiency in response to aerobic training in untrained women and lower BMI in physically active men.

Anti-Citrullinated Peptide Antibodies Control Oral Porphyromonas and Aggregatibacter species in Patients with Rheumatoid Arthritis.

Oral microbiome changes take place at the initiation of rheumatoid arthritis (RA); however, questions remain regarding the oral microbiome at pre-RA stages in individuals with clinically suspect arthralgia (CSA). Two cross-sectional cohorts were selected including 84 Tatarstan women (15 early-RA as compared to individuals with CSA ranging from CSA = 0 [n = 22], CSA = 1 [n = 19], CSA = 2 [n = 11], and CSA ≥ 3 [n = 17]) and 42 women with established RA (median: 5 years from diagnosis [IQ: 2-11]). Amplicon sequence variants (ASVs) obtained from oral samples (16S rRNA) were analyzed for alpha and beta diversity along with the abundance at the genus level. A decrease in oral Porphyromonas sp. is observed in ACPA-positive individuals, and this predominates in early-RA patients as compared to non-RA individuals irrespective of their CSA score. In the RA-established cohort, Porphyromonas sp. and Aggregatibacter sp. reductions were associated with elevated ACPA levels. In contrast, no associations were reported when considering individual, genetic and clinical RA-associated factors. Oral microbiome changes related to the genera implicated in post-translational citrullination (Porphyromonas sp. and Aggregatibacter sp.) characterized RA patients with elevated ACPA levels, which supports that the role of ACPA in controlling the oral microbiome needs further evaluation.

Intergeneric hybridization of two stickleback species leads to introgression of membrane-associated genes and invasive TE expansion.

Interspecific hybridization has occurred relatively frequently during the evolution of vertebrates. This process usually abolishes reproductive isolation between the parental species. Moreover, it results in the exchange of genetic material and can lead to hybridogenic speciation. Hybridization between species has predominately been observed at the interspecific level, whereas intergeneric hybridization is rarer. Here, using whole-genome sequencing analysis, we describe clear and reliable signals of intergeneric introgression between the three-spined stickleback (Gasterosteus aculeatus) and its distant mostly freshwater relative the nine-spined stickleback (Pungitius pungitius) that inhabit northwestern Russia. Through comparative analysis, we demonstrate that such introgression phenomena apparently take place in the moderate-salinity White Sea basin, although it is not detected in Japanese sea stickleback populations. Bioinformatical analysis of the sites influenced by introgression showed that they are located near transposable elements, whereas those in protein-coding sequences are mostly found in membrane-associated and alternative splicing-related genes.

A de novo genome assembly of cultivated Prunus persica cv. 'Sovetskiy'.

Prunus persica is one of the main stone fruit crops in Crimea and southern Russia. The P. persica genome has recently been sequenced and annotated in good quality. However, for a deeper assessment of the peach genome, it is necessary to include in the research other cultivars that are in the collection of the Nikitsky Botanical Garden. The cultivars of the Nikitsky Botanical Garden are unique and differ from Western European and American ones, as they are derived from cultivars and forms originating from Central Asian, North Caucasian, Transcaucasian and Eastern European countries. In this paper, we present the assembly of the P. persica cv. 'Sovetskiy' genome obtained using Oxford Nanopore long reads and Illumina short reads by hybrid assembly methods. The assembled genome of P. persica cv. 'Sovetskiy' is 206.26 MB in 226 scaffolds, with N50 24 Mb, including 8 chromosomes. It contains 27140 coding genes, 26973 (99.38%) of which are annotated in at least one functional database. More than 36.05% of the genome regions were identified as repeating elements.

Significance of both alkB and P450 alkane-degrading systems in Tsukamurella tyrosinosolvens: proteomic evidence.

