Obesity represents a growing problem due to its impacts on human health and reproduction. In this study, we analysed semen quality, sperm DNA integrity and gene-specific CpG methylation in 116 healthy men from normal population. The men were divided into three groups according to their body mass index (BMI), and their ejaculates were analysed using standard methods, sperm chromatin structure assay (SCSA), methylation next generation sequencing (NGS) and amplicon sequencing. The sperm methylation NGS revealed six significantly differentially methylated regions (DMRs). Using subsequent targeted amplicon sequencing in 116 men, two of the DMRs were proved as differentially methylated in sperm of men with normal BMI vs. BMI ≥ 25. The DMRs were located in the EPHA8 and ANKRD11 gene. Also, we detected a significant decline in the EPHA8, ANKRD11 and CFAP46 gene methylation in association with increasing BMI values. The genes EPHA8 and ANKRD11 are involved in the nervous system and brain development; the CFAP46 gene plays a role in a flagellar assembly and is associated with sperm motility. Significantly lower rates of motile and progressive motile sperm were observed in men with BMI ≥ 30. Our results show that excess body weight can modify CpG methylation of specific genes, affect sperm motility, and compromise sperm chromatin integrity. These factors can stand behind the observed reduced fertility in men with obesity. The methylation changes might be transmitted to their offspring through sperm, and become a basis for possible developmental and reproductive issues in the next generation.
- MeSH
- Semen Analysis * MeSH
- Chromatin * metabolism MeSH
- CpG Islands MeSH
- Adult MeSH
- Body Mass Index * MeSH
- Humans MeSH
- DNA Methylation * MeSH
- Young Adult MeSH
- Sperm Motility genetics MeSH
- Obesity genetics MeSH
- Spermatozoa * metabolism MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
Persons living in industrial environments are exposed to levels of air pollution that can affect their health and fertility. The Czech capital city, Prague, and the Ostrava industrial agglomeration differ in their major sources of air pollution. In Prague, heavy traffic produces high levels of nitrogen oxides throughout the year. In the Ostrava region, an iron industry and local heating are sources of particulate matter (PM) and benzo[a]pyrene (B[a]P), especially in the winter. We evaluated the effects of air pollution on human sperm mitochondrial DNA (mtDNA). Using real-time PCR, we analysed sperm mtDNA copy number and deletion rate in Prague city policemen in two seasons (spring and autumn) and compared the results with those from Ostrava. In Prague, the sperm mtDNA deletion rate was significantly higher in autumn than in spring, which is the opposite of the results from Ostrava. The sperm mtDNA copy number did not show any seasonal differences in either of the cities; it was correlated negatively with sperm concentration, motility, and viability, and with sperm chromatin integrity (assessed with the Sperm Chromatin Structure Assay). The comparison between the two cities showed that the sperm mtDNA deletion rate in spring and the sperm mtDNA copy number in autumn were significantly lower in Prague vs. Ostrava. Our study supports the hypothesis that sperm mtDNA deletion rate is affected by the composition of air pollution. Sperm mtDNA abundance is closely associated with chromatin damage and standard semen characteristics.
- MeSH
- Adult MeSH
- Air Pollutants toxicity adverse effects MeSH
- Humans MeSH
- DNA, Mitochondrial * genetics MeSH
- Sperm Motility drug effects MeSH
- Particulate Matter toxicity adverse effects MeSH
- Police MeSH
- Seasons MeSH
- Spermatozoa * drug effects MeSH
- DNA Copy Number Variations * MeSH
- Air Pollution * adverse effects MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
- Comparative Study MeSH
- Geographicals
- Czech Republic MeSH
Environmental exposure is associated with increased incidence of respiratory and cardiovascular diseases and reduced fertility. Exposure to air pollution can influence gene expression through epigenetic mechanisms. In this study, we analysed gene-specific CpG methylation in spermatozoa of city policemen occupationally exposed to air pollution in two Czech cities differing by sources and composition of the air pollution. In Prague, the pollution is mainly formed by NO2 from heavy traffic. Ostrava is a hotspot of industrial air pollution with high concentrations of particular matter (PM) and benzo[a]pyrene (B[a]P). We performed genome-wide methylation sequencing using the SureSelectXT Human Methyl-Seq system (Agilent Technologies) and next-generation sequencing to reveal differentially methylated CpG sites and regions. We identified differential methylation in the region chr5:662169 - 663376 annotated to genes CEP72 and TPPP. The region was then analysed in sperm DNA from 117 policemen using targeted methylation sequencing, which proved its hypermethylation in sperm of Ostrava policemen.
