1
|
Baxter FA, Drake AJ. Non-genetic inheritance via the male germline in mammals. Philos Trans R Soc Lond B Biol Sci 2020; 374:20180118. [PMID: 30966887 PMCID: PMC6460076 DOI: 10.1098/rstb.2018.0118] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Numerous studies in humans and in animal models have demonstrated that exposure to adverse environmental conditions in early life results in long-term structural and functional changes in an organism, increasing the risk of cardiometabolic, neurobehavioural and reproductive disorders in later life. Such effects are not limited to the first generation offspring but may be transmitted to a second or a number of subsequent generations, through non-genomic mechanisms. While the transmission of ‘programmed’ effects through the maternal line could occur as a consequence of multiple influences, for example, altered maternal physiology, the inheritance of effects through the male line is more difficult to explain and there is much interest in a potential role for transgenerational epigenetic inheritance. In this review, we will discuss the mechanisms by which induced effects may be transmitted through the paternal lineage, with a particular focus on the role of epigenetic inheritance. This article is part of the theme issue ‘Developing differences: early-life effects and evolutionary medicine’.
Collapse
Affiliation(s)
- Faye A Baxter
- 1 Royal Hospital for Sick Children , 9 Sciennes Road, Edinburgh EH9 1LF , UK
| | - Amanda J Drake
- 1 Royal Hospital for Sick Children , 9 Sciennes Road, Edinburgh EH9 1LF , UK.,2 University/British Heart Foundation Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh , 47 Little France Crescent, Edinburgh EH16 4TJ , UK
| |
Collapse
|
2
|
Cartier J, Smith T, Thomson JP, Rose CM, Khulan B, Heger A, Meehan RR, Drake AJ. Investigation into the role of the germline epigenome in the transmission of glucocorticoid-programmed effects across generations. Genome Biol 2018; 19:50. [PMID: 29636086 PMCID: PMC5891941 DOI: 10.1186/s13059-018-1422-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 03/16/2018] [Indexed: 12/13/2022] Open
Abstract
Background Early life exposure to adverse environments affects cardiovascular and metabolic systems in the offspring. These programmed effects are transmissible to a second generation through both male and female lines, suggesting germline transmission. We have previously shown that prenatal overexposure to the synthetic glucocorticoid dexamethasone (Dex) in rats reduces birth weight in the first generation (F1), a phenotype which is transmitted to a second generation (F2), particularly through the male line. We hypothesize that Dex exposure affects developing germ cells, resulting in transmissible alterations in DNA methylation, histone marks and/or small RNA in the male germline. Results We profile epigenetic marks in sperm from F1 Sprague Dawley rats expressing a germ cell-specific GFP transgene following Dex or vehicle treatment of the mothers, using methylated DNA immunoprecipitation sequencing, small RNA sequencing and chromatin immunoprecipitation sequencing for H3K4me3, H3K4me1, H3K27me3 and H3K9me3. Although effects on birth weight are transmitted to the F2 generation through the male line, no differences in DNA methylation, histone modifications or small RNA were detected between germ cells and sperm from Dex-exposed animals and controls. Conclusions Although the phenotype is transmitted to a second generation, we are unable to detect specific changes in DNA methylation, common histone modifications or small RNA profiles in sperm. Dex exposure is associated with more variable 5mC levels, particularly at non-promoter loci. Although this could be one mechanism contributing to the observed phenotype, other germline epigenetic modifications or non-epigenetic mechanisms may be responsible for the transmission of programmed effects across generations in this model. Electronic supplementary material The online version of this article (10.1186/s13059-018-1422-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Jessy Cartier
- University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK
| | - Thomas Smith
- MRC Computational Genomics Analysis and Training Programme, University of Oxford, MRC WIMM Centre for Computational Biology, The Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DS, UK
| | - John P Thomson
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh, EH4 2XU, UK
| | - Catherine M Rose
- University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK
| | - Batbayar Khulan
- University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK
| | - Andreas Heger
- MRC Computational Genomics Analysis and Training Programme, University of Oxford, MRC WIMM Centre for Computational Biology, The Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DS, UK
| | - Richard R Meehan
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road, Edinburgh, EH4 2XU, UK
| | - Amanda J Drake
- University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, The Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK.
| |
Collapse
|