@phdthesis{Prell2024,
  author    = {Prell, Andreas},
  title     = {The effects of paternal age on DNA methylation of developmentally important genes in human and bovine sperm},
  doi       = {10.25972/OPUS-34786},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-347866},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Western societies are steadily becoming older undergoing a clear trend of delayed parenthood. Children of older fathers have an undeniably higher risk for certain neurodevelopmental disorders and other medical conditions. Changes in the epigenetic landscape and especially in DNA methylation patterns are likely to account for a portion of this inherited disease susceptibility. DNA methylation changes during the ageing process are a well-known epigenetic feature. These so-called age-DMRs exist in developmentally important genes in the methylome of several mammalian species. However, there is only a minor overlap between the age-DMR datasets of different studies. We therefore replicated age-DMRs (which were obtained from a genome wide technique) by applying a different technical approach in a larger sample number. Here, this study confirmed 10 age-DMRs in the human and 4 in the bovine sperm epigenome from a preliminary candidate list based on RRBS. For this purpose, we used bisulphite Pyrosequencing in 94 human and 36 bovine sperm samples. These Pyrosequencing results confirm RRBS as an effective and reliable method to screen for age-DMRs in the vertebrate genome. To decipher whether paternal age effects are an evolutionary conserved feature of mammalian development, we compared methylation patterns between human and bovine sperm in orthologous regulatory regions. We discovered that the level of methylation and the age effect are both species-specific and speculate that these methylation marks reflect the lineage-specific development of each species to hit evolutionary requirements and adaptation processes. Different methylation levels between species in developmentally important genes also imply a differing mutational burden, representing a potential driver for point mutations and consequently deviations in the underlying DNA sequence of different species. Using the example of different haplotypes, this study showed the great effect of single base variations on the methylation of adjacent CpGs. Nonetheless, this study could not provide further evidence or a mechanism for the transfer of epigenetic marks to future generations. Therefore, further research in tissues from the progeny of old and young fathers is required to determine if the observed methylation changes are transmitted to the next generation and if they are associated with altered transcriptional activity of the respective genes. This could provide a direct link between the methylome of sperm from elderly fathers and the development potential of the next generation.},
  subject      = {Epigenetik},
  language  = {en}
}
@article{PrellSenPotabattulaetal.2022,
  author    = {Prell, Andreas and Sen, Mustafa Orkun and Potabattula, Ramya and Bernhardt, Laura and Dittrich, Marcus and Hahn, Thomas and Schorsch, Martin and Zacchini, Federica and Ptak, Grazyna Ewa and Niemann, Heiner and Haaf, Thomas},
  title     = {Species-specific paternal age effects and sperm methylation levels of developmentally important genes},
  series = {Cells},
  volume    = {11},
  journal   = {Cells},
  number    = {4},
  issn      = {2073-4409},
  doi       = {10.3390/cells11040731},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-262301},
  year      = {2022},
  abstract  = {A growing number of sperm methylome analyses have identified genomic loci that are susceptible to paternal age effects in a variety of mammalian species, including human, bovine, and mouse. However, there is little overlap between different data sets. Here, we studied whether or not paternal age effects on the sperm epigenome have been conserved in mammalian evolution and compared methylation patterns of orthologous regulatory regions (mainly gene promoters) containing both conserved and non-conserved CpG sites in 94 human, 36 bovine, and 94 mouse sperm samples, using bisulfite pyrosequencing. We discovered three (NFKB2, RASGEF1C, and RPL6) age-related differentially methylated regions (ageDMRs) in humans, four (CHD7, HDAC11, PAK1, and PTK2B) in bovines, and three (Def6, Nrxn2, and Tbx19) in mice. Remarkably, the identified sperm ageDMRs were all species-specific. Most ageDMRs were in genomic regions with medium methylation levels and large methylation variation. Orthologous regions in species not showing this age effect were either hypermethylated (>80\%) or hypomethylated (<20\%). In humans and mice, ageDMRs lost methylation, whereas bovine ageDMRs gained methylation with age. Our results are in line with the hypothesis that sperm ageDMRs are in regions under epigenomic evolution and may be part of an epigenetic mechanism(s) for lineage-specific environmental adaptations and provide a solid basis for studies on downstream effects in the genes analyzed here.},
  language  = {en}
}