The Tsukamurella tyrosinosolvens PS2 strain was isolated from hydrocarbons-contaminated petrochemical sludge as a long chain alkane-utilizing bacteria. Complete genome analysis showed the presence of two alkane oxidation systems: alkane 1-monooxygenase (alkB) and cytochrome P450 monooxygenase (P450) genes with established high homology to the well-known alkane-degrading actinobacteria. According to the comparative genome analysis, both systems have a wide distribution among environmental and clinical isolates of the genus Tsukamurella and other members of Actinobacteria. We compared the expression of different proteins during the growth of Tsukamurella on sucrose and on hexadecane. Both alkane monooxygenases were upregulated on hexadecane: AlkB-up to 2.5 times, P450-up to 276 times. All proteins of the hexadecane oxidation pathway to acetyl-CoA were also upregulated. Accompanying proteins for alkane degradation involved in biosurfactant synthesis and transport of organic and inorganic molecules were increased. The change in the carbon source affected the pathways for the regulation of translation and transcription. The proteomic profile showed that hexadecane is an adverse factor causing activation of general and universal stress proteins as well as shock and resistance proteins. Differently expressed proteins of Tsukamurella tyrosinosolvens PS2 shed light on the alkane degradation in other members of Actinobacteria class. KEY POINTS: • alkB and P450 systems have a wide distribution among the genus Tsukamurella. • alkB and P450 systems have coexpression with the predominant role of P450 protein. • Hexadecane causes significant changes in bacterial proteome.

Non-GCB Diffuse Large B-Cell Lymphoma With an Atypical Disease Course: A Case Report and Clinical Exome Analysis.

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoid tumor among other non-Hodgkin lymphomas (30-40% of all cases). This type of lymphoma is characterized by significant differences in treatment response and the heterogeneity of clinical traits. Approximately 60% of patients are cured using standard chemotherapy (CT), while in 10-15% of cases, the tumor is characterized by an extremely aggressive course and resistance to even the most high-dose programs with autologous stem cell transplantation (auto-SCT). The activated B-cell (ABC) subtype of DLBCL is characterized by poor prognosis. Here, we describe a clinical case of diffuse ABC-DLBCL with an atypical disease course. Complete remission was achieved after four courses of CT, followed by autologous hematopoietic stem cell transplantation (auto-HSCT). However, early relapse occurred 2 months after the completion of treatment. According to the results of cytogenetic studies, significant chromosome breakdowns were observed. Exome sequencing allowed for the detection of several novel mutations that affect components of the NOTCH2 and NF-κB signaling pathways, a number of epigenetic regulators (KMT2D, CREBBP, EP300, ARID1A, MEF2B), as well as members of the immunoglobulin superfamily (CD58 and CD70). Whether these mutations were the result of therapy or were originally present in the lymphoid tumor remains unclear. Nevertheless, the introduction of genomic technologies into clinical practice is important for making a diagnosis and developing a DLBCL treatment regimen with the use of targeted drugs.

The complete chloroplast genome sequence of cultivated Prunus persica cv. 'Sovetskiy'.

The peach (Prunus persica L. Batsch) is one of the important stone fruit crops in the Crimea Peninsula and the southern part of Russia. The complete chloroplast genome of the peach cultivar 'Sovetskiy' is published in this paper. The chloroplast genome size is 157,756 bp. It contains 126 genes, including 81 protein-coding genes (PCGs), eight ribosomal RNA (rRNA) genes, and 37 transfer RNA (tRNA) genes. The chloroplast genome also contains a large single-copy region of 85,960 bp, a small single-copy (SSC) region of 19,045 bp, and two inverted repeats regions of 26,375 bp and 26,372 bp. The overall base composition of the genome in descending order is 31.2% - A, 32.1% - T, 18.7% - C, and 18.0% - G. The total GC content of the chloroplast genome is 36.7%. Maximum-likelihood phylogenetic analysis involving nine chloroplast genomes of the Prunus genus revealed a separate cluster for P. persica and its possible landrace - P. ferganensis.

Diversity and Adaptations of Escherichia coli Strains: Exploring the Intestinal Community in Crohn's Disease Patients and Healthy Individuals.

Crohn's disease (CD) is characterized by a chronic, progressive inflammation across the gastrointestinal tract with a series of exacerbations and remissions. A significant factor in the CD pathogenesis is an imbalance in gut microbiota composition, particularly the prevalence of Escherichia coli. In the present study, the genomes of sixty-three E. coli strains from the gut of patients with CD and healthy subjects were sequenced. In addition, eighteen E. coli-like metagenome-assembled genomes (MAGs) were reconstructed from the shotgun-metagenome sequencing data of fecal samples. The comparative analysis revealed the similarity of E. coli genomes regardless of the origin of the strain. The strains exhibited similar genetic patterns of virulence, antibiotic resistance, and bacteriocin-producing systems. The study showed antagonistic activity of E. coli strains and the metabolic features needed for their successful competition in the human gut environment. These observations suggest complex bacterial interactions within the gut which may affect the host and cause intestinal damage.

