Environmental memories transmitted from a father to his grandchildren
… in recent years, scientists have shown that, before his offspring are even conceived, a father’s life experiences involving food, drugs, exposure to toxic products and even stress can affect the development and health not only of his children, but even of his grandchildren.
This group, whose paper was just published in Science, has been studying the role of histones (proteins) in the process.
So, to test their theory about the possible role of histones in guiding embryo development the researchers created mice in which they slightly altered the biochemical information on the histones during sperm cell formation and then measured the results. (It’s a bit like putting a nick in a spool of thread and seeing how it affects the way the thread then loops around the spool.) They then studied the effects on the offspring.
What they discovered was that there were dire consequences for the offspring both in terms of their development e.g. where offspring were prone to birth defects and had abnormal skeletal formation, and in terms of their surviving at all. Moreover, what was most surprising, was that these effects could still be seen two generations later.
“When we saw the decreased survivability across generations and the developmental abnormalities we were really blown away as it was never thought that altering something outside the DNA, i.e. a protein, could be involved in inheritance,” said Sarah Kimmins, from McGill’s Dept. of Animal Science, and one of the lead authors on the paper. Kimmins is also the Canada Research Chair in Epigenetics, Reproduction and Development.
Does anyone remember that Central Dogma? You know, “information flow proceeds from DNA to RNA to proteins” to life form: chunk!
Hey, we were still sweeping up the splinters from the lecterns when
Since chemical modifications on histones are susceptible to environmental exposures, the work opens new avenues of investigation for the possible prevention and treatment of diseases of various kinds, affecting health across generations.” More.
Now, not everything in epigenetics is going to hold up, but it certainly is an open window for fresh air on the subject of genetic inheritance, long cursed by Darwinism and eugenics.
See also: Epigenetic change: Lamarck, wake up, you’re wanted in the conference room!
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A father’s lifetime experiences can be transmitted to his offspring to affect health and development. The mechanisms underlying paternal epigenetic transmission are unclear. Unlike somatic cells, there are few nucleosomes in sperm and their function in epigenetic inheritance is unknown. We generated transgenic mice in which overexpression of the histone H3 lysine 4 (H3K4) demethylase LSD1/KDM1A during spermatogenesis reduced H3K4 dimethylation in sperm. KDM1A overexpression in one generation severely impaired development and survivability of offspring. These defects persisted transgenerationally in the absence of KDM1A germ line expression and were associated with altered RNA profiles in sperm and offspring. We show that epigenetic inheritance of aberrant development can be initiated by histone demethylase activity in developing sperm, without changes to DNA methylation at CpG-rich regions. (paywall) – Keith Siklenka, Serap Erkek, Maren Godmann, Romain Lambrot, Serge McGraw, Christine Lafleur, Tamara Cohen, Jianguo Xia, Matthew Suderman, Michael Hallett, Jacquetta Trasler, Antoine H. F. M. Peters, and Sarah Kimmins. Disruption of histone methylation in developing sperm impairs offspring health transgenerationally. Science, 8 October 2015 DOI: 10.1126/science.aab2006