- MeSH
- Adult MeSH
- Air Pollutants * analysis toxicity MeSH
- Middle Aged MeSH
- Humans MeSH
- DNA Methylation * drug effects MeSH
- Particulate Matter analysis toxicity MeSH
- Police MeSH
- Occupational Exposure MeSH
- Spermatozoa * drug effects MeSH
- Air Pollution * adverse effects analysis MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
Sperm mtDNA status can serve as a molecular marker of oxidative stress and environmental exposure. High levels of air pollution may be associated with increased mitochondrial DNA (mtDNA) deletion rates in sperm. We compared the length spectra of sperm mtDNA deletions in semen samples collected from city policemen exposed to traffic and industrial air pollution in two seasons with different levels of air pollution. We used long-range PCR to amplify a fragment of mtDNA (8066 bp) frequently affected by deletions, visualized the PCR products by gel electrophoresis, and analysed aberrant bands corresponding to deleted mtDNA, using gel documentation software. The predominance of undeleted sperm mtDNA was accompanied by a variety of shorter PCR product lengths in the vast majority of sperm samples, in both seasons. Sperm mtDNA molecules and bands corresponding to long deletions were more frequently detected than shorter deletions, in both seasons. We did not detect any difference in the total number of electrophoretic bands corresponding to deleted sperm mtDNA and in the number of deleted sperm mtDNA molecules between the two seasons. In our study, air pollution during sperm maturation did not induce formation of large mtDNA deletions detectable by long PCR and gel electrophoresis (>1 kb) in maturing sperm mtDNA.
- MeSH
- Humans MeSH
- DNA, Mitochondrial genetics MeSH
- Mitochondria genetics MeSH
- Semen * MeSH
- Spermatozoa MeSH
- Air Pollution * adverse effects MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
Human populations living in urban industrial regions of developed countries are exposed to high levels of environmental pollutants. The reproductive consequences of the exposure to air pollution can be monitored through semen analysis and molecular methods. In this study, we tested the possible impact of seasonal changes in the level of air pollution on the semen quality and sperm DNA methylation of 24 men living and working in the industrial agglomeration of Ostrava (Czech Republic). The study participants were healthy non-smokers. The study group was homogeneous regarding their profession, moderate alcohol consumption, no drug abuse and no additional exposure to chemical toxicants. We performed targeted methylation next generation sequencing (NGS) using Agilent SureSelect Human Methyl-Seq and Illumina NextSeq 500 platform to analyze semen samples collected repeatedly from the same men following the season of high (winter) and low (summer) air pollution exposure. We did not detect any adverse effects of the increased exposure on the semen quality; neither we found any difference in average sperm DNA methylation between the two sampling periods. Our search for differentially methylated CpG sites did not reveal any specific CpG methylation change. Our data indicate that the seasonal changes in the level of the air pollution probably do not have any substantial effect on sperm DNA methylation of men living in the highly polluted industrial agglomeration for a long period of time.