Steller's sea cow genome suggests this species began going extinct before the arrival of Paleolithic humans.

Anthropogenic activity is the top factor directly related to the extinction of several animal species. The last Steller's sea cow (Hydrodamalis gigas) population on the Commander Islands (Russia) was wiped out in the second half of the 18th century due to sailors and fur traders hunting it for the meat and fat. However, new data suggests that the extinction process of this species began much earlier. Here, we present a nuclear de novo assembled genome of H. gigas with a 25.4× depth coverage. Our results demonstrate that the heterozygosity of the last population of this animal is low and comparable to the last woolly mammoth population that inhabited Wrangel Island 4000 years ago. Besides, as a matter of consideration, our findings also demonstrate that the extinction of this marine mammal starts along the North Pacific coastal line much earlier than the first Paleolithic humans arrived in the Bering sea region.

Genomic evidence supports the introgression between two sympatric stickleback species inhabiting the White Sea basin.

Interspecies hybridization is driven by a complex interplay of factors where introgression plays an important role. In the present study, the transfer of genetic material, between two quite distant fish species from different genera, through spontaneous hybridization was documented with dedicated molecular and bioinformatics tools. We investigate the genomic landscape of putative stickleback-relative introgression by carefully analyzing the tractable transposable elements (TE) on the admixed genome of some individuals of two sympatric stickleback species inhabiting northwestern Russia, namely the three-spined (Gasterosteus aculeatus) and the nine-spined (Pungitius pungitius) sticklebacks. Our data revealed that unique TE amplification types exist, supporting our proposed hypothesis that infers on the interspecific introgression. By running a restriction site-associated DNA sequencing (RAD-Seq) with eight samples of G. aculeatus and P. pungitius and subjecting further the results to a contrasting analysis by variated bioinformatic tools, we identified the related introgression-linked markers. The admixture nature observed in a single sample of the nine-spined stickleback demonstrated the possible traces of remote introgression between these two species. Our work reveals the potential that introgression has on providing particular variants at a high-frequency speed while linking blocks of sequence with multiple functional mutations. However, even though our results are of significant interest, an increased number of samples displaying the introgression are required to further ascertain our conclusions.

Inflammatory Bowel Disease-Associated Changes in the Gut: Focus on Kazan Patients.

BACKGROUND: Several studies have highlighted the role of host-microbiome interactions in the pathogenesis of inflammatory bowel disease (IBD), resulting in an increasing amount of data mainly focusing on Western patients. Because of the increasing prevalence of IBD in newly industrialized countries such as those in Asia, the Middle East, and South America, there is mounting interest in elucidating the gut microbiota of these populations. We present a comprehensive analysis of several IBD-related biomarkers and gut microbiota profiles and functions of a unique population of patients with IBD and healthy patients from Kazan (Republic of Tatarstan, Russia). METHODS: Blood and fecal IBD biomarkers, serum cytokines, and fecal short-chain fatty acid (SCFA) content were profiled. Finally, fecal microbiota composition was analyzed by 16S and whole-genome shotgun sequencing. RESULTS: Fecal microbiota whole-genome sequencing confirmed the presence of classic IBD dysbiotic features at the phylum level, with increased abundance of Proteobacteria, Actinobacteria, and Fusobacteria and decreased abundance of Firmicutes, Bacteroidetes, and Verrucomicrobia. At the genus level, the abundance of both fermentative (SCFA-producing and hydrogen (H2)-releasing) and hydrogenotrophic (H2-consuming) microbes was affected in patients with IBD. This imbalance was confirmed by the decreased abundance of SCFA species in the feces of patients with IBD and the change in anaerobic index, which mirrors the redox status of the intestine. CONCLUSIONS: Our analyses highlighted how IBD-related dysbiotic microbiota-which are generally mainly linked to SCFA imbalance-may affect other important metabolic pathways, such as H2 metabolism, that are critical for host physiology and disease development.

Whole genome sequencing of elite athletes.

