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
Chromosomal rearrangements are often associated with playing a role in the speciation process. However, the underlying mechanism that favors the genetic isolation associated with chromosomal changes remains elusive. In this sense, the genus Mazama is recognized by its high level of karyotype diversity among species with similar morphology. A cryptic species complex has been identified within the genus, with the red brocket deer (Mazama americana and Mazama rufa) being the most impressive example. The chromosome variation was clustered in cytotypes with diploid numbers ranging from 42 to 53 and was correlated with geographical location. We conducted an analysis of chromosome evolution of the red brocket deer complex using comparative chromosome painting and Bacterial Artificial Chromosome (BAC) clones among different cytotypes. The aim was to deepen our understanding of the karyotypic relationships within the red brocket, thereby elucidating the significant chromosome variation among closely related species. This underscores the significance of chromosome changes as a key evolutionary process shaping their genomes. The results revealed the presence of three distinct cytogenetic lineages characterized by significant karyotypic divergence, suggesting the existence of efficient post-zygotic barriers. Tandem fusions constitute the main mechanism driving karyotype evolution, following a few centric fusions, inversion X-autosomal fusions. The BAC mapping has improved our comprehension of the karyotypic relationships within the red brocket deer complex, prompting questions regarding the role of these changes in the speciation process. We propose the red brocket as a model group to investigate how chromosomal changes contribute to isolation and explore the implications of these changes in taxonomy and conservation.
- MeSH
- Karyotype * MeSH
- Karyotyping * MeSH
- Chromosome Painting MeSH
- Evolution, Molecular * MeSH
- Chromosomes, Artificial, Bacterial genetics MeSH
- Deer * genetics classification MeSH
- Genetic Speciation * MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Comparative Study 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
Repetitive sequences form a substantial and still enigmatic part of the mammalian genome. We isolated repetitive DNA blocks of the X chromosomes of three species of the family Bovidae: Kobus defassa (KDEXr sequence), Bos taurus (BTAXr sequence) and Antilope cervicapra (ACEXr sequence). The copy numbers of the isolated sequences were assessed using qPCR, and their chromosomal localisations were analysed using FISH in ten bovid tribes and in outgroup species. Besides their localisation on the X chromosome, their presence was also revealed on the Y chromosome and autosomes in several species. The KDEXr sequence abundant in most Bovidae species also occurs in distant taxa (Perissodactyla and Carnivora) and seems to be evolutionarily older than BTAXr and ACEXr. The ACEXr sequence, visible only in several Antilopini species using FISH, is probably the youngest, and arised in an ancestor common to Bovidae and Cervidae. All three repetitive sequences analysed in this study are interspersed among gene-rich regions on the X chromosomes, apparently preventing the crossing-over in their close vicinity. This study demonstrates that repetitive sequences on the X chromosomes have undergone a fast evolution, and their variation among related species can be beneficial for evolutionary studies.
- MeSH
- Antelopes * genetics MeSH
- Y Chromosome genetics MeSH
- DNA MeSH
- Humans MeSH
- Chromosomes, Human, X MeSH
- Repetitive Sequences, Nucleic Acid genetics MeSH
- Cattle genetics MeSH
- Deer * genetics MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Cattle genetics MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
The study assessed occupationally induced chromosomal damage in hospital personnel at risk of exposure to antineoplastic drugs and/or low doses of ionizing radiation by two cytogenetic methods. Cultured peripheral blood lymphocytes of eighty-five hospital workers were examined twice over 2 to 3 years by classical chromosomal aberration analysis and fluorescence in situ hybridization. The comparison of the 1st and the 2nd sampling of hospital workers showed a significant increase in chromatid and chromosomal aberrations (all p < .05) examined by classical chromosomal aberration analysis, and in unstable aberrations (all p < .05) detected by fluorescence in situ hybridization. Both cytogenetic methods were able to detect an increase of unstable aberrations in the 2nd sampling. The raised frequency of unstable cytogenetic parameters suggested higher recent exposure to genotoxic agents.
Cervids are characterized by their greatest karyotypic diversity among mammals. A great diversity of chromosome numbers in notably similar morphological groups leads to the existence of several complexes of cryptic species and taxonomic uncertainties. Some deer lineages, such as those of Neotropical deer, stand out for a rapid chromosomal reorganization and intraspecific chromosome polymorphisms, which have not been properly explored yet. For that reason, we contribute to the study of deer karyotype diversity and taxonomy by producing and characterizing new molecular cytogenetic markers for the gray brocket deer (Subulo gouazoubira), a deer species that retained the hypothetical ancestral karyotype of Cervidae. We used bacterial artificial chromosome (BAC) clones derived from the cattle genome (Bos taurus) as markers, which were hybridized on S. gouazoubira metaphase chromosomes. In total, we mapped 108 markers, encompassing all gray brocket deer chromosomes, except the Y chromosome. The detailed analysis of fluorescent in situ hybridization results showed 6 fissions and 1 fusion as interchromosomal rearrangements that have separated cattle and gray brocket deer karyotypes. Each group of BAC probes derived from bovine chromosome pairs 1, 2, 5, 6, 8, and 9 showed hybridization signals on 2 different chromosomes, while pairs 28 and 26 are fused in tandem in a single acrocentric chromosome in S. gouazoubira. Furthermore, the BAC markers detected the occurrence of intrachromosomal rearrangements in the S. gouazoubira chromosomes homologous to pair 1 and the X chromosome of cattle. We present a karyotypic map of the 108 new markers, which will be of great importance for future karyotypic evolution studies in cervids and, consequently, help in their conservation and taxonomy resolution.
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