- MeSH
- Semen Analysis * MeSH
- Humans MeSH
- DNA Methylation genetics MeSH
- Industry MeSH
- Spermatozoa MeSH
- Air Pollution * adverse effects MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The effects of air pollution on men's reproductive health can be monitored by evaluating semen quality and sperm DNA damage. We used real-time PCR to analyse the effects of air pollution on sperm mitochondrial DNA copy number (mtDNAcn) and deletion (mtDNAdel) rates in semen samples collected from 54 men in two seasons with different levels of industrial and traffic air pollution. MtDNAdel rates were significantly higher following the high exposure period and were positively correlated with mtDNAcn. However, we did not find any difference in mtDNAcn between the two seasons. MtDNAcn was positively correlated with the DNA fragmentation index and the rates of sperm with chromatin condensation defects, previously assessed by sperm chromatin structure assay, and negatively correlated with sperm concentration, progressive motility, viability, and normal morphology. This indicates that mtDNAcn is more closely associated with male fertility than mtDNAdel rates. In contrast, mtDNAdel might be a more sensitive biomarker of air pollution exposure in urban industrial environments.
- MeSH
- Semen Analysis * MeSH
- Chromatin MeSH
- Humans MeSH
- DNA, Mitochondrial genetics MeSH
- Sperm Motility MeSH
- Spermatozoa MeSH
- DNA Copy Number Variations MeSH
- Air Pollution * adverse effects MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The taxonomy and phylogenetics of Neotropical deer have been mostly based on morphological criteria and needs a critical revision on the basis of new molecular and cytogenetic markers. In this study, we used the variation in the sequence, copy number, and chromosome localization of satellite I-IV DNA to evaluate evolutionary relationships among eight Neotropical deer species. Using FISH with satI-IV probes derived from Mazama gouazoubira, we proved the presence of satellite DNA blocks in peri/centromeric regions of all analyzed deer. Satellite DNA was also detected in the interstitial chromosome regions of species of the genus Mazama with highly reduced chromosome numbers. In contrast to Blastocerus dichotomus, Ozotoceros bezoarticus, and Odocoileus virginianus, Mazama species showed high abundance of satIV DNA by FISH. The phylogenetic analysis of the satellite DNA showed close relationships between O. bezoarticus and B. dichotomus. Furthermore, the Neotropical and Nearctic populations of O. virginianus formed a single clade. However, the satellite DNA phylogeny did not allow resolving the relationships within the genus Mazama. The high abundance of the satellite DNA in centromeres probably contributes to the formation of chromosomal rearrangements, thus leading to a fast and ongoing speciation in this genus, which has not yet been reflected in the satellite DNA sequence diversification.
- MeSH
- Fibroblasts MeSH
- Phylogeny * MeSH
- Genetic Markers MeSH
- In Situ Hybridization, Fluorescence MeSH
- Cells, Cultured MeSH
- Skin cytology MeSH
- Primary Cell Culture MeSH
- DNA, Satellite genetics MeSH
- Deer classification genetics MeSH
- Genetic Speciation MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Cutaneous and subcutaneous mast cell tumours (MCTs) are counted among the most frequent cancers in dogs. However, the genetic aetiology of their development is still mostly unknown, with the exception of KIT and tumor protein p53 (TP53 ) mutations reported in less than a half of cutaneous MCTs. In subcutaneous MCTs, no gene alterations were previously detected. We analysed KIT and TP53 mutations in cutaneous and subcutaneous MCTs, and identified methylated CpG sites in KIT and TP53 promoters and adjacent exon 1 regions. The mutation analysis focused on KIT exons 8, 9 and 11, and TP53 exons 5-8, and revealed mutations in 26% and 7% cutaneous MCT cases, respectively. Moreover, we report a first case of KIT mutation ever detected in subcutaneous MCTs. KIT exon 11 mutations and high Kiupel and Patnaik grades were associated with reduced survival in this study. Both KIT and TP53 gene were generally unmethylated in canine cutaneous MCTs. A sporadic methylation of the CpG positions in KIT promoter and adjacent exon 1 was detected in 70.4% of cutaneous and 82% of subcutaneous MCTs. A sporadic methylation of the CpG positions in the TP53 promoter and exon 1 was observed in 36.8% of the analysed cutaneous MCT samples. Only in two subcutaneous MCTs, we observed more than 30% of clones showing KIT methylation at the CpG positions 13 or 14. The CpG position 14 is involved in a predicted binding site for Sp1 transcription factor. However, the significance of KIT promoter methylation at this specific position needs further evaluation.