Whole genome sequencing (WGS) has great potential to explore all possible DNA variants associated with physical performance, psychological traits and health conditions of athletes. Here we present, for the first time, annotation of genomic variants of elite athletes, based on the WGS of 20 Tatar male wrestlers. The maximum number of high-quality variants per sample was over 3.8 M for single nucleotide polymorphisms (SNPs) and about 0.64 M for indels. The maximum number of nonsense mutations was 148 single nucleotide variants (SNVs) per individual. Athletes' genomes on average contained 18.9 nonsense SNPs in a homozygous state per sample, while non-athletes' exomes (Tatar controls, n = 19) contained 18 nonsense SNPs. Finally, we applied genomic data for the association analysis and used reaction time (RT) as an example. Out of 1884 known genome-wide significant SNPs related to RT, we identified four SNPs (KIF27 rs10125715, APC rs518013, TMEM229A rs7783359, LRRN3 rs80054135) associated with RT in wrestlers. The cumulative number of favourable alleles (KIF27 A, APC A, TMEM229A T, LRRN3 T) was significantly correlated with RT both in wrestlers (P = 0.0003) and an independent cohort (n = 43) of physically active subjects (P = 0.029). Furthermore, we found that the frequencies of the APC A (53.3 vs 44.0%, P = 0.033) and LRRN3 T (7.5 vs 2.8%, P = 0.009) alleles were significantly higher in elite athletes (n = 107) involved in sports with RT as an essential component of performance (combat sports, table tennis and volleyball) compared to less successful (n = 176) athletes. The LRRN3 T allele was also over-represented in elite athletes (7.5%) in comparison with 189 controls (2.9%, P = 0.009). In conclusion, we present the first WGS study of athletes showing that WGS can be applied in sport and exercise science.

A new strain group of common carp: The genetic differences and admixture events between Cyprinus carpio breeds.

Common carp (Cyprinus carpio) has an outstanding economic importance in freshwater aquaculture due to its high adaptive capacity to both food and environment. In fact, it is the third most farmed fish species worldwide according to the Food and Agriculture Organization. More than four million tons of common carp are produced annually in aquaculture, and more than a hundred thousand tons are caught from the wild. Historically, the common carp was also the first fish species to be domesticated in ancient China, and now, there is a huge variety of domestic carp strains worldwide. In the present study, we used double digestion restriction site-associated DNA sequencing to genotype several European common carp strains and showed that they are divided into two distinct groups. One of them includes central European common carp strains as well as Ponto-Caspian wild common carp populations, whereas the other group contains several common carp strains that originated in the Soviet Union, mostly as cold-resistant strains. We believe that breeding with wild Amur carp and subsequent selection of the hybrids for resistance to adverse environmental conditions was the attribute of the second group. We assessed the contribution of wild Amur carp inheritance to the common carp strains and discovered discriminating genes, which differed in allele frequencies between groups. Taken together, our results improve our current understanding of the genetic variability of common carp, namely the structure of natural and artificial carp populations, and the contribution of wild carp traits to domestic strains.

The association of HFE gene H63D polymorphism with endurance athlete status and aerobic capacity: novel findings and a meta-analysis.

PURPOSE: Iron is an important component of the oxygen-binding proteins and may be critical to optimal athletic performance. Previous studies have suggested that the G allele of C/G rare variant (rs1799945), which causes H63D amino acid replacement, in the HFE is associated with elevated iron indexes and may give some advantage in endurance-oriented sports. The aim of the present study was to investigate the association between the HFE H63D polymorphism and elite endurance athlete status in Japanese and Russian populations, aerobic capacity and to perform a meta-analysis using current findings and three previous studies. METHODS: The study involved 315 international-level endurance athletes (255 Russian and 60 Japanese) and 809 healthy controls (405 Russian and 404 Japanese). Genotyping was performed using micro-array analysis or by PCR. VO2max in 46 male Russian endurance athletes was determined using gas analysis system. RESULTS: The frequency of the iron-increasing CG/GG genotypes was significantly higher in Russian (38.0 vs 24.9%; OR 1.85, P = 0.0003) and Japanese (13.3 vs 5.0%; OR 2.95, P = 0.011) endurance athletes compared to ethnically matched controls. The meta-analysis using five cohorts (two French, Japanese, Spanish, and Russian; 586 athletes and 1416 controls) showed significant prevalence of the CG/GG genotypes in endurance athletes compared to controls (OR 1.96, 95% CI 1.58-2.45; P = 1.7 × 10-9). Furthermore, the HFE G allele was associated with high V̇O2max in male athletes [CC: 61.8 (6.1), CG/GG: 66.3 (7.8) ml/min/kg; P = 0.036]. CONCLUSIONS: We have shown that the HFE H63D polymorphism is strongly associated with elite endurance athlete status, regardless ethnicities and aerobic capacity in Russian athletes.