- MeSH
- Mastocytosis, Cutaneous genetics surgery veterinary MeSH
- Mutation MeSH
- Tumor Suppressor Protein p53 genetics MeSH
- Skin Neoplasms genetics surgery veterinary MeSH
- Dog Diseases genetics surgery MeSH
- Pilot Projects MeSH
- Survival MeSH
- Proto-Oncogene Proteins c-kit genetics MeSH
- Dogs MeSH
- Subcutaneous Tissue MeSH
- Animals MeSH
- Check Tag
- Dogs MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Centromeric and pericentromeric chromosome regions are occupied by satellite DNA. Satellite DNAs play essential roles in chromosome segregation, and, thanks to their extensive sequence variability, to some extent, they can also be used as phylogenetic markers. In this paper, we isolated and sequenced satellite DNA I-IV in 11 species of Cervidae. The obtained satellite DNA sequences and their chromosomal distribution were compared among the analysed representatives of cervid subfamilies Cervinae and Capreolinae. Only satI and satII sequences are probably present in all analysed species with high abundance. On the other hand, fluorescence in situ hybridisation (FISH) with satIII and satIV probes showed signals only in a part of the analysed species, indicating interspecies copy number variations. Several indices, including FISH patterns, the high guanine and cytosine (GC) content, and the presence of centromere protein B (CENP-B) binding motif, suggest that the satII DNA may represent the most important satellite DNA family that might be involved in the centromeric function in Cervidae. The absence or low intensity of satellite DNA FISH signals on biarmed chromosomes probably reflects the evolutionary reduction of heterochromatin following the formation of chromosome fusions. The phylogenetic trees constructed on the basis of the satellite I-IV DNA relationships generally support the present cervid taxonomy.
- MeSH
- Centromere genetics MeSH
- Heterochromatin genetics MeSH
- In Situ Hybridization, Fluorescence methods MeSH
- Humans MeSH
- Ruminants genetics MeSH
- Repetitive Sequences, Nucleic Acid genetics MeSH
- DNA, Satellite genetics MeSH
- DNA Copy Number Variations genetics MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Genetic causes of canine mast cell tumours (MCTs), except for mutations in the KIT gene detected in some MCTs, are generally unknown. We used whole exome sequencing to reveal mutation spectra in canine MCTs. We detected somatic mutations in 87 genes including 10 genes recognized as human cancer drivers. Besides KIT, 14 other genes were recurrently mutated. Subsequently, we performed next generation sequencing of a panel of 50 selected genes in additional MCT samples. In this group, the most frequently altered gene was GNB1 showing a recurrent dinucleotide substitution at position of Gly116 in 30% of the MCT samples (n = 6/20) and Ile80 substitution accompanied by a splice region mutation in one case. We extended the study by analysis of the above mentioned GNB1 regions in additional MCT samples by Sanger sequencing, and assessed the overall prevalence of GNB1 mutations to 17.3% (n = 14/81), which is similar to the prevalence of KIT alterations. Our results indicate that GNB1 mutations are probably involved in canine MCT pathogenesis in both cutaneous and subcutaneous MCT cases. As opposed to KIT alterations, the presence of GNB1 mutations did not negatively affect survival times, and our data even showed a trend towards positive prognosis. If our results are confirmed in a larger number of MCTs, an extension of molecular testing of canine MCTs by GNB1 analysis would help to refine the molecular stratification of MCTs, and become useful for targeted treatment strategies.
- MeSH
- Mast-Cell Sarcoma genetics pathology veterinary MeSH
- Mast Cells pathology MeSH
- Mutation MeSH
- Dog Diseases genetics pathology MeSH
- GTP-Binding Protein beta Subunits genetics MeSH
- Proto-Oncogene Proteins c-kit genetics MeSH
- Dogs MeSH
- High-Throughput Nucleotide Sequencing veterinary MeSH
- Animals MeSH
- Check Tag
- Dogs